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d3279d4304
tor/src/or/directory.c
Nick Mathewson d3279d4304 Do not try to uncompress an empty spool
2017-05-15 18:13:38 -04:00

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/* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#define DIRECTORY_PRIVATE
#include "or.h"
#include "backtrace.h"
#include "bridges.h"
#include "buffers.h"
#include "circuitbuild.h"
#include "config.h"
#include "connection.h"
#include "connection_edge.h"
#include "conscache.h"
#include "consdiff.h"
#include "consdiffmgr.h"
#include "control.h"
#include "compat.h"
#define DIRECTORY_PRIVATE
#include "directory.h"
#include "dirserv.h"
#include "dirvote.h"
#include "entrynodes.h"
#include "geoip.h"
#include "hs_cache.h"
#include "hs_common.h"
#include "main.h"
#include "microdesc.h"
#include "networkstatus.h"
#include "nodelist.h"
#include "policies.h"
#include "relay.h"
#include "rendclient.h"
#include "rendcommon.h"
#include "rendservice.h"
#include "rephist.h"
#include "router.h"
#include "routerlist.h"
#include "routerparse.h"
#include "routerset.h"
#include "shared_random.h"
#if defined(EXPORTMALLINFO) && defined(HAVE_MALLOC_H) && defined(HAVE_MALLINFO)
#if !defined(OpenBSD)
#include <malloc.h>
#endif
#endif
/**
* \file directory.c
* \brief Code to send and fetch information from directory authorities and
* caches via HTTP.
*
* Directory caches and authorities use dirserv.c to generate the results of a
* query and stream them to the connection; clients use routerparse.c to parse
* them.
*
* Every directory request has a dir_connection_t on the client side and on
* the server side. In most cases, the dir_connection_t object is a linked
* connection, tunneled through an edge_connection_t so that it can be a
* stream on the Tor network. The only non-tunneled connections are those
* that are used to upload material (descriptors and votes) to authorities.
* Among tunneled connections, some use one-hop circuits, and others use
* multi-hop circuits for anonymity.
*
* Directory requests are launched by calling
* directory_initiate_request(). This
* launch the connection, will construct an HTTP request with
* directory_send_command(), send the and wait for a response. The client
* later handles the response with connection_dir_client_reached_eof(),
* which passes the information received to another part of Tor.
*
* On the server side, requests are read in directory_handle_command(),
* which dispatches first on the request type (GET or POST), and then on
* the URL requested. GET requests are processed with a table-based
* dispatcher in url_table[]. The process of handling larger GET requests
* is complicated because we need to avoid allocating a copy of all the
* data to be sent to the client in one huge buffer. Instead, we spool the
* data into the buffer using logic in connection_dirserv_flushed_some() in
* dirserv.c. (TODO: If we extended buf.c to have a zero-copy
* reference-based buffer type, we could remove most of that code, at the
* cost of a bit more reference counting.)
**/
/* In-points to directory.c:
*
* - directory_post_to_dirservers(), called from
* router_upload_dir_desc_to_dirservers() in router.c
* upload_service_descriptor() in rendservice.c
* - directory_get_from_dirserver(), called from
* rend_client_refetch_renddesc() in rendclient.c
* run_scheduled_events() in main.c
* do_hup() in main.c
* - connection_dir_process_inbuf(), called from
* connection_process_inbuf() in connection.c
* - connection_dir_finished_flushing(), called from
* connection_finished_flushing() in connection.c
* - connection_dir_finished_connecting(), called from
* connection_finished_connecting() in connection.c
*/
static void directory_send_command(dir_connection_t *conn,
int direct,
const directory_request_t *request);
static int body_is_plausible(const char *body, size_t body_len, int purpose);
static char *http_get_header(const char *headers, const char *which);
static void http_set_address_origin(const char *headers, connection_t *conn);
static void connection_dir_download_routerdesc_failed(dir_connection_t *conn);
static void connection_dir_bridge_routerdesc_failed(dir_connection_t *conn);
static void connection_dir_download_cert_failed(
dir_connection_t *conn, int status_code);
static void connection_dir_retry_bridges(smartlist_t *descs);
static void dir_routerdesc_download_failed(smartlist_t *failed,
int status_code,
int router_purpose,
int was_extrainfo,
int was_descriptor_digests);
static void dir_microdesc_download_failed(smartlist_t *failed,
int status_code);
static int client_likes_consensus(const struct consensus_cache_entry_t *ent,
const char *want_url);
static void connection_dir_close_consensus_fetches(
dir_connection_t *except_this_one, const char *resource);
static void directory_request_set_guard_state(directory_request_t *req,
struct circuit_guard_state_t *state);
/********* START VARIABLES **********/
/** How far in the future do we allow a directory server to tell us it is
* before deciding that one of us has the wrong time? */
#define ALLOW_DIRECTORY_TIME_SKEW (30*60)
#define X_ADDRESS_HEADER "X-Your-Address-Is: "
#define X_OR_DIFF_FROM_CONSENSUS_HEADER "X-Or-Diff-From-Consensus: "
/** HTTP cache control: how long do we tell proxies they can cache each
* kind of document we serve? */
#define FULL_DIR_CACHE_LIFETIME (60*60)
#define RUNNINGROUTERS_CACHE_LIFETIME (20*60)
#define DIRPORTFRONTPAGE_CACHE_LIFETIME (20*60)
#define NETWORKSTATUS_CACHE_LIFETIME (5*60)
#define ROUTERDESC_CACHE_LIFETIME (30*60)
#define ROUTERDESC_BY_DIGEST_CACHE_LIFETIME (48*60*60)
#define ROBOTS_CACHE_LIFETIME (24*60*60)
#define MICRODESC_CACHE_LIFETIME (48*60*60)
/********* END VARIABLES ************/
/** Return false if the directory purpose <b>dir_purpose</b>
* does not require an anonymous (three-hop) connection.
*
* Return true 1) by default, 2) if all directory actions have
* specifically been configured to be over an anonymous connection,
* or 3) if the router is a bridge */
int
purpose_needs_anonymity(uint8_t dir_purpose, uint8_t router_purpose,
const char *resource)
{
if (get_options()->AllDirActionsPrivate)
return 1;
if (router_purpose == ROUTER_PURPOSE_BRIDGE) {
if (dir_purpose == DIR_PURPOSE_FETCH_SERVERDESC
&& resource && !strcmp(resource, "authority.z")) {
/* We are asking a bridge for its own descriptor. That doesn't need
anonymity. */
return 0;
}
/* Assume all other bridge stuff needs anonymity. */
return 1; /* if no circuits yet, this might break bootstrapping, but it's
* needed to be safe. */
}
switch (dir_purpose)
{
case DIR_PURPOSE_UPLOAD_DIR:
case DIR_PURPOSE_UPLOAD_VOTE:
case DIR_PURPOSE_UPLOAD_SIGNATURES:
case DIR_PURPOSE_FETCH_STATUS_VOTE:
case DIR_PURPOSE_FETCH_DETACHED_SIGNATURES:
case DIR_PURPOSE_FETCH_CONSENSUS:
case DIR_PURPOSE_FETCH_CERTIFICATE:
case DIR_PURPOSE_FETCH_SERVERDESC:
case DIR_PURPOSE_FETCH_EXTRAINFO:
case DIR_PURPOSE_FETCH_MICRODESC:
return 0;
case DIR_PURPOSE_HAS_FETCHED_RENDDESC_V2:
case DIR_PURPOSE_UPLOAD_RENDDESC_V2:
case DIR_PURPOSE_FETCH_RENDDESC_V2:
return 1;
case DIR_PURPOSE_SERVER:
default:
log_warn(LD_BUG, "Called with dir_purpose=%d, router_purpose=%d",
dir_purpose, router_purpose);
tor_assert_nonfatal_unreached();
return 1; /* Assume it needs anonymity; better safe than sorry. */
}
}
/** Return a newly allocated string describing <b>auth</b>. Only describes
* authority features. */
STATIC char *
authdir_type_to_string(dirinfo_type_t auth)
{
char *result;
smartlist_t *lst = smartlist_new();
if (auth & V3_DIRINFO)
smartlist_add(lst, (void*)"V3");
if (auth & BRIDGE_DIRINFO)
smartlist_add(lst, (void*)"Bridge");
if (smartlist_len(lst)) {
result = smartlist_join_strings(lst, ", ", 0, NULL);
} else {
result = tor_strdup("[Not an authority]");
}
smartlist_free(lst);
return result;
}
/** Return a string describing a given directory connection purpose. */
STATIC const char *
dir_conn_purpose_to_string(int purpose)
{
switch (purpose)
{
case DIR_PURPOSE_UPLOAD_DIR:
return "server descriptor upload";
case DIR_PURPOSE_UPLOAD_VOTE:
return "server vote upload";
case DIR_PURPOSE_UPLOAD_SIGNATURES:
return "consensus signature upload";
case DIR_PURPOSE_FETCH_SERVERDESC:
return "server descriptor fetch";
case DIR_PURPOSE_FETCH_EXTRAINFO:
return "extra-info fetch";
case DIR_PURPOSE_FETCH_CONSENSUS:
return "consensus network-status fetch";
case DIR_PURPOSE_FETCH_CERTIFICATE:
return "authority cert fetch";
case DIR_PURPOSE_FETCH_STATUS_VOTE:
return "status vote fetch";
case DIR_PURPOSE_FETCH_DETACHED_SIGNATURES:
return "consensus signature fetch";
case DIR_PURPOSE_FETCH_RENDDESC_V2:
return "hidden-service v2 descriptor fetch";
case DIR_PURPOSE_UPLOAD_RENDDESC_V2:
return "hidden-service v2 descriptor upload";
case DIR_PURPOSE_FETCH_MICRODESC:
return "microdescriptor fetch";
}
log_warn(LD_BUG, "Called with unknown purpose %d", purpose);
return "(unknown)";
}
/** Return the requisite directory information types. */
STATIC dirinfo_type_t
dir_fetch_type(int dir_purpose, int router_purpose, const char *resource)
{
dirinfo_type_t type;
switch (dir_purpose) {
case DIR_PURPOSE_FETCH_EXTRAINFO:
type = EXTRAINFO_DIRINFO;
if (router_purpose == ROUTER_PURPOSE_BRIDGE)
type |= BRIDGE_DIRINFO;
else
type |= V3_DIRINFO;
break;
case DIR_PURPOSE_FETCH_SERVERDESC:
if (router_purpose == ROUTER_PURPOSE_BRIDGE)
type = BRIDGE_DIRINFO;
else
type = V3_DIRINFO;
break;
case DIR_PURPOSE_FETCH_STATUS_VOTE:
case DIR_PURPOSE_FETCH_DETACHED_SIGNATURES:
case DIR_PURPOSE_FETCH_CERTIFICATE:
type = V3_DIRINFO;
break;
case DIR_PURPOSE_FETCH_CONSENSUS:
type = V3_DIRINFO;
if (resource && !strcmp(resource, "microdesc"))
type |= MICRODESC_DIRINFO;
break;
case DIR_PURPOSE_FETCH_MICRODESC:
type = MICRODESC_DIRINFO;
break;
default:
log_warn(LD_BUG, "Unexpected purpose %d", (int)dir_purpose);
type = NO_DIRINFO;
break;
}
return type;
}
/** Return true iff <b>identity_digest</b> is the digest of a router which
* says that it caches extrainfos. (If <b>is_authority</b> we always
* believe that to be true.) */
int
router_supports_extrainfo(const char *identity_digest, int is_authority)
{
const node_t *node = node_get_by_id(identity_digest);
if (node && node->ri) {
if (node->ri->caches_extra_info)
return 1;
}
if (is_authority) {
return 1;
}
return 0;
}
/** Return true iff any trusted directory authority has accepted our
* server descriptor.
*
* We consider any authority sufficient because waiting for all of
* them means it never happens while any authority is down; we don't
* go for something more complex in the middle (like \>1/3 or \>1/2 or
* \>=1/2) because that doesn't seem necessary yet.
*/
int
directories_have_accepted_server_descriptor(void)
{
const smartlist_t *servers = router_get_trusted_dir_servers();
const or_options_t *options = get_options();
SMARTLIST_FOREACH(servers, dir_server_t *, d, {
if ((d->type & options->PublishServerDescriptor_) &&
d->has_accepted_serverdesc) {
return 1;
}
});
return 0;
}
/** Start a connection to every suitable directory authority, using
* connection purpose <b>dir_purpose</b> and uploading <b>payload</b>
* (of length <b>payload_len</b>). The dir_purpose should be one of
* 'DIR_PURPOSE_UPLOAD_{DIR|VOTE|SIGNATURES}'.
*
* <b>router_purpose</b> describes the type of descriptor we're
* publishing, if we're publishing a descriptor -- e.g. general or bridge.
*
* <b>type</b> specifies what sort of dir authorities (V3,
* BRIDGE, etc) we should upload to.
*
* If <b>extrainfo_len</b> is nonzero, the first <b>payload_len</b> bytes of
* <b>payload</b> hold a router descriptor, and the next <b>extrainfo_len</b>
* bytes of <b>payload</b> hold an extra-info document. Upload the descriptor
* to all authorities, and the extra-info document to all authorities that
* support it.
*/
void
directory_post_to_dirservers(uint8_t dir_purpose, uint8_t router_purpose,
dirinfo_type_t type,
const char *payload,
size_t payload_len, size_t extrainfo_len)
{
const or_options_t *options = get_options();
dir_indirection_t indirection;
const smartlist_t *dirservers = router_get_trusted_dir_servers();
int found = 0;
const int exclude_self = (dir_purpose == DIR_PURPOSE_UPLOAD_VOTE ||
dir_purpose == DIR_PURPOSE_UPLOAD_SIGNATURES);
tor_assert(dirservers);
/* This tries dirservers which we believe to be down, but ultimately, that's
* harmless, and we may as well err on the side of getting things uploaded.
*/
SMARTLIST_FOREACH_BEGIN(dirservers, dir_server_t *, ds) {
routerstatus_t *rs = &(ds->fake_status);
size_t upload_len = payload_len;
if ((type & ds->type) == 0)
continue;
if (exclude_self && router_digest_is_me(ds->digest)) {
/* we don't upload to ourselves, but at least there's now at least
* one authority of this type that has what we wanted to upload. */
found = 1;
continue;
}
if (options->StrictNodes &&
routerset_contains_routerstatus(options->ExcludeNodes, rs, -1)) {
log_warn(LD_DIR, "Wanted to contact authority '%s' for %s, but "
"it's in our ExcludedNodes list and StrictNodes is set. "
"Skipping.",
ds->nickname,
dir_conn_purpose_to_string(dir_purpose));
continue;
}
found = 1; /* at least one authority of this type was listed */
if (dir_purpose == DIR_PURPOSE_UPLOAD_DIR)
ds->has_accepted_serverdesc = 0;
if (extrainfo_len && router_supports_extrainfo(ds->digest, 1)) {
upload_len += extrainfo_len;
log_info(LD_DIR, "Uploading an extrainfo too (length %d)",
(int) extrainfo_len);
}
if (purpose_needs_anonymity(dir_purpose, router_purpose, NULL)) {
indirection = DIRIND_ANONYMOUS;
} else if (!fascist_firewall_allows_dir_server(ds,
FIREWALL_DIR_CONNECTION,
0)) {
if (fascist_firewall_allows_dir_server(ds, FIREWALL_OR_CONNECTION, 0))
indirection = DIRIND_ONEHOP;
else
indirection = DIRIND_ANONYMOUS;
} else {
indirection = DIRIND_DIRECT_CONN;
}
directory_request_t *req = directory_request_new(dir_purpose);
directory_request_set_routerstatus(req, rs);
directory_request_set_router_purpose(req, router_purpose);
directory_request_set_indirection(req, indirection);
directory_request_set_payload(req, payload, upload_len);
directory_initiate_request(req);
directory_request_free(req);
} SMARTLIST_FOREACH_END(ds);
if (!found) {
char *s = authdir_type_to_string(type);
log_warn(LD_DIR, "Publishing server descriptor to directory authorities "
"of type '%s', but no authorities of that type listed!", s);
tor_free(s);
}
}
/** Return true iff, according to the values in <b>options</b>, we should be
* using directory guards for direct downloads of directory information. */
STATIC int
should_use_directory_guards(const or_options_t *options)
{
/* Public (non-bridge) servers never use directory guards. */
if (public_server_mode(options))
return 0;
/* If guards are disabled, we can't use directory guards.
*/
if (!options->UseEntryGuards)
return 0;
/* If we're configured to fetch directory info aggressively or of a
* nonstandard type, don't use directory guards. */
if (options->DownloadExtraInfo || options->FetchDirInfoEarly ||
options->FetchDirInfoExtraEarly || options->FetchUselessDescriptors)
return 0;
return 1;
}
/** Pick an unconstrained directory server from among our guards, the latest
* networkstatus, or the fallback dirservers, for use in downloading
* information of type <b>type</b>, and return its routerstatus. */
static const routerstatus_t *
directory_pick_generic_dirserver(dirinfo_type_t type, int pds_flags,
uint8_t dir_purpose,
circuit_guard_state_t **guard_state_out)
{
const routerstatus_t *rs = NULL;
const or_options_t *options = get_options();
if (options->UseBridges)
log_warn(LD_BUG, "Called when we have UseBridges set.");
if (should_use_directory_guards(options)) {
const node_t *node = guards_choose_dirguard(guard_state_out);
if (node)
rs = node->rs;
} else {
/* anybody with a non-zero dirport will do */
rs = router_pick_directory_server(type, pds_flags);
}
if (!rs) {
log_info(LD_DIR, "No router found for %s; falling back to "
"dirserver list.", dir_conn_purpose_to_string(dir_purpose));
rs = router_pick_fallback_dirserver(type, pds_flags);
}
return rs;
}
/**
* Set the extra fields in <b>req</b> that are used when requesting a
* consensus of type <b>resource</b>.
*
* Right now, these fields are if-modified-since and x-or-diff-from-consensus.
*/
static void
dir_consensus_request_set_additional_headers(directory_request_t *req,
const char *resource)
{
time_t if_modified_since = 0;
uint8_t or_diff_from[DIGEST256_LEN];
int or_diff_from_is_set = 0;
/* DEFAULT_IF_MODIFIED_SINCE_DELAY is 1/20 of the default consensus
* period of 1 hour.
*/
const int DEFAULT_IF_MODIFIED_SINCE_DELAY = 180;
const int32_t DEFAULT_TRY_DIFF_FOR_CONSENSUS_NEWER = 72;
const int32_t MIN_TRY_DIFF_FOR_CONSENSUS_NEWER = 0;
const int32_t MAX_TRY_DIFF_FOR_CONSENSUS_NEWER = 8192;
const char TRY_DIFF_FOR_CONSENSUS_NEWER_NAME[] =
"try-diff-for-consensus-newer-than";
int flav = FLAV_NS;
if (resource)
flav = networkstatus_parse_flavor_name(resource);
int32_t max_age_for_diff = 3600 *
networkstatus_get_param(NULL,
TRY_DIFF_FOR_CONSENSUS_NEWER_NAME,
DEFAULT_TRY_DIFF_FOR_CONSENSUS_NEWER,
MIN_TRY_DIFF_FOR_CONSENSUS_NEWER,
MAX_TRY_DIFF_FOR_CONSENSUS_NEWER);
if (flav != -1) {
/* IF we have a parsed consensus of this type, we can do an
* if-modified-time based on it. */
networkstatus_t *v;
v = networkstatus_get_latest_consensus_by_flavor(flav);
if (v) {
/* In networks with particularly short V3AuthVotingIntervals,
* ask for the consensus if it's been modified since half the
* V3AuthVotingInterval of the most recent consensus. */
time_t ims_delay = DEFAULT_IF_MODIFIED_SINCE_DELAY;
if (v->fresh_until > v->valid_after
&& ims_delay > (v->fresh_until - v->valid_after)/2) {
ims_delay = (v->fresh_until - v->valid_after)/2;
}
if_modified_since = v->valid_after + ims_delay;
if (v->valid_after >= approx_time() - max_age_for_diff) {
memcpy(or_diff_from, v->digest_sha3_as_signed, DIGEST256_LEN);
or_diff_from_is_set = 1;
}
}
} else {
/* Otherwise it might be a consensus we don't parse, but which we
* do cache. Look at the cached copy, perhaps. */
cached_dir_t *cd = dirserv_get_consensus(resource);
/* We have no method of determining the voting interval from an
* unparsed consensus, so we use the default. */
if (cd) {
if_modified_since = cd->published + DEFAULT_IF_MODIFIED_SINCE_DELAY;
if (cd->published >= approx_time() - max_age_for_diff) {
memcpy(or_diff_from, cd->digest_sha3_as_signed, DIGEST256_LEN);
or_diff_from_is_set = 1;
}
}
}
if (if_modified_since > 0)
directory_request_set_if_modified_since(req, if_modified_since);
if (or_diff_from_is_set) {
char hex[HEX_DIGEST256_LEN + 1];
base16_encode(hex, sizeof(hex),
(const char*)or_diff_from, sizeof(or_diff_from));
directory_request_add_header(req, X_OR_DIFF_FROM_CONSENSUS_HEADER, hex);
}
}
/** Start a connection to a random running directory server, using
* connection purpose <b>dir_purpose</b>, intending to fetch descriptors
* of purpose <b>router_purpose</b>, and requesting <b>resource</b>.
* Use <b>pds_flags</b> as arguments to router_pick_directory_server()
* or router_pick_trusteddirserver().
*/
MOCK_IMPL(void, directory_get_from_dirserver, (
uint8_t dir_purpose,
uint8_t router_purpose,
const char *resource,
int pds_flags,
download_want_authority_t want_authority))
{
const routerstatus_t *rs = NULL;
const or_options_t *options = get_options();
int prefer_authority = (directory_fetches_from_authorities(options)
|| want_authority == DL_WANT_AUTHORITY);
int require_authority = 0;
int get_via_tor = purpose_needs_anonymity(dir_purpose, router_purpose,
resource);
dirinfo_type_t type = dir_fetch_type(dir_purpose, router_purpose, resource);
if (type == NO_DIRINFO)
return;
if (!options->FetchServerDescriptors)
return;
circuit_guard_state_t *guard_state = NULL;
if (!get_via_tor) {
if (options->UseBridges && !(type & BRIDGE_DIRINFO)) {
/* We want to ask a running bridge for which we have a descriptor.
*
* When we ask choose_random_entry() for a bridge, we specify what
* sort of dir fetch we'll be doing, so it won't return a bridge
* that can't answer our question.
