diff options
Diffstat (limited to 'src/feature/rend/rendcache.c')
| -rw-r--r-- | src/feature/rend/rendcache.c | 1029 |
1 files changed, 0 insertions, 1029 deletions
diff --git a/src/feature/rend/rendcache.c b/src/feature/rend/rendcache.c deleted file mode 100644 index 04f6390a7f..0000000000 --- a/src/feature/rend/rendcache.c +++ /dev/null @@ -1,1029 +0,0 @@ -/* Copyright (c) 2015-2020, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file rendcache.c - * \brief Hidden service descriptor cache. - **/ - -#define RENDCACHE_PRIVATE -#include "feature/rend/rendcache.h" - -#include "app/config/config.h" -#include "feature/stats/rephist.h" -#include "feature/nodelist/routerlist.h" -#include "feature/rend/rendcommon.h" -#include "feature/rend/rendparse.h" - -#include "core/or/extend_info_st.h" -#include "feature/rend/rend_intro_point_st.h" -#include "feature/rend/rend_service_descriptor_st.h" - -#include "lib/ctime/di_ops.h" - -/** Map from service id (as generated by rend_get_service_id) to - * rend_cache_entry_t. */ -STATIC strmap_t *rend_cache = NULL; - -/** Map from service id to rend_cache_entry_t; only for hidden services. */ -static strmap_t *rend_cache_local_service = NULL; - -/** Map from descriptor id to rend_cache_entry_t; only for hidden service - * directories. */ -STATIC digestmap_t *rend_cache_v2_dir = NULL; - -/** (Client side only) Map from service id to rend_cache_failure_t. This - * cache is used to track intro point(IP) failures so we know when to keep - * or discard a new descriptor we just fetched. Here is a description of the - * cache behavior. - * - * Every time tor discards an IP (ex: receives a NACK), we add an entry to - * this cache noting the identity digest of the IP and it's failure type for - * the service ID. The reason we indexed this cache by service ID is to - * differentiate errors that can occur only for a specific service like a - * NACK for instance. It applies for one but maybe not for the others. - * - * Once a service descriptor is fetched and considered valid, each IP is - * looked up in this cache and if present, it is discarded from the fetched - * descriptor. At the end, all IP(s) in the cache, for a specific service - * ID, that were NOT present in the descriptor are removed from this cache. - * Which means that if at least one IP was not in this cache, thus usable, - * it's considered a new descriptor so we keep it. Else, if all IPs were in - * this cache, we discard the descriptor as it's considered unusable. - * - * Once a descriptor is removed from the rend cache or expires, the entry - * in this cache is also removed for the service ID. - * - * This scheme allows us to not rely on the descriptor's timestamp (which - * is rounded down to the hour) to know if we have a newer descriptor. We - * only rely on the usability of intro points from an internal state. */ -STATIC strmap_t *rend_cache_failure = NULL; - -/* DOCDOC */ -STATIC size_t rend_cache_total_allocation = 0; - -/** Initializes the service descriptor cache. -*/ -void -rend_cache_init(void) -{ - rend_cache = strmap_new(); - rend_cache_v2_dir = digestmap_new(); - rend_cache_local_service = strmap_new(); - rend_cache_failure = strmap_new(); -} - -/** Return the approximate number of bytes needed to hold <b>e</b>. */ -STATIC size_t -rend_cache_entry_allocation(const rend_cache_entry_t *e) -{ - if (!e) - return 0; - - /* This doesn't count intro_nodes or key size */ - return sizeof(*e) + e->len + sizeof(*e->parsed); -} - -/* DOCDOC */ -size_t -rend_cache_get_total_allocation(void) -{ - return rend_cache_total_allocation; -} - -/** Decrement the total bytes attributed to the rendezvous cache by n. */ -void -rend_cache_decrement_allocation(size_t n) -{ - static int have_underflowed = 0; - - if (rend_cache_total_allocation >= n) { - rend_cache_total_allocation -= n; - } else { - rend_cache_total_allocation = 0; - if (! have_underflowed) { - have_underflowed = 1; - log_warn(LD_BUG, "Underflow in rend_cache_decrement_allocation"); - } - } -} - -/** Increase the total bytes attributed to the rendezvous cache by n. */ -void -rend_cache_increment_allocation(size_t n) -{ - static int have_overflowed = 0; - if (rend_cache_total_allocation <= SIZE_MAX - n) { - rend_cache_total_allocation += n; - } else { - rend_cache_total_allocation = SIZE_MAX; - if (! have_overflowed) { - have_overflowed = 1; - log_warn(LD_BUG, "Overflow in rend_cache_increment_allocation"); - } - } -} - -/** Helper: free a rend cache failure intro object. */ -STATIC void -rend_cache_failure_intro_entry_free_(rend_cache_failure_intro_t *entry) -{ - if (entry == NULL) { - return; - } - tor_free(entry); -} - -static void -rend_cache_failure_intro_entry_free_void(void *entry) -{ - rend_cache_failure_intro_entry_free_(entry); -} - -/** Allocate a rend cache failure intro object and return it. <b>failure</b> - * is set into the object. This function can not fail. */ -STATIC rend_cache_failure_intro_t * -rend_cache_failure_intro_entry_new(rend_intro_point_failure_t failure) -{ - rend_cache_failure_intro_t *entry = tor_malloc(sizeof(*entry)); - entry->failure_type = failure; - entry->created_ts = time(NULL); - return entry; -} - -/** Helper: free a rend cache failure object. */ -STATIC void -rend_cache_failure_entry_free_(rend_cache_failure_t *entry) -{ - if (entry == NULL) { - return; - } - - /* Free and remove every intro failure object. */ - digestmap_free(entry->intro_failures, - rend_cache_failure_intro_entry_free_void); - - tor_free(entry); -} - -/** Helper: deallocate a rend_cache_failure_t. (Used with strmap_free(), - * which requires a function pointer whose argument is void*). */ -STATIC void -rend_cache_failure_entry_free_void(void *entry) -{ - rend_cache_failure_entry_free_(entry); -} - -/** Allocate a rend cache failure object and return it. This function can - * not fail. */ -STATIC rend_cache_failure_t * -rend_cache_failure_entry_new(void) -{ - rend_cache_failure_t *entry = tor_malloc(sizeof(*entry)); - entry->intro_failures = digestmap_new(); - return entry; -} - -/** Remove failure cache entry for the service ID in the given descriptor - * <b>desc</b>. */ -STATIC void -rend_cache_failure_remove(rend_service_descriptor_t *desc) -{ - char service_id[REND_SERVICE_ID_LEN_BASE32 + 1]; - rend_cache_failure_t *entry; - - if (desc == NULL) { - return; - } - if (rend_get_service_id(desc->pk, service_id) < 0) { - return; - } - entry = strmap_get_lc(rend_cache_failure, service_id); - if (entry != NULL) { - strmap_remove_lc(rend_cache_failure, service_id); - rend_cache_failure_entry_free(entry); - } -} - -/** Helper: free storage held by a single service descriptor cache entry. */ -STATIC void -rend_cache_entry_free_(rend_cache_entry_t *e) -{ - if (!e) - return; - rend_cache_decrement_allocation(rend_cache_entry_allocation(e)); - /* We are about to remove a descriptor from the cache so remove the entry - * in the failure cache. */ - rend_cache_failure_remove(e->parsed); - rend_service_descriptor_free(e->parsed); - tor_free(e->desc); - tor_free(e); -} - -/** Helper: deallocate a rend_cache_entry_t. (Used with strmap_free(), which - * requires a function pointer whose argument is void*). */ -static void -rend_cache_entry_free_void(void *p) -{ - rend_cache_entry_free_(p); -} - -/** Check if a failure cache entry exists for the given intro point. */ -bool -rend_cache_intro_failure_exists(const char *service_id, - const uint8_t *intro_identity) -{ - tor_assert(service_id); - tor_assert(intro_identity); - - return cache_failure_intro_lookup(intro_identity, service_id, NULL); -} - -/** Free all storage held by the service descriptor cache. */ -void -rend_cache_free_all(void) -{ - strmap_free(rend_cache, rend_cache_entry_free_void); - digestmap_free(rend_cache_v2_dir, rend_cache_entry_free_void); - strmap_free(rend_cache_local_service, rend_cache_entry_free_void); - strmap_free(rend_cache_failure, rend_cache_failure_entry_free_void); - rend_cache = NULL; - rend_cache_v2_dir = NULL; - rend_cache_local_service = NULL; - rend_cache_failure = NULL; - rend_cache_total_allocation = 0; -} - -/** Remove all entries that re REND_CACHE_FAILURE_MAX_AGE old. This is - * called every second. - * - * We have to clean these regularly else if for whatever reasons an hidden - * service goes offline and a client tries to connect to it during that - * time, a failure entry is created and the client will be unable to connect - * for a while even though the service has return online. */ -void -rend_cache_failure_clean(time_t now) -{ - time_t cutoff = now - REND_CACHE_FAILURE_MAX_AGE; - STRMAP_FOREACH_MODIFY(rend_cache_failure, key, - rend_cache_failure_t *, ent) { - /* Free and remove every intro failure object that match the cutoff. */ - DIGESTMAP_FOREACH_MODIFY(ent->intro_failures, ip_key, - rend_cache_failure_intro_t *, ip_ent) { - if (ip_ent->created_ts < cutoff) { - rend_cache_failure_intro_entry_free(ip_ent); - MAP_DEL_CURRENT(ip_key); - } - } DIGESTMAP_FOREACH_END; - /* If the entry is now empty of intro point failures, remove it. */ - if (digestmap_isempty(ent->intro_failures)) { - rend_cache_failure_entry_free(ent); - MAP_DEL_CURRENT(key); - } - } STRMAP_FOREACH_END; -} - -/** Removes all old entries from the client or service descriptor cache. -*/ -void -rend_cache_clean(time_t now, rend_cache_type_t cache_type) -{ - strmap_iter_t *iter; - const char *key; - void *val; - rend_cache_entry_t *ent; - time_t cutoff = now - REND_CACHE_MAX_AGE - REND_CACHE_MAX_SKEW; - strmap_t *cache = NULL; - - if (cache_type == REND_CACHE_TYPE_CLIENT) { - cache = rend_cache; - } else if (cache_type == REND_CACHE_TYPE_SERVICE) { - cache = rend_cache_local_service; - } - tor_assert(cache); - - for (iter = strmap_iter_init(cache); !strmap_iter_done(iter); ) { - strmap_iter_get(iter, &key, &val); - ent = (rend_cache_entry_t*)val; - if (ent->parsed->timestamp < cutoff) { - iter = strmap_iter_next_rmv(cache, iter); - rend_cache_entry_free(ent); - } else { - iter = strmap_iter_next(cache, iter); - } - } -} - -/** Remove ALL entries from the rendezvous service descriptor cache. -*/ -void -rend_cache_purge(void) -{ - if (rend_cache) { - log_info(LD_REND, "Purging HS v2 descriptor cache"); - strmap_free(rend_cache, rend_cache_entry_free_void); - } - rend_cache = strmap_new(); -} - -/** Remove ALL entries from the failure cache. This is also called when a - * NEWNYM signal is received. */ -void -rend_cache_failure_purge(void) -{ - if (rend_cache_failure) { - log_info(LD_REND, "Purging HS v2 failure cache"); - strmap_free(rend_cache_failure, rend_cache_failure_entry_free_void); - } - rend_cache_failure = strmap_new(); -} - -/** Lookup the rend failure cache using a relay identity digest in - * <b>identity</b> which has DIGEST_LEN bytes and service ID <b>service_id</b> - * which is a null-terminated string. If @a intro_entry is provided, then it - * is set to the entry on success, and to NULL on failure. - * Return 1 iff found else 0. */ -STATIC int -cache_failure_intro_lookup(const uint8_t *identity, const char *service_id, - rend_cache_failure_intro_t **intro_entry) -{ - rend_cache_failure_t *elem; - rend_cache_failure_intro_t *intro_elem; - - tor_assert(rend_cache_failure); - - if (intro_entry) { - *intro_entry = NULL; - } - - /* Lookup descriptor and return it. */ - elem = strmap_get_lc(rend_cache_failure, service_id); - if (elem == NULL) { - goto not_found; - } - intro_elem = digestmap_get(elem->intro_failures, (char *) identity); - if (intro_elem == NULL) { - goto not_found; - } - if (intro_entry) { - *intro_entry = intro_elem; - } - return 1; - not_found: - return 0; -} - -/** Allocate a new cache failure intro object and copy the content from - * <b>entry</b> to this newly allocated object. Return it. */ -static rend_cache_failure_intro_t * -cache_failure_intro_dup(const rend_cache_failure_intro_t *entry) -{ - rend_cache_failure_intro_t *ent_dup = - rend_cache_failure_intro_entry_new(entry->failure_type); - ent_dup->created_ts = entry->created_ts; - return ent_dup; -} - -/** Add an intro point failure to the failure cache using the relay - * <b>identity</b> and service ID <b>service_id</b>. Record the - * <b>failure</b> in that object. */ -STATIC void -cache_failure_intro_add(const uint8_t *identity, const char *service_id, - rend_intro_point_failure_t failure) -{ - rend_cache_failure_t *fail_entry; - rend_cache_failure_intro_t *entry, *old_entry; - - /* Make sure we have a failure object for this service ID and if not, - * create it with this new intro failure entry. */ - fail_entry = strmap_get_lc(rend_cache_failure, service_id); - if (fail_entry == NULL) { - fail_entry = rend_cache_failure_entry_new(); - /* Add failure entry to global rend failure cache. */ - strmap_set_lc(rend_cache_failure, service_id, fail_entry); - } - entry = rend_cache_failure_intro_entry_new(failure); - old_entry = digestmap_set(fail_entry->intro_failures, - (char *) identity, entry); - /* This _should_ be NULL, but in case it isn't, free it. */ - rend_cache_failure_intro_entry_free(old_entry); -} - -/** Using a parsed descriptor <b>desc</b>, check if the introduction points - * are present in the failure cache and if so they are removed from the - * descriptor and kept into the failure cache. Then, each intro points that - * are NOT in the descriptor but in the failure cache for the given - * <b>service_id</b> are removed from the failure cache. */ -STATIC void -validate_intro_point_failure(const rend_service_descriptor_t *desc, - const char *service_id) -{ - rend_cache_failure_t *new_entry, *cur_entry; - /* New entry for the service ID that will be replacing the one in the - * failure cache since we have a new descriptor. In the case where all - * intro points are removed, we are assured that the new entry is the same - * as the current one. */ - new_entry = tor_malloc(sizeof(*new_entry)); - new_entry->intro_failures = digestmap_new(); - - tor_assert(desc); - - SMARTLIST_FOREACH_BEGIN(desc->intro_nodes, rend_intro_point_t *, intro) { - int found; - rend_cache_failure_intro_t *entry; - const uint8_t *identity = - (uint8_t *) intro->extend_info->identity_digest; - - found = cache_failure_intro_lookup(identity, service_id, &entry); - if (found) { - /* Dup here since it will be freed at the end when removing the - * original entry in the cache. */ - rend_cache_failure_intro_t *ent_dup = cache_failure_intro_dup(entry); - /* This intro point is in our cache, discard it from the descriptor - * because chances are that it's unusable. */ - SMARTLIST_DEL_CURRENT(desc->intro_nodes, intro); - /* Keep it for our new entry. */ - digestmap_set(new_entry->intro_failures, (char *) identity, ent_dup); - /* Only free it when we're done looking at it. */ - rend_intro_point_free(intro); - continue; - } - } SMARTLIST_FOREACH_END(intro); - - /* Swap the failure entry in the cache and free the current one. */ - cur_entry = strmap_get_lc(rend_cache_failure, service_id); - if (cur_entry != NULL) { - rend_cache_failure_entry_free(cur_entry); - } - strmap_set_lc(rend_cache_failure, service_id, new_entry); -} - -/** Note down an intro failure in the rend failure cache using the type of - * failure in <b>failure</b> for the relay identity digest in - * <b>identity</b> and service ID <b>service_id</b>. If an entry already - * exists in the cache, the failure type is changed with <b>failure</b>. */ -void -rend_cache_intro_failure_note(rend_intro_point_failure_t failure, - const uint8_t *identity, - const char *service_id) -{ - int found; - rend_cache_failure_intro_t *entry; - - found = cache_failure_intro_lookup(identity, service_id, &entry); - if (!found) { - cache_failure_intro_add(identity, service_id, failure); - } else { - /* Replace introduction point failure with this one. */ - entry->failure_type = failure; - } -} - -/** Remove all old v2 descriptors and those for which this hidden service - * directory is not responsible for any more. The cutoff is the time limit for - * which we want to keep the cache entry. In other words, any entry created - * before will be removed. */ -size_t -rend_cache_clean_v2_descs_as_dir(time_t cutoff) -{ - digestmap_iter_t *iter; - size_t bytes_removed = 0; - - for (iter = digestmap_iter_init(rend_cache_v2_dir); - !digestmap_iter_done(iter); ) { - const char *key; - void *val; - rend_cache_entry_t *ent; - digestmap_iter_get(iter, &key, &val); - ent = val; - if (ent->parsed->timestamp < cutoff) { - char key_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; - base32_encode(key_base32, sizeof(key_base32), key, DIGEST_LEN); - log_info(LD_REND, "Removing descriptor with ID '%s' from cache", - safe_str_client(key_base32)); - bytes_removed += rend_cache_entry_allocation(ent); - iter = digestmap_iter_next_rmv(rend_cache_v2_dir, iter); - rend_cache_entry_free(ent); - } else { - iter = digestmap_iter_next(rend_cache_v2_dir, iter); - } - } - - return bytes_removed; -} - -/** Lookup in the client cache the given service ID <b>query</b> for - * <b>version</b>. - * - * Return 0 if found and if <b>e</b> is non NULL, set it with the entry - * found. Else, a negative value is returned and <b>e</b> is untouched. - * -EINVAL means that <b>query</b> is not a valid service