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Diffstat (limited to 'src/or/channel.c')
| -rw-r--r-- | src/or/channel.c | 4086 |
1 files changed, 4086 insertions, 0 deletions
diff --git a/src/or/channel.c b/src/or/channel.c new file mode 100644 index 0000000000..b52db405e1 --- /dev/null +++ b/src/or/channel.c @@ -0,0 +1,4086 @@ +/* * 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)); + + /* Call a free method if there is one */ + if (chan->free) chan->free(chan); + + channel_clear_remote_end(chan); + + 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; + + /* 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); + + /* Call a free method if there is one */ + if (chan->free) chan->free(chan); + + channel_clear_remote_end(chan); + + /* 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); + + /* 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) +{ + 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; + + /* + * Process cells until we're done or find one we have no current handler + * for. + */ + SMARTLIST_FOREACH_BEGIN(chan->incoming_queue, + cell_queue_entry_t *, q) { + tor_assert(q); + tor_assert(q->type == CELL_QUEUE_FIXED || + q->type == CELL_QUEUE_VAR); + + 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); + SMARTLIST_DEL_CURRENT(chan->incoming_queue, q); + 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); + SMARTLIST_DEL_CURRENT(chan->incoming_queue, q); + tor_free(q); + } else { + /* Can't handle this one */ + break; + } + } SMARTLIST_FOREACH_END(q); + + /* If the list is empty, free it */ + if (smartlist_len(chan->incoming_queue) == 0 ) { + smartlist_free(chan->incoming_queue); + chan->incoming_queue = NULL; + } +} + +/** + * 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 <b>circ_id</b> and reason <b>reason</b> + * onto channel <b>chan</b>. 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. + */ + +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, 1); +} + +/** + * 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. + */ + +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. + */ + +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; + } +} + |