2 * libwebsockets - small server side websockets and web server implementation
4 * Copyright (C) 2010 Andy Green <andy@warmcat.com>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation:
9 * version 2.1 of the License.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
22 #include "private-libwebsockets.h"
25 libwebsocket_close_and_free_session(struct libwebsocket *wsi)
28 unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + 2 +
29 LWS_SEND_BUFFER_POST_PADDING];
31 if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
36 if (n == WSI_STATE_DEAD_SOCKET)
40 * signal we are closing, libsocket_write will
41 * add any necessary version-specific stuff. If the write fails,
42 * no worries we are closing anyway. If we didn't initiate this
43 * close, then our state has been changed to
44 * WSI_STATE_RETURNED_CLOSE_ALREADY and we can skip this
47 if (n == WSI_STATE_ESTABLISHED)
48 libwebsocket_write(wsi, &buf[LWS_SEND_BUFFER_PRE_PADDING], 0,
51 wsi->state = WSI_STATE_DEAD_SOCKET;
53 if (wsi->protocol->callback && n == WSI_STATE_ESTABLISHED)
54 wsi->protocol->callback(wsi, LWS_CALLBACK_CLOSED,
55 wsi->user_space, NULL, 0);
57 for (n = 0; n < WSI_TOKEN_COUNT; n++)
58 if (wsi->utf8_token[n].token)
59 free(wsi->utf8_token[n].token);
61 /* fprintf(stderr, "closing fd=%d\n", wsi->sock); */
63 #ifdef LWS_OPENSSL_SUPPORT
65 n = SSL_get_fd(wsi->ssl);
66 SSL_shutdown(wsi->ssl);
71 shutdown(wsi->sock, SHUT_RDWR);
73 #ifdef LWS_OPENSSL_SUPPORT
77 free(wsi->user_space);
83 libwebsocket_poll_connections(struct libwebsocket_context *this)
85 unsigned char buf[LWS_SEND_BUFFER_PRE_PADDING + MAX_BROADCAST_PAYLOAD +
86 LWS_SEND_BUFFER_POST_PADDING];
87 int client = this->count_protocols + 1;
88 struct libwebsocket *wsi;
92 /* check for activity on client sockets */
94 for (; client < this->fds_count; client++) {
96 /* handle session socket closed */
98 if (this->fds[client].revents & (POLLERR | POLLHUP)) {
100 debug("Session Socket %d %p (fd=%d) dead\n",
101 client, (void *)this->wsi[client],
102 this->fds[client].fd);
104 libwebsocket_close_and_free_session(this->wsi[client]);
108 /* the guy requested a callback when it was OK to write */
110 if ((unsigned long)this->wsi[client] > LWS_MAX_PROTOCOLS &&
111 this->fds[client].revents & POLLOUT) {
113 this->fds[client].events &= ~POLLOUT;
115 this->wsi[client]->protocol->callback(this->wsi[client],
116 LWS_CALLBACK_CLIENT_WRITEABLE,
117 this->wsi[client]->user_space,
121 /* any incoming data ready? */
123 if (!(this->fds[client].revents & POLLIN))
128 if ((unsigned long)this->wsi[client] < LWS_MAX_PROTOCOLS) {
130 /* get the issued broadcast payload from the socket */
132 len = read(this->fds[client].fd,
133 buf + LWS_SEND_BUFFER_PRE_PADDING,
134 MAX_BROADCAST_PAYLOAD);
138 "Error reading broadcast payload\n");
142 /* broadcast it to all guys with this protocol index */
144 for (n = this->count_protocols + 1;
145 n < this->fds_count; n++) {
149 if ((unsigned long)wsi < LWS_MAX_PROTOCOLS)
153 * never broadcast to non-established
157 if (wsi->state != WSI_STATE_ESTABLISHED)
160 /* only to clients connected to us */
162 if (wsi->mode != LWS_CONNMODE_WS_SERVING)
166 * only broadcast to connections using
167 * the requested protocol
170 if (wsi->protocol->protocol_index !=
171 (int)(unsigned long)this->wsi[client])
