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tor/src/or/dirvote.c
Nick Mathewson 7505f452c8 Run the copyright update script.
2017-03-15 16:13:17 -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 DIRVOTE_PRIVATE
#include "or.h"
#include "config.h"
#include "dircollate.h"
#include "directory.h"
#include "dirserv.h"
#include "dirvote.h"
#include "microdesc.h"
#include "networkstatus.h"
#include "policies.h"
#include "protover.h"
#include "rephist.h"
#include "router.h"
#include "routerkeys.h"
#include "routerlist.h"
#include "routerparse.h"
#include "entrynodes.h" /* needed for guardfraction methods */
#include "torcert.h"
#include "shared_random_state.h"
/**
* \file dirvote.c
* \brief Functions to compute directory consensus, and schedule voting.
*
* This module is the center of the consensus-voting based directory
* authority system. With this system, a set of authorities first
* publish vote based on their opinions of the network, and then compute
* a consensus from those votes. Each authority signs the consensus,
* and clients trust the consensus if enough known authorities have
* signed it.
*
* The code in this module is only invoked on directory authorities. It's
* responsible for:
*
* <ul>
* <li>Generating this authority's vote networkstatus, based on the
* authority's view of the network as represented in dirserv.c
* <li>Formatting the vote networkstatus objects.
* <li>Generating the microdescriptors that correspond to our own
* vote.
* <li>Sending votes to all the other authorities.
* <li>Trying to fetch missing votes from other authorities.
* <li>Computing the consensus from a set of votes, as well as
* a "detached signature" object for other authorities to fetch.
* <li>Collecting other authorities' signatures on the same consensus,
* until there are enough.
* <li>Publishing the consensus to the reset of the directory system.
* <li>Scheduling all of the above operations.
* </ul>
*
* The main entry points are in dirvote_act(), which handles scheduled
* actions; and dirvote_add_vote() and dirvote_add_signatures(), which
* handle uploaded and downloaded votes and signatures.
*
* (See dir-spec.txt from torspec.git for a complete specification of
* the directory protocol and voting algorithms.)
**/
/** A consensus that we have built and are appending signatures to. Once it's
* time to publish it, it will become an active consensus if it accumulates
* enough signatures. */
typedef struct pending_consensus_t {
/** The body of the consensus that we're currently building. Once we
* have it built, it goes into dirserv.c */
char *body;
/** The parsed in-progress consensus document. */
networkstatus_t *consensus;
} pending_consensus_t;
/* DOCDOC dirvote_add_signatures_to_all_pending_consensuses */
static int dirvote_add_signatures_to_all_pending_consensuses(
const char *detached_signatures_body,
const char *source,
const char **msg_out);
static int dirvote_add_signatures_to_pending_consensus(
pending_consensus_t *pc,
ns_detached_signatures_t *sigs,
const char *source,
int severity,
const char **msg_out);
static char *list_v3_auth_ids(void);
static void dirvote_fetch_missing_votes(void);
static void dirvote_fetch_missing_signatures(void);
static int dirvote_perform_vote(void);
static void dirvote_clear_votes(int all_votes);
static int dirvote_compute_consensuses(void);
static int dirvote_publish_consensus(void);
/* =====
* Voting
* =====*/
/* If <b>opt_value</b> is non-NULL, return "keyword opt_value\n" in a new
* string. Otherwise return a new empty string. */
static char *
format_line_if_present(const char *keyword, const char *opt_value)
{
if (opt_value) {
char *result = NULL;
tor_asprintf(&result, "%s %s\n", keyword, opt_value);
return result;
} else {
return tor_strdup("");
}
}
/** Format the recommended/required-relay-client protocols lines for a vote in
* a newly allocated string, and return that string. */
static char *
format_protocols_lines_for_vote(const networkstatus_t *v3_ns)
{
char *recommended_relay_protocols_line = NULL;
char *recommended_client_protocols_line = NULL;
char *required_relay_protocols_line = NULL;
char *required_client_protocols_line = NULL;
recommended_relay_protocols_line =
format_line_if_present("recommended-relay-protocols",
v3_ns->recommended_relay_protocols);
recommended_client_protocols_line =
format_line_if_present("recommended-client-protocols",
v3_ns->recommended_client_protocols);
required_relay_protocols_line =
format_line_if_present("required-relay-protocols",
v3_ns->required_relay_protocols);
required_client_protocols_line =
format_line_if_present("required-client-protocols",
v3_ns->required_client_protocols);
char *result = NULL;
tor_asprintf(&result, "%s%s%s%s",
recommended_relay_protocols_line,
recommended_client_protocols_line,
required_relay_protocols_line,
required_client_protocols_line);
tor_free(recommended_relay_protocols_line);
tor_free(recommended_client_protocols_line);
tor_free(required_relay_protocols_line);
tor_free(required_client_protocols_line);
return result;
}
/** Return a new string containing the string representation of the vote in
* <b>v3_ns</b>, signed with our v3 signing key <b>private_signing_key</b>.
* For v3 authorities. */
STATIC char *
format_networkstatus_vote(crypto_pk_t *private_signing_key,
networkstatus_t *v3_ns)
{
smartlist_t *chunks = smartlist_new();
char *packages = NULL;
char fingerprint[FINGERPRINT_LEN+1];
char digest[DIGEST_LEN];
uint32_t addr;
char *protocols_lines = NULL;
char *client_versions_line = NULL, *server_versions_line = NULL;
char *shared_random_vote_str = NULL;
networkstatus_voter_info_t *voter;
char *status = NULL;
tor_assert(private_signing_key);
tor_assert(v3_ns->type == NS_TYPE_VOTE || v3_ns->type == NS_TYPE_OPINION);
voter = smartlist_get(v3_ns->voters, 0);
addr = voter->addr;
base16_encode(fingerprint, sizeof(fingerprint),
v3_ns->cert->cache_info.identity_digest, DIGEST_LEN);
client_versions_line = format_line_if_present("client-versions",
v3_ns->client_versions);
server_versions_line = format_line_if_present("server-versions",
v3_ns->server_versions);
protocols_lines = format_protocols_lines_for_vote(v3_ns);
if (v3_ns->package_lines) {
smartlist_t *tmp = smartlist_new();
SMARTLIST_FOREACH(v3_ns->package_lines, const char *, p,
if (validate_recommended_package_line(p))
smartlist_add_asprintf(tmp, "package %s\n", p));
smartlist_sort_strings(tmp);
packages = smartlist_join_strings(tmp, "", 0, NULL);
SMARTLIST_FOREACH(tmp, char *, cp, tor_free(cp));
smartlist_free(tmp);
} else {
packages = tor_strdup("");
}
/* Get shared random commitments/reveals line(s). */
shared_random_vote_str = sr_get_string_for_vote();
{
char published[ISO_TIME_LEN+1];
char va[ISO_TIME_LEN+1];
char fu[ISO_TIME_LEN+1];
char vu[ISO_TIME_LEN+1];
char *flags = smartlist_join_strings(v3_ns->known_flags, " ", 0, NULL);
/* XXXX Abstraction violation: should be pulling a field out of v3_ns.*/
char *flag_thresholds = dirserv_get_flag_thresholds_line();
char *params;
authority_cert_t *cert = v3_ns->cert;
char *methods =
make_consensus_method_list(MIN_SUPPORTED_CONSENSUS_METHOD,
MAX_SUPPORTED_CONSENSUS_METHOD, " ");
format_iso_time(published, v3_ns->published);
format_iso_time(va, v3_ns->valid_after);
format_iso_time(fu, v3_ns->fresh_until);
format_iso_time(vu, v3_ns->valid_until);
if (v3_ns->net_params)
params = smartlist_join_strings(v3_ns->net_params, " ", 0, NULL);
else
params = tor_strdup("");
tor_assert(cert);
smartlist_add_asprintf(chunks,
"network-status-version 3\n"
"vote-status %s\n"
"consensus-methods %s\n"
"published %s\n"
"valid-after %s\n"
"fresh-until %s\n"
"valid-until %s\n"
"voting-delay %d %d\n"
"%s%s" /* versions */
"%s" /* protocols */
"%s" /* packages */
"known-flags %s\n"
"flag-thresholds %s\n"
"params %s\n"
"dir-source %s %s %s %s %d %d\n"
"contact %s\n"
"%s", /* shared randomness information */
v3_ns->type == NS_TYPE_VOTE ? "vote" : "opinion",
methods,
published, va, fu, vu,
v3_ns->vote_seconds, v3_ns->dist_seconds,
client_versions_line,
server_versions_line,
protocols_lines,
packages,
flags,
flag_thresholds,
params,
voter->nickname, fingerprint, voter->address,
fmt_addr32(addr), voter->dir_port, voter->or_port,
voter->contact,
shared_random_vote_str ?
shared_random_vote_str : "");
tor_free(params);
tor_free(flags);
tor_free(flag_thresholds);
tor_free(methods);
tor_free(shared_random_vote_str);
if (!tor_digest_is_zero(voter->legacy_id_digest)) {
char fpbuf[HEX_DIGEST_LEN+1];
base16_encode(fpbuf, sizeof(fpbuf), voter->legacy_id_digest, DIGEST_LEN);
smartlist_add_asprintf(chunks, "legacy-dir-key %s\n", fpbuf);
}
smartlist_add(chunks, tor_strndup(cert->cache_info.signed_descriptor_body,
cert->cache_info.signed_descriptor_len));
}
SMARTLIST_FOREACH_BEGIN(v3_ns->routerstatus_list, vote_routerstatus_t *,
vrs) {
char *rsf;
vote_microdesc_hash_t *h;
rsf = routerstatus_format_entry(&vrs->status,
vrs->version, vrs->protocols,
NS_V3_VOTE, vrs);
if (rsf)
smartlist_add(chunks, rsf);
for (h = vrs->microdesc; h; h = h->next) {
smartlist_add_strdup(chunks, h->microdesc_hash_line);
}
} SMARTLIST_FOREACH_END(vrs);
smartlist_add_strdup(chunks, "directory-footer\n");
/* The digest includes everything up through the space after
* directory-signature. (Yuck.) */
crypto_digest_smartlist(digest, DIGEST_LEN, chunks,
"directory-signature ", DIGEST_SHA1);
{
char signing_key_fingerprint[FINGERPRINT_LEN+1];
if (crypto_pk_get_fingerprint(private_signing_key,
signing_key_fingerprint, 0)<0) {
log_warn(LD_BUG, "Unable to get fingerprint for signing key");
goto err;
}
smartlist_add_asprintf(chunks, "directory-signature %s %s\n", fingerprint,
signing_key_fingerprint);
}
note_crypto_pk_op(SIGN_DIR);
{
char *sig = router_get_dirobj_signature(digest, DIGEST_LEN,
private_signing_key);
if (!sig) {
log_warn(LD_BUG, "Unable to sign networkstatus vote.");
goto err;
}
smartlist_add(chunks, sig);
}
status = smartlist_join_strings(chunks, "", 0, NULL);
{
networkstatus_t *v;
if (!(v = networkstatus_parse_vote_from_string(status, NULL,
v3_ns->type))) {
log_err(LD_BUG,"Generated a networkstatus %s we couldn't parse: "
"<<%s>>",
v3_ns->type == NS_TYPE_VOTE ? "vote" : "opinion", status);
goto err;
}
networkstatus_vote_free(v);
}
goto done;
err:
tor_free(status);
done:
tor_free(client_versions_line);
tor_free(server_versions_line);
tor_free(protocols_lines);
tor_free(packages);
SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
smartlist_free(chunks);
return status;
}
/* =====
* Consensus generation
* ===== */
/** Given a vote <b>vote</b> (not a consensus!), return its associated
* networkstatus_voter_info_t. */
static networkstatus_voter_info_t *
get_voter(const networkstatus_t *vote)
{
tor_assert(vote);
tor_assert(vote->type == NS_TYPE_VOTE);
tor_assert(vote->voters);
tor_assert(smartlist_len(vote->voters) == 1);
return smartlist_get(vote->voters, 0);
}
/** Return the signature made by <b>voter</b> using the algorithm
* <b>alg</b>, or NULL if none is found. */
document_signature_t *
voter_get_sig_by_algorithm(const networkstatus_voter_info_t *voter,
digest_algorithm_t alg)
{
if (!voter->sigs)
return NULL;
SMARTLIST_FOREACH(voter->sigs, document_signature_t *, sig,
if (sig->alg == alg)
return sig);
return NULL;
}
/** Temporary structure used in constructing a list of dir-source entries
* for a consensus. One of these is generated for every vote, and one more
* for every legacy key in each vote. */
typedef struct dir_src_ent_t {
networkstatus_t *v;
const char *digest;
int is_legacy;
} dir_src_ent_t;
/** Helper for sorting networkstatus_t votes (not consensuses) by the
* hash of their voters' identity digests. */
static int
compare_votes_by_authority_id_(const void **_a, const void **_b)
{
const networkstatus_t *a = *_a, *b = *_b;
return fast_memcmp(get_voter(a)->identity_digest,
get_voter(b)->identity_digest, DIGEST_LEN);
}
/** Helper: Compare the dir_src_ent_ts in *<b>_a</b> and *<b>_b</b> by
* their identity digests, and return -1, 0, or 1 depending on their
* ordering */
static int
compare_dir_src_ents_by_authority_id_(const void **_a, const void **_b)
{
const dir_src_ent_t *a = *_a, *b = *_b;
const networkstatus_voter_info_t *a_v = get_voter(a->v),
*b_v = get_voter(b->v);
const char *a_id, *b_id;
a_id = a->is_legacy ? a_v->legacy_id_digest : a_v->identity_digest;
b_id = b->is_legacy ? b_v->legacy_id_digest : b_v->identity_digest;
return fast_memcmp(a_id, b_id, DIGEST_LEN);
}
/** Given a sorted list of strings <b>in</b>, add every member to <b>out</b>
* that occurs more than <b>min</b> times. */
static void
get_frequent_members(smartlist_t *out, smartlist_t *in, int min)
{
char *cur = NULL;
int count = 0;
SMARTLIST_FOREACH_BEGIN(in, char *, cp) {
if (cur && !strcmp(cp, cur)) {
++count;
} else {
if (count > min)
smartlist_add(out, cur);
cur = cp;
count = 1;
}
} SMARTLIST_FOREACH_END(cp);
if (count > min)
smartlist_add(out, cur);
}
/** Given a sorted list of strings <b>lst</b>, return the member that appears
* most. Break ties in favor of later-occurring members. */
#define get_most_frequent_member(lst) \
smartlist_get_most_frequent_string(lst)
/** Return 0 if and only if <b>a</b> and <b>b</b> are routerstatuses
* that come from the same routerinfo, with the same derived elements.
*/
static int
compare_vote_rs(const vote_routerstatus_t *a, const vote_routerstatus_t *b)
{
int r;
tor_assert(a);
tor_assert(b);
if ((r = fast_memcmp(a->status.identity_digest, b->status.identity_digest,
DIGEST_LEN)))
return r;
if ((r = fast_memcmp(a->status.descriptor_digest,
b->status.descriptor_digest,
DIGEST_LEN)))
return r;
/* If we actually reached this point, then the identities and
* the descriptor digests matched, so somebody is making SHA1 collisions.
*/
#define CMP_FIELD(utype, itype, field) do { \
utype aval = (utype) (itype) a->status.field; \
utype bval = (utype) (itype) b->status.field; \
utype u = bval - aval; \
itype r2 = (itype) u; \
if (r2 < 0) { \
return -1; \
} else if (r2 > 0) { \
return 1; \
} \
} while (0)
CMP_FIELD(uint64_t, int64_t, published_on);
if ((r = strcmp(b->status.nickname, a->status.nickname)))
return r;
CMP_FIELD(unsigned, int, addr);
CMP_FIELD(unsigned, int, or_port);
CMP_FIELD(unsigned, int, dir_port);
return 0;
}
/** Helper for sorting routerlists based on compare_vote_rs. */
static int
compare_vote_rs_(const void **_a, const void **_b)
{
const vote_routerstatus_t *a = *_a, *b = *_b;
return compare_vote_rs(a,b);
}
/** Helper for sorting OR ports. */
static int
compare_orports_(const void **_a, const void **_b)
{
const tor_addr_port_t *a = *_a, *b = *_b;
int r;
if ((r = tor_addr_compare(&a->addr, &b->addr, CMP_EXACT)))
return r;
if ((r = (((int) b->port) - ((int) a->port))))
return r;
return 0;
}
/** Given a list of vote_routerstatus_t, all for the same router identity,
* return whichever is most frequent, breaking ties in favor of more
* recently published vote_routerstatus_t and in case of ties there,
* in favor of smaller descriptor digest.
*/
static vote_routerstatus_t *
compute_routerstatus_consensus(smartlist_t *votes, int consensus_method,
char *microdesc_digest256_out,
tor_addr_port_t *best_alt_orport_out)
{
vote_routerstatus_t *most = NULL, *cur = NULL;
int most_n = 0, cur_n = 0;
time_t most_published = 0;
/* compare_vote_rs_() sorts the items by identity digest (all the same),
* then by SD digest. That way, if we have a tie that the published_on
* date cannot tie, we use the descriptor with the smaller digest.
*/
smartlist_sort(votes, compare_vote_rs_);
SMARTLIST_FOREACH_BEGIN(votes, vote_routerstatus_t *, rs) {
if (cur && !compare_vote_rs(cur, rs)) {
++cur_n;
} else {
if (cur && (cur_n > most_n ||
(cur_n == most_n &&
cur->status.published_on > most_published))) {
most = cur;
most_n = cur_n;
most_published = cur->status.published_on;
}
cur_n = 1;
cur = rs;
}
} SMARTLIST_FOREACH_END(rs);
if (cur_n > most_n ||
(cur && cur_n == most_n && cur->status.published_on > most_published)) {
most = cur;
most_n = cur_n;
most_published = cur->status.published_on;
}
tor_assert(most);
/* If we're producing "a" lines, vote on potential alternative (sets
* of) OR port(s) in the winning routerstatuses.
