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/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2016, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file connection_edge.c
* \brief Handle edge streams.
*
* An edge_connection_t is a subtype of a connection_t, and represents two
* critical concepts in Tor: a stream, and an edge connection. From the Tor
* protocol's point of view, a stream is a bi-directional channel that is
* multiplexed on a single circuit. Each stream on a circuit is identified
* with a separate 16-bit stream ID, local to the (circuit,exit) pair.
* Streams are created in response to client requests.
*
* An edge connection is one thing that can implement a stream: it is either a
* TCP application socket that has arrived via (e.g.) a SOCKS request, or an
* exit connection.
*
* Not every instance of edge_connection_t truly represents an edge connction,
* however. (Sorry!) We also create edge_connection_t objects for streams that
* we will not be handling with TCP. The types of these streams are:
* <ul>
* <li>DNS lookup streams, created on the client side in response to
* a UDP DNS request received on a DNSPort, or a RESOLVE command
* on a controller.
* <li>DNS lookup streams, created on the exit side in response to
* a RELAY_RESOLVE cell from a client.
* <li>Tunneled directory streams, created on the directory cache side
* in response to a RELAY_BEGINDIR cell. These streams attach directly
* to a dir_connection_t object without ever using TCP.
* </ul>
*
* This module handles general-purpose functionality having to do with
* edge_connection_t. On the client side, it accepts various types of
* application requests on SocksPorts, TransPorts, and NATDPorts, and
* creates streams appropriately.
*
* This module is also responsible for implementing stream isolation:
* ensuring that streams that should not be linkable to one another are
* kept to different circuits.
*
* On the exit side, this module handles the various stream-creating
* type of RELAY cells by launching appropriate outgoing connections,
* DNS requests, or directory connection objects.
*
* And for all edge connections, this module is responsible for handling
* incoming and outdoing data as it arrives or leaves in the relay.c
* module. (Outgoing data will be packaged in
* connection_edge_process_inbuf() as it calls
* connection_edge_package_raw_inbuf(); incoming data from RELAY_DATA
* cells is applied in connection_edge_process_relay_cell().)
**/
#define CONNECTION_EDGE_PRIVATE
#include "or.h"
#include "backtrace.h"
#include "addressmap.h"
#include "buffers.h"
#include "channel.h"
#include "circpathbias.h"
#include "circuitlist.h"
#include "circuituse.h"
#include "config.h"
#include "connection.h"
#include "connection_edge.h"
#include "connection_or.h"
#include "control.h"
#include "dns.h"
#include "dnsserv.h"
#include "directory.h"
#include "dirserv.h"
#include "hibernate.h"
#include "hs_common.h"
#include "main.h"
#include "nodelist.h"
#include "policies.h"
#include "reasons.h"
#include "relay.h"
#include "rendclient.h"
#include "rendcommon.h"
#include "rendservice.h"
#include "rephist.h"
#include "router.h"
#include "routerlist.h"
#include "routerset.h"
#include "circuitbuild.h"
#ifdef HAVE_LINUX_TYPES_H
#include <linux/types.h>
#endif
#ifdef HAVE_LINUX_NETFILTER_IPV4_H
#include <linux/netfilter_ipv4.h>
#define TRANS_NETFILTER
#define TRANS_NETFILTER_IPV4
#endif
#ifdef HAVE_LINUX_IF_H
#include <linux/if.h>
#endif
#ifdef HAVE_LINUX_NETFILTER_IPV6_IP6_TABLES_H
#include <linux/netfilter_ipv6/ip6_tables.h>
#if defined(IP6T_SO_ORIGINAL_DST)
#define TRANS_NETFILTER
#define TRANS_NETFILTER_IPV6
#endif
#endif
#if defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H)
#include <net/if.h>
#include <net/pfvar.h>
#define TRANS_PF
#endif
#ifdef IP_TRANSPARENT
#define TRANS_TPROXY
#endif
#define SOCKS4_GRANTED 90
#define SOCKS4_REJECT 91
static int connection_ap_handshake_process_socks(entry_connection_t *conn);
static int connection_ap_process_natd(entry_connection_t *conn);
static int connection_exit_connect_dir(edge_connection_t *exitconn);
static int consider_plaintext_ports(entry_connection_t *conn, uint16_t port);
static int connection_ap_supports_optimistic_data(const entry_connection_t *);
/** An AP stream has failed/finished. If it hasn't already sent back
* a socks reply, send one now (based on endreason). Also set
* has_sent_end to 1, and mark the conn.
*/
MOCK_IMPL(void,
connection_mark_unattached_ap_,(entry_connection_t *conn, int endreason,
int line, const char *file))
{
connection_t *base_conn = ENTRY_TO_CONN(conn);
edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
tor_assert(base_conn->type == CONN_TYPE_AP);
ENTRY_TO_EDGE_CONN(conn)->edge_has_sent_end = 1; /* no circ yet */
/* If this is a rendezvous stream and it is failing without ever
* being attached to a circuit, assume that an attempt to connect to
* the destination hidden service has just ended.
*
* XXXX This condition doesn't limit to only streams failing
* without ever being attached. That sloppiness should be harmless,
* but we should fix it someday anyway. */
if ((edge_conn->on_circuit != NULL || edge_conn->edge_has_sent_end) &&
connection_edge_is_rendezvous_stream(edge_conn)) {
rend_client_note_connection_attempt_ended(edge_conn->rend_data);
}
if (base_conn->marked_for_close) {
/* This call will warn as appropriate. */
connection_mark_for_close_(base_conn, line, file);
return;
}
if (!conn->socks_request->has_finished) {
if (endreason & END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED)
log_warn(LD_BUG,
"stream (marked at %s:%d) sending two socks replies?",
file, line);
if (SOCKS_COMMAND_IS_CONNECT(conn->socks_request->command))
connection_ap_handshake_socks_reply(conn, NULL, 0, endreason);
else if (SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command))
connection_ap_handshake_socks_resolved(conn,
RESOLVED_TYPE_ERROR_TRANSIENT,
0, NULL, -1, -1);
else /* unknown or no handshake at all. send no response. */
conn->socks_request->has_finished = 1;
}
connection_mark_and_flush_(base_conn, line, file);
ENTRY_TO_EDGE_CONN(conn)->end_reason = endreason;
}
/** There was an EOF. Send an end and mark the connection for close.
*/
int
connection_edge_reached_eof(edge_connection_t *conn)
{
if (connection_get_inbuf_len(TO_CONN(conn)) &&
connection_state_is_open(TO_CONN(conn))) {
/* it still has stuff to process. don't let it die yet. */
return 0;
}
log_info(LD_EDGE,"conn (fd "TOR_SOCKET_T_FORMAT") reached eof. Closing.",
conn->base_.s);
if (!conn->base_.marked_for_close) {
/* only mark it if not already marked. it's possible to
* get the 'end' right around when the client hangs up on us. */
connection_edge_end(conn, END_STREAM_REASON_DONE);
if (conn->base_.type == CONN_TYPE_AP) {
/* eof, so don't send a socks reply back */
if (EDGE_TO_ENTRY_CONN(conn)->socks_request)
EDGE_TO_ENTRY_CONN(conn)->socks_request->has_finished = 1;
}
connection_mark_for_close(TO_CONN(conn));
}
return 0;
}
/** Handle new bytes on conn->inbuf based on state:
* - If it's waiting for socks info, try to read another step of the
* socks handshake out of conn->inbuf.
* - If it's waiting for the original destination, fetch it.
* - If it's open, then package more relay cells from the stream.
* - Else, leave the bytes on inbuf alone for now.
*
* Mark and return -1 if there was an unexpected error with the conn,
* else return 0.
*/
int
connection_edge_process_inbuf(edge_connection_t *conn, int package_partial)
{
tor_assert(conn);
switch (conn->base_.state) {
case AP_CONN_STATE_SOCKS_WAIT:
if (connection_ap_handshake_process_socks(EDGE_TO_ENTRY_CONN(conn)) <0) {
/* already marked */
return -1;
}
return 0;
case AP_CONN_STATE_NATD_WAIT:
if (connection_ap_process_natd(EDGE_TO_ENTRY_CONN(conn)) < 0) {
/* already marked */
return -1;
}
return 0;
case AP_CONN_STATE_OPEN:
case EXIT_CONN_STATE_OPEN:
if (connection_edge_package_raw_inbuf(conn, package_partial, NULL) < 0) {
/* (We already sent an end cell if possible) */
connection_mark_for_close(TO_CONN(conn));
return -1;
}
return 0;
case AP_CONN_STATE_CONNECT_WAIT:
if (connection_ap_supports_optimistic_data(EDGE_TO_ENTRY_CONN(conn))) {
log_info(LD_EDGE,
"data from edge while in '%s' state. Sending it anyway. "
"package_partial=%d, buflen=%ld",
conn_state_to_string(conn->base_.type, conn->base_.state),
package_partial,
(long)connection_get_inbuf_len(TO_CONN(conn)));
if (connection_edge_package_raw_inbuf(conn, package_partial, NULL)<0) {
/* (We already sent an end cell if possible) */
connection_mark_for_close(TO_CONN(conn));
return -1;
}
return 0;
}
/* Fall through if the connection is on a circuit without optimistic
* data support. */
/* Falls through. */
case EXIT_CONN_STATE_CONNECTING:
case AP_CONN_STATE_RENDDESC_WAIT:
case AP_CONN_STATE_CIRCUIT_WAIT:
case AP_CONN_STATE_RESOLVE_WAIT:
case AP_CONN_STATE_CONTROLLER_WAIT:
log_info(LD_EDGE,
"data from edge while in '%s' state. Leaving it on buffer.",
conn_state_to_string(conn->base_.type, conn->base_.state));
return 0;
}
log_warn(LD_BUG,"Got unexpected state %d. Closing.",conn->base_.state);
tor_fragile_assert();
connection_edge_end(conn, END_STREAM_REASON_INTERNAL);
connection_mark_for_close(TO_CONN(conn));
return -1;
}
/** This edge needs to be closed, because its circuit has closed.
* Mark it for close and return 0.
*/
int
connection_edge_destroy(circid_t circ_id, edge_connection_t *conn)
{
if (!conn->base_.marked_for_close) {
log_info(LD_EDGE, "CircID %u: At an edge. Marking connection for close.",
(unsigned) circ_id);
if (conn->base_.type == CONN_TYPE_AP) {
entry_connection_t *entry_conn = EDGE_TO_ENTRY_CONN(conn);
connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_DESTROY);
control_event_stream_bandwidth(conn);
control_event_stream_status(entry_conn, STREAM_EVENT_CLOSED,
END_STREAM_REASON_DESTROY);
conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
} else {
/* closing the circuit, nothing to send an END to */
conn->edge_has_sent_end = 1;
conn->end_reason = END_STREAM_REASON_DESTROY;
conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED;
connection_mark_and_flush(TO_CONN(conn));
}
}
conn->cpath_layer = NULL;
conn->on_circuit = NULL;
return 0;
}
/** Send a raw end cell to the stream with ID <b>stream_id</b> out over the
* <b>circ</b> towards the hop identified with <b>cpath_layer</b>. If this
* is not a client connection, set the relay end cell's reason for closing
* as <b>reason</b> */
static int
relay_send_end_cell_from_edge(streamid_t stream_id, circuit_t *circ,
uint8_t reason, crypt_path_t *cpath_layer)
{
char payload[1];
if (CIRCUIT_PURPOSE_IS_CLIENT(circ->purpose)) {
/* Never send the server an informative reason code; it doesn't need to
* know why the client stream is failing. */
reason = END_STREAM_REASON_MISC;
}
payload[0] = (char) reason;
return relay_send_command_from_edge(stream_id, circ, RELAY_COMMAND_END,
payload, 1, cpath_layer);
}
/* If the connection <b>conn</b> is attempting to connect to an external
* destination that is an hidden service and the reason is a connection
* refused or timeout, log it so the operator can take appropriate actions.
* The log statement is a rate limited warning. */
static void
warn_if_hs_unreachable(const edge_connection_t *conn, uint8_t reason)
{
tor_assert(conn);
if (conn->base_.type == CONN_TYPE_EXIT &&
connection_edge_is_rendezvous_stream(conn) &&
(reason == END_STREAM_REASON_CONNECTREFUSED ||
reason == END_STREAM_REASON_TIMEOUT)) {
#define WARN_FAILED_HS_CONNECTION 300
static ratelim_t warn_limit = RATELIM_INIT(WARN_FAILED_HS_CONNECTION);
char *m;
if ((m = rate_limit_log(&warn_limit, approx_time()))) {
log_warn(LD_EDGE, "Onion service connection to %s failed (%s)",
(conn->base_.socket_family == AF_UNIX) ?
safe_str(conn->base_.address) :
safe_str(fmt_addrport(&conn->base_.addr, conn->base_.port)),
stream_end_reason_to_string(reason));
tor_free(m);
}
}
}
/** Send a relay end cell from stream <b>conn</b> down conn's circuit, and
* remember that we've done so. If this is not a client connection, set the
* relay end cell's reason for closing as <b>reason</b>.
*
* Return -1 if this function has already been called on this conn,
* else return 0.
*/
int
connection_edge_end(edge_connection_t *conn, uint8_t reason)
{
char payload[RELAY_PAYLOAD_SIZE];
size_t payload_len=1;
circuit_t *circ;
uint8_t control_reason = reason;
if (conn->edge_has_sent_end) {
log_warn(LD_BUG,"(Harmless.) Calling connection_edge_end (reason %d) "
"on an already ended stream?", reason);
tor_fragile_assert();
return -1;
}
if (conn->base_.marked_for_close) {
log_warn(LD_BUG,
"called on conn that's already marked for close at %s:%d.",
conn->base_.marked_for_close_file, conn->base_.marked_for_close);
return 0;
}
circ = circuit_get_by_edge_conn(conn);
if (circ && CIRCUIT_PURPOSE_IS_CLIENT(circ->purpose)) {
/* If this is a client circuit, don't send the server an informative
* reason code; it doesn't need to know why the client stream is
* failing. */
reason = END_STREAM_REASON_MISC;
}
payload[0] = (char)reason;
if (reason == END_STREAM_REASON_EXITPOLICY &&
!connection_edge_is_rendezvous_stream(conn)) {
int addrlen;
if (tor_addr_family(&conn->base_.addr) == AF_INET) {
set_uint32(payload+1, tor_addr_to_ipv4n(&conn->base_.addr));
addrlen = 4;
} else {
memcpy(payload+1, tor_addr_to_in6_addr8(&conn->base_.addr), 16);
addrlen = 16;
}
set_uint32(payload+1+addrlen, htonl(dns_clip_ttl(conn->address_ttl)));
payload_len += 4+addrlen;
}
if (circ && !circ->marked_for_close) {
log_debug(LD_EDGE,"Sending end on conn (fd "TOR_SOCKET_T_FORMAT").",
conn->base_.s);
connection_edge_send_command(conn, RELAY_COMMAND_END,
payload, payload_len);
/* We'll log warn if the connection was an hidden service and couldn't be
* made because the service wasn't available. */
warn_if_hs_unreachable(conn, control_reason);
} else {
log_debug(LD_EDGE,"No circ to send end on conn "
"(fd "TOR_SOCKET_T_FORMAT").",
conn->base_.s);
}
conn->edge_has_sent_end = 1;
conn->end_reason = control_reason;
return 0;
}
/** An error has just occurred on an operation on an edge connection
* <b>conn</b>. Extract the errno; convert it to an end reason, and send an
* appropriate relay end cell to the other end of the connection's circuit.
**/
int
connection_edge_end_errno(edge_connection_t *conn)
{
uint8_t reason;
tor_assert(conn);
reason = errno_to_stream_end_reason(tor_socket_errno(conn->base_.s));
return connection_edge_end(conn, reason);
}
/** We just wrote some data to <b>conn</b>; act appropriately.
*
* (That is, if it's open, consider sending a stream-level sendme cell if we
* have just flushed enough.)
*/
int
connection_edge_flushed_some(edge_connection_t *conn)
{
switch (conn->base_.state) {
case AP_CONN_STATE_OPEN:
case EXIT_CONN_STATE_OPEN:
connection_edge_consider_sending_sendme(conn);
break;
}
return 0;
}
/** Connection <b>conn</b> has finished writing and has no bytes left on
* its outbuf.
*
* If it's in state 'open', stop writing, consider responding with a
* sendme, and return.
* Otherwise, stop writing and return.
*
* If <b>conn</b> is broken, mark it for close and return -1, else
* return 0.
