/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2010, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file connection_edge.c
* \brief Handle edge streams.
**/
#include "or.h"
#include "buffers.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 "dirserv.h"
#include "hibernate.h"
#include "main.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"
#ifdef HAVE_LINUX_TYPES_H
#include <linux/types.h>
#endif
#ifdef HAVE_LINUX_NETFILTER_IPV4_H
#include <linux/netfilter_ipv4.h>
#define TRANS_NETFILTER
#endif
#if defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H)
#include <net/if.h>
#include <net/pfvar.h>
#define TRANS_PF
#endif
#define SOCKS4_GRANTED 90
#define SOCKS4_REJECT 91
static int connection_ap_handshake_process_socks(edge_connection_t *conn);
static int connection_ap_process_natd(edge_connection_t *conn);
static int connection_exit_connect_dir(edge_connection_t *exitconn);
static int address_is_in_virtual_range(const char *addr);
static int consider_plaintext_ports(edge_connection_t *conn, uint16_t port);
static void clear_trackexithost_mappings(const char *exitname);
/** 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.
*/
void
_connection_mark_unattached_ap(edge_connection_t *conn, int endreason,
int line, const char *file)
{
tor_assert(conn->_base.type == CONN_TYPE_AP);
conn->edge_has_sent_end = 1; /* no circ yet */
if (conn->_base.marked_for_close) {
/* This call will warn as appropriate. */
_connection_mark_for_close(TO_CONN(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_for_close(TO_CONN(conn), line, file);
conn->_base.hold_open_until_flushed = 1;
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 (buf_datalen(conn->_base.inbuf) &&
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 %d) 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->socks_request) /* eof, so don't send a socks reply back */
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(conn) < 0) {
/* already marked */
return -1;
}
return 0;
case AP_CONN_STATE_NATD_WAIT:
if (connection_ap_process_natd(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) < 0) {
/* (We already sent an end cell if possible) */
connection_mark_for_close(TO_CONN(conn));
return -1;
}
return 0;
case EXIT_CONN_STATE_CONNECTING:
case AP_CONN_STATE_RENDDESC_WAIT:
case AP_CONN_STATE_CIRCUIT_WAIT:
case AP_CONN_STATE_CONNECT_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 %d: At an edge. Marking connection for close.", circ_id);
if (conn->_base.type == CONN_TYPE_AP) {
connection_mark_unattached_ap(conn, END_STREAM_REASON_DESTROY);
control_event_stream_bandwidth(conn);
control_event_stream_status(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_for_close(TO_CONN(conn));
conn->_base.hold_open_until_flushed = 1;
}
}
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);
}
/** 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 %d).",conn->_base.s);
connection_edge_send_command(conn, RELAY_COMMAND_END,
payload, payload_len);
} else {
log_debug(LD_EDGE,"No circ to send end on conn (fd %d).",
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);
}
/** 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_stop_writing(TO_CONN(conn));
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:
connection_stop_writing(TO_CONN(conn));
return 0;
default:
log_warn(LD_BUG, "Called in unexpected state %d.",conn->_base.state);
tor_fragile_assert();
return -1;
}
return 0;
}
/** 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_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_wants_to_flush(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 {
char connected_payload[20];
int connected_payload_len;
if (tor_addr_family(&conn->addr) == AF_INET) {
set_uint32(connected_payload, tor_addr_to_ipv4n(&conn->addr));
set_uint32(connected_payload+4,
htonl(dns_clip_ttl(edge_conn->address_ttl)));
connected_payload_len = 8;
} else {
memcpy(connected_payload, tor_addr_to_in6_addr8(&conn->addr), 16);
set_uint32(connected_payload+16,
htonl(dns_clip_ttl(edge_conn->address_ttl)));
connected_payload_len = 20;
}
if (connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED,
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);
}
/** 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(edge_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;
circuit_t *circ;
time_t now = time(NULL);
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 *, c) {
if (c->type != CONN_TYPE_AP || c->marked_for_close)
continue;
conn = TO_EDGE_CONN(c);
/* if it's an internal linked connection, don't yell its status. */
severity = (tor_addr_is_null(&conn->_base.addr) && !conn->_base.port)
? LOG_INFO : LOG_NOTICE;
seconds_idle = (int)( now - conn->_base.timestamp_lastread );
seconds_since_born = (int)( now - conn->_base.timestamp_created );
if (conn->_base.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(conn->_base.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(conn->socks_request->address),
conn->socks_request->port,
conn_state_to_string(CONN_TYPE_AP, conn->_base.state));
connection_mark_unattached_ap(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(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(conn->socks_request->address));
connection_mark_unattached_ap(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(conn->socks_request->address));
connection_edge_end(conn, END_STREAM_REASON_TIMEOUT);
connection_mark_unattached_ap(conn, END_STREAM_REASON_TIMEOUT);
}
continue;
}
tor_assert(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL);
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(conn->socks_request->address),
conn->cpath_layer ?
conn->cpath_layer->extend_info->nickname : "*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;
/* kludge to make us not try this circuit again, yet to allow
* current streams on it to survive if they can: make it
* unattractive to use for new streams */
tor_assert(circ->timestamp_dirty);
circ->timestamp_dirty -= options->MaxCircuitDirtiness;
/* give our stream another 'cutoff' seconds to try */
conn->_base.timestamp_lastread += cutoff;
if (conn->num_socks_retries < 250) /* avoid overflow */
conn->num_socks_retries++;
/* move it back into 'pending' state, and try to attach. */
if (connection_ap_detach_retriable(conn, TO_ORIGIN_CIRCUIT(circ),
END_STREAM_REASON_TIMEOUT)<0) {
if (!conn->_base.marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
}
} SMARTLIST_FOREACH_END(conn);
}
/** Tell any AP streams that are waiting for a new circuit to try again,
* either attaching to an available circ or launching a new one.
*/
void
connection_ap_attach_pending(void)
{
edge_connection_t *edge_conn;
smartlist_t *conns = get_connection_array();
SMARTLIST_FOREACH(conns, connection_t *, conn,
{
if (conn->marked_for_close ||
conn->type != CONN_TYPE_AP ||
conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
continue;
edge_conn = TO_EDGE_CONN(conn);
if (connection_ap_handshake_attach_circuit(edge_conn) < 0) {
if (!edge_conn->_base.marked_for_close)
connection_mark_unattached_ap(edge_conn,
END_STREAM_REASON_CANT_ATTACH);
}
});
}
/** Tell any AP streams that are waiting for a one-hop tunnel to
* <b>failed_digest</b> that they are going to fail. */
/* XXX022 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)
{
edge_connection_t *edge_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;
edge_conn = TO_EDGE_CONN(conn);
if (!edge_conn->want_onehop)
continue;
if (hexdigest_to_digest(edge_conn->chosen_exit_name, digest) < 0 ||
memcmp(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 ||
!edge_conn->socks_request || !edge_conn->socks_request->address)
continue;
if (tor_addr_from_str(&addr, edge_conn->socks_request->address)<0 ||
!tor_addr_eq(&build_state->chosen_exit->addr, &addr) ||
build_state->chosen_exit->port != edge_conn->socks_request->port)
continue;
}
log_info(LD_APP, "Closing one-hop stream to '%s/%s' because the OR conn "
"just failed.", edge_conn->chosen_exit_name,
edge_conn->socks_request->address);
connection_mark_unattached_ap(edge_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)
{
edge_connection_t *edge_conn;
routerinfo_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;
edge_conn = TO_EDGE_CONN(conn);
if (!edge_conn->chosen_exit_optional &&
!edge_conn->chosen_exit_retries)
continue;
r1 = router_get_by_nickname(edge_conn->chosen_exit_name, 0);
r2 = router_get_by_nickname(info->nickname, 0);
if (!r1 || !r2 || r1 != r2)
continue;
tor_assert(edge_conn->socks_request);
if (edge_conn->chosen_exit_optional) {
log_info(LD_APP, "Giving up on enclave exit '%s' for destination %s.",
safe_str_client(edge_conn->chosen_exit_name),
escaped_safe_str_client(edge_conn->socks_request->address));
edge_conn->chosen_exit_optional = 0;
tor_free(edge_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(edge_conn, edge_conn->socks_request->port);
}
if (edge_conn->chosen_exit_retries) {
if (--edge_conn->chosen_exit_retries == 0) { /* give up! */
clear_trackexithost_mappings(edge_conn->chosen_exit_name);
tor_free(edge_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(edge_conn, edge_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 a appropriate.
