diff options
Diffstat (limited to 'src/or/microdesc.c')
| -rw-r--r-- | src/or/microdesc.c | 235 |
1 files changed, 222 insertions, 13 deletions
diff --git a/src/or/microdesc.c b/src/or/microdesc.c index 7c67d51448..7ebb1e14fd 100644 --- a/src/or/microdesc.c +++ b/src/or/microdesc.c @@ -3,7 +3,14 @@ #include "or.h" #include "config.h" +#include "directory.h" +#include "dirserv.h" #include "microdesc.h" +#include "networkstatus.h" +#include "nodelist.h" +#include "policies.h" +#include "router.h" +#include "routerlist.h" #include "routerparse.h" /** A data structure to hold a bunch of cached microdescriptors. There are @@ -121,15 +128,19 @@ get_microdesc_cache(void) * ending at <b>eos</b>, and store them in <b>cache</b>. If <b>no-save</b>, * mark them as non-writable to disk. If <b>where</b> is SAVED_IN_CACHE, * leave their bodies as pointers to the mmap'd cache. If where is - * <b>SAVED_NOWHERE</b>, do not allow annotations. Return a list of the added - * microdescriptors. */ + * <b>SAVED_NOWHERE</b>, do not allow annotations. If listed_at is positive, + * set the last_listed field of every microdesc to listed_at. If + * requested_digests is non-null, then it contains a list of digests we mean + * to allow, so we should reject any non-requested microdesc with a different + * digest, and alter the list to contain only the digests of those microdescs + * we didn't find. + * Return a newly allocated list of the added microdescriptors, or NULL */ smartlist_t * microdescs_add_to_cache(microdesc_cache_t *cache, const char *s, const char *eos, saved_location_t where, - int no_save) + int no_save, time_t listed_at, + smartlist_t *requested_digests256) { - /*XXXX need an argument that sets last_listed as appropriate. */ - smartlist_t *descriptors, *added; const int allow_annotations = (where != SAVED_NOWHERE); const int copy_body = (where != SAVED_IN_CACHE); @@ -137,6 +148,33 @@ microdescs_add_to_cache(microdesc_cache_t *cache, descriptors = microdescs_parse_from_string(s, eos, allow_annotations, copy_body); + if (listed_at > 0) { + SMARTLIST_FOREACH(descriptors, microdesc_t *, md, + md->last_listed = listed_at); + } + if (requested_digests256) { + digestmap_t *requested; /* XXXX actuqlly we should just use a + digest256map */ + requested = digestmap_new(); + SMARTLIST_FOREACH(requested_digests256, const char *, cp, + digestmap_set(requested, cp, (void*)1)); + SMARTLIST_FOREACH_BEGIN(descriptors, microdesc_t *, md) { + if (digestmap_get(requested, md->digest)) { + digestmap_set(requested, md->digest, (void*)2); + } else { + log_fn(LOG_PROTOCOL_WARN, LD_DIR, "Received non-requested microcdesc"); + microdesc_free(md); + SMARTLIST_DEL_CURRENT(descriptors, md); + } + } SMARTLIST_FOREACH_END(md); + SMARTLIST_FOREACH_BEGIN(requested_digests256, char *, cp) { + if (digestmap_get(requested, cp) == (void*)2) { + tor_free(cp); + SMARTLIST_DEL_CURRENT(requested_digests256, cp); + } + } SMARTLIST_FOREACH_END(cp); + digestmap_free(requested, NULL); + } added = microdescs_add_list_to_cache(cache, descriptors, where, no_save); smartlist_free(descriptors); @@ -144,7 +182,7 @@ microdescs_add_to_cache(microdesc_cache_t *cache, } /* As microdescs_add_to_cache, but takes a list of micrdescriptors instead of - * a string to encode. Frees any members of <b>descriptors</b> that it does + * a string to decode. Frees any members of <b>descriptors</b> that it does * not add. */ smartlist_t * microdescs_add_list_to_cache(microdesc_cache_t *cache, @@ -208,6 +246,15 @@ microdescs_add_list_to_cache(microdesc_cache_t *cache, if (f) finish_writing_to_file(open_file); /*XXX Check me.