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channeltls.c
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channeltls.c
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/* * Copyright (c) 2012-2019, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file channeltls.c
*
* \brief A concrete subclass of channel_t using or_connection_t to transfer
* cells between Tor instances.
*
* This module fills in the various function pointers in channel_t, to
* implement the channel_tls_t channels as used in Tor today. These channels
* are created from channel_tls_connect() and
* channel_tls_handle_incoming(). Each corresponds 1:1 to or_connection_t
* object, as implemented in connection_or.c. These channels transmit cells
* to the underlying or_connection_t by calling
* connection_or_write_*_cell_to_buf(), and receive cells from the underlying
* or_connection_t when connection_or_process_cells_from_inbuf() calls
* channel_tls_handle_*_cell().
*
* Here we also implement the server (responder) side of the v3+ Tor link
* handshake, which uses CERTS and AUTHENTICATE cell to negotiate versions,
* exchange expected and observed IP and time information, and bootstrap a
* level of authentication higher than we have gotten on the raw TLS
* handshake.
*
* NOTE: Since there is currently only one type of channel, there are probably
* more than a few cases where functionality that is currently in
* channeltls.c, connection_or.c, and channel.c ought to be divided up
* differently. The right time to do this is probably whenever we introduce
* our next channel type.
**/
/*
* Define this so channel.h gives us things only channel_t subclasses
* should touch.
*/
#define CHANNEL_OBJECT_PRIVATE
#define CHANNELTLS_PRIVATE
#include "core/or/or.h"
#include "core/or/channel.h"
#include "core/or/channeltls.h"
#include "core/or/circuitmux.h"
#include "core/or/circuitmux_ewma.h"
#include "core/or/command.h"
#include "app/config/config.h"
#include "core/mainloop/connection.h"
#include "core/or/connection_or.h"
#include "feature/control/control.h"
#include "feature/client/entrynodes.h"
#include "trunnel/link_handshake.h"
#include "core/or/relay.h"
#include "feature/stats/rephist.h"
#include "feature/relay/router.h"
#include "feature/relay/routermode.h"
#include "feature/nodelist/dirlist.h"
#include "core/or/scheduler.h"
#include "feature/nodelist/torcert.h"
#include "feature/nodelist/networkstatus.h"
#include "trunnel/channelpadding_negotiation.h"
#include "trunnel/netinfo.h"
#include "core/or/channelpadding.h"
#include "core/or/cell_st.h"
#include "core/or/cell_queue_st.h"
#include "core/or/extend_info_st.h"
#include "core/or/or_connection_st.h"
#include "core/or/or_handshake_certs_st.h"
#include "core/or/or_handshake_state_st.h"
#include "feature/nodelist/routerinfo_st.h"
#include "core/or/var_cell_st.h"
#include "lib/tls/tortls.h"
#include "lib/tls/x509.h"
/** How many CELL_PADDING cells have we received, ever? */
uint64_t stats_n_padding_cells_processed = 0;
/** How many CELL_VERSIONS cells have we received, ever? */
uint64_t stats_n_versions_cells_processed = 0;
/** How many CELL_NETINFO cells have we received, ever? */
uint64_t stats_n_netinfo_cells_processed = 0;
/** How many CELL_VPADDING cells have we received, ever? */
uint64_t stats_n_vpadding_cells_processed = 0;
/** How many CELL_CERTS cells have we received, ever? */
uint64_t stats_n_certs_cells_processed = 0;
/** How many CELL_AUTH_CHALLENGE cells have we received, ever? */
uint64_t stats_n_auth_challenge_cells_processed = 0;
/** How many CELL_AUTHENTICATE cells have we received, ever? */
uint64_t stats_n_authenticate_cells_processed = 0;
/** How many CELL_AUTHORIZE cells have we received, ever? */
uint64_t stats_n_authorize_cells_processed = 0;
