[tor-commits] [tor/maint-0.3.1] Introduce cache for outdated microdesc dirservers.
nickm at torproject.org
nickm at torproject.org
Mon Dec 11 21:46:21 UTC 2017
commit 7fc64f02a3057405f9e75d70848afd2e9b95da05
Author: George Kadianakis <desnacked at riseup.net>
Date: Mon Nov 6 14:48:22 2017 +0200
Introduce cache for outdated microdesc dirservers.
We gonna use this cache to avoid dirservers without outdated md info.
---
src/or/directory.c | 36 +++++++++++-------
src/or/directory.h | 7 +++-
src/or/microdesc.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++++
src/or/microdesc.h | 6 ++-
src/or/networkstatus.c | 3 ++
5 files changed, 138 insertions(+), 15 deletions(-)
diff --git a/src/or/directory.c b/src/or/directory.c
index 9494cf02b..129309ae4 100644
--- a/src/or/directory.c
+++ b/src/or/directory.c
@@ -117,7 +117,8 @@ static void dir_routerdesc_download_failed(smartlist_t *failed,
int was_extrainfo,
int was_descriptor_digests);
static void dir_microdesc_download_failed(smartlist_t *failed,
- int status_code);
+ int status_code,
+ const char *dir_id);
static int client_likes_consensus(const struct consensus_cache_entry_t *ent,
const char *want_url);
@@ -2178,8 +2179,6 @@ static int handle_response_fetch_detached_signatures(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_fetch_desc(dir_connection_t *,
const response_handler_args_t *);
-static int handle_response_fetch_microdesc(dir_connection_t *,
- const response_handler_args_t *);
static int handle_response_upload_dir(dir_connection_t *,
const response_handler_args_t *);
static int handle_response_upload_vote(dir_connection_t *,
@@ -2839,7 +2838,7 @@ handle_response_fetch_desc(dir_connection_t *conn,
* Handler function: processes a response to a request for a group of
* microdescriptors
**/
-static int
+STATIC int
handle_response_fetch_microdesc(dir_connection_t *conn,
const response_handler_args_t *args)
{
@@ -2856,6 +2855,7 @@ handle_response_fetch_microdesc(dir_connection_t *conn,
conn->base_.port);
tor_assert(conn->requested_resource &&
!strcmpstart(conn->requested_resource, "d/"));
+ tor_assert_nonfatal(!tor_mem_is_zero(conn->identity_digest, DIGEST_LEN));
which = smartlist_new();
dir_split_resource_into_fingerprints(conn->requested_resource+2,
which, NULL,
@@ -2866,7 +2866,7 @@ handle_response_fetch_microdesc(dir_connection_t *conn,
"soon.",
status_code, escaped(reason), conn->base_.address,
(int)conn->base_.port, conn->requested_resource);
- dir_microdesc_download_failed(which, status_code);
+ dir_microdesc_download_failed(which, status_code, conn->identity_digest);
SMARTLIST_FOREACH(which, char *, cp, tor_free(cp));
smartlist_free(which);
return 0;
@@ -2878,7 +2878,7 @@ handle_response_fetch_microdesc(dir_connection_t *conn,
now, which);
if (smartlist_len(which)) {
/* Mark remaining ones as failed. */
- dir_microdesc_download_failed(which, status_code);
+ dir_microdesc_download_failed(which, status_code, conn->identity_digest);
}
if (mds && smartlist_len(mds)) {
control_event_bootstrap(BOOTSTRAP_STATUS_LOADING_DESCRIPTORS,
@@ -5546,13 +5546,14 @@ dir_routerdesc_download_failed(smartlist_t *failed, int status_code,
* every 10 or 60 seconds (FOO_DESCRIPTOR_RETRY_INTERVAL) in main.c. */
}
-/** Called when a connection to download microdescriptors has failed in whole
- * or in part. <b>failed</b> is a list of every microdesc digest we didn't
- * get. <b>status_code</b> is the http status code we received. Reschedule the
