/** Process a 'create' <b>cell</b> that just arrived from <b>conn</b>. Make a
* new circuit with the p_circ_id specified in cell. Put the circuit in state
* onionskin_pending, and pass the onionskin to the cpuworker. Circ will get
* picked up again when the cpuworker finishes decrypting it.
*/
static void
command_process_create_cell(cell_t *cell, or_connection_t *conn)
{
or_circuit_t *circ;
const or_options_t *options = get_options();
int id_is_high;
if (we_are_hibernating()) {
log_info(LD_OR,
"Received create cell but we're shutting down. Sending back "
"destroy.");
connection_or_send_destroy(cell->circ_id, conn,
END_CIRC_REASON_HIBERNATING);
return;
}
if (!server_mode(options) ||
(!public_server_mode(options) && conn->is_outgoing)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received create cell (type %d) from %s:%d, but we're connected "
"to it as a client. "
"Sending back a destroy.",
(int)cell->command, conn->_base.address, conn->_base.port);
connection_or_send_destroy(cell->circ_id, conn,
END_CIRC_REASON_TORPROTOCOL);
return;
}
/* If the high bit of the circuit ID is not as expected, close the
* circ. */
id_is_high = cell->circ_id & (1<<15);
if ((id_is_high && conn->circ_id_type == CIRC_ID_TYPE_HIGHER) ||
(!id_is_high && conn->circ_id_type == CIRC_ID_TYPE_LOWER)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received create cell with unexpected circ_id %d. Closing.",
cell->circ_id);
connection_or_send_destroy(cell->circ_id, conn,
END_CIRC_REASON_TORPROTOCOL);
return;
}
if (circuit_id_in_use_on_orconn(cell->circ_id, conn)) {
const node_t *node = node_get_by_id(conn->identity_digest);
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received CREATE cell (circID %d) for known circ. "
"Dropping (age %d).",
cell->circ_id, (int)(time(NULL) - conn->_base.timestamp_created));
if (node) {
char *p = esc_for_log(node_get_platform(node));
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Details: router %s, platform %s.",
node_describe(node), p);
tor_free(p);
}
return;
}
circ = or_circuit_new(cell->circ_id, conn);
circ->_base.purpose = CIRCUIT_PURPOSE_OR;
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_ONIONSKIN_PENDING);
if (cell->command == CELL_CREATE) {
char *onionskin = tor_malloc(ONIONSKIN_CHALLENGE_LEN);
memcpy(onionskin, cell->payload, ONIONSKIN_CHALLENGE_LEN);
/* hand it off to the cpuworkers, and then return. */
if (assign_onionskin_to_cpuworker(NULL, circ, onionskin) < 0) {
#define WARN_HANDOFF_FAILURE_INTERVAL (6*60*60)
static ratelim_t handoff_warning =
RATELIM_INIT(WARN_HANDOFF_FAILURE_INTERVAL);
char *m;
if ((m = rate_limit_log(&handoff_warning, approx_time()))) {
log_warn(LD_GENERAL,"Failed to hand off onionskin. Closing.%s",m);
tor_free(m);
}
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
log_debug(LD_OR,"success: handed off onionskin.");
} else {
/* This is a CREATE_FAST cell; we can handle it immediately without using
* a CPU worker. */
char keys[CPATH_KEY_MATERIAL_LEN];
char reply[DIGEST_LEN*2];
tor_assert(cell->command == CELL_CREATE_FAST);
/* Make sure we never try to use the OR connection on which we
* received this cell to satisfy an EXTEND request, */
conn->is_connection_with_client = 1;
if (fast_server_handshake(cell->payload, (uint8_t*)reply,
(uint8_t*)keys, sizeof(keys))<0) {
log_warn(LD_OR,"Failed to generate key material. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
if (onionskin_answer(circ, CELL_CREATED_FAST, reply, keys)<0) {
log_warn(LD_OR,"Failed to reply to CREATE_FAST cell. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
}
}
/** Called when we get data from a cpuworker. If the answer is not complete,
* wait for a complete answer. If the answer is complete,
* process it as appropriate.