/** Active listener, if any */
static channel_listener_t *channel_tls_listener = NULL;
/* channel_tls_t method declarations */
static void channel_tls_close_method(channel_t *chan);
static const char * channel_tls_describe_transport_method(channel_t *chan);
static void channel_tls_free_method(channel_t *chan);
static double channel_tls_get_overhead_estimate_method(channel_t *chan);
static int
channel_tls_get_remote_addr_method(channel_t *chan, tor_addr_t *addr_out);
static int
channel_tls_get_transport_name_method(channel_t *chan, char **transport_out);
static const char *
channel_tls_get_remote_descr_method(channel_t *chan, int flags);
static int channel_tls_has_queued_writes_method(channel_t *chan);
static int channel_tls_is_canonical_method(channel_t *chan, int req);
static int
channel_tls_matches_extend_info_method(channel_t *chan,
extend_info_t *extend_info);
static int channel_tls_matches_target_method(channel_t *chan,
const tor_addr_t *target);
static int channel_tls_num_cells_writeable_method(channel_t *chan);
static size_t channel_tls_num_bytes_queued_method(channel_t *chan);
static int channel_tls_write_cell_method(channel_t *chan,
cell_t *cell);
static int channel_tls_write_packed_cell_method(channel_t *chan,
packed_cell_t *packed_cell);
static int channel_tls_write_var_cell_method(channel_t *chan,
var_cell_t *var_cell);
/* channel_listener_tls_t method declarations */
static void channel_tls_listener_close_method(channel_listener_t *chan_l);
static const char *
channel_tls_listener_describe_transport_method(channel_listener_t *chan_l);
/** Handle incoming cells for the handshake stuff here rather than
* passing them on up. */
static void channel_tls_process_versions_cell(var_cell_t *cell,
channel_tls_t *tlschan);
static void channel_tls_process_netinfo_cell(cell_t *cell,
channel_tls_t *tlschan);
static int command_allowed_before_handshake(uint8_t command);
static int enter_v3_handshake_with_cell(var_cell_t *cell,
channel_tls_t *tlschan);
static void channel_tls_process_padding_negotiate_cell(cell_t *cell,
channel_tls_t *chan);
/**
* Do parts of channel_tls_t initialization common to channel_tls_connect()
* and channel_tls_handle_incoming().
*/
STATIC void
channel_tls_common_init(channel_tls_t *tlschan)
{
channel_t *chan;
tor_assert(tlschan);
chan = &(tlschan->base_);
channel_init(chan);
chan->magic = TLS_CHAN_MAGIC;
chan->state = CHANNEL_STATE_OPENING;
chan->close = channel_tls_close_method;
chan->describe_transport = channel_tls_describe_transport_method;
chan->free_fn = channel_tls_free_method;
chan->get_overhead_estimate = channel_tls_get_overhead_estimate_method;
chan->get_remote_addr = channel_tls_get_remote_addr_method;
chan->get_remote_descr = channel_tls_get_remote_descr_method;
chan->get_transport_name = channel_tls_get_transport_name_method;
chan->has_queued_writes = channel_tls_has_queued_writes_method;
chan->is_canonical = channel_tls_is_canonical_method;
chan->matches_extend_info = channel_tls_matches_extend_info_method;
chan->matches_target = channel_tls_matches_target_method;
chan->num_bytes_queued = channel_tls_num_bytes_queued_method;
chan->num_cells_writeable = channel_tls_num_cells_writeable_method;
chan->write_cell = channel_tls_write_cell_method;
chan->write_packed_cell = channel_tls_write_packed_cell_method;
chan->write_var_cell = channel_tls_write_var_cell_method;
chan->cmux = circuitmux_alloc();
/* We only have one policy for now so always set it to EWMA. */
circuitmux_set_policy(chan->cmux, &ewma_policy);
}
/**
* Start a new TLS channel.
*
* Launch a new OR connection to <b>addr</b>:<b>port</b> and expect to
* handshake with an OR with identity digest <b>id_digest</b>, and wrap
* it in a channel_tls_t.