*
* Returns -1 on err, 1 on success, 0 on not-yet-sure.
*/
int
connection_ap_detach_retriable(edge_connection_t *conn, origin_circuit_t *circ,
int reason)
{
control_event_stream_status(conn, STREAM_EVENT_FAILED_RETRIABLE, reason);
conn->_base.timestamp_lastread = time(NULL);
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. */
conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
circuit_detach_stream(TO_CIRCUIT(circ),conn);
return connection_ap_handshake_attach_circuit(conn);
} else {
conn->_base.state = AP_CONN_STATE_CONTROLLER_WAIT;
circuit_detach_stream(TO_CIRCUIT(circ),conn);
return 0;
}
}
/** A client-side struct to remember requests to rewrite addresses
* to new addresses. These structs are stored in the hash table
* "addressmap" below.
*
* There are 5 ways to set an address mapping:
* - A MapAddress command from the controller [permanent]
* - An AddressMap directive in the torrc [permanent]
* - When a TrackHostExits torrc directive is triggered [temporary]
* - When a DNS resolve succeeds [temporary]
* - When a DNS resolve fails [temporary]
*
* When an addressmap request is made but one is already registered,
* the new one is replaced only if the currently registered one has
* no "new_address" (that is, it's in the process of DNS resolve),
* or if the new one is permanent (expires==0 or 1).
*
* (We overload the 'expires' field, using "0" for mappings set via
* the configuration file, "1" for mappings set from the control
* interface, and other values for DNS and TrackHostExit mappings that can
* expire.)
*/
typedef struct {
char *new_address;
time_t expires;
addressmap_entry_source_t source:3;
short num_resolve_failures;
} addressmap_entry_t;
/** Entry for mapping addresses to which virtual address we mapped them to. */
typedef struct {
char *ipv4_address;
char *hostname_address;
} virtaddress_entry_t;
/** A hash table to store client-side address rewrite instructions. */
static strmap_t *addressmap=NULL;
/**
* Table mapping addresses to which virtual address, if any, we
* assigned them to.
*
* We maintain the following invariant: if [A,B] is in
* virtaddress_reversemap, then B must be a virtual address, and [A,B]
* must be in addressmap. We do not require that the converse hold:
* if it fails, then we could end up mapping two virtual addresses to
* the same address, which is no disaster.
**/
static strmap_t *virtaddress_reversemap=NULL;
/** Initialize addressmap. */
void
addressmap_init(void)
{
addressmap = strmap_new();
virtaddress_reversemap = strmap_new();
}
/** Free the memory associated with the addressmap entry <b>_ent</b>. */
static void
addressmap_ent_free(void *_ent)
{
addressmap_entry_t *ent;
if (!_ent)
return;
ent = _ent;
tor_free(ent->new_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b>. */
static void
addressmap_virtaddress_ent_free(void *_ent)
{
virtaddress_entry_t *ent;
if (!_ent)
return;
ent = _ent;
tor_free(ent->ipv4_address);
tor_free(ent->hostname_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b>. */
static void
addressmap_virtaddress_remove(const char *address, addressmap_entry_t *ent)
{
if (ent && ent->new_address &&
address_is_in_virtual_range(ent->new_address)) {
virtaddress_entry_t *ve =
strmap_get(virtaddress_reversemap, ent->new_address);
/*log_fn(LOG_NOTICE,"remove reverse mapping for %s",ent->new_address);*/
if (ve) {
if (!strcmp(address, ve->ipv4_address))
tor_free(ve->ipv4_address);
if (!strcmp(address, ve->hostname_address))
tor_free(ve->hostname_address);
if (!ve->ipv4_address && !ve->hostname_address) {
tor_free(ve);
strmap_remove(virtaddress_reversemap, ent->new_address);
}
}
}
}
/** Remove <b>ent</b> (which must be mapped to by <b>address</b>) from the
* client address maps. */
static void
addressmap_ent_remove(const char *address, addressmap_entry_t *ent)
{
addressmap_virtaddress_remove(address, ent);
addressmap_ent_free(ent);
}
/** Unregister all TrackHostExits mappings from any address to
* *.exitname.exit. */
static void
clear_trackexithost_mappings(const char *exitname)
{
char *suffix;
size_t suffix_len;
if (!addressmap || !exitname)
return;
suffix_len = strlen(exitname) + 16;
suffix = tor_malloc(suffix_len);
tor_snprintf(suffix, suffix_len, ".%s.exit", exitname);
tor_strlower(suffix);
STRMAP_FOREACH_MODIFY(addressmap, address, addressmap_entry_t *, ent) {
if (ent->source == ADDRMAPSRC_TRACKEXIT && !strcmpend(address, suffix)) {
addressmap_ent_remove(address, ent);
MAP_DEL_CURRENT(address);
}
} STRMAP_FOREACH_END;
tor_free(suffix);
}
/** Remove all entries from the addressmap that were set via the
* configuration file or the command line. */
void
addressmap_clear_configured(void)
{
addressmap_get_mappings(NULL, 0, 0, 0);
}
/** Remove all entries from the addressmap that are set to expire, ever. */
void
addressmap_clear_transient(void)
{
addressmap_get_mappings(NULL, 2, TIME_MAX, 0);
}
/** Clean out entries from the addressmap cache that were
* added long enough ago that they are no longer valid.
*/
void
addressmap_clean(time_t now)
{
addressmap_get_mappings(NULL, 2, now, 0);
}
/** Free all the elements in the addressmap, and free the addressmap
* itself. */
void
addressmap_free_all(void)
{
strmap_free(addressmap, addressmap_ent_free);
addressmap = NULL;
strmap_free(virtaddress_reversemap, addressmap_virtaddress_ent_free);
virtaddress_reversemap = NULL;
}
/** Look at address, and rewrite it until it doesn't want any
* more rewrites; but don't get into an infinite loop.
* Don't write more than maxlen chars into address. Return true if the
* address changed; false otherwise. Set *<b>expires_out</b> to the
* expiry time of the result, or to <b>time_max</b> if the result does
* not expire.
