/* * Copyright (c) 2012-2013, 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 "circuitstats.h"
#include "connection_or.h" /* For var_cell_free() */
#include "circuitmux.h"
#include "entrynodes.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 {
TOR_SIMPLEQ_ENTRY(cell_queue_entry_s) next;
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.
*/
HT_HEAD(channel_idmap, channel_idmap_entry_s) channel_identity_map =
HT_INITIALIZER();
typedef struct channel_idmap_entry_s {
HT_ENTRY(channel_idmap_entry_s) node;
uint8_t digest[DIGEST_LEN];
TOR_LIST_HEAD(channel_list_s, channel_s) channel_list;
} channel_idmap_entry_t;
static INLINE unsigned
channel_idmap_hash(const channel_idmap_entry_t *ent)
{
const unsigned *a = (const unsigned *)ent->digest;
#if SIZEOF_INT == 4
return a[0] ^ a[1] ^ a[2] ^ a[3] ^ a[4];
#elif SIZEOF_INT == 8
return a[0] ^ a[1];
#endif
}
static INLINE int
channel_idmap_eq(const channel_idmap_entry_t *a,
const channel_idmap_entry_t *b)
{
return tor_memeq(a->digest, b->digest, DIGEST_LEN);
}
HT_PROTOTYPE(channel_idmap, channel_idmap_entry_s, node, channel_idmap_hash,
channel_idmap_eq);
HT_GENERATE(channel_idmap, channel_idmap_entry_s, node, channel_idmap_hash,
channel_idmap_eq, 0.5, tor_malloc, tor_realloc, tor_free_);
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_idmap_entry_t *ent, search;
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));
memcpy(search.digest, chan->identity_digest, DIGEST_LEN);
ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
if (! ent) {
ent = tor_malloc(sizeof(channel_idmap_entry_t));
memcpy(ent->digest, chan->identity_digest, DIGEST_LEN);
TOR_LIST_INIT(&ent->channel_list);
HT_INSERT(channel_idmap, &channel_identity_map, ent);
}
TOR_LIST_INSERT_HEAD(&ent->channel_list, chan, next_with_same_id);
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_idmap_entry_t *ent, search;
tor_assert(chan);
/* Assert that there is a digest */
tor_assert(!tor_digest_is_zero(chan->identity_digest));
#if 0
/* 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;
}
#endif
/* Pull it out of its list, wherever that list is */
TOR_LIST_REMOVE(chan, next_with_same_id);
memcpy(search.digest, chan->identity_digest, DIGEST_LEN);
ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
/* Look for it in the map */
if (ent) {
/* Okay, it's here */
if (TOR_LIST_EMPTY(&ent->channel_list)) {
HT_REMOVE(channel_idmap, &channel_identity_map, ent);
tor_free(ent);
}
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 {
/* 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));
}
}
/****************************
* 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() to walk the list.
*/
channel_t *
channel_find_by_remote_digest(const char *identity_digest)
{
channel_t *rv = NULL;
channel_idmap_entry_t *ent, search;
tor_assert(identity_digest);
memcpy(search.digest, identity_digest, DIGEST_LEN);
ent = HT_FIND(channel_idmap, &channel_identity_map, &search);
if (ent) {
rv = TOR_LIST_FIRST(&ent->channel_list);
}
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 TOR_LIST_NEXT(chan, next_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);
/* Initialize queues. */
TOR_SIMPLEQ_INIT(&chan->incoming_queue);
TOR_SIMPLEQ_INIT(&chan->outgoing_queue);
/* Initialize list entries. */
memset(&chan->next_with_same_id, 0, sizeof(chan->next_with_same_id));
/* Timestamp it */
channel_timestamp_created(chan);
}
/**
* Initialize a channel listener
*
* This function should be called by subclasses to set up some per-channel
* variables. I.e., this is the superclass constructor. Before this, the
* channel listener should be allocated with tor_malloc_zero().
*/
void
channel_init_listener(channel_listener_t *chan_l)
{
tor_assert(chan_l);
/* Assign an ID and bump the counter */
chan_l->global_identifier = n_channels_allocated++;
/* Timestamp it */
channel_listener_timestamp_created(chan_l);
}
/**
* Free a channel; nothing outside of channel.c and subclasses should call
* this - it frees channels after they have closed and been unregistered.
