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/*
** broadcaster.c -- a datagram "client" like talker.c, except
** this one can broadcast
*/
#include "common.h"
int main(int argc, char **argv)
{
int fd;
struct sockaddr_in6 addr;
int broadcast = 1;
/* assemble packet, parse cmd line */
if (argc < 3 || argc > 4) {
fprintf(stderr, "usage: %s interface task [message]\n", argv[0]);
exit(1);
}
char buf[MAXBUFLEN],
*task = argv[2],
*message = (argc == 4) ? argv[3] : "";
int task_len = strlen(task),
total_len = task_len + 1 + strlen(message);
if (total_len > MAXBUFLEN) {
fprintf(stderr,"payload to long: max %d bytes, was %d\n", MAXBUFLEN, total_len);
exit(1);
}
strcpy(buf, task);
buf[task_len] = 0;
strcpy(buf + 1 + task_len, message);
/* setup socket */
if ((fd = socket(AF_INET6, SOCK_DGRAM, 0)) == -1) {
perror("socket");
exit(1);
}
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(SERVERPORT);
addr.sin6_flowinfo = 0;
inet_pton(AF_INET6, "ff02::1", &(addr.sin6_addr));
if ((addr.sin6_scope_id = if_nametoindex(argv[1])) == 0) {
fprintf(stderr, "interface not found\n");
exit(1);
}
/* send packet */
if (sendto(fd, buf, total_len, 0, (struct sockaddr *)&addr, sizeof addr) == -1) {
perror("sendto");
exit(1);
}
return 0;
}
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