[or-cvs] r10867: timeout and retry schedules for fetching bridge descriptors (in tor/trunk: doc src/or)
arma at seul.org
arma at seul.org
Wed Jul 18 10:06:03 UTC 2007
Author: arma
Date: 2007-07-18 06:06:03 -0400 (Wed, 18 Jul 2007)
New Revision: 10867
Modified:
tor/trunk/doc/TODO
tor/trunk/src/or/circuitbuild.c
tor/trunk/src/or/main.c
tor/trunk/src/or/or.h
tor/trunk/src/or/routerlist.c
Log:
timeout and retry schedules for fetching bridge descriptors
Modified: tor/trunk/doc/TODO
===================================================================
--- tor/trunk/doc/TODO 2007-07-18 09:23:23 UTC (rev 10866)
+++ tor/trunk/doc/TODO 2007-07-18 10:06:03 UTC (rev 10867)
@@ -238,7 +238,7 @@
manually listed in the torrc.
D and some mechanism for specifying that we want to stop using
a given bridge in this cache.
- - timeout and retry schedules for fetching bridge descriptors
+ o timeout and retry schedules for fetching bridge descriptors
- give extend_info_t a router_purpose again
o react faster to download networkstatuses after the first bridge
descriptor arrives
@@ -247,7 +247,7 @@
- Bridges operators (rudimentary version)
- Ability to act as dir cache without a dir port.
o Bridges publish to bridge authorities
- - Fix BEGIN_DIR so that you connect to bridge of which you only
+ o Fix BEGIN_DIR so that you connect to bridge of which you only
know IP (and optionally fingerprint), and then use BEGIN_DIR to learn
more about it.
- look at server_mode() and decide if it always applies to bridges too.
Modified: tor/trunk/src/or/circuitbuild.c
===================================================================
--- tor/trunk/src/or/circuitbuild.c 2007-07-18 09:23:23 UTC (rev 10866)
+++ tor/trunk/src/or/circuitbuild.c 2007-07-18 10:06:03 UTC (rev 10867)
@@ -2668,6 +2668,7 @@
uint32_t addr;
uint16_t port;
char identity[DIGEST_LEN];
+ download_status_t fetch_status;
} bridge_info_t;
/** A list of known bridges. */
@@ -2697,23 +2698,30 @@
}
#endif
-/** Return 1 if <b>ri</b> is one of our known bridges (either by
- * comparing keys if possible, else by comparing addr/port). */
-int
-routerinfo_is_a_bridge(routerinfo_t *ri)
+/** Return a bridge pointer if <b>ri</b> is one of our known bridges
+ * (either by comparing keys if possible, else by comparing addr/port).
+ * Else return NULL. */
+static bridge_info_t *
+routerinfo_get_configured_bridge(routerinfo_t *ri)
{
SMARTLIST_FOREACH(bridge_list, bridge_info_t *, bridge,
{
if (tor_digest_is_zero(bridge->identity) &&
bridge->addr == ri->addr && bridge->port == ri->or_port)
- return 1;
+ return bridge;
if (!memcmp(bridge->identity, ri->cache_info.identity_digest,
DIGEST_LEN))
- return 1;
+ return bridge;
});
- return 0;
+ return NULL;
}
+int
+routerinfo_is_a_configured_bridge(routerinfo_t *ri)
+{
+ return routerinfo_get_configured_bridge(ri) ? 1 : 0;
+}
+
/** Remember a new bridge at <b>addr</b>:<b>port</b>. If <b>digest</b>
* is set, it tells us the identity key too. */
void
@@ -2729,11 +2737,34 @@
smartlist_add(bridge_list, b);
}
+/** Schedule the next fetch for <b>bridge</b>, based on
+ * some retry schedule. */
+static void
+bridge_fetch_status_increment(bridge_info_t *bridge, time_t now)
+{
+ switch (bridge->fetch_status.n_download_failures) {
+ case 0: bridge->fetch_status.next_attempt_at = now+60*15; break;
+ case 1: bridge->fetch_status.next_attempt_at = now+60*15; break;
+ default: bridge->fetch_status.next_attempt_at = now+60*60; break;
+ }
+ if (bridge->fetch_status.n_download_failures < 10)
+ bridge->fetch_status.n_download_failures++;
+}
+
+/** We just got a new descriptor for <b>bridge</b>. Reschedule the
+ * next fetch for a long time from <b>now</b>. */
+static void
+bridge_fetch_status_arrived(bridge_info_t *bridge, time_t now)
+{
+ bridge->fetch_status.next_attempt_at = now+60*60;
+ bridge->fetch_status.n_download_failures = 0;
+}
+
/** For each bridge in our list for which we don't currently have a
* descriptor, fetch a new copy of its descriptor -- either directly
* from the bridge or via a bridge authority. */
void
-fetch_bridge_descriptors(void)
+fetch_bridge_descriptors(time_t now)
{
char address_buf[INET_NTOA_BUF_LEN+1];
struct in_addr in;
@@ -2746,8 +2777,12 @@
SMARTLIST_FOREACH(bridge_list, bridge_info_t *, bridge,
{
- if (router_get_by_digest(bridge->identity))
- continue; /* we've already got one. great. */
+ if (bridge->fetch_status.next_attempt_at >= now)
+ continue; /* don't bother, no need to retry yet */
+
+ /* schedule another fetch as if this one failed, in case it does */
+ bridge_fetch_status_increment(bridge, now);
+
in.s_addr = htonl(bridge->addr);
tor_inet_ntoa(&in, address_buf, sizeof(address_buf));
@@ -2792,16 +2827,22 @@
tor_assert(ri->purpose == ROUTER_PURPOSE_BRIDGE);
if (get_options()->UseBridges) {
int first = !any_bridge_descriptors_known();
+ bridge_info_t *bridge = routerinfo_get_configured_bridge(ri);
+ time_t now = time(NULL);
ri->is_running = 1;
+
+ /* it's here; schedule its re-fetch for a long time from now. */
+ bridge_fetch_status_arrived(bridge, now);
+
add_an_entry_guard(ri, 1);
log_notice(LD_DIR, "new bridge descriptor '%s'", ri->nickname);
if (first)
- routerlist_retry_directory_downloads(time(NULL));
+ routerlist_retry_directory_downloads(now);
}
}
/** Return 1 if any of our entry guards have descriptors that
- * are marked with purpose 'bridge'. Else return 0.