174 /* broadcast it to this connection */
176 wsi->protocol->callback(wsi,
177 LWS_CALLBACK_BROADCAST,
179 buf + LWS_SEND_BUFFER_PRE_PADDING, len);
185 #ifdef LWS_OPENSSL_SUPPORT
186 if (this->wsi[client]->ssl)
187 n = SSL_read(this->wsi[client]->ssl, buf, sizeof buf);
190 n = recv(this->fds[client].fd, buf, sizeof buf, 0);
193 fprintf(stderr, "Socket read returned %d\n", n);
197 libwebsocket_close_and_free_session(this->wsi[client]);
201 /* service incoming data */
203 n = libwebsocket_read(this->wsi[client], buf, n);
207 * it closed and nuked wsi[client], so remove the
208 * socket handle and wsi from our service list
212 debug("nuking wsi %p, fsd_count = %d\n",
213 (void *)this->wsi[client], this->fds_count - 1);
216 for (n = client; n < this->fds_count; n++) {
217 this->fds[n] = this->fds[n + 1];
218 this->wsi[n] = this->wsi[n + 1];
229 * libwebsocket_context_destroy() - Destroy the websocket context
230 * @this: Websocket context
232 * This function closes any active connections and then frees the
233 * context. After calling this, any further use of the context is
237 libwebsocket_context_destroy(struct libwebsocket_context *this)
241 /* close listening skt and per-protocol broadcast sockets */
242 for (client = this->count_protocols + 1; client < this->fds_count; client++)
243 switch (this->wsi[client]->mode) {
244 case LWS_CONNMODE_WS_SERVING:
245 libwebsocket_close_and_free_session(this->wsi[client]);
247 case LWS_CONNMODE_WS_CLIENT:
248 libwebsocket_client_close(this->wsi[client]);
252 #ifdef LWS_OPENSSL_SUPPORT
253 if (this && this->ssl_ctx)
254 SSL_CTX_free(this->ssl_ctx);
255 if (this && this->ssl_client_ctx)
256 SSL_CTX_free(this->ssl_client_ctx);
264 * libwebsocket_service() - Service any pending websocket activity
265 * @this: Websocket context
266 * @timeout_ms: Timeout for poll; 0 means return immediately if nothing needed
267 * service otherwise block and service immediately, returning
268 * after the timeout if nothing needed service.
270 * This function deals with any pending websocket traffic, for three
271 * kinds of event. It handles these events on both server and client
272 * types of connection the same.
274 * 1) Accept new connections to our context's server
276 * 2) Perform pending broadcast writes initiated from other forked
277 * processes (effectively serializing asynchronous broadcasts)
279 * 3) Call the receive callback for incoming frame data received by
280 * server or client connections.
282 * You need to call this service function periodically to all the above
283 * functions to happen; if your application is single-threaded you can
284 * just call it in your main event loop.
286 * Alternatively you can fork a new process that asynchronously handles
287 * calling this service in a loop. In that case you are happy if this
288 * call blocks your thread until it needs to take care of something and
289 * would call it with a large nonzero timeout. Your loop then takes no
290 * CPU while there is nothing happening.
292 * If you are calling it in a single-threaded app, you don't want it to
293 * wait around blocking other things in your loop from happening, so you
294 * would call it with a timeout_ms of 0, so it returns immediately if
295 * nothing is pending, or as soon as it services whatever was pending.