*/
channel_t *
channel_tls_connect(const tor_addr_t *addr, uint16_t port,
const char *id_digest,
const ed25519_public_key_t *ed_id)
{
channel_tls_t *tlschan = tor_malloc_zero(sizeof(*tlschan));
channel_t *chan = &(tlschan->base_);
channel_tls_common_init(tlschan);
log_debug(LD_CHANNEL,
"In channel_tls_connect() for channel %p "
"(global id %"PRIu64 ")",
tlschan,
(chan->global_identifier));
if (is_local_addr(addr)) {
log_debug(LD_CHANNEL,
"Marking new outgoing channel %"PRIu64 " at %p as local",
(chan->global_identifier), chan);
channel_mark_local(chan);
} else {
log_debug(LD_CHANNEL,
"Marking new outgoing channel %"PRIu64 " at %p as remote",
(chan->global_identifier), chan);
channel_mark_remote(chan);
}
channel_mark_outgoing(chan);
/* Set up or_connection stuff */
tlschan->conn = connection_or_connect(addr, port, id_digest, ed_id, tlschan);
/* connection_or_connect() will fill in tlschan->conn */
if (!(tlschan->conn)) {
chan->reason_for_closing = CHANNEL_CLOSE_FOR_ERROR;
channel_change_state(chan, CHANNEL_STATE_ERROR);
goto err;
}
log_debug(LD_CHANNEL,
"Got orconn %p for channel with global id %"PRIu64,
tlschan->conn, (chan->global_identifier));
goto done;
err:
circuitmux_free(chan->cmux);
tor_free(tlschan);
chan = NULL;
done:
/* If we got one, we should register it */
if (chan) channel_register(chan);
return chan;
}
/**
* Return the current channel_tls_t listener.
*
* Returns the current channel listener for incoming TLS connections, or
* NULL if none has been established
*/
channel_listener_t *
channel_tls_get_listener(void)
{
return channel_tls_listener;
}
/**
* Start a channel_tls_t listener if necessary.
*
* Return the current channel_tls_t listener, or start one if we haven't yet,
* and return that.
*/
channel_listener_t *
channel_tls_start_listener(void)
{
channel_listener_t *listener;
if (!channel_tls_listener) {
listener = tor_malloc_zero(sizeof(*listener));
channel_init_listener(listener);
listener->state = CHANNEL_LISTENER_STATE_LISTENING;
listener->close = channel_tls_listener_close_method;
listener->describe_transport =
channel_tls_listener_describe_transport_method;
channel_tls_listener = listener;
log_debug(LD_CHANNEL,
"Starting TLS channel listener %p with global id %"PRIu64,
listener, (listener->global_identifier));
channel_listener_register(listener);
} else listener = channel_tls_listener;
return listener;
}
/**
* Free everything on shutdown.
*
* Not much to do here, since channel_free_all() takes care of a lot, but let's
* get rid of the listener.
*/
void
channel_tls_free_all(void)
{
channel_listener_t *old_listener = NULL;
log_debug(LD_CHANNEL,
"Shutting down TLS channels...");
if (channel_tls_listener) {
/*
* When we close it, channel_tls_listener will get nulled out, so save
* a pointer so we can free it.
*/
old_listener = channel_tls_listener;
log_debug(LD_CHANNEL,
"Closing channel_tls_listener with ID %"PRIu64
" at %p.",
(old_listener->global_identifier),
old_listener);
channel_listener_unregister(old_listener);
channel_listener_mark_for_close(old_listener);
channel_listener_free(old_listener);
tor_assert(channel_tls_listener == NULL);
}
log_debug(LD_CHANNEL,
"Done shutting down TLS channels");
}
/**
* Create a new channel around an incoming or_connection_t.
*/
channel_t *
channel_tls_handle_incoming(or_connection_t *orconn)
{
channel_tls_t *tlschan = tor_malloc_zero(sizeof(*tlschan));
channel_t *chan = &(tlschan->base_);
tor_assert(orconn);
tor_assert(!(orconn->chan));
channel_tls_common_init(tlschan);
/* Link the channel and orconn to each other */
tlschan->conn = orconn;
orconn->chan = tlschan;
if (is_local_addr(&(TO_CONN(orconn)->addr))) {
log_debug(LD_CHANNEL,
"Marking new incoming channel %"PRIu64 " at %p as local",
(chan->global_identifier), chan);
channel_mark_local(chan);
} else {
log_debug(LD_CHANNEL,
"Marking new incoming channel %"PRIu64 " at %p as remote",
(chan->global_identifier), chan);
channel_mark_remote(chan);
}
channel_mark_incoming(chan);
/* Register it */
channel_register(chan);
return chan;
}
/*********
* Casts *
********/
/**
* Cast a channel_tls_t to a channel_t.
