[tor-commits] [tor/maint-0.2.7] Merge branch 'maint-0.2.6' into maint-0.2.7
nickm at torproject.org
nickm at torproject.org
Tue Dec 20 23:16:34 UTC 2016
commit a9c8a5ff18c1944ddcea0116419edc2f199583b8
Merge: b49369b b18bde2
Author: Nick Mathewson <nickm at torproject.org>
Date: Tue Dec 20 18:14:21 2016 -0500
Merge branch 'maint-0.2.6' into maint-0.2.7
changes/bug21018 | 11 +++++++++++
src/or/rendcache.c | 6 ++++--
src/or/routerparse.c | 6 +++---
3 files changed, 18 insertions(+), 5 deletions(-)
diff --cc src/or/rendcache.c
index d4bdd68,0000000..e7b1ce9
mode 100644,000000..100644
--- a/src/or/rendcache.c
+++ b/src/or/rendcache.c
@@@ -1,898 -1,0 +1,900 @@@
+/* Copyright (c) 2015, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+/**
+ * \file rendcache.c
+ * \brief Hidden service desriptor cache.
+ **/
+
+#include "rendcache.h"
+
+#include "config.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;
+
+/** (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.
+ *
+ * Everytime 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 usuable,
+ * 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 unsuable.
+ *
+ * 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 realy 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_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. */
+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 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 *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_);
+
+ 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 *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 *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_);
+ strmap_free(rend_cache_failure, rend_cache_failure_entry_free_);
+ rend_cache = NULL;
+ rend_cache_v2_dir = 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 regurlarly 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 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 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 failure cache");
+ strmap_free(rend_cache_failure, rend_cache_failure_entry_free_);
+ }
+ rend_cache_failure = strmap_new();
+}
+
+/** Lookup the rend failure cache using a relay identity digest in
+ * <b>identity</b> and service ID <b>service_id</b>. If found, the intro
+ * failure is set in <b>intro_entry</b> else it stays untouched. 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.
+ *
+ * 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.");
++ "service has published a corrupt descriptor, or you have "
++ "provided invalid authorization data, or (maybe!) the "
++ "server is deliberately serving broken data in an attempt "
++ "to crash you with bug 21018.");
+ 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 tells 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 unsuable. */
+ validate_intro_point_failure(parsed, service_id);
+ /* It's now possible that our intro point list is empty, this 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, every "
+ "intro points are unusable. Discarding it.",
+ safe_str_client(service_id));
+ goto err;
+ }
+ /* Now either purge the current one and replace it's 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 RCS_OKAY;
+
+ okay:
+ if (entry) {
+ *entry = e;
+ }
+ retval = RCS_OKAY;
+
+ err:
+ rend_service_descriptor_free(parsed);
+ tor_free(intro_content);
+ return retval;
+}
+
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