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- /* Copyright 2001 Matej Pfajfar, 2001-2004 Roger Dingledine. */
- /* See LICENSE for licensing information */
- /* $Id$ */
- /**
- * \file connection_edge.c
- * \brief Handle edge streams.
- **/
- #include "or.h"
- #include "tree.h"
- extern or_options_t options; /* command-line and config-file options */
- static struct exit_policy_t *socks_policy = NULL;
- static int connection_ap_handshake_process_socks(connection_t *conn);
- static void parse_socks_policy(void);
- /** Handle new bytes on conn->inbuf, or notification of eof.
- *
- * If there was an EOF, then send an end and mark the connection
- * for close.
- *
- * Otherwise handle it 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 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(connection_t *conn) {
- tor_assert(conn);
- tor_assert(conn->type == CONN_TYPE_AP || conn->type == CONN_TYPE_EXIT);
- if(conn->inbuf_reached_eof) {
- #ifdef HALF_OPEN
- /* eof reached; we're done reading, but we might want to write more. */
- conn->done_receiving = 1;
- shutdown(conn->s, 0); /* XXX check return, refactor NM */
- if (conn->done_sending) {
- connection_edge_end(conn, END_STREAM_REASON_DONE, conn->cpath_layer);
- connection_mark_for_close(conn);
- } else {
- connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_END,
- NULL, 0, conn->cpath_layer);
- }
- return 0;
- #else
- /* eof reached, kill it. */
- log_fn(LOG_INFO,"conn (fd %d) reached eof. Closing.", conn->s);
- connection_edge_end(conn, END_STREAM_REASON_DONE, conn->cpath_layer);
- if(!conn->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_mark_for_close(conn);
- }
- conn->hold_open_until_flushed = 1; /* just because we shouldn't read
- doesn't mean we shouldn't write */
- return 0;
- #endif
- }
- switch(conn->state) {
- case AP_CONN_STATE_SOCKS_WAIT:
- if(connection_ap_handshake_process_socks(conn) < 0) {
- conn->has_sent_end = 1; /* no circ yet */
- connection_mark_for_close(conn);
- conn->hold_open_until_flushed = 1;
- return -1;
- }
- return 0;
- case AP_CONN_STATE_OPEN:
- case EXIT_CONN_STATE_OPEN:
- if(conn->package_window <= 0) {
- /* XXX this is still getting called rarely :( */
- log_fn(LOG_WARN,"called with package_window %d. Tell Roger.", conn->package_window);
- return 0;
- }
- if(connection_edge_package_raw_inbuf(conn) < 0) {
- connection_edge_end(conn, END_STREAM_REASON_MISC, conn->cpath_layer);
- connection_mark_for_close(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:
- log_fn(LOG_INFO,"data from edge while in '%s' state. Leaving it on buffer.",
- conn_state_to_string[conn->type][conn->state]);
- return 0;
- }
- log_fn(LOG_WARN,"Got unexpected state %d. Closing.",conn->state);
- connection_edge_end(conn, END_STREAM_REASON_MISC, conn->cpath_layer);
- connection_mark_for_close(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, connection_t *conn) {
- tor_assert(conn->type == CONN_TYPE_AP || conn->type == CONN_TYPE_EXIT);
- if(conn->marked_for_close)
- return 0; /* already marked; probably got an 'end' */
- log_fn(LOG_INFO,"CircID %d: At an edge. Marking connection for close.",
- circ_id);
- conn->has_sent_end = 1; /* we're closing the circuit, nothing to send to */
- connection_mark_for_close(conn);
- conn->hold_open_until_flushed = 1;
- return 0;
- }
- /** Send a relay end cell from stream <b>conn</b> to conn's circuit,
- * with a destination of cpath_layer. (If cpath_layer is NULL, the
- * destination is the circuit's origin.) Mark the relay end cell as
- * closing because of <b>reason</b>.
- *
- * Return -1 if this function has already been called on this conn,
- * else return 0.
- */
- int
- connection_edge_end(connection_t *conn, char reason, crypt_path_t *cpath_layer)
- {
- char payload[5];
- size_t payload_len=1;
- circuit_t *circ;
- if(conn->has_sent_end) {
- log_fn(LOG_WARN,"It appears I've already sent the end. Are you calling me twice?");
- return -1;
- }
- payload[0] = reason;
- if(reason == END_STREAM_REASON_EXITPOLICY) {
- /* this is safe even for rend circs, because they never fail
- * because of exitpolicy */
- set_uint32(payload+1, htonl(conn->addr));
- payload_len += 4;
- }
- circ = circuit_get_by_conn(conn);
- if(circ && !circ->marked_for_close) {
- log_fn(LOG_DEBUG,"Marking conn (fd %d) and sending end.",conn->s);
- connection_edge_send_command(conn, circ, RELAY_COMMAND_END,
- payload, payload_len, cpath_layer);
- } else {
- log_fn(LOG_DEBUG,"Marking conn (fd %d); no circ to send end.",conn->s);
- }
- conn->has_sent_end = 1;
- return 0;
- }
- /** Connection <b>conn</b> has finished writing and has no bytes left on
- * its outbuf.
