| #include "private-libwebsockets.h" |
| #include <netdb.h> |
| |
| |
| /* |
| * In-place str to lower case |
| */ |
| |
| void |
| strtolower(char *s) |
| { |
| while (*s) { |
| *s = tolower(*s); |
| s++; |
| } |
| } |
| |
| void |
| libwebsocket_client_close(struct libwebsocket *wsi) |
| { |
| int n = wsi->state; |
| struct libwebsocket_context *clients; |
| unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 + |
| LWS_SEND_BUFFER_POST_PADDING]; |
| |
| if (n == WSI_STATE_DEAD_SOCKET) |
| return; |
| |
| /* |
| * signal we are closing, libsocket_write will |
| * add any necessary version-specific stuff. If the write fails, |
| * no worries we are closing anyway. If we didn't initiate this |
| * close, then our state has been changed to |
| * WSI_STATE_RETURNED_CLOSE_ALREADY and we can skip this |
| */ |
| |
| if (n == WSI_STATE_ESTABLISHED) |
| libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0, |
| LWS_WRITE_CLOSE); |
| /* mark the WSI as dead and let the callback know */ |
| |
| wsi->state = WSI_STATE_DEAD_SOCKET; |
| |
| if (wsi->protocol) { |
| if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED) |
| wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED, |
| wsi->user_space, NULL, 0); |
| |
| /* remove it from the client polling list */ |
| clients = wsi->protocol->owning_server; |
| if (clients) |
| for (n = 0; n < clients->fds_count; n++) { |
| if (clients->fds[n].fd != wsi->sock) |
| continue; |
| while (n < clients->fds_count - 1) { |
| clients->fds[n] = clients->fds[n + 1]; |
| n++; |
| } |
| /* we only have to deal with one */ |
| n = clients->fds_count; |
| } |
| |
| } |
| |
| /* clean out any parsing allocations */ |
| |
| for (n = 0; n < WSI_TOKEN_COUNT; n++) |
| if (wsi->utf8_token[n].token) |
| free(wsi->utf8_token[n].token); |
| |
| /* shut down reasonably cleanly */ |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (wsi->ssl) { |
| n = SSL_get_fd(wsi->ssl); |
| SSL_shutdown(wsi->ssl); |
| close(n); |
| SSL_free(wsi->ssl); |
| } else { |
| #endif |
| shutdown(wsi->sock, SHUT_RDWR); |
| close(wsi->sock); |
| #ifdef LWS_OPENSSL_SUPPORT |
| } |
| #endif |
| } |
| |
| |
| /** |
| * 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 buf[150]; |
| char key_b64[150]; |
| char hash[20]; |
| struct pollfd pfd; |
| static const char magic_websocket_guid[] = |
| "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; |
| static const char magic_websocket_04_masking_guid[] = |
| "61AC5F19-FBBA-4540-B96F-6561F1AB40A8"; |
| char pkt[1024]; |
| char *p = &pkt[0]; |
| const char *pc; |
| int len; |
| int okay = 0; |
| struct libwebsocket *wsi; |
| int n; |
| int plen = 0; |
| #ifdef LWS_OPENSSL_SUPPORT |
| char ssl_err_buf[512]; |
| #else |
| if (ssl_connection) { |
| fprintf(stderr, "libwebsockets not configured for ssl\n"); |
| return NULL; |
| } |
| #endif |
| |
| wsi = malloc(sizeof(struct libwebsocket)); |
| if (wsi == NULL) { |
| fprintf(stderr, "Out of memory allocing new connection\n"); |
| return NULL; |
| } |
| |
| /* -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; |
| |
| /* 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); |
| return NULL; |
| } |
| |
| /* 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 bail1; |
| } |
| |
| wsi->sock = socket(AF_INET, SOCK_STREAM, 0); |
