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77f52e3467
tor/src/or/directory.c
Roger Dingledine 77f52e3467 fix some logs and comments 
svn:r4864
2005-08-26 21:55:38 +00:00

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/* Copyright 2001-2004 Roger Dingledine.
* Copyright 2004-2005 Roger Dingledine, Nick Mathewson. */
/* See LICENSE for licensing information */
/* $Id$ */
const char directory_c_id[] = "$Id$";
#include "or.h"
/**
* \file directory.c
* \brief Code to send and fetch directories and router
* descriptors via HTTP. Directories use dirserv.c to generate the
* results; clients use routers.c to parse them.
**/
/* 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_initiate_command_trusted_dir(trusted_dir_server_t *dirserv,
uint8_t purpose, int private_connection,
const char *resource,
const char *payload, size_t payload_len);
static void
directory_initiate_command(const char *address, uint32_t addr, uint16_t port,
const char *platform,
const char *digest, uint8_t purpose,
int private_connection, const char *resource,
const char *payload, size_t payload_len);
static void
directory_send_command(connection_t *conn, const char *platform,
int purpose, const char *resource,
const char *payload, size_t payload_len);
static int directory_handle_command(connection_t *conn);
static int body_is_plausible(const char *body, size_t body_len, int purpose);
static int purpose_is_private(uint8_t purpose);
static char *http_get_header(const char *headers, const char *which);
static char *http_get_origin(const char *headers, connection_t *conn);
/********* START VARIABLES **********/
static addr_policy_t *dir_policy = NULL;
#define ALLOW_DIRECTORY_TIME_SKEW 30*60 /* 30 minutes */
/********* END VARIABLES ************/
/** Parse get_options()->DirPolicy, and put the processed version in
* &dir_policy. Ignore port specifiers.
*/
void
parse_dir_policy(void)
{
addr_policy_t *n;
if (dir_policy) {
addr_policy_free(dir_policy);
dir_policy = NULL;
}
config_parse_addr_policy(get_options()->DirPolicy, &dir_policy, -1);
/* ports aren't used. */
for (n=dir_policy; n; n = n->next) {
n->prt_min = 1;
n->prt_max = 65535;
}
}
/** Free storage used to hold parsed directory policy */
void
free_dir_policy(void)
{
addr_policy_free(dir_policy);
dir_policy = NULL;
}
/** Return 1 if <b>addr</b> is permitted to connect to our dir port,
* based on <b>dir_policy</b>. Else return 0.
*/
int
dir_policy_permits_address(uint32_t addr)
{
int a;
if (!dir_policy) /* 'no dir policy' means 'accept' */
return 1;
a = router_compare_addr_to_addr_policy(addr, 1, dir_policy);
if (a==ADDR_POLICY_REJECTED)
return 0;
else if (a==ADDR_POLICY_ACCEPTED)
return 1;
log_fn(LOG_WARN, "Bug: got unexpected 'maybe' answer from dir policy");
return 0;
}
/** Return true iff the directory purpose 'purpose' must use an
* anonymous connection to a directory. */
static int
purpose_is_private(uint8_t purpose)
{
if (purpose == DIR_PURPOSE_FETCH_DIR ||
purpose == DIR_PURPOSE_UPLOAD_DIR ||
purpose == DIR_PURPOSE_FETCH_RUNNING_LIST)
return 0;
return 1;
}
/** Start a connection to every known directory server, using
* connection purpose 'purpose' and uploading the payload 'payload'
* (length 'payload_len'). The purpose should be one of
* 'DIR_PURPOSE_UPLOAD_DIR' or 'DIR_PURPOSE_UPLOAD_RENDDESC'.
*/
void
directory_post_to_dirservers(uint8_t purpose, const char *payload,
size_t payload_len)
{
smartlist_t *dirservers;
router_get_trusted_dir_servers(&dirservers);
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(dirservers, trusted_dir_server_t *, ds,
{
/* Pay attention to fascistfirewall when we're uploading a
* router descriptor, but not when uploading a service
* descriptor -- those use Tor. */
if (purpose == DIR_PURPOSE_UPLOAD_DIR && !get_options()->HttpProxy) {
if (!fascist_firewall_allows_address(ds->addr,ds->dir_port))
continue;
}
directory_initiate_command_trusted_dir(ds, purpose, purpose_is_private(purpose),
NULL, payload, payload_len);
});
}
/** Start a connection to a random running directory server, using
* connection purpose 'purpose' requesting 'resource'. The purpose
* should be one of 'DIR_PURPOSE_FETCH_DIR',
* 'DIR_PURPOSE_FETCH_RENDDESC', 'DIR_PURPOSE_FETCH_RUNNING_LIST.'