- *
- * If it's in state 'open', stop writing, consider responding with a
- * sendme, and return.
- * Otherwise, stop writing and return.
- *
- * If <b>conn</b> is broken, mark it for close and return -1, else
- * return 0.
- */
- int connection_edge_finished_flushing(connection_t *conn) {
- tor_assert(conn);
- tor_assert(conn->type == CONN_TYPE_AP || conn->type == CONN_TYPE_EXIT);
- switch(conn->state) {
- case AP_CONN_STATE_OPEN:
- case EXIT_CONN_STATE_OPEN:
- connection_stop_writing(conn);
- connection_edge_consider_sending_sendme(conn);
- return 0;
- case AP_CONN_STATE_SOCKS_WAIT:
- case AP_CONN_STATE_RENDDESC_WAIT:
- case AP_CONN_STATE_CIRCUIT_WAIT:
- case AP_CONN_STATE_CONNECT_WAIT:
- connection_stop_writing(conn);
- return 0;
- default:
- log_fn(LOG_WARN,"BUG: called in unexpected state %d.", conn->state);
- 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(connection_t *conn)
- {
- unsigned char connected_payload[4];
- tor_assert(conn);
- tor_assert(conn->type == CONN_TYPE_EXIT);
- tor_assert(conn->state == EXIT_CONN_STATE_CONNECTING);
- log_fn(LOG_INFO,"Exit connection to %s:%u established.",
- conn->address,conn->port);
- conn->state = EXIT_CONN_STATE_OPEN;
- connection_watch_events(conn, POLLIN); /* 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(conn)) {
- if(connection_edge_send_command(conn, circuit_get_by_conn(conn),
- RELAY_COMMAND_CONNECTED, NULL, 0, conn->cpath_layer) < 0)
- return 0; /* circuit is closed, don't continue */
- } else {
- *(uint32_t*)connected_payload = htonl(conn->addr);
- if(connection_edge_send_command(conn, circuit_get_by_conn(conn),
- RELAY_COMMAND_CONNECTED, connected_payload, 4, conn->cpath_layer) < 0)
- return 0; /* circuit is closed, don't continue */
- }
- tor_assert(conn->package_window > 0);
- return connection_edge_process_inbuf(conn); /* in case the server has written anything */
- }
- /** How many times do we retry a general-purpose stream (detach it from
- * one circuit and try another, after we wait a while with no 'connected'
- * cell) before giving up?
- */
- #define MAX_STREAM_RETRIES 4
- /** Find all general-purpose AP streams in state connect_wait that sent
- * their begin 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 45 seconds (with no
- * retry attempt).
- */
- void connection_ap_expire_beginning(void) {
- connection_t **carray;
- connection_t *conn;
- circuit_t *circ;
- int n, i;
- time_t now = time(NULL);
- get_connection_array(&carray, &n);
- for (i = 0; i < n; ++i) {
- conn = carray[i];
- if (conn->type != CONN_TYPE_AP ||
- conn->state != AP_CONN_STATE_CONNECT_WAIT)
- continue;
- if (now - conn->timestamp_lastread < 15)
- continue;
- conn->num_retries++;
- circ = circuit_get_by_conn(conn);
- if(!circ) { /* it's vanished? */
- log_fn(LOG_INFO,"Conn is in connect-wait, but lost its circ.");
- connection_mark_for_close(conn);
- continue;
- }
- if(circ->purpose == CIRCUIT_PURPOSE_C_REND_JOINED) {
- if (now - conn->timestamp_lastread > 45) {
- log_fn(LOG_WARN,"Rend stream is %d seconds late. Giving up.",
- (int)(now - conn->timestamp_lastread));
- connection_edge_end(conn, END_STREAM_REASON_TIMEOUT, conn->cpath_layer);
- connection_mark_for_close(conn);
- }
- continue;
- }
- tor_assert(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL);
- if(conn->num_retries >= MAX_STREAM_RETRIES) {
- log_fn(LOG_WARN,"Stream is %d seconds late. Giving up.",
- 15*conn->num_retries);
- circuit_log_path(LOG_WARN, circ);
- connection_edge_end(conn, END_STREAM_REASON_TIMEOUT, conn->cpath_layer);
- connection_mark_for_close(conn);
- } else {
- log_fn(LOG_WARN,"Stream is %d seconds late. Retrying.",
- (int)(now - conn->timestamp_lastread));
- circuit_log_path(LOG_WARN, circ);
- /* send an end down the circuit */
- connection_edge_end(conn, END_STREAM_REASON_TIMEOUT, conn->cpath_layer);
- /* un-mark it as ending, since we're going to reuse it */
- conn->has_sent_end = 0;
- /* move it back into 'pending' state. */
- conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- circuit_detach_stream(circ, conn);
- /* 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.NewCircuitPeriod;
- /* give our stream another 15 seconds to try */
- conn->timestamp_lastread += 15;
- /* attaching to a dirty circuit is fine */
- if(connection_ap_handshake_attach_circuit(conn)<0) {
- /* it will never work */
- /* Don't need to send end -- we're not connected */
- conn->has_sent_end = 1;
- connection_mark_for_close(conn);
- }
- } /* end if max_retries */
- } /* end for */
- }
- /** Tell any AP streamss that are waiting for a new circuit that one is
- * available.