*/
int
connection_cpu_process_inbuf(connection_t *conn)
{
uint64_t chan_id;
circid_t circ_id;
channel_t *p_chan = NULL;
circuit_t *circ;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_CPUWORKER);
if (!connection_get_inbuf_len(conn))
return 0;
if (conn->state == CPUWORKER_STATE_BUSY_ONION) {
cpuworker_reply_t rpl;
if (connection_get_inbuf_len(conn) < sizeof(cpuworker_reply_t))
return 0; /* not yet */
tor_assert(connection_get_inbuf_len(conn) == sizeof(cpuworker_reply_t));
connection_fetch_from_buf((void*)&rpl,sizeof(cpuworker_reply_t),conn);
tor_assert(rpl.magic == CPUWORKER_REPLY_MAGIC);
if (rpl.timed && rpl.success &&
rpl.handshake_type <= MAX_ONION_HANDSHAKE_TYPE) {
/* Time how long this request took. The handshake_type check should be
needless, but let's leave it in to be safe. */
struct timeval tv_end, tv_diff;
int64_t usec_roundtrip;
tor_gettimeofday(&tv_end);
timersub(&tv_end, &rpl.started_at, &tv_diff);
usec_roundtrip = ((int64_t)tv_diff.tv_sec)*1000000 + tv_diff.tv_usec;
if (usec_roundtrip >= 0 &&
usec_roundtrip < MAX_BELIEVABLE_ONIONSKIN_DELAY) {
++onionskins_n_processed[rpl.handshake_type];
onionskins_usec_internal[rpl.handshake_type] += rpl.n_usec;
onionskins_usec_roundtrip[rpl.handshake_type] += usec_roundtrip;
if (onionskins_n_processed[rpl.handshake_type] >= 500000) {
/* Scale down every 500000 handshakes. On a busy server, that's
* less impressive than it sounds. */
onionskins_n_processed[rpl.handshake_type] /= 2;
onionskins_usec_internal[rpl.handshake_type] /= 2;
onionskins_usec_roundtrip[rpl.handshake_type] /= 2;
}
}
}
/* parse out the circ it was talking about */
tag_unpack(rpl.tag, &chan_id, &circ_id);
circ = NULL;
log_debug(LD_OR,
"Unpacking cpuworker reply, chan_id is " U64_FORMAT
", circ_id is %u",
U64_PRINTF_ARG(chan_id), (unsigned)circ_id);
p_chan = channel_find_by_global_id(chan_id);
if (p_chan)
circ = circuit_get_by_circid_channel(circ_id, p_chan);
if (rpl.success == 0) {
log_debug(LD_OR,
"decoding onionskin failed. "
"(Old key or bad software.) Closing.");
if (circ)
circuit_mark_for_close(circ, END_CIRC_REASON_TORPROTOCOL);
goto done_processing;
}
if (!circ) {
/* This happens because somebody sends us a destroy cell and the
* circuit goes away, while the cpuworker is working. This is also
* why our tag doesn't include a pointer to the circ, because we'd
* never know if it's still valid.
*/
log_debug(LD_OR,"processed onion for a circ that's gone. Dropping.");
goto done_processing;
}
tor_assert(! CIRCUIT_IS_ORIGIN(circ));
if (onionskin_answer(TO_OR_CIRCUIT(circ),
&rpl.created_cell,
(const char*)rpl.keys,
rpl.rend_auth_material) < 0) {
log_warn(LD_OR,"onionskin_answer failed. Closing.");
circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
goto done_processing;
}
log_debug(LD_OR,"onionskin_answer succeeded. Yay.");
} else {
tor_assert(0); /* don't ask me to do handshakes yet */
}
done_processing:
conn->state = CPUWORKER_STATE_IDLE;
num_cpuworkers_busy--;
if (conn->timestamp_created < last_rotation_time) {
connection_mark_for_close(conn);
num_cpuworkers--;
spawn_enough_cpuworkers();
} else {
process_pending_task(conn);
}
return 0;
}
/** Process a 'create' <b>cell</b> that just arrived from <b>conn</b>. Make a
* new circuit with the p_circ_id specified in cell. Put the circuit in state
* onionskin_pending, and pass the onionskin to the cpuworker. Circ will get
* picked up again when the cpuworker finishes decrypting it.
