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r9289@31-35-219: nickm | 2006-10-20 09:43:22 -0400

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Fix longstanding bug in connection_exit_begin_conn():  Since connection_edge_end() exits when the connection is unattached, we were never sending RELAY_END cells back for failed RELAY_BEGIN attempts. Fix this.  This might make clients that were otherwise timing out either fail faster or retry faster, which is good news for us.


svn:r8770
This commit is contained in:
Nick Mathewson
2006-10-20 14:57:46 +00:00
parent 77936aa337
commit 136ed33071
5 changed files with 113 additions and 58 deletions
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ChangeLog
+4
View File
@@ -48,6 +48,10 @@ Changes in version 0.1.2.3-alpha - 2006-10-??
- Detect the size of the routers file correctly even if it is corrupted
(on systems without mmap) or not page-aligned (on systems with mmap).
This bug was harmless.
- Implement the protocol correctly by always sending a RELAY_END cell
when an attempt to open a stream fails. This should make clients
able to find a good exit faster in some cases, since unhandleable
requests will now get an error rather than timing out.
Changes in version 0.1.2.2-alpha - 2006-10-07
doc/TODO
+2 -2
View File
@@ -57,9 +57,9 @@ N . Have (and document) a BEGIN_DIR relay cell that means "Connect to your
- Use for something, so we can be sure it works.
- Test and debug
N - Send back RELAY_END cells on malformed RELAY_BEGIN.
o Send back RELAY_END cells on malformed RELAY_BEGIN.
N - Change the circuit end reason display a little for reasons from
o Change the circuit end reason display a little for reasons from
destroyed/truncated circuits. We want to indicate both that we're
closing because somebody told us to, and why they told us they wanted to
close.
src/or/connection_edge.c
+45 -20
View File
@@ -1838,36 +1838,51 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
relay_header_t rh;
char *address=NULL;
uint16_t port;
char end_payload[1];
assert_circuit_ok(circ);
/* XXX currently we don't send an end cell back if we drop the
* begin because it's malformed.
*/
relay_header_unpack(&rh, cell->payload);
/* Note: we have to use relay_send_command_from_edge here, not
* connection_edge_end or connection_edge_send_command, since those require
* that we have a stream connected to a circuit, and we don't connect to a
* circuit unitl we have a pending/sucessful resolve. */
if (!server_mode(get_options()) &&
circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell at non-server. Dropping.");
end_payload[0] = END_STREAM_REASON_EXITPOLICY;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
return 0;
}
relay_header_unpack(&rh, cell->payload);
if (rh.command == RELAY_COMMAND_BEGIN) {
if (!memchr(cell->payload+RELAY_HEADER_SIZE, 0, rh.length)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell has no \\0. Dropping.");
end_payload[0] = END_STREAM_REASON_TORPROTOCOL;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
return 0;
}
if (parse_addr_port(LOG_PROTOCOL_WARN, cell->payload+RELAY_HEADER_SIZE,
&address,NULL,&port)<0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Unable to parse addr:port in relay begin cell. Dropping.");
end_payload[0] = END_STREAM_REASON_TORPROTOCOL;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
return 0;
}
if (port==0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Missing port in relay begin cell. Dropping.");
end_payload[0] = END_STREAM_REASON_TORPROTOCOL;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
tor_free(address);
return 0;
}
@@ -1876,6 +1891,9 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Non-printing characters in address %s in relay "
"begin cell. Dropping.", escaped(address));
end_payload[0] = END_STREAM_REASON_TORPROTOCOL;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
tor_free(address);
return 0;
}
@@ -1886,15 +1904,27 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
*/
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Attempt to open a stream on first hop of circuit. Dropping.");
end_payload[0] = END_STREAM_REASON_TORPROTOCOL;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