*/
const node_t *node = guards_choose_dirguard(&guard_state);
if (node && node->ri) {
/* every bridge has a routerinfo. */
routerinfo_t *ri = node->ri;
/* clients always make OR connections to bridges */
tor_addr_port_t or_ap;
directory_request_t *req = directory_request_new(dir_purpose);
/* we are willing to use a non-preferred address if we need to */
fascist_firewall_choose_address_node(node, FIREWALL_OR_CONNECTION, 0,
&or_ap);
directory_request_set_or_addr_port(req, &or_ap);
directory_request_set_directory_id_digest(req,
ri->cache_info.identity_digest);
directory_request_set_router_purpose(req, router_purpose);
directory_request_set_resource(req, resource);
if (dir_purpose == DIR_PURPOSE_FETCH_CONSENSUS)
dir_consensus_request_set_additional_headers(req, resource);
directory_request_set_guard_state(req, guard_state);
directory_initiate_request(req);
directory_request_free(req);
} else {
if (guard_state) {
entry_guard_cancel(&guard_state);
}
log_notice(LD_DIR, "Ignoring directory request, since no bridge "
"nodes are available yet.");
}
return;
} else {
if (prefer_authority || (type & BRIDGE_DIRINFO)) {
/* only ask authdirservers, and don't ask myself */
rs = router_pick_trusteddirserver(type, pds_flags);
if (rs == NULL && (pds_flags & (PDS_NO_EXISTING_SERVERDESC_FETCH|
PDS_NO_EXISTING_MICRODESC_FETCH))) {
/* We don't want to fetch from any authorities that we're currently
* fetching server descriptors from, and we got no match. Did we
* get no match because all the authorities have connections
* fetching server descriptors (in which case we should just
* return,) or because all the authorities are down or on fire or
* unreachable or something (in which case we should go on with
* our fallback code)? */
pds_flags &= ~(PDS_NO_EXISTING_SERVERDESC_FETCH|
PDS_NO_EXISTING_MICRODESC_FETCH);
rs = router_pick_trusteddirserver(type, pds_flags);
if (rs) {
log_debug(LD_DIR, "Deferring serverdesc fetch: all authorities "
"are in use.");
return;
}
}
if (rs == NULL && require_authority) {
log_info(LD_DIR, "No authorities were available for %s: will try "
"later.", dir_conn_purpose_to_string(dir_purpose));
return;
}
}
if (!rs && !(type & BRIDGE_DIRINFO)) {
rs = directory_pick_generic_dirserver(type, pds_flags,
dir_purpose,
&guard_state);
if (!rs)
get_via_tor = 1; /* last resort: try routing it via Tor */
}
}
}
if (get_via_tor) {
/* Never use fascistfirewall; we're going via Tor. */
pds_flags |= PDS_IGNORE_FASCISTFIREWALL;
rs = router_pick_directory_server(type, pds_flags);
}
/* If we have any hope of building an indirect conn, we know some router
* descriptors. If (rs==NULL), we can't build circuits anyway, so
* there's no point in falling back to the authorities in this case. */
if (rs) {
const dir_indirection_t indirection =
get_via_tor ? DIRIND_ANONYMOUS : DIRIND_ONEHOP;
directory_request_t *req = directory_request_new(dir_purpose);
directory_request_set_routerstatus(req, rs);
directory_request_set_router_purpose(req, router_purpose);
directory_request_set_indirection(req, indirection);
directory_request_set_resource(req, resource);
if (dir_purpose == DIR_PURPOSE_FETCH_CONSENSUS)
dir_consensus_request_set_additional_headers(req, resource);
if (guard_state)
directory_request_set_guard_state(req, guard_state);
directory_initiate_request(req);
directory_request_free(req);
} else {
log_notice(LD_DIR,
"While fetching directory info, "
"no running dirservers known. Will try again later. "
"(purpose %d)", dir_purpose);
if (!purpose_needs_anonymity(dir_purpose, router_purpose, resource)) {
/* remember we tried them all and failed. */
directory_all_unreachable(time(NULL));
}
}
}
/** As directory_get_from_dirserver, but initiates a request to <i>every</i>
* directory authority other than ourself. Only for use by authorities when
* searching for missing information while voting. */
void
directory_get_from_all_authorities(uint8_t dir_purpose,
uint8_t router_purpose,
const char *resource)
{
tor_assert(dir_purpose == DIR_PURPOSE_FETCH_STATUS_VOTE ||
dir_purpose == DIR_PURPOSE_FETCH_DETACHED_SIGNATURES);
SMARTLIST_FOREACH_BEGIN(router_get_trusted_dir_servers(),
dir_server_t *, ds) {
if (router_digest_is_me(ds->digest))
continue;
if (!(ds->type & V3_DIRINFO))
continue;
const routerstatus_t *rs = &ds->fake_status;
directory_request_t *req = directory_request_new(dir_purpose);
directory_request_set_routerstatus(req, rs);
directory_request_set_router_purpose(req, router_purpose);
directory_request_set_resource(req, resource);
directory_initiate_request(req);
directory_request_free(req);
} SMARTLIST_FOREACH_END(ds);
}
/** Return true iff <b>ind</b> requires a multihop circuit. */
static int
dirind_is_anon(dir_indirection_t ind)
{
return ind == DIRIND_ANON_DIRPORT || ind == DIRIND_ANONYMOUS;
}
/* Choose reachable OR and Dir addresses and ports from status, copying them
* into use_or_ap and use_dir_ap. If indirection is anonymous, then we're
* connecting via another relay, so choose the primary IPv4 address and ports.
*
* status should have at least one reachable address, if we can't choose a
* reachable address, warn and return -1. Otherwise, return 0.
*/
static int
directory_choose_address_routerstatus(const routerstatus_t *status,
dir_indirection_t indirection,
tor_addr_port_t *use_or_ap,
tor_addr_port_t *use_dir_ap)
{
tor_assert(status != NULL);
tor_assert(use_or_ap != NULL);
tor_assert(use_dir_ap != NULL);
const or_options_t *options = get_options();
int have_or = 0, have_dir = 0;
/* We expect status to have at least one reachable address if we're
* connecting to it directly.
*
* Therefore, we can simply use the other address if the one we want isn't
* allowed by the firewall.
*
* (When Tor uploads and downloads a hidden service descriptor, it uses
* DIRIND_ANONYMOUS, except for Tor2Web, which uses DIRIND_ONEHOP.
* So this code will only modify the address for Tor2Web's HS descriptor
* fetches. Even Single Onion Servers (NYI) use DIRIND_ANONYMOUS, to avoid
* HSDirs denying service by rejecting descriptors.)
*/
/* Initialise the OR / Dir addresses */
tor_addr_make_null(&use_or_ap->addr, AF_UNSPEC);
use_or_ap->port = 0;
tor_addr_make_null(&use_dir_ap->addr, AF_UNSPEC);
use_dir_ap->port = 0;
/* ORPort connections */
if (indirection == DIRIND_ANONYMOUS) {
if (status->addr) {
/* Since we're going to build a 3-hop circuit and ask the 2nd relay
* to extend to this address, always use the primary (IPv4) OR address */
tor_addr_from_ipv4h(&use_or_ap->addr, status->addr);
use_or_ap->port = status->or_port;
have_or = 1;
}
} else if (indirection == DIRIND_ONEHOP) {
/* We use an IPv6 address if we have one and we prefer it.
* Use the preferred address and port if they are reachable, otherwise,
* use the alternate address and port (if any).
*/
have_or = fascist_firewall_choose_address_rs(status,
FIREWALL_OR_CONNECTION, 0,
use_or_ap);
}
/* DirPort connections
* DIRIND_ONEHOP uses ORPort, but may fall back to the DirPort on relays */
if (indirection == DIRIND_DIRECT_CONN ||
indirection == DIRIND_ANON_DIRPORT ||
(indirection == DIRIND_ONEHOP
&& !directory_must_use_begindir(options))) {
have_dir = fascist_firewall_choose_address_rs(status,
FIREWALL_DIR_CONNECTION, 0,
use_dir_ap);
}
/* We rejected all addresses in the relay's status. This means we can't
* connect to it. */
if (!have_or && !have_dir) {
static int logged_backtrace = 0;
log_info(LD_BUG, "Rejected all OR and Dir addresses from %s when "
"launching an outgoing directory connection to: IPv4 %s OR %d "
"Dir %d IPv6 %s OR %d Dir %d", routerstatus_describe(status),
fmt_addr32(status->addr), status->or_port,
status->dir_port, fmt_addr(&status->ipv6_addr),
status->ipv6_orport, status->dir_port);
if (!logged_backtrace) {
log_backtrace(LOG_INFO, LD_BUG, "Addresses came from");
logged_backtrace = 1;
}
return -1;
}
return 0;
}
/** Return true iff <b>conn</b> is the client side of a directory connection
* we launched to ourself in order to determine the reachability of our
* dir_port. */
static int
directory_conn_is_self_reachability_test(dir_connection_t *conn)
{
if (conn->requested_resource &&
!strcmpstart(conn->requested_resource,"authority")) {
const routerinfo_t *me = router_get_my_routerinfo();
if (me &&
router_digest_is_me(conn->identity_digest) &&
tor_addr_eq_ipv4h(&conn->base_.addr, me->addr) && /*XXXX prop 118*/
me->dir_port == conn->base_.port)
return 1;
}
return 0;
}
/** Called when we are unable to complete the client's request to a directory
* server due to a network error: Mark the router as down and try again if
* possible.
*/
static void
connection_dir_request_failed(dir_connection_t *conn)
{
if (conn->guard_state) {
/* We haven't seen a success on this guard state, so consider it to have
* failed. */
entry_guard_failed(&conn->guard_state);
}
if (directory_conn_is_self_reachability_test(conn)) {
return; /* this was a test fetch. don't retry. */
}
if (!entry_list_is_constrained(get_options()))
router_set_status(conn->identity_digest, 0); /* don't try this one again */
if (conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO) {
log_info(LD_DIR, "Giving up on serverdesc/extrainfo fetch from "
"directory server at '%s'; retrying",
conn->base_.address);
if (conn->router_purpose == ROUTER_PURPOSE_BRIDGE)
connection_dir_bridge_routerdesc_failed(conn);
connection_dir_download_routerdesc_failed(conn);
} else if (conn->base_.purpose == DIR_PURPOSE_FETCH_CONSENSUS) {
if (conn->requested_resource)
networkstatus_consensus_download_failed(0, conn->requested_resource);
} else if (conn->base_.purpose == DIR_PURPOSE_FETCH_CERTIFICATE) {
log_info(LD_DIR, "Giving up on certificate fetch from directory server "
"at '%s'; retrying",
conn->base_.address);
connection_dir_download_cert_failed(conn, 0);
} else if (conn->base_.purpose == DIR_PURPOSE_FETCH_DETACHED_SIGNATURES) {
log_info(LD_DIR, "Giving up downloading detached signatures from '%s'",
conn->base_.address);
} else if (conn->base_.purpose == DIR_PURPOSE_FETCH_STATUS_VOTE) {
log_info(LD_DIR, "Giving up downloading votes from '%s'",
conn->base_.address);
} else if (conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC) {
log_info(LD_DIR, "Giving up on downloading microdescriptors from "
"directory server at '%s'; will retry", conn->base_.address);
connection_dir_download_routerdesc_failed(conn);
}
}
/** Helper: Attempt to fetch directly the descriptors of each bridge
* listed in <b>failed</b>.
*/
static void
connection_dir_retry_bridges(smartlist_t *descs)
{
char digest[DIGEST_LEN];
SMARTLIST_FOREACH(descs, const char *, cp,
{
if (base16_decode(digest, DIGEST_LEN, cp, strlen(cp)) != DIGEST_LEN) {
log_warn(LD_BUG, "Malformed fingerprint in list: %s",
escaped(cp));
continue;
}
retry_bridge_descriptor_fetch_directly(digest);
});
}
/** Called when an attempt to download one or more router descriptors
* or extra-info documents on connection <b>conn</b> failed.
*/
static void
connection_dir_download_routerdesc_failed(dir_connection_t *conn)
{
/* No need to increment the failure count for routerdescs, since
* it's not their fault. */
/* No need to relaunch descriptor downloads here: we already do it
* every 10 or 60 seconds (FOO_DESCRIPTOR_RETRY_INTERVAL) in main.c. */
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO ||
conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC);
(void) conn;
}
/** Called when an attempt to download a bridge's routerdesc from
* one of the authorities failed due to a network error. If
* possible attempt to download descriptors from the bridge directly.
*/
static void
connection_dir_bridge_routerdesc_failed(dir_connection_t *conn)
{
smartlist_t *which = NULL;
/* Requests for bridge descriptors are in the form 'fp/', so ignore
anything else. */
if (!conn->requested_resource || strcmpstart(conn->requested_resource,"fp/"))
return;
which = smartlist_new();
dir_split_resource_into_fingerprints(conn->requested_resource
+ strlen("fp/"),
which, NULL, 0);
tor_assert(conn->base_.purpose != DIR_PURPOSE_FETCH_EXTRAINFO);
if (smartlist_len(which)) {
connection_dir_retry_bridges(which);
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
}
smartlist_free(which);
}
/** Called when an attempt to fetch a certificate fails. */
static void
connection_dir_download_cert_failed(dir_connection_t *conn, int status)
{
const char *fp_pfx = "fp/";
const char *fpsk_pfx = "fp-sk/";
smartlist_t *failed;
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_CERTIFICATE);
if (!conn->requested_resource)
return;
failed = smartlist_new();
/*
* We have two cases download by fingerprint (resource starts
* with "fp/") or download by fingerprint/signing key pair
* (resource starts with "fp-sk/").
*/
if (!strcmpstart(conn->requested_resource, fp_pfx)) {
/* Download by fingerprint case */
dir_split_resource_into_fingerprints(conn->requested_resource +
strlen(fp_pfx),
failed, NULL, DSR_HEX);
SMARTLIST_FOREACH_BEGIN(failed, char *, cp) {
/* Null signing key digest indicates download by fp only */
authority_cert_dl_failed(cp, NULL, status);
tor_free(cp);
} SMARTLIST_FOREACH_END(cp);
} else if (!strcmpstart(conn->requested_resource, fpsk_pfx)) {
/* Download by (fp,sk) pairs */
dir_split_resource_into_fingerprint_pairs(conn->requested_resource +
strlen(fpsk_pfx), failed);
SMARTLIST_FOREACH_BEGIN(failed, fp_pair_t *, cp) {
authority_cert_dl_failed(cp->first, cp->second, status);
tor_free(cp);
} SMARTLIST_FOREACH_END(cp);
} else {
log_warn(LD_DIR,
"Don't know what to do with failure for cert fetch %s",
conn->requested_resource);
}
smartlist_free(failed);
update_certificate_downloads(time(NULL));
}
/* Should this tor instance only use begindir for all its directory requests?
*/
int
directory_must_use_begindir(const or_options_t *options)
{
/* Clients, onion services, and bridges must use begindir,
* relays and authorities do not have to */
return !public_server_mode(options);
}
struct directory_request_t {
/**
* These fields specify which directory we're contacting. Routerstatus,
* if present, overrides the other fields.
*
* @{ */
tor_addr_port_t or_addr_port;
tor_addr_port_t dir_addr_port;
char digest[DIGEST_LEN];
const routerstatus_t *routerstatus;
/** @} */
/** One of DIR_PURPOSE_* other than DIR_PURPOSE_SERVER. Describes what
* kind of operation we'll be doing (upload/download), and of what kind
* of document. */
uint8_t dir_purpose;
/** One of ROUTER_PURPOSE_*; used for uploads and downloads of routerinfo
* and extrainfo docs. */
uint8_t router_purpose;
/** Enum: determines whether to anonymize, and whether to use dirport or
* orport. */
dir_indirection_t indirection;
/** Alias to the variable part of the URL for this request */
const char *resource;
/** Alias to the payload to upload (if any) */
const char *payload;
/** Number of bytes to upload from payload</b> */
size_t payload_len;
/** Value to send in an if-modified-since header, or 0 for none. */
time_t if_modified_since;
/** Hidden-service-specific information */
const rend_data_t *rend_query;
/** Extra headers to append to the request */
config_line_t *additional_headers;
/** */
/** Used internally to directory.c: gets informed when the attempt to
* connect to the directory succeeds or fails, if that attempt bears on the
* directory's usability as a directory guard. */
circuit_guard_state_t *guard_state;
};
/** Evaluate the situation and decide if we should use an encrypted
* "begindir-style" connection for this directory request.
* 0) If there is no DirPort, yes.
* 1) If or_port is 0, or it's a direct conn and or_port is firewalled
* or we're a dir mirror, no.
* 2) If we prefer to avoid begindir conns, and we're not fetching or
* publishing a bridge relay descriptor, no.
* 3) Else yes.
* If returning 0, return in *reason why we can't use begindir.
* reason must not be NULL.
*/
static int
directory_command_should_use_begindir(const or_options_t *options,
const directory_request_t *req,
const char **reason)
{
const tor_addr_t *or_addr = &req->or_addr_port.addr;
//const tor_addr_t *dir_addr = &req->dir_addr_port.addr;
const int or_port = req->or_addr_port.port;
const int dir_port = req->dir_addr_port.port;
const dir_indirection_t indirection = req->indirection;
tor_assert(reason);
*reason = NULL;
/* Reasons why we must use begindir */
if (!dir_port) {
*reason = "(using begindir - directory with no DirPort)";
return 1; /* We don't know a DirPort -- must begindir. */
}
/* Reasons why we can't possibly use begindir */
if (!or_port) {
*reason = "directory with unknown ORPort";
return 0; /* We don't know an ORPort -- no chance. */
}
if (indirection == DIRIND_DIRECT_CONN ||
indirection == DIRIND_ANON_DIRPORT) {
*reason = "DirPort connection";
return 0;
}
if (indirection == DIRIND_ONEHOP) {
/* We're firewalled and want a direct OR connection */
if (!fascist_firewall_allows_address_addr(or_addr, or_port,
FIREWALL_OR_CONNECTION, 0, 0)) {
*reason = "ORPort not reachable";
return 0;
}
}
/* Reasons why we want to avoid using begindir */
if (indirection == DIRIND_ONEHOP) {
if (!directory_must_use_begindir(options)) {
*reason = "in relay mode";
return 0;
}
}
/* DIRIND_ONEHOP on a client, or DIRIND_ANONYMOUS
*/
*reason = "(using begindir)";
return 1;
}
/**
* Create and return a new directory_request_t with purpose
* <b>dir_purpose</b>.
*/
directory_request_t *
directory_request_new(uint8_t dir_purpose)
{
tor_assert(dir_purpose >= DIR_PURPOSE_MIN_);
tor_assert(dir_purpose <= DIR_PURPOSE_MAX_);
tor_assert(dir_purpose != DIR_PURPOSE_SERVER);
tor_assert(dir_purpose != DIR_PURPOSE_HAS_FETCHED_RENDDESC_V2);
directory_request_t *result = tor_malloc_zero(sizeof(*result));
tor_addr_make_null(&result->or_addr_port.addr, AF_INET);
result->or_addr_port.port = 0;
tor_addr_make_null(&result->dir_addr_port.addr, AF_INET);
result->dir_addr_port.port = 0;
result->dir_purpose = dir_purpose;
result->router_purpose = ROUTER_PURPOSE_GENERAL;
result->indirection = DIRIND_ONEHOP;
return result;
}
/**
* Release all resources held by <b>req</b>.
*/
void
directory_request_free(directory_request_t *req)
{
if (req == NULL)
return;
config_free_lines(req->additional_headers);
tor_free(req);
}
/**
* Set the address and OR port to use for this directory request. If there is
* no OR port, we'll have to connect over the dirport. (If there are both,
* the indirection setting determins which to use.)
*/
void
directory_request_set_or_addr_port(directory_request_t *req,
const tor_addr_port_t *p)
{
memcpy(&req->or_addr_port, p, sizeof(*p));
}
/**
* Set the address and dirport to use for this directory request. If there
* is no dirport, we'll have to connect over the OR port. (If there are both,
* the indirection setting determins which to use.)
*/
void
directory_request_set_dir_addr_port(directory_request_t *req,
const tor_addr_port_t *p)
{
memcpy(&req->dir_addr_port, p, sizeof(*p));
}
/**
* Set the RSA identity digest of the directory to use for this directory
* request.
*/
void
directory_request_set_directory_id_digest(directory_request_t *req,
const char *digest)
{
memcpy(req->digest, digest, DIGEST_LEN);
}
/**
* Set the router purpose associated with uploaded and downloaded router
* descriptors and extrainfo documents in this directory request. The purpose
* must be one of ROUTER_PURPOSE_GENERAL (the default) or
* ROUTER_PURPOSE_BRIDGE.
*/
void
directory_request_set_router_purpose(directory_request_t *req,
uint8_t router_purpose)
{
tor_assert(router_purpose == ROUTER_PURPOSE_GENERAL ||
router_purpose == ROUTER_PURPOSE_BRIDGE);
// assert that it actually makes sense to set this purpose, given
// the dir_purpose.
req->router_purpose = router_purpose;
}
/**
* Set the indirection to be used for the directory request. The indirection
* parameter configures whether to connect to a DirPort or ORPort, and whether
* to anonymize the connection. DIRIND_ONEHOP (use ORPort, don't anonymize)
* is the default. See dir_indirection_t for more information.
*/
void
directory_request_set_indirection(directory_request_t *req,
dir_indirection_t indirection)
{
req->indirection = indirection;
}
/**
* Set a pointer to the resource to request from a directory. Different
* request types use resources to indicate different components of their URL.
* Note that only an alias to <b>resource</b> is stored, so the
* <b>resource</b> must outlive the request.
*/
void
directory_request_set_resource(directory_request_t *req,
const char *resource)
{
req->resource = resource;
}
/**
* Set a pointer to the payload to include with this directory request, along
* with its length. Note that only an alias to <b>payload</b> is stored, so
* the <b>payload</b> must outlive the request.
*/
void
directory_request_set_payload(directory_request_t *req,
const char *payload,
size_t payload_len)
{
tor_assert(DIR_PURPOSE_IS_UPLOAD(req->dir_purpose));
req->payload = payload;
req->payload_len = payload_len;
}
/**
* Set an if-modified-since date to send along with the request. The
* default is 0 (meaning, send no if-modified-since header).
*/
void
directory_request_set_if_modified_since(directory_request_t *req,
time_t if_modified_since)
{
req->if_modified_since = if_modified_since;
}
/** Include a header of name <b>key</b> with content <b>val</b> in the
* request. Neither may include newlines or other odd characters. Their
* ordering is not currently guaranteed.
*
* Note that, as elsewhere in this module, header keys include a trailing
* colon and space.
*/
void
directory_request_add_header(directory_request_t *req,
const char *key,
const char *val)
{
config_line_prepend(&req->additional_headers, key, val);
}
/**
* Set an object containing HS data to be associated with this request. Note
* that only an alias to <b>query</b> is stored, so the <b>query</b> object
* must outlive the request.
*/
void
directory_request_set_rend_query(directory_request_t *req,
const rend_data_t *query)
{
if (query) {
tor_assert(req->dir_purpose == DIR_PURPOSE_FETCH_RENDDESC_V2 ||
req->dir_purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2);
}
req->rend_query = query;
}
/** Set a static circuit_guard_state_t object to affliate with the request in
* <b>req</b>. This object will receive notification when the attempt to
* connect to the guard either succeeds or fails. */
static void
directory_request_set_guard_state(directory_request_t *req,
circuit_guard_state_t *state)
{
req->guard_state = state;
}
/**
* Internal: Return true if any information for contacting the directory in
* <b>req</b> has been set, other than by the routerstatus. */
static int
directory_request_dir_contact_info_specified(const directory_request_t *req)
{
/* We only check for ports here, since we don't use an addr unless the port
* is set */
return (req->or_addr_port.port ||
req->dir_addr_port.port ||
! tor_digest_is_zero(req->digest));
}
/**
* Set the routerstatus to use for the directory associated with this
* request. If this option is set, then no other function to set the
* directory's address or identity should be called.
*/
void
directory_request_set_routerstatus(directory_request_t *req,
const routerstatus_t *status)
{
req->routerstatus = status;
}
/**
* Helper: update the addresses, ports, and identities in <b>req</b>
* from the routerstatus object in <b>req</b>. Return 0 on success.
* On failure, warn and return -1.