*/
int
connection_edge_finished_flushing(edge_connection_t *conn)
{
tor_assert(conn);
switch (conn->base_.state) {
case AP_CONN_STATE_OPEN:
case EXIT_CONN_STATE_OPEN:
connection_edge_consider_sending_sendme(conn);
return 0;
case AP_CONN_STATE_SOCKS_WAIT:
case AP_CONN_STATE_NATD_WAIT:
case AP_CONN_STATE_RENDDESC_WAIT:
case AP_CONN_STATE_CIRCUIT_WAIT:
case AP_CONN_STATE_CONNECT_WAIT:
case AP_CONN_STATE_CONTROLLER_WAIT:
case AP_CONN_STATE_RESOLVE_WAIT:
return 0;
default:
log_warn(LD_BUG, "Called in unexpected state %d.",conn->base_.state);
tor_fragile_assert();
return -1;
}
return 0;
}
/** Longest size for the relay payload of a RELAY_CONNECTED cell that we're
* able to generate. */
/* 4 zero bytes; 1 type byte; 16 byte IPv6 address; 4 byte TTL. */
#define MAX_CONNECTED_CELL_PAYLOAD_LEN 25
/** Set the buffer at <b>payload_out</b> -- which must have at least
* MAX_CONNECTED_CELL_PAYLOAD_LEN bytes available -- to the body of a
* RELAY_CONNECTED cell indicating that we have connected to <b>addr</b>, and
* that the name resolution that led us to <b>addr</b> will be valid for
* <b>ttl</b> seconds. Return -1 on error, or the number of bytes used on
* success. */
STATIC int
connected_cell_format_payload(uint8_t *payload_out,
const tor_addr_t *addr,
uint32_t ttl)
{
const sa_family_t family = tor_addr_family(addr);
int connected_payload_len;
/* should be needless */
memset(payload_out, 0, MAX_CONNECTED_CELL_PAYLOAD_LEN);
if (family == AF_INET) {
set_uint32(payload_out, tor_addr_to_ipv4n(addr));
connected_payload_len = 4;
} else if (family == AF_INET6) {
set_uint32(payload_out, 0);
set_uint8(payload_out + 4, 6);
memcpy(payload_out + 5, tor_addr_to_in6_addr8(addr), 16);
connected_payload_len = 21;
} else {
return -1;
}
set_uint32(payload_out + connected_payload_len, htonl(dns_clip_ttl(ttl)));
connected_payload_len += 4;
tor_assert(connected_payload_len <= MAX_CONNECTED_CELL_PAYLOAD_LEN);
return connected_payload_len;
}
/** Connected handler for exit connections: start writing pending
* data, deliver 'CONNECTED' relay cells as appropriate, and check
* any pending data that may have been received. */
int
connection_edge_finished_connecting(edge_connection_t *edge_conn)
{
connection_t *conn;
tor_assert(edge_conn);
tor_assert(edge_conn->base_.type == CONN_TYPE_EXIT);
conn = TO_CONN(edge_conn);
tor_assert(conn->state == EXIT_CONN_STATE_CONNECTING);
log_info(LD_EXIT,"Exit connection to %s:%u (%s) established.",
escaped_safe_str(conn->address), conn->port,
safe_str(fmt_and_decorate_addr(&conn->addr)));
rep_hist_note_exit_stream_opened(conn->port);
conn->state = EXIT_CONN_STATE_OPEN;
connection_watch_events(conn, READ_EVENT); /* stop writing, keep reading */
if (connection_get_outbuf_len(conn)) /* in case there are any queued relay
* cells */
connection_start_writing(conn);
/* deliver a 'connected' relay cell back through the circuit. */
if (connection_edge_is_rendezvous_stream(edge_conn)) {
if (connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED, NULL, 0) < 0)
return 0; /* circuit is closed, don't continue */
} else {
uint8_t connected_payload[MAX_CONNECTED_CELL_PAYLOAD_LEN];
int connected_payload_len =
connected_cell_format_payload(connected_payload, &conn->addr,
edge_conn->address_ttl);
if (connected_payload_len < 0)
return -1;
if (connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED,
(char*)connected_payload, connected_payload_len) < 0)
return 0; /* circuit is closed, don't continue */
}
tor_assert(edge_conn->package_window > 0);
/* in case the server has written anything */
return connection_edge_process_inbuf(edge_conn, 1);
}
/** A list of all the entry_connection_t * objects that are not marked
* for close, and are in AP_CONN_STATE_CIRCUIT_WAIT.
*
* (Right now, we check in several places to make sure that this list is
* correct. When it's incorrect, we'll fix it, and log a BUG message.)
*/
static smartlist_t *pending_entry_connections = NULL;
static int untried_pending_connections = 0;
/** Common code to connection_(ap|exit)_about_to_close. */
static void
connection_edge_about_to_close(edge_connection_t *edge_conn)
{
if (!edge_conn->edge_has_sent_end) {
connection_t *conn = TO_CONN(edge_conn);
log_warn(LD_BUG, "(Harmless.) Edge connection (marked at %s:%d) "
"hasn't sent end yet?",
conn->marked_for_close_file, conn->marked_for_close);
tor_fragile_assert();
}
}
/** Called when we're about to finally unlink and free an AP (client)
* connection: perform necessary accounting and cleanup */
void
connection_ap_about_to_close(entry_connection_t *entry_conn)
{
circuit_t *circ;
edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(entry_conn);
connection_t *conn = ENTRY_TO_CONN(entry_conn);
connection_edge_about_to_close(edge_conn);
if (entry_conn->socks_request->has_finished == 0) {
/* since conn gets removed right after this function finishes,
* there's no point trying to send back a reply at this point. */
log_warn(LD_BUG,"Closing stream (marked at %s:%d) without sending"
" back a socks reply.",
conn->marked_for_close_file, conn->marked_for_close);
}
if (!edge_conn->end_reason) {
log_warn(LD_BUG,"Closing stream (marked at %s:%d) without having"
" set end_reason.",
conn->marked_for_close_file, conn->marked_for_close);
}
if (entry_conn->dns_server_request) {
log_warn(LD_BUG,"Closing stream (marked at %s:%d) without having"
" replied to DNS request.",
conn->marked_for_close_file, conn->marked_for_close);
dnsserv_reject_request(entry_conn);
}
if (TO_CONN(edge_conn)->state == AP_CONN_STATE_CIRCUIT_WAIT) {
smartlist_remove(pending_entry_connections, entry_conn);
}
#if 1
/* Check to make sure that this isn't in pending_entry_connections if it
* didn't actually belong there. */
if (TO_CONN(edge_conn)->type == CONN_TYPE_AP) {
connection_ap_warn_and_unmark_if_pending_circ(entry_conn,
"about_to_close");
}
#endif
control_event_stream_bandwidth(edge_conn);
control_event_stream_status(entry_conn, STREAM_EVENT_CLOSED,
edge_conn->end_reason);
circ = circuit_get_by_edge_conn(edge_conn);
if (circ)
circuit_detach_stream(circ, edge_conn);
}
/** Called when we're about to finally unlink and free an exit
* connection: perform necessary accounting and cleanup */
void
connection_exit_about_to_close(edge_connection_t *edge_conn)
{
circuit_t *circ;
connection_t *conn = TO_CONN(edge_conn);
connection_edge_about_to_close(edge_conn);
circ = circuit_get_by_edge_conn(edge_conn);
if (circ)
circuit_detach_stream(circ, edge_conn);
if (conn->state == EXIT_CONN_STATE_RESOLVING) {
connection_dns_remove(edge_conn);
}
}
/** Define a schedule for how long to wait between retrying
* application connections. Rather than waiting a fixed amount of
* time between each retry, we wait 10 seconds each for the first
* two tries, and 15 seconds for each retry after
* that. Hopefully this will improve the expected user experience. */
static int
compute_retry_timeout(entry_connection_t *conn)
{
int timeout = get_options()->CircuitStreamTimeout;
if (timeout) /* if our config options override the default, use them */
return timeout;
if (conn->num_socks_retries < 2) /* try 0 and try 1 */
return 10;
return 15;
}
/** Find all general-purpose AP streams waiting for a response that sent their
* begin/resolve cell too long ago. Detach from their current circuit, and
* mark their current circuit as unsuitable for new streams. Then call
* connection_ap_handshake_attach_circuit() to attach to a new circuit (if
* available) or launch a new one.
*
* For rendezvous streams, simply give up after SocksTimeout seconds (with no
* retry attempt).
*/
void
connection_ap_expire_beginning(void)
{
edge_connection_t *conn;
entry_connection_t *entry_conn;
circuit_t *circ;
time_t now = time(NULL);
const or_options_t *options = get_options();
int severity;
int cutoff;
int seconds_idle, seconds_since_born;
smartlist_t *conns = get_connection_array();
SMARTLIST_FOREACH_BEGIN(conns, connection_t *, base_conn) {
if (base_conn->type != CONN_TYPE_AP || base_conn->marked_for_close)
continue;
entry_conn = TO_ENTRY_CONN(base_conn);
conn = ENTRY_TO_EDGE_CONN(entry_conn);
/* if it's an internal linked connection, don't yell its status. */
severity = (tor_addr_is_null(&base_conn->addr) && !base_conn->port)
? LOG_INFO : LOG_NOTICE;
seconds_idle = (int)( now - base_conn->timestamp_lastread );
seconds_since_born = (int)( now - base_conn->timestamp_created );
if (base_conn->state == AP_CONN_STATE_OPEN)
continue;
/* We already consider SocksTimeout in
* connection_ap_handshake_attach_circuit(), but we need to consider
* it here too because controllers that put streams in controller_wait
* state never ask Tor to attach the circuit. */
if (AP_CONN_STATE_IS_UNATTACHED(base_conn->state)) {
if (seconds_since_born >= options->SocksTimeout) {
log_fn(severity, LD_APP,
"Tried for %d seconds to get a connection to %s:%d. "
"Giving up. (%s)",
seconds_since_born,
safe_str_client(entry_conn->socks_request->address),
entry_conn->socks_request->port,
conn_state_to_string(CONN_TYPE_AP, base_conn->state));
connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
}
continue;
}
/* We're in state connect_wait or resolve_wait now -- waiting for a
* reply to our relay cell. See if we want to retry/give up. */
cutoff = compute_retry_timeout(entry_conn);
if (seconds_idle < cutoff)
continue;
circ = circuit_get_by_edge_conn(conn);
if (!circ) { /* it's vanished? */
log_info(LD_APP,"Conn is waiting (address %s), but lost its circ.",
safe_str_client(entry_conn->socks_request->address));
connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
continue;
}
if (circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
if (seconds_idle >= options->SocksTimeout) {
log_fn(severity, LD_REND,
"Rend stream is %d seconds late. Giving up on address"
" '%s.onion'.",
seconds_idle,
safe_str_client(entry_conn->socks_request->address));
/* Roll back path bias use state so that we probe the circuit
* if nothing else succeeds on it */
pathbias_mark_use_rollback(TO_ORIGIN_CIRCUIT(circ));
connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
}
continue;
}
if (circ->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
circ->purpose != CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT &&
circ->purpose != CIRCUIT_PURPOSE_PATH_BIAS_TESTING) {
log_warn(LD_BUG, "circuit->purpose == CIRCUIT_PURPOSE_C_GENERAL failed. "
"The purpose on the circuit was %s; it was in state %s, "
"path_state %s.",
circuit_purpose_to_string(circ->purpose),
circuit_state_to_string(circ->state),
CIRCUIT_IS_ORIGIN(circ) ?
pathbias_state_to_string(TO_ORIGIN_CIRCUIT(circ)->path_state) :
"none");
}
log_fn(cutoff < 15 ? LOG_INFO : severity, LD_APP,
"We tried for %d seconds to connect to '%s' using exit %s."
" Retrying on a new circuit.",
seconds_idle,
safe_str_client(entry_conn->socks_request->address),
conn->cpath_layer ?
extend_info_describe(conn->cpath_layer->extend_info):
"*unnamed*");
/* send an end down the circuit */
connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
/* un-mark it as ending, since we're going to reuse it */
conn->edge_has_sent_end = 0;
conn->end_reason = 0;
/* make us not try this circuit again, but allow
* current streams on it to survive if they can */
mark_circuit_unusable_for_new_conns(TO_ORIGIN_CIRCUIT(circ));
/* give our stream another 'cutoff' seconds to try */
conn->base_.timestamp_lastread += cutoff;
if (entry_conn->num_socks_retries < 250) /* avoid overflow */
entry_conn->num_socks_retries++;
/* move it back into 'pending' state, and try to attach. */
if (connection_ap_detach_retriable(entry_conn, TO_ORIGIN_CIRCUIT(circ),
END_STREAM_REASON_TIMEOUT)<0) {
if (!base_conn->marked_for_close)
connection_mark_unattached_ap(entry_conn,
END_STREAM_REASON_CANT_ATTACH);
}
} SMARTLIST_FOREACH_END(base_conn);
}
/**
* As connection_ap_attach_pending, but first scans the entire connection
* array to see if any elements are missing.
*/
void
connection_ap_rescan_and_attach_pending(void)
{
entry_connection_t *entry_conn;
smartlist_t *conns = get_connection_array();
if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
pending_entry_connections = smartlist_new();
SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
if (conn->marked_for_close ||
conn->type != CONN_TYPE_AP ||
conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
continue;
entry_conn = TO_ENTRY_CONN(conn);
tor_assert(entry_conn);
if (! smartlist_contains(pending_entry_connections, entry_conn)) {
log_warn(LD_BUG, "Found a connection %p that was supposed to be "
"in pending_entry_connections, but wasn't. No worries; "
"adding it.",
pending_entry_connections);
untried_pending_connections = 1;
connection_ap_mark_as_pending_circuit(entry_conn);
}
} SMARTLIST_FOREACH_END(conn);
connection_ap_attach_pending(1);
}
#ifdef DEBUGGING_17659
#define UNMARK() do { \
entry_conn->marked_pending_circ_line = 0; \
entry_conn->marked_pending_circ_file = 0; \
} while (0)
#else
#define UNMARK() do { } while (0)
#endif
/** Tell any AP streams that are listed as waiting for a new circuit to try
* again. If there is an available circuit for a stream, attach it. Otherwise,
* launch a new circuit.
*
* If <b>retry</b> is false, only check the list if it contains at least one
* streams that we have not yet tried to attach to a circuit.
*/
void
connection_ap_attach_pending(int retry)
{
if (PREDICT_UNLIKELY(!pending_entry_connections)) {
return;
}
if (untried_pending_connections == 0 && !retry)
return;
/* Don't allow any modifications to list while we are iterating over
* it. We'll put streams back on this list if we can't attach them
* immediately. */
smartlist_t *pending = pending_entry_connections;
pending_entry_connections = smartlist_new();
SMARTLIST_FOREACH_BEGIN(pending,
entry_connection_t *, entry_conn) {
connection_t *conn = ENTRY_TO_CONN(entry_conn);
tor_assert(conn && entry_conn);
if (conn->marked_for_close) {
UNMARK();
continue;
}
if (conn->magic != ENTRY_CONNECTION_MAGIC) {
log_warn(LD_BUG, "%p has impossible magic value %u.",
entry_conn, (unsigned)conn->magic);
UNMARK();
continue;
}
if (conn->state != AP_CONN_STATE_CIRCUIT_WAIT) {
log_warn(LD_BUG, "%p is no longer in circuit_wait. Its current state "
"is %s. Why is it on pending_entry_connections?",
entry_conn,
conn_state_to_string(conn->type, conn->state));
UNMARK();
continue;
}
/* Okay, we're through the sanity checks. Try to handle this stream. */
if (connection_ap_handshake_attach_circuit(entry_conn) < 0) {
if (!conn->marked_for_close)
connection_mark_unattached_ap(entry_conn,
END_STREAM_REASON_CANT_ATTACH);
}
if (! conn->marked_for_close &&
conn->type == CONN_TYPE_AP &&
conn->state == AP_CONN_STATE_CIRCUIT_WAIT) {
/* Is it still waiting for a circuit? If so, we didn't attach it,
* so it's still pending. Put it back on the list.
*/
if (!smartlist_contains(pending_entry_connections, entry_conn)) {
smartlist_add(pending_entry_connections, entry_conn);
continue;
}
}
/* If we got here, then we either closed the connection, or
* we attached it. */
UNMARK();
} SMARTLIST_FOREACH_END(entry_conn);
smartlist_free(pending);
untried_pending_connections = 0;
}
/** Mark <b>entry_conn</b> as needing to get attached to a circuit.
*
* And <b>entry_conn</b> must be in AP_CONN_STATE_CIRCUIT_WAIT,
* should not already be pending a circuit. The circuit will get
* launched or the connection will get attached the next time we
* call connection_ap_attach_pending().
*/
void
connection_ap_mark_as_pending_circuit_(entry_connection_t *entry_conn,
const char *fname, int lineno)
{
connection_t *conn = ENTRY_TO_CONN(entry_conn);
tor_assert(conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
tor_assert(conn->magic == ENTRY_CONNECTION_MAGIC);
if (conn->marked_for_close)
return;
if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
pending_entry_connections = smartlist_new();
if (PREDICT_UNLIKELY(smartlist_contains(pending_entry_connections,
entry_conn))) {
log_warn(LD_BUG, "What?? pending_entry_connections already contains %p! "
"(Called from %s:%d.)",
entry_conn, fname, lineno);
#ifdef DEBUGGING_17659
const char *f2 = entry_conn->marked_pending_circ_file;
log_warn(LD_BUG, "(Previously called from %s:%d.)\n",
f2 ? f2 : "<NULL>",
entry_conn->marked_pending_circ_line);
#endif
log_backtrace(LOG_WARN, LD_BUG, "To debug, this may help");
return;
}
#ifdef DEBUGGING_17659
entry_conn->marked_pending_circ_line = (uint16_t) lineno;
entry_conn->marked_pending_circ_file = fname;
#endif
untried_pending_connections = 1;
smartlist_add(pending_entry_connections, entry_conn);
/* Work-around for bug 19969: we handle pending_entry_connections at
* the end of run_main_loop_once(), but in many cases that function will
* take a very long time, if ever, to finish its call to event_base_loop().