*/
channel_t *
channel_tls_to_base(channel_tls_t *tlschan)
{
if (!tlschan) return NULL;
return &(tlschan->base_);
}
/**
* Cast a channel_t to a channel_tls_t, with appropriate type-checking
* asserts.
*/
channel_tls_t *
channel_tls_from_base(channel_t *chan)
{
if (!chan) return NULL;
tor_assert(chan->magic == TLS_CHAN_MAGIC);
return (channel_tls_t *)(chan);
}
/********************************************
* Method implementations for channel_tls_t *
*******************************************/
/**
* Close a channel_tls_t.
*
* This implements the close method for channel_tls_t.
*/
static void
channel_tls_close_method(channel_t *chan)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
if (tlschan->conn) connection_or_close_normally(tlschan->conn, 1);
else {
/* Weird - we'll have to change the state ourselves, I guess */
log_info(LD_CHANNEL,
"Tried to close channel_tls_t %p with NULL conn",
tlschan);
channel_change_state(chan, CHANNEL_STATE_ERROR);
}
}
/**
* Describe the transport for a channel_tls_t.
*
* This returns the string "TLS channel on connection <id>" to the upper
* layer.
*/
static const char *
channel_tls_describe_transport_method(channel_t *chan)
{
static char *buf = NULL;
uint64_t id;
channel_tls_t *tlschan;
const char *rv = NULL;
tor_assert(chan);
tlschan = BASE_CHAN_TO_TLS(chan);
if (tlschan->conn) {
id = TO_CONN(tlschan->conn)->global_identifier;
if (buf) tor_free(buf);
tor_asprintf(&buf,
"TLS channel (connection %"PRIu64 ")",
(id));
rv = buf;
} else {
rv = "TLS channel (no connection)";
}
return rv;
}
/**
* Free a channel_tls_t.
*
* This is called by the generic channel layer when freeing a channel_tls_t;
* this happens either on a channel which has already reached
* CHANNEL_STATE_CLOSED or CHANNEL_STATE_ERROR from channel_run_cleanup() or
* on shutdown from channel_free_all(). In the latter case we might still
* have an orconn active (which connection_free_all() will get to later),
* so we should null out its channel pointer now.
*/
static void
channel_tls_free_method(channel_t *chan)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
if (tlschan->conn) {
tlschan->conn->chan = NULL;
tlschan->conn = NULL;
}
}
/**
* Get an estimate of the average TLS overhead for the upper layer.
*/
static double
channel_tls_get_overhead_estimate_method(channel_t *chan)
{
double overhead = 1.0;
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
tor_assert(tlschan->conn);
/* Just return 1.0f if we don't have sensible data */
if (tlschan->conn->bytes_xmitted > 0 &&
tlschan->conn->bytes_xmitted_by_tls >=
tlschan->conn->bytes_xmitted) {
overhead = ((double)(tlschan->conn->bytes_xmitted_by_tls)) /
((double)(tlschan->conn->bytes_xmitted));
/*
* Never estimate more than 2.0; otherwise we get silly large estimates
* at the very start of a new TLS connection.
*/
if (overhead > 2.0)
overhead = 2.0;
}
log_debug(LD_CHANNEL,
"Estimated overhead ratio for TLS chan %"PRIu64 " is %f",
(chan->global_identifier), overhead);
return overhead;
}
/**
* Get the remote address of a channel_tls_t.
*
* This implements the get_remote_addr method for channel_tls_t; copy the
* remote endpoint of the channel to addr_out and return 1 (always
* succeeds for this transport).
*/
static int
channel_tls_get_remote_addr_method(channel_t *chan, tor_addr_t *addr_out)
{
int rv = 0;
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
tor_assert(addr_out);
if (tlschan->conn) {
tor_addr_copy(addr_out, &(tlschan->conn->real_addr));
rv = 1;
} else tor_addr_make_unspec(addr_out);
return rv;
}
/**
* Get the name of the pluggable transport used by a channel_tls_t.
*
* This implements the get_transport_name for channel_tls_t. If the
* channel uses a pluggable transport, copy its name to
* <b>transport_out</b> and return 0. If the channel did not use a
* pluggable transport, return -1.
