Commit 93a8ed3b authored by teor's avatar teor Committed by Nick Mathewson
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Make clients wait to refresh bridges when they have a recent descriptor

But when clients are just starting, make them try each bridge a few times
before giving up on it.

These changes make the bridge download schedules more explicit: before
17750, they relied on undocumented behaviour and specific schedule
entries. (And between 17750 and this fix, they were broken.)

Fixes 23347, not in any released version of tor.
parent 6370fb77
o Minor bug fixes (bridge client bootstrap):
- Make bridge clients download bridge descriptors immediately.
The bridge schedules were never correct, but we didn't realise until
the fix for 17750 made bridge clients hang for 15 minutes before
bootstrapping.
Fixes bug 23347. Not in any released version of Tor.
o Minor fixes (bridge client bootstrap):
- Make bridge clients with no running bridges try to download
bridge descriptors immediately. But when bridge clients have
running bridges, make them wait at least 3 hours before
refreshing recently received bridge descriptors.
Download schedules used to start with an implicit 0, but the
fix for 17750 changed this undocumented behaviour, and made
bridge clients hang for 15 minutes before bootstrapping.
Fixes bug 23347, not in any released version of Tor.
......@@ -2475,7 +2475,8 @@ The following options are used for running a testing Tor network.
TestingClientDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingServerConsensusDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingClientConsensusDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingBridgeDownloadSchedule 0, 5, 10, 30, 60
TestingBridgeDownloadSchedule 10, 30, 60
TestingBridgeBootstrapDownloadSchedule 0, 0, 5, 10, 15, 20, 30, 60
TestingClientMaxIntervalWithoutRequest 5 seconds
TestingDirConnectionMaxStall 30 seconds
TestingConsensusMaxDownloadTries 80
......@@ -2540,9 +2541,16 @@ The following options are used for running a testing Tor network.
1800, 3600, 3600, 3600, 10800, 21600, 43200)
[[TestingBridgeDownloadSchedule]] **TestingBridgeDownloadSchedule** __N__,__N__,__...__::
Schedule for when clients should download bridge descriptors. Changing this
requires that **TestingTorNetwork** is set. (Default: 0, 8, 3600, 10800,
25200, 54000, 111600, 262800)
Schedule for when clients should download each bridge descriptor when they
know that one or more of their configured bridges are running. Changing
this requires that **TestingTorNetwork** is set. (Default: 10800, 25200,
54000, 111600, 262800)
[[TestingBridgeBootstrapDownloadSchedule]] **TestingBridgeBootstrapDownloadSchedule** __N__,__N__,__...__::
Schedule for when clients should download each bridge descriptor when they
have just started, or when they can not contact any of their bridges.
Changing this requires that **TestingTorNetwork** is set. (Default: 0, 30,
90, 600, 3600, 10800, 25200, 54000, 111600, 262800)
[[TestingClientMaxIntervalWithoutRequest]] **TestingClientMaxIntervalWithoutRequest** __N__ **seconds**|**minutes**::
When directory clients have only a few descriptors to request, they batch
......
......@@ -794,17 +794,10 @@ learned_bridge_descriptor(routerinfo_t *ri, int from_cache)
node_t *node;
/* it's here; schedule its re-fetch for a long time from now. */
if (!from_cache) {
/* This schedules the re-fetch at a constant interval, which produces
* a pattern of bridge traffic. But it's better than trying all
* configured briges several times in the first few minutes. */
download_status_reset(&bridge->fetch_status);
/* We have two quick attempts in the bridge schedule, and then slow
* ones */
download_status_increment_attempt(
&bridge->fetch_status,
safe_str_client(fmt_and_decorate_addr(&bridge->addr)),
now);
download_status_increment_attempt(
&bridge->fetch_status,
safe_str_client(fmt_and_decorate_addr(&bridge->addr)),
now);
}
node = node_get_mutable_by_id(ri->cache_info.identity_digest);
......@@ -837,8 +830,8 @@ learned_bridge_descriptor(routerinfo_t *ri, int from_cache)
* 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
* directory "server/authority" requests finish. */
int
any_bridge_descriptors_known(void)
MOCK_IMPL(int,
any_bridge_descriptors_known, (void))
{
tor_assert(get_options()->UseBridges);
......