*/
static int
directory_request_set_dir_from_routerstatus(directory_request_t *req)
{
const routerstatus_t *status = req->routerstatus;
if (BUG(status == NULL))
return -1;
const or_options_t *options = get_options();
const node_t *node;
tor_addr_port_t use_or_ap, use_dir_ap;
const int anonymized_connection = dirind_is_anon(req->indirection);
tor_assert(status != NULL);
node = node_get_by_id(status->identity_digest);
/* XXX The below check is wrong: !node means it's not in the consensus,
* but we haven't checked if we have a descriptor for it -- and also,
* we only care about the descriptor if it's a begindir-style anonymized
* connection. */
if (!node && anonymized_connection) {
log_info(LD_DIR, "Not sending anonymized request to directory '%s'; we "
"don't have its router descriptor.",
routerstatus_describe(status));
return -1;
}
if (options->ExcludeNodes && options->StrictNodes &&
routerset_contains_routerstatus(options->ExcludeNodes, status, -1)) {
log_warn(LD_DIR, "Wanted to contact directory mirror %s for %s, but "
"it's in our ExcludedNodes list and StrictNodes is set. "
"Skipping. This choice might make your Tor not work.",
routerstatus_describe(status),
dir_conn_purpose_to_string(req->dir_purpose));
return -1;
}
/* At this point, if we are a client making a direct connection to a
* directory server, we have selected a server that has at least one address
* allowed by ClientUseIPv4/6 and Reachable{"",OR,Dir}Addresses. This
* selection uses the preference in ClientPreferIPv6{OR,Dir}Port, if
* possible. (If UseBridges is set, clients always use IPv6, and prefer it
* by default.)
*
* Now choose an address that we can use to connect to the directory server.
*/
if (directory_choose_address_routerstatus(status,
req->indirection, &use_or_ap,
&use_dir_ap) < 0) {
return -1;
}
directory_request_set_or_addr_port(req, &use_or_ap);
directory_request_set_dir_addr_port(req, &use_dir_ap);
directory_request_set_directory_id_digest(req, status->identity_digest);
return 0;
}
/**
* Launch the provided directory request, configured in <b>request</b>.
* After this function is called, you can free <b>request</b>.
*/
MOCK_IMPL(void,
directory_initiate_request,(directory_request_t *request))
{
tor_assert(request);
if (request->routerstatus) {
tor_assert_nonfatal(
! directory_request_dir_contact_info_specified(request));
if (directory_request_set_dir_from_routerstatus(request) < 0) {
return;
}
}
const tor_addr_port_t *or_addr_port = &request->or_addr_port;
const tor_addr_port_t *dir_addr_port = &request->dir_addr_port;
const char *digest = request->digest;
const uint8_t dir_purpose = request->dir_purpose;
const uint8_t router_purpose = request->router_purpose;
const dir_indirection_t indirection = request->indirection;
const char *resource = request->resource;
const rend_data_t *rend_query = request->rend_query;
circuit_guard_state_t *guard_state = request->guard_state;
tor_assert(or_addr_port->port || dir_addr_port->port);
tor_assert(digest);
dir_connection_t *conn;
const or_options_t *options = get_options();
int socket_error = 0;
const char *begindir_reason = NULL;
/* Should the connection be to a relay's OR port (and inside that we will
* send our directory request)? */
const int use_begindir =
directory_command_should_use_begindir(options, request, &begindir_reason);
/* Will the connection go via a three-hop Tor circuit? Note that this
* is separate from whether it will use_begindir. */
const int anonymized_connection = dirind_is_anon(indirection);
/* What is the address we want to make the directory request to? If
* we're making a begindir request this is the ORPort of the relay
* we're contacting; if not a begindir request, this is its DirPort.
* Note that if anonymized_connection is true, we won't be initiating
* a connection directly to this address. */
tor_addr_t addr;
tor_addr_copy(&addr, &(use_begindir ? or_addr_port : dir_addr_port)->addr);
uint16_t port = (use_begindir ? or_addr_port : dir_addr_port)->port;
log_debug(LD_DIR, "anonymized %d, use_begindir %d.",
anonymized_connection, use_begindir);
log_debug(LD_DIR, "Initiating %s", dir_conn_purpose_to_string(dir_purpose));
if (purpose_needs_anonymity(dir_purpose, router_purpose, resource)) {
tor_assert(anonymized_connection ||
rend_non_anonymous_mode_enabled(options));
}
/* use encrypted begindir connections for everything except relays
* this provides better protection for directory fetches */
if (!use_begindir && directory_must_use_begindir(options)) {
log_warn(LD_BUG, "Client could not use begindir connection: %s",
begindir_reason ? begindir_reason : "(NULL)");
return;
}
/* ensure that we don't make direct connections when a SOCKS server is
* configured. */
if (!anonymized_connection && !use_begindir && !options->HTTPProxy &&
(options->Socks4Proxy || options->Socks5Proxy)) {
log_warn(LD_DIR, "Cannot connect to a directory server through a "
"SOCKS proxy!");
return;
}
/* Make sure that the destination addr and port we picked is viable. */
if (!port || tor_addr_is_null(&addr)) {
static int logged_backtrace = 0;
log_warn(LD_DIR,
"Cannot make an outgoing %sconnection without a remote %sPort.",
use_begindir ? "begindir " : "",
use_begindir ? "OR" : "Dir");
if (!logged_backtrace) {
log_backtrace(LOG_INFO, LD_BUG, "Address came from");
logged_backtrace = 1;
}
return;
}
conn = dir_connection_new(tor_addr_family(&addr));
/* set up conn so it's got all the data we need to remember */
tor_addr_copy(&conn->base_.addr, &addr);
conn->base_.port = port;
conn->base_.address = tor_addr_to_str_dup(&addr);
memcpy(conn->identity_digest, digest, DIGEST_LEN);
conn->base_.purpose = dir_purpose;
conn->router_purpose = router_purpose;
/* give it an initial state */
conn->base_.state = DIR_CONN_STATE_CONNECTING;
/* decide whether we can learn our IP address from this conn */
/* XXXX This is a bad name for this field now. */
conn->dirconn_direct = !anonymized_connection;
/* copy rendezvous data, if any */
if (rend_query)
conn->rend_data = rend_data_dup(rend_query);
if (!anonymized_connection && !use_begindir) {
/* then we want to connect to dirport directly */
if (options->HTTPProxy) {
tor_addr_copy(&addr, &options->HTTPProxyAddr);
port = options->HTTPProxyPort;
}
// In this case we should not have picked a directory guard.
if (BUG(guard_state)) {
entry_guard_cancel(&guard_state);
}
switch (connection_connect(TO_CONN(conn), conn->base_.address, &addr,
port, &socket_error)) {
case -1:
connection_mark_for_close(TO_CONN(conn));
return;
case 1:
/* start flushing conn */
conn->base_.state = DIR_CONN_STATE_CLIENT_SENDING;
/* fall through */
case 0:
/* queue the command on the outbuf */
directory_send_command(conn, 1, request);
connection_watch_events(TO_CONN(conn), READ_EVENT | WRITE_EVENT);
/* writable indicates finish, readable indicates broken link,
error indicates broken link in windowsland. */
}
} else {
/* We will use a Tor circuit (maybe 1-hop, maybe 3-hop, maybe with
* begindir, maybe not with begindir) */
entry_connection_t *linked_conn;
/* Anonymized tunneled connections can never share a circuit.
* One-hop directory connections can share circuits with each other
* but nothing else. */
int iso_flags = anonymized_connection ? ISO_STREAM : ISO_SESSIONGRP;
/* If it's an anonymized connection, remember the fact that we
* wanted it for later: maybe we'll want it again soon. */
if (anonymized_connection && use_begindir)
rep_hist_note_used_internal(time(NULL), 0, 1);
else if (anonymized_connection && !use_begindir)
rep_hist_note_used_port(time(NULL), conn->base_.port);
// In this case we should not have a directory guard; we'll
// get a regular guard later when we build the circuit.
if (BUG(anonymized_connection && guard_state)) {
entry_guard_cancel(&guard_state);
}
conn->guard_state = guard_state;
/* make an AP connection
* populate it and add it at the right state
* hook up both sides
*/
linked_conn =
connection_ap_make_link(TO_CONN(conn),
conn->base_.address, conn->base_.port,
digest,
SESSION_GROUP_DIRCONN, iso_flags,
use_begindir, !anonymized_connection);
if (!linked_conn) {
log_warn(LD_NET,"Making tunnel to dirserver failed.");
connection_mark_for_close(TO_CONN(conn));
return;
}
if (connection_add(TO_CONN(conn)) < 0) {
log_warn(LD_NET,"Unable to add connection for link to dirserver.");
connection_mark_for_close(TO_CONN(conn));
return;
}
conn->base_.state = DIR_CONN_STATE_CLIENT_SENDING;
/* queue the command on the outbuf */
directory_send_command(conn, 0, request);
connection_watch_events(TO_CONN(conn), READ_EVENT|WRITE_EVENT);
connection_start_reading(ENTRY_TO_CONN(linked_conn));
}
}
/** Return true iff anything we say on <b>conn</b> is being encrypted before
* we send it to the client/server. */
int
connection_dir_is_encrypted(const dir_connection_t *conn)
{
/* Right now it's sufficient to see if conn is or has been linked, since
* the only thing it could be linked to is an edge connection on a
* circuit, and the only way it could have been unlinked is at the edge
* connection getting closed.
*/
return TO_CONN(conn)->linked;
}
/** Helper for sorting
*
* sort strings alphabetically
*/
static int
compare_strs_(const void **a, const void **b)
{
const char *s1 = *a, *s2 = *b;
return strcmp(s1, s2);
}
#define CONDITIONAL_CONSENSUS_FPR_LEN 3
#if (CONDITIONAL_CONSENSUS_FPR_LEN > DIGEST_LEN)
#error "conditional consensus fingerprint length is larger than digest length"
#endif
/** Return the URL we should use for a consensus download.
*
* Use the "conditional consensus downloading" feature described in
* dir-spec.txt, i.e.
* GET .../consensus/<b>fpr</b>+<b>fpr</b>+<b>fpr</b>
*
* If 'resource' is provided, it is the name of a consensus flavor to request.
*/
static char *
directory_get_consensus_url(const char *resource)
{
char *url = NULL;
const char *hyphen, *flavor;
if (resource==NULL || strcmp(resource, "ns")==0) {
flavor = ""; /* Request ns consensuses as "", so older servers will work*/
hyphen = "";
} else {
flavor = resource;
hyphen = "-";
}
{
char *authority_id_list;
smartlist_t *authority_digests = smartlist_new();
SMARTLIST_FOREACH_BEGIN(router_get_trusted_dir_servers(),
dir_server_t *, ds) {
char *hex;
if (!(ds->type & V3_DIRINFO))
continue;
hex = tor_malloc(2*CONDITIONAL_CONSENSUS_FPR_LEN+1);
base16_encode(hex, 2*CONDITIONAL_CONSENSUS_FPR_LEN+1,
ds->v3_identity_digest, CONDITIONAL_CONSENSUS_FPR_LEN);
smartlist_add(authority_digests, hex);
} SMARTLIST_FOREACH_END(ds);
smartlist_sort(authority_digests, compare_strs_);
authority_id_list = smartlist_join_strings(authority_digests,
"+", 0, NULL);
tor_asprintf(&url, "/tor/status-vote/current/consensus%s%s/%s.z",
hyphen, flavor, authority_id_list);
SMARTLIST_FOREACH(authority_digests, char *, cp, tor_free(cp));
smartlist_free(authority_digests);
tor_free(authority_id_list);
}
return url;
}
/**
* Copies the ipv6 from source to destination, subject to buffer size limit
* size. If decorate is true, makes sure the copied address is decorated.
*/
static void
copy_ipv6_address(char* destination, const char* source, size_t len,
int decorate) {
tor_assert(destination);
tor_assert(source);
if (decorate && source[0] != '[') {
tor_snprintf(destination, len, "[%s]", source);
} else {
strlcpy(destination, source, len);
}
}
/** Queue an appropriate HTTP command for <b>request</b> on
* <b>conn</b>-\>outbuf. If <b>direct</b> is true, we're making a
* non-anonymized connection to the dirport.
*/
static void
directory_send_command(dir_connection_t *conn,
const int direct,
const directory_request_t *req)
{
tor_assert(req);
const int purpose = req->dir_purpose;
const char *resource = req->resource;
const char *payload = req->payload;
const size_t payload_len = req->payload_len;
const time_t if_modified_since = req->if_modified_since;
char proxystring[256];
char hoststring[128];
/* NEEDS to be the same size hoststring.
Will be decorated with brackets around it if it is ipv6. */
char decorated_address[128];
smartlist_t *headers = smartlist_new();
char *url;
char *accept_encoding;
size_t url_len;
char request[8192];
size_t request_len, total_request_len = 0;
const char *httpcommand = NULL;
tor_assert(conn);
tor_assert(conn->base_.type == CONN_TYPE_DIR);
tor_free(conn->requested_resource);
if (resource)
conn->requested_resource = tor_strdup(resource);
/* decorate the ip address if it is ipv6 */
if (strchr(conn->base_.address, ':')) {
copy_ipv6_address(decorated_address, conn->base_.address,
sizeof(decorated_address), 1);
} else {
strlcpy(decorated_address, conn->base_.address, sizeof(decorated_address));
}
/* come up with a string for which Host: we want */
if (conn->base_.port == 80) {
strlcpy(hoststring, decorated_address, sizeof(hoststring));
} else {
tor_snprintf(hoststring, sizeof(hoststring), "%s:%d",
decorated_address, conn->base_.port);
}
/* Format if-modified-since */
if (if_modified_since) {
char b[RFC1123_TIME_LEN+1];
format_rfc1123_time(b, if_modified_since);
smartlist_add_asprintf(headers, "If-Modified-Since: %s\r\n", b);
}
/* come up with some proxy lines, if we're using one. */
if (direct && get_options()->HTTPProxy) {
char *base64_authenticator=NULL;
const char *authenticator = get_options()->HTTPProxyAuthenticator;
tor_snprintf(proxystring, sizeof(proxystring),"http://%s", hoststring);
if (authenticator) {
base64_authenticator = alloc_http_authenticator(authenticator);
if (!base64_authenticator)
log_warn(LD_BUG, "Encoding http authenticator failed");
}
if (base64_authenticator) {
smartlist_add_asprintf(headers,
"Proxy-Authorization: Basic %s\r\n",
base64_authenticator);
tor_free(base64_authenticator);
}
} else {
proxystring[0] = 0;
}
/* Add Accept-Encoding. */
accept_encoding = accept_encoding_header();
smartlist_add_asprintf(headers, "Accept-Encoding: %s\r\n",
accept_encoding);
tor_free(accept_encoding);
/* Add additional headers, if any */
{
config_line_t *h;
for (h = req->additional_headers; h; h = h->next) {
smartlist_add_asprintf(headers, "%s%s\r\n", h->key, h->value);
}
}
switch (purpose) {
case DIR_PURPOSE_FETCH_CONSENSUS:
/* resource is optional. If present, it's a flavor name */
tor_assert(!payload);
httpcommand = "GET";
url = directory_get_consensus_url(resource);
log_info(LD_DIR, "Downloading consensus from %s using %s",
hoststring, url);
break;
case DIR_PURPOSE_FETCH_CERTIFICATE:
tor_assert(resource);
tor_assert(!payload);
httpcommand = "GET";
tor_asprintf(&url, "/tor/keys/%s", resource);
break;
case DIR_PURPOSE_FETCH_STATUS_VOTE:
tor_assert(resource);
tor_assert(!payload);
httpcommand = "GET";
tor_asprintf(&url, "/tor/status-vote/next/%s.z", resource);
break;
case DIR_PURPOSE_FETCH_DETACHED_SIGNATURES:
tor_assert(!resource);
tor_assert(!payload);
httpcommand = "GET";
url = tor_strdup("/tor/status-vote/next/consensus-signatures.z");
break;
case DIR_PURPOSE_FETCH_SERVERDESC:
tor_assert(resource);
httpcommand = "GET";
tor_asprintf(&url, "/tor/server/%s", resource);
break;
case DIR_PURPOSE_FETCH_EXTRAINFO:
tor_assert(resource);
httpcommand = "GET";
tor_asprintf(&url, "/tor/extra/%s", resource);
break;
case DIR_PURPOSE_FETCH_MICRODESC:
tor_assert(resource);
httpcommand = "GET";
tor_asprintf(&url, "/tor/micro/%s", resource);
break;
case DIR_PURPOSE_UPLOAD_DIR: {
const char *why = router_get_descriptor_gen_reason();
tor_assert(!resource);
tor_assert(payload);
httpcommand = "POST";
url = tor_strdup("/tor/");
if (why) {
smartlist_add_asprintf(headers, "X-Desc-Gen-Reason: %s\r\n", why);
}
break;
}
case DIR_PURPOSE_UPLOAD_VOTE:
tor_assert(!resource);
tor_assert(payload);
httpcommand = "POST";
url = tor_strdup("/tor/post/vote");
break;
case DIR_PURPOSE_UPLOAD_SIGNATURES:
tor_assert(!resource);
tor_assert(payload);
httpcommand = "POST";
url = tor_strdup("/tor/post/consensus-signature");
break;
case DIR_PURPOSE_FETCH_RENDDESC_V2:
tor_assert(resource);
tor_assert(strlen(resource) <= REND_DESC_ID_V2_LEN_BASE32);
tor_assert(!payload);
httpcommand = "GET";
tor_asprintf(&url, "/tor/rendezvous2/%s", resource);
break;
case DIR_PURPOSE_UPLOAD_RENDDESC_V2:
tor_assert(!resource);
tor_assert(payload);
httpcommand = "POST";
url = tor_strdup("/tor/rendezvous2/publish");
break;
default:
tor_assert(0);
return;
}
/* warn in the non-tunneled case */
if (direct && (strlen(proxystring) + strlen(url) >= 4096)) {
log_warn(LD_BUG,
"Squid does not like URLs longer than 4095 bytes, and this "
"one is %d bytes long: %s%s",
(int)(strlen(proxystring) + strlen(url)), proxystring, url);
}
tor_snprintf(request, sizeof(request), "%s %s", httpcommand, proxystring);
request_len = strlen(request);
total_request_len += request_len;
connection_write_to_buf(request, request_len, TO_CONN(conn));
url_len = strlen(url);
total_request_len += url_len;
connection_write_to_buf(url, url_len, TO_CONN(conn));
tor_free(url);
if (!strcmp(httpcommand, "POST") || payload) {
smartlist_add_asprintf(headers, "Content-Length: %lu\r\n",
payload ? (unsigned long)payload_len : 0);
}
{
char *header = smartlist_join_strings(headers, "", 0, NULL);
tor_snprintf(request, sizeof(request), " HTTP/1.0\r\nHost: %s\r\n%s\r\n",
hoststring, header);
tor_free(header);
}
request_len = strlen(request);
total_request_len += request_len;
connection_write_to_buf(request, request_len, TO_CONN(conn));
if (payload) {
/* then send the payload afterwards too */
connection_write_to_buf(payload, payload_len, TO_CONN(conn));
total_request_len += payload_len;
}
SMARTLIST_FOREACH(headers, char *, h, tor_free(h));
smartlist_free(headers);
log_debug(LD_DIR,
"Sent request to directory server '%s:%d': "
"(purpose: %d, request size: " U64_FORMAT ", "
"payload size: " U64_FORMAT ")",
conn->base_.address, conn->base_.port,
conn->base_.purpose,
U64_PRINTF_ARG(total_request_len),
U64_PRINTF_ARG(payload ? payload_len : 0));
}
/** Parse an HTTP request string <b>headers</b> of the form
* \verbatim
* "\%s [http[s]://]\%s HTTP/1..."
* \endverbatim
* If it's well-formed, strdup the second \%s into *<b>url</b>, and
* nul-terminate it. If the url doesn't start with "/tor/", rewrite it
* so it does. Return 0.
* Otherwise, return -1.
*/
STATIC int
parse_http_url(const char *headers, char **url)
{
char *s, *start, *tmp;
s = (char *)eat_whitespace_no_nl(headers);
if (!*s) return -1;
s = (char *)find_whitespace(s); /* get past GET/POST */
if (!*s) return -1;
s = (char *)eat_whitespace_no_nl(s);
if (!*s) return -1;
start = s; /* this is it, assuming it's valid */
s = (char *)find_whitespace(start);
if (!*s) return -1;
/* tolerate the http[s] proxy style of putting the hostname in the url */
if (s-start >= 4 && !strcmpstart(start,"http")) {
tmp = start + 4;
if (*tmp == 's')
tmp++;
if (s-tmp >= 3 && !strcmpstart(tmp,"://")) {
tmp = strchr(tmp+3, '/');
if (tmp && tmp < s) {
log_debug(LD_DIR,"Skipping over 'http[s]://hostname/' string");
start = tmp;
}
}
}
/* Check if the header is well formed (next sequence
* should be HTTP/1.X\r\n). Assumes we're supporting 1.0? */
{
unsigned minor_ver;
char ch;
char *e = (char *)eat_whitespace_no_nl(s);
if (2 != tor_sscanf(e, "HTTP/1.%u%c", &minor_ver, &ch)) {
return -1;
}
if (ch != '\r')
return -1;
}
if (s-start < 5 || strcmpstart(start,"/tor/")) { /* need to rewrite it */
*url = tor_malloc(s - start + 5);
strlcpy(*url,"/tor", s-start+5);
strlcat((*url)+4, start, s-start+1);
} else {
*url = tor_strndup(start, s-start);
}
return 0;
}
/** Return a copy of the first HTTP header in <b>headers</b> whose key is
* <b>which</b>. The key should be given with a terminating colon and space;
* this function copies everything after, up to but not including the
* following \\r\\n. */
static char *
http_get_header(const char *headers, const char *which)
{
const char *cp = headers;
while (cp) {
if (!strcasecmpstart(cp, which)) {
char *eos;
cp += strlen(which);
if ((eos = strchr(cp,'\r')))
return tor_strndup(cp, eos-cp);
else
return tor_strdup(cp);
}
cp = strchr(cp, '\n');
if (cp)
++cp;
}
return NULL;
}
/** If <b>headers</b> indicates that a proxy was involved, then rewrite
* <b>conn</b>-\>address to describe our best guess of the address that
* originated this HTTP request. */
static void
http_set_address_origin(const char *headers, connection_t *conn)
{
char *fwd;
fwd = http_get_header(headers, "Forwarded-For: ");
if (!fwd)
fwd = http_get_header(headers, "X-Forwarded-For: ");
if (fwd) {
tor_addr_t toraddr;
if (tor_addr_parse(&toraddr,fwd) == -1 ||
tor_addr_is_internal(&toraddr,0)) {
log_debug(LD_DIR, "Ignoring local/internal IP %s", escaped(fwd));
tor_free(fwd);
return;
}
tor_free(conn->address);
conn->address = tor_strdup(fwd);
tor_free(fwd);
}
}
/** Parse an HTTP response string <b>headers</b> of the form
* \verbatim
* "HTTP/1.\%d \%d\%s\r\n...".
* \endverbatim
*
* If it's well-formed, assign the status code to *<b>code</b> and
* return 0. Otherwise, return -1.
*
* On success: If <b>date</b> is provided, set *date to the Date
* header in the http headers, or 0 if no such header is found. If
* <b>compression</b> is provided, set *<b>compression</b> to the
* compression method given in the Content-Encoding header, or 0 if no
* such header is found, or -1 if the value of the header is not
* recognized. If <b>reason</b> is provided, strdup the reason string
* into it.
