| /* |
| * libwebsockets - small server side websockets and web server implementation |
| * |
| * Copyright (C) 2010 Andy Green <andy@warmcat.com> |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation: |
| * version 2.1 of the License. |
| * |
| * This library is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, |
| * MA 02110-1301 USA |
| */ |
| |
| #include "private-libwebsockets.h" |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| SSL_CTX *ssl_ctx; |
| int use_ssl; |
| #endif |
| |
| |
| extern int |
| libwebsocket_read(struct libwebsocket *wsi, unsigned char * buf, size_t len); |
| |
| |
| /* document the generic callback (it's a fake prototype under this) */ |
| /** |
| * callback() - User server actions |
| * @wsi: Opaque websocket instance pointer |
| * @reason: The reason for the call |
| * @user: Pointer to per-session user data allocated by library |
| * @in: Pointer used for some callback reasons |
| * @len: Length set for some callback reasons |
| * |
| * This callback is the way the user controls what is served. All the |
| * protocol detail is hidden and handled by the library. |
| * |
| * For each connection / session there is user data allocated that is |
| * pointed to by "user". You set the size of this user data area when |
| * the library is initialized with libwebsocket_create_server. |
| * |
| * You get an opportunity to initialize user data when called back with |
| * LWS_CALLBACK_ESTABLISHED reason. |
| * |
| * LWS_CALLBACK_ESTABLISHED: after successful websocket handshake |
| * |
| * LWS_CALLBACK_CLOSED: when the websocket session ends |
| * |
| * LWS_CALLBACK_SEND: opportunity to send to client (you would use |
| * libwebsocket_write() taking care about the |
| * special buffer requirements |
| * LWS_CALLBACK_RECEIVE: data has appeared for the server, it can be |
| * found at *in and is len bytes long |
| * |
| * LWS_CALLBACK_HTTP: an http request has come from a client that is not |
| * asking to upgrade the connection to a websocket |
| * one. This is a chance to serve http content, |
| * for example, to send a script to the client |
| * which will then open the websockets connection. |
| * @in points to the URI path requested and |
| * libwebsockets_serve_http_file() makes it very |
| * simple to send back a file to the client. |
| */ |
| extern int callback(struct libwebsocket * wsi, |
| enum libwebsocket_callback_reasons reason, void * user, |
| void *in, size_t len); |
| |
| |
| void |
| libwebsocket_close_and_free_session(struct libwebsocket *wsi) |
| { |
| int n = wsi->state; |
| |
| wsi->state = WSI_STATE_DEAD_SOCKET; |
| |
| if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED) |
| wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED, |
| wsi->user_space, NULL, 0); |
| |
| for (n = 0; n < WSI_TOKEN_COUNT; n++) |
| if (wsi->utf8_token[n].token) |
| free(wsi->utf8_token[n].token); |
| |
| // fprintf(stderr, "closing fd=%d\n", wsi->sock); |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (use_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 |
| if (wsi->user_space) |
| free(wsi->user_space); |
| |
| free(wsi); |
| } |
| |
| /** |
| * libwebsocket_create_server() - Create the listening websockets server |
| * @port: Port to listen on |
| * @protocols: Array of structures listing supported protocols and a protocol- |
| * specific callback for each one. The list is ended with an |
| * entry that has a NULL callback pointer. |