+ * are marked with purpose 'bridge' and are running. Else return 0.
*
* We use this function to decide if we're ready to start building
* circuits through our bridges, or if we need to wait until the
@@ -2810,19 +2851,30 @@
any_bridge_descriptors_known(void)
{
return choose_random_entry(NULL)!=NULL ? 1 : 0;
+}
+
#if 0
+/** Return 1 if we have at least one descriptor for a bridge and
+ * all descriptors we know are down. Else return 0. */
+int
+all_bridges_down(void)
+{
routerinfo_t *ri;
+ int any_known = 0;
if (!entry_guards)
entry_guards = smartlist_create();
SMARTLIST_FOREACH(entry_guards, entry_guard_t *, e,
{
ri = router_get_by_digest(e->identity);
- if (ri && ri->purpose == ROUTER_PURPOSE_BRIDGE)
- return 1;
+ if (ri && ri->purpose == ROUTER_PURPOSE_BRIDGE) {
+ any_known = 1;
+ if (ri->is_running)
+ return 0; /* some bridge is both known and running */
+ }
});
- return 0;
+ return any_known;
+}
#endif
-}
/** Release all storage held by the list of entry guards and related
* memory structs. */
Modified: tor/trunk/src/or/main.c
===================================================================
--- tor/trunk/src/or/main.c 2007-07-18 09:23:23 UTC (rev 10866)
+++ tor/trunk/src/or/main.c 2007-07-18 10:06:03 UTC (rev 10867)
@@ -881,16 +881,16 @@
if (time_to_try_getting_descriptors < now) {
/* XXXX Maybe we should do this every 10sec when not enough info,
- * and every 60sec when we have enough info -NM */
+ * and every 60sec when we have enough info -NM Great idea -RD */
update_router_descriptor_downloads(now);
update_extrainfo_downloads(now);
+ if (options->UseBridges)
+ fetch_bridge_descriptors(now);
time_to_try_getting_descriptors = now + DESCRIPTOR_RETRY_INTERVAL;
}
if (time_to_reset_descriptor_failures < now) {
router_reset_descriptor_download_failures();
- if (options->UseBridges)
- fetch_bridge_descriptors(); /* XXX get this its own retry schedule -RD */
time_to_reset_descriptor_failures =
now + DESCRIPTOR_FAILURE_RESET_INTERVAL;
}
Modified: tor/trunk/src/or/or.h
===================================================================
--- tor/trunk/src/or/or.h 2007-07-18 09:23:23 UTC (rev 10866)
+++ tor/trunk/src/or/or.h 2007-07-18 10:06:03 UTC (rev 10867)
@@ -2231,15 +2231,16 @@
void entry_guards_update_state(or_state_t *state);
int getinfo_helper_entry_guards(control_connection_t *conn,
const char *question, char **answer);
-void entry_guards_free_all(void);
void clear_bridge_list(void);
-int routerinfo_is_a_bridge(routerinfo_t *ri);
+int routerinfo_is_a_configured_bridge(routerinfo_t *ri);
void bridge_add_from_config(uint32_t addr, uint16_t port, char *digest);
-void fetch_bridge_descriptors(void);
+void fetch_bridge_descriptors(time_t now);
void learned_bridge_descriptor(routerinfo_t *ri);
int any_bridge_descriptors_known(void);
+void entry_guards_free_all(void);
+
/********************************* circuitlist.c ***********************/
circuit_t * _circuit_get_global_list(void);
Modified: tor/trunk/src/or/routerlist.c
===================================================================
--- tor/trunk/src/or/routerlist.c 2007-07-18 09:23:23 UTC (rev 10866)
+++ tor/trunk/src/or/routerlist.c 2007-07-18 10:06:03 UTC (rev 10867)
@@ -2413,7 +2413,7 @@
* we are receiving in response to a fetch. */
if (!signed_desc_digest_is_recognized(&router->cache_info) &&
- !routerinfo_is_a_bridge(router)) {
+ !routerinfo_is_a_configured_bridge(router)) {
/* We asked for it, so some networkstatus must have listed it when we
* did. Save it if we're a cache in case somebody else asks for it. */
log_info(LD_DIR,
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