* If <b>retry_if_no_servers</b>, then if all the possible servers seem
* down, mark them up and try again.
*/
void
directory_get_from_dirserver(uint8_t purpose, const char *resource,
int retry_if_no_servers)
{
routerinfo_t *r = NULL;
trusted_dir_server_t *ds = NULL;
int fascistfirewall = firewall_is_fascist();
int directconn = purpose == DIR_PURPOSE_FETCH_DIR ||
purpose == DIR_PURPOSE_FETCH_RUNNING_LIST;
int fetch_fresh_first = advertised_server_mode();
int priv = purpose_is_private(purpose);
if (directconn) {
if (fetch_fresh_first) {
/* only ask authdirservers, and don't ask myself */
ds = router_pick_trusteddirserver(1, fascistfirewall,
retry_if_no_servers);
}
if (!ds) {
/* anybody with a non-zero dirport will do */
r = router_pick_directory_server(1, fascistfirewall,
purpose==DIR_PURPOSE_FETCH_RUNNING_LIST,
retry_if_no_servers);
if (!r) {
log_fn(LOG_INFO, "No router found for %s; falling back to dirserver list",
purpose == DIR_PURPOSE_FETCH_RUNNING_LIST
? "status list" : "directory");
ds = router_pick_trusteddirserver(1, fascistfirewall,
retry_if_no_servers);
}
}
} else { // (purpose == DIR_PURPOSE_FETCH_RENDDESC)
/* only ask authdirservers, any of them will do */
/* Never use fascistfirewall; we're going via Tor. */
ds = router_pick_trusteddirserver(0, 0, retry_if_no_servers);
}
if (r)
directory_initiate_command_router(r, purpose, priv, resource, NULL, 0);
else if (ds)
directory_initiate_command_trusted_dir(ds, purpose, priv, resource, NULL, 0);
else {
log_fn(LOG_NOTICE,"No running dirservers known. Will try again later. (purpose %d)",
purpose);
if (directconn) {
/* remember we tried them all and failed. */
directory_all_unreachable(time(NULL));
}
}
}
/** Launch a new connection to the directory server <b>router</b> to upload or
* download a service or rendezvous descriptor. <b>purpose</b> determines what
* kind of directory connection we're launching, and must be one of
* DIR_PURPOSE_{FETCH|UPLOAD}_{DIR|RENDDESC}.
*
* When uploading, <b>payload</b> and <b>payload_len</b> determine the content
* of the HTTP post. Otherwise, <b>payload</b> should be NULL.
*
* When fetching a rendezvous descriptor, <b>resource</b> is the service ID we
* want to fetch.
*/
void
directory_initiate_command_router(routerinfo_t *router, uint8_t purpose,
int private_connection, const char *resource,
const char *payload, size_t payload_len)
{
directory_initiate_command(router->address, router->addr, router->dir_port,
router->platform, router->identity_digest,
purpose, private_connection, resource,
payload, payload_len);
}
/** As directory_initiate_command_router, but send the command to a trusted
* directory server <b>dirserv</b>. **/
static void
directory_initiate_command_trusted_dir(trusted_dir_server_t *dirserv,
uint8_t purpose, int private_connection,
const char *resource,
const char *payload, size_t payload_len)
{
directory_initiate_command(dirserv->address, dirserv->addr,dirserv->dir_port,
NULL, dirserv->digest, purpose, private_connection, resource,
payload, payload_len);
}
/** Called when we are unable to complete our connection to a
* directory server: Mark the router as down and try again if possible.