| |
| if (wsi->sock < 0) { |
| fprintf(stderr, "Unable to open socket\n"); |
| goto bail1; |
| } |
| |
| insert_wsi(this, wsi); |
| |
| 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 bail1; |
| } |
| |
| /* 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; |
| } |
| |
| pfd.fd = wsi->sock; |
| pfd.events = POLLIN; |
| pfd.revents = 0; |
| |
| n = poll(&pfd, 1, 5000); |
| if (n <= 0) { |
| close(wsi->sock); |
| fprintf(stderr, "libwebsocket_client_handshake " |
| "timeout on proxy response"); |
| goto bail1; |
| } |
| |
| n = recv(wsi->sock, pkt, sizeof pkt, 0); |
| if (n < 0) { |
| close(wsi->sock); |
| fprintf(stderr, "ERROR reading from proxy socket\n"); |
| goto bail1; |
| } |
| |
| pkt[13] = '\0'; |
| if (strcmp(pkt, "HTTP/1.0 200 ") != 0) { |
| close(wsi->sock); |
| fprintf(stderr, "ERROR from proxy: %s\n", pkt); |
| goto bail1; |
| } |
| |
| /* we can just start sending to proxy */ |
| } |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (ssl_connection) { |
| |
| wsi->ssl = SSL_new(this->ssl_client_ctx); |
| wsi->client_bio = BIO_new_socket(wsi->sock, BIO_NOCLOSE); |
| SSL_set_bio(wsi->ssl, wsi->client_bio, wsi->client_bio); |
| |
| if (SSL_connect(wsi->ssl) <= 0) { |
| fprintf(stderr, "SSL connect error %s\n", |
| ERR_error_string(ERR_get_error(), ssl_err_buf)); |
| goto bail1; |
| } |
| |
| n = SSL_get_verify_result(wsi->ssl); |
| if (n != X509_V_OK) { |
| if (n != X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT || |
| ssl_connection != 2) { |
| |
| fprintf(stderr, "server's cert didn't " |
| "look good %d\n", n); |
| goto bail2; |
| } |
| } |
| } else { |
| wsi->ssl = NULL; |
| #endif |
| |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| } |
| #endif |
| |
| /* |
| * create the random key |
| */ |
| |
| n = read(this->fd_random, hash, 16); |
| if (n != 16) { |
| fprintf(stderr, "Unable to read from random device %s\n", |
| SYSTEM_RANDOM_FILEPATH); |
| goto bail2; |
| } |
| |
| lws_b64_encode_string(hash, 16, key_b64, sizeof key_b64); |
| |
| /* |
| * 04 example client handshake |
| * |
| * GET /chat HTTP/1.1 |
| * Host: server.example.com |
| * Upgrade: websocket |
| * Connection: Upgrade |
| * Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ== |
| * Sec-WebSocket-Origin: http://example.com |
| * Sec-WebSocket-Protocol: chat, superchat |
| * Sec-WebSocket-Version: 4 |
| */ |
| |
| p += sprintf(p, "GET %s HTTP/1.1\x0d\x0a", path); |
| p += sprintf(p, "Host: %s\x0d\x0a", host); |
| p += sprintf(p, "Upgrade: websocket\x0d\x0a"); |
| p += sprintf(p, "Connection: Upgrade\x0d\x0aSec-WebSocket-Key: "); |
| strcpy(p, key_b64); |
| p += strlen(key_b64); |
| p += sprintf(p, "\x0d\x0aSec-WebSocket-Origin: %s\x0d\x0a", origin); |
| if (protocol != NULL) |
| p += sprintf(p, "Sec-WebSocket-Protocol: %s\x0d\x0a", protocol); |
| p += sprintf(p, "Sec-WebSocket-Version: %d\x0d\x0a\x0d\x0a", |
| wsi->ietf_spec_revision); |
| |
| |
| /* prepare the expected server accept response */ |
| |
| strcpy(buf, key_b64); |
| strcpy(&buf[strlen(buf)], magic_websocket_guid); |
| |
| SHA1((unsigned char *)buf, strlen(buf), (unsigned char *)hash); |
| |
| lws_b64_encode_string(hash, 20, wsi->initial_handshake_hash_base64, |
| sizeof wsi->initial_handshake_hash_base64); |
| |