*
* So the fix is to tell it right now that it ought to finish its loop at
* its next available opportunity.
*/
tell_event_loop_to_finish();
}
/** Mark <b>entry_conn</b> as no longer waiting for a circuit. */
void
connection_ap_mark_as_non_pending_circuit(entry_connection_t *entry_conn)
{
if (PREDICT_UNLIKELY(NULL == pending_entry_connections))
return;
UNMARK();
smartlist_remove(pending_entry_connections, entry_conn);
}
/* DOCDOC */
void
connection_ap_warn_and_unmark_if_pending_circ(entry_connection_t *entry_conn,
const char *where)
{
if (pending_entry_connections &&
smartlist_contains(pending_entry_connections, entry_conn)) {
log_warn(LD_BUG, "What was %p doing in pending_entry_connections in %s?",
entry_conn, where);
connection_ap_mark_as_non_pending_circuit(entry_conn);
}
}
/** Tell any AP streams that are waiting for a one-hop tunnel to
* <b>failed_digest</b> that they are going to fail. */
/* XXXX We should get rid of this function, and instead attach
* one-hop streams to circ->p_streams so they get marked in
* circuit_mark_for_close like normal p_streams. */
void
connection_ap_fail_onehop(const char *failed_digest,
cpath_build_state_t *build_state)
{
entry_connection_t *entry_conn;
char digest[DIGEST_LEN];
smartlist_t *conns = get_connection_array();
SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
if (conn->marked_for_close ||
conn->type != CONN_TYPE_AP ||
conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
continue;
entry_conn = TO_ENTRY_CONN(conn);
if (!entry_conn->want_onehop)
continue;
if (hexdigest_to_digest(entry_conn->chosen_exit_name, digest) < 0 ||
tor_memneq(digest, failed_digest, DIGEST_LEN))
continue;
if (tor_digest_is_zero(digest)) {
/* we don't know the digest; have to compare addr:port */
tor_addr_t addr;
if (!build_state || !build_state->chosen_exit ||
!entry_conn->socks_request) {
continue;
}
if (tor_addr_parse(&addr, entry_conn->socks_request->address)<0 ||
!tor_addr_eq(&build_state->chosen_exit->addr, &addr) ||
build_state->chosen_exit->port != entry_conn->socks_request->port)
continue;
}
log_info(LD_APP, "Closing one-hop stream to '%s/%s' because the OR conn "
"just failed.", entry_conn->chosen_exit_name,
entry_conn->socks_request->address);
connection_mark_unattached_ap(entry_conn, END_STREAM_REASON_TIMEOUT);
} SMARTLIST_FOREACH_END(conn);
}
/** A circuit failed to finish on its last hop <b>info</b>. If there
* are any streams waiting with this exit node in mind, but they
* don't absolutely require it, make them give up on it.
*/
void
circuit_discard_optional_exit_enclaves(extend_info_t *info)
{
entry_connection_t *entry_conn;
const node_t *r1, *r2;
smartlist_t *conns = get_connection_array();
SMARTLIST_FOREACH_BEGIN(conns, connection_t *, conn) {
if (conn->marked_for_close ||
conn->type != CONN_TYPE_AP ||
conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
continue;
entry_conn = TO_ENTRY_CONN(conn);
if (!entry_conn->chosen_exit_optional &&
!entry_conn->chosen_exit_retries)
continue;
r1 = node_get_by_nickname(entry_conn->chosen_exit_name, 0);
r2 = node_get_by_id(info->identity_digest);
if (!r1 || !r2 || r1 != r2)
continue;
tor_assert(entry_conn->socks_request);
if (entry_conn->chosen_exit_optional) {
log_info(LD_APP, "Giving up on enclave exit '%s' for destination %s.",
safe_str_client(entry_conn->chosen_exit_name),
escaped_safe_str_client(entry_conn->socks_request->address));
entry_conn->chosen_exit_optional = 0;
tor_free(entry_conn->chosen_exit_name); /* clears it */
/* if this port is dangerous, warn or reject it now that we don't
* think it'll be using an enclave. */
consider_plaintext_ports(entry_conn, entry_conn->socks_request->port);
}
if (entry_conn->chosen_exit_retries) {
if (--entry_conn->chosen_exit_retries == 0) { /* give up! */
clear_trackexithost_mappings(entry_conn->chosen_exit_name);
tor_free(entry_conn->chosen_exit_name); /* clears it */
/* if this port is dangerous, warn or reject it now that we don't
* think it'll be using an enclave. */
consider_plaintext_ports(entry_conn, entry_conn->socks_request->port);
}
}
} SMARTLIST_FOREACH_END(conn);
}
/** The AP connection <b>conn</b> has just failed while attaching or
* sending a BEGIN or resolving on <b>circ</b>, but another circuit
* might work. Detach the circuit, and either reattach it, launch a
* new circuit, tell the controller, or give up as appropriate.
*
* Returns -1 on err, 1 on success, 0 on not-yet-sure.
*/
int
connection_ap_detach_retriable(entry_connection_t *conn,
origin_circuit_t *circ,
int reason)
{
control_event_stream_status(conn, STREAM_EVENT_FAILED_RETRIABLE, reason);
ENTRY_TO_CONN(conn)->timestamp_lastread = time(NULL);
/* Roll back path bias use state so that we probe the circuit
* if nothing else succeeds on it */
pathbias_mark_use_rollback(circ);
if (conn->pending_optimistic_data) {
buf_set_to_copy(&conn->sending_optimistic_data,
conn->pending_optimistic_data);
}
if (!get_options()->LeaveStreamsUnattached || conn->use_begindir) {
/* If we're attaching streams ourself, or if this connection is
* a tunneled directory connection, then just attach it. */
ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CIRCUIT_WAIT;
circuit_detach_stream(TO_CIRCUIT(circ),ENTRY_TO_EDGE_CONN(conn));
connection_ap_mark_as_pending_circuit(conn);
} else {
CONNECTION_AP_EXPECT_NONPENDING(conn);
ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CONTROLLER_WAIT;
circuit_detach_stream(TO_CIRCUIT(circ),ENTRY_TO_EDGE_CONN(conn));
}
return 0;
}
/** Check if <b>conn</b> is using a dangerous port. Then warn and/or
* reject depending on our config options. */
static int
consider_plaintext_ports(entry_connection_t *conn, uint16_t port)
{
const or_options_t *options = get_options();
int reject = smartlist_contains_int_as_string(
options->RejectPlaintextPorts, port);
if (smartlist_contains_int_as_string(options->WarnPlaintextPorts, port)) {
log_warn(LD_APP, "Application request to port %d: this port is "
"commonly used for unencrypted protocols. Please make sure "
"you don't send anything you would mind the rest of the "
"Internet reading!%s", port, reject ? " Closing." : "");
control_event_client_status(LOG_WARN, "DANGEROUS_PORT PORT=%d RESULT=%s",
port, reject ? "REJECT" : "WARN");
}
if (reject) {
log_info(LD_APP, "Port %d listed in RejectPlaintextPorts. Closing.", port);
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
return 0;
}
/** How many times do we try connecting with an exit configured via
* TrackHostExits before concluding that it won't work any more and trying a
* different one? */
#define TRACKHOSTEXITS_RETRIES 5
/** Call connection_ap_handshake_rewrite_and_attach() unless a controller
* asked us to leave streams unattached. Return 0 in that case.
*
* See connection_ap_handshake_rewrite_and_attach()'s
* documentation for arguments and return value.
*/
int
connection_ap_rewrite_and_attach_if_allowed(entry_connection_t *conn,
origin_circuit_t *circ,
crypt_path_t *cpath)
{
const or_options_t *options = get_options();
if (options->LeaveStreamsUnattached) {
CONNECTION_AP_EXPECT_NONPENDING(conn);
ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CONTROLLER_WAIT;
return 0;
}
return connection_ap_handshake_rewrite_and_attach(conn, circ, cpath);
}
/* Try to perform any map-based rewriting of the target address in
* <b>conn</b>, filling in the fields of <b>out</b> as we go, and modifying
* conn->socks_request.address as appropriate.
*/
STATIC void
connection_ap_handshake_rewrite(entry_connection_t *conn,
rewrite_result_t *out)
{
socks_request_t *socks = conn->socks_request;
const or_options_t *options = get_options();
tor_addr_t addr_tmp;
/* Initialize all the fields of 'out' to reasonable defaults */
out->automap = 0;
out->exit_source = ADDRMAPSRC_NONE;
out->map_expires = TIME_MAX;
out->end_reason = 0;
out->should_close = 0;
out->orig_address[0] = 0;
/* We convert all incoming addresses to lowercase. */
tor_strlower(socks->address);
/* Remember the original address. */
strlcpy(out->orig_address, socks->address, sizeof(out->orig_address));
log_debug(LD_APP,"Client asked for %s:%d",
safe_str_client(socks->address),
socks->port);
/* Check for whether this is a .exit address. By default, those are
* disallowed when they're coming straight from the client, but you're
* allowed to have them in MapAddress commands and so forth. */
if (!strcmpend(socks->address, ".exit") && !options->AllowDotExit) {
log_warn(LD_APP, "The \".exit\" notation is disabled in Tor due to "
"security risks. Set AllowDotExit in your torrc to enable "
"it (at your own risk).");
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
out->end_reason = END_STREAM_REASON_TORPROTOCOL;
out->should_close = 1;
return;
}
/* Remember the original address so we can tell the user about what
* they actually said, not just what it turned into. */
/* XXX yes, this is the same as out->orig_address above. One is
* in the output, and one is in the connection. */
if (! conn->original_dest_address) {
/* Is the 'if' necessary here? XXXX */
conn->original_dest_address = tor_strdup(conn->socks_request->address);
}
/* First, apply MapAddress and MAPADDRESS mappings. We need to do
* these only for non-reverse lookups, since they don't exist for those.
* We also need to do this before we consider automapping, since we might
* e.g. resolve irc.oftc.net into irconionaddress.onion, at which point
* we'd need to automap it. */
if (socks->command != SOCKS_COMMAND_RESOLVE_PTR) {
const unsigned rewrite_flags = AMR_FLAG_USE_MAPADDRESS;
if (addressmap_rewrite(socks->address, sizeof(socks->address),
rewrite_flags, &out->map_expires, &out->exit_source)) {
control_event_stream_status(conn, STREAM_EVENT_REMAP,
REMAP_STREAM_SOURCE_CACHE);
}
}
/* Now see if we need to create or return an existing Hostname->IP
* automapping. Automapping happens when we're asked to resolve a
* hostname, and AutomapHostsOnResolve is set, and the hostname has a
* suffix listed in AutomapHostsSuffixes. It's a handy feature
* that lets you have Tor assign e.g. IPv6 addresses for .onion
* names, and return them safely from DNSPort.
*/
if (socks->command == SOCKS_COMMAND_RESOLVE &&
tor_addr_parse(&addr_tmp, socks->address)<0 &&
options->AutomapHostsOnResolve) {
/* Check the suffix... */
out->automap = addressmap_address_should_automap(socks->address, options);
if (out->automap) {
/* If we get here, then we should apply an automapping for this. */
const char *new_addr;
/* We return an IPv4 address by default, or an IPv6 address if we
* are allowed to do so. */
int addr_type = RESOLVED_TYPE_IPV4;
if (conn->socks_request->socks_version != 4) {
if (!conn->entry_cfg.ipv4_traffic ||
(conn->entry_cfg.ipv6_traffic && conn->entry_cfg.prefer_ipv6) ||
conn->entry_cfg.prefer_ipv6_virtaddr)
addr_type = RESOLVED_TYPE_IPV6;
}
/* Okay, register the target address as automapped, and find the new
* address we're supposed to give as a resolve answer. (Return a cached
* value if we've looked up this address before.
*/
new_addr = addressmap_register_virtual_address(
addr_type, tor_strdup(socks->address));
if (! new_addr) {
log_warn(LD_APP, "Unable to automap address %s",
escaped_safe_str(socks->address));
out->end_reason = END_STREAM_REASON_INTERNAL;
out->should_close = 1;
return;
}
log_info(LD_APP, "Automapping %s to %s",
escaped_safe_str_client(socks->address),
safe_str_client(new_addr));
strlcpy(socks->address, new_addr, sizeof(socks->address));
}
}
/* Now handle reverse lookups, if they're in the cache. This doesn't
* happen too often, since client-side DNS caching is off by default,
* and very deprecated. */
if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
unsigned rewrite_flags = 0;
if (conn->entry_cfg.use_cached_ipv4_answers)
rewrite_flags |= AMR_FLAG_USE_IPV4_DNS;
if (conn->entry_cfg.use_cached_ipv6_answers)
rewrite_flags |= AMR_FLAG_USE_IPV6_DNS;
if (addressmap_rewrite_reverse(socks->address, sizeof(socks->address),
rewrite_flags, &out->map_expires)) {
char *result = tor_strdup(socks->address);
/* remember _what_ is supposed to have been resolved. */
tor_snprintf(socks->address, sizeof(socks->address), "REVERSE[%s]",
out->orig_address);
connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_HOSTNAME,
strlen(result), (uint8_t*)result,
-1,
out->map_expires);
tor_free(result);
out->end_reason = END_STREAM_REASON_DONE |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED;
out->should_close = 1;
return;
}
/* Hang on, did we find an answer saying that this is a reverse lookup for
* an internal address? If so, we should reject it if we're configured to
* do so. */
if (options->ClientDNSRejectInternalAddresses) {
/* Don't let clients try to do a reverse lookup on 10.0.0.1. */
tor_addr_t addr;
int ok;
ok = tor_addr_parse_PTR_name(
&addr, socks->address, AF_UNSPEC, 1);
if (ok == 1 && tor_addr_is_internal(&addr, 0)) {
connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_ERROR,
0, NULL, -1, TIME_MAX);
out->end_reason = END_STREAM_REASON_SOCKSPROTOCOL |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED;
out->should_close = 1;
return;
}
}
}
/* If we didn't automap it before, then this is still the address that
* came straight from the user, mapped according to any
* MapAddress/MAPADDRESS commands. Now apply other mappings,
* including previously registered Automap entries (IP back to
* hostname), TrackHostExits entries, and client-side DNS cache
* entries (if they're turned on).
*/
if (socks->command != SOCKS_COMMAND_RESOLVE_PTR &&
!out->automap) {
unsigned rewrite_flags = AMR_FLAG_USE_AUTOMAP | AMR_FLAG_USE_TRACKEXIT;
addressmap_entry_source_t exit_source2;
if (conn->entry_cfg.use_cached_ipv4_answers)
rewrite_flags |= AMR_FLAG_USE_IPV4_DNS;
if (conn->entry_cfg.use_cached_ipv6_answers)
rewrite_flags |= AMR_FLAG_USE_IPV6_DNS;
if (addressmap_rewrite(socks->address, sizeof(socks->address),
rewrite_flags, &out->map_expires, &exit_source2)) {
control_event_stream_status(conn, STREAM_EVENT_REMAP,
REMAP_STREAM_SOURCE_CACHE);
}
if (out->exit_source == ADDRMAPSRC_NONE) {
/* If it wasn't a .exit before, maybe it turned into a .exit. Remember
* the original source of a .exit. */
out->exit_source = exit_source2;
}
}
/* Check to see whether we're about to use an address in the virtual
* range without actually having gotten it from an Automap. */
if (!out->automap && address_is_in_virtual_range(socks->address)) {
/* This address was probably handed out by
* client_dns_get_unmapped_address, but the mapping was discarded for some
* reason. Or the user typed in a virtual address range manually. We
* *don't* want to send the address through Tor; that's likely to fail,
* and may leak information.
*/
log_warn(LD_APP,"Missing mapping for virtual address '%s'. Refusing.",
safe_str_client(socks->address));
out->end_reason = END_STREAM_REASON_INTERNAL;
out->should_close = 1;
return;
}
}
/** Connection <b>conn</b> just finished its socks handshake, or the
* controller asked us to take care of it. If <b>circ</b> is defined,
* then that's where we'll want to attach it. Otherwise we have to
* figure it out ourselves.
*
* First, parse whether it's a .exit address, remap it, and so on. Then
* if it's for a general circuit, try to attach it to a circuit (or launch
* one as needed), else if it's for a rendezvous circuit, fetch a
* rendezvous descriptor first (or attach/launch a circuit if the
* rendezvous descriptor is already here and fresh enough).
*
* The stream will exit from the hop
* indicated by <b>cpath</b>, or from the last hop in circ's cpath if
* <b>cpath</b> is NULL.
*/
int
connection_ap_handshake_rewrite_and_attach(entry_connection_t *conn,
origin_circuit_t *circ,
crypt_path_t *cpath)
{
socks_request_t *socks = conn->socks_request;
const or_options_t *options = get_options();
connection_t *base_conn = ENTRY_TO_CONN(conn);
time_t now = time(NULL);
rewrite_result_t rr;
/* First we'll do the rewrite part. Let's see if we get a reasonable
* answer.
