commit a7624de1aac959ed273199d4cded5095502cdd8a Author: David Goulet <dgoulet@ev0ke.net> Date: Thu Jun 18 11:23:08 2015 -0400 Move cache objects and functions to rendcache.{c|h} Every functions and objects that are used for hidden service descriptor caches are moved to rendcache.{c|h}. This commit does NOT change anything, just moving code around. Fixes #16399 Signed-off-by: David Goulet <dgoulet@ev0ke.net> --- src/or/relay.c | 1 + src/or/rendcache.c | 570 +++++++++++++++++++++++++++++++++++++++++++++++++ src/or/rendcache.h | 33 +++ src/or/rendcommon.c | 583 --------------------------------------------------- src/or/rendcommon.h | 23 -- 5 files changed, 604 insertions(+), 606 deletions(-) diff --git a/src/or/relay.c b/src/or/relay.c index 50eaab8..be09c95 100644 --- a/src/or/relay.c +++ b/src/or/relay.c @@ -32,6 +32,7 @@ #include "policies.h" #include "reasons.h" #include "relay.h" +#include "rendcache.h" #include "rendcommon.h" #include "router.h" #include "routerlist.h" diff --git a/src/or/rendcache.c b/src/or/rendcache.c index 758d7e6..37d3f12 100644 --- a/src/or/rendcache.c +++ b/src/or/rendcache.c @@ -7,3 +7,573 @@ **/ #include "rendcache.h" + +#include "config.h" +#include "rendcommon.h" +#include "rephist.h" +#include "routerlist.h" +#include "routerparse.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 descriptor id to rend_cache_entry_t; only for hidden service + * directories. */ +static digestmap_t *rend_cache_v2_dir = 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(); +} + +/** 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. */ +static 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. */ +static 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 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)); + 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 *p) +{ + rend_cache_entry_free(p); +} + +/** Free all storage held by the service descriptor cache. */ +void +rend_cache_free_all(void) +{ + strmap_free(rend_cache, rend_cache_entry_free_); + digestmap_free(rend_cache_v2_dir, rend_cache_entry_free_); + rend_cache = NULL; + rend_cache_v2_dir = NULL; + rend_cache_total_allocation = 0; +} + +/** Removes all old entries from the service descriptor cache. +*/ +void +rend_cache_clean(time_t now) +{ + 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; + for (iter = strmap_iter_init(rend_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(rend_cache, iter); + rend_cache_entry_free(ent); + } else { + iter = strmap_iter_next(rend_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 descriptor cache"); + strmap_free(rend_cache, rend_cache_entry_free_); + } + rend_cache = strmap_new(); +} + +/** Remove all old v2 descriptors and those for which this hidden service + * directory is not responsible for any more. + * + * If at all possible, remove at least <b>force_remove</b> bytes of data. + */ +void +rend_cache_clean_v2_descs_as_dir(time_t now, size_t force_remove) +{ + digestmap_iter_t *iter; + time_t cutoff = now - REND_CACHE_MAX_AGE - REND_CACHE_MAX_SKEW; + const int LAST_SERVED_CUTOFF_STEP = 1800; + time_t last_served_cutoff = cutoff; + size_t bytes_removed = 0; + do { + 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 || + ent->last_served < last_served_cutoff || + !hid_serv_responsible_for_desc_id(key)) { + 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); + } + } + + /* In case we didn't remove enough bytes, advance the cutoff a little. */ + last_served_cutoff += LAST_SERVED_CUTOFF_STEP; + if (last_served_cutoff > now) + break; + } while (bytes_removed < force_remove); +} + +/** 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(rend_cache); + tor_assert(query); + + if (!rend_valid_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 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) < 0) { + log_fn(LOG_PROTOCOL_WARN, LD_REND, + "Rejecting v2 rendezvous descriptor request -- descriptor ID " + "contains 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 an appropriate rend_cache_store_status_t. + */ +rend_cache_store_status_t +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); + if (!hid_serv_acting_as_directory()) { + /* Cannot