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Diffstat (limited to 'src/feature/control/btrack_orconn.c')
-rw-r--r-- | src/feature/control/btrack_orconn.c | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/src/feature/control/btrack_orconn.c b/src/feature/control/btrack_orconn.c new file mode 100644 index 0000000000..104c8af230 --- /dev/null +++ b/src/feature/control/btrack_orconn.c @@ -0,0 +1,206 @@ +/* Copyright (c) 2007-2020, 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(); +} |