/* adapted from ipsec-tools 0.6 src/racoon/sockmisc.c */
/*
 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <netinet/in.h>
#include <string.h>

#include "recvfromto.h"

/*
 * Receive packet, with src/dst information.  It is assumed that necessary
 * setsockopt() have already performed on socket.
 */
int
recvfromto(s, buf, buflen, flags, from, fromlen, to, tolen)
	int s;
	void *buf;
	size_t buflen;
	int flags;
	struct sockaddr *from;
	u_int *fromlen;
	struct sockaddr *to;
	u_int *tolen;
{
	int otolen;
	ssize_t len;
	struct sockaddr_storage ss;
	struct msghdr m;
	struct cmsghdr *cm;
	struct iovec iov[2];
	u_char cmsgbuf[256];
#if defined(INET6) && defined(INET6_ADVAPI)
	struct in6_pktinfo *pi;
#endif /*INET6_ADVAPI*/
	struct sockaddr_in *sin4;
	socklen_t sslen;
#ifdef INET6
	struct sockaddr_in6 *sin6;
#endif

	sslen = sizeof(ss);
	if (getsockname(s, (struct sockaddr *)&ss, &sslen) < 0)
		return -1;

	m.msg_name = (caddr_t)from;
	m.msg_namelen = *fromlen;
	iov[0].iov_base = (caddr_t)buf;
	iov[0].iov_len = buflen;
	m.msg_iov = iov;
	m.msg_iovlen = 1;
	memset(cmsgbuf, 0, sizeof(cmsgbuf));
	cm = (struct cmsghdr *)cmsgbuf;
	m.msg_control = (caddr_t)cm;
	m.msg_controllen = sizeof(cmsgbuf);
	if ((len = recvmsg(s, &m, flags)) <= 0) {
		return len;
	}
	*fromlen = m.msg_namelen;

	otolen = *tolen;
	*tolen = 0;
	for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&m);
	     m.msg_controllen != 0 && cm;
	     cm = (struct cmsghdr *)CMSG_NXTHDR(&m, cm)) {
#if defined(INET6) && defined(INET6_ADVAPI)
		if (ss.ss_family == AF_INET6
		 && cm->cmsg_level == IPPROTO_IPV6
		 && cm->cmsg_type == IPV6_PKTINFO
		 && otolen >= sizeof(*sin6)) {
			pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
			*tolen = sizeof(*sin6);
			sin6 = (struct sockaddr_in6 *)to;
			memset(sin6, 0, sizeof(*sin6));
			sin6->sin6_family = AF_INET6;
#ifndef __linux__
			sin6->sin6_len = sizeof(*sin6);
#endif
			memcpy(&sin6->sin6_addr, &pi->ipi6_addr,
				sizeof(sin6->sin6_addr));
			/* XXX other cases, such as site-local? */
			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
				sin6->sin6_scope_id = pi->ipi6_ifindex;
			else
				sin6->sin6_scope_id = 0;
			sin6->sin6_port =
				((struct sockaddr_in6 *)&ss)->sin6_port;
			otolen = -1;	/* "to" already set */
			continue;
		}
#endif
#ifdef __linux__
		if (ss.ss_family == AF_INET
		 && cm->cmsg_level == IPPROTO_IP
		 && cm->cmsg_type == IP_PKTINFO
		 && otolen >= sizeof(sin4)) {
			struct in_pktinfo *pi = (struct in_pktinfo *)(CMSG_DATA(cm));
			*tolen = sizeof(*sin4);
			sin4 = (struct sockaddr_in *)to;
			memset(sin4, 0, sizeof(*sin4));
			sin4->sin_family = AF_INET;
			memcpy(&sin4->sin_addr, &pi->ipi_addr,
				sizeof(sin4->sin_addr));
			sin4->sin_port =
				((struct sockaddr_in *)&ss)->sin_port;
			otolen = -1;	/* "to" already set */
			continue;
		}
#endif
#if defined(INET6) && defined(IPV6_RECVDSTADDR)
		if (ss.ss_family == AF_INET6
		      && cm->cmsg_level == IPPROTO_IPV6
		      && cm->cmsg_type == IPV6_RECVDSTADDR
		      && otolen >= sizeof(*sin6)) {
			*tolen = sizeof(*sin6);
			sin6 = (struct sockaddr_in6 *)to;
			memset(sin6, 0, sizeof(*sin6));
			sin6->sin6_family = AF_INET6;
			sin6->sin6_len = sizeof(*sin6);
			memcpy(&sin6->sin6_addr, CMSG_DATA(cm),
				sizeof(sin6->sin6_addr));
			sin6->sin6_port =
				((struct sockaddr_in6 *)&ss)->sin6_port;
			otolen = -1;	/* "to" already set */
			continue;
		}
#endif
#ifndef __linux__
		if (ss.ss_family == AF_INET
		 && cm->cmsg_level == IPPROTO_IP
		 && cm->cmsg_type == IP_RECVDSTADDR
		 && otolen >= sizeof(*sin4)) {
			*tolen = sizeof(*sin4);
			sin4 = (struct sockaddr_in *)to;
			memset(sin4, 0, sizeof(*sin4));
			sin4->sin_family = AF_INET;
			sin4->sin_len = sizeof(*sin4);
			memcpy(&sin4->sin_addr, CMSG_DATA(cm),
				sizeof(sin4->sin_addr));
			sin4->sin_port = ((struct sockaddr_in *)&ss)->sin_port;
			otolen = -1;	/* "to" already set */
			continue;
		}
#endif
	}

	return len;
}