[or-cvs] r13250: put in karsten's "patch 14". needs a lot of cleanup and a ch (tor/trunk/src/or)
arma at seul.org
arma at seul.org
Thu Jan 24 03:28:50 UTC 2008
Author: arma
Date: 2008-01-23 22:28:50 -0500 (Wed, 23 Jan 2008)
New Revision: 13250
Modified:
tor/trunk/src/or/directory.c
tor/trunk/src/or/or.h
tor/trunk/src/or/rendclient.c
Log:
put in karsten's "patch 14". needs a lot of cleanup and a changelog.
Modified: tor/trunk/src/or/directory.c
===================================================================
--- tor/trunk/src/or/directory.c 2008-01-24 02:31:37 UTC (rev 13249)
+++ tor/trunk/src/or/directory.c 2008-01-24 03:28:50 UTC (rev 13250)
@@ -893,8 +893,10 @@
break;
case DIR_PURPOSE_FETCH_RENDDESC_V2:
tor_assert(resource);
- tor_assert(!payload);
tor_assert(strlen(resource) <= REND_DESC_ID_V2_LEN_BASE32);
+ /* Remember the query to refer to it when a response arrives. */
+ strlcpy(conn->rend_query, payload, sizeof(conn->rend_query));
+ payload = NULL;
httpcommand = "GET";
len = strlen(resource) + 32;
url = tor_malloc(len);
@@ -1804,9 +1806,11 @@
switch (status_code) {
case 200:
if (rend_cache_store_v2_desc_as_client(body, NULL) < 0) {
- log_warn(LD_REND,"Fetching v2 rendezvous descriptor failed.");
+ log_warn(LD_REND,"Fetching v2 rendezvous descriptor failed. "
+ "Retrying at another directory.");
/* alice's ap_stream will notice when connection_mark_for_close
* cleans it up */
+ rend_client_refetch_v2_renddesc(conn->rend_query);
} else {
/* success. notify pending connections about this. */
log_info(LD_REND, "Successfully fetched rendezvous descriptor.");
@@ -1817,18 +1821,25 @@
case 404:
/* not there. pending connections will be notified when
* connection_mark_for_close cleans it up. */
+ log_info(LD_REND,"Fetching v2 rendezvous descriptor failed: "
+ "Retrying at another directory.");
+ rend_client_refetch_v2_renddesc(conn->rend_query);
break;
case 400:
log_warn(LD_REND, "Fetching v2 rendezvous descriptor failed: "
"http status 400 (%s). Dirserver didn't like our "
- "v2 rendezvous query?", escaped(reason));
+ "v2 rendezvous query? Retrying at another directory.",
+ escaped(reason));
+ rend_client_refetch_v2_renddesc(conn->rend_query);
break;
default:
log_warn(LD_REND, "Fetching v2 rendezvous descriptor failed: "
"http status %d (%s) response unexpected while "
- "fetching v2 hidden service descriptor (server '%s:%d').",
+ "fetching v2 hidden service descriptor (server '%s:%d'). "
+ "Retrying at another directory.",
status_code, escaped(reason), conn->_base.address,
conn->_base.port);
+ rend_client_refetch_v2_renddesc(conn->rend_query);
break;
}
}
@@ -3237,15 +3248,90 @@
smartlist_free(responsible_dirs);
}
+/** The period for which a hidden service directory cannot be queried for
+ * the same descriptor ID again. */
+#define REND_HID_SERV_DIR_REQUERY_PERIOD (15 * 60)
+
+/** Contains the last request times to hidden service directories for
+ * certain queries; keys are strings consisting of base32-encoded
+ * hidden service directory identities and base32-encoded descriptor IDs;
+ * values are pointers to timestamps of the last requests. */
+static strmap_t *last_hid_serv_requests = NULL;
+
+/** Return the last request time to hidden service directory <b>hs_dir</b>
+ * for descriptor ID <b>desc_id_base32</b> or 0 if no such request has been
+ * sent before. */
+static time_t
+get_last_hid_serv_request(routerstatus_t *hs_dir, const char *desc_id_base32)
+{
+ char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
+ char hsdir_desc_comb_id[2 * REND_DESC_ID_V2_LEN_BASE32 + 1];
+ time_t *last_request_ptr;
+ base32_encode(hsdir_id_base32, sizeof(hsdir_id_base32),
+ hs_dir->identity_digest, DIGEST_LEN);
+ tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s",
+ hsdir_id_base32, desc_id_base32);
+ last_request_ptr = strmap_get_lc(last_hid_serv_requests, hsdir_desc_comb_id);
+ return (last_request_ptr) ? *last_request_ptr : 0;
+}
+
+/** Store the time in <b>now</b> as the last request time to hidden service