*/
int
addressmap_rewrite(char *address, size_t maxlen, time_t *expires_out)
{
addressmap_entry_t *ent;
int rewrites;
char *cp;
time_t expires = TIME_MAX;
for (rewrites = 0; rewrites < 16; rewrites++) {
ent = strmap_get(addressmap, address);
if (!ent || !ent->new_address) {
if (expires_out)
*expires_out = expires;
return (rewrites > 0); /* done, no rewrite needed */
}
cp = tor_strdup(escaped_safe_str_client(ent->new_address));
log_info(LD_APP, "Addressmap: rewriting %s to %s",
escaped_safe_str_client(address), cp);
if (ent->expires > 1 && ent->expires < expires)
expires = ent->expires;
tor_free(cp);
strlcpy(address, ent->new_address, maxlen);
}
log_warn(LD_CONFIG,
"Loop detected: we've rewritten %s 16 times! Using it as-is.",
escaped_safe_str_client(address));
/* it's fine to rewrite a rewrite, but don't loop forever */
if (expires_out)
*expires_out = TIME_MAX;
return 1;
}
/** If we have a cached reverse DNS entry for the address stored in the
* <b>maxlen</b>-byte buffer <b>address</b> (typically, a dotted quad) then
* rewrite to the cached value and return 1. Otherwise return 0. Set
* *<b>expires_out</b> to the expiry time of the result, or to <b>time_max</b>
* if the result does not expire. */
static int
addressmap_rewrite_reverse(char *address, size_t maxlen, time_t *expires_out)
{
size_t len = maxlen + 16;
char *s = tor_malloc(len), *cp;
addressmap_entry_t *ent;
int r = 0;
tor_snprintf(s, len, "REVERSE[%s]", address);
ent = strmap_get(addressmap, s);
if (ent) {
cp = tor_strdup(escaped_safe_str_client(ent->new_address));
log_info(LD_APP, "Rewrote reverse lookup %s -> %s",
escaped_safe_str_client(s), cp);
tor_free(cp);
strlcpy(address, ent->new_address, maxlen);
r = 1;
}
if (expires_out)
*expires_out = (ent && ent->expires > 1) ? ent->expires : TIME_MAX;
tor_free(s);
return r;
}
/** Return 1 if <b>address</b> is already registered, else return 0. If address
* is already registered, and <b>update_expires</b> is non-zero, then update
* the expiry time on the mapping with update_expires if it is a
* mapping created by TrackHostExits. */
int
addressmap_have_mapping(const char *address, int update_expiry)
{
addressmap_entry_t *ent;
if (!(ent=strmap_get_lc(addressmap, address)))
return 0;
if (update_expiry && ent->source==ADDRMAPSRC_TRACKEXIT)
ent->expires=time(NULL) + update_expiry;
return 1;
}
/** Register a request to map <b>address</b> to <b>new_address</b>,
* which will expire on <b>expires</b> (or 0 if never expires from
* config file, 1 if never expires from controller, 2 if never expires
* (virtual address mapping) from the controller.)
*
* <b>new_address</b> should be a newly dup'ed string, which we'll use or
* free as appropriate. We will leave address alone.
*
* If <b>new_address</b> is NULL, or equal to <b>address</b>, remove
* any mappings that exist from <b>address</b>.
*/
void
addressmap_register(const char *address, char *new_address, time_t expires,
addressmap_entry_source_t source)
{
addressmap_entry_t *ent;
ent = strmap_get(addressmap, address);
if (!new_address || !strcasecmp(address,new_address)) {
/* Remove the mapping, if any. */
tor_free(new_address);
if (ent) {
addressmap_ent_remove(address,ent);
strmap_remove(addressmap, address);
}
return;
}
if (!ent) { /* make a new one and register it */
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
strmap_set(addressmap, address, ent);
} else if (ent->new_address) { /* we need to clean up the old mapping. */
if (expires > 1) {
log_info(LD_APP,"Temporary addressmap ('%s' to '%s') not performed, "
"since it's already mapped to '%s'",
safe_str_client(address),
safe_str_client(new_address),
safe_str_client(ent->new_address));
tor_free(new_address);
return;
}
if (address_is_in_virtual_range(ent->new_address) &&
expires != 2) {
/* XXX This isn't the perfect test; we want to avoid removing
* mappings set from the control interface _as virtual mapping */
addressmap_virtaddress_remove(address, ent);
}
tor_free(ent->new_address);
} /* else { we have an in-progress resolve with no mapping. } */
ent->new_address = new_address;
ent->expires = expires==2 ? 1 : expires;
ent->num_resolve_failures = 0;
ent->source = source;
log_info(LD_CONFIG, "Addressmap: (re)mapped '%s' to '%s'",
safe_str_client(address),
safe_str_client(ent->new_address));
control_event_address_mapped(address, ent->new_address, expires, NULL);
}
/** An attempt to resolve <b>address</b> failed at some OR.
* Increment the number of resolve failures we have on record
* for it, and then return that number.
*/
int
client_dns_incr_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (!ent) {
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
ent->expires = time(NULL) + MAX_DNS_ENTRY_AGE;
strmap_set(addressmap,address,ent);
}
if (ent->num_resolve_failures < SHORT_MAX)
++ent->num_resolve_failures; /* don't overflow */
log_info(LD_APP, "Address %s now has %d resolve failures.",
safe_str_client(address),
ent->num_resolve_failures);
return ent->num_resolve_failures;
}
/** If <b>address</b> is in the client DNS addressmap, reset
* the number of resolve failures we have on record for it.
* This is used when we fail a stream because it won't resolve:
* otherwise future attempts on that address will only try once.
*/
void
client_dns_clear_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (ent)
ent->num_resolve_failures = 0;
}
/** Record the fact that <b>address</b> resolved to <b>name</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
static void
client_dns_set_addressmap_impl(const char *address, const char *name,
const char *exitname,
int ttl)
{
/* <address>.<hex or nickname>.exit\0 or just <address>\0 */
char extendedaddress[MAX_SOCKS_ADDR_LEN+MAX_VERBOSE_NICKNAME_LEN+10];
/* 123.123.123.123.<hex or nickname>.exit\0 or just 123.123.123.123\0 */
char extendedval[INET_NTOA_BUF_LEN+MAX_VERBOSE_NICKNAME_LEN+10];
tor_assert(address);
tor_assert(name);
if (ttl<0)
ttl = DEFAULT_DNS_TTL;
else
ttl = dns_clip_ttl(ttl);
if (exitname) {
/* XXXX fails to ever get attempts to get an exit address of
* google.com.digest[=~]nickname.exit; we need a syntax for this that
* won't make strict RFC952-compliant applications (like us) barf. */
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s.%s.exit", address, exitname);
tor_snprintf(extendedval, sizeof(extendedval),
"%s.%s.exit", name, exitname);
} else {
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s", address);
tor_snprintf(extendedval, sizeof(extendedval),
"%s", name);
}
addressmap_register(extendedaddress, tor_strdup(extendedval),
time(NULL) + ttl, ADDRMAPSRC_DNS);
}
/** Record the fact that <b>address</b> resolved to <b>val</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
void
client_dns_set_addressmap(const char *address, uint32_t val,
const char *exitname,
int ttl)
{
struct in_addr in;
char valbuf[INET_NTOA_BUF_LEN];
tor_assert(address);
if (tor_inet_aton(address, &in))
return; /* If address was an IP address already, don't add a mapping. */
in.s_addr = htonl(val);
tor_inet_ntoa(&in,valbuf,sizeof(valbuf));
client_dns_set_addressmap_impl(address, valbuf, exitname, ttl);
}
/** Add a cache entry noting that <b>address</b> (ordinarily a dotted quad)
* resolved via a RESOLVE_PTR request to the hostname <b>v</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
static void
client_dns_set_reverse_addressmap(const char *address, const char *v,
const char *exitname,
int ttl)
{
size_t len = strlen(address) + 16;
char *s = tor_malloc(len);
tor_snprintf(s, len, "REVERSE[%s]", address);
client_dns_set_addressmap_impl(s, v, exitname, ttl);
tor_free(s);
}
/* By default, we hand out 127.192.0.1 through 127.254.254.254.