| * @ssl_cert_filepath: If libwebsockets was compiled to use ssl, and you want |
| * to listen using SSL, set to the filepath to fetch the |
| * server cert from, otherwise NULL for unencrypted |
| * @ssl_private_key_filepath: filepath to private key if wanting SSL mode, |
| * else ignored |
| * @gid: group id to change to after setting listen socket, or -1. |
| * @uid: user id to change to after setting listen socket, or -1. |
| * |
| * This function creates the listening socket and takes care |
| * of all initialization in one step. |
| * |
| * It does not return since it sits in a service loop and operates via the |
| * callbacks given in @protocol. User code should fork before calling |
| * libwebsocket_create_server() if it wants to do other things in |
| * parallel other than serve websockets. |
| * |
| * The protocol callback functions are called for a handful of events |
| * including http requests coming in, websocket connections becoming |
| * established, and data arriving; it's also called periodically to allow |
| * async transmission. |
| * |
| * HTTP requests are sent always to the FIRST protocol in @protocol, since |
| * at that time websocket protocol has not been negotiated. Other |
| * protocols after the first one never see any HTTP callack activity. |
| * |
| * The server created is a simple http server by default; part of the |
| * websocket standard is upgrading this http connection to a websocket one. |
| * |
| * This allows the same server to provide files like scripts and favicon / |
| * images or whatever over http and dynamic data over websockets all in |
| * one place; they're all handled in the user callback. |
| */ |
| |
| int libwebsocket_create_server(int port, |
| const struct libwebsocket_protocols *protocols, |
| const char * ssl_cert_filepath, |
| const char * ssl_private_key_filepath, |
| int gid, int uid) |
| { |
| int n; |
| int client; |
| int sockfd; |
| int fd; |
| unsigned int clilen; |
| struct sockaddr_in serv_addr, cli_addr; |
| struct libwebsocket *wsi[MAX_CLIENTS + 1]; |
| struct pollfd fds[MAX_CLIENTS + 1]; |
| int fds_count = 0; |
| unsigned char buf[1024]; |
| int opt = 1; |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| SSL_METHOD *method; |
| char ssl_err_buf[512]; |
| |
| use_ssl = ssl_cert_filepath != NULL && ssl_private_key_filepath != NULL; |
| if (use_ssl) |
| fprintf(stderr, " Compiled with SSL support, using it\n"); |
| else |
| fprintf(stderr, " Compiled with SSL support, not using it\n"); |
| |
| #else |
| if (ssl_cert_filepath != NULL && ssl_private_key_filepath != NULL) { |
| fprintf(stderr, " Not compiled for OpenSSl support!\n"); |
| return -1; |
| } |
| fprintf(stderr, " Compiled without SSL support, serving unencrypted\n"); |
| #endif |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (use_ssl) { |
| SSL_library_init(); |
| |
| OpenSSL_add_all_algorithms(); |
| SSL_load_error_strings(); |
| |
| // Firefox insists on SSLv23 not SSLv3 |
| // Konq disables SSLv2 by default now, SSLv23 works |
| |
| method = SSLv23_server_method(); // create server instance |
| if (!method) { |
| fprintf(stderr, "problem creating ssl method: %s\n", |
| ERR_error_string(ERR_get_error(), ssl_err_buf)); |
| return -1; |
| } |
| ssl_ctx = SSL_CTX_new(method); /* create context */ |
| if (!ssl_ctx) { |
| printf("problem creating ssl context: %s\n", |
| ERR_error_string(ERR_get_error(), ssl_err_buf)); |
| return -1; |
| } |
