diff --git a/changes/bug2183 b/changes/bug2183 new file mode 100644 index 0000000000..01a8d76aca --- /dev/null +++ b/changes/bug2183 @@ -0,0 +1,6 @@ + o Minor bugfixes: + - Try harder not to exceed the maximum length of 50 KB when writing + statistics to extra-info descriptors. This bug was triggered by very + fast relays reporting exit-port, entry, and dirreq statistics. + Reported by Olaf Selke. Bugfix on 0.2.2.1-alpha. Fixes bug 2183. + diff --git a/changes/bug2195 b/changes/bug2195 new file mode 100644 index 0000000000..1724fd0e21 --- /dev/null +++ b/changes/bug2195 @@ -0,0 +1,7 @@ + o Minor bugfixes + - Publish a router descriptor even if generating an extra-info + descriptor fails. Previously we would not publish a router + descriptor without an extra-info descriptor; this can cause fast + exit relays collecting exit-port statistics to drop from the + consensus. Bugfix on 0.1.2.9-rc; fixes bug 2195. + diff --git a/src/or/rephist.c b/src/or/rephist.c index 412b864a3f..d41d715aee 100644 --- a/src/or/rephist.c +++ b/src/or/rephist.c @@ -1445,7 +1445,7 @@ rep_hist_fill_bandwidth_history(char *buf, size_t len, bw_array_t *b) * history in its descriptor. */ char * -rep_hist_get_bandwidth_lines(int for_extrainfo) +rep_hist_get_bandwidth_lines(void) { char *buf, *cp; char t[ISO_TIME_LEN+1]; @@ -1479,9 +1479,8 @@ rep_hist_get_bandwidth_lines(int for_extrainfo) } tor_assert(b); format_iso_time(t, b->next_period-NUM_SECS_BW_SUM_INTERVAL); - tor_snprintf(cp, len-(cp-buf), "%s%s %s (%d s) ", - for_extrainfo ? "" : "opt ", desc, t, - NUM_SECS_BW_SUM_INTERVAL); + tor_snprintf(cp, len-(cp-buf), "%s %s (%d s) ", + desc, t, NUM_SECS_BW_SUM_INTERVAL); cp += strlen(cp); cp += rep_hist_fill_bandwidth_history(cp, len-(cp-buf), b); strlcat(cp, "\n", len-(cp-buf)); diff --git a/src/or/rephist.h b/src/or/rephist.h index c3914dcaf2..8f5a34dacf 100644 --- a/src/or/rephist.h +++ b/src/or/rephist.h @@ -28,7 +28,7 @@ void rep_hist_note_dir_bytes_read(size_t num_bytes, time_t when); void rep_hist_note_dir_bytes_written(size_t num_bytes, time_t when); int rep_hist_bandwidth_assess(void); -char *rep_hist_get_bandwidth_lines(int for_extrainfo); +char *rep_hist_get_bandwidth_lines(void); void rep_hist_update_state(or_state_t *state); int rep_hist_load_state(or_state_t *state, char **err); void rep_history_clean(time_t before); diff --git a/src/or/router.c b/src/or/router.c index f0f72eff3e..b612d0dafb 100644 --- a/src/or/router.c +++ b/src/or/router.c @@ -1371,7 +1371,6 @@ router_rebuild_descriptor(int force) uint32_t addr; char platform[256]; int hibernating = we_are_hibernating(); - size_t ei_size; or_options_t *options = get_options(); if (desc_clean_since && !force) @@ -1487,25 +1486,27 @@ router_rebuild_descriptor(int force) ei->cache_info.published_on = ri->cache_info.published_on; memcpy(ei->cache_info.identity_digest, ri->cache_info.identity_digest, DIGEST_LEN); - ei_size = options->ExtraInfoStatistics ? MAX_EXTRAINFO_UPLOAD_SIZE : 8192; - ei->cache_info.signed_descriptor_body = tor_malloc(ei_size); - if (extrainfo_dump_to_string(ei->cache_info.signed_descriptor_body, - ei_size, ei, - get_server_identity_key()) < 0) { + if (extrainfo_dump_to_string(&ei->cache_info.signed_descriptor_body, + ei, get_server_identity_key()) < 0) { log_warn(LD_BUG, "Couldn't generate extra-info descriptor."); - routerinfo_free(ri); extrainfo_free(ei); - return -1; + ei = NULL; + } else { + ei->cache_info.signed_descriptor_len = + strlen(ei->cache_info.signed_descriptor_body); + router_get_extrainfo_hash(ei->cache_info.signed_descriptor_body, + ei->cache_info.signed_descriptor_digest); } - ei->cache_info.signed_descriptor_len = - strlen(ei->cache_info.signed_descriptor_body); - router_get_extrainfo_hash(ei->cache_info.signed_descriptor_body, - ei->cache_info.signed_descriptor_digest); /* Now finish the router descriptor. */ - memcpy(ri->cache_info.extra_info_digest, - ei->cache_info.signed_descriptor_digest, - DIGEST_LEN); + if (ei) { + memcpy(ri->cache_info.extra_info_digest, + ei->cache_info.signed_descriptor_digest, + DIGEST_LEN); + } else { + /* ri was allocated with tor_malloc_zero, so there is no need to + * zero ri->cache_info.extra_info_digest here. */ + } ri->cache_info.signed_descriptor_body = tor_malloc(8192); if (router_dump_router_to_string(ri->cache_info.signed_descriptor_body, 8192, ri, get_server_identity_key()) < 0) { @@ -1530,7 +1531,9 @@ router_rebuild_descriptor(int force) strlen(ri->cache_info.signed_descriptor_body), ri->cache_info.signed_descriptor_digest); - tor_assert(! routerinfo_incompatible_with_extrainfo(ri, ei, NULL, NULL)); + if (ei) { + tor_assert(! routerinfo_incompatible_with_extrainfo(ri, ei, NULL, NULL)); + } routerinfo_free(desc_routerinfo); desc_routerinfo = ri; @@ -1745,6 +1748,7 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, char digest[DIGEST_LEN]; char published[ISO_TIME_LEN+1]; char fingerprint[FINGERPRINT_LEN+1]; + int has_extra_info_digest; char extra_info_digest[HEX_DIGEST_LEN+1]; size_t onion_pkeylen, identity_pkeylen; size_t written; @@ -1795,8 +1799,13 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, family_line = tor_strdup(""); } - base16_encode(extra_info_digest, sizeof(extra_info_digest), - router->cache_info.extra_info_digest, DIGEST_LEN); + has_extra_info_digest = + ! tor_digest_is_zero(router->cache_info.extra_info_digest); + + if (has_extra_info_digest) { + base16_encode(extra_info_digest, sizeof(extra_info_digest), + router->cache_info.extra_info_digest, DIGEST_LEN); + } /* Generate the easy portion of the router descriptor. */ result = tor_snprintf(s, maxlen, @@ -1807,7 +1816,7 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, "opt fingerprint %s\n" "uptime %ld\n" "bandwidth %d %d %d\n" - "opt extra-info-digest %s\n%s" + "%s%s%s%s" "onion-key\n%s" "signing-key\n%s" "%s%s%s%s", @@ -1822,7 +1831,9 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, (int) router->bandwidthrate, (int) router->bandwidthburst, (int) router->bandwidthcapacity, - extra_info_digest, + has_extra_info_digest ? "opt extra-info-digest " : "", + has_extra_info_digest ? extra_info_digest : "", + has_extra_info_digest ? "\n" : "", options->DownloadExtraInfo ? "opt caches-extra-info\n" : "", onion_pkey, identity_pkey, family_line, @@ -1879,7 +1890,8 @@ router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, } } - if (written+256 > maxlen) { /* Not enough room for signature. */ + if (written + DIROBJ_MAX_SIG_LEN > maxlen) { + /* Not enough room for signature. */ log_warn(LD_BUG,"not enough room left in descriptor for signature!"); return -1; } @@ -1980,11 +1992,11 @@ load_stats_file(const char *filename, const char *end_line, time_t now, return r; } -/** Write the contents of extrainfo to the maxlen-byte string - * s, signing them with ident_key. Return 0 on success, - * negative on failure. */ +/** Write the contents of extrainfo and aggregated statistics to + * *s_out, signing them with ident_key. Return 0 on + * success, negative on failure. */ int -extrainfo_dump_to_string(char *s, size_t maxlen, extrainfo_t *extrainfo, +extrainfo_dump_to_string(char **s_out, extrainfo_t *extrainfo, crypto_pk_env_t *ident_key) { or_options_t *options = get_options(); @@ -1993,150 +2005,134 @@ extrainfo_dump_to_string(char *s, size_t maxlen, extrainfo_t *extrainfo, char digest[DIGEST_LEN]; char *bandwidth_usage; int result; - size_t len; static int write_stats_to_extrainfo = 1; + char sig[DIROBJ_MAX_SIG_LEN+1]; + char *s, *pre, *contents, *cp, *s_dup = NULL; time_t now = time(NULL); + smartlist_t *chunks = smartlist_create(); + extrainfo_t *ei_tmp = NULL; base16_encode(identity, sizeof(identity), extrainfo->cache_info.identity_digest, DIGEST_LEN); format_iso_time(published, extrainfo->cache_info.published_on); - bandwidth_usage = rep_hist_get_bandwidth_lines(1); - - result = tor_snprintf(s, maxlen, - "extra-info %s %s\n" - "published %s\n%s", - extrainfo->nickname, identity, - published, bandwidth_usage); + bandwidth_usage = rep_hist_get_bandwidth_lines(); + tor_asprintf(&pre, "extra-info %s %s\npublished %s\n%s", + extrainfo->nickname, identity, + published, bandwidth_usage); tor_free(bandwidth_usage); - if (result<0) - return -1; + smartlist_add(chunks, pre); if (geoip_is_loaded()) { - if (tor_snprintf(s + strlen(s), maxlen - strlen(s), - "geoip-db-digest %s\n", - geoip_db_digest()) < 0) { - log_warn(LD_DIR, "Could not write geoip-db-digest to extra-info " - "descriptor."); - return -1; - } + char *chunk=NULL; + tor_asprintf(&chunk, "geoip-db-digest %s\n", geoip_db_digest()); + smartlist_add(chunks, chunk); } if (options->ExtraInfoStatistics && write_stats_to_extrainfo) { - char *contents = NULL; log_info(LD_GENERAL, "Adding stats to extra-info descriptor."); if (options->DirReqStatistics && load_stats_file("stats"PATH_SEPARATOR"dirreq-stats", "dirreq-stats-end", now, &contents) > 0) { - size_t pos = strlen(s); - if (strlcpy(s + pos, contents, maxlen - strlen(s)) != - strlen(contents)) { - log_warn(LD_DIR, "Could not write dirreq-stats to extra-info " - "descriptor."); - s[pos] = '\0'; - write_stats_to_extrainfo = 0; - } - tor_free(contents); + smartlist_add(chunks, contents); } if (options->EntryStatistics && load_stats_file("stats"PATH_SEPARATOR"entry-stats", "entry-stats-end", now, &contents) > 0) { - size_t pos = strlen(s); - if (strlcpy(s + pos, contents, maxlen - strlen(s)) != - strlen(contents)) { - log_warn(LD_DIR, "Could not write entry-stats to extra-info " - "descriptor."); - s[pos] = '\0'; - write_stats_to_extrainfo = 0; - } - tor_free(contents); + smartlist_add(chunks, contents); } if (options->CellStatistics && load_stats_file("stats"PATH_SEPARATOR"buffer-stats", "cell-stats-end", now, &contents) > 0) { - size_t pos = strlen(s); - if (strlcpy(s + pos, contents, maxlen - strlen(s)) != - strlen(contents)) { - log_warn(LD_DIR, "Could not write buffer-stats to extra-info " - "descriptor."); - s[pos] = '\0'; - write_stats_to_extrainfo = 0; - } - tor_free(contents); + smartlist_add(chunks, contents); } if (options->ExitPortStatistics && load_stats_file("stats"PATH_SEPARATOR"exit-stats", "exit-stats-end", now, &contents) > 0) { - size_t pos = strlen(s); - if (strlcpy(s + pos, contents, maxlen - strlen(s)) != - strlen(contents)) { - log_warn(LD_DIR, "Could not write exit-stats to extra-info " - "descriptor."); - s[pos] = '\0'; - write_stats_to_extrainfo = 0; - } - tor_free(contents); + smartlist_add(chunks, contents); } } if (should_record_bridge_info(options) && write_stats_to_extrainfo) { const char *bridge_stats = geoip_get_bridge_stats_extrainfo(now); if (bridge_stats) { - size_t pos = strlen(s); - if (strlcpy(s + pos, bridge_stats, maxlen - strlen(s)) != - strlen(bridge_stats)) { - log_warn(LD_DIR, "Could not write bridge-stats to extra-info " - "descriptor."); - s[pos] = '\0'; - write_stats_to_extrainfo = 0; - } + smartlist_add(chunks, tor_strdup(bridge_stats)); } } - len = strlen(s); - strlcat(s+len, "router-signature\n", maxlen-len); - len += strlen(s+len); - if (router_get_extrainfo_hash(s, digest)<0) - return -1; - if (router_append_dirobj_signature(s+len, maxlen-len, digest, DIGEST_LEN, - ident_key)<0) - return -1; + smartlist_add(chunks, tor_strdup("router-signature\n")); + s = smartlist_join_strings(chunks, "", 0, NULL); - { - char *cp, *s_dup; - extrainfo_t *ei_tmp; - cp = s_dup = tor_strdup(s); - ei_tmp = extrainfo_parse_entry_from_string(cp, NULL, 1, NULL); - if (!ei_tmp) { - log_err(LD_BUG, - "We just generated an extrainfo descriptor we can't parse."); - log_err(LD_BUG, "Descriptor was: <<%s>>", s); - tor_free(s_dup); - return -1; + while (strlen(s) > MAX_EXTRAINFO_UPLOAD_SIZE - DIROBJ_MAX_SIG_LEN) { + /* So long as there are at least two chunks (one for the initial + * extra-info line and one for the router-signature), we can keep removing + * things. */ + if (smartlist_len(chunks) > 2) { + /* We remove the next-to-last element (remember, len-1 is the last + element), since we need to keep the router-signature element. */ + int idx = smartlist_len(chunks) - 2; + char *e = smartlist_get(chunks, idx); + smartlist_del_keeporder(chunks, idx); + log_warn(LD_GENERAL, "We just generated an extra-info descriptor " + "with statistics that exceeds the 50 KB " + "upload limit. Removing last added " + "statistics."); + tor_free(e); + tor_free(s); + s = smartlist_join_strings(chunks, "", 0, NULL); + } else { + log_warn(LD_BUG, "We just generated an extra-info descriptors that " + "exceeds the 50 KB upload limit."); + goto err; } - tor_free(s_dup); - extrainfo_free(ei_tmp); } - if (options->ExtraInfoStatistics && write_stats_to_extrainfo) { - char *cp, *s_dup; - extrainfo_t *ei_tmp; - cp = s_dup = tor_strdup(s); - ei_tmp = extrainfo_parse_entry_from_string(cp, NULL, 1, NULL); - if (!ei_tmp) { - log_warn(LD_GENERAL, - "We just generated an extra-info descriptor