*
* XXX prop186 There's at most one alternative OR port (_the_ IPv6
* port) for now. */
if (consensus_method >= MIN_METHOD_FOR_A_LINES && best_alt_orport_out) {
smartlist_t *alt_orports = smartlist_new();
const tor_addr_port_t *most_alt_orport = NULL;
SMARTLIST_FOREACH_BEGIN(votes, vote_routerstatus_t *, rs) {
tor_assert(rs);
if (compare_vote_rs(most, rs) == 0 &&
!tor_addr_is_null(&rs->status.ipv6_addr)
&& rs->status.ipv6_orport) {
smartlist_add(alt_orports, tor_addr_port_new(&rs->status.ipv6_addr,
rs->status.ipv6_orport));
}
} SMARTLIST_FOREACH_END(rs);
smartlist_sort(alt_orports, compare_orports_);
most_alt_orport = smartlist_get_most_frequent(alt_orports,
compare_orports_);
if (most_alt_orport) {
memcpy(best_alt_orport_out, most_alt_orport, sizeof(tor_addr_port_t));
log_debug(LD_DIR, "\"a\" line winner for %s is %s",
most->status.nickname,
fmt_addrport(&most_alt_orport->addr, most_alt_orport->port));
}
SMARTLIST_FOREACH(alt_orports, tor_addr_port_t *, ap, tor_free(ap));
smartlist_free(alt_orports);
}
if (microdesc_digest256_out) {
smartlist_t *digests = smartlist_new();
const uint8_t *best_microdesc_digest;
SMARTLIST_FOREACH_BEGIN(votes, vote_routerstatus_t *, rs) {
char d[DIGEST256_LEN];
if (compare_vote_rs(rs, most))
continue;
if (!vote_routerstatus_find_microdesc_hash(d, rs, consensus_method,
DIGEST_SHA256))
smartlist_add(digests, tor_memdup(d, sizeof(d)));
} SMARTLIST_FOREACH_END(rs);
smartlist_sort_digests256(digests);
best_microdesc_digest = smartlist_get_most_frequent_digest256(digests);
if (best_microdesc_digest)
memcpy(microdesc_digest256_out, best_microdesc_digest, DIGEST256_LEN);
SMARTLIST_FOREACH(digests, char *, cp, tor_free(cp));
smartlist_free(digests);
}
return most;
}
/** Sorting helper: compare two strings based on their values as base-ten
* positive integers. (Non-integers are treated as prior to all integers, and
* compared lexically.) */
static int
cmp_int_strings_(const void **_a, const void **_b)
{
const char *a = *_a, *b = *_b;
int ai = (int)tor_parse_long(a, 10, 1, INT_MAX, NULL, NULL);
int bi = (int)tor_parse_long(b, 10, 1, INT_MAX, NULL, NULL);
if (ai<bi) {
return -1;
} else if (ai==bi) {
if (ai == 0) /* Parsing failed. */
return strcmp(a, b);
return 0;
} else {
return 1;
}
}
/** Given a list of networkstatus_t votes, determine and return the number of
* the highest consensus method that is supported by 2/3 of the voters. */
static int
compute_consensus_method(smartlist_t *votes)
{
smartlist_t *all_methods = smartlist_new();
smartlist_t *acceptable_methods = smartlist_new();
smartlist_t *tmp = smartlist_new();
int min = (smartlist_len(votes) * 2) / 3;
int n_ok;
int result;
SMARTLIST_FOREACH(votes, networkstatus_t *, vote,
{
tor_assert(vote->supported_methods);
smartlist_add_all(tmp, vote->supported_methods);
smartlist_sort(tmp, cmp_int_strings_);
smartlist_uniq(tmp, cmp_int_strings_, NULL);
smartlist_add_all(all_methods, tmp);
smartlist_clear(tmp);
});
smartlist_sort(all_methods, cmp_int_strings_);
get_frequent_members(acceptable_methods, all_methods, min);
n_ok = smartlist_len(acceptable_methods);
if (n_ok) {
const char *best = smartlist_get(acceptable_methods, n_ok-1);
result = (int)tor_parse_long(best, 10, 1, INT_MAX, NULL, NULL);
} else {
result = 1;
}
smartlist_free(tmp);
smartlist_free(all_methods);
smartlist_free(acceptable_methods);
return result;
}
/** Return true iff <b>method</b> is a consensus method that we support. */
static int
consensus_method_is_supported(int method)
{
if (method == MIN_METHOD_FOR_ED25519_ID_IN_MD) {
/* This method was broken due to buggy code accidently left in
* dircollate.c; do not actually use it.
*/
return 0;
}
return (method >= MIN_SUPPORTED_CONSENSUS_METHOD) &&
(method <= MAX_SUPPORTED_CONSENSUS_METHOD);
}
/** Return a newly allocated string holding the numbers between low and high
* (inclusive) that are supported consensus methods. */
STATIC char *
make_consensus_method_list(int low, int high, const char *separator)
{
char *list;
int i;
smartlist_t *lst;
lst = smartlist_new();
for (i = low; i <= high; ++i) {
if (!consensus_method_is_supported(i))
continue;
smartlist_add_asprintf(lst, "%d", i);
}
list = smartlist_join_strings(lst, separator, 0, NULL);
tor_assert(list);
SMARTLIST_FOREACH(lst, char *, cp, tor_free(cp));
smartlist_free(lst);
return list;
}
/** Helper: given <b>lst</b>, a list of version strings such that every
* version appears once for every versioning voter who recommends it, return a
* newly allocated string holding the resulting client-versions or
* server-versions list. May change contents of <b>lst</b> */
static char *
compute_consensus_versions_list(smartlist_t *lst, int n_versioning)
{
int min = n_versioning / 2;
smartlist_t *good = smartlist_new();
char *result;
sort_version_list(lst, 0);
get_frequent_members(good, lst, min);
result = smartlist_join_strings(good, ",", 0, NULL);
smartlist_free(good);
return result;
}
/** Given a list of K=V values, return the int32_t value corresponding to
* KEYWORD=, or default_val if no such value exists, or if the value is
* corrupt.
*/
STATIC int32_t
dirvote_get_intermediate_param_value(const smartlist_t *param_list,
const char *keyword,
int32_t default_val)
{
unsigned int n_found = 0;
int32_t value = default_val;
SMARTLIST_FOREACH_BEGIN(param_list, const char *, k_v_pair) {
if (!strcmpstart(k_v_pair, keyword) && k_v_pair[strlen(keyword)] == '=') {
const char *integer_str = &k_v_pair[strlen(keyword)+1];
int ok;
value = (int32_t)
tor_parse_long(integer_str, 10, INT32_MIN, INT32_MAX, &ok, NULL);
if (BUG(! ok))
return default_val;
++n_found;
}
} SMARTLIST_FOREACH_END(k_v_pair);
if (n_found == 1)
return value;
else if (BUG(n_found > 1))
return default_val;
else
return default_val;
}
/** Minimum number of directory authorities voting for a parameter to
* include it in the consensus, if consensus method 12 or later is to be
* used. See proposal 178 for details. */
#define MIN_VOTES_FOR_PARAM 3
/** Helper: given a list of valid networkstatus_t, return a new smartlist
* containing the contents of the consensus network parameter set.
*/
STATIC smartlist_t *
dirvote_compute_params(smartlist_t *votes, int method, int total_authorities)
{
int i;
int32_t *vals;
int cur_param_len;
const char *cur_param;
const char *eq;
const int n_votes = smartlist_len(votes);
smartlist_t *output;
smartlist_t *param_list = smartlist_new();
(void) method;
/* We require that the parameter lists in the votes are well-formed: that
is, that their keywords are unique and sorted, and that their values are
between INT32_MIN and INT32_MAX inclusive. This should be guaranteed by
the parsing code. */
vals = tor_calloc(n_votes, sizeof(int));
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
if (!v->net_params)
continue;
smartlist_add_all(param_list, v->net_params);
} SMARTLIST_FOREACH_END(v);
if (smartlist_len(param_list) == 0) {
tor_free(vals);
return param_list;
}
smartlist_sort_strings(param_list);
i = 0;
cur_param = smartlist_get(param_list, 0);
eq = strchr(cur_param, '=');
tor_assert(eq);
cur_param_len = (int)(eq+1 - cur_param);
output = smartlist_new();
SMARTLIST_FOREACH_BEGIN(param_list, const char *, param) {
const char *next_param;
int ok=0;
eq = strchr(param, '=');
tor_assert(i<n_votes); /* Make sure we prevented vote-stuffing. */
vals[i++] = (int32_t)
tor_parse_long(eq+1, 10, INT32_MIN, INT32_MAX, &ok, NULL);
tor_assert(ok); /* Already checked these when parsing. */
if (param_sl_idx+1 == smartlist_len(param_list))
next_param = NULL;
else
next_param = smartlist_get(param_list, param_sl_idx+1);
/* resolve spurious clang shallow analysis null pointer errors */
tor_assert(param);
if (!next_param || strncmp(next_param, param, cur_param_len)) {
/* We've reached the end of a series. */
/* Make sure enough authorities voted on this param, unless the
* the consensus method we use is too old for that. */
if (i > total_authorities/2 ||
i >= MIN_VOTES_FOR_PARAM) {
int32_t median = median_int32(vals, i);
char *out_string = tor_malloc(64+cur_param_len);
memcpy(out_string, param, cur_param_len);
tor_snprintf(out_string+cur_param_len,64, "%ld", (long)median);
smartlist_add(output, out_string);
}
i = 0;
if (next_param) {
eq = strchr(next_param, '=');
cur_param_len = (int)(eq+1 - next_param);
}
}
} SMARTLIST_FOREACH_END(param);
smartlist_free(param_list);
tor_free(vals);
return output;
}
#define RANGE_CHECK(a,b,c,d,e,f,g,mx) \
((a) >= 0 && (a) <= (mx) && (b) >= 0 && (b) <= (mx) && \
(c) >= 0 && (c) <= (mx) && (d) >= 0 && (d) <= (mx) && \
(e) >= 0 && (e) <= (mx) && (f) >= 0 && (f) <= (mx) && \
(g) >= 0 && (g) <= (mx))
#define CHECK_EQ(a, b, margin) \
((a)-(b) >= 0 ? (a)-(b) <= (margin) : (b)-(a) <= (margin))
typedef enum {
BW_WEIGHTS_NO_ERROR = 0,
BW_WEIGHTS_RANGE_ERROR = 1,
BW_WEIGHTS_SUMG_ERROR = 2,
BW_WEIGHTS_SUME_ERROR = 3,
BW_WEIGHTS_SUMD_ERROR = 4,
BW_WEIGHTS_BALANCE_MID_ERROR = 5,
BW_WEIGHTS_BALANCE_EG_ERROR = 6
} bw_weights_error_t;
/**
* Verify that any weightings satisfy the balanced formulas.
*/
static bw_weights_error_t
networkstatus_check_weights(int64_t Wgg, int64_t Wgd, int64_t Wmg,
int64_t Wme, int64_t Wmd, int64_t Wee,
int64_t Wed, int64_t scale, int64_t G,
int64_t M, int64_t E, int64_t D, int64_t T,
int64_t margin, int do_balance) {
bw_weights_error_t berr = BW_WEIGHTS_NO_ERROR;
// Wed + Wmd + Wgd == 1
if (!CHECK_EQ(Wed + Wmd + Wgd, scale, margin)) {
berr = BW_WEIGHTS_SUMD_ERROR;
goto out;
}
// Wmg + Wgg == 1
if (!CHECK_EQ(Wmg + Wgg, scale, margin)) {
berr = BW_WEIGHTS_SUMG_ERROR;
goto out;
}
// Wme + Wee == 1
if (!CHECK_EQ(Wme + Wee, scale, margin)) {
berr = BW_WEIGHTS_SUME_ERROR;
goto out;
}
// Verify weights within range 0->1
if (!RANGE_CHECK(Wgg, Wgd, Wmg, Wme, Wmd, Wed, Wee, scale)) {
berr = BW_WEIGHTS_RANGE_ERROR;
goto out;
}
if (do_balance) {
// Wgg*G + Wgd*D == Wee*E + Wed*D, already scaled
if (!CHECK_EQ(Wgg*G + Wgd*D, Wee*E + Wed*D, (margin*T)/3)) {
berr = BW_WEIGHTS_BALANCE_EG_ERROR;
goto out;
}
// Wgg*G + Wgd*D == M*scale + Wmd*D + Wme*E + Wmg*G, already scaled
if (!CHECK_EQ(Wgg*G + Wgd*D, M*scale + Wmd*D + Wme*E + Wmg*G,
(margin*T)/3)) {
berr = BW_WEIGHTS_BALANCE_MID_ERROR;
goto out;
}
}
out:
if (berr) {
log_info(LD_DIR,
"Bw weight mismatch %d. G="I64_FORMAT" M="I64_FORMAT
" E="I64_FORMAT" D="I64_FORMAT" T="I64_FORMAT
" Wmd=%d Wme=%d Wmg=%d Wed=%d Wee=%d"
" Wgd=%d Wgg=%d Wme=%d Wmg=%d",
berr,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T),
(int)Wmd, (int)Wme, (int)Wmg, (int)Wed, (int)Wee,
(int)Wgd, (int)Wgg, (int)Wme, (int)Wmg);
}
return berr;
}
/**
* This function computes the bandwidth weights for consensus method 10.
*
* It returns true if weights could be computed, false otherwise.
*/
int
networkstatus_compute_bw_weights_v10(smartlist_t *chunks, int64_t G,
int64_t M, int64_t E, int64_t D,
int64_t T, int64_t weight_scale)
{
bw_weights_error_t berr = 0;
int64_t Wgg = -1, Wgd = -1;
int64_t Wmg = -1, Wme = -1, Wmd = -1;
int64_t Wed = -1, Wee = -1;
const char *casename;
if (G <= 0 || M <= 0 || E <= 0 || D <= 0) {
log_warn(LD_DIR, "Consensus with empty bandwidth: "
"G="I64_FORMAT" M="I64_FORMAT" E="I64_FORMAT
" D="I64_FORMAT" T="I64_FORMAT,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T));
return 0;
}
/*
* Computed from cases in 3.8.3 of dir-spec.txt
*
* 1. Neither are scarce
* 2. Both Guard and Exit are scarce
* a. R+D <= S
* b. R+D > S
* 3. One of Guard or Exit is scarce
* a. S+D < T/3
* b. S+D >= T/3
*/
if (3*E >= T && 3*G >= T) { // E >= T/3 && G >= T/3
/* Case 1: Neither are scarce. */
casename = "Case 1 (Wgd=Wmd=Wed)";
Wgd = weight_scale/3;
Wed = weight_scale/3;
Wmd = weight_scale/3;
Wee = (weight_scale*(E+G+M))/(3*E);
Wme = weight_scale - Wee;
Wmg = (weight_scale*(2*G-E-M))/(3*G);
Wgg = weight_scale - Wmg;
berr = networkstatus_check_weights(Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed,
weight_scale, G, M, E, D, T, 10, 1);
if (berr) {
log_warn(LD_DIR,
"Bw Weights error %d for %s v10. G="I64_FORMAT" M="I64_FORMAT
" E="I64_FORMAT" D="I64_FORMAT" T="I64_FORMAT
" Wmd=%d Wme=%d Wmg=%d Wed=%d Wee=%d"
" Wgd=%d Wgg=%d Wme=%d Wmg=%d weight_scale=%d",
berr, casename,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T),
(int)Wmd, (int)Wme, (int)Wmg, (int)Wed, (int)Wee,
(int)Wgd, (int)Wgg, (int)Wme, (int)Wmg, (int)weight_scale);
return 0;
}
} else if (3*E < T && 3*G < T) { // E < T/3 && G < T/3
int64_t R = MIN(E, G);
int64_t S = MAX(E, G);
/*
* Case 2: Both Guards and Exits are scarce
* Balance D between E and G, depending upon
* D capacity and scarcity.