*/
int
parse_http_response(const char *headers, int *code, time_t *date,
compress_method_t *compression, char **reason)
{
unsigned n1, n2;
char datestr[RFC1123_TIME_LEN+1];
smartlist_t *parsed_headers;
tor_assert(headers);
tor_assert(code);
while (TOR_ISSPACE(*headers)) headers++; /* tolerate leading whitespace */
if (tor_sscanf(headers, "HTTP/1.%u %u", &n1, &n2) < 2 ||
(n1 != 0 && n1 != 1) ||
(n2 < 100 || n2 >= 600)) {
log_warn(LD_HTTP,"Failed to parse header %s",escaped(headers));
return -1;
}
*code = n2;
parsed_headers = smartlist_new();
smartlist_split_string(parsed_headers, headers, "\n",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
if (reason) {
smartlist_t *status_line_elements = smartlist_new();
tor_assert(smartlist_len(parsed_headers));
smartlist_split_string(status_line_elements,
smartlist_get(parsed_headers, 0),
" ", SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 3);
tor_assert(smartlist_len(status_line_elements) <= 3);
if (smartlist_len(status_line_elements) == 3) {
*reason = smartlist_get(status_line_elements, 2);
smartlist_set(status_line_elements, 2, NULL); /* Prevent free */
}
SMARTLIST_FOREACH(status_line_elements, char *, cp, tor_free(cp));
smartlist_free(status_line_elements);
}
if (date) {
*date = 0;
SMARTLIST_FOREACH(parsed_headers, const char *, s,
if (!strcmpstart(s, "Date: ")) {
strlcpy(datestr, s+6, sizeof(datestr));
/* This will do nothing on failure, so we don't need to check
the result. We shouldn't warn, since there are many other valid
date formats besides the one we use. */
parse_rfc1123_time(datestr, date);
break;
});
}
if (compression) {
const char *enc = NULL;
SMARTLIST_FOREACH(parsed_headers, const char *, s,
if (!strcmpstart(s, "Content-Encoding: ")) {
enc = s+18; break;
});
if (enc == NULL)
*compression = NO_METHOD;
else {
*compression = compression_method_get_by_name(enc);
if (*compression == UNKNOWN_METHOD)
log_info(LD_HTTP, "Unrecognized content encoding: %s. Trying to deal.",
escaped(enc));
}
}
SMARTLIST_FOREACH(parsed_headers, char *, s, tor_free(s));
smartlist_free(parsed_headers);
return 0;
}
/** Return true iff <b>body</b> doesn't start with a plausible router or
* network-status or microdescriptor opening. This is a sign of possible
* compression. */
static int
body_is_plausible(const char *body, size_t len, int purpose)
{
int i;
if (len == 0)
return 1; /* empty bodies don't need decompression */
if (len < 32)
return 0;
if (purpose == DIR_PURPOSE_FETCH_MICRODESC) {
return (!strcmpstart(body,"onion-key"));
}
if (!strcmpstart(body,"router") ||
!strcmpstart(body,"network-status"))
return 1;
for (i=0;i<32;++i) {
if (!TOR_ISPRINT(body[i]) && !TOR_ISSPACE(body[i]))
return 0;
}
return 1;
}
/** Called when we've just fetched a bunch of router descriptors in
* <b>body</b>. The list <b>which</b>, if present, holds digests for
* descriptors we requested: descriptor digests if <b>descriptor_digests</b>
* is true, or identity digests otherwise. Parse the descriptors, validate
* them, and annotate them as having purpose <b>purpose</b> and as having been
* downloaded from <b>source</b>.
*
* Return the number of routers actually added. */
static int
load_downloaded_routers(const char *body, smartlist_t *which,
int descriptor_digests,
int router_purpose,
const char *source)
{
char buf[256];
char time_buf[ISO_TIME_LEN+1];
int added = 0;
int general = router_purpose == ROUTER_PURPOSE_GENERAL;
format_iso_time(time_buf, time(NULL));
tor_assert(source);
if (tor_snprintf(buf, sizeof(buf),
"@downloaded-at %s\n"
"@source %s\n"
"%s%s%s", time_buf, escaped(source),
!general ? "@purpose " : "",
!general ? router_purpose_to_string(router_purpose) : "",
!general ? "\n" : "")<0)
return added;
added = router_load_routers_from_string(body, NULL, SAVED_NOWHERE, which,
descriptor_digests, buf);
if (added && general)
control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
count_loading_descriptors_progress());
return added;
}
/** A structure to hold arguments passed into each directory response
* handler */
typedef struct response_handler_args_t {
int status_code;
const char *reason;
const char *body;
size_t body_len;
const char *headers;
} response_handler_args_t;
static int handle_response_fetch_consensus(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_certificate(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_status_vote(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_detached_signatures(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_desc(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_microdesc(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_dir(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_vote(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_signatures(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_renddesc_v2(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_renddesc_v2(dir_connection_t *,
const response_handler_args_t *);
/** We are a client, and we've finished reading the server's
* response. Parse it and act appropriately.
*
* If we're still happy with using this directory server in the future, return
* 0. Otherwise return -1; and the caller should consider trying the request
* again.
*
* The caller will take care of marking the connection for close.
*/
static int
connection_dir_client_reached_eof(dir_connection_t *conn)
{
char *body;
char *headers;
char *reason = NULL;
size_t body_len = 0;
int status_code;
time_t date_header = 0;
long apparent_skew;
compress_method_t compression;
int plausible;
int skewed = 0;
int allow_partial = (conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO ||
conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC);
size_t received_bytes;
received_bytes = connection_get_inbuf_len(TO_CONN(conn));
switch (connection_fetch_from_buf_http(TO_CONN(conn),
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_DIR_DL_SIZE,
allow_partial)) {
case -1: /* overflow */
log_warn(LD_PROTOCOL,
"'fetch' response too large (server '%s:%d'). Closing.",
conn->base_.address, conn->base_.port);
return -1;
case 0:
log_info(LD_HTTP,
"'fetch' response not all here, but we're at eof. Closing.");
return -1;
/* case 1, fall through */
}
if (parse_http_response(headers, &status_code, &date_header,
&compression, &reason) < 0) {
log_warn(LD_HTTP,"Unparseable headers (server '%s:%d'). Closing.",
conn->base_.address, conn->base_.port);
tor_free(body); tor_free(headers);
return -1;
}
if (!reason) reason = tor_strdup("[no reason given]");
tor_log(LOG_DEBUG, LD_DIR,
"Received response from directory server '%s:%d': %d %s "
"(purpose: %d, response size: " U64_FORMAT
#ifdef MEASUREMENTS_21206
", data cells received: %d, data cells sent: %d"
#endif
", compression: %d)",
conn->base_.address, conn->base_.port, status_code,
escaped(reason), conn->base_.purpose,
U64_PRINTF_ARG(received_bytes),
#ifdef MEASUREMENTS_21206
conn->data_cells_received, conn->data_cells_sent,
#endif
compression);
if (conn->guard_state) {
/* we count the connection as successful once we can read from it. We do
* not, however, delay use of the circuit here, since it's just for a
* one-hop directory request. */
/* XXXXprop271 note that this will not do the right thing for other
* waiting circuits that would be triggered by this circuit becoming
* complete/usable. But that's ok, I think.
*/
entry_guard_succeeded(&conn->guard_state);
circuit_guard_state_free(conn->guard_state);
conn->guard_state = NULL;
}
/* now check if it's got any hints for us about our IP address. */
if (conn->dirconn_direct) {
char *guess = http_get_header(headers, X_ADDRESS_HEADER);
if (guess) {
router_new_address_suggestion(guess, conn);
tor_free(guess);
}
}
if (date_header > 0) {
/* The date header was written very soon after we sent our request,
* so compute the skew as the difference between sending the request
* and the date header. (We used to check now-date_header, but that's
* inaccurate if we spend a lot of time downloading.)
*/
apparent_skew = conn->base_.timestamp_lastwritten - date_header;
if (labs(apparent_skew)>ALLOW_DIRECTORY_TIME_SKEW) {
int trusted = router_digest_is_trusted_dir(conn->identity_digest);
clock_skew_warning(TO_CONN(conn), apparent_skew, trusted, LD_HTTP,
"directory", "DIRSERV");
skewed = 1; /* don't check the recommended-versions line */
} else {
log_debug(LD_HTTP, "Time on received directory is within tolerance; "
"we are %ld seconds skewed. (That's okay.)", apparent_skew);
}
}
(void) skewed; /* skewed isn't used yet. */
if (status_code == 503) {
routerstatus_t *rs;
dir_server_t *ds;
const char *id_digest = conn->identity_digest;
log_info(LD_DIR,"Received http status code %d (%s) from server "
"'%s:%d'. I'll try again soon.",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
time_t now = approx_time();
if ((rs = router_get_mutable_consensus_status_by_id(id_digest)))
rs->last_dir_503_at = now;
if ((ds = router_get_fallback_dirserver_by_digest(id_digest)))
ds->fake_status.last_dir_503_at = now;
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
plausible = body_is_plausible(body, body_len, conn->base_.purpose);
if (compression != NO_METHOD || !plausible) {
char *new_body = NULL;
size_t new_len = 0;
compress_method_t guessed = detect_compression_method(body, body_len);
if (compression == UNKNOWN_METHOD || guessed != compression) {
/* Tell the user if we don't believe what we're told about compression.*/
const char *description1, *description2;
description1 = compression_method_get_human_name(compression);
if (BUG(description1 == NULL))
description1 = compression_method_get_human_name(UNKNOWN_METHOD);
if (guessed == UNKNOWN_METHOD && !plausible)
description2 = "confusing binary junk";
else
description2 = compression_method_get_human_name(guessed);
log_info(LD_HTTP, "HTTP body from server '%s:%d' was labeled as %s, "
"but it seems to be %s.%s",
conn->base_.address, conn->base_.port, description1,
description2,
(compression>0 && guessed>0)?" Trying both.":"");
}
/* Try declared compression first if we can.
* tor_compress_supports_method() also returns true for NO_METHOD. */
if (tor_compress_supports_method(compression))
tor_uncompress(&new_body, &new_len, body, body_len, compression,
!allow_partial, LOG_PROTOCOL_WARN);
/* Okay, if that didn't work, and we think that it was compressed
* differently, try that. */
if (!new_body && tor_compress_supports_method(guessed) &&
compression != guessed)
tor_uncompress(&new_body, &new_len, body, body_len, guessed,
!allow_partial, LOG_PROTOCOL_WARN);
/* If we're pretty sure that we have a compressed directory, and
* we didn't manage to uncompress it, then warn and bail. */
if (!plausible && !new_body) {
log_fn(LOG_PROTOCOL_WARN, LD_HTTP,
"Unable to decompress HTTP body (server '%s:%d').",
conn->base_.address, conn->base_.port);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
if (new_body) {
tor_free(body);
body = new_body;
body_len = new_len;
}
}
int rv;
response_handler_args_t args;
memset(&args, 0, sizeof(args));
args.status_code = status_code;
args.reason = reason;
args.body = body;
args.body_len = body_len;
args.headers = headers;
switch (conn->base_.purpose) {
case DIR_PURPOSE_FETCH_CONSENSUS:
rv = handle_response_fetch_consensus(conn, &args);
break;
case DIR_PURPOSE_FETCH_CERTIFICATE:
rv = handle_response_fetch_certificate(conn, &args);
break;
case DIR_PURPOSE_FETCH_STATUS_VOTE:
rv = handle_response_fetch_status_vote(conn, &args);
break;
case DIR_PURPOSE_FETCH_DETACHED_SIGNATURES:
rv = handle_response_fetch_detached_signatures(conn, &args);
break;
case DIR_PURPOSE_FETCH_SERVERDESC:
case DIR_PURPOSE_FETCH_EXTRAINFO:
rv = handle_response_fetch_desc(conn, &args);
break;
case DIR_PURPOSE_FETCH_MICRODESC:
rv = handle_response_fetch_microdesc(conn, &args);
break;
case DIR_PURPOSE_FETCH_RENDDESC_V2:
rv = handle_response_fetch_renddesc_v2(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_DIR:
rv = handle_response_upload_dir(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_SIGNATURES:
rv = handle_response_upload_signatures(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_VOTE:
rv = handle_response_upload_vote(conn, &args);
break;
case DIR_PURPOSE_UPLOAD_RENDDESC_V2:
rv = handle_response_upload_renddesc_v2(conn, &args);
break;
default:
tor_assert_nonfatal_unreached();
rv = -1;
break;
}
tor_free(body);
tor_free(headers);
tor_free(reason);
return rv;
}
/**
* Handler function: processes a response to a request for a networkstatus
* consensus document by checking the consensus, storing it, and marking
* router requests as reachable.
**/
static int
handle_response_fetch_consensus(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_CONSENSUS);
const int status_code = args->status_code;
const char *body = args->body;
const size_t body_len = args->body_len;
const char *reason = args->reason;
const time_t now = approx_time();
const char *consensus;
char *new_consensus = NULL;
const char *sourcename;
int r;
const char *flavname = conn->requested_resource;
if (status_code != 200) {
int severity = (status_code == 304) ? LOG_INFO : LOG_WARN;
tor_log(severity, LD_DIR,
"Received http status code %d (%s) from server "
"'%s:%d' while fetching consensus directory.",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
networkstatus_consensus_download_failed(status_code, flavname);
return -1;
}
if (looks_like_a_consensus_diff(body, body_len)) {
/* First find our previous consensus. Maybe it's in ram, maybe not. */
cached_dir_t *cd = dirserv_get_consensus(flavname);
const char *consensus_body;
char *owned_consensus = NULL;
if (cd) {
consensus_body = cd->dir;
} else {
owned_consensus = networkstatus_read_cached_consensus(flavname);
consensus_body = owned_consensus;
}
if (!consensus_body) {
log_warn(LD_DIR, "Received a consensus diff, but we can't find "
"any %s-flavored consensus in our current cache.",flavname);
networkstatus_consensus_download_failed(0, flavname);
// XXXX if this happens too much, see below
return -1;
}
new_consensus = consensus_diff_apply(consensus_body, body);
tor_free(owned_consensus);
if (new_consensus == NULL) {
log_warn(LD_DIR, "Could not apply consensus diff received from server "
"'%s:%d'", conn->base_.address, conn->base_.port);
// XXXX If this happens too many times, we should maybe not use
// XXXX this directory for diffs any more?
networkstatus_consensus_download_failed(0, flavname);
return -1;
}
log_info(LD_DIR, "Applied consensus diff (size %d) from server "
"'%s:%d', resulting in a new consensus document (size %d).",
(int)body_len, conn->base_.address, conn->base_.port,
(int)strlen(new_consensus));
consensus = new_consensus;
sourcename = "generated based on a diff";
} else {
log_info(LD_DIR,"Received consensus directory (body size %d) from server "
"'%s:%d'", (int)body_len, conn->base_.address, conn->base_.port);
consensus = body;
sourcename = "downloaded";
}
if ((r=networkstatus_set_current_consensus(consensus, flavname, 0,
conn->identity_digest))<0) {
log_fn(r<-1?LOG_WARN:LOG_INFO, LD_DIR,
"Unable to load %s consensus directory %s from "
"server '%s:%d'. I'll try again soon.",
flavname, sourcename, conn->base_.address, conn->base_.port);
networkstatus_consensus_download_failed(0, flavname);
tor_free(new_consensus);
return -1;
}
/* If we launched other fetches for this consensus, cancel them. */
connection_dir_close_consensus_fetches(conn, flavname);
/* launches router downloads as needed */
routers_update_all_from_networkstatus(now, 3);
update_microdescs_from_networkstatus(now);
update_microdesc_downloads(now);
directory_info_has_arrived(now, 0, 0);
if (authdir_mode_v3(get_options())) {
sr_act_post_consensus(
networkstatus_get_latest_consensus_by_flavor(FLAV_NS));
}
log_info(LD_DIR, "Successfully loaded consensus.");
tor_free(new_consensus);
return 0;
}
/**
* Handler function: processes a response to a request for one or more
* authority certificates
**/
static int
handle_response_fetch_certificate(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_CERTIFICATE);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
if (status_code != 200) {
log_warn(LD_DIR,
"Received http status code %d (%s) from server "
"'%s:%d' while fetching \"/tor/keys/%s\".",
status_code, escaped(reason), conn->base_.address,
conn->base_.port, conn->requested_resource);
connection_dir_download_cert_failed(conn, status_code);
return -1;
}
log_info(LD_DIR,"Received authority certificates (body size %d) from "
"server '%s:%d'",
(int)body_len, conn->base_.address, conn->base_.port);
/*
* Tell trusted_dirs_load_certs_from_string() whether it was by fp
* or fp-sk pair.
*/
int src_code = -1;
if (!strcmpstart(conn->requested_resource, "fp/")) {
src_code = TRUSTED_DIRS_CERTS_SRC_DL_BY_ID_DIGEST;
} else if (!strcmpstart(conn->requested_resource, "fp-sk/")) {
src_code = TRUSTED_DIRS_CERTS_SRC_DL_BY_ID_SK_DIGEST;
}
if (src_code != -1) {
if (trusted_dirs_load_certs_from_string(body, src_code, 1,
conn->identity_digest)<0) {
log_warn(LD_DIR, "Unable to parse fetched certificates");
/* if we fetched more than one and only some failed, the successful
* ones got flushed to disk so it's safe to call this on them */
connection_dir_download_cert_failed(conn, status_code);
} else {
time_t now = approx_time();
directory_info_has_arrived(now, 0, 0);
log_info(LD_DIR, "Successfully loaded certificates from fetch.");
}
} else {
log_warn(LD_DIR,
"Couldn't figure out what to do with fetched certificates for "
"unknown resource %s",
conn->requested_resource);
connection_dir_download_cert_failed(conn, status_code);
}
return 0;
}
/**
* Handler function: processes a response to a request for an authority's
* current networkstatus vote.
**/
static int
handle_response_fetch_status_vote(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_STATUS_VOTE);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
const char *msg;
int st;
log_info(LD_DIR,"Got votes (body size %d) from server %s:%d",
(int)body_len, conn->base_.address, conn->base_.port);
if (status_code != 200) {
log_warn(LD_DIR,
"Received http status code %d (%s) from server "
"'%s:%d' while fetching \"/tor/status-vote/next/%s.z\".",
status_code, escaped(reason), conn->base_.address,
conn->base_.port, conn->requested_resource);
return -1;
}
dirvote_add_vote(body, &msg, &st);
if (st > 299) {
log_warn(LD_DIR, "Error adding retrieved vote: %s", msg);
} else {
log_info(LD_DIR, "Added vote(s) successfully [msg: %s]", msg);
}
return 0;
}
/**
* Handler function: processes a response to a request for the signatures
* that an authority knows about on a given consensus.
**/
static int
handle_response_fetch_detached_signatures(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_DETACHED_SIGNATURES);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
const char *msg = NULL;
log_info(LD_DIR,"Got detached signatures (body size %d) from server %s:%d",
(int)body_len, conn->base_.address, conn->base_.port);
if (status_code != 200) {
log_warn(LD_DIR,
"Received http status code %d (%s) from server '%s:%d' while fetching "
"\"/tor/status-vote/next/consensus-signatures.z\".",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
return -1;
}
if (dirvote_add_signatures(body, conn->base_.address, &msg)<0) {
log_warn(LD_DIR, "Problem adding detached signatures from %s:%d: %s",
conn->base_.address, conn->base_.port, msg?msg:"???");
}
return 0;
}
/**
* Handler function: processes a response to a request for a group of server
* descriptors or an extrainfo documents.
**/
static int
handle_response_fetch_desc(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_SERVERDESC ||
conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
int was_ei = conn->base_.purpose == DIR_PURPOSE_FETCH_EXTRAINFO;
smartlist_t *which = NULL;
int n_asked_for = 0;
int descriptor_digests = conn->requested_resource &&
!strcmpstart(conn->requested_resource,"d/");
log_info(LD_DIR,"Received %s (body size %d) from server '%s:%d'",
was_ei ? "extra server info" : "server info",
(int)body_len, conn->base_.address, conn->base_.port);
if (conn->requested_resource &&
(!strcmpstart(conn->requested_resource,"d/") ||
!strcmpstart(conn->requested_resource,"fp/"))) {
which = smartlist_new();
dir_split_resource_into_fingerprints(conn->requested_resource +
(descriptor_digests ? 2 : 3),
which, NULL, 0);
n_asked_for = smartlist_len(which);
}
if (status_code != 200) {
int dir_okay = status_code == 404 ||
(status_code == 400 && !strcmp(reason, "Servers unavailable."));
/* 404 means that it didn't have them; no big deal.
* Older (pre-0.1.1.8) servers said 400 Servers unavailable instead. */
log_fn(dir_okay ? LOG_INFO : LOG_WARN, LD_DIR,
"Received http status code %d (%s) from server '%s:%d' "
"while fetching \"/tor/server/%s\". I'll try again soon.",
status_code, escaped(reason), conn->base_.address,
conn->base_.port, conn->requested_resource);
if (!which) {
connection_dir_download_routerdesc_failed(conn);
} else {
dir_routerdesc_download_failed(which, status_code,
conn->router_purpose,
was_ei, descriptor_digests);
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
}
return dir_okay ? 0 : -1;
}
/* Learn the routers, assuming we requested by fingerprint or "all"
* or "authority".
*
* We use "authority" to fetch our own descriptor for
* testing, and to fetch bridge descriptors for bootstrapping. Ignore
* the output of "authority" requests unless we are using bridges,
* since otherwise they'll be the response from reachability tests,
* and we don't really want to add that to our routerlist. */
if (which || (conn->requested_resource &&
(!strcmpstart(conn->requested_resource, "all") ||
(!strcmpstart(conn->requested_resource, "authority") &&
get_options()->UseBridges)))) {
/* as we learn from them, we remove them from 'which' */
if (was_ei) {
router_load_extrainfo_from_string(body, NULL, SAVED_NOWHERE, which,
descriptor_digests);
} else {
//router_load_routers_from_string(body, NULL, SAVED_NOWHERE, which,
// descriptor_digests, conn->router_purpose);
if (load_downloaded_routers(body, which, descriptor_digests,
conn->router_purpose,
conn->base_.address)) {
time_t now = approx_time();
directory_info_has_arrived(now, 0, 0);
}
}
}
if (which) { /* mark remaining ones as failed */
log_info(LD_DIR, "Received %d/%d %s requested from %s:%d",
n_asked_for-smartlist_len(which), n_asked_for,
was_ei ? "extra-info documents" : "router descriptors",
conn->base_.address, (int)conn->base_.port);
if (smartlist_len(which)) {
dir_routerdesc_download_failed(which, status_code,
conn->router_purpose,
was_ei, descriptor_digests);
}
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
}
if (directory_conn_is_self_reachability_test(conn))
router_dirport_found_reachable();
return 0;
}
/**
* Handler function: processes a response to a request for a group of
* microdescriptors
**/
static int
handle_response_fetch_microdesc(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_MICRODESC);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
smartlist_t *which = NULL;
log_info(LD_DIR,"Received answer to microdescriptor request (status %d, "
"body size %d) from server '%s:%d'",
status_code, (int)body_len, conn->base_.address,
conn->base_.port);
tor_assert(conn->requested_resource &&
!strcmpstart(conn->requested_resource, "d/"));
which = smartlist_new();
dir_split_resource_into_fingerprints(conn->requested_resource+2,
which, NULL,
DSR_DIGEST256|DSR_BASE64);
if (status_code != 200) {
log_info(LD_DIR, "Received status code %d (%s) from server "
"'%s:%d' while fetching \"/tor/micro/%s\". I'll try again "
"soon.",
status_code, escaped(reason), conn->base_.address,
(int)conn->base_.port, conn->requested_resource);
dir_microdesc_download_failed(which, status_code);
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
return 0;
} else {
smartlist_t *mds;
time_t now = approx_time();
mds = microdescs_add_to_cache(get_microdesc_cache(),
body, body+body_len, SAVED_NOWHERE, 0,
now, which);
if (smartlist_len(which)) {
/* Mark remaining ones as failed. */
dir_microdesc_download_failed(which, status_code);
}
if (mds && smartlist_len(mds)) {
control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
count_loading_descriptors_progress());
directory_info_has_arrived(now, 0, 1);
}
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
smartlist_free(mds);
}
return 0;
}
/**
* Handler function: processes a response to a POST request to upload our
* router descriptor.