* These addresses should map to localhost, so even if the
* application accidentally tried to connect to them directly (not
* via Tor), it wouldn't get too far astray.
*
* These options are configured by parse_virtual_addr_network().
*/
/** Which network should we use for virtual IPv4 addresses? Only the first
* bits of this value are fixed. */
static uint32_t virtual_addr_network = 0x7fc00000u;
/** How many bits of <b>virtual_addr_network</b> are fixed? */
static maskbits_t virtual_addr_netmask_bits = 10;
/** What's the next virtual address we will hand out? */
static uint32_t next_virtual_addr = 0x7fc00000u;
/** Read a netmask of the form 127.192.0.0/10 from "val", and check whether
* it's a valid set of virtual addresses to hand out in response to MAPADDRESS
* requests. Return 0 on success; set *msg (if provided) to a newly allocated
* string and return -1 on failure. If validate_only is false, sets the
* actual virtual address range to the parsed value. */
int
parse_virtual_addr_network(const char *val, int validate_only,
char **msg)
{
uint32_t addr;
uint16_t port_min, port_max;
maskbits_t bits;
if (parse_addr_and_port_range(val, &addr, &bits, &port_min, &port_max)) {
if (msg) *msg = tor_strdup("Error parsing VirtualAddressNetwork");
return -1;
}
if (port_min != 1 || port_max != 65535) {
if (msg) *msg = tor_strdup("Can't specify ports on VirtualAddressNetwork");
return -1;
}
if (bits > 16) {
if (msg) *msg = tor_strdup("VirtualAddressNetwork expects a /16 "
"network or larger");
return -1;
}
if (validate_only)
return 0;
virtual_addr_network = (uint32_t)( addr & (0xfffffffful << (32-bits)) );
virtual_addr_netmask_bits = bits;
if (addr_mask_cmp_bits(next_virtual_addr, addr, bits))
next_virtual_addr = addr;
return 0;
}
/**
* Return true iff <b>addr</b> is likely to have been returned by
* client_dns_get_unused_address.
**/
static int
address_is_in_virtual_range(const char *address)
{
struct in_addr in;
tor_assert(address);
if (!strcasecmpend(address, ".virtual")) {
return 1;
} else if (tor_inet_aton(address, &in)) {
uint32_t addr = ntohl(in.s_addr);
if (!addr_mask_cmp_bits(addr, virtual_addr_network,
virtual_addr_netmask_bits))
return 1;
}
return 0;
}
/** Return a newly allocated string holding an address of <b>type</b>
* (one of RESOLVED_TYPE_{IPV4|HOSTNAME}) that has not yet been mapped,
* and that is very unlikely to be the address of any real host.
*/
static char *
addressmap_get_virtual_address(int type)
{
char buf[64];
struct in_addr in;
tor_assert(addressmap);
if (type == RESOLVED_TYPE_HOSTNAME) {
char rand[10];
do {
crypto_rand(rand, sizeof(rand));
base32_encode(buf,sizeof(buf),rand,sizeof(rand));
strlcat(buf, ".virtual", sizeof(buf));
} while (strmap_get(addressmap, buf));
return tor_strdup(buf);
} else if (type == RESOLVED_TYPE_IPV4) {
// This is an imperfect estimate of how many addresses are available, but
// that's ok.
uint32_t available = 1u << (32-virtual_addr_netmask_bits);
while (available) {
/* Don't hand out any .0 or .255 address. */
while ((next_virtual_addr & 0xff) == 0 ||
(next_virtual_addr & 0xff) == 0xff) {
++next_virtual_addr;
}
in.s_addr = htonl(next_virtual_addr);
tor_inet_ntoa(&in, buf, sizeof(buf));
if (!strmap_get(addressmap, buf)) {
++next_virtual_addr;
break;
}
++next_virtual_addr;
--available;
log_info(LD_CONFIG, "%d addrs available", (int)available);
if (! --available) {
log_warn(LD_CONFIG, "Ran out of virtual addresses!");
return NULL;
}
if (addr_mask_cmp_bits(next_virtual_addr, virtual_addr_network,
virtual_addr_netmask_bits))
next_virtual_addr = virtual_addr_network;
}
return tor_strdup(buf);
} else {
log_warn(LD_BUG, "Called with unsupported address type (%d)", type);
return NULL;
}
}
/** A controller has requested that we map some address of type
* <b>type</b> to the address <b>new_address</b>. Choose an address
* that is unlikely to be used, and map it, and return it in a newly
* allocated string. If another address of the same type is already
* mapped to <b>new_address</b>, try to return a copy of that address.
*
* The string in <b>new_address</b> may be freed, or inserted into a map
* as appropriate.
**/
const char *
addressmap_register_virtual_address(int type, char *new_address)
{
char **addrp;
virtaddress_entry_t *vent;
tor_assert(new_address);
tor_assert(addressmap);
tor_assert(virtaddress_reversemap);
vent = strmap_get(virtaddress_reversemap, new_address);
if (!vent) {
vent = tor_malloc_zero(sizeof(virtaddress_entry_t));
strmap_set(virtaddress_reversemap, new_address, vent);
}
addrp = (type == RESOLVED_TYPE_IPV4) ?
&vent->ipv4_address : &vent->hostname_address;
if (*addrp) {
addressmap_entry_t *ent = strmap_get(addressmap, *addrp);
if (ent && ent->new_address &&
!strcasecmp(new_address, ent->new_address)) {
tor_free(new_address);
return tor_strdup(*addrp);
} else
log_warn(LD_BUG,
"Internal confusion: I thought that '%s' was mapped to by "
"'%s', but '%s' really maps to '%s'. This is a harmless bug.",
safe_str_client(new_address),
safe_str_client(*addrp),
safe_str_client(*addrp),
ent?safe_str_client(ent->new_address):"(nothing)");
}
tor_free(*addrp);
*addrp = addressmap_get_virtual_address(type);
log_info(LD_APP, "Registering map from %s to %s", *addrp, new_address);
addressmap_register(*addrp, new_address, 2, ADDRMAPSRC_CONTROLLER);
#if 0
{
/* Try to catch possible bugs */
addressmap_entry_t *ent;
ent = strmap_get(addressmap, *addrp);
tor_assert(ent);
tor_assert(!strcasecmp(ent->new_address,new_address));
vent = strmap_get(virtaddress_reversemap, new_address);
tor_assert(vent);
tor_assert(!strcasecmp(*addrp,
(type == RESOLVED_TYPE_IPV4) ?
vent->ipv4_address : vent->hostname_address));
log_info(LD_APP, "Map from %s to %s okay.",
safe_str_client(*addrp),
safe_str_client(new_address));
}
#endif
return *addrp;
}
/** Return 1 if <b>address</b> has funny characters in it like colons. Return
* 0 if it's fine, or if we're configured to allow it anyway. <b>client</b>
* should be true if we're using this address as a client; false if we're
* using it as a server.
