Split out major functionality of circuit_get_best; rephrase a few booleans (60772ec9) · Commits · Legacy / gitolite / user / hiviah / rpm-tor

src/or/circuit.c

+69 −50

Changes for src/or/circuit.c: 69 added lines, 50 removed lines.
Original line number	Diff line number	Diff line
		@@ -250,56 +250,38 @@ circuit_t circuit_get_by_conn(connection_t conn) {
		return NULL;
		}

		/* Dear god this function needs refactoring. */
		/* Find the best circ that conn can use, preferably one which is
		* dirty. Circ must not be too old.
		* If !conn, return newest.
		*
		* If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN.
		*
		* circ_purpose specifies what sort of circuit we must have.
		* It can be C_GENERAL, C_INTRODUCING, or C_REND_JOINED.
		*
		* If it's REND_JOINED and must_be_open==0, then return the closest
		* rendezvous-purposed circuit that you can find.
		*
		* If circ_purpose is not GENERAL, then conn must be defined.
		/* Return 1 iff 'c' could be returned by circuit_get_best.
		*/
		circuit_t circuit_get_best(connection_t conn,
		int must_be_open, uint8_t purpose) {
		circuit_t circ, best=NULL;
		static int circuit_is_acceptable(circuit_t *circ,
		connection_t *conn,
		int must_be_open,
		uint8_t purpose,
		time_t now)
		{
		routerinfo_t *exitrouter;
		time_t now = time(NULL);

		assert(purpose == CIRCUIT_PURPOSE_C_GENERAL \|\|
		purpose == CIRCUIT_PURPOSE_C_INTRODUCING \|\|
		purpose == CIRCUIT_PURPOSE_C_REND_JOINED);

		for (circ=global_circuitlist;circ;circ = circ->next) {
		if (!circ->cpath)
		continue; /* this circ doesn't start at us */
		return 0; /* this circ doesn't start at us */
		if (must_be_open && (circ->state != CIRCUIT_STATE_OPEN \|\| !circ->n_conn))
		continue; /* ignore non-open circs */
		return 0; /* ignore non-open circs */
		if (circ->marked_for_close)
		continue;
		return 0;

		/* if this circ isn't our purpose, skip. */
		if(purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
		if(must_be_open && purpose != circ->purpose)
		continue;
		if(purpose == CIRCUIT_PURPOSE_C_REND_JOINED && !must_be_open) {
		if(circ->purpose != CIRCUIT_PURPOSE_C_ESTABLISH_REND &&
		circ->purpose != CIRCUIT_PURPOSE_C_REND_READY &&
		circ->purpose != CIRCUIT_PURPOSE_C_REND_JOINED)
		continue;
		return 0;
		} else {
		if(purpose != circ->purpose)
		continue;
		return 0;
		}

		if(purpose == CIRCUIT_PURPOSE_C_GENERAL)
		if(circ->timestamp_dirty &&
		circ->timestamp_dirty+options.NewCircuitPeriod < now)
		continue; /* too old */
		return 0;

		if(conn) {
		/* decide if this circ is suitable for this conn */
		@@ -316,53 +298,90 @@ circuit_t circuit_get_best(connection_t conn,

		if(!exitrouter) {
		log_fn(LOG_INFO,"Skipping broken circ (exit router vanished)");
		continue; /* this circuit is screwed and doesn't know it yet */
		return 0; /* this circuit is screwed and doesn't know it yet */
		}

		if(purpose == CIRCUIT_PURPOSE_C_GENERAL) {
		if(connection_ap_can_use_exit(conn, exitrouter) == ADDR_POLICY_REJECTED) {
		/* can't exit from this router */
		continue;
		return 0;
		}
		} else { /* not general */
		if(rend_cmp_service_ids(conn->rend_query, circ->rend_query)) {
		/* this circ is not for this conn */
		continue;
		return 0;
		}
		}
		}
		return 0;
		}

		/* now this is an acceptable circ to hand back. but that doesn't
		* mean it's the best circ to hand back. try to decide.
		/* Return 1 iff circuit 'a' is better than circuit 'b' for purpose. Used by
		* circuit_get_best
		*/
		if(!best)
		best = circ;
		static int circuit_is_better(circuit_t a, circuit_t b, uint8_t purpose)
		{
		switch(purpose) {
		case CIRCUIT_PURPOSE_C_GENERAL:
		/* if it's used but less dirty it's best;
		* else if it's more recently created it's best
		*/
		if(best->timestamp_dirty) {
		if(circ->timestamp_dirty &&
		circ->timestamp_dirty > best->timestamp_dirty)
		best = circ;
		if(b->timestamp_dirty) {
		if(a->timestamp_dirty &&
		a->timestamp_dirty > b->timestamp_dirty)
		return 1;
		} else {
		if(circ->timestamp_dirty \|\|
		circ->timestamp_created > best->timestamp_created)
		best = circ;
		if(a->timestamp_dirty \|\|
		a->timestamp_created > b->timestamp_created)
		return 1;
		}
		break;
		case CIRCUIT_PURPOSE_C_INTRODUCING:
		/* more recently created is best */
		if(circ->timestamp_created > best->timestamp_created)
		best = circ;
		if(a->timestamp_created > b->timestamp_created)
		return 1;
		break;
		case CIRCUIT_PURPOSE_C_REND_JOINED:
		/* the closer it is to rend_joined the better it is */
		if(circ->purpose > best->purpose)
		best = circ;
		if(a->purpose > b->purpose)
		return 1;
		break;
		}
		return 0;
		}

		/* Find the best circ that conn can use, preferably one which is
		* dirty. Circ must not be too old.
		* If !conn, return newest.
		*
		* If must_be_open, ignore circs not in CIRCUIT_STATE_OPEN.
		*
		* circ_purpose specifies what sort of circuit we must have.
		* It can be C_GENERAL, C_INTRODUCING, or C_REND_JOINED.
		*
		* If it's REND_JOINED and must_be_open==0, then return the closest
		* rendezvous-purposed circuit that you can find.
		*
		* If circ_purpose is not GENERAL, then conn must be defined.
		*/
		circuit_t circuit_get_best(connection_t conn,
		int must_be_open, uint8_t purpose) {
		circuit_t circ, best=NULL;
		time_t now = time(NULL);

		assert(purpose == CIRCUIT_PURPOSE_C_GENERAL \|\|
		purpose == CIRCUIT_PURPOSE_C_INTRODUCING \|\|
		purpose == CIRCUIT_PURPOSE_C_REND_JOINED);

		for (circ=global_circuitlist;circ;circ = circ->next) {
		if (!circuit_is_acceptable(circ,conn,must_be_open,purpose,now))
		continue;

		/* now this is an acceptable circ to hand back. but that doesn't
		* mean it's the best circ to hand back. try to decide.
		*/
		if(!best \|\| circuit_is_better(circ,best,purpose))
		best = circ;
		}

		return best;