136 lines
3.3 KiB
C
136 lines
3.3 KiB
C
/*
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* Copyright (C) 2022 Amazon.com Inc. or its affiliates. All rights reserved.
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* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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*/
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#include <arpa/inet.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <unistd.h>
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#ifdef __wasi__
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#include <wasi_socket_ext.h>
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#endif
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static void
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init_sockaddr_inet(struct sockaddr_in *addr)
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{
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addr->sin_family = AF_INET;
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addr->sin_port = htons(1234);
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}
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static void
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init_sockaddr_inet6(struct sockaddr_in6 *addr)
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{
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addr->sin6_family = AF_INET6;
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addr->sin6_port = htons(1234);
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}
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static int
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get_ip_addr_type(char *addr, char *buf)
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{
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if (inet_pton(AF_INET6, addr, buf)) {
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return AF_INET6;
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}
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if (inet_pton(AF_INET, addr, buf)) {
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return AF_INET;
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}
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return -1;
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}
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static int
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is_valid_addr_type(int addr_type)
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{
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return !(addr_type == -1
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|| (addr_type != AF_INET && addr_type != AF_INET6));
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}
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int
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main(int argc, char *argv[])
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{
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struct ipv6_mreq ipv6_group;
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struct ip_mreq ipv4_group;
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int sd;
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int datalen;
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char databuf[1024] = { 0 };
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char multicast_addr_buffer[16];
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struct sockaddr_storage local_address = { 0 };
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int addr_type = -1;
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int read_result;
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int bool_opt = 1;
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if (argc < 2) {
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printf("Usage is <Multicast IP>\n");
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return EXIT_FAILURE;
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}
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addr_type = get_ip_addr_type(argv[1], multicast_addr_buffer);
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if (!is_valid_addr_type(addr_type)) {
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printf("Not a valid ipv4 or ipv6 address\n");
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return EXIT_FAILURE;
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}
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if ((sd = socket(addr_type, SOCK_DGRAM, 0)) == -1) {
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perror("Failed opening socket");
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return EXIT_FAILURE;
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}
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if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &bool_opt, sizeof(bool_opt))
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== -1) {
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perror("Failed setting SO_REUSEADDR");
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goto fail;
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}
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if (addr_type == AF_INET) {
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init_sockaddr_inet((struct sockaddr_in *)&local_address);
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memcpy(&(ipv4_group.imr_multiaddr), multicast_addr_buffer, 4);
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ipv4_group.imr_interface.s_addr = htonl(INADDR_ANY);
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if (setsockopt(sd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &ipv4_group,
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sizeof(ipv4_group))
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== -1) {
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perror("Failed joining IPv4 multicast group");
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goto fail;
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}
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}
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else {
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init_sockaddr_inet6((struct sockaddr_in6 *)&local_address);
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memcpy(&(ipv6_group.ipv6mr_multiaddr), multicast_addr_buffer, 16);
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ipv6_group.ipv6mr_interface = 0;
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if (setsockopt(sd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &ipv6_group,
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sizeof(ipv6_group))
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== -1) {
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perror("Failed joining IPv6 multicast group");
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goto fail;
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}
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}
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if (bind(sd, (struct sockaddr *)&local_address, sizeof(local_address))
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== -1) {
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perror("Failed binding socket");
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goto fail;
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}
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printf("Joined multicast group. Waiting for datagram...\n");
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datalen = sizeof(databuf) - 1;
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read_result = read(sd, databuf, datalen);
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if (read_result < 0) {
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perror("Failed binding socket");
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goto fail;
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}
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printf("Reading datagram message...OK.\n");
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printf("The message from multicast server is: \"%s\"\n", databuf);
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close(sd);
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return EXIT_SUCCESS;
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fail:
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close(sd);
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return EXIT_FAILURE;
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}
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