id. - * -ENOENT means that no entry in the cache was found. */ -int -rend_cache_lookup_entry(const char *query, int version, rend_cache_entry_t **e) -{ - int ret = 0; - char key[REND_SERVICE_ID_LEN_BASE32 + 2]; /* <version><query>\0 */ - rend_cache_entry_t *entry = NULL; - static const int default_version = 2; - - tor_assert(query); - - /* This is possible if we are in the shutdown process and the cache was - * freed while some other subsystem might do a lookup to the cache for - * cleanup reasons such HS circuit cleanup for instance. */ - if (!rend_cache) { - ret = -ENOENT; - goto end; - } - - if (!rend_valid_v2_service_id(query)) { - ret = -EINVAL; - goto end; - } - - switch (version) { - case 0: - log_warn(LD_REND, "Cache lookup of a v0 renddesc is deprecated."); - break; - case 2: - /* Default is version 2. */ - default: - tor_snprintf(key, sizeof(key), "%d%s", default_version, query); - entry = strmap_get_lc(rend_cache, key); - break; - } - if (!entry) { - ret = -ENOENT; - goto end; - } - tor_assert(entry->parsed && entry->parsed->intro_nodes); - - if (e) { - *e = entry; - } - - end: - return ret; -} - -/* - * Lookup the v2 service descriptor with the service ID <b>query</b> in the - * local service descriptor cache. Return 0 if found and if <b>e</b> is - * non NULL, set it with the entry found. Else, a negative value is returned - * and <b>e</b> is untouched. - * -EINVAL means that <b>query</b> is not a valid service id. - * -ENOENT means that no entry in the cache was found. */ -int -rend_cache_lookup_v2_desc_as_service(const char *query, rend_cache_entry_t **e) -{ - int ret = 0; - rend_cache_entry_t *entry = NULL; - - tor_assert(rend_cache_local_service); - tor_assert(query); - - if (!rend_valid_v2_service_id(query)) { - ret = -EINVAL; - goto end; - } - - /* Lookup descriptor and return. */ - entry = strmap_get_lc(rend_cache_local_service, query); - if (!entry) { - ret = -ENOENT; - goto end; - } - - if (e) { - *e = entry; - } - - end: - return ret; -} - -/** Lookup the v2 service descriptor with base32-encoded <b>desc_id</b> and - * copy the pointer to it to *<b>desc</b>. Return 1 on success, 0 on - * well-formed-but-not-found, and -1 on failure. - */ -int -rend_cache_lookup_v2_desc_as_dir(const char *desc_id, const char **desc) -{ - rend_cache_entry_t *e; - char desc_id_digest[DIGEST_LEN]; - tor_assert(rend_cache_v2_dir); - if (base32_decode(desc_id_digest, DIGEST_LEN, - desc_id, REND_DESC_ID_V2_LEN_BASE32) != DIGEST_LEN) { - log_fn(LOG_PROTOCOL_WARN, LD_REND, - "Rejecting v2 rendezvous descriptor request -- descriptor ID " - "has wrong length or illegal characters: %s", - safe_str(desc_id)); - return -1; - } - /* Lookup descriptor and return. */ - e = digestmap_get(rend_cache_v2_dir, desc_id_digest); - if (e) { - *desc = e->desc; - e->last_served = approx_time(); - return 1; - } - return 0; -} - -/** Parse the v2 service descriptor(s) in <b>desc</b> and store it/them to the - * local rend cache. Don't attempt to decrypt the included list of introduction - * points (as we don't have a descriptor cookie for it). - * - * If we have a newer descriptor with the same ID, ignore this one. - * If we have an older descriptor with the same ID, replace it. - * - * Return 0 on success, or -1 if we couldn't parse any of them. - * - * We should only call this function for public (e.g. non bridge) relays. - */ -int -rend_cache_store_v2_desc_as_dir(const char *desc) -{ - const or_options_t *options = get_options(); - rend_service_descriptor_t *parsed; - char desc_id[DIGEST_LEN]; - char *intro_content; - size_t intro_size; - size_t encoded_size; - char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1]; - int number_parsed = 0, number_stored = 0; - const char *current_desc = desc; - const char *next_desc; - rend_cache_entry_t *e; - time_t now = time(NULL); - tor_assert(rend_cache_v2_dir); - tor_assert(desc); - while (rend_parse_v2_service_descriptor(&parsed, desc_id, &intro_content, - &intro_size, &encoded_size, - &next_desc, current_desc, 1) >= 0) { - number_parsed++; - /* We don't care about the introduction points. */ - tor_free(intro_content); - /* For pretty log statements. */ - base32_encode(desc_id_base32, sizeof(desc_id_base32), - desc_id, DIGEST_LEN); - /* Is descriptor too old? */ - if (parsed->timestamp < now - REND_CACHE_MAX_AGE-REND_CACHE_MAX_SKEW) { - log_info(LD_REND, "Service descriptor with desc ID %s is too old.", - safe_str(desc_id_base32)); - goto skip; - } - /* Is descriptor too far in the future? */ - if (parsed->timestamp > now + REND_CACHE_MAX_SKEW) { - log_info(LD_REND, "Service descriptor with desc ID %s is too far in the " - "future.", - safe_str(desc_id_base32)); - goto skip; - } - /* Do we already have a newer descriptor? */ - e = digestmap_get(rend_cache_v2_dir, desc_id); - if (e && e->parsed->timestamp > parsed->timestamp) { - log_info(LD_REND, "We already have a newer service descriptor with the " - "same desc ID %s and version.", - safe_str(desc_id_base32)); - goto skip; - } - /* Do we already have this descriptor? */ - if (e && !strcmp(desc, e->desc)) { - log_info(LD_REND, "We already have this service descriptor with desc " - "ID %s.", safe_str(desc_id_base32)); - goto skip; - } - /* Store received descriptor. */ - if (!e) { - e = tor_malloc_zero(sizeof(rend_cache_entry_t)); - digestmap_set(rend_cache_v2_dir, desc_id, e); - /* Treat something just uploaded as having been served a little - * while ago, so that flooding with new descriptors doesn't help - * too much. - */ - e->last_served = approx_time() - 3600; - } else { - rend_cache_decrement_allocation(rend_cache_entry_allocation(e)); - rend_service_descriptor_free(e->parsed); - tor_free(e->desc); - } - e->parsed = parsed; - e->desc = tor_strndup(current_desc, encoded_size); - e->len = encoded_size; - rend_cache_increment_allocation(rend_cache_entry_allocation(e)); - log_info(LD_REND, "Successfully stored service descriptor with desc ID " - "'%s' and len %d.", - safe_str(desc_id_base32), (int)encoded_size); - /* Statistics: Note down this potentially new HS. */ - if (options->HiddenServiceStatistics) { - rep_hist_stored_maybe_new_hs(e->parsed->pk); - } - - number_stored++; - goto advance; - skip: - rend_service_descriptor_free(parsed); - advance: - /* advance to next descriptor, if available. */ - current_desc = next_desc; - /* check if there is a next descriptor. */ - if (!current_desc || - strcmpstart(current_desc, "rendezvous-service-descriptor ")) - break; - } - if (!number_parsed) { - log_info(LD_REND, "Could not parse any descriptor."); - return -1; - } - log_info(LD_REND, "Parsed %d and added %d descriptor%s.", - number_parsed, number_stored, number_stored != 1 ? "s" : ""); - return 0; -} - -/** Parse the v2 service descriptor in <b>desc</b> and store it to the -* local service rend cache. Don't attempt to decrypt the included list of -* introduction points. -* -* If we have a newer descriptor with the same ID, ignore this one. -* If we have an older descriptor with the same ID, replace it. -* -* Return 0 on success, or -1 if we couldn't understand the descriptor. -*/ -int -rend_cache_store_v2_desc_as_service(const char *desc) -{ - rend_service_descriptor_t *parsed = NULL; - char desc_id[DIGEST_LEN]; - char *intro_content = NULL; - size_t intro_size; - size_t encoded_size; - const char *next_desc; - char service_id[REND_SERVICE_ID_LEN_BASE32+1]; - rend_cache_entry_t *e; - int retval = -1; - tor_assert(rend_cache_local_service); - tor_assert(desc); - - /* Parse the descriptor. */ - if (rend_parse_v2_service_descriptor(&parsed, desc_id, &intro_content, - &intro_size, &encoded_size, - &next_desc, desc, 0) < 0) { - log_warn(LD_REND, "Could not parse descriptor."); - goto err; - } - /* Compute service ID from public key. */ - if (rend_get_service_id(parsed->pk, service_id)<0) { - log_warn(LD_REND, "Couldn't compute service ID."); - goto err; - } - - /* Do we already have a newer descriptor? Allow new descriptors with a - rounded timestamp equal to or newer than the current descriptor */ - e = (rend_cache_entry_t*) strmap_get_lc(rend_cache_local_service, - service_id); - if (e && e->parsed->timestamp > parsed->timestamp) { - log_info(LD_REND, "We already have a newer service descriptor for " - "service ID %s.", safe_str_client(service_id)); - goto okay; - } - /* We don't care about the introduction points. */ - tor_free(intro_content); - if (!e) { - e = tor_malloc_zero(sizeof(rend_cache_entry_t)); - strmap_set_lc(rend_cache_local_service, service_id, e); - } else { - rend_cache_decrement_allocation(rend_cache_entry_allocation(e)); - rend_service_descriptor_free(e->parsed); - tor_free(e->desc); - } - e->parsed = parsed; - e->desc = tor_malloc_zero(encoded_size + 1); - strlcpy(e->desc, desc, encoded_size + 1); - e->len = encoded_size; - rend_cache_increment_allocation(rend_cache_entry_allocation(e)); - log_debug(LD_REND,"Successfully stored rend desc '%s', len %d.", - safe_str_client(service_id), (int)encoded_size); - return 0; - - okay: - retval = 0; - - err: - rend_service_descriptor_free(parsed); - tor_free(intro_content); - return retval; -} - -/** Parse the v2 service descriptor in <b>desc</b>, decrypt the included list - * of introduction points with <b>descriptor_cookie</b> (which may also be - * <b>NULL</b> if decryption is not necessary), and store the descriptor to - * the local cache under its version and service id. - * - * If we have a newer v2 descriptor with the same ID, ignore this one. - * If we have an older descriptor with the same ID, replace it. - * If the descriptor's service ID does not match - * <b>rend_query</b>-\>onion_address, reject it. - * - * If the descriptor's descriptor ID doesn't match <b>desc_id_base32</b>, - * reject it. - * - * Return 0 on success, or -1 if we rejected the descriptor. - * If entry is not NULL, set it with the cache entry pointer of the descriptor. - */ -int -rend_cache_store_v2_desc_as_client(const char *desc, - const char *desc_id_base32, - const rend_data_t *rend_query, - rend_cache_entry_t **entry) -{ - /*XXXX this seems to have a bit of duplicate code with - * rend_cache_store_v2_desc_as_dir(). Fix that. */ - /* Though having similar elements, both functions were separated on - * purpose: - * - dirs don't care about encoded/encrypted introduction points, clients - * do. - * - dirs store descriptors in a separate cache by descriptor ID, whereas - * clients store them by service ID; both caches are different data - * structures and have different access methods. - * - dirs store a descriptor only if they are responsible for its ID, - * clients do so in every way (because they have requested it before). - * - dirs can process multiple concatenated descriptors which is required - * for replication, whereas clients only accept a single descriptor. - * Thus, combining both methods would result in a lot of if statements - * which probably would not improve, but worsen code readability. -KL */ - rend_service_descriptor_t *parsed = NULL; - char desc_id[DIGEST_LEN]; - char *intro_content = NULL; - size_t intro_size; - size_t encoded_size; - const char *next_desc; - time_t now = time(NULL); - char key[REND_SERVICE_ID_LEN_BASE32+2]; - char service_id[REND_SERVICE_ID_LEN_BASE32+1]; - char want_desc_id[DIGEST_LEN]; - rend_cache_entry_t *e; - int retval = -1; - rend_data_v2_t *rend_data = TO_REND_DATA_V2(rend_query); - - tor_assert(rend_cache); - tor_assert(desc); - tor_assert(desc_id_base32); - memset(want_desc_id, 0, sizeof(want_desc_id)); - if (entry) { - *entry = NULL; - } - if (base32_decode(want_desc_id, sizeof(want_desc_id), - desc_id_base32, strlen(desc_id_base32)) != - sizeof(want_desc_id)) { - log_warn(LD_BUG, "Couldn't decode base32 %s for descriptor id.", - escaped_safe_str_client(desc_id_base32)); - goto err; - } - /* Parse the descriptor. */ - if (rend_parse_v2_service_descriptor(&parsed, desc_id, &intro_content, - &intro_size, &encoded_size, - &next_desc, desc, 0) < 0) { - log_warn(LD_REND, "Could not parse descriptor."); - goto err; - } - /* Compute service ID from public key. */ - if (rend_get_service_id(parsed->pk, service_id)<0) { - log_warn(LD_REND, "Couldn't compute service ID."); - goto err; - } - if (rend_data->onion_address[0] != '\0' && - strcmp(rend_data->onion_address, service_id)) { - log_warn(LD_REND, "Received service descriptor for service ID %s; " - "expected descriptor for service ID %s.", - service_id, safe_str(rend_data->onion_address)); - goto err; - } - if (tor_memneq(desc_id, want_desc_id, DIGEST_LEN)) { - log_warn(LD_REND, "Received service descriptor for %s with incorrect " - "descriptor ID.", service_id); - goto err; - } - - /* Decode/decrypt introduction points. */ - if (intro_content && intro_size > 0) { - int n_intro_points; - if (rend_data->auth_type != REND_NO_AUTH && - !safe_mem_is_zero(rend_data->descriptor_cookie, - sizeof(rend_data->descriptor_cookie))) { - char *ipos_decrypted = NULL; - size_t ipos_decrypted_size; - if (rend_decrypt_introduction_points(&ipos_decrypted, - &ipos_decrypted_size, - rend_data->descriptor_cookie, - intro_content, - intro_size) < 0) { - log_warn(LD_REND, "Failed to decrypt introduction points. We are " - "probably unable to parse the encoded introduction points."); - } else { - /* Replace encrypted with decrypted introduction points. */ - log_info(LD_REND, "Successfully decrypted introduction points."); - tor_free(intro_content); - intro_content = ipos_decrypted; - intro_size = ipos_decrypted_size; - } - } - n_intro_points = rend_parse_introduction_points(parsed, intro_content, - intro_size); - if (n_intro_points <= 0) { - log_warn(LD_REND, "Failed to parse introduction points. Either the " - "service has published a corrupt descriptor or you have " - "provided invalid authorization data."); - goto err; - } else if (n_intro_points > MAX_INTRO_POINTS) { - log_warn(LD_REND, "Found too many introduction points on a hidden " - "service descriptor for %s. This is probably a (misguided) " - "attempt to improve reliability, but it could also be an " - "attempt to do a guard enumeration attack. Rejecting.", - safe_str_client(service_id)); - - goto err; - } - } else { - log_info(LD_REND, "Descriptor does not contain any introduction points."); - parsed->intro_nodes = smartlist_new(); - } - /* We don't need the encoded/encrypted introduction points any longer. */ - tor_free(intro_content); - /* Is descriptor too old? */ - if (parsed->timestamp < now - REND_CACHE_MAX_AGE-REND_CACHE_MAX_SKEW) { - log_warn(LD_REND, "Service descriptor with service ID %s is too old.", - safe_str_client(service_id)); - goto err; - } - /* Is descriptor too far in the future? */ - if (parsed->timestamp > now + REND_CACHE_MAX_SKEW) { - log_warn(LD_REND, "Service descriptor with service ID %s is too far in " - "the future.", safe_str_client(service_id)); - goto err; - } - /* Do we have the same exact copy already in our cache? */ - tor_snprintf(key, sizeof(key), "2%s", service_id); - e = (rend_cache_entry_t*) strmap_get_lc(rend_cache, key); - if (e && !strcmp(desc, e->desc)) { - log_info(LD_REND,"We already have this service descriptor %s.", - safe_str_client(service_id)); - goto okay; - } - /* Verify that we are not replacing an older descriptor. It's important to - * avoid an evil HSDir serving old descriptor. We validate if the - * timestamp is greater than and not equal because it's a rounded down - * timestamp to the hour so if the descriptor changed in the same hour, - * the rend cache failure will tell us if we have a new descriptor. */ - if (e && e->parsed->timestamp > parsed->timestamp) { - log_info(LD_REND, "We already have a new enough service descriptor for " - "service ID %s with the same desc ID and version.", - safe_str_client(service_id)); - goto okay; - } - /* Lookup our failure cache for intro point that might be unusable. */ - validate_intro_point_failure(parsed, service_id); - /* It's now possible that our intro point list is empty, which means that - * this descriptor is useless to us because intro points have all failed - * somehow before. Discard the descriptor. */ - if (smartlist_len(parsed->intro_nodes) == 0) { - log_info(LD_REND, "Service descriptor with service ID %s has no " - "usable intro points. Discarding it.", - safe_str_client(service_id)); - goto err; - } - /* Now either purge the current one and replace its content or create a - * new one and add it to the rend cache. */ - if (!e) { - e = tor_malloc_zero(sizeof(rend_cache_entry_t)); - strmap_set_lc(rend_cache, key, e); - } else { - rend_cache_decrement_allocation(rend_cache_entry_allocation(e)); - rend_cache_failure_remove(e->parsed); - rend_service_descriptor_free(e->parsed); - tor_free(e->desc); - } - e->parsed = parsed; - e->desc = tor_malloc_zero(encoded_size + 1); - strlcpy(e->desc, desc, encoded_size + 1); - e->len = encoded_size; - rend_cache_increment_allocation(rend_cache_entry_allocation(e)); - log_debug(LD_REND,"Successfully stored rend desc '%s', len %d.", - safe_str_client(service_id), (int)encoded_size); - if (entry) { - *entry = e; - } - return 0; - - okay: - if (entry) { - *entry = e; - } - retval = 0; - - err: - rend_service_descriptor_free(parsed); - tor_free(intro_content); - return retval; -} |