/* * Copyright (c) 2012, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /** * \file channel.c * \brief OR-to-OR channel abstraction layer **/ /* * Define this so channel.h gives us things only channel_t subclasses * should touch. */ #define TOR_CHANNEL_INTERNAL_ #include "or.h" #include "channel.h" #include "channeltls.h" #include "circuitbuild.h" #include "circuitlist.h" #include "connection_or.h" /* For var_cell_free() */ #include "circuitmux.h" #include "geoip.h" #include "nodelist.h" #include "relay.h" #include "rephist.h" #include "router.h" #include "routerlist.h" /* Cell queue structure */ typedef struct cell_queue_entry_s cell_queue_entry_t; struct cell_queue_entry_s { enum { CELL_QUEUE_FIXED, CELL_QUEUE_VAR, CELL_QUEUE_PACKED } type; union { struct { cell_t *cell; } fixed; struct { var_cell_t *var_cell; } var; struct { packed_cell_t *packed_cell; } packed; } u; }; /* Global lists of channels */ /* All channel_t instances */ static smartlist_t *all_channels = NULL; /* All channel_t instances not in ERROR or CLOSED states */ static smartlist_t *active_channels = NULL; /* All channel_t instances in ERROR or CLOSED states */ static smartlist_t *finished_channels = NULL; /* All channel_listener_t instances */ static smartlist_t *all_listeners = NULL; /* All channel_listener_t instances in LISTENING state */ static smartlist_t *active_listeners = NULL; /* All channel_listener_t instances in LISTENING state */ static smartlist_t *finished_listeners = NULL; /* Counter for ID numbers */ static uint64_t n_channels_allocated = 0; /* Digest->channel map * * Similar to the one used in connection_or.c, this maps from the identity * digest of a remote endpoint to a channel_t to that endpoint. Channels * should be placed here when registered and removed when they close or error. * If more than one channel exists, follow the next_with_same_id pointer * as a linked list. */ static digestmap_t *channel_identity_map = NULL; static cell_queue_entry_t * cell_queue_entry_dup(cell_queue_entry_t *q); static void cell_queue_entry_free(cell_queue_entry_t *q, int handed_off); static int cell_queue_entry_is_padding(cell_queue_entry_t *q); static cell_queue_entry_t * cell_queue_entry_new_fixed(cell_t *cell); static cell_queue_entry_t * cell_queue_entry_new_var(var_cell_t *var_cell); /* Functions to maintain the digest map */ static void channel_add_to_digest_map(channel_t *chan); static void channel_remove_from_digest_map(channel_t *chan); /* * Flush cells from just the outgoing queue without trying to get them * from circuits; used internall by channel_flush_some_cells(). */ static ssize_t channel_flush_some_cells_from_outgoing_queue(channel_t *chan, ssize_t num_cells); static void channel_force_free(channel_t *chan); static void channel_free_list(smartlist_t *channels, int mark_for_close); static void channel_listener_free_list(smartlist_t *channels, int mark_for_close); static void channel_listener_force_free(channel_listener_t *chan_l); static void channel_write_cell_queue_entry(channel_t *chan, cell_queue_entry_t *q); /*********************************** * Channel state utility functions * **********************************/ /** * Indicate whether a given channel state is valid */ int channel_state_is_valid(channel_state_t state) { int is_valid; switch (state) { case CHANNEL_STATE_CLOSED: case CHANNEL_STATE_CLOSING: case CHANNEL_STATE_ERROR: case CHANNEL_STATE_MAINT: case CHANNEL_STATE_OPENING: case CHANNEL_STATE_OPEN: is_valid = 1; break; case CHANNEL_STATE_LAST: default: is_valid = 0; } return is_valid; } /** * Indicate whether a given channel listener state is valid */ int channel_listener_state_is_valid(channel_listener_state_t state) { int is_valid; switch (state) { case CHANNEL_LISTENER_STATE_CLOSED: case CHANNEL_LISTENER_STATE_LISTENING: case CHANNEL_LISTENER_STATE_CLOSING: case CHANNEL_LISTENER_STATE_ERROR: is_valid = 1; break; case CHANNEL_LISTENER_STATE_LAST: default: is_valid = 0; } return is_valid; } /** * Indicate whether a channel state transition is valid * * This function takes two channel states and indicates whether a * transition between them is permitted (see the state definitions and * transition table in or.h at the channel_state_t typedef). */ int channel_state_can_transition(channel_state_t from, channel_state_t to) { int is_valid; switch (from) { case CHANNEL_STATE_CLOSED: is_valid = (to == CHANNEL_STATE_OPENING); break; case CHANNEL_STATE_CLOSING: is_valid = (to == CHANNEL_STATE_CLOSED || to == CHANNEL_STATE_ERROR); break; case CHANNEL_STATE_ERROR: is_valid = 0; break; case CHANNEL_STATE_MAINT: is_valid = (to == CHANNEL_STATE_CLOSING || to == CHANNEL_STATE_ERROR || to == CHANNEL_STATE_OPEN); break; case CHANNEL_STATE_OPENING: is_valid = (to == CHANNEL_STATE_CLOSING || to == CHANNEL_STATE_ERROR || to == CHANNEL_STATE_OPEN); break; case CHANNEL_STATE_OPEN: is_valid = (to == CHANNEL_STATE_CLOSING || to == CHANNEL_STATE_ERROR || to == CHANNEL_STATE_MAINT); break; case CHANNEL_STATE_LAST: default: is_valid = 0; } return is_valid; } /** * Indicate whether a channel listener state transition is valid * * This function takes two channel listener states and indicates whether a * transition between them is permitted (see the state definitions and * transition table in or.h at the channel_listener_state_t typedef). */ int channel_listener_state_can_transition(channel_listener_state_t from, channel_listener_state_t to) { int is_valid; switch (from) { case CHANNEL_LISTENER_STATE_CLOSED: is_valid = (to == CHANNEL_LISTENER_STATE_LISTENING); break; case CHANNEL_LISTENER_STATE_CLOSING: is_valid = (to == CHANNEL_LISTENER_STATE_CLOSED || to == CHANNEL_LISTENER_STATE_ERROR); break; case CHANNEL_LISTENER_STATE_ERROR: is_valid = 0; break; case CHANNEL_LISTENER_STATE_LISTENING: is_valid = (to == CHANNEL_LISTENER_STATE_CLOSING || to == CHANNEL_LISTENER_STATE_ERROR); break; case CHANNEL_LISTENER_STATE_LAST: default: is_valid = 0; } return is_valid; } /** * Return a human-readable description for a channel state */ const char * channel_state_to_string(channel_state_t state) { const char *descr; switch (state) { case CHANNEL_STATE_CLOSED: descr = "closed"; break; case CHANNEL_STATE_CLOSING: descr = "closing"; break; case CHANNEL_STATE_ERROR: descr = "channel error"; break; case CHANNEL_STATE_MAINT: descr = "temporarily suspended for maintenance"; break; case CHANNEL_STATE_OPENING: descr = "opening"; break; case CHANNEL_STATE_OPEN: descr = "open"; break; case CHANNEL_STATE_LAST: default: descr = "unknown or invalid channel state"; } return descr; } /** * Return a human-readable description for a channel listenier state */ const char * channel_listener_state_to_string(channel_listener_state_t state) { const char *descr; switch (state) { case CHANNEL_LISTENER_STATE_CLOSED: descr = "closed"; break; case CHANNEL_LISTENER_STATE_CLOSING: descr = "closing"; break; case CHANNEL_LISTENER_STATE_ERROR: descr = "channel listener error"; break; case CHANNEL_LISTENER_STATE_LISTENING: descr = "listening"; break; case CHANNEL_LISTENER_STATE_LAST: default: descr = "unknown or invalid channel listener state"; } return descr; } /*************************************** * Channel registration/unregistration * ***************************************/ /** * Register a channel * * This function registers a newly created channel in the global lists/maps * of active channels. */ void channel_register(channel_t *chan) { tor_assert(chan); /* No-op if already registered */ if (chan->registered) return; log_debug(LD_CHANNEL, "Registering channel %p (ID " U64_FORMAT ") " "in state %s (%d) with digest %s", chan, U64_PRINTF_ARG(chan->global_identifier), channel_state_to_string(chan->state), chan->state, hex_str(chan->identity_digest, DIGEST_LEN)); /* Make sure we have all_channels, then add it */ if (!all_channels) all_channels = smartlist_new(); smartlist_add(all_channels, chan); /* Is it finished? */ if (chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) { /* Put it in the finished list, creating it if necessary */ if (!finished_channels) finished_channels = smartlist_new(); smartlist_add(finished_channels, chan); } else { /* Put it in the active list, creating it if necessary */ if (!active_channels) active_channels = smartlist_new(); smartlist_add(active_channels, chan); if (chan->state != CHANNEL_STATE_CLOSING) { /* It should have a digest set */ if (!tor_digest_is_zero(chan->identity_digest)) { /* Yeah, we're good, add it to the map */ channel_add_to_digest_map(chan); } else { log_info(LD_CHANNEL, "Channel %p (global ID " U64_FORMAT ") " "in state %s (%d) registered with no identity digest", chan, U64_PRINTF_ARG(chan->global_identifier), channel_state_to_string(chan->state), chan->state); } } } /* Mark it as registered */ chan->registered = 1; } /** * Unregister a channel * * This function removes a channel from the global lists and maps and is used * when freeing a closed/errored channel. */ void channel_unregister(channel_t *chan) { tor_assert(chan); /* No-op if not registered */ if (!(chan->registered)) return; /* Is it finished? */ if (chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) { /* Get it out of the finished list */ if (finished_channels) smartlist_remove(finished_channels, chan); } else { /* Get it out of the active list */ if (active_channels) smartlist_remove(active_channels, chan); } /* Get it out of all_channels */ if (all_channels) smartlist_remove(all_channels, chan); /* Mark it as unregistered */ chan->registered = 0; /* Should it be in the digest map? */ if (!tor_digest_is_zero(chan->identity_digest) && !(chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR)) { /* Remove it */ channel_remove_from_digest_map(chan); } } /** * Register a channel listener * * This function registers a newly created channel listner in the global * lists/maps of active channel listeners. */ void channel_listener_register(channel_listener_t *chan_l) { tor_assert(chan_l); /* No-op if already registered */ if (chan_l->registered) return; log_debug(LD_CHANNEL, "Registering channel listener %p (ID " U64_FORMAT ") " "in state %s (%d)", chan_l, U64_PRINTF_ARG(chan_l->global_identifier), channel_listener_state_to_string(chan_l->state), chan_l->state); /* Make sure we have all_channels, then add it */ if (!all_listeners) all_listeners = smartlist_new(); smartlist_add(all_listeners, chan_l); /* Is it finished? */ if (chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR) { /* Put it in the finished list, creating it if necessary */ if (!finished_listeners) finished_listeners = smartlist_new(); smartlist_add(finished_listeners, chan_l); } else { /* Put it in the active list, creating it if necessary */ if (!active_listeners) active_listeners = smartlist_new(); smartlist_add(active_listeners, chan_l); } /* Mark it as registered */ chan_l->registered = 1; } /** * Unregister a channel listener * * This function removes a channel listener from the global lists and maps * and is used when freeing a closed/errored channel listener. */ void channel_listener_unregister(channel_listener_t *chan_l) { tor_assert(chan_l); /* No-op if not registered */ if (!(chan_l->registered)) return; /* Is it finished? */ if (chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR) { /* Get it out of the finished list */ if (finished_listeners) smartlist_remove(finished_listeners, chan_l); } else { /* Get it out of the active list */ if (active_listeners) smartlist_remove(active_listeners, chan_l); } /* Get it out of all_channels */ if (all_listeners) smartlist_remove(all_listeners, chan_l); /* Mark it as unregistered */ chan_l->registered = 0; } /********************************* * Channel digest map maintenance *********************************/ /** * Add a channel to the digest map * * This function adds a channel to the digest map and inserts it into the * correct linked list if channels with that remote endpoint identity digest * already exist. */ static void channel_add_to_digest_map(channel_t *chan) { channel_t *tmp; tor_assert(chan); /* Assert that the state makes sense */ tor_assert(!(chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR)); /* Assert that there is a digest */ tor_assert(!tor_digest_is_zero(chan->identity_digest)); /* Allocate the identity map if we have to */ if (!channel_identity_map) channel_identity_map = digestmap_new(); /* Insert it */ tmp = digestmap_set(channel_identity_map, chan->identity_digest, chan); if (tmp) { /* There already was one, this goes at the head of the list */ chan->next_with_same_id = tmp; chan->prev_with_same_id = NULL; tmp->prev_with_same_id = chan; } else { /* First with this digest */ chan->next_with_same_id = NULL; chan->prev_with_same_id = NULL; } log_debug(LD_CHANNEL, "Added channel %p (global ID " U64_FORMAT ") " "to identity map in state %s (%d) with digest %s", chan, U64_PRINTF_ARG(chan->global_identifier), channel_state_to_string(chan->state), chan->state, hex_str(chan->identity_digest, DIGEST_LEN)); } /** * Remove a channel from the digest map * * This function removes a channel from the digest map and the linked list of * channels for that digest if more than one exists. */ static void channel_remove_from_digest_map(channel_t *chan) { channel_t *tmp; tor_assert(chan); /* Assert that there is a digest */ tor_assert(!tor_digest_is_zero(chan->identity_digest)); /* Make sure we have a map */ if (!channel_identity_map) { /* * No identity map, so we can't find it by definition. This * case is similar to digestmap_get() failing below. */ log_warn(LD_BUG, "Trying to remove channel %p (global ID " U64_FORMAT ") " "with digest %s from identity map, but didn't have any identity " "map", chan, U64_PRINTF_ARG(chan->global_identifier), hex_str(chan->identity_digest, DIGEST_LEN)); /* Clear out its next/prev pointers */ if (chan->next_with_same_id) { chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id; } if (chan->prev_with_same_id) { chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id; } chan->next_with_same_id = NULL; chan->prev_with_same_id = NULL; return; } /* Look for it in the map */ tmp = digestmap_get(channel_identity_map, chan->identity_digest); if (tmp) { /* Okay, it's here */ /* Look for this channel */ while (tmp && tmp != chan) { tmp = tmp->next_with_same_id; } if (tmp == chan) { /* Found it, good */ if (chan->next_with_same_id) { chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id; } /* else we're the tail of the list */ if (chan->prev_with_same_id) { /* We're not the head of the list, so we can *just* unlink */ chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id; } else { /* We're the head, so we have to point the digest map entry at our * next if we have one, or remove it if we're also the tail */ if (chan->next_with_same_id) { digestmap_set(channel_identity_map, chan->identity_digest, chan->next_with_same_id); } else { digestmap_remove(channel_identity_map, chan->identity_digest); } } /* NULL out its next/prev pointers, and we're finished */ chan->next_with_same_id = NULL; chan->prev_with_same_id = NULL; log_debug(LD_CHANNEL, "Removed channel %p (global ID " U64_FORMAT ") from " "identity map in state %s (%d) with digest %s", chan, U64_PRINTF_ARG(chan->global_identifier), channel_state_to_string(chan->state), chan->state, hex_str(chan->identity_digest, DIGEST_LEN)); } else { /* This is not good */ log_warn(LD_BUG, "Trying to remove channel %p (global ID " U64_FORMAT ") " "with digest %s from identity map, but couldn't find it in " "the list for that digest", chan, U64_PRINTF_ARG(chan->global_identifier), hex_str(chan->identity_digest, DIGEST_LEN)); /* Unlink it and hope for the best */ if (chan->next_with_same_id) { chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id; } if (chan->prev_with_same_id) { chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id; } chan->next_with_same_id = NULL; chan->prev_with_same_id = NULL; } } else { /* Shouldn't happen */ log_warn(LD_BUG, "Trying to remove channel %p (global ID " U64_FORMAT ") with " "digest %s from identity map, but couldn't find any with " "that digest", chan, U64_PRINTF_ARG(chan->global_identifier), hex_str(chan->identity_digest, DIGEST_LEN)); /* Clear out its next/prev pointers */ if (chan->next_with_same_id) { chan->next_with_same_id->prev_with_same_id = chan->prev_with_same_id; } if (chan->prev_with_same_id) { chan->prev_with_same_id->next_with_same_id = chan->next_with_same_id; } chan->next_with_same_id = NULL; chan->prev_with_same_id = NULL; } } /**************************** * Channel lookup functions * ***************************/ /** * Find channel by global ID * * This function searches for a channel by the global_identifier assigned * at initialization time. This identifier is unique for the lifetime of the * Tor process. */ channel_t * channel_find_by_global_id(uint64_t global_identifier) { channel_t *rv = NULL; if (all_channels && smartlist_len(all_channels) > 0) { SMARTLIST_FOREACH_BEGIN(all_channels, channel_t *, curr) { if (curr->global_identifier == global_identifier) { rv = curr; break; } } SMARTLIST_FOREACH_END(curr); } return rv; } /** * Find channel by digest of the remote endpoint * * This function looks up a channel by the digest of its remote endpoint in * the channel digest map. It's possible that more than one channel to a * given endpoint exists. Use channel_next_with_digest() and * channel_prev_with_digest() to walk the list. */ channel_t * channel_find_by_remote_digest(const char *identity_digest) { channel_t *rv = NULL; tor_assert(identity_digest); /* Search for it in the identity map */ if (channel_identity_map) { rv = digestmap_get(channel_identity_map, identity_digest); } return rv; } /** * Get next channel with digest * * This function takes a channel and finds the next channel in the list * with the same digest. */ channel_t * channel_next_with_digest(channel_t *chan) { tor_assert(chan); return chan->next_with_same_id; } /** * Get previous channel with digest * * This function takes a channel and finds the previos channel in the list * with the same digest. */ channel_t * channel_prev_with_digest(channel_t *chan) { tor_assert(chan); return chan->prev_with_same_id; } /** * Initialize a channel * * This function should be called by subclasses to set up some per-channel * variables. I.e., this is the superclass constructor. Before this, the * channel should be allocated with tor_malloc_zero(). */ void channel_init(channel_t *chan) { tor_assert(chan); /* Assign an ID and bump the counter */ chan->global_identifier = n_channels_allocated++; /* Init timestamp */ chan->timestamp_last_added_nonpadding = time(NULL); /* Init next_circ_id */ chan->next_circ_id = crypto_rand_int(1 << 15); /* Timestamp it */ channel_timestamp_created(chan); } /** * Initialize a channel listener * * This function should be called by subclasses to set up some per-channel * variables. I.e., this is the superclass constructor. Before this, the * channel listener should be allocated with tor_malloc_zero(). */ void channel_init_listener(channel_listener_t *chan_l) { tor_assert(chan_l); /* Assign an ID and bump the counter */ chan_l->global_identifier = n_channels_allocated++; /* Timestamp it */ channel_listener_timestamp_created(chan_l); } /** * Free a channel; nothing outside of channel.c and subclasses should call * this - it frees channels after they have closed and been unregistered. */ void channel_free(channel_t *chan) { if (!chan) return; /* It must be closed or errored */ tor_assert(chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR); /* It must be deregistered */ tor_assert(!(chan->registered)); log_debug(LD_CHANNEL, "Freeing channel " U64_FORMAT " at %p", U64_PRINTF_ARG(chan->global_identifier), chan); /* * Get rid of cmux policy before we do anything, so cmux policies don't * see channels in weird half-freed states. */ if (chan->cmux) { circuitmux_set_policy(chan->cmux, NULL); } /* Call a free method if there is one */ if (chan->free) chan->free(chan); channel_clear_remote_end(chan); /* Get rid of cmux */ if (chan->cmux) { circuitmux_detach_all_circuits(chan->cmux); circuitmux_free(chan->cmux); chan->cmux = NULL; } /* We're in CLOSED or ERROR, so the cell queue is already empty */ tor_free(chan); } /** * Free a channel listener; nothing outside of channel.c and subclasses * should call this - it frees channel listeners after they have closed and * been unregistered. */ void channel_listener_free(channel_listener_t *chan_l) { if (!chan_l) return; log_debug(LD_CHANNEL, "Freeing channel_listener_t " U64_FORMAT " at %p", U64_PRINTF_ARG(chan_l->global_identifier), chan_l); /* It must be closed or errored */ tor_assert(chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR); /* It must be deregistered */ tor_assert(!(chan_l->registered)); /* Call a free method if there is one */ if (chan_l->free) chan_l->free(chan_l); /* * We're in CLOSED or ERROR, so the incoming channel queue is already * empty. */ tor_free(chan_l); } /** * Free a channel and skip the state/registration asserts; this internal- * use-only function should be called only from channel_free_all() when * shutting down the Tor process. */ static void channel_force_free(channel_t *chan) { tor_assert(chan); log_debug(LD_CHANNEL, "Force-freeing channel " U64_FORMAT " at %p", U64_PRINTF_ARG(chan->global_identifier), chan); /* * Get rid of cmux policy before we do anything, so cmux policies don't * see channels in weird half-freed states. */ if (chan->cmux) { circuitmux_set_policy(chan->cmux, NULL); } /* Call a free method if there is one */ if (chan->free) chan->free(chan); channel_clear_remote_end(chan); /* Get rid of cmux */ if (chan->cmux) { circuitmux_free(chan->cmux); chan->cmux = NULL; } /* We might still have a cell queue; kill it */ if (chan->incoming_queue) { SMARTLIST_FOREACH_BEGIN(chan->incoming_queue, cell_queue_entry_t *, q) { cell_queue_entry_free(q, 0); } SMARTLIST_FOREACH_END(q); smartlist_free(chan->incoming_queue); chan->incoming_queue = NULL; } /* Outgoing cell queue is similar, but we can have to free packed cells */ if (chan->outgoing_queue) { SMARTLIST_FOREACH_BEGIN(chan->outgoing_queue, cell_queue_entry_t *, q) { cell_queue_entry_free(q, 0); } SMARTLIST_FOREACH_END(q); smartlist_free(chan->outgoing_queue); chan->outgoing_queue = NULL; } tor_free(chan); } /** * Free a channel listener and skip the state/reigstration asserts; this * internal-use-only function should be called only from channel_free_all() * when shutting down the Tor process. */ static void channel_listener_force_free(channel_listener_t *chan_l) { tor_assert(chan_l); log_debug(LD_CHANNEL, "Force-freeing channel_listener_t " U64_FORMAT " at %p", U64_PRINTF_ARG(chan_l->global_identifier), chan_l); /* Call a free method if there is one */ if (chan_l->free) chan_l->free(chan_l); /* * The incoming list just gets emptied and freed; we request close on * any channels we find there, but since we got called while shutting * down they will get deregistered and freed elsewhere anyway. */ if (chan_l->incoming_list) { SMARTLIST_FOREACH_BEGIN(chan_l->incoming_list, channel_t *, qchan) { channel_mark_for_close(qchan); } SMARTLIST_FOREACH_END(qchan); smartlist_free(chan_l->incoming_list); chan_l->incoming_list = NULL; } tor_free(chan_l); } /** * Return the current registered listener for a channel listener * * This function returns a function pointer to the current registered * handler for new incoming channels on a channel listener. */ channel_listener_fn_ptr channel_listener_get_listener_fn(channel_listener_t *chan_l) { tor_assert(chan_l); if (chan_l->state == CHANNEL_LISTENER_STATE_LISTENING) return chan_l->listener; return NULL; } /** * Set the listener for a channel listener * * This function sets the handler for new incoming channels on a channel * listener. */ void channel_listener_set_listener_fn(channel_listener_t *chan_l, channel_listener_fn_ptr listener) { tor_assert(chan_l); tor_assert(chan_l->state == CHANNEL_LISTENER_STATE_LISTENING); log_debug(LD_CHANNEL, "Setting listener callback for channel listener %p " "(global ID " U64_FORMAT ") to %p", chan_l, U64_PRINTF_ARG(chan_l->global_identifier), listener); chan_l->listener = listener; if (chan_l->listener) channel_listener_process_incoming(chan_l); } /** * Return the fixed-length cell handler for a channel * * This function gets the handler for incoming fixed-length cells installed * on a channel. */ channel_cell_handler_fn_ptr channel_get_cell_handler(channel_t *chan) { tor_assert(chan); if (chan->state == CHANNEL_STATE_OPENING || chan->state == CHANNEL_STATE_OPEN || chan->state == CHANNEL_STATE_MAINT) return chan->cell_handler; return NULL; } /** * Return the variable-length cell handler for a channel * * This function gets the handler for incoming variable-length cells * installed on a channel. */ channel_var_cell_handler_fn_ptr channel_get_var_cell_handler(channel_t *chan) { tor_assert(chan); if (chan->state == CHANNEL_STATE_OPENING || chan->state == CHANNEL_STATE_OPEN || chan->state == CHANNEL_STATE_MAINT) return chan->var_cell_handler; return NULL; } /** * Set both cell handlers for a channel * * This function sets both the fixed-length and variable length cell handlers * for a channel and processes any incoming cells that had been blocked in the * queue because none were available. */ void channel_set_cell_handlers(channel_t *chan, channel_cell_handler_fn_ptr cell_handler, channel_var_cell_handler_fn_ptr var_cell_handler) { int try_again = 0; tor_assert(chan); tor_assert(chan->state == CHANNEL_STATE_OPENING || chan->state == CHANNEL_STATE_OPEN || chan->state == CHANNEL_STATE_MAINT); log_debug(LD_CHANNEL, "Setting cell_handler callback for channel %p to %p", chan, cell_handler); log_debug(LD_CHANNEL, "Setting