#include "private-libwebsockets.h" #include /** * libwebsocket_client_connect() - Connect to another websocket server * @this: Websocket context * @address: Remote server address, eg, "myserver.com" * @port: Port to connect to on the remote server, eg, 80 * @ssl_connection: 0 = ws://, 1 = wss:// encrypted, 2 = wss:// allow self * signed certs * @path: Websocket path on server * @host: Hostname on server * @origin: Socket origin name * @protocol: Comma-separated list of protocols being asked for from * the server, or just one. The server will pick the one it * likes best. * @ietf_version_or_minus_one: -1 to ask to connect using the default, latest * protocol supported, or the specific protocol ordinal * * This function creates a connection to a remote server */ struct libwebsocket * libwebsocket_client_connect(struct libwebsocket_context *this, const char *address, int port, int ssl_connection, const char *path, const char *host, const char *origin, const char *protocol, int ietf_version_or_minus_one) { struct hostent *server_hostent; struct sockaddr_in server_addr; char pkt[512]; struct pollfd pfd; struct libwebsocket *wsi; int n; int plen = 0; #ifndef LWS_OPENSSL_SUPPORT if (ssl_connection) { fprintf(stderr, "libwebsockets not configured for ssl\n"); return NULL; } #endif wsi = malloc(sizeof(struct libwebsocket)); if (wsi == NULL) goto bail1; memset(wsi, 0, sizeof *wsi); /* -1 means just use latest supported */ if (ietf_version_or_minus_one == -1) ietf_version_or_minus_one = 5; wsi->ietf_spec_revision = ietf_version_or_minus_one; wsi->name_buffer_pos = 0; wsi->user_space = NULL; wsi->state = WSI_STATE_CLIENT_UNCONNECTED; wsi->pings_vs_pongs = 0; wsi->protocol = NULL; wsi->pending_timeout = NO_PENDING_TIMEOUT; #ifdef LWS_OPENSSL_SUPPORT wsi->use_ssl = ssl_connection; #endif /* copy parameters over so state machine has access */ wsi->c_path = malloc(strlen(path) + 1); if (wsi->c_path == NULL) goto bail1; strcpy(wsi->c_path, path); wsi->c_host = malloc(strlen(host) + 1); if (wsi->c_host == NULL) goto oom1; strcpy(wsi->c_host, host); wsi->c_origin = malloc(strlen(origin) + 1); if (wsi->c_origin == NULL) goto oom2; strcpy(wsi->c_origin, origin); if (protocol) { wsi->c_protocol = malloc(strlen(protocol) + 1); if (wsi->c_protocol == NULL) goto oom3; strcpy(wsi->c_protocol, protocol); } else wsi->c_protocol = NULL; /* set up appropriate masking */ wsi->xor_mask = xor_no_mask; switch (wsi->ietf_spec_revision) { case 4: wsi->xor_mask = xor_mask_04; break; case 5: wsi->xor_mask = xor_mask_05; break; default: fprintf(stderr, "Client ietf version %d not supported\n", wsi->ietf_spec_revision); goto oom4; } /* force no mask if he asks for that though */ if (this->options & LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK) wsi->xor_mask = xor_no_mask; for (n = 0; n < WSI_TOKEN_COUNT; n++) { wsi->utf8_token[n].token = NULL; wsi->utf8_token[n].token_len = 0; } /* * proxy? */ if (this->http_proxy_port) { plen = sprintf(pkt, "CONNECT %s:%u HTTP/1.0\x0d\x0a" "User-agent: libwebsockets\x0d\x0a" /*Proxy-authorization: basic aGVsbG86d29ybGQ= */ "\x0d\x0a", address, port); /* OK from now on we talk via the proxy */ address = this->http_proxy_address; port = this->http_proxy_port; } /* * prepare the actual connection (to the proxy, if any) */ server_hostent = gethostbyname(address); if (server_hostent == NULL) { fprintf(stderr, "Unable to get host name from %s\n", address); goto oom4; } wsi->sock = socket(AF_INET, SOCK_STREAM, 0); if (wsi->sock < 0) { fprintf(stderr, "Unable to open socket\n"); goto oom4; } server_addr.sin_family = AF_INET; server_addr.sin_port = htons(port); server_addr.sin_addr = *((struct in_addr *)server_hostent->h_addr); bzero(&server_addr.sin_zero, 8); if (connect(wsi->sock, (struct sockaddr *)&server_addr, sizeof(struct sockaddr)) == -1) { fprintf(stderr, "Connect failed\n"); goto oom4; } /* into fd -> wsi hashtable */ insert_wsi(this, wsi); /* into internal poll list */ this->fds[this->fds_count].fd = wsi->sock; this->fds[this->fds_count].revents = 0; this->fds[this->fds_count++].events = POLLIN; /* external POLL support via protocol 0 */ this->protocols[0].callback(this, wsi, LWS_CALLBACK_ADD_POLL_FD, (void *)(long)wsi->sock, NULL, POLLIN); /* we are connected to server, or proxy */ if (this->http_proxy_port) { n = send(wsi->sock, pkt, plen, 0); if (n < 0) { close(wsi->sock); fprintf(stderr, "ERROR writing to proxy socket\n"); goto bail1; } libwebsocket_set_timeout(wsi, PENDING_TIMEOUT_AWAITING_PROXY_RESPONSE, 5); wsi->mode = LWS_CONNMODE_WS_CLIENT_WAITING_PROXY_REPLY; return wsi; } /* * provoke service to issue the handshake directly * we need to do it this way because in the proxy case, this is the * next state and executed only if and when we get a good proxy * response inside the state machine */ wsi->mode = LWS_CONNMODE_WS_CLIENT_ISSUE_HANDSHAKE; pfd.fd = wsi->sock; pfd.revents = POLLIN; libwebsocket_service_fd(this, &pfd); return wsi; oom4: if (wsi->c_protocol) free(wsi->c_protocol); oom3: free(wsi->c_origin); oom2: free(wsi->c_host); oom1: free(wsi->c_path); bail1: free(wsi); return NULL; }