*/
static void
command_process_create_cell(cell_t *cell, or_connection_t *conn)
{
or_circuit_t *circ;
int id_is_high;
if (we_are_hibernating()) {
log_info(LD_OR,
"Received create cell but we're shutting down. Sending back "
"destroy.");
connection_or_send_destroy(cell->circ_id, conn,
END_CIRC_REASON_HIBERNATING);
return;
}
if (!server_mode(get_options())) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received create cell (type %d) from %s:%d, but we're a client. "
"Sending back a destroy.",
(int)cell->command, conn->_base.address, conn->_base.port);
connection_or_send_destroy(cell->circ_id, conn,
END_CIRC_REASON_TORPROTOCOL);
return;
}
/* If the high bit of the circuit ID is not as expected, close the
* circ. */
id_is_high = cell->circ_id & (1<<15);
if ((id_is_high && conn->circ_id_type == CIRC_ID_TYPE_HIGHER) ||
(!id_is_high && conn->circ_id_type == CIRC_ID_TYPE_LOWER)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received create cell with unexpected circ_id %d. Closing.",
cell->circ_id);
connection_or_send_destroy(cell->circ_id, conn,
END_CIRC_REASON_TORPROTOCOL);
return;
}
if (circuit_id_in_use_on_orconn(cell->circ_id, conn)) {
routerinfo_t *router = router_get_by_digest(conn->identity_digest);
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received CREATE cell (circID %d) for known circ. "
"Dropping (age %d).",
cell->circ_id, (int)(time(NULL) - conn->_base.timestamp_created));
if (router)
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Details: nickname \"%s\", platform %s.",
router->nickname, escaped(router->platform));
return;
}
circ = or_circuit_new(cell->circ_id, conn);
circ->_base.purpose = CIRCUIT_PURPOSE_OR;
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_ONIONSKIN_PENDING);
if (cell->command == CELL_CREATE) {
char *onionskin = tor_malloc(ONIONSKIN_CHALLENGE_LEN);
memcpy(onionskin, cell->payload, ONIONSKIN_CHALLENGE_LEN);
/* hand it off to the cpuworkers, and then return. */
if (assign_onionskin_to_cpuworker(NULL, circ, onionskin) < 0) {
log_warn(LD_GENERAL,"Failed to hand off onionskin. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
log_debug(LD_OR,"success: handed off onionskin.");
} else {
/* This is a CREATE_FAST cell; we can handle it immediately without using
* a CPU worker. */
char keys[CPATH_KEY_MATERIAL_LEN];
char reply[DIGEST_LEN*2];
tor_assert(cell->command == CELL_CREATE_FAST);
if (fast_server_handshake(cell->payload, reply, keys, sizeof(keys))<0) {
log_warn(LD_OR,"Failed to generate key material. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
if (onionskin_answer(circ, CELL_CREATED_FAST, reply, keys)<0) {
log_warn(LD_OR,"Failed to reply to CREATE_FAST cell. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
}
}
/** Called when we get data from a cpuworker. If the answer is not complete,
* wait for a complete answer. If the answer is complete,
* process it as appropriate.