- */
- void connection_ap_attach_pending(void)
- {
- connection_t **carray;
- connection_t *conn;
- int n, i;
- get_connection_array(&carray, &n);
- for (i = 0; i < n; ++i) {
- conn = carray[i];
- if (conn->marked_for_close ||
- conn->type != CONN_TYPE_AP ||
- conn->state != AP_CONN_STATE_CIRCUIT_WAIT)
- continue;
- if(connection_ap_handshake_attach_circuit(conn) < 0) {
- /* -1 means it will never work */
- /* Don't send end; there is no 'other side' yet */
- conn->has_sent_end = 1;
- connection_mark_for_close(conn);
- }
- }
- }
- /** 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, and it's for a general circuit, then
- * try to attach it to a circuit (or launch one as needed). If it's for
- * a rendezvous circuit, then fetch a rendezvous descriptor first (or
- * attach/launch a circuit if the rendezvous descriptor is already here
- * and fresh enough).
- *
- * Return -1 if an unexpected error with conn (and it should be marked
- * for close), else return 0.
- */
- static int connection_ap_handshake_process_socks(connection_t *conn) {
- socks_request_t *socks;
- int sockshere;
- tor_assert(conn);
- tor_assert(conn->type == CONN_TYPE_AP);
- tor_assert(conn->state == AP_CONN_STATE_SOCKS_WAIT);
- tor_assert(conn->socks_request);
- socks = conn->socks_request;
- log_fn(LOG_DEBUG,"entered.");
- sockshere = fetch_from_buf_socks(conn->inbuf, socks);
- if(sockshere == -1 || sockshere == 0) {
- if(socks->replylen) { /* we should send reply back */
- log_fn(LOG_DEBUG,"reply is already set for us. Using it.");
- connection_ap_handshake_socks_reply(conn, socks->reply, socks->replylen, 0);
- } else if(sockshere == -1) { /* send normal reject */
- log_fn(LOG_WARN,"Fetching socks handshake failed. Closing.");
- connection_ap_handshake_socks_reply(conn, NULL, 0, 0);
- } else {
- log_fn(LOG_DEBUG,"socks handshake not all here yet.");
- }
- if (sockshere == -1)
- socks->has_finished = 1;
- return sockshere;
- } /* else socks handshake is done, continue processing */
- if (socks->command == SOCKS_COMMAND_RESOLVE) {
- uint32_t answer;
- /* Reply to resolves immediately if we can. */
- if (strlen(socks->address) > RELAY_PAYLOAD_SIZE) {
- connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL);
- conn->socks_request->has_finished = 1;
- conn->has_sent_end = 1;
- connection_mark_for_close(conn);
- conn->hold_open_until_flushed = 1;
- return 0;
- }
- answer = htonl(client_dns_lookup_entry(socks->address));
- if (answer) {
- connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_IPV4,4,
- (char*)&answer);
- conn->socks_request->has_finished = 1;
- conn->has_sent_end = 1;
- connection_mark_for_close(conn);
- conn->hold_open_until_flushed = 1;
- return 0;
- }
- }
- /* this call _modifies_ socks->address iff it's a hidden-service request */
- if (rend_parse_rendezvous_address(socks->address) < 0) {
- /* normal request */
- conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- return connection_ap_handshake_attach_circuit(conn);
- } else {
- /* it's a hidden-service request */
- rend_cache_entry_t *entry;
- int r;
- if (socks->command == SOCKS_COMMAND_RESOLVE) {
- /* if it's a resolve request, fail it right now, rather than
- * building all the circuits and then realizing it won't work. */
- connection_ap_handshake_socks_resolved(conn,RESOLVED_TYPE_ERROR,0,NULL);
- conn->socks_request->has_finished = 1;
- conn->has_sent_end = 1;
- connection_mark_for_close(conn);
- conn->hold_open_until_flushed = 1;
- return 0;
- }
- strlcpy(conn->rend_query, socks->address, sizeof(conn->rend_query));
- log_fn(LOG_INFO,"Got a hidden service request for ID '%s'", conn->rend_query);
- /* see if we already have it cached */
- r = rend_cache_lookup_entry(conn->rend_query, &entry);
- if(r<0) {
- log_fn(LOG_WARN,"Invalid service descriptor %s", conn->rend_query);
- return -1;
- }
