/* Copyright 2001,2002,2003 Roger Dingledine. */ /* See LICENSE for licensing information */ /* $Id$ */ #include "or.h" /** * \file directory.c * \brief Implement directory HTTP protocol. **/ /* In-points to directory.c: * * - directory_post_to_dirservers(), called from * router_upload_dir_desc_to_dirservers() in router.c * upload_service_descriptor() in rendservice.c * - directory_get_from_dirserver(), called from * rend_client_refetch_renddesc() in rendclient.c * run_scheduled_events() in main.c * do_hup() in main.c * - connection_dir_process_inbuf(), called from * connection_process_inbuf() in connection.c * - connection_dir_finished_flushing(), called from * connection_finished_flushing() in connection.c * - connection_dir_finished_connecting(), called from * connection_finished_connecting() in connection.c */ static void directory_initiate_command(routerinfo_t *router, uint8_t purpose, const char *payload, int payload_len); static void directory_send_command(connection_t *conn, int purpose, const char *payload, int payload_len); static int directory_handle_command(connection_t *conn); /********* START VARIABLES **********/ extern or_options_t options; /* command-line and config-file options */ /** URL for publishing rendezvous descriptors. */ char rend_publish_string[] = "/rendezvous/publish"; /** Prefix for downloading rendezvous descriptors. */ char rend_fetch_url[] = "/rendezvous/"; #define MAX_HEADERS_SIZE 50000 #define MAX_BODY_SIZE 500000 /********* END VARIABLES ************/ /** Start a connection to every known directory server, using * connection purpose 'purpose' and uploading the payload 'payload' * (length 'payload_len'). The purpose should be one of * 'DIR_PURPOSE_UPLOAD_DIR' or 'DIR_PURPOSE_UPLOAD_RENDDESC'. */ void directory_post_to_dirservers(uint8_t purpose, const char *payload, int payload_len) { int i; routerinfo_t *router; routerlist_t *rl; router_get_routerlist(&rl); if(!rl) return; for(i=0; i < smartlist_len(rl->routers); i++) { router = smartlist_get(rl->routers, i); if(router->is_trusted_dir) directory_initiate_command(router, purpose, payload, payload_len); } } /** Start a connection to a random running directory server, using * connection purpose 'purpose' requesting 'payload' (length * 'payload_len'). The purpose should be one of * 'DIR_PURPOSE_FETCH_DIR' or 'DIR_PURPOSE_FETCH_RENDDESC'. */ void directory_get_from_dirserver(uint8_t purpose, const char *payload, int payload_len) { routerinfo_t *ds; if (purpose == DIR_PURPOSE_FETCH_DIR) { if (advertised_server_mode()) { /* only ask authdirservers, and don't ask myself */ ds = router_pick_directory_server(1, 1); } else { /* anybody with a non-zero dirport will do */ ds = router_pick_directory_server(0, 1); } } else { // (purpose == DIR_PURPOSE_FETCH_RENDDESC) /* only ask authdirservers, any of them will do */ ds = router_pick_directory_server(1, 0); } if (!ds) { /* no viable dirserver found */ log_fn(LOG_WARN,"No running dirservers known. Not trying. (purpose %d)", purpose); return; } directory_initiate_command(ds, purpose, payload, payload_len); } /** Launch a new connection to the directory server router to upload or * download a service or rendezvous descriptor. purpose determines what * kind of directory connection we're launching, and must be one of * DIR_PURPOSE_{FETCH|UPLOAD}_{DIR|RENDDESC}. * * When uploading, payload and payload_len determine the content * of the HTTP post. When fetching a rendezvous descriptor, payload * and payload_len are the service ID we want to fetch. */ static void directory_initiate_command(routerinfo_t *router, uint8_t