*/
if (R+D < S) { // Subcase a
Wgg = weight_scale;
Wee = weight_scale;
Wmg = 0;
Wme = 0;
Wmd = 0;
if (E < G) {
casename = "Case 2a (E scarce)";
Wed = weight_scale;
Wgd = 0;
} else { /* E >= G */
casename = "Case 2a (G scarce)";
Wed = 0;
Wgd = weight_scale;
}
} else { // Subcase b: R+D >= S
casename = "Case 2b1 (Wgg=weight_scale, Wmd=Wgd)";
Wee = (weight_scale*(E - G + M))/E;
Wed = (weight_scale*(D - 2*E + 4*G - 2*M))/(3*D);
Wme = (weight_scale*(G-M))/E;
Wmg = 0;
Wgg = weight_scale;
Wmd = (weight_scale - Wed)/2;
Wgd = (weight_scale - Wed)/2;
berr = networkstatus_check_weights(Wgg, Wgd, Wmg, Wme, Wmd, Wee, Wed,
weight_scale, G, M, E, D, T, 10, 1);
if (berr) {
casename = "Case 2b2 (Wgg=weight_scale, Wee=weight_scale)";
Wgg = weight_scale;
Wee = weight_scale;
Wed = (weight_scale*(D - 2*E + G + M))/(3*D);
Wmd = (weight_scale*(D - 2*M + G + E))/(3*D);
Wme = 0;
Wmg = 0;
if (Wmd < 0) { // Can happen if M > T/3
casename = "Case 2b3 (Wmd=0)";
Wmd = 0;
log_warn(LD_DIR,
"Too much Middle bandwidth on the network to calculate "
"balanced bandwidth-weights. Consider increasing the "
"number of Guard nodes by lowering the requirements.");
}
Wgd = weight_scale - Wed - Wmd;
berr = networkstatus_check_weights(Wgg, Wgd, Wmg, Wme, Wmd, Wee,
Wed, weight_scale, G, M, E, D, T, 10, 1);
}
if (berr != BW_WEIGHTS_NO_ERROR &&
berr != BW_WEIGHTS_BALANCE_MID_ERROR) {
log_warn(LD_DIR,
"Bw Weights error %d for %s v10. G="I64_FORMAT" M="I64_FORMAT
" E="I64_FORMAT" D="I64_FORMAT" T="I64_FORMAT
" Wmd=%d Wme=%d Wmg=%d Wed=%d Wee=%d"
" Wgd=%d Wgg=%d Wme=%d Wmg=%d weight_scale=%d",
berr, casename,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T),
(int)Wmd, (int)Wme, (int)Wmg, (int)Wed, (int)Wee,
(int)Wgd, (int)Wgg, (int)Wme, (int)Wmg, (int)weight_scale);
return 0;
}
}
} else { // if (E < T/3 || G < T/3) {
int64_t S = MIN(E, G);
// Case 3: Exactly one of Guard or Exit is scarce
if (!(3*E < T || 3*G < T) || !(3*G >= T || 3*E >= T)) {
log_warn(LD_BUG,
"Bw-Weights Case 3 v10 but with G="I64_FORMAT" M="
I64_FORMAT" E="I64_FORMAT" D="I64_FORMAT" T="I64_FORMAT,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T));
}
if (3*(S+D) < T) { // Subcase a: S+D < T/3
if (G < E) {
casename = "Case 3a (G scarce)";
Wgg = Wgd = weight_scale;
Wmd = Wed = Wmg = 0;
// Minor subcase, if E is more scarce than M,
// keep its bandwidth in place.
if (E < M) Wme = 0;
else Wme = (weight_scale*(E-M))/(2*E);
Wee = weight_scale-Wme;
} else { // G >= E
casename = "Case 3a (E scarce)";
Wee = Wed = weight_scale;
Wmd = Wgd = Wme = 0;
// Minor subcase, if G is more scarce than M,
// keep its bandwidth in place.
if (G < M) Wmg = 0;
else Wmg = (weight_scale*(G-M))/(2*G);
Wgg = weight_scale-Wmg;
}
} else { // Subcase b: S+D >= T/3
// D != 0 because S+D >= T/3
if (G < E) {
casename = "Case 3bg (G scarce, Wgg=weight_scale, Wmd == Wed)";
Wgg = weight_scale;
Wgd = (weight_scale*(D - 2*G + E + M))/(3*D);
Wmg = 0;
Wee = (weight_scale*(E+M))/(2*E);
Wme = weight_scale - Wee;
Wmd = (weight_scale - Wgd)/2;
Wed = (weight_scale - Wgd)/2;
berr = networkstatus_check_weights(Wgg, Wgd, Wmg, Wme, Wmd, Wee,
Wed, weight_scale, G, M, E, D, T, 10, 1);
} else { // G >= E
casename = "Case 3be (E scarce, Wee=weight_scale, Wmd == Wgd)";
Wee = weight_scale;
Wed = (weight_scale*(D - 2*E + G + M))/(3*D);
Wme = 0;
Wgg = (weight_scale*(G+M))/(2*G);
Wmg = weight_scale - Wgg;
Wmd = (weight_scale - Wed)/2;
Wgd = (weight_scale - Wed)/2;
berr = networkstatus_check_weights(Wgg, Wgd, Wmg, Wme, Wmd, Wee,
Wed, weight_scale, G, M, E, D, T, 10, 1);
}
if (berr) {
log_warn(LD_DIR,
"Bw Weights error %d for %s v10. G="I64_FORMAT" M="I64_FORMAT
" E="I64_FORMAT" D="I64_FORMAT" T="I64_FORMAT
" Wmd=%d Wme=%d Wmg=%d Wed=%d Wee=%d"
" Wgd=%d Wgg=%d Wme=%d Wmg=%d weight_scale=%d",
berr, casename,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T),
(int)Wmd, (int)Wme, (int)Wmg, (int)Wed, (int)Wee,
(int)Wgd, (int)Wgg, (int)Wme, (int)Wmg, (int)weight_scale);
return 0;
}
}
}
/* We cast down the weights to 32 bit ints on the assumption that
* weight_scale is ~= 10000. We need to ensure a rogue authority
* doesn't break this assumption to rig our weights */
tor_assert(0 < weight_scale && weight_scale <= INT32_MAX);
/*
* Provide Wgm=Wgg, Wmm=weight_scale, Wem=Wee, Weg=Wed. May later determine
* that middle nodes need different bandwidth weights for dirport traffic,
* or that weird exit policies need special weight, or that bridges
* need special weight.
*
* NOTE: This list is sorted.
*/
smartlist_add_asprintf(chunks,
"bandwidth-weights Wbd=%d Wbe=%d Wbg=%d Wbm=%d "
"Wdb=%d "
"Web=%d Wed=%d Wee=%d Weg=%d Wem=%d "
"Wgb=%d Wgd=%d Wgg=%d Wgm=%d "
"Wmb=%d Wmd=%d Wme=%d Wmg=%d Wmm=%d\n",
(int)Wmd, (int)Wme, (int)Wmg, (int)weight_scale,
(int)weight_scale,
(int)weight_scale, (int)Wed, (int)Wee, (int)Wed, (int)Wee,
(int)weight_scale, (int)Wgd, (int)Wgg, (int)Wgg,
(int)weight_scale, (int)Wmd, (int)Wme, (int)Wmg, (int)weight_scale);
log_notice(LD_CIRC, "Computed bandwidth weights for %s with v10: "
"G="I64_FORMAT" M="I64_FORMAT" E="I64_FORMAT" D="I64_FORMAT
" T="I64_FORMAT,
casename,
I64_PRINTF_ARG(G), I64_PRINTF_ARG(M), I64_PRINTF_ARG(E),
I64_PRINTF_ARG(D), I64_PRINTF_ARG(T));
return 1;
}
/** Update total bandwidth weights (G/M/E/D/T) with the bandwidth of
* the router in <b>rs</b>. */
static void
update_total_bandwidth_weights(const routerstatus_t *rs,
int is_exit, int is_guard,
int64_t *G, int64_t *M, int64_t *E, int64_t *D,
int64_t *T)
{
int default_bandwidth = rs->bandwidth_kb;
int guardfraction_bandwidth = 0;
if (!rs->has_bandwidth) {
log_info(LD_BUG, "Missing consensus bandwidth for router %s",
rs->nickname);
return;
}
/* If this routerstatus represents a guard that we have
* guardfraction information on, use it to calculate its actual
* bandwidth. From proposal236:
*
* Similarly, when calculating the bandwidth-weights line as in
* section 3.8.3 of dir-spec.txt, directory authorities should treat N
* as if fraction F of its bandwidth has the guard flag and (1-F) does
* not. So when computing the totals G,M,E,D, each relay N with guard
* visibility fraction F and bandwidth B should be added as follows:
*
* G' = G + F*B, if N does not have the exit flag
* M' = M + (1-F)*B, if N does not have the exit flag
*
* or
*
* D' = D + F*B, if N has the exit flag
* E' = E + (1-F)*B, if N has the exit flag
*
* In this block of code, we prepare the bandwidth values by setting
* the default_bandwidth to F*B and guardfraction_bandwidth to (1-F)*B.
*/
if (rs->has_guardfraction) {
guardfraction_bandwidth_t guardfraction_bw;
tor_assert(is_guard);
guard_get_guardfraction_bandwidth(&guardfraction_bw,
rs->bandwidth_kb,
rs->guardfraction_percentage);
default_bandwidth = guardfraction_bw.guard_bw;
guardfraction_bandwidth = guardfraction_bw.non_guard_bw;
}
/* Now calculate the total bandwidth weights with or without
* guardfraction. Depending on the flags of the relay, add its
* bandwidth to the appropriate weight pool. If it's a guard and
* guardfraction is enabled, add its bandwidth to both pools as
* indicated by the previous comment.
*/
*T += default_bandwidth;
if (is_exit && is_guard) {
*D += default_bandwidth;
if (rs->has_guardfraction) {
*E += guardfraction_bandwidth;
}
} else if (is_exit) {
*E += default_bandwidth;
} else if (is_guard) {
*G += default_bandwidth;
if (rs->has_guardfraction) {
*M += guardfraction_bandwidth;
}
} else {
*M += default_bandwidth;
}
}
/** Considering the different recommended/required protocols sets as a
* 4-element array, return the element from <b>vote</b> for that protocol
* set.
*/
static const char *
get_nth_protocol_set_vote(int n, const networkstatus_t *vote)
{
switch (n) {
case 0: return vote->recommended_client_protocols;
case 1: return vote->recommended_relay_protocols;
case 2: return vote->required_client_protocols;
case 3: return vote->required_relay_protocols;
default:
tor_assert_unreached();
return NULL;
}
}
/** Considering the different recommended/required protocols sets as a
* 4-element array, return a newly allocated string for the consensus value
* for the n'th set.
*/
static char *
compute_nth_protocol_set(int n, int n_voters, const smartlist_t *votes)
{
const char *keyword;
smartlist_t *proto_votes = smartlist_new();
int threshold;
switch (n) {
case 0:
keyword = "recommended-client-protocols";
threshold = CEIL_DIV(n_voters, 2);
break;
case 1:
keyword = "recommended-relay-protocols";
threshold = CEIL_DIV(n_voters, 2);
break;
case 2:
keyword = "required-client-protocols";
threshold = CEIL_DIV(n_voters * 2, 3);
break;
case 3:
keyword = "required-relay-protocols";
threshold = CEIL_DIV(n_voters * 2, 3);
break;
default:
tor_assert_unreached();
return NULL;
}
SMARTLIST_FOREACH_BEGIN(votes, const networkstatus_t *, ns) {
const char *v = get_nth_protocol_set_vote(n, ns);
if (v)
smartlist_add(proto_votes, (void*)v);
} SMARTLIST_FOREACH_END(ns);
char *protocols = protover_compute_vote(proto_votes, threshold);
smartlist_free(proto_votes);
char *result = NULL;
tor_asprintf(&result, "%s %s\n", keyword, protocols);
tor_free(protocols);
return result;
}
/** Given a list of vote networkstatus_t in <b>votes</b>, our public
* authority <b>identity_key</b>, our private authority <b>signing_key</b>,
* and the number of <b>total_authorities</b> that we believe exist in our
* voting quorum, generate the text of a new v3 consensus vote, and return the
* value in a newly allocated string.
*
* Note: this function DOES NOT check whether the votes are from
* recognized authorities. (dirvote_add_vote does that.)
*
* <strong>WATCH OUT</strong>: You need to think before you change the
* behavior of this function, or of the functions it calls! If some
* authorities compute the consensus with a different algorithm than
* others, they will not reach the same result, and they will not all
* sign the same thing! If you really need to change the algorithm
* here, you should allocate a new "consensus_method" for the new
* behavior, and make the new behavior conditional on a new-enough
* consensus_method.
**/
char *
networkstatus_compute_consensus(smartlist_t *votes,
int total_authorities,
crypto_pk_t *identity_key,
crypto_pk_t *signing_key,
const char *legacy_id_key_digest,
crypto_pk_t *legacy_signing_key,
consensus_flavor_t flavor)
{
smartlist_t *chunks;
char *result = NULL;
int consensus_method;
time_t valid_after, fresh_until, valid_until;
int vote_seconds, dist_seconds;
char *client_versions = NULL, *server_versions = NULL;
smartlist_t *flags;
const char *flavor_name;
uint32_t max_unmeasured_bw_kb = DEFAULT_MAX_UNMEASURED_BW_KB;
int64_t G, M, E, D, T; /* For bandwidth weights */
const routerstatus_format_type_t rs_format =
flavor == FLAV_NS ? NS_V3_CONSENSUS : NS_V3_CONSENSUS_MICRODESC;
char *params = NULL;
char *packages = NULL;
int added_weights = 0;
dircollator_t *collator = NULL;
smartlist_t *param_list = NULL;
tor_assert(flavor == FLAV_NS || flavor == FLAV_MICRODESC);
tor_assert(total_authorities >= smartlist_len(votes));
tor_assert(total_authorities > 0);
flavor_name = networkstatus_get_flavor_name(flavor);
if (!smartlist_len(votes)) {
log_warn(LD_DIR, "Can't compute a consensus from no votes.");
return NULL;
}
flags = smartlist_new();
consensus_method = compute_consensus_method(votes);
if (consensus_method_is_supported(consensus_method)) {
log_info(LD_DIR, "Generating consensus using method %d.",
consensus_method);
} else {
log_warn(LD_DIR, "The other authorities will use consensus method %d, "
"which I don't support. Maybe I should upgrade!",
consensus_method);
consensus_method = MAX_SUPPORTED_CONSENSUS_METHOD;
}
if (consensus_method >= MIN_METHOD_FOR_INIT_BW_WEIGHTS_ONE) {
/* It's smarter to initialize these weights to 1, so that later on,
* we can't accidentally divide by zero. */
G = M = E = D = 1;
T = 4;
} else {
/* ...but originally, they were set to zero. */
G = M = E = D = T = 0;
}
/* Compute medians of time-related things, and figure out how many
* routers we might need to talk about. */
{
int n_votes = smartlist_len(votes);
time_t *va_times = tor_calloc(n_votes, sizeof(time_t));
time_t *fu_times = tor_calloc(n_votes, sizeof(time_t));
time_t *vu_times = tor_calloc(n_votes, sizeof(time_t));
int *votesec_list = tor_calloc(n_votes, sizeof(int));
int *distsec_list = tor_calloc(n_votes, sizeof(int));
int n_versioning_clients = 0, n_versioning_servers = 0;
smartlist_t *combined_client_versions = smartlist_new();
smartlist_t *combined_server_versions = smartlist_new();
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
tor_assert(v->type == NS_TYPE_VOTE);
va_times[v_sl_idx] = v->valid_after;
fu_times[v_sl_idx] = v->fresh_until;
vu_times[v_sl_idx] = v->valid_until;
votesec_list[v_sl_idx] = v->vote_seconds;
distsec_list[v_sl_idx] = v->dist_seconds;
if (v->client_versions) {
smartlist_t *cv = smartlist_new();
++n_versioning_clients;
smartlist_split_string(cv, v->client_versions, ",",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
sort_version_list(cv, 1);
smartlist_add_all(combined_client_versions, cv);
smartlist_free(cv); /* elements get freed later. */
}
if (v->server_versions) {
smartlist_t *sv = smartlist_new();
++n_versioning_servers;
smartlist_split_string(sv, v->server_versions, ",",
SPLIT_SKIP_SPACE|SPLIT_IGNORE_BLANK, 0);
sort_version_list(sv, 1);
smartlist_add_all(combined_server_versions, sv);
smartlist_free(sv); /* elements get freed later. */
}
SMARTLIST_FOREACH(v->known_flags, const char *, cp,
smartlist_add_strdup(flags, cp));
} SMARTLIST_FOREACH_END(v);
valid_after = median_time(va_times, n_votes);
fresh_until = median_time(fu_times, n_votes);
valid_until = median_time(vu_times, n_votes);
vote_seconds = median_int(votesec_list, n_votes);
dist_seconds = median_int(distsec_list, n_votes);
tor_assert(valid_after +
(get_options()->TestingTorNetwork ?
MIN_VOTE_INTERVAL_TESTING : MIN_VOTE_INTERVAL) <= fresh_until);
tor_assert(fresh_until +
(get_options()->TestingTorNetwork ?
