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>

1 files changed, 0 insertions, 583 deletions

diff --git a/src/or/rendcommon.c b/src/or/rendcommon.c
index 13d21802b5..411a87c004 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