*/
int
address_is_invalid_destination(const char *address, int client)
{
if (client) {
if (get_options()->AllowNonRFC953Hostnames)
return 0;
} else {
if (get_options()->ServerDNSAllowNonRFC953Hostnames)
return 0;
}
while (*address) {
if (TOR_ISALNUM(*address) ||
*address == '-' ||
*address == '.' ||
*address == '_') /* Underscore is not allowed, but Windows does it
* sometimes, just to thumb its nose at the IETF. */
++address;
else
return 1;
}
return 0;
}
/** Iterate over all address mappings which have expiry times between
* min_expires and max_expires, inclusive. If sl is provided, add an
* "old-addr new-addr expiry" string to sl for each mapping, omitting
* the expiry time if want_expiry is false. If sl is NULL, remove the
* mappings.
*/
void
addressmap_get_mappings(smartlist_t *sl, time_t min_expires,
time_t max_expires, int want_expiry)
{
strmap_iter_t *iter;
const char *key;
void *_val;
addressmap_entry_t *val;
if (!addressmap)
addressmap_init();
for (iter = strmap_iter_init(addressmap); !strmap_iter_done(iter); ) {
strmap_iter_get(iter, &key, &_val);
val = _val;
if (val->expires >= min_expires && val->expires <= max_expires) {
if (!sl) {
iter = strmap_iter_next_rmv(addressmap,iter);
addressmap_ent_remove(key, val);
continue;
} else if (val->new_address) {
size_t len = strlen(key)+strlen(val->new_address)+ISO_TIME_LEN+5;
char *line = tor_malloc(len);
if (want_expiry) {
if (val->expires < 3 || val->expires == TIME_MAX)
tor_snprintf(line, len, "%s %s NEVER", key, val->new_address);
else {
char time[ISO_TIME_LEN+1];
format_iso_time(time, val->expires);
tor_snprintf(line, len, "%s %s \"%s\"", key, val->new_address,
time);
}
} else {
tor_snprintf(line, len, "%s %s", key, val->new_address);
}
smartlist_add(sl, line);
}
}
iter = strmap_iter_next(addressmap,iter);
}
}
/** 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(edge_connection_t *conn, uint16_t port)
{
or_options_t *options = get_options();
int reject = smartlist_string_num_isin(options->RejectPlaintextPorts, port);
if (smartlist_string_num_isin(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
/** 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(edge_connection_t *conn,
origin_circuit_t *circ,
crypt_path_t *cpath)
{
socks_request_t *socks = conn->socks_request;
hostname_type_t addresstype;
or_options_t *options = get_options();
struct in_addr addr_tmp;
int automap = 0;
char orig_address[MAX_SOCKS_ADDR_LEN];
time_t map_expires = TIME_MAX;
int remapped_to_exit = 0;
time_t now = time(NULL);
tor_strlower(socks->address); /* normalize it */
strlcpy(orig_address, socks->address, sizeof(orig_address));
log_debug(LD_APP,"Client asked for %s:%d",
safe_str_client(socks->address),
socks->port);
if (socks->command == SOCKS_COMMAND_RESOLVE &&
!tor_inet_aton(socks->address, &addr_tmp) &&
options->AutomapHostsOnResolve && options->AutomapHostsSuffixes) {
SMARTLIST_FOREACH(options->AutomapHostsSuffixes, const char *, cp,
if (!strcasecmpend(socks->address, cp)) {
automap = 1;
break;
});
if (automap) {
const char *new_addr;
new_addr = addressmap_register_virtual_address(
RESOLVED_TYPE_IPV4, tor_strdup(socks->address));
tor_assert(new_addr);
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));
}
}
if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) {
if (addressmap_rewrite_reverse(socks->address, sizeof(socks->address),
&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]",
orig_address);
connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_HOSTNAME,
strlen(result), result, -1,
map_expires);
connection_mark_unattached_ap(conn,
END_STREAM_REASON_DONE |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
return 0;
}
if (options->ClientDNSRejectInternalAddresses) {
/* Don't let people try to do a reverse lookup on 10.0.0.1. */
tor_addr_t addr;
int ok;
ok = tor_addr_parse_reverse_lookup_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);
connection_mark_unattached_ap(conn,
END_STREAM_REASON_SOCKSPROTOCOL |
END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED);
return -1;
}
}
} else if (!automap) {
int started_without_chosen_exit = strcasecmpend(socks->address, ".exit");
/* For address map controls, remap the address. */
if (addressmap_rewrite(socks->address, sizeof(socks->address),
&map_expires)) {
control_event_stream_status(conn, STREAM_EVENT_REMAP,
REMAP_STREAM_SOURCE_CACHE);
if (started_without_chosen_exit &&
!strcasecmpend(socks->address, ".exit") &&
map_expires < TIME_MAX)
remapped_to_exit = 1;
}
}
if (!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. 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));
connection_mark_unattached_ap(conn, END_STREAM_REASON_INTERNAL);
return -1;
}
/* Parse the address provided by SOCKS. Modify it in-place if it
* specifies a hidden-service (.onion) or particular exit node (.exit).