- if(r==0) {
- conn->state = AP_CONN_STATE_RENDDESC_WAIT;
- log_fn(LOG_INFO, "Unknown descriptor %s. Fetching.", conn->rend_query);
- rend_client_refetch_renddesc(conn->rend_query);
- return 0;
- }
- if(r>0) {
- #define NUM_SECONDS_BEFORE_REFETCH (60*15)
- if(time(NULL) - entry->received < NUM_SECONDS_BEFORE_REFETCH) {
- conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- log_fn(LOG_INFO, "Descriptor is here and fresh enough. Great.");
- return connection_ap_handshake_attach_circuit(conn);
- } else {
- conn->state = AP_CONN_STATE_RENDDESC_WAIT;
- log_fn(LOG_INFO, "Stale descriptor %s. Refetching.", conn->rend_query);
- rend_client_refetch_renddesc(conn->rend_query);
- return 0;
- }
- }
- }
- return 0;
- }
- /** 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(circuit_t *circ) {
- 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_fn(LOG_WARN,"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(connection_t *ap_conn, circuit_t *circ)
- {
- char payload[CELL_PAYLOAD_SIZE];
- int payload_len;
- struct in_addr in;
- const char *string_addr;
- tor_assert(ap_conn->type == CONN_TYPE_AP);
- tor_assert(ap_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
- tor_assert(ap_conn->socks_request);
- ap_conn->stream_id = get_unique_stream_id_by_circ(circ);
- if (ap_conn->stream_id==0) {
- /* Don't send end: there is no 'other side' yet */
- ap_conn->has_sent_end = 1;
- connection_mark_for_close(ap_conn);
- circuit_mark_for_close(circ);
- return -1;
- }
- if(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL) {
- in.s_addr = htonl(client_dns_lookup_entry(ap_conn->socks_request->address));
- string_addr = in.s_addr ? inet_ntoa(in) : NULL;
- tor_snprintf(payload,RELAY_PAYLOAD_SIZE,
- "%s:%d",
- string_addr ? string_addr : ap_conn->socks_request->address,
- ap_conn->socks_request->port);
- } else {
- tor_snprintf(payload,RELAY_PAYLOAD_SIZE,
- ":%d", ap_conn->socks_request->port);
- }
- payload_len = strlen(payload)+1;
- log_fn(LOG_DEBUG,"Sending relay cell to begin stream %d.",ap_conn->stream_id);
- if(connection_edge_send_command(ap_conn, circ, RELAY_COMMAND_BEGIN,
- payload, payload_len, ap_conn->cpath_layer) < 0)
- return -1; /* circuit is closed, don't continue */
- ap_conn->package_window = STREAMWINDOW_START;
- ap_conn->deliver_window = STREAMWINDOW_START;
- ap_conn->state = AP_CONN_STATE_CONNECT_WAIT;
- log_fn(LOG_INFO,"Address/port sent, ap socket %d, n_circ_id %d",ap_conn->s,circ->n_circ_id);
- 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(connection_t *ap_conn, circuit_t *circ)
- {
- int payload_len;
- const char *string_addr;
- tor_assert(ap_conn->type == CONN_TYPE_AP);
- tor_assert(ap_conn->state == AP_CONN_STATE_CIRCUIT_WAIT);
- tor_assert(ap_conn->socks_request);
- tor_assert(ap_conn->socks_request->command == SOCKS_COMMAND_RESOLVE);
- tor_assert(circ->purpose == CIRCUIT_PURPOSE_C_GENERAL);
- ap_conn->stream_id = get_unique_stream_id_by_circ(circ);
- if (ap_conn->stream_id==0) {
- /* Don't send end: there is no 'other side' yet */
- ap_conn->has_sent_end = 1;
- connection_mark_for_close(ap_conn);
- circuit_mark_for_close(circ);
- return -1;
- }
- string_addr = ap_conn->socks_request->address;
- payload_len = strlen(string_addr);
- tor_assert(strlen(string_addr) <= RELAY_PAYLOAD_SIZE);
- log_fn(LOG_DEBUG,"Sending relay cell to begin stream %d.",ap_conn->stream_id);
- if(connection_edge_send_command(ap_conn, circ, RELAY_COMMAND_RESOLVE,
- string_addr, payload_len, ap_conn->cpath_layer) < 0)
- return -1; /* circuit is closed, don't continue */
- ap_conn->state = AP_CONN_STATE_RESOLVE_WAIT;
- log_fn(LOG_INFO,"Address sent for resolve, ap socket %d, n_circ_id %d",ap_conn->s,circ->n_circ_id);
- return 0;
- }
- /** Make an AP connection_t, do a socketpair 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 socketpair, or -1 if error.
