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Choose bridge addresses by IPv4/IPv6 preferences

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This commit is contained in:
teor (Tim Wilson-Brown) 2016-01-03 18:20:37 +11:00
parent c3cc8e16e9
commit 1648666203
4 changed files with 123 additions and 75 deletions
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176
src/or/directory.c
View File

@ -497,11 +497,14 @@ MOCK_IMPL(void, directory_get_from_dirserver, (
const node_t *node = choose_random_dirguard(type);
if (node && node->ri) {
/* every bridge has a routerinfo. */
tor_addr_t addr;
routerinfo_t *ri = node->ri;
node_get_addr(node, &addr);
directory_initiate_command(&addr,
ri->or_port, 0/*no dirport*/,
/* clients always make OR connections to bridges */
tor_addr_port_t or_ap;
/* we are willing to use a non-preferred address if we need to */
fascist_firewall_choose_address_node(node, FIREWALL_OR_CONNECTION, 0,
&or_ap);
directory_initiate_command(&or_ap.addr, or_ap.port,
NULL, 0, /*no dirport*/
ri->cache_info.identity_digest,
dir_purpose,
router_purpose,
@ -610,6 +613,80 @@ dirind_is_anon(dir_indirection_t ind)
return ind == DIRIND_ANON_DIRPORT || ind == DIRIND_ANONYMOUS;
}
/* Choose reachable OR and Dir addresses and ports from status, copying them
* into use_or_ap and use_dir_ap. If indirection is anonymous, then we're
* connecting via another relay, so choose the primary IPv4 address and ports.
*
* status should have at least one reachable address, if we can't choose a
* reachable address, warn and return -1. Otherwise, return 0.
*/
static int
directory_choose_address_routerstatus(const routerstatus_t *status,
dir_indirection_t indirection,
tor_addr_port_t *use_or_ap,
tor_addr_port_t *use_dir_ap)
{
tor_assert(status != NULL);
tor_assert(use_or_ap != NULL);
tor_assert(use_dir_ap != NULL);
const int anonymized_connection = dirind_is_anon(indirection);
int have_or = 0, have_dir = 0;
/* We expect status to have at least one reachable address if we're
* connecting to it directly.
*
* Therefore, we can simply use the other address if the one we want isn't
* allowed by the firewall.
*
* (When Tor uploads and downloads a hidden service descriptor, it uses
* DIRIND_ANONYMOUS, except for Tor2Web, which uses DIRIND_ONEHOP.
* So this code will only modify the address for Tor2Web's HS descriptor
* fetches. Even Single Onion Servers (NYI) use DIRIND_ANONYMOUS, to avoid
* HSDirs denying service by rejecting descriptors.)
*/
/* Initialise the OR / Dir addresses */
tor_addr_make_null(&use_or_ap->addr, AF_UNSPEC);
use_or_ap->port = 0;
tor_addr_make_null(&use_dir_ap->addr, AF_UNSPEC);
use_dir_ap->port = 0;
if (anonymized_connection) {
/* Use the primary (IPv4) OR address if we're making an indirect
* connection. */
tor_addr_from_ipv4h(&use_or_ap->addr, status->addr);
use_or_ap->port = status->or_port;
have_or = 1;
} else {
/* We use an IPv6 address if we have one and we prefer it.
* Use the preferred address and port if they are reachable, otherwise,
* use the alternate address and port (if any).
*/
have_or = fascist_firewall_choose_address_rs(status,
FIREWALL_OR_CONNECTION, 0,
use_or_ap);
}
have_dir = fascist_firewall_choose_address_rs(status,
FIREWALL_DIR_CONNECTION, 0,
use_dir_ap);
/* We rejected both addresses. This isn't great. */
if (!have_or && !have_dir) {
log_warn(LD_BUG, "Rejected all OR and Dir addresses from %s when "
"launching a directory connection to: IPv4 %s OR %d Dir %d "
"IPv6 %s OR %d Dir %d", routerstatus_describe(status),
fmt_addr32(status->addr), status->or_port,
status->dir_port, fmt_addr(&status->ipv6_addr),
status->ipv6_orport, status->dir_port);
log_backtrace(LOG_WARN, LD_BUG, "Addresses came from");
return -1;
}
return 0;
}
/** Same as directory_initiate_command_routerstatus(), but accepts
* rendezvous data to fetch a hidden service descriptor. */
void
@ -627,7 +704,8 @@ directory_initiate_command_routerstatus_rend(const routerstatus_t *status,
const node_t *node;
tor_addr_port_t use_or_ap, use_dir_ap;
const int anonymized_connection = dirind_is_anon(indirection);
int have_or = 0, have_dir = 0;
tor_assert(status != NULL);
node = node_get_by_id(status->identity_digest);
@ -654,57 +732,16 @@ directory_initiate_command_routerstatus_rend(const routerstatus_t *status,
* selection uses the preference in ClientPreferIPv6{OR,Dir}Port, if
* possible. (If UseBridges is set, clients ignore all these settings.)
*
* Now we use a similar process to select an address for the relay,
* but simply use the other address if the one we want isn't allowed by