*/
void
channel_free(channel_t *chan)
{
if (!chan) return;
/* It must be closed or errored */
tor_assert(chan->state == CHANNEL_STATE_CLOSED ||
chan->state == CHANNEL_STATE_ERROR);
/* It must be deregistered */
tor_assert(!(chan->registered));
log_debug(LD_CHANNEL,
"Freeing channel " U64_FORMAT " at %p",
U64_PRINTF_ARG(chan->global_identifier), chan);
/*
* Get rid of cmux policy before we do anything, so cmux policies don't
* see channels in weird half-freed states.
*/
if (chan->cmux) {
circuitmux_set_policy(chan->cmux, NULL);
}
/* Call a free method if there is one */
if (chan->free) chan->free(chan);
channel_clear_remote_end(chan);
/* Get rid of cmux */
if (chan->cmux) {
circuitmux_detach_all_circuits(chan->cmux);
circuitmux_free(chan->cmux);
chan->cmux = NULL;
}
/* We're in CLOSED or ERROR, so the cell queue is already empty */
tor_free(chan);
}
/**
* Free a channel listener; nothing outside of channel.c and subclasses
* should call this - it frees channel listeners after they have closed and
* been unregistered.
*/
void
channel_listener_free(channel_listener_t *chan_l)
{
if (!chan_l) return;
log_debug(LD_CHANNEL,
"Freeing channel_listener_t " U64_FORMAT " at %p",
U64_PRINTF_ARG(chan_l->global_identifier),
chan_l);
/* It must be closed or errored */
tor_assert(chan_l->state == CHANNEL_LISTENER_STATE_CLOSED ||
chan_l->state == CHANNEL_LISTENER_STATE_ERROR);
/* It must be deregistered */
tor_assert(!(chan_l->registered));
/* Call a free method if there is one */
if (chan_l->free) chan_l->free(chan_l);
/*
* We're in CLOSED or ERROR, so the incoming channel queue is already
* empty.
*/
tor_free(chan_l);
}
/**
* Free a channel and skip the state/registration asserts; this internal-
* use-only function should be called only from channel_free_all() when
* shutting down the Tor process.
*/
static void
channel_force_free(channel_t *chan)
{
cell_queue_entry_t *cell, *cell_tmp;
tor_assert(chan);
log_debug(LD_CHANNEL,
"Force-freeing channel " U64_FORMAT " at %p",
U64_PRINTF_ARG(chan->global_identifier), chan);
/*
* Get rid of cmux policy before we do anything, so cmux policies don't
* see channels in weird half-freed states.
*/
if (chan->cmux) {
circuitmux_set_policy(chan->cmux, NULL);
}
/* Call a free method if there is one */
if (chan->free) chan->free(chan);
channel_clear_remote_end(chan);
/* Get rid of cmux */
if (chan->cmux) {
circuitmux_free(chan->cmux);
chan->cmux = NULL;
}
/* We might still have a cell queue; kill it */
TOR_SIMPLEQ_FOREACH_SAFE(cell, &chan->incoming_queue, next, cell_tmp) {
cell_queue_entry_free(cell, 0);
}
TOR_SIMPLEQ_INIT(&chan->incoming_queue);
/* Outgoing cell queue is similar, but we can have to free packed cells */
TOR_SIMPLEQ_FOREACH_SAFE(cell, &chan->outgoing_queue, next, cell_tmp) {
cell_queue_entry_free(cell, 0);
}
TOR_SIMPLEQ_INIT(&chan->outgoing_queue);
tor_free(chan);
}
/**
* Free a channel listener and skip the state/reigstration asserts; this
* internal-use-only function should be called only from channel_free_all()
* when shutting down the Tor process.
*/
static void
channel_listener_force_free(channel_listener_t *chan_l)
{
tor_assert(chan_l);
log_debug(LD_CHANNEL,
"Force-freeing channel_listener_t " U64_FORMAT " at %p",
U64_PRINTF_ARG(chan_l->global_identifier),
chan_l);
/* Call a free method if there is one */
if (chan_l->free) chan_l->free(chan_l);
/*
* The incoming list just gets emptied and freed; we request close on
* any channels we find there, but since we got called while shutting
* down they will get deregistered and freed elsewhere anyway.
*/
if (chan_l->incoming_list) {
SMARTLIST_FOREACH_BEGIN(chan_l->incoming_list,
channel_t *, qchan) {
channel_mark_for_close(qchan);
} SMARTLIST_FOREACH_END(qchan);
smartlist_free(chan_l->incoming_list);
chan_l->incoming_list = NULL;
}
tor_free(chan_l);
}
/**
* Return the current registered listener for a channel listener
*
* This function returns a function pointer to the current registered
* handler for new incoming channels on a channel listener.
