/* Copyright (c) 2017, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file consdiffmsr.c * * \brief consensus diff manager functions * * This module is run by directory authorities and caches in order * to remember a number of past consensus documents, and to generate * and serve the diffs from those documents to the latest consensus. */ #define CONSDIFFMGR_PRIVATE #include "or.h" #include "config.h" #include "conscache.h" #include "consdiff.h" #include "consdiffmgr.h" #include "cpuworker.h" #include "networkstatus.h" #include "routerparse.h" #include "workqueue.h" /** * Labels to apply to items in the conscache object. * * @{ */ /* One of DOCTYPE_CONSENSUS or DOCTYPE_CONSENSUS_DIFF */ #define LABEL_DOCTYPE "document-type" /* The valid-after time for a consensus (or for the target consensus of a * diff), encoded as ISO UTC. */ #define LABEL_VALID_AFTER "consensus-valid-after" /* The fresh-until time for a consensus (or for the target consensus of a * diff), encoded as ISO UTC. */ #define LABEL_FRESH_UNTIL "consensus-fresh-until" /* The valid-until time for a consensus (or for the target consensus of a * diff), encoded as ISO UTC. */ #define LABEL_VALID_UNTIL "consensus-valid-until" /* Comma-separated list of hex-encoded identity digests for the voting * authorities. */ #define LABEL_SIGNATORIES "consensus-signatories" /* A hex encoded SHA3 digest of the object, as compressed (if any) */ #define LABEL_SHA3_DIGEST "sha3-digest" /* A hex encoded SHA3 digest of the object before compression. */ #define LABEL_SHA3_DIGEST_UNCOMPRESSED "sha3-digest-uncompressed" /* A hex encoded SHA3 digest-as-signed of a consensus */ #define LABEL_SHA3_DIGEST_AS_SIGNED "sha3-digest-as-signed" /* The flavor of the consensus or consensuses diff */ #define LABEL_FLAVOR "consensus-flavor" /* Diff only: the SHA3 digest-as-signed of the source consensus. */ #define LABEL_FROM_SHA3_DIGEST "from-sha3-digest" /* Diff only: the SHA3 digest-in-full of the target consensus. */ #define LABEL_TARGET_SHA3_DIGEST "target-sha3-digest" /* Diff only: the valid-after date of the source consensus. */ #define LABEL_FROM_VALID_AFTER "from-valid-after" /* What kind of compression was used? */ #define LABEL_COMPRESSION_TYPE "compression" /** @} */ #define DOCTYPE_CONSENSUS "consensus" #define DOCTYPE_CONSENSUS_DIFF "consensus-diff" /** * Underlying directory that stores consensuses and consensus diffs. Don't * use this directly: use cdm_cache_get() instead. */ static consensus_cache_t *cons_diff_cache = NULL; /** * If true, we have learned at least one new consensus since the * consensus cache was last up-to-date. */ static int cdm_cache_dirty = 0; /** * If true, we have scanned the cache to update our hashtable of diffs. */ static int cdm_cache_loaded = 0; /** * Possible status values for cdm_diff_t.cdm_diff_status **/ typedef enum cdm_diff_status_t { CDM_DIFF_PRESENT=1, CDM_DIFF_IN_PROGRESS=2, CDM_DIFF_ERROR=3, } cdm_diff_status_t; /** Which methods do we use for precompressing diffs? */ static const compress_method_t compress_diffs_with[] = { NO_METHOD, GZIP_METHOD, #ifdef HAVE_LZMA LZMA_METHOD, #endif #ifdef HAVE_ZSTD ZSTD_METHOD, #endif }; /** How many different methods will we try to use for diff compression? */ STATIC unsigned n_diff_compression_methods(void) { return ARRAY_LENGTH(compress_diffs_with); } /** Which methods do we use for precompressing consensuses? */ static const compress_method_t compress_consensus_with[] = { ZLIB_METHOD, #ifdef HAVE_LZMA LZMA_METHOD, #endif #ifdef HAVE_ZSTD ZSTD_METHOD, #endif }; /** How many different methods will we try to use for diff compression? */ STATIC unsigned n_consensus_compression_methods(void) { return ARRAY_LENGTH(compress_consensus_with); } /** For which compression method do we retain old consensuses? There's no * need to keep all of them, since we won't be serving them. We'll * go with ZLIB_METHOD because it's pretty fast and everyone has it. */ #define RETAIN_CONSENSUS_COMPRESSED_WITH_METHOD ZLIB_METHOD /** Handles pointing to the latest consensus entries as compressed and * stored. */ static consensus_cache_entry_handle_t * latest_consensus[N_CONSENSUS_FLAVORS] [ARRAY_LENGTH(compress_consensus_with)]; /** Hashtable node used to remember the current status of the diff * from a given sha3 digest to the current consensus. */ typedef struct cdm_diff_t { HT_ENTRY(cdm_diff_t) node; /** Consensus flavor for this diff (part of ht key) */ consensus_flavor_t flavor; /** SHA3-256 digest of the consensus that this diff is _from_. (part of the * ht key) */ uint8_t from_sha3[DIGEST256_LEN]; /** Method by which the diff is compressed. (part of the ht key */ compress_method_t compress_method; /** One of the CDM_DIFF_* values, depending on whether this diff * is available, in progress, or impossible to compute. */ cdm_diff_status_t cdm_diff_status; /** SHA3-256 digest of the consensus that this diff is _to. */ uint8_t target_sha3[DIGEST256_LEN]; /** Handle to the cache entry for this diff, if any. We use a handle here * to avoid thinking too hard about cache entry lifetime issues. */ consensus_cache_entry_handle_t *entry; } cdm_diff_t; /** Hashtable mapping flavor and source consensus digest to status. */ static HT_HEAD(cdm_diff_ht, cdm_diff_t) cdm_diff_ht = HT_INITIALIZER(); /** * Configuration for this module */ static consdiff_cfg_t consdiff_cfg = { // XXXX I'd like to make this number bigger, but it interferes with the // XXXX seccomp2 syscall filter, which tops out at BPF_MAXINS (4096) // XXXX rules. /* .cache_max_num = */ 128 }; static int consdiffmgr_ensure_space_for_files(int n); static int consensus_queue_compression_work(const char *consensus, const networkstatus_t *as_parsed); static int consensus_diff_queue_diff_work(consensus_cache_entry_t *diff_from, consensus_cache_entry_t *diff_to); static void consdiffmgr_set_cache_flags(void); /* ===== * Hashtable setup * ===== */ /** Helper: hash the key of a cdm_diff_t. */ static unsigned cdm_diff_hash(const cdm_diff_t *diff) { uint8_t tmp[DIGEST256_LEN + 2]; memcpy(tmp, diff->from_sha3, DIGEST256_LEN); tmp[DIGEST256_LEN] = (uint8_t) diff->flavor; tmp[DIGEST256_LEN+1] = (uint8_t) diff->compress_method; return (unsigned) siphash24g(tmp, sizeof(tmp)); } /** Helper: compare two cdm_diff_t objects for key equality */ static int cdm_diff_eq(const cdm_diff_t *diff1, const cdm_diff_t *diff2) { return fast_memeq(diff1->from_sha3, diff2->from_sha3, DIGEST256_LEN) && diff1->flavor == diff2->flavor && diff1->compress_method == diff2->compress_method; } HT_PROTOTYPE(cdm_diff_ht, cdm_diff_t, node, cdm_diff_hash, cdm_diff_eq) HT_GENERATE2(cdm_diff_ht, cdm_diff_t, node, cdm_diff_hash, cdm_diff_eq, 0.6, tor_reallocarray, tor_free_) #define cdm_diff_free(diff) \ FREE_AND_NULL(cdm_diff_t, cdm_diff_free_, (diff)) /** Release all storage held in diff. */ static void cdm_diff_free_(cdm_diff_t *diff) { if (!diff) return; consensus_cache_entry_handle_free(diff->entry); tor_free(diff); } /** Create and return a new cdm_diff_t with the given values. Does not * add it to the