**/
static int
handle_response_upload_dir(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_DIR);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *headers = args->headers;
switch (status_code) {
case 200: {
dir_server_t *ds =
router_get_trusteddirserver_by_digest(conn->identity_digest);
char *rejected_hdr = http_get_header(headers,
"X-Descriptor-Not-New: ");
if (rejected_hdr) {
if (!strcmp(rejected_hdr, "Yes")) {
log_info(LD_GENERAL,
"Authority '%s' declined our descriptor (not new)",
ds->nickname);
/* XXXX use this information; be sure to upload next one
* sooner. -NM */
/* XXXX++ On further thought, the task above implies that we're
* basing our regenerate-descriptor time on when we uploaded the
* last descriptor, not on the published time of the last
* descriptor. If those are different, that's a bad thing to
* do. -NM */
}
tor_free(rejected_hdr);
}
log_info(LD_GENERAL,"eof (status 200) after uploading server "
"descriptor: finished.");
control_event_server_status(
LOG_NOTICE, "ACCEPTED_SERVER_DESCRIPTOR DIRAUTH=%s:%d",
conn->base_.address, conn->base_.port);
ds->has_accepted_serverdesc = 1;
if (directories_have_accepted_server_descriptor())
control_event_server_status(LOG_NOTICE, "GOOD_SERVER_DESCRIPTOR");
}
break;
case 400:
log_warn(LD_GENERAL,"http status 400 (%s) response from "
"dirserver '%s:%d'. Please correct.",
escaped(reason), conn->base_.address, conn->base_.port);
control_event_server_status(LOG_WARN,
"BAD_SERVER_DESCRIPTOR DIRAUTH=%s:%d REASON=\"%s\"",
conn->base_.address, conn->base_.port, escaped(reason));
break;
default:
log_warn(LD_GENERAL,
"http status %d (%s) reason unexpected while uploading "
"descriptor to server '%s:%d').",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
break;
}
/* return 0 in all cases, since we don't want to mark any
* dirservers down just because they don't like us. */
return 0;
}
/**
* Handler function: processes a response to POST request to upload our
* own networkstatus vote.
**/
static int
handle_response_upload_vote(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_VOTE);
const int status_code = args->status_code;
const char *reason = args->reason;
switch (status_code) {
case 200: {
log_notice(LD_DIR,"Uploaded a vote to dirserver %s:%d",
conn->base_.address, conn->base_.port);
}
break;
case 400:
log_warn(LD_DIR,"http status 400 (%s) response after uploading "
"vote to dirserver '%s:%d'. Please correct.",
escaped(reason), conn->base_.address, conn->base_.port);
break;
default:
log_warn(LD_GENERAL,
"http status %d (%s) reason unexpected while uploading "
"vote to server '%s:%d').",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
break;
}
/* return 0 in all cases, since we don't want to mark any
* dirservers down just because they don't like us. */
return 0;
}
/**
* Handler function: processes a response to POST request to upload our
* view of the signatures on the current consensus.
**/
static int
handle_response_upload_signatures(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_SIGNATURES);
const int status_code = args->status_code;
const char *reason = args->reason;
switch (status_code) {
case 200: {
log_notice(LD_DIR,"Uploaded signature(s) to dirserver %s:%d",
conn->base_.address, conn->base_.port);
}
break;
case 400:
log_warn(LD_DIR,"http status 400 (%s) response after uploading "
"signatures to dirserver '%s:%d'. Please correct.",
escaped(reason), conn->base_.address, conn->base_.port);
break;
default:
log_warn(LD_GENERAL,
"http status %d (%s) reason unexpected while uploading "
"signatures to server '%s:%d').",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
break;
}
/* return 0 in all cases, since we don't want to mark any
* dirservers down just because they don't like us. */
return 0;
}
/**
* Handler function: processes a response to a request for a v2 hidden service
* descriptor.
**/
static int
handle_response_fetch_renddesc_v2(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_FETCH_RENDDESC_V2);
const int status_code = args->status_code;
const char *reason = args->reason;
const char *body = args->body;
const size_t body_len = args->body_len;
#define SEND_HS_DESC_FAILED_EVENT(reason) \
(control_event_hs_descriptor_failed(conn->rend_data, \
conn->identity_digest, \
reason))
#define SEND_HS_DESC_FAILED_CONTENT() \
(control_event_hs_descriptor_content( \
rend_data_get_address(conn->rend_data), \
conn->requested_resource, \
conn->identity_digest, \
NULL))
tor_assert(conn->rend_data);
log_info(LD_REND,"Received rendezvous descriptor (body size %d, status %d "
"(%s))",
(int)body_len, status_code, escaped(reason));
switch (status_code) {
case 200:
{
rend_cache_entry_t *entry = NULL;
if (rend_cache_store_v2_desc_as_client(body,
conn->requested_resource,
conn->rend_data, &entry) < 0) {
log_warn(LD_REND,"Fetching v2 rendezvous descriptor failed. "
"Retrying at another directory.");
/* We'll retry when connection_about_to_close_connection()
* cleans this dir conn up. */
SEND_HS_DESC_FAILED_EVENT("BAD_DESC");
SEND_HS_DESC_FAILED_CONTENT();
} else {
char service_id[REND_SERVICE_ID_LEN_BASE32 + 1];
/* Should never be NULL here if we found the descriptor. */
tor_assert(entry);
rend_get_service_id(entry->parsed->pk, service_id);
/* success. notify pending connections about this. */
log_info(LD_REND, "Successfully fetched v2 rendezvous "
"descriptor.");
control_event_hs_descriptor_received(service_id,
conn->rend_data,
conn->identity_digest);
control_event_hs_descriptor_content(service_id,
conn->requested_resource,
conn->identity_digest,
body);
conn->base_.purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC_V2;
rend_client_desc_trynow(service_id);
memwipe(service_id, 0, sizeof(service_id));
}
break;
}
case 404:
/* Not there. We'll retry when
* connection_about_to_close_connection() cleans this conn up. */
log_info(LD_REND,"Fetching v2 rendezvous descriptor failed: "
"Retrying at another directory.");
SEND_HS_DESC_FAILED_EVENT("NOT_FOUND");
SEND_HS_DESC_FAILED_CONTENT();
break;
case 400:
log_warn(LD_REND, "Fetching v2 rendezvous descriptor failed: "
"http status 400 (%s). Dirserver didn't like our "
"v2 rendezvous query? Retrying at another directory.",
escaped(reason));
SEND_HS_DESC_FAILED_EVENT("QUERY_REJECTED");
SEND_HS_DESC_FAILED_CONTENT();
break;
default:
log_warn(LD_REND, "Fetching v2 rendezvous descriptor failed: "
"http status %d (%s) response unexpected while "
"fetching v2 hidden service descriptor (server '%s:%d'). "
"Retrying at another directory.",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
SEND_HS_DESC_FAILED_EVENT("UNEXPECTED");
SEND_HS_DESC_FAILED_CONTENT();
break;
}
return 0;
}
/**
* Handler function: processes a response to a POST request to upload a v2
* hidden service descriptor.
**/
static int
handle_response_upload_renddesc_v2(dir_connection_t *conn,
const response_handler_args_t *args)
{
tor_assert(conn->base_.purpose == DIR_PURPOSE_UPLOAD_RENDDESC_V2);
const int status_code = args->status_code;
const char *reason = args->reason;
#define SEND_HS_DESC_UPLOAD_FAILED_EVENT(reason) \
(control_event_hs_descriptor_upload_failed( \
conn->identity_digest, \
rend_data_get_address(conn->rend_data), \
reason))
log_info(LD_REND,"Uploaded rendezvous descriptor (status %d "
"(%s))",
status_code, escaped(reason));
/* Without the rend data, we'll have a problem identifying what has been
* uploaded for which service. */
tor_assert(conn->rend_data);
switch (status_code) {
case 200:
log_info(LD_REND,
"Uploading rendezvous descriptor: finished with status "
"200 (%s)", escaped(reason));
control_event_hs_descriptor_uploaded(conn->identity_digest,
rend_data_get_address(conn->rend_data));
rend_service_desc_has_uploaded(conn->rend_data);
break;
case 400:
log_warn(LD_REND,"http status 400 (%s) response from dirserver "
"'%s:%d'. Malformed rendezvous descriptor?",
escaped(reason), conn->base_.address, conn->base_.port);
SEND_HS_DESC_UPLOAD_FAILED_EVENT("UPLOAD_REJECTED");
break;
default:
log_warn(LD_REND,"http status %d (%s) response unexpected (server "
"'%s:%d').",
status_code, escaped(reason), conn->base_.address,
conn->base_.port);
SEND_HS_DESC_UPLOAD_FAILED_EVENT("UNEXPECTED");
break;
}
return 0;
}
/** Called when a directory connection reaches EOF. */
int
connection_dir_reached_eof(dir_connection_t *conn)
{
int retval;
if (conn->base_.state != DIR_CONN_STATE_CLIENT_READING) {
log_info(LD_HTTP,"conn reached eof, not reading. [state=%d] Closing.",
conn->base_.state);
connection_close_immediate(TO_CONN(conn)); /* error: give up on flushing */
connection_mark_for_close(TO_CONN(conn));
return -1;
}
retval = connection_dir_client_reached_eof(conn);
if (retval == 0) /* success */
conn->base_.state = DIR_CONN_STATE_CLIENT_FINISHED;
connection_mark_for_close(TO_CONN(conn));
return retval;
}
/** If any directory object is arriving, and it's over 10MB large, we're
* getting DoS'd. (As of 0.1.2.x, raw directories are about 1MB, and we never
* ask for more than 96 router descriptors at a time.)
*/
#define MAX_DIRECTORY_OBJECT_SIZE (10*(1<<20))
#define MAX_VOTE_DL_SIZE (MAX_DIRECTORY_OBJECT_SIZE * 5)
/** Read handler for directory connections. (That's connections <em>to</em>
* directory servers and connections <em>at</em> directory servers.)
*/
int
connection_dir_process_inbuf(dir_connection_t *conn)
{
size_t max_size;
tor_assert(conn);
tor_assert(conn->base_.type == CONN_TYPE_DIR);
/* Directory clients write, then read data until they receive EOF;
* directory servers read data until they get an HTTP command, then
* write their response (when it's finished flushing, they mark for
* close).
*/
/* If we're on the dirserver side, look for a command. */
if (conn->base_.state == DIR_CONN_STATE_SERVER_COMMAND_WAIT) {
if (directory_handle_command(conn) < 0) {
connection_mark_for_close(TO_CONN(conn));
return -1;
}
return 0;
}
max_size =
(TO_CONN(conn)->purpose == DIR_PURPOSE_FETCH_STATUS_VOTE) ?
MAX_VOTE_DL_SIZE : MAX_DIRECTORY_OBJECT_SIZE;
if (connection_get_inbuf_len(TO_CONN(conn)) > max_size) {
log_warn(LD_HTTP,
"Too much data received from directory connection (%s): "
"denial of service attempt, or you need to upgrade?",
conn->base_.address);
connection_mark_for_close(TO_CONN(conn));
return -1;
}
if (!conn->base_.inbuf_reached_eof)
log_debug(LD_HTTP,"Got data, not eof. Leaving on inbuf.");
return 0;
}
/** Called when we're about to finally unlink and free a directory connection:
* perform necessary accounting and cleanup */
void
connection_dir_about_to_close(dir_connection_t *dir_conn)
{
connection_t *conn = TO_CONN(dir_conn);
if (conn->state < DIR_CONN_STATE_CLIENT_FINISHED) {
/* It's a directory connection and connecting or fetching
* failed: forget about this router, and maybe try again. */
connection_dir_request_failed(dir_conn);
}
/* If we were trying to fetch a v2 rend desc and did not succeed,
* retry as needed. (If a fetch is successful, the connection state
* is changed to DIR_PURPOSE_HAS_FETCHED_RENDDESC_V2 to mark that
* refetching is unnecessary.) */
if (conn->purpose == DIR_PURPOSE_FETCH_RENDDESC_V2 &&
dir_conn->rend_data &&
strlen(rend_data_get_address(dir_conn->rend_data)) ==
REND_SERVICE_ID_LEN_BASE32)
rend_client_refetch_v2_renddesc(dir_conn->rend_data);
}
/** Create an http response for the client <b>conn</b> out of
* <b>status</b> and <b>reason_phrase</b>. Write it to <b>conn</b>.
*/
static void
write_http_status_line(dir_connection_t *conn, int status,
const char *reason_phrase)
{
char buf[256];
if (tor_snprintf(buf, sizeof(buf), "HTTP/1.0 %d %s\r\n\r\n",
status, reason_phrase ? reason_phrase : "OK") < 0) {
log_warn(LD_BUG,"status line too long.");
return;
}
log_debug(LD_DIRSERV,"Wrote status 'HTTP/1.0 %d %s'", status, reason_phrase);
connection_write_to_buf(buf, strlen(buf), TO_CONN(conn));
}
/** Write the header for an HTTP/1.0 response onto <b>conn</b>-\>outbuf,
* with <b>type</b> as the Content-Type.
*
* If <b>length</b> is nonnegative, it is the Content-Length.
* If <b>encoding</b> is provided, it is the Content-Encoding.
* If <b>cache_lifetime</b> is greater than 0, the content may be cached for
* up to cache_lifetime seconds. Otherwise, the content may not be cached. */
static void
write_http_response_header_impl(dir_connection_t *conn, ssize_t length,
const char *type, const char *encoding,
const char *extra_headers,
long cache_lifetime)
{
char date[RFC1123_TIME_LEN+1];
char tmp[1024];
char *cp;
time_t now = time(NULL);
tor_assert(conn);
format_rfc1123_time(date, now);
cp = tmp;
tor_snprintf(cp, sizeof(tmp),
"HTTP/1.0 200 OK\r\nDate: %s\r\n",
date);
cp += strlen(tmp);
if (type) {
tor_snprintf(cp, sizeof(tmp)-(cp-tmp), "Content-Type: %s\r\n", type);
cp += strlen(cp);
}
if (!is_local_addr(&conn->base_.addr)) {
/* Don't report the source address for a nearby/private connection.
* Otherwise we tend to mis-report in cases where incoming ports are
* being forwarded to a Tor server running behind the firewall. */
tor_snprintf(cp, sizeof(tmp)-(cp-tmp),
X_ADDRESS_HEADER "%s\r\n", conn->base_.address);
cp += strlen(cp);
}
if (encoding) {
tor_snprintf(cp, sizeof(tmp)-(cp-tmp),
"Content-Encoding: %s\r\n", encoding);
cp += strlen(cp);
}
if (length >= 0) {
tor_snprintf(cp, sizeof(tmp)-(cp-tmp),
"Content-Length: %ld\r\n", (long)length);
cp += strlen(cp);
}
if (cache_lifetime > 0) {
char expbuf[RFC1123_TIME_LEN+1];
format_rfc1123_time(expbuf, (time_t)(now + cache_lifetime));
/* We could say 'Cache-control: max-age=%d' here if we start doing
* http/1.1 */
tor_snprintf(cp, sizeof(tmp)-(cp-tmp),
"Expires: %s\r\n", expbuf);
cp += strlen(cp);
} else if (cache_lifetime == 0) {
/* We could say 'Cache-control: no-cache' here if we start doing
* http/1.1 */
strlcpy(cp, "Pragma: no-cache\r\n", sizeof(tmp)-(cp-tmp));
cp += strlen(cp);
}
if (extra_headers) {
strlcpy(cp, extra_headers, sizeof(tmp)-(cp-tmp));
cp += strlen(cp);
}
if (sizeof(tmp)-(cp-tmp) > 3)
memcpy(cp, "\r\n", 3);
else
tor_assert(0);
connection_write_to_buf(tmp, strlen(tmp), TO_CONN(conn));
}
/** As write_http_response_header_impl, but sets encoding and content-typed
* based on whether the response will be <b>compressed</b> or not. */
static void
write_http_response_headers(dir_connection_t *conn, ssize_t length,
compress_method_t method,
const char *extra_headers, long cache_lifetime)
{
const char *methodname = compression_method_get_name(method);
const char *doctype;
if (method == NO_METHOD)
doctype = "text/plain";
else
doctype = "application/octet-stream";
write_http_response_header_impl(conn, length,
doctype,
methodname,
extra_headers,
cache_lifetime);
}
/** As write_http_response_headers, but assumes extra_headers is NULL */
static void
write_http_response_header(dir_connection_t *conn, ssize_t length,
compress_method_t method,
long cache_lifetime)
{
write_http_response_headers(conn, length, method, NULL, cache_lifetime);
}
/** Array of compression methods to use (if supported) for serving
* precompressed data, ordered from best to worst. */
static compress_method_t srv_meth_pref_precompressed[] = {
LZMA_METHOD,
ZSTD_METHOD,
ZLIB_METHOD,
GZIP_METHOD,
NO_METHOD
};
/** Array of compression methods to use (if supported) for serving
* streamed data, ordered from best to worst. */
static compress_method_t srv_meth_pref_streaming_compression[] = {
ZSTD_METHOD,
ZLIB_METHOD,
GZIP_METHOD,
NO_METHOD
};
/** Parse the compression methods listed in an Accept-Encoding header <b>h</b>,
* and convert them to a bitfield where compression method x is supported if
* and only if 1 &lt;&lt; x is set in the bitfield. */
STATIC unsigned
parse_accept_encoding_header(const char *h)
{
unsigned result = (1u << NO_METHOD);
smartlist_t *methods = smartlist_new();
smartlist_split_string(methods, h, ",",
SPLIT_SKIP_SPACE|SPLIT_STRIP_SPACE|SPLIT_IGNORE_BLANK, 0);
SMARTLIST_FOREACH_BEGIN(methods, const char *, m) {
compress_method_t method = compression_method_get_by_name(m);
if (method != UNKNOWN_METHOD) {
tor_assert(((unsigned)method) < 8*sizeof(unsigned));
result |= (1u << method);
}
} SMARTLIST_FOREACH_END(m);
SMARTLIST_FOREACH_BEGIN(methods, char *, m) {
tor_free(m);
} SMARTLIST_FOREACH_END(m);
smartlist_free(methods);
return result;
}
/** Array of compression methods to use (if supported) for requesting
* compressed data, ordered from best to worst. */
static compress_method_t client_meth_pref[] = {
LZMA_METHOD,
ZSTD_METHOD,
ZLIB_METHOD,
GZIP_METHOD,
NO_METHOD
};
/** Return a newly allocated string containing a comma separated list of
* supported encodings. */
STATIC char *
accept_encoding_header(void)
{
smartlist_t *methods = smartlist_new();
char *header = NULL;
compress_method_t method;
unsigned i;
for (i = 0; i < ARRAY_LENGTH(client_meth_pref); ++i) {
method = client_meth_pref[i];
if (tor_compress_supports_method(method))
smartlist_add(methods, (char *)compression_method_get_name(method));
}
header = smartlist_join_strings(methods, ", ", 0, NULL);
smartlist_free(methods);
return header;
}
/** Decide whether a client would accept the consensus we have.
*
* Clients can say they only want a consensus if it's signed by more
* than half the authorities in a list. They pass this list in
* the url as "...consensus/<b>fpr</b>+<b>fpr</b>+<b>fpr</b>".
*
* <b>fpr</b> may be an abbreviated fingerprint, i.e. only a left substring
* of the full authority identity digest. (Only strings of even length,
* i.e. encodings of full bytes, are handled correctly. In the case
* of an odd number of hex digits the last one is silently ignored.)
*
* Returns 1 if more than half of the requested authorities signed the
* consensus, 0 otherwise.
*/
int
client_likes_consensus(const struct consensus_cache_entry_t *ent,
const char *want_url)
{
smartlist_t *voters = smartlist_new();
int need_at_least;
int have = 0;
if (consensus_cache_entry_get_voter_id_digests(ent, voters) != 0) {
return 1; // We don't know the voters; assume the client won't mind. */
}
smartlist_t *want_authorities = smartlist_new();
dir_split_resource_into_fingerprints(want_url, want_authorities, NULL, 0);
need_at_least = smartlist_len(want_authorities)/2+1;
SMARTLIST_FOREACH_BEGIN(want_authorities, const char *, want_digest) {
SMARTLIST_FOREACH_BEGIN(voters, const char *, digest) {
if (!strcasecmpstart(digest, want_digest)) {
have++;
break;
};
} SMARTLIST_FOREACH_END(digest);
/* early exit, if we already have enough */
if (have >= need_at_least)
break;
} SMARTLIST_FOREACH_END(want_digest);
SMARTLIST_FOREACH(want_authorities, char *, d, tor_free(d));
smartlist_free(want_authorities);
SMARTLIST_FOREACH(voters, char *, cp, tor_free(cp));
smartlist_free(voters);
return (have >= need_at_least);
}
/** Return the compression level we should use for sending a compressed
* response of size <b>n_bytes</b>. */
STATIC compression_level_t
choose_compression_level(ssize_t n_bytes)
{
if (! have_been_under_memory_pressure()) {
return HIGH_COMPRESSION; /* we have plenty of RAM. */
} else if (n_bytes < 0) {
return HIGH_COMPRESSION; /* unknown; might be big. */
} else if (n_bytes < 1024) {
return LOW_COMPRESSION;
} else if (n_bytes < 2048) {
return MEDIUM_COMPRESSION;
} else {
return HIGH_COMPRESSION;
}
}
/** Information passed to handle a GET request. */
typedef struct get_handler_args_t {
/** Bitmask of compression methods that the client said (or implied) it
* supported. */
unsigned compression_supported;
/** If nonzero, the time included an if-modified-since header with this
* value. */
time_t if_modified_since;
/** String containing the requested URL or resource. */
const char *url;
/** String containing the HTTP headers */
const char *headers;
} get_handler_args_t;
/** Entry for handling an HTTP GET request.
*
* This entry matches a request if "string" is equal to the requested
* resource, or if "is_prefix" is true and "string" is a prefix of the
* requested resource.
*
* The 'handler' function is called to handle the request. It receives
* an arguments structure, and must return 0 on success or -1 if we should
* close the connection.