*/ + { + networkstatus_t *ns = networkstatus_get_latest_consensus(); + if (ns && ns->flavor == FLAV_MICRODESC) + SMARTLIST_FOREACH(added, microdesc_t *, md, nodelist_add_microdesc(md)); + } + + if (smartlist_len(added)) + router_dir_info_changed(); + return added; } @@ -247,7 +294,7 @@ microdesc_cache_reload(microdesc_cache_t *cache) mm = cache->cache_content = tor_mmap_file(cache->cache_fname); if (mm) { added = microdescs_add_to_cache(cache, mm->data, mm->data+mm->size, - SAVED_IN_CACHE, 0); + SAVED_IN_CACHE, 0, -1, NULL); if (added) { total += smartlist_len(added); smartlist_free(added); @@ -260,7 +307,7 @@ microdesc_cache_reload(microdesc_cache_t *cache) cache->journal_len = (size_t) st.st_size; added = microdescs_add_to_cache(cache, journal_content, journal_content+st.st_size, - SAVED_IN_JOURNAL, 0); + SAVED_IN_JOURNAL, 0, -1, NULL); if (added) { total += smartlist_len(added); smartlist_free(added); @@ -293,9 +340,11 @@ microdesc_cache_clean(microdesc_cache_t *cache, time_t cutoff, int force) size_t bytes_dropped = 0; time_t now = time(NULL); - (void) force; - /* In 0.2.2, we let this proceed unconditionally: only authorities have - * microdesc caches. */ + /* If we don't know a live consensus, don't believe last_listed values: we + * might be starting up after being down for a while. */ + if (! force && + ! networkstatus_get_reasonably_live_consensus(now, FLAV_MICRODESC)) + return; if (cutoff <= 0) cutoff = now - TOLERATE_MICRODESC_AGE; @@ -390,6 +439,7 @@ microdesc_cache_rebuild(microdesc_cache_t *cache, int force) /* log? return -1? die? coredump the universe? */ continue; } + tor_assert(((size_t)size) == annotation_len + md->bodylen); md->off = off + annotation_len; off += size; if (md->saved_location != SAVED_IN_CACHE) { @@ -415,7 +465,21 @@ microdesc_cache_rebuild(microdesc_cache_t *cache, int force) SMARTLIST_FOREACH_BEGIN(wrote, microdesc_t *, md) { tor_assert(md->saved_location == SAVED_IN_CACHE); md->body = (char*)cache->cache_content->data + md->off; - tor_assert(fast_memeq(md->body, "onion-key", 9)); + if (PREDICT_UNLIKELY( + md->bodylen < 9 || fast_memneq(md->body, "onion-key", 9) != 0)) { + /* XXXX023 once bug 2022 is solved, we can kill this block and turn it + * into just the tor_assert(!memcmp) */ + off_t avail = cache->cache_content->size - md->off; + char *bad_str; + tor_assert(avail >= 0); + bad_str = tor_strndup(md->body, MIN(128, (size_t)avail)); + log_err(LD_BUG, "After rebuilding microdesc cache, offsets seem wrong. " + " At offset %d, I expected to find a microdescriptor starting " + " with \"onion-key\". Instead I got %s.", + (int)md->off, escaped(bad_str)); + tor_free(bad_str); + tor_assert(fast_memeq(md->body, "onion-key", 9)); + } } SMARTLIST_FOREACH_END(md); smartlist_free(wrote); @@ -449,7 +513,7 @@ microdesc_free(microdesc_t *md) SMARTLIST_FOREACH(md->family, char *, cp, tor_free(cp)); smartlist_free(md->family); } - tor_free(md->exitsummary); + short_policy_free(md->exit_policy); tor_free(md); } @@ -491,3 +555,148 @@ microdesc_average_size(microdesc_cache_t *cache) return (size_t)(cache->total_len_seen / cache->n_seen); } +/** Return a smartlist of all the sha256 digest of the microdescriptors that + * are listed in <b>ns</b> but not present in <b>cache</b>. Returns pointers + * to internals of <b>ns</b>; you should not free the members of the resulting + * smartlist. Omit all microdescriptors whose digest appear in <b>skip</b>. */ +smartlist_t * +microdesc_list_missing_digest256(networkstatus_t *ns, microdesc_cache_t *cache, + int downloadable_only, digestmap_t *skip) +{ + smartlist_t *result = smartlist_create(); + time_t now = time(NULL); + tor_assert(ns->flavor == FLAV_MICRODESC); + SMARTLIST_FOREACH_BEGIN(ns->routerstatus_list, routerstatus_t *, rs) { + if (microdesc_cache_lookup_by_digest256(cache, rs->descriptor_digest)) + continue; + if (downloadable_only && + !download_status_is_ready(&rs->dl_status, now, + MAX_MICRODESC_DOWNLOAD_FAILURES)) + continue; + if (skip && digestmap_get(skip, rs->descriptor_digest)) + continue; + if (tor_mem_is_zero(rs->descriptor_digest, DIGEST256_LEN)) + continue; /* This indicates a bug somewhere XXXX023*/ + /* XXXX Also skip if we're a noncache and wouldn't use this router. + * XXXX NM Microdesc + */ + smartlist_add(result, rs->descriptor_digest); + } SMARTLIST_FOREACH_END(rs); + return result; +} + +/** Launch download requests for mircodescriptors as appropriate. + * + * Specifically, we should launch download requests if we are configured to + * download mirodescriptors, and there are some microdescriptors listed the + * current microdesc consensus that we don't have, and either we never asked + * for them, or we failed to download them but we're willing to retry. + */ +void +update_microdesc_downloads(time_t now) +{ + or_options_t *options = get_options(); + networkstatus_t *consensus; + smartlist_t *missing; + digestmap_t *pending; + + if (should_delay_dir_fetches(options)) + return; + if (directory_too_idle_to_fetch_descriptors(options, now)) + return; + + consensus = networkstatus_get_reasonably_live_consensus(now, FLAV_MICRODESC); + if (!consensus) + return; + + if (!we_fetch_microdescriptors(options)) + return; + + pending = digestmap_new(); + list_pending_microdesc_downloads(pending); + + missing = microdesc_list_missing_digest256(consensus, + get_microdesc_cache(), + 1, + pending); + digestmap_free(pending, NULL); + + launch_descriptor_downloads(DIR_PURPOSE_FETCH_MICRODESC, + missing, NULL, now); + + smartlist_free(missing); +} + +/** For every microdescriptor listed in the current microdecriptor consensus, + * update its last_listed field to be at least as recent as the publication + * time of the current microdescriptor consensus. + */ +void +update_microdescs_from_networkstatus(time_t now) +{ + microdesc_cache_t *cache = get_microdesc_cache(); + microdesc_t *md; + networkstatus_t *ns = + networkstatus_get_reasonably_live_consensus(now, FLAV_MICRODESC); + + if (! ns) + return; + + tor_assert(ns->flavor == FLAV_MICRODESC); + + SMARTLIST_FOREACH_BEGIN(ns->routerstatus_list, routerstatus_t *, rs) { + md = microdesc_cache_lookup_by_digest256(cache, rs->descriptor_digest); + if (md && ns->valid_after > md->last_listed) + md->last_listed = ns->valid_after; + } SMARTLIST_FOREACH_END(rs); +} + +/** Return true iff we should prefer to use microdescriptors rather than + * routerdescs for building circuits. */ +int +we_use_microdescriptors_for_circuits(or_options_t *options) +{ + int ret = options->UseMicrodescriptors; + if (ret == -1) { + /* UseMicrodescriptors is "auto"; we need to decide: */ +#if 0 + /* So we decide that we'll use microdescriptors iff we are not a server */ + ret = ! server_mode(options); +#else + /* We don't use microdescs for now: not enough caches are running + * 0.2.3.1-alpha */ + ret = 0; +#endif + } + return ret; +} + +/** Return true iff we should try to download microdescriptors at all. */ +int +we_fetch_microdescriptors(or_options_t *options) +{ + if (directory_caches_dir_info(options)) + return 1; + return we_use_microdescriptors_for_circuits(options); +} + +/** Return true iff we should try to download router descriptors at all. */ +int +we_fetch_router_descriptors(or_options_t *options) +{ + if (directory_caches_dir_info(options)) + return 1; + return ! we_use_microdescriptors_for_circuits(options); +} + +/** Return the consensus flavor we actually want to use to build circuits. */ +int +usable_consensus_flavor(void) +{ + if (we_use_microdescriptors_for_circuits(get_options())) { + return FLAV_MICRODESC; + } else { + return FLAV_NS; + } +} + |