MIN_VOTE_INTERVAL_TESTING : MIN_VOTE_INTERVAL) <= valid_until);
tor_assert(vote_seconds >= MIN_VOTE_SECONDS);
tor_assert(dist_seconds >= MIN_DIST_SECONDS);
server_versions = compute_consensus_versions_list(combined_server_versions,
n_versioning_servers);
client_versions = compute_consensus_versions_list(combined_client_versions,
n_versioning_clients);
if (consensus_method >= MIN_METHOD_FOR_PACKAGE_LINES) {
packages = compute_consensus_package_lines(votes);
} else {
packages = tor_strdup("");
}
SMARTLIST_FOREACH(combined_server_versions, char *, cp, tor_free(cp));
SMARTLIST_FOREACH(combined_client_versions, char *, cp, tor_free(cp));
smartlist_free(combined_server_versions);
smartlist_free(combined_client_versions);
if (consensus_method >= MIN_METHOD_FOR_ED25519_ID_VOTING)
smartlist_add_strdup(flags, "NoEdConsensus");
smartlist_sort_strings(flags);
smartlist_uniq_strings(flags);
tor_free(va_times);
tor_free(fu_times);
tor_free(vu_times);
tor_free(votesec_list);
tor_free(distsec_list);
}
chunks = smartlist_new();
{
char va_buf[ISO_TIME_LEN+1], fu_buf[ISO_TIME_LEN+1],
vu_buf[ISO_TIME_LEN+1];
char *flaglist;
format_iso_time(va_buf, valid_after);
format_iso_time(fu_buf, fresh_until);
format_iso_time(vu_buf, valid_until);
flaglist = smartlist_join_strings(flags, " ", 0, NULL);
smartlist_add_asprintf(chunks, "network-status-version 3%s%s\n"
"vote-status consensus\n",
flavor == FLAV_NS ? "" : " ",
flavor == FLAV_NS ? "" : flavor_name);
smartlist_add_asprintf(chunks, "consensus-method %d\n",
consensus_method);
smartlist_add_asprintf(chunks,
"valid-after %s\n"
"fresh-until %s\n"
"valid-until %s\n"
"voting-delay %d %d\n"
"client-versions %s\n"
"server-versions %s\n"
"%s" /* packages */
"known-flags %s\n",
va_buf, fu_buf, vu_buf,
vote_seconds, dist_seconds,
client_versions, server_versions,
packages,
flaglist);
tor_free(flaglist);
}
if (consensus_method >= MIN_METHOD_FOR_RECOMMENDED_PROTOCOLS) {
int num_dirauth = get_n_authorities(V3_DIRINFO);
int idx;
for (idx = 0; idx < 4; ++idx) {
char *proto_line = compute_nth_protocol_set(idx, num_dirauth, votes);
if (BUG(!proto_line))
continue;
smartlist_add(chunks, proto_line);
}
}
param_list = dirvote_compute_params(votes, consensus_method,
total_authorities);
if (smartlist_len(param_list)) {
params = smartlist_join_strings(param_list, " ", 0, NULL);
smartlist_add_strdup(chunks, "params ");
smartlist_add(chunks, params);
smartlist_add_strdup(chunks, "\n");
}
if (consensus_method >= MIN_METHOD_FOR_SHARED_RANDOM) {
int num_dirauth = get_n_authorities(V3_DIRINFO);
/* Default value of this is 2/3 of the total number of authorities. For
* instance, if we have 9 dirauth, the default value is 6. The following
* calculation will round it down. */
int32_t num_srv_agreements =
dirvote_get_intermediate_param_value(param_list,
"AuthDirNumSRVAgreements",
(num_dirauth * 2) / 3);
/* Add the shared random value. */
char *srv_lines = sr_get_string_for_consensus(votes, num_srv_agreements);
if (srv_lines != NULL) {
smartlist_add(chunks, srv_lines);
}
}
/* Sort the votes. */
smartlist_sort(votes, compare_votes_by_authority_id_);
/* Add the authority sections. */
{
smartlist_t *dir_sources = smartlist_new();
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
dir_src_ent_t *e = tor_malloc_zero(sizeof(dir_src_ent_t));
e->v = v;
e->digest = get_voter(v)->identity_digest;
e->is_legacy = 0;
smartlist_add(dir_sources, e);
if (!tor_digest_is_zero(get_voter(v)->legacy_id_digest)) {
dir_src_ent_t *e_legacy = tor_malloc_zero(sizeof(dir_src_ent_t));
e_legacy->v = v;
e_legacy->digest = get_voter(v)->legacy_id_digest;
e_legacy->is_legacy = 1;
smartlist_add(dir_sources, e_legacy);
}
} SMARTLIST_FOREACH_END(v);
smartlist_sort(dir_sources, compare_dir_src_ents_by_authority_id_);
SMARTLIST_FOREACH_BEGIN(dir_sources, const dir_src_ent_t *, e) {
char fingerprint[HEX_DIGEST_LEN+1];
char votedigest[HEX_DIGEST_LEN+1];
networkstatus_t *v = e->v;
networkstatus_voter_info_t *voter = get_voter(v);
base16_encode(fingerprint, sizeof(fingerprint), e->digest, DIGEST_LEN);
base16_encode(votedigest, sizeof(votedigest), voter->vote_digest,
DIGEST_LEN);
smartlist_add_asprintf(chunks,
"dir-source %s%s %s %s %s %d %d\n",
voter->nickname, e->is_legacy ? "-legacy" : "",
fingerprint, voter->address, fmt_addr32(voter->addr),
voter->dir_port,
voter->or_port);
if (! e->is_legacy) {
smartlist_add_asprintf(chunks,
"contact %s\n"
"vote-digest %s\n",
voter->contact,
votedigest);
}
} SMARTLIST_FOREACH_END(e);
SMARTLIST_FOREACH(dir_sources, dir_src_ent_t *, e, tor_free(e));
smartlist_free(dir_sources);
}
if (consensus_method >= MIN_METHOD_TO_CLIP_UNMEASURED_BW) {
char *max_unmeasured_param = NULL;
/* XXXX Extract this code into a common function. Or don't! see #19011 */
if (params) {
if (strcmpstart(params, "maxunmeasuredbw=") == 0)
max_unmeasured_param = params;
else
max_unmeasured_param = strstr(params, " maxunmeasuredbw=");
}
if (max_unmeasured_param) {
int ok = 0;
char *eq = strchr(max_unmeasured_param, '=');
if (eq) {
max_unmeasured_bw_kb = (uint32_t)
tor_parse_ulong(eq+1, 10, 1, UINT32_MAX, &ok, NULL);
if (!ok) {
log_warn(LD_DIR, "Bad element '%s' in max unmeasured bw param",
escaped(max_unmeasured_param));
max_unmeasured_bw_kb = DEFAULT_MAX_UNMEASURED_BW_KB;
}
}
}
}
/* Add the actual router entries. */
{
int *size; /* size[j] is the number of routerstatuses in votes[j]. */
int *flag_counts; /* The number of voters that list flag[j] for the
* currently considered router. */
int i;
smartlist_t *matching_descs = smartlist_new();
smartlist_t *chosen_flags = smartlist_new();
smartlist_t *versions = smartlist_new();
smartlist_t *protocols = smartlist_new();
smartlist_t *exitsummaries = smartlist_new();
uint32_t *bandwidths_kb = tor_calloc(smartlist_len(votes),
sizeof(uint32_t));
uint32_t *measured_bws_kb = tor_calloc(smartlist_len(votes),
sizeof(uint32_t));
uint32_t *measured_guardfraction = tor_calloc(smartlist_len(votes),
sizeof(uint32_t));
int num_bandwidths;
int num_mbws;
int num_guardfraction_inputs;
int *n_voter_flags; /* n_voter_flags[j] is the number of flags that
* votes[j] knows about. */
int *n_flag_voters; /* n_flag_voters[f] is the number of votes that care
* about flags[f]. */
int **flag_map; /* flag_map[j][b] is an index f such that flag_map[f]
* is the same flag as votes[j]->known_flags[b]. */
int *named_flag; /* Index of the flag "Named" for votes[j] */
int *unnamed_flag; /* Index of the flag "Unnamed" for votes[j] */
int n_authorities_measuring_bandwidth;
strmap_t *name_to_id_map = strmap_new();
char conflict[DIGEST_LEN];
char unknown[DIGEST_LEN];
memset(conflict, 0, sizeof(conflict));
memset(unknown, 0xff, sizeof(conflict));
size = tor_calloc(smartlist_len(votes), sizeof(int));
n_voter_flags = tor_calloc(smartlist_len(votes), sizeof(int));
n_flag_voters = tor_calloc(smartlist_len(flags), sizeof(int));
flag_map = tor_calloc(smartlist_len(votes), sizeof(int *));
named_flag = tor_calloc(smartlist_len(votes), sizeof(int));
unnamed_flag = tor_calloc(smartlist_len(votes), sizeof(int));
for (i = 0; i < smartlist_len(votes); ++i)
unnamed_flag[i] = named_flag[i] = -1;
/* Build the flag indexes. Note that no vote can have more than 64 members
* for known_flags, so no value will be greater than 63, so it's safe to
* do U64_LITERAL(1) << index on these values. But note also that
* named_flag and unnamed_flag are initialized to -1, so we need to check
* that they're actually set before doing U64_LITERAL(1) << index with
* them.*/
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
flag_map[v_sl_idx] = tor_calloc(smartlist_len(v->known_flags),
sizeof(int));
if (smartlist_len(v->known_flags) > MAX_KNOWN_FLAGS_IN_VOTE) {
log_warn(LD_BUG, "Somehow, a vote has %d entries in known_flags",
smartlist_len(v->known_flags));
}
SMARTLIST_FOREACH_BEGIN(v->known_flags, const char *, fl) {
int p = smartlist_string_pos(flags, fl);
tor_assert(p >= 0);
flag_map[v_sl_idx][fl_sl_idx] = p;
++n_flag_voters[p];
if (!strcmp(fl, "Named"))
named_flag[v_sl_idx] = fl_sl_idx;
if (!strcmp(fl, "Unnamed"))
unnamed_flag[v_sl_idx] = fl_sl_idx;
} SMARTLIST_FOREACH_END(fl);
n_voter_flags[v_sl_idx] = smartlist_len(v->known_flags);
size[v_sl_idx] = smartlist_len(v->routerstatus_list);
} SMARTLIST_FOREACH_END(v);
/* Named and Unnamed get treated specially */
{
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
uint64_t nf;
if (named_flag[v_sl_idx]<0)
continue;
nf = U64_LITERAL(1) << named_flag[v_sl_idx];
SMARTLIST_FOREACH_BEGIN(v->routerstatus_list,
vote_routerstatus_t *, rs) {
if ((rs->flags & nf) != 0) {
const char *d = strmap_get_lc(name_to_id_map, rs->status.nickname);
if (!d) {
/* We have no name officially mapped to this digest. */
strmap_set_lc(name_to_id_map, rs->status.nickname,
rs->status.identity_digest);
} else if (d != conflict &&
fast_memcmp(d, rs->status.identity_digest, DIGEST_LEN)) {
/* Authorities disagree about this nickname. */
strmap_set_lc(name_to_id_map, rs->status.nickname, conflict);
} else {
/* It's already a conflict, or it's already this ID. */
}
}
} SMARTLIST_FOREACH_END(rs);
} SMARTLIST_FOREACH_END(v);
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
uint64_t uf;
if (unnamed_flag[v_sl_idx]<0)
continue;
uf = U64_LITERAL(1) << unnamed_flag[v_sl_idx];
SMARTLIST_FOREACH_BEGIN(v->routerstatus_list,
vote_routerstatus_t *, rs) {
if ((rs->flags & uf) != 0) {
const char *d = strmap_get_lc(name_to_id_map, rs->status.nickname);
if (d == conflict || d == unknown) {
/* Leave it alone; we know what it is. */
} else if (!d) {
/* We have no name officially mapped to this digest. */
strmap_set_lc(name_to_id_map, rs->status.nickname, unknown);
} else if (fast_memeq(d, rs->status.identity_digest, DIGEST_LEN)) {
/* Authorities disagree about this nickname. */
strmap_set_lc(name_to_id_map, rs->status.nickname, conflict);
} else {
/* It's mapped to a different name. */
}
}
} SMARTLIST_FOREACH_END(rs);
} SMARTLIST_FOREACH_END(v);
}
/* We need to know how many votes measure bandwidth. */
n_authorities_measuring_bandwidth = 0;
SMARTLIST_FOREACH(votes, const networkstatus_t *, v,
if (v->has_measured_bws) {
++n_authorities_measuring_bandwidth;
}
);
/* Populate the collator */
collator = dircollator_new(smartlist_len(votes), total_authorities);
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
dircollator_add_vote(collator, v);
} SMARTLIST_FOREACH_END(v);
dircollator_collate(collator, consensus_method);
/* Now go through all the votes */
flag_counts = tor_calloc(smartlist_len(flags), sizeof(int));
const int num_routers = dircollator_n_routers(collator);
for (i = 0; i < num_routers; ++i) {
vote_routerstatus_t **vrs_lst =
dircollator_get_votes_for_router(collator, i);
vote_routerstatus_t *rs;
routerstatus_t rs_out;
const char *current_rsa_id = NULL;
const char *chosen_version;
const char *chosen_protocol_list;
const char *chosen_name = NULL;
int exitsummary_disagreement = 0;
int is_named = 0, is_unnamed = 0, is_running = 0, is_valid = 0;
int is_guard = 0, is_exit = 0, is_bad_exit = 0;
int naming_conflict = 0;
int n_listing = 0;
char microdesc_digest[DIGEST256_LEN];
tor_addr_port_t alt_orport = {TOR_ADDR_NULL, 0};
memset(flag_counts, 0, sizeof(int)*smartlist_len(flags));
smartlist_clear(matching_descs);
smartlist_clear(chosen_flags);
smartlist_clear(versions);
smartlist_clear(protocols);
num_bandwidths = 0;
num_mbws = 0;
num_guardfraction_inputs = 0;
int ed_consensus = 0;
const uint8_t *ed_consensus_val = NULL;
/* Okay, go through all the entries for this digest. */
for (int voter_idx = 0; voter_idx < smartlist_len(votes); ++voter_idx) {
if (vrs_lst[voter_idx] == NULL)
continue; /* This voter had nothing to say about this entry. */
rs = vrs_lst[voter_idx];
++n_listing;
current_rsa_id = rs->status.identity_digest;
smartlist_add(matching_descs, rs);
if (rs->version && rs->version[0])
smartlist_add(versions, rs->version);
if (rs->protocols) {
/* We include this one even if it's empty: voting for an
* empty protocol list actually is meaningful. */
smartlist_add(protocols, rs->protocols);
}
/* Tally up all the flags. */
for (int flag = 0; flag < n_voter_flags[voter_idx]; ++flag) {
if (rs->flags & (U64_LITERAL(1) << flag))
++flag_counts[flag_map[voter_idx][flag]];
}
if (named_flag[voter_idx] >= 0 &&
(rs->flags & (U64_LITERAL(1) << named_flag[voter_idx]))) {
if (chosen_name && strcmp(chosen_name, rs->status.nickname)) {
log_notice(LD_DIR, "Conflict on naming for router: %s vs %s",
chosen_name, rs->status.nickname);
naming_conflict = 1;
}
chosen_name = rs->status.nickname;
}
/* Count guardfraction votes and note down the values. */
if (rs->status.has_guardfraction) {
measured_guardfraction[num_guardfraction_inputs++] =
rs->status.guardfraction_percentage;
}
/* count bandwidths */
if (rs->has_measured_bw)
measured_bws_kb[num_mbws++] = rs->measured_bw_kb;
if (rs->status.has_bandwidth)
bandwidths_kb[num_bandwidths++] = rs->status.bandwidth_kb;
/* Count number for which ed25519 is canonical. */
if (rs->ed25519_reflects_consensus) {
++ed_consensus;
if (ed_consensus_val) {
tor_assert(fast_memeq(ed_consensus_val, rs->ed25519_id,
ED25519_PUBKEY_LEN));
} else {
ed_consensus_val = rs->ed25519_id;
}
}
}
/* We don't include this router at all unless more than half of
* the authorities we believe in list it. */
if (n_listing <= total_authorities/2)
continue;
if (ed_consensus > 0) {
tor_assert(consensus_method >= MIN_METHOD_FOR_ED25519_ID_VOTING);
if (ed_consensus <= total_authorities / 2) {
log_warn(LD_BUG, "Not enough entries had ed_consensus set; how "
"can we have a consensus of %d?", ed_consensus);
}
}
/* The clangalyzer can't figure out that this will never be NULL
* if n_listing is at least 1 */
tor_assert(current_rsa_id);
/* Figure out the most popular opinion of what the most recent
* routerinfo and its contents are. */
memset(microdesc_digest, 0, sizeof(microdesc_digest));
rs = compute_routerstatus_consensus(matching_descs, consensus_method,
microdesc_digest, &alt_orport);
/* Copy bits of that into rs_out. */
memset(&rs_out, 0, sizeof(rs_out));
tor_assert(fast_memeq(current_rsa_id,
rs->status.identity_digest,DIGEST_LEN));
memcpy(rs_out.identity_digest, current_rsa_id, DIGEST_LEN);
memcpy(rs_out.descriptor_digest, rs->status.descriptor_digest,
DIGEST_LEN);
rs_out.addr = rs->status.addr;
rs_out.published_on = rs->status.published_on;
rs_out.dir_port = rs->status.dir_port;
rs_out.or_port = rs->status.or_port;
if (consensus_method >= MIN_METHOD_FOR_A_LINES) {
tor_addr_copy(&rs_out.ipv6_addr, &alt_orport.addr);
rs_out.ipv6_orport = alt_orport.port;
}
rs_out.has_bandwidth = 0;
rs_out.has_exitsummary = 0;
if (chosen_name && !naming_conflict) {
strlcpy(rs_out.nickname, chosen_name, sizeof(rs_out.nickname));
} else {
strlcpy(rs_out.nickname, rs->status.nickname, sizeof(rs_out.nickname));
}
{
const char *d = strmap_get_lc(name_to_id_map, rs_out.nickname);
if (!d) {
is_named = is_unnamed = 0;
} else if (fast_memeq(d, current_rsa_id, DIGEST_LEN)) {
is_named = 1; is_unnamed = 0;
} else {
is_named = 0; is_unnamed = 1;
}
}
/* Set the flags. */
smartlist_add(chosen_flags, (char*)"s"); /* for the start of the line. */
SMARTLIST_FOREACH_BEGIN(flags, const char *, fl) {
if (!strcmp(fl, "Named")) {
if (is_named)
smartlist_add(chosen_flags, (char*)fl);
} else if (!strcmp(fl, "Unnamed")) {
if (is_unnamed)
smartlist_add(chosen_flags, (char*)fl);
} else if (!strcmp(fl, "NoEdConsensus") &&
consensus_method >= MIN_METHOD_FOR_ED25519_ID_VOTING) {
if (ed_consensus <= total_authorities/2)
smartlist_add(chosen_flags, (char*)fl);
} else {
if (flag_counts[fl_sl_idx] > n_flag_voters[fl_sl_idx]/2) {
smartlist_add(chosen_flags, (char*)fl);
if (!strcmp(fl, "Exit"))
is_exit = 1;
else if (!strcmp(fl, "Guard"))
is_guard = 1;
else if (!strcmp(fl, "Running"))
is_running = 1;
else if (!strcmp(fl, "BadExit"))
is_bad_exit = 1;
else if (!strcmp(fl, "Valid"))
is_valid = 1;
}
}
} SMARTLIST_FOREACH_END(fl);
/* Starting with consensus method 4 we do not list servers
* that are not running in a consensus. See Proposal 138 */
if (!is_running)
continue;
/* Starting with consensus method 24, we don't list servers
* that are not valid in a consensus. See Proposal 272 */
if (!is_valid &&
consensus_method >= MIN_METHOD_FOR_EXCLUDING_INVALID_NODES)
continue;
/* Pick the version. */
if (smartlist_len(versions)) {
sort_version_list(versions, 0);
chosen_version = get_most_frequent_member(versions);
} else {
chosen_version = NULL;
}
/* Pick the protocol list */
if (smartlist_len(protocols)) {
smartlist_sort_strings(protocols);
chosen_protocol_list = get_most_frequent_member(protocols);
} else {
chosen_protocol_list = NULL;
}
/* If it's a guard and we have enough guardfraction votes,
calculate its consensus guardfraction value. */
if (is_guard && num_guardfraction_inputs > 2 &&
consensus_method >= MIN_METHOD_FOR_GUARDFRACTION) {
rs_out.has_guardfraction = 1;
rs_out.guardfraction_percentage = median_uint32(measured_guardfraction,
num_guardfraction_inputs);
/* final value should be an integer percentage! */
tor_assert(rs_out.guardfraction_percentage <= 100);
}
/* Pick a bandwidth */
if (num_mbws > 2) {
rs_out.has_bandwidth = 1;
rs_out.bw_is_unmeasured = 0;
rs_out.bandwidth_kb = median_uint32(measured_bws_kb, num_mbws);
} else if (num_bandwidths > 0) {
rs_out.has_bandwidth = 1;
rs_out.bw_is_unmeasured = 1;
rs_out.bandwidth_kb = median_uint32(bandwidths_kb, num_bandwidths);
if (consensus_method >= MIN_METHOD_TO_CLIP_UNMEASURED_BW &&
n_authorities_measuring_bandwidth > 2) {
/* Cap non-measured bandwidths. */
if (rs_out.bandwidth_kb > max_unmeasured_bw_kb) {
rs_out.bandwidth_kb = max_unmeasured_bw_kb;
}
}
}
/* Fix bug 2203: Do not count BadExit nodes as Exits for bw weights */
is_exit = is_exit && !is_bad_exit;
/* Update total bandwidth weights with the bandwidths of this router. */
{
update_total_bandwidth_weights(&rs_out,
is_exit, is_guard,
&G, &M, &E, &D, &T);
}
/* Ok, we already picked a descriptor digest we want to list
* previously. Now we want to use the exit policy summary from
* that descriptor. If everybody plays nice all the voters who
* listed that descriptor will have the same summary. If not then
* something is fishy and we'll use the most common one (breaking
* ties in favor of lexicographically larger one (only because it
* lets me reuse more existing code)).