purpose, const char *payload, int payload_len) { connection_t *conn; tor_assert(router); tor_assert(router->dir_port); switch (purpose) { case DIR_PURPOSE_FETCH_DIR: log_fn(LOG_DEBUG,"initiating directory fetch"); break; case DIR_PURPOSE_FETCH_RENDDESC: log_fn(LOG_DEBUG,"initiating hidden-service descriptor fetch"); break; case DIR_PURPOSE_UPLOAD_DIR: log_fn(LOG_DEBUG,"initiating server descriptor upload"); break; case DIR_PURPOSE_UPLOAD_RENDDESC: log_fn(LOG_DEBUG,"initiating hidden-service descriptor upload"); break; default: log_fn(LOG_ERR, "Unrecognized directory connection purpose."); tor_assert(0); } conn = connection_new(CONN_TYPE_DIR); /* set up conn so it's got all the data we need to remember */ conn->addr = router->addr; conn->port = router->dir_port; conn->address = tor_strdup(router->address); conn->nickname = tor_strdup(router->nickname); tor_assert(router->identity_pkey); conn->identity_pkey = crypto_pk_dup_key(router->identity_pkey); crypto_pk_get_digest(conn->identity_pkey, conn->identity_digest); conn->purpose = purpose; /* give it an initial state */ conn->state = DIR_CONN_STATE_CONNECTING; if(purpose == DIR_PURPOSE_FETCH_DIR || purpose == DIR_PURPOSE_UPLOAD_DIR) { /* then we want to connect directly */ switch(connection_connect(conn, conn->address, conn->addr, conn->port)) { case -1: router_mark_as_down(conn->identity_digest); /* don't try him again */ if(purpose == DIR_PURPOSE_FETCH_DIR && !all_directory_servers_down()) { log_fn(LOG_INFO,"Giving up on dirserver %s; trying another.", conn->nickname); directory_get_from_dirserver(purpose, payload, payload_len); } connection_free(conn); return; case 1: conn->state = DIR_CONN_STATE_CLIENT_SENDING; /* start flushing conn */ /* fall through */ case 0: /* queue the command on the outbuf */ directory_send_command(conn, purpose, payload, payload_len); connection_watch_events(conn, POLLIN | POLLOUT | POLLERR); /* writable indicates finish, readable indicates broken link, error indicates broken link in windowsland. */ } } else { /* we want to connect via tor */ /* make an AP connection * populate it and add it at the right state * socketpair and hook up both sides */ conn->s = connection_ap_make_bridge(conn->address, conn->port); if(conn->s < 0) { log_fn(LOG_WARN,"Making AP bridge to dirserver failed."); connection_mark_for_close(conn); return; } conn->state = DIR_CONN_STATE_CLIENT_SENDING; connection_add(conn); /* queue the command on the outbuf */ directory_send_command(conn, purpose, payload, payload_len); connection_watch_events(conn, POLLIN | POLLOUT | POLLERR); } } /** Queue an appropriate HTTP command on conn-\>outbuf. The args * purpose, payload, and payload_len are as in * directory_initiate_command. */ static void directory_send_command(connection_t *conn, int purpose, const char *payload, int payload_len) { char fetchwholedir[] = "GET / HTTP/1.0\r\n\r\n"; char fetchrunninglist[] = "GET /running-routers HTTP/1.0\r\n\r\n"; char tmp[8192]; tor_assert(conn && conn->type == CONN_TYPE_DIR); switch(purpose) { case DIR_PURPOSE_FETCH_DIR: tor_assert(payload == NULL); connection_write_to_buf(fetchwholedir, strlen(fetchwholedir), conn); break; case DIR_PURPOSE_FETCH_RUNNING_LIST: tor_assert(payload == NULL); connection_write_to_buf(fetchrunninglist, strlen(fetchrunninglist), conn); break; case DIR_PURPOSE_UPLOAD_DIR: tor_assert(payload); snprintf(tmp, sizeof(tmp), "POST / HTTP/1.0\r\nContent-Length: %d\r\n\r\n", payload_len); connection_write_to_buf(tmp, strlen(tmp), conn); connection_write_to_buf(payload, payload_len, conn); break; case DIR_PURPOSE_FETCH_RENDDESC: tor_assert(payload); /* this must be true or we wouldn't be doing the lookup */ tor_assert(payload_len <= REND_SERVICE_ID_LEN); /* This breaks the function abstraction. */ memcpy(conn->rend_query, payload, payload_len); conn->rend_query[payload_len] = 0; snprintf(tmp, sizeof(tmp), "GET %s%s HTTP/1.0\r\n\r\n", rend_fetch_url, payload); connection_write_to_buf(tmp, strlen(tmp), conn); break; case DIR_PURPOSE_UPLOAD_RENDDESC: tor_assert(payload); snprintf(tmp, sizeof(tmp), "POST %s HTTP/1.0\r\nContent-Length: %d\r\n\r\n", rend_publish_string, payload_len); connection_write_to_buf(tmp, strlen(tmp), conn); /* could include nuls, need to write it separately */ connection_write_to_buf(payload, payload_len, conn); break; } } /** Parse an HTTP request string headers of the form "\%s \%s HTTP/1..." * If it's well-formed, point *url to the second \%s, * null-terminate it (this modifies headers!) and return 0. * Otherwise, return -1. */ static int parse_http_url(char *headers, char **url) { char *s, *tmp; s = (char *)eat_whitespace_no_nl(headers); if (!*s) return -1; s = (char *)find_whitespace(s); /* get past GET/POST */ if (!*s) return -1; s = (char *)eat_whitespace_no_nl(s); if (!*s) return -1; tmp = s; /* this is it, assuming it's valid */ s = (char *)find_whitespace(s); if (!*s) return -1; *s = 0; *url = tmp; return 0; } /** Parse an HTTP response string headers of the form * "HTTP/1.\%d \%d\%s\r\n...". * If it's well-formed, assign *code, point *message to the first * non-space character after code if there is one and message is non-NULL * (else leave it alone), and return 0. * Otherwise, return -1. */ static int parse_http_response(char *headers, int *code, char **message) { int n1, n2; tor_assert(headers && code); while(isspace((int)*headers)) headers++; /* tolerate leading whitespace */ if(sscanf(headers, "HTTP/1.%d %d", &n1, &n2) < 2 || (n1 != 0 && n1 != 1) || (n2 < 100 || n2 >= 600)) { log_fn(LOG_WARN,"Failed to parse header '%s'",headers); return -1; } *code = n2; if(message) { /* XXX should set *message correctly */ } return 0; } /** We are a client, and we've finished reading the server's * response. Parse and it and act appropriately. * * Return -1 if an error has occurred, or 0 normally. The caller * will take care of marking the connection for close. */ static int connection_dir_client_reached_eof(connection_t *conn) { char *body; char *headers; int body_len=0; int status_code; switch(fetch_from_buf_http(conn->inbuf, &headers, MAX_HEADERS_SIZE, &body, &body_len, MAX_DIR_SIZE)) { case -1: /* overflow */ log_fn(LOG_WARN,"'fetch' response too large. Failing."); return -1; case 0: log_fn(LOG_INFO,"'fetch' response not all here, but we're at eof. Closing."); return -1; /* case 1, fall through */ } if(parse_http_response(headers, &status_code, NULL) < 0) { log_fn(LOG_WARN,"Unparseable headers. Closing."); free(body); free(headers); return -1; } if(conn->purpose == DIR_PURPOSE_FETCH_DIR) { /* fetch/process the directory to learn about new routers. */ log_fn(LOG_INFO,"Received directory (size %d):\n%s", body_len, body); if(status_code == 503 || body_len == 0) { log_fn(LOG_INFO,"Empty directory. Ignoring."); free(body); free(headers); return 0; } if(status_code != 200) { log_fn(LOG_WARN,"Received http status code %d from dirserver. Failing.", status_code); free(body); free(headers); return -1; } if(router_load_routerlist_from_directory(body, NULL) < 0){ log_fn(LOG_INFO,"...but parsing failed. Ignoring."); } else { log_fn(LOG_INFO,"updated routers."); } directory_has_arrived(); /* do things we've been waiting to do */ } if(conn->purpose == DIR_PURPOSE_FETCH_RUNNING_LIST) { running_routers_t *rrs; routerlist_t *rl; /* just update our list of running routers, if this list is new info */ log_fn(LOG_INFO,"Received running-routers list (size %d):\n%s", body_len, body); if(status_code != 200) { log_fn(LOG_WARN,"Received http status code %d from dirserver. Failing.", status_code); free(body); free(headers); return -1; } if (!