store descs, because we are (currently) not acting as + * hidden service directory. */ + log_info(LD_REND, "Cannot store descs: Not acting as hs dir"); + return RCS_NOTDIR; + } + 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 desc ID in the range that we are (directly or indirectly) responsible + * for? */ + if (!hid_serv_responsible_for_desc_id(desc_id)) { + log_info(LD_REND, "Service descriptor with desc ID %s is not in " + "interval that we are responsible for.", + safe_str_client(desc_id_base32)); + goto skip; + } + /* 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 RCS_BADDESC; + } + log_info(LD_REND, "Parsed %d and added %d descriptor%s.", + number_parsed, number_stored, number_stored != 1 ? "s" : ""); + return RCS_OKAY; +} + +/** 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 an appropriate rend_cache_store_status_t. If entry is not NULL, + * set it with the cache entry pointer of the descriptor. + */ +rend_cache_store_status_t +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; + rend_cache_store_status_t retval = RCS_BADDESC; + 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)) != 0) { + 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_query->onion_address[0] != '\0' && + strcmp(rend_query->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_query->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_query->auth_type != REND_NO_AUTH && + !tor_mem_is_zero(rend_query->descriptor_cookie, + sizeof(rend_query->descriptor_cookie))) { + char *ipos_decrypted = NULL; + size_t ipos_decrypted_size; + if (rend_decrypt_introduction_points(&ipos_decrypted, + &ipos_decrypted_size, + rend_query->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 already have a newer descriptor? */ + tor_snprintf(key, sizeof(key), "2%s", service_id); + e = (rend_cache_entry_t*) strmap_get_lc(rend_cache, key); + 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; + } + 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_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 RCS_OKAY; + +okay: + if (entry) { + *entry = e; + } + retval = RCS_OKAY; + +err: + rend_service_descriptor_free(parsed); + tor_free(intro_content); + return retval; +} diff --git a/src/or/rendcache.h b/src/or/rendcache.h index 1b78436..f34f599 100644 --- a/src/or/rendcache.h +++ b/src/or/rendcache.h @@ -11,6 +11,17 @@ #include "or.h" +/** How old do we let hidden service descriptors get before discarding + * them as too old? */ +#define REND_CACHE_MAX_AGE (2*24*60*60) +/** How wrong do we assume our clock may be when checking whether hidden + * services are too old or too new? */ +#define REND_CACHE_MAX_SKEW (24*60*60) + +/* Do not allow more than this many introduction points in a hidden service + * descriptor */ +#define MAX_INTRO_POINTS 10 + /** A cached rendezvous descriptor. */ typedef struct rend_cache_entry_t { size_t len; /**< Length of <b>desc</b> */ @@ -20,4 +31,26 @@ typedef struct rend_cache_entry_t { rend_service_descriptor_t *parsed; /**< Parsed value of 'desc' */ } rend_cache_entry_t; +void rend_cache_init(void); +void rend_cache_clean(time_t now); +void rend_cache_clean_v2_descs_as_dir(time_t now, size_t min_to_remove); +void rend_cache_purge(void); +void rend_cache_free_all(void); +int rend_cache_lookup_entry(const char *query, int version, + rend_cache_entry_t **entry_out); +int rend_cache_lookup_v2_desc_as_dir(const char *query, const char **desc); +/** Return value from rend_cache_store_v2_desc_as_{dir,client}. */ +typedef enum { + RCS_NOTDIR = -2, /**< We're not a directory */ + RCS_BADDESC = -1, /**< This descriptor is no good. */ + RCS_OKAY = 0 /**< All worked as expected */ +} rend_cache_store_status_t; + +rend_cache_store_status_t rend_cache_store_v2_desc_as_dir(const char *desc); +rend_cache_store_status_t 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); +size_t rend_cache_get_total_allocation(void); + #endif /* TOR_RENDCACHE_H */ diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c index 13d2180..411a87c 100644 --- a/src/or/rendcommon.c +++ b/src/or/rendcommon.c @@ -687,194 +687,6 @@ rend_get_service_id(crypto_pk_t *pk, char *out) return 0; } -/* ==== Rendezvous service