*/
addresstype = parse_extended_hostname(socks->address,
remapped_to_exit || options->AllowDotExit);
if (addresstype == BAD_HOSTNAME) {
log_warn(LD_APP, "Invalid onion hostname %s; rejecting",
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;
}
if (addresstype == EXIT_HOSTNAME) {
/* foo.exit -- modify conn->chosen_exit_node to specify the exit
* node, and conn->address to hold only the address portion. */
char *s = strrchr(socks->address,'.');
tor_assert(!automap);
if (s) {
if (s[1] != '\0') {
conn->chosen_exit_name = tor_strdup(s+1);
if (remapped_to_exit) /* 5 tries before it expires the addressmap */
conn->chosen_exit_retries = TRACKHOSTEXITS_RETRIES;
*s = 0;
} else {
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 {
routerinfo_t *r;
conn->chosen_exit_name = tor_strdup(socks->address);
r = router_get_by_nickname(conn->chosen_exit_name, 1);
*socks->address = 0;
if (r) {
strlcpy(socks->address, r->address, sizeof(socks->address));
} else {
log_warn(LD_APP,
"Unrecognized server in exit address '%s.exit'. Refusing.",
safe_str_client(socks->address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
}
}
if (addresstype != ONION_HOSTNAME) {
/* not a hidden-service request (i.e. normal or .exit) */
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;
}
if (socks->command == SOCKS_COMMAND_RESOLVE) {
uint32_t answer;
struct in_addr in;
/* Reply to resolves immediately if we can. */
if (tor_inet_aton(socks->address, &in)) { /* see if it's an IP already */
/* leave it in network order */
answer = in.s_addr;
/* remember _what_ is supposed to have been resolved. */
strlcpy(socks->address, orig_address, sizeof(socks->address));
connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
(char*)&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) {
tor_assert(!automap);
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;
}
if (!conn->use_begindir && !conn->chosen_exit_name && !circ) {
/* see if we can find a suitable enclave exit */
routerinfo_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), r->nickname);
/* use the hex digest, not nickname, in case there are two
routers with this nickname */
conn->chosen_exit_name =
tor_strdup(hex_str(r->cache_info.identity_digest, DIGEST_LEN));
conn->chosen_exit_optional = 1;
}
}
/* 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;
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 {
tor_fragile_assert();
}
conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
if ((circ && connection_ap_handshake_attach_chosen_circuit(
conn, circ, cpath) < 0) ||
(!circ &&
connection_ap_handshake_attach_circuit(conn) < 0)) {
if (!conn->_base.marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
return -1;
}
return 0;
} else {
/* it's a hidden-service request */
rend_cache_entry_t *entry;
int r;
rend_service_authorization_t *client_auth;
tor_assert(!automap);
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 (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;
}
conn->rend_data = tor_malloc_zero(sizeof(rend_data_t));
strlcpy(conn->rend_data->onion_address, socks->address,
sizeof(conn->rend_data->onion_address));
log_info(LD_REND,"Got a hidden service request for ID '%s'",
safe_str_client(conn->rend_data->onion_address));
/* see if we already have it cached */
r = rend_cache_lookup_entry(conn->rend_data->onion_address, -1, &entry);
if (r<0) {
log_warn(LD_BUG,"Invalid service name '%s'",
safe_str_client(conn->rend_data->onion_address));
connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL);
return -1;
}
/* Help predict this next time. 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);
/* Look up if we have client authorization for it. */
client_auth = rend_client_lookup_service_authorization(
conn->rend_data->onion_address);
if (client_auth) {
log_info(LD_REND, "Using previously configured client authorization "
"for hidden service request.");
memcpy(conn->rend_data->descriptor_cookie,
client_auth->descriptor_cookie, REND_DESC_COOKIE_LEN);
conn->rend_data->auth_type = client_auth->auth_type;
}
if (r==0) {
conn->_base.state = AP_CONN_STATE_RENDDESC_WAIT;
log_info(LD_REND, "Unknown descriptor %s. Fetching.",
safe_str_client(conn->rend_data->onion_address));
rend_client_refetch_v2_renddesc(conn->rend_data);
} else { /* r > 0 */
conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
log_info(LD_REND, "Descriptor is here. Great.");
if (connection_ap_handshake_attach_circuit(conn) < 0) {
if (!conn->_base.marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
return -1;
}
}
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;
#ifdef OPENBSD
/* only works on OpenBSD */
pf = open("/dev/pf", O_RDONLY);
#else
/* works on NetBSD and FreeBSD */
pf = open("/dev/pf", O_RDWR);
#endif
if (pf < 0) {
log_warn(LD_NET, "open(\"/dev/pf\") failed: %s", strerror(errno));
return -1;
}
pf_socket = pf;
return pf_socket;
}
#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(edge_connection_t *conn,
socks_request_t *req)
{
#ifdef TRANS_NETFILTER
/* Linux 2.4+ */
struct sockaddr_storage orig_dst;
socklen_t orig_dst_len = sizeof(orig_dst);
tor_addr_t addr;
if (getsockopt(conn->_base.s, SOL_IP, SO_ORIGINAL_DST,
(struct sockaddr*)&orig_dst, &orig_dst_len) < 0) {
int e = tor_socket_errno(conn->_base.s);
log_warn(LD_NET, "getsockopt() failed: %s", tor_socket_strerror(e));
return -1;
}
tor_addr_from_sockaddr(&addr, (struct sockaddr*)&orig_dst, &req->port);
tor_addr_to_str(req->address, &addr, sizeof(req->address), 0);
return 0;
#elif defined(TRANS_PF)
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(conn->_base.s, (struct sockaddr*)&proxy_addr,
&proxy_addr_len) < 0) {
int e = tor_socket_errno(conn->_base.s);
log_warn(LD_NET, "getsockname() to determine transocks destination "
"failed: %s", tor_socket_strerror(e));
return -1;
}
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(&conn->_base.addr);
pnl.sport = htons(conn->_base.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(&conn->_base.addr),
sizeof(struct in6_addr));
pnl.sport = htons(conn->_base.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), 0);
req->port = ntohs(pnl.rdport);
return 0;
#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(edge_connection_t *conn)
{
socks_request_t *socks;
int sockshere;
or_options_t *options = get_options();
tor_assert(conn);
tor_assert(conn->_base.type == CONN_TYPE_AP);
tor_assert(conn->_base.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(conn->_base.inbuf, socks,
options->TestSocks, options->SafeSocks);
if (sockshere == 0) {
if (socks->replylen) {
connection_write_to_buf(socks->reply, socks->replylen, TO_CONN(conn));
/* zero it out so we can do another round of negotiation */
socks->replylen = 0;
} else {
log_debug(LD_APP,"socks handshake not all here yet.");
}
return 0;
} else if (sockshere == -1) {
if (socks->replylen) { /* we should send reply back */
log_debug(LD_APP,"reply is already set for us. Using it.");
connection_ap_handshake_socks_reply(conn, socks->reply, socks->replylen,
END_STREAM_REASON_SOCKSPROTOCOL);
} else {
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);
if (options->LeaveStreamsUnattached) {
conn->_base.state = AP_CONN_STATE_CONTROLLER_WAIT;
return 0;
}
return connection_ap_handshake_rewrite_and_attach(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(edge_connection_t *conn)
{
socks_request_t *socks;
or_options_t *options = get_options();
tor_assert(conn);
tor_assert(conn->_base.type == CONN_TYPE_AP);
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);
if (options->LeaveStreamsUnattached) {
conn->_base.state = AP_CONN_STATE_CONTROLLER_WAIT;
return 0;
}
return connection_ap_handshake_rewrite_and_attach(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(edge_connection_t *conn)
{
char tmp_buf[36], *tbuf, *daddr;
size_t tlen = 30;
int err, port_ok;
socks_request_t *socks;
or_options_t *options = get_options();
tor_assert(conn);
tor_assert(conn->_base.type == CONN_TYPE_AP);
tor_assert(conn->_base.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 = fetch_from_buf_line(conn->_base.inbuf, 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);
if (options->LeaveStreamsUnattached) {
conn->_base.state = AP_CONN_STATE_CONTROLLER_WAIT;
return 0;
}
conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
return connection_ap_handshake_rewrite_and_attach(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.
*/
static 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;
}
/** 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(edge_connection_t *ap_conn)
{
char payload[CELL_PAYLOAD_SIZE];
int payload_len;
int begin_type;
origin_circuit_t *circ;
tor_assert(ap_conn->on_circuit);
circ = TO_ORIGIN_CIRCUIT(ap_conn->on_circuit);
tor_assert(ap_conn->_base.type == CONN_TYPE_AP);
tor_assert(ap_conn->_base.state == AP_CONN_STATE_CIRCUIT_WAIT);
tor_assert(ap_conn->socks_request);
tor_assert(SOCKS_COMMAND_IS_CONNECT(ap_conn->socks_request->command));
ap_conn->stream_id = get_unique_stream_id_by_circ(circ);
if (ap_conn->stream_id==0) {
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_RESOURCELIMIT);
return -1;
}
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;
log_debug(LD_APP,
"Sending relay cell to begin stream %d.", ap_conn->stream_id);
begin_type = ap_conn->use_begindir ?