(rrs = router_parse_runningrouters(body))) { log_fn(LOG_WARN, "Can't parse runningrouters list"); free(body); free(headers); return -1; } router_get_routerlist(&rl); routerlist_update_from_runningrouters(rl,rrs); running_routers_free(rrs); } if(conn->purpose == DIR_PURPOSE_UPLOAD_DIR) { switch(status_code) { case 200: log_fn(LOG_INFO,"eof (status 200) after uploading server descriptor: finished."); break; case 400: log_fn(LOG_WARN,"http status 400 (bad request) response from dirserver. Malformed server descriptor?"); break; case 403: log_fn(LOG_WARN,"http status 403 (unapproved server) response from dirserver. Is your clock skewed? Have you mailed us your identity fingerprint? Are you using the right key? See README."); break; default: log_fn(LOG_WARN,"http status %d response unrecognized.", status_code); break; } } if(conn->purpose == DIR_PURPOSE_FETCH_RENDDESC) { log_fn(LOG_INFO,"Received rendezvous descriptor (size %d, status code %d)", body_len, status_code); switch(status_code) { case 200: if(rend_cache_store(body, body_len) < 0) { log_fn(LOG_WARN,"Failed to store rendezvous descriptor."); /* alice's ap_stream will notice when connection_mark_for_close * cleans it up */ } else { /* success. notify pending connections about this. */ rend_client_desc_fetched(conn->rend_query, 1); conn->purpose = DIR_PURPOSE_HAS_FETCHED_RENDDESC; } break; case 404: /* not there. pending connections will be notified when * connection_mark_for_close cleans it up. */ break; case 400: log_fn(LOG_WARN,"http status 400 (bad request). Dirserver didn't like our rendezvous query?"); break; } } if(conn->purpose == DIR_PURPOSE_UPLOAD_RENDDESC) { switch(status_code) { case 200: log_fn(LOG_INFO,"eof (status 200) after uploading rendezvous descriptor: finished."); break; case 400: log_fn(LOG_WARN,"http status 400 (bad request) response from dirserver. Malformed rendezvous descriptor?"); break; default: log_fn(LOG_WARN,"http status %d response unrecognized.", status_code); break; } } free(body); free(headers); return 0; } /** Read handler for directory connections. (That's connections to * directory servers and connections at directory servers.) */ int connection_dir_process_inbuf(connection_t *conn) { int retval; tor_assert(conn && conn->type == CONN_TYPE_DIR); /* Directory clients write, then read data until they receive EOF; * directory servers read data until they get an HTTP command, then * write their response (when it's finished flushing, they mark for * close). */ if(conn->inbuf_reached_eof) { if(conn->state != DIR_CONN_STATE_CLIENT_READING) { log_fn(LOG_INFO,"conn reached eof, not reading. Closing."); connection_close_immediate(conn); /* it was an error; give up on flushing */ connection_mark_for_close(conn); return -1; } retval = connection_dir_client_reached_eof(conn); connection_mark_for_close(conn); return retval; } /* endif 'reached eof' */ /* If we're on the dirserver side, look for a command. */ if(conn->state == DIR_CONN_STATE_SERVER_COMMAND_WAIT) { if (directory_handle_command(conn) < 0) { connection_mark_for_close(conn); return -1; } return 0; } /* XXX for READ states, might want to make sure inbuf isn't too big */ log_fn(LOG_DEBUG,"Got data, not eof. Leaving on inbuf."); return 