*/
int
connection_cpu_process_inbuf(connection_t *conn)
{
char success;
char buf[LEN_ONION_RESPONSE];
uint64_t conn_id;
circid_t circ_id;
connection_t *tmp_conn;
or_connection_t *p_conn = NULL;
circuit_t *circ;
tor_assert(conn);
tor_assert(conn->type == CONN_TYPE_CPUWORKER);
if (!buf_datalen(conn->inbuf))
return 0;
if (conn->state == CPUWORKER_STATE_BUSY_ONION) {
if (buf_datalen(conn->inbuf) < LEN_ONION_RESPONSE) /* answer available? */
return 0; /* not yet */
tor_assert(buf_datalen(conn->inbuf) == LEN_ONION_RESPONSE);
connection_fetch_from_buf(&success,1,conn);
connection_fetch_from_buf(buf,LEN_ONION_RESPONSE-1,conn);
/* parse out the circ it was talking about */
tag_unpack(buf, &conn_id, &circ_id);
circ = NULL;
tmp_conn = connection_get_by_global_id(conn_id);
if (tmp_conn && !tmp_conn->marked_for_close &&
tmp_conn->type == CONN_TYPE_OR)
p_conn = TO_OR_CONN(tmp_conn);
if (p_conn)
circ = circuit_get_by_circid_orconn(circ_id, p_conn);
if (success == 0) {
log_debug(LD_OR,
"decoding onionskin failed. "
"(Old key or bad software.) Closing.");
if (circ)
circuit_mark_for_close(circ, END_CIRC_REASON_TORPROTOCOL);
goto done_processing;
}
if (!circ) {
/* This happens because somebody sends us a destroy cell and the
* circuit goes away, while the cpuworker is working. This is also
* why our tag doesn't include a pointer to the circ, because we'd
* never know if it's still valid.
*/
log_debug(LD_OR,"processed onion for a circ that's gone. Dropping.");
goto done_processing;
}
tor_assert(! CIRCUIT_IS_ORIGIN(circ));
if (onionskin_answer(TO_OR_CIRCUIT(circ), CELL_CREATED, buf+TAG_LEN,
buf+TAG_LEN+ONIONSKIN_REPLY_LEN) < 0) {
log_warn(LD_OR,"onionskin_answer failed. Closing.");
circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
goto done_processing;
}
log_debug(LD_OR,"onionskin_answer succeeded. Yay.");
} else {
tor_assert(0); /* don't ask me to do handshakes yet */
}
done_processing:
conn->state = CPUWORKER_STATE_IDLE;
num_cpuworkers_busy--;
if (conn->timestamp_created < last_rotation_time) {
connection_mark_for_close(conn);
num_cpuworkers--;
spawn_enough_cpuworkers();
} else {
process_pending_task(conn);
}
return 0;
}
/** Process a 'create' <b>cell</b> that just arrived from <b>chan</b>. Make a
* new circuit with the p_circ_id specified in cell. Put the circuit in state
* onionskin_pending, and pass the onionskin to the cpuworker. Circ will get
* picked up again when the cpuworker finishes decrypting it.
