Make authority_certs_fetch_missing support bridge hints (516c02b1) · Commits · Nick Mathewson / Tor

src/or/routerlist.c

+69 −24

Original line number	Diff line number	Diff line
		@@ -835,31 +835,66 @@ authority_cert_dl_looks_uncertain(const char *id_digest)
		}

		/* Fetch the authority certificates specified in resource.
		* If rs is not NULL, fetch from rs, otherwise, fetch from a random directory
		* mirror. */
		* If we are a bridge client, and node is a configured bridge, fetch from node
		* using dir_hint as the fingerprint. Otherwise, if rs is not NULL, fetch from
		* rs. Otherwise, fetch from a random directory mirror. */
		static void
		authority_certs_fetch_resource_impl(const char *resource,
		const char *dir_hint,
		const node_t *node,
		const routerstatus_t *rs)
		{
		const or_options_t *options = get_options();
		int get_via_tor = purpose_needs_anonymity(DIR_PURPOSE_FETCH_CERTIFICATE, 0);

		/* Make sure bridge clients never connect to anything but a bridge */
		if (options->UseBridges) {
		if (node && !node_is_a_configured_bridge(node)) {
		/* If we're using bridges, and node is not a bridge, use a 3-hop path. */
		get_via_tor = 1;
		} else if (!node) {
		/* If we're using bridges, and there's no node, use a 3-hop path. */
		get_via_tor = 1;
		}
		}

		const dir_indirection_t indirection = get_via_tor ? DIRIND_ANONYMOUS
		: DIRIND_ONEHOP;

		/* If we've just downloaded a consensus from a bridge, re-use that
		* bridge */
		if (options->UseBridges && node && !get_via_tor) {
		/* 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/
		dir_hint,
		DIR_PURPOSE_FETCH_CERTIFICATE,
		0,
		indirection,
		resource, NULL, 0, 0);
		return;
		}

		if (rs) {
		/* If we've just downloaded a consensus from a directory, re-use that
		* directory */
		int get_via_tor = purpose_needs_anonymity(
		DIR_PURPOSE_FETCH_CERTIFICATE, 0);
		const dir_indirection_t indirection = get_via_tor ? DIRIND_ANONYMOUS
		: DIRIND_ONEHOP;
		directory_initiate_command_routerstatus(rs,
		DIR_PURPOSE_FETCH_CERTIFICATE,
		0, indirection, resource, NULL,
		0, 0);
		} else {
		return;
		}

		/* Otherwise, we want certs from a random fallback or directory
		* mirror, because they will almost always succeed. */
		directory_get_from_dirserver(DIR_PURPOSE_FETCH_CERTIFICATE, 0,
		resource, PDS_RETRY_IF_NO_SERVERS,
		DL_WANT_ANY_DIRSERVER);
		}
		}

		/** Try to download any v3 authority certificates that we may be missing. If
		* <b>status</b> is provided, try to get all the ones that were used to sign
		@@ -1038,7 +1073,10 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now,
		} SMARTLIST_FOREACH_END(voter);
		}

		/* Look up the routerstatus for the dir_hint */
		/* Bridge clients look up the node for the dir_hint */
		const node_t *node = NULL;
		/* All clients, including bridge clients, look up the routerstatus for the
		* dir_hint */
		const routerstatus_t *rs = NULL;

		/* If we still need certificates, try the directory that just successfully
		@@ -1046,12 +1084,16 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now,
		* As soon as the directory fails to provide additional certificates, we try
		* another, randomly selected directory. This avoids continual retries.
		* (We only ever have one outstanding request per certificate.)
		*
		* Bridge clients won't find their bridges using this hint, so they will
		* fall back to using directory_get_from_dirserver, which selects a bridge.
		*/
		if (dir_hint) {
		/* First try the consensus routerstatus, then the fallback
		if (options->UseBridges) {
		/* Bridge clients try the nodelist. If the dir_hint is from an authority,
		* or something else fetched over tor, we won't find the node here, but
		* we will find the rs. */
		node = node_get_by_id(dir_hint);
		}

		/* All clients try the consensus routerstatus, then the fallback
		* routerstatus */
		rs = router_get_consensus_status_by_id(dir_hint);
		if (!rs) {
		@@ -1063,9 +1105,10 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now,
		}
		}

		if (!rs) {
		log_warn(LD_BUG, "Directory %s delivered a consensus, but a "
		"routerstatus could not be found for it.",
		if (!node && !rs) {
		log_warn(LD_BUG, "Directory %s delivered a consensus, but %s"
		"no routerstatus could be found for it.",
		options->UseBridges ? "no node and " : "",
		hex_str(dir_hint, DIGEST_LEN));
		}
		}
		@@ -1099,8 +1142,9 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now,

		if (smartlist_len(fps) > 1) {
		resource = smartlist_join_strings(fps, "", 0, NULL);
		/* rs is the directory that just gave us a consensus or certificates */
		authority_certs_fetch_resource_impl(resource, rs);
		/* node and rs are directories that just gave us a consensus or
		* certificates */
		authority_certs_fetch_resource_impl(resource, dir_hint, node, rs);
		tor_free(resource);
		}
		/* else we didn't add any: they were all pending */
		@@ -1143,8 +1187,9 @@ authority_certs_fetch_missing(networkstatus_t *status, time_t now,

		if (smartlist_len(fp_pairs) > 1) {
		resource = smartlist_join_strings(fp_pairs, "", 0, NULL);
		/* rs is the directory that just gave us a consensus or certificates */
		authority_certs_fetch_resource_impl(resource, rs);
		/* node and rs are directories that just gave us a consensus or
		* certificates */
		authority_certs_fetch_resource_impl(resource, dir_hint, node, rs);
		tor_free(resource);
		}
		/* else they were all pending */