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-rw-r--r--src/or/circuitbuild.c81
1 files changed, 67 insertions, 14 deletions
diff --git a/src/or/circuitbuild.c b/src/or/circuitbuild.c
index 0e033a5899..860cd27567 100644
--- a/src/or/circuitbuild.c
+++ b/src/or/circuitbuild.c
@@ -559,7 +559,9 @@ circuit_build_times_create_histogram(circuit_build_times_t *cbt,
* Return the Pareto start-of-curve parameter Xm.
*
* Because we are not a true Pareto curve, we compute this as the
- * weighted average of the N=3 most frequent build time bins.
+ * weighted average of the N most frequent build time bins. N is either
+ * 1 if we don't have enough circuit build time data collected, or
+ * determined by the consensus parameter cbtnummodes (default 3).
*/
static build_time_t
circuit_build_times_get_xm(circuit_build_times_t *cbt)
@@ -572,6 +574,9 @@ circuit_build_times_get_xm(circuit_build_times_t *cbt)
int n=0;
int num_modes = circuit_build_times_default_num_xm_modes();
+ tor_assert(nbins > 0);
+ tor_assert(num_modes > 0);
+
// Only use one mode if < 1000 buildtimes. Not enough data
// for multiple.
if (cbt->total_build_times < CBT_NCIRCUITS_TO_OBSERVE)
@@ -579,6 +584,7 @@ circuit_build_times_get_xm(circuit_build_times_t *cbt)
nth_max_bin = (build_time_t*)tor_malloc_zero(num_modes*sizeof(build_time_t));
+ /* Determine the N most common build times */
for (i = 0; i < nbins; i++) {
if (histogram[i] >= histogram[nth_max_bin[0]]) {
nth_max_bin[0] = i;
@@ -600,6 +606,10 @@ circuit_build_times_get_xm(circuit_build_times_t *cbt)
histogram[nth_max_bin[n]]);
}
+ /* The following assert is safe, because we don't get called when we
+ * haven't observed at least CBT_MIN_MIN_CIRCUITS_TO_OBSERVE circuits. */
+ tor_assert(bin_counts > 0);
+
ret /= bin_counts;
tor_free(histogram);
tor_free(nth_max_bin);
@@ -1813,7 +1823,7 @@ circuit_n_conn_done(or_connection_t *or_conn, int status)
continue;
} else {
/* We expected a key. See if it's the right one. */
- if (memcmp(or_conn->identity_digest,
+ if (tor_memneq(or_conn->identity_digest,
circ->n_hop->identity_digest, DIGEST_LEN))
continue;
}
@@ -2221,7 +2231,7 @@ circuit_extend(cell_t *cell, circuit_t *circ)
/* Next, check if we're being asked to connect to the hop that the
* extend cell came from. There isn't any reason for that, and it can
* assist circular-path attacks. */
- if (!memcmp(id_digest, TO_OR_CIRCUIT(circ)->p_conn->identity_digest,
+ if (tor_memeq(id_digest, TO_OR_CIRCUIT(circ)->p_conn->identity_digest,
DIGEST_LEN)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Client asked me to extend back to the previous hop.");
@@ -3502,7 +3512,7 @@ static INLINE entry_guard_t *
is_an_entry_guard(const char *digest)
{
SMARTLIST_FOREACH(entry_guards, entry_guard_t *, entry,
- if (!memcmp(digest, entry->identity, DIGEST_LEN))
+ if (tor_memeq(digest, entry->identity, DIGEST_LEN))
return entry;
);
return NULL;
@@ -3834,7 +3844,7 @@ entry_guard_register_connect_status(const char *digest, int succeeded,
SMARTLIST_FOREACH(entry_guards, entry_guard_t *, e,
{
- if (!memcmp(e->identity, digest, DIGEST_LEN)) {
+ if (tor_memeq(e->identity, digest, DIGEST_LEN)) {
entry = e;
idx = e_sl_idx;
break;
@@ -4461,6 +4471,9 @@ typedef struct {
tor_addr_t addr;
/** TLS port for the bridge. */
uint16_t port;
+ /** Boolean: We are re-parsing our bridge list, and we are going to remove
+ * this one if we don't find it in the list of configured bridges. */
+ unsigned marked_for_removal : 1;
/** Expected identity digest, or all zero bytes if we don't know what the
* digest should be. */
char identity[DIGEST_LEN];
@@ -4469,11 +4482,39 @@ typedef struct {
} bridge_info_t;
/** A list of configured bridges. Whenever we actually get a descriptor
