Merge branch 'bug21242' (78011bb7) · Commits · The Tor Project / Core / Tor

changes/bug21242

0 → 100644

+10 −0

Original line number	Diff line number	Diff line
		o Major bugfixes (entry guards):
		- Stop trying to build circuits through entry guards for which we
		have no descriptor yet. Also, stop crashing if we do accidentally
		try to build a circuit in such a state. Fixes bug 21242; bugfix
		on 0.3.0.1-alpha.

		o Minor features (entry guards):
		- Do not try to build circuits until we have descriptors for our
		primary entry guards. Related to fix for bug 21242.

src/or/circuitbuild.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -2369,7 +2369,7 @@ onion_extend_cpath(origin_circuit_t *circ)
		int client = (server_mode(get_options()) == 0);
		info = extend_info_from_node(r, client);
		/* Clients can fail to find an allowed address */
		tor_assert(info \|\| client);
		tor_assert_nonfatal(info \|\| client);
		}
		} else {
		const node_t *r =

src/or/entrynodes.c

+63 −1

Original line number	Diff line number	Diff line
		@@ -185,6 +185,16 @@ should_apply_guardfraction(const networkstatus_t *ns)
		return options->UseGuardFraction;
		}

		/** Return true iff we know a descriptor for <b>guard</b> */
		static int
		guard_has_descriptor(const entry_guard_t *guard)
		{
		const node_t *node = node_get_by_id(guard->identity);
		if (!node)
		return 0;
		return node_has_descriptor(node);
		}

		/**
		* Try to determine the correct type for a selection named "name",
		* if <b>type</b> is GS_TYPE_INFER.
		@@ -1436,6 +1446,7 @@ sample_reachable_filtered_entry_guards(guard_selection_t *gs,
		const unsigned exclude_primary = flags & SAMPLE_EXCLUDE_PRIMARY;
		const unsigned exclude_pending = flags & SAMPLE_EXCLUDE_PENDING;
		const unsigned no_update_primary = flags & SAMPLE_NO_UPDATE_PRIMARY;
		const unsigned need_descriptor = flags & SAMPLE_EXCLUDE_NO_DESCRIPTOR;

		SMARTLIST_FOREACH_BEGIN(gs->sampled_entry_guards, entry_guard_t *, guard) {
		entry_guard_consider_retry(guard);
		@@ -1469,6 +1480,8 @@ sample_reachable_filtered_entry_guards(guard_selection_t *gs,
		continue;
		if (exclude_pending && guard->is_pending)
		continue;
		if (need_descriptor && !guard_has_descriptor(guard))
		continue;
		smartlist_add(reachable_filtered_sample, guard);
		} SMARTLIST_FOREACH_END(guard);

		@@ -1766,6 +1779,7 @@ select_entry_guard_for_circuit(guard_selection_t *gs,
		const entry_guard_restriction_t *rst,
		unsigned *state_out)
		{
		const int need_descriptor = (usage == GUARD_USAGE_TRAFFIC);
		tor_assert(gs);
		tor_assert(state_out);

		@@ -1782,6 +1796,9 @@ select_entry_guard_for_circuit(guard_selection_t *gs,
		if (! entry_guard_obeys_restriction(guard, rst))
		continue;
		if (guard->is_reachable != GUARD_REACHABLE_NO) {
		if (need_descriptor && BUG(!guard_has_descriptor(guard))) {
		continue;
		}
		*state_out = GUARD_CIRC_STATE_USABLE_ON_COMPLETION;
		guard->last_tried_to_connect = approx_time();
		smartlist_add(usable_primary_guards, guard);
		@@ -1810,6 +1827,8 @@ select_entry_guard_for_circuit(guard_selection_t *gs,
		continue;
		entry_guard_consider_retry(guard);
		if (guard->is_usable_filtered_guard && ! guard->is_pending) {
		if (need_descriptor && !guard_has_descriptor(guard))
		continue; /* not a bug */
		guard->is_pending = 1;
		guard->last_tried_to_connect = approx_time();
		*state_out = GUARD_CIRC_STATE_USABLE_IF_NO_BETTER_GUARD;
		@@ -1825,11 +1844,15 @@ select_entry_guard_for_circuit(guard_selection_t *gs,
		random from {USABLE_FILTERED_GUARDS}." */
		{
		entry_guard_t *guard;
		unsigned flags = 0;
		if (need_descriptor)
		flags \|= SAMPLE_EXCLUDE_NO_DESCRIPTOR;
		guard = sample_reachable_filtered_entry_guards(gs,
		rst,
		SAMPLE_EXCLUDE_CONFIRMED \|
		SAMPLE_EXCLUDE_PRIMARY \|
		SAMPLE_EXCLUDE_PENDING);
		SAMPLE_EXCLUDE_PENDING \|
		flags);
		if (guard == NULL) {
		log_info(LD_GUARD, "Absolutely no sampled guards were available.");
		return NULL;
		@@ -2057,6 +2080,8 @@ entry_guard_pick_for_circuit(guard_selection_t *gs,
		// XXXX prop271 check Ed ID.
		if (! node)
		goto fail;
		if (BUG(usage != GUARD_USAGE_DIRGUARD && !node_has_descriptor(node)))
		goto fail;