*/
static int
channel_tls_get_transport_name_method(channel_t *chan, char **transport_out)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
tor_assert(transport_out);
tor_assert(tlschan->conn);
if (!tlschan->conn->ext_or_transport)
return -1;
*transport_out = tor_strdup(tlschan->conn->ext_or_transport);
return 0;
}
/**
* Get endpoint description of a channel_tls_t.
*
* This implements the get_remote_descr method for channel_tls_t; it returns
* a text description of the remote endpoint of the channel suitable for use
* in log messages. The req parameter is 0 for the canonical address or 1 for
* the actual address seen.
*/
static const char *
channel_tls_get_remote_descr_method(channel_t *chan, int flags)
{
#define MAX_DESCR_LEN 32
static char buf[MAX_DESCR_LEN + 1];
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
connection_t *conn;
const char *answer = NULL;
char *addr_str;
tor_assert(tlschan);
if (tlschan->conn) {
conn = TO_CONN(tlschan->conn);
switch (flags) {
case 0:
/* Canonical address with port*/
tor_snprintf(buf, MAX_DESCR_LEN + 1,
"%s:%u", conn->address, conn->port);
answer = buf;
break;
case GRD_FLAG_ORIGINAL:
/* Actual address with port */
addr_str = tor_addr_to_str_dup(&(tlschan->conn->real_addr));
tor_snprintf(buf, MAX_DESCR_LEN + 1,
"%s:%u", addr_str, conn->port);
tor_free(addr_str);
answer = buf;
break;
case GRD_FLAG_ADDR_ONLY:
/* Canonical address, no port */
strlcpy(buf, conn->address, sizeof(buf));
answer = buf;
break;
case GRD_FLAG_ORIGINAL|GRD_FLAG_ADDR_ONLY:
/* Actual address, no port */
addr_str = tor_addr_to_str_dup(&(tlschan->conn->real_addr));
strlcpy(buf, addr_str, sizeof(buf));
tor_free(addr_str);
answer = buf;
break;
default:
/* Something's broken in channel.c */
tor_assert_nonfatal_unreached_once();
}
} else {
strlcpy(buf, "(No connection)", sizeof(buf));
answer = buf;
}
return answer;
}
/**
* Tell the upper layer if we have queued writes.
*
* This implements the has_queued_writes method for channel_tls t_; it returns
* 1 iff we have queued writes on the outbuf of the underlying or_connection_t.
*/
static int
channel_tls_has_queued_writes_method(channel_t *chan)
{
size_t outbuf_len;
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
if (!(tlschan->conn)) {
log_info(LD_CHANNEL,
"something called has_queued_writes on a tlschan "
"(%p with ID %"PRIu64 " but no conn",
chan, (chan->global_identifier));
}
outbuf_len = (tlschan->conn != NULL) ?
connection_get_outbuf_len(TO_CONN(tlschan->conn)) :
0;
return (outbuf_len > 0);
}
/**
* Tell the upper layer if we're canonical.
*
* This implements the is_canonical method for channel_tls_t; if req is zero,
* it returns whether this is a canonical channel, and if it is one it returns
* whether that can be relied upon.
*/
static int
channel_tls_is_canonical_method(channel_t *chan, int req)
{
int answer = 0;
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
if (tlschan->conn) {
switch (req) {
case 0:
answer = tlschan->conn->is_canonical;
break;
case 1:
/*
* Is the is_canonical bit reliable? In protocols version 2 and up
* we get the canonical address from a NETINFO cell, but in older
* versions it might be based on an obsolete descriptor.
*/
answer = (tlschan->conn->link_proto >= 2);
break;
default:
/* This shouldn't happen; channel.c is broken if it does */
tor_assert_nonfatal_unreached_once();
}
}
/* else return 0 for tlschan->conn == NULL */
return answer;
}
/**
* Check if we match an extend_info_t.
*
* This implements the matches_extend_info method for channel_tls_t; the upper
* layer wants to know if this channel matches an extend_info_t.
*/
static int
channel_tls_matches_extend_info_method(channel_t *chan,
extend_info_t *extend_info)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
tor_assert(extend_info);
/* Never match if we have no conn */
if (!(tlschan->conn)) {
log_info(LD_CHANNEL,
"something called matches_extend_info on a tlschan "
"(%p with ID %"PRIu64 " but no conn",
chan, (chan->global_identifier));
return 0;
}
return (tor_addr_eq(&(extend_info->addr),
&(TO_CONN(tlschan->conn)->addr)) &&
(extend_info->port == TO_CONN(tlschan->conn)->port));
}
/**
* Check if we match a target address; return true iff we do.