*/
void
connection_dir_connect_failed(connection_t *conn)
{
router_mark_as_down(conn->identity_digest); /* don't try him again */
if (conn->purpose == DIR_PURPOSE_FETCH_DIR ||
conn->purpose == DIR_PURPOSE_FETCH_RUNNING_LIST) {
log_fn(LOG_INFO, "Giving up on directory server at '%s'; retrying",
conn->address);
directory_get_from_dirserver(conn->purpose, NULL,
0 /* don't retry_if_no_servers */);
}
}
/** Helper for directory_initiate_command_(router|trusted_dir): send the
* command to a server whose address is <b>address</b>, whose IP is
* <b>addr</b>, whose directory port is <b>dir_port</b>, whose tor version is
* <b>platform</b>, and whose identity key digest is <b>digest</b>. The
* <b>platform</b> argument is optional; the others are required. */
static void
directory_initiate_command(const char *address, uint32_t addr,
uint16_t dir_port, const char *platform,
const char *digest, uint8_t purpose,
int private_connection, const char *resource,
const char *payload, size_t payload_len)
{
connection_t *conn;
tor_assert(address);
tor_assert(addr);
tor_assert(dir_port);
tor_assert(digest);
switch (purpose) {
case DIR_PURPOSE_FETCH_DIR:
log_fn(LOG_DEBUG,"initiating directory fetch");
break;
case DIR_PURPOSE_FETCH_RENDDESC:
log_fn(LOG_DEBUG,"initiating hidden-service descriptor fetch");
break;
case DIR_PURPOSE_UPLOAD_DIR:
log_fn(LOG_DEBUG,"initiating server descriptor upload");
break;
case DIR_PURPOSE_UPLOAD_RENDDESC:
log_fn(LOG_DEBUG,"initiating hidden-service descriptor upload");
break;
case DIR_PURPOSE_FETCH_RUNNING_LIST:
log_fn(LOG_DEBUG,"initiating running-routers fetch");
break;
default:
log_fn(LOG_ERR, "Unrecognized directory connection purpose.");
tor_assert(0);
}
conn = connection_new(CONN_TYPE_DIR);
/* set up conn so it's got all the data we need to remember */
conn->addr = addr;
conn->port = dir_port;
conn->address = tor_strdup(address);
memcpy(conn->identity_digest, digest, DIGEST_LEN);
conn->purpose = purpose;
/* give it an initial state */
conn->state = DIR_CONN_STATE_CONNECTING;
if (!private_connection) {
/* then we want to connect directly */
if (get_options()->HttpProxy) {
addr = get_options()->HttpProxyAddr;
dir_port = get_options()->HttpProxyPort;
}
switch (connection_connect(conn, conn->address, addr, dir_port)) {
case -1:
connection_dir_connect_failed(conn);
connection_free(conn);
return;
case 1:
conn->state = DIR_CONN_STATE_CLIENT_SENDING; /* start flushing conn */
/* fall through */
case 0:
/* queue the command on the outbuf */
directory_send_command(conn, platform, purpose, resource,
payload, payload_len);
connection_watch_events(conn, EV_READ | EV_WRITE);
/* writable indicates finish, readable indicates broken link,
error indicates broken link in windowsland. */
}
} else { /* we want to connect via tor */
/* make an AP connection
* populate it and add it at the right state
* socketpair and hook up both sides
*/
conn->s = connection_ap_make_bridge(conn->address, conn->port);
if (conn->s < 0) {
log_fn(LOG_WARN,"Making AP bridge to dirserver failed.");
connection_mark_for_close(conn);
return;
}
conn->state = DIR_CONN_STATE_CLIENT_SENDING;
connection_add(conn);
/* queue the command on the outbuf */
directory_send_command(conn, platform, purpose, resource,
payload, payload_len);
connection_watch_events(conn, EV_READ | EV_WRITE);
}
}
/** Queue an appropriate HTTP command on conn-\>outbuf. The other args
* are as in directory_initiate_command.
*/
static void
directory_send_command(connection_t *conn, const char *platform,
int purpose, const char *resource,
const char *payload, size_t payload_len)
{
char tmp[8192];
char proxystring[256];
char proxyauthstring[256];
char hoststring[128];
char url[128];
const char *httpcommand = NULL;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_DIR);
/* come up with a string for which Host: we want */
if (conn->port == 80) {
strlcpy(hoststring, conn->address, sizeof(hoststring));
} else {
tor_snprintf(hoststring, sizeof(hoststring),"%s:%d",conn->address, conn->port);
}
/* come up with some proxy lines, if we're using one. */
if (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_fn(LOG_WARN, "Encoding http authenticator failed");
}
if (base64_authenticator) {
tor_snprintf(proxyauthstring, sizeof(proxyauthstring),
"\r\nProxy-Authorization: Basic %s",
base64_authenticator);
tor_free(base64_authenticator);
} else {
proxyauthstring[0] = 0;
}
} else {
proxystring[0] = 0;
proxyauthstring[0] = 0;
}
switch (purpose) {