- */
- int connection_ap_make_bridge(char *address, uint16_t port) {
- int fd[2];
- connection_t *conn;
- log_fn(LOG_INFO,"Making AP bridge to %s:%d ...",address,port);
- if(tor_socketpair(AF_UNIX, SOCK_STREAM, 0, fd) < 0) {
- log(LOG_WARN,"Couldn't construct socketpair (%s). Network down? Delaying.",
- tor_socket_strerror(tor_socket_errno(-1)));
- return -1;
- }
- set_socket_nonblocking(fd[0]);
- set_socket_nonblocking(fd[1]);
- conn = connection_new(CONN_TYPE_AP);
- conn->s = fd[0];
- /* 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->address = tor_strdup("(local bridge)");
- conn->addr = 0;
- conn->port = 0;
- if(connection_add(conn) < 0) { /* no space, forget it */
- connection_free(conn); /* this closes fd[0] */
- tor_close_socket(fd[1]);
- return -1;
- }
- conn->state = AP_CONN_STATE_CIRCUIT_WAIT;
- connection_start_reading(conn);
- /* attaching to a dirty circuit is fine */
- if (connection_ap_handshake_attach_circuit(conn) < 0) {
- conn->has_sent_end = 1; /* no circ to send to */
- connection_mark_for_close(conn);
- tor_close_socket(fd[1]);
- return -1;
- }
- log_fn(LOG_INFO,"... AP bridge created and connected.");
- return fd[1];
- }
- void connection_ap_handshake_socks_resolved(connection_t *conn,
- int answer_type,
- size_t answer_len,
- const char *answer)
- {
- char buf[256];
- size_t replylen;
- if (answer_type == RESOLVED_TYPE_IPV4) {
- uint32_t a = get_uint32(answer);
- if(a)
- client_dns_set_entry(conn->socks_request->address, ntohl(a));
- }
- 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 {
- /* SOCKS5 */
- buf[0] = 0x05; /* version */
- if (answer_type == RESOLVED_TYPE_IPV4 && answer_len == 4) {
- buf[1] = 0; /* 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] = 0; /* 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 {
- buf[1] = 0x04; /* host unreachable */
- memset(buf+2, 0, 8);
- replylen = 10;
- }
- }
- connection_ap_handshake_socks_reply(conn, buf, replylen,
- answer_type == RESOLVED_TYPE_IPV4 ||
- answer_type == RESOLVED_TYPE_IPV6);
- }
- /** Send a socks reply to stream <b>conn</b>, using the appropriate
- * socks version, etc.
- *
- * If <b>reply</b> is defined, then write <b>replylen</b> bytes of it
- * to conn and return.
- *
- * Otherwise, send back a reply based on whether <b>success</b> is 1 or 0.
- */
- void connection_ap_handshake_socks_reply(connection_t *conn, char *reply,
- size_t replylen, int success) {
- char buf[256];
- if(replylen) { /* we already have a reply in mind */
- connection_write_to_buf(reply, replylen, conn);
- return;
- }
- tor_assert(conn->socks_request);
- if(conn->socks_request->socks_version == 4) {
- memset(buf,0,SOCKS4_NETWORK_LEN);
- #define SOCKS4_GRANTED 90
- #define SOCKS4_REJECT 91
- buf[1] = (success ? SOCKS4_GRANTED : SOCKS4_REJECT);
- /* leave version, destport, destip zero */
- connection_write_to_buf(buf, SOCKS4_NETWORK_LEN, conn);
- }
- if(conn->socks_request->socks_version == 5) {
- buf[0] = 5; /* version 5 */
- #define SOCKS5_SUCCESS 0
- #define SOCKS5_GENERIC_ERROR 1
- buf[1] = success ? SOCKS5_SUCCESS : SOCKS5_GENERIC_ERROR;
- 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,conn);
- }
- /* If socks_version isn't 4 or 5, don't send anything.
- * This can happen in the case of AP bridges. */
- return;
- }
- /** A relay 'begin' 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 -1 if we want to tear down <b>circ</b>. Else return 0.
- */
- int connection_exit_begin_conn(cell_t *cell, circuit_t *circ) {
- connection_t *n_stream;
- relay_header_t rh;
- char *address=NULL;
- uint16_t port;
- assert_circuit_ok(circ);
- relay_header_unpack(&rh, cell->payload);
- /* XXX currently we don't send an end cell back if we drop the
- * begin because it's malformed.