**/
typedef struct url_table_ent_s {
const char *string;
int is_prefix;
int (*handler)(dir_connection_t *conn, const get_handler_args_t *args);
} url_table_ent_t;
static int handle_get_frontpage(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_current_consensus(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_status_vote(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_microdesc(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_descriptor(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_keys(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_hs_descriptor_v2(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_robots(dir_connection_t *conn,
const get_handler_args_t *args);
static int handle_get_networkstatus_bridges(dir_connection_t *conn,
const get_handler_args_t *args);
/** Table for handling GET requests. */
static const url_table_ent_t url_table[] = {
{ "/tor/", 0, handle_get_frontpage },
{ "/tor/status-vote/current/consensus", 1, handle_get_current_consensus },
{ "/tor/status-vote/current/", 1, handle_get_status_vote },
{ "/tor/status-vote/next/", 1, handle_get_status_vote },
{ "/tor/micro/d/", 1, handle_get_microdesc },
{ "/tor/server/", 1, handle_get_descriptor },
{ "/tor/extra/", 1, handle_get_descriptor },
{ "/tor/keys/", 1, handle_get_keys },
{ "/tor/rendezvous2/", 1, handle_get_hs_descriptor_v2 },
{ "/tor/hs/3/", 1, handle_get_hs_descriptor_v3 },
{ "/tor/robots.txt", 0, handle_get_robots },
{ "/tor/networkstatus-bridges", 0, handle_get_networkstatus_bridges },
{ NULL, 0, NULL },
};
/** Helper function: called when a dirserver gets a complete HTTP GET
* request. Look for a request for a directory or for a rendezvous
* service descriptor. On finding one, write a response into
* conn-\>outbuf. If the request is unrecognized, send a 404.
* Return 0 if we handled this successfully, or -1 if we need to close
* the connection. */
MOCK_IMPL(STATIC int,
directory_handle_command_get,(dir_connection_t *conn, const char *headers,
const char *req_body, size_t req_body_len))
{
char *url, *url_mem, *header;
time_t if_modified_since = 0;
int zlib_compressed_in_url;
size_t url_len;
unsigned compression_methods_supported;
/* We ignore the body of a GET request. */
(void)req_body;
(void)req_body_len;
log_debug(LD_DIRSERV,"Received GET command.");
conn->base_.state = DIR_CONN_STATE_SERVER_WRITING;
if (parse_http_url(headers, &url) < 0) {
write_http_status_line(conn, 400, "Bad request");
return 0;
}
if ((header = http_get_header(headers, "If-Modified-Since: "))) {
struct tm tm;
if (parse_http_time(header, &tm) == 0) {
if (tor_timegm(&tm, &if_modified_since)<0) {
if_modified_since = 0;
} else {
log_debug(LD_DIRSERV, "If-Modified-Since is '%s'.", escaped(header));
}
}
/* The correct behavior on a malformed If-Modified-Since header is to
* act as if no If-Modified-Since header had been given. */
tor_free(header);
}
log_debug(LD_DIRSERV,"rewritten url as '%s'.", escaped(url));
url_mem = url;
url_len = strlen(url);
zlib_compressed_in_url = url_len > 2 && !strcmp(url+url_len-2, ".z");
if (zlib_compressed_in_url) {
url[url_len-2] = '\0';
url_len -= 2;
}
if ((header = http_get_header(headers, "Accept-Encoding: "))) {
compression_methods_supported = parse_accept_encoding_header(header);
tor_free(header);
} else {
compression_methods_supported = (1u << NO_METHOD);
}
if (zlib_compressed_in_url) {
compression_methods_supported |= (1u << ZLIB_METHOD);
}
/* Remove all methods that we don't both support. */
compression_methods_supported &= tor_compress_get_supported_method_bitmask();
get_handler_args_t args;
args.url = url;
args.headers = headers;
args.if_modified_since = if_modified_since;
args.compression_supported = compression_methods_supported;
int i, result = -1;
for (i = 0; url_table[i].string; ++i) {
int match;
if (url_table[i].is_prefix) {
match = !strcmpstart(url, url_table[i].string);
} else {
match = !strcmp(url, url_table[i].string);
}
if (match) {
result = url_table[i].handler(conn, &args);
goto done;
}
}
/* we didn't recognize the url */
write_http_status_line(conn, 404, "Not found");
result = 0;
done:
tor_free(url_mem);
return result;
}
/** Helper function for GET / or GET /tor/
*/
static int
handle_get_frontpage(dir_connection_t *conn, const get_handler_args_t *args)
{
(void) args; /* unused */
const char *frontpage = get_dirportfrontpage();
if (frontpage) {
size_t dlen;
dlen = strlen(frontpage);
/* Let's return a disclaimer page (users shouldn't use V1 anymore,
and caches don't fetch '/', so this is safe). */
/* [We don't check for write_bucket_low here, since we want to serve
* this page no matter what.] */
write_http_response_header_impl(conn, dlen, "text/html", "identity",
NULL, DIRPORTFRONTPAGE_CACHE_LIFETIME);
connection_write_to_buf(frontpage, dlen, TO_CONN(conn));
} else {
write_http_status_line(conn, 404, "Not found");
}
return 0;
}
/** Warn that the cached consensus <b>consensus</b> of type
* <b>flavor</b> is too old and will not be served to clients. Rate-limit the
* warning to avoid logging an entry on every request.
*/
static void
warn_consensus_is_too_old(const struct consensus_cache_entry_t *consensus,
const char *flavor, time_t now)
{
#define TOO_OLD_WARNING_INTERVAL (60*60)
static ratelim_t warned = RATELIM_INIT(TOO_OLD_WARNING_INTERVAL);
char timestamp[ISO_TIME_LEN+1];
time_t valid_until;
char *dupes;
if (consensus_cache_entry_get_valid_until(consensus, &valid_until))
return;
if ((dupes = rate_limit_log(&warned, now))) {
format_local_iso_time(timestamp, valid_until);
log_warn(LD_DIRSERV, "Our %s%sconsensus is too old, so we will not "
"serve it to clients. It was valid until %s local time and we "
"continued to serve it for up to 24 hours after it expired.%s",
flavor ? flavor : "", flavor ? " " : "", timestamp, dupes);
tor_free(dupes);
}
}
/**
* Parse a single hex-encoded sha3-256 digest from <b>hex</b> into
* <b>digest</b>. Return 0 on success. On failure, report that the hash came
* from <b>location</b>, report that we are taking <b>action</b> with it, and
* return -1.
*/
static int
parse_one_diff_hash(uint8_t *digest, const char *hex, const char *location,
const char *action)
{
if (base16_decode((char*)digest, DIGEST256_LEN, hex, strlen(hex)) ==
DIGEST256_LEN) {
return 0;
} else {
log_fn(LOG_PROTOCOL_WARN, LD_DIR,
"%s contained bogus digest %s; %s.",
location, escaped(hex), action);
return -1;
}
}
/** If there is an X-Or-Diff-From-Consensus header included in <b>headers</b>,
* set <b>digest_out<b> to a new smartlist containing every 256-bit
* hex-encoded digest listed in that header and return 0. Otherwise return
* -1. */
static int
parse_or_diff_from_header(smartlist_t **digests_out, const char *headers)
{
char *hdr = http_get_header(headers, X_OR_DIFF_FROM_CONSENSUS_HEADER);
if (hdr == NULL) {
return -1;
}
smartlist_t *hex_digests = smartlist_new();
*digests_out = smartlist_new();
smartlist_split_string(hex_digests, hdr, " ",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
SMARTLIST_FOREACH_BEGIN(hex_digests, const char *, hex) {
uint8_t digest[DIGEST256_LEN];
if (!parse_one_diff_hash(digest, hex, "X-Or-Diff-From-Consensus header",
"ignoring")) {
smartlist_add(*digests_out, tor_memdup(digest, sizeof(digest)));
}
} SMARTLIST_FOREACH_END(hex);
SMARTLIST_FOREACH(hex_digests, char *, cp, tor_free(cp));
smartlist_free(hex_digests);
tor_free(hdr);
return 0;
}
/** Fallback compression method. The fallback compression method is used in
* case a client requests a non-compressed document. We only store compressed
* documents, so we use this compression method to fetch the document and let
* the spooling system do the streaming decompression.
*/
#define FALLBACK_COMPRESS_METHOD ZLIB_METHOD
/**
* Try to find the best consensus diff possible in order to serve a client
* request for a diff from one of the consensuses in <b>digests</b> to the
* current consensus of flavor <b>flav</b>. The client supports the
* compression methods listed in the <b>compression_methods</b> bitfield:
* place the method chosen (if any) into <b>compression_used_out</b>.
*/
static struct consensus_cache_entry_t *
find_best_diff(const smartlist_t *digests, int flav,
unsigned compression_methods,
compress_method_t *compression_used_out)
{
struct consensus_cache_entry_t *result = NULL;
SMARTLIST_FOREACH_BEGIN(digests, const uint8_t *, diff_from) {
unsigned u;
for (u = 0; u < ARRAY_LENGTH(srv_meth_pref_precompressed); ++u) {
compress_method_t method = srv_meth_pref_precompressed[u];
if (0 == (compression_methods & (1u<<method)))
continue; // client doesn't like this one, or we don't have it.
if (consdiffmgr_find_diff_from(&result, flav, DIGEST_SHA3_256,
diff_from, DIGEST256_LEN,
method) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = method;
return result;
}
}
} SMARTLIST_FOREACH_END(diff_from);
SMARTLIST_FOREACH_BEGIN(digests, const uint8_t *, diff_from) {
if (consdiffmgr_find_diff_from(&result, flav, DIGEST_SHA3_256, diff_from,
DIGEST256_LEN, FALLBACK_COMPRESS_METHOD) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = FALLBACK_COMPRESS_METHOD;
return result;
}
} SMARTLIST_FOREACH_END(diff_from);
return NULL;
}
/** Lookup the cached consensus document by the flavor found in <b>flav</b>.
* The prefered set of compression methods should be listed in the
* <b>compression_methods</b> bitfield. The compression method chosen (if any)
* is stored in <b>compression_used_out</b>. */
static struct consensus_cache_entry_t *
find_best_consensus(int flav,
unsigned compression_methods,
compress_method_t *compression_used_out)
{
struct consensus_cache_entry_t *result = NULL;
unsigned u;
for (u = 0; u < ARRAY_LENGTH(srv_meth_pref_precompressed); ++u) {
compress_method_t method = srv_meth_pref_precompressed[u];
if (0 == (compression_methods & (1u<<method)))
continue;
if (consdiffmgr_find_consensus(&result, flav,
method) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = method;
return result;
}
}
if (consdiffmgr_find_consensus(&result, flav,
FALLBACK_COMPRESS_METHOD) == CONSDIFF_AVAILABLE) {
tor_assert_nonfatal(result);
*compression_used_out = FALLBACK_COMPRESS_METHOD;
return result;
}
return NULL;
}
/** Try to find the best supported compression method possible from a given
* <b>compression_methods</b>. Return NO_METHOD if no mutually supported
* compression method could be found. */
static compress_method_t
find_best_compression_method(unsigned compression_methods, int stream)
{
unsigned u;
compress_method_t *methods;
size_t length;
if (stream) {
methods = srv_meth_pref_streaming_compression;
length = ARRAY_LENGTH(srv_meth_pref_streaming_compression);
} else {
methods = srv_meth_pref_precompressed;
length = ARRAY_LENGTH(srv_meth_pref_precompressed);
}
for (u = 0; u < length; ++u) {
compress_method_t method = methods[u];
if (compression_methods & (1u<<method))
return method;
}
return NO_METHOD;
}
/** Encodes the results of parsing a consensus request to figure out what
* consensus, and possibly what diffs, the user asked for. */
typedef struct {
/** name of the flavor to retrieve. */
char *flavor;
/** flavor to retrive, as enum. */
consensus_flavor_t flav;
/** plus-separated list of authority fingerprints; see
* client_likes_consensus(). Aliases the URL in the request passed to
* parse_consensus_request(). */
const char *want_fps;
/** Optionally, a smartlist of sha3 digests-as-signed of the consensuses
* to return a diff from. */
smartlist_t *diff_from_digests;
/** If true, never send a full consensus. If there is no diff, send
* a 404 instead. */
int diff_only;
} parsed_consensus_request_t;
/** Remove all data held in <b>req</b>. Do not free <b>req</b> itself, since
* it is stack-allocated. */
static void
parsed_consensus_request_clear(parsed_consensus_request_t *req)
{
if (!req)
return;
tor_free(req->flavor);
if (req->diff_from_digests) {
SMARTLIST_FOREACH(req->diff_from_digests, uint8_t *, d, tor_free(d));
smartlist_free(req->diff_from_digests);
}
memset(req, 0, sizeof(parsed_consensus_request_t));
}
/**
* Parse the URL and relevant headers of <b>args</b> for a current-consensus
* request to learn what flavor of consensus we want, what keys it must be
* signed with, and what diffs we would accept (or demand) instead. Return 0
* on success and -1 on failure.
*/
static int
parse_consensus_request(parsed_consensus_request_t *out,
const get_handler_args_t *args)
{
const char *url = args->url;
memset(out, 0, sizeof(parsed_consensus_request_t));
out->flav = FLAV_NS;
const char CONSENSUS_URL_PREFIX[] = "/tor/status-vote/current/consensus/";
const char CONSENSUS_FLAVORED_PREFIX[] =
"/tor/status-vote/current/consensus-";
/* figure out the flavor if any, and who we wanted to sign the thing */
const char *after_flavor = NULL;
if (!strcmpstart(url, CONSENSUS_FLAVORED_PREFIX)) {
const char *f, *cp;
f = url + strlen(CONSENSUS_FLAVORED_PREFIX);
cp = strchr(f, '/');
if (cp) {
after_flavor = cp+1;
out->flavor = tor_strndup(f, cp-f);
} else {
out->flavor = tor_strdup(f);
}
int flav = networkstatus_parse_flavor_name(out->flavor);
if (flav < 0)
flav = FLAV_NS;
out->flav = flav;
} else {
if (!strcmpstart(url, CONSENSUS_URL_PREFIX))
after_flavor = url+strlen(CONSENSUS_URL_PREFIX);
}
/* see whether we've been asked explicitly for a diff from an older
* consensus. (The user might also have said that a diff would be okay,
* via X-Or-Diff-From-Consensus */
const char DIFF_COMPONENT[] = "diff/";
char *diff_hash_in_url = NULL;
if (after_flavor && !strcmpstart(after_flavor, DIFF_COMPONENT)) {
after_flavor += strlen(DIFF_COMPONENT);
const char *cp = strchr(after_flavor, '/');
if (cp) {
diff_hash_in_url = tor_strndup(after_flavor, cp-after_flavor);
out->want_fps = cp+1;
} else {
diff_hash_in_url = tor_strdup(after_flavor);
out->want_fps = NULL;
}
} else {
out->want_fps = after_flavor;
}
if (diff_hash_in_url) {
uint8_t diff_from[DIGEST256_LEN];
out->diff_from_digests = smartlist_new();
out->diff_only = 1;
if (!parse_one_diff_hash(diff_from, diff_hash_in_url, "URL",
"rejecting")) {
smartlist_add(out->diff_from_digests,
tor_memdup(diff_from, DIGEST256_LEN));
} else {
return -1;
}
} else {
parse_or_diff_from_header(&out->diff_from_digests, args->headers);
}
return 0;
}
/** Helper function for GET /tor/status-vote/current/consensus
*/
static int
handle_get_current_consensus(dir_connection_t *conn,
const get_handler_args_t *args)
{
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 0);
const time_t if_modified_since = args->if_modified_since;
int clear_spool = 0;
/* v3 network status fetch. */
long lifetime = NETWORKSTATUS_CACHE_LIFETIME;
time_t now = time(NULL);
const char *want_fps = NULL;
parsed_consensus_request_t req;
if (parse_consensus_request(&req, args) < 0) {
write_http_status_line(conn, 404, "Couldn't parse request");
goto done;
}
struct consensus_cache_entry_t *cached_consensus = NULL;
compress_method_t compression_used = NO_METHOD;
if (req.diff_from_digests) {
cached_consensus = find_best_diff(req.diff_from_digests, req.flav,
args->compression_supported,
&compression_used);
}
if (req.diff_only && !cached_consensus) {
write_http_status_line(conn, 404, "No such diff available");
// XXXX warn_consensus_is_too_old(v, req.flavor, now);
geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND);
goto done;
}
if (! cached_consensus) {
cached_consensus = find_best_consensus(req.flav,
args->compression_supported,
&compression_used);
}
time_t fresh_until, valid_until;
int have_fresh_until = 0, have_valid_until = 0;
if (cached_consensus) {
have_fresh_until =
!consensus_cache_entry_get_fresh_until(cached_consensus, &fresh_until);
have_valid_until =
!consensus_cache_entry_get_valid_until(cached_consensus, &valid_until);
}
if (cached_consensus && have_valid_until &&
!networkstatus_valid_until_is_reasonably_live(valid_until, now)) {
write_http_status_line(conn, 404, "Consensus is too old");
warn_consensus_is_too_old(cached_consensus, req.flavor, now);
geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND);
goto done;
}
if (cached_consensus && want_fps &&
!client_likes_consensus(cached_consensus, want_fps)) {
write_http_status_line(conn, 404, "Consensus not signed by sufficient "
"number of requested authorities");
geoip_note_ns_response(GEOIP_REJECT_NOT_ENOUGH_SIGS);
goto done;
}
conn->spool = smartlist_new();
clear_spool = 1;
{
spooled_resource_t *spooled;
if (cached_consensus) {
spooled = spooled_resource_new_from_cache_entry(cached_consensus);
smartlist_add(conn->spool, spooled);
}
}
lifetime = (have_fresh_until && fresh_until > now) ? fresh_until - now : 0;
size_t size_guess = 0;
int n_expired = 0;
dirserv_spool_remove_missing_and_guess_size(conn, if_modified_since,
compress_method != NO_METHOD,
&size_guess,
&n_expired);
if (!smartlist_len(conn->spool) && !n_expired) {
write_http_status_line(conn, 404, "Not found");
geoip_note_ns_response(GEOIP_REJECT_NOT_FOUND);
goto done;
} else if (!smartlist_len(conn->spool)) {
write_http_status_line(conn, 304, "Not modified");
geoip_note_ns_response(GEOIP_REJECT_NOT_MODIFIED);
goto done;
}
if (global_write_bucket_low(TO_CONN(conn), size_guess, 2)) {
log_debug(LD_DIRSERV,
"Client asked for network status lists, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_http_status_line(conn, 503, "Directory busy, try again later");
geoip_note_ns_response(GEOIP_REJECT_BUSY);
goto done;
}
tor_addr_t addr;
if (tor_addr_parse(&addr, (TO_CONN(conn))->address) >= 0) {
geoip_note_client_seen(GEOIP_CLIENT_NETWORKSTATUS,
&addr, NULL,
time(NULL));
geoip_note_ns_response(GEOIP_SUCCESS);
/* Note that a request for a network status has started, so that we
* can measure the download time later on. */
if (conn->dirreq_id)
geoip_start_dirreq(conn->dirreq_id, size_guess, DIRREQ_TUNNELED);
else
geoip_start_dirreq(TO_CONN(conn)->global_identifier, size_guess,
DIRREQ_DIRECT);
}
/* Use this header to tell caches that the response depends on the
* X-Or-Diff-From-Consensus header (or lack thereof). */
const char vary_header[] = "Vary: X-Or-Diff-From-Consensus\r\n";
clear_spool = 0;
// The compress_method might have been NO_METHOD, but we store the data
// compressed. Decompress them using `compression_used`. See fallback code in
// find_best_consensus() and find_best_diff().
write_http_response_headers(conn, -1,
compress_method == NO_METHOD ?
NO_METHOD : compression_used,
vary_header,
smartlist_len(conn->spool) == 1 ? lifetime : 0);
if (compress_method == NO_METHOD && smartlist_len(conn->spool))
conn->compress_state = tor_compress_new(0, compression_used,
HIGH_COMPRESSION);
/* Prime the connection with some data. */
const int initial_flush_result = connection_dirserv_flushed_some(conn);
tor_assert_nonfatal(initial_flush_result == 0);
goto done;
done:
parsed_consensus_request_clear(&req);
if (clear_spool) {
dir_conn_clear_spool(conn);
}
return 0;
}
/** Helper function for GET /tor/status-vote/{current,next}/...
*/
static int
handle_get_status_vote(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
{
int current;
ssize_t body_len = 0;
ssize_t estimated_len = 0;
smartlist_t *items = smartlist_new();
smartlist_t *dir_items = smartlist_new();
int lifetime = 60; /* XXXX?? should actually use vote intervals. */
url += strlen("/tor/status-vote/");
current = !strcmpstart(url, "current/");
url = strchr(url, '/');
tor_assert(url);
++url;
if (!strcmp(url, "consensus")) {
const char *item;
tor_assert(!current); /* we handle current consensus specially above,
* since it wants to be spooled. */
if ((item = dirvote_get_pending_consensus(FLAV_NS)))
smartlist_add(items, (char*)item);
} else if (!current && !strcmp(url, "consensus-signatures")) {
/* XXXX the spec says that we should implement
* current/consensus-signatures too. It doesn't seem to be needed,
* though. */
const char *item;
if ((item=dirvote_get_pending_detached_signatures()))
smartlist_add(items, (char*)item);
} else if (!strcmp(url, "authority")) {
const cached_dir_t *d;
int flags = DGV_BY_ID |
(current ? DGV_INCLUDE_PREVIOUS : DGV_INCLUDE_PENDING);
if ((d=dirvote_get_vote(NULL, flags)))
smartlist_add(dir_items, (cached_dir_t*)d);
} else {
const cached_dir_t *d;
smartlist_t *fps = smartlist_new();
int flags;
if (!strcmpstart(url, "d/")) {
url += 2;
flags = DGV_INCLUDE_PENDING | DGV_INCLUDE_PREVIOUS;
} else {
flags = DGV_BY_ID |
(current ? DGV_INCLUDE_PREVIOUS : DGV_INCLUDE_PENDING);
}
dir_split_resource_into_fingerprints(url, fps, NULL,
DSR_HEX|DSR_SORT_UNIQ);
SMARTLIST_FOREACH(fps, char *, fp, {
if ((d = dirvote_get_vote(fp, flags)))
smartlist_add(dir_items, (cached_dir_t*)d);
tor_free(fp);
});
smartlist_free(fps);
}
if (!smartlist_len(dir_items) && !smartlist_len(items)) {
write_http_status_line(conn, 404, "Not found");
goto vote_done;
}
SMARTLIST_FOREACH(dir_items, cached_dir_t *, d,
body_len += compress_method != NO_METHOD ?
d->dir_compressed_len : d->dir_len);
estimated_len += body_len;
SMARTLIST_FOREACH(items, const char *, item, {
size_t ln = strlen(item);
if (compress_method != NO_METHOD) {
estimated_len += ln/2;
} else {
body_len += ln; estimated_len += ln;
}
});
if (global_write_bucket_low(TO_CONN(conn), estimated_len, 2)) {
write_http_status_line(conn, 503, "Directory busy, try again later");
goto vote_done;
}
write_http_response_header(conn, body_len ? body_len : -1,
compress_method,
lifetime);
if (smartlist_len(items)) {
if (compress_method != NO_METHOD) {
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(estimated_len));
SMARTLIST_FOREACH(items, const char *, c,
connection_write_to_buf_compress(c, strlen(c), conn, 0));
connection_write_to_buf_compress("", 0, conn, 1);
} else {
SMARTLIST_FOREACH(items, const char *, c,
connection_write_to_buf(c, strlen(c), TO_CONN(conn)));
}
} else {
SMARTLIST_FOREACH(dir_items, cached_dir_t *, d,
connection_write_to_buf(compress_method != NO_METHOD ?
d->dir_compressed : d->dir,
compress_method != NO_METHOD ?
d->dir_compressed_len : d->dir_len,
TO_CONN(conn)));
}
vote_done:
smartlist_free(items);
smartlist_free(dir_items);
goto done;
}
done:
return 0;
}
/** Helper function for GET /tor/micro/d/...