case DIR_PURPOSE_FETCH_DIR:
tor_assert(!resource);
tor_assert(!payload);
log_fn(LOG_DEBUG, "Asking for compressed directory from server running %s",
platform?platform:"<unknown version>");
httpcommand = "GET";
strlcpy(url, "/tor/dir.z", sizeof(url));
break;
case DIR_PURPOSE_FETCH_RUNNING_LIST:
tor_assert(!resource);
tor_assert(!payload);
httpcommand = "GET";
strlcpy(url, "/tor/running-routers", sizeof(url));
break;
case DIR_PURPOSE_UPLOAD_DIR:
tor_assert(!resource);
tor_assert(payload);
httpcommand = "POST";
strlcpy(url, "/tor/", sizeof(url));
break;
case DIR_PURPOSE_FETCH_RENDDESC:
tor_assert(resource);
tor_assert(!payload);
/* this must be true or we wouldn't be doing the lookup */
tor_assert(strlen(resource) <= REND_SERVICE_ID_LEN);
/* This breaks the function abstraction. */
strlcpy(conn->rend_query, resource, sizeof(conn->rend_query));
httpcommand = "GET";
/* Request the most recent versioned descriptor. */
tor_snprintf(url, sizeof(url), "/tor/rendezvous1/%s", resource);
//tor_snprintf(url, sizeof(url), "/tor/rendezvous/%s", resource);
break;
case DIR_PURPOSE_UPLOAD_RENDDESC:
tor_assert(!resource);
tor_assert(payload);
httpcommand = "POST";
tor_snprintf(url, sizeof(url), "/tor/rendezvous/publish");
break;
}
tor_snprintf(tmp, sizeof(tmp), "%s %s%s HTTP/1.0\r\nContent-Length: %lu\r\nHost: %s%s\r\n\r\n",
httpcommand,
proxystring,
url,
payload ? (unsigned long)payload_len : 0,
hoststring,
proxyauthstring);
connection_write_to_buf(tmp, strlen(tmp), conn);
if (payload) {
/* then send the payload afterwards too */
connection_write_to_buf(payload, payload_len, conn);
}
}
/** 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
* null-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(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_fn(LOG_DEBUG,"Skipping over 'http[s]://hostname' string");
start = tmp;
}
}
}
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 newline. */
static char *
http_get_header(const char *headers, const char *which)
{
const char *cp = headers;
while (cp) {
if (!strcmpstart(cp, which)) {
char *eos;
cp += strlen(which);
if ((eos = strchr(cp,'\n')))
return tor_strndup(cp, eos-cp);
else
return tor_strdup(cp);
}
cp = strchr(cp, '\n');
if (cp)
++cp;
}
return NULL;
}
/** Allocate and return a string describing the source of an HTTP request with
* headers <b>headers</b> received on <b>conn</b>. The format is either
* "'1.2.3.4'", or "'1.2.3.4' (forwarded for '5.6.7.8')".
*/
static char *
http_get_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) {
size_t len = strlen(fwd)+strlen(conn->address)+32;
char *result = tor_malloc(len);
tor_snprintf(result, len, "'%s' (forwarded for '%s')", conn->address, fwd);
tor_free(fwd);
return result;
} else {
size_t len = strlen(conn->address)+3;
char *result = tor_malloc(len);
tor_snprintf(result, len, "'%s'", conn->address);
return result;
}
}
/** 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,
int *compression, char **reason)
{
int 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 (sscanf(headers, "HTTP/1.%d %d", &n1, &n2) < 2 ||
(n1 != 0 && n1 != 1) ||
(n2 < 100 || n2 >= 600)) {
log_fn(LOG_WARN,"Failed to parse header '%s'",headers);
return -1;
}
*code = n2;
parsed_headers = smartlist_create();
smartlist_split_string(parsed_headers, headers, "\n",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, -1);
if (reason) {
smartlist_t *status_line_elements = smartlist_create();
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 || !strcmp(enc, "identity")) {
*compression = 0;
} else if (!strcmp(enc, "deflate") || !strcmp(enc, "x-deflate")) {
*compression = ZLIB_METHOD;
} else if (!strcmp(enc, "gzip") || !strcmp(enc, "x-gzip")) {
*compression = GZIP_METHOD;
} else {
log_fn(LOG_INFO, "Unrecognized content encoding: '%s'. Trying to deal.", enc);
*compression = -1;
}
}
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
* running-list or directory 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_RENDDESC) {
if (!strcmpstart(body,"router") ||
!strcmpstart(body,"signed-directory") ||
!strcmpstart(body,"network-status") ||
!strcmpstart(body,"running-routers"))
return 1;
for (i=0;i<32;++i) {
if (!TOR_ISPRINT(body[i]) && !TOR_ISSPACE(body[i]))
return 0;
}
return 1;
} else {
return 1;
}
}
/** We are a client, and we've finished reading the server's
* response. Parse and it and act appropriately.
*
* Return -1 if an error has occurred, or 0 normally. The caller
* will take care of marking the connection for close.