*
* This implements the matches_target method for channel_tls t_; the upper
* layer wants to know if this channel matches a target address when extending
* a circuit.
*/
static int
channel_tls_matches_target_method(channel_t *chan,
const tor_addr_t *target)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
tor_assert(target);
/* Never match if we have no conn */
if (!(tlschan->conn)) {
log_info(LD_CHANNEL,
"something called matches_target on a tlschan "
"(%p with ID %"PRIu64 " but no conn",
chan, (chan->global_identifier));
return 0;
}
/* real_addr is the address this connection came from.
* base_.addr is updated by connection_or_init_conn_from_address()
* to be the address in the descriptor. It may be tempting to
* allow either address to be allowed, but if we did so, it would
* enable someone who steals a relay's keys to impersonate/MITM it
* from anywhere on the Internet! (Because they could make long-lived
* TLS connections from anywhere to all relays, and wait for them to
* be used for extends).
*/
return tor_addr_eq(&(tlschan->conn->real_addr), target);
}
/**
* Tell the upper layer how many bytes we have queued and not yet
* sent.
*/
static size_t
channel_tls_num_bytes_queued_method(channel_t *chan)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
tor_assert(tlschan);
tor_assert(tlschan->conn);
return connection_get_outbuf_len(TO_CONN(tlschan->conn));
}
/**
* Tell the upper layer how many cells we can accept to write.
*
* This implements the num_cells_writeable method for channel_tls_t; it
* returns an estimate of the number of cells we can accept with
* channel_tls_write_*_cell().
*/
static int
channel_tls_num_cells_writeable_method(channel_t *chan)
{
size_t outbuf_len;
ssize_t n;
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
size_t cell_network_size;
tor_assert(tlschan);
tor_assert(tlschan->conn);
cell_network_size = get_cell_network_size(tlschan->conn->wide_circ_ids);
outbuf_len = connection_get_outbuf_len(TO_CONN(tlschan->conn));
/* Get the number of cells */
n = CEIL_DIV(OR_CONN_HIGHWATER - outbuf_len, cell_network_size);
if (n < 0) n = 0;
#if SIZEOF_SIZE_T > SIZEOF_INT
if (n > INT_MAX) n = INT_MAX;
#endif
return (int)n;
}
/**
* Write a cell to a channel_tls_t.
*
* This implements the write_cell method for channel_tls_t; given a
* channel_tls_t and a cell_t, transmit the cell_t.
*/
static int
channel_tls_write_cell_method(channel_t *chan, cell_t *cell)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
int written = 0;
tor_assert(tlschan);
tor_assert(cell);
if (tlschan->conn) {
connection_or_write_cell_to_buf(cell, tlschan->conn);
++written;
} else {
log_info(LD_CHANNEL,
"something called write_cell on a tlschan "
"(%p with ID %"PRIu64 " but no conn",
chan, (chan->global_identifier));
}
return written;
}
/**
* Write a packed cell to a channel_tls_t.
*
* This implements the write_packed_cell method for channel_tls_t; given a
* channel_tls_t and a packed_cell_t, transmit the packed_cell_t.
*
* Return 0 on success or negative value on error. The caller must free the
* packed cell.
*/
static int
channel_tls_write_packed_cell_method(channel_t *chan,
packed_cell_t *packed_cell)
{
tor_assert(chan);
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
size_t cell_network_size = get_cell_network_size(chan->wide_circ_ids);
tor_assert(tlschan);
tor_assert(packed_cell);
if (tlschan->conn) {
connection_buf_add(packed_cell->body, cell_network_size,
TO_CONN(tlschan->conn));
} else {
log_info(LD_CHANNEL,
"something called write_packed_cell on a tlschan "
"(%p with ID %"PRIu64 " but no conn",
chan, (chan->global_identifier));
return -1;
}
return 0;
}
/**
* Write a variable-length cell to a channel_tls_t.
*
* This implements the write_var_cell method for channel_tls_t; given a
* channel_tls_t and a var_cell_t, transmit the var_cell_t.