*/
static int
handle_get_microdesc(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
int clear_spool = 1;
{
conn->spool = smartlist_new();
dir_split_resource_into_spoolable(url+strlen("/tor/micro/d/"),
DIR_SPOOL_MICRODESC,
conn->spool, NULL,
DSR_DIGEST256|DSR_BASE64|DSR_SORT_UNIQ);
size_t size_guess = 0;
dirserv_spool_remove_missing_and_guess_size(conn, 0,
compress_method != NO_METHOD,
&size_guess, NULL);
if (smartlist_len(conn->spool) == 0) {
write_http_status_line(conn, 404, "Not found");
goto done;
}
if (global_write_bucket_low(TO_CONN(conn), size_guess, 2)) {
log_info(LD_DIRSERV,
"Client asked for server descriptors, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_http_status_line(conn, 503, "Directory busy, try again later");
goto done;
}
clear_spool = 0;
write_http_response_header(conn, -1,
compress_method,
MICRODESC_CACHE_LIFETIME);
if (compress_method != NO_METHOD)
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(size_guess));
const int initial_flush_result = connection_dirserv_flushed_some(conn);
tor_assert_nonfatal(initial_flush_result == 0);
goto done;
}
done:
if (clear_spool) {
dir_conn_clear_spool(conn);
}
return 0;
}
/** Helper function for GET /tor/{server,extra}/...
*/
static int
handle_get_descriptor(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
const or_options_t *options = get_options();
int clear_spool = 1;
if (!strcmpstart(url,"/tor/server/") ||
(!options->BridgeAuthoritativeDir &&
!options->BridgeRelay && !strcmpstart(url,"/tor/extra/"))) {
int res;
const char *msg = NULL;
int cache_lifetime = 0;
int is_extra = !strcmpstart(url,"/tor/extra/");
url += is_extra ? strlen("/tor/extra/") : strlen("/tor/server/");
dir_spool_source_t source;
time_t publish_cutoff = 0;
if (!strcmpstart(url, "d/")) {
source =
is_extra ? DIR_SPOOL_EXTRA_BY_DIGEST : DIR_SPOOL_SERVER_BY_DIGEST;
} else {
source =
is_extra ? DIR_SPOOL_EXTRA_BY_FP : DIR_SPOOL_SERVER_BY_FP;
/* We only want to apply a publish cutoff when we're requesting
* resources by fingerprint. */
publish_cutoff = time(NULL) - ROUTER_MAX_AGE_TO_PUBLISH;
}
conn->spool = smartlist_new();
res = dirserv_get_routerdesc_spool(conn->spool, url,
source,
connection_dir_is_encrypted(conn),
&msg);
if (!strcmpstart(url, "all")) {
cache_lifetime = FULL_DIR_CACHE_LIFETIME;
} else if (smartlist_len(conn->spool) == 1) {
cache_lifetime = ROUTERDESC_BY_DIGEST_CACHE_LIFETIME;
}
size_t size_guess = 0;
int n_expired = 0;
dirserv_spool_remove_missing_and_guess_size(conn, publish_cutoff,
compress_method != NO_METHOD,
&size_guess, &n_expired);
/* If we are the bridge authority and the descriptor is a bridge
* descriptor, remember that we served this descriptor for desc stats. */
/* XXXX it's a bit of a kludge to have this here. */
if (get_options()->BridgeAuthoritativeDir &&
source == DIR_SPOOL_SERVER_BY_FP) {
SMARTLIST_FOREACH_BEGIN(conn->spool, spooled_resource_t *, spooled) {
const routerinfo_t *router =
router_get_by_id_digest((const char *)spooled->digest);
/* router can be NULL here when the bridge auth is asked for its own
* descriptor. */
if (router && router->purpose == ROUTER_PURPOSE_BRIDGE)
rep_hist_note_desc_served(router->cache_info.identity_digest);
} SMARTLIST_FOREACH_END(spooled);
}
if (res < 0 || size_guess == 0 || smartlist_len(conn->spool) == 0) {
if (msg == NULL)
msg = "Not found";
write_http_status_line(conn, 404, msg);
} else {
if (global_write_bucket_low(TO_CONN(conn), size_guess, 2)) {
log_info(LD_DIRSERV,
"Client asked for server descriptors, but we've been "
"writing too many bytes lately. Sending 503 Dir busy.");
write_http_status_line(conn, 503, "Directory busy, try again later");
dir_conn_clear_spool(conn);
goto done;
}
write_http_response_header(conn, -1, compress_method, cache_lifetime);
if (compress_method != NO_METHOD)
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(size_guess));
clear_spool = 0;
/* Prime the connection with some data. */
int initial_flush_result = connection_dirserv_flushed_some(conn);
tor_assert_nonfatal(initial_flush_result == 0);
}
goto done;
}
done:
if (clear_spool)
dir_conn_clear_spool(conn);
return 0;
}
/** Helper function for GET /tor/keys/...
*/
static int
handle_get_keys(dir_connection_t *conn, const get_handler_args_t *args)
{
const char *url = args->url;
const compress_method_t compress_method =
find_best_compression_method(args->compression_supported, 1);
const time_t if_modified_since = args->if_modified_since;
{
smartlist_t *certs = smartlist_new();
ssize_t len = -1;
if (!strcmp(url, "/tor/keys/all")) {
authority_cert_get_all(certs);
} else if (!strcmp(url, "/tor/keys/authority")) {
authority_cert_t *cert = get_my_v3_authority_cert();
if (cert)
smartlist_add(certs, cert);
} else if (!strcmpstart(url, "/tor/keys/fp/")) {
smartlist_t *fps = smartlist_new();
dir_split_resource_into_fingerprints(url+strlen("/tor/keys/fp/"),
fps, NULL,
DSR_HEX|DSR_SORT_UNIQ);
SMARTLIST_FOREACH(fps, char *, d, {
authority_cert_t *c = authority_cert_get_newest_by_id(d);
if (c) smartlist_add(certs, c);
tor_free(d);
});
smartlist_free(fps);
} else if (!strcmpstart(url, "/tor/keys/sk/")) {
smartlist_t *fps = smartlist_new();
dir_split_resource_into_fingerprints(url+strlen("/tor/keys/sk/"),
fps, NULL,
DSR_HEX|DSR_SORT_UNIQ);
SMARTLIST_FOREACH(fps, char *, d, {
authority_cert_t *c = authority_cert_get_by_sk_digest(d);
if (c) smartlist_add(certs, c);
tor_free(d);
});
smartlist_free(fps);
} else if (!strcmpstart(url, "/tor/keys/fp-sk/")) {
smartlist_t *fp_sks = smartlist_new();
dir_split_resource_into_fingerprint_pairs(url+strlen("/tor/keys/fp-sk/"),
fp_sks);
SMARTLIST_FOREACH(fp_sks, fp_pair_t *, pair, {
authority_cert_t *c = authority_cert_get_by_digests(pair->first,
pair->second);
if (c) smartlist_add(certs, c);
tor_free(pair);
});
smartlist_free(fp_sks);
} else {
write_http_status_line(conn, 400, "Bad request");
goto keys_done;
}
if (!smartlist_len(certs)) {
write_http_status_line(conn, 404, "Not found");
goto keys_done;
}
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
if (c->cache_info.published_on < if_modified_since)
SMARTLIST_DEL_CURRENT(certs, c));
if (!smartlist_len(certs)) {
write_http_status_line(conn, 304, "Not modified");
goto keys_done;
}
len = 0;
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
len += c->cache_info.signed_descriptor_len);
if (global_write_bucket_low(TO_CONN(conn),
compress_method != NO_METHOD ? len/2 : len,
2)) {
write_http_status_line(conn, 503, "Directory busy, try again later");
goto keys_done;
}
write_http_response_header(conn,
compress_method != NO_METHOD ? -1 : len,
compress_method,
60*60);
if (compress_method != NO_METHOD) {
conn->compress_state = tor_compress_new(1, compress_method,
choose_compression_level(len));
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
connection_write_to_buf_compress(
c->cache_info.signed_descriptor_body,
c->cache_info.signed_descriptor_len,
conn, 0));
connection_write_to_buf_compress("", 0, conn, 1);
} else {
SMARTLIST_FOREACH(certs, authority_cert_t *, c,
connection_write_to_buf(c->cache_info.signed_descriptor_body,
c->cache_info.signed_descriptor_len,
TO_CONN(conn)));
}
keys_done:
smartlist_free(certs);
goto done;
}
done:
return 0;
}
/** Helper function for GET /tor/rendezvous2/
*/
static int
handle_get_hs_descriptor_v2(dir_connection_t *conn,
const get_handler_args_t *args)
{
const char *url = args->url;
if (connection_dir_is_encrypted(conn)) {
/* Handle v2 rendezvous descriptor fetch request. */
const char *descp;
const char *query = url + strlen("/tor/rendezvous2/");
if (rend_valid_descriptor_id(query)) {
log_info(LD_REND, "Got a v2 rendezvous descriptor request for ID '%s'",
safe_str(escaped(query)));
switch (rend_cache_lookup_v2_desc_as_dir(query, &descp)) {
case 1: /* valid */
write_http_response_header(conn, strlen(descp), NO_METHOD, 0);
connection_write_to_buf(descp, strlen(descp), TO_CONN(conn));
break;
case 0: /* well-formed but not present */
write_http_status_line(conn, 404, "Not found");
break;
case -1: /* not well-formed */
write_http_status_line(conn, 400, "Bad request");
break;
}
} else { /* not well-formed */
write_http_status_line(conn, 400, "Bad request");
}
goto done;
} else {
/* Not encrypted! */
write_http_status_line(conn, 404, "Not found");
}
done:
return 0;
}
/** Helper function for GET /tor/hs/3/<z>. Only for version 3.
*/
STATIC int
handle_get_hs_descriptor_v3(dir_connection_t *conn,
const get_handler_args_t *args)
{
int retval;
const char *desc_str = NULL;
const char *pubkey_str = NULL;
const char *url = args->url;
/* Reject unencrypted dir connections */
if (!connection_dir_is_encrypted(conn)) {
write_http_status_line(conn, 404, "Not found");
goto done;
}
/* After the path prefix follows the base64 encoded blinded pubkey which we
* use to get the descriptor from the cache. Skip the prefix and get the
* pubkey. */
tor_assert(!strcmpstart(url, "/tor/hs/3/"));
pubkey_str = url + strlen("/tor/hs/3/");
retval = hs_cache_lookup_as_dir(HS_VERSION_THREE,
pubkey_str, &desc_str);
if (retval <= 0 || desc_str == NULL) {
write_http_status_line(conn, 404, "Not found");
goto done;
}
/* Found requested descriptor! Pass it to this nice client. */
write_http_response_header(conn, strlen(desc_str), NO_METHOD, 0);
connection_write_to_buf(desc_str, strlen(desc_str), TO_CONN(conn));
done:
return 0;
}
/** Helper function for GET /tor/networkstatus-bridges
*/
static int
handle_get_networkstatus_bridges(dir_connection_t *conn,
const get_handler_args_t *args)
{
const char *headers = args->headers;
const or_options_t *options = get_options();
if (options->BridgeAuthoritativeDir &&
options->BridgePassword_AuthDigest_ &&
connection_dir_is_encrypted(conn)) {
char *status;
char digest[DIGEST256_LEN];
char *header = http_get_header(headers, "Authorization: Basic ");
if (header)
crypto_digest256(digest, header, strlen(header), DIGEST_SHA256);
/* now make sure the password is there and right */
if (!header ||
tor_memneq(digest,
options->BridgePassword_AuthDigest_, DIGEST256_LEN)) {
write_http_status_line(conn, 404, "Not found");
tor_free(header);
goto done;
}
tor_free(header);
/* all happy now. send an answer. */
status = networkstatus_getinfo_by_purpose("bridge", time(NULL));
size_t dlen = strlen(status);
write_http_response_header(conn, dlen, NO_METHOD, 0);
connection_write_to_buf(status, dlen, TO_CONN(conn));
tor_free(status);
goto done;
}
done:
return 0;
}
/** Helper function for GET robots.txt or /tor/robots.txt */
static int
handle_get_robots(dir_connection_t *conn, const get_handler_args_t *args)
{
(void)args;
{
const char robots[] = "User-agent: *\r\nDisallow: /\r\n";
size_t len = strlen(robots);
write_http_response_header(conn, len, NO_METHOD, ROBOTS_CACHE_LIFETIME);
connection_write_to_buf(robots, len, TO_CONN(conn));
}
return 0;
}
/* Given the <b>url</b> from a POST request, try to extract the version number
* using the provided <b>prefix</b>. The version should be after the prefix and
* ending with the seperator "/". For instance:
* /tor/hs/3/publish
*
* On success, <b>end_pos</b> points to the position right after the version
* was found. On error, it is set to NULL.
*
* Return version on success else negative value. */
STATIC int
parse_hs_version_from_post(const char *url, const char *prefix,
const char **end_pos)
{
int ok;
unsigned long version;
const char *start;
char *end = NULL;
tor_assert(url);
tor_assert(prefix);
tor_assert(end_pos);
/* Check if the prefix does start the url. */
if (strcmpstart(url, prefix)) {
goto err;
}
/* Move pointer to the end of the prefix string. */
start = url + strlen(prefix);
/* Try this to be the HS version and if we are still at the separator, next
* will be move to the right value. */
version = tor_parse_long(start, 10, 0, INT_MAX, &ok, &end);
if (!ok) {
goto err;
}
*end_pos = end;
return (int) version;
err:
*end_pos = NULL;
return -1;
}
/* Handle the POST request for a hidden service descripror. The request is in
* <b>url</b>, the body of the request is in <b>body</b>. Return 200 on success
* else return 400 indicating a bad request. */
STATIC int
handle_post_hs_descriptor(const char *url, const char *body)
{
int version;
const char *end_pos;
tor_assert(url);
tor_assert(body);
version = parse_hs_version_from_post(url, "/tor/hs/", &end_pos);
if (version < 0) {
goto err;
}
/* We have a valid version number, now make sure it's a publish request. Use
* the end position just after the version and check for the command. */
if (strcmpstart(end_pos, "/publish")) {
goto err;
}
switch (version) {
case HS_VERSION_THREE:
if (hs_cache_store_as_dir(body) < 0) {
goto err;
}
log_info(LD_REND, "Publish request for HS descriptor handled "
"successfully.");
break;
default:
/* Unsupported version, return a bad request. */
goto err;
}
return 200;
err:
/* Bad request. */
return 400;
}
/** Helper function: called when a dirserver gets a complete HTTP POST
* request. Look for an uploaded server descriptor or rendezvous
* service descriptor. On finding one, process it and write a
* response into conn-\>outbuf. If the request is unrecognized, send a
* 400. Always return 0. */
MOCK_IMPL(STATIC int,
directory_handle_command_post,(dir_connection_t *conn, const char *headers,
const char *body, size_t body_len))
{
char *url = NULL;
const or_options_t *options = get_options();
log_debug(LD_DIRSERV,"Received POST command.");
conn->base_.state = DIR_CONN_STATE_SERVER_WRITING;
if (!public_server_mode(options)) {
log_info(LD_DIR, "Rejected dir post request from %s "
"since we're not a public relay.", conn->base_.address);
write_http_status_line(conn, 503, "Not acting as a public relay");
goto done;
}
if (parse_http_url(headers, &url) < 0) {
write_http_status_line(conn, 400, "Bad request");
return 0;
}
log_debug(LD_DIRSERV,"rewritten url as '%s'.", escaped(url));
/* Handle v2 rendezvous service publish request. */
if (connection_dir_is_encrypted(conn) &&
!strcmpstart(url,"/tor/rendezvous2/publish")) {
if (rend_cache_store_v2_desc_as_dir(body) < 0) {
log_warn(LD_REND, "Rejected v2 rend descriptor (body size %d) from %s.",
(int)body_len, conn->base_.address);
write_http_status_line(conn, 400,
"Invalid v2 service descriptor rejected");
} else {
write_http_status_line(conn, 200, "Service descriptor (v2) stored");
log_info(LD_REND, "Handled v2 rendezvous descriptor post: accepted");
}
goto done;
}
/* Handle HS descriptor publish request. */
/* XXX: This should be disabled with a consensus param until we want to
* the prop224 be deployed and thus use. */
if (connection_dir_is_encrypted(conn) && !strcmpstart(url, "/tor/hs/")) {
const char *msg = "HS descriptor stored successfully.";
/* We most probably have a publish request for an HS descriptor. */
int code = handle_post_hs_descriptor(url, body);
if (code != 200) {
msg = "Invalid HS descriptor. Rejected.";
}
write_http_status_line(conn, code, msg);
goto done;
}
if (!authdir_mode(options)) {
/* we just provide cached directories; we don't want to
* receive anything. */
write_http_status_line(conn, 400, "Nonauthoritative directory does not "
"accept posted server descriptors");
goto done;
}
if (authdir_mode_handles_descs(options, -1) &&
!strcmp(url,"/tor/")) { /* server descriptor post */
const char *msg = "[None]";
uint8_t purpose = authdir_mode_bridge(options) ?
ROUTER_PURPOSE_BRIDGE : ROUTER_PURPOSE_GENERAL;
was_router_added_t r = dirserv_add_multiple_descriptors(body, purpose,
conn->base_.address, &msg);
tor_assert(msg);
if (r == ROUTER_ADDED_SUCCESSFULLY) {
write_http_status_line(conn, 200, msg);
} else if (WRA_WAS_OUTDATED(r)) {
write_http_response_header_impl(conn, -1, NULL, NULL,
"X-Descriptor-Not-New: Yes\r\n", -1);
} else {
log_info(LD_DIRSERV,
"Rejected router descriptor or extra-info from %s "
"(\"%s\").",
conn->base_.address, msg);
write_http_status_line(conn, 400, msg);
}
goto done;
}
if (authdir_mode_v3(options) &&
!strcmp(url,"/tor/post/vote")) { /* v3 networkstatus vote */
const char *msg = "OK";
int status;
if (dirvote_add_vote(body, &msg, &status)) {
write_http_status_line(conn, status, "Vote stored");
} else {
tor_assert(msg);
log_warn(LD_DIRSERV, "Rejected vote from %s (\"%s\").",
conn->base_.address, msg);
write_http_status_line(conn, status, msg);
}
goto done;
}
if (authdir_mode_v3(options) &&
!strcmp(url,"/tor/post/consensus-signature")) { /* sigs on consensus. */
const char *msg = NULL;
if (dirvote_add_signatures(body, conn->base_.address, &msg)>=0) {
write_http_status_line(conn, 200, msg?msg:"Signatures stored");
} else {
log_warn(LD_DIR, "Unable to store signatures posted by %s: %s",
conn->base_.address, msg?msg:"???");
write_http_status_line(conn, 400, msg?msg:"Unable to store signatures");
}
goto done;
}
/* we didn't recognize the url */
write_http_status_line(conn, 404, "Not found");
done:
tor_free(url);
return 0;
}
/** Called when a dirserver receives data on a directory connection;
* looks for an HTTP request. If the request is complete, remove it
* from the inbuf, try to process it; otherwise, leave it on the
* buffer. Return a 0 on success, or -1 on error.
*/
STATIC int
directory_handle_command(dir_connection_t *conn)
{
char *headers=NULL, *body=NULL;
size_t body_len=0;
int r;
tor_assert(conn);
tor_assert(conn->base_.type == CONN_TYPE_DIR);
switch (connection_fetch_from_buf_http(TO_CONN(conn),
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_DIR_UL_SIZE, 0)) {
case -1: /* overflow */
log_warn(LD_DIRSERV,
"Request too large from address '%s' to DirPort. Closing.",
safe_str(conn->base_.address));
return -1;
case 0:
log_debug(LD_DIRSERV,"command not all here yet.");
return 0;
/* case 1, fall through */
}
http_set_address_origin(headers, TO_CONN(conn));
// we should escape headers here as well,
// but we can't call escaped() twice, as it uses the same buffer
//log_debug(LD_DIRSERV,"headers %s, body %s.", headers, escaped(body));
if (!strncasecmp(headers,"GET",3))
r = directory_handle_command_get(conn, headers, body, body_len);
else if (!strncasecmp(headers,"POST",4))
r = directory_handle_command_post(conn, headers, body, body_len);
else {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Got headers %s with unknown command. Closing.",
escaped(headers));
r = -1;
}
tor_free(headers); tor_free(body);
return r;
}
/** Write handler for directory connections; called when all data has
* been flushed. Close the connection or wait for a response as
* appropriate.
*/
int
connection_dir_finished_flushing(dir_connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->base_.type == CONN_TYPE_DIR);
/* Note that we have finished writing the directory response. For direct
* connections this means we're done; for tunneled connections it's only
* an intermediate step. */
if (conn->dirreq_id)
geoip_change_dirreq_state(conn->dirreq_id, DIRREQ_TUNNELED,
DIRREQ_FLUSHING_DIR_CONN_FINISHED);
else
geoip_change_dirreq_state(TO_CONN(conn)->global_identifier,
DIRREQ_DIRECT,
DIRREQ_FLUSHING_DIR_CONN_FINISHED);
switch (conn->base_.state) {
case DIR_CONN_STATE_CONNECTING:
case DIR_CONN_STATE_CLIENT_SENDING:
log_debug(LD_DIR,"client finished sending command.");
conn->base_.state = DIR_CONN_STATE_CLIENT_READING;
return 0;
case DIR_CONN_STATE_SERVER_WRITING:
if (conn->spool) {
log_warn(LD_BUG, "Emptied a dirserv buffer, but it's still spooling!");
connection_mark_for_close(TO_CONN(conn));
} else {
log_debug(LD_DIRSERV, "Finished writing server response. Closing.");
connection_mark_for_close(TO_CONN(conn));
}
return 0;
default:
log_warn(LD_BUG,"called in unexpected state %d.",
conn->base_.state);
tor_fragile_assert();
return -1;
}
return 0;
}
/* We just got a new consensus! If there are other in-progress requests
* for this consensus flavor (for example because we launched several in
* parallel), cancel them.
*
* We do this check here (not just in
* connection_ap_handshake_attach_circuit()) to handle the edge case where
* a consensus fetch begins and ends before some other one tries to attach to
* a circuit, in which case the other one won't know that we're all happy now.
*
* Don't mark the conn that just gave us the consensus -- otherwise we
* would end up double-marking it when it cleans itself up.
*/
static void
connection_dir_close_consensus_fetches(dir_connection_t *except_this_one,
const char *resource)
{
smartlist_t *conns_to_close =
connection_dir_list_by_purpose_and_resource(DIR_PURPOSE_FETCH_CONSENSUS,
resource);
SMARTLIST_FOREACH_BEGIN(conns_to_close, dir_connection_t *, d) {
if (d == except_this_one)
continue;
log_info(LD_DIR, "Closing consensus fetch (to %s) since one "
"has just arrived.", TO_CONN(d)->address);
connection_mark_for_close(TO_CONN(d));
} SMARTLIST_FOREACH_END(d);
smartlist_free(conns_to_close);
}
/** Connected handler for directory connections: begin sending data to the
* server, and return 0.
* Only used when connections don't immediately connect. */
int
connection_dir_finished_connecting(dir_connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->base_.type == CONN_TYPE_DIR);
tor_assert(conn->base_.state == DIR_CONN_STATE_CONNECTING);
log_debug(LD_HTTP,"Dir connection to router %s:%u established.",
conn->base_.address,conn->base_.port);
/* start flushing conn */
conn->base_.state = DIR_CONN_STATE_CLIENT_SENDING;
return 0;
}
/** Decide which download schedule we want to use based on descriptor type
* in <b>dls</b> and <b>options</b>.
* Then return a list of int pointers defining download delays in seconds.
