/* Copyright (c) 2001 Matej Pfajfar. * Copyright (c) 2001-2004, Roger Dingledine. * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. * Copyright (c) 2007, The Tor Project, Inc. */ /* See LICENSE for licensing information */ /* $Id$ */ const char connection_edge_c_id[] = "$Id$"; /** * \file connection_edge.c * \brief Handle edge streams. **/ #include "or.h" #ifdef HAVE_LINUX_NETFILTER_IPV4_H #include #define TRANS_NETFILTER #endif #if defined(HAVE_NET_IF_H) && defined(HAVE_NET_PFVAR_H) #include #include #define TRANS_PF #endif /** List of exit_redirect_t for every configured RedirectExit. */ static smartlist_t *redirect_exit_list = NULL; 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); /** 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->_base.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(uint16_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); } else { /* closing the circuit, nothing to send an END to */ conn->_base.edge_has_sent_end = 1; conn->end_reason = END_STREAM_REASON_DESTROY; conn->end_reason |= END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED; if (conn->_base.type == CONN_TYPE_AP) control_event_stream_status(conn, STREAM_EVENT_CLOSED, END_STREAM_REASON_DESTROY); 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 relay end cell from stream conn down conn's circuit. Set * the relay end cell's reason for closing as reason. * * Return -1 if this function has already been called on this conn, * else return 0. */ int connection_edge_end(edge_connection_t *conn, char reason) { char payload[RELAY_PAYLOAD_SIZE]; size_t payload_len=1; circuit_t *circ; if (conn->_base.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; } payload[0] = reason; if (reason == END_STREAM_REASON_EXITPOLICY && !connection_edge_is_rendezvous_stream(conn)) { set_uint32(payload+1, htonl(conn->_base.addr)); set_uint32(payload+5, htonl(dns_clip_ttl(conn->address_ttl))); payload_len += 8; } circ = circuit_get_by_edge_conn(conn); 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->_base.edge_has_sent_end = 1; conn->end_reason = reason; return 0; } /** An error has just occured on an operation on an edge connection * conn. 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 = (uint8_t)errno_to_end_reason(tor_socket_errno(conn->_base.s)); return connection_edge_end(conn, reason); } /** Connection conn 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 conn 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) { char valbuf[INET_NTOA_BUF_LEN]; connection_t *conn; struct in_addr in; 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); in.s_addr = htonl(conn->addr); tor_inet_ntoa(&in,valbuf,sizeof(valbuf)); log_info(LD_EXIT,"Exit connection to %s:%u (%s) established.", escaped_safe_str(conn->address),conn->port,safe_str(valbuf)); conn->state = EXIT_CONN_STATE_OPEN; connection_watch_events(conn, EV_READ); /* stop writing, continue 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[8]; set_uint32(connected_payload, htonl(conn->addr)); set_uint32(connected_payload+4, htonl(dns_clip_ttl(edge_conn->address_ttl))); if (connection_edge_send_command(edge_conn, RELAY_COMMAND_CONNECTED, connected_payload, 8) < 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) { 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 >=15 seconds 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; smartlist_t *conns = get_connection_array(); SMARTLIST_FOREACH(conns, connection_t *, c, { if (c->type != CONN_TYPE_AP) continue; conn = TO_EDGE_CONN(c); /* if it's an internal linked connection, don't yell its status. */ severity = (!conn->_base.addr && !conn->_base.port) ? LOG_INFO : LOG_NOTICE; seconds_idle = now - conn->_base.timestamp_lastread; if (AP_CONN_STATE_IS_UNATTACHED(conn->_base.state)) { if (seconds_idle >= options->SocksTimeout) { log_fn(severity, LD_APP, "Tried for %d seconds to get a connection to %s:%d. " "Giving up. (%s)", seconds_idle, safe_str(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; } if (conn->_base.state == AP_CONN_STATE_OPEN) 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(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(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(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->_base.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) { connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH); } }); /* end foreach */ } /** 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) { connection_mark_unattached_ap(edge_conn, END_STREAM_REASON_CANT_ATTACH); } }); } /** A circuit failed to finish on its last hop info. 