| /* send our request to the server */ |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (ssl_connection) |
| n = SSL_write(wsi->ssl, pkt, p - pkt); |
| else |
| #endif |
| n = send(wsi->sock, pkt, p - pkt, 0); |
| |
| if (n < 0) { |
| fprintf(stderr, "ERROR writing to client socket\n"); |
| goto bail2; |
| } |
| |
| wsi->parser_state = WSI_TOKEN_NAME_PART; |
| |
| pfd.fd = wsi->sock; |
| pfd.events = POLLIN; |
| pfd.revents = 0; |
| |
| n = poll(&pfd, 1, 5000); |
| if (n < 0) { |
| fprintf(stderr, "libwebsocket_client_handshake socket error " |
| "while waiting for handshake response"); |
| goto bail2; |
| } |
| if (n == 0) { |
| fprintf(stderr, "libwebsocket_client_handshake timeout " |
| "while waiting for handshake response"); |
| goto bail2; |
| } |
| |
| /* interpret the server response */ |
| |
| /* |
| * HTTP/1.1 101 Switching Protocols |
| * Upgrade: websocket |
| * Connection: Upgrade |
| * Sec-WebSocket-Accept: me89jWimTRKTWwrS3aRrL53YZSo= |
| * Sec-WebSocket-Nonce: AQIDBAUGBwgJCgsMDQ4PEC== |
| * Sec-WebSocket-Protocol: chat |
| */ |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (ssl_connection) |
| len = SSL_read(wsi->ssl, pkt, sizeof pkt); |
| else |
| #endif |
| len = recv(wsi->sock, pkt, sizeof pkt, 0); |
| |
| if (len < 0) { |
| fprintf(stderr, "libwebsocket_client_handshake read error\n"); |
| goto bail2; |
| } |
| |
| p = pkt; |
| for (n = 0; n < len; n++) |
| libwebsocket_parse(wsi, *p++); |
| |
| if (wsi->parser_state != WSI_PARSING_COMPLETE) { |
| fprintf(stderr, "libwebsocket_client_handshake server response" |
| " failed parsing\n"); |
| goto bail2; |
| } |
| |
| /* |
| * well, what the server sent looked reasonable for syntax. |
| * Now let's confirm it sent all the necessary headers |
| */ |
| |
| if (!wsi->utf8_token[WSI_TOKEN_HTTP].token_len || |
| !wsi->utf8_token[WSI_TOKEN_UPGRADE].token_len || |
| !wsi->utf8_token[WSI_TOKEN_CONNECTION].token_len || |
| !wsi->utf8_token[WSI_TOKEN_ACCEPT].token_len || |
| !wsi->utf8_token[WSI_TOKEN_NONCE].token_len || |
| (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len && |
| protocol != NULL)) { |
| fprintf(stderr, "libwebsocket_client_handshake " |
| "missing required header(s)\n"); |
| pkt[len] = '\0'; |
| fprintf(stderr, "%s", pkt); |
| goto bail2; |
| } |
| |
| /* |
| * Everything seems to be there, now take a closer look at what is in |
| * each header |
| */ |
| |
| strtolower(wsi->utf8_token[WSI_TOKEN_HTTP].token); |
| if (strcmp(wsi->utf8_token[WSI_TOKEN_HTTP].token, |
| "101 switching protocols")) { |
| fprintf(stderr, "libwebsocket_client_handshake server sent bad" |
| " HTTP response '%s'\n", |
| wsi->utf8_token[WSI_TOKEN_HTTP].token); |
| goto bail2; |
| } |
| |
| strtolower(wsi->utf8_token[WSI_TOKEN_UPGRADE].token); |
| if (strcmp(wsi->utf8_token[WSI_TOKEN_UPGRADE].token, "websocket")) { |
| fprintf(stderr, "libwebsocket_client_handshake server sent bad" |
| " Upgrade header '%s'\n", |
| wsi->utf8_token[WSI_TOKEN_UPGRADE].token); |
| goto bail2; |
| } |
| |
| strtolower(wsi->utf8_token[WSI_TOKEN_CONNECTION].token); |
| if (strcmp(wsi->utf8_token[WSI_TOKEN_CONNECTION].token, "upgrade")) { |
| fprintf(stderr, "libwebsocket_client_handshake server sent bad" |
| " Connection hdr '%s'\n", |
| wsi->utf8_token[WSI_TOKEN_CONNECTION].token); |
| goto bail2; |