*
* The other case that can happen is that no authority that voted
* for that descriptor has an exit policy summary. That's
* probably quite unlikely but can happen. In that case we use
* the policy that was most often listed in votes, again breaking
* ties like in the previous case.
*/
{
/* Okay, go through all the votes for this router. We prepared
* that list previously */
const char *chosen_exitsummary = NULL;
smartlist_clear(exitsummaries);
SMARTLIST_FOREACH_BEGIN(matching_descs, vote_routerstatus_t *, vsr) {
/* Check if the vote where this status comes from had the
* proper descriptor */
tor_assert(fast_memeq(rs_out.identity_digest,
vsr->status.identity_digest,
DIGEST_LEN));
if (vsr->status.has_exitsummary &&
fast_memeq(rs_out.descriptor_digest,
vsr->status.descriptor_digest,
DIGEST_LEN)) {
tor_assert(vsr->status.exitsummary);
smartlist_add(exitsummaries, vsr->status.exitsummary);
if (!chosen_exitsummary) {
chosen_exitsummary = vsr->status.exitsummary;
} else if (strcmp(chosen_exitsummary, vsr->status.exitsummary)) {
/* Great. There's disagreement among the voters. That
* really shouldn't be */
exitsummary_disagreement = 1;
}
}
} SMARTLIST_FOREACH_END(vsr);
if (exitsummary_disagreement) {
char id[HEX_DIGEST_LEN+1];
char dd[HEX_DIGEST_LEN+1];
base16_encode(id, sizeof(dd), rs_out.identity_digest, DIGEST_LEN);
base16_encode(dd, sizeof(dd), rs_out.descriptor_digest, DIGEST_LEN);
log_warn(LD_DIR, "The voters disagreed on the exit policy summary "
" for router %s with descriptor %s. This really shouldn't"
" have happened.", id, dd);
smartlist_sort_strings(exitsummaries);
chosen_exitsummary = get_most_frequent_member(exitsummaries);
} else if (!chosen_exitsummary) {
char id[HEX_DIGEST_LEN+1];
char dd[HEX_DIGEST_LEN+1];
base16_encode(id, sizeof(dd), rs_out.identity_digest, DIGEST_LEN);
base16_encode(dd, sizeof(dd), rs_out.descriptor_digest, DIGEST_LEN);
log_warn(LD_DIR, "Not one of the voters that made us select"
"descriptor %s for router %s had an exit policy"
"summary", dd, id);
/* Ok, none of those voting for the digest we chose had an
* exit policy for us. Well, that kinda sucks.
*/
smartlist_clear(exitsummaries);
SMARTLIST_FOREACH(matching_descs, vote_routerstatus_t *, vsr, {
if (vsr->status.has_exitsummary)
smartlist_add(exitsummaries, vsr->status.exitsummary);
});
smartlist_sort_strings(exitsummaries);
chosen_exitsummary = get_most_frequent_member(exitsummaries);
if (!chosen_exitsummary)
log_warn(LD_DIR, "Wow, not one of the voters had an exit "
"policy summary for %s. Wow.", id);
}
if (chosen_exitsummary) {
rs_out.has_exitsummary = 1;
/* yea, discards the const */
rs_out.exitsummary = (char *)chosen_exitsummary;
}
}
if (flavor == FLAV_MICRODESC &&
tor_digest256_is_zero(microdesc_digest)) {
/* With no microdescriptor digest, we omit the entry entirely. */
continue;
}
{
char *buf;
/* Okay!! Now we can write the descriptor... */
/* First line goes into "buf". */
buf = routerstatus_format_entry(&rs_out, NULL, NULL, rs_format, NULL);
if (buf)
smartlist_add(chunks, buf);
}
/* Now an m line, if applicable. */
if (flavor == FLAV_MICRODESC &&
!tor_digest256_is_zero(microdesc_digest)) {
char m[BASE64_DIGEST256_LEN+1];
digest256_to_base64(m, microdesc_digest);
smartlist_add_asprintf(chunks, "m %s\n", m);
}
/* Next line is all flags. The "\n" is missing. */
smartlist_add(chunks,
smartlist_join_strings(chosen_flags, " ", 0, NULL));
/* Now the version line. */
if (chosen_version) {
smartlist_add_strdup(chunks, "\nv ");
smartlist_add_strdup(chunks, chosen_version);
}
smartlist_add_strdup(chunks, "\n");
if (chosen_protocol_list &&
consensus_method >= MIN_METHOD_FOR_RS_PROTOCOLS) {
smartlist_add_asprintf(chunks, "pr %s\n", chosen_protocol_list);
}
/* Now the weight line. */
if (rs_out.has_bandwidth) {
char *guardfraction_str = NULL;
int unmeasured = rs_out.bw_is_unmeasured &&
consensus_method >= MIN_METHOD_TO_CLIP_UNMEASURED_BW;
/* If we have guardfraction info, include it in the 'w' line. */
if (rs_out.has_guardfraction) {
tor_asprintf(&guardfraction_str,
" GuardFraction=%u", rs_out.guardfraction_percentage);
}
smartlist_add_asprintf(chunks, "w Bandwidth=%d%s%s\n",
rs_out.bandwidth_kb,
unmeasured?" Unmeasured=1":"",
guardfraction_str ? guardfraction_str : "");
tor_free(guardfraction_str);
}
/* Now the exitpolicy summary line. */
if (rs_out.has_exitsummary && flavor == FLAV_NS) {
smartlist_add_asprintf(chunks, "p %s\n", rs_out.exitsummary);
}
/* And the loop is over and we move on to the next router */
}
tor_free(size);
tor_free(n_voter_flags);
tor_free(n_flag_voters);
for (i = 0; i < smartlist_len(votes); ++i)
tor_free(flag_map[i]);
tor_free(flag_map);
tor_free(flag_counts);
tor_free(named_flag);
tor_free(unnamed_flag);
strmap_free(name_to_id_map, NULL);
smartlist_free(matching_descs);
smartlist_free(chosen_flags);
smartlist_free(versions);
smartlist_free(protocols);
smartlist_free(exitsummaries);
tor_free(bandwidths_kb);
tor_free(measured_bws_kb);
tor_free(measured_guardfraction);
}
/* Mark the directory footer region */
smartlist_add_strdup(chunks, "directory-footer\n");
{
int64_t weight_scale = BW_WEIGHT_SCALE;
char *bw_weight_param = NULL;
// Parse params, extract BW_WEIGHT_SCALE if present
// DO NOT use consensus_param_bw_weight_scale() in this code!
// The consensus is not formed yet!
/* XXXX Extract this code into a common function. Or not: #19011. */
if (params) {
if (strcmpstart(params, "bwweightscale=") == 0)
bw_weight_param = params;
else
bw_weight_param = strstr(params, " bwweightscale=");
}
if (bw_weight_param) {
int ok=0;
char *eq = strchr(bw_weight_param, '=');
if (eq) {
weight_scale = tor_parse_long(eq+1, 10, 1, INT32_MAX, &ok,
NULL);
if (!ok) {
log_warn(LD_DIR, "Bad element '%s' in bw weight param",
escaped(bw_weight_param));
weight_scale = BW_WEIGHT_SCALE;
}
} else {
log_warn(LD_DIR, "Bad element '%s' in bw weight param",
escaped(bw_weight_param));
weight_scale = BW_WEIGHT_SCALE;
}
}
added_weights = networkstatus_compute_bw_weights_v10(chunks, G, M, E, D,
T, weight_scale);
}
/* Add a signature. */
{
char digest[DIGEST256_LEN];
char fingerprint[HEX_DIGEST_LEN+1];
char signing_key_fingerprint[HEX_DIGEST_LEN+1];
digest_algorithm_t digest_alg =
flavor == FLAV_NS ? DIGEST_SHA1 : DIGEST_SHA256;
size_t digest_len =
flavor == FLAV_NS ? DIGEST_LEN : DIGEST256_LEN;
const char *algname = crypto_digest_algorithm_get_name(digest_alg);
char *signature;
smartlist_add_strdup(chunks, "directory-signature ");
/* Compute the hash of the chunks. */
crypto_digest_smartlist(digest, digest_len, chunks, "", digest_alg);
/* Get the fingerprints */
crypto_pk_get_fingerprint(identity_key, fingerprint, 0);
crypto_pk_get_fingerprint(signing_key, signing_key_fingerprint, 0);
/* add the junk that will go at the end of the line. */
if (flavor == FLAV_NS) {
smartlist_add_asprintf(chunks, "%s %s\n", fingerprint,
signing_key_fingerprint);
} else {
smartlist_add_asprintf(chunks, "%s %s %s\n",
algname, fingerprint,
signing_key_fingerprint);
}
/* And the signature. */
if (!(signature = router_get_dirobj_signature(digest, digest_len,
signing_key))) {
log_warn(LD_BUG, "Couldn't sign consensus networkstatus.");
goto done;
}
smartlist_add(chunks, signature);
if (legacy_id_key_digest && legacy_signing_key) {
smartlist_add_strdup(chunks, "directory-signature ");
base16_encode(fingerprint, sizeof(fingerprint),
legacy_id_key_digest, DIGEST_LEN);
crypto_pk_get_fingerprint(legacy_signing_key,
signing_key_fingerprint, 0);
if (flavor == FLAV_NS) {
smartlist_add_asprintf(chunks, "%s %s\n", fingerprint,
signing_key_fingerprint);
} else {
smartlist_add_asprintf(chunks, "%s %s %s\n",
algname, fingerprint,
signing_key_fingerprint);
}
if (!(signature = router_get_dirobj_signature(digest, digest_len,
legacy_signing_key))) {
log_warn(LD_BUG, "Couldn't sign consensus networkstatus.");
goto done;
}
smartlist_add(chunks, signature);
}
}
result = smartlist_join_strings(chunks, "", 0, NULL);
{
networkstatus_t *c;
if (!(c = networkstatus_parse_vote_from_string(result, NULL,
NS_TYPE_CONSENSUS))) {
log_err(LD_BUG, "Generated a networkstatus consensus we couldn't "
"parse.");
tor_free(result);
goto done;
}
// Verify balancing parameters
if (added_weights) {
networkstatus_verify_bw_weights(c, consensus_method);
}
networkstatus_vote_free(c);
}
done:
dircollator_free(collator);
tor_free(client_versions);
tor_free(server_versions);
tor_free(packages);
SMARTLIST_FOREACH(flags, char *, cp, tor_free(cp));
smartlist_free(flags);
SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
smartlist_free(chunks);
SMARTLIST_FOREACH(param_list, char *, cp, tor_free(cp));
smartlist_free(param_list);
return result;
}
/** Given a list of networkstatus_t for each vote, return a newly allocated
* string containing the "package" lines for the vote. */
STATIC char *
compute_consensus_package_lines(smartlist_t *votes)
{
const int n_votes = smartlist_len(votes);
/* This will be a map from "packagename version" strings to arrays
* of const char *, with the i'th member of the array corresponding to the
* package line from the i'th vote.