tor_free(address);
return 0;
}
} else if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
or_options_t *options = get_options();
port = options->DirPort; /* not actually used to open a connection */
if (!port || circ->purpose != CIRCUIT_PURPOSE_OR) {
end_payload[0] = END_STREAM_REASON_NOTDIRECTORY;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
return 0;
}
address = tor_strdup("127.0.0.1");
port = options->DirPort; /* not actually used. */
} else {
log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command);
end_payload[0] = END_STREAM_REASON_INTERNAL;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
return 0;
}
@@ -1908,15 +1938,6 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
n_stream->package_window = STREAMWINDOW_START;
n_stream->deliver_window = STREAMWINDOW_START;
if (rh.command == RELAY_COMMAND_BEGIN_DIR &&
(!get_options()->DirPort || circ->purpose != CIRCUIT_PURPOSE_OR)) {
connection_edge_end(n_stream, END_STREAM_REASON_NOTDIRECTORY,
n_stream->cpath_layer);
connection_free(TO_CONN(n_stream));
tor_free(address);
return 0;
}
if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) {
origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(circ);
log_debug(LD_REND,"begin is for rendezvous. configuring stream.");
@@ -1929,8 +1950,9 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
if (rend_service_set_connection_addr_port(n_stream, origin_circ) < 0) {
log_info(LD_REND,"Didn't find rendezvous service (port %d)",
n_stream->_base.port);
connection_edge_end(n_stream, END_STREAM_REASON_EXITPOLICY,
n_stream->cpath_layer);
end_payload[0] = END_STREAM_REASON_EXITPOLICY;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
connection_free(TO_CONN(n_stream));
/* knock the whole thing down, somebody screwed up */
circuit_mark_for_close(circ, END_CIRC_REASON_CONNECTFAILED);
@@ -1957,8 +1979,9 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
/* default to failed, change in dns_resolve if it turns out not to fail */
if (we_are_hibernating()) {
connection_edge_end(n_stream, END_STREAM_REASON_HIBERNATING,
n_stream->cpath_layer);
end_payload[0] = END_STREAM_REASON_HIBERNATING;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
connection_free(TO_CONN(n_stream));
return 0;
}
@@ -1985,7 +2008,9 @@ connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
connection_exit_connect(n_stream);
return 0;
case -1: /* resolve failed */
/* XXXX send back indication of failure for connect case? -NM*/
end_payload[0] = END_STREAM_REASON_RESOLVEFAILED;
relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END,
end_payload, 1, NULL);
/* n_stream got freed. don't touch it. */
break;
case 0: /* resolve added to pending list */
@@ -2157,7 +2182,7 @@ connection_exit_connect_dir(edge_connection_t *exit_conn)
if ((err = tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fd)) < 0) {
log_warn(LD_NET,
"Couldn't construct socketpair (%s). Network down? Delaying.",
"Couldn't construct socketpair (%s). Out of sockets?",
tor_socket_strerror(-err));
connection_edge_end(exit_conn, END_STREAM_REASON_RESOURCELIMIT,
exit_conn->cpath_layer);
src/or/or.h
+3
View File
@@ -2332,6 +2332,9 @@ int circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
void relay_header_pack(char *dest, const relay_header_t *src);
void relay_header_unpack(relay_header_t *dest, const char *src);
int relay_send_command_from_edge(uint16_t stream_id, circuit_t *circ,
int relay_command, const char *payload,
size_t payload_len, crypt_path_t *cpath_layer);
int connection_edge_send_command(edge_connection_t *fromconn, circuit_t *circ,
int relay_command, const char *payload,
size_t payload_len,
src/or/relay.c
+59 -36
View File
@@ -446,6 +446,61 @@ relay_header_unpack(relay_header_t *dest, const char *src)
dest->length = ntohs(get_uint16(src+9));
}
/** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and send
* it onto the open circuit <b>circ</b>. <b>stream_id</b> is the ID on
* <b>circ</b> for the stream that's sending the relay cell, or 0 if it's a
* control cell. <b>cpath_layer</b> is NULL for OR->OP cells, or the
* destination hop for OP->OR cells.
*
* If you can't send the cell, mark the circuit for close and return -1. Else
* return 0.