*/
static int
connection_dir_client_reached_eof(connection_t *conn)
{
char *body;
char *headers;
char *reason = NULL;
size_t body_len=0;
int status_code;
time_t now, date_header=0;
int delta;
int compression;
int plausible;
int skewed=0;
switch (fetch_from_buf_http(conn->inbuf,
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_DIR_SIZE)) {
case -1: /* overflow */
log_fn(LOG_WARN,"'fetch' response too large (server '%s'). Failing.", conn->address);
return -1;
case 0:
log_fn(LOG_INFO,"'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_fn(LOG_WARN,"Unparseable headers (server '%s'). Closing.", conn->address);
tor_free(body); tor_free(headers);
return -1;
}
if (!reason) reason = tor_strdup("[no reason given]");
log_fn(LOG_DEBUG,
"Received response from directory server '%s': %d \"%s\"",
conn->address, status_code, reason);
if (date_header > 0) {
now = time(NULL);
delta = now-date_header;
if (abs(delta)>ALLOW_DIRECTORY_TIME_SKEW) {
log_fn(router_digest_is_trusted_dir(conn->identity_digest) ? LOG_WARN : LOG_INFO,
"Received directory with skewed time (server '%s'): we are %d minutes %s, or the directory is %d minutes %s.",
conn->address,
abs(delta)/60, delta>0 ? "ahead" : "behind",
abs(delta)/60, delta>0 ? "behind" : "ahead");
skewed = 1; /* don't check the recommended-versions line */
} else {
log_fn(LOG_INFO, "Time on received directory is within tolerance; we are %d seconds skewed. (That's okay.)", delta);
}
}
plausible = body_is_plausible(body, body_len, conn->purpose);
if (compression || !plausible) {
char *new_body = NULL;
size_t new_len = 0;
int guessed = detect_compression_method(body, body_len);
if (compression <= 0 || guessed != compression) {
/* Tell the user if we don't believe what we're told about compression.*/
const char *description1, *description2;
if (compression == ZLIB_METHOD)
description1 = "as deflated";
else if (compression == GZIP_METHOD)
description1 = "as gzipped";
else if (compression == 0)
description1 = "as uncompressed";
else
description1 = "with an unknown Content-Encoding";
if (guessed == ZLIB_METHOD)
description2 = "deflated";
else if (guessed == GZIP_METHOD)
description2 = "gzipped";
else if (!plausible)
description2 = "confusing binary junk";
else
description2 = "uncompressed";
log_fn(LOG_INFO, "HTTP body from server '%s' was labeled %s, "
"but it seems to be %s.%s",
conn->address, description1, description2,
(compression>0 && guessed>0)?" Trying both.":"");
}
/* Try declared compression first if we can. */
if (compression > 0)
tor_gzip_uncompress(&new_body, &new_len, body, body_len, compression);
/* Okay, if that didn't work, and we think that it was compressed
* differently, try that. */
if (!new_body && guessed > 0 && compression != guessed)
tor_gzip_uncompress(&new_body, &new_len, body, body_len, guessed);
/* 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_WARN, "Unable to decompress HTTP body (server '%s').", conn->address);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
if (new_body) {
tor_free(body);
body = new_body;
body_len = new_len;
}
}
if (conn->purpose == DIR_PURPOSE_FETCH_DIR) {
/* fetch/process the directory to learn about new routers. */
log_fn(LOG_INFO,"Received directory (size %d) from server '%s'",
(int)body_len, conn->address);
if (status_code == 503 || body_len == 0) {
log_fn(LOG_INFO,"Empty directory; status %d (\"%s\") Ignoring.",
status_code, reason);
tor_free(body); tor_free(headers); tor_free(reason);
return 0;
}
if (status_code != 200) {
log_fn(LOG_WARN,"Received http status code %d (\"%s\") from server '%s'. Failing.",
status_code, reason, conn->address);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
if (router_load_routerlist_from_directory(body, NULL, !skewed, 0) < 0) {
log_fn(LOG_NOTICE,"I failed to parse the directory I fetched from %s:%d. Ignoring.", conn->address, conn->port);
} else {
log_fn(LOG_INFO,"updated routers.");
}
/* do things we've been waiting to do */
directory_has_arrived(time(NULL), conn->identity_digest);
}
if (conn->purpose == DIR_PURPOSE_FETCH_RUNNING_LIST) {
running_routers_t *rrs;
routerlist_t *rl;
/* just update our list of running routers, if this list is new info */
log_fn(LOG_INFO,"Received running-routers list (size %d)", (int)body_len);
if (status_code != 200) {
log_fn(LOG_WARN,"Received http status code %d (\"%s\") from server '%s'. Failing.",