| /* set the local certificate from CertFile */ |
| n = SSL_CTX_use_certificate_file(ssl_ctx, |
| ssl_cert_filepath, SSL_FILETYPE_PEM); |
| if (n != 1) { |
| fprintf(stderr, "problem getting cert '%s': %s\n", |
| ssl_cert_filepath, |
| ERR_error_string(ERR_get_error(), ssl_err_buf)); |
| return -1; |
| } |
| /* set the private key from KeyFile */ |
| if (SSL_CTX_use_PrivateKey_file(ssl_ctx, |
| ssl_private_key_filepath, |
| SSL_FILETYPE_PEM) != 1) { |
| fprintf(stderr, "ssl problem getting key '%s': %s\n", |
| ssl_private_key_filepath, |
| ERR_error_string(ERR_get_error(), ssl_err_buf)); |
| return (-1); |
| } |
| /* verify private key */ |
| if (!SSL_CTX_check_private_key(ssl_ctx)) { |
| fprintf(stderr, "Private SSL key doesn't match cert\n"); |
| return (-1); |
| } |
| |
| /* SSL is happy and has a cert it's content with */ |
| } |
| #endif |
| |
| sockfd = socket(AF_INET, SOCK_STREAM, 0); |
| if (sockfd < 0) { |
| fprintf(stderr, "ERROR opening socket"); |
| return -1; |
| } |
| |
| /* allow us to restart even if old sockets in TIME_WAIT */ |
| setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)); |
| |
| bzero((char *) &serv_addr, sizeof(serv_addr)); |
| serv_addr.sin_family = AF_INET; |
| serv_addr.sin_addr.s_addr = INADDR_ANY; |
| serv_addr.sin_port = htons(port); |
| |
| n = bind(sockfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)); |
| if (n < 0) { |
| fprintf(stderr, "ERROR on binding to port %d (%d %d)\n", port, n, |
| errno); |
| return -1; |
| } |
| |
| /* drop any root privs for this process */ |
| |
| if (gid != -1) |
| if (setgid(gid)) |
| fprintf(stderr, "setgid: %s\n", strerror(errno)); |
| if (uid != -1) |
| if (setuid(uid)) |
| fprintf(stderr, "setuid: %s\n", strerror(errno)); |
| |
| /* |
| * sit there listening for connects, accept and service connections |
| * in a poll loop, without any forking |
| */ |
| |
| listen(sockfd, 5); |
| fprintf(stderr, " Listening on port %d\n", port); |
| |
| fds[0].fd = sockfd; |
| fds_count = 1; |
| fds[0].events = POLLIN; |
| |
| while (1) { |
| |
| n = poll(fds, fds_count, 50); |
| if (n < 0 || fds[0].revents & (POLLERR | POLLHUP)) { |
| fprintf(stderr, "Listen Socket dead\n"); |
| goto fatal; |
| } |
| if (n == 0) /* poll timeout */ |
| goto poll_out; |
| |
| if (fds[0].revents & POLLIN) { |
| |
| /* listen socket got an unencrypted connection... */ |
| |
| clilen = sizeof(cli_addr); |
| fd = accept(sockfd, |
| (struct sockaddr *)&cli_addr, |
| &clilen); |
| if (fd < 0) { |
| fprintf(stderr, "ERROR on accept"); |
| continue; |
| } |
| |
| if (fds_count >= MAX_CLIENTS) { |
| fprintf(stderr, "too busy"); |
| close(fd); |
| continue; |
| } |
| |
| wsi[fds_count] = malloc(sizeof(struct libwebsocket)); |
| if (!wsi[fds_count]) |
| return -1; |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (use_ssl) { |
| |
| wsi[fds_count]->ssl = SSL_new(ssl_ctx); |
| if (wsi[fds_count]->ssl == NULL) { |
| fprintf(stderr, "SSL_new failed: %s\n", |
| ERR_error_string(SSL_get_error( |
| wsi[fds_count]->ssl, 0), NULL)); |
| free(wsi[fds_count]); |
| continue; |
| } |
| |
| SSL_set_fd(wsi[fds_count]->ssl, fd); |
| |
| n = SSL_accept(wsi[fds_count]->ssl); |
| if (n != 1) { |
| /* |
| * browsers seem to probe with various |
| * ssl params which fail then retry |
| * and succeed |
| */ |
| debug("SSL_accept failed skt %u: %s\n", |
| fd, |
| ERR_error_string(SSL_get_error( |
| wsi[fds_count]->ssl, n), NULL)); |
| SSL_free(wsi[fds_count]->ssl); |
| free(wsi[fds_count]); |
