/*	$OpenBSD: raw_ip.c,v 1.20 1999/12/19 02:54:29 itojun Exp $	*/
/*	$NetBSD: raw_ip.c,v 1.25 1996/02/18 18:58:33 christos Exp $	*/

/*
 * Copyright (c) 1982, 1986, 1988, 1993
 *	The Regents of the University of California.  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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 *	@(#)raw_ip.c	8.2 (Berkeley) 1/4/94
 */

/*
%%% portions-copyright-nrl-95
Portions of this software are Copyright 1995-1998 by Randall Atkinson,
Ronald Lee, Daniel McDonald, Bao Phan, and Chris Winters. All Rights
Reserved. All rights under this copyright have been assigned to the US
Naval Research Laboratory (NRL). The NRL Copyright Notice and License
Agreement Version 1.1 (January 17, 1995) applies to these portions of the
software.
You should have received a copy of the license with this software. If you
didn't get a copy, you may request one from <license@ipv6.nrl.navy.mil>.
*/

#include <sys/param.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/systm.h>

#include <net/if.h>
#include <net/route.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_mroute.h>
#include <netinet/ip_var.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_icmp.h>

#ifdef IPSEC
extern int     	check_ipsec_policy  __P((struct inpcb *, u_int32_t));
#endif

#include <machine/stdarg.h>

struct inpcbtable rawcbtable;

/*
 * Nominal space allocated to a raw ip socket.
 */
#define	RIPSNDQ		8192
#define	RIPRCVQ		8192

/*
 * Raw interface to IP protocol.
 */

/*
 * Initialize raw connection block q.
 */
void
rip_init()
{

	in_pcbinit(&rawcbtable, 1);
}

struct sockaddr_in ripsrc = { sizeof(ripsrc), AF_INET };

/*
 * Setup generic address and protocol structures
 * for raw_input routine, then pass them along with
 * mbuf chain.
 */
void
#if __STDC__
rip_input(struct mbuf *m, ...)
#else
rip_input(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	register struct ip *ip = mtod(m, struct ip *);
	register struct inpcb *inp;
	struct socket *last = 0;

	ripsrc.sin_addr = ip->ip_src;
	for (inp = rawcbtable.inpt_queue.cqh_first;
	    inp != (struct inpcb *)&rawcbtable.inpt_queue;
	    inp = inp->inp_queue.cqe_next) {
#ifdef INET6
		if (inp->inp_flags & INP_IPV6)
			continue;
#endif
		if (inp->inp_ip.ip_p && inp->inp_ip.ip_p != ip->ip_p)
			continue;
		if (inp->inp_laddr.s_addr &&
		    inp->inp_laddr.s_addr != ip->ip_dst.s_addr)
			continue;
		if (inp->inp_faddr.s_addr &&
		    inp->inp_faddr.s_addr != ip->ip_src.s_addr)
			continue;
		if (last) {
			struct mbuf *n;
			if ((n = m_copy(m, 0, (int)M_COPYALL)) != NULL) {
				if (sbappendaddr(&last->so_rcv,
				    sintosa(&ripsrc), n,
				    (struct mbuf *)0) == 0)
					/* should notify about lost packet */
					m_freem(n);
				else
					sorwakeup(last);
			}
		}
		last = inp->inp_socket;
	}
	if (last) {
		if (sbappendaddr(&last->so_rcv, sintosa(&ripsrc), m,
		    (struct mbuf *)0) == 0)
			m_freem(m);
		else
			sorwakeup(last);
	} else {
		if (ip->ip_p != IPPROTO_ICMP)
			icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PROTOCOL, 0, 0);
		else
			m_freem(m);
		ipstat.ips_noproto++;
		ipstat.ips_delivered--;
	}
}

/*
 * Generate IP header and pass packet to ip_output.
 * Tack on options user may have setup with control call.
 */
int
#if __STDC__
rip_output(struct mbuf *m, ...)
#else
rip_output(m, va_alist)
	struct mbuf *m;
	va_dcl
#endif
{
	struct socket *so;
	u_long dst;
	register struct ip *ip;
	register struct inpcb *inp;
	int flags;
	va_list ap;

	va_start(ap, m);
	so = va_arg(ap, struct socket *);
	dst = va_arg(ap, u_long);
	va_end(ap);

	inp = sotoinpcb(so);
	flags = (so->so_options & SO_DONTROUTE) | IP_ALLOWBROADCAST;

	/*
	 * If the user handed us a complete IP packet, use it.
	 * Otherwise, allocate an mbuf for a header and fill it in.
	 */
	if ((inp->inp_flags & INP_HDRINCL) == 0) {
		if ((m->m_pkthdr.len + sizeof(struct ip)) > IP_MAXPACKET) {
			m_freem(m);
			return (EMSGSIZE);
		}
		M_PREPEND(m, sizeof(struct ip), M_WAIT);
		ip = mtod(m, struct ip *);
		ip->ip_tos = 0;
		ip->ip_off = 0;
		ip->ip_p = inp->inp_ip.ip_p;
		ip->ip_len = m->m_pkthdr.len;
		ip->ip_src = inp->inp_laddr;
		ip->ip_dst.s_addr = dst;
		ip->ip_ttl = MAXTTL;
	} else {
		if (m->m_pkthdr.len > IP_MAXPACKET) {
			m_freem(m);
			return (EMSGSIZE);
		}
		ip = mtod(m, struct ip *);
		NTOHS(ip->ip_len);
		NTOHS(ip->ip_off);
		/*
		 * don't allow both user specified and setsockopt options,
		 * and don't allow packet length sizes that will crash
		 */
		if ((ip->ip_hl != (sizeof (*ip) >> 2) && inp->inp_options) ||
		    ip->ip_len > m->m_pkthdr.len ||
		    ip->ip_len < ip->ip_hl << 2) {
			m_freem(m);
			return (EINVAL);
		}
		if (ip->ip_id == 0) {
			ip->ip_id = ip_randomid();
			HTONS(ip->ip_id);
		}
		/* XXX prevent ip_output from overwriting header fields */
		flags |= IP_RAWOUTPUT;
		ipstat.ips_rawout++;
	}
#ifdef INET6
	/*
	 * A thought:  Even though raw IP shouldn't be able to set IPv6
	 *             multicast options, if it does, the last parameter to
	 *             ip_output should be guarded against v6/v4 problems.
	 */
#endif
	return (ip_output(m, inp->inp_options, &inp->inp_route, flags,
	    inp->inp_moptions, inp));
}

