int main(int argc, char **argv)
{
struct sockaddr_in from, to, in;
char buf[TESTLEN];
char *destip = DESTIP;
int port = DEF_PORT;
int n, server_socket, client_socket, fl, tl, pid;
if (argc > 1) destip = argv[1];
if (argc > 2) port = atoi(argv[2]);
in.sin_family = AF_INET;
#ifdef NEED_SIN_LEN
in.sin_len = sizeof( struct sockaddr_in );
#endif
in.sin_addr.s_addr = INADDR_ANY;
in.sin_port = htons(port);
fl = tl = sizeof(struct sockaddr_in);
memset(&from, 0, sizeof(from));
memset(&to, 0, sizeof(to));
switch(pid = fork()) {
case -1:
perror("fork");
return 0;
case 0:
/* child */
usleep(100000);
goto client;
}
/* parent: server */
server_socket = safe_socket(PF_INET, SOCK_DGRAM, 0);
if (udpfromto_init(server_socket) != 0) {
perror("udpfromto_init\n");
waitpid(pid, NULL, WNOHANG);
return 0;
}
if (bind(server_socket, (struct sockaddr *)&in, sizeof(in)) < 0) {
perror("server: bind");
waitpid(pid, NULL, WNOHANG);
return 0;
}
printf("server: waiting for packets on INADDR_ANY:%d\n", port);
if ((n = recvfromto(server_socket, buf, sizeof(buf), 0,
(struct sockaddr *)&from, &fl,
(struct sockaddr *)&to, &tl)) < 0) {
perror("server: recvfromto");
waitpid(pid, NULL, WNOHANG);
return 0;
}
printf("server: received a packet of %d bytes [%s] ", n, buf);
printf("(src ip:port %s:%d ",
inet_ntoa(from.sin_addr), ntohs(from.sin_port));
printf(" dst ip:port %s:%d)\n",
inet_ntoa(to.sin_addr), ntohs(to.sin_port));
printf("server: replying from address packet was received on to source address\n");
if ((n = sendfromto(server_socket, buf, n, 0,
(struct sockaddr *)&to, tl,
(struct sockaddr *)&from, fl)) < 0) {
perror("server: sendfromto");
}
waitpid(pid, NULL, 0);
return 0;
client:
close(server_socket);
client_socket = safe_socket(PF_INET, SOCK_DGRAM, 0);
if (udpfromto_init(client_socket) != 0) {
perror("udpfromto_init");
_exit(0);
}
/* bind client on different port */
in.sin_port = htons(port+1);
if (bind(client_socket, (struct sockaddr *)&in, sizeof(in)) < 0) {
perror("client: bind");
_exit(0);
}
in.sin_port = htons(port);
in.sin_addr.s_addr = inet_addr(destip);
printf("client: sending packet to %s:%d\n", destip, port);
if (sendto(client_socket, TESTSTRING, TESTLEN, 0,
(struct sockaddr *)&in, sizeof(in)) < 0) {
perror("client: sendto");
_exit(0);
}
printf("client: waiting for reply from server on INADDR_ANY:%d\n", port+1);
if ((n = recvfromto(client_socket, buf, sizeof(buf), 0,
(struct sockaddr *)&from, &fl,
(struct sockaddr *)&to, &tl)) < 0) {
perror("client: recvfromto");
_exit(0);
}
printf("client: received a packet of %d bytes [%s] ", n, buf);
printf("(src ip:port %s:%d",
inet_ntoa(from.sin_addr), ntohs(from.sin_port));
printf(" dst ip:port %s:%d)\n",
inet_ntoa(to.sin_addr), ntohs(to.sin_port));
_exit(0);
}
/*
* Open a socket on the given IP and port.
*/
int fr_socket(fr_ipaddr_t *ipaddr, int port)
{
int sockfd;
struct sockaddr_storage salocal;
socklen_t salen;
if ((port < 0) || (port > 65535)) {
fr_strerror_printf("Port %d is out of allowed bounds", port);
return -1;
}
sockfd = socket(ipaddr->af, SOCK_DGRAM, 0);
if (sockfd < 0) {
fr_strerror_printf("cannot open socket: %s", strerror(errno));
return sockfd;
}
#ifdef WITH_UDPFROMTO
/*
* Initialize udpfromto for all sockets.
*/
if (udpfromto_init(sockfd) != 0) {
close(sockfd);
fr_strerror_printf("cannot initialize udpfromto: %s", strerror(errno));
return -1;
}
#endif
if (!fr_ipaddr2sockaddr(ipaddr, port, &salocal, &salen)) {
return sockfd;
}
#ifdef HAVE_STRUCT_SOCKADDR_IN6
if (ipaddr->af == AF_INET6) {
/*
* Listening on '::' does NOT get you IPv4 to
* IPv6 mapping. You've got to listen on an IPv4
* address, too. This makes the rest of the server
* design a little simpler.
*/
#ifdef IPV6_V6ONLY
if (IN6_IS_ADDR_UNSPECIFIED(&ipaddr->ipaddr.ip6addr)) {
int on = 1;
setsockopt(sockfd, IPPROTO_IPV6, IPV6_V6ONLY,
(char *)&on, sizeof(on));
}
#endif /* IPV6_V6ONLY */
}
#endif /* HAVE_STRUCT_SOCKADDR_IN6 */
if (ipaddr->af == AF_INET) {
UNUSED int flag;
#if defined(IP_MTU_DISCOVER) && defined(IP_PMTUDISC_DONT)
/*
* Disable PMTU discovery. On Linux, this
* also makes sure that the "don't fragment"
* flag is zero.
*/
flag = IP_PMTUDISC_DONT;
setsockopt(sockfd, IPPROTO_IP, IP_MTU_DISCOVER,
&flag, sizeof(flag));
#endif
#if defined(IP_DONTFRAG)
/*
* Ensure that the "don't fragment" flag is zero.
*/
flag = 0;
setsockopt(sockfd, IPPROTO_IP, IP_DONTFRAG,
&flag, sizeof(flag));
#endif
}
if (bind(sockfd, (struct sockaddr *) &salocal, salen) < 0) {
close(sockfd);
fr_strerror_printf("cannot bind socket: %s", strerror(errno));
return -1;
}
return sockfd;
}