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(conns, connection_t *, conn, { if (conn->marked_for_close || conn->type != CONN_TYPE_AP || !conn->chosen_exit_optional) continue; edge_conn = TO_EDGE_CONN(conn); r1 = router_get_by_nickname(edge_conn->chosen_exit_name, 0); r2 = router_get_by_nickname(info->nickname, 0); if (r1 && r2 && r1==r2) { tor_assert(edge_conn->socks_request); log_info(LD_APP, "Giving up on enclave exit '%s' for destination %s.", safe_str(edge_conn->chosen_exit_name), escaped_safe_str(edge_conn->socks_request->address)); conn->chosen_exit_optional = 0; tor_free(edge_conn->chosen_exit_name); /* clears it */ } }); } /** The AP connection conn has just failed while attaching or * sending a BEGIN or resolving on circ, 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->_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 mappings that can expire.) */ typedef struct { char *new_address; time_t expires; int 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 _ent. */ static void addressmap_ent_free(void *_ent) { addressmap_entry_t *ent = _ent; tor_free(ent->new_address); tor_free(ent); } /** Free storage held by a virtaddress_entry_t* entry in ent. */ static void addressmap_virtaddress_ent_free(void *_ent) { virtaddress_entry_t *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 ent. */ 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 ent (which must be mapped to by address) 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); } /** 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) { if (addressmap) { strmap_free(addressmap, addressmap_ent_free); addressmap = NULL; } if (virtaddress_reversemap) { 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 *expires_out to the * expiry time of the result, or to time_max 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(ent->new_address)); log_info(LD_APP, "Addressmap: rewriting %s to %s", escaped_safe_str(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(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 * maxlen-byte buffer address (typically, a dotted quad) then * rewrite to the cached value and return 1. Otherwise return 0. Set * *expires_out to the expiry time of the result, or to time_max * 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(ent->new_address)); log_info(LD_APP, "Rewrote reverse lookup %s -> %s", escaped_safe_str(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 address is already registered, else return 0 */ int addressmap_have_mapping(const char *address) { return strmap_get_lc(addressmap, address) ? 1 : 0; } /** Register a request to map address to new_address, * which will expire on expires (or 0 if never expires from * config file, 1 if never expires from controller, 2 if never expires * (virtual address mapping) from the controller.) * * new_address should be a newly dup'ed string, which we'll use or * free as appropriate. We will leave address alone. * * If new_address is NULL, or equal to address, remove * any mappings that exist from address. */ void addressmap_register(const char *address, char *new_address, time_t expires) { 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(address), safe_str(new_address), safe_str(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; log_info(LD_CONFIG, "Addressmap: (re)mapped '%s' to '%s'", safe_str(address), safe_str(ent->new_address)); control_event_address_mapped(address, ent->new_address, expires, NULL); } /** An attempt to resolve address 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); } ++ent->num_resolve_failures; log_info(LD_APP, "Address %s now has %d resolve failures.", safe_str(address), ent->num_resolve_failures); return ent->num_resolve_failures; } /** If address 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 address resolved to name. * We can now use this in subsequent streams via addressmap_rewrite() * so we can more correctly choose an exit that will allow address. * * If exitname is defined, then append the addresses with * ".exitname.exit" before registering the mapping. * * If ttl is nonnegative, the mapping will be valid for * ttlseconds; otherwise, we use the default. */ static void client_dns_set_addressmap_impl(const char *address, const char *name, const char *exitname, int ttl) { /*
..exit\0 or just