- */
- if(!memchr(cell->payload+RELAY_HEADER_SIZE, 0, rh.length)) {
- log_fn(LOG_WARN,"relay begin cell has no \\0. Dropping.");
- return 0;
- }
- if (parse_addr_port(cell->payload+RELAY_HEADER_SIZE, &address, NULL,&port)<0){
- log_fn(LOG_WARN,"Unable to parse addr:port in relay begin cell. Dropping.");
- return 0;
- }
- if (port==0) {
- log_fn(LOG_WARN,"Missing port in relay begin cell. Dropping.");
- tor_free(address);
- return 0;
- }
- log_fn(LOG_DEBUG,"Creating new exit connection.");
- n_stream = connection_new(CONN_TYPE_EXIT);
- n_stream->purpose = EXIT_PURPOSE_CONNECT;
- n_stream->stream_id = rh.stream_id;
- n_stream->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) {
- log_fn(LOG_DEBUG,"begin is for rendezvous. configuring stream.");
- n_stream->address = tor_strdup("(rendezvous)");
- n_stream->state = EXIT_CONN_STATE_CONNECTING;
- strlcpy(n_stream->rend_query, 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, circ) < 0) {
- log_fn(LOG_INFO,"Didn't find rendezvous service (port %d)",n_stream->port);
- connection_edge_end(n_stream, END_STREAM_REASON_EXITPOLICY, n_stream->cpath_layer);
- connection_free(n_stream);
- circuit_mark_for_close(circ); /* knock the whole thing down, somebody screwed up */
- tor_free(address);
- return 0;
- }
- assert_circuit_ok(circ);
- log_fn(LOG_DEBUG,"Finished assigning addr/port");
- n_stream->cpath_layer = circ->cpath->prev; /* link it */
- /* add it into the linked list of n_streams on this circuit */
- n_stream->next_stream = circ->n_streams;
- circ->n_streams = n_stream;
- assert_circuit_ok(circ);
- connection_exit_connect(n_stream);
- tor_free(address);
- return 0;
- }
- n_stream->address = address;
- n_stream->state = EXIT_CONN_STATE_RESOLVEFAILED;
- /* default to failed, change in dns_resolve if it turns out not to fail */
- if(we_are_hibernating()) {
- connection_edge_end(n_stream, END_STREAM_REASON_EXITPOLICY, n_stream->cpath_layer);
- connection_free(n_stream);
- }
- /* send it off to the gethostbyname farm */
- switch(dns_resolve(n_stream)) {
- case 1: /* resolve worked */
- /* add it into the linked list of n_streams on this circuit */
- n_stream->next_stream = circ->n_streams;
- circ->n_streams = n_stream;
- assert_circuit_ok(circ);
- connection_exit_connect(n_stream);
- return 0;
- case -1: /* resolve failed */
- log_fn(LOG_INFO,"Resolve failed (%s).", n_stream->address);
- connection_edge_end(n_stream, END_STREAM_REASON_RESOLVEFAILED, n_stream->cpath_layer);
- connection_free(n_stream);
- break;
- case 0: /* resolve added to pending list */
- /* add it into the linked list of resolving_streams on this circuit */
- n_stream->next_stream = circ->resolving_streams;
- circ->resolving_streams = n_stream;
- assert_circuit_ok(circ);
- ;
- }
- 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, circuit_t *circ) {
- connection_t *dummy_conn;
- relay_header_t rh;
- assert_circuit_ok(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 = connection_new(CONN_TYPE_EXIT);
- dummy_conn->stream_id = rh.stream_id;
- dummy_conn->address = tor_strndup(cell->payload+RELAY_HEADER_SIZE,
- rh.length);
- dummy_conn->port = 0;
- dummy_conn->state = EXIT_CONN_STATE_RESOLVEFAILED;
- dummy_conn->purpose = EXIT_PURPOSE_RESOLVE;
- dummy_conn->next_stream = circ->resolving_streams;
- circ->resolving_streams = dummy_conn;
- /* send it off to the gethostbyname farm */
- switch(dns_resolve(dummy_conn)) {
- case 1: /* The result was cached; a resolved cell was sent. */
- case -1:
- circuit_detach_stream(circuit_get_by_conn(dummy_conn), dummy_conn);
- connection_free(dummy_conn);
- return 0;
- case 0: /* resolve added to pending list */
- assert_circuit_ok(circ);
- ;
- }
- 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(connection_t *conn) {
- unsigned char connected_payload[4];
- uint32_t addr;
- uint16_t port;
- if (!connection_edge_is_rendezvous_stream(conn) &&
- router_compare_to_my_exit_policy(conn) == ADDR_POLICY_REJECTED) {
- log_fn(LOG_INFO,"%s:%d failed exit policy. Closing.", conn->address, conn->port);
- connection_edge_end(conn, END_STREAM_REASON_EXITPOLICY, conn->cpath_layer);
- circuit_detach_stream(circuit_get_by_conn(conn), conn);
- connection_free(conn);
- return;
- }
- addr = conn->addr;
- port = conn->port;
- SMARTLIST_FOREACH(options.RedirectExitList, exit_redirect_t *, r,