hashtable. */ static cdm_diff_t * cdm_diff_new(consensus_flavor_t flav, const uint8_t *from_sha3, const uint8_t *target_sha3, compress_method_t method) { cdm_diff_t *ent; ent = tor_malloc_zero(sizeof(cdm_diff_t)); ent->flavor = flav; memcpy(ent->from_sha3, from_sha3, DIGEST256_LEN); memcpy(ent->target_sha3, target_sha3, DIGEST256_LEN); ent->compress_method = method; return ent; } /** * Examine the diff hashtable to see whether we know anything about computing * a diff of type flav between consensuses with the two provided * SHA3-256 digests. If a computation is in progress, or if the computation * has already been tried and failed, return 1. Otherwise, note the * computation as "in progress" so that we don't reattempt it later, and * return 0. */ static int cdm_diff_ht_check_and_note_pending(consensus_flavor_t flav, const uint8_t *from_sha3, const uint8_t *target_sha3) { struct cdm_diff_t search, *ent; unsigned u; int result = 0; for (u = 0; u < n_diff_compression_methods(); ++u) { compress_method_t method = compress_diffs_with[u]; memset(&search, 0, sizeof(cdm_diff_t)); search.flavor = flav; search.compress_method = method; memcpy(search.from_sha3, from_sha3, DIGEST256_LEN); ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search); if (ent) { tor_assert_nonfatal(ent->cdm_diff_status != CDM_DIFF_PRESENT); result = 1; continue; } ent = cdm_diff_new(flav, from_sha3, target_sha3, method); ent->cdm_diff_status = CDM_DIFF_IN_PROGRESS; HT_INSERT(cdm_diff_ht, &cdm_diff_ht, ent); } return result; } /** * Update the status of the diff of type flav between consensuses with * the two provided SHA3-256 digests, so that its status becomes * status, and its value becomes the handle. If handle * is NULL, then the old handle (if any) is freed, and replaced with NULL. */ static void cdm_diff_ht_set_status(consensus_flavor_t flav, const uint8_t *from_sha3, const uint8_t *to_sha3, compress_method_t method, int status, consensus_cache_entry_handle_t *handle) { if (handle == NULL) { tor_assert_nonfatal(status != CDM_DIFF_PRESENT); } struct cdm_diff_t search, *ent; memset(&search, 0, sizeof(cdm_diff_t)); search.flavor = flav; search.compress_method = method, memcpy(search.from_sha3, from_sha3, DIGEST256_LEN); ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search); if (!ent) { ent = cdm_diff_new(flav, from_sha3, to_sha3, method); ent->cdm_diff_status = CDM_DIFF_IN_PROGRESS; HT_INSERT(cdm_diff_ht, &cdm_diff_ht, ent); } else if (fast_memneq(ent->target_sha3, to_sha3, DIGEST256_LEN)) { // This can happen under certain really pathological conditions // if we decide we don't care about a diff before it is actually // done computing. return; } tor_assert_nonfatal(ent->cdm_diff_status == CDM_DIFF_IN_PROGRESS); ent->cdm_diff_status = status; consensus_cache_entry_handle_free(ent->entry); ent->entry = handle; } /** * Helper: Remove from the hash table every present (actually computed) diff * of type flav whose target digest does not match * unless_target_sha3_matches. * * This function is used for the hash table to throw away references to diffs * that do not lead to the most given consensus of a given flavor. */ static void cdm_diff_ht_purge(consensus_flavor_t flav, const uint8_t *unless_target_sha3_matches) { cdm_diff_t **diff, **next; for (diff = HT_START(cdm_diff_ht, &cdm_diff_ht); diff; diff = next) { cdm_diff_t *this = *diff; if ((*diff)->cdm_diff_status == CDM_DIFF_PRESENT && flav == (*diff)->flavor) { if (BUG((*diff)->entry == NULL) || consensus_cache_entry_handle_get((*diff)->entry) == NULL) { /* the underlying entry has gone away; drop this. */ next = HT_NEXT_RMV(cdm_diff_ht, &cdm_diff_ht, diff); cdm_diff_free(this); continue; } if (unless_target_sha3_matches && fast_memneq(unless_target_sha3_matches, (*diff)->target_sha3, DIGEST256_LEN)) { /* target hash doesn't match; drop this. */ next = HT_NEXT_RMV(cdm_diff_ht, &cdm_diff_ht, diff); cdm_diff_free(this); continue; } } next = HT_NEXT(cdm_diff_ht, &cdm_diff_ht, diff); } } /** * Helper: initialize cons_diff_cache. */ static void cdm_cache_init(void) { unsigned n_entries = consdiff_cfg.cache_max_num * 2; tor_assert(cons_diff_cache == NULL); cons_diff_cache = consensus_cache_open("diff-cache", n_entries); if (cons_diff_cache == NULL) { // LCOV_EXCL_START log_err(LD_FS, "Error: Couldn't open storage for consensus diffs."); tor_assert_unreached(); // LCOV_EXCL_STOP } else { consdiffmgr_set_cache_flags(); } cdm_cache_dirty = 1; cdm_cache_loaded = 0; } /** * Helper: return the consensus_cache_t * that backs this manager, * initializing it if needed. */ STATIC consensus_cache_t * cdm_cache_get(void) { if (PREDICT_UNLIKELY(cons_diff_cache == NULL)) { cdm_cache_init(); } return cons_diff_cache; } /** * Helper: given a list of labels, prepend the hex-encoded SHA3 digest * of the bodylen-byte object at body to those labels, * with label as its label. */ static void cdm_labels_prepend_sha3(config_line_t **labels, const char *label, const uint8_t *body, size_t bodylen) { uint8_t sha3_digest[DIGEST256_LEN]; char hexdigest[HEX_DIGEST256_LEN+1]; crypto_digest256((char *)sha3_digest, (const char *)body, bodylen, DIGEST_SHA3_256); base16_encode(hexdigest, sizeof(hexdigest), (const char *)sha3_digest, sizeof(sha3_digest)); config_line_prepend(labels, label, hexdigest); } /** Helper: if there is a sha3-256 hex-encoded digest in ent with the * given label, set digest_out to that value (decoded), and return 0. * * Return -1 if there is no such label, and -2 if it is badly formatted. */ STATIC int cdm_entry_get_sha3_value(uint8_t *digest_out, consensus_cache_entry_t *ent, const char *label) { if (ent == NULL) return -1; const char *hex = consensus_cache_entry_get_value(ent, label); if (hex == NULL) return -1; int n = base16_decode((char*)digest_out, DIGEST256_LEN, hex, strlen(hex)); if (n != DIGEST256_LEN) return -2; else return 0; } /** * Helper: look for a consensus with the given flavor and * valid_after time in the cache. Return that consensus if it's * present, or NULL if it's missing. */ STATIC consensus_cache_entry_t * cdm_cache_lookup_consensus(consensus_flavor_t flavor, time_t valid_after) { char formatted_time[ISO_TIME_LEN+1]; format_iso_time_nospace(formatted_time, valid_after); const char *flavname = networkstatus_get_flavor_name(flavor); /* We'll filter by valid-after time first, since that should * match the fewest documents. */ /* We could add an extra hashtable here, but since we only do this scan * when adding a new consensus, it probably doesn't matter much. */ smartlist_t *matches = smartlist_new(); consensus_cache_find_all(matches, cdm_cache_get(), LABEL_VALID_AFTER, formatted_time); consensus_cache_filter_list(matches, LABEL_FLAVOR, flavname); consensus_cache_filter_list(matches, LABEL_DOCTYPE, DOCTYPE_CONSENSUS); consensus_cache_entry_t *result = NULL; if (smartlist_len(matches)) { result = smartlist_get(matches, 0); } smartlist_free(matches); return result; } /** Return the maximum age (in seconds) of consensuses that we should consider * storing. The available space