* the firewall.
*
* (When Tor uploads and downloads a hidden service descriptor, it uses
* DIRIND_ANONYMOUS, except for Tor2Web, which uses DIRIND_ONEHOP.
* So this code will only modify the address for Tor2Web's HS descriptor
* fetches. Even Single Onion Servers (NYI) use DIRIND_ANONYMOUS, to avoid
* HSDirs denying service by rejecting descriptors.)
* Now choose an address that we can use to connect to the directory server.
*/
/* Initialise the OR / Dir addresses */
tor_addr_make_null(&use_or_ap.addr, AF_UNSPEC);
use_or_ap.port = 0;
tor_addr_make_null(&use_dir_ap.addr, AF_UNSPEC);
use_dir_ap.port = 0;
if (anonymized_connection) {
/* Use the primary (IPv4) OR address if we're making an indirect
* connection. */
tor_addr_from_ipv4h(&use_or_ap.addr, status->addr);
use_or_ap.port = status->or_port;
have_or = 1;
} else {
/* We use an IPv6 address if we have one and we prefer it.
* Use the preferred address and port if they are reachable, otherwise,
* use the alternate address and port (if any).
*/
have_or = fascist_firewall_choose_address_rs(status,
FIREWALL_OR_CONNECTION, 0,
&use_or_ap);
}
have_dir = fascist_firewall_choose_address_rs(status,
FIREWALL_DIR_CONNECTION, 0,
&use_dir_ap);
/* We rejected both addresses. This isn't great. */
if (!have_or && !have_dir) {
log_warn(LD_BUG, "Rejected all OR and Dir addresses from %s when "
"launching a directory connection to: IPv4 %s OR %d Dir %d "
"IPv6 %s OR %d Dir %d", routerstatus_describe(status),
fmt_addr32(status->addr), status->or_port,
status->dir_port, fmt_addr(&status->ipv6_addr),
status->ipv6_orport, status->dir_port);
log_backtrace(LOG_WARN, LD_BUG, "Addresses came from");
if (directory_choose_address_routerstatus(status, indirection, &use_or_ap,
&use_dir_ap) < 0) {
return;
}
/* XX/teor - we don't retry the alternate OR/Dir address if this one fails.
* (See #6772.) Instead, we'll retry another directory on failure. */
/* We don't retry the alternate OR/Dir address for the same directory if
* the address we choose fails (#6772).
* Instead, we'll retry another directory on failure. */
directory_initiate_command_rend(&use_or_ap, &use_dir_ap,
status->identity_digest,
@ -941,41 +978,42 @@ directory_command_should_use_begindir(const or_options_t *options,
}
/** Helper for directory_initiate_command_rend: send the
* command to a server whose address is <b>_addr</b>, whose OR port is
* <b>or_port</b>, whose directory port is <b>dir_port</b>, whose identity key
* digest is <b>digest</b>, with purposes <b>dir_purpose</b> and
* command to a server whose OR address/port is <b>or_addr</b>/<b>or_port</b>,
* whose directory address/port is <b>dir_addr</b>/<b>dir_port</b>, whose
* identity key digest is <b>digest</b>, with purposes <b>dir_purpose</b> and
* <b>router_purpose</b>, making an (in)direct connection as specified in
* <b>indirection</b>, with command <b>resource</b>, <b>payload</b> of
* <b>payload_len</b>, and asking for a result only <b>if_modified_since</b>.
*/
void
directory_initiate_command(const tor_addr_t *_addr,
uint16_t or_port, uint16_t dir_port,
directory_initiate_command(const tor_addr_t *or_addr, uint16_t or_port,
const tor_addr_t *dir_addr, uint16_t dir_port,
const char *digest,
uint8_t dir_purpose, uint8_t router_purpose,
dir_indirection_t indirection, const char *resource,
const char *payload, size_t payload_len,
time_t if_modified_since)
{
/* Assume _addr applies to both the ORPort and the DirPort, but use the
* null tor_addr if ORPort or DirPort are 0. */
tor_addr_port_t or_ap, dir_ap;
if (or_port) {
tor_addr_copy(&or_ap.addr, _addr);
/* Use the null tor_addr and 0 port if the address or port isn't valid. */
if (tor_addr_port_is_valid(or_addr, or_port, 0)) {
tor_addr_copy(&or_ap.addr, or_addr);
or_ap.port = or_port;
} else {
/* the family doesn't matter here, so make it the same as _addr */
tor_addr_make_null(&or_ap.addr, tor_addr_family(_addr));
/* the family doesn't matter here, so make it IPv4 */
tor_addr_make_null(&or_ap.addr, AF_INET);
or_port = 0;
}
or_ap.port = or_port;
if (dir_port) {
tor_addr_copy(&dir_ap.addr, _addr);
if (tor_addr_port_is_valid(dir_addr, dir_port, 0)) {
tor_addr_copy(&dir_ap.addr, dir_addr);
dir_ap.port = dir_port;
} else {
/* the family doesn't matter here, so make it the same as _addr */
tor_addr_make_null(&dir_ap.addr, tor_addr_family(_addr));
/* the family doesn't matter here, so make it IPv4 */
tor_addr_make_null(&dir_ap.addr, AF_INET);
dir_port = 0;
}
dir_ap.port = dir_port;
directory_initiate_command_rend(&or_ap, &dir_ap,
digest, dir_purpose,

