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/***********************************************************************\
* SEND_UDP.C *
* Test of UDP/IP. Send a single dippy datagram to a receiver process *
* assumed to exist on port 0x3333 on the internet host specified as *
* the single argument to this program. *
* *
* To use: *
* 1) Make sure that recv_udp is running (probably in the *
* background on the target host. *
* 2) Issue the command "send_udp xx", where xx is a host name. *
* *
* Phil Kearns *
* April 11, 1987 *
* *
* Modified February 2009: use getaddrinfo() *
\***********************************************************************/
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
int main(int argc,char **argv)
{
int socket_fd, cc, ecode;
struct sockaddr_in *dest;
struct addrinfo hints, *addrlist;
struct {
char head;
u_long body;
char tail;
} msgbuf;
/*
Use getaddrinfo to create a SOCK_DGRAM sockarddr_in set
up for the host specified as argv[1] and port 0x3333.
*/
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_INET; hints.ai_socktype = SOCK_DGRAM;
hints.ai_flags = AI_NUMERICSERV; hints.ai_protocol = 0;
hints.ai_canonname = NULL; hints.ai_addr = NULL;
hints.ai_next = NULL;
ecode = getaddrinfo(argv[1], "13107", &hints, &addrlist);
if (ecode != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(ecode));
exit(1);
}
dest = (struct sockaddr_in *) addrlist->ai_addr; // Will use in sendto().
/*
Set up a datagram (UDP/IP) socket in the Internet domain.
We will use it as the handle thru which we will send a
single datagram. Note that, since this no message is ever
addressed TO this socket, we do not bind an internet address
to it. It will be assigned a (temporary) address when we send
a message thru it.
*/
socket_fd = socket (addrlist->ai_family, addrlist->ai_socktype, 0);
if (socket_fd == -1) {
perror ("send_udp:socket");
exit (1);
}
msgbuf.head = '<';
msgbuf.body = htonl(getpid());
msgbuf.tail = '>';
cc = sendto(socket_fd,&msgbuf,sizeof(msgbuf),0,(struct sockaddr *) dest,
sizeof(struct sockaddr_in));
if (cc < 0) {
perror("send_udp:sendto");
exit(1);
}
exit(0);
}
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