\0 */ char extendedaddress[MAX_SOCKS_ADDR_LEN+MAX_VERBOSE_NICKNAME_LEN+10]; /* 123.123.123.123..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); } /** Record the fact that address resolved to val. * We can now use this in subsequent streams via addressmap_rewrite() * so we can more correctly choose an exit that will allow address. * * If exitname is defined, then append the addresses with * ".exitname.exit" before registering the mapping. * * If ttl is nonnegative, the mapping will be valid for * ttlseconds; 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 address (ordinarily a dotted quad) * resolved via a RESOLVE_PTR request to the hostname v. * * If exitname is defined, then append the addresses with * ".exitname.exit" before registering the mapping. * * If ttl is nonnegative, the mapping will be valid for * ttlseconds; 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(). */ static uint32_t virtual_addr_network = 0x7fc00000u; static maskbits_t virtual_addr_netmask_bits = 10; 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 = 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 addr 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 type * (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 * type to the address new_address. 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 new_address, try to return a copy of that address. * * The string in new_address 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(new_address), safe_str(*addrp), safe_str(*addrp), ent?safe_str(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); #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(*addrp),safe_str(new_address)); } #endif return *addrp; } /** Return 1 if address has funny characters in it like colons. Return * 0 if it's fine, or if we're configured to allow it anyway. client * 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); } } /** Connection conn just finished its socks handshake, or the * controller asked us to take care of it. If circ 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 cpath, or from the last hop in circ's cpath if * cpath 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; 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(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(socks->address), safe_str(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. */ strlcpy(socks->address, orig_address, sizeof(socks->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; if (tor_addr_from_str(&addr, socks->address) >= 0 && 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) { /* 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 (!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.", socks->address); /* don't safe_str() this yet. */ 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); if (addresstype == BAD_HOSTNAME) { log_warn(LD_APP, "Invalid hostname %s; rejecting", 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); *s = 0; } else { log_warn(LD_APP,"Malformed exit address '%s.exit'. Refusing.", safe_str(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(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(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 (strlen(socks->address) > RELAY_PAYLOAD_SIZE) { log_warn(LD_APP,"Address to be resolved is too large. Failing."); control_event_client_status(LOG_WARN, "SOCKS_BAD_HOSTNAME HOSTNAME=%s", escaped(socks->address)); connection_ap_handshake_socks_resolved(conn, RESOLVED_TYPE_ERROR_TRANSIENT, 0,NULL,-1,TIME_MAX); connection_mark_unattached_ap(conn, END_STREAM_REASON_SOCKSPROTOCOL | END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED); return -1; } 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(time(NULL)); /* 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(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->_base.chosen_exit_optional = 1; } } if (!conn->use_begindir) { /* help predict this next time */ rep_hist_note_used_port(socks->port, time(NULL)); } } else if (socks->command == SOCKS_COMMAND_RESOLVE_PTR) { rep_hist_note_used_resolve(time(NULL)); /* 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)) { 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; 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; } strlcpy(conn->rend_query, socks->address, sizeof(conn->rend_query)); log_info(LD_REND,"Got a hidden service request for ID '%s'", safe_str(conn->rend_query)); /* see if we already have it cached */ r = rend_cache_lookup_entry(conn->rend_query, -1, &entry); if (r<0) { log_warn(LD_BUG,"Invalid service name '%s'", safe_str(conn->rend_query)); connection_mark_unattached_ap(conn, END_STREAM_REASON_TORPROTOCOL); return -1; } if (r==0) { conn->_base.state = AP_CONN_STATE_RENDDESC_WAIT; log_info(LD_REND, "Unknown descriptor %s. Fetching.", safe_str(conn->rend_query)); /* Fetch both, v0 and v2 rend descriptors in parallel. Use whichever * arrives first. */ rend_client_refetch_v2_renddesc(conn->rend_query); rend_client_refetch_renddesc(conn->rend_query); } else { /* r > 0 */ /** How long after we receive a hidden service descriptor do we consider * it valid? */ #define NUM_SECONDS_BEFORE_HS_REFETCH (60*15) if (time(NULL) - entry->received < NUM_SECONDS_BEFORE_HS_REFETCH) { conn->_base.state = AP_CONN_STATE_CIRCUIT_WAIT; log_info(LD_REND, "Descriptor is here and fresh enough. Great."); if (connection_ap_handshake_attach_circuit(conn) < 0) { connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH); return -1; } } else { conn->_base.state = AP_CONN_STATE_RENDDESC_WAIT; log_info(LD_REND, "Stale descriptor %s. Refetching.", safe_str(conn->rend_query)); /* Fetch both, v0 and v2 rend descriptors in parallel. Use whichever * arrives first. */ rend_client_refetch_v2_renddesc(conn->rend_query); rend_client_refetch_renddesc(conn->rend_query); } } return 0; } return 0; /* unreached but keeps the compiler happy */ } #ifdef TRANS_PF static int pf_socket = -1; static int get_pf_socket(void) { int pf; /* Ideally, this should be opened before dropping privs. */ 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_in orig_dst; socklen_t orig_dst_len = sizeof(orig_dst); char tmpbuf[INET_NTOA_BUF_LEN]; 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_inet_ntoa(&orig_dst.sin_addr, tmpbuf, sizeof(tmpbuf)); strlcpy(req->address, tmpbuf, sizeof(req->address)); req->port = ntohs(orig_dst.sin_port); return 0; #elif defined(TRANS_PF) struct sockaddr_in proxy_addr; socklen_t proxy_addr_len = sizeof(proxy_addr); char tmpbuf[INET_NTOA_BUF_LEN]; struct pfioc_natlook pnl; 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.af = AF_INET; pnl.proto = IPPROTO_TCP; pnl.direction = PF_OUT; pnl.saddr.v4.s_addr = htonl(conn->_base.addr); pnl.sport = htons(conn->_base.port); pnl.daddr.v4.s_addr = proxy_addr.sin_addr.s_addr; pnl.dport = proxy_addr.sin_port; 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; } tor_inet_ntoa(&pnl.rdaddr.v4, tmpbuf, sizeof(tmpbuf)); strlcpy(req->address, tmpbuf, sizeof(req->address)); 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 (hostname_is_noconnect_address(socks->address)) { control_event_stream_status(conn, STREAM_EVENT_NEW, 0); control_event_stream_status(conn, STREAM_EVENT_CLOSED, 0); connection_mark_unattached_ap(conn, END_STREAM_REASON_DONE); return -1; } 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 uint16_t get_unique_stream_id_by_circ(origin_circuit_t *circ) { edge_connection_t *tmpconn; uint16_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 = 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[32]; 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); 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 = strlen(string_addr)+1; tor_assert(payload_len <= RELAY_PAYLOAD_SIZE); } else { struct in_addr in; uint32_t a; size_t len = strlen(ap_conn->socks_request->address); char c = 0; /* XXXX020 This logic is a little ugly: we check for an in-addr.arpa ending * on the address. If we have one, the address is already in the right * order, so we'll leave it alone later. Otherwise, we reverse it and * turn it into an in-addr.arpa address. */ if (!strcasecmpend(ap_conn->socks_request->address, ".in-addr.arpa")) { /* Temporarily truncate the address, so we can give it to inet_aton. */ c = ap_conn->socks_request->address[len-13]; ap_conn->socks_request->address[len-13] = '\0'; } if (tor_inet_aton(ap_conn->socks_request->address, &in) == 0) { connection_mark_unattached_ap(ap_conn, END_STREAM_REASON_INTERNAL); return -1; } if (c) { /* this path happens on DNS. Can we unify? XXXX020 */ ap_conn->socks_request->address[len-13] = c; strlcpy(inaddr_buf, ap_conn->socks_request->address, sizeof(inaddr_buf)); } else { /* this path happens on tor-resolve. Can we unify? XXXX020 */ a = ntohl(in.s_addr); tor_snprintf(inaddr_buf, sizeof(inaddr_buf), "%d.%d.%d.