in the directory may impose additional limits * on how much we store. */ static int32_t get_max_age_to_cache(void) { const int32_t DEFAULT_MAX_AGE_TO_CACHE = 8192; const int32_t MIN_MAX_AGE_TO_CACHE = 0; const int32_t MAX_MAX_AGE_TO_CACHE = 8192; const char MAX_AGE_TO_CACHE_NAME[] = "max-consensus-age-to-cache-for-diff"; const or_options_t *options = get_options(); if (options->MaxConsensusAgeForDiffs) { const int v = options->MaxConsensusAgeForDiffs; if (v >= MAX_MAX_AGE_TO_CACHE * 3600) return MAX_MAX_AGE_TO_CACHE; else return v; } /* The parameter is in hours, so we multiply */ return 3600 * networkstatus_get_param(NULL, MAX_AGE_TO_CACHE_NAME, DEFAULT_MAX_AGE_TO_CACHE, MIN_MAX_AGE_TO_CACHE, MAX_MAX_AGE_TO_CACHE); } /** * Given a string containing a networkstatus consensus, and the results of * having parsed that consensus, add that consensus to the cache if it is not * already present and not too old. Create new consensus diffs from or to * that consensus as appropriate. * * Return 0 on success and -1 on failure. */ int consdiffmgr_add_consensus(const char *consensus, const networkstatus_t *as_parsed) { if (BUG(consensus == NULL) || BUG(as_parsed == NULL)) return -1; // LCOV_EXCL_LINE if (BUG(as_parsed->type != NS_TYPE_CONSENSUS)) return -1; // LCOV_EXCL_LINE const consensus_flavor_t flavor = as_parsed->flavor; const time_t valid_after = as_parsed->valid_after; if (valid_after < approx_time() - get_max_age_to_cache()) { log_info(LD_DIRSERV, "We don't care about this consensus document; it's " "too old."); return -1; } /* Do we already have this one? */ consensus_cache_entry_t *entry = cdm_cache_lookup_consensus(flavor, valid_after); if (entry) { log_info(LD_DIRSERV, "We already have a copy of that consensus"); return -1; } /* We don't have it. Add it to the cache. */ return consensus_queue_compression_work(consensus, as_parsed); } /** * Helper: used to sort two smartlists of consensus_cache_entry_t by their * LABEL_VALID_AFTER labels. */ static int compare_by_valid_after_(const void **a, const void **b) { const consensus_cache_entry_t *e1 = *a; const consensus_cache_entry_t *e2 = *b; /* We're in luck here: sorting UTC iso-encoded values lexically will work * fine (until 9999). */ return strcmp_opt(consensus_cache_entry_get_value(e1, LABEL_VALID_AFTER), consensus_cache_entry_get_value(e2, LABEL_VALID_AFTER)); } /** * Helper: Sort lst by LABEL_VALID_AFTER and return the most recent * entry. */ static consensus_cache_entry_t * sort_and_find_most_recent(smartlist_t *lst) { smartlist_sort(lst, compare_by_valid_after_); if (smartlist_len(lst)) { return smartlist_get(lst, smartlist_len(lst) - 1); } else { return NULL; } } /** Return i such that compress_consensus_with[i] == method. Return * -1 if no such i exists. */ static int consensus_compression_method_pos(compress_method_t method) { unsigned i; for (i = 0; i < n_consensus_compression_methods(); ++i) { if (compress_consensus_with[i] == method) { return i; } } return -1; } /** * If we know a consensus with the flavor flavor compressed with * method, set *entry_out to that value. Return values are as * for consdiffmgr_find_diff_from(). */ consdiff_status_t consdiffmgr_find_consensus(struct consensus_cache_entry_t **entry_out, consensus_flavor_t flavor, compress_method_t method) { tor_assert(entry_out); tor_assert((int)flavor < N_CONSENSUS_FLAVORS); int pos = consensus_compression_method_pos(method); if (pos < 0) { // We don't compress consensuses with this method. return CONSDIFF_NOT_FOUND; } consensus_cache_entry_handle_t *handle = latest_consensus[flavor][pos]; if (!handle) return CONSDIFF_NOT_FOUND; *entry_out = consensus_cache_entry_handle_get(handle); if (*entry_out) return CONSDIFF_AVAILABLE; else return CONSDIFF_NOT_FOUND; } /** * Look up consensus_cache_entry_t for the consensus of type flavor, * from the source consensus with the specified digest (which must be SHA3). * * If the diff is present, store it into *entry_out and return * CONSDIFF_AVAILABLE. Otherwise return CONSDIFF_NOT_FOUND or * CONSDIFF_IN_PROGRESS. */ consdiff_status_t consdiffmgr_find_diff_from(consensus_cache_entry_t **entry_out, consensus_flavor_t flavor, int digest_type, const uint8_t *digest, size_t digestlen, compress_method_t method) { if (BUG(digest_type != DIGEST_SHA3_256) || BUG(digestlen != DIGEST256_LEN)) { return CONSDIFF_NOT_FOUND; // LCOV_EXCL_LINE } // Try to look up the entry in the hashtable. cdm_diff_t search, *ent; memset(&search, 0, sizeof(search)); search.flavor = flavor; search.compress_method = method; memcpy(search.from_sha3, digest, DIGEST256_LEN); ent = HT_FIND(cdm_diff_ht, &cdm_diff_ht, &search); if (ent == NULL || ent->cdm_diff_status == CDM_DIFF_ERROR) { return CONSDIFF_NOT_FOUND; } else if (ent->cdm_diff_status == CDM_DIFF_IN_PROGRESS) { return CONSDIFF_IN_PROGRESS; } else if (BUG(ent->cdm_diff_status != CDM_DIFF_PRESENT)) { return CONSDIFF_IN_PROGRESS; } if (BUG(ent->entry == NULL)) { return CONSDIFF_NOT_FOUND; } *entry_out = consensus_cache_entry_handle_get(ent->entry); return (*entry_out) ? CONSDIFF_AVAILABLE : CONSDIFF_NOT_FOUND; #if 0 // XXXX Remove this. I'm keeping it around for now in case we need to // XXXX debug issues in the hashtable. char hex[HEX_DIGEST256_LEN+1]; base16_encode(hex, sizeof(hex), (const char *)digest, digestlen); const char *flavname = networkstatus_get_flavor_name(flavor); smartlist_t *matches = smartlist_new(); consensus_cache_find_all(matches, cdm_cache_get(), LABEL_FROM_SHA3_DIGEST, hex); consensus_cache_filter_list(matches, LABEL_FLAVOR, flavname); consensus_cache_filter_list(matches, LABEL_DOCTYPE, DOCTYPE_CONSENSUS_DIFF); *entry_out = sort_and_find_most_recent(matches); consdiff_status_t result = (*entry_out) ? CONSDIFF_AVAILABLE : CONSDIFF_NOT_FOUND; smartlist_free(matches); return result; #endif /* 0 */ } /** * Perform periodic cleanup tasks on the consensus diff cache. Return * the number of objects marked for deletion. */ int consdiffmgr_cleanup(void) { smartlist_t *objects = smartlist_new(); smartlist_t *consensuses = smartlist_new(); smartlist_t *diffs = smartlist_new(); int n_to_delete = 0; log_debug(LD_DIRSERV, "Looking for consdiffmgr entries to remove"); // 1. Delete any consensus or diff or anything whose valid_after is too old. const time_t valid_after_cutoff = approx_time() - get_max_age_to_cache(); consensus_cache_find_all(objects, cdm_cache_get(), NULL, NULL); SMARTLIST_FOREACH_BEGIN(objects, consensus_cache_entry_t *, ent) { const char *lv_valid_after = consensus_cache_entry_get_value(ent, LABEL_VALID_AFTER); if (! lv_valid_after) { log_debug(LD_DIRSERV, "Ignoring entry because it had no %s label", LABEL_VALID_AFTER); continue; } time_t valid_after = 0; if (parse_iso_time_nospace(lv_valid_after, &valid_after) < 0) { log_debug(LD_DIRSERV, "Ignoring entry because its %s value (%s) was " "unparseable", LABEL_VALID_AFTER, escaped(lv_valid_after)); continue; } if (valid_after < valid_after_cutoff) { log_debug(LD_DIRSERV, "Deleting entry because its %s value (%s) was " "too