var_cell_handler callback for channel %p to %p", chan, var_cell_handler); /* Should we try the queue? */ if (cell_handler && cell_handler != chan->cell_handler) try_again = 1; if (var_cell_handler && var_cell_handler != chan->var_cell_handler) try_again = 1; /* Change them */ chan->cell_handler = cell_handler; chan->var_cell_handler = var_cell_handler; /* Re-run the queue if we have one and there's any reason to */ if (chan->incoming_queue && (smartlist_len(chan->incoming_queue) > 0) && try_again && (chan->cell_handler || chan->var_cell_handler)) channel_process_cells(chan); } /** * Mark a channel for closure * * This function tries to close a channel_t; it will go into the CLOSING * state, and eventually the lower layer should put it into the CLOSED or * ERROR state. Then, channel_run_cleanup() will eventually free it. */ void channel_mark_for_close(channel_t *chan) { tor_assert(chan != NULL); tor_assert(chan->close != NULL); /* If it's already in CLOSING, CLOSED or ERROR, this is a no-op */ if (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) return; log_debug(LD_CHANNEL, "Closing channel %p (global ID " U64_FORMAT ") " "by request", chan, U64_PRINTF_ARG(chan->global_identifier)); /* Note closing by request from above */ chan->reason_for_closing = CHANNEL_CLOSE_REQUESTED; /* Change state to CLOSING */ channel_change_state(chan, CHANNEL_STATE_CLOSING); /* Tell the lower layer */ chan->close(chan); /* * It's up to the lower layer to change state to CLOSED or ERROR when we're * ready; we'll try to free channels that are in the finished list from * channel_run_cleanup(). The lower layer should do this by calling * channel_closed(). */ } /** * Mark a channel listener for closure * * This function tries to close a channel_listener_t; it will go into the * CLOSING state, and eventually the lower layer should put it into the CLOSED * or ERROR state. Then, channel_run_cleanup() will eventually free it. */ void channel_listener_mark_for_close(channel_listener_t *chan_l) { tor_assert(chan_l != NULL); tor_assert(chan_l->close != NULL); /* If it's already in CLOSING, CLOSED or ERROR, this is a no-op */ if (chan_l->state == CHANNEL_LISTENER_STATE_CLOSING || chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR) return; log_debug(LD_CHANNEL, "Closing channel listener %p (global ID " U64_FORMAT ") " "by request", chan_l, U64_PRINTF_ARG(chan_l->global_identifier)); /* Note closing by request from above */ chan_l->reason_for_closing = CHANNEL_LISTENER_CLOSE_REQUESTED; /* Change state to CLOSING */ channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSING); /* Tell the lower layer */ chan_l->close(chan_l); /* * It's up to the lower layer to change state to CLOSED or ERROR when we're * ready; we'll try to free channels that are in the finished list from * channel_run_cleanup(). The lower layer should do this by calling * channel_listener_closed(). */ } /** * Close a channel from the lower layer * * Notify the channel code that the channel is being closed due to a non-error * condition in the lower layer. This does not call the close() method, since * the lower layer already knows. */ void channel_close_from_lower_layer(channel_t *chan) { tor_assert(chan != NULL); /* If it's already in CLOSING, CLOSED or ERROR, this is a no-op */ if (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) return; log_debug(LD_CHANNEL, "Closing channel %p (global ID " U64_FORMAT ") " "due to lower-layer event", chan, U64_PRINTF_ARG(chan->global_identifier)); /* Note closing by event from below */ chan->reason_for_closing = CHANNEL_CLOSE_FROM_BELOW; /* Change state to CLOSING */ channel_change_state(chan, CHANNEL_STATE_CLOSING); } /** * Close a channel listener from the lower layer * * Notify the channel code that the channel listener is being closed due to a * non-error condition in the lower layer. This does not call the close() * method, since the lower layer already knows. */ void channel_listener_close_from_lower_layer(channel_listener_t *chan_l) { tor_assert(chan_l != NULL); /* If it's already in CLOSING, CLOSED or ERROR, this is a no-op */ if (chan_l->state == CHANNEL_LISTENER_STATE_CLOSING || chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR) return; log_debug(LD_CHANNEL, "Closing channel listener %p (global ID " U64_FORMAT ") " "due to lower-layer event", chan_l, U64_PRINTF_ARG(chan_l->global_identifier)); /* Note closing by event from below */ chan_l->reason_for_closing = CHANNEL_LISTENER_CLOSE_FROM_BELOW; /* Change state to CLOSING */ channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSING); } /** * Notify that the channel is being closed due to an error condition * * This function is called by the lower layer implementing the transport * when a channel must be closed due to an error condition. This does not * call the channel's close method, since the lower layer already knows. */ void channel_close_for_error(channel_t *chan) { tor_assert(chan != NULL); /* If it's already in CLOSING, CLOSED or ERROR, this is a no-op */ if (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) return; log_debug(LD_CHANNEL, "Closing channel %p due to lower-layer error", chan); /* Note closing by event from below */ chan->reason_for_closing = CHANNEL_CLOSE_FOR_ERROR; /* Change state to CLOSING */ channel_change_state(chan, CHANNEL_STATE_CLOSING); } /** * Notify that the channel listener is being closed due to an error condition * * This function is called by the lower layer implementing the transport * when a channel listener must be closed due to an error condition. This * does not call the channel listener's close method, since the lower layer * already knows. */ void channel_listener_close_for_error(channel_listener_t *chan_l) { tor_assert(chan_l != NULL); /* If it's already in CLOSING, CLOSED or ERROR, this is a no-op */ if (chan_l->state == CHANNEL_LISTENER_STATE_CLOSING || chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR) return; log_debug(LD_CHANNEL, "Closing channel listener %p (global ID " U64_FORMAT ") " "due to lower-layer error", chan_l, U64_PRINTF_ARG(chan_l->global_identifier)); /* Note closing by event from below */ chan_l->reason_for_closing = CHANNEL_LISTENER_CLOSE_FOR_ERROR; /* Change state to CLOSING */ channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSING); } /** * Notify that the lower layer is finished closing the channel * * This function should be called by the lower layer when a channel * is finished closing and it should be regarded as inactive and * freed by the channel code. */ void channel_closed(channel_t *chan) { tor_assert(chan); tor_assert(chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR); /* No-op if already inactive */ if (chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) return; if (chan->reason_for_closing == CHANNEL_CLOSE_FOR_ERROR) { /* Inform any pending (not attached) circs that they should * give up. */ circuit_n_chan_done(chan, 0); } /* Now close all the attached circuits on it. */ circuit_unlink_all_from_channel(chan, END_CIRC_REASON_CHANNEL_CLOSED); if (chan->reason_for_closing != CHANNEL_CLOSE_FOR_ERROR) { channel_change_state(chan, CHANNEL_STATE_CLOSED); } else { channel_change_state(chan, CHANNEL_STATE_ERROR); } } /** * Notify that the lower layer is finished closing the channel listener * * This function should be called by the lower layer when a channel listener * is finished closing and it should be regarded as inactive and * freed by the channel code. */ void channel_listener_closed(channel_listener_t *chan_l) { tor_assert(chan_l); tor_assert(chan_l->state == CHANNEL_LISTENER_STATE_CLOSING || chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR); /* No-op if already inactive */ if (chan_l->state == CHANNEL_LISTENER_STATE_CLOSED || chan_l->state == CHANNEL_LISTENER_STATE_ERROR) return; if (chan_l->reason_for_closing != CHANNEL_LISTENER_CLOSE_FOR_ERROR) { channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSED); } else { channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_ERROR); } } /** * Clear the identity_digest of a channel * * This function clears the identity digest of the remote endpoint for a * channel; this is intended for use by the lower layer. */ void channel_clear_identity_digest(channel_t *chan) { int state_not_in_map; tor_assert(chan); log_debug(LD_CHANNEL, "Clearing remote endpoint digest on channel %p with " "global ID " U64_FORMAT, chan, U64_PRINTF_ARG(chan->global_identifier)); state_not_in_map = (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR); if (!state_not_in_map && chan->registered && !tor_digest_is_zero(chan->identity_digest)) /* if it's registered get it out of the digest map */ channel_remove_from_digest_map(chan); memset(chan->identity_digest, 0, sizeof(chan->identity_digest)); } /** * Set the identity_digest of a channel * * This function sets the identity digest of the remote endpoint for a * channel; this is intended for use by the lower layer. */ void channel_set_identity_digest(channel_t *chan, const char *identity_digest) { int was_in_digest_map, should_be_in_digest_map, state_not_in_map; tor_assert(chan); log_debug(LD_CHANNEL, "Setting remote endpoint digest on channel %p with " "global ID " U64_FORMAT " to digest %s", chan, U64_PRINTF_ARG(chan->global_identifier), identity_digest ? hex_str(identity_digest, DIGEST_LEN) : "(null)"); state_not_in_map = (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR); was_in_digest_map = !state_not_in_map && chan->registered && !tor_digest_is_zero(chan->identity_digest); should_be_in_digest_map = !state_not_in_map && chan->registered && (identity_digest && !tor_digest_is_zero(identity_digest)); if (was_in_digest_map) /* We should always remove it; we'll add it back if we're writing * in a new digest. */ channel_remove_from_digest_map(chan); if (identity_digest) { memcpy(chan->identity_digest, identity_digest, sizeof(chan->identity_digest)); } else { memset(chan->identity_digest, 0, sizeof(chan->identity_digest)); } /* Put it in the digest map if we should */ if (should_be_in_digest_map) channel_add_to_digest_map(chan); } /** * Clear the remote end metadata (identity_digest/nickname) of a channel * * This function clears all the remote end info from a channel; this is * intended for use by the lower layer. */ void channel_clear_remote_end(channel_t *chan) { int state_not_in_map; tor_assert(chan); log_debug(LD_CHANNEL, "Clearing remote endpoint identity on channel %p with " "global ID " U64_FORMAT, chan, U64_PRINTF_ARG(chan->global_identifier)); state_not_in_map = (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR); if (!state_not_in_map && chan->registered && !tor_digest_is_zero(chan->identity_digest)) /* if it's registered get it out of the digest map */ channel_remove_from_digest_map(chan); memset(chan->identity_digest, 0, sizeof(chan->identity_digest)); tor_free(chan->nickname); } /** * Set the remote end metadata (identity_digest/nickname) of a channel * * This function sets new remote end info on a channel; this is intended * for use by the lower layer. */ void channel_set_remote_end(channel_t *chan, const char *identity_digest, const char *nickname) { int was_in_digest_map, should_be_in_digest_map, state_not_in_map; tor_assert(chan); log_debug(LD_CHANNEL, "Setting remote endpoint identity on channel %p with " "global ID " U64_FORMAT " to nickname %s, digest %s", chan, U64_PRINTF_ARG(chan->global_identifier), nickname ? nickname : "(null)", identity_digest ? hex_str(identity_digest, DIGEST_LEN) : "(null)"); state_not_in_map = (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR); was_in_digest_map = !state_not_in_map && chan->registered && !tor_digest_is_zero(chan->identity_digest); should_be_in_digest_map = !state_not_in_map && chan->registered && (identity_digest && !tor_digest_is_zero(identity_digest)); if (was_in_digest_map) /* We should always remove it; we'll add it back if we're writing * in a new digest. */ channel_remove_from_digest_map(chan); if (identity_digest) { memcpy(chan->identity_digest, identity_digest, sizeof(chan->identity_digest)); } else { memset(chan->identity_digest, 0, sizeof(chan->identity_digest)); } tor_free(chan->nickname); if (nickname) chan->nickname = tor_strdup(nickname); /* Put it in the digest map if we should */ if (should_be_in_digest_map) channel_add_to_digest_map(chan); } /** * Duplicate a cell queue entry; this is a shallow copy intended for use * in channel_write_cell_queue_entry(). */ static cell_queue_entry_t * cell_queue_entry_dup(cell_queue_entry_t *q) { cell_queue_entry_t *rv = NULL; tor_assert(q); rv = tor_malloc(sizeof(*rv)); memcpy(rv, q, sizeof(*rv)); return rv; } /** * Free a cell_queue_entry_t; the handed_off parameter indicates whether * the contents were passed to the lower layer (it is responsible for * them) or not (we should free). */ static void cell_queue_entry_free(cell_queue_entry_t *q, int handed_off) { if (!q) return; if (!handed_off) { /* * If we handed it off, the recipient becomes responsible (or * with packed cells the channel_t subclass calls packed_cell * free after writing out its contents; see, e.g., * channel_tls_write_packed_cell_method(). Otherwise, we have * to take care of it here if possible. */ switch (q->type) { case CELL_QUEUE_FIXED: if (q->u.fixed.cell) { /* * There doesn't seem to be a cell_free() function anywhere in the * pre-channel code; just use tor_free() */ tor_free(q->u.fixed.cell); } break; case CELL_QUEUE_PACKED: if (q->u.packed.packed_cell) { packed_cell_free(q->u.packed.packed_cell); } break; case CELL_QUEUE_VAR: if (q->u.var.var_cell) { /* * This one's in connection_or.c; it'd be nice to figure out the * whole flow of cells from one end to the other and factor the * cell memory management functions like this out of the specific * TLS lower layer. */ var_cell_free(q->u.var.var_cell); } break; default: /* * Nothing we can do if we don't know the type; this will * have been warned about elsewhere. */ break; } } tor_free(q); } /** * Check whether a cell queue entry is padding; this is a helper function * for channel_write_cell_queue_entry() */ static int cell_queue_entry_is_padding(cell_queue_entry_t *q) { tor_assert(q); if (q->type == CELL_QUEUE_FIXED) { if (q->u.fixed.cell) { if (q->u.fixed.cell->command == CELL_PADDING || q->u.fixed.cell->command == CELL_VPADDING) { return 1; } } } else if (q->type == CELL_QUEUE_VAR) { if (q->u.var.var_cell) { if (q->u.var.var_cell->command == CELL_PADDING || q->u.var.var_cell->command == CELL_VPADDING) { return 1; } } } return 0; } /** * Allocate a new cell queue entry for a fixed-size cell */ static cell_queue_entry_t * cell_queue_entry_new_fixed(cell_t *cell) { cell_queue_entry_t *q = NULL; tor_assert(cell); q = tor_malloc(sizeof(*q)); q->type = CELL_QUEUE_FIXED; q->u.fixed.cell = cell; return q; } /** * Allocate a new cell queue entry for a variable-size cell */ static cell_queue_entry_t * cell_queue_entry_new_var(var_cell_t *var_cell) { cell_queue_entry_t *q = NULL; tor_assert(var_cell); q = tor_malloc(sizeof(*q)); q->type = CELL_QUEUE_VAR; q->u.var.var_cell = var_cell; return q; } /** * Write to a channel based on a cell_queue_entry_t * * Given a cell_queue_entry_t filled out by the caller, try to send the cell * and queue it if we can't. */ static void channel_write_cell_queue_entry(channel_t *chan, cell_queue_entry_t *q) { int result = 0, sent = 0; cell_queue_entry_t *tmp = NULL; tor_assert(chan); tor_assert(q); /* Assert that the state makes sense for a cell write */ tor_assert(chan->state == CHANNEL_STATE_OPENING || chan->state == CHANNEL_STATE_OPEN || chan->state == CHANNEL_STATE_MAINT); /* Increment the timestamp unless it's padding */ if (!cell_queue_entry_is_padding(q)) { chan->timestamp_last_added_nonpadding = approx_time(); } /* Can we send it right out? If so, try */ if (!(chan->outgoing_queue && (smartlist_len(chan->outgoing_queue) > 0)) && chan->state == CHANNEL_STATE_OPEN) { /* Pick the right write function for this cell type and save the result */ switch (q->type) { case CELL_QUEUE_FIXED: tor_assert(chan->write_cell); tor_assert(q->u.fixed.cell); result = chan->write_cell(chan, q->u.fixed.cell); break; case CELL_QUEUE_PACKED: tor_assert(chan->write_packed_cell); tor_assert(q->u.packed.packed_cell); result = chan->write_packed_cell(chan, q->u.packed.packed_cell); break; case CELL_QUEUE_VAR: tor_assert(chan->write_var_cell); tor_assert(q->u.var.var_cell); result = chan->write_var_cell(chan, q->u.var.var_cell); break; default: tor_assert(1); } /* Check if we got it out */ if (result > 0) { sent = 1; /* Timestamp for transmission */ channel_timestamp_xmit(chan); /* If we're here the queue is empty, so it's drained too */ channel_timestamp_drained(chan); /* Update the counter */ ++(chan->n_cells_xmitted); } } if (!sent) { /* Not sent, queue it */ if (!(chan->outgoing_queue)) chan->outgoing_queue = smartlist_new(); /* * We have to copy the queue entry passed in, since the caller probably * used the stack. */ tmp = cell_queue_entry_dup(q); smartlist_add(chan->outgoing_queue, tmp); /* Try to process the queue? */ if (chan->state == CHANNEL_STATE_OPEN) channel_flush_cells(chan); } } /** * Write a cell to a channel * * Write a fixed-length cell to a channel using the write_cell() method. * This is equivalent to the pre-channels connection_or_write_cell_to_buf(); * it is called by the transport-independent code to deliver a cell to a * channel for transmission. */ void channel_write_cell(channel_t *chan, cell_t *cell) { cell_queue_entry_t q; tor_assert(chan); tor_assert(cell); log_debug(LD_CHANNEL, "Writing cell_t %p to channel %p with global ID " U64_FORMAT, cell, chan, U64_PRINTF_ARG(chan->global_identifier)); q.type = CELL_QUEUE_FIXED; q.u.fixed.cell = cell; channel_write_cell_queue_entry(chan, &q); } /** * Write a packed cell to a channel * * Write a packed cell to a channel using the write_cell() method. This is * called by the transport-independent code to deliver a packed cell to a * channel for transmission. */ void channel_write_packed_cell(channel_t *chan, packed_cell_t *packed_cell) { cell_queue_entry_t q; tor_assert(chan); tor_assert(packed_cell); log_debug(LD_CHANNEL, "Writing packed_cell_t %p to channel %p with global ID " U64_FORMAT, packed_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); q.type = CELL_QUEUE_PACKED; q.u.packed.packed_cell = packed_cell; channel_write_cell_queue_entry(chan, &q); } /** * Write a variable-length cell to a channel * * Write a variable-length cell to a channel using the write_cell() method. * This is equivalent to the pre-channels * connection_or_write_var_cell_to_buf(); it's called by the transport- * independent code to deliver a var_cell to a channel for transmission. */ void channel_write_var_cell(channel_t *chan, var_cell_t *var_cell) { cell_queue_entry_t q; tor_assert(chan); tor_assert(var_cell); log_debug(LD_CHANNEL, "Writing var_cell_t %p to channel %p with global ID " U64_FORMAT, var_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); q.type = CELL_QUEUE_VAR; q.u.var.var_cell = var_cell; channel_write_cell_queue_entry(chan, &q); } /** * Change channel state * * This internal and subclass use only function is used to change channel * state, performing all transition validity checks and whatever actions * are appropriate to the state transition in question. */ void channel_change_state(channel_t *chan, channel_state_t to_state) { channel_state_t from_state; unsigned char was_active, is_active; unsigned char was_in_id_map, is_in_id_map; tor_assert(chan); from_state = chan->state; tor_assert(channel_state_is_valid(from_state)); tor_assert(channel_state_is_valid(to_state)); tor_assert(channel_state_can_transition(chan->state, to_state)); /* Check for no-op transitions */ if (from_state == to_state) { log_debug(LD_CHANNEL, "Got no-op transition from \"%s\" to itself on channel %p" "(global ID " U64_FORMAT ")", channel_state_to_string(to_state), chan, U64_PRINTF_ARG(chan->global_identifier)); return; } /* If we're going to a closing or closed state, we must have a reason set */ if (to_state == CHANNEL_STATE_CLOSING || to_state == CHANNEL_STATE_CLOSED || to_state == CHANNEL_STATE_ERROR) { tor_assert(chan->reason_for_closing != CHANNEL_NOT_CLOSING); } /* * We need to maintain the queues here for some transitions: * when we enter CHANNEL_STATE_OPEN (especially from CHANNEL_STATE_MAINT) * we may have a backlog of cells to transmit, so drain the queues in * that case, and when going to CHANNEL_STATE_CLOSED the subclass * should have made sure to finish sending things (or gone to * CHANNEL_STATE_ERROR if not possible), so we assert for that here. */ log_debug(LD_CHANNEL, "Changing state of channel %p (global ID " U64_FORMAT ") from \"%s\" to \"%s\"", chan, U64_PRINTF_ARG(chan->global_identifier), channel_state_to_string(chan->state), channel_state_to_string(to_state)); chan->state = to_state; /* Need to add to the right lists if the channel is registered */ if (chan->registered) { was_active = !(from_state == CHANNEL_STATE_CLOSED || from_state == CHANNEL_STATE_ERROR); is_active = !(to_state == CHANNEL_STATE_CLOSED || to_state == CHANNEL_STATE_ERROR); /* Need to take off active list and put on finished list? */ if (was_active && !is_active) { if (active_channels) smartlist_remove(active_channels, chan); if (!finished_channels) finished_channels = smartlist_new(); smartlist_add(finished_channels, chan); } /* Need to put on active list? */ else if (!was_active && is_active) { if (finished_channels) smartlist_remove(finished_channels, chan); if (!active_channels) active_channels = smartlist_new(); smartlist_add(active_channels, chan); } if (!tor_digest_is_zero(chan->identity_digest)) { /* Now we need to handle the identity map */ was_in_id_map = !(from_state == CHANNEL_STATE_CLOSING || from_state == CHANNEL_STATE_CLOSED || from_state == CHANNEL_STATE_ERROR); is_in_id_map = !(to_state == CHANNEL_STATE_CLOSING || to_state == CHANNEL_STATE_CLOSED || to_state == CHANNEL_STATE_ERROR); if (!was_in_id_map && is_in_id_map) channel_add_to_digest_map(chan); else if (was_in_id_map && !is_in_id_map) channel_remove_from_digest_map(chan); } } /* Tell circuits if we opened and stuff */ if (to_state == CHANNEL_STATE_OPEN) { channel_do_open_actions(chan); /* Check for queued cells to process */ if (chan->incoming_queue && smartlist_len(chan->incoming_queue) > 0) channel_process_cells(chan); if (chan->outgoing_queue && smartlist_len(chan->outgoing_queue) > 0) channel_flush_cells(chan); } else if (to_state == CHANNEL_STATE_CLOSED || to_state == CHANNEL_STATE_ERROR) { /* Assert that all queues are empty */ tor_assert(!(chan->incoming_queue) || smartlist_len(chan->incoming_queue) == 0); tor_assert(!(chan->outgoing_queue) || smartlist_len(chan->outgoing_queue) == 0); } } /** * Change channel listener state * * This internal and subclass use only function is used to change channel * listener state, performing all transition validity checks and whatever * actions are appropriate to the state transition in question. */ void channel_listener_change_state(channel_listener_t *chan_l, channel_listener_state_t to_state) { channel_listener_state_t from_state; unsigned char was_active, is_active; tor_assert(chan_l); from_state = chan_l->state; tor_assert(channel_listener_state_is_valid(from_state)); tor_assert(channel_listener_state_is_valid(to_state)); tor_assert(channel_listener_state_can_transition(chan_l->state, to_state)); /* Check for no-op transitions */ if (from_state == to_state) { log_debug(LD_CHANNEL, "Got no-op transition from \"%s\" to itself on channel " "listener %p (global ID " U64_FORMAT ")", channel_listener_state_to_string(to_state), chan_l, U64_PRINTF_ARG(chan_l->global_identifier)); return; } /* If we're going to a closing or closed state, we must have a reason set */ if (to_state == CHANNEL_LISTENER_STATE_CLOSING || to_state == CHANNEL_LISTENER_STATE_CLOSED || to_state == CHANNEL_LISTENER_STATE_ERROR) { tor_assert(chan_l->reason_for_closing != CHANNEL_LISTENER_NOT_CLOSING); } /* * We need to maintain the queues here for some transitions: * when we enter CHANNEL_STATE_OPEN (especially from CHANNEL_STATE_MAINT) * we may have a backlog of cells to transmit, so drain the queues in * that case, and when going to CHANNEL_STATE_CLOSED the subclass * should have made sure to finish sending things (or gone to * CHANNEL_STATE_ERROR if not possible), so we assert for that here. */ log_debug(LD_CHANNEL, "Changing state of channel listener %p (global ID " U64_FORMAT "from \"%s\" to \"%s\"", chan_l, U64_PRINTF_ARG(chan_l->global_identifier), channel_listener_state_to_string(chan_l->state), channel_listener_state_to_string(to_state)); chan_l->state = to_state; /* Need to add to the right lists if the channel listener is registered */ if (chan_l->registered) { was_active = !(from_state == CHANNEL_LISTENER_STATE_CLOSED || from_state == CHANNEL_LISTENER_STATE_ERROR); is_active = !(to_state == CHANNEL_LISTENER_STATE_CLOSED || to_state == CHANNEL_LISTENER_STATE_ERROR); /* Need to take off active list and put on finished list? */ if (was_active && !is_active) { if (active_listeners) smartlist_remove(active_listeners, chan_l); if (!finished_listeners) finished_listeners = smartlist_new(); smartlist_add(finished_listeners, chan_l); } /* Need to put on active list? */ else if (!was_active && is_active) { if (finished_listeners) smartlist_remove(finished_listeners, chan_l); if (!active_listeners) active_listeners = smartlist_new(); smartlist_add(active_listeners, chan_l); } } if (to_state == CHANNEL_LISTENER_STATE_CLOSED || to_state == CHANNEL_LISTENER_STATE_ERROR) { /* Assert that the queue is empty */ tor_assert(!