status_code, reason, conn->address);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
if (!(rrs = router_parse_runningrouters(body, 1))) {
log_fn(LOG_WARN, "Can't parse runningrouters list (server '%s')", conn->address);
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}
router_get_routerlist(&rl);
if (rl) {
routerlist_set_runningrouters(rl,rrs);
helper_nodes_set_status_from_directory();
} else {
running_routers_free(rrs);
}
}
if (conn->purpose == DIR_PURPOSE_UPLOAD_DIR) {
switch (status_code) {
case 200:
log_fn(LOG_INFO,"eof (status 200) after uploading server descriptor: finished.");
break;
case 400:
log_fn(LOG_WARN,"http status 400 (\"%s\") response from dirserver '%s'. Malformed server descriptor?", reason, conn->address);
break;
case 403:
log_fn(LOG_WARN,"http status 403 (\"%s\") response from dirserver '%s'. Is your clock skewed? Have you mailed us your key fingerprint? Are you using the right key? Are you using a private IP address? See http://tor.eff.org/doc/tor-doc.html#server.", reason, conn->address);
break;
default:
log_fn(LOG_WARN,"http status %d (\"%s\") reason unexpected (server '%s').", status_code, reason, conn->address);
break;
}
}
if (conn->purpose == DIR_PURPOSE_FETCH_RENDDESC) {
log_fn(LOG_INFO,"Received rendezvous descriptor (size %d, status %d (\"%s\"))",
(int)body_len, status_code, reason);
switch (status_code) {
case 200:
if (rend_cache_store(body, body_len) < 0) {
log_fn(LOG_WARN,"Failed to store rendezvous descriptor.");
/* alice's ap_stream will notice when connection_mark_for_close
* cleans it up */
} else {
/* success. notify pending connections about this. */
conn->purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC;
rend_client_desc_here(conn->rend_query);
}
break;
case 404:
/* not there. pending connections will be notified when
* connection_mark_for_close cleans it up. */
break;
case 400:
log_fn(LOG_WARN,"http status 400 (\"%s\"). Dirserver didn't like our rendezvous query?", reason);
break;
default:
log_fn(LOG_WARN,"http status %d (\"%s\") response unexpected (server '%s').", status_code, reason, conn->address);
break;
}
}
if (conn->purpose == DIR_PURPOSE_UPLOAD_RENDDESC) {
switch (status_code) {
case 200:
log_fn(LOG_INFO,"Uploading rendezvous descriptor: finished with status 200 (\"%s\")", reason);
break;
case 400:
log_fn(LOG_WARN,"http status 400 (\"%s\") response from dirserver '%s'. Malformed rendezvous descriptor?", reason, conn->address);
break;
default:
log_fn(LOG_WARN,"http status %d (\"%s\") response unexpected (server '%s').", status_code, reason, conn->address);
break;
}
}
tor_free(body); tor_free(headers); tor_free(reason);
return 0;
}
/** Called when a directory connection reaches EOF */
int
connection_dir_reached_eof(connection_t *conn)
{
int retval;
if (conn->state != DIR_CONN_STATE_CLIENT_READING) {
log_fn(LOG_INFO,"conn reached eof, not reading. Closing.");
connection_close_immediate(conn); /* it was an error; give up on flushing */
connection_mark_for_close(conn);
return -1;
}
retval = connection_dir_client_reached_eof(conn);
connection_mark_for_close(conn);
return retval;
}
/** 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(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->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->state == DIR_CONN_STATE_SERVER_COMMAND_WAIT) {
if (directory_handle_command(conn) < 0) {
connection_mark_for_close(conn);
return -1;
}
return 0;
}
/* XXX for READ states, might want to make sure inbuf isn't too big */
log_fn(LOG_DEBUG,"Got data, not eof. Leaving on inbuf.");
return 0;
}
/** 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(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) < 0) {
log_fn(LOG_WARN,"Bug: status line too long.");
return;
}
connection_write_to_buf(buf, strlen(buf), conn);
}
/** Helper function: return 1 if there are any dir conns of purpose
* <b>purpose</b> that are going elsewhere than our own ORPort/Dirport.
* Else return 0.
*/
static int
already_fetching_directory(int purpose)
{
int i, n;
connection_t *conn;
connection_t **carray;
get_connection_array(&carray,&n);
for (i=0;i<n;i++) {
conn = carray[i];
if (conn->type == CONN_TYPE_DIR &&
conn->purpose == purpose &&
!conn->marked_for_close &&
!router_digest_is_me(conn->identity_digest))
return 1;
}
return 0;
}
/** 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 400.