300 libwebsocket_service(struct libwebsocket_context *this, int timeout_ms)
305 struct sockaddr_in cli_addr;
308 /* stay dead once we are dead */
313 /* don't check listen socket if we are not listening */
315 if (this->listen_port)
316 n = poll(this->fds, this->fds_count, timeout_ms);
318 n = poll(&this->fds[1], this->fds_count - 1, timeout_ms);
321 if (n < 0 || this->fds[0].revents & (POLLERR | POLLHUP)) {
323 fprintf(stderr, "Listen Socket dead\n");
327 if (n == 0) /* poll timeout */
330 /* handle accept on listening socket? */
332 for (client = 0; client < this->count_protocols + 1; client++) {
334 if (!this->fds[client].revents & POLLIN)
337 /* listen socket got an unencrypted connection... */
339 clilen = sizeof(cli_addr);
340 fd = accept(this->fds[client].fd,
341 (struct sockaddr *)&cli_addr, &clilen);
343 fprintf(stderr, "ERROR on accept");
347 if (this->fds_count >= MAX_CLIENTS) {
348 fprintf(stderr, "too busy");
355 * accepting a connection to broadcast socket
356 * set wsi to be protocol index not pointer
359 this->wsi[this->fds_count] =
360 (struct libwebsocket *)(long)(client - 1);
365 /* accepting connection to main listener */
367 this->wsi[this->fds_count] =
368 malloc(sizeof(struct libwebsocket));
369 if (!this->wsi[this->fds_count]) {
370 fprintf(stderr, "Out of memory for new connection\n");
374 #ifdef LWS_OPENSSL_SUPPORT
375 this->wsi[this->fds_count]->ssl = NULL;
376 this->ssl_ctx = NULL;
380 this->wsi[this->fds_count]->ssl =
381 SSL_new(this->ssl_ctx);
382 if (this->wsi[this->fds_count]->ssl == NULL) {
383 fprintf(stderr, "SSL_new failed: %s\n",
384 ERR_error_string(SSL_get_error(
385 this->wsi[this->fds_count]->ssl, 0),
387 free(this->wsi[this->fds_count]);
391 SSL_set_fd(this->wsi[this->fds_count]->ssl, fd);
393 n = SSL_accept(this->wsi[this->fds_count]->ssl);
396 * browsers seem to probe with various
397 * ssl params which fail then retry
400 debug("SSL_accept failed skt %u: %s\n",
402 ERR_error_string(SSL_get_error(
403 this->wsi[this->fds_count]->ssl,
406 this->wsi[this->fds_count]->ssl);
407 free(this->wsi[this->fds_count]);
410 debug("accepted new SSL conn "
411 "port %u on fd=%d SSL ver %s\n",
412 ntohs(cli_addr.sin_port), fd,
413 SSL_get_version(this->wsi[
414 this->fds_count]->ssl));
418 debug("accepted new conn port %u on fd=%d\n",
419 ntohs(cli_addr.sin_port), fd);
421 /* intialize the instance struct */
423 this->wsi[this->fds_count]->sock = fd;
424 this->wsi[this->fds_count]->state = WSI_STATE_HTTP;
425 this->wsi[this->fds_count]->name_buffer_pos = 0;
426 this->wsi[this->fds_count]->mode = LWS_CONNMODE_WS_SERVING;
428 for (n = 0; n < WSI_TOKEN_COUNT; n++) {
429 this->wsi[this->fds_count]->
430 utf8_token[n].token = NULL;
431 this->wsi[this->fds_count]->
432 utf8_token[n].token_len = 0;
436 * these can only be set once the protocol is known
437 * we set an unestablished connection's protocol pointer
438 * to the start of the supported list, so it can look
439 * for matching ones during the handshake
441 this->wsi[this->fds_count]->protocol = this->protocols;
442 this->wsi[this->fds_count]->user_space = NULL;
445 * Default protocol is 76 / 00
446 * After 76, there's a header specified to inform which
447 * draft the client wants, when that's seen we modify
448 * the individual connection's spec revision accordingly
450 this->wsi[this->fds_count]->ietf_spec_revision = 0;
455 * make sure NO events are seen yet on this new socket
456 * (otherwise we inherit old fds[client].revents from
457 * previous socket there and die mysteriously! )
459 this->fds[this->fds_count].revents = 0;
461 this->fds[this->fds_count].events = POLLIN;
462 this->fds[this->fds_count++].fd = fd;
466 /* service anything incoming on websocket connection */
468 libwebsocket_poll_connections(this);
470 /* this round is done */
476 /* inform caller we are dead */
482 * libwebsocket_callback_on_writable() - Request a callback when this socket
483 * becomes able to be written to without
486 * @wsi: Websocket connection instance to get callback for
490 libwebsocket_callback_on_writable(struct libwebsocket *wsi)
492 struct libwebsocket_context *this = wsi->protocol->owning_server;
495 for (n = this->count_protocols + 1; n < this->fds_count; n++)