*/
channel_listener_fn_ptr
channel_listener_get_listener_fn(channel_listener_t *chan_l)
{
tor_assert(chan_l);
if (chan_l->state == CHANNEL_LISTENER_STATE_LISTENING)
return chan_l->listener;
return NULL;
}
/**
* Set the listener for a channel listener
*
* This function sets the handler for new incoming channels on a channel
* listener.
*/
void
channel_listener_set_listener_fn(channel_listener_t *chan_l,
channel_listener_fn_ptr listener)
{
tor_assert(chan_l);
tor_assert(chan_l->state == CHANNEL_LISTENER_STATE_LISTENING);
log_debug(LD_CHANNEL,
"Setting listener callback for channel listener %p "
"(global ID " U64_FORMAT ") to %p",
chan_l, U64_PRINTF_ARG(chan_l->global_identifier),
listener);
chan_l->listener = listener;
if (chan_l->listener) channel_listener_process_incoming(chan_l);
}
/**
* Return the fixed-length cell handler for a channel
*
* This function gets the handler for incoming fixed-length cells installed
* on a channel.
*/
channel_cell_handler_fn_ptr
channel_get_cell_handler(channel_t *chan)
{
tor_assert(chan);
if (chan->state == CHANNEL_STATE_OPENING ||
chan->state == CHANNEL_STATE_OPEN ||
chan->state == CHANNEL_STATE_MAINT)
return chan->cell_handler;
return NULL;
}
/**
* Return the variable-length cell handler for a channel
*
* This function gets the handler for incoming variable-length cells
* installed on a channel.
*/
channel_var_cell_handler_fn_ptr
channel_get_var_cell_handler(channel_t *chan)
{
tor_assert(chan);
if (chan->state == CHANNEL_STATE_OPENING ||
chan->state == CHANNEL_STATE_OPEN ||
chan->state == CHANNEL_STATE_MAINT)
return chan->var_cell_handler;
return NULL;
}
/**
* Set both cell handlers for a channel
*
* This function sets both the fixed-length and variable length cell handlers
* for a channel and processes any incoming cells that had been blocked in the
* queue because none were available.
*/
void
channel_set_cell_handlers(channel_t *chan,
channel_cell_handler_fn_ptr cell_handler,
channel_var_cell_handler_fn_ptr
var_cell_handler)
{
int try_again = 0;
tor_assert(chan);
tor_assert(chan->state == CHANNEL_STATE_OPENING ||
chan->state == CHANNEL_STATE_OPEN ||
chan->state == CHANNEL_STATE_MAINT);
log_debug(LD_CHANNEL,
"Setting cell_handler callback for channel %p to %p",
chan, cell_handler);
log_debug(LD_CHANNEL,
"Setting var_cell_handler callback for channel %p to %p",
chan, var_cell_handler);
/* Should we try the queue? */
if (cell_handler &&
cell_handler != chan->cell_handler) try_again = 1;
if (var_cell_handler &&
var_cell_handler != chan->var_cell_handler) try_again = 1;
/* Change them */
chan->cell_handler = cell_handler;
chan->var_cell_handler = var_cell_handler;
/* Re-run the queue if we have one and there's any reason to */
if (! TOR_SIMPLEQ_EMPTY(&chan->incoming_queue) &&
try_again &&
(chan->cell_handler ||
chan->var_cell_handler)) channel_process_cells(chan);
}
/*
* On closing channels
*
* There are three functions that close channels, for use in
* different circumstances:
*
* - Use channel_mark_for_close() for most cases
* - Use channel_close_from_lower_layer() if you are connection_or.c
* and the other end closes the underlying connection.
* - Use channel_close_for_error() if you are connection_or.c and
* some sort of error has occurred.
*/
/**
* 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 (TOR_SIMPLEQ_EMPTY(&chan->outgoing_queue) &&
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 */
/*
* We have to copy the queue entry passed in, since the caller probably
* used the stack.