- {
- if ((addr&r->mask)==(r->addr&r->mask) &&
- (r->port_min <= port) && (port <= r->port_max)) {
- struct in_addr in;
- if (r->is_redirect) {
- addr = r->addr_dest;
- port = r->port_dest;
- in.s_addr = htonl(addr);
- log_fn(LOG_DEBUG, "Redirecting connection from %s:%d to %s:%d",
- conn->address, conn->port, inet_ntoa(in), port);
- }
- break;
- }
- });
- log_fn(LOG_DEBUG,"about to try connecting");
- switch(connection_connect(conn, conn->address, addr, port)) {
- case -1:
- connection_edge_end(conn, END_STREAM_REASON_CONNECTFAILED, conn->cpath_layer);
- circuit_detach_stream(circuit_get_by_conn(conn), conn);
- connection_free(conn);
- return;
- case 0:
- conn->state = EXIT_CONN_STATE_CONNECTING;
- connection_watch_events(conn, POLLOUT | POLLIN | POLLERR);
- /* writable indicates finish, readable indicates broken link,
- 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_fn(LOG_WARN,"tell roger: newly connected conn had data waiting!");
- // connection_start_writing(conn);
- }
- connection_watch_events(conn, POLLIN);
- /* also, deliver a 'connected' cell back through the circuit. */
- if(connection_edge_is_rendezvous_stream(conn)) { /* rendezvous stream */
- /* don't send an address back! */
- connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_CONNECTED,
- NULL, 0, conn->cpath_layer);
- } else { /* normal stream */
- /* This must be the original address, not the redirected address. */
- *(uint32_t*)connected_payload = htonl(conn->addr);
- connection_edge_send_command(conn, circuit_get_by_conn(conn), RELAY_COMMAND_CONNECTED,
- connected_payload, 4, conn->cpath_layer);
- }
- }
- /** Return 1 if <b>conn</b> is a rendezvous stream, or 0 if
- * it is a general stream.
- */
- int connection_edge_is_rendezvous_stream(connection_t *conn) {
- tor_assert(conn);
- if(*conn->rend_query) /* XXX */
- return 1;
- return 0;
- }
- /** Return 1 if router <b>exit</b> might allow stream <b>conn</b>
- * to exit from it, or 0 if it definitely will not allow it.
- * (We might be uncertain if conn's destination address has not yet been
- * resolved.)
- */
- int connection_ap_can_use_exit(connection_t *conn, routerinfo_t *exit)
- {
- uint32_t addr;
- tor_assert(conn);
- tor_assert(conn->type == CONN_TYPE_AP);
- tor_assert(conn->socks_request);
- log_fn(LOG_DEBUG,"considering nickname %s, for address %s / port %d:",
- exit->nickname, conn->socks_request->address,
- conn->socks_request->port);
- if (conn->socks_request->command == SOCKS_COMMAND_RESOLVE) {
- /* 0.0.8 servers have buggy resolve support. */
- return tor_version_as_new_as(exit->platform, "0.0.9pre1");
- }
- addr = client_dns_lookup_entry(conn->socks_request->address);
- if(router_compare_addr_to_exit_policy(addr,
- conn->socks_request->port, exit->exit_policy) < 0)
- return 0;
- return 1;
- }
- /** A helper function for socks_policy_permits_address() below.
- *
- * Parse options.SocksPolicy in the same way that the exit policy
- * is parsed, and put the processed version in &socks_policy.
- * Ignore port specifiers.
- */
- static void parse_socks_policy(void)
- {
- struct exit_policy_t *n;
- if (socks_policy) {
- exit_policy_free(socks_policy);
- socks_policy = NULL;
- }
- config_parse_exit_policy(options.SocksPolicy, &socks_policy);
- /* ports aren't used. */
- for (n=socks_policy; n; n = n->next) {
- n->prt_min = 1;
- n->prt_max = 65535;
- }
- }
- /** Return 1 if <b>addr</b> is permitted to connect to our socks port,
- * based on <b>socks_policy</b>. Else return 0.
- */
- int socks_policy_permits_address(uint32_t addr)
- {
- int a;
- if (options.SocksPolicy && !socks_policy)
- parse_socks_policy();
- if(!socks_policy) /* 'no socks policy' means 'accept' */
- return 1;
- a = router_compare_addr_to_exit_policy(addr, 1, socks_policy);
- if (a==-1)
- return 0;
- else if (a==0)
- return 1;
- tor_assert(a==1);
- log_fn(LOG_WARN, "Got unexpected 'maybe' answer from socks policy");
- return 0;
- }
- /* ***** Client DNS code ***** */
- /* XXX Perhaps this should get merged with the dns.c code somehow. */
- /* XXX But we can't just merge them, because then nodes that act as
- * both OR and OP could be attacked: people could rig the dns cache
- * by answering funny things to stream begin requests, and later
- * other clients would reuse those funny addr's. Hm.
