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- /* Copyright (c) 2007-2019, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- /**
- * \file btrack_orconn.c
- * \brief Bootstrap tracker for OR connections
- *
- * Track state changes of OR connections, as published by the
- * connection subsystem. Also track circuit launch events, because
- * they're one of the few ways to discover the association between a
- * channel (and OR connection) and a circuit.
- *
- * We track all OR connections that we receive events for, whether or
- * not they're carrying origin circuits. (An OR connection might
- * carry origin circuits only after we first find out about that
- * connection.)
- *
- * All origin ORCONN events update the "any" state variables, while
- * only application ORCONN events update the "ap" state variables (and
- * also update the "any") variables.
- *
- * We do this because we want to report the first increments of
- * connection progress as the earliest bootstrap phases. This results
- * in a better user experience because failures here translate into
- * zero or very small amounts of displayed progress, instead of
- * progress stuck near completion. The first connection to a relay
- * might be a one-hop circuit for directory lookups, or it might be a
- * connection for an application circuit because we already have
- * enough directory info to build an application circuit.
- *
- * We call functions in btrack_orconn_cevent.c to generate the actual
- * controller events, because some of the state decoding we need to do
- * is complicated.
- **/
- #include <stdbool.h>
- #include "core/or/or.h"
- #define BTRACK_ORCONN_PRIVATE
- #include "core/or/ocirc_event.h"
- #include "core/or/orconn_event.h"
- #include "feature/control/btrack_orconn.h"
- #include "feature/control/btrack_orconn_cevent.h"
- #include "feature/control/btrack_orconn_maps.h"
- #include "lib/log/log.h"
- #include "lib/pubsub/pubsub.h"
- DECLARE_SUBSCRIBE(orconn_state, bto_state_rcvr);
- DECLARE_SUBSCRIBE(orconn_status, bto_status_rcvr);
- DECLARE_SUBSCRIBE(ocirc_chan, bto_chan_rcvr);
- /** Pair of a best ORCONN GID and with its state */
- typedef struct bto_best_t {
- uint64_t gid;
- int state;
- } bto_best_t;
- /** GID and state of the best ORCONN we've seen so far */
- static bto_best_t best_any = { 0, -1 };
- /** GID and state of the best application circuit ORCONN we've seen so far */
- static bto_best_t best_ap = { 0, -1 };
- /**
- * Update a cached state of a best ORCONN progress we've seen so far.
- *
- * Return true if the new state is better than the old.
- **/
- static bool
- bto_update_best(const bt_orconn_t *bto, bto_best_t *best, const char *type)
- {
- if (bto->state < best->state)
- return false;
- /* Update even if we won't change best->state, because it's more
- * recent information that a particular connection transitioned to
- * that state. */
- best->gid = bto->gid;
- if (bto->state > best->state) {
- log_info(LD_BTRACK, "ORCONN BEST_%s state %d->%d gid=%"PRIu64, type,
- best->state, bto->state, bto->gid);
- best->state = bto->state;
- return true;
- }
- return false;
- }
- /**
- * Update cached states of best ORCONN progress we've seen
- *
- * Only update the application ORCONN state if we know it's carrying
- * an application circuit.
- **/
- static void
- bto_update_bests(const bt_orconn_t *bto)
- {
- tor_assert(bto->is_orig);
- if (bto_update_best(bto, &best_any, "ANY"))
- bto_cevent_anyconn(bto);
- if (!bto->is_onehop && bto_update_best(bto, &best_ap, "AP"))
- bto_cevent_apconn(bto);
- }
- /** Reset cached "best" values */
- static void
- bto_reset_bests(void)
- {
- best_any.gid = best_ap.gid = 0;
- best_any.state = best_ap.state = -1;
- }
- /**
- * Update cached states of ORCONNs from the incoming message. This
- * message comes from code in connection_or.c.
- **/
- static void
- bto_state_rcvr(const msg_t *msg, const orconn_state_msg_t *arg)
- {
- bt_orconn_t *bto;
- (void)msg;
- bto = bto_find_or_new(arg->gid, arg->chan);
- log_debug(LD_BTRACK, "ORCONN gid=%"PRIu64" chan=%"PRIu64
- " proxy_type=%d state=%d",
- arg->gid, arg->chan, arg->proxy_type, arg->state);
- bto->proxy_type = arg->proxy_type;
- bto->state = arg->state;
- if (bto->is_orig)
- bto_update_bests(bto);
- }
- /**
- * Delete a cached ORCONN state if we get an incoming message saying
- * the ORCONN is failed or closed. This message comes from code in
- * control.c.
- **/
- static void
- bto_status_rcvr(const msg_t *msg, const orconn_status_msg_t *arg)
- {
- (void)msg;
- switch (arg->status) {
- case OR_CONN_EVENT_FAILED:
- case OR_CONN_EVENT_CLOSED:
- log_info(LD_BTRACK, "ORCONN DELETE gid=%"PRIu64" status=%d reason=%d",
- arg->gid, arg->status, arg->reason);
- return bto_delete(arg->gid);
- default:
- break;
- }
- }
- /**
- * Create or update a cached ORCONN state for a newly launched
- * connection, including whether it's launched by an origin circuit
- * and whether it's a one-hop circuit.
- **/
- static void
- bto_chan_rcvr(const msg_t *msg, const ocirc_chan_msg_t *arg)
- {
- bt_orconn_t *bto;
- (void)msg;
- bto = bto_find_or_new(0, arg->chan);
- if (!bto->is_orig || (bto->is_onehop && !arg->onehop)) {
- log_debug(LD_BTRACK, "ORCONN LAUNCH chan=%"PRIu64" onehop=%d",
- arg->chan, arg->onehop);
- }
- bto->is_orig = true;
- if (!arg->onehop)
- bto->is_onehop = false;
- bto_update_bests(bto);
- }
- /**
- * Initialize the hash maps and subscribe to ORCONN and origin
- * circuit events.
- **/
- int
- btrack_orconn_init(void)
- {
- bto_init_maps();
- return 0;
- }
- int
- btrack_orconn_add_pubsub(pubsub_connector_t *connector)
- {
- if (DISPATCH_ADD_SUB(connector, orconn, orconn_state))
- return -1;
- if (DISPATCH_ADD_SUB(connector, orconn, orconn_status))
- return -1;
- if (DISPATCH_ADD_SUB(connector, ocirc, ocirc_chan))
- return -1;
- return 0;
- }
- /** Clear the hash maps and reset the "best" states */
- void
- btrack_orconn_fini(void)
- {
- bto_clear_maps();
- bto_reset_bests();
- bto_cevent_reset();
- }
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