with " - "statistics that we can't parse. Not adding statistics to " - "this or any future extra-info descriptors. Descriptor " - "was:\n%s", s); + memset(sig, 0, sizeof(sig)); + if (router_get_extrainfo_hash(s, digest) < 0 || + router_append_dirobj_signature(sig, sizeof(sig), digest, DIGEST_LEN, + ident_key) < 0) { + log_warn(LD_BUG, "Could not append signature to extra-info " + "descriptor."); + goto err; + } + smartlist_add(chunks, tor_strdup(sig)); + tor_free(s); + s = smartlist_join_strings(chunks, "", 0, NULL); + + cp = s_dup = tor_strdup(s); + ei_tmp = extrainfo_parse_entry_from_string(cp, NULL, 1, NULL); + if (!ei_tmp) { + if (write_stats_to_extrainfo) { + log_warn(LD_GENERAL, "We just generated an extra-info descriptor " + "with statistics that we can't parse. Not " + "adding statistics to this or any future " + "extra-info descriptors."); write_stats_to_extrainfo = 0; - extrainfo_dump_to_string(s, maxlen, extrainfo, ident_key); + result = extrainfo_dump_to_string(s_out, extrainfo, ident_key); + goto done; + } else { + log_warn(LD_BUG, "We just generated an extrainfo descriptor we " + "can't parse."); + goto err; } - tor_free(s_dup); - extrainfo_free(ei_tmp); } - return (int)strlen(s)+1; + *s_out = s; + s = NULL; /* prevent free */ + result = 0; + goto done; + + err: + result = -1; + + done: + tor_free(s); + SMARTLIST_FOREACH(chunks, char *, cp, tor_free(cp)); + smartlist_free(chunks); + tor_free(s_dup); + extrainfo_free(ei_tmp); + + return result; } /** Return true iff s is a legally valid server nickname. */ diff --git a/src/or/router.h b/src/or/router.h index 41a9f7119c..f6a88d7637 100644 --- a/src/or/router.h +++ b/src/or/router.h @@ -77,7 +77,7 @@ int router_pick_published_address(or_options_t *options, uint32_t *addr); int router_rebuild_descriptor(int force); int router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router, crypto_pk_env_t *ident_key); -int extrainfo_dump_to_string(char *s, size_t maxlen, extrainfo_t *extrainfo, +int extrainfo_dump_to_string(char **s, extrainfo_t *extrainfo, crypto_pk_env_t *ident_key); int is_legal_nickname(const char *s); int is_legal_nickname_or_hexdigest(const char *s); diff --git a/src/or/routerparse.h b/src/or/routerparse.h index e5ebf07615..f41743bcfb 100644 --- a/src/or/routerparse.h +++ b/src/or/routerparse.h @@ -20,6 +20,7 @@ int router_get_networkstatus_v3_hash(const char *s, char *digest, digest_algorithm_t algorithm); int router_get_networkstatus_v3_hashes(const char *s, digests_t *digests); int router_get_extrainfo_hash(const char *s, char *digest); +#define DIROBJ_MAX_SIG_LEN 256 int router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest, size_t digest_len, diff --git a/src/test/test_dir.c b/src/test/test_dir.c index 3c660a7575..ce13f34ce4 100644 --- a/src/test/test_dir.c +++ b/src/test/test_dir.c @@ -150,7 +150,6 @@ test_dir_formats(void) * uptime, that still wouldn't make it right, because the two * descriptors might be made on different seconds... hm. */ "bandwidth 1000 5000 10000\n" - "opt extra-info-digest 0000000000000000000000000000000000000000\n" "onion-key\n", sizeof(buf2)); strlcat(buf2, pk1_str, sizeof(buf2)); strlcat(buf2, "signing-key\n", sizeof(buf2));