use the smartlist to pick random routers, rather than our own idiom (c425f2e0) · Commits · Benjamin J. Thompson / Tor

src/or/onion.c

+36 −51

Original line number	Diff line number	Diff line
		@@ -223,7 +223,8 @@ static routerinfo_t choose_good_exit_server(routerlist_t dir)
		int best_support_idx = -1;
		int best_maybe_support_idx = -1;
		int n_best_support=0, n_best_maybe_support=0;
		int n_running_routers=0;
		smartlist_t *sl;
		routerinfo_t *router;

		get_connection_array(&carray, &n_connections);

		@@ -262,7 +263,6 @@ static routerinfo_t choose_good_exit_server(routerlist_t dir)
		continue; /* skip routers that reject all */
		}
		n_supported[i] = n_maybe_supported[i] = 0;
		++n_running_routers;
		for (j = 0; j < n_connections; ++j) { /* iterate over connections */
		if (carray[j]->type != CONN_TYPE_AP \|\|
		carray[j]->state != AP_CONN_STATE_CIRCUIT_WAIT \|\|
		@@ -314,63 +314,48 @@ static routerinfo_t choose_good_exit_server(routerlist_t dir)
		/* If any routers definitely support any pending connections, choose one
		* at random. */
		if (best_support > 0) {
		i = crypto_pseudo_rand_int(n_best_support);
		/* Iterate over the routers, until we find the i-th one such that
		* n_supported[j] == best_support
		*/
		for (j = best_support_idx; j < dir->n_routers; ++j) {
		if (n_supported[j] == best_support) {
		if (i)
		--i;
		else {
		sl = smartlist_create(MAX_ROUTERS_IN_DIR);
		for(i = best_support_idx; i < dir->n_routers; i++)
		if(n_supported[i] == best_support)
		smartlist_add(sl, dir->routers[i]);

		router = smartlist_choose(sl);
		smartlist_free(sl);
		tor_free(n_supported); tor_free(n_maybe_supported);
		log_fn(LOG_DEBUG, "Chose exit server '%s'", dir->routers[j]->nickname);
		return dir->routers[j];
		}
		}
		}
		/* This point should never be reached. */
		assert(0);
		log_fn(LOG_DEBUG, "Chose exit server '%s'", router->nickname);
		return router;
		}

		/* If any routers _maybe_ support pending connections, choose one at
		* random, as above. */
		if (best_maybe_support > 0) {
		i = crypto_pseudo_rand_int(n_best_maybe_support);
		for (j = best_maybe_support_idx; j < dir->n_routers; ++j) {
		if (n_maybe_supported[j] == best_maybe_support) {
		if (i)
		--i;
		else {
		sl = smartlist_create(MAX_ROUTERS_IN_DIR);
		for(i = best_maybe_support_idx; i < dir->n_routers; i++)
		if(n_maybe_supported[i] == best_maybe_support)
		smartlist_add(sl, dir->routers[i]);

		router = smartlist_choose(sl);
		smartlist_free(sl);
		tor_free(n_supported); tor_free(n_maybe_supported);
		log_fn(LOG_DEBUG, "Chose exit server '%s'", dir->routers[j]->nickname);
		return dir->routers[j];
		}
		}
		}
		/* This point should never be reached. */
		assert(0);
		log_fn(LOG_DEBUG, "Chose exit server '%s'", router->nickname);
		return router;
		}