descriptor cache. */ - -/** How old do we let hidden service descriptors get before discarding - * them as too old? */ -#define REND_CACHE_MAX_AGE (2*24*60*60) -/** How wrong do we assume our clock may be when checking whether hidden - * services are too old or too new? */ -#define REND_CACHE_MAX_SKEW (24*60*60) - -/** Map from service id (as generated by rend_get_service_id) to - * rend_cache_entry_t. */ -static strmap_t *rend_cache = NULL; - -/** Map from descriptor id to rend_cache_entry_t; only for hidden service - * directories. */ -static digestmap_t *rend_cache_v2_dir = 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(); -} - -/** 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. */ -static 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. */ -static 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 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)); - 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 *p) -{ - rend_cache_entry_free(p); -} - -/** Free all storage held by the service descriptor cache. */ -void -rend_cache_free_all(void) -{ - strmap_free(rend_cache, rend_cache_entry_free_); - digestmap_free(rend_cache_v2_dir, rend_cache_entry_free_); - rend_cache = NULL; - rend_cache_v2_dir = NULL; - rend_cache_total_allocation = 0; -} - -/** Removes all old entries from the service descriptor cache. - */ -void -rend_cache_clean(time_t now) -{ - 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; - for (iter = strmap_iter_init(rend_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(rend_cache, iter); - rend_cache_entry_free(ent); - } else { - iter = strmap_iter_next(rend_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 descriptor cache"); - strmap_free(rend_cache, rend_cache_entry_free_); - } - rend_cache = strmap_new(); -} - -/** Remove all old v2 descriptors and those for which this hidden service - * directory is not responsible for any more. - * - * If at all possible, remove at least <b>force_remove</b> bytes of data. - */ -void -rend_cache_clean_v2_descs_as_dir(time_t now, size_t force_remove) -{ - digestmap_iter_t *iter; - time_t cutoff = now - REND_CACHE_MAX_AGE - REND_CACHE_MAX_SKEW; - const int LAST_SERVED_CUTOFF_STEP = 1800; - time_t last_served_cutoff = cutoff; - size_t bytes_removed = 0; - do { - 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 || - ent->last_served < last_served_cutoff || - !hid_serv_responsible_for_desc_id(key)) { - 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); - } - } - - /* In case we didn't remove enough bytes, advance the cutoff a little. */ - last_served_cutoff += LAST_SERVED_CUTOFF_STEP; - if (last_served_cutoff > now) - break; - } while (bytes_removed < force_remove); -} - /** Determines whether <b>a</b> is in the interval of <b>b</b> (excluded) and * <b>c</b> (included) in a circular digest ring; returns 1 if this is the * case, and 0 otherwise. @@ -938,401 +750,6 @@ rend_valid_descriptor_id(const char *query) return 0; } -/** 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(rend_cache); - tor_assert(query); - - if (!rend_valid_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 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) < 0) { - log_fn(LOG_PROTOCOL_WARN, LD_REND, - "Rejecting v2 rendezvous descriptor request -- descriptor ID " - "contains 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; -} - -/* Do not allow more than this many introduction points in a hidden service - * descriptor */ -#define MAX_INTRO_POINTS 10 - -/** 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 an appropriate rend_cache_store_status_t. - */ -rend_cache_store_status_t -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); - if (!hid_serv_acting_as_directory()) { - /* Cannot store descs, because we are (currently) not acting as - * hidden service directory. */ - log_info(LD_REND, "Cannot store descs: Not acting as hs dir"); - return RCS_NOTDIR; - } - 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 desc ID in the range that we are (directly or indirectly) responsible - * for? */ - if (!hid_serv_responsible_for_desc_id(desc_id)) { - log_info(LD_REND, "Service descriptor with desc ID %s is