*/
memset(&rr, 0, sizeof(rr));
connection_ap_handshake_rewrite(conn,&rr);
if (rr.should_close) {
/* connection_ap_handshake_rewrite told us to close the connection:
* either because it sent back an answer, or because it sent back an
* error */
connection_mark_unattached_ap(conn, rr.end_reason);
if (END_STREAM_REASON_DONE == (rr.end_reason & END_STREAM_REASON_MASK))
return 0;
else
return -1;
}
const time_t map_expires = rr.map_expires;
const int automap = rr.automap;
const addressmap_entry_source_t exit_source = rr.exit_source;
/* Now, we parse the address to see if it's an .onion or .exit or
* other special address.
*/
const hostname_type_t addresstype = parse_extended_hostname(socks->address);
/* Now see whether the hostname is bogus. This could happen because of an
* onion hostname whose format we don't recognize. */
if (addresstype == BAD_HOSTNAME) {
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* If this is a .exit hostname, strip off the .name.exit part, and
* see whether we're willing to connect there, and and otherwise handle the
* .exit address.
*
* We'll set chosen_exit_name and/or close the connection as appropriate.
*/
if (addresstype == EXIT_HOSTNAME) {
/* If StrictNodes is not set, then .exit overrides ExcludeNodes but
* not ExcludeExitNodes. */
routerset_t *excludeset = options->StrictNodes ?
options->ExcludeExitNodesUnion_ : options->ExcludeExitNodes;
const node_t *node = NULL;
/* If this .exit was added by an AUTOMAP, then it came straight from
* a user. Make sure that options->AllowDotExit permits that! */
if (exit_source == ADDRMAPSRC_AUTOMAP && !options->AllowDotExit) {
/* Whoops; this one is stale. It must have gotten added earlier,
* when AllowDotExit was on. */
log_warn(LD_APP,"Stale automapped address for '%s.exit', with "
"AllowDotExit disabled. Refusing.",
safe_str_client(socks->address));
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* Double-check to make sure there are no .exits coming from
* impossible/weird sources. */
if (exit_source == ADDRMAPSRC_DNS ||
(exit_source == ADDRMAPSRC_NONE && !options->AllowDotExit)) {
/* It shouldn't be possible to get a .exit address from any of these
* sources. */
log_warn(LD_BUG,"Address '%s.exit', with impossible source for the "
".exit part. Refusing.",
safe_str_client(socks->address));
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
tor_assert(!automap);
/* Now, find the character before the .(name) part.
* (The ".exit" part got stripped off by "parse_extended_hostname").
*
* We're going to put the exit name into conn->chosen_exit_name, and
* look up a node correspondingly. */
char *s = strrchr(socks->address,'.');
if (s) {
/* The address was of the form "(stuff).(name).exit */
if (s[1] != '\0') {
/* Looks like a real .exit one. */
conn->chosen_exit_name = tor_strdup(s+1);
node = node_get_by_nickname(conn->chosen_exit_name, 1);
if (exit_source == ADDRMAPSRC_TRACKEXIT) {
/* We 5 tries before it expires the addressmap */
conn->chosen_exit_retries = TRACKHOSTEXITS_RETRIES;
}
*s = 0;
} else {
/* Oops, the address was (stuff)..exit. That's not okay. */
log_warn(LD_APP,"Malformed exit address '%s.exit'. Refusing.",
safe_str_client(socks->address));
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
} else {
/* It looks like they just asked for "foo.exit". That's a special
* form that means (foo's address).foo.exit. */
conn->chosen_exit_name = tor_strdup(socks->address);
node = node_get_by_nickname(conn->chosen_exit_name, 1);
if (node) {
*socks->address = 0;
node_get_address_string(node, socks->address, sizeof(socks->address));
}
}
/* Now make sure that the chosen exit exists... */
if (!node) {
log_warn(LD_APP,
"Unrecognized relay in exit address '%s.exit'. Refusing.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* ...and make sure that it isn't excluded. */
if (routerset_contains_node(excludeset, node)) {
log_warn(LD_APP,
"Excluded relay in exit address '%s.exit'. Refusing.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* XXXX-1090 Should we also allow foo.bar.exit if ExitNodes is set and
Bar is not listed in it? I say yes, but our revised manpage branch
implies no. */
}
/* Now, we handle everything that isn't a .onion address. */
if (addresstype != ONION_HOSTNAME) {
/* Not a hidden-service request. It's either a hostname or an IP,
* possibly with a .exit that we stripped off. We're going to check
* if we're allowed to connect/resolve there, and then launch the
* appropriate request. */
/* Check for funny characters in the address. */
if (address_is_invalid_destination(socks->address, 1)) {
control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s",
escaped(socks->address));
log_warn(LD_APP,
"Destination '%s' seems to be an invalid hostname. Failing.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
#ifdef ENABLE_TOR2WEB_MODE
/* If we're running in Tor2webMode, we don't allow anything BUT .onion
* addresses. */
if (options->Tor2webMode) {
log_warn(LD_APP, "Refusing to connect to non-hidden-service hostname "
"or IP address %s because tor2web mode is enabled.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
#endif
/* socks->address is a non-onion hostname or IP address.
* If we can't do any non-onion requests, refuse the connection.
* If we have a hostname but can't do DNS, refuse the connection.
* If we have an IP address, but we can't use that address family,
* refuse the connection.
*
* If we can do DNS requests, and we can use at least one address family,
* then we have to resolve the address first. Then we'll know if it
* resolves to a usable address family. */
/* First, check if all non-onion traffic is disabled */
if (!conn->entry_cfg.dns_request && !conn->entry_cfg.ipv4_traffic
&& !conn->entry_cfg.ipv6_traffic) {
log_warn(LD_APP, "Refusing to connect to non-hidden-service hostname "
"or IP address %s because Port has OnionTrafficOnly set (or "
"NoDNSRequest, NoIPv4Traffic, and NoIPv6Traffic).",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
/* Then check if we have a hostname or IP address, and whether DNS or
* the IP address family are permitted. Reject if not. */
tor_addr_t dummy_addr;
int socks_family = tor_addr_parse(&dummy_addr, socks->address);
/* family will be -1 for a non-onion hostname that's not an IP */
if (socks_family == -1) {
if (!conn->entry_cfg.dns_request) {
log_warn(LD_APP, "Refusing to connect to hostname %s "
"because Port has NoDNSRequest set.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
} else if (socks_family == AF_INET) {
if (!conn->entry_cfg.ipv4_traffic) {
log_warn(LD_APP, "Refusing to connect to IPv4 address %s because "
"Port has NoIPv4Traffic set.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
} else if (socks_family == AF_INET6) {
if (!conn->entry_cfg.ipv6_traffic) {
log_warn(LD_APP, "Refusing to connect to IPv6 address %s because "
"Port has NoIPv6Traffic set.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
} else {
tor_assert_nonfatal_unreached_once();
}
/* See if this is a hostname lookup that we can answer immediately.
* (For example, an attempt to look up the IP address for an IP address.)
*/
if (socks->command == SOCKS_COMMAND_RESOLVE) {
tor_addr_t answer;
/* Reply to resolves immediately if we can. */
if (tor_addr_parse(&answer, socks->address) >= 0) {/* is it an IP? */
/* remember _what_ is supposed to have been resolved. */
strlcpy(socks->address, rr.orig_address, sizeof(socks->address));
connection_ap_handshake_socks_resolved_addr(conn, &answer, -1,
map_expires);
connection_mark_unattached_ap(conn,
END_STREAM_REASON_DONE |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
return 0;
}
tor_assert(!automap);
rep_hist_note_used_resolve(now); /* help predict this next time */
} else if (socks->command == SOCKS_COMMAND_CONNECT) {
/* Now see if this is a connect request that we can reject immediately */
tor_assert(!automap);
/* Don't allow connections to port 0. */
if (socks->port == 0) {
log_notice(LD_APP,"Application asked to connect to port 0. Refusing.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* You can't make connections to internal addresses, by default.
* Exceptions are begindir requests (where the address is meaningless),
* or cases where you've hand-configured a particular exit, thereby
* making the local address meaningful. */
if (options->ClientRejectInternalAddresses &&
!conn->use_begindir && !conn->chosen_exit_name && !circ) {
/* If we reach this point then we don't want to allow internal
* addresses. Check if we got one. */
tor_addr_t addr;
if (tor_addr_hostname_is_local(socks->address) ||
(tor_addr_parse(&addr, socks->address) >= 0 &&
tor_addr_is_internal(&addr, 0))) {
/* If this is an explicit private address with no chosen exit node,
* then we really don't want to try to connect to it. That's
* probably an error. */
if (conn->is_transparent_ap) {
#define WARN_INTRVL_LOOP 300
static ratelim_t loop_warn_limit = RATELIM_INIT(WARN_INTRVL_LOOP);
char *m;
if ((m = rate_limit_log(&loop_warn_limit, approx_time()))) {
log_warn(LD_NET,
"Rejecting request for anonymous connection to private "
"address %s on a TransPort or NATDPort. Possible loop "
"in your NAT rules?%s", safe_str_client(socks->address),
m);
tor_free(m);
}
} else {
#define WARN_INTRVL_PRIV 300
static ratelim_t priv_warn_limit = RATELIM_INIT(WARN_INTRVL_PRIV);
char *m;
if ((m = rate_limit_log(&priv_warn_limit, approx_time()))) {
log_warn(LD_NET,
"Rejecting SOCKS request for anonymous connection to "
"private address %s.%s",
safe_str_client(socks->address),m);
tor_free(m);
}
}
connection_mark_unattached_ap(conn, END_STREAM_REASON_PRIVATE_ADDR);
return -1;
}
} /* end "if we should check for internal addresses" */
/* Okay. We're still doing a CONNECT, and it wasn't a private
* address. Here we do special handling for literal IP addresses,
* to see if we should reject this preemptively, and to set up
* fields in conn->entry_cfg to tell the exit what AF we want. */
{
tor_addr_t addr;
/* XXX Duplicate call to tor_addr_parse. */
if (tor_addr_parse(&addr, socks->address) >= 0) {
/* If we reach this point, it's an IPv4 or an IPv6 address. */
sa_family_t family = tor_addr_family(&addr);
if ((family == AF_INET && ! conn->entry_cfg.ipv4_traffic) ||
(family == AF_INET6 && ! conn->entry_cfg.ipv6_traffic)) {
/* You can't do an IPv4 address on a v6-only socks listener,
* or vice versa. */
log_warn(LD_NET, "Rejecting SOCKS request for an IP address "
"family that this listener does not support.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
} else if (family == AF_INET6 && socks->socks_version == 4) {
/* You can't make a socks4 request to an IPv6 address. Socks4
* doesn't support that. */
log_warn(LD_NET, "Rejecting SOCKS4 request for an IPv6 address.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
} else if (socks->socks_version == 4 &&
!conn->entry_cfg.ipv4_traffic) {
/* You can't do any kind of Socks4 request when IPv4 is forbidden.
*
* XXX raise this check outside the enclosing block? */
log_warn(LD_NET, "Rejecting SOCKS4 request on a listener with "
"no IPv4 traffic supported.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
} else if (family == AF_INET6) {
/* Tell the exit: we won't accept any ipv4 connection to an IPv6
* address. */
conn->entry_cfg.ipv4_traffic = 0;
} else if (family == AF_INET) {
/* Tell the exit: we won't accept any ipv6 connection to an IPv4
* address. */
conn->entry_cfg.ipv6_traffic = 0;
}
}
}
/* we never allow IPv6 answers on socks4. (TODO: Is this smart?) */
if (socks->socks_version == 4)
conn->entry_cfg.ipv6_traffic = 0;
/* Still handling CONNECT. Now, check for exit enclaves. (Which we
* don't do on BEGINDIR, or when there is a chosen exit.)
*
* TODO: Should we remove this? Exit enclaves are nutty and don't
* work very well
*/
if (!conn->use_begindir && !conn->chosen_exit_name && !circ) {
/* see if we can find a suitable enclave exit */
const node_t *r =
router_find_exact_exit_enclave(socks->address, socks->port);
if (r) {
log_info(LD_APP,
"Redirecting address %s to exit at enclave router %s",
safe_str_client(socks->address), node_describe(r));
/* use the hex digest, not nickname, in case there are two
routers with this nickname */
conn->chosen_exit_name =
tor_strdup(hex_str(r->identity, DIGEST_LEN));
conn->chosen_exit_optional = 1;
}
}
/* Still handling CONNECT: warn or reject if it's using a dangerous
* port. */
if (!conn->use_begindir && !conn->chosen_exit_name && !circ)
if (consider_plaintext_ports(conn, socks->port) < 0)
return -1;
/* Remember the port so that we will predict that more requests
there will happen in the future. */
if (!conn->use_begindir) {
/* help predict this next time */
rep_hist_note_used_port(now, socks->port);
}
} else if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
rep_hist_note_used_resolve(now); /* help predict this next time */
/* no extra processing needed */
} else {
/* We should only be doing CONNECT, RESOLVE, or RESOLVE_PTR! */
tor_fragile_assert();
}
/* Okay. At this point we've set chosen_exit_name if needed, rewritten the
* address, and decided not to reject it for any number of reasons. Now
* mark the connection as waiting for a circuit, and try to attach it!
*/
base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
/* If we were given a circuit to attach to, try to attach. Otherwise,
* try to find a good one and attach to that. */
int rv;
if (circ) {
rv = connection_ap_handshake_attach_chosen_circuit(conn, circ, cpath);
} else {
/* We'll try to attach it at the next event loop, or whenever
* we call connection_ap_attach_pending() */
connection_ap_mark_as_pending_circuit(conn);
rv = 0;
}
/* If the above function returned 0 then we're waiting for a circuit.
* if it returned 1, we're attached. Both are okay. But if it returned
* -1, there was an error, so make sure the connection is marked, and
* return -1. */
if (rv < 0) {
if (!base_conn->marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
return -1;
}
return 0;
} else {
/* If we get here, it's a request for a .onion address! */
tor_assert(!automap);
/* If .onion address requests are disabled, refuse the request */
if (!conn->entry_cfg.onion_traffic) {
log_warn(LD_APP, "Onion address %s requested from a port with .onion "
"disabled", safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_ENTRYPOLICY);
return -1;
}
/* Check whether it's RESOLVE or RESOLVE_PTR. We don't handle those
* for hidden service addresses. */
if (SOCKS_COMMAND_IS_RESOLVE(socks->command)) {
/* if it's a resolve request, fail it right now, rather than
* building all the circuits and then realizing it won't work. */
log_warn(LD_APP,
"Resolve requests to hidden services not allowed. Failing.");
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,
0,NULL,-1,TIME_MAX);
connection_mark_unattached_ap(conn,
END_STREAM_REASON_SOCKSPROTOCOL |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
return -1;
}
/* If we were passed a circuit, then we need to fail. .onion addresses
* only work when we launch our own circuits for now. */
if (circ) {
log_warn(LD_CONTROL, "Attachstream to a circuit is not "
"supported for .onion addresses currently. Failing.");
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* Look up if we have client authorization configured for this hidden
* service. If we do, associate it with the rend_data. */
rend_service_authorization_t *client_auth =
rend_client_lookup_service_authorization(socks->address);
const uint8_t *cookie = NULL;
rend_auth_type_t auth_type = REND_NO_AUTH;
if (client_auth) {
log_info(LD_REND, "Using previously configured client authorization "
"for hidden service request.");
auth_type = client_auth->auth_type;
cookie = client_auth->descriptor_cookie;
}
/* Fill in the rend_data field so we can start doing a connection to
* a hidden service. */
rend_data_t *rend_data = ENTRY_TO_EDGE_CONN(conn)->rend_data =
rend_data_client_create(socks->address, NULL, (char *) cookie,
auth_type);
if (rend_data == NULL) {
return -1;
}
const char *onion_address = rend_data_get_address(rend_data);
log_info(LD_REND,"Got a hidden service request for ID '%s'",
safe_str_client(onion_address));
/* Lookup the given onion address. If invalid, stop right now.
* Otherwise, we might have it in the cache or not. */
unsigned int refetch_desc = 0;
rend_cache_entry_t *entry = NULL;
const int rend_cache_lookup_result =
rend_cache_lookup_entry(onion_address, -1, &entry);
if (rend_cache_lookup_result < 0) {
switch (-rend_cache_lookup_result) {
case EINVAL:
/* We should already have rejected this address! */
log_warn(LD_BUG,"Invalid service name '%s'",
safe_str_client(onion_address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
case ENOENT:
/* We didn't have this; we should look it up. */
refetch_desc = 1;
break;
default:
log_warn(LD_BUG, "Unknown cache lookup error %d",
rend_cache_lookup_result);
return -1;
}
}
/* Help predict that we'll want to do hidden service circuits in the
* future. We're not sure if it will need a stable circuit yet, but
* we know we'll need *something*. */
rep_hist_note_used_internal(now, 0, 1);
/* Now we have a descriptor but is it usable or not? If not, refetch.