0; } static char answer200[] = "HTTP/1.0 200 OK\r\n\r\n"; static char answer400[] = "HTTP/1.0 400 Bad request\r\n\r\n"; static char answer403[] = "HTTP/1.0 403 Unapproved server\r\n\r\n"; static char answer404[] = "HTTP/1.0 404 Not found\r\n\r\n"; static char answer503[] = "HTTP/1.0 503 Directory unavailable\r\n\r\n"; /** Helper function: called when a dirserver gets a complete HTTP GET * request. Look for a request for a directory or for a rendezvous * service descriptor. On finding one, write a response into * conn-\>outbuf. If the request is unrecognized, send a 404. * Always return 0. */ static int directory_handle_command_get(connection_t *conn, char *headers, char *body, int body_len) { size_t dlen; const char *cp; char *url; char tmp[8192]; log_fn(LOG_DEBUG,"Received GET command."); conn->state = DIR_CONN_STATE_SERVER_WRITING; if (parse_http_url(headers, &url) < 0) { connection_write_to_buf(answer400, strlen(answer400), conn); return 0; } if(!strcmp(url,"/")) { /* directory fetch */ dlen = dirserv_get_directory(&cp); if(dlen == 0) { log_fn(LOG_WARN,"My directory is empty. Closing."); connection_write_to_buf(answer503, strlen(answer503), conn); return 0; } log_fn(LOG_DEBUG,"Dumping directory to client."); snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: text/plain\r\n\r\n", (int)dlen); connection_write_to_buf(tmp, strlen(tmp), conn); connection_write_to_buf(cp, strlen(cp), conn); return 0; } if(!strcmp(url,"/running-routers")) { /* running-routers fetch */ if(!authdir_mode()) { /* XXX008 for now, we don't cache running-routers. Reject. */ connection_write_to_buf(answer400, strlen(answer400), conn); return 0; } dlen = dirserv_get_runningrouters(&cp); if(dlen < 0) { /* we failed to create cp */ connection_write_to_buf(answer503, strlen(answer503), conn); return 0; } snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: text/plain\r\n\r\n", (int)dlen); connection_write_to_buf(tmp, strlen(tmp), conn); connection_write_to_buf(cp, strlen(cp), conn); return 0; } if(!strncmp(url,rend_fetch_url,strlen(rend_fetch_url))) { /* rendezvous descriptor fetch */ const char *descp; int desc_len; if(!authdir_mode()) { /* We don't hand out rend descs. In fact, it could be a security * risk, since rend_cache_lookup_desc() below would provide it * if we're gone to the site recently, and 404 if we haven't. * * Reject. */ connection_write_to_buf(answer400, strlen(answer400), conn); return 0; } switch(rend_cache_lookup_desc(url+strlen(rend_fetch_url), &descp, &desc_len)) { case 1: /* valid */ snprintf(tmp, sizeof(tmp), "HTTP/1.0 200 OK\r\nContent-Length: %d\r\nContent-Type: application/octet-stream\r\n\r\n", desc_len); /* can't include descp here, because it's got nuls */ connection_write_to_buf(tmp, strlen(tmp), conn); connection_write_to_buf(descp, desc_len, conn); break; case 0: /* well-formed but not present */ connection_write_to_buf(answer404, strlen(answer404), conn); break; case -1: /* not well-formed */ connection_write_to_buf(answer400, strlen(answer400), conn); break; } return 0; } /* we didn't recognize the url */ connection_write_to_buf(answer404, strlen(answer404), conn); return 0; } /** Helper function: called when a dirserver gets a complete HTTP POST * request. Look for an uploaded server descriptor or rendezvous * service descriptor. On finding one, process it and write a * response into conn-\>outbuf. If the request is unrecognized, send a * 404. Always return 0. */ static int directory_handle_command_post(connection_t *conn, char *headers, char *body, int body_len) { const char *cp; char *url; log_fn(LOG_DEBUG,"Received