Merge remote-tracking branch 'tor-github/pr/1209' into combined31343_31374_029 (7667c1cb) · Commits · Nick Mathewson / Tor

changes/bug31343

0 → 100644

+9 −0

Original line number	Diff line number	Diff line
		o Minor bugfixes (compilation):
		- Avoid using labs() on time_t, which can cause compilation warnings
		on 64-bit Windows builds. Fixes bug 31343; bugfix on 0.2.4.4-alpha.

		o Minor bugfixes (clock skew detection):
		- Don't believe clock skew results from NETINFO cells that appear to
		arrive before the VERSIONS cells they are responding to were sent.
		Previously, we would accept them up to 3 minutes "in the past".
		Fixes bug 31343; bugfix on 0.2.4.4-alpha.

src/or/channeltls.c

+19 −4

Original line number	Diff line number	Diff line
		@@ -1583,6 +1583,18 @@ channel_tls_process_versions_cell(var_cell_t cell, channel_tls_t chan)
		}
		}

		/**
		* Helper: compute the absolute value of a time_t.
		*
		* (we need this because labs() doesn't always work for time_t, since
		* long can be shorter than time_t.)
		*/
		static inline time_t
		time_abs(time_t val)
		{
		return (val < 0) ? -val : val;
		}

		/**
		* Process a 'netinfo' cell
		*
		@@ -1601,7 +1613,7 @@ channel_tls_process_netinfo_cell(cell_t cell, channel_tls_t chan)
		uint8_t n_other_addrs;
		time_t now = time(NULL);

		long apparent_skew = 0;
		time_t apparent_skew = 0;
		tor_addr_t my_apparent_addr = TOR_ADDR_NULL;

		tor_assert(cell);
		@@ -1659,7 +1671,11 @@ channel_tls_process_netinfo_cell(cell_t cell, channel_tls_t chan)

		/* Decode the cell. */
		timestamp = ntohl(get_uint32(cell->payload));
		if (labs(now - chan->conn->handshake_state->sent_versions_at) < 180) {
		const time_t sent_versions_at =
		chan->conn->handshake_state->sent_versions_at;
		if (now > sent_versions_at && (now - sent_versions_at) < 180) {
		/* If we have gotten the NETINFO cell reasonably soon after having
		* sent our VERSIONS cell, maybe we can learn skew information from it. */
		apparent_skew = now - timestamp;
		}

		@@ -1705,7 +1721,7 @@ channel_tls_process_netinfo_cell(cell_t cell, channel_tls_t chan)
		/* Act on apparent skew. */
		/** Warn when we get a netinfo skew with at least this value. */
		#define NETINFO_NOTICE_SKEW 3600
		if (labs(apparent_skew) > NETINFO_NOTICE_SKEW &&
		if (time_abs(apparent_skew) > NETINFO_NOTICE_SKEW &&
		router_get_by_id_digest(chan->conn->identity_digest)) {
		int trusted = router_digest_is_trusted_dir(chan->conn->identity_digest);
		clock_skew_warning(TO_CONN(chan->conn), apparent_skew, trusted, LD_GENERAL,
		@@ -2182,4 +2198,3 @@ channel_tls_process_authenticate_cell(var_cell_t cell, channel_tls_t chan)

		#undef ERR
		}

src/or/routerlist.c

+4 −3

Original line number	Diff line number	Diff line
		@@ -5443,7 +5443,7 @@ int
		router_differences_are_cosmetic(const routerinfo_t r1, const routerinfo_t r2)
		{
		time_t r1pub, r2pub;
		long time_difference;
		time_t time_difference;
		tor_assert(r1 && r2);

		/* r1 should be the one that was published first. */
		@@ -5506,7 +5506,9 @@ router_differences_are_cosmetic(const routerinfo_t r1, const routerinfo_t r2)
		* give or take some slop? */
		r1pub = r1->cache_info.published_on;
		r2pub = r2->cache_info.published_on;
		time_difference = labs(r2->uptime - (r1->uptime + (r2pub - r1pub)));
		time_difference = r2->uptime - (r1->uptime + (r2pub - r1pub));
		if (time_difference < 0)
		time_difference = - time_difference;
		if (time_difference > ROUTER_ALLOW_UPTIME_DRIFT &&
		time_difference > r1->uptime * .05 &&
		time_difference > r2->uptime * .05)
		@@ -5816,4 +5818,3 @@ refresh_all_country_info(void)

		nodelist_refresh_countries();
		}