diff options
Diffstat (limited to 'src/or/networkstatus.c')
| -rw-r--r-- | src/or/networkstatus.c | 228 |
1 files changed, 183 insertions, 45 deletions
diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c index d8e2c00273..fdaa469faf 100644 --- a/src/or/networkstatus.c +++ b/src/or/networkstatus.c @@ -1,17 +1,44 @@ /* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2016, The Tor Project, Inc. */ + * Copyright (c) 2007-2017, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file networkstatus.c - * \brief Functions and structures for handling network status documents as a - * client or cache. + * \brief Functions and structures for handling networkstatus documents as a + * client or as a directory cache. + * + * A consensus networkstatus object is created by the directory + * authorities. It authenticates a set of network parameters--most + * importantly, the list of all the relays in the network. This list + * of relays is represented as an array of routerstatus_t objects. + * + * There are currently two flavors of consensus. With the older "NS" + * flavor, each relay is associated with a digest of its router + * descriptor. Tor instances that use this consensus keep the list of + * router descriptors as routerinfo_t objects stored and managed in + * routerlist.c. With the newer "microdesc" flavor, each relay is + * associated with a digest of the microdescriptor that the authorities + * made for it. These are stored and managed in microdesc.c. Information + * about the router is divided between the the networkstatus and the + * microdescriptor according to the general rule that microdescriptors + * should hold information that changes much less frequently than the + * information in the networkstatus. + * + * Modern clients use microdescriptor networkstatuses. Directory caches + * need to keep both kinds of networkstatus document, so they can serve them. + * + * This module manages fetching, holding, storing, updating, and + * validating networkstatus objects. The download-and-validate process + * is slightly complicated by the fact that the keys you need to + * validate a consensus are stored in the authority certificates, which + * you might not have yet when you download the consensus. */ #define NETWORKSTATUS_PRIVATE #include "or.h" +#include "bridges.h" #include "channel.h" #include "circuitmux.h" #include "circuitmux_ewma.h" @@ -19,6 +46,7 @@ #include "config.h" #include "connection.h" #include "connection_or.h" +#include "consdiffmgr.h" #include "control.h" #include "directory.h" #include "dirserv.h" @@ -37,6 +65,7 @@ #include "shared_random.h" #include "transports.h" #include "torcert.h" +#include "channelpadding.h" /** Map from lowercase nickname to identity digest of named server, if any. */ static strmap_t *named_server_map = NULL; @@ -46,11 +75,11 @@ static strmap_t *unnamed_server_map = NULL; /** Most recently received and validated v3 "ns"-flavored consensus network * status. */ -static networkstatus_t *current_ns_consensus = NULL; +STATIC networkstatus_t *current_ns_consensus = NULL; /** Most recently received and validated v3 "microdec"-flavored consensus * network status. */ -static networkstatus_t *current_md_consensus = NULL; +STATIC networkstatus_t *current_md_consensus = NULL; /** A v3 consensus networkstatus that we've received, but which we don't * have enough certificates to be happy about. */ @@ -152,53 +181,74 @@ networkstatus_reset_download_failures(void) download_status_reset(&consensus_bootstrap_dl_status[i]); } +/** + * Read and and return the cached consensus of type <b>flavorname</b>. If + * <b>unverified</b> is false, get the one we haven't verified. Return NULL if + * the file isn't there. */ +static char * +networkstatus_read_cached_consensus_impl(int flav, + const char *flavorname, + int unverified_consensus) +{ + char buf[128]; + const char *prefix; + if (unverified_consensus) { + prefix = "unverified"; + } else { + prefix = "cached"; + } + if (flav == FLAV_NS) { + tor_snprintf(buf, sizeof(buf), "%s-consensus", prefix); + } else { + tor_snprintf(buf, sizeof(buf), "%s-%s-consensus", prefix, flavorname); + } + + char *filename = get_datadir_fname(buf); + char *result = read_file_to_str(filename, RFTS_IGNORE_MISSING, NULL); + tor_free(filename); + return result; +} + +/** Return a new string containing the current cached consensus of flavor + * <b>flavorname</b>. */ +char * +networkstatus_read_cached_consensus(const char *flavorname) + { + int flav = networkstatus_parse_flavor_name(flavorname); + if (flav < 0) + return NULL; + return networkstatus_read_cached_consensus_impl(flav, flavorname, 0); +} + /** Read every cached v3 consensus networkstatus from the disk. */ int