%d.in-addr.arpa", (int)(uint8_t)((a )&0xff), (int)(uint8_t)((a>>8 )&0xff), (int)(uint8_t)((a>>16)&0xff), (int)(uint8_t)((a>>24)&0xff)); } string_addr = inaddr_buf; payload_len = strlen(inaddr_buf)+1; tor_assert(payload_len <= RELAY_PAYLOAD_SIZE); } 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 */ 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_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. * * DOCDOC start_reading */ 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 anonymized tunnel to %s:%d ...", safe_str(address),port); conn = TO_EDGE_CONN(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)"); conn->_base.addr = 0; 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) { connection_mark_unattached_ap(conn, END_STREAM_REASON_CANT_ATTACH); return NULL; } log_info(LD_APP,"... application connection created and linked."); return conn; } /** DOCDOC */ 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, "", 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. * DOCDOC expires **/ 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; } /* XXXX020 are we freeing conn anywhere? */ } if (conn->socks_request->socks_version == 4) { buf[0] = 0x00; /* version */ if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) { buf[1] = 90; /* "Granted" */ set_uint16(buf+2, 0); memcpy(buf+4, answer, 4); /* address */ replylen = SOCKS4_NETWORK_LEN; } else { buf[1] = 91; /* "error" */ 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 conn, using the appropriate * socks version, etc, and mark conn as completed with SOCKS * handshaking. * * If reply is defined, then write replylen bytes of it to conn * and return, else reply based on endreason (one of * END_STREAM_REASON_*). If reply is undefined, endreason 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 = connection_edge_end_reason_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); #define SOCKS4_GRANTED 90 #define SOCKS4_REJECT 91 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 circ. * 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; char end_payload[1]; 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."); end_payload[0] = END_STREAM_REASON_EXITPOLICY; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); return 0; } 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."); end_payload[0] = END_STREAM_REASON_TORPROTOCOL; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); return 0; } if (parse_addr_port(LOG_PROTOCOL_WARN, cell->payload+RELAY_HEADER_SIZE, &address,NULL,&port)<0) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Unable to parse addr:port in relay begin cell. Closing."); end_payload[0] = END_STREAM_REASON_TORPROTOCOL; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); return 0; } if (port==0) { log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Missing port in relay begin cell. Closing."); end_payload[0] = END_STREAM_REASON_TORPROTOCOL; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); tor_free(address); return 0; } if (or_circ && or_circ->is_first_hop) { /* Don't let clients use us as a single-hop proxy; it attracts attackers * and users who'd be better off with, well, single-hop proxies. */ log_fn(LOG_PROTOCOL_WARN, LD_PROTOCOL, "Attempt to open a stream on first hop of circuit. Closing."); end_payload[0] = END_STREAM_REASON_TORPROTOCOL; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); tor_free(address); return 0; } } else if (rh.command == RELAY_COMMAND_BEGIN_DIR) { if (!directory_permits_begindir_requests(get_options()) || circ->purpose != CIRCUIT_PURPOSE_OR) { end_payload[0] = END_STREAM_REASON_NOTDIRECTORY; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); return 0; } if (or_circ && or_circ->p_conn && or_circ->p_conn->_base.address) address = tor_strdup(or_circ->p_conn->_base.address); else address = tor_strdup("127.0.0.1"); port = 1; /*XXXX020 set this to something sensible? - NM*/ } else { log_warn(LD_BUG, "Got an unexpected command %d", (int)rh.command); end_payload[0] = END_STREAM_REASON_INTERNAL; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); return 0; } log_debug(LD_EXIT,"Creating new exit connection."); n_stream = TO_EDGE_CONN(connection_new(CONN_TYPE_EXIT, AF_INET)); 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; strlcpy(n_stream->rend_query, origin_circ->rend_query, sizeof(n_stream->rend_query)); 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); end_payload[0] = END_STREAM_REASON_EXITPOLICY; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); connection_free(TO_CONN(n_stream)); 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()) { end_payload[0] = END_STREAM_REASON_HIBERNATING; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); connection_free(TO_CONN(n_stream)); return 0; } n_stream->on_circuit = circ; if (rh.command == RELAY_COMMAND_BEGIN_DIR) { tor_assert(or_circ); if (or_circ->p_conn && or_circ->p_conn->_base.addr) n_stream->_base.addr = or_circ->p_conn->_base.