......@@ -45,7 +45,7 @@ void bridge_add_from_config(struct bridge_line_t *bridge_line);
void retry_bridge_descriptor_fetch_directly(const char *digest);
void fetch_bridge_descriptors(const or_options_t *options, time_t now);
void learned_bridge_descriptor(routerinfo_t *ri, int from_cache);
int any_bridge_descriptors_known(void);
MOCK_DECL(int, any_bridge_descriptors_known, (void));
const smartlist_t *get_socks_args_by_bridge_addrport(const tor_addr_t *addr,
uint16_t port);
......
......@@ -586,10 +586,16 @@ static config_var_t option_vars_[] = {
* blackholed. Clients will try 3 directories simultaneously.
* (Relays never use simultaneous connections.) */
V(ClientBootstrapConsensusMaxInProgressTries, UINT, "3"),
/* The bridge code relies on the third item in this schedule being slow
* (~ 1 consensus interval) */
/* When a client has any running bridges, check each bridge occasionally,
* whether or not that bridge is actually up. */
V(TestingBridgeDownloadSchedule, CSV_INTERVAL,
"0, 8, 3600, 10800, 25200, 54000, 111600, 262800"),
"10800, 25200, 54000, 111600, 262800"),
/* When a client is just starting, or has no running bridges, check each
* bridge a few times quickly, and then try again later. These schedules
* are much longer than the other schedules, because we try each and every
* configured bridge with this schedule. */
V(TestingBridgeBootstrapDownloadSchedule, CSV_INTERVAL,
"0, 30, 90, 600, 3600, 10800, 25200, 54000, 111600, 262800"),
V(TestingClientMaxIntervalWithoutRequest, INTERVAL, "10 minutes"),
V(TestingDirConnectionMaxStall, INTERVAL, "5 minutes"),
V(TestingConsensusMaxDownloadTries, UINT, "8"),
......@@ -651,9 +657,9 @@ static const config_var_t testing_tor_network_defaults[] = {
"15, 20, 30, 60"),
V(TestingClientConsensusDownloadSchedule, CSV_INTERVAL, "0, 0, 5, 10, "
"15, 20, 30, 60"),
/* The bridge code relies on the third item in this schedule being slow
* (~ 1 consensus interval) */
V(TestingBridgeDownloadSchedule, CSV_INTERVAL, "0, 5, 10, 30, 60"),
V(TestingBridgeDownloadSchedule, CSV_INTERVAL, "10, 30, 60"),
V(TestingBridgeBootstrapDownloadSchedule, CSV_INTERVAL, "0, 0, 5, 10, "
"15, 20, 30, 60"),
V(TestingClientMaxIntervalWithoutRequest, INTERVAL, "5 seconds"),
V(TestingDirConnectionMaxStall, INTERVAL, "30 seconds"),
V(TestingConsensusMaxDownloadTries, UINT, "80"),
......@@ -4066,6 +4072,7 @@ options_validate(or_options_t *old_options, or_options_t *options,
CHECK_DEFAULT(TestingServerConsensusDownloadSchedule);
CHECK_DEFAULT(TestingClientConsensusDownloadSchedule);
CHECK_DEFAULT(TestingBridgeDownloadSchedule);
CHECK_DEFAULT(TestingBridgeBootstrapDownloadSchedule);
CHECK_DEFAULT(TestingClientMaxIntervalWithoutRequest);
CHECK_DEFAULT(TestingDirConnectionMaxStall);
CHECK_DEFAULT(TestingConsensusMaxDownloadTries);
......