router_reload_consensus_networkstatus(void) { - char *filename; - char *s; const unsigned int flags = NSSET_FROM_CACHE | NSSET_DONT_DOWNLOAD_CERTS; int flav; /* FFFF Suppress warnings if cached consensus is bad? */ for (flav = 0; flav < N_CONSENSUS_FLAVORS; ++flav) { - char buf[128]; const char *flavor = networkstatus_get_flavor_name(flav); - if (flav == FLAV_NS) { - filename = get_datadir_fname("cached-consensus"); - } else { - tor_snprintf(buf, sizeof(buf), "cached-%s-consensus", flavor); - filename = get_datadir_fname(buf); - } - s = read_file_to_str(filename, RFTS_IGNORE_MISSING, NULL); + char *s = networkstatus_read_cached_consensus_impl(flav, flavor, 0); if (s) { if (networkstatus_set_current_consensus(s, flavor, flags, NULL) < -1) { - log_warn(LD_FS, "Couldn't load consensus %s networkstatus from \"%s\"", - flavor, filename); + log_warn(LD_FS, "Couldn't load consensus %s networkstatus from cache", + flavor); } tor_free(s); } - tor_free(filename); - if (flav == FLAV_NS) { - filename = get_datadir_fname("unverified-consensus"); - } else { - tor_snprintf(buf, sizeof(buf), "unverified-%s-consensus", flavor); - filename = get_datadir_fname(buf); - } - - s = read_file_to_str(filename, RFTS_IGNORE_MISSING, NULL); + s = networkstatus_read_cached_consensus_impl(flav, flavor, 1); if (s) { if (networkstatus_set_current_consensus(s, flavor, flags|NSSET_WAS_WAITING_FOR_CERTS, NULL)) { - log_info(LD_FS, "Couldn't load consensus %s networkstatus from \"%s\"", - flavor, filename); - } + log_info(LD_FS, "Couldn't load unverified consensus %s networkstatus " + "from cache", flavor); + } tor_free(s); } - tor_free(filename); } if (!networkstatus_get_latest_consensus()) { @@ -217,7 +267,7 @@ router_reload_consensus_networkstatus(void) } /** Free all storage held by the vote_routerstatus object <b>rs</b>. */ -STATIC void +void vote_routerstatus_free(vote_routerstatus_t *rs) { vote_microdesc_hash_t *h, *next; @@ -789,8 +839,11 @@ networkstatus_nickname_is_unnamed(const char *nickname) #define NONAUTHORITY_NS_CACHE_INTERVAL (60*60) /** Return true iff, given the options listed in <b>options</b>, <b>flavor</b> - * is the flavor of a consensus networkstatus that we would like to fetch. */ -static int + * is the flavor of a consensus networkstatus that we would like to fetch. + * + * For certificate fetches, use we_want_to_fetch_unknown_auth_certs, and + * for serving fetched documents, use directory_caches_dir_info. */ +int we_want_to_fetch_flavor(const or_options_t *options, int flavor) { if (flavor < 0 || flavor > N_CONSENSUS_FLAVORS) { @@ -812,6 +865,29 @@ we_want_to_fetch_flavor(const or_options_t *options, int flavor) return flavor == usable_consensus_flavor(); } +/** Return true iff, given the options listed in <b>options</b>, we would like + * to fetch and store unknown authority certificates. + * + * For consensus and descriptor fetches, use we_want_to_fetch_flavor, and + * for serving fetched certificates, use directory_caches_unknown_auth_certs. + */ +int +we_want_to_fetch_unknown_auth_certs(const or_options_t *options) +{ + if (authdir_mode_v3(options) || + directory_caches_unknown_auth_certs((options))) { + /* We want to serve all certs to others, regardless if we would use + * them ourselves. */ + return 1; + } + if (options->FetchUselessDescriptors) { + /* Unknown certificates are definitely useless. */ + return 1; + } + /* Otherwise, don't fetch unknown certificates. */ + return 0; +} + /** How long will we hang onto a possibly live consensus for which we're * fetching certs before we check whether there is a better one? */ #define DELAY_WHILE_FETCHING_CERTS (20*60) @@ -1326,6 +1402,32 @@ networkstatus_get_live_consensus,(time_t now)) return NULL; } +/** Determine if <b>consensus</b> is valid or expired recently enough that + * we can still use it. + * + * Return 1 if the consensus is reasonably live, or 0 if it is too old. + */ +int +networkstatus_consensus_reasonably_live(const networkstatus_t *consensus, + time_t now) +{ + if (BUG(!consensus)) + return 0; + + return networkstatus_valid_until_is_reasonably_live(consensus->valid_until, + now); +} + +/** As networkstatus_consensus_reasonably_live, but takes a valid_until + * time rather than an entire consensus. */ +int +networkstatus_valid_until_is_reasonably_live(time_t valid_until, + time_t now) +{ +#define REASONABLY_LIVE_TIME (24*60*60) + return (now <= valid_until + REASONABLY_LIVE_TIME); +} + /* XXXX remove this in favor of get_live_consensus. But actually, * leave something like it for bridge users, who need to not totally * lose if they spend a while fetching a new consensus. */ @@ -1334,12 +1436,11 @@ networkstatus_get_live_consensus,(time_t now)) networkstatus_t * networkstatus_get_reasonably_live_consensus(time_t now, int flavor) { -#define REASONABLY_LIVE_TIME (24*60*60) networkstatus_t *consensus = networkstatus_get_latest_consensus_by_flavor(flavor); if (consensus && consensus->valid_after <= now && - now <= consensus->valid_until+REASONABLY_LIVE_TIME) + networkstatus_consensus_reasonably_live(consensus, now)) return consensus; else return NULL; @@ -1711,9 +1812,9 @@ networkstatus_set_current_consensus(const char *consensus, } if (flav != usable_consensus_flavor() && - !directory_caches_dir_info(options)) { - /* This consensus is totally boring to us: we won't use it, and we won't - * serve it. Drop it. */ + !we_want_to_fetch_flavor(options, flav)) { + /* This consensus is totally boring to us: we won't use it, we didn't want + * it, and we won't serve it. Drop it. */ goto done; } @@ -1904,6 +2005,7 @@ networkstatus_set_current_consensus(const char *consensus, circuit_build_times_new_consensus_params( get_circuit_build_times_mutable(), c); + channelpadding_new_consensus_params(c); } /* Reset the failure count only if this consensus is actually valid. */ @@ -1914,11 +2016,15 @@ networkstatus_set_current_consensus(const char *consensus, download_status_failed(&consensus_dl_status[flav], 0); } - if (directory_caches_dir_info(options)) { + if (we_want_to_fetch_flavor(options, flav)) { dirserv_set_cached_consensus_networkstatus(consensus, flavor, &c->digests, + c->digest_sha3_as_signed, c->valid_after); + if (dir_server_mode(get_options())) { + consdiffmgr_add_consensus(consensus, c); + } } if (!from_cache) { @@ -1943,6 +2049,9 @@ networkstatus_set_current_consensus(const char *consensus, "CLOCK_SKEW MIN_SKEW=%ld SOURCE=CONSENSUS", delta); } + /* We got a new consesus. Reset our md fetch fail cache */ + microdesc_reset_outdated_dirservers_list(); + router_dir_info_changed(); result = 0; @@ -2210,13 +2319,23 @@ networkstatus_dump_bridge_status_to_file(time_t now) char *thresholds = NULL; char *published_thresholds_and_status = NULL; char published[ISO_TIME_LEN+1]; + const routerinfo_t *me = router_get_my_routerinfo(); + char fingerprint[FINGERPRINT_LEN+1]; + char *fingerprint_line = NULL; + if (me && crypto_pk_get_fingerprint(me->identity_pkey, + fingerprint, 0) >= 0) { + tor_asprintf(&fingerprint_line, "fingerprint %s\n", fingerprint); + } else { + log_warn(LD_BUG, "Error computing fingerprint for bridge status."); + } format_iso_time(published, now); dirserv_compute_bridge_flag_thresholds(); thresholds = dirserv_get_flag_thresholds_line(); tor_asprintf(&published_thresholds_and_status, - "published %s\nflag-thresholds %s\n%s", - published, thresholds, status); + "published %s\nflag-thresholds %s\n%s%s", + published, thresholds, fingerprint_line ? fingerprint_line : "", + status); tor_asprintf(&fname, "%s"PATH_SEPARATOR"networkstatus-bridges", options->DataDirectory); write_str_to_file(fname,published_thresholds_and_status,0); @@ -2224,6 +2343,7 @@ networkstatus_dump_bridge_status_to_file(time_t now) tor_free(published_thresholds_and_status); tor_free(fname); tor_free(status); + tor_free(fingerprint_line); } /* DOCDOC get_net_param_from_list */ @@ -2285,6 +2405,25 @@ networkstatus_get_param(const networkstatus_t *ns, const char *param_name, } /** + * As networkstatus_get_param(), but check torrc_value before checking the + * consensus. If torrc_value is in-range, then return it instead of the + * value from the consensus. + */ +int32_t +networkstatus_get_overridable_param(const networkstatus_t *ns, + int32_t torrc_value, + const char *param_name, + int32_t default_val, + int32_t min_val, int32_t max_val) +{ + if (torrc_value >= min_val && torrc_value <= max_val) + return torrc_value; + else + return networkstatus_get_param( + ns, param_name, default_val, min_val, max_val); +} + +/** * Retrieve the consensus parameter that governs the * fixed-point precision of our network balancing 'bandwidth-weights' * (which are themselves integer consensus values). We divide them @@ -2360,12 +2499,11 @@ networkstatus_parse_flavor_name(const char *flavname) * running, or otherwise not a descriptor that we would make any * use of even if we had it. Else return 1. */ int -client_would_use_router(const routerstatus_t *rs, time_t now, - const or_options_t *options) +client_would_use_router(const routerstatus_t *rs, time_t now) { - if (!rs->is_flagged_running && !options->FetchUselessDescriptors) { + if (!rs->is_flagged_running) { /* If we had this router descriptor, we wouldn't even bother using it. - * But, if we want to have a complete list, fetch it anyway. */ + * (Fetching and storing depends on by we_want_to_fetch_flavor().) */ return 0; } if (rs->published_on + OLD_ROUTER_DESC_MAX_AGE < now) { |