void
dg_echo(int sockfd, SA *pcliaddr, socklen_t clilen)
{
int flags;
const int on = 1;
socklen_t len;
ssize_t n;
char mesg[MAXLINE], str[INET6_ADDRSTRLEN],
ifname[IFNAMSIZ];
struct in_addr in_zero;
struct unp_in_pktinfo pktinfo;
#ifdef IP_RECVDSTADDR
if (setsockopt(sockfd, IPPROTO_IP, IP_RECVDSTADDR, &on, sizeof(on)) < 0)
err_ret("setsockopt of IP_RECVDSTADDR");
#endif
#ifdef IP_RECVIF
if (setsockopt(sockfd, IPPROTO_IP, IP_RECVIF, &on, sizeof(on)) < 0)
err_ret("setsockopt of IP_RECVIF");
#endif
bzero(&in_zero, sizeof(struct in_addr)); /* all 0 IPv4 address */
for ( ; ; )
{
len = clilen;
flags = 0;
n = Recvfrom_flags(sockfd, mesg, MAXLINE, &flags,
pcliaddr, &len, &pktinfo);
printf("%d-byte datagram from %s", n, Sock_ntop(pcliaddr, len));
if (memcmp(&pktinfo.ipi_addr, &in_zero, sizeof(in_zero)) != 0)
printf(", to %s", Inet_ntop(AF_INET, &pktinfo.ipi_addr,
str, sizeof(str)));
if (pktinfo.ipi_ifindex > 0)
printf(", recv i/f = %s",
If_indextoname(pktinfo.ipi_ifindex, ifname));
#ifdef MSG_TRUNC
if (flags & MSG_TRUNC) printf(" (datagram truncated)");
#endif
#ifdef MSG_CTRUNC
if (flags & MSG_CTRUNC) printf(" (control info truncated)");
#endif
#ifdef MSG_BCAST
if (flags & MSG_BCAST) printf(" (broadcast)");
#endif
#ifdef MSG_MCAST
if (flags & MSG_MCAST) printf(" (multicast)");
#endif
printf("\n");
Sendto(sockfd, mesg, n, 0, pcliaddr, len);
}
}
void
dg_echo(int sockfd, SA *pcliaddr, socklen_t clilen)
{
int flags;
const int on = 1;
socklen_t len;
ssize_t n;
char mesg[MAXLINE], str[INET6_ADDRSTRLEN];
struct in_addr dstaddr;
#ifdef IP_RECVDSTADDR
Setsockopt(sockfd, IPPROTO_IP, IP_RECVDSTADDR, &on, sizeof(on));
#endif
for ( ; ; ) {
len = clilen;
flags = 0;
n = Recvfrom_flags(sockfd, mesg, MAXLINE, &flags,
pcliaddr, &len, &dstaddr);
printf("%d-byte datagram from %s", n, Sock_ntop(pcliaddr, len));
if ((flags & MSG_CTRUNC) == 0)
printf(", to %s", Inet_ntop(AF_INET, &dstaddr, str, sizeof(str)));
#ifdef MSG_TRUNC
if (flags & MSG_TRUNC) printf(" (datagram truncated)");
#endif
#ifdef MSG_BCAST
if (flags & MSG_BCAST) printf(" (broadcast)");
#endif
#ifdef MSG_MCAST
if (flags & MSG_MCAST) printf(" (multicast)");
#endif
printf("\n");
Sendto(sockfd, mesg, n, 0, pcliaddr, clilen);
}
}