*/
tmp = cell_queue_entry_dup(q);
TOR_SIMPLEQ_INSERT_TAIL(&chan->outgoing_queue, tmp, next);
/* 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 (! TOR_SIMPLEQ_EMPTY(&chan->incoming_queue))
channel_process_cells(chan);
if (! TOR_SIMPLEQ_EMPTY(&chan->outgoing_queue))
channel_flush_cells(chan);
} else if (to_state == CHANNEL_STATE_CLOSED ||
to_state == CHANNEL_STATE_ERROR) {
/* Assert that all queues are empty */
tor_assert(TOR_SIMPLEQ_EMPTY(&chan->incoming_queue));
tor_assert(TOR_SIMPLEQ_EMPTY(&chan->outgoing_queue));
}
}
/**
* 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) &&
NULL != (q = TOR_SIMPLEQ_FIRST(&chan->outgoing_queue))) {
if (1) {
/*
* 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;
}
/* if q got NULLed out, we used it and should remove the queue entry */
if (!q) TOR_SIMPLEQ_REMOVE_HEAD(&chan->outgoing_queue, next);
/* No cell removed from list, so we can't go on any further */
else break;
}
}
}
/* Did we drain the queue? */
if (TOR_SIMPLEQ_EMPTY(&chan->outgoing_queue)) {
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 (! TOR_SIMPLEQ_EMPTY(&chan->incoming_queue))
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)
{
cell_queue_entry_t *q;
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 (TOR_SIMPLEQ_EMPTY(&chan->incoming_queue)) return;
/*
* Process cells until we're done or find one we have no current handler
* for.
*/
while (NULL != (q = TOR_SIMPLEQ_FIRST(&chan->incoming_queue))) {
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_SIMPLEQ_REMOVE_HEAD(&chan->incoming_queue, next);
tor_assert(q->u.fixed.cell);
log_debug(LD_CHANNEL,
"Processing incoming cell_t %p for channel %p (global ID "
U64_FORMAT ")",
q->u.fixed.cell, chan,
U64_PRINTF_ARG(chan->global_identifier));
chan->cell_handler(chan, q->u.fixed.cell);
tor_free(q);
} else if (q->type == CELL_QUEUE_VAR &&
chan->var_cell_handler) {
/* Handle a variable-length cell */
TOR_SIMPLEQ_REMOVE_HEAD(&chan->incoming_queue, next);
tor_assert(q->u.var.var_cell);
log_debug(LD_CHANNEL,
"Processing incoming var_cell_t %p for channel %p (global ID "
U64_FORMAT ")",
q->u.var.var_cell, chan,
U64_PRINTF_ARG(chan->global_identifier));
chan->var_cell_handler(chan, q->u.var.var_cell);
tor_free(q);
} else {
/* Can't handle this one */
break;
}
}
}
/**
* 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 (! TOR_SIMPLEQ_EMPTY(&chan->incoming_queue))
need_to_queue = 1;
/* 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. */
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));
TOR_SIMPLEQ_INSERT_TAIL(&chan->incoming_queue, q, next);
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 (! TOR_SIMPLEQ_EMPTY(&chan->incoming_queue))
need_to_queue = 1;
/* 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. */
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));
TOR_SIMPLEQ_INSERT_TAIL(&chan->incoming_queue, q, next);
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);
/* Check to make sure we can send on this channel first */
if (!(chan->state == CHANNEL_STATE_CLOSING ||
chan->state == CHANNEL_STATE_CLOSED ||
chan->state == CHANNEL_STATE_ERROR)) {
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);
} else {
log_warn(LD_BUG,
"Someone called channel_send_destroy() for circID %d "
"on a channel " U64_FORMAT " at %p in state %s (%d)",
circ_id, U64_PRINTF_ARG(chan->global_identifier),
chan, channel_state_to_string(chan->state),
chan->state);
}
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) {
tor_log(severity, LD_GENERAL,
"Dumping statistics about %d channels:",
smartlist_len(all_channels));
tor_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));
tor_log(severity, LD_GENERAL,
"Done spamming about channels now");
} else {
tor_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) {
tor_log(severity, LD_GENERAL,
"Dumping statistics about %d channel listeners:",
smartlist_len(all_listeners));
tor_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));
tor_log(severity, LD_GENERAL,
"Done spamming about channel listeners now");
} else {
tor_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 */
log_debug(LD_CHANNEL,
"Freeing channel_identity_map");
/* Geez, anything still left over just won't die ... let it leak then */
HT_CLEAR(channel_idmap, &channel_identity_map);
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);
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);
}
/**
* Return the number of entries in <b>queue</b>
*/
static int
chan_cell_queue_len(const chan_cell_queue_t *queue)
{
int r = 0;
cell_queue_entry_t *cell;
TOR_SIMPLEQ_FOREACH(cell, queue, next)
++r;
return r;
}
/**
* 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);
tor_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);
tor_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) {
tor_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 {
tor_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) {
tor_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 {
tor_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) {
char *actual = tor_strdup(channel_get_actual_remote_descr(chan));
remote_addr_str = tor_dup_addr(&remote_addr);