* Also, a fetch could have been requested if the onion address was not
* found in the cache previously. */
if (refetch_desc || !rend_client_any_intro_points_usable(entry)) {
connection_ap_mark_as_non_pending_circuit(conn);
base_conn->state = AP_CONN_STATE_RENDDESC_WAIT;
log_info(LD_REND, "Unknown descriptor %s. Fetching.",
safe_str_client(onion_address));
rend_client_refetch_v2_renddesc(rend_data);
return 0;
}
/* We have the descriptor! So launch a connection to the HS. */
base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
log_info(LD_REND, "Descriptor is here. Great.");
/* We'll try to attach it at the next event loop, or whenever
* we call connection_ap_attach_pending() */
connection_ap_mark_as_pending_circuit(conn);
return 0;
}
return 0; /* unreached but keeps the compiler happy */
}
#ifdef TRANS_PF
static int pf_socket = -1;
int
get_pf_socket(void)
{
int pf;
/* This should be opened before dropping privileges. */
if (pf_socket >= 0)
return pf_socket;
#if defined(OpenBSD)
/* only works on OpenBSD */
pf = tor_open_cloexec("/dev/pf", O_RDONLY, 0);
#else
/* works on NetBSD and FreeBSD */
pf = tor_open_cloexec("/dev/pf", O_RDWR, 0);
#endif
if (pf < 0) {
log_warn(LD_NET, "open(\"/dev/pf\") failed: %s", strerror(errno));
return -1;
}
pf_socket = pf;
return pf_socket;
}
#endif
#if defined(TRANS_NETFILTER) || defined(TRANS_PF) || defined(TRANS_TPROXY)
/** Try fill in the address of <b>req</b> from the socket configured
* with <b>conn</b>. */
static int
destination_from_socket(entry_connection_t *conn, socks_request_t *req)
{
struct sockaddr_storage orig_dst;
socklen_t orig_dst_len = sizeof(orig_dst);
tor_addr_t addr;
#ifdef TRANS_TPROXY
if (get_options()->TransProxyType_parsed == TPT_TPROXY) {
if (getsockname(ENTRY_TO_CONN(conn)->s, (struct sockaddr*)&orig_dst,
&orig_dst_len) < 0) {
int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
log_warn(LD_NET, "getsockname() failed: %s", tor_socket_strerror(e));
return -1;
}
goto done;
}
#endif
#ifdef TRANS_NETFILTER
int rv = -1;
switch (ENTRY_TO_CONN(conn)->socket_family) {
#ifdef TRANS_NETFILTER_IPV4
case AF_INET:
rv = getsockopt(ENTRY_TO_CONN(conn)->s, SOL_IP, SO_ORIGINAL_DST,
(struct sockaddr*)&orig_dst, &orig_dst_len);
break;
#endif
#ifdef TRANS_NETFILTER_IPV6
case AF_INET6:
rv = getsockopt(ENTRY_TO_CONN(conn)->s, SOL_IPV6, IP6T_SO_ORIGINAL_DST,
(struct sockaddr*)&orig_dst, &orig_dst_len);
break;
#endif
default:
log_warn(LD_BUG,
"Received transparent data from an unsuported socket family %d",
ENTRY_TO_CONN(conn)->socket_family);
return -1;
}
if (rv < 0) {
int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
log_warn(LD_NET, "getsockopt() failed: %s", tor_socket_strerror(e));
return -1;
}
goto done;
#elif defined(TRANS_PF)
if (getsockname(ENTRY_TO_CONN(conn)->s, (struct sockaddr*)&orig_dst,
&orig_dst_len) < 0) {
int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
log_warn(LD_NET, "getsockname() failed: %s", tor_socket_strerror(e));
return -1;
}
goto done;
#else
(void)conn;
(void)req;
log_warn(LD_BUG, "Unable to determine destination from socket.");
return -1;
#endif
done:
tor_addr_from_sockaddr(&addr, (struct sockaddr*)&orig_dst, &req->port);
tor_addr_to_str(req->address, &addr, sizeof(req->address), 1);
return 0;
}
#endif
#ifdef TRANS_PF
static int
destination_from_pf(entry_connection_t *conn, socks_request_t *req)
{
struct sockaddr_storage proxy_addr;
socklen_t proxy_addr_len = sizeof(proxy_addr);
struct sockaddr *proxy_sa = (struct sockaddr*) &proxy_addr;
struct pfioc_natlook pnl;
tor_addr_t addr;
int pf = -1;
if (getsockname(ENTRY_TO_CONN(conn)->s, (struct sockaddr*)&proxy_addr,
&proxy_addr_len) < 0) {
int e = tor_socket_errno(ENTRY_TO_CONN(conn)->s);
log_warn(LD_NET, "getsockname() to determine transocks destination "
"failed: %s", tor_socket_strerror(e));
return -1;
}
#ifdef __FreeBSD__
if (get_options()->TransProxyType_parsed == TPT_IPFW) {
/* ipfw(8) is used and in this case getsockname returned the original
destination */
if (tor_addr_from_sockaddr(&addr, proxy_sa, &req->port) < 0) {
tor_fragile_assert();
return -1;
}
tor_addr_to_str(req->address, &addr, sizeof(req->address), 0);
return 0;
}
#endif
memset(&pnl, 0, sizeof(pnl));
pnl.proto = IPPROTO_TCP;
pnl.direction = PF_OUT;
if (proxy_sa->sa_family == AF_INET) {
struct sockaddr_in *sin = (struct sockaddr_in *)proxy_sa;
pnl.af = AF_INET;
pnl.saddr.v4.s_addr = tor_addr_to_ipv4n(&ENTRY_TO_CONN(conn)->addr);
pnl.sport = htons(ENTRY_TO_CONN(conn)->port);
pnl.daddr.v4.s_addr = sin->sin_addr.s_addr;
pnl.dport = sin->sin_port;
} else if (proxy_sa->sa_family == AF_INET6) {
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)proxy_sa;
pnl.af = AF_INET6;
memcpy(&pnl.saddr.v6, tor_addr_to_in6(&ENTRY_TO_CONN(conn)->addr),
sizeof(struct in6_addr));
pnl.sport = htons(ENTRY_TO_CONN(conn)->port);
memcpy(&pnl.daddr.v6, &sin6->sin6_addr, sizeof(struct in6_addr));
pnl.dport = sin6->sin6_port;
} else {
log_warn(LD_NET, "getsockname() gave an unexpected address family (%d)",
(int)proxy_sa->sa_family);
return -1;
}
pf = get_pf_socket();
if (pf<0)
return -1;
if (ioctl(pf, DIOCNATLOOK, &pnl) < 0) {
log_warn(LD_NET, "ioctl(DIOCNATLOOK) failed: %s", strerror(errno));
return -1;
}
if (pnl.af == AF_INET) {
tor_addr_from_ipv4n(&addr, pnl.rdaddr.v4.s_addr);
} else if (pnl.af == AF_INET6) {
tor_addr_from_in6(&addr, &pnl.rdaddr.v6);
} else {
tor_fragile_assert();
return -1;
}
tor_addr_to_str(req->address, &addr, sizeof(req->address), 1);
req->port = ntohs(pnl.rdport);
return 0;
}
#endif
/** Fetch the original destination address and port from a
* system-specific interface and put them into a
* socks_request_t as if they came from a socks request.
*
* Return -1 if an error prevents fetching the destination,
* else return 0.
*/
static int
connection_ap_get_original_destination(entry_connection_t *conn,
socks_request_t *req)
{
#ifdef TRANS_NETFILTER
return destination_from_socket(conn, req);
#elif defined(TRANS_PF)
const or_options_t *options = get_options();
if (options->TransProxyType_parsed == TPT_PF_DIVERT)
return destination_from_socket(conn, req);
if (options->TransProxyType_parsed == TPT_DEFAULT ||
options->TransProxyType_parsed == TPT_IPFW)
return destination_from_pf(conn, req);
(void)conn;
(void)req;
log_warn(LD_BUG, "Proxy destination determination mechanism %s unknown.",
options->TransProxyType);
return -1;
#else
(void)conn;
(void)req;
log_warn(LD_BUG, "Called connection_ap_get_original_destination, but no "
"transparent proxy method was configured.");
return -1;
#endif
}
/** connection_edge_process_inbuf() found a conn in state
* socks_wait. See if conn->inbuf has the right bytes to proceed with
* the socks handshake.
*
* If the handshake is complete, send it to
* connection_ap_handshake_rewrite_and_attach().
*
* Return -1 if an unexpected error with conn occurs (and mark it for close),
* else return 0.
*/
static int
connection_ap_handshake_process_socks(entry_connection_t *conn)
{
socks_request_t *socks;
int sockshere;
const or_options_t *options = get_options();
int had_reply = 0;
connection_t *base_conn = ENTRY_TO_CONN(conn);
tor_assert(conn);
tor_assert(base_conn->type == CONN_TYPE_AP);
tor_assert(base_conn->state == AP_CONN_STATE_SOCKS_WAIT);
tor_assert(conn->socks_request);
socks = conn->socks_request;
log_debug(LD_APP,"entered.");
sockshere = fetch_from_buf_socks(base_conn->inbuf, socks,
options->TestSocks, options->SafeSocks);
if (socks->replylen) {
had_reply = 1;
connection_write_to_buf((const char*)socks->reply, socks->replylen,
base_conn);
socks->replylen = 0;
if (sockshere == -1) {
/* An invalid request just got a reply, no additional
* one is necessary. */
socks->has_finished = 1;
}
}
if (sockshere == 0) {
log_debug(LD_APP,"socks handshake not all here yet.");
return 0;
} else if (sockshere == -1) {
if (!had_reply) {
log_warn(LD_APP,"Fetching socks handshake failed. Closing.");
connection_ap_handshake_socks_reply(conn, NULL, 0,
END_STREAM_REASON_SOCKSPROTOCOL);
}
connection_mark_unattached_ap(conn,
END_STREAM_REASON_SOCKSPROTOCOL |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
return -1;
} /* else socks handshake is done, continue processing */
if (SOCKS_COMMAND_IS_CONNECT(socks->command))
control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
else
control_event_stream_status(conn, STREAM_EVENT_NEW_RESOLVE, 0);
return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
}
/** connection_init_accepted_conn() found a new trans AP conn.
* Get the original destination and send it to
* connection_ap_handshake_rewrite_and_attach().
*
* Return -1 if an unexpected error with conn (and it should be marked
* for close), else return 0.
*/
int
connection_ap_process_transparent(entry_connection_t *conn)
{
socks_request_t *socks;
tor_assert(conn);
tor_assert(conn->socks_request);
socks = conn->socks_request;
/* pretend that a socks handshake completed so we don't try to
* send a socks reply down a transparent conn */
socks->command = SOCKS_COMMAND_CONNECT;
socks->has_finished = 1;
log_debug(LD_APP,"entered.");
if (connection_ap_get_original_destination(conn, socks) < 0) {
log_warn(LD_APP,"Fetching original destination failed. Closing.");
connection_mark_unattached_ap(conn,
END_STREAM_REASON_CANT_FETCH_ORIG_DEST);
return -1;
}
/* we have the original destination */
control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
}
/** connection_edge_process_inbuf() found a conn in state natd_wait. See if
* conn-\>inbuf has the right bytes to proceed. See FreeBSD's libalias(3) and
* ProxyEncodeTcpStream() in src/lib/libalias/alias_proxy.c for the encoding
* form of the original destination.
*
* If the original destination is complete, send it to
* connection_ap_handshake_rewrite_and_attach().
*
* Return -1 if an unexpected error with conn (and it should be marked
* for close), else return 0.
*/
static int
connection_ap_process_natd(entry_connection_t *conn)
{
char tmp_buf[36], *tbuf, *daddr;
size_t tlen = 30;
int err, port_ok;
socks_request_t *socks;
tor_assert(conn);
tor_assert(ENTRY_TO_CONN(conn)->state == AP_CONN_STATE_NATD_WAIT);
tor_assert(conn->socks_request);
socks = conn->socks_request;
log_debug(LD_APP,"entered.");
/* look for LF-terminated "[DEST ip_addr port]"
* where ip_addr is a dotted-quad and port is in string form */
err = connection_fetch_from_buf_line(ENTRY_TO_CONN(conn), tmp_buf, &tlen);
if (err == 0)
return 0;
if (err < 0) {
log_warn(LD_APP,"NATD handshake failed (DEST too long). Closing");
connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
return -1;
}
if (strcmpstart(tmp_buf, "[DEST ")) {
log_warn(LD_APP,"NATD handshake was ill-formed; closing. The client "
"said: %s",
escaped(tmp_buf));
connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
return -1;
}
daddr = tbuf = &tmp_buf[0] + 6; /* after end of "[DEST " */
if (!(tbuf = strchr(tbuf, ' '))) {
log_warn(LD_APP,"NATD handshake was ill-formed; closing. The client "
"said: %s",
escaped(tmp_buf));
connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
return -1;
}
*tbuf++ = '\0';
/* pretend that a socks handshake completed so we don't try to
* send a socks reply down a natd conn */
strlcpy(socks->address, daddr, sizeof(socks->address));
socks->port = (uint16_t)
tor_parse_long(tbuf, 10, 1, 65535, &port_ok, &daddr);
if (!port_ok) {
log_warn(LD_APP,"NATD handshake failed; port %s is ill-formed or out "
"of range.", escaped(tbuf));
connection_mark_unattached_ap(conn, END_STREAM_REASON_INVALID_NATD_DEST);
return -1;
}
socks->command = SOCKS_COMMAND_CONNECT;
socks->has_finished = 1;
control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
ENTRY_TO_CONN(conn)->state = AP_CONN_STATE_CIRCUIT_WAIT;
return connection_ap_rewrite_and_attach_if_allowed(conn, NULL, NULL);
}
/** Iterate over the two bytes of stream_id until we get one that is not
* already in use; return it. Return 0 if can't get a unique stream_id.
*/
streamid_t
get_unique_stream_id_by_circ(origin_circuit_t *circ)
{
edge_connection_t *tmpconn;
streamid_t test_stream_id;
uint32_t attempts=0;
again:
test_stream_id = circ->next_stream_id++;
if (++attempts > 1<<16) {
/* Make sure we don't loop forever if all stream_id's are used. */
log_warn(LD_APP,"No unused stream IDs. Failing.");
return 0;
}
if (test_stream_id == 0)
goto again;
for (tmpconn = circ->p_streams; tmpconn; tmpconn=tmpconn->next_stream)
if (tmpconn->stream_id == test_stream_id)
goto again;
return test_stream_id;
}
/** Return true iff <b>conn</b> is linked to a circuit and configured to use
* an exit that supports optimistic data. */
static int
connection_ap_supports_optimistic_data(const entry_connection_t *conn)
{
const edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(conn);
/* We can only send optimistic data if we're connected to an open
general circuit. */
if (edge_conn->on_circuit == NULL ||
edge_conn->on_circuit->state != CIRCUIT_STATE_OPEN ||
(edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL &&
edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_REND_JOINED))
return 0;
return conn->may_use_optimistic_data;
}
/** Return a bitmask of BEGIN_FLAG_* flags that we should transmit in the
* RELAY_BEGIN cell for <b>ap_conn</b>. */
static uint32_t
connection_ap_get_begincell_flags(entry_connection_t *ap_conn)
{
edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
const node_t *exitnode = NULL;
const crypt_path_t *cpath_layer = edge_conn->cpath_layer;
uint32_t flags = 0;
/* No flags for begindir */
if (ap_conn->use_begindir)
return 0;
/* No flags for hidden services. */
if (edge_conn->on_circuit->purpose != CIRCUIT_PURPOSE_C_GENERAL)
return 0;
/* If only IPv4 is supported, no flags */
if (ap_conn->entry_cfg.ipv4_traffic && !ap_conn->entry_cfg.ipv6_traffic)
return 0;
if (! cpath_layer ||
! cpath_layer->extend_info)
return 0;
if (!ap_conn->entry_cfg.ipv4_traffic)
flags |= BEGIN_FLAG_IPV4_NOT_OK;
exitnode = node_get_by_id(cpath_layer->extend_info->identity_digest);
if (ap_conn->entry_cfg.ipv6_traffic && exitnode) {
tor_addr_t a;
tor_addr_make_null(&a, AF_INET6);
if (compare_tor_addr_to_node_policy(&a, ap_conn->socks_request->port,
exitnode)
!= ADDR_POLICY_REJECTED) {
/* Only say "IPv6 OK" if the exit node supports IPv6. Otherwise there's
* no point. */
flags |= BEGIN_FLAG_IPV6_OK;
}
}
if (flags == BEGIN_FLAG_IPV6_OK) {
/* When IPv4 and IPv6 are both allowed, consider whether to say we
* prefer IPv6. Otherwise there's no point in declaring a preference */
if (ap_conn->entry_cfg.prefer_ipv6)
flags |= BEGIN_FLAG_IPV6_PREFERRED;
}
if (flags == BEGIN_FLAG_IPV4_NOT_OK) {
log_warn(LD_EDGE, "I'm about to ask a node for a connection that I "
"am telling it to fulfil with neither IPv4 nor IPv6. That's "
"not going to work. Did you perhaps ask for an IPv6 address "
"on an IPv4Only port, or vice versa?");
}
return flags;
}
/** Write a relay begin cell, using destaddr and destport from ap_conn's
* socks_request field, and send it down circ.
*
* If ap_conn is broken, mark it for close and return -1. Else return 0.