(chan_l->incoming_list) || smartlist_len(chan_l->incoming_list) == 0); } } /** * Try to flush cells to the lower layer * * this is called by the lower layer to indicate that it wants more cells; * it will try to write up to num_cells cells from the channel's cell queue or * from circuits active on that channel, or as many as it has available if * num_cells == -1. */ #define MAX_CELLS_TO_GET_FROM_CIRCUITS_FOR_UNLIMITED 256 ssize_t channel_flush_some_cells(channel_t *chan, ssize_t num_cells) { unsigned int unlimited = 0; ssize_t flushed = 0; int num_cells_from_circs, clamped_num_cells; tor_assert(chan); if (num_cells < 0) unlimited = 1; if (!unlimited && num_cells <= flushed) goto done; /* If we aren't in CHANNEL_STATE_OPEN, nothing goes through */ if (chan->state == CHANNEL_STATE_OPEN) { /* Try to flush as much as we can that's already queued */ flushed += channel_flush_some_cells_from_outgoing_queue(chan, (unlimited ? -1 : num_cells - flushed)); if (!unlimited && num_cells <= flushed) goto done; if (circuitmux_num_cells(chan->cmux) > 0) { /* Calculate number of cells, including clamp */ if (unlimited) { clamped_num_cells = MAX_CELLS_TO_GET_FROM_CIRCUITS_FOR_UNLIMITED; } else { if (num_cells - flushed > MAX_CELLS_TO_GET_FROM_CIRCUITS_FOR_UNLIMITED) { clamped_num_cells = MAX_CELLS_TO_GET_FROM_CIRCUITS_FOR_UNLIMITED; } else { clamped_num_cells = (int)(num_cells - flushed); } } /* Try to get more cells from any active circuits */ num_cells_from_circs = channel_flush_from_first_active_circuit( chan, clamped_num_cells); /* If it claims we got some, process the queue again */ if (num_cells_from_circs > 0) { flushed += channel_flush_some_cells_from_outgoing_queue(chan, (unlimited ? -1 : num_cells - flushed)); } } } done: return flushed; } /** * Flush cells from just the channel's outgoing cell queue * * This gets called from channel_flush_some_cells() above to flush cells * just from the queue without trying for active_circuits. */ static ssize_t channel_flush_some_cells_from_outgoing_queue(channel_t *chan, ssize_t num_cells) { unsigned int unlimited = 0; ssize_t flushed = 0; cell_queue_entry_t *q = NULL; tor_assert(chan); tor_assert(chan->write_cell); tor_assert(chan->write_packed_cell); tor_assert(chan->write_var_cell); if (num_cells < 0) unlimited = 1; if (!unlimited && num_cells <= flushed) return 0; /* If we aren't in CHANNEL_STATE_OPEN, nothing goes through */ if (chan->state == CHANNEL_STATE_OPEN) { while ((unlimited || num_cells > flushed) && (chan->outgoing_queue && (smartlist_len(chan->outgoing_queue) > 0))) { /* * Ewww, smartlist_del_keeporder() is O(n) in list length; maybe a * a linked list would make more sense for the queue. */ /* Get the head of the queue */ q = smartlist_get(chan->outgoing_queue, 0); if (q) { /* * Okay, we have a good queue entry, try to give it to the lower * layer. */ switch (q->type) { case CELL_QUEUE_FIXED: if (q->u.fixed.cell) { if (chan->write_cell(chan, q->u.fixed.cell)) { ++flushed; channel_timestamp_xmit(chan); ++(chan->n_cells_xmitted); cell_queue_entry_free(q, 1); q = NULL; } /* Else couldn't write it; leave it on the queue */ } else { /* This shouldn't happen */ log_info(LD_CHANNEL, "Saw broken cell queue entry of type CELL_QUEUE_FIXED " "with no cell on channel %p " "(global ID " U64_FORMAT ").", chan, U64_PRINTF_ARG(chan->global_identifier)); /* Throw it away */ cell_queue_entry_free(q, 0); q = NULL; } break; case CELL_QUEUE_PACKED: if (q->u.packed.packed_cell) { if (chan->write_packed_cell(chan, q->u.packed.packed_cell)) { ++flushed; channel_timestamp_xmit(chan); ++(chan->n_cells_xmitted); cell_queue_entry_free(q, 1); q = NULL; } /* Else couldn't write it; leave it on the queue */ } else { /* This shouldn't happen */ log_info(LD_CHANNEL, "Saw broken cell queue entry of type CELL_QUEUE_PACKED " "with no cell on channel %p " "(global ID " U64_FORMAT ").", chan, U64_PRINTF_ARG(chan->global_identifier)); /* Throw it away */ cell_queue_entry_free(q, 0); q = NULL; } break; case CELL_QUEUE_VAR: if (q->u.var.var_cell) { if (chan->write_var_cell(chan, q->u.var.var_cell)) { ++flushed; channel_timestamp_xmit(chan); ++(chan->n_cells_xmitted); cell_queue_entry_free(q, 1); q = NULL; } /* Else couldn't write it; leave it on the queue */ } else { /* This shouldn't happen */ log_info(LD_CHANNEL, "Saw broken cell queue entry of type CELL_QUEUE_VAR " "with no cell on channel %p " "(global ID " U64_FORMAT ").", chan, U64_PRINTF_ARG(chan->global_identifier)); /* Throw it away */ cell_queue_entry_free(q, 0); q = NULL; } break; default: /* Unknown type, log and free it */ log_info(LD_CHANNEL, "Saw an unknown cell queue entry type %d on channel %p " "(global ID " U64_FORMAT "; ignoring it." " Someone should fix this.", q->type, chan, U64_PRINTF_ARG(chan->global_identifier)); cell_queue_entry_free(q, 0); q = NULL; } } else { /* This shouldn't happen; log and throw it away */ log_info(LD_CHANNEL, "Saw a NULL entry in the outgoing cell queue on channel %p " "(global ID " U64_FORMAT "); this is definitely a bug.", chan, U64_PRINTF_ARG(chan->global_identifier)); /* q is already NULL, so we know to delete that queue entry */ } /* if q got NULLed out, we used it and should remove the queue entry */ if (!q) smartlist_del_keeporder(chan->outgoing_queue, 0); /* No cell removed from list, so we can't go on any further */ else break; } } /* Did we drain the queue? */ if (!(chan->outgoing_queue) || smartlist_len(chan->outgoing_queue) == 0) { /* Timestamp it */ channel_timestamp_drained(chan); } return flushed; } /** * Flush as many cells as we possibly can from the queue * * This tries to flush as many cells from the queue as the lower layer * will take. It just calls channel_flush_some_cells_from_outgoing_queue() * in unlimited mode. */ void channel_flush_cells(channel_t *chan) { channel_flush_some_cells_from_outgoing_queue(chan, -1); } /** * Check if any cells are available * * This gets used from the lower layer to check if any more cells are * available. */ int channel_more_to_flush(channel_t *chan) { tor_assert(chan); /* Check if we have any queued */ if (chan->incoming_queue && smartlist_len(chan->incoming_queue) > 0) return 1; /* Check if any circuits would like to queue some */ if (circuitmux_num_cells(chan->cmux) > 0) return 1; /* Else no */ return 0; } /** * Notify the channel we're done flushing the output in the lower layer * * Connection.c will call this when we've flushed the output; there's some * dirreq-related maintenance to do. */ void channel_notify_flushed(channel_t *chan) { tor_assert(chan); if (chan->dirreq_id != 0) geoip_change_dirreq_state(chan->dirreq_id, DIRREQ_TUNNELED, DIRREQ_CHANNEL_BUFFER_FLUSHED); } /** * Process the queue of incoming channels on a listener * * Use a listener's registered callback to process as many entries in the * queue of incoming channels as possible. */ void channel_listener_process_incoming(channel_listener_t *listener) { tor_assert(listener); /* * CHANNEL_LISTENER_STATE_CLOSING permitted because we drain the queue * while closing a listener. */ tor_assert(listener->state == CHANNEL_LISTENER_STATE_LISTENING || listener->state == CHANNEL_LISTENER_STATE_CLOSING); tor_assert(listener->listener); log_debug(LD_CHANNEL, "Processing queue of incoming connections for channel " "listener %p (global ID " U64_FORMAT ")", listener, U64_PRINTF_ARG(listener->global_identifier)); if (!(listener->incoming_list)) return; SMARTLIST_FOREACH_BEGIN(listener->incoming_list, channel_t *, chan) { tor_assert(chan); log_debug(LD_CHANNEL, "Handling incoming channel %p (" U64_FORMAT ") " "for listener %p (" U64_FORMAT ")", chan, U64_PRINTF_ARG(chan->global_identifier), listener, U64_PRINTF_ARG(listener->global_identifier)); /* Make sure this is set correctly */ channel_mark_incoming(chan); listener->listener(listener, chan); } SMARTLIST_FOREACH_END(chan); smartlist_free(listener->incoming_list); listener->incoming_list = NULL; } /** * Take actions required when a channel becomes open * * Handle actions we should do when we know a channel is open; a lot of * this comes from the old connection_or_set_state_open() of connection_or.c. * * Because of this mechanism, future channel_t subclasses should take care * not to change a channel to from CHANNEL_STATE_OPENING to CHANNEL_STATE_OPEN * until there is positive confirmation that the network is operational. * In particular, anything UDP-based should not make this transition until a * packet is received from the other side. */ void channel_do_open_actions(channel_t *chan) { tor_addr_t remote_addr; int started_here, not_using = 0; time_t now = time(NULL); tor_assert(chan); started_here = channel_is_outgoing(chan); if (started_here) { circuit_build_times_network_is_live(&circ_times); rep_hist_note_connect_succeeded(chan->identity_digest, now); if (entry_guard_register_connect_status( chan->identity_digest, 1, 0, now) < 0) { /* Close any circuits pending on this channel. We leave it in state * 'open' though, because it didn't actually *fail* -- we just * chose not to use it. */ log_debug(LD_OR, "New entry guard was reachable, but closing this " "connection so we can retry the earlier entry guards."); circuit_n_chan_done(chan, 0); not_using = 1; } router_set_status(chan->identity_digest, 1); } else { /* only report it to the geoip module if it's not a known router */ if (!router_get_by_id_digest(chan->identity_digest)) { if (channel_get_addr_if_possible(chan, &remote_addr)) { geoip_note_client_seen(GEOIP_CLIENT_CONNECT, &remote_addr, now); } /* Otherwise the underlying transport can't tell us this, so skip it */ } } if (!not_using) circuit_n_chan_done(chan, 1); } /** * Queue an incoming channel on a listener * * Internal and subclass use only function to queue an incoming channel from * a listener. A subclass of channel_listener_t should call this when a new * incoming channel is created. */ void channel_listener_queue_incoming(channel_listener_t *listener, channel_t *incoming) { int need_to_queue = 0; tor_assert(listener); tor_assert(listener->state == CHANNEL_LISTENER_STATE_LISTENING); tor_assert(incoming); log_debug(LD_CHANNEL, "Queueing incoming channel %p (global ID " U64_FORMAT ") on " "channel listener %p (global ID " U64_FORMAT ")", incoming, U64_PRINTF_ARG(incoming->global_identifier), listener, U64_PRINTF_ARG(listener->global_identifier)); /* Do we need to queue it, or can we just call the listener right away? */ if (!(listener->listener)) need_to_queue = 1; if (listener->incoming_list && (smartlist_len(listener->incoming_list) > 0)) need_to_queue = 1; /* If we need to queue and have no queue, create one */ if (need_to_queue && !(listener->incoming_list)) { listener->incoming_list = smartlist_new(); } /* Bump the counter and timestamp it */ channel_listener_timestamp_active(listener); channel_listener_timestamp_accepted(listener); ++(listener->n_accepted); /* If we don't need to queue, process it right away */ if (!need_to_queue) { tor_assert(listener->listener); listener->listener(listener, incoming); } /* * Otherwise, we need to queue; queue and then process the queue if * we can. */ else { tor_assert(listener->incoming_list); smartlist_add(listener->incoming_list, incoming); if (listener->listener) channel_listener_process_incoming(listener); } } /** * Process queued incoming cells * * Process as many queued cells as we can from the incoming * cell queue. */ void channel_process_cells(channel_t *chan) { smartlist_t *queue; int putback = 0; tor_assert(chan); tor_assert(chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_MAINT || chan->state == CHANNEL_STATE_OPEN); log_debug(LD_CHANNEL, "Processing as many incoming cells as we can for channel %p", chan); /* Nothing we can do if we have no registered cell handlers */ if (!(chan->cell_handler || chan->var_cell_handler)) return; /* Nothing we can do if we have no cells */ if (!(chan->incoming_queue)) return; queue = chan->incoming_queue; chan->incoming_queue = NULL; /* * Process cells until we're done or find one we have no current handler * for. */ SMARTLIST_FOREACH_BEGIN(queue, cell_queue_entry_t *, q) { tor_assert(q); tor_assert(q->type == CELL_QUEUE_FIXED || q->type == CELL_QUEUE_VAR); if (putback) { smartlist_add(chan->incoming_queue, q); } else if (q->type == CELL_QUEUE_FIXED && chan->cell_handler) { /* Handle a fixed-length cell */ tor_assert(q->u.fixed.cell); log_debug(LD_CHANNEL, "Processing incoming cell_t %p for channel %p (global ID " U64_FORMAT ")", q->u.fixed.cell, chan, U64_PRINTF_ARG(chan->global_identifier)); chan->cell_handler(chan, q->u.fixed.cell); tor_free(q); } else if (q->type == CELL_QUEUE_VAR && chan->var_cell_handler) { /* Handle a variable-length cell */ tor_assert(q->u.var.var_cell); log_debug(LD_CHANNEL, "Processing incoming var_cell_t %p for channel %p (global ID " U64_FORMAT ")", q->u.var.var_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); chan->var_cell_handler(chan, q->u.var.var_cell); tor_free(q); } else { /* Can't handle this one */ if (!chan->incoming_queue) chan->incoming_queue = smartlist_new(); smartlist_add(chan->incoming_queue, q); putback = 1; } } SMARTLIST_FOREACH_END(q); /* If the list is empty, free it */ smartlist_free(queue); } /** * Queue incoming cell * * This should be called by a channel_t subclass to queue an incoming fixed- * length cell for processing, and process it if possible. */ void channel_queue_cell(channel_t *chan, cell_t *cell) { int need_to_queue = 0; cell_queue_entry_t *q; tor_assert(chan); tor_assert(cell); tor_assert(chan->state == CHANNEL_STATE_OPEN); /* Do we need to queue it, or can we just call the handler right away? */ if (!