tor_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),
actual);
tor_free(remote_addr_str);
tor_free(actual);
} else {
char *actual = tor_strdup(channel_get_actual_remote_descr(chan));
tor_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),
actual);
tor_free(actual);
}
/* Handle marks */
tor_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 */
tor_log(severity, LD_GENERAL,
" * Channel " U64_FORMAT " has %d queued incoming cells"
" and %d queued outgoing cells",
U64_PRINTF_ARG(chan->global_identifier),
chan_cell_queue_len(&chan->incoming_queue),
chan_cell_queue_len(&chan->outgoing_queue));
/* Describe circuits */
tor_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 */
tor_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));
tor_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));
tor_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));
tor_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 */
tor_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) {
tor_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;
tor_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) {
tor_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;
tor_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);
tor_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);
tor_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));
tor_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) {
tor_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;
tor_log(severity, LD_GENERAL,
" * Channel listener " U64_FORMAT " has averaged %f seconds "
"between incoming channels",
U64_PRINTF_ARG(chan_l->global_identifier), interval);
}
}
/* Dump anything the lower layer has to say */
channel_listener_dump_transport_statistics(chan_l, severity);
}
/**
* Invoke transport-specific stats dump for channel
*
* If there is a lower-layer statistics dump method, invoke it
*/
void
channel_dump_transport_statistics(channel_t *chan, int severity)
{
tor_assert(chan);
if (chan->dumpstats) chan->dumpstats(chan, severity);
}
/**
* Invoke transport-specific stats dump for channel listener
*
* If there is a lower-layer statistics dump method, invoke it
*/
void
channel_listener_dump_transport_statistics(channel_listener_t *chan_l,
int severity)
{
tor_assert(chan_l);
if (chan_l->dumpstats) chan_l->dumpstats(chan_l, severity);
}
/**
* Return text description of the remote endpoint
*
* This function return a test provided by the lower layer of the remote
* endpoint for this channel; it should specify the actual address connected
* to/from.
*
* Subsequent calls to channel_get_{actual,canonical}_remote_{address,descr}
* may invalidate the return value from this function.
*/
const char *
channel_get_actual_remote_descr(channel_t *chan)
{
tor_assert(chan);
tor_assert(chan->get_remote_descr);
/* Param 1 indicates the actual description */
return chan->get_remote_descr(chan, GRD_FLAG_ORIGINAL);
}
/**
* Return the text address of the remote endpoint.
*
* Subsequent calls to channel_get_{actual,canonical}_remote_{address,descr}
* may invalidate the return value from this function.
*/
const char *
channel_get_actual_remote_address(channel_t *chan)
{
/* Param 1 indicates the actual description */
return chan->get_remote_descr(chan, GRD_FLAG_ORIGINAL|GRD_FLAG_ADDR_ONLY);
}
/**
* Return text description of the remote endpoint canonical address
*
* This function return a test provided by the lower layer of the remote
* endpoint for this channel; it should use the known canonical address for
* this OR's identity digest if possible.
*
* Subsequent calls to channel_get_{actual,canonical}_remote_{address,descr}
* may invalidate the return value from this function.
*/
const char *
channel_get_canonical_remote_descr(channel_t *chan)
{
tor_assert(chan);
tor_assert(chan->get_remote_descr);
/* Param 0 indicates the canonicalized description */
return chan->get_remote_descr(chan, 0);
}
/**
* Get remote address if possible.
*
* Write the remote address out to a tor_addr_t if the underlying transport
* supports this operation, and return 1. Return 0 if the underlying transport
* doesn't let us do this.
*/
int
channel_get_addr_if_possible(channel_t *chan, tor_addr_t *addr_out)
{
tor_assert(chan);
tor_assert(addr_out);
if (chan->get_remote_addr)
return chan->get_remote_addr(chan, addr_out);
/* Else no support, method not implemented */
else return 0;
}
/**
* Check if there are outgoing queue writes on this channel
*
* Indicate if either we have queued cells, or if not, whether the underlying
* lower-layer transport thinks it has an output queue.
*/
int
channel_has_queued_writes(channel_t *chan)
{
int has_writes = 0;
tor_assert(chan);
tor_assert(chan->has_queued_writes);
if (! TOR_SIMPLEQ_EMPTY(&chan->outgoing_queue)) {
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 consider_identity)
{
int started_here;
crypto_pk_t *our_identity;
tor_assert(chan);
started_here = channel_is_outgoing(chan);
if (! consider_identity) {
if (started_here)
chan->circ_id_type = CIRC_ID_TYPE_HIGHER;
else
chan->circ_id_type = CIRC_ID_TYPE_LOWER;
return;
}
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;
}
}