- * microdesc downloads as appropriate. */
+/** Called when a connection to download microdescriptors from relay with
+ * <b>dir_id</b> has failed in whole or in part. <b>failed</b> is a list
+ * of every microdesc digest we didn't get. <b>status_code</b> is the http
+ * status code we received. Reschedule the microdesc downloads as
+ * appropriate. */
static void
dir_microdesc_download_failed(smartlist_t *failed,
- int status_code)
+ int status_code, const char *dir_id)
{
networkstatus_t *consensus
= networkstatus_get_latest_consensus_by_flavor(FLAV_MICRODESC);
@@ -5563,17 +5564,26 @@ dir_microdesc_download_failed(smartlist_t *failed,
if (! consensus)
return;
+
+ /* We failed to fetch a microdescriptor from 'dir_id', note it down
+ * so that we don't try the same relay next time... */
+ microdesc_note_outdated_dirserver(dir_id);
+
SMARTLIST_FOREACH_BEGIN(failed, const char *, d) {
rs = router_get_mutable_consensus_status_by_descriptor_digest(consensus,d);
if (!rs)
continue;
dls = &rs->dl_status;
if (dls->n_download_failures >=
- get_options()->TestingMicrodescMaxDownloadTries)
+ get_options()->TestingMicrodescMaxDownloadTries) {
continue;
- {
+ }
+
+ { /* Increment the failure count for this md fetch */
char buf[BASE64_DIGEST256_LEN+1];
digest256_to_base64(buf, d);
+ log_info(LD_DIR, "Failed to download md %s from %s",
+ buf, hex_str(dir_id, DIGEST_LEN));
download_status_increment_failure(dls, status_code, buf,
server, now);
}
diff --git a/src/or/directory.h b/src/or/directory.h
index 14d5ae9ef..571c30a0f 100644
--- a/src/or/directory.h
+++ b/src/or/directory.h
@@ -166,7 +166,12 @@ STATIC char *accept_encoding_header(void);
STATIC int allowed_anonymous_connection_compression_method(compress_method_t);
STATIC void warn_disallowed_anonymous_compression_method(compress_method_t);
-#endif
+struct response_handler_args_t;
+
+STATIC int handle_response_fetch_microdesc(dir_connection_t *conn,
+ const struct response_handler_args_t *args);
+
+#endif /* defined(DIRECTORY_PRIVATE) */
#ifdef TOR_UNIT_TESTS
/* Used only by test_dir.c */
diff --git a/src/or/microdesc.c b/src/or/microdesc.c
index a4e6b409c..32242d005 100644
--- a/src/or/microdesc.c
+++ b/src/or/microdesc.c
@@ -74,6 +74,102 @@ HT_GENERATE2(microdesc_map, microdesc_t, node,
microdesc_hash_, microdesc_eq_, 0.6,
tor_reallocarray_, tor_free_)
+/************************* md fetch fail cache *****************************/
+
+/* If we end up with too many outdated dirservers, something probably went
+ * wrong so clean up the list. */
+#define TOO_MANY_OUTDATED_DIRSERVERS 30
+
+/** List of dirservers with outdated microdesc information. The smartlist is
+ * filled with the hex digests of outdated dirservers. */
+static smartlist_t *outdated_dirserver_list = NULL;
+
+/** Note that we failed to fetch a microdescriptor from the relay with
+ * <b>relay_digest</b> (of size DIGEST_LEN). */
+void
+microdesc_note_outdated_dirserver(const char *relay_digest)
+{
+ char relay_hexdigest[HEX_DIGEST_LEN+1];
+
+ /* Don't register outdated dirservers if we don't have a live consensus,
+ * since we might be trying to fetch microdescriptors that are not even
+ * currently active. */
+ if (!networkstatus_get_live_consensus(approx_time())) {
+ return;
+ }
+
+ if (!outdated_dirserver_list) {
+ outdated_dirserver_list = smartlist_new();
+ }
+
+ tor_assert(outdated_dirserver_list);
+
+ /* If the list grows too big, clean it up */
+ if (BUG(smartlist_len(outdated_dirserver_list) >
+ TOO_MANY_OUTDATED_DIRSERVERS)) {