+ * directory <b>hs_dir</b> for descriptor ID <b>desc_id_base32</b>. */
+static void
+set_last_hid_serv_request(routerstatus_t *hs_dir, const char *desc_id_base32,
+ time_t now)
+{
+ char hsdir_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
+ char hsdir_desc_comb_id[2 * REND_DESC_ID_V2_LEN_BASE32 + 1];
+ time_t *last_request_ptr = tor_malloc_zero(sizeof(time_t *));
+ if (!last_hid_serv_requests) last_hid_serv_requests = strmap_new();
+ *last_request_ptr = now;
+ base32_encode(hsdir_id_base32, sizeof(hsdir_id_base32),
+ hs_dir->identity_digest, DIGEST_LEN);
+ tor_snprintf(hsdir_desc_comb_id, sizeof(hsdir_desc_comb_id), "%s%s",
+ hsdir_id_base32, desc_id_base32);
+ strmap_set(last_hid_serv_requests, hsdir_desc_comb_id, last_request_ptr);
+}
+
+/** Clean the history of request times to hidden service directories, so that
+ * it does not contain requests older than REND_HID_SERV_DIR_REQUERY_PERIOD
+ * seconds any more. */
+static void
+directory_clean_last_hid_serv_requests(void)
+{
+ strmap_iter_t *iter;
+ time_t cutoff = time(NULL) - REND_HID_SERV_DIR_REQUERY_PERIOD;
+ for (iter = strmap_iter_init(last_hid_serv_requests);
+ !strmap_iter_done(iter); ) {
+ const char *key;
+ void *val;
+ time_t *ent;
+ strmap_iter_get(iter, &key, &val);
+ ent = (time_t *) val;
+ if (*ent < cutoff) {
+ iter = strmap_iter_next_rmv(last_hid_serv_requests, iter);
+ tor_free(ent);
+ } else {
+ iter = strmap_iter_next(last_hid_serv_requests, iter);
+ }
+ }
+}
+
/** Determine the responsible hidden service directories for <b>desc_id</b>
- * and fetch the descriptor belonging to this ID from one of them;
- * <b>query</b> is only passed for pretty log statements. */
-void
+ * and fetch the descriptor belonging to that ID from one of them. Only
+ * send a request to hidden service directories that we did not try within
+ * the last REND_HID_SERV_DIR_REQUERY_PERIOD seconds; on success, return 1,
+ * in the case that no hidden service directory is left to ask for the
+ * descriptor, return 0, and in case of a failure -1. <b>query</b> is only
+ * passed for pretty log statements. */
+int
directory_get_from_hs_dir(const char *desc_id, const char *query)
{
smartlist_t *responsible_dirs = smartlist_create();
+ smartlist_t *selectible_dirs = smartlist_create();
routerstatus_t *hs_dir;
char desc_id_base32[REND_DESC_ID_V2_LEN_BASE32 + 1];
+ time_t now = time(NULL);
tor_assert(desc_id);
tor_assert(query);
tor_assert(strlen(query) == REND_SERVICE_ID_LEN_BASE32);
@@ -3255,26 +3341,57 @@
log_info(LD_REND, "Could not determine the responsible hidden service "
"directories to fetch descriptors.");
smartlist_free(responsible_dirs);
- return;
+ return -1;
}
- hs_dir = smartlist_choose(responsible_dirs);
+
+ base32_encode(desc_id_base32, sizeof(desc_id_base32),
+ desc_id, DIGEST_LEN);
+
+ /* Only select those hidden service directories to which we did not send
+ * a request earlier. */
+ if (last_hid_serv_requests) {
+ /* Clean up request history first. */
+ directory_clean_last_hid_serv_requests();
+
+ SMARTLIST_FOREACH(responsible_dirs, routerstatus_t *, dir, {
+ time_t last_request = get_last_hid_serv_request(dir, desc_id_base32);
+ if (!last_request ||
+ last_request + REND_HID_SERV_DIR_REQUERY_PERIOD < now)
+ smartlist_add(selectible_dirs, dir);
+ });
+ } else {
+ smartlist_add_all(selectible_dirs, responsible_dirs);
+ }
smartlist_free(responsible_dirs);
+
+ if (smartlist_len(selectible_dirs) == 0) {
+ log_info(LD_REND, "Could not pick one of the responsible hidden "
+ "service directories, because we requested them all "
+ "recently without success.");
+ return 0;
+ }
+ hs_dir = smartlist_choose(selectible_dirs);
+ smartlist_free(selectible_dirs);
if (!hs_dir) {
log_warn(LD_BUG, "Could not pick one of the responsible hidden service "
"directories to fetch descriptors.");
- return;
+ return -1;
}
- /* XXXX020 if hsdir fails, use another one... */
- base32_encode(desc_id_base32, sizeof(desc_id_base32),
- desc_id, DIGEST_LEN);