old", LABEL_VALID_AFTER, lv_valid_after); consensus_cache_entry_mark_for_removal(ent); ++n_to_delete; } } SMARTLIST_FOREACH_END(ent); // 2. Delete all diffs that lead to a consensus whose valid-after is not the // latest. for (int flav = 0; flav < N_CONSENSUS_FLAVORS; ++flav) { const char *flavname = networkstatus_get_flavor_name(flav); /* Determine the most recent consensus of this flavor */ consensus_cache_find_all(consensuses, cdm_cache_get(), LABEL_DOCTYPE, DOCTYPE_CONSENSUS); consensus_cache_filter_list(consensuses, LABEL_FLAVOR, flavname); consensus_cache_entry_t *most_recent = sort_and_find_most_recent(consensuses); if (most_recent == NULL) continue; const char *most_recent_sha3 = consensus_cache_entry_get_value(most_recent, LABEL_SHA3_DIGEST_UNCOMPRESSED); if (BUG(most_recent_sha3 == NULL)) continue; // LCOV_EXCL_LINE /* consider all such-flavored diffs, and look to see if they match. */ consensus_cache_find_all(diffs, cdm_cache_get(), LABEL_DOCTYPE, DOCTYPE_CONSENSUS_DIFF); consensus_cache_filter_list(diffs, LABEL_FLAVOR, flavname); SMARTLIST_FOREACH_BEGIN(diffs, consensus_cache_entry_t *, diff) { const char *this_diff_target_sha3 = consensus_cache_entry_get_value(diff, LABEL_TARGET_SHA3_DIGEST); if (!this_diff_target_sha3) continue; if (strcmp(this_diff_target_sha3, most_recent_sha3)) { consensus_cache_entry_mark_for_removal(diff); ++n_to_delete; } } SMARTLIST_FOREACH_END(diff); smartlist_clear(consensuses); smartlist_clear(diffs); } // 3. Delete all consensuses except the most recent that are compressed with // an un-preferred method. for (int flav = 0; flav < N_CONSENSUS_FLAVORS; ++flav) { const char *flavname = networkstatus_get_flavor_name(flav); /* Determine the most recent consensus of this flavor */ consensus_cache_find_all(consensuses, cdm_cache_get(), LABEL_DOCTYPE, DOCTYPE_CONSENSUS); consensus_cache_filter_list(consensuses, LABEL_FLAVOR, flavname); consensus_cache_entry_t *most_recent = sort_and_find_most_recent(consensuses); if (most_recent == NULL) continue; const char *most_recent_sha3_uncompressed = consensus_cache_entry_get_value(most_recent, LABEL_SHA3_DIGEST_UNCOMPRESSED); const char *retain_methodname = compression_method_get_name( RETAIN_CONSENSUS_COMPRESSED_WITH_METHOD); if (BUG(most_recent_sha3_uncompressed == NULL)) continue; SMARTLIST_FOREACH_BEGIN(consensuses, consensus_cache_entry_t *, ent) { const char *lv_sha3_uncompressed = consensus_cache_entry_get_value(ent, LABEL_SHA3_DIGEST_UNCOMPRESSED); if (BUG(! lv_sha3_uncompressed)) continue; if (!strcmp(lv_sha3_uncompressed, most_recent_sha3_uncompressed)) continue; // This _is_ the most recent. const char *lv_methodname = consensus_cache_entry_get_value(ent, LABEL_COMPRESSION_TYPE); if (! lv_methodname || strcmp(lv_methodname, retain_methodname)) { consensus_cache_entry_mark_for_removal(ent); ++n_to_delete; } } SMARTLIST_FOREACH_END(ent); } smartlist_free(objects); smartlist_free(consensuses); smartlist_free(diffs); // Actually remove files, if they're not used. consensus_cache_delete_pending(cdm_cache_get(), 0); return n_to_delete; } /** * Initialize the consensus diff manager and its cache, and configure * its parameters based on the latest torrc and networkstatus parameters. */ void consdiffmgr_configure(const consdiff_cfg_t *cfg) { if (cfg) memcpy(&consdiff_cfg, cfg, sizeof(consdiff_cfg)); (void) cdm_cache_get(); } /** * Tell the sandbox (if any) configured by cfg to allow the * operations that the consensus diff manager will need. */ int consdiffmgr_register_with_sandbox(struct sandbox_cfg_elem **cfg) { return consensus_cache_register_with_sandbox(cdm_cache_get(), cfg); } /** * Scan the consensus diff manager's cache for any grossly malformed entries, * and mark them as deletable. Return 0 if no problems were found; 1 * if problems were found and fixed. */ int consdiffmgr_validate(void) { /* Right now, we only check for entries that have bad sha3 values */ int problems = 0; smartlist_t *objects = smartlist_new(); consensus_cache_find_all(objects, cdm_cache_get(), NULL, NULL); SMARTLIST_FOREACH_BEGIN(objects, consensus_cache_entry_t *, obj) { uint8_t sha3_expected[DIGEST256_LEN]; uint8_t sha3_received[DIGEST256_LEN]; int r = cdm_entry_get_sha3_value(sha3_expected, obj, LABEL_SHA3_DIGEST); if (r == -1) { /* digest isn't there; that's allowed */ continue; } else if (r == -2) { /* digest is malformed; that's not allowed */ problems = 1; consensus_cache_entry_mark_for_removal(obj); continue; } const uint8_t *body; size_t bodylen; consensus_cache_entry_incref(obj); r = consensus_cache_entry_get_body(obj, &body, &bodylen); if (r == 0) { crypto_digest256((char *)sha3_received, (const char *)body, bodylen, DIGEST_SHA3_256); } consensus_cache_entry_decref(obj); if (r < 0) continue; // Deconfuse coverity about the possibility of sha3_received being // uninitialized tor_assert(r <= 0); if (fast_memneq(sha3_received, sha3_expected, DIGEST256_LEN)) { problems = 1; consensus_cache_entry_mark_for_removal(obj); continue; } } SMARTLIST_FOREACH_END(obj); smartlist_free(objects); return problems; } /** * Helper: build new diffs of flavor as needed */ static void consdiffmgr_rescan_flavor_(consensus_flavor_t flavor) { smartlist_t *matches = NULL; smartlist_t *diffs = NULL; smartlist_t *compute_diffs_from = NULL; strmap_t *have_diff_from = NULL; // look for the most recent consensus, and for all previous in-range // consensuses. Do they all have diffs to it? const char *flavname = networkstatus_get_flavor_name(flavor); // 1. find the most recent consensus, and the ones that we might want // to diff to it. const char *methodname = compression_method_get_name( RETAIN_CONSENSUS_COMPRESSED_WITH_METHOD); matches = smartlist_new(); consensus_cache_find_all(matches, cdm_cache_get(), LABEL_FLAVOR, flavname); consensus_cache_filter_list(matches, LABEL_DOCTYPE, DOCTYPE_CONSENSUS); consensus_cache_filter_list(matches, LABEL_COMPRESSION_TYPE, methodname); consensus_cache_entry_t *most_recent = sort_and_find_most_recent(matches); if (!most_recent) { log_info(LD_DIRSERV, "No 'most recent' %s consensus found; " "not making diffs", flavname); goto done; } tor_assert(smartlist_len(matches)); smartlist_del(matches, smartlist_len(matches) - 1); const char *most_recent_valid_after = consensus_cache_entry_get_value(most_recent, LABEL_VALID_AFTER); if (BUG(most_recent_valid_after == NULL)) goto done; //LCOV_EXCL_LINE uint8_t most_recent_sha3[DIGEST256_LEN]; if (BUG(cdm_entry_get_sha3_value(most_recent_sha3, most_recent, LABEL_SHA3_DIGEST_UNCOMPRESSED) < 0)) goto done; //LCOV_EXCL_LINE // 2. Find all the relevant diffs _to_ this consensus. These are ones // that we don't need to compute. diffs = smartlist_new(); consensus_cache_find_all(diffs, cdm_cache_get(), LABEL_VALID_AFTER, most_recent_valid_after); consensus_cache_filter_list(diffs, LABEL_DOCTYPE, DOCTYPE_CONSENSUS_DIFF); consensus_cache_filter_list(diffs, LABEL_FLAVOR, flavname); have_diff_from = strmap_new(); SMARTLIST_FOREACH_BEGIN(diffs, consensus_cache_entry_t *, diff) { const char *va = consensus_cache_entry_get_value(diff, LABEL_FROM_VALID_AFTER); if (BUG(va == NULL)) continue; // LCOV_EXCL_LINE strmap_set(have_diff_from, va, diff); } SMARTLIST_FOREACH_END(diff); // 3. See which consensuses in 'matches' don't have diffs yet. smartlist_reverse(matches); // from newest to oldest. compute_diffs_from = smartlist_new(); SMARTLIST_FOREACH_BEGIN(matches, consensus_cache_entry_t *, ent) { const char *va = consensus_cache_entry_get_value(ent, LABEL_VALID_AFTER); if (BUG(va == NULL)) continue; // LCOV_EXCL_LINE if (strmap_get(have_diff_from, va) != NULL) continue; /* we already have this one. */ smartlist_add(compute_diffs_from, ent); /* Since we are not going to serve this as the most recent consensus * any more, we should stop keeping it mmap'd when it's not in use. */ consensus_cache_entry_mark_for_aggressive_release(ent); } SMARTLIST_FOREACH_END(ent); log_info(LD_DIRSERV, "The most recent %s consensus is valid-after %s. We have diffs to " "this consensus for %d/%d older %s consensuses. Generating diffs " "for the other %d.", flavname, most_recent_valid_after, smartlist_len(matches) - smartlist_len(compute_diffs_from), smartlist_len(matches), flavname, smartlist_len(compute_diffs_from)); // 4. Update the hashtable; remove entries in this flavor to other // target consensuses. cdm_diff_ht_purge(flavor, most_recent_sha3); // 5. Actually launch the requests. SMARTLIST_FOREACH_BEGIN(compute_diffs_from, consensus_cache_entry_t *, c) { if (BUG(c == most_recent)) continue; // LCOV_EXCL_LINE uint8_t this_sha3[DIGEST256_LEN]; if (cdm_entry_get_sha3_value(this_sha3, c, LABEL_SHA3_DIGEST_AS_SIGNED)<0) { // Not actually a bug, since we might be running with a directory // with stale files from before the #22143 fixes. continue; } if (cdm_diff_ht_check_and_note_pending(flavor, this_sha3, most_recent_sha3)) { // This is already pending, or we encountered an error. continue; } consensus_diff_queue_diff_work(c, most_recent); } SMARTLIST_FOREACH_END(c); done: smartlist_free(matches); smartlist_free(diffs); smartlist_free(compute_diffs_from); strmap_free(have_diff_from, NULL); } /** * Scan the cache for the latest consensuses and add their handles to * latest_consensus */ static void consdiffmgr_consensus_load(void) { smartlist_t *matches = smartlist_new(); for (int flav = 0; flav < N_CONSENSUS_FLAVORS; ++flav) { const char *flavname = networkstatus_get_flavor_name(flav); smartlist_clear(matches); consensus_cache_find_all(matches, cdm_cache_get(), LABEL_FLAVOR, flavname); consensus_cache_filter_list(matches, LABEL_DOCTYPE, DOCTYPE_CONSENSUS); consensus_cache_entry_t *most_recent = sort_and_find_most_recent(matches); if (! most_recent) continue; // no consensuses. const char *most_recent_sha3 = consensus_cache_entry_get_value(most_recent, LABEL_SHA3_DIGEST_UNCOMPRESSED); if (BUG(most_recent_sha3 == NULL)) continue; // LCOV_EXCL_LINE consensus_cache_filter_list(matches, LABEL_SHA3_DIGEST_UNCOMPRESSED, most_recent_sha3); // Everything that remains matches the most recent consensus of this // flavor. SMARTLIST_FOREACH_BEGIN(matches, consensus_cache_entry_t *, ent) { const char *lv_compression = consensus_cache_entry_get_value(ent, LABEL_COMPRESSION_TYPE); compress_method_t method = compression_method_get_by_name(lv_compression); int pos = consensus_compression_method_pos(method); if (pos < 0) continue; consensus_cache_entry_handle_free(latest_consensus[flav][pos]); latest_consensus[flav][pos] = consensus_cache_entry_handle_new(ent); } SMARTLIST_FOREACH_END(ent); } smartlist_free(matches); } /** * Scan the cache for diffs, and add them to the hashtable. */ static void consdiffmgr_diffs_load(void) { smartlist_t *diffs = smartlist_new(); consensus_cache_find_all(diffs, cdm_cache_get(), LABEL_DOCTYPE, DOCTYPE_CONSENSUS_DIFF); SMARTLIST_FOREACH_BEGIN(diffs, consensus_cache_entry_t *, diff) { const char *lv_flavor = consensus_cache_entry_get_value(diff, LABEL_FLAVOR); if (!lv_flavor) continue; int flavor = networkstatus_parse_flavor_name(lv_flavor); if (flavor < 0) continue; const char *lv_compression = consensus_cache_entry_get_value(diff, LABEL_COMPRESSION_TYPE); compress_method_t method = NO_METHOD; if (lv_compression) { method = compression_method_get_by_name(lv_compression); if (method == UNKNOWN_METHOD) { continue; } } uint8_t from_sha3[DIGEST256_LEN]; uint8_t to_sha3[DIGEST256_LEN]; if (cdm_entry_get_sha3_value(from_sha3, diff, LABEL_FROM_SHA3_DIGEST)<0) continue; if (cdm_entry_get_sha3_value(to_sha3, diff, LABEL_TARGET_SHA3_DIGEST)<0) continue; cdm_diff_ht_set_status(flavor, from_sha3, to_sha3, method, CDM_DIFF_PRESENT, consensus_cache_entry_handle_new(diff)); } SMARTLIST_FOREACH_END(diff); smartlist_free(diffs); } /** * Build new diffs as needed. */ void consdiffmgr_rescan(void) { if (cdm_cache_dirty == 0) return; // Clean up here to make room for new diffs, and to ensure that older // consensuses do not have any entries. consdiffmgr_cleanup(); if (cdm_cache_loaded == 0) { consdiffmgr_diffs_load(); consdiffmgr_consensus_load(); cdm_cache_loaded = 1; } for (int flav = 0; flav < N_CONSENSUS_FLAVORS; ++flav) { consdiffmgr_rescan_flavor_((consensus_flavor_t) flav); } cdm_cache_dirty = 0; } /** * Helper: compare two files by their from-valid-after and valid-after labels, * trying to sort in ascending order by from-valid-after (when present) and * valid-after (when not). Place everything that has neither label first in * the list. */ static int compare_by_staleness_(const void **a, const void **b) { const consensus_cache_entry_t *e1 = *a; const consensus_cache_entry_t *e2 = *b; const char *va1, *fva1, *va2, *fva2; va1 = consensus_cache_entry_get_value(e1, LABEL_VALID_AFTER); va2 = consensus_cache_entry_get_value(e2, LABEL_VALID_AFTER); fva1 = consensus_cache_entry_get_value(e1, LABEL_FROM_VALID_AFTER); fva2 = consensus_cache_entry_get_value(e2, LABEL_FROM_VALID_AFTER); if (fva1) va1 = fva1; if (fva2) va2 = fva2; /* See note about iso-encoded values in compare_by_valid_after_. Also note * that missing dates will get placed first. */ return strcmp_opt(va1, va2); } /** If there are not enough unused filenames to store n files, then * delete old consensuses until there are. (We have to keep track of the * number of filenames because of the way that the seccomp2 cache works.) * * Return 0 on success, -1 on failure. **/ static int consdiffmgr_ensure_space_for_files(int n) { consensus_cache_t *cache = cdm_cache_get(); if (consensus_cache_get_n_filenames_available(cache) >= n) { // there are already enough unused filenames. return 0; } // Try a cheap deletion of stuff that's waiting to get deleted. consensus_cache_delete_pending(cache, 0); if (consensus_cache_get_n_filenames_available(cache) >= n) { // okay, _that_ made enough filenames available. return 0; } // Let's get more assertive: clean out unused stuff, and force-remove // the files that we can. consdiffmgr_cleanup(); consensus_cache_delete_pending(cache, 1); const int n_to_remove = n - consensus_cache_get_n_filenames_available(cache); if (n_to_remove <= 0) { // okay, finally! return 0; } // At this point, we're