| } |
| /* |
| * confirm the protocol the server wants to talk was in the list of |
| * protocols we offered |
| */ |
| |
| if (!wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len) { |
| |
| /* no protocol name to work from, default to first protocol */ |
| wsi->protocol = &this->protocols[0]; |
| |
| goto check_accept; |
| } |
| |
| pc = protocol; |
| while (*pc && !okay) { |
| if ((!strncmp(pc, wsi->utf8_token[WSI_TOKEN_PROTOCOL].token, |
| wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len)) && |
| (pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == ',' || |
| pc[wsi->utf8_token[WSI_TOKEN_PROTOCOL].token_len] == '\0')) { |
| okay = 1; |
| continue; |
| } |
| while (*pc && *pc != ',') |
| pc++; |
| while (*pc && *pc != ' ') |
| pc++; |
| } |
| if (!okay) { |
| fprintf(stderr, "libwebsocket_client_handshake server " |
| "sent bad protocol '%s'\n", |
| wsi->utf8_token[WSI_TOKEN_PROTOCOL].token); |
| goto bail2; |
| } |
| |
| /* |
| * identify the selected protocol struct and set it |
| */ |
| n = 0; |
| wsi->protocol = NULL; |
| while (this->protocols[n].callback) { |
| if (strcmp(wsi->utf8_token[WSI_TOKEN_PROTOCOL].token, |
| this->protocols[n].name) == 0) |
| wsi->protocol = &this->protocols[n]; |
| n++; |
| } |
| |
| if (wsi->protocol == NULL) { |
| fprintf(stderr, "libwebsocket_client_handshake server " |
| "requested protocol '%s', which we " |
| "said we supported but we don't!\n", |
| wsi->utf8_token[WSI_TOKEN_PROTOCOL].token); |
| goto bail2; |
| } |
| |
| check_accept: |
| /* |
| * Confirm his accept token is the same as the one we precomputed |
| */ |
| |
| if (strcmp(wsi->utf8_token[WSI_TOKEN_ACCEPT].token, |
| wsi->initial_handshake_hash_base64)) { |
| fprintf(stderr, "libwebsocket_client_handshake server sent " |
| "bad ACCEPT '%s' vs computed '%s'\n", |
| wsi->utf8_token[WSI_TOKEN_ACCEPT].token, |
| wsi->initial_handshake_hash_base64); |
| goto bail2; |
| } |
| |
| /* |
| * Calculate the masking key to use when sending data to server |
| */ |
| |
| strcpy(buf, key_b64); |
| p = buf + strlen(key_b64); |
| strcpy(p, wsi->utf8_token[WSI_TOKEN_NONCE].token); |
| p += wsi->utf8_token[WSI_TOKEN_NONCE].token_len; |
| strcpy(p, magic_websocket_04_masking_guid); |
| SHA1((unsigned char *)buf, strlen(buf), wsi->masking_key_04); |
| |
| /* allocate the per-connection user memory (if any) */ |
| |
| if (wsi->protocol->per_session_data_size) { |
| wsi->user_space = malloc( |
| wsi->protocol->per_session_data_size); |
| if (wsi->user_space == NULL) { |
| fprintf(stderr, "Out of memory for " |
| "conn user space\n"); |
| goto bail2; |
| } |
| } else |
| wsi->user_space = NULL; |
| |
| /* okay he is good to go */ |
| |
| this->fds[this->fds_count].fd = wsi->sock; |
| this->fds[this->fds_count].revents = 0; |
| this->fds[this->fds_count++].events = POLLIN; |
| |
| wsi->state = WSI_STATE_ESTABLISHED; |
| wsi->mode = LWS_CONNMODE_WS_CLIENT; |
| |
| fprintf(stderr, "handshake OK for protocol %s\n", wsi->protocol->name); |
| |
| /* call him back to inform him he is up */ |
| |
| wsi->protocol->callback(wsi, |
| LWS_CALLBACK_CLIENT_ESTABLISHED, |
| wsi->user_space, |
| NULL, 0); |
| return wsi; |
| |
| |
| bail2: |
| libwebsocket_client_close(wsi); |
| bail1: |
| free(wsi); |
| |
| return NULL; |
| } |