Don't check create cells too much when we're relaying them (5c68a1ef) · Commits · Mike Perry / Tor

src/or/circuitbuild.c

+12 −9

Original line number	Diff line number	Diff line
		@@ -55,7 +55,8 @@ static channel_t * channel_connect_for_circuit(const tor_addr_t *addr,
		uint16_t port,
		const char *id_digest);
		static int circuit_deliver_create_cell(circuit_t *circ,
		const create_cell_t *create_cell);
		const create_cell_t *create_cell,
		int relayed);
		static int onion_pick_cpath_exit(origin_circuit_t circ, extend_info_t exit);
		static crypt_path_t onion_next_hop_in_cpath(crypt_path_t cpath);
		static int onion_extend_cpath(origin_circuit_t *circ);
		@@ -474,7 +475,7 @@ circuit_n_chan_done(channel_t *chan, int status)
		} else {
		/* pull the create cell out of circ->n_chan_create_cell, and send it */
		tor_assert(circ->n_chan_create_cell);
		if (circuit_deliver_create_cell(circ, circ->n_chan_create_cell)<0) {
		if (circuit_deliver_create_cell(circ, circ->n_chan_create_cell, 1)<0) {
		circuit_mark_for_close(circ, END_CIRC_REASON_RESOURCELIMIT);
		continue;
		}
		@@ -491,14 +492,16 @@ circuit_n_chan_done(channel_t *chan, int status)
		* for the outgoing
		* circuit <b>circ</b>, and deliver a cell of type <b>cell_type</b>
		* (either CELL_CREATE or CELL_CREATE_FAST) with payload <b>payload</b>
		* to this circuit. DOCDOC payload_len
		* to this circuit. DOCDOC new arguments
		* Return -1 if we failed to find a suitable circid, else return 0.
		*/
		static int
		circuit_deliver_create_cell(circuit_t circ, const create_cell_t create_cell)
		circuit_deliver_create_cell(circuit_t circ, const create_cell_t create_cell,
		int relayed)
		{
		cell_t cell;
		circid_t id;
		int r;

		tor_assert(circ);
		tor_assert(circ->n_chan);
		@@ -516,7 +519,9 @@ circuit_deliver_create_cell(circuit_t circ, const create_cell_t create_cell)
		circuit_set_n_circid_chan(circ, id, circ->n_chan);

		memset(&cell, 0, sizeof(cell_t));
		if (create_cell_format(&cell, create_cell) < 0) {
		r = relayed ? create_cell_format_relayed(&cell, create_cell)
		: create_cell_format(&cell, create_cell);
		if (r < 0) {
		log_warn(LD_CIRC,"Couldn't format create cell");
		return -1;
		}
		@@ -657,7 +662,7 @@ circuit_send_next_onion_skin(origin_circuit_t *circ)
		}
		cc.handshake_len = len;

		if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc) < 0)
		if (circuit_deliver_create_cell(TO_CIRCUIT(circ), &cc, 0) < 0)
		return - END_CIRC_REASON_RESOURCELIMIT;

		circ->cpath->state = CPATH_STATE_AWAITING_KEYS;
		@@ -901,8 +906,6 @@ circuit_extend(cell_t cell, circuit_t circ)
		&ec.orport_ipv4.addr,
		ec.orport_ipv4.port);

		/* XXXX Make sure we can eventually deliver create cell with weird
		* content */
		circ->n_chan_create_cell = tor_memdup(&ec.create_cell,
		sizeof(ec.create_cell));

		@@ -933,7 +936,7 @@ circuit_extend(cell_t cell, circuit_t circ)
		"n_chan is %s",
		channel_get_canonical_remote_descr(n_chan));

		if (circuit_deliver_create_cell(circ, &ec.create_cell) < 0)
		if (circuit_deliver_create_cell(circ, &ec.create_cell, 1) < 0)
		return -1;
		return 0;
		}

src/or/onion.c

+17 −4

Original line number	Diff line number	Diff line
		@@ -808,13 +808,14 @@ extended_cell_parse(extended_cell_t *cell_out,

		/** Fill <b>cell_out</b> with a correctly formatted version of the
		* CREATE{,_FAST,2} cell in <b>cell_in</b>. Return 0 on success, -1 on
		* failure. */
		int
		create_cell_format(cell_t cell_out, const create_cell_t cell_in)
		* failure. This is a cell we didn't originate if <b>relayed</b> is true. */
		static int
		create_cell_format_impl(cell_t cell_out, const create_cell_t cell_in,
		int relayed)
		{
		uint8_t *p;
		size_t space;
		if (check_create_cell(cell_in, 0) < 0)
		if (check_create_cell(cell_in, relayed) < 0)
		return -1;

		memset(cell_out->payload, 0, sizeof(cell_out->payload));
		@@ -848,6 +849,18 @@ create_cell_format(cell_t cell_out, const create_cell_t cell_in)
		return 0;
		}

		int
		create_cell_format(cell_t cell_out, const create_cell_t cell_in)
		{
		return create_cell_format_impl(cell_out, cell_in, 0);
		}

		int
		create_cell_format_relayed(cell_t cell_out, const create_cell_t cell_in)
		{
		return create_cell_format_impl(cell_out, cell_in, 1);
		}

		/** Fill <b>cell_out</b> with a correctly formatted version of the
		* CREATED{,_FAST,2} cell in <b>cell_in</b>. Return 0 on success, -1 on
		* failure. */

src/or/onion.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -106,6 +106,7 @@ int extended_cell_parse(extended_cell_t *cell_out, uint8_t command,
		const uint8_t *payload_in, size_t payload_len);

		int create_cell_format(cell_t cell_out, const create_cell_t cell_in);
		int create_cell_format_relayed(cell_t cell_out, const create_cell_t cell_in);
		int created_cell_format(cell_t cell_out, const created_cell_t cell_in);
		int extend_cell_format(uint8_t command_out, uint16_t len_out,
		uint8_t payload_out, const extend_cell_t cell_in);

src/test/test_cell_formats.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -651,7 +651,7 @@ test_cfmt_extend_cells(void *arg)
		tt_int_op(p2_cmd, ==, RELAY_COMMAND_EXTEND);
		tt_int_op(p2_len, ==, 26+TAP_ONIONSKIN_CHALLENGE_LEN);
		test_memeq(p2, p, RELAY_PAYLOAD_SIZE);
		tt_int_op(0, ==, create_cell_format(&cell, cc));
		tt_int_op(0, ==, create_cell_format_relayed(&cell, cc));

		/* Now let's do a minimal ntor EXTEND2 cell. */
		memset(&ec, 0xff, sizeof(ec));
		@@ -721,6 +721,7 @@ test_cfmt_extend_cells(void *arg)
		/* Now the handshake prologue */
		"01050063");
		test_memeq(p2+1+8+22+4, b, 99+20);
		tt_int_op(0, ==, create_cell_format_relayed(&cell, cc));

		/* == Now try parsing some junk */