going to have to throw out objects that will be // missed. Too bad! smartlist_t *objects = smartlist_new(); consensus_cache_find_all(objects, cache, NULL, NULL); smartlist_sort(objects, compare_by_staleness_); int n_marked = 0; SMARTLIST_FOREACH_BEGIN(objects, consensus_cache_entry_t *, ent) { consensus_cache_entry_mark_for_removal(ent); if (++n_marked >= n_to_remove) break; } SMARTLIST_FOREACH_END(ent); smartlist_free(objects); consensus_cache_delete_pending(cache, 1); if (consensus_cache_may_overallocate(cache)) { /* If we're allowed to throw extra files into the cache, let's do so * rather getting upset. */ return 0; } if (BUG(n_marked < n_to_remove)) return -1; else return 0; } /** * Set consensus cache flags on the objects in this consdiffmgr. */ static void consdiffmgr_set_cache_flags(void) { /* Right now, we just mark the consensus objects for aggressive release, * so that they get mmapped for as little time as possible. */ smartlist_t *objects = smartlist_new(); consensus_cache_find_all(objects, cdm_cache_get(), LABEL_DOCTYPE, DOCTYPE_CONSENSUS); SMARTLIST_FOREACH_BEGIN(objects, consensus_cache_entry_t *, ent) { consensus_cache_entry_mark_for_aggressive_release(ent); } SMARTLIST_FOREACH_END(ent); smartlist_free(objects); } /** * Called before shutdown: drop all storage held by the consdiffmgr.c module. */ void consdiffmgr_free_all(void) { cdm_diff_t **diff, **next; for (diff = HT_START(cdm_diff_ht, &cdm_diff_ht); diff; diff = next) { cdm_diff_t *this = *diff; next = HT_NEXT_RMV(cdm_diff_ht, &cdm_diff_ht, diff); cdm_diff_free(this); } int i; unsigned j; for (i = 0; i < N_CONSENSUS_FLAVORS; ++i) { for (j = 0; j < n_consensus_compression_methods(); ++j) { consensus_cache_entry_handle_free(latest_consensus[i][j]); } } memset(latest_consensus, 0, sizeof(latest_consensus)); consensus_cache_free(cons_diff_cache); cons_diff_cache = NULL; } /* ===== Thread workers =====*/ typedef struct compressed_result_t { config_line_t *labels; /** * Output: Body of the diff, as compressed. */ uint8_t *body; /** * Output: length of body_out */ size_t bodylen; } compressed_result_t; /** * Compress the bytestring input of length len using the * n_methods compression methods listed in the array methods. * * For each successful compression, set the fields in the results_out * array in the position corresponding to the compression method. Use * labels_in as a basis for the labels of the result. * * Return 0 if all compression succeeded; -1 if any failed. */ static int compress_multiple(compressed_result_t *results_out, int n_methods, const compress_method_t *methods, const uint8_t *input, size_t len, const config_line_t *labels_in) { int rv = 0; int i; for (i = 0; i < n_methods; ++i) { compress_method_t method = methods[i]; const char *methodname = compression_method_get_name(method); char *result; size_t sz; if (0 == tor_compress(&result, &sz, (const char*)input, len, method)) { results_out[i].body = (uint8_t*)result; results_out[i].bodylen = sz; results_out[i].labels = config_lines_dup(labels_in); cdm_labels_prepend_sha3(&results_out[i].labels, LABEL_SHA3_DIGEST, results_out[i].body, results_out[i].bodylen); config_line_prepend(&results_out[i].labels, LABEL_COMPRESSION_TYPE, methodname); } else { rv = -1; } } return rv; } /** * Given an array of n compressed_result_t in results, * as produced by compress_multiple, store them all into the * consdiffmgr, and store handles to them in the handles_out * array. * * Return CDM_DIFF_PRESENT if any was stored, and CDM_DIFF_ERROR if none * was stored. */ static cdm_diff_status_t store_multiple(consensus_cache_entry_handle_t **handles_out, int n, const compress_method_t *methods, const compressed_result_t *results, const char *description) { cdm_diff_status_t status = CDM_DIFF_ERROR; consdiffmgr_ensure_space_for_files(n); int i; for (i = 0; i < n; ++i) { compress_method_t method = methods[i]; uint8_t *body_out = results[i].body; size_t bodylen_out = results[i].bodylen; config_line_t *labels = results[i].labels; const char *methodname = compression_method_get_name(method); if (body_out && bodylen_out && labels) { /* Success! Store the results */ log_info(LD_DIRSERV, "Adding %s, compressed with %s", description, methodname); consensus_cache_entry_t *ent = consensus_cache_add(cdm_cache_get(), labels, body_out, bodylen_out); if (ent == NULL) { static ratelim_t cant_store_ratelim = RATELIM_INIT(5*60); log_fn_ratelim(&cant_store_ratelim, LOG_WARN, LD_FS, "Unable to store object %s compressed with %s.", description, methodname); continue; } status = CDM_DIFF_PRESENT; handles_out[i] = consensus_cache_entry_handle_new(ent); consensus_cache_entry_decref(ent); } } return status; } /** * An object passed to a worker thread that will try to produce a consensus * diff. */ typedef struct consensus_diff_worker_job_t { /** * Input: The consensus to compute the diff from. Holds a reference to the * cache entry, which must not be released until the job is passed back to * the main thread. The body must be mapped into memory in the main thread. */ consensus_cache_entry_t *diff_from; /** * Input: The consensus to compute the diff to. Holds a reference to the * cache entry, which must not be released until the job is passed back to * the main thread. The body must be mapped into memory in the main thread. */ consensus_cache_entry_t *diff_to; /** Output: labels and bodies */ compressed_result_t out[ARRAY_LENGTH(compress_diffs_with)]; } consensus_diff_worker_job_t; /** Given a consensus_cache_entry_t, check whether it has a label claiming * that it was compressed. If so, uncompress its contents into out and * set outlen to hold their size. If not, just copy the body into * out and set outlen to its length. Return 0 on success, * -1 on failure. * * In all cases, the output is nul-terminated. */ STATIC int uncompress_or_copy(char **out, size_t *outlen, consensus_cache_entry_t *ent) { const uint8_t *body; size_t bodylen; if (consensus_cache_entry_get_body(ent, &body, &bodylen) < 0) return -1; const char *lv_compression = consensus_cache_entry_get_value(ent, LABEL_COMPRESSION_TYPE); compress_method_t method = NO_METHOD; if (lv_compression) method = compression_method_get_by_name(lv_compression); return tor_uncompress(out, outlen, (const char *)body, bodylen, method, 1, LOG_WARN); } /** * Worker function. This function runs inside a worker thread and receives * a consensus_diff_worker_job_t as its input. */ static workqueue_reply_t consensus_diff_worker_threadfn(void *state_, void *work_) { (void)state_; consensus_diff_worker_job_t *job = work_; const uint8_t *diff_from, *diff_to; size_t len_from, len_to; int r; /* We need to have the body already mapped into RAM here. */ r = consensus_cache_entry_get_body(job->diff_from, &diff_from, &len_from); if (BUG(r < 0)) return WQ_RPL_REPLY; // LCOV_EXCL_LINE r = consensus_cache_entry_get_body(job->diff_to, &diff_to, &len_to); if (BUG(r < 0)) return WQ_RPL_REPLY; // LCOV_EXCL_LINE const char *lv_to_valid_after = consensus_cache_entry_get_value(job->diff_to, LABEL_VALID_AFTER); const