| continue; |
| } |
| debug("accepted new SSL conn " |
| "port %u on fd=%d SSL ver %s\n", |
| ntohs(cli_addr.sin_port), fd, |
| SSL_get_version(wsi[fds_count]->ssl)); |
| |
| } else |
| #endif |
| debug("accepted new conn port %u on fd=%d\n", |
| ntohs(cli_addr.sin_port), fd); |
| |
| /* intialize the instance struct */ |
| |
| wsi[fds_count]->sock = fd; |
| wsi[fds_count]->state = WSI_STATE_HTTP; |
| wsi[fds_count]->name_buffer_pos = 0; |
| |
| for (n = 0; n < WSI_TOKEN_COUNT; n++) { |
| wsi[fds_count]->utf8_token[n].token = NULL; |
| wsi[fds_count]->utf8_token[n].token_len = 0; |
| } |
| |
| /* |
| * these can only be set once the protocol is known |
| * we set an unestablished connection's protocol pointer |
| * to the start of the supported list, so it can look |
| * for matching ones during the handshake |
| */ |
| wsi[fds_count]->protocol = protocols; |
| wsi[fds_count]->user_space = NULL; |
| |
| /* |
| * Default protocol is 76 |
| * After 76, there's a header specified to inform which |
| * draft the client wants, when that's seen we modify |
| * the individual connection's spec revision accordingly |
| */ |
| wsi[fds_count]->ietf_spec_revision = 76; |
| |
| fds[fds_count].events = POLLIN; |
| fds[fds_count++].fd = fd; |
| |
| /* |
| * make sure NO events are seen yet on this new socket |
| * (otherwise we inherit old fds[client].revents from |
| * previous socket there and die mysteriously! ) |
| */ |
| fds[client].revents = 0; |
| } |
| |
| /* check for activity on client sockets */ |
| |
| for (client = 1; client < fds_count; client++) { |
| |
| /* handle session socket closed */ |
| |
| if (fds[client].revents & (POLLERR | POLLHUP)) { |
| |
| debug("Session Socket %d %p (fd=%d) dead\n", |
| client, wsi[client], fds[client]); |
| |
| libwebsocket_close_and_free_session( |
| wsi[client]); |
| goto nuke_this; |
| } |
| |
| /* any incoming data ready? */ |
| |
| if (!(fds[client].revents & POLLIN)) |
| continue; |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| if (use_ssl) |
| n = SSL_read(wsi[client]->ssl, buf, sizeof buf); |
| else |
| #endif |
| n = recv(fds[client].fd, buf, sizeof(buf), 0); |
| |
| if (n < 0) { |
| fprintf(stderr, "Socket read returned %d\n", n); |
| continue; |
| } |
| if (!n) { |
| // fprintf(stderr, "POLLIN with 0 len waiting\n"); |
| libwebsocket_close_and_free_session( |
| wsi[client]); |
| goto nuke_this; |
| } |
| |
| /* service incoming data */ |
| |
| if (libwebsocket_read(wsi[client], buf, n) >= 0) |
| continue; |
| |
| /* |
| * it closed and nuked wsi[client], so remove the |
| * socket handle and wsi from our service list |
| */ |
| nuke_this: |
| |
| debug("nuking wsi %p, fsd_count = %d\n", |
| wsi[client], fds_count - 1); |
| |
| fds_count--; |
| for (n = client; n < fds_count; n++) { |
| fds[n] = fds[n + 1]; |
| wsi[n] = wsi[n + 1]; |
| } |
| break; |
| } |
| |
| poll_out: |
| for (client = 1; client < fds_count; client++) { |
| |
| if (wsi[client]->state != WSI_STATE_ESTABLISHED) |
| continue; |
| |
| wsi[client]->protocol->callback(wsi[client], |
| LWS_CALLBACK_SEND, |
| wsi[client]->user_space, |
| NULL, 0); |
| } |
| |
| continue; |
| } |
| |
| fatal: |
| /* listening socket */ |
| close(fds[0].fd); |
| for (client = 1; client < fds_count; client++) |
| libwebsocket_close_and_free_session(wsi[client]); |
| |
| #ifdef LWS_OPENSSL_SUPPORT |
| SSL_CTX_free(ssl_ctx); |
| #endif |
| kill(0, SIGTERM); |
| |
| return 0; |
| } |
| |
| |