4
src/or/directory.h
View File

@ -66,8 +66,8 @@ int connection_dir_process_inbuf(dir_connection_t *conn);
int connection_dir_finished_flushing(dir_connection_t *conn);
int connection_dir_finished_connecting(dir_connection_t *conn);
void connection_dir_about_to_close(dir_connection_t *dir_conn);
void directory_initiate_command(const tor_addr_t *addr,
uint16_t or_port, uint16_t dir_port,
void directory_initiate_command(const tor_addr_t *or_addr, uint16_t or_port,
const tor_addr_t *dir_addr, uint16_t dir_port,
const char *digest,
uint8_t dir_purpose, uint8_t router_purpose,
dir_indirection_t indirection,

13
src/or/entrynodes.c
View File

@ -2117,8 +2117,17 @@ launch_direct_bridge_descriptor_fetch(bridge_info_t *bridge)
return;
}
directory_initiate_command(&bridge->addr,
bridge->port, 0/*no dirport*/,
/* Until we get a descriptor for the bridge, we only know one address for
* it. If we */
if (!fascist_firewall_allows_address_addr(&bridge->addr, bridge->port,
FIREWALL_OR_CONNECTION, 0)) {
log_notice(LD_CONFIG, "Tried to fetch a descriptor directly from a bridge, "
"but that bridge is not reachable through our firewall.");
return;
}
directory_initiate_command(&bridge->addr, bridge->port,
NULL, 0, /*no dirport*/
bridge->identity,
DIR_PURPOSE_FETCH_SERVERDESC,
ROUTER_PURPOSE_BRIDGE,

5
src/or/router.c
View File

@ -1244,14 +1244,15 @@ consider_testing_reachability(int test_or, int test_dir)
extend_info_free(ei);
}
/* XXX IPv6 self testing */
tor_addr_from_ipv4h(&addr, me->addr);
if (test_dir && !check_whether_dirport_reachable() &&
!connection_get_by_type_addr_port_purpose(
CONN_TYPE_DIR, &addr, me->dir_port,
DIR_PURPOSE_FETCH_SERVERDESC)) {
/* ask myself, via tor, for my server descriptor. */
directory_initiate_command(&addr,
me->or_port, me->dir_port,
directory_initiate_command(&addr, me->or_port,
&addr, me->dir_port,
me->cache_info.identity_digest,
DIR_PURPOSE_FETCH_SERVERDESC,
ROUTER_PURPOSE_GENERAL,