Function sppp_get_ip_addrs

freebsd/net/if_spppsubr.c:4812–4851

* Get both IP addresses. */

 * Get both IP addresses.
 */
void
sppp_get_ip_addrs(struct sppp *sp, u_long *src, u_long *dst, u_long *srcmask)
{
	struct epoch_tracker et;
	struct ifnet *ifp = SP2IFP(sp);
	struct ifaddr *ifa;
	struct sockaddr_in *si, *sm;
	u_long ssrc, ddst;

	sm = NULL;
	ssrc = ddst = 0L;
	/*
	 * Pick the first AF_INET address from the list,
	 * aliases don't make any sense on a p2p link anyway.
	 */
	si = NULL;
	NET_EPOCH_ENTER(et);
	CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link)
		if (ifa->ifa_addr->sa_family == AF_INET) {
			si = (struct sockaddr_in *)ifa->ifa_addr;
			sm = (struct sockaddr_in *)ifa->ifa_netmask;
			if (si)
				break;
		}
	if (ifa) {
		if (si && si->sin_addr.s_addr) {
			ssrc = si->sin_addr.s_addr;
			if (srcmask)
				*srcmask = ntohl(sm->sin_addr.s_addr);
		}

		si = (struct sockaddr_in *)ifa->ifa_dstaddr;
		if (si && si->sin_addr.s_addr)
			ddst = si->sin_addr.s_addr;
	}
	NET_EPOCH_EXIT(et);

	if (dst) *dst = ntohl(ddst);
	if (src) *src = ntohl(ssrc);
}

#ifdef INET
/*