r11677@Kushana: nickm | 2006-12-23 21:17:54 -0500

Track when we get 503s from directory servers.  Do not use directory servers that have given us a 503 until either an hour has passed, or we are are out of non-busy servers.


svn:r9172
This commit is contained in:
Nick Mathewson 2006-12-24 02:45:35 +00:00
parent 4d948281c3
commit 9efdf6acc5
5 changed files with 63 additions and 16 deletions

View File

@ -39,6 +39,10 @@ Changes in version 0.1.2.5-xxxx - 200?-??-??
- DirServer configuration lines now have an orport option so clients can
open encrypted tunnels to the authorities without having downloaded
their descriptors yet.
- Clients track responses with status 503 from dirservers. After a
dirserver has given us a 503, we try not to use it until an hour
has gone by, or until we have no dirservers that haven't given us
a 503.
o Security bugfixes:
- Stop sending the HttpProxyAuthenticator string to directory

View File

@ -134,12 +134,16 @@ R o Take out the '5 second' timeout from the socks detach schedule.
N - they don't count toward the 3-strikes rule
- should there be some threshold of 503's after which we give up?
- Delay when we get a lot of 503s?
N - split "router is down" from "dirport shouldn't be tried for a while"?
o split "router is down" from "dirport shouldn't be tried for a while"?
We want a field to hold "when did we last get a 503 from this
directory server." Probably, it should go in local_routerstatus_t,
not in routerinfo_t, since we can try to use servers as directories
before we have their descriptors. Possibly, it should also go in
trusted_dir_server_t.
o Add a last_dir_503_at field.
o Have it get updated correctly.
o Prefer to use directories that haven't given us a 503 for the last
60 minutes.
- authorities should *never* 503 a cache, and should never 503
network status requests. They can 503 client descriptor requests
when they feel like it.

View File

@ -109,7 +109,7 @@ directory_post_to_dirservers(uint8_t purpose, const char *payload,
*/
SMARTLIST_FOREACH(dirservers, trusted_dir_server_t *, ds,
{
routerstatus_t *rs = &(ds->fake_status);
routerstatus_t *rs = &(ds->fake_status.status);
if (post_to_hidserv_only && !ds->is_hidserv_authority)
continue;
if (!post_to_hidserv_only &&
@ -921,10 +921,18 @@ connection_dir_client_reached_eof(dir_connection_t *conn)
(void) skewed; /* skewed isn't used yet. */
if (status_code == 503) {
local_routerstatus_t *rs;
trusted_dir_server_t *ds;
time_t now = time(NULL);
log_info(LD_DIR,"Received http status code %d (%s) from server "
"'%s:%d'. I'll try again soon.",
status_code, escaped(reason), conn->_base.address,
conn->_base.port);
if ((rs = router_get_combined_status_by_digest(conn->identity_digest)))
rs->last_dir_503_at = now;
if ((ds = router_get_trusteddirserver_by_digest(conn->identity_digest)))
ds->fake_status.last_dir_503_at = now;
tor_free(body); tor_free(headers); tor_free(reason);
return -1;
}

View File

@ -1028,7 +1028,10 @@ typedef struct local_routerstatus_t {
* descriptor_digest represents the descriptor we would most like to use for
* this router. */
routerstatus_t status;
time_t next_attempt_at; /**< When should we try this descriptor again? */
time_t next_attempt_at; /**< When should we try downloading this descriptor
* again? */
time_t last_dir_503_at; /**< When did this router last tell us that it
* was too busy to serve directory info? */
uint8_t n_download_failures; /**< Number of failures trying to download the
* most recent descriptor. */
unsigned int name_lookup_warned:1; /**< Have we warned the user for referring
@ -2675,7 +2678,7 @@ typedef struct trusted_dir_server_t {
int n_networkstatus_failures; /**< How many times have we asked for this
* server's network-status unsuccessfully? */
routerstatus_t fake_status; /**< Used when we need to pass this trusted
local_routerstatus_t fake_status; /**< Used when we need to pass this trusted
* dir_server_t to directory_initiate_command_*
* as a routerstatus_t. Not updated by the
* router-status management code!