RELAY_COMMAND_BEGIN_DIR : RELAY_COMMAND_BEGIN;
if (begin_type == RELAY_COMMAND_BEGIN) {
tor_assert(circ->build_state->onehop_tunnel == 0);
}
if (connection_edge_send_command(ap_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 */
ap_conn->package_window = STREAMWINDOW_START;
ap_conn->deliver_window = STREAMWINDOW_START;
ap_conn->_base.state = AP_CONN_STATE_CONNECT_WAIT;
log_info(LD_APP,"Address/port sent, ap socket %d, n_circ_id %d",
ap_conn->_base.s, circ->_base.n_circ_id);
control_event_stream_status(ap_conn, STREAM_EVENT_SENT_CONNECT, 0);
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(edge_connection_t *ap_conn)
{
int payload_len, command;
const char *string_addr;
char inaddr_buf[REVERSE_LOOKUP_NAME_BUF_LEN];
origin_circuit_t *circ;
tor_assert(ap_conn->on_circuit);
circ = TO_ORIGIN_CIRCUIT(ap_conn->on_circuit);
tor_assert(ap_conn->_base.type == CONN_TYPE_AP);
tor_assert(ap_conn->_base.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));
ap_conn->stream_id = get_unique_stream_id_by_circ(circ);
if (ap_conn->stream_id==0) {
connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL);
/*XXXX022 _close_ the circuit because it's full? That sounds dumb. */
circuit_mark_for_close(TO_CIRCUIT(circ), END_CIRC_REASON_RESOURCELIMIT);
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_reverse_lookup_name(&addr, a, AF_INET, 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_reverse_lookup_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.", ap_conn->stream_id);
if (connection_edge_send_command(ap_conn,
RELAY_COMMAND_RESOLVE,
string_addr, payload_len) < 0)
return -1; /* circuit is closed, don't continue */
tor_free(ap_conn->_base.address); /* Maybe already set by dnsserv. */
ap_conn->_base.address = tor_strdup("(Tor_internal)");
ap_conn->_base.state = AP_CONN_STATE_RESOLVE_WAIT;
log_info(LD_APP,"Address sent for resolve, ap socket %d, n_circ_id %d",
ap_conn->_base.s, circ->_base.n_circ_id);
control_event_stream_status(ap_conn, STREAM_EVENT_NEW, 0);
control_event_stream_status(ap_conn, STREAM_EVENT_SENT_RESOLVE, 0);
return 0;
}
/** Make an AP connection_t, 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 other end of the linked connection pair, or -1 if error.
*/
edge_connection_t *
connection_ap_make_link(char *address, uint16_t port,
const char *digest, int use_begindir, int want_onehop)
{
edge_connection_t *conn;
log_info(LD_APP,"Making internal %s tunnel to %s:%d ...",
want_onehop ? "direct" : "anonymized",
safe_str_client(address), port);
conn = edge_connection_new(CONN_TYPE_AP, AF_INET);
conn->_base.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);
}
conn->_base.address = tor_strdup("(Tor_internal)");
tor_addr_make_unspec(&conn->_base.addr);
conn->_base.port = 0;
if (connection_add(TO_CONN(conn)) < 0) { /* no space, forget it */
connection_free(TO_CONN(conn));
return NULL;
}
conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT;
control_event_stream_status(conn, STREAM_EVENT_NEW, 0);
/* attaching to a dirty circuit is fine */
if (connection_ap_handshake_attach_circuit(conn) < 0) {
if (!conn->_base.marked_for_close)
connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH);
return NULL;
}
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(edge_connection_t *conn,
int answer_type,
size_t answer_len,
const char *answer,
int ttl,
time_t expires)
{
if (ttl >= 0 && (answer_type == RESOLVED_TYPE_IPV4 ||
answer_type == RESOLVED_TYPE_HOSTNAME)) {
return; /* we already told the controller. */
} else if (answer_type == RESOLVED_TYPE_IPV4 && answer_len >= 4) {
struct in_addr in;
char buf[INET_NTOA_BUF_LEN];
in.s_addr = get_uint32(answer);
tor_inet_ntoa(&in, buf, sizeof(buf));
control_event_address_mapped(conn->socks_request->address,
buf, expires, NULL);
} 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);
tor_free(cp);
} else {
control_event_address_mapped(conn->socks_request->address,
"<error>",
time(NULL)+ttl,
"error=yes");
}
}
/** 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.
**/
/* XXXX022 the use of the ttl and expires fields is nutty. Let's make this
* interface and those that use it less ugly. */
void
connection_ap_handshake_socks_resolved(edge_connection_t *conn,
int answer_type,
size_t answer_len,
const char *answer,
int ttl,
time_t expires)
{
char buf[384];
size_t replylen;
if (ttl >= 0) {
if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
uint32_t a = ntohl(get_uint32(answer));
if (a)
client_dns_set_addressmap(conn->socks_request->address, a,
conn->chosen_exit_name, ttl);
} else if (answer_type == RESOLVED_TYPE_HOSTNAME && answer_len < 256) {
char *cp = tor_strndup(answer, answer_len);
client_dns_set_reverse_addressmap(conn->socks_request->address,
cp,
conn->chosen_exit_name, ttl);
tor_free(cp);
}
}
if (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, answer, ttl);
conn->socks_request->has_finished = 1;
return;
} else {
/* This must be a request from the controller. We already sent
* a mapaddress if there's a ttl. */
tell_controller_about_resolved_result(conn, answer_type, answer_len,
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) ?
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(edge_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 */
control_event_stream_status(conn,
status==SOCKS5_SUCCEEDED ? STREAM_EVENT_SUCCEEDED : STREAM_EVENT_FAILED,
endreason);
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, 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, TO_CONN(conn));
} else if (conn->socks_request->socks_version == 5) {
buf[0] = 5; /* version 5 */
buf[1] = (char)status;
buf[2] = 0;
buf[3] = 1; /* ipv4 addr */
memset(buf+4,0,6); /* Set external addr/port to 0.