*/
strmap_t *package_status = strmap_new();
SMARTLIST_FOREACH_BEGIN(votes, networkstatus_t *, v) {
if (! v->package_lines)
continue;
SMARTLIST_FOREACH_BEGIN(v->package_lines, const char *, line) {
if (! validate_recommended_package_line(line))
continue;
/* Skip 'cp' to the second space in the line. */
const char *cp = strchr(line, ' ');
if (!cp) continue;
++cp;
cp = strchr(cp, ' ');
if (!cp) continue;
char *key = tor_strndup(line, cp - line);
const char **status = strmap_get(package_status, key);
if (!status) {
status = tor_calloc(n_votes, sizeof(const char *));
strmap_set(package_status, key, status);
}
status[v_sl_idx] = line; /* overwrite old value */
tor_free(key);
} SMARTLIST_FOREACH_END(line);
} SMARTLIST_FOREACH_END(v);
smartlist_t *entries = smartlist_new(); /* temporary */
smartlist_t *result_list = smartlist_new(); /* output */
STRMAP_FOREACH(package_status, key, const char **, values) {
int i, count=-1;
for (i = 0; i < n_votes; ++i) {
if (values[i])
smartlist_add(entries, (void*) values[i]);
}
smartlist_sort_strings(entries);
int n_voting_for_entry = smartlist_len(entries);
const char *most_frequent =
smartlist_get_most_frequent_string_(entries, &count);
if (n_voting_for_entry >= 3 && count > n_voting_for_entry / 2) {
smartlist_add_asprintf(result_list, "package %s\n", most_frequent);
}
smartlist_clear(entries);
} STRMAP_FOREACH_END;
smartlist_sort_strings(result_list);
char *result = smartlist_join_strings(result_list, "", 0, NULL);
SMARTLIST_FOREACH(result_list, char *, cp, tor_free(cp));
smartlist_free(result_list);
smartlist_free(entries);
strmap_free(package_status, tor_free_);
return result;
}
/** Given a consensus vote <b>target</b> and a set of detached signatures in
* <b>sigs</b> that correspond to the same consensus, check whether there are
* any new signatures in <b>src_voter_list</b> that should be added to
* <b>target</b>. (A signature should be added if we have no signature for that
* voter in <b>target</b> yet, or if we have no verifiable signature and the
* new signature is verifiable.) Return the number of signatures added or
* changed, or -1 if the document signed by <b>sigs</b> isn't the same
* document as <b>target</b>. */
int
networkstatus_add_detached_signatures(networkstatus_t *target,
ns_detached_signatures_t *sigs,
const char *source,
int severity,
const char **msg_out)
{
int r = 0;
const char *flavor;
smartlist_t *siglist;
tor_assert(sigs);
tor_assert(target);
tor_assert(target->type == NS_TYPE_CONSENSUS);
flavor = networkstatus_get_flavor_name(target->flavor);
/* Do the times seem right? */
if (target->valid_after != sigs->valid_after) {
*msg_out = "Valid-After times do not match "
"when adding detached signatures to consensus";
return -1;
}
if (target->fresh_until != sigs->fresh_until) {
*msg_out = "Fresh-until times do not match "
"when adding detached signatures to consensus";
return -1;
}
if (target->valid_until != sigs->valid_until) {
*msg_out = "Valid-until times do not match "
"when adding detached signatures to consensus";
return -1;
}
siglist = strmap_get(sigs->signatures, flavor);
if (!siglist) {
*msg_out = "No signatures for given consensus flavor";
return -1;
}
/** Make sure all the digests we know match, and at least one matches. */
{
common_digests_t *digests = strmap_get(sigs->digests, flavor);
int n_matches = 0;
int alg;
if (!digests) {
*msg_out = "No digests for given consensus flavor";
return -1;
}
for (alg = DIGEST_SHA1; alg < N_COMMON_DIGEST_ALGORITHMS; ++alg) {
if (!tor_mem_is_zero(digests->d[alg], DIGEST256_LEN)) {
if (fast_memeq(target->digests.d[alg], digests->d[alg],
DIGEST256_LEN)) {
++n_matches;
} else {
*msg_out = "Mismatched digest.";
return -1;
}
}
}
if (!n_matches) {
*msg_out = "No recognized digests for given consensus flavor";
}
}
/* For each voter in src... */
SMARTLIST_FOREACH_BEGIN(siglist, document_signature_t *, sig) {
char voter_identity[HEX_DIGEST_LEN+1];
networkstatus_voter_info_t *target_voter =
networkstatus_get_voter_by_id(target, sig->identity_digest);
authority_cert_t *cert = NULL;
const char *algorithm;
document_signature_t *old_sig = NULL;
algorithm = crypto_digest_algorithm_get_name(sig->alg);
base16_encode(voter_identity, sizeof(voter_identity),
sig->identity_digest, DIGEST_LEN);
log_info(LD_DIR, "Looking at signature from %s using %s", voter_identity,
algorithm);
/* If the target doesn't know about this voter, then forget it. */
if (!target_voter) {
log_info(LD_DIR, "We do not know any voter with ID %s", voter_identity);
continue;
}
old_sig = voter_get_sig_by_algorithm(target_voter, sig->alg);
/* If the target already has a good signature from this voter, then skip
* this one. */
if (old_sig && old_sig->good_signature) {
log_info(LD_DIR, "We already have a good signature from %s using %s",
voter_identity, algorithm);
continue;
}
/* Try checking the signature if we haven't already. */
if (!sig->good_signature && !sig->bad_signature) {
cert = authority_cert_get_by_digests(sig->identity_digest,
sig->signing_key_digest);
if (cert) {
/* Not checking the return value here, since we are going to look
* at the status of sig->good_signature in a moment. */
(void) networkstatus_check_document_signature(target, sig, cert);
}
}
/* If this signature is good, or we don't have any signature yet,
* then maybe add it. */
if (sig->good_signature || !old_sig || old_sig->bad_signature) {
log_info(LD_DIR, "Adding signature from %s with %s", voter_identity,
algorithm);
tor_log(severity, LD_DIR, "Added a signature for %s from %s.",
target_voter->nickname, source);
++r;
if (old_sig) {
smartlist_remove(target_voter->sigs, old_sig);
document_signature_free(old_sig);
}
smartlist_add(target_voter->sigs, document_signature_dup(sig));
} else {
log_info(LD_DIR, "Not adding signature from %s", voter_identity);
}
} SMARTLIST_FOREACH_END(sig);
return r;
}
/** Return a newly allocated string containing all the signatures on
* <b>consensus</b> by all voters. If <b>for_detached_signatures</b> is true,
* then the signatures will be put in a detached signatures document, so
* prefix any non-NS-flavored signatures with "additional-signature" rather
* than "directory-signature". */
static char *
networkstatus_format_signatures(networkstatus_t *consensus,
int for_detached_signatures)
{
smartlist_t *elements;
char buf[4096];
char *result = NULL;
int n_sigs = 0;
const consensus_flavor_t flavor = consensus->flavor;
const char *flavor_name = networkstatus_get_flavor_name(flavor);
const char *keyword;
if (for_detached_signatures && flavor != FLAV_NS)
keyword = "additional-signature";
else
keyword = "directory-signature";
elements = smartlist_new();
SMARTLIST_FOREACH_BEGIN(consensus->voters, networkstatus_voter_info_t *, v) {
SMARTLIST_FOREACH_BEGIN(v->sigs, document_signature_t *, sig) {
char sk[HEX_DIGEST_LEN+1];
char id[HEX_DIGEST_LEN+1];
if (!sig->signature || sig->bad_signature)
continue;
++n_sigs;
base16_encode(sk, sizeof(sk), sig->signing_key_digest, DIGEST_LEN);
base16_encode(id, sizeof(id), sig->identity_digest, DIGEST_LEN);
if (flavor == FLAV_NS) {
smartlist_add_asprintf(elements,
"%s %s %s\n-----BEGIN SIGNATURE-----\n",
keyword, id, sk);
} else {
const char *digest_name =
crypto_digest_algorithm_get_name(sig->alg);
smartlist_add_asprintf(elements,
"%s%s%s %s %s %s\n-----BEGIN SIGNATURE-----\n",
keyword,
for_detached_signatures ? " " : "",
for_detached_signatures ? flavor_name : "",
digest_name, id, sk);
}
base64_encode(buf, sizeof(buf), sig->signature, sig->signature_len,
BASE64_ENCODE_MULTILINE);
strlcat(buf, "-----END SIGNATURE-----\n", sizeof(buf));
smartlist_add_strdup(elements, buf);
} SMARTLIST_FOREACH_END(sig);
} SMARTLIST_FOREACH_END(v);
result = smartlist_join_strings(elements, "", 0, NULL);
SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp));
smartlist_free(elements);
if (!n_sigs)
tor_free(result);
return result;
}
/** Return a newly allocated string holding the detached-signatures document
* corresponding to the signatures on <b>consensuses</b>, which must contain
* exactly one FLAV_NS consensus, and no more than one consensus for each
* other flavor. */
char *
networkstatus_get_detached_signatures(smartlist_t *consensuses)
{
smartlist_t *elements;
char *result = NULL, *sigs = NULL;
networkstatus_t *consensus_ns = NULL;
tor_assert(consensuses);
SMARTLIST_FOREACH(consensuses, networkstatus_t *, ns, {
tor_assert(ns);
tor_assert(ns->type == NS_TYPE_CONSENSUS);
if (ns && ns->flavor == FLAV_NS)
consensus_ns = ns;
});
if (!consensus_ns) {
log_warn(LD_BUG, "No NS consensus given.");
return NULL;
}
elements = smartlist_new();
{
char va_buf[ISO_TIME_LEN+1], fu_buf[ISO_TIME_LEN+1],
vu_buf[ISO_TIME_LEN+1];
char d[HEX_DIGEST_LEN+1];
base16_encode(d, sizeof(d),
consensus_ns->digests.d[DIGEST_SHA1], DIGEST_LEN);
format_iso_time(va_buf, consensus_ns->valid_after);
format_iso_time(fu_buf, consensus_ns->fresh_until);
format_iso_time(vu_buf, consensus_ns->valid_until);
smartlist_add_asprintf(elements,
"consensus-digest %s\n"
"valid-after %s\n"
"fresh-until %s\n"
"valid-until %s\n", d, va_buf, fu_buf, vu_buf);
}
/* Get all the digests for the non-FLAV_NS consensuses */
SMARTLIST_FOREACH_BEGIN(consensuses, networkstatus_t *, ns) {
const char *flavor_name = networkstatus_get_flavor_name(ns->flavor);
int alg;
if (ns->flavor == FLAV_NS)
continue;
/* start with SHA256; we don't include SHA1 for anything but the basic
* consensus. */
for (alg = DIGEST_SHA256; alg < N_COMMON_DIGEST_ALGORITHMS; ++alg) {
char d[HEX_DIGEST256_LEN+1];
const char *alg_name =
crypto_digest_algorithm_get_name(alg);
if (tor_mem_is_zero(ns->digests.d[alg], DIGEST256_LEN))
continue;
base16_encode(d, sizeof(d), ns->digests.d[alg], DIGEST256_LEN);
smartlist_add_asprintf(elements, "additional-digest %s %s %s\n",
flavor_name, alg_name, d);
}
} SMARTLIST_FOREACH_END(ns);
/* Now get all the sigs for non-FLAV_NS consensuses */
SMARTLIST_FOREACH_BEGIN(consensuses, networkstatus_t *, ns) {
char *sigs_on_this_consensus;
if (ns->flavor == FLAV_NS)
continue;
sigs_on_this_consensus = networkstatus_format_signatures(ns, 1);
if (!sigs_on_this_consensus) {
log_warn(LD_DIR, "Couldn't format signatures");
goto err;
}
smartlist_add(elements, sigs_on_this_consensus);
} SMARTLIST_FOREACH_END(ns);
/* Now add the FLAV_NS consensus signatrures. */
sigs = networkstatus_format_signatures(consensus_ns, 1);
if (!sigs)
goto err;
smartlist_add(elements, sigs);
result = smartlist_join_strings(elements, "", 0, NULL);
err:
SMARTLIST_FOREACH(elements, char *, cp, tor_free(cp));
smartlist_free(elements);
return result;
}
/** Return a newly allocated string holding a detached-signatures document for
* all of the in-progress consensuses in the <b>n_flavors</b>-element array at
* <b>pending</b>. */
static char *
get_detached_signatures_from_pending_consensuses(pending_consensus_t *pending,
int n_flavors)
{
int flav;
char *signatures;
smartlist_t *c = smartlist_new();
for (flav = 0; flav < n_flavors; ++flav) {
if (pending[flav].consensus)
smartlist_add(c, pending[flav].consensus);
}
signatures = networkstatus_get_detached_signatures(c);
smartlist_free(c);
return signatures;
}
/** Release all storage held in <b>s</b>. */
void
ns_detached_signatures_free(ns_detached_signatures_t *s)
{
if (!s)
return;
if (s->signatures) {
STRMAP_FOREACH(s->signatures, flavor, smartlist_t *, sigs) {
SMARTLIST_FOREACH(sigs, document_signature_t *, sig,
document_signature_free(sig));
smartlist_free(sigs);
} STRMAP_FOREACH_END;
strmap_free(s->signatures, NULL);
strmap_free(s->digests, tor_free_);
}
tor_free(s);
}
/* =====
* Certificate functions
* ===== */
/** Allocate and return a new authority_cert_t with the same contents as
* <b>cert</b>. */
authority_cert_t *
authority_cert_dup(authority_cert_t *cert)
{
authority_cert_t *out = tor_malloc(sizeof(authority_cert_t));
tor_assert(cert);
memcpy(out, cert, sizeof(authority_cert_t));
/* Now copy pointed-to things. */
out->cache_info.signed_descriptor_body =
tor_strndup(cert->cache_info.signed_descriptor_body,
cert->cache_info.signed_descriptor_len);
out->cache_info.saved_location = SAVED_NOWHERE;
out->identity_key = crypto_pk_dup_key(cert->identity_key);
out->signing_key = crypto_pk_dup_key(cert->signing_key);
return out;
}
/* =====
* Vote scheduling
* ===== */
/** Set *<b>timing_out</b> to the intervals at which we would like to vote.
* Note that these aren't the intervals we'll use to vote; they're the ones
* that we'll vote to use. */
void
dirvote_get_preferred_voting_intervals(vote_timing_t *timing_out)
{
const or_options_t *options = get_options();
tor_assert(timing_out);
timing_out->vote_interval = options->V3AuthVotingInterval;
timing_out->n_intervals_valid = options->V3AuthNIntervalsValid;
timing_out->vote_delay = options->V3AuthVoteDelay;
timing_out->dist_delay = options->V3AuthDistDelay;
}
/** Return the start of the next interval of size <b>interval</b> (in
* seconds) after <b>now</b>, plus <b>offset</b>. Midnight always
* starts a fresh interval, and if the last interval of a day would be
* truncated to less than half its size, it is rolled into the
* previous interval. */
time_t
dirvote_get_start_of_next_interval(time_t now, int interval, int offset)
{
struct tm tm;
time_t midnight_today=0;
time_t midnight_tomorrow;
time_t next;
tor_gmtime_r(&now, &tm);
tm.tm_hour = 0;
tm.tm_min = 0;
tm.tm_sec = 0;
if (tor_timegm(&tm, &midnight_today) < 0) {
log_warn(LD_BUG, "Ran into an invalid time when trying to find midnight.");
}
midnight_tomorrow = midnight_today + (24*60*60);
next = midnight_today + ((now-midnight_today)/interval + 1)*interval;
/* Intervals never cross midnight. */
if (next > midnight_tomorrow)
next = midnight_tomorrow;
/* If the interval would only last half as long as it's supposed to, then
* skip over to the next day. */
if (next + interval/2 > midnight_tomorrow)
next = midnight_tomorrow;
next += offset;
if (next - interval > now)
next -= interval;
return next;
}
/* Using the time <b>now</b>, return the next voting valid-after time. */
time_t
get_next_valid_after_time(time_t now)
{
time_t next_valid_after_time;
const or_options_t *options = get_options();
voting_schedule_t *new_voting_schedule =
get_voting_schedule(options, now, LOG_INFO);
tor_assert(new_voting_schedule);
next_valid_after_time = new_voting_schedule->interval_starts;
voting_schedule_free(new_voting_schedule);
return next_valid_after_time;
}
static voting_schedule_t voting_schedule;
/** Set voting_schedule to hold the timing for the next vote we should be
* doing. */
void
dirvote_recalculate_timing(const or_options_t *options, time_t now)
{
voting_schedule_t *new_voting_schedule;
if (!authdir_mode_v3(options)) {
return;
}
/* get the new voting schedule */
new_voting_schedule = get_voting_schedule(options, now, LOG_NOTICE);
tor_assert(new_voting_schedule);
/* Fill in the global static struct now */
memcpy(&voting_schedule, new_voting_schedule, sizeof(voting_schedule));
voting_schedule_free(new_voting_schedule);
}
/* Populate and return a new voting_schedule_t that can be used to schedule
* voting. The object is allocated on the heap and it's the responsibility of
* the caller to free it. Can't fail. */
voting_schedule_t *
get_voting_schedule(const or_options_t *options, time_t now, int severity)
{
int interval, vote_delay, dist_delay;
time_t start;
time_t end;
networkstatus_t *consensus;
voting_schedule_t *new_voting_schedule;
new_voting_schedule = tor_malloc_zero(sizeof(voting_schedule_t));
consensus = networkstatus_get_live_consensus(now);
if (consensus) {
interval = (int)( consensus->fresh_until - consensus->valid_after );
vote_delay = consensus->vote_seconds;
dist_delay = consensus->dist_seconds;
} else {
interval = options->TestingV3AuthInitialVotingInterval;
vote_delay = options->TestingV3AuthInitialVoteDelay;
dist_delay = options->TestingV3AuthInitialDistDelay;
}
tor_assert(interval > 0);
if (vote_delay + dist_delay > interval/2)
vote_delay = dist_delay = interval / 4;
start = new_voting_schedule->interval_starts =
dirvote_get_start_of_next_interval(now,interval,
options->TestingV3AuthVotingStartOffset);
end = dirvote_get_start_of_next_interval(start+1, interval,
options->TestingV3AuthVotingStartOffset);
tor_assert(end > start);
new_voting_schedule->fetch_missing_signatures = start - (dist_delay/2);
new_voting_schedule->voting_ends = start - dist_delay;
new_voting_schedule->fetch_missing_votes =
start - dist_delay - (vote_delay/2);
new_voting_schedule->voting_starts = start - dist_delay - vote_delay;
{
char tbuf[ISO_TIME_LEN+1];
format_iso_time(tbuf, new_voting_schedule->interval_starts);
tor_log(severity, LD_DIR,"Choosing expected valid-after time as %s: "
"consensus_set=%d, interval=%d",
tbuf, consensus?1:0, interval);
}
return new_voting_schedule;
}
/** Frees a voting_schedule_t. This should be used instead of the generic
* tor_free. */
void
voting_schedule_free(voting_schedule_t *voting_schedule_to_free)
{
if (!voting_schedule_to_free)
return;
tor_free(voting_schedule_to_free);
}
/** Entry point: Take whatever voting actions are pending as of <b>now</b>. */
void
dirvote_act(const or_options_t *options, time_t now)
{
if (!authdir_mode_v3(options))
return;
if (!voting_schedule.voting_starts) {
char *keys = list_v3_auth_ids();
authority_cert_t *c = get_my_v3_authority_cert();
log_notice(LD_DIR, "Scheduling voting. Known authority IDs are %s. "
"Mine is %s.",
keys, hex_str(c->cache_info.identity_digest, DIGEST_LEN));
tor_free(keys);
dirvote_recalculate_timing(options, now);
}
if (voting_schedule.voting_starts < now && !voting_schedule.have_voted) {
log_notice(LD_DIR, "Time to vote.");
dirvote_perform_vote();
voting_schedule.have_voted = 1;
}
if (voting_schedule.fetch_missing_votes < now &&
!voting_schedule.have_fetched_missing_votes) {
log_notice(LD_DIR, "Time to fetch any votes that we're missing.");
dirvote_fetch_missing_votes();
voting_schedule.have_fetched_missing_votes = 1;
}
if (voting_schedule.voting_ends < now &&
!voting_schedule.have_built_consensus) {
log_notice(LD_DIR, "Time to compute a consensus.");
dirvote_compute_consensuses();
/* XXXX We will want to try again later if we haven't got enough
* votes yet. Implement this if it turns out to ever happen. */
voting_schedule.have_built_consensus = 1;
}
if (voting_schedule.fetch_missing_signatures < now &&
!voting_schedule.have_fetched_missing_signatures) {
log_notice(LD_DIR, "Time to fetch any signatures that we're missing.");
dirvote_fetch_missing_signatures();
voting_schedule.have_fetched_missing_signatures = 1;
}
if (voting_schedule.interval_starts < now &&
!voting_schedule.have_published_consensus) {
log_notice(LD_DIR, "Time to publish the consensus and discard old votes");
dirvote_publish_consensus();
dirvote_clear_votes(0);
voting_schedule.have_published_consensus = 1;
/* Update our shared random state with the consensus just published. */
sr_act_post_consensus(
networkstatus_get_latest_consensus_by_flavor(FLAV_NS));
/* XXXX We will want to try again later if we haven't got enough
* signatures yet. Implement this if it turns out to ever happen. */
dirvote_recalculate_timing(options, now);
}
}
/** A vote networkstatus_t and its unparsed body: held around so we can
* use it to generate a consensus (at voting_ends) and so we can serve it to
* other authorities that might want it. */
typedef struct pending_vote_t {
cached_dir_t *vote_body;
networkstatus_t *vote;
} pending_vote_t;
/** List of pending_vote_t for the current vote. Before we've used them to
* build a consensus, the votes go here. */
static smartlist_t *pending_vote_list = NULL;
/** List of pending_vote_t for the previous vote. After we've used them to
* build a consensus, the votes go here for the next period. */
static smartlist_t *previous_vote_list = NULL;
/* DOCDOC pending_consensuses */
static pending_consensus_t pending_consensuses[N_CONSENSUS_FLAVORS];
/** The detached signatures for the consensus that we're currently
* building. */
static char *pending_consensus_signatures = NULL;
/** List of ns_detached_signatures_t: hold signatures that get posted to us
* before we have generated the consensus on our own. */
static smartlist_t *pending_consensus_signature_list = NULL;
/** Generate a networkstatus vote and post it to all the v3 authorities.