- /* Send fetch request. */
+
+ /* Remember, that we are requesting a descriptor from this hidden service
+ * directory now. */
+ set_last_hid_serv_request(hs_dir, desc_id_base32, now);
+
+ /* Send fetch request. (Pass query as payload to write it to the directory
+ * connection so that it can be referred to when the response arrives.) */
directory_initiate_command_routerstatus(hs_dir,
DIR_PURPOSE_FETCH_RENDDESC_V2,
ROUTER_PURPOSE_GENERAL,
- 1, desc_id_base32, NULL, 0, 0);
+ 1, desc_id_base32, query, 0, 0);
log_info(LD_REND, "Sending fetch request for v2 descriptor for "
"service '%s' with descriptor ID '%s' to hidden "
"service directory '%s' on port %d.",
query, desc_id_base32, hs_dir->nickname, hs_dir->dir_port);
+ return 1;
}
Modified: tor/trunk/src/or/or.h
===================================================================
--- tor/trunk/src/or/or.h 2008-01-24 02:31:37 UTC (rev 13249)
+++ tor/trunk/src/or/or.h 2008-01-24 03:28:50 UTC (rev 13250)
@@ -3035,7 +3035,7 @@
void directory_post_to_hs_dir(smartlist_t *descs, const char *service_id,
int seconds_valid);
-void directory_get_from_hs_dir(const char *desc_id, const char *query);
+int directory_get_from_hs_dir(const char *desc_id, const char *query);
time_t download_status_increment_failure(download_status_t *dls,
int status_code, const char *item,
Modified: tor/trunk/src/or/rendclient.c
===================================================================
--- tor/trunk/src/or/rendclient.c 2008-01-24 02:31:37 UTC (rev 13249)
+++ tor/trunk/src/or/rendclient.c 2008-01-24 03:28:50 UTC (rev 13250)
@@ -295,7 +295,8 @@
rend_client_refetch_v2_renddesc(const char *query)
{
char descriptor_id[DIGEST_LEN];
- int replica;
+ int replicas_left_to_try[REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS];
+ int i, tries_left;
tor_assert(query);
tor_assert(strlen(query) == REND_SERVICE_ID_LEN_BASE32);
/* Are we configured to fetch descriptors? */
@@ -306,14 +307,44 @@
}
log_debug(LD_REND, "Fetching v2 rendezvous descriptor for service %s",
query);
- replica = crypto_rand_int(REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS);
- if (rend_compute_v2_desc_id(descriptor_id, query, NULL, time(NULL),
- replica) < 0) {
- log_warn(LD_REND, "Internal error: Computing v2 rendezvous "
- "descriptor ID did not succeed.");
- return;
+ /* Randomly iterate over the replicas until a descriptor can be fetched
+ * from one of the consecutive nodes, or no options are left. */
+ tries_left = REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS;
+ for (i = 0; i < REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS; i++)
+ replicas_left_to_try[i] = i;
+ while (tries_left > 0) {
+ int rand = crypto_rand_int(tries_left);
+ int chosen_replica = replicas_left_to_try[rand];
+ replicas_left_to_try[rand] = replicas_left_to_try[--tries_left];
+
+ if (rend_compute_v2_desc_id(descriptor_id, query, NULL, time(NULL),
+ chosen_replica) < 0) {
+ log_warn(LD_REND, "Internal error: Computing v2 rendezvous "
+ "descriptor ID did not succeed.");
+ return;
+ }
+ switch (directory_get_from_hs_dir(descriptor_id, query)) {
+ case -1:
+ /* Whatever error this was, it was already logged. */
+ log_info(LD_REND, "Error while trying to fetch descriptor from "
+ "hidden service directory!");
+ return;
+ case 0:
+ /* Try the next replica, if available. */
+ log_info(LD_REND, "No hidden service directory left for this replica; "
+ "trying another.");
+ continue;
+ case 1:
+ /* Request was sent, we are done here. */
+ log_info(LD_REND, "Request to fetch descriptor from hidden service "
+ "directory sent; waiting for response.");
+ return;
+ }
}
- directory_get_from_hs_dir(descriptor_id, query);
+ /* If we come here, there are no hidden service directories left. */
+ log_info(LD_REND, "Could not pick one of the responsible hidden "
+ "service directories to fetch descriptors, because "
+ "we already tried them all unsuccessfully.");
return;
}
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