diff --git a/examples/mcast_udp_server/Makefile b/examples/mcast_udp_server/Makefile new file mode 100644 index 0000000000000000000000000000000000000000..dea055616178ae93997eb659ebda703c023e34ef --- /dev/null +++ b/examples/mcast_udp_server/Makefile @@ -0,0 +1,10 @@ +PROG = mcast_udp_server + +ifeq ($(OS),Windows_NT) +all: + @echo "This example is not yet supported on $(OS)" +else +include ../examples.mk +endif + +clean: diff --git a/examples/mcast_udp_server/mcast_udp_server.c b/examples/mcast_udp_server/mcast_udp_server.c new file mode 100644 index 0000000000000000000000000000000000000000..4c0b2c9fe90c99a83fad575badd8d9a1fb0ae5e1 --- /dev/null +++ b/examples/mcast_udp_server/mcast_udp_server.c @@ -0,0 +1,100 @@ +// Copyright (c) 2016 Cesanta Software Limited +// All rights reserved +// +// This software is dual-licensed: you can redistribute it and/or modify +// it under the terms of the GNU General Public License version 2 as +// published by the Free Software Foundation. For the terms of this +// license, see <http://www.gnu.org/licenses/>. +// +// You are free to use this software under the terms of the GNU General +// Public License, but WITHOUT ANY WARRANTY; without even the implied +// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. +// See the GNU General Public License for more details. +// +// Alternatively, you can license this software under a commercial +// license, as set out in <https://www.cesanta.com/license>. +// +// This demo shows how to configure a mongoose UDP connection to receive +// multicast traffic. + +#include <netinet/in.h> + +#include "mongoose.h" + +#define MCAST_GROUP "224.0.22.1" +#define DEFAULT_PORT "1234" + +static void ev_handler(struct mg_connection *nc, int ev, void *p) { + struct mbuf *io = &nc->recv_mbuf; + (void) p; + switch (ev) { + case MG_EV_RECV: + printf("Received (%zu bytes): '%.*s'\n", io->len, (int) io->len, io->buf); + mbuf_remove(io, io->len); + nc->flags |= MG_F_SEND_AND_CLOSE; + break; + default: + break; + } +} + +void usage(char **argv) { + fprintf(stderr, "%s: -i address_of_mcast_interface [ -g %s ] [ -p %s ]\n", + argv[0], MCAST_GROUP, DEFAULT_PORT); + exit(1); +} + +int main(int argc, char **argv) { + struct mg_mgr mgr; + const char *port = "1234"; + struct mg_connection *nc; + struct ip_mreq group; + const char *interface = NULL; + const char *mcast_group = MCAST_GROUP; + int i; + + /* Parse command line arguments */ + for (i = 1; i < argc; i++) { + // IP address of the interface where to join a multicast group. + if (strcmp(argv[i], "-i") == 0) { + interface = argv[++i]; + } else if (strcmp(argv[i], "-g") == 0) { + mcast_group = argv[++i]; + } else if (strcmp(argv[i], "-p") == 0) { + port = argv[++i]; + } + } + + if (interface == NULL) { + usage(argv); + } + + mg_mgr_init(&mgr, NULL); + { + char listen[256]; + sprintf(listen, "udp://%s", port); + nc = mg_bind(&mgr, listen, ev_handler); + } + + if (nc == NULL) { + perror("cannot bind\n"); + exit(1); + } + + group.imr_multiaddr.s_addr = inet_addr(mcast_group); + group.imr_interface.s_addr = inet_addr(interface); + if (setsockopt(nc->sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char *) &group, + sizeof(group)) < 0) { + perror("Adding multicast group error"); + exit(1); + } + + printf("Starting mcast server on port %s listening to group %s\n", port, + mcast_group); + for (;;) { + mg_mgr_poll(&mgr, 1000); + } + mg_mgr_free(&mgr); + + return 0; +}