POST command."); conn->state = DIR_CONN_STATE_SERVER_WRITING; if(!authdir_mode()) { /* we just provide cached directories; we don't want to * receive anything. */ connection_write_to_buf(answer400, strlen(answer400), conn); return 0; } if (parse_http_url(headers, &url) < 0) { connection_write_to_buf(answer400, strlen(answer400), conn); return 0; } log_fn(LOG_INFO,"url '%s' posted to us.", url); if(!strcmp(url,"/")) { /* server descriptor post */ cp = body; switch(dirserv_add_descriptor(&cp)) { case -1: /* malformed descriptor, or something wrong */ connection_write_to_buf(answer400, strlen(answer400), conn); break; case 0: /* descriptor was well-formed but server has not been approved */ connection_write_to_buf(answer403, strlen(answer403), conn); break; case 1: dirserv_get_directory(&cp); /* rebuild and write to disk */ connection_write_to_buf(answer200, strlen(answer200), conn); break; } return 0; } if(!strncmp(url,rend_publish_string,strlen(rend_publish_string))) { /* rendezvous descriptor post */ if(rend_cache_store(body, body_len) < 0) connection_write_to_buf(answer400, strlen(answer400), conn); else connection_write_to_buf(answer200, strlen(answer200), conn); return 0; } /* we didn't recognize the url */ connection_write_to_buf(answer404, strlen(answer404), conn); return 0; } /** Called when a dirserver receives data on a directory connection; * looks for an HTTP request. If the request is complete, remove it * from the inbuf, try to process it; otherwise, leave it on the * buffer. Return a 0 on success, or -1 on error. */ static int directory_handle_command(connection_t *conn) { char *headers=NULL, *body=NULL; int body_len=0; int r; tor_assert(conn && conn->type == CONN_TYPE_DIR); switch(fetch_from_buf_http(conn->inbuf, &headers, MAX_HEADERS_SIZE, &body, &body_len, MAX_BODY_SIZE)) { case -1: /* overflow */ log_fn(LOG_WARN,"input too large. Failing."); return -1; case 0: log_fn(LOG_DEBUG,"command not all here yet."); return 0; /* case 1, fall through */ } log_fn(LOG_DEBUG,"headers '%s', body '%s'.", headers, body); if(!strncasecmp(headers,"GET",3)) r = directory_handle_command_get(conn, headers, body, body_len); else if (!strncasecmp(headers,"POST",4)) r = directory_handle_command_post(conn, headers, body, body_len); else { log_fn(LOG_WARN,"Got headers '%s' with unknown command. Closing.", headers); r = -1; } tor_free(headers); tor_free(body); return r; } /** Write handler for directory connections; called when all data has * been flushed. Close the connection or wait for a response as * appropriate. */ int connection_dir_finished_flushing(connection_t *conn) { tor_assert(conn && conn->type == CONN_TYPE_DIR); switch(conn->state) { case DIR_CONN_STATE_CLIENT_SENDING: log_fn(LOG_DEBUG,"client finished sending command."); conn->state = DIR_CONN_STATE_CLIENT_READING; connection_stop_writing(conn); return 0; case DIR_CONN_STATE_SERVER_WRITING: log_fn(LOG_INFO,"Finished writing server response. Closing."); connection_mark_for_close(conn); return 0; default: log_fn(LOG_WARN,"BUG: called in unexpected state %d.", conn->state); return -1; } return 0; } /** Connected handler for directory connections: begin sending data to the * server */ int connection_dir_finished_connecting(connection_t *conn) { tor_assert(conn && conn->type == CONN_TYPE_DIR); tor_assert(conn->state == DIR_CONN_STATE_CONNECTING); log_fn(LOG_INFO,"Dir connection to router %s:%u established.", conn->address,conn->port); conn->state = DIR_CONN_STATE_CLIENT_SENDING; /* start flushing conn */ return 0; } /* Local Variables: mode:c indent-tabs-mode:nil c-basic-offset:2 End: */