		/* Either there are no pending connections, or no routers even seem to
		* possibly support any of them. Choose a router at random. */
		if (!n_running_routers) {
		log_fn(LOG_WARN, "No exit routers seem to be running; can't choose an exit.");
		return NULL;
		}
		/* Iterate over the routers, till we find the i'th one that has ->is_running
		* and allows exits. */
		i = crypto_pseudo_rand_int(n_running_routers);
		for (j = 0; j < dir->n_routers; ++j) {
		if (n_supported[j] != -1) {
		if (i)
		--i;
		else {
		sl = smartlist_create(MAX_ROUTERS_IN_DIR);
		for(i = best_maybe_support_idx; i < dir->n_routers; i++)
		if(n_supported[i] != -1)
		smartlist_add(sl, dir->routers[i]);

		router = smartlist_choose(sl);
		smartlist_free(sl);
		if(router) {
		tor_free(n_supported); tor_free(n_maybe_supported);
		log_fn(LOG_DEBUG, "Chose exit server '%s'", dir->routers[j]->nickname);
		return dir->routers[j];
		}
		log_fn(LOG_DEBUG, "Chose exit server '%s'", router->nickname);
		return router;
		}
		}
		assert(0);
		log_fn(LOG_WARN, "No exit routers seem to be running; can't choose an exit.");
		return NULL;
		}

src/or/routerlist.c

+28 −50

Original line number	Diff line number	Diff line
		@@ -94,22 +94,28 @@ static void router_release_token(directory_token_t *tok);


		/****************************************************************************/
		routerinfo_t *router_pick_directory_server(void) {

		/* pick a random running router with a positive dir_port */
		int i,j;
		routerinfo_t *router_pick_directory_server(void) {
		int i;
		routerinfo_t router, dirserver=NULL;
		int num_dirservers=0;
		smartlist_t *sl;

		if(!routerlist)
		return NULL;

		sl = smartlist_create(MAX_ROUTERS_IN_DIR);
		for(i=0;i<routerlist->n_routers;i++) {
		router = routerlist->routers[i];
		if(router->dir_port > 0 && router->is_running)
		num_dirservers++;
		smartlist_add(sl, router);
		}

		if(!num_dirservers) {
		router = smartlist_choose(sl);
		smartlist_free(sl);

		if(router)
		return router;
		log_fn(LOG_INFO,"No dirservers are reachable. Trying them all again.");
		/* no running dir servers found? go through and mark them all as up,
		* and we'll cycle through the list again. */
		@@ -123,51 +129,23 @@ routerinfo_t *router_pick_directory_server(void) {
		return dirserver;
		}

		j = crypto_pseudo_rand_int(num_dirservers);
		for (i=0;i<routerlist->n_routers;i++) {
		router = routerlist->routers[i];
		if (router->dir_port > 0 && router->is_running) {
		if (j)
		--j;
		else {
		log_fn(LOG_DEBUG, "Chose server '%s'", router->nickname);
		return router;
		}
		}
		}
		assert(0);
		return NULL;
		}

		routerinfo_t *router_pick_randomly_from_running(void) {
		int i,j;
		int num_running=0;
		int i;
		routerinfo_t *router;
		smartlist_t *sl;

		if(!routerlist)
		return NULL;

		for(i=0;i<routerlist->n_routers;i++) {
		sl = smartlist_create(MAX_ROUTERS_IN_DIR);
		for(i=0;i<routerlist->n_routers;i++)
		if(routerlist->routers[i]->is_running)
		num_running++;
		}
		smartlist_add(sl, routerlist->routers[i]);

		if(!num_running) {
		log_fn(LOG_INFO,"No routers are running. Returning NULL.");
		return NULL;
		}
		j = crypto_pseudo_rand_int(num_running);
		for (i=0;i<routerlist->n_routers;i++) {
		if (routerlist->routers[i]->is_running) {
		if (j)
		--j;
		else {
		log_fn(LOG_DEBUG, "Chose server '%s'", routerlist->routers[i]->nickname);
		return routerlist->routers[i];
		}
		}
		}
		assert(0);
		return NULL;
		router = smartlist_choose(sl);
		smartlist_free(sl);
		log_fn(LOG_DEBUG, "Chose server '%s'", router ? router->nickname : "<none>");
		return router;
		}

		routerinfo_t *router_get_by_addr_port(uint32_t addr, uint16_t port) {