		*chosen_node_out = node;
		*guard_state_out = tor_malloc_zero(sizeof(circuit_guard_state_t));
		@@ -3303,6 +3328,43 @@ guards_retry_optimistic(const or_options_t *options)
		return 1;
		}

		/**
		* Return true iff we know enough directory information to construct
		* circuits through all of the primary guards we'd currently use.
		*/
		int
		guard_selection_have_enough_dir_info_to_build_circuits(guard_selection_t *gs)
		{
		if (!gs->primary_guards_up_to_date)
		entry_guards_update_primary(gs);

		const int num_primary = get_n_primary_guards_to_use(GUARD_USAGE_TRAFFIC);
		int n_missing_descriptors = 0;
		int n_considered = 0;

		SMARTLIST_FOREACH_BEGIN(gs->primary_entry_guards, entry_guard_t *, guard) {
		entry_guard_consider_retry(guard);
		if (guard->is_reachable == GUARD_REACHABLE_NO)
		continue;
		n_considered++;
		if (!guard_has_descriptor(guard))
		n_missing_descriptors++;
		if (n_considered >= num_primary)
		break;
		} SMARTLIST_FOREACH_END(guard);

		return n_missing_descriptors == 0;
		}

		/** As guard_selection_have_enough_dir_info_to_build_circuits, but uses
		* the default guard selection. */
		int
		entry_guards_have_enough_dir_info_to_build_circuits(void)
		{
		return guard_selection_have_enough_dir_info_to_build_circuits(
		get_guard_selection_info());
		}

		/** Free one guard selection context */
		STATIC void
		guard_selection_free(guard_selection_t *gs)

src/or/entrynodes.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -482,6 +482,7 @@ STATIC entry_guard_t get_sampled_guard_with_id(guard_selection_t gs,
		const uint8_t *rsa_id);

		MOCK_DECL(STATIC time_t, randomize_time, (time_t now, time_t max_backdate));

		STATIC entry_guard_t entry_guard_add_to_sample(guard_selection_t gs,
		const node_t *node);
		STATIC entry_guard_t entry_guards_expand_sample(guard_selection_t gs);
		@@ -498,6 +499,7 @@ STATIC int entry_guards_all_primary_guards_are_down(guard_selection_t *gs);
		#define SAMPLE_EXCLUDE_PRIMARY (1u<<1)
		#define SAMPLE_EXCLUDE_PENDING (1u<<2)
		#define SAMPLE_NO_UPDATE_PRIMARY (1u<<3)
		#define SAMPLE_EXCLUDE_NO_DESCRIPTOR (1u<<4)
		/*@}/
		STATIC entry_guard_t *sample_reachable_filtered_entry_guards(
		guard_selection_t *gs,
		@@ -565,6 +567,10 @@ int getinfo_helper_entry_guards(control_connection_t *conn,
		int entries_known_but_down(const or_options_t *options);
		void entries_retry_all(const or_options_t *options);

		int guard_selection_have_enough_dir_info_to_build_circuits(
		guard_selection_t *gs);
		int entry_guards_have_enough_dir_info_to_build_circuits(void);

		void entry_guards_free_all(void);

		double pathbias_get_close_success_count(entry_guard_t *guard);

src/or/nodelist.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@
		#include "config.h"
		#include "control.h"
		#include "dirserv.h"
		#include "entrynodes.h"
		#include "geoip.h"
		#include "main.h"
		#include "microdesc.h"
		@@ -1991,6 +1992,13 @@ update_router_have_minimum_dir_info(void)

		using_md = consensus->flavor == FLAV_MICRODESC;

		if (! entry_guards_have_enough_dir_info_to_build_circuits()) {
		strlcpy(dir_info_status, "We're missing descriptors for some of our "
		"primary entry guards", sizeof(dir_info_status));
		res = 0;
		goto done;
		}

		/* Check fraction of available paths */
		{
		char *status = NULL;