*/
int
relay_send_command_from_edge(uint16_t stream_id, circuit_t *circ,
int relay_command, const char *payload,
size_t payload_len, crypt_path_t *cpath_layer)
{
cell_t cell;
relay_header_t rh;
int cell_direction;
/* XXXX NM Split this function into a separate versions per circuit type? */
tor_assert(circ);
memset(&cell, 0, sizeof(cell_t));
cell.command = CELL_RELAY;
if (cpath_layer) {
cell.circ_id = circ->n_circ_id;
cell_direction = CELL_DIRECTION_OUT;
} else if (! CIRCUIT_IS_ORIGIN(circ)) {
cell.circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
cell_direction = CELL_DIRECTION_IN;
} else {
return -1;
}
memset(&rh, 0, sizeof(rh));
rh.command = relay_command;
rh.stream_id = stream_id;
rh.length = payload_len;
relay_header_pack(cell.payload, &rh);
if (payload_len) {
tor_assert(payload_len <= RELAY_PAYLOAD_SIZE);
memcpy(cell.payload+RELAY_HEADER_SIZE, payload, payload_len);
}
log_debug(LD_OR,"delivering %d cell %s.", relay_command,
cell_direction == CELL_DIRECTION_OUT ? "forward" : "backward");
if (circuit_package_relay_cell(&cell, circ, cell_direction, cpath_layer)
< 0) {
log_warn(LD_BUG,"circuit_package_relay_cell failed. Closing.");
circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
return -1;
}
return 0;
}
/** Make a relay cell out of <b>relay_command</b> and <b>payload</b>, and
* send it onto the open circuit <b>circ</b>. <b>fromconn</b> is the stream
* that's sending the relay cell, or NULL if it's a control cell.
@@ -460,9 +515,6 @@ connection_edge_send_command(edge_connection_t *fromconn, circuit_t *circ,
int relay_command, const char *payload,
size_t payload_len, crypt_path_t *cpath_layer)
{
cell_t cell;
relay_header_t rh;
int cell_direction;
/* XXXX NM Split this function into a separate versions per circuit type? */
if (fromconn && fromconn->_base.marked_for_close) {
@@ -486,39 +538,9 @@ connection_edge_send_command(edge_connection_t *fromconn, circuit_t *circ,
return -1;
}
memset(&cell, 0, sizeof(cell_t));
cell.command = CELL_RELAY;
if (cpath_layer) {
cell.circ_id = circ->n_circ_id;
cell_direction = CELL_DIRECTION_OUT;
} else if (! CIRCUIT_IS_ORIGIN(circ)) {
cell.circ_id = TO_OR_CIRCUIT(circ)->p_circ_id;
cell_direction = CELL_DIRECTION_IN;
} else {
return -1;
}
memset(&rh, 0, sizeof(rh));
rh.command = relay_command;
if (fromconn)
rh.stream_id = fromconn->stream_id; /* else it's 0 */
rh.length = payload_len;
relay_header_pack(cell.payload, &rh);
if (payload_len) {
tor_assert(payload_len <= RELAY_PAYLOAD_SIZE);
memcpy(cell.payload+RELAY_HEADER_SIZE, payload, payload_len);
}
log_debug(LD_OR,"delivering %d cell %s.", relay_command,
cell_direction == CELL_DIRECTION_OUT ? "forward" : "backward");
if (circuit_package_relay_cell(&cell, circ, cell_direction, cpath_layer)
< 0) {
log_warn(LD_BUG,"circuit_package_relay_cell failed. Closing.");
circuit_mark_for_close(circ, END_CIRC_REASON_INTERNAL);
return -1;
}
return 0;
return relay_send_command_from_edge(fromconn ? fromconn->stream_id : 0,
circ, relay_command, payload,
payload_len, cpath_layer);
}
/** Translate <b>reason</b>, which came from a relay 'end' cell,
@@ -545,6 +567,7 @@ connection_edge_end_reason_str(int reason)
case END_STREAM_REASON_RESOURCELIMIT: return "server out of resources";
case END_STREAM_REASON_CONNRESET: return "connection reset";
case END_STREAM_REASON_TORPROTOCOL: return "Tor protocol error";
case END_STREAM_REASON_NOTDIRECTORY: return "not a directory";
default:
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Reason for ending (%d) not recognized.",reason);