char *lv_to_fresh_until = consensus_cache_entry_get_value(job->diff_to, LABEL_FRESH_UNTIL); const char *lv_to_valid_until = consensus_cache_entry_get_value(job->diff_to, LABEL_VALID_UNTIL); const char *lv_to_signatories = consensus_cache_entry_get_value(job->diff_to, LABEL_SIGNATORIES); const char *lv_from_valid_after = consensus_cache_entry_get_value(job->diff_from, LABEL_VALID_AFTER); const char *lv_from_digest = consensus_cache_entry_get_value(job->diff_from, LABEL_SHA3_DIGEST_AS_SIGNED); const char *lv_from_flavor = consensus_cache_entry_get_value(job->diff_from, LABEL_FLAVOR); const char *lv_to_flavor = consensus_cache_entry_get_value(job->diff_to, LABEL_FLAVOR); const char *lv_to_digest = consensus_cache_entry_get_value(job->diff_to, LABEL_SHA3_DIGEST_UNCOMPRESSED); if (! lv_from_digest) { /* This isn't a bug right now, since it can happen if you're migrating * from an older version of master to a newer one. The older ones didn't * annotate their stored consensus objects with sha3-digest-as-signed. */ return WQ_RPL_REPLY; // LCOV_EXCL_LINE } /* All these values are mandatory on the input */ if (BUG(!lv_to_valid_after) || BUG(!lv_from_valid_after) || BUG(!lv_from_flavor) || BUG(!lv_to_flavor)) { return WQ_RPL_REPLY; // LCOV_EXCL_LINE } /* The flavors need to match */ if (BUG(strcmp(lv_from_flavor, lv_to_flavor))) { return WQ_RPL_REPLY; // LCOV_EXCL_LINE } char *consensus_diff; { char *diff_from_nt = NULL, *diff_to_nt = NULL; size_t diff_from_nt_len, diff_to_nt_len; if (uncompress_or_copy(&diff_from_nt, &diff_from_nt_len, job->diff_from) < 0) { return WQ_RPL_REPLY; } if (uncompress_or_copy(&diff_to_nt, &diff_to_nt_len, job->diff_to) < 0) { tor_free(diff_from_nt); return WQ_RPL_REPLY; } tor_assert(diff_from_nt); tor_assert(diff_to_nt); // XXXX ugh; this is going to calculate the SHA3 of both its // XXXX inputs again, even though we already have that. Maybe it's time // XXXX to change the API here? consensus_diff = consensus_diff_generate(diff_from_nt, diff_to_nt); tor_free(diff_from_nt); tor_free(diff_to_nt); } if (!consensus_diff) { /* Couldn't generate consensus; we'll leave the reply blank. */ return WQ_RPL_REPLY; } /* Compress the results and send the reply */ tor_assert(compress_diffs_with[0] == NO_METHOD); size_t difflen = strlen(consensus_diff); job->out[0].body = (uint8_t *) consensus_diff; job->out[0].bodylen = difflen; config_line_t *common_labels = NULL; if (lv_to_valid_until) config_line_prepend(&common_labels, LABEL_VALID_UNTIL, lv_to_valid_until); if (lv_to_fresh_until) config_line_prepend(&common_labels, LABEL_FRESH_UNTIL, lv_to_fresh_until); if (lv_to_signatories) config_line_prepend(&common_labels, LABEL_SIGNATORIES, lv_to_signatories); cdm_labels_prepend_sha3(&common_labels, LABEL_SHA3_DIGEST_UNCOMPRESSED, job->out[0].body, job->out[0].bodylen); config_line_prepend(&common_labels, LABEL_FROM_VALID_AFTER, lv_from_valid_after); config_line_prepend(&common_labels, LABEL_VALID_AFTER, lv_to_valid_after); config_line_prepend(&common_labels, LABEL_FLAVOR, lv_from_flavor); config_line_prepend(&common_labels, LABEL_FROM_SHA3_DIGEST, lv_from_digest); config_line_prepend(&common_labels, LABEL_TARGET_SHA3_DIGEST, lv_to_digest); config_line_prepend(&common_labels, LABEL_DOCTYPE, DOCTYPE_CONSENSUS_DIFF); job->out[0].labels = config_lines_dup(common_labels); cdm_labels_prepend_sha3(&job->out[0].labels, LABEL_SHA3_DIGEST, job->out[0].body, job->out[0].bodylen); compress_multiple(job->out+1, n_diff_compression_methods()-1, compress_diffs_with+1, (const uint8_t*)consensus_diff, difflen, common_labels); config_free_lines(common_labels); return WQ_RPL_REPLY; } #define consensus_diff_worker_job_free(job) \ FREE_AND_NULL(consensus_diff_worker_job_t, \ consensus_diff_worker_job_free_, (job)) /** * Helper: release all storage held in job. */ static void consensus_diff_worker_job_free_(consensus_diff_worker_job_t *job) { if (!job) return; unsigned u; for (u = 0; u < n_diff_compression_methods(); ++u) { config_free_lines(job->out[u].labels); tor_free(job->out[u].body); } consensus_cache_entry_decref(job->diff_from); consensus_cache_entry_decref(job->diff_to); tor_free(job); } /** * Worker function: This function runs in the main thread, and receives * a consensus_diff_worker_job_t that the worker thread has already * processed. */ static void consensus_diff_worker_replyfn(void *work_) { tor_assert(in_main_thread()); tor_assert(work_); consensus_diff_worker_job_t *job = work_; const char *lv_from_digest = consensus_cache_entry_get_value(job->diff_from, LABEL_SHA3_DIGEST_AS_SIGNED); const char *lv_to_digest = consensus_cache_entry_get_value(job->diff_to, LABEL_SHA3_DIGEST_UNCOMPRESSED); const char *lv_flavor = consensus_cache_entry_get_value(job->diff_to, LABEL_FLAVOR); if (BUG(lv_from_digest == NULL)) lv_from_digest = "???"; // LCOV_EXCL_LINE if (BUG(lv_to_digest == NULL)) lv_to_digest = "???"; // LCOV_EXCL_LINE uint8_t from_sha3[DIGEST256_LEN]; uint8_t to_sha3[DIGEST256_LEN]; int flav = -1; int cache = 1; if (BUG(cdm_entry_get_sha3_value(from_sha3, job->diff_from, LABEL_SHA3_DIGEST_AS_SIGNED) < 0)) cache = 0; if (BUG(cdm_entry_get_sha3_value(to_sha3, job->diff_to, LABEL_SHA3_DIGEST_UNCOMPRESSED) < 0)) cache = 0; if (BUG(lv_flavor == NULL)) { cache = 0; } else if ((flav = networkstatus_parse_flavor_name(lv_flavor)) < 0) { cache = 0; } consensus_cache_entry_handle_t *handles[ARRAY_LENGTH(compress_diffs_with)]; memset(handles, 0, sizeof(handles)); char description[128]; tor_snprintf(description, sizeof(description), "consensus diff from %s to %s", lv_from_digest, lv_to_digest); int status = store_multiple(handles, n_diff_compression_methods(), compress_diffs_with, job->out, description); if (status != CDM_DIFF_PRESENT) { /* Failure! Nothing to do but complain */ log_warn(LD_DIRSERV, "Worker was unable to compute consensus diff " "from %s to %s", lv_from_digest, lv_to_digest); /* Cache this error so we don't try to compute this one again. */ status = CDM_DIFF_ERROR; } unsigned u; for (u = 0; u < ARRAY_LENGTH(handles); ++u) { compress_method_t method = compress_diffs_with[u]; if (cache) { consensus_cache_entry_handle_t *h = handles[u]; int this_status = status; if (h == NULL) { this_status = CDM_DIFF_ERROR; } tor_assert_nonfatal(h != NULL || this_status == CDM_DIFF_ERROR); cdm_diff_ht_set_status(flav, from_sha3, to_sha3, method, this_status, h); } else { consensus_cache_entry_handle_free(handles[u]); } } consensus_diff_worker_job_free(job); } /** * Queue the job of computing the diff from diff_from to diff_to * in a worker thread. */ static int consensus_diff_queue_diff_work(consensus_cache_entry_t *diff_from, consensus_cache_entry_t *diff_to) { tor_assert(in_main_thread()); consensus_cache_entry_incref(diff_from); consensus_cache_entry_incref(diff_to); consensus_diff_worker_job_t *job = tor_malloc_zero(sizeof(*job)); job->diff_from = diff_from; job->diff_to = diff_to; /* Make sure body is mapped. */ const uint8_t *body; size_t bodylen; int r1 = consensus_cache_entry_get_body(diff_from, &body, &bodylen); int