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 */ end_payload[0] = END_STREAM_REASON_RESOLVEFAILED; relay_send_command_from_edge(rh.stream_id, circ, RELAY_COMMAND_END, end_payload, 1, NULL); /* n_stream got freed. don't touch it. */ break; case 0: /* resolve added to pending list */ assert_circuit_ok(circ); break; } return 0; } /** * Called when we receive a RELAY_RESOLVE cell 'cell' along the circuit 'circ'; * 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 = TO_EDGE_CONN(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 only 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) { uint32_t addr; uint16_t port; connection_t *conn = TO_CONN(edge_conn); 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(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; if (redirect_exit_list) { SMARTLIST_FOREACH(redirect_exit_list, exit_redirect_t *, r, { if (!addr_mask_cmp_bits(addr, r->addr, r->maskbits) && (r->port_min <= port) && (port <= r->port_max)) { struct in_addr in; if (r->is_redirect) { char tmpbuf[INET_NTOA_BUF_LEN]; addr = r->addr_dest; port = r->port_dest; in.s_addr = htonl(addr); tor_inet_ntoa(&in, tmpbuf, sizeof(tmpbuf)); log_debug(LD_EXIT, "Redirecting connection from %s:%d to %s:%d", escaped_safe_str(conn->address), conn->port, safe_str(tmpbuf), port); } break; } }); } log_debug(LD_EXIT,"about to try connecting"); switch (connection_connect(conn, conn->address, addr, port)) { case -1: 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, EV_WRITE | EV_READ); /* writable indicates finish; * readable/error indicates broken link in windowsland. */ 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, EV_READ); /* 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 */ /* This must be the original address, not the redirected address. */ char connected_payload[8]; set_uint32(connected_payload, htonl(conn->addr)); set_uint32(connected_payload+4, htonl(dns_clip_ttl(edge_conn->address_ttl))); connection_edge_send_command(edge_conn, RELAY_COMMAND_CONNECTED, connected_payload, 8); } } /** 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 * exitconn, 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 = TO_DIR_CONN(connection_new(CONN_TYPE_DIR, AF_INET)); dirconn->_base.addr = 0x7f000001; dirconn->_base.port = 0; dirconn->_base.address = tor_strdup("Tor network"); dirconn->_base.type = CONN_TYPE_DIR; dirconn->_base.purpose = DIR_PURPOSE_SERVER; dirconn->_base.state = DIR_CONN_STATE_SERVER_COMMAND_WAIT; 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 conn 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_query) /* XXX */ /* XXXX Why is this XXX? -NM */ return 1; return 0; } /** Return 1 if router exit is likely to allow stream conn * to exit from it, or 0 if it probably will not allow it. * (We might be uncertain if conn's destination address has not yet been * resolved.) */ int connection_ap_can_use_exit(edge_connection_t *conn, routerinfo_t *exit) { 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) { if (router_get_by_nickname(conn->chosen_exit_name, 1) != exit) { /* 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 || r == ADDR_POLICY_PROBABLY_REJECTED) return 0; } 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; } return 1; } /** Make connection redirection follow the provided list of * exit_redirect_t */ void set_exit_redirects(smartlist_t *lst) { if (redirect_exit_list) { SMARTLIST_FOREACH(redirect_exit_list, exit_redirect_t *, p, tor_free(p)); smartlist_free(redirect_exit_list); } if (lst && smartlist_len(lst)) { log_warn(LD_GENERAL, "The RedirectExit option is deprecated; it will go away in a " "future version of Tor."); } redirect_exit_list = lst; } /** 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": * Put a NUL after y and return EXIT_HOSTNAME. * * Otherwise: * Return NORMAL_HOSTNAME and change nothing. */ hostname_type_t parse_extended_hostname(char *address) { char *s; char query[REND_SERVICE_ID_LEN_BASE32+1]; s = strrchr(address,'.'); if (!s) return NORMAL_HOSTNAME; /* no dot, thus normal */ if (!strcmp(s+1,"exit")) { *s = 0; /* nul-terminate it */ return EXIT_HOSTNAME; /* .exit */ } if (strcmp(s+1,"onion")) return NORMAL_HOSTNAME; /* neither .exit nor .onion, thus normal */ /* so it is .onion */ *s = 0; /* nul-terminate it */ 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; } /** Check if the address is of the form "y.noconnect" */ int hostname_is_noconnect_address(const char *address) { return ! strcasecmpend(address, ".noconnect"); }