......@@ -5342,7 +5342,14 @@ find_dl_schedule(const download_status_t *dls, const or_options_t *options)
}
}
case DL_SCHED_BRIDGE:
return options->TestingBridgeDownloadSchedule;
/* A bridge client downloading bridge descriptors */
if (any_bridge_descriptors_known()) {
/* A bridge client with one or more running bridges */
return options->TestingBridgeDownloadSchedule;
} else {
/* A bridge client with no running bridges */
return options->TestingBridgeBootstrapDownloadSchedule;
}
default:
tor_assert(0);
}
......
......@@ -4314,6 +4314,10 @@ typedef struct {
* altered on testing networks. */
smartlist_t *TestingBridgeDownloadSchedule;
/** Schedule for when clients should download bridge descriptors when they
* have no running bridges. Only altered on testing networks. */
smartlist_t *TestingBridgeBootstrapDownloadSchedule;
/** When directory clients have only a few descriptors to request, they
* batch them until they have more, or until this amount of time has
* passed. Only altered on testing networks. */
......
......@@ -18,6 +18,7 @@
#define RELAY_PRIVATE
#include "or.h"
#include "bridges.h"
#include "confparse.h"
#include "config.h"
#include "control.h"
......@@ -4245,7 +4246,7 @@ test_dir_download_status_increment(void *arg)
/* Put it in the options */
mock_options = &test_options;
reset_options(mock_options, &mock_get_options_calls);
mock_options->TestingBridgeDownloadSchedule = schedule;
mock_options->TestingBridgeBootstrapDownloadSchedule = schedule;
mock_options->TestingClientDownloadSchedule = schedule;
MOCK(get_options, mock_get_options);
......@@ -4425,6 +4426,7 @@ test_dir_download_status_increment(void *arg)
/* Check that failure increments do happen on attempt-based schedules,
* but that the retry is set at the end of time */
mock_options->UseBridges = 1;
mock_get_options_calls = 0;
next_at = download_status_increment_failure(&dls_attempt, 404, "test", 0,
current_time);
......@@ -4539,6 +4541,7 @@ test_dir_download_status_increment(void *arg)
tt_int_op(download_status_get_n_failures(&dls_attempt), OP_EQ, 0);
tt_int_op(download_status_get_n_attempts(&dls_attempt), OP_EQ, 0);
tt_int_op(mock_get_options_calls, OP_GE, 1);
mock_options->UseBridges = 0;
/* Check that attempt increments don't happen on failure-based schedules,
* and that the attempt is set at the end of time */
......@@ -5859,9 +5862,17 @@ mock_networkstatus_consensus_can_use_extra_fallbacks(
return mock_networkstatus_consensus_can_use_extra_fallbacks_value;
}
/* data is a 2 character nul-terminated string.
static int mock_any_bridge_descriptors_known_value = 0;
static int
mock_any_bridge_descriptors_known(void)
{
return mock_any_bridge_descriptors_known_value;
}
/* data is a 3 character nul-terminated string.
* If data[0] is 'b', set bootstrapping, anything else means not bootstrapping
* If data[1] is 'f', set extra fallbacks, anything else means no extra
* If data[2] is 'f', set running bridges, anything else means no extra
* fallbacks.