(chan->cell_handler)) need_to_queue = 1; if (chan->incoming_queue && (smartlist_len(chan->incoming_queue) > 0)) need_to_queue = 1; /* If we need to queue and have no queue, create one */ if (need_to_queue && !(chan->incoming_queue)) { chan->incoming_queue = smartlist_new(); } /* Timestamp for receiving */ channel_timestamp_recv(chan); /* Update the counter */ ++(chan->n_cells_recved); /* If we don't need to queue we can just call cell_handler */ if (!need_to_queue) { tor_assert(chan->cell_handler); log_debug(LD_CHANNEL, "Directly handling incoming cell_t %p for channel %p " "(global ID " U64_FORMAT ")", cell, chan, U64_PRINTF_ARG(chan->global_identifier)); chan->cell_handler(chan, cell); } else { /* Otherwise queue it and then process the queue if possible. */ tor_assert(chan->incoming_queue); q = cell_queue_entry_new_fixed(cell); log_debug(LD_CHANNEL, "Queueing incoming cell_t %p for channel %p " "(global ID " U64_FORMAT ")", cell, chan, U64_PRINTF_ARG(chan->global_identifier)); smartlist_add(chan->incoming_queue, q); if (chan->cell_handler || chan->var_cell_handler) { channel_process_cells(chan); } } } /** * Queue incoming variable-length cell * * This should be called by a channel_t subclass to queue an incoming * variable-length cell for processing, and process it if possible. */ void channel_queue_var_cell(channel_t *chan, var_cell_t *var_cell) { int need_to_queue = 0; cell_queue_entry_t *q; tor_assert(chan); tor_assert(var_cell); tor_assert(chan->state == CHANNEL_STATE_OPEN); /* Do we need to queue it, or can we just call the handler right away? */ if (!(chan->var_cell_handler)) need_to_queue = 1; if (chan->incoming_queue && (smartlist_len(chan->incoming_queue) > 0)) need_to_queue = 1; /* If we need to queue and have no queue, create one */ if (need_to_queue && !(chan->incoming_queue)) { chan->incoming_queue = smartlist_new(); } /* Timestamp for receiving */ channel_timestamp_recv(chan); /* Update the counter */ ++(chan->n_cells_recved); /* If we don't need to queue we can just call cell_handler */ if (!need_to_queue) { tor_assert(chan->var_cell_handler); log_debug(LD_CHANNEL, "Directly handling incoming var_cell_t %p for channel %p " "(global ID " U64_FORMAT ")", var_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); chan->var_cell_handler(chan, var_cell); } else { /* Otherwise queue it and then process the queue if possible. */ tor_assert(chan->incoming_queue); q = cell_queue_entry_new_var(var_cell); log_debug(LD_CHANNEL, "Queueing incoming var_cell_t %p for channel %p " "(global ID " U64_FORMAT ")", var_cell, chan, U64_PRINTF_ARG(chan->global_identifier)); smartlist_add(chan->incoming_queue, q); if (chan->cell_handler || chan->var_cell_handler) { channel_process_cells(chan); } } } /** * Send destroy cell on a channel * * Write a destroy cell with circ ID circ_id and reason reason * onto channel chan. Don't perform range-checking on reason: * we may want to propagate reasons from other cells. */ int channel_send_destroy(circid_t circ_id, channel_t *chan, int reason) { cell_t cell; tor_assert(chan); memset(&cell, 0, sizeof(cell_t)); cell.circ_id = circ_id; cell.command = CELL_DESTROY; cell.payload[0] = (uint8_t) reason; log_debug(LD_OR, "Sending destroy (circID %d) on channel %p " "(global ID " U64_FORMAT ")", circ_id, chan, U64_PRINTF_ARG(chan->global_identifier)); channel_write_cell(chan, &cell); return 0; } /** * Dump channel statistics to the log * * This is called from dumpstats() in main.c and spams the log with * statistics on channels. */ void channel_dumpstats(int severity) { if (all_channels && smartlist_len(all_channels) > 0) { log(severity, LD_GENERAL, "Dumping statistics about %d channels:", smartlist_len(all_channels)); log(severity, LD_GENERAL, "%d are active, and %d are done and waiting for cleanup", (active_channels != NULL) ? smartlist_len(active_channels) : 0, (finished_channels != NULL) ? smartlist_len(finished_channels) : 0); SMARTLIST_FOREACH(all_channels, channel_t *, chan, channel_dump_statistics(chan, severity)); log(severity, LD_GENERAL, "Done spamming about channels now"); } else { log(severity, LD_GENERAL, "No channels to dump"); } } /** * Dump channel listener statistics to the log * * This is called from dumpstats() in main.c and spams the log with * statistics on channel listeners. */ void channel_listener_dumpstats(int severity) { if (all_listeners && smartlist_len(all_listeners) > 0) { log(severity, LD_GENERAL, "Dumping statistics about %d channel listeners:", smartlist_len(all_listeners)); log(severity, LD_GENERAL, "%d are active and %d are done and waiting for cleanup", (active_listeners != NULL) ? smartlist_len(active_listeners) : 0, (finished_listeners != NULL) ? smartlist_len(finished_listeners) : 0); SMARTLIST_FOREACH(all_listeners, channel_listener_t *, chan_l, channel_listener_dump_statistics(chan_l, severity)); log(severity, LD_GENERAL, "Done spamming about channel listeners now"); } else { log(severity, LD_GENERAL, "No channel listeners to dump"); } } /** * Set the cmux policy on all active channels */ void channel_set_cmux_policy_everywhere(circuitmux_policy_t *pol) { if (!active_channels) return; SMARTLIST_FOREACH_BEGIN(active_channels, channel_t *, curr) { if (curr->cmux) { circuitmux_set_policy(curr->cmux, pol); } } SMARTLIST_FOREACH_END(curr); } /** * Clean up channels * * This gets called periodically from run_scheduled_events() in main.c; * it cleans up after closed channels. */ void channel_run_cleanup(void) { channel_t *tmp = NULL; /* Check if we need to do anything */ if (!finished_channels || smartlist_len(finished_channels) == 0) return; /* Iterate through finished_channels and get rid of them */ SMARTLIST_FOREACH_BEGIN(finished_channels, channel_t *, curr) { tmp = curr; /* Remove it from the list */ SMARTLIST_DEL_CURRENT(finished_channels, curr); /* Also unregister it */ channel_unregister(tmp); /* ... and free it */ channel_free(tmp); } SMARTLIST_FOREACH_END(curr); } /** * Clean up channel listeners * * This gets called periodically from run_scheduled_events() in main.c; * it cleans up after closed channel listeners. */ void channel_listener_run_cleanup(void) { channel_listener_t *tmp = NULL; /* Check if we need to do anything */ if (!finished_listeners || smartlist_len(finished_listeners) == 0) return; /* Iterate through finished_channels and get rid of them */ SMARTLIST_FOREACH_BEGIN(finished_listeners, channel_listener_t *, curr) { tmp = curr; /* Remove it from the list */ SMARTLIST_DEL_CURRENT(finished_listeners, curr); /* Also unregister it */ channel_listener_unregister(tmp); /* ... and free it */ channel_listener_free(tmp); } SMARTLIST_FOREACH_END(curr); } /** * Free a list of channels for channel_free_all() */ static void channel_free_list(smartlist_t *channels, int mark_for_close) { if (!channels) return; SMARTLIST_FOREACH_BEGIN(channels, channel_t *, curr) { /* Deregister and free it */ tor_assert(curr); log_debug(LD_CHANNEL, "Cleaning up channel %p (global ID " U64_FORMAT ") " "in state %s (%d)", curr, U64_PRINTF_ARG(curr->global_identifier), channel_state_to_string(curr->state), curr->state); /* Detach circuits early so they can find the channel */ if (curr->cmux) { circuitmux_detach_all_circuits(curr->cmux); } channel_unregister(curr); if (mark_for_close) { if (!(curr->state == CHANNEL_STATE_CLOSING || curr->state == CHANNEL_STATE_CLOSED || curr->state == CHANNEL_STATE_ERROR)) { channel_mark_for_close(curr); } channel_force_free(curr); } else channel_free(curr); } SMARTLIST_FOREACH_END(curr); } /** * Free a list of channel listeners for channel_free_all() */ static void channel_listener_free_list(smartlist_t *listeners, int mark_for_close) { if (!listeners) return; SMARTLIST_FOREACH_BEGIN(listeners, channel_listener_t *, curr) { /* Deregister and free it */ tor_assert(curr); log_debug(LD_CHANNEL, "Cleaning up channel listener %p (global ID " U64_FORMAT ") " "in state %s (%d)", curr, U64_PRINTF_ARG(curr->global_identifier), channel_listener_state_to_string(curr->state), curr->state); channel_listener_unregister(curr); if (mark_for_close) { if (!(curr->state == CHANNEL_LISTENER_STATE_CLOSING || curr->state == CHANNEL_LISTENER_STATE_CLOSED || curr->state == CHANNEL_LISTENER_STATE_ERROR)) { channel_listener_mark_for_close(curr); } channel_listener_force_free(curr); } else channel_listener_free(curr); } SMARTLIST_FOREACH_END(curr); } /** * Close all channels and free everything * * This gets called from tor_free_all() in main.c to clean up on exit. * It will close all registered channels and free associated storage, * then free the all_channels, active_channels, listening_channels and * finished_channels lists and also channel_identity_map. */ void channel_free_all(void) { log_debug(LD_CHANNEL, "Shutting down channels..."); /* First, let's go for finished channels */ if (finished_channels) { channel_free_list(finished_channels, 0); smartlist_free(finished_channels); finished_channels = NULL; } /* Now the finished listeners */ if (finished_listeners) { channel_listener_free_list(finished_listeners, 0); smartlist_free(finished_listeners); finished_listeners = NULL; } /* Now all active channels */ if (active_channels) { channel_free_list(active_channels, 1); smartlist_free(active_channels); active_channels = NULL; } /* Now all active listeners */ if (active_listeners) { channel_listener_free_list(active_listeners, 1); smartlist_free(active_listeners); active_listeners = NULL; } /* Now all channels, in case any are left over */ if (all_channels) { channel_free_list(all_channels, 1); smartlist_free(all_channels); all_channels = NULL; } /* Now all listeners, in case any are left over */ if (all_listeners) { channel_listener_free_list(all_listeners, 1); smartlist_free(all_listeners); all_listeners = NULL; } /* Now free channel_identity_map */ if (channel_identity_map) { log_debug(LD_CHANNEL, "Freeing channel_identity_map"); /* Geez, anything still left over just won't die ... let it leak then */ digestmap_free(channel_identity_map, NULL); channel_identity_map = NULL; } log_debug(LD_CHANNEL, "Done cleaning up after channels"); } /** * Connect to a given addr/port/digest * * This sets up a new outgoing channel; in the future if multiple * channel_t subclasses are available, this is where the selection policy * should go. It may also be desirable to fold port into tor_addr_t * or make a new type including a tor_addr_t and port, so we have a * single abstract object encapsulating all the protocol details of * how to contact an OR. */ channel_t * channel_connect(const tor_addr_t *addr, uint16_t port, const char *id_digest) { return channel_tls_connect(addr, port, id_digest); } /** * Decide which of two channels to prefer for extending a circuit * * This function is called while extending a circuit and returns true iff * a is 'better' than b. The most important criterion here is that a * canonical channel is always better than a non-canonical one, but the * number of circuits and the age are used as tie-breakers. * * This is based on the former connection_or_is_better() of connection_or.c */ int channel_is_better(time_t now, channel_t *a, channel_t *b, int forgive_new_connections) { int a_grace, b_grace; int a_is_canonical, b_is_canonical; int a_has_circs, b_has_circs; /* * Do not definitively deprecate a new channel with no circuits on it * until this much time has passed. */ #define NEW_CHAN_GRACE_PERIOD (15*60) tor_assert(a); tor_assert(b); /* Check if one is canonical and the other isn't first */ a_is_canonical = channel_is_canonical(a); b_is_canonical = channel_is_canonical(b); if (a_is_canonical && !b_is_canonical) return 1; if (!a_is_canonical && b_is_canonical) return 0; /* * Okay, if we're here they tied on canonicity. Next we check if * they have any circuits, and if one does and the other doesn't, * we prefer the one that does, unless we are forgiving and the * one that has no circuits is in its grace period. */ a_has_circs = (channel_num_circuits(a) > 0); b_has_circs = (channel_num_circuits(b) > 0); a_grace = (forgive_new_connections && (now < channel_when_created(a) + NEW_CHAN_GRACE_PERIOD)); b_grace = (forgive_new_connections && (now < channel_when_created(b) + NEW_CHAN_GRACE_PERIOD)); if (a_has_circs && !b_has_circs && !b_grace) return 1; if (!a_has_circs && b_has_circs && !a_grace) return 0; /* They tied on circuits too; just prefer whichever is newer */ if (channel_when_created(a) > channel_when_created(b)) return 1; else return 0; } /** * Get a channel to extend a circuit * * Pick a suitable channel to extend a circuit to given the desired digest * the address we believe is correct for that digest; this tries to see * if we already have one for the requested endpoint, but if there is no good * channel, set *msg_out to a message describing the channel's state * and our next action, and set *launch_out to a boolean indicated whether * the caller should try to launch a new channel with channel_connect(). */ channel_t * channel_get_for_extend(const char *digest, const tor_addr_t *target_addr, const char **msg_out, int *launch_out) { channel_t *chan, *best = NULL; int n_inprogress_goodaddr = 0, n_old = 0; int n_noncanonical = 0, n_possible = 0; time_t now = approx_time(); tor_assert(msg_out); tor_assert(launch_out); if (!channel_identity_map) { *msg_out = "Router not connected (nothing is). Connecting."; *launch_out = 1; return NULL; } chan = channel_find_by_remote_digest(digest); /* Walk the list, unrefing the old one and refing the new at each * iteration. */ for (; chan; chan = channel_next_with_digest(chan)) { tor_assert(tor_memeq(chan->identity_digest, digest, DIGEST_LEN)); if (chan->state == CHANNEL_STATE_CLOSING || chan->state == CHANNEL_STATE_CLOSED || chan->state == CHANNEL_STATE_ERROR) continue; /* Never return a channel on which the other end appears to be * a client. */ if (channel_is_client(chan)) { continue; } /* Never return a non-open connection. */ if (chan->state != CHANNEL_STATE_OPEN) { /* If the address matches, don't launch a new connection for this * circuit. */ if (!channel_matches_target_addr_for_extend(chan, target_addr)) ++n_inprogress_goodaddr; continue; } /* Never return a connection that shouldn't be used for circs. */ if (channel_is_bad_for_new_circs(chan)) { ++n_old; continue; } /* Never return a non-canonical connection using a recent link protocol * if the address is not what we wanted. * * The channel_is_canonical_is_reliable() function asks the lower layer * if we should trust channel_is_canonical(). The below is from the * comments of the old circuit_or_get_for_extend() and applies when * the lower-layer transport is channel_tls_t. * * (For old link protocols, we can't rely on is_canonical getting * set properly if we're talking to the right address, since we might * have an out-of-date descriptor, and we will get no NETINFO cell to * tell us about the right address.) */ if (!channel_is_canonical(chan) && channel_is_canonical_is_reliable(chan) && !channel_matches_target_addr_for_extend(chan, target_addr)) { ++n_noncanonical; continue; } ++n_possible; if (!best) { best = chan; /* If we have no 'best' so far, this one is good enough. */ continue; } if (channel_is_better(now, chan, best, 0)) best = chan; } if (best) { *msg_out = "Connection is fine; using it."; *launch_out = 0; return best; } else if (n_inprogress_goodaddr) { *msg_out = "Connection in progress; waiting."; *launch_out = 0; return NULL; } else if (n_old || n_noncanonical) { *msg_out = "Connections all too old, or too non-canonical. " " Launching a new one."; *launch_out = 1; return NULL; } else { *msg_out = "Not connected. Connecting."; *launch_out = 1; return NULL; } } /** * Describe the transport subclass for a channel * * Invoke a method to get a string description of the lower-layer * transport for this channel. */ const char * channel_describe_transport(channel_t *chan) { tor_assert(chan); tor_assert(chan->describe_transport); return chan->describe_transport(chan); } /** * Describe the transport subclass for a channel listener * * Invoke a method to get a string description of the lower-layer * transport for this channel listener. */ const char * channel_listener_describe_transport(channel_listener_t *chan_l) { tor_assert(chan_l); tor_assert(chan_l->describe_transport); return chan_l->describe_transport(chan_l); } /** * Dump channel statistics * * Dump statistics for one channel to the log */ void channel_dump_statistics(channel_t *chan, int severity) { double avg, interval, age; time_t now = time(NULL); tor_addr_t remote_addr; int have_remote_addr; char *remote_addr_str; tor_assert(chan); age = (double)(now - chan->timestamp_created); log(severity, LD_GENERAL, "Channel " U64_FORMAT " (at %p) with transport %s is in state " "%s (%d)", U64_PRINTF_ARG(chan->global_identifier), chan, channel_describe_transport(chan), channel_state_to_string(chan->state), chan->state); log(severity, LD_GENERAL, " * Channel " U64_FORMAT " was created at " U64_FORMAT " (" U64_FORMAT " seconds ago) " "and last active at " U64_FORMAT " (" U64_FORMAT " seconds ago)", U64_PRINTF_ARG(chan->global_identifier), U64_PRINTF_ARG(chan->timestamp_created), U64_PRINTF_ARG(now - chan->timestamp_created), U64_PRINTF_ARG(chan->timestamp_active), U64_PRINTF_ARG(now - chan->timestamp_active)); /* Handle digest and nickname */ if (!tor_digest_is_zero(chan->identity_digest)) { if (chan->nickname) { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " says it is connected " "to an OR with digest %s and nickname %s", U64_PRINTF_ARG(chan->global_identifier), hex_str(chan->identity_digest, DIGEST_LEN), chan->nickname); } else { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " says it is connected " "to an OR with digest %s and no known nickname", U64_PRINTF_ARG(chan->global_identifier), hex_str(chan->identity_digest, DIGEST_LEN)); } } else { if (chan->nickname) { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " does not know the digest" " of the OR it is connected to, but reports its nickname is %s", U64_PRINTF_ARG(chan->global_identifier), chan->nickname); } else { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " does not know the digest" " or the nickname of the OR it is connected to", U64_PRINTF_ARG(chan->global_identifier)); } } /* Handle remote address and descriptions */ have_remote_addr = channel_get_addr_if_possible(chan, &remote_addr); if (have_remote_addr) { remote_addr_str = tor_dup_addr(&remote_addr); log(severity, LD_GENERAL, " * Channel " U64_FORMAT " says its remote address" " is %s, and gives a canonical description of \"%s\" and an " "actual description of \"%s\"", U64_PRINTF_ARG(chan->global_identifier), remote_addr_str, channel_get_canonical_remote_descr(chan), channel_get_actual_remote_descr(chan)); tor_free(remote_addr_str); } else { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " does not know its remote " "address, but gives a canonical description of \"%s\" and an " "actual description of \"%s\"", U64_PRINTF_ARG(chan->global_identifier), channel_get_canonical_remote_descr(chan), channel_get_actual_remote_descr(chan)); } /* Handle marks */ log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has these marks: %s %s %s " "%s %s %s", U64_PRINTF_ARG(chan->global_identifier), channel_is_bad_for_new_circs(chan) ? "bad_for_new_circs" : "!bad_for_new_circs", channel_is_canonical(chan) ? "canonical" : "!canonical", channel_is_canonical_is_reliable(chan) ? "is_canonical_is_reliable" : "!is_canonical_is_reliable", channel_is_client(chan) ? "client" : "!client", channel_is_local(chan) ? "local" : "!local", channel_is_incoming(chan) ? "incoming" : "outgoing"); /* Describe queues */ log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has %d queued incoming cells" " and %d queued outgoing cells", U64_PRINTF_ARG(chan->global_identifier), (chan->incoming_queue != NULL) ? smartlist_len(chan->incoming_queue) : 0, (chan->outgoing_queue != NULL) ? smartlist_len(chan->outgoing_queue) : 0); /* Describe circuits */ log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has %d active circuits out of" " %d in total", U64_PRINTF_ARG(chan->global_identifier), (chan->cmux != NULL) ? circuitmux_num_active_circuits(chan->cmux) : 0, (chan->cmux != NULL) ? circuitmux_num_circuits(chan->cmux) : 0); /* Describe timestamps */ log(severity, LD_GENERAL, " * Channel " U64_FORMAT " was last used by a " "client at " U64_FORMAT " (" U64_FORMAT " seconds ago)", U64_PRINTF_ARG(chan->global_identifier), U64_PRINTF_ARG(chan->timestamp_client), U64_PRINTF_ARG(now - chan->timestamp_client)); log(severity, LD_GENERAL, " * Channel " U64_FORMAT " was last drained at " U64_FORMAT " (" U64_FORMAT " seconds ago)", U64_PRINTF_ARG(chan->global_identifier), U64_PRINTF_ARG(chan->timestamp_drained), U64_PRINTF_ARG(now - chan->timestamp_drained)); log(severity, LD_GENERAL, " * Channel " U64_FORMAT " last received a cell " "at " U64_FORMAT " (" U64_FORMAT " seconds ago)", U64_PRINTF_ARG(chan->global_identifier), U64_PRINTF_ARG(chan->timestamp_recv), U64_PRINTF_ARG(now - chan->timestamp_recv)); log(severity, LD_GENERAL, " * Channel " U64_FORMAT " last trasmitted a cell " "at " U64_FORMAT " (" U64_FORMAT " seconds ago)", U64_PRINTF_ARG(chan->global_identifier), U64_PRINTF_ARG(chan->timestamp_xmit), U64_PRINTF_ARG(now - chan->timestamp_xmit)); /* Describe counters and rates */ log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has received " U64_FORMAT " cells and transmitted " U64_FORMAT, U64_PRINTF_ARG(chan->global_identifier), U64_PRINTF_ARG(chan->n_cells_recved), U64_PRINTF_ARG(chan->n_cells_xmitted)); if (now > chan->timestamp_created && chan->timestamp_created > 0) { if (chan->n_cells_recved > 0) { avg = (double)(chan->n_cells_recved) / age; if (avg >= 1.0) { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has averaged %f " "cells received per second", U64_PRINTF_ARG(chan->global_identifier), avg); } else if (avg >= 0.0) { interval = 1.0 / avg; log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has averaged %f " "seconds between received cells", U64_PRINTF_ARG(chan->global_identifier), interval); } } if (chan->n_cells_xmitted > 0) { avg = (double)(chan->n_cells_xmitted) / age; if (avg >= 1.0) { log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has averaged %f " "cells transmitted per second", U64_PRINTF_ARG(chan->global_identifier), avg); } else if (avg >= 0.0) { interval = 1.0 / avg; log(severity, LD_GENERAL, " * Channel " U64_FORMAT " has averaged %f " "seconds between transmitted cells", U64_PRINTF_ARG(chan->global_identifier), interval); } } } /* Dump anything the lower layer has to say */ channel_dump_transport_statistics(chan, severity); } /** * Dump channel listener statistics * * Dump statistics for one channel listener to the log */ void channel_listener_dump_statistics(channel_listener_t *chan_l, int severity) { double avg, interval, age; time_t now = time(NULL); tor_assert(chan_l); age = (double)(now - chan_l->timestamp_created); log(severity, LD_GENERAL, "Channel listener " U64_FORMAT " (at %p) with transport %s is in " "state %s (%d)", U64_PRINTF_ARG(chan_l->global_identifier), chan_l, channel_listener_describe_transport(chan_l), channel_listener_state_to_string(chan_l->state), chan_l->state); log(severity, LD_GENERAL, " * Channel listener " U64_FORMAT " was created at " U64_FORMAT " (" U64_FORMAT " seconds ago) " "and last active at " U64_FORMAT " (" U64_FORMAT " seconds ago)", U64_PRINTF_ARG(chan_l->global_identifier), U64_PRINTF_ARG(chan_l->timestamp_created), U64_PRINTF_ARG(now - chan_l->timestamp_created), U64_PRINTF_ARG(chan_l->timestamp_active), U64_PRINTF_ARG(now - chan_l->timestamp_active)); log(severity, LD_GENERAL, " * Channel listener " U64_FORMAT " last accepted an incoming " "channel at " U64_FORMAT " (" U64_FORMAT " seconds ago) " "and has accepted " U64_FORMAT " channels in total", U64_PRINTF_ARG(chan_l->global_identifier), U64_PRINTF_ARG(chan_l->timestamp_accepted), U64_PRINTF_ARG(now - chan_l->timestamp_accepted), U64_PRINTF_ARG(chan_l->n_accepted)); /* * If it's sensible to do so, get the rate of incoming channels on this * listener */ if (now > chan_l->timestamp_created && chan_l->timestamp_created > 0 && chan_l->n_accepted > 0) { avg = (double)(chan_l->n_accepted) / age; if (avg >= 1.0) { log(severity, LD_GENERAL, " * Channel listener " U64_FORMAT " has averaged %f incoming " "channels per second", U64_PRINTF_ARG(chan_l->global_identifier), avg); } else if (avg >= 0.0) { interval = 1.0 / avg; log(severity, LD_GENERAL, " * Channel listener " U64_FORMAT " has averaged %f seconds " "between incoming channels", U64_PRINTF_ARG(chan_l->global_identifier), interval); } } /* Dump anything the lower layer has to say */ channel_listener_dump_transport_statistics(chan_l, severity); } /** * Invoke transport-specific stats dump for channel * * If there is a lower-layer statistics dump method, invoke it */ void channel_dump_transport_statistics(channel_t *chan, int severity) { tor_assert(chan); if (chan->dumpstats) chan->dumpstats(chan, severity); } /** * Invoke transport-specific