* Always return 0. */
static int
directory_handle_command_get(connection_t *conn, char *headers,
char *body, size_t body_len)
{
size_t dlen;
const char *cp;
char *url = NULL;
char tmp[8192];
char date[RFC1123_TIME_LEN+1];
log_fn(LOG_DEBUG,"Received GET command.");
conn->state = DIR_CONN_STATE_SERVER_WRITING;
if (parse_http_url(headers, &url) < 0) {
write_http_status_line(conn, 400, "Bad request");
return 0;
}
log_fn(LOG_INFO,"rewritten url as '%s'.", url);
if (!strcmp(url,"/tor/") || !strcmp(url,"/tor/dir.z")) { /* directory fetch */
int deflated = !strcmp(url,"/tor/dir.z");
dlen = dirserv_get_directory(&cp, deflated);
tor_free(url);
if (dlen == 0) {
log_fn(LOG_NOTICE,"Client asked for the mirrored directory, but we don't have a good one yet. Sending 503 Dir not available.");
write_http_status_line(conn, 503, "Directory unavailable");
/* try to get a new one now */
if (!already_fetching_directory(DIR_PURPOSE_FETCH_DIR))
directory_get_from_dirserver(DIR_PURPOSE_FETCH_DIR, NULL, 1);
return 0;
}
log_fn(LOG_DEBUG,"Dumping %sdirectory to client.",
deflated?"deflated ":"");
format_rfc1123_time(date, time(NULL));
tor_snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nDate: %s\r\nContent-Length: %d\r\nContent-Type: text/plain\r\nContent-Encoding: %s\r\n\r\n",
date,
(int)dlen,
deflated?"deflate":"identity");
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(cp, dlen, conn);
return 0;
}
if (!strcmp(url,"/tor/running-routers") ||
!strcmp(url,"/tor/running-routers.z")) { /* running-routers fetch */
int deflated = !strcmp(url,"/tor/running-routers.z");
tor_free(url);
dlen = dirserv_get_runningrouters(&cp, deflated);
if (!dlen) { /* we failed to create/cache cp */
write_http_status_line(conn, 503, "Directory unavailable");
/* try to get a new one now */
if (!already_fetching_directory(DIR_PURPOSE_FETCH_RUNNING_LIST))
directory_get_from_dirserver(DIR_PURPOSE_FETCH_RUNNING_LIST, NULL, 1);
return 0;
}
format_rfc1123_time(date, time(NULL));
tor_snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nDate: %s\r\nContent-Length: %d\r\nContent-Type: text/plain\r\nContent-Encoding: %s\r\n\r\n",
date,
(int)dlen,
deflated?"deflate":"identity");
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(cp, strlen(cp), conn);
return 0;
}
if (!strcmpstart(url,"/tor/status/")) {
/* v2 network status fetch. */
size_t url_len = strlen(url);
int deflated = !strcmp(url+url_len-2, ".z");
const char *key = url + strlen("/tor/status/");
if (deflated)
url[url_len-2] = '\0';
dlen = dirserv_get_networkstatus_v2(&cp, key, deflated);
tor_free(url);
if (!dlen) { /* we failed to create/cache cp */
write_http_status_line(conn, 503, "Network status object unavailable");
/* try to get a new one now */
// XXXX NM
return 0;
}
format_rfc1123_time(date, time(NULL));
tor_snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nDate: %s\r\nContent-Length: %d\r\nContent-Type: text/plain\r\nContent-Encoding: %s\r\n\r\n",
date,
(int)dlen,
deflated?"deflate":"identity");
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(cp, strlen(cp), conn);
return 0;
}
if (!strcmpstart(url,"/tor/server/")) {
size_t url_len = strlen(url);
int deflated = !strcmp(url+url_len-2, ".z");
smartlist_t *descs = smartlist_create();
if (deflated)
url[url_len-2] = '\0';
dirserv_get_routerdescs(descs, url);
tor_free(url);
if (!smartlist_len(descs)) {
write_http_status_line(conn, 400, "Servers unavailable.");
} else {
size_t len = 0;
format_rfc1123_time(date, time(NULL));
SMARTLIST_FOREACH(descs, routerinfo_t *, ri,
len += ri->signed_descriptor_len);
/* XXXX We need to support deflate here. */
tor_snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nDate: %s\r\nContent-Length: %d\r\nContent-Type: application/octet-stream\r\n\r\n",
date,
(int)len);
connection_write_to_buf(tmp, strlen(tmp), conn);
SMARTLIST_FOREACH(descs, routerinfo_t *, ri,
connection_write_to_buf(ri->signed_descriptor,
ri->signed_descriptor_len,
conn));
}
smartlist_free(descs);
return 0;
}
if (!strcmpstart(url,"/tor/rendezvous/") ||
!strcmpstart(url,"/tor/rendezvous1/")) {
/* rendezvous descriptor fetch */
const char *descp;
size_t desc_len;
int versioned = !strcmpstart(url,"/tor/rendezvous1/");
const char *query = url+strlen("/tor/rendezvous/")+(versioned?1:0);
if (!authdir_mode(get_options())) {
/* We don't hand out rend descs. In fact, it could be a security
* risk, since rend_cache_lookup_desc() below would provide it
* if we're gone to the site recently, and 404 if we haven't.