*/
static void
......@@ -5869,7 +5880,7 @@ test_dir_find_dl_schedule(void* data)
{
const char *str = (const char *)data;
tt_assert(strlen(data) == 2);
tt_assert(strlen(data) == 3);
if (str[0] == 'b') {
mock_networkstatus_consensus_is_bootstrapping_value = 1;
......@@ -5883,15 +5894,23 @@ test_dir_find_dl_schedule(void* data)
mock_networkstatus_consensus_can_use_extra_fallbacks_value = 0;
}
if (str[2] == 'r') {
mock_any_bridge_descriptors_known_value = 1;
} else {
mock_any_bridge_descriptors_known_value = 0;
}
MOCK(networkstatus_consensus_is_bootstrapping,
mock_networkstatus_consensus_is_bootstrapping);
MOCK(networkstatus_consensus_can_use_extra_fallbacks,
mock_networkstatus_consensus_can_use_extra_fallbacks);
MOCK(any_bridge_descriptors_known,
mock_any_bridge_descriptors_known);
download_status_t dls;
smartlist_t server, client, server_cons, client_cons;
smartlist_t client_boot_auth_only_cons, client_boot_auth_cons;
smartlist_t client_boot_fallback_cons, bridge;
smartlist_t client_boot_fallback_cons, bridge, bridge_bootstrap;
mock_options = tor_malloc(sizeof(or_options_t));
reset_options(mock_options, &mock_get_options_calls);
......@@ -5908,6 +5927,7 @@ test_dir_find_dl_schedule(void* data)
mock_options->ClientBootstrapConsensusFallbackDownloadSchedule =
&client_boot_fallback_cons;
mock_options->TestingBridgeDownloadSchedule = &bridge;
mock_options->TestingBridgeBootstrapDownloadSchedule = &bridge_bootstrap;
dls.schedule = DL_SCHED_GENERIC;
/* client */
......@@ -5996,11 +6016,17 @@ test_dir_find_dl_schedule(void* data)
dls.schedule = DL_SCHED_BRIDGE;
/* client */
mock_options->ClientOnly = 1;
tt_ptr_op(find_dl_schedule(&dls, mock_options), OP_EQ, &bridge);
mock_options->UseBridges = 1;
if (any_bridge_descriptors_known()) {
tt_ptr_op(find_dl_schedule(&dls, mock_options), OP_EQ, &bridge);
} else {
tt_ptr_op(find_dl_schedule(&dls, mock_options), OP_EQ, &bridge_bootstrap);
}
done:
UNMOCK(networkstatus_consensus_is_bootstrapping);
UNMOCK(networkstatus_consensus_can_use_extra_fallbacks);
UNMOCK(any_bridge_descriptors_known);
UNMOCK(get_options);
tor_free(mock_options);
mock_options = NULL;
......@@ -6165,10 +6191,14 @@ struct testcase_t dir_tests[] = {
DIR(dump_unparseable_descriptors, 0),
DIR(populate_dump_desc_fifo, 0),
DIR(populate_dump_desc_fifo_2, 0),
DIR_ARG(find_dl_schedule, TT_FORK, "bf"),
DIR_ARG(find_dl_schedule, TT_FORK, "ba"),
DIR_ARG(find_dl_schedule, TT_FORK, "cf"),
DIR_ARG(find_dl_schedule, TT_FORK, "ca"),
DIR_ARG(find_dl_schedule, TT_FORK, "bfd"),
DIR_ARG(find_dl_schedule, TT_FORK, "bad"),
DIR_ARG(find_dl_schedule, TT_FORK, "cfd"),
DIR_ARG(find_dl_schedule, TT_FORK, "cad"),
DIR_ARG(find_dl_schedule, TT_FORK, "bfr"),
DIR_ARG(find_dl_schedule, TT_FORK, "bar"),
DIR_ARG(find_dl_schedule, TT_FORK, "cfr"),
DIR_ARG(find_dl_schedule, TT_FORK, "car"),
DIR(assumed_flags, 0),
DIR(networkstatus_compute_bw_weights_v10, 0),
END_OF_TESTCASES
......
......@@ -2230,6 +2230,7 @@ test_options_validate__testing(void *ignored)
ENSURE_DEFAULT(TestingServerConsensusDownloadSchedule, 3000);
ENSURE_DEFAULT(TestingClientConsensusDownloadSchedule, 3000);
ENSURE_DEFAULT(TestingBridgeDownloadSchedule, 3000);
ENSURE_DEFAULT(TestingBridgeBootstrapDownloadSchedule, 3000);
ENSURE_DEFAULT(TestingClientMaxIntervalWithoutRequest, 3000);
ENSURE_DEFAULT(TestingDirConnectionMaxStall, 3000);
ENSURE_DEFAULT(TestingConsensusMaxDownloadTries, 3000);
......
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