496 if (this->wsi[n] == wsi) {
497 this->fds[n].events |= POLLOUT;
501 fprintf(stderr, "libwebsocket_callback_on_writable "
502 "didn't find socket\n");
507 * libwebsocket_callback_on_writable_all_protocol() - Request a callback for
508 * all connections using the given protocol when it
509 * becomes possible to write to each socket without
512 * @protocol: Protocol whose connections will get callbacks
516 libwebsocket_callback_on_writable_all_protocol(
517 const struct libwebsocket_protocols *protocol)
519 struct libwebsocket_context *this = protocol->owning_server;
522 for (n = this->count_protocols + 1; n < this->fds_count; n++)
523 if ((unsigned long)this->wsi[n] > LWS_MAX_PROTOCOLS)
524 if (this->wsi[n]->protocol == protocol)
525 this->fds[n].events |= POLLOUT;
532 * libwebsocket_get_socket_fd() - returns the socket file descriptor
534 * You will not need this unless you are doing something special
536 * @wsi: Websocket connection instance
540 libwebsocket_get_socket_fd(struct libwebsocket *wsi)
546 * libwebsocket_rx_flow_control() - Enable and disable socket servicing for
549 * If the output side of a server process becomes choked, this allows flow
550 * control for the input side.
552 * @wsi: Websocket connection instance to get callback for
553 * @enable: 0 = disable read servicing for this connection, 1 = enable
557 libwebsocket_rx_flow_control(struct libwebsocket *wsi, int enable)
559 struct libwebsocket_context *this = wsi->protocol->owning_server;
562 for (n = this->count_protocols + 1; n < this->fds_count; n++)
563 if (this->wsi[n] == wsi) {
565 this->fds[n].events |= POLLIN;
567 this->fds[n].events &= ~POLLIN;
572 fprintf(stderr, "libwebsocket_callback_on_writable "
573 "unable to find socket\n");
578 * libwebsocket_canonical_hostname() - returns this host's hostname
580 * This is typically used by client code to fill in the host parameter
581 * when making a client connection. You can only call it after the context
584 * @this: Websocket context
589 libwebsocket_canonical_hostname(struct libwebsocket_context *this)
591 return (const char *)this->canonical_hostname;
595 static void sigpipe_handler(int x)
601 * libwebsocket_create_context() - Create the websocket handler
602 * @port: Port to listen on... you can use 0 to suppress listening on
603 * any port, that's what you want if you are not running a
604 * websocket server at all but just using it as a client
605 * @protocols: Array of structures listing supported protocols and a protocol-
606 * specific callback for each one. The list is ended with an
607 * entry that has a NULL callback pointer.
608 * It's not const because we write the owning_server member
609 * @ssl_cert_filepath: If libwebsockets was compiled to use ssl, and you want
610 * to listen using SSL, set to the filepath to fetch the
611 * server cert from, otherwise NULL for unencrypted
612 * @ssl_private_key_filepath: filepath to private key if wanting SSL mode,
614 * @gid: group id to change to after setting listen socket, or -1.
615 * @uid: user id to change to after setting listen socket, or -1.
616 * @options: 0, or LWS_SERVER_OPTION_DEFEAT_CLIENT_MASK
618 * This function creates the listening socket and takes care
619 * of all initialization in one step.
621 * After initialization, it returns a struct libwebsocket_context * that
622 * represents this server. After calling, user code needs to take care
623 * of calling libwebsocket_service() with the context pointer to get the
624 * server's sockets serviced. This can be done in the same process context
625 * or a forked process, or another thread,
627 * The protocol callback functions are called for a handful of events
628 * including http requests coming in, websocket connections becoming
629 * established, and data arriving; it's also called periodically to allow
630 * async transmission.
632 * HTTP requests are sent always to the FIRST protocol in @protocol, since
633 * at that time websocket protocol has not been negotiated. Other
634 * protocols after the first one never see any HTTP callack activity.
636 * The server created is a simple http server by default; part of the
637 * websocket standard is upgrading this http connection to a websocket one.