* Helper function for download_status_increment_failure(),
* download_status_reset(), and download_status_increment_attempt(). */
STATIC const smartlist_t *
find_dl_schedule(download_status_t *dls, const or_options_t *options)
{
const int dir_server = dir_server_mode(options);
const int multi_d = networkstatus_consensus_can_use_multiple_directories(
options);
const int we_are_bootstrapping = networkstatus_consensus_is_bootstrapping(
time(NULL));
const int use_fallbacks = networkstatus_consensus_can_use_extra_fallbacks(
options);
switch (dls->schedule) {
case DL_SCHED_GENERIC:
if (dir_server) {
return options->TestingServerDownloadSchedule;
} else {
return options->TestingClientDownloadSchedule;
}
case DL_SCHED_CONSENSUS:
if (!multi_d) {
return options->TestingServerConsensusDownloadSchedule;
} else {
if (we_are_bootstrapping) {
if (!use_fallbacks) {
/* A bootstrapping client without extra fallback directories */
return
options->ClientBootstrapConsensusAuthorityOnlyDownloadSchedule;
} else if (dls->want_authority) {
/* A bootstrapping client with extra fallback directories, but
* connecting to an authority */
return
options->ClientBootstrapConsensusAuthorityDownloadSchedule;
} else {
/* A bootstrapping client connecting to extra fallback directories
*/
return
options->ClientBootstrapConsensusFallbackDownloadSchedule;
}
} else {
return options->TestingClientConsensusDownloadSchedule;
}
}
case DL_SCHED_BRIDGE:
return options->TestingBridgeDownloadSchedule;
default:
tor_assert(0);
}
/* Impossible, but gcc will fail with -Werror without a `return`. */
return NULL;
}
/** Decide which minimum and maximum delay step we want to use based on
* descriptor type in <b>dls</b> and <b>options</b>.
* Helper function for download_status_schedule_get_delay(). */
STATIC void
find_dl_min_and_max_delay(download_status_t *dls, const or_options_t *options,
int *min, int *max)
{
tor_assert(dls);
tor_assert(options);
tor_assert(min);
tor_assert(max);
/*
* For now, just use the existing schedule config stuff and pick the
* first/last entries off to get min/max delay for backoff purposes
*/
const smartlist_t *schedule = find_dl_schedule(dls, options);
tor_assert(schedule != NULL && smartlist_len(schedule) >= 2);
*min = *((int *)(smartlist_get(schedule, 0)));
if (dls->backoff == DL_SCHED_DETERMINISTIC)
*max = *((int *)((smartlist_get(schedule, smartlist_len(schedule) - 1))));
else
*max = INT_MAX;
}
/** Advance one delay step. The algorithm is to use the previous delay to
* compute an increment, we construct a value uniformly at random between
* delay and MAX(delay*2,delay+1). We then clamp that value to be no larger
* than max_delay, and return it.
*
* Requires that delay is less than INT_MAX, and delay is in [0,max_delay].
*/
STATIC int
next_random_exponential_delay(int delay, int max_delay)
{
/* Check preconditions */
if (BUG(max_delay < 0))
max_delay = 0;
if (BUG(delay > max_delay))
delay = max_delay;
if (delay == INT_MAX)
return INT_MAX; /* prevent overflow */
if (BUG(delay < 0))
delay = 0;
/* How much are we willing to add to the delay? */
int max_increment;
int multiplier = 3; /* no more than quadruple the previous delay */
if (get_options()->TestingTorNetwork) {
/* Decrease the multiplier in testing networks. This reduces the variance,
* so that bootstrap is more reliable. */
multiplier = 2; /* no more than triple the previous delay */
}
if (delay && delay < (INT_MAX-1) / multiplier) {
max_increment = delay * multiplier;
} else if (delay) {
max_increment = INT_MAX-1;
} else {
max_increment = 1;
}
if (BUG(max_increment < 1))
max_increment = 1;
/* the + 1 here is so that we always wait longer than last time. */
int increment = crypto_rand_int(max_increment)+1;
if (increment < max_delay - delay)
return delay + increment;
else
return max_delay;
}
/** Find the current delay for dls based on schedule or min_delay/
* max_delay if we're using exponential backoff. If dls->backoff is
* DL_SCHED_RANDOM_EXPONENTIAL, we must have 0 <= min_delay <= max_delay <=
* INT_MAX, but schedule may be set to NULL; otherwise schedule is required.
* This function sets dls->next_attempt_at based on now, and returns the delay.
* Helper for download_status_increment_failure and
* download_status_increment_attempt. */
STATIC int
download_status_schedule_get_delay(download_status_t *dls,
const smartlist_t *schedule,
int min_delay, int max_delay,
time_t now)
{
tor_assert(dls);
/* We don't need a schedule if we're using random exponential backoff */
tor_assert(dls->backoff == DL_SCHED_RANDOM_EXPONENTIAL ||
schedule != NULL);
/* If we're using random exponential backoff, we do need min/max delay */
tor_assert(dls->backoff != DL_SCHED_RANDOM_EXPONENTIAL ||
(min_delay >= 0 && max_delay >= min_delay));
int delay = INT_MAX;
uint8_t dls_schedule_position = (dls->increment_on
== DL_SCHED_INCREMENT_ATTEMPT
? dls->n_download_attempts
: dls->n_download_failures);
if (dls->backoff == DL_SCHED_DETERMINISTIC) {
if (dls_schedule_position < smartlist_len(schedule))
delay = *(int *)smartlist_get(schedule, dls_schedule_position);
else if (dls_schedule_position == IMPOSSIBLE_TO_DOWNLOAD)
delay = INT_MAX;
else
delay = *(int *)smartlist_get(schedule, smartlist_len(schedule) - 1);
} else if (dls->backoff == DL_SCHED_RANDOM_EXPONENTIAL) {
/* Check if we missed a reset somehow */
IF_BUG_ONCE(dls->last_backoff_position > dls_schedule_position) {
dls->last_backoff_position = 0;
dls->last_delay_used = 0;
}
if (dls_schedule_position > 0) {
delay = dls->last_delay_used;
while (dls->last_backoff_position < dls_schedule_position) {
/* Do one increment step */
delay = next_random_exponential_delay(delay, max_delay);
/* Update our position */
++(dls->last_backoff_position);
}
} else {
/* If we're just starting out, use the minimum delay */
delay = min_delay;
}
/* Clamp it within min/max if we have them */
if (min_delay >= 0 && delay < min_delay) delay = min_delay;
if (max_delay != INT_MAX && delay > max_delay) delay = max_delay;
/* Store it for next time */
dls->last_backoff_position = dls_schedule_position;
dls->last_delay_used = delay;
}
/* A negative delay makes no sense. Knowing that delay is
* non-negative allows us to safely do the wrapping check below. */
tor_assert(delay >= 0);
/* Avoid now+delay overflowing TIME_MAX, by comparing with a subtraction
* that won't overflow (since delay is non-negative). */
if (delay < INT_MAX && now <= TIME_MAX - delay) {
dls->next_attempt_at = now+delay;
} else {
dls->next_attempt_at = TIME_MAX;
}
return delay;
}
/* Log a debug message about item, which increments on increment_action, has
* incremented dls_n_download_increments times. The message varies based on
* was_schedule_incremented (if not, not_incremented_response is logged), and
* the values of increment, dls_next_attempt_at, and now.
* Helper for download_status_increment_failure and
* download_status_increment_attempt. */
static void
download_status_log_helper(const char *item, int was_schedule_incremented,
const char *increment_action,
const char *not_incremented_response,
uint8_t dls_n_download_increments, int increment,
time_t dls_next_attempt_at, time_t now)
{
if (item) {
if (!was_schedule_incremented)
log_debug(LD_DIR, "%s %s %d time(s); I'll try again %s.",
item, increment_action, (int)dls_n_download_increments,
not_incremented_response);
else if (increment == 0)
log_debug(LD_DIR, "%s %s %d time(s); I'll try again immediately.",
item, increment_action, (int)dls_n_download_increments);
else if (dls_next_attempt_at < TIME_MAX)
log_debug(LD_DIR, "%s %s %d time(s); I'll try again in %d seconds.",
item, increment_action, (int)dls_n_download_increments,
(int)(dls_next_attempt_at-now));
else
log_debug(LD_DIR, "%s %s %d time(s); Giving up for a while.",
item, increment_action, (int)dls_n_download_increments);
}
}
/** Determine when a failed download attempt should be retried.
* Called when an attempt to download <b>dls</b> has failed with HTTP status
* <b>status_code</b>. Increment the failure count (if the code indicates a
* real failure, or if we're a server) and set <b>dls</b>-\>next_attempt_at to
* an appropriate time in the future and return it.
* If <b>dls->increment_on</b> is DL_SCHED_INCREMENT_ATTEMPT, increment the
* failure count, and return a time in the far future for the next attempt (to
* avoid an immediate retry). */
time_t
download_status_increment_failure(download_status_t *dls, int status_code,
const char *item, int server, time_t now)
{
(void) status_code; // XXXX no longer used.
(void) server; // XXXX no longer used.
int increment = -1;
int min_delay = 0, max_delay = INT_MAX;
tor_assert(dls);
/* count the failure */
if (dls->n_download_failures < IMPOSSIBLE_TO_DOWNLOAD-1) {
++dls->n_download_failures;
}
if (dls->increment_on == DL_SCHED_INCREMENT_FAILURE) {
/* We don't find out that a failure-based schedule has attempted a
* connection until that connection fails.
* We'll never find out about successful connections, but this doesn't
* matter, because schedules are reset after a successful download.
*/
if (dls->n_download_attempts < IMPOSSIBLE_TO_DOWNLOAD-1)
++dls->n_download_attempts;
/* only return a failure retry time if this schedule increments on failures
*/
const smartlist_t *schedule = find_dl_schedule(dls, get_options());
find_dl_min_and_max_delay(dls, get_options(), &min_delay, &max_delay);
increment = download_status_schedule_get_delay(dls, schedule,
min_delay, max_delay, now);
}
download_status_log_helper(item, !dls->increment_on, "failed",
"concurrently", dls->n_download_failures,
increment, dls->next_attempt_at, now);
if (dls->increment_on == DL_SCHED_INCREMENT_ATTEMPT) {
/* stop this schedule retrying on failure, it will launch concurrent
* connections instead */
return TIME_MAX;
} else {
return dls->next_attempt_at;
}
}
/** Determine when the next download attempt should be made when using an
* attempt-based (potentially concurrent) download schedule.
* Called when an attempt to download <b>dls</b> is being initiated.
* Increment the attempt count and set <b>dls</b>-\>next_attempt_at to an
* appropriate time in the future and return it.
* If <b>dls->increment_on</b> is DL_SCHED_INCREMENT_FAILURE, don't increment
* the attempts, and return a time in the far future (to avoid launching a
* concurrent attempt). */
time_t
download_status_increment_attempt(download_status_t *dls, const char *item,
time_t now)
{
int delay = -1;
int min_delay = 0, max_delay = INT_MAX;
tor_assert(dls);
if (dls->increment_on == DL_SCHED_INCREMENT_FAILURE) {
/* this schedule should retry on failure, and not launch any concurrent
attempts */
log_warn(LD_BUG, "Tried to launch an attempt-based connection on a "
"failure-based schedule.");
return TIME_MAX;
}
if (dls->n_download_attempts < IMPOSSIBLE_TO_DOWNLOAD-1)
++dls->n_download_attempts;
const smartlist_t *schedule = find_dl_schedule(dls, get_options());
find_dl_min_and_max_delay(dls, get_options(), &min_delay, &max_delay);
delay = download_status_schedule_get_delay(dls, schedule,
min_delay, max_delay, now);
download_status_log_helper(item, dls->increment_on, "attempted",
"on failure", dls->n_download_attempts,
delay, dls->next_attempt_at, now);
return dls->next_attempt_at;
}
/** Reset <b>dls</b> so that it will be considered downloadable
* immediately, and/or to show that we don't need it anymore.
*
* Must be called to initialise a download schedule, otherwise the zeroth item
* in the schedule will never be used.
*
* (We find the zeroth element of the download schedule, and set
* next_attempt_at to be the appropriate offset from 'now'. In most
* cases this means setting it to 'now', so the item will be immediately
* downloadable; in the case of bridge descriptors, the zeroth element
* is an hour from now.) */
void
download_status_reset(download_status_t *dls)
{
if (dls->n_download_failures == IMPOSSIBLE_TO_DOWNLOAD
|| dls->n_download_attempts == IMPOSSIBLE_TO_DOWNLOAD)
return; /* Don't reset this. */
const smartlist_t *schedule = find_dl_schedule(dls, get_options());
dls->n_download_failures = 0;
dls->n_download_attempts = 0;
dls->next_attempt_at = time(NULL) + *(int *)smartlist_get(schedule, 0);
dls->last_backoff_position = 0;
dls->last_delay_used = 0;
/* Don't reset dls->want_authority or dls->increment_on */
}
/** Return the number of failures on <b>dls</b> since the last success (if
* any). */
int
download_status_get_n_failures(const download_status_t *dls)
{
return dls->n_download_failures;
}
/** Return the number of attempts to download <b>dls</b> since the last success
* (if any). This can differ from download_status_get_n_failures() due to
* outstanding concurrent attempts. */
int
download_status_get_n_attempts(const download_status_t *dls)
{
return dls->n_download_attempts;
}
/** Return the next time to attempt to download <b>dls</b>. */
time_t
download_status_get_next_attempt_at(const download_status_t *dls)
{
return dls->next_attempt_at;
}
/** Called when one or more routerdesc (or extrainfo, if <b>was_extrainfo</b>)
* fetches have failed (with uppercase fingerprints listed in <b>failed</b>,
* either as descriptor digests or as identity digests based on
* <b>was_descriptor_digests</b>).
*/
static void
dir_routerdesc_download_failed(smartlist_t *failed, int status_code,
int router_purpose,
int was_extrainfo, int was_descriptor_digests)
{
char digest[DIGEST_LEN];
time_t now = time(NULL);
int server = directory_fetches_from_authorities(get_options());
if (!was_descriptor_digests) {
if (router_purpose == ROUTER_PURPOSE_BRIDGE) {
tor_assert(!was_extrainfo);
connection_dir_retry_bridges(failed);
}
return; /* FFFF should implement for other-than-router-purpose someday */
}
SMARTLIST_FOREACH_BEGIN(failed, const char *, cp) {
download_status_t *dls = NULL;
if (base16_decode(digest, DIGEST_LEN, cp, strlen(cp)) != DIGEST_LEN) {
log_warn(LD_BUG, "Malformed fingerprint in list: %s", escaped(cp));
continue;
}
if (was_extrainfo) {
signed_descriptor_t *sd =
router_get_by_extrainfo_digest(digest);
if (sd)
dls = &sd->ei_dl_status;
} else {
dls = router_get_dl_status_by_descriptor_digest(digest);
}
if (!dls || dls->n_download_failures >=
get_options()->TestingDescriptorMaxDownloadTries)
continue;
download_status_increment_failure(dls, status_code, cp, server, now);
} SMARTLIST_FOREACH_END(cp);
/* No need to relaunch descriptor downloads here: we already do it
* every 10 or 60 seconds (FOO_DESCRIPTOR_RETRY_INTERVAL) in main.c. */
}
/** Called when a connection to download microdescriptors has failed in whole
* or in part. <b>failed</b> is a list of every microdesc digest we didn't
* get. <b>status_code</b> is the http status code we received. Reschedule the
* microdesc downloads as appropriate. */
static void
dir_microdesc_download_failed(smartlist_t *failed,
int status_code)
{
networkstatus_t *consensus
= networkstatus_get_latest_consensus_by_flavor(FLAV_MICRODESC);
routerstatus_t *rs;
download_status_t *dls;
time_t now = time(NULL);
int server = directory_fetches_from_authorities(get_options());
if (! consensus)
return;
SMARTLIST_FOREACH_BEGIN(failed, const char *, d) {
rs = router_get_mutable_consensus_status_by_descriptor_digest(consensus,d);
if (!rs)
continue;
dls = &rs->dl_status;
if (dls->n_download_failures >=
get_options()->TestingMicrodescMaxDownloadTries)
continue;
{
char buf[BASE64_DIGEST256_LEN+1];
digest256_to_base64(buf, d);
download_status_increment_failure(dls, status_code, buf,
server, now);
}
} SMARTLIST_FOREACH_END(d);
}
/** Helper. Compare two fp_pair_t objects, and return negative, 0, or
* positive as appropriate. */
static int
compare_pairs_(const void **a, const void **b)
{
const fp_pair_t *fp1 = *a, *fp2 = *b;
int r;
if ((r = fast_memcmp(fp1->first, fp2->first, DIGEST_LEN)))
return r;
else
return fast_memcmp(fp1->second, fp2->second, DIGEST_LEN);
}
/** Divide a string <b>res</b> of the form FP1-FP2+FP3-FP4...[.z], where each
* FP is a hex-encoded fingerprint, into a sequence of distinct sorted
* fp_pair_t. Skip malformed pairs. On success, return 0 and add those
* fp_pair_t into <b>pairs_out</b>. On failure, return -1. */
int
dir_split_resource_into_fingerprint_pairs(const char *res,
smartlist_t *pairs_out)
{
smartlist_t *pairs_tmp = smartlist_new();
smartlist_t *pairs_result = smartlist_new();
smartlist_split_string(pairs_tmp, res, "+", 0, 0);
if (smartlist_len(pairs_tmp)) {
char *last = smartlist_get(pairs_tmp,smartlist_len(pairs_tmp)-1);
size_t last_len = strlen(last);
if (last_len > 2 && !strcmp(last+last_len-2, ".z")) {
last[last_len-2] = '\0';
}
}
SMARTLIST_FOREACH_BEGIN(pairs_tmp, char *, cp) {
if (strlen(cp) != HEX_DIGEST_LEN*2+1) {
log_info(LD_DIR,
"Skipping digest pair %s with non-standard length.", escaped(cp));
} else if (cp[HEX_DIGEST_LEN] != '-') {
log_info(LD_DIR,
"Skipping digest pair %s with missing dash.", escaped(cp));
} else {
fp_pair_t pair;
if (base16_decode(pair.first, DIGEST_LEN,
cp, HEX_DIGEST_LEN) != DIGEST_LEN ||
base16_decode(pair.second,DIGEST_LEN,
cp+HEX_DIGEST_LEN+1, HEX_DIGEST_LEN) != DIGEST_LEN) {
log_info(LD_DIR, "Skipping non-decodable digest pair %s", escaped(cp));
} else {
smartlist_add(pairs_result, tor_memdup(&pair, sizeof(pair)));
}
}
tor_free(cp);
} SMARTLIST_FOREACH_END(cp);
smartlist_free(pairs_tmp);
/* Uniq-and-sort */
smartlist_sort(pairs_result, compare_pairs_);
smartlist_uniq(pairs_result, compare_pairs_, tor_free_);
smartlist_add_all(pairs_out, pairs_result);
smartlist_free(pairs_result);
return 0;
}
/** Given a directory <b>resource</b> request, containing zero
* or more strings separated by plus signs, followed optionally by ".z", store
* the strings, in order, into <b>fp_out</b>. If <b>compressed_out</b> is
* non-NULL, set it to 1 if the resource ends in ".z", else set it to 0.
*
* If (flags & DSR_HEX), then delete all elements that aren't hex digests, and
* decode the rest. If (flags & DSR_BASE64), then use "-" rather than "+" as
* a separator, delete all the elements that aren't base64-encoded digests,
* and decode the rest. If (flags & DSR_DIGEST256), these digests should be
* 256 bits long; else they should be 160.
*
* If (flags & DSR_SORT_UNIQ), then sort the list and remove all duplicates.
*/
int
dir_split_resource_into_fingerprints(const char *resource,
smartlist_t *fp_out, int *compressed_out,
int flags)
{
const int decode_hex = flags & DSR_HEX;
const int decode_base64 = flags & DSR_BASE64;
const int digests_are_256 = flags & DSR_DIGEST256;
const int sort_uniq = flags & DSR_SORT_UNIQ;
const int digest_len = digests_are_256 ? DIGEST256_LEN : DIGEST_LEN;
const int hex_digest_len = digests_are_256 ?
HEX_DIGEST256_LEN : HEX_DIGEST_LEN;
const int base64_digest_len = digests_are_256 ?
BASE64_DIGEST256_LEN : BASE64_DIGEST_LEN;
smartlist_t *fp_tmp = smartlist_new();
tor_assert(!(decode_hex && decode_base64));
tor_assert(fp_out);
smartlist_split_string(fp_tmp, resource, decode_base64?"-":"+", 0, 0);
if (compressed_out)
*compressed_out = 0;
if (smartlist_len(fp_tmp)) {
char *last = smartlist_get(fp_tmp,smartlist_len(fp_tmp)-1);
size_t last_len = strlen(last);
if (last_len > 2 && !strcmp(last+last_len-2, ".z")) {
last[last_len-2] = '\0';
if (compressed_out)
*compressed_out = 1;
}
}
if (decode_hex || decode_base64) {
const size_t encoded_len = decode_hex ? hex_digest_len : base64_digest_len;
int i;
char *cp, *d = NULL;
for (i = 0; i < smartlist_len(fp_tmp); ++i) {
cp = smartlist_get(fp_tmp, i);
if (strlen(cp) != encoded_len) {
log_info(LD_DIR,
"Skipping digest %s with non-standard length.", escaped(cp));
smartlist_del_keeporder(fp_tmp, i--);
goto again;
}
d = tor_malloc_zero(digest_len);
if (decode_hex ?
(base16_decode(d, digest_len, cp, hex_digest_len) != digest_len) :
(base64_decode(d, digest_len, cp, base64_digest_len)
!= digest_len)) {
log_info(LD_DIR, "Skipping non-decodable digest %s", escaped(cp));
smartlist_del_keeporder(fp_tmp, i--);
goto again;
}
smartlist_set(fp_tmp, i, d);
d = NULL;
again:
tor_free(cp);
tor_free(d);
}
}
if (sort_uniq) {
if (decode_hex || decode_base64) {
if (digests_are_256) {
smartlist_sort_digests256(fp_tmp);
smartlist_uniq_digests256(fp_tmp);
} else {
smartlist_sort_digests(fp_tmp);
smartlist_uniq_digests(fp_tmp);
}
} else {
smartlist_sort_strings(fp_tmp);
smartlist_uniq_strings(fp_tmp);
}
}
smartlist_add_all(fp_out, fp_tmp);
smartlist_free(fp_tmp);
return 0;
}
/** As dir_split_resource_into_fingerprints, but instead fills
* <b>spool_out</b> with a list of spoolable_resource_t for the resource
* identified through <b>source</b>. */
int
dir_split_resource_into_spoolable(const char *resource,
dir_spool_source_t source,
smartlist_t *spool_out,
int *compressed_out,
int flags)
{
smartlist_t *fingerprints = smartlist_new();
tor_assert(flags & (DSR_HEX|DSR_BASE64));
const size_t digest_len =
(flags & DSR_DIGEST256) ? DIGEST256_LEN : DIGEST_LEN;
int r = dir_split_resource_into_fingerprints(resource, fingerprints,
compressed_out, flags);
/* This is not a very efficient implementation XXXX */
SMARTLIST_FOREACH_BEGIN(fingerprints, uint8_t *, digest) {
spooled_resource_t *spooled =
spooled_resource_new(source, digest, digest_len);
if (spooled)
smartlist_add(spool_out, spooled);
tor_free(digest);
} SMARTLIST_FOREACH_END(digest);
smartlist_free(fingerprints);
return r;
}
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