* (V3 Authority only) */
static int
dirvote_perform_vote(void)
{
crypto_pk_t *key = get_my_v3_authority_signing_key();
authority_cert_t *cert = get_my_v3_authority_cert();
networkstatus_t *ns;
char *contents;
pending_vote_t *pending_vote;
time_t now = time(NULL);
int status;
const char *msg = "";
if (!cert || !key) {
log_warn(LD_NET, "Didn't find key/certificate to generate v3 vote");
return -1;
} else if (cert->expires < now) {
log_warn(LD_NET, "Can't generate v3 vote with expired certificate");
return -1;
}
if (!(ns = dirserv_generate_networkstatus_vote_obj(key, cert)))
return -1;
contents = format_networkstatus_vote(key, ns);
networkstatus_vote_free(ns);
if (!contents)
return -1;
pending_vote = dirvote_add_vote(contents, &msg, &status);
tor_free(contents);
if (!pending_vote) {
log_warn(LD_DIR, "Couldn't store my own vote! (I told myself, '%s'.)",
msg);
return -1;
}
directory_post_to_dirservers(DIR_PURPOSE_UPLOAD_VOTE,
ROUTER_PURPOSE_GENERAL,
V3_DIRINFO,
pending_vote->vote_body->dir,
pending_vote->vote_body->dir_len, 0);
log_notice(LD_DIR, "Vote posted.");
return 0;
}
/** Send an HTTP request to every other v3 authority, for the votes of every
* authority for which we haven't received a vote yet in this period. (V3
* authority only) */
static void
dirvote_fetch_missing_votes(void)
{
smartlist_t *missing_fps = smartlist_new();
char *resource;
SMARTLIST_FOREACH_BEGIN(router_get_trusted_dir_servers(),
dir_server_t *, ds) {
if (!(ds->type & V3_DIRINFO))
continue;
if (!dirvote_get_vote(ds->v3_identity_digest,
DGV_BY_ID|DGV_INCLUDE_PENDING)) {
char *cp = tor_malloc(HEX_DIGEST_LEN+1);
base16_encode(cp, HEX_DIGEST_LEN+1, ds->v3_identity_digest,
DIGEST_LEN);
smartlist_add(missing_fps, cp);
}
} SMARTLIST_FOREACH_END(ds);
if (!smartlist_len(missing_fps)) {
smartlist_free(missing_fps);
return;
}
{
char *tmp = smartlist_join_strings(missing_fps, " ", 0, NULL);
log_notice(LOG_NOTICE, "We're missing votes from %d authorities (%s). "
"Asking every other authority for a copy.",
smartlist_len(missing_fps), tmp);
tor_free(tmp);
}
resource = smartlist_join_strings(missing_fps, "+", 0, NULL);
directory_get_from_all_authorities(DIR_PURPOSE_FETCH_STATUS_VOTE,
0, resource);
tor_free(resource);
SMARTLIST_FOREACH(missing_fps, char *, cp, tor_free(cp));
smartlist_free(missing_fps);
}
/** Send a request to every other authority for its detached signatures,
* unless we have signatures from all other v3 authorities already. */
static void
dirvote_fetch_missing_signatures(void)
{
int need_any = 0;
int i;
for (i=0; i < N_CONSENSUS_FLAVORS; ++i) {
networkstatus_t *consensus = pending_consensuses[i].consensus;
if (!consensus ||
networkstatus_check_consensus_signature(consensus, -1) == 1) {
/* We have no consensus, or we have one that's signed by everybody. */
continue;
}
need_any = 1;
}
if (!need_any)
return;
directory_get_from_all_authorities(DIR_PURPOSE_FETCH_DETACHED_SIGNATURES,
0, NULL);
}
/** Release all storage held by pending consensuses (those waiting for
* signatures). */
static void
dirvote_clear_pending_consensuses(void)
{
int i;
for (i = 0; i < N_CONSENSUS_FLAVORS; ++i) {
pending_consensus_t *pc = &pending_consensuses[i];
tor_free(pc->body);
networkstatus_vote_free(pc->consensus);
pc->consensus = NULL;
}
}
/** Drop all currently pending votes, consensus, and detached signatures. */
static void
dirvote_clear_votes(int all_votes)
{
if (!previous_vote_list)
previous_vote_list = smartlist_new();
if (!pending_vote_list)
pending_vote_list = smartlist_new();
/* All "previous" votes are now junk. */
SMARTLIST_FOREACH(previous_vote_list, pending_vote_t *, v, {
cached_dir_decref(v->vote_body);
v->vote_body = NULL;
networkstatus_vote_free(v->vote);
tor_free(v);
});
smartlist_clear(previous_vote_list);
if (all_votes) {
/* If we're dumping all the votes, we delete the pending ones. */
SMARTLIST_FOREACH(pending_vote_list, pending_vote_t *, v, {
cached_dir_decref(v->vote_body);
v->vote_body = NULL;
networkstatus_vote_free(v->vote);
tor_free(v);
});
} else {
/* Otherwise, we move them into "previous". */
smartlist_add_all(previous_vote_list, pending_vote_list);
}
smartlist_clear(pending_vote_list);
if (pending_consensus_signature_list) {
SMARTLIST_FOREACH(pending_consensus_signature_list, char *, cp,
tor_free(cp));
smartlist_clear(pending_consensus_signature_list);
}
tor_free(pending_consensus_signatures);
dirvote_clear_pending_consensuses();
}
/** Return a newly allocated string containing the hex-encoded v3 authority
identity digest of every recognized v3 authority. */
static char *
list_v3_auth_ids(void)
{
smartlist_t *known_v3_keys = smartlist_new();
char *keys;
SMARTLIST_FOREACH(router_get_trusted_dir_servers(),
dir_server_t *, ds,
if ((ds->type & V3_DIRINFO) &&
!tor_digest_is_zero(ds->v3_identity_digest))
smartlist_add(known_v3_keys,
tor_strdup(hex_str(ds->v3_identity_digest, DIGEST_LEN))));
keys = smartlist_join_strings(known_v3_keys, ", ", 0, NULL);
SMARTLIST_FOREACH(known_v3_keys, char *, cp, tor_free(cp));
smartlist_free(known_v3_keys);
return keys;
}
/** Called when we have received a networkstatus vote in <b>vote_body</b>.
* Parse and validate it, and on success store it as a pending vote (which we
* then return). Return NULL on failure. Sets *<b>msg_out</b> and
* *<b>status_out</b> to an HTTP response and status code. (V3 authority
* only) */
pending_vote_t *
dirvote_add_vote(const char *vote_body, const char **msg_out, int *status_out)
{
networkstatus_t *vote;
networkstatus_voter_info_t *vi;
dir_server_t *ds;
pending_vote_t *pending_vote = NULL;
const char *end_of_vote = NULL;
int any_failed = 0;
tor_assert(vote_body);
tor_assert(msg_out);
tor_assert(status_out);
if (!pending_vote_list)
pending_vote_list = smartlist_new();
*status_out = 0;
*msg_out = NULL;
again:
vote = networkstatus_parse_vote_from_string(vote_body, &end_of_vote,
NS_TYPE_VOTE);
if (!end_of_vote)
end_of_vote = vote_body + strlen(vote_body);
if (!vote) {
log_warn(LD_DIR, "Couldn't parse vote: length was %d",
(int)strlen(vote_body));
*msg_out = "Unable to parse vote";
goto err;
}
tor_assert(smartlist_len(vote->voters) == 1);
vi = get_voter(vote);
{
int any_sig_good = 0;
SMARTLIST_FOREACH(vi->sigs, document_signature_t *, sig,
if (sig->good_signature)
any_sig_good = 1);
tor_assert(any_sig_good);
}
ds = trusteddirserver_get_by_v3_auth_digest(vi->identity_digest);
if (!ds) {
char *keys = list_v3_auth_ids();
log_warn(LD_DIR, "Got a vote from an authority (nickname %s, address %s) "
"with authority key ID %s. "
"This key ID is not recognized. Known v3 key IDs are: %s",
vi->nickname, vi->address,
hex_str(vi->identity_digest, DIGEST_LEN), keys);
tor_free(keys);
*msg_out = "Vote not from a recognized v3 authority";
goto err;
}
tor_assert(vote->cert);
if (!authority_cert_get_by_digests(vote->cert->cache_info.identity_digest,
vote->cert->signing_key_digest)) {
/* Hey, it's a new cert! */
trusted_dirs_load_certs_from_string(
vote->cert->cache_info.signed_descriptor_body,
TRUSTED_DIRS_CERTS_SRC_FROM_VOTE, 1 /*flush*/,
NULL);
if (!authority_cert_get_by_digests(vote->cert->cache_info.identity_digest,
vote->cert->signing_key_digest)) {
log_warn(LD_BUG, "We added a cert, but still couldn't find it.");
}
}
/* Is it for the right period? */
if (vote->valid_after != voting_schedule.interval_starts) {
char tbuf1[ISO_TIME_LEN+1], tbuf2[ISO_TIME_LEN+1];
format_iso_time(tbuf1, vote->valid_after);
format_iso_time(tbuf2, voting_schedule.interval_starts);
log_warn(LD_DIR, "Rejecting vote from %s with valid-after time of %s; "
"we were expecting %s", vi->address, tbuf1, tbuf2);
*msg_out = "Bad valid-after time";
goto err;
}
/* Fetch any new router descriptors we just learned about */
update_consensus_router_descriptor_downloads(time(NULL), 1, vote);
/* Now see whether we already have a vote from this authority. */
SMARTLIST_FOREACH_BEGIN(pending_vote_list, pending_vote_t *, v) {
if (fast_memeq(v->vote->cert->cache_info.identity_digest,
vote->cert->cache_info.identity_digest,
DIGEST_LEN)) {
networkstatus_voter_info_t *vi_old = get_voter(v->vote);
if (fast_memeq(vi_old->vote_digest, vi->vote_digest, DIGEST_LEN)) {
/* Ah, it's the same vote. Not a problem. */
log_info(LD_DIR, "Discarding a vote we already have (from %s).",
vi->address);
if (*status_out < 200)
*status_out = 200;
goto discard;
} else if (v->vote->published < vote->published) {
log_notice(LD_DIR, "Replacing an older pending vote from this "
"directory (%s)", vi->address);
cached_dir_decref(v->vote_body);
networkstatus_vote_free(v->vote);
v->vote_body = new_cached_dir(tor_strndup(vote_body,
end_of_vote-vote_body),
vote->published);
v->vote = vote;
if (end_of_vote &&
!strcmpstart(end_of_vote, "network-status-version"))
goto again;
if (*status_out < 200)
*status_out = 200;
if (!*msg_out)
*msg_out = "OK";
return v;
} else {
*msg_out = "Already have a newer pending vote";
goto err;
}
}
} SMARTLIST_FOREACH_END(v);
/* This a valid vote, update our shared random state. */
sr_handle_received_commits(vote->sr_info.commits,
vote->cert->identity_key);
pending_vote = tor_malloc_zero(sizeof(pending_vote_t));
pending_vote->vote_body = new_cached_dir(tor_strndup(vote_body,
end_of_vote-vote_body),
vote->published);
pending_vote->vote = vote;
smartlist_add(pending_vote_list, pending_vote);
if (!strcmpstart(end_of_vote, "network-status-version ")) {
vote_body = end_of_vote;
goto again;
}
goto done;
err:
any_failed = 1;
if (!*msg_out)
*msg_out = "Error adding vote";
if (*status_out < 400)
*status_out = 400;
discard:
networkstatus_vote_free(vote);
if (end_of_vote && !strcmpstart(end_of_vote, "network-status-version ")) {
vote_body = end_of_vote;
goto again;
}
done:
if (*status_out < 200)
*status_out = 200;
if (!*msg_out) {
if (!any_failed && !pending_vote) {
*msg_out = "Duplicate discarded";
} else {
*msg_out = "ok";
}
}
return any_failed ? NULL : pending_vote;
}
/* Write the votes in <b>pending_vote_list</b> to disk. */
static void
write_v3_votes_to_disk(const smartlist_t *pending_votes)
{
smartlist_t *votestrings = smartlist_new();
char *votefile = NULL;
SMARTLIST_FOREACH(pending_votes, pending_vote_t *, v,
{
sized_chunk_t *c = tor_malloc(sizeof(sized_chunk_t));
c->bytes = v->vote_body->dir;
c->len = v->vote_body->dir_len;
smartlist_add(votestrings, c); /* collect strings to write to disk */
});
votefile = get_datadir_fname("v3-status-votes");
write_chunks_to_file(votefile, votestrings, 0, 0);
log_debug(LD_DIR, "Wrote votes to disk (%s)!", votefile);
tor_free(votefile);
SMARTLIST_FOREACH(votestrings, sized_chunk_t *, c, tor_free(c));
smartlist_free(votestrings);
}
/** Try to compute a v3 networkstatus consensus from the currently pending
* votes. Return 0 on success, -1 on failure. Store the consensus in
* pending_consensus: it won't be ready to be published until we have
* everybody else's signatures collected too. (V3 Authority only) */
static int
dirvote_compute_consensuses(void)
{
/* Have we got enough votes to try? */
int n_votes, n_voters, n_vote_running = 0;
smartlist_t *votes = NULL;
char *consensus_body = NULL, *signatures = NULL;
networkstatus_t *consensus = NULL;
authority_cert_t *my_cert;
pending_consensus_t pending[N_CONSENSUS_FLAVORS];
int flav;
memset(pending, 0, sizeof(pending));
if (!pending_vote_list)
pending_vote_list = smartlist_new();
/* Write votes to disk */
write_v3_votes_to_disk(pending_vote_list);
/* Setup votes smartlist */
votes = smartlist_new();
SMARTLIST_FOREACH(pending_vote_list, pending_vote_t *, v,
{
smartlist_add(votes, v->vote); /* collect votes to compute consensus */
});
/* See if consensus managed to achieve majority */
n_voters = get_n_authorities(V3_DIRINFO);
n_votes = smartlist_len(pending_vote_list);
if (n_votes <= n_voters/2) {
log_warn(LD_DIR, "We don't have enough votes to generate a consensus: "
"%d of %d", n_votes, n_voters/2+1);
goto err;
}
tor_assert(pending_vote_list);
SMARTLIST_FOREACH(pending_vote_list, pending_vote_t *, v, {
if (smartlist_contains_string(v->vote->known_flags, "Running"))
n_vote_running++;
});
if (!n_vote_running) {
/* See task 1066. */
log_warn(LD_DIR, "Nobody has voted on the Running flag. Generating "
"and publishing a consensus without Running nodes "
"would make many clients stop working. Not "
"generating a consensus!");
goto err;
}
if (!(my_cert = get_my_v3_authority_cert())) {
log_warn(LD_DIR, "Can't generate consensus without a certificate.");
goto err;
}
{
char legacy_dbuf[DIGEST_LEN];
crypto_pk_t *legacy_sign=NULL;
char *legacy_id_digest = NULL;
int n_generated = 0;
if (get_options()->V3AuthUseLegacyKey) {
authority_cert_t *cert = get_my_v3_legacy_cert();
legacy_sign = get_my_v3_legacy_signing_key();
if (cert) {
if (crypto_pk_get_digest(cert->identity_key, legacy_dbuf)) {
log_warn(LD_BUG,
"Unable to compute digest of legacy v3 identity key");
} else {
legacy_id_digest = legacy_dbuf;
}
}
}
for (flav = 0; flav < N_CONSENSUS_FLAVORS; ++flav) {
const char *flavor_name = networkstatus_get_flavor_name(flav);
consensus_body = networkstatus_compute_consensus(
votes, n_voters,
my_cert->identity_key,
get_my_v3_authority_signing_key(), legacy_id_digest, legacy_sign,
flav);
if (!consensus_body) {
log_warn(LD_DIR, "Couldn't generate a %s consensus at all!",
flavor_name);
continue;
}
consensus = networkstatus_parse_vote_from_string(consensus_body, NULL,
NS_TYPE_CONSENSUS);
if (!consensus) {
log_warn(LD_DIR, "Couldn't parse %s consensus we generated!",
flavor_name);
tor_free(consensus_body);
continue;
}
/* 'Check' our own signature, to mark it valid. */
networkstatus_check_consensus_signature(consensus, -1);
pending[flav].body = consensus_body;
pending[flav].consensus = consensus;
n_generated++;
consensus_body = NULL;
consensus = NULL;
}
if (!n_generated) {
log_warn(LD_DIR, "Couldn't generate any consensus flavors at all.");
goto err;
}
}
signatures = get_detached_signatures_from_pending_consensuses(
pending, N_CONSENSUS_FLAVORS);
if (!signatures) {
log_warn(LD_DIR, "Couldn't extract signatures.");
goto err;
}
dirvote_clear_pending_consensuses();
memcpy(pending_consensuses, pending, sizeof(pending));
tor_free(pending_consensus_signatures);
pending_consensus_signatures = signatures;
if (pending_consensus_signature_list) {
int n_sigs = 0;
/* we may have gotten signatures for this consensus before we built
* it ourself. Add them now. */
SMARTLIST_FOREACH_BEGIN(pending_consensus_signature_list, char *, sig) {
const char *msg = NULL;
int r = dirvote_add_signatures_to_all_pending_consensuses(sig,
"pending", &msg);
if (r >= 0)
n_sigs += r;
else
log_warn(LD_DIR,
"Could not add queued signature to new consensus: %s",
msg);
tor_free(sig);
} SMARTLIST_FOREACH_END(sig);
if (n_sigs)
log_notice(LD_DIR, "Added %d pending signatures while building "
"consensus.", n_sigs);
smartlist_clear(pending_consensus_signature_list);
}
log_notice(LD_DIR, "Consensus computed; uploading signature(s)");
directory_post_to_dirservers(DIR_PURPOSE_UPLOAD_SIGNATURES,
ROUTER_PURPOSE_GENERAL,
V3_DIRINFO,
pending_consensus_signatures,
strlen(pending_consensus_signatures), 0);
log_notice(LD_DIR, "Signature(s) posted.");
smartlist_free(votes);
return 0;
err:
smartlist_free(votes);
tor_free(consensus_body);
tor_free(signatures);
networkstatus_vote_free(consensus);
return -1;
}
/** Helper: we just got the <b>detached_signatures_body</b> sent to us as
* signatures on the currently pending consensus. Add them to <b>pc</b>
* as appropriate. Return the number of signatures added. (?) */