not in " - "interval that we are responsible for.", - safe_str_client(desc_id_base32)); - goto skip; - } - /* 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 RCS_BADDESC; - } - log_info(LD_REND, "Parsed %d and added %d descriptor%s.", - number_parsed, number_stored, number_stored != 1 ? "s" : ""); - return RCS_OKAY; -} - -/** 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 an appropriate rend_cache_store_status_t. If entry is not NULL, - * set it with the cache entry pointer of the descriptor. - */ -rend_cache_store_status_t -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; - rend_cache_store_status_t retval = RCS_BADDESC; - 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)) != 0) { - 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_query->onion_address[0] != '\0' && - strcmp(rend_query->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_query->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_query->auth_type != REND_NO_AUTH && - !tor_mem_is_zero(rend_query->descriptor_cookie, - sizeof(rend_query->descriptor_cookie))) { - char *ipos_decrypted = NULL; - size_t ipos_decrypted_size; - if (rend_decrypt_introduction_points(&ipos_decrypted, - &ipos_decrypted_size, - rend_query->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 already have a newer descriptor? */ - tor_snprintf(key, sizeof(key), "2%s", service_id); - e = (rend_cache_entry_t*) strmap_get_lc(rend_cache, key); - if (e && e->parsed->timestamp > parsed->timestamp) { - log_info(LD_REND, "We already have a newer service descriptor for " - "service ID %s with the same desc ID and version.", - safe_str_client(service_id)); - goto okay; - } - /* Do we already have this descriptor? */ - if (e && !strcmp(desc, e->desc)) { - log_info(LD_REND,"We already have this service descriptor %s.", - safe_str_client(service_id)); - goto okay; - } - 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_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 RCS_OKAY; - - okay: - if (entry) { - *entry = e; - } - retval = RCS_OKAY; - - err: - rend_service_descriptor_free(parsed); - tor_free(intro_content); - return retval; -} - /** Called when we get a rendezvous-related relay cell on circuit * <b>circ</b>. Dispatch on rendezvous relay command. */ void diff --git a/src/or/rendcommon.h b/src/or/rendcommon.h index c6f2b8e..ba5e077 100644 --- a/src/or/rendcommon.h +++ b/src/or/rendcommon.h @@ -12,8 +12,6 @@ #ifndef TOR_RENDCOMMON_H #define TOR_RENDCOMMON_H -#include "rendcache.h" - /** Free all storage associated with <b>data</b> */ static INLINE void rend_data_free(rend_data_t *data) @@ -39,28 +37,8 @@ void rend_encoded_v2_service_descriptor_free( rend_encoded_v2_service_descriptor_t *desc); void rend_intro_point_free(rend_intro_point_t *intro); -void rend_cache_init(void); -void rend_cache_clean(time_t now); -void rend_cache_clean_v2_descs_as_dir(time_t now, size_t min_to_remove); -void rend_cache_purge(void); -void rend_cache_free_all(void); int rend_valid_service_id(const char *query); int rend_valid_descriptor_id(const char *query); -int rend_cache_lookup_entry(const char *query, int version, - rend_cache_entry_t **entry_out); -int rend_cache_lookup_v2_desc_as_dir(const char *query, const char **desc); -/** Return value from rend_cache_store_v2_desc_as_{dir,client}. */ -typedef enum { - RCS_NOTDIR = -2, /**< We're not a directory */ - RCS_BADDESC = -1, /**< This descriptor is no good. */ - RCS_OKAY = 0 /**< All worked as expected */ -} rend_cache_store_status_t; - -rend_cache_store_status_t rend_cache_store_v2_desc_as_dir(const char *desc); -rend_cache_store_status_t 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); int rend_encode_v2_descriptors(smartlist_t *descs_out, rend_service_descriptor_t *desc, time_t now, uint8_t period, rend_auth_type_t auth_type, @@ -73,7 +51,6 @@ int rend_id_is_in_interval(const char *a, const char *b, const char *c); void rend_get_descriptor_id_bytes(char *descriptor_id_out, const char *service_id, const char *secret_id_part); -size_t rend_cache_get_total_allocation(void); rend_data_t *rend_data_dup(const rend_data_t *data); rend_data_t *rend_data_client_create(const char *onion_address,