639 * This allows the same server to provide files like scripts and favicon /
640 * images or whatever over http and dynamic data over websockets all in
641 * one place; they're all handled in the user callback.
644 struct libwebsocket_context *
645 libwebsocket_create_context(int port,
646 struct libwebsocket_protocols *protocols,
647 const char *ssl_cert_filepath,
648 const char *ssl_private_key_filepath,
649 int gid, int uid, unsigned int options)
654 struct sockaddr_in serv_addr, cli_addr;
656 struct libwebsocket_context *this = NULL;
662 #ifdef LWS_OPENSSL_SUPPORT
664 char ssl_err_buf[512];
667 this = malloc(sizeof(struct libwebsocket_context));
669 fprintf(stderr, "No memory for websocket context\n");
672 this->protocols = protocols;
673 this->listen_port = port;
674 this->http_proxy_port = 0;
675 this->http_proxy_address[0] = '\0';
676 this->options = options;
678 /* find canonical hostname */
680 hostname[(sizeof hostname) - 1] = '\0';
681 gethostname(hostname, (sizeof hostname) - 1);
682 he = gethostbyname(hostname);
683 strncpy(this->canonical_hostname, he->h_name,
684 sizeof this->canonical_hostname - 1);
685 this->canonical_hostname[sizeof this->canonical_hostname - 1] = '\0';
686 fprintf(stderr, " canonical hostname = '%s'\n",
687 this->canonical_hostname);
689 /* split the proxy ads:port if given */
691 p = getenv("http_proxy");
693 strncpy(this->http_proxy_address, p,
694 sizeof this->http_proxy_address - 1);
695 this->http_proxy_address[
696 sizeof this->http_proxy_address - 1] = '\0';
698 p = strchr(this->http_proxy_address, ':');
700 fprintf(stderr, "http_proxy needs to be ads:port\n");
704 this->http_proxy_port = atoi(p + 1);
706 fprintf(stderr, "Using proxy %s:%u\n",
707 this->http_proxy_address,
708 this->http_proxy_port);
713 #ifdef LWS_OPENSSL_SUPPORT
714 this->use_ssl = ssl_cert_filepath != NULL &&
715 ssl_private_key_filepath != NULL;
717 fprintf(stderr, " Compiled with SSL support, "
720 fprintf(stderr, " Compiled with SSL support, "
724 if (ssl_cert_filepath != NULL &&
725 ssl_private_key_filepath != NULL) {
726 fprintf(stderr, " Not compiled for OpenSSl support!\n");
729 fprintf(stderr, " Compiled without SSL support, "
730 "serving unencrypted\n");
736 signal(SIGPIPE, sigpipe_handler);
739 #ifdef LWS_OPENSSL_SUPPORT
741 /* basic openssl init */
745 OpenSSL_add_all_algorithms();
746 SSL_load_error_strings();
749 * Firefox insists on SSLv23 not SSLv3
750 * Konq disables SSLv2 by default now, SSLv23 works
753 method = (SSL_METHOD *)SSLv23_server_method();
755 fprintf(stderr, "problem creating ssl method: %s\n",
756 ERR_error_string(ERR_get_error(), ssl_err_buf));
759 this->ssl_ctx = SSL_CTX_new(method); /* create context */
760 if (!this->ssl_ctx) {
761 fprintf(stderr, "problem creating ssl context: %s\n",
762 ERR_error_string(ERR_get_error(), ssl_err_buf));
768 method = (SSL_METHOD *)SSLv23_client_method();
770 fprintf(stderr, "problem creating ssl method: %s\n",
771 ERR_error_string(ERR_get_error(), ssl_err_buf));
774 this->ssl_client_ctx = SSL_CTX_new(method); /* create context */
775 if (!this->ssl_client_ctx) {
776 fprintf(stderr, "problem creating ssl context: %s\n",
777 ERR_error_string(ERR_get_error(), ssl_err_buf));
782 /* openssl init for cert verification (used with client sockets) */
784 if (!SSL_CTX_load_verify_locations(this->ssl_client_ctx, NULL,
785 LWS_OPENSSL_CLIENT_CERTS)) {
786 fprintf(stderr, "Unable to load SSL Client certs from %s "
787 "(set by --with-client-cert-dir= in configure) -- "