View File

@ -499,6 +499,9 @@ router_pick_trusteddirserver(authority_type_t type,
requireother, fascistfirewall);
}
/** How long do we avoid using a directory server after it's given us a 503? */
#define DIR_503_TIMEOUT (60*60)
/** Pick a random running valid directory server/mirror from our
* routerlist. Don't pick an authority if any non-authorities are viable.
* If <b>fascistfirewall</b>,
@ -513,13 +516,16 @@ router_pick_directory_server_impl(int requireother, int fascistfirewall,
{
routerstatus_t *result;
smartlist_t *sl;
smartlist_t *overloaded;
smartlist_t *trusted;
time_t now = time(NULL);
if (!routerstatus_list)
return NULL;
/* Find all the running dirservers we know about. */
sl = smartlist_create();
overloaded = smartlist_create();
trusted = smartlist_create();
SMARTLIST_FOREACH(routerstatus_list, local_routerstatus_t *, _local_status,
{
@ -536,14 +542,23 @@ router_pick_directory_server_impl(int requireother, int fascistfirewall,
is_trusted = router_digest_is_trusted_dir(status->identity_digest);
if (for_v2_directory && !(status->is_v2_dir || is_trusted))
continue;
smartlist_add(is_trusted ? trusted : sl, status);
if (is_trusted) {
smartlist_add(trusted, status);
} else if (_local_status->last_dir_503_at + DIR_503_TIMEOUT > now) {
smartlist_add(overloaded, status);
} else {
smartlist_add(sl, status);
}
});
if (smartlist_len(sl))
result = smartlist_choose(sl);
else if (smartlist_len(overloaded))
result = smartlist_choose(overloaded);
else
result = smartlist_choose(trusted);
smartlist_free(sl);
smartlist_free(overloaded);
smartlist_free(trusted);
return result;
}
@ -559,9 +574,12 @@ router_pick_trusteddirserver_impl(authority_type_t type,
int requireother, int fascistfirewall)
{
smartlist_t *sl;
smartlist_t *overloaded;
routerinfo_t *me;
routerstatus_t *rs;
time_t now = time(NULL);
sl = smartlist_create();
overloaded = smartlist_create();
me = router_get_my_routerinfo();
if (!trusted_dir_servers)
@ -582,11 +600,18 @@ router_pick_trusteddirserver_impl(authority_type_t type,
if (!fascist_firewall_allows_address_dir(d->addr, d->dir_port))
continue;
}
smartlist_add(sl, &d->fake_status);
if (d->fake_status.last_dir_503_at + DIR_503_TIMEOUT > now)
smartlist_add(overloaded, &d->fake_status.status);
else
smartlist_add(sl, &d->fake_status.status);
});
rs = smartlist_choose(sl);
if (smartlist_len(sl))
rs = smartlist_choose(sl);
else
rs = smartlist_choose(overloaded);
smartlist_free(sl);
smartlist_free(overloaded);
return rs;
}
@ -607,9 +632,11 @@ mark_all_trusteddirservers_up(void)
local_routerstatus_t *rs;
dir->is_running = 1;
dir->n_networkstatus_failures = 0;
dir->fake_status.last_dir_503_at = 0;
rs = router_get_combined_status_by_digest(dir->digest);
if (rs && !rs->status.is_running) {
rs->status.is_running = 1;
rs->last_dir_503_at = 0;
control_event_networkstatus_changed_single(rs);
}
});
@ -2637,7 +2664,7 @@ update_networkstatus_cache_downloads(time_t now)
base16_encode(resource+3, sizeof(resource)-3, ds->digest, DIGEST_LEN);
strlcat(resource, ".z", sizeof(resource));
directory_initiate_command_routerstatus(
&ds->fake_status, DIR_PURPOSE_FETCH_NETWORKSTATUS,
&ds->fake_status.status, DIR_PURPOSE_FETCH_NETWORKSTATUS,
0, /* Not private */
resource,
NULL, 0 /* No payload. */);
@ -2869,15 +2896,15 @@ add_trusted_dir_server(const char *nickname, const char *address,
tor_snprintf(ent->description, dlen, "directory server at %s:%d",
hostname, (int)dir_port);
ent->fake_status.addr = ent->addr;
memcpy(ent->fake_status.identity_digest, digest, DIGEST_LEN);
ent->fake_status.status.addr = ent->addr;
memcpy(ent->fake_status.status.identity_digest, digest, DIGEST_LEN);
if (nickname)
strlcpy(ent->fake_status.nickname, nickname,
sizeof(ent->fake_status.nickname));
strlcpy(ent->fake_status.status.nickname, nickname,
sizeof(ent->fake_status.status.nickname));
else
ent->fake_status.nickname[0] = '\0';
ent->fake_status.dir_port = ent->dir_port;
ent->fake_status.or_port = ent->or_port;
ent->fake_status.status.nickname[0] = '\0';
ent->fake_status.status.dir_port = ent->dir_port;
ent->fake_status.status.or_port = ent->or_port;
smartlist_add(trusted_dir_servers, ent);
router_dir_info_changed();
@ -3427,6 +3454,7 @@ routerstatus_list_update_from_networkstatus(time_t now)
rs_out->next_attempt_at = rs_old->next_attempt_at;
}
rs_out->name_lookup_warned = rs_old->name_lookup_warned;
rs_out->last_dir_503_at = rs_old->last_dir_503_at;
}
smartlist_add(result, rs_out);
log_debug(LD_DIR, "Router '%s' is listed by %d/%d directories, "
@ -3900,7 +3928,7 @@ update_router_descriptor_cache_downloads(time_t now)
log_info(LD_DIR, "Requesting %d descriptors from authority \"%s\"",
smartlist_len(dl), ds->nickname);
for (j=0; j < smartlist_len(dl); j += MAX_DL_PER_REQUEST) {
initiate_descriptor_downloads(&(ds->fake_status), dl, j,
initiate_descriptor_downloads(&(ds->fake_status.status), dl, j,
j+MAX_DL_PER_REQUEST);
}
}