+ microdesc_reset_outdated_dirservers_list();
+ }
+
+ /* Turn the binary relay digest to a hex since smartlists have better support
+ * for strings than digests. */
+ base16_encode(relay_hexdigest,sizeof(relay_hexdigest),
+ relay_digest, DIGEST_LEN);
+
+ /* Make sure we don't add a dirauth as an outdated dirserver */
+ if (router_get_trusteddirserver_by_digest(relay_digest)) {
+ log_info(LD_GENERAL, "Auth %s gave us outdated dirinfo.", relay_hexdigest);
+ return;
+ }
+
+ /* Don't double-add outdated dirservers */
+ if (smartlist_contains_string(outdated_dirserver_list, relay_hexdigest)) {
+ return;
+ }
+
+ /* Add it to the list of outdated dirservers */
+ smartlist_add_strdup(outdated_dirserver_list, relay_hexdigest);
+
+ log_info(LD_GENERAL, "Noted %s as outdated md dirserver", relay_hexdigest);
+}
+
+/** Return True if the relay with <b>relay_digest</b> (size DIGEST_LEN) is an
+ * outdated dirserver */
+int
+microdesc_relay_is_outdated_dirserver(const char *relay_digest)
+{
+ char relay_hexdigest[HEX_DIGEST_LEN+1];
+
+ if (!outdated_dirserver_list) {
+ return 0;
+ }
+
+ /* Convert identity digest to hex digest */
+ base16_encode(relay_hexdigest, sizeof(relay_hexdigest),
+ relay_digest, DIGEST_LEN);
+
+ /* Last time we tried to fetch microdescs, was this directory mirror missing
+ * any mds we asked for? */
+ if (smartlist_contains_string(outdated_dirserver_list, relay_hexdigest)) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/** Reset the list of outdated dirservers. */
+void
+microdesc_reset_outdated_dirservers_list(void)
+{
+ if (!outdated_dirserver_list) {
+ return;
+ }
+
+ SMARTLIST_FOREACH(outdated_dirserver_list, char *, cp, tor_free(cp));
+ smartlist_clear(outdated_dirserver_list);
+}
+
+/****************************************************************************/
+
/** Write the body of <b>md</b> into <b>f</b>, with appropriate annotations.
* On success, return the total number of bytes written, and set
* *<b>annotation_len_out</b> to the number of bytes written as
@@ -789,6 +885,11 @@ microdesc_free_all(void)
tor_free(the_microdesc_cache->journal_fname);
tor_free(the_microdesc_cache);
}
+
+ if (outdated_dirserver_list) {
+ SMARTLIST_FOREACH(outdated_dirserver_list, char *, cp, tor_free(cp));
+ smartlist_free(outdated_dirserver_list);
+ }
}
/** If there is a microdescriptor in <b>cache</b> whose sha256 digest is
diff --git a/src/or/microdesc.h b/src/or/microdesc.h
index 943873066..1be12156a 100644
--- a/src/or/microdesc.h
+++ b/src/or/microdesc.h
@@ -50,5 +50,9 @@ int we_fetch_microdescriptors(const or_options_t *options);
int we_fetch_router_descriptors(const or_options_t *options);
int we_use_microdescriptors_for_circuits(const or_options_t *options);
-#endif
+void microdesc_note_outdated_dirserver(const char *relay_digest);
+int microdesc_relay_is_outdated_dirserver(const char *relay_digest);
+void microdesc_reset_outdated_dirservers_list(void);
+
+#endif /* !defined(TOR_MICRODESC_H) */
diff --git a/src/or/networkstatus.c b/src/or/networkstatus.c
index 997280de5..36e62020e 100644
--- a/src/or/networkstatus.c
+++ b/src/or/networkstatus.c
@@ -2041,6 +2041,9 @@ networkstatus_set_current_consensus(const char *consensus,
"CLOCK_SKEW MIN_SKEW=%ld SOURCE=CONSENSUS", delta);
}
+ /* We got a new consesus. Reset our md fetch fail cache */
+ microdesc_reset_outdated_dirservers_list();
+
router_dir_info_changed();
result = 0;
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