The spec doesn't seem to say what to do here. -RD */
connection_write_to_buf(buf,10,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;
}
/** 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;
or_circuit_t *or_circ = NULL;
assert_circuit_ok(circ);
if (!CIRCUIT_IS_ORIGIN(circ))
or_circ = TO_OR_CIRCUIT(circ);
relay_header_unpack(&rh, cell->payload);
/* Note: we have to use relay_send_command_from_edge here, not
* connection_edge_end or connection_edge_send_command, since those require
* that we have a stream connected to a circuit, and we don't connect to a
* circuit until we have a pending/successful resolve. */
if (!server_mode(get_options()) &&
circ->purpose != CIRCUIT_PURPOSE_S_REND_JOINED) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell at non-server. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_EXITPOLICY, NULL);
return 0;
}
if (rh.command == RELAY_COMMAND_BEGIN) {
if (!memchr(cell->payload+RELAY_HEADER_SIZE, 0, rh.length)) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Relay begin cell has no \\0. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_TORPROTOCOL, NULL);
return 0;
}
if (parse_addr_port(LOG_PROTOCOL_WARN, cell->payload+RELAY_HEADER_SIZE,
&address,NULL,&port)<0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Unable to parse addr:port in relay begin cell. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_TORPROTOCOL, NULL);
return 0;
}
if (port==0) {
log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL,
"Missing port in relay begin cell. Closing.");
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_TORPROTOCOL, NULL);
tor_free(address);
return 0;
}
if (or_circ && or_circ->p_conn && !get_options()->AllowSingleHopExits &&
(or_circ->is_first_hop ||
(!connection_or_digest_is_known_relay(
or_circ->p_conn->identity_digest) &&
// XXX022 commented out so we can test it first in 0.2.2.11 -RD
// networkstatus_get_param(NULL, "refuseunknownexits", 1)))) {
get_options()->RefuseUnknownExits))) {
/* 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,
log_notice(LD_PROTOCOL,
"Attempt by %s to open a stream %s. Closing.",
safe_str(or_circ->p_conn->_base.address),
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(get_options()) ||
circ->purpose != CIRCUIT_PURPOSE_OR) {
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_NOTDIRECTORY, NULL);
return 0;
}
/* Make sure to get the 'real' address of the previous hop: the
* caller might want to know whether his 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_conn)
address = tor_dup_addr(&or_circ->p_conn->real_addr);
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, NULL);
return 0;
}
log_debug(LD_EXIT,"Creating new exit connection.");
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. */
TO_CONN(n_stream)->dirreq_id = circ->dirreq_id;
n_stream->_base.purpose = EXIT_PURPOSE_CONNECT;
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) {
origin_circuit_t *origin_circ = TO_ORIGIN_CIRCUIT(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);
if (rend_service_set_connection_addr_port(n_stream, origin_circ) < 0) {
log_info(LD_REND,"Didn't find rendezvous service (port %d)",
n_stream->_base.port);
relay_send_end_cell_from_edge(rh.stream_id, circ,
END_STREAM_REASON_EXITPOLICY,
origin_circ->cpath->prev);
connection_free(TO_CONN(n_stream));
tor_free(address);
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 n_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);
connection_exit_connect(n_stream);
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_assert(or_circ);
if (or_circ->p_conn && !tor_addr_is_null(&or_circ->p_conn->real_addr))
tor_addr_copy(&n_stream->_base.addr, &or_circ->p_conn->real_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);
/* 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(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;
}
/** 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;
if (!connection_edge_is_rendezvous_stream(edge_conn) &&
router_compare_to_my_exit_policy(edge_conn)) {
log_info(LD_EXIT,"%s:%d failed exit policy. Closing.",
escaped_safe_str_client(conn->address), conn->port);
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;
}
addr = &conn->addr;
port = conn->port;
log_debug(LD_EXIT,"about to try connecting");
switch (connection_connect(conn, conn->address, addr, port, &socket_error)) {
case -1:
/* XXX021 use socket_error below rather than trying to piece things
* together from the current errno, which may have been clobbered. */
connection_edge_end_errno(edge_conn);
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_wants_to_flush(conn)) {
/* in case there are any queued data cells */
log_warn(LD_BUG,"newly connected conn had data waiting!");
// connection_start_writing(conn);
}
connection_watch_events(conn, READ_EVENT);
/* also, deliver a 'connected' cell back through the circuit. */
if (connection_edge_is_rendezvous_stream(edge_conn)) {
/* rendezvous stream */
/* don't send an address back! */
connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED,
NULL, 0);
} else { /* normal stream */
char connected_payload[20];
int connected_payload_len;
if (tor_addr_family(&conn->addr) == AF_INET) {
set_uint32(connected_payload, tor_addr_to_ipv4n(&conn->addr));
connected_payload_len = 4;
} else {
memcpy(connected_payload, tor_addr_to_in6_addr8(&conn->addr), 16);
connected_payload_len = 16;
}
set_uint32(connected_payload+connected_payload_len,
htonl(dns_clip_ttl(edge_conn->address_ttl)));
connected_payload_len += 4;
connection_edge_send_command(edge_conn,
RELAY_COMMAND_CONNECTED,
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(AF_INET);
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. */
TO_CONN(dirconn)->dirreq_id = TO_CONN(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(edge_connection_t *conn)
{
tor_assert(conn);
if (conn->rend_data)
return 1;
return 0;
}
/** Return 1 if router <b>exit</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.)
*
* If <b>excluded_means_no</b> is 1 and Exclude*Nodes is set and excludes
* this relay, return 0.
*/
int
connection_ap_can_use_exit(edge_connection_t *conn, routerinfo_t *exit,
int excluded_means_no)
{
or_options_t *options = get_options();
tor_assert(conn);
tor_assert(conn->_base.type == CONN_TYPE_AP);
tor_assert(conn->socks_request);
tor_assert(exit);
/* 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) {
routerinfo_t *chosen_exit =
router_get_by_nickname(conn->chosen_exit_name, 1);
if (!chosen_exit || memcmp(chosen_exit->cache_info.identity_digest,
exit->cache_info.identity_digest, 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->socks_request->command == SOCKS_COMMAND_CONNECT &&
!conn->use_begindir) {
struct in_addr in;
uint32_t addr = 0;
addr_policy_result_t r;
if (tor_inet_aton(conn->socks_request->address, &in))
addr = ntohl(in.s_addr);
r = compare_addr_to_addr_policy(addr, conn->socks_request->port,
exit->exit_policy);
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)) {
/* Can't support reverse lookups without eventdns. */
if (conn->socks_request->command == SOCKS_COMMAND_RESOLVE_PTR &&
exit->has_old_dnsworkers)
return 0;
/* Don't send DNS requests to non-exit servers by default. */
if (!conn->chosen_exit_name && policy_is_reject_star(exit->exit_policy))
return 0;
}
if (options->_ExcludeExitNodesUnion &&
(options->StrictNodes || excluded_means_no) &&
routerset_contains_router(options->_ExcludeExitNodesUnion, exit)) {
/* If we are trying to avoid this node as exit, and we have StrictNodes
* set, then this is not a suitable exit. Refuse it.
*
* If we don't have StrictNodes set, then this function gets called in
* two contexts. First, we've got a circuit open and we want to know
* whether we can use it. In that case, we somehow built this circuit
* despite having the last hop in ExcludeExitNodes, so we should be
* willing to use it. Second, we are evaluating whether this is an
* acceptable exit for a new circuit. In that case, skip 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 "y.exit" and <b>allowdotexit</b> is true:
* Put a NUL after y and return EXIT_HOSTNAME.
*
* Otherwise:
* Return NORMAL_HOSTNAME and change nothing.
*/
hostname_type_t
parse_extended_hostname(char *address, int allowdotexit)
{
char *s;
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")) {
if (allowdotexit) {
*s = 0; /* NUL-terminate it */
return EXIT_HOSTNAME; /* .exit */
} else {
log_warn(LD_APP, "The \".exit\" notation is disabled in Tor due to "
"security risks. Set AllowDotExit in your torrc to enable "
"it.");
/* FFFF send a controller event too to notify Vidalia users */
return BAD_HOSTNAME;
}
}
if (strcmp(s+1,"onion"))
return NORMAL_HOSTNAME; /* neither .exit nor .onion, thus normal */
/* so it is .onion */
*s = 0; /* NUL-terminate it */
if (strlcpy(query, address, REND_SERVICE_ID_LEN_BASE32+1) >=
REND_SERVICE_ID_LEN_BASE32+1)
goto failed;
if (rend_valid_service_id(query)) {
return ONION_HOSTNAME; /* success */
}
failed:
/* otherwise, return to previous state and return 0 */
*s = '.';
return BAD_HOSTNAME;
}