*/
int
connection_ap_handshake_send_begin(entry_connection_t *ap_conn)
{
char payload[CELL_PAYLOAD_SIZE];
int payload_len;
int begin_type;
const or_options_t *options = get_options();
origin_circuit_t *circ;
edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
connection_t *base_conn = TO_CONN(edge_conn);
tor_assert(edge_conn->on_circuit);
circ = TO_ORIGIN_CIRCUIT(edge_conn->on_circuit);
tor_assert(base_conn->type == CONN_TYPE_AP);
tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
tor_assert(ap_conn->socks_request);
tor_assert(SOCKS_COMMAND_IS_CONNECT(ap_conn->socks_request->command));
edge_conn->stream_id = get_unique_stream_id_by_circ(circ);
if (edge_conn->stream_id==0) {
/* XXXX+ Instead of closing this stream, we should make it get
* retried on another circuit. */
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
/* Mark this circuit "unusable for new streams". */
mark_circuit_unusable_for_new_conns(circ);
return -1;
}
/* Set up begin cell flags. */
edge_conn->begincell_flags = connection_ap_get_begincell_flags(ap_conn);
tor_snprintf(payload,RELAY_PAYLOAD_SIZE, "%s:%d",
(circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL) ?
ap_conn->socks_request->address : "",
ap_conn->socks_request->port);
payload_len = (int)strlen(payload)+1;
if (payload_len <= RELAY_PAYLOAD_SIZE - 4 && edge_conn->begincell_flags) {
set_uint32(payload + payload_len, htonl(edge_conn->begincell_flags));
payload_len += 4;
}
log_info(LD_APP,
"Sending relay cell %d on circ %u to begin stream %d.",
(int)ap_conn->use_begindir,
(unsigned)circ->base_.n_circ_id,
edge_conn->stream_id);
begin_type = ap_conn->use_begindir ?
RELAY_COMMAND_BEGIN_DIR : RELAY_COMMAND_BEGIN;
/* Check that circuits are anonymised, based on their type. */
if (begin_type == RELAY_COMMAND_BEGIN) {
/* This connection is a standard OR connection.
* Make sure its path length is anonymous, or that we're in a
* non-anonymous mode. */
assert_circ_anonymity_ok(circ, options);
} else if (begin_type == RELAY_COMMAND_BEGIN_DIR) {
/* This connection is a begindir directory connection.
* Look at the linked directory connection to access the directory purpose.
* If a BEGINDIR connection is ever not linked, that's a bug. */
if (BUG(!base_conn->linked)) {
return -1;
}
connection_t *linked_dir_conn_base = base_conn->linked_conn;
/* If the linked connection has been unlinked by other code, we can't send
* a begin cell on it. */
if (!linked_dir_conn_base) {
return -1;
}
/* Sensitive directory connections must have an anonymous path length.
* Otherwise, directory connections are typically one-hop.
* This matches the earlier check for directory connection path anonymity
* in directory_initiate_command_rend(). */
if (purpose_needs_anonymity(linked_dir_conn_base->purpose,
TO_DIR_CONN(linked_dir_conn_base)->router_purpose,
TO_DIR_CONN(linked_dir_conn_base)->requested_resource)) {
assert_circ_anonymity_ok(circ, options);
}
} else {
/* This code was written for the two connection types BEGIN and BEGIN_DIR
*/
tor_assert_unreached();
}
if (connection_edge_send_command(edge_conn, begin_type,
begin_type == RELAY_COMMAND_BEGIN ? payload : NULL,
begin_type == RELAY_COMMAND_BEGIN ? payload_len : 0) < 0)
return -1; /* circuit is closed, don't continue */
edge_conn->package_window = STREAMWINDOW_START;
edge_conn->deliver_window = STREAMWINDOW_START;
base_conn->state = AP_CONN_STATE_CONNECT_WAIT;
log_info(LD_APP,"Address/port sent, ap socket "TOR_SOCKET_T_FORMAT
", n_circ_id %u",
base_conn->s, (unsigned)circ->base_.n_circ_id);
control_event_stream_status(ap_conn, STREAM_EVENT_SENT_CONNECT, 0);
/* If there's queued-up data, send it now */
if ((connection_get_inbuf_len(base_conn) ||
ap_conn->sending_optimistic_data) &&
connection_ap_supports_optimistic_data(ap_conn)) {
log_info(LD_APP, "Sending up to %ld + %ld bytes of queued-up data",
(long)connection_get_inbuf_len(base_conn),
ap_conn->sending_optimistic_data ?
(long)buf_datalen(ap_conn->sending_optimistic_data) : 0);
if (connection_edge_package_raw_inbuf(edge_conn, 1, NULL) < 0) {
connection_mark_for_close(base_conn);
}
}
return 0;
}
/** Write a relay resolve cell, using destaddr and destport from ap_conn's
* socks_request field, and send it down circ.
*
* If ap_conn is broken, mark it for close and return -1. Else return 0.
*/
int
connection_ap_handshake_send_resolve(entry_connection_t *ap_conn)
{
int payload_len, command;
const char *string_addr;
char inaddr_buf[REVERSE_LOOKUP_NAME_BUF_LEN];
origin_circuit_t *circ;
edge_connection_t *edge_conn = ENTRY_TO_EDGE_CONN(ap_conn);
connection_t *base_conn = TO_CONN(edge_conn);
tor_assert(edge_conn->on_circuit);
circ = TO_ORIGIN_CIRCUIT(edge_conn->on_circuit);
tor_assert(base_conn->type == CONN_TYPE_AP);
tor_assert(base_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
tor_assert(ap_conn->socks_request);
tor_assert(circ->base_.purpose == CIRCUIT_PURPOSE_C_GENERAL);
command = ap_conn->socks_request->command;
tor_assert(SOCKS_COMMAND_IS_RESOLVE(command));
edge_conn->stream_id = get_unique_stream_id_by_circ(circ);
if (edge_conn->stream_id==0) {
/* XXXX+ Instead of closing this stream, we should make it get
* retried on another circuit. */
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
/* Mark this circuit "unusable for new streams". */
mark_circuit_unusable_for_new_conns(circ);
return -1;
}
if (command == SOCKS_COMMAND_RESOLVE) {
string_addr = ap_conn->socks_request->address;
payload_len = (int)strlen(string_addr)+1;
} else {
/* command == SOCKS_COMMAND_RESOLVE_PTR */
const char *a = ap_conn->socks_request->address;
tor_addr_t addr;
int r;
/* We're doing a reverse lookup. The input could be an IP address, or
* could be an .in-addr.arpa or .ip6.arpa address */
r = tor_addr_parse_PTR_name(&addr, a, AF_UNSPEC, 1);
if (r <= 0) {
log_warn(LD_APP, "Rejecting ill-formed reverse lookup of %s",
safe_str_client(a));
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
return -1;
}
r = tor_addr_to_PTR_name(inaddr_buf, sizeof(inaddr_buf), &addr);
if (r < 0) {
log_warn(LD_BUG, "Couldn't generate reverse lookup hostname of %s",
safe_str_client(a));
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
return -1;
}
string_addr = inaddr_buf;
payload_len = (int)strlen(inaddr_buf)+1;
tor_assert(payload_len <= (int)sizeof(inaddr_buf));
}
log_debug(LD_APP,
"Sending relay cell to begin stream %d.", edge_conn->stream_id);
if (connection_edge_send_command(edge_conn,
RELAY_COMMAND_RESOLVE,
string_addr, payload_len) < 0)
return -1; /* circuit is closed, don't continue */
if (!base_conn->address) {
/* This might be unnecessary. XXXX */
base_conn->address = tor_addr_to_str_dup(&base_conn->addr);
}
base_conn->state = AP_CONN_STATE_RESOLVE_WAIT;
log_info(LD_APP,"Address sent for resolve, ap socket "TOR_SOCKET_T_FORMAT
", n_circ_id %u",
base_conn->s, (unsigned)circ->base_.n_circ_id);
control_event_stream_status(ap_conn, STREAM_EVENT_SENT_RESOLVE, 0);
return 0;
}
/** Make an AP connection_t linked to the connection_t <b>partner</b>. make a
* new linked connection pair, and attach one side to the conn, connection_add
* it, initialize it to circuit_wait, and call
* connection_ap_handshake_attach_circuit(conn) on it.
*
* Return the newly created end of the linked connection pair, or -1 if error.
*/
entry_connection_t *
connection_ap_make_link(connection_t *partner,
char *address, uint16_t port,
const char *digest,
int session_group, int isolation_flags,
int use_begindir, int want_onehop)
{
entry_connection_t *conn;
connection_t *base_conn;
log_info(LD_APP,"Making internal %s tunnel to %s:%d ...",
want_onehop ? "direct" : "anonymized",
safe_str_client(address), port);
conn = entry_connection_new(CONN_TYPE_AP, tor_addr_family(&partner->addr));
base_conn = ENTRY_TO_CONN(conn);
base_conn->linked = 1; /* so that we can add it safely below. */
/* populate conn->socks_request */
/* leave version at zero, so the socks_reply is empty */
conn->socks_request->socks_version = 0;
conn->socks_request->has_finished = 0; /* waiting for 'connected' */
strlcpy(conn->socks_request->address, address,
sizeof(conn->socks_request->address));
conn->socks_request->port = port;
conn->socks_request->command = SOCKS_COMMAND_CONNECT;
conn->want_onehop = want_onehop;
conn->use_begindir = use_begindir;
if (use_begindir) {
conn->chosen_exit_name = tor_malloc(HEX_DIGEST_LEN+2);
conn->chosen_exit_name[0] = '$';
tor_assert(digest);
base16_encode(conn->chosen_exit_name+1,HEX_DIGEST_LEN+1,
digest, DIGEST_LEN);
}
/* Populate isolation fields. */
conn->socks_request->listener_type = CONN_TYPE_DIR_LISTENER;
conn->original_dest_address = tor_strdup(address);
conn->entry_cfg.session_group = session_group;
conn->entry_cfg.isolation_flags = isolation_flags;
base_conn->address = tor_strdup("(Tor_internal)");
tor_addr_make_unspec(&base_conn->addr);
base_conn->port = 0;
connection_link_connections(partner, base_conn);
if (connection_add(base_conn) < 0) { /* no space, forget it */
connection_free(base_conn);
return NULL;
}
base_conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
/* attaching to a dirty circuit is fine */
connection_ap_mark_as_pending_circuit(conn);
log_info(LD_APP,"... application connection created and linked.");
return conn;
}
/** Notify any interested controller connections about a new hostname resolve
* or resolve error. Takes the same arguments as does
* connection_ap_handshake_socks_resolved(). */
static void
tell_controller_about_resolved_result(entry_connection_t *conn,
int answer_type,
size_t answer_len,
const char *answer,
int ttl,
time_t expires)
{
expires = time(NULL) + ttl;
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len >= 4) {
char *cp = tor_dup_ip(ntohl(get_uint32(answer)));
control_event_address_mapped(conn->socks_request->address,
cp, expires, NULL, 0);
tor_free(cp);
} else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
char *cp = tor_strndup(answer, answer_len);
control_event_address_mapped(conn->socks_request->address,
cp, expires, NULL, 0);
tor_free(cp);
} else {
control_event_address_mapped(conn->socks_request->address,
"<error>", time(NULL)+ttl,
"error=yes", 0);
}
}
/**
* As connection_ap_handshake_socks_resolved, but take a tor_addr_t to send
* as the answer.
*/
void
connection_ap_handshake_socks_resolved_addr(entry_connection_t *conn,
const tor_addr_t *answer,
int ttl,
time_t expires)
{
if (tor_addr_family(answer) == AF_INET) {
uint32_t a = tor_addr_to_ipv4n(answer); /* network order */
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
(uint8_t*)&a,
ttl, expires);
} else if (tor_addr_family(answer) == AF_INET6) {
const uint8_t *a = tor_addr_to_in6_addr8(answer);
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV6,16,
a,
ttl, expires);
} else {
log_warn(LD_BUG, "Got called with address of unexpected family %d",
tor_addr_family(answer));
connection_ap_handshake_socks_resolved(conn,
RESOLVED_TYPE_ERROR,0,NULL,-1,-1);
}
}
/** Send an answer to an AP connection that has requested a DNS lookup via
* SOCKS. The type should be one of RESOLVED_TYPE_(IPV4|IPV6|HOSTNAME) or -1
* for unreachable; the answer should be in the format specified in the socks
* extensions document. <b>ttl</b> is the ttl for the answer, or -1 on
* certain errors or for values that didn't come via DNS. <b>expires</b> is
* a time when the answer expires, or -1 or TIME_MAX if there's a good TTL.
**/
/* XXXX the use of the ttl and expires fields is nutty. Let's make this
* interface and those that use it less ugly. */
MOCK_IMPL(void,
connection_ap_handshake_socks_resolved,(entry_connection_t *conn,
int answer_type,
size_t answer_len,
const uint8_t *answer,
int ttl,
time_t expires))
{
char buf[384];
size_t replylen;
if (ttl >= 0) {
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
tor_addr_t a;
tor_addr_from_ipv4n(&a, get_uint32(answer));
if (! tor_addr_is_null(&a)) {
client_dns_set_addressmap(conn,
conn->socks_request->address, &a,
conn->chosen_exit_name, ttl);
}
} else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
tor_addr_t a;
tor_addr_from_ipv6_bytes(&a, (char*)answer);
if (! tor_addr_is_null(&a)) {
client_dns_set_addressmap(conn,
conn->socks_request->address, &a,
conn->chosen_exit_name, ttl);
}
} else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
char *cp = tor_strndup((char*)answer, answer_len);
client_dns_set_reverse_addressmap(conn,
conn->socks_request->address,
cp,
conn->chosen_exit_name, ttl);
tor_free(cp);
}
}
if (ENTRY_TO_EDGE_CONN(conn)->is_dns_request) {
if (conn->dns_server_request) {
/* We had a request on our DNS port: answer it. */
dnsserv_resolved(conn, answer_type, answer_len, (char*)answer, ttl);
conn->socks_request->has_finished = 1;
return;
} else {
/* This must be a request from the controller. Since answers to those
* requests are not cached, they do not generate an ADDRMAP event on
* their own. */
tell_controller_about_resolved_result(conn, answer_type, answer_len,
(char*)answer, ttl, expires);
conn->socks_request->has_finished = 1;
return;
}
/* We shouldn't need to free conn here; it gets marked by the caller. */
}
if (conn->socks_request->socks_version == 4) {
buf[0] = 0x00; /* version */
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
buf[1] = SOCKS4_GRANTED;
set_uint16(buf+2, 0);
memcpy(buf+4, answer, 4); /* address */
replylen = SOCKS4_NETWORK_LEN;
} else { /* "error" */
buf[1] = SOCKS4_REJECT;
memset(buf+2, 0, 6);
replylen = SOCKS4_NETWORK_LEN;
}
} else if (conn->socks_request->socks_version == 5) {
/* SOCKS5 */
buf[0] = 0x05; /* version */
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
buf[1] = SOCKS5_SUCCEEDED;
buf[2] = 0; /* reserved */
buf[3] = 0x01; /* IPv4 address type */
memcpy(buf+4, answer, 4); /* address */
set_uint16(buf+8, 0); /* port == 0. */
replylen = 10;
} else if (answer_type == RESOLVED_TYPE_IPV6 && answer_len == 16) {
buf[1] = SOCKS5_SUCCEEDED;
buf[2] = 0; /* reserved */
buf[3] = 0x04; /* IPv6 address type */
memcpy(buf+4, answer, 16); /* address */
set_uint16(buf+20, 0); /* port == 0. */
replylen = 22;
} else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
buf[1] = SOCKS5_SUCCEEDED;
buf[2] = 0; /* reserved */
buf[3] = 0x03; /* Domainname address type */
buf[4] = (char)answer_len;
memcpy(buf+5, answer, answer_len); /* address */
set_uint16(buf+5+answer_len, 0); /* port == 0. */
replylen = 5+answer_len+2;
} else {
buf[1] = SOCKS5_HOST_UNREACHABLE;
memset(buf+2, 0, 8);
replylen = 10;
}
} else {
/* no socks version info; don't send anything back */
return;
}
connection_ap_handshake_socks_reply(conn, buf, replylen,
(answer_type == RESOLVED_TYPE_IPV4 ||
answer_type == RESOLVED_TYPE_IPV6 ||
answer_type == RESOLVED_TYPE_HOSTNAME) ?
0 : END_STREAM_REASON_RESOLVEFAILED);
}
/** Send a socks reply to stream <b>conn</b>, using the appropriate
* socks version, etc, and mark <b>conn</b> as completed with SOCKS
* handshaking.
*
* If <b>reply</b> is defined, then write <b>replylen</b> bytes of it to conn
* and return, else reply based on <b>endreason</b> (one of
* END_STREAM_REASON_*). If <b>reply</b> is undefined, <b>endreason</b> can't
* be 0 or REASON_DONE. Send endreason to the controller, if appropriate.
*/
void
connection_ap_handshake_socks_reply(entry_connection_t *conn, char *reply,
size_t replylen, int endreason)
{
char buf[256];
socks5_reply_status_t status =
stream_end_reason_to_socks5_response(endreason);
tor_assert(conn->socks_request); /* make sure it's an AP stream */
if (!SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command)) {
control_event_stream_status(conn, status==SOCKS5_SUCCEEDED ?