static int
dirvote_add_signatures_to_pending_consensus(
pending_consensus_t *pc,
ns_detached_signatures_t *sigs,
const char *source,
int severity,
const char **msg_out)
{
const char *flavor_name;
int r = -1;
/* Only call if we have a pending consensus right now. */
tor_assert(pc->consensus);
tor_assert(pc->body);
tor_assert(pending_consensus_signatures);
flavor_name = networkstatus_get_flavor_name(pc->consensus->flavor);
*msg_out = NULL;
{
smartlist_t *sig_list = strmap_get(sigs->signatures, flavor_name);
log_info(LD_DIR, "Have %d signatures for adding to %s consensus.",
sig_list ? smartlist_len(sig_list) : 0, flavor_name);
}
r = networkstatus_add_detached_signatures(pc->consensus, sigs,
source, severity, msg_out);
log_info(LD_DIR,"Added %d signatures to consensus.", r);
if (r >= 1) {
char *new_signatures =
networkstatus_format_signatures(pc->consensus, 0);
char *dst, *dst_end;
size_t new_consensus_len;
if (!new_signatures) {
*msg_out = "No signatures to add";
goto err;
}
new_consensus_len =
strlen(pc->body) + strlen(new_signatures) + 1;
pc->body = tor_realloc(pc->body, new_consensus_len);
dst_end = pc->body + new_consensus_len;
dst = strstr(pc->body, "directory-signature ");
tor_assert(dst);
strlcpy(dst, new_signatures, dst_end-dst);
/* We remove this block once it has failed to crash for a while. But
* unless it shows up in profiles, we're probably better leaving it in,
* just in case we break detached signature processing at some point. */
{
networkstatus_t *v = networkstatus_parse_vote_from_string(
pc->body, NULL,
NS_TYPE_CONSENSUS);
tor_assert(v);
networkstatus_vote_free(v);
}
*msg_out = "Signatures added";
tor_free(new_signatures);
} else if (r == 0) {
*msg_out = "Signatures ignored";
} else {
goto err;
}
goto done;
err:
if (!*msg_out)
*msg_out = "Unrecognized error while adding detached signatures.";
done:
return r;
}
static int
dirvote_add_signatures_to_all_pending_consensuses(
const char *detached_signatures_body,
const char *source,
const char **msg_out)
{
int r=0, i, n_added = 0, errors = 0;
ns_detached_signatures_t *sigs;
tor_assert(detached_signatures_body);
tor_assert(msg_out);
tor_assert(pending_consensus_signatures);
if (!(sigs = networkstatus_parse_detached_signatures(
detached_signatures_body, NULL))) {
*msg_out = "Couldn't parse detached signatures.";
goto err;
}
for (i = 0; i < N_CONSENSUS_FLAVORS; ++i) {
int res;
int severity = i == FLAV_NS ? LOG_NOTICE : LOG_INFO;
pending_consensus_t *pc = &pending_consensuses[i];
if (!pc->consensus)
continue;
res = dirvote_add_signatures_to_pending_consensus(pc, sigs, source,
severity, msg_out);
if (res < 0)
errors++;
else
n_added += res;
}
if (errors && !n_added) {
r = -1;
goto err;
}
if (n_added && pending_consensuses[FLAV_NS].consensus) {
char *new_detached =
get_detached_signatures_from_pending_consensuses(
pending_consensuses, N_CONSENSUS_FLAVORS);
if (new_detached) {
tor_free(pending_consensus_signatures);
pending_consensus_signatures = new_detached;
}
}
r = n_added;
goto done;
err:
if (!*msg_out)
*msg_out = "Unrecognized error while adding detached signatures.";
done:
ns_detached_signatures_free(sigs);
/* XXXX NM Check how return is used. We can now have an error *and*
signatures added. */
return r;
}
/** Helper: we just got the <b>detached_signatures_body</b> sent to us as
* signatures on the currently pending consensus. Add them to the pending
* consensus (if we have one); otherwise queue them until we have a
* consensus. Return negative on failure, nonnegative on success. */
int
dirvote_add_signatures(const char *detached_signatures_body,
const char *source,
const char **msg)
{
if (pending_consensuses[FLAV_NS].consensus) {
log_notice(LD_DIR, "Got a signature from %s. "
"Adding it to the pending consensus.", source);
return dirvote_add_signatures_to_all_pending_consensuses(
detached_signatures_body, source, msg);
} else {
log_notice(LD_DIR, "Got a signature from %s. "
"Queuing it for the next consensus.", source);
if (!pending_consensus_signature_list)
pending_consensus_signature_list = smartlist_new();
smartlist_add_strdup(pending_consensus_signature_list,
detached_signatures_body);
*msg = "Signature queued";
return 0;
}
}
/** Replace the consensus that we're currently serving with the one that we've
* been building. (V3 Authority only) */
static int
dirvote_publish_consensus(void)
{
int i;
/* Now remember all the other consensuses as if we were a directory cache. */
for (i = 0; i < N_CONSENSUS_FLAVORS; ++i) {
pending_consensus_t *pending = &pending_consensuses[i];
const char *name;
name = networkstatus_get_flavor_name(i);
tor_assert(name);
if (!pending->consensus ||
networkstatus_check_consensus_signature(pending->consensus, 1)<0) {
log_warn(LD_DIR, "Not enough info to publish pending %s consensus",name);
continue;
}
if (networkstatus_set_current_consensus(pending->body, name, 0, NULL))
log_warn(LD_DIR, "Error publishing %s consensus", name);
else
log_notice(LD_DIR, "Published %s consensus", name);
}
return 0;
}
/** Release all static storage held in dirvote.c */
void
dirvote_free_all(void)
{
dirvote_clear_votes(1);
/* now empty as a result of dirvote_clear_votes(). */
smartlist_free(pending_vote_list);
pending_vote_list = NULL;
smartlist_free(previous_vote_list);
previous_vote_list = NULL;
dirvote_clear_pending_consensuses();
tor_free(pending_consensus_signatures);
if (pending_consensus_signature_list) {
/* now empty as a result of dirvote_clear_votes(). */
smartlist_free(pending_consensus_signature_list);
pending_consensus_signature_list = NULL;
}
}
/* ====
* Access to pending items.
* ==== */
/** Return the body of the consensus that we're currently trying to build. */
MOCK_IMPL(const char *,
dirvote_get_pending_consensus, (consensus_flavor_t flav))
{
tor_assert(((int)flav) >= 0 && (int)flav < N_CONSENSUS_FLAVORS);
return pending_consensuses[flav].body;
}
/** Return the signatures that we know for the consensus that we're currently
* trying to build. */
MOCK_IMPL(const char *,
dirvote_get_pending_detached_signatures, (void))
{
return pending_consensus_signatures;
}
/** Return a given vote specified by <b>fp</b>. If <b>by_id</b>, return the
* vote for the authority with the v3 authority identity key digest <b>fp</b>;
* if <b>by_id</b> is false, return the vote whose digest is <b>fp</b>. If
* <b>fp</b> is NULL, return our own vote. If <b>include_previous</b> is
* false, do not consider any votes for a consensus that's already been built.
* If <b>include_pending</b> is false, do not consider any votes for the
* consensus that's in progress. May return NULL if we have no vote for the
* authority in question. */
const cached_dir_t *
dirvote_get_vote(const char *fp, int flags)
{
int by_id = flags & DGV_BY_ID;
const int include_pending = flags & DGV_INCLUDE_PENDING;
const int include_previous = flags & DGV_INCLUDE_PREVIOUS;
if (!pending_vote_list && !previous_vote_list)
return NULL;
if (fp == NULL) {
authority_cert_t *c = get_my_v3_authority_cert();
if (c) {
fp = c->cache_info.identity_digest;
by_id = 1;
} else
return NULL;
}
if (by_id) {
if (pending_vote_list && include_pending) {
SMARTLIST_FOREACH(pending_vote_list, pending_vote_t *, pv,
if (fast_memeq(get_voter(pv->vote)->identity_digest, fp, DIGEST_LEN))
return pv->vote_body);
}
if (previous_vote_list && include_previous) {
SMARTLIST_FOREACH(previous_vote_list, pending_vote_t *, pv,
if (fast_memeq(get_voter(pv->vote)->identity_digest, fp, DIGEST_LEN))
return pv->vote_body);
}
} else {
if (pending_vote_list && include_pending) {
SMARTLIST_FOREACH(pending_vote_list, pending_vote_t *, pv,
if (fast_memeq(pv->vote->digests.d[DIGEST_SHA1], fp, DIGEST_LEN))
return pv->vote_body);
}
if (previous_vote_list && include_previous) {
SMARTLIST_FOREACH(previous_vote_list, pending_vote_t *, pv,
if (fast_memeq(pv->vote->digests.d[DIGEST_SHA1], fp, DIGEST_LEN))
return pv->vote_body);
}
}
return NULL;
}
/** Construct and return a new microdescriptor from a routerinfo <b>ri</b>
* according to <b>consensus_method</b>.
**/
microdesc_t *
dirvote_create_microdescriptor(const routerinfo_t *ri, int consensus_method)
{
microdesc_t *result = NULL;
char *key = NULL, *summary = NULL, *family = NULL;
size_t keylen;
smartlist_t *chunks = smartlist_new();
char *output = NULL;
if (crypto_pk_write_public_key_to_string(ri->onion_pkey, &key, &keylen)<0)
goto done;
summary = policy_summarize(ri->exit_policy, AF_INET);
if (ri->declared_family)
family = smartlist_join_strings(ri->declared_family, " ", 0, NULL);
smartlist_add_asprintf(chunks, "onion-key\n%s", key);
if (consensus_method >= MIN_METHOD_FOR_NTOR_KEY &&
ri->onion_curve25519_pkey) {
char kbuf[128];
base64_encode(kbuf, sizeof(kbuf),
(const char*)ri->onion_curve25519_pkey->public_key,
CURVE25519_PUBKEY_LEN, BASE64_ENCODE_MULTILINE);
smartlist_add_asprintf(chunks, "ntor-onion-key %s", kbuf);
}
if (consensus_method >= MIN_METHOD_FOR_A_LINES &&
!tor_addr_is_null(&ri->ipv6_addr) && ri->ipv6_orport)
smartlist_add_asprintf(chunks, "a %s\n",
fmt_addrport(&ri->ipv6_addr, ri->ipv6_orport));
if (family)
smartlist_add_asprintf(chunks, "family %s\n", family);
if (summary && strcmp(summary, "reject 1-65535"))
smartlist_add_asprintf(chunks, "p %s\n", summary);
if (consensus_method >= MIN_METHOD_FOR_P6_LINES &&
ri->ipv6_exit_policy) {
/* XXXX+++ This doesn't match proposal 208, which says these should
* be taken unchanged from the routerinfo. That's bogosity, IMO:
* the proposal should have said to do this instead.*/
char *p6 = write_short_policy(ri->ipv6_exit_policy);
if (p6 && strcmp(p6, "reject 1-65535"))
smartlist_add_asprintf(chunks, "p6 %s\n", p6);
tor_free(p6);
}
if (consensus_method >= MIN_METHOD_FOR_ID_HASH_IN_MD) {
char idbuf[ED25519_BASE64_LEN+1];
const char *keytype;
if (consensus_method >= MIN_METHOD_FOR_ED25519_ID_IN_MD &&
ri->cache_info.signing_key_cert &&
ri->cache_info.signing_key_cert->signing_key_included) {
keytype = "ed25519";
ed25519_public_to_base64(idbuf,
&ri->cache_info.signing_key_cert->signing_key);
} else {
keytype = "rsa1024";
digest_to_base64(idbuf, ri->cache_info.identity_digest);
}
smartlist_add_asprintf(chunks, "id %s %s\n", keytype, idbuf);
}
output = smartlist_join_strings(chunks, "", 0, NULL);
{
smartlist_t *lst = microdescs_parse_from_string(output,
output+strlen(output), 0,
SAVED_NOWHERE, NULL);
if (smartlist_len(lst) != 1) {
log_warn(LD_DIR, "We generated a microdescriptor we couldn't parse.");
SMARTLIST_FOREACH(lst, microdesc_t *, md, microdesc_free(md));
smartlist_free(lst);
goto done;
}
result = smartlist_get(lst, 0);
smartlist_free(lst);
}
done:
tor_free(output);
tor_free(key);
tor_free(summary);
tor_free(family);
if (chunks) {
SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp));
smartlist_free(chunks);
}
return result;
}
/** Format the appropriate vote line to describe the microdescriptor <b>md</b>
* in a consensus vote document. Write it into the <b>out_len</b>-byte buffer
* in <b>out</b>. Return -1 on failure and the number of characters written
* on success. */
ssize_t
dirvote_format_microdesc_vote_line(char *out_buf, size_t out_buf_len,
const microdesc_t *md,
int consensus_method_low,
int consensus_method_high)
{
ssize_t ret = -1;
char d64[BASE64_DIGEST256_LEN+1];
char *microdesc_consensus_methods =
make_consensus_method_list(consensus_method_low,
consensus_method_high,
",");
tor_assert(microdesc_consensus_methods);
if (digest256_to_base64(d64, md->digest)<0)
goto out;
if (tor_snprintf(out_buf, out_buf_len, "m %s sha256=%s\n",
microdesc_consensus_methods, d64)<0)
goto out;
ret = strlen(out_buf);
out:
tor_free(microdesc_consensus_methods);
return ret;
}
/** Array of start and end of consensus methods used for supported
microdescriptor formats. */
static const struct consensus_method_range_t {
int low;
int high;
} microdesc_consensus_methods[] = {
{MIN_SUPPORTED_CONSENSUS_METHOD, MIN_METHOD_FOR_A_LINES - 1},
{MIN_METHOD_FOR_A_LINES, MIN_METHOD_FOR_P6_LINES - 1},
{MIN_METHOD_FOR_P6_LINES, MIN_METHOD_FOR_NTOR_KEY - 1},
{MIN_METHOD_FOR_NTOR_KEY, MIN_METHOD_FOR_ID_HASH_IN_MD - 1},
{MIN_METHOD_FOR_ID_HASH_IN_MD, MIN_METHOD_FOR_ED25519_ID_IN_MD - 1},
{MIN_METHOD_FOR_ED25519_ID_IN_MD, MAX_SUPPORTED_CONSENSUS_METHOD},
{-1, -1}
};
/** Helper type used when generating the microdescriptor lines in a directory
* vote. */
typedef struct microdesc_vote_line_t {
int low;
int high;
microdesc_t *md;
struct microdesc_vote_line_t *next;
} microdesc_vote_line_t;
/** Generate and return a linked list of all the lines that should appear to
* describe a router's microdescriptor versions in a directory vote.
* Add the generated microdescriptors to <b>microdescriptors_out</b>. */
vote_microdesc_hash_t *
dirvote_format_all_microdesc_vote_lines(const routerinfo_t *ri, time_t now,
smartlist_t *microdescriptors_out)
{
const struct consensus_method_range_t *cmr;
microdesc_vote_line_t *entries = NULL, *ep;
vote_microdesc_hash_t *result = NULL;
/* Generate the microdescriptors. */
for (cmr = microdesc_consensus_methods;
cmr->low != -1 && cmr->high != -1;
cmr++) {
microdesc_t *md = dirvote_create_microdescriptor(ri, cmr->low);
if (md) {
microdesc_vote_line_t *e =
tor_malloc_zero(sizeof(microdesc_vote_line_t));
e->md = md;
e->low = cmr->low;
e->high = cmr->high;
e->next = entries;
entries = e;
}
}
/* Compress adjacent identical ones */
for (ep = entries; ep; ep = ep->next) {
while (ep->next &&
fast_memeq(ep->md->digest, ep->next->md->digest, DIGEST256_LEN) &&
ep->low == ep->next->high + 1) {
microdesc_vote_line_t *next = ep->next;
ep->low = next->low;
microdesc_free(next->md);
ep->next = next->next;
tor_free(next);
}
}
/* Format them into vote_microdesc_hash_t, and add to microdescriptors_out.*/
while ((ep = entries)) {
char buf[128];
vote_microdesc_hash_t *h;
dirvote_format_microdesc_vote_line(buf, sizeof(buf), ep->md,
ep->low, ep->high);
h = tor_malloc_zero(sizeof(vote_microdesc_hash_t));
h->microdesc_hash_line = tor_strdup(buf);
h->next = result;
result = h;
ep->md->last_listed = now;
smartlist_add(microdescriptors_out, ep->md);
entries = ep->next;
tor_free(ep);
}
return result;
}
/** If <b>vrs</b> has a hash made for the consensus method <b>method</b> with
* the digest algorithm <b>alg</b>, decode it and copy it into
* <b>digest256_out</b> and return 0. Otherwise return -1. */
int
vote_routerstatus_find_microdesc_hash(char *digest256_out,
const vote_routerstatus_t *vrs,
int method,
digest_algorithm_t alg)
{
/* XXXX only returns the sha256 method. */
const vote_microdesc_hash_t *h;
char mstr[64];
size_t mlen;
char dstr[64];
tor_snprintf(mstr, sizeof(mstr), "%d", method);
mlen = strlen(mstr);
tor_snprintf(dstr, sizeof(dstr), " %s=",
crypto_digest_algorithm_get_name(alg));
for (h = vrs->microdesc; h; h = h->next) {
const char *cp = h->microdesc_hash_line;
size_t num_len;
/* cp looks like \d+(,\d+)* (digesttype=val )+ . Let's hunt for mstr in
* the first part. */
while (1) {
num_len = strspn(cp, "1234567890");
if (num_len == mlen && fast_memeq(mstr, cp, mlen)) {
/* This is the line. */
char buf[BASE64_DIGEST256_LEN+1];
/* XXXX ignores extraneous stuff if the digest is too long. This
* seems harmless enough, right? */
cp = strstr(cp, dstr);
if (!cp)
return -1;
cp += strlen(dstr);
strlcpy(buf, cp, sizeof(buf));
return digest256_from_base64(digest256_out, buf);
}
if (num_len == 0 || cp[num_len] != ',')
break;
cp += num_len + 1;
}
}
return -1;
}
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