- */
- /** A client-side struct to remember the resolved IP (addr) for
- * a given address. These structs make up a tree, with client_dns_map
- * below as its root.
- */
- struct client_dns_entry {
- uint32_t addr; /**< The resolved IP of this entry. */
- time_t expires; /**< At what second does addr expire? */
- int n_failures; /**< How many times has this entry failed to resolve so far? */
- };
- /** How many elements are in the client dns cache currently? */
- static int client_dns_size = 0;
- /** The tree of client-side cached DNS resolves. */
- static strmap_t *client_dns_map = NULL;
- /** Initialize client_dns_map and client_dns_size. */
- void client_dns_init(void) {
- client_dns_map = strmap_new();
- client_dns_size = 0;
- }
- /** Return the client_dns_entry that corresponds to <b>address</b>.
- * If it's not there, allocate and return a new entry for <b>address</b>.
- */
- static struct client_dns_entry *
- _get_or_create_ent(const char *address)
- {
- struct client_dns_entry *ent;
- ent = strmap_get_lc(client_dns_map,address);
- if (!ent) {
- ent = tor_malloc_zero(sizeof(struct client_dns_entry));
- ent->expires = time(NULL)+MAX_DNS_ENTRY_AGE;
- strmap_set_lc(client_dns_map,address,ent);
- ++client_dns_size;
- }
- return ent;
- }
- /** Return the IP associated with <b>address</b>, if we know it
- * and it's still fresh enough. Otherwise return 0.
- */
- uint32_t client_dns_lookup_entry(const char *address)
- {
- struct client_dns_entry *ent;
- struct in_addr in;
- time_t now;
- tor_assert(address);
- if (tor_inet_aton(address, &in)) {
- log_fn(LOG_DEBUG, "Using static address %s (%08lX)", address,
- (unsigned long)ntohl(in.s_addr));
- return ntohl(in.s_addr);
- }
- ent = strmap_get_lc(client_dns_map,address);
- if (!ent || !ent->addr) {
- log_fn(LOG_DEBUG, "No entry found for address %s", address);
- return 0;
- } else {
- now = time(NULL);
- if (ent->expires < now) {
- log_fn(LOG_DEBUG, "Expired entry found for address %s", address);
- strmap_remove_lc(client_dns_map,address);
- tor_free(ent);
- --client_dns_size;
- return 0;
- }
- in.s_addr = htonl(ent->addr);
- log_fn(LOG_DEBUG, "Found cached entry for address %s: %s", address,
- inet_ntoa(in));
- return ent->addr;
- }
- }
- /** 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)
- {
- struct client_dns_entry *ent;
- ent = _get_or_create_ent(address);
- ++ent->n_failures;
- log_fn(LOG_DEBUG,"Address %s now has %d resolve failures.",
- address, ent->n_failures);
- return ent->n_failures;
- }
- /** Record the fact that <b>address</b> resolved to <b>val</b>.
- * We can now use this in subsequent streams in client_dns_lookup_entry(),
- * so we can more correctly choose a router that will allow <b>address</b>
- * to exit from him.
- */
- void client_dns_set_entry(const char *address, uint32_t val)
- {
- struct client_dns_entry *ent;
- struct in_addr in;
- time_t now;
- tor_assert(address);
- tor_assert(val);
- if (tor_inet_aton(address, &in))
- return;
- now = time(NULL);
- ent = _get_or_create_ent(address);
- in.s_addr = htonl(val);
- log_fn(LOG_DEBUG, "Updating entry for address %s: %s", address,
- inet_ntoa(in));
- ent->addr = val;
- ent->expires = now+MAX_DNS_ENTRY_AGE;
- ent->n_failures = 0;
- }
- /** A helper function for client_dns_clean() below. If ent is too old,
- * then remove it from the tree and return NULL, else return ent.
- */
- static void* _remove_if_expired(const char *addr,
- struct client_dns_entry *ent,
- time_t *nowp)
- {
- if (ent->expires < *nowp) {
- --client_dns_size;
- tor_free(ent);
- return NULL;
- } else {
- return ent;
- }
- }
- /** Clean out entries from the client-side DNS cache that were
- * resolved long enough ago that they are no longer valid.
- */
- void client_dns_clean(void)
- {
- time_t now;
- if(!client_dns_size)
- return;
- now = time(NULL);
- strmap_foreach(client_dns_map, (strmap_foreach_fn)_remove_if_expired, &now);
- }
- /*
- Local Variables:
- mode:c
- indent-tabs-mode:nil
- c-basic-offset:2
- End:
- */
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