STREAM_EVENT_SUCCEEDED : STREAM_EVENT_FAILED,
endreason);
}
/* Flag this stream's circuit as having completed a stream successfully
* (for path bias) */
if (status == SOCKS5_SUCCEEDED ||
endreason == END_STREAM_REASON_RESOLVEFAILED ||
endreason == END_STREAM_REASON_CONNECTREFUSED ||
endreason == END_STREAM_REASON_CONNRESET ||
endreason == END_STREAM_REASON_NOROUTE ||
endreason == END_STREAM_REASON_RESOURCELIMIT) {
if (!conn->edge_.on_circuit ||
!CIRCUIT_IS_ORIGIN(conn->edge_.on_circuit)) {
if (endreason != END_STREAM_REASON_RESOLVEFAILED) {
log_info(LD_BUG,
"No origin circuit for successful SOCKS stream "U64_FORMAT
". Reason: %d",
U64_PRINTF_ARG(ENTRY_TO_CONN(conn)->global_identifier),
endreason);
}
/*
* Else DNS remaps and failed hidden service lookups can send us
* here with END_STREAM_REASON_RESOLVEFAILED; ignore it
*
* Perhaps we could make the test more precise; we can tell hidden
* services by conn->edge_.renddata != NULL; anything analogous for
* the DNS remap case?
*/
} else {
// XXX: Hrmm. It looks like optimistic data can't go through this
// codepath, but someone should probably test it and make sure.
// We don't want to mark optimistically opened streams as successful.
pathbias_mark_use_success(TO_ORIGIN_CIRCUIT(conn->edge_.on_circuit));
}
}
if (conn->socks_request->has_finished) {
log_warn(LD_BUG, "(Harmless.) duplicate calls to "
"connection_ap_handshake_socks_reply.");
return;
}
if (replylen) { /* we already have a reply in mind */
connection_write_to_buf(reply, replylen, ENTRY_TO_CONN(conn));
conn->socks_request->has_finished = 1;
return;
}
if (conn->socks_request->socks_version == 4) {
memset(buf,0,SOCKS4_NETWORK_LEN);
buf[1] = (status==SOCKS5_SUCCEEDED ? SOCKS4_GRANTED : SOCKS4_REJECT);
/* leave version, destport, destip zero */
connection_write_to_buf(buf, SOCKS4_NETWORK_LEN, ENTRY_TO_CONN(conn));
} else if (conn->socks_request->socks_version == 5) {
size_t buf_len;
memset(buf,0,sizeof(buf));
if (tor_addr_family(&conn->edge_.base_.addr) == AF_INET) {
buf[0] = 5; /* version 5 */
buf[1] = (char)status;
buf[2] = 0;
buf[3] = 1; /* ipv4 addr */
/* 4 bytes for the header, 2 bytes for the port, 4 for the address. */
buf_len = 10;
} else { /* AF_INET6. */
buf[0] = 5; /* version 5 */
buf[1] = (char)status;
buf[2] = 0;
buf[3] = 4; /* ipv6 addr */
/* 4 bytes for the header, 2 bytes for the port, 16 for the address. */
buf_len = 22;
}
connection_write_to_buf(buf,buf_len,ENTRY_TO_CONN(conn));
}
/* If socks_version isn't 4 or 5, don't send anything.
* This can happen in the case of AP bridges. */
conn->socks_request->has_finished = 1;
return;
}
/** Read a RELAY_BEGIN or RELAY_BEGINDIR cell from <b>cell</b>, decode it, and
* place the result in <b>bcell</b>. On success return 0; on failure return
* <0 and set *<b>end_reason_out</b> to the end reason we should send back to
* the client.
*
* Return -1 in the case where want to send a RELAY_END cell, and < -1 when
* we don't.
**/
STATIC int
begin_cell_parse(const cell_t *cell, begin_cell_t *bcell,
uint8_t *end_reason_out)
{
relay_header_t rh;
const uint8_t *body, *nul;
memset(bcell, 0, sizeof(*bcell));
*end_reason_out = END_STREAM_REASON_MISC;
relay_header_unpack(&rh, cell->payload);
if (rh.length > RELAY_PAYLOAD_SIZE) {
return -2; /*XXXX why not TORPROTOCOL? */
}
bcell->stream_id = rh.stream_id;
if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
bcell->is_begindir = 1;
return 0;
} else if (rh.command != RELAY_COMMAND_BEGIN) {
log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command);
*end_reason_out = END_STREAM_REASON_INTERNAL;
return -1;
}
body = cell->payload + RELAY_HEADER_SIZE;
nul = memchr(body, 0, rh.length);
if (! nul) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell has no \\0. Closing.");
*end_reason_out = END_STREAM_REASON_TORPROTOCOL;
return -1;
}
if (tor_addr_port_split(LOG_PROTOCOL_WARN,
(char*)(body),
&bcell->address,&bcell->port)<0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Unable to parse addr:port in relay begin cell. Closing.");
*end_reason_out = END_STREAM_REASON_TORPROTOCOL;
return -1;
}
if (bcell->port == 0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Missing port in relay begin cell. Closing.");
tor_free(bcell->address);
*end_reason_out = END_STREAM_REASON_TORPROTOCOL;
return -1;
}
if (body + rh.length >= nul + 4)
bcell->flags = ntohl(get_uint32(nul+1));
return 0;
}
/** A relay 'begin' or 'begin_dir' cell has arrived, and either we are
* an exit hop for the circuit, or we are the origin and it is a
* rendezvous begin.
*
* Launch a new exit connection and initialize things appropriately.
*
* If it's a rendezvous stream, call connection_exit_connect() on
* it.
*
* For general streams, call dns_resolve() on it first, and only call
* connection_exit_connect() if the dns answer is already known.
*
* Note that we don't call connection_add() on the new stream! We wait
* for connection_exit_connect() to do that.
*
* Return -(some circuit end reason) if we want to tear down <b>circ</b>.
* Else return 0.
*/
int
connection_exit_begin_conn(cell_t *cell, circuit_t *circ)
{
edge_connection_t *n_stream;
relay_header_t rh;
char *address = NULL;
uint16_t port = 0;
or_circuit_t *or_circ = NULL;
origin_circuit_t *origin_circ = NULL;
crypt_path_t *layer_hint = NULL;
const or_options_t *options = get_options();
begin_cell_t bcell;
int rv;
uint8_t end_reason=0;
assert_circuit_ok(circ);
if (!CIRCUIT_IS_ORIGIN(circ)) {
or_circ = TO_OR_CIRCUIT(circ);
} else {
tor_assert(circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED);
origin_circ = TO_ORIGIN_CIRCUIT(circ);
layer_hint = origin_circ->cpath->prev;
}
relay_header_unpack(&rh, cell->payload);
if (rh.length > RELAY_PAYLOAD_SIZE)
return -END_CIRC_REASON_TORPROTOCOL;
/* 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 until we have a pending/successful resolve. */
if (!server_mode(options) &&
circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell at non-server. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_EXITPOLICY, NULL);
return 0;
}
rv = begin_cell_parse(cell, &bcell, &end_reason);
if (rv < -1) {
return -END_CIRC_REASON_TORPROTOCOL;
} else if (rv == -1) {
tor_free(bcell.address);
relay_send_end_cell_from_edge(rh.stream_id, circ, end_reason, layer_hint);
return 0;
}
if (! bcell.is_begindir) {
/* Steal reference */
address = bcell.address;
port = bcell.port;
if (or_circ && or_circ->p_chan) {
if (!options->AllowSingleHopExits &&
(or_circ->is_first_hop ||
(!connection_or_digest_is_known_relay(
or_circ->p_chan->identity_digest) &&
should_refuse_unknown_exits(options)))) {
/* Don't let clients use us as a single-hop proxy, unless the user
* has explicitly allowed that in the config. It attracts attackers
* and users who'd be better off with, well, single-hop proxies.
*/
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Attempt by %s to open a stream %s. Closing.",
safe_str(channel_get_canonical_remote_descr(or_circ->p_chan)),
or_circ->is_first_hop ? "on first hop of circuit" :
"from unknown relay");
relay_send_end_cell_from_edge(rh.stream_id, circ,
or_circ->is_first_hop ?
END_STREAM_REASON_TORPROTOCOL :
END_STREAM_REASON_MISC,
NULL);
tor_free(address);
return 0;
}
}
} else if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
if (!directory_permits_begindir_requests(options) ||
circ->purpose != CIRCUIT_PURPOSE_OR) {
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_NOTDIRECTORY, layer_hint);
return 0;
}
/* Make sure to get the 'real' address of the previous hop: the
* caller might want to know whether the remote IP address has changed,
* and we might already have corrected base_.addr[ess] for the relay's
* canonical IP address. */
if (or_circ && or_circ->p_chan)
address = tor_strdup(channel_get_actual_remote_address(or_circ->p_chan));
else
address = tor_strdup("127.0.0.1");
port = 1; /* XXXX This value is never actually used anywhere, and there
* isn't "really" a connection here. But we
* need to set it to something nonzero. */
} else {
log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command);
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_INTERNAL, layer_hint);
return 0;
}
if (! options->IPv6Exit) {
/* I don't care if you prefer IPv6; I can't give you any. */
bcell.flags &= ~BEGIN_FLAG_IPV6_PREFERRED;
/* If you don't want IPv4, I can't help. */
if (bcell.flags & BEGIN_FLAG_IPV4_NOT_OK) {
tor_free(address);
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_EXITPOLICY, layer_hint);
return 0;
}
}
log_debug(LD_EXIT,"Creating new exit connection.");
/* The 'AF_INET' here is temporary; we might need to change it later in
* connection_exit_connect(). */
n_stream = edge_connection_new(CONN_TYPE_EXIT, AF_INET);
/* Remember the tunneled request ID in the new edge connection, so that
* we can measure download times. */
n_stream->dirreq_id = circ->dirreq_id;
n_stream->base_.purpose = EXIT_PURPOSE_CONNECT;
n_stream->begincell_flags = bcell.flags;
n_stream->stream_id = rh.stream_id;
n_stream->base_.port = port;
/* leave n_stream->s at -1, because it's not yet valid */
n_stream->package_window = STREAMWINDOW_START;
n_stream->deliver_window = STREAMWINDOW_START;
if (circ->purpose == CIRCUIT_PURPOSE_S_REND_JOINED) {
tor_assert(origin_circ);
log_info(LD_REND,"begin is for rendezvous. configuring stream.");
n_stream->base_.address = tor_strdup("(rendezvous)");
n_stream->base_.state = EXIT_CONN_STATE_CONNECTING;
n_stream->rend_data = rend_data_dup(origin_circ->rend_data);
tor_assert(connection_edge_is_rendezvous_stream(n_stream));
assert_circuit_ok(circ);
const int r = rend_service_set_connection_addr_port(n_stream, origin_circ);
if (r < 0) {
log_info(LD_REND,"Didn't find rendezvous service (port %d)",
n_stream->base_.port);
/* Send back reason DONE because we want to make hidden service port
* scanning harder thus instead of returning that the exit policy
* didn't match, which makes it obvious that the port is closed,
* return DONE and kill the circuit. That way, a user (malicious or
* not) needs one circuit per bad port unless it matches the policy of
* the hidden service. */
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_DONE,
layer_hint);
connection_free(TO_CONN(n_stream));
tor_free(address);
/* Drop the circuit here since it might be someone deliberately
* scanning the hidden service ports. Note that this mitigates port
* scanning by adding more work on the attacker side to successfully
* scan but does not fully solve it. */
if (r < -1)
return END_CIRC_AT_ORIGIN;
else
return 0;
}
assert_circuit_ok(circ);
log_debug(LD_REND,"Finished assigning addr/port");
n_stream->cpath_layer = origin_circ->cpath->prev; /* link it */
/* add it into the linked list of p_streams on this circuit */
n_stream->next_stream = origin_circ->p_streams;
n_stream->on_circuit = circ;
origin_circ->p_streams = n_stream;
assert_circuit_ok(circ);
origin_circ->rend_data->nr_streams++;
connection_exit_connect(n_stream);
/* For path bias: This circuit was used successfully */
pathbias_mark_use_success(origin_circ);
tor_free(address);
return 0;
}
tor_strlower(address);
n_stream->base_.address = address;
n_stream->base_.state = EXIT_CONN_STATE_RESOLVEFAILED;
/* default to failed, change in dns_resolve if it turns out not to fail */
if (we_are_hibernating()) {
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_HIBERNATING, NULL);
connection_free(TO_CONN(n_stream));
return 0;
}
n_stream->on_circuit = circ;
if (rh.command == RELAY_COMMAND_BEGIN_DIR) {
tor_addr_t tmp_addr;
tor_assert(or_circ);
if (or_circ->p_chan &&
channel_get_addr_if_possible(or_circ->p_chan, &tmp_addr)) {
tor_addr_copy(&n_stream->base_.addr, &tmp_addr);
}
return connection_exit_connect_dir(n_stream);
}
log_debug(LD_EXIT,"about to start the dns_resolve().");
/* send it off to the gethostbyname farm */
switch (dns_resolve(n_stream)) {
case 1: /* resolve worked; now n_stream is attached to circ. */
assert_circuit_ok(circ);
log_debug(LD_EXIT,"about to call connection_exit_connect().");
connection_exit_connect(n_stream);
return 0;
case -1: /* resolve failed */
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_RESOLVEFAILED, NULL);
/* n_stream got freed. don't touch it. */
break;
case 0: /* resolve added to pending list */
assert_circuit_ok(circ);
break;
}
return 0;
}
/**
* Called when we receive a RELAY_COMMAND_RESOLVE cell 'cell' along the
* circuit <b>circ</b>;
* begin resolving the hostname, and (eventually) reply with a RESOLVED cell.
*/
int
connection_exit_begin_resolve(cell_t *cell, or_circuit_t *circ)
{
edge_connection_t *dummy_conn;
relay_header_t rh;
assert_circuit_ok(TO_CIRCUIT(circ));
relay_header_unpack(&rh, cell->payload);
if (rh.length > RELAY_PAYLOAD_SIZE)
return -1;
/* This 'dummy_conn' only exists to remember the stream ID
* associated with the resolve request; and to make the
* implementation of dns.c more uniform. (We really only need to
* remember the circuit, the stream ID, and the hostname to be
* resolved; but if we didn't store them in a connection like this,
* the housekeeping in dns.c would get way more complicated.)
*/
dummy_conn = edge_connection_new(CONN_TYPE_EXIT, AF_INET);
dummy_conn->stream_id = rh.stream_id;
dummy_conn->base_.address = tor_strndup(
(char*)cell->payload+RELAY_HEADER_SIZE,
rh.length);
dummy_conn->base_.port = 0;
dummy_conn->base_.state = EXIT_CONN_STATE_RESOLVEFAILED;
dummy_conn->base_.purpose = EXIT_PURPOSE_RESOLVE;
dummy_conn->on_circuit = TO_CIRCUIT(circ);
/* send it off to the gethostbyname farm */
switch (dns_resolve(dummy_conn)) {
case -1: /* Impossible to resolve; a resolved cell was sent. */
/* Connection freed; don't touch it. */
return 0;
case 1: /* The result was cached; a resolved cell was sent. */
if (!dummy_conn->base_.marked_for_close)
connection_free(TO_CONN(dummy_conn));
return 0;
case 0: /* resolve added to pending list */
assert_circuit_ok(TO_CIRCUIT(circ));
break;
}
return 0;
}
/** Helper: Return true and set *<b>why_rejected</b> to an optional clarifying
* message message iff we do not allow connections to <b>addr</b>:<b>port</b>.
*/
static int
my_exit_policy_rejects(const tor_addr_t *addr,
uint16_t port,
const char **why_rejected)
{
if (router_compare_to_my_exit_policy(addr, port)) {
*why_rejected = "";
return 1;
} else if (tor_addr_family(addr) == AF_INET6 && !get_options()->IPv6Exit) {
*why_rejected = " (IPv6 address without IPv6Exit configured)";
return 1;
}
return 0;
}
/** Connect to conn's specified addr and port. If it worked, conn
* has now been added to the connection_array.
*
* Send back a connected cell. Include the resolved IP of the destination
* address, but <em>only</em> if it's a general exit stream. (Rendezvous
* streams must not reveal what IP they connected to.)
*/
void
connection_exit_connect(edge_connection_t *edge_conn)
{
const tor_addr_t *addr;
uint16_t port;
connection_t *conn = TO_CONN(edge_conn);
int socket_error = 0, result;
const char *why_failed_exit_policy = NULL;
/* Apply exit policy to non-rendezvous connections. */
if (! connection_edge_is_rendezvous_stream(edge_conn) &&
my_exit_policy_rejects(&edge_conn->base_.addr,
edge_conn->base_.port,
&why_failed_exit_policy)) {
if (BUG(!why_failed_exit_policy))
why_failed_exit_policy = "";
log_info(LD_EXIT,"%s:%d failed exit policy%s. Closing.",
escaped_safe_str_client(conn->address), conn->port,
why_failed_exit_policy);
connection_edge_end(edge_conn, END_STREAM_REASON_EXITPOLICY);
circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
connection_free(conn);
return;
}
#ifdef HAVE_SYS_UN_H
if (conn->socket_family != AF_UNIX) {
#else
{
#endif /* defined(HAVE_SYS_UN_H) */
addr = &conn->addr;
port = conn->port;
if (tor_addr_family(addr) == AF_INET6)
conn->socket_family = AF_INET6;
log_debug(LD_EXIT, "about to try connecting");
result = connection_connect(conn, conn->address,
addr, port, &socket_error);
#ifdef HAVE_SYS_UN_H
} else {
/*
* In the AF_UNIX case, we expect to have already had conn->port = 1,
* tor_addr_make_unspec(conn->addr) (cf. the way we mark in the incoming
* case in connection_handle_listener_read()), and conn->address should
* have the socket path to connect to.