r2 = consensus_cache_entry_get_body(diff_to, &body, &bodylen); if (r1 < 0 || r2 < 0) goto err; workqueue_entry_t *work; work = cpuworker_queue_work(WQ_PRI_LOW, consensus_diff_worker_threadfn, consensus_diff_worker_replyfn, job); if (!work) goto err; return 0; err: consensus_diff_worker_job_free(job); // includes decrefs. return -1; } /** * Holds requests and replies for consensus_compress_workers. */ typedef struct consensus_compress_worker_job_t { char *consensus; size_t consensus_len; consensus_flavor_t flavor; config_line_t *labels_in; compressed_result_t out[ARRAY_LENGTH(compress_consensus_with)]; } consensus_compress_worker_job_t; #define consensus_compress_worker_job_free(job) \ FREE_AND_NULL(consensus_compress_worker_job_t, \ consensus_compress_worker_job_free_, (job)) /** * Free all resources held in job */ static void consensus_compress_worker_job_free_(consensus_compress_worker_job_t *job) { if (!job) return; tor_free(job->consensus); config_free_lines(job->labels_in); unsigned u; for (u = 0; u < n_consensus_compression_methods(); ++u) { config_free_lines(job->out[u].labels); tor_free(job->out[u].body); } tor_free(job); } /** * Worker function. This function runs inside a worker thread and receives * a consensus_compress_worker_job_t as its input. */ static workqueue_reply_t consensus_compress_worker_threadfn(void *state_, void *work_) { (void)state_; consensus_compress_worker_job_t *job = work_; consensus_flavor_t flavor = job->flavor; const char *consensus = job->consensus; size_t bodylen = job->consensus_len; config_line_t *labels = config_lines_dup(job->labels_in); const char *flavname = networkstatus_get_flavor_name(flavor); cdm_labels_prepend_sha3(&labels, LABEL_SHA3_DIGEST_UNCOMPRESSED, (const uint8_t *)consensus, bodylen); { const char *start, *end; if (router_get_networkstatus_v3_signed_boundaries(consensus, &start, &end) < 0) { start = consensus; end = consensus+bodylen; } cdm_labels_prepend_sha3(&labels, LABEL_SHA3_DIGEST_AS_SIGNED, (const uint8_t *)start, end - start); } config_line_prepend(&labels, LABEL_FLAVOR, flavname); config_line_prepend(&labels, LABEL_DOCTYPE, DOCTYPE_CONSENSUS); compress_multiple(job->out, n_consensus_compression_methods(), compress_consensus_with, (const uint8_t*)consensus, bodylen, labels); config_free_lines(labels); return WQ_RPL_REPLY; } /** * Worker function: This function runs in the main thread, and receives * a consensus_diff_compress_job_t that the worker thread has already * processed. */ static void consensus_compress_worker_replyfn(void *work_) { consensus_compress_worker_job_t *job = work_; consensus_cache_entry_handle_t *handles[ ARRAY_LENGTH(compress_consensus_with)]; memset(handles, 0, sizeof(handles)); store_multiple(handles, n_consensus_compression_methods(), compress_consensus_with, job->out, "consensus"); cdm_cache_dirty = 1; unsigned u; consensus_flavor_t f = job->flavor; tor_assert((int)f < N_CONSENSUS_FLAVORS); for (u = 0; u < ARRAY_LENGTH(handles); ++u) { if (handles[u] == NULL) continue; consensus_cache_entry_handle_free(latest_consensus[f][u]); latest_consensus[f][u] = handles[u]; } consensus_compress_worker_job_free(job); } /** * If true, we compress in worker threads. */ static int background_compression = 0; /** * Queue a job to compress consensus and store its compressed * text in the cache. */ static int consensus_queue_compression_work(const char *consensus, const networkstatus_t *as_parsed) { tor_assert(consensus); tor_assert(as_parsed); consensus_compress_worker_job_t *job = tor_malloc_zero(sizeof(*job)); job->consensus = tor_strdup(consensus); job->consensus_len = strlen(consensus); job->flavor = as_parsed->flavor; char va_str[ISO_TIME_LEN+1]; char vu_str[ISO_TIME_LEN+1]; char fu_str[ISO_TIME_LEN+1]; format_iso_time_nospace(va_str, as_parsed->valid_after); format_iso_time_nospace(fu_str, as_parsed->fresh_until); format_iso_time_nospace(vu_str, as_parsed->valid_until); config_line_append(&job->labels_in, LABEL_VALID_AFTER, va_str); config_line_append(&job->labels_in, LABEL_FRESH_UNTIL, fu_str); config_line_append(&job->labels_in, LABEL_VALID_UNTIL, vu_str); if (as_parsed->voters) { smartlist_t *hexvoters = smartlist_new(); SMARTLIST_FOREACH_BEGIN(as_parsed->voters, networkstatus_voter_info_t *, vi) { if (smartlist_len(vi->sigs) == 0) continue; // didn't sign. char d[HEX_DIGEST_LEN+1]; base16_encode(d, sizeof(d), vi->identity_digest, DIGEST_LEN); smartlist_add_strdup(hexvoters, d); } SMARTLIST_FOREACH_END(vi); char *signers = smartlist_join_strings(hexvoters, ",", 0, NULL); config_line_prepend(&job->labels_in, LABEL_SIGNATORIES, signers); tor_free(signers); SMARTLIST_FOREACH(hexvoters, char *, cp, tor_free(cp)); smartlist_free(hexvoters); } if (background_compression) { workqueue_entry_t *work; work = cpuworker_queue_work(WQ_PRI_LOW, consensus_compress_worker_threadfn, consensus_compress_worker_replyfn, job); if (!work) { consensus_compress_worker_job_free(job); return -1; } return 0; } else { consensus_compress_worker_threadfn(NULL, job); consensus_compress_worker_replyfn(job); return 0; } } /** * Tell the consdiffmgr backend to compress consensuses in worker threads. */ void consdiffmgr_enable_background_compression(void) { // This isn't the default behavior because it would break unit tests. background_compression = 1; } /** Read the set of voters from the cached object ent into * out, as a list of hex-encoded digests. Return 0 on success, * -1 if no signatories were recorded. */ int consensus_cache_entry_get_voter_id_digests(const consensus_cache_entry_t *ent, smartlist_t *out) { tor_assert(ent); tor_assert(out); const char *s; s = consensus_cache_entry_get_value(ent, LABEL_SIGNATORIES); if (s == NULL) return -1; smartlist_split_string(out, s, ",", SPLIT_SKIP_SPACE|SPLIT_STRIP_SPACE, 0); return 0; } /** Read the fresh-until time of cached object ent into *out * and return 0, or return -1 if no such time was recorded. */ int consensus_cache_entry_get_fresh_until(const consensus_cache_entry_t *ent, time_t *out) { tor_assert(ent); tor_assert(out); const char *s; s = consensus_cache_entry_get_value(ent, LABEL_FRESH_UNTIL); if (s == NULL || parse_iso_time_nospace(s, out) < 0) return -1; else return 0; } /** Read the valid until timestamp from the cached object ent into * *out and return 0, or return -1 if no such time was recorded. */ int consensus_cache_entry_get_valid_until(const consensus_cache_entry_t *ent, time_t *out) { tor_assert(ent); tor_assert(out); const char *s; s = consensus_cache_entry_get_value(ent, LABEL_VALID_UNTIL); if (s == NULL || parse_iso_time_nospace(s, out) < 0) return -1; else return 0; } /** Read the valid after timestamp from the cached object ent into * *out and return 0, or return -1 if no such time was recorded. */ int consensus_cache_entry_get_valid_after(const consensus_cache_entry_t *ent, time_t *out) { tor_assert(ent); tor_assert(out); const char *s; s = consensus_cache_entry_get_value(ent, LABEL_VALID_AFTER); if (s == NULL || parse_iso_time_nospace(s, out) < 0) return -1; else return 0; }