*/
static void
command_process_create_cell(cell_t *cell, channel_t *chan)
{
or_circuit_t *circ;
const or_options_t *options = get_options();
int id_is_high;
create_cell_t *create_cell;
tor_assert(cell);
tor_assert(chan);
log_debug(LD_OR,
"Got a CREATE cell for circ_id %u on channel " U64_FORMAT
" (%p)",
(unsigned)cell->circ_id,
U64_PRINTF_ARG(chan->global_identifier), chan);
if (we_are_hibernating()) {
log_info(LD_OR,
"Received create cell but we're shutting down. Sending back "
"destroy.");
channel_send_destroy(cell->circ_id, chan,
END_CIRC_REASON_HIBERNATING);
return;
}
if (!server_mode(options) ||
(!public_server_mode(options) && channel_is_outgoing(chan))) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received create cell (type %d) from %s, but we're connected "
"to it as a client. "
"Sending back a destroy.",
(int)cell->command, channel_get_canonical_remote_descr(chan));
channel_send_destroy(cell->circ_id, chan,
END_CIRC_REASON_TORPROTOCOL);
return;
}
if (cell->circ_id == 0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received a create cell (type %d) from %s with zero circID; "
" ignoring.", (int)cell->command,
channel_get_actual_remote_descr(chan));
return;
}
/* If the high bit of the circuit ID is not as expected, close the
* circ. */
if (chan->wide_circ_ids)
id_is_high = cell->circ_id & (1u<<31);
else
id_is_high = cell->circ_id & (1u<<15);
if ((id_is_high &&
chan->circ_id_type == CIRC_ID_TYPE_HIGHER) ||
(!id_is_high &&
chan->circ_id_type == CIRC_ID_TYPE_LOWER)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received create cell with unexpected circ_id %u. Closing.",
(unsigned)cell->circ_id);
channel_send_destroy(cell->circ_id, chan,
END_CIRC_REASON_TORPROTOCOL);
return;
}
if (circuit_id_in_use_on_channel(cell->circ_id, chan)) {
const node_t *node = node_get_by_id(chan->identity_digest);
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Received CREATE cell (circID %u) for known circ. "
"Dropping (age %d).",
(unsigned)cell->circ_id,
(int)(time(NULL) - channel_when_created(chan)));
if (node) {
char *p = esc_for_log(node_get_platform(node));
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Details: router %s, platform %s.",
node_describe(node), p);
tor_free(p);
}
return;
}
circ = or_circuit_new(cell->circ_id, chan);
circ->base_.purpose = CIRCUIT_PURPOSE_OR;
circuit_set_state(TO_CIRCUIT(circ), CIRCUIT_STATE_ONIONSKIN_PENDING);
create_cell = tor_malloc_zero(sizeof(create_cell_t));
if (create_cell_parse(create_cell, cell) < 0) {
tor_free(create_cell);
log_fn(LOG_PROTOCOL_WARN, LD_OR,
"Bogus/unrecognized create cell; closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_TORPROTOCOL);
return;
}
if (create_cell->handshake_type != ONION_HANDSHAKE_TYPE_FAST) {
/* hand it off to the cpuworkers, and then return. */
if (connection_or_digest_is_known_relay(chan->identity_digest))
rep_hist_note_circuit_handshake_requested(create_cell->handshake_type);
if (assign_onionskin_to_cpuworker(NULL, circ, create_cell) < 0) {
log_debug(LD_GENERAL,"Failed to hand off onionskin. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_RESOURCELIMIT);
return;
}
log_debug(LD_OR,"success: handed off onionskin.");
} else {
/* This is a CREATE_FAST cell; we can handle it immediately without using
* a CPU worker. */
uint8_t keys[CPATH_KEY_MATERIAL_LEN];
uint8_t rend_circ_nonce[DIGEST_LEN];
int len;
created_cell_t created_cell;
/* Make sure we never try to use the OR connection on which we
* received this cell to satisfy an EXTEND request, */
channel_mark_client(chan);
memset(&created_cell, 0, sizeof(created_cell));
len = onion_skin_server_handshake(ONION_HANDSHAKE_TYPE_FAST,
create_cell->onionskin,
create_cell->handshake_len,
NULL,
created_cell.reply,
keys, CPATH_KEY_MATERIAL_LEN,
rend_circ_nonce);
tor_free(create_cell);
if (len < 0) {
log_warn(LD_OR,"Failed to generate key material. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
tor_free(create_cell);
return;
}
created_cell.cell_type = CELL_CREATED_FAST;
created_cell.handshake_len = len;
if (onionskin_answer(circ, &created_cell,
(const char *)keys, rend_circ_nonce)<0) {
log_warn(LD_OR,"Failed to reply to CREATE_FAST cell. Closing.");
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_INTERNAL);
return;
}
memwipe(keys, 0, sizeof(keys));
}
}