- * for one, we add it as an entry guard. */
+ * for one, we add it as an entry guard. Note that the order of bridges
+ * in this list does not necessarily correspond to the order of bridges
+ * in the torrc. */
static smartlist_t *bridge_list = NULL;
-/** Initialize the bridge list to empty, creating it if needed. */
+/** Mark every entry of the bridge list to be removed on our next call to
+ * sweep_bridge_list unless it has first been un-marked. */
void
+mark_bridge_list(void)
+{
+ if (!bridge_list)
+ bridge_list = smartlist_create();
+ SMARTLIST_FOREACH(bridge_list, bridge_info_t *, b,
+ b->marked_for_removal = 1);
+}
+
+/** Remove every entry of the bridge list that was marked with
+ * mark_bridge_list if it has not subsequently been un-marked. */
+void
+sweep_bridge_list(void)
+{
+ if (!bridge_list)
+ bridge_list = smartlist_create();
+ SMARTLIST_FOREACH_BEGIN(bridge_list, bridge_info_t *, b) {
+ if (b->marked_for_removal) {
+ SMARTLIST_DEL_CURRENT(bridge_list, b);
+ tor_free(b);
+ }
+ } SMARTLIST_FOREACH_END(b);
+}
+
+/** Initialize the bridge list to empty, creating it if needed. */
+static void
clear_bridge_list(void)
{
if (!bridge_list)
@@ -4486,7 +4527,8 @@ clear_bridge_list(void)
* (either by comparing keys if possible, else by comparing addr/port).
* Else return NULL. */
static bridge_info_t *
-get_configured_bridge_by_addr_port_digest(tor_addr_t *addr, uint16_t port,
+get_configured_bridge_by_addr_port_digest(const tor_addr_t *addr,
+ uint16_t port,
const char *digest)
{
if (!bridge_list)
@@ -4497,7 +4539,7 @@ get_configured_bridge_by_addr_port_digest(tor_addr_t *addr, uint16_t port,
!tor_addr_compare(&bridge->addr, addr, CMP_EXACT) &&
bridge->port == port)
return bridge;
- if (!memcmp(bridge->identity, digest, DIGEST_LEN))
+ if (tor_memeq(bridge->identity, digest, DIGEST_LEN))
return bridge;
}
SMARTLIST_FOREACH_END(bridge);
@@ -4527,7 +4569,8 @@ routerinfo_is_a_configured_bridge(routerinfo_t *ri)
* If it was a bridge, and we still don't know its digest, record it.
*/
void
-learned_router_identity(tor_addr_t *addr, uint16_t port, const char *digest)
+learned_router_identity(const tor_addr_t *addr, uint16_t port,
+ const char *digest)
{
bridge_info_t *bridge =
get_configured_bridge_by_addr_port_digest(addr, port, digest);
@@ -4539,11 +4582,20 @@ learned_router_identity(tor_addr_t *addr, uint16_t port, const char *digest)
}
/** Remember a new bridge at <b>addr</b>:<b>port</b>. If <b>digest</b>
- * is set, it tells us the identity key too. */
+ * is set, it tells us the identity key too. If we already had the
+ * bridge in our list, unmark it, and don't actually add anything new. */
void
-bridge_add_from_config(const tor_addr_t *addr, uint16_t port, char *digest)
+bridge_add_from_config(const tor_addr_t *addr, uint16_t port,
+ const char *digest)
{
- bridge_info_t *b = tor_malloc_zero(sizeof(bridge_info_t));
+ bridge_info_t *b;
+
+ if ((b = get_configured_bridge_by_addr_port_digest(addr, port, digest))) {
+ b->marked_for_removal = 0;
+ return;
+ }
+
+ b = tor_malloc_zero(sizeof(bridge_info_t));
tor_addr_copy(&b->addr, addr);
b->port = port;
if (digest)
@@ -4551,6 +4603,7 @@ bridge_add_from_config(const tor_addr_t *addr, uint16_t port, char *digest)
b->fetch_status.schedule = DL_SCHED_BRIDGE;
if (!bridge_list)
bridge_list = smartlist_create();
+
smartlist_add(bridge_list, b);
}
@@ -4578,7 +4631,7 @@ find_bridge_by_digest(const char *digest)
{
SMARTLIST_FOREACH(bridge_list, bridge_info_t *, bridge,
{
- if (!memcmp(bridge->identity, digest, DIGEST_LEN))
+ if (tor_memeq(bridge->identity, digest, DIGEST_LEN))
return bridge;
});
return NULL;
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