788 " client ssl isn't going to work",
789 LWS_OPENSSL_CLIENT_CERTS);
794 /* openssl init for server sockets */
796 /* set the local certificate from CertFile */
797 n = SSL_CTX_use_certificate_file(this->ssl_ctx,
798 ssl_cert_filepath, SSL_FILETYPE_PEM);
800 fprintf(stderr, "problem getting cert '%s': %s\n",
802 ERR_error_string(ERR_get_error(), ssl_err_buf));
805 /* set the private key from KeyFile */
806 if (SSL_CTX_use_PrivateKey_file(this->ssl_ctx,
807 ssl_private_key_filepath,
808 SSL_FILETYPE_PEM) != 1) {
809 fprintf(stderr, "ssl problem getting key '%s': %s\n",
810 ssl_private_key_filepath,
811 ERR_error_string(ERR_get_error(), ssl_err_buf));
814 /* verify private key */
815 if (!SSL_CTX_check_private_key(this->ssl_ctx)) {
816 fprintf(stderr, "Private SSL key doesn't match cert\n");
820 /* SSL is happy and has a cert it's content with */
826 if (lws_b64_selftest())
829 /* set up our external listening socket we serve on */
833 sockfd = socket(AF_INET, SOCK_STREAM, 0);
835 fprintf(stderr, "ERROR opening socket");
839 /* allow us to restart even if old sockets in TIME_WAIT */
840 setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
842 bzero((char *) &serv_addr, sizeof(serv_addr));
843 serv_addr.sin_family = AF_INET;
844 serv_addr.sin_addr.s_addr = INADDR_ANY;
845 serv_addr.sin_port = htons(port);
847 n = bind(sockfd, (struct sockaddr *) &serv_addr,
850 fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
856 /* drop any root privs for this process */
860 fprintf(stderr, "setgid: %s\n", strerror(errno));
863 fprintf(stderr, "setuid: %s\n", strerror(errno));
866 * prepare the poll() fd array... it's like this
868 * [0] = external listening socket
869 * [1 .. this->count_protocols] = per-protocol broadcast sockets
870 * [this->count_protocols + 1 ... this->fds_count-1] = connection skts
874 this->fds[0].fd = sockfd;
875 this->fds[0].events = POLLIN;
876 this->count_protocols = 0;
880 fprintf(stderr, " Listening on port %d\n", port);
883 /* set up our internal broadcast trigger sockets per-protocol */
885 for (; protocols[this->count_protocols].callback;
886 this->count_protocols++) {
887 protocols[this->count_protocols].owning_server = this;
888 protocols[this->count_protocols].protocol_index =
889 this->count_protocols;
891 fd = socket(AF_INET, SOCK_STREAM, 0);
893 fprintf(stderr, "ERROR opening socket");
897 /* allow us to restart even if old sockets in TIME_WAIT */
898 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
900 bzero((char *) &serv_addr, sizeof(serv_addr));
901 serv_addr.sin_family = AF_INET;
902 serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
903 serv_addr.sin_port = 0; /* pick the port for us */
905 n = bind(fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr));
907 fprintf(stderr, "ERROR on binding to port %d (%d %d)\n",
912 slen = sizeof cli_addr;
913 n = getsockname(fd, (struct sockaddr *)&cli_addr, &slen);
915 fprintf(stderr, "getsockname failed\n");
918 protocols[this->count_protocols].broadcast_socket_port =
919 ntohs(cli_addr.sin_port);
922 debug(" Protocol %s broadcast socket %d\n",
923 protocols[this->count_protocols].name,
924 ntohs(cli_addr.sin_port));
926 this->fds[this->fds_count].fd = fd;
927 this->fds[this->fds_count].events = POLLIN;
928 /* wsi only exists for connections, not broadcast listener */
929 this->wsi[this->fds_count] = NULL;
940 * libwebsockets_fork_service_loop() - Optional helper function forks off
941 * a process for the websocket server loop.