*/
static int
channel_tls_write_var_cell_method(channel_t *chan, var_cell_t *var_cell)
{
channel_tls_t *tlschan = BASE_CHAN_TO_TLS(chan);
int written = 0;
tor_assert(tlschan);
tor_assert(var_cell);
if (tlschan->conn) {
connection_or_write_var_cell_to_buf(var_cell, tlschan->conn);
++written;
} else {
log_info(LD_CHANNEL,
"something called write_var_cell on a tlschan "
"(%p with ID %"PRIu64 " but no conn",
chan, (chan->global_identifier));
}
return written;
}
/*************************************************
* Method implementations for channel_listener_t *
************************************************/
/**
* Close a channel_listener_t.
*
* This implements the close method for channel_listener_t.
*/
static void
channel_tls_listener_close_method(channel_listener_t *chan_l)
{
tor_assert(chan_l);
/*
* Listeners we just go ahead and change state through to CLOSED, but
* make sure to check if they're channel_tls_listener to NULL it out.
*/
if (chan_l == channel_tls_listener)
channel_tls_listener = NULL;
if (!(chan_l->state == CHANNEL_LISTENER_STATE_CLOSING ||
chan_l->state == CHANNEL_LISTENER_STATE_CLOSED ||
chan_l->state == CHANNEL_LISTENER_STATE_ERROR)) {
channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSING);
}
if (chan_l->incoming_list) {
SMARTLIST_FOREACH_BEGIN(chan_l->incoming_list,
channel_t *, ichan) {
channel_mark_for_close(ichan);
} SMARTLIST_FOREACH_END(ichan);
smartlist_free(chan_l->incoming_list);
chan_l->incoming_list = NULL;
}
if (!(chan_l->state == CHANNEL_LISTENER_STATE_CLOSED ||
chan_l->state == CHANNEL_LISTENER_STATE_ERROR)) {
channel_listener_change_state(chan_l, CHANNEL_LISTENER_STATE_CLOSED);
}
}
/**
* Describe the transport for a channel_listener_t.
*
* This returns the string "TLS channel (listening)" to the upper
* layer.
*/
static const char *
channel_tls_listener_describe_transport_method(channel_listener_t *chan_l)
{
tor_assert(chan_l);
return "TLS channel (listening)";
}
/*******************************************************
* Functions for handling events on an or_connection_t *
******************************************************/
/**
* Handle an orconn state change.
*
* This function will be called by connection_or.c when the or_connection_t
* associated with this channel_tls_t changes state.
*/
void
channel_tls_handle_state_change_on_orconn(channel_tls_t *chan,
or_connection_t *conn,
uint8_t state)
{
channel_t *base_chan;
tor_assert(chan);
tor_assert(conn);
tor_assert(conn->chan == chan);
tor_assert(chan->conn == conn);
base_chan = TLS_CHAN_TO_BASE(chan);
/* Make sure the base connection state makes sense - shouldn't be error
* or closed. */
tor_assert(CHANNEL_IS_OPENING(base_chan) ||
CHANNEL_IS_OPEN(base_chan) ||
CHANNEL_IS_MAINT(base_chan) ||
CHANNEL_IS_CLOSING(base_chan));
/* Did we just go to state open? */
if (state == OR_CONN_STATE_OPEN) {
/*
* We can go to CHANNEL_STATE_OPEN from CHANNEL_STATE_OPENING or
* CHANNEL_STATE_MAINT on this.
*/
channel_change_state_open(base_chan);
/* We might have just become writeable; check and tell the scheduler */
if (connection_or_num_cells_writeable(conn) > 0) {
scheduler_channel_wants_writes(base_chan);
}
} else {
/*
* Not open, so from CHANNEL_STATE_OPEN we go to CHANNEL_STATE_MAINT,
* otherwise no change.
*/
if (CHANNEL_IS_OPEN(base_chan)) {
channel_change_state(base_chan, CHANNEL_STATE_MAINT);
}
}
}
#ifdef KEEP_TIMING_STATS
/**
* Timing states wrapper.
*
* This is a wrapper function around the actual function that processes the
* <b>cell</b> that just arrived on <b>chan</b>. Increment <b>*time</b>