*
* Reject. */
write_http_status_line(conn, 400, "Nonauthoritative directory does not not store rendezvous descriptors.");
tor_free(url);
return 0;
}
switch (rend_cache_lookup_desc(query, versioned?-1:0, &descp, &desc_len)) {
case 1: /* valid */
format_rfc1123_time(date, time(NULL));
tor_snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nDate: %s\r\nContent-Length: %d\r\nContent-Type: application/octet-stream\r\n\r\n",
date,
(int)desc_len); /* can't include descp here, because it's got nuls */
connection_write_to_buf(tmp, strlen(tmp), conn);
connection_write_to_buf(descp, desc_len, 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;
}
tor_free(url);
return 0;
}
/* we didn't recognize the url */
write_http_status_line(conn, 404, "Not found");
tor_free(url);
return 0;
}
/** 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. */
static int
directory_handle_command_post(connection_t *conn, char *headers,
char *body, size_t body_len)
{
const char *cp;
char *origin = NULL;
char *url = NULL;
log_fn(LOG_DEBUG,"Received POST command.");
conn->state = DIR_CONN_STATE_SERVER_WRITING;
if (!authdir_mode(get_options())) {
/* we just provide cached directories; we don't want to
* receive anything. */
write_http_status_line(conn, 400, "Nonauthoritative directory does not not store server descriptors.");
return 0;
}
if (parse_http_url(headers, &url) < 0) {
write_http_status_line(conn, 400, "Bad request");
return 0;
}
log_fn(LOG_INFO,"rewritten url as '%s'.", url);
origin = http_get_origin(headers, conn);
if (!strcmp(url,"/tor/")) { /* server descriptor post */
const char *msg;
switch (dirserv_add_descriptor(body, &msg)) {
case -2:
case -1:
/* malformed descriptor, or something wrong */
write_http_status_line(conn, 400, msg?msg:"Malformed or unacceptable server descriptor");
log_fn(LOG_NOTICE,"Rejected descriptor published by %s.", origin);
break;
case 0:
write_http_status_line(conn, 200, msg?msg:"Server descriptor okay, but not accepted.");
break;
case 1:
dirserv_get_directory(&cp, 0); /* rebuild and write to disk */
write_http_status_line(conn, 200, msg?msg:"Server descriptor accepted");
break;
}
goto done;
}
if (!strcmpstart(url,"/tor/rendezvous/publish")) {
/* rendezvous descriptor post */
if (rend_cache_store(body, body_len) < 0)
write_http_status_line(conn, 400, "Invalid service descriptor rejected");
else
write_http_status_line(conn, 200, "Service descriptor stored");
goto done;
}
/* we didn't recognize the url */
write_http_status_line(conn, 404, "Not found");
done:
tor_free(url);
tor_free(origin);
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(connection_t *conn)
{
char *headers=NULL, *body=NULL;
size_t body_len=0;
int r;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_DIR);
switch (fetch_from_buf_http(conn->inbuf,
&headers, MAX_HEADERS_SIZE,
&body, &body_len, MAX_BODY_SIZE)) {
case -1: /* overflow */
log_fn(LOG_WARN,"Invalid input from address '%s'. Closing.", conn->address);
return -1;
case 0:
log_fn(LOG_DEBUG,"command not all here yet.");
return 0;
/* case 1, fall through */
}
log_fn(LOG_DEBUG,"headers '%s', body '%s'.", headers, 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_WARN,"Got headers '%s' with unknown command. Closing.", 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(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_DIR);
switch (conn->state) {
case DIR_CONN_STATE_CLIENT_SENDING:
log_fn(LOG_DEBUG,"client finished sending command.");
conn->state = DIR_CONN_STATE_CLIENT_READING;
connection_stop_writing(conn);
return 0;
case DIR_CONN_STATE_SERVER_WRITING:
log_fn(LOG_INFO,"Finished writing server response. Closing.");
connection_mark_for_close(conn);
return 0;
default:
log_fn(LOG_WARN,"Bug: called in unexpected state %d.", conn->state);
tor_fragile_assert();
return -1;
}
return 0;
}
/** Connected handler for directory connections: begin sending data to the
* server */
int
connection_dir_finished_connecting(connection_t *conn)
{
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_DIR);
tor_assert(conn->state == DIR_CONN_STATE_CONNECTING);
log_fn(LOG_INFO,"Dir connection to router %s:%u established.",
conn->address,conn->port);
conn->state = DIR_CONN_STATE_CLIENT_SENDING; /* start flushing conn */
return 0;
}
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