942 * You don't have to use this but if not, you
943 * have to make sure you are calling
944 * libwebsocket_service periodically to service
945 * the websocket traffic
946 * @this: server context returned by creation function
950 libwebsockets_fork_service_loop(struct libwebsocket_context *this)
954 struct sockaddr_in cli_addr;
963 /* main process context */
965 for (client = 1; client < this->count_protocols + 1; client++) {
966 fd = socket(AF_INET, SOCK_STREAM, 0);
968 fprintf(stderr, "Unable to create socket\n");
971 cli_addr.sin_family = AF_INET;
972 cli_addr.sin_port = htons(
973 this->protocols[client - 1].broadcast_socket_port);
974 cli_addr.sin_addr.s_addr = inet_addr("127.0.0.1");
975 n = connect(fd, (struct sockaddr *)&cli_addr,
978 fprintf(stderr, "Unable to connect to "
979 "broadcast socket %d, %s\n",
980 client, strerror(errno));
984 this->protocols[client - 1].broadcast_socket_user_fd =
992 /* we want a SIGHUP when our parent goes down */
993 prctl(PR_SET_PDEATHSIG, SIGHUP);
995 /* in this forked process, sit and service websocket connections */
998 if (libwebsocket_service(this, 1000))
1007 * libwebsockets_get_protocol() - Returns a protocol pointer from a websocket
1009 * @wsi: pointer to struct websocket you want to know the protocol of
1012 * This is useful to get the protocol to broadcast back to from inside
1016 const struct libwebsocket_protocols *
1017 libwebsockets_get_protocol(struct libwebsocket *wsi)
1019 return wsi->protocol;
1023 * libwebsockets_broadcast() - Sends a buffer to the callback for all active
1024 * connections of the given protocol.
1025 * @protocol: pointer to the protocol you will broadcast to all members of
1026 * @buf: buffer containing the data to be broadcase. NOTE: this has to be
1027 * allocated with LWS_SEND_BUFFER_PRE_PADDING valid bytes before
1028 * the pointer and LWS_SEND_BUFFER_POST_PADDING afterwards in the
1029 * case you are calling this function from callback context.
1030 * @len: length of payload data in buf, starting from buf.
1032 * This function allows bulk sending of a packet to every connection using
1033 * the given protocol. It does not send the data directly; instead it calls
1034 * the callback with a reason type of LWS_CALLBACK_BROADCAST. If the callback
1035 * wants to actually send the data for that connection, the callback itself
1036 * should call libwebsocket_write().
1038 * libwebsockets_broadcast() can be called from another fork context without
1039 * having to take any care about data visibility between the processes, it'll
1045 libwebsockets_broadcast(const struct libwebsocket_protocols *protocol,
1046 unsigned char *buf, size_t len)
1048 struct libwebsocket_context *this = protocol->owning_server;
1051 if (!protocol->broadcast_socket_user_fd) {
1053 * We are either running unforked / flat, or we are being
1054 * called from poll thread context
1055 * eg, from a callback. In that case don't use sockets for
1056 * broadcast IPC (since we can't open a socket connection to
1057 * a socket listening on our own thread) but directly do the
1060 * Locking is not needed because we are by definition being
1061 * called in the poll thread context and are serialized.
1064 for (n = this->count_protocols + 1; n < this->fds_count; n++) {
1066 if ((unsigned long)this->wsi[n] < LWS_MAX_PROTOCOLS)
1069 /* never broadcast to non-established connection */
1070 if (this->wsi[n]->state != WSI_STATE_ESTABLISHED)
1073 /* only broadcast to guys using requested protocol */
1074 if (this->wsi[n]->protocol != protocol)
1077 this->wsi[n]->protocol->callback(this->wsi[n],
1078 LWS_CALLBACK_BROADCAST,
1079 this->wsi[n]->user_space,
1087 * We're being called from a different process context than the server
1088 * loop. Instead of broadcasting directly, we send our
1089 * payload on a socket to do the IPC; the server process will serialize
1090 * the broadcast action in its main poll() loop.
1092 * There's one broadcast socket listening for each protocol supported
1093 * set up when the websocket server initializes
1096 n = send(protocol->broadcast_socket_user_fd, buf, len, MSG_NOSIGNAL);