stats dump for channel listener * * If there is a lower-layer statistics dump method, invoke it */ void channel_listener_dump_transport_statistics(channel_listener_t *chan_l, int severity) { tor_assert(chan_l); if (chan_l->dumpstats) chan_l->dumpstats(chan_l, severity); } /** * Return text description of the remote endpoint * * This function return a test provided by the lower layer of the remote * endpoint for this channel; it should specify the actual address connected * to/from. * * Subsequent calls to channel_get_{actual,canonical}_remote_{address,descr} * may invalidate the return value from this function. */ const char * channel_get_actual_remote_descr(channel_t *chan) { tor_assert(chan); tor_assert(chan->get_remote_descr); /* Param 1 indicates the actual description */ return chan->get_remote_descr(chan, GRD_FLAG_ORIGINAL); } /** * Return the text address of the remote endpoint. * * Subsequent calls to channel_get_{actual,canonical}_remote_{address,descr} * may invalidate the return value from this function. */ const char * channel_get_actual_remote_address(channel_t *chan) { /* Param 1 indicates the actual description */ return chan->get_remote_descr(chan, GRD_FLAG_ORIGINAL|GRD_FLAG_ADDR_ONLY); } /** * Return text description of the remote endpoint canonical address * * This function return a test provided by the lower layer of the remote * endpoint for this channel; it should use the known canonical address for * this OR's identity digest if possible. * * Subsequent calls to channel_get_{actual,canonical}_remote_{address,descr} * may invalidate the return value from this function. */ const char * channel_get_canonical_remote_descr(channel_t *chan) { tor_assert(chan); tor_assert(chan->get_remote_descr); /* Param 0 indicates the canonicalized description */ return chan->get_remote_descr(chan, 0); } /** * Get remote address if possible. * * Write the remote address out to a tor_addr_t if the underlying transport * supports this operation, and return 1. Return 0 if the underlying transport * doesn't let us do this. */ int channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out) { tor_assert(chan); tor_assert(addr_out); if (chan->get_remote_addr) return chan->get_remote_addr(chan, addr_out); /* Else no support, method not implemented */ else return 0; } /** * Check if there are outgoing queue writes on this channel * * Indicate if either we have queued cells, or if not, whether the underlying * lower-layer transport thinks it has an output queue. */ int channel_has_queued_writes(channel_t *chan) { int has_writes = 0; tor_assert(chan); tor_assert(chan->has_queued_writes); if (chan->outgoing_queue && smartlist_len(chan->outgoing_queue) > 0) { has_writes = 1; } else { /* Check with the lower layer */ has_writes = chan->has_queued_writes(chan); } return has_writes; } /** * Check the is_bad_for_new_circs flag * * This function returns the is_bad_for_new_circs flag of the specified * channel. */ int channel_is_bad_for_new_circs(channel_t *chan) { tor_assert(chan); return chan->is_bad_for_new_circs; } /** * Mark a channel as bad for new circuits * * Set the is_bad_for_new_circs_flag on chan. */ void channel_mark_bad_for_new_circs(channel_t *chan) { tor_assert(chan); chan->is_bad_for_new_circs = 1; } /** * Get the client flag * * This returns the client flag of a channel, which will be set if * command_process_create_cell() in command.c thinks this is a connection * from a client. */ int channel_is_client(channel_t *chan) { tor_assert(chan); return chan->is_client; } /** * Set the client flag * * Mark a channel as being from a client */ void channel_mark_client(channel_t *chan) { tor_assert(chan); chan->is_client = 1; } /** * Get the canonical flag for a channel * * This returns the is_canonical for a channel; this flag is determined by * the lower layer and can't be set in a transport-independent way. */ int channel_is_canonical(channel_t *chan) { tor_assert(chan); tor_assert(chan->is_canonical); return chan->is_canonical(chan, 0); } /** * Test if the canonical flag is reliable * * This function asks if the lower layer thinks it's safe to trust the * result of channel_is_canonical() */ int channel_is_canonical_is_reliable(channel_t *chan) { tor_assert(chan); tor_assert(chan->is_canonical); return chan->is_canonical(chan, 1); } /** * Test incoming flag * * This function gets the incoming flag; this is set when a listener spawns * a channel. If this returns true the channel was remotely initiated. */ int channel_is_incoming(channel_t *chan) { tor_assert(chan); return chan->is_incoming; } /** * Set the incoming flag * * This function is called when a channel arrives on a listening channel * to mark it as incoming. */ void channel_mark_incoming(channel_t *chan) { tor_assert(chan); chan->is_incoming = 1; } /** * Test local flag * * This function gets the local flag; the lower layer should set this when * setting up the channel if is_local_addr() is true for all of the * destinations it will communicate with on behalf of this channel. It's * used to decide whether to declare the network reachable when seeing incoming * traffic on the channel. */ int channel_is_local(channel_t *chan) { tor_assert(chan); return chan->is_local; } /** * Set the local flag * * This internal-only function should be called by the lower layer if the * channel is to a local address. See channel_is_local() above or the * description of the is_local bit in channel.h */ void channel_mark_local(channel_t *chan) { tor_assert(chan); chan->is_local = 1; } /** * Test outgoing flag * * This function gets the outgoing flag; this is the inverse of the incoming * bit set when a listener spawns a channel. If this returns true the channel * was locally initiated. */ int channel_is_outgoing(channel_t *chan) { tor_assert(chan); return !(chan->is_incoming); } /** * Mark a channel as outgoing * * This function clears the incoming flag and thus marks a channel as * outgoing. */ void channel_mark_outgoing(channel_t *chan) { tor_assert(chan); chan->is_incoming = 0; } /********************* * Timestamp updates * ********************/ /** * Update the created timestamp for a channel * * This updates the channel's created timestamp and should only be called * from channel_init(). */ void channel_timestamp_created(channel_t *chan) { time_t now = time(NULL); tor_assert(chan); chan->timestamp_created = now; } /** * Update the created timestamp for a channel listener * * This updates the channel listener's created timestamp and should only be * called from channel_init_listener(). */ void channel_listener_timestamp_created(channel_listener_t *chan_l) { time_t now = time(NULL); tor_assert(chan_l); chan_l->timestamp_created = now; } /** * Update the last active timestamp for a channel * * This function updates the channel's last active timestamp; it should be * called by the lower layer whenever there is activity on the channel which * does not lead to a cell being transmitted or received; the active timestamp * is also updated from channel_timestamp_recv() and channel_timestamp_xmit(), * but it should be updated for things like the v3 handshake and stuff that * produce activity only visible to the lower layer. */ void channel_timestamp_active(channel_t *chan) { time_t now = time(NULL); tor_assert(chan); chan->timestamp_active = now; } /** * Update the last active timestamp for a channel listener */ void channel_listener_timestamp_active(channel_listener_t *chan_l) { time_t now = time(NULL); tor_assert(chan_l); chan_l->timestamp_active = now; } /** * Update the last accepted timestamp. * * This function updates the channel listener's last accepted timestamp; it * should be called whenever a new incoming channel is accepted on a * listener. */ void channel_listener_timestamp_accepted(channel_listener_t *chan_l) { time_t now = time(NULL); tor_assert(chan_l); chan_l->timestamp_active = now; chan_l->timestamp_accepted = now; } /** * Update client timestamp * * This function is called by relay.c to timestamp a channel that appears to * be used as a client. */ void channel_timestamp_client(channel_t *chan) { time_t now = time(NULL); tor_assert(chan); chan->timestamp_client = now; } /** * Update the last drained timestamp * * This is called whenever we transmit a cell which leaves the outgoing cell * queue completely empty. It also updates the xmit time and the active time. */ void channel_timestamp_drained(channel_t *chan) { time_t now = time(NULL); tor_assert(chan); chan->timestamp_active = now; chan->timestamp_drained = now; chan->timestamp_xmit = now; } /** * Update the recv timestamp * * This is called whenever we get an incoming cell from the lower layer. * This also updates the active timestamp. */ void channel_timestamp_recv(channel_t *chan) { time_t now = time(NULL); tor_assert(chan); chan->timestamp_active = now; chan->timestamp_recv = now; } /** * Update the xmit timestamp * This is called whenever we pass an outgoing cell to the lower layer. This * also updates the active timestamp. */ void channel_timestamp_xmit(channel_t *chan) { time_t now = time(NULL); tor_assert(chan); chan->timestamp_active = now; chan->timestamp_xmit = now; } /*************************************************************** * Timestamp queries - see above for definitions of timestamps * **************************************************************/ /** * Query created timestamp for a channel */ time_t channel_when_created(channel_t *chan) { tor_assert(chan); return chan->timestamp_created; } /** * Query created timestamp for a channel listener */ time_t channel_listener_when_created(channel_listener_t *chan_l) { tor_assert(chan_l); return chan_l->timestamp_created; } /** * Query last active timestamp for a channel */ time_t channel_when_last_active(channel_t *chan) { tor_assert(chan); return chan->timestamp_active; } /** * Query last active timestamp for a channel listener */ time_t channel_listener_when_last_active(channel_listener_t *chan_l) { tor_assert(chan_l); return chan_l->timestamp_active; } /** * Query last accepted timestamp for a channel listener */ time_t channel_listener_when_last_accepted(channel_listener_t *chan_l) { tor_assert(chan_l); return chan_l->timestamp_accepted; } /** * Query client timestamp */ time_t channel_when_last_client(channel_t *chan) { tor_assert(chan); return chan->timestamp_client; } /** * Query drained timestamp */ time_t channel_when_last_drained(channel_t *chan) { tor_assert(chan); return chan->timestamp_drained; } /** * Query recv timestamp */ time_t channel_when_last_recv(channel_t *chan) { tor_assert(chan); return chan->timestamp_recv; } /** * Query xmit timestamp */ time_t channel_when_last_xmit(channel_t *chan) { tor_assert(chan); return chan->timestamp_xmit; } /** * Query accepted counter */ uint64_t channel_listener_count_accepted(channel_listener_t *chan_l) { tor_assert(chan_l); return chan_l->n_accepted; } /** * Query received cell counter */ uint64_t channel_count_recved(channel_t *chan) { tor_assert(chan); return chan->n_cells_recved; } /** * Query transmitted cell counter */ uint64_t channel_count_xmitted(channel_t *chan) { tor_assert(chan); return chan->n_cells_xmitted; } /** * Check if a channel matches an extend_info_t * * This function calls the lower layer and asks if this channel matches a * given extend_info_t. */ int channel_matches_extend_info(channel_t *chan, extend_info_t *extend_info) { tor_assert(chan); tor_assert(chan->matches_extend_info); tor_assert(extend_info); return chan->matches_extend_info(chan, extend_info); } /** * Check if a channel matches a given target address * * This function calls into the lower layer and asks if this channel thinks * it matches a given target address for circuit extension purposes. */ int channel_matches_target_addr_for_extend(channel_t *chan, const tor_addr_t *target) { tor_assert(chan); tor_assert(chan->matches_target); tor_assert(target); return chan->matches_target(chan, target); } /** * Return the total number of circuits used by a channel * * @param chan Channel to query * @return Number of circuits using this as n_chan or p_chan */ unsigned int channel_num_circuits(channel_t *chan) { tor_assert(chan); return chan->num_n_circuits + chan->num_p_circuits; } /** * Set up circuit ID generation * * This is called when setting up a channel and replaces the old * connection_or_set_circid_type() */ void channel_set_circid_type(channel_t *chan, crypto_pk_t *identity_rcvd) { int started_here; crypto_pk_t *our_identity; tor_assert(chan); started_here = channel_is_outgoing(chan); our_identity = started_here ? get_tlsclient_identity_key() : get_server_identity_key(); if (identity_rcvd) { if (crypto_pk_cmp_keys(our_identity, identity_rcvd) < 0) { chan->circ_id_type = CIRC_ID_TYPE_LOWER; } else { chan->circ_id_type = CIRC_ID_TYPE_HIGHER; } } else { chan->circ_id_type = CIRC_ID_TYPE_NEITHER; } }