*/
tor_assert(conn->address && strlen(conn->address) > 0);
log_debug(LD_EXIT, "about to try connecting");
result = connection_connect_unix(conn, conn->address, &socket_error);
#endif /* defined(HAVE_SYS_UN_H) */
}
switch (result) {
case -1: {
int reason = errno_to_stream_end_reason(socket_error);
connection_edge_end(edge_conn, reason);
circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
connection_free(conn);
return;
}
case 0:
conn->state = EXIT_CONN_STATE_CONNECTING;
connection_watch_events(conn, READ_EVENT | WRITE_EVENT);
/* writable indicates finish;
* readable/error indicates broken link in windows-land. */
return;
/* case 1: fall through */
}
conn->state = EXIT_CONN_STATE_OPEN;
if (connection_get_outbuf_len(conn)) {
/* in case there are any queued data cells, from e.g. optimistic data */
connection_watch_events(conn, READ_EVENT|WRITE_EVENT);
} else {
connection_watch_events(conn, READ_EVENT);
}
/* also, deliver a 'connected' cell back through the circuit. */
if (connection_edge_is_rendezvous_stream(edge_conn)) {
/* don't send an address back! */
connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED,
NULL, 0);
} else { /* normal stream */
uint8_t connected_payload[MAX_CONNECTED_CELL_PAYLOAD_LEN];
int connected_payload_len =
connected_cell_format_payload(connected_payload, &conn->addr,
edge_conn->address_ttl);
if (connected_payload_len < 0) {
connection_edge_end(edge_conn, END_STREAM_REASON_INTERNAL);
circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
connection_free(conn);
return;
}
connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED,
(char*)connected_payload,
connected_payload_len);
}
}
/** Given an exit conn that should attach to us as a directory server, open a
* bridge connection with a linked connection pair, create a new directory
* conn, and join them together. Return 0 on success (or if there was an
* error we could send back an end cell for). Return -(some circuit end
* reason) if the circuit needs to be torn down. Either connects
* <b>exitconn</b>, frees it, or marks it, as appropriate.
*/
static int
connection_exit_connect_dir(edge_connection_t *exitconn)
{
dir_connection_t *dirconn = NULL;
or_circuit_t *circ = TO_OR_CIRCUIT(exitconn->on_circuit);
log_info(LD_EXIT, "Opening local connection for anonymized directory exit");
exitconn->base_.state = EXIT_CONN_STATE_OPEN;
dirconn = dir_connection_new(tor_addr_family(&exitconn->base_.addr));
tor_addr_copy(&dirconn->base_.addr, &exitconn->base_.addr);
dirconn->base_.port = 0;
dirconn->base_.address = tor_strdup(exitconn->base_.address);
dirconn->base_.type = CONN_TYPE_DIR;
dirconn->base_.purpose = DIR_PURPOSE_SERVER;
dirconn->base_.state = DIR_CONN_STATE_SERVER_COMMAND_WAIT;
/* Note that the new dir conn belongs to the same tunneled request as
* the edge conn, so that we can measure download times. */
dirconn->dirreq_id = exitconn->dirreq_id;
connection_link_connections(TO_CONN(dirconn), TO_CONN(exitconn));
if (connection_add(TO_CONN(exitconn))<0) {
connection_edge_end(exitconn, END_STREAM_REASON_RESOURCELIMIT);
connection_free(TO_CONN(exitconn));
connection_free(TO_CONN(dirconn));
return 0;
}
/* link exitconn to circ, now that we know we can use it. */
exitconn->next_stream = circ->n_streams;
circ->n_streams = exitconn;
if (connection_add(TO_CONN(dirconn))<0) {
connection_edge_end(exitconn, END_STREAM_REASON_RESOURCELIMIT);
connection_close_immediate(TO_CONN(exitconn));
connection_mark_for_close(TO_CONN(exitconn));
connection_free(TO_CONN(dirconn));
return 0;
}
connection_start_reading(TO_CONN(dirconn));
connection_start_reading(TO_CONN(exitconn));
if (connection_edge_send_command(exitconn,
RELAY_COMMAND_CONNECTED, NULL, 0) < 0) {
connection_mark_for_close(TO_CONN(exitconn));
connection_mark_for_close(TO_CONN(dirconn));
return 0;
}
return 0;
}
/** Return 1 if <b>conn</b> is a rendezvous stream, or 0 if
* it is a general stream.
*/
int
connection_edge_is_rendezvous_stream(const edge_connection_t *conn)
{
tor_assert(conn);
if (conn->rend_data)
return 1;
return 0;
}
/** Return 1 if router <b>exit_node</b> is likely to allow stream <b>conn</b>
* to exit from it, or 0 if it probably will not allow it.
* (We might be uncertain if conn's destination address has not yet been
* resolved.)
*/
int
connection_ap_can_use_exit(const entry_connection_t *conn,
const node_t *exit_node)
{
const or_options_t *options = get_options();
tor_assert(conn);
tor_assert(conn->socks_request);
tor_assert(exit_node);
/* If a particular exit node has been requested for the new connection,
* make sure the exit node of the existing circuit matches exactly.
*/
if (conn->chosen_exit_name) {
const node_t *chosen_exit =
node_get_by_nickname(conn->chosen_exit_name, 1);
if (!chosen_exit || tor_memneq(chosen_exit->identity,
exit_node->identity, DIGEST_LEN)) {
/* doesn't match */
// log_debug(LD_APP,"Requested node '%s', considering node '%s'. No.",
// conn->chosen_exit_name, exit->nickname);
return 0;
}
}
if (conn->use_begindir) {
/* Internal directory fetches do not count as exiting. */
return 1;
}
if (conn->socks_request->command == SOCKS_COMMAND_CONNECT) {
tor_addr_t addr, *addrp = NULL;
addr_policy_result_t r;
if (0 == tor_addr_parse(&addr, conn->socks_request->address)) {
addrp = &addr;
} else if (!conn->entry_cfg.ipv4_traffic && conn->entry_cfg.ipv6_traffic) {
tor_addr_make_null(&addr, AF_INET6);
addrp = &addr;
} else if (conn->entry_cfg.ipv4_traffic && !conn->entry_cfg.ipv6_traffic) {
tor_addr_make_null(&addr, AF_INET);
addrp = &addr;
}
r = compare_tor_addr_to_node_policy(addrp, conn->socks_request->port,
exit_node);
if (r == ADDR_POLICY_REJECTED)
return 0; /* We know the address, and the exit policy rejects it. */
if (r == ADDR_POLICY_PROBABLY_REJECTED && !conn->chosen_exit_name)
return 0; /* We don't know the addr, but the exit policy rejects most
* addresses with this port. Since the user didn't ask for
* this node, err on the side of caution. */
} else if (SOCKS_COMMAND_IS_RESOLVE(conn->socks_request->command)) {
/* Don't send DNS requests to non-exit servers by default. */
if (!conn->chosen_exit_name && node_exit_policy_rejects_all(exit_node))
return 0;
}
if (routerset_contains_node(options->ExcludeExitNodesUnion_, exit_node)) {
/* Not a suitable exit. Refuse it. */
return 0;
}
return 1;
}
/** If address is of the form "y.onion" with a well-formed handle y:
* Put a NUL after y, lower-case it, and return ONION_HOSTNAME.
*
* If address is of the form "x.y.onion" with a well-formed handle x:
* Drop "x.", put a NUL after y, lower-case it, and return ONION_HOSTNAME.
*
* If address is of the form "y.onion" with a badly-formed handle y:
* Return BAD_HOSTNAME and log a message.
*
* If address is of the form "y.exit":
* Put a NUL after y and return EXIT_HOSTNAME.
*
* Otherwise:
* Return NORMAL_HOSTNAME and change nothing.
*/
hostname_type_t
parse_extended_hostname(char *address)
{
char *s;
char *q;
char query[REND_SERVICE_ID_LEN_BASE32+1];
s = strrchr(address,'.');
if (!s)
return NORMAL_HOSTNAME; /* no dot, thus normal */
if (!strcmp(s+1,"exit")) {
*s = 0; /* NUL-terminate it */
return EXIT_HOSTNAME; /* .exit */
}
if (strcmp(s+1,"onion"))
return NORMAL_HOSTNAME; /* neither .exit nor .onion, thus normal */
/* so it is .onion */
*s = 0; /* NUL-terminate it */
/* locate a 'sub-domain' component, in order to remove it */
q = strrchr(address, '.');
if (q == address) {
goto failed; /* reject sub-domain, as DNS does */
}
q = (NULL == q) ? address : q + 1;
if (strlcpy(query, q, REND_SERVICE_ID_LEN_BASE32+1) >=
REND_SERVICE_ID_LEN_BASE32+1)
goto failed;
if (q != address) {
memmove(address, q, strlen(q) + 1 /* also get \0 */);
}
if (rend_valid_service_id(query)) {
return ONION_HOSTNAME; /* success */
}
failed:
/* otherwise, return to previous state and return 0 */
*s = '.';
log_warn(LD_APP, "Invalid onion hostname %s; rejecting",
safe_str_client(address));
return BAD_HOSTNAME;
}
/** Return true iff the (possibly NULL) <b>alen</b>-byte chunk of memory at
* <b>a</b> is equal to the (possibly NULL) <b>blen</b>-byte chunk of memory
* at <b>b</b>. */
static int
memeq_opt(const char *a, size_t alen, const char *b, size_t blen)
{
if (a == NULL) {
return (b == NULL);
} else if (b == NULL) {
return 0;
} else if (alen != blen) {
return 0;
} else {
return tor_memeq(a, b, alen);
}
}
/**
* Return true iff none of the isolation flags and fields in <b>conn</b>
* should prevent it from being attached to <b>circ</b>.
*/
int
connection_edge_compatible_with_circuit(const entry_connection_t *conn,
const origin_circuit_t *circ)
{
const uint8_t iso = conn->entry_cfg.isolation_flags;
const socks_request_t *sr = conn->socks_request;
/* If circ has never been used for an isolated connection, we can
* totally use it for this one. */
if (!circ->isolation_values_set)
return 1;
/* If circ has been used for connections having more than one value
* for some field f, it will have the corresponding bit set in
* isolation_flags_mixed. If isolation_flags_mixed has any bits
* in common with iso, then conn must be isolated from at least
* one stream that has been attached to circ. */
if ((iso & circ->isolation_flags_mixed) != 0) {
/* For at least one field where conn is isolated, the circuit
* already has mixed streams. */
return 0;
}
if (! conn->original_dest_address) {
log_warn(LD_BUG, "Reached connection_edge_compatible_with_circuit without "
"having set conn->original_dest_address");
((entry_connection_t*)conn)->original_dest_address =
tor_strdup(conn->socks_request->address);
}
if ((iso & ISO_STREAM) &&
(circ->associated_isolated_stream_global_id !=
ENTRY_TO_CONN(conn)->global_identifier))
return 0;
if ((iso & ISO_DESTPORT) && conn->socks_request->port != circ->dest_port)
return 0;
if ((iso & ISO_DESTADDR) &&
strcasecmp(conn->original_dest_address, circ->dest_address))
return 0;
if ((iso & ISO_SOCKSAUTH) &&
(! memeq_opt(sr->username, sr->usernamelen,
circ->socks_username, circ->socks_username_len) ||
! memeq_opt(sr->password, sr->passwordlen,
circ->socks_password, circ->socks_password_len)))
return 0;
if ((iso & ISO_CLIENTPROTO) &&
(conn->socks_request->listener_type != circ->client_proto_type ||
conn->socks_request->socks_version != circ->client_proto_socksver))
return 0;
if ((iso & ISO_CLIENTADDR) &&
!tor_addr_eq(&ENTRY_TO_CONN(conn)->addr, &circ->client_addr))
return 0;
if ((iso & ISO_SESSIONGRP) &&
conn->entry_cfg.session_group != circ->session_group)
return 0;
if ((iso & ISO_NYM_EPOCH) && conn->nym_epoch != circ->nym_epoch)
return 0;
return 1;
}
/**
* If <b>dry_run</b> is false, update <b>circ</b>'s isolation flags and fields
* to reflect having had <b>conn</b> attached to it, and return 0. Otherwise,
* if <b>dry_run</b> is true, then make no changes to <b>circ</b>, and return
* a bitfield of isolation flags that we would have to set in
* isolation_flags_mixed to add <b>conn</b> to <b>circ</b>, or -1 if
* <b>circ</b> has had no streams attached to it.
*/
int
connection_edge_update_circuit_isolation(const entry_connection_t *conn,
origin_circuit_t *circ,
int dry_run)
{
const socks_request_t *sr = conn->socks_request;
if (! conn->original_dest_address) {
log_warn(LD_BUG, "Reached connection_update_circuit_isolation without "
"having set conn->original_dest_address");
((entry_connection_t*)conn)->original_dest_address =
tor_strdup(conn->socks_request->address);
}
if (!circ->isolation_values_set) {
if (dry_run)
return -1;
circ->associated_isolated_stream_global_id =
ENTRY_TO_CONN(conn)->global_identifier;
circ->dest_port = conn->socks_request->port;
circ->dest_address = tor_strdup(conn->original_dest_address);
circ->client_proto_type = conn->socks_request->listener_type;
circ->client_proto_socksver = conn->socks_request->socks_version;
tor_addr_copy(&circ->client_addr, &ENTRY_TO_CONN(conn)->addr);
circ->session_group = conn->entry_cfg.session_group;
circ->nym_epoch = conn->nym_epoch;
circ->socks_username = sr->username ?
tor_memdup(sr->username, sr->usernamelen) : NULL;
circ->socks_password = sr->password ?
tor_memdup(sr->password, sr->passwordlen) : NULL;
circ->socks_username_len = sr->usernamelen;
circ->socks_password_len = sr->passwordlen;
circ->isolation_values_set = 1;
return 0;
} else {
uint8_t mixed = 0;
if (conn->socks_request->port != circ->dest_port)
mixed |= ISO_DESTPORT;
if (strcasecmp(conn->original_dest_address, circ->dest_address))
mixed |= ISO_DESTADDR;
if (!memeq_opt(sr->username, sr->usernamelen,
circ->socks_username, circ->socks_username_len) ||
!memeq_opt(sr->password, sr->passwordlen,
circ->socks_password, circ->socks_password_len))
mixed |= ISO_SOCKSAUTH;
if ((conn->socks_request->listener_type != circ->client_proto_type ||
conn->socks_request->socks_version != circ->client_proto_socksver))
mixed |= ISO_CLIENTPROTO;
if (!tor_addr_eq(&ENTRY_TO_CONN(conn)->addr, &circ->client_addr))
mixed |= ISO_CLIENTADDR;
if (conn->entry_cfg.session_group != circ->session_group)
mixed |= ISO_SESSIONGRP;
if (conn->nym_epoch != circ->nym_epoch)
mixed |= ISO_NYM_EPOCH;
if (dry_run)
return mixed;
if ((mixed & conn->entry_cfg.isolation_flags) != 0) {
log_warn(LD_BUG, "Updating a circuit with seemingly incompatible "
"isolation flags.");
}
circ->isolation_flags_mixed |= mixed;
return 0;
}
}
/**
* Clear the isolation settings on <b>circ</b>.
*
* This only works on an open circuit that has never had a stream attached to
* it, and whose isolation settings are hypothetical. (We set hypothetical
* isolation settings on circuits as we're launching them, so that we
* know whether they can handle more streams or whether we need to launch
* even more circuits. Once the circuit is open, if it turns out that
* we no longer have any streams to attach to it, we clear the isolation flags
* and data so that other streams can have a chance.)
*/
void
circuit_clear_isolation(origin_circuit_t *circ)
{
if (circ->isolation_any_streams_attached) {
log_warn(LD_BUG, "Tried to clear the isolation status of a dirty circuit");
return;
}
if (TO_CIRCUIT(circ)->state != CIRCUIT_STATE_OPEN) {
log_warn(LD_BUG, "Tried to clear the isolation status of a non-open "
"circuit");
return;
}
circ->isolation_values_set = 0;
circ->isolation_flags_mixed = 0;
circ->associated_isolated_stream_global_id = 0;
circ->client_proto_type = 0;
circ->client_proto_socksver = 0;
circ->dest_port = 0;
tor_addr_make_unspec(&circ->client_addr);
tor_free(circ->dest_address);
circ->session_group = -1;
circ->nym_epoch = 0;
if (circ->socks_username) {
memwipe(circ->socks_username, 0x11, circ->socks_username_len);
tor_free(circ->socks_username);
}
if (circ->socks_password) {
memwipe(circ->socks_password, 0x05, circ->socks_password_len);
tor_free(circ->socks_password);
}
circ->socks_username_len = circ->socks_password_len = 0;
}
/** Free all storage held in module-scoped variables for connection_edge.c */
void
connection_edge_free_all(void)
{
untried_pending_connections = 0;
smartlist_free(pending_entry_connections);
pending_entry_connections = NULL;
}
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