/*
 * Raw IP socket option processing.
 */
int
rip_ctloutput(op, so, level, optname, m)
	int op;
	struct socket *so;
	int level, optname;
	struct mbuf **m;
{
	register struct inpcb *inp = sotoinpcb(so);
	register int error;

	if (level != IPPROTO_IP) {
		if (op == PRCO_SETOPT && *m)
			(void) m_free(*m);
		return (EINVAL);
	}

	switch (optname) {

	case IP_HDRINCL:
		error = 0;
		if (op == PRCO_SETOPT) {
			if (*m == 0 || (*m)->m_len < sizeof (int))
				error = EINVAL;
			else if (*mtod(*m, int *))
				inp->inp_flags |= INP_HDRINCL;
			else
				inp->inp_flags &= ~INP_HDRINCL;
			if (*m)
				(void)m_free(*m);
		} else {
			*m = m_get(M_WAIT, M_SOOPTS);
			(*m)->m_len = sizeof(int);
			*mtod(*m, int *) = inp->inp_flags & INP_HDRINCL;
		}
		return (error);

	case MRT_INIT:
	case MRT_DONE:
	case MRT_ADD_VIF:
	case MRT_DEL_VIF:
	case MRT_ADD_MFC:
	case MRT_DEL_MFC:
	case MRT_VERSION:
	case MRT_ASSERT:
#ifdef MROUTING
		switch (op) {
		case PRCO_SETOPT:
			error = ip_mrouter_set(optname, so, m);
			break;
		case PRCO_GETOPT:
			error = ip_mrouter_get(optname, so, m);
			break;
		default:
			error = EINVAL;
			break;
		}
		return (error);
#else
		if (op == PRCO_SETOPT && *m)
			m_free(*m);
		return (EOPNOTSUPP);
#endif
	}
	return (ip_ctloutput(op, so, level, optname, m));
}

u_long	rip_sendspace = RIPSNDQ;
u_long	rip_recvspace = RIPRCVQ;

/*ARGSUSED*/
int
rip_usrreq(so, req, m, nam, control)
	register struct socket *so;
	int req;
	struct mbuf *m, *nam, *control;
{
	register int error = 0;
	register struct inpcb *inp = sotoinpcb(so);
#ifdef MROUTING
	extern struct socket *ip_mrouter;
#endif
	if (req == PRU_CONTROL)
		return (in_control(so, (u_long)m, (caddr_t)nam,
			(struct ifnet *)control));

	if (inp == NULL && req != PRU_ATTACH) {
		error = EINVAL;
		goto release;
	}

	switch (req) {

	case PRU_ATTACH:
		if (inp)
			panic("rip_attach");
		if ((so->so_state & SS_PRIV) == 0) {
			error = EACCES;
			break;
		}
		if ((error = soreserve(so, rip_sendspace, rip_recvspace)) ||
		    (error = in_pcballoc(so, &rawcbtable)))
			break;
		inp = (struct inpcb *)so->so_pcb;
		inp->inp_ip.ip_p = (long)nam;
		break;

	case PRU_DISCONNECT:
		if ((so->so_state & SS_ISCONNECTED) == 0) {
			error = ENOTCONN;
			break;
		}
		/* FALLTHROUGH */
	case PRU_ABORT:
		soisdisconnected(so);
		/* FALLTHROUGH */
	case PRU_DETACH:
		if (inp == 0)
			panic("rip_detach");
#ifdef MROUTING
		if (so == ip_mrouter)
			ip_mrouter_done();
#endif
		in_pcbdetach(inp);
		break;

	case PRU_BIND:
	    {
		struct sockaddr_in *addr = mtod(nam, struct sockaddr_in *);

		if (nam->m_len != sizeof(*addr)) {
			error = EINVAL;
			break;
		}
		if ((ifnet.tqh_first == 0) ||
		    ((addr->sin_family != AF_INET) &&
		     (addr->sin_family != AF_IMPLINK)) ||
		    (addr->sin_addr.s_addr &&
		     ifa_ifwithaddr(sintosa(addr)) == 0)) {
			error = EADDRNOTAVAIL;
			break;
		}
		inp->inp_laddr = addr->sin_addr;
		break;
	    }
	case PRU_CONNECT:
	    {
		struct sockaddr_in *addr = mtod(nam, struct sockaddr_in *);

		if (nam->m_len != sizeof(*addr)) {
			error = EINVAL;
			break;
		}
		if (ifnet.tqh_first == 0) {
			error = EADDRNOTAVAIL;
			break;
		}
		if ((addr->sin_family != AF_INET) &&
		     (addr->sin_family != AF_IMPLINK)) {
			error = EAFNOSUPPORT;
			break;
		}
		inp->inp_faddr = addr->sin_addr;
		soisconnected(so);
		break;
	    }

	case PRU_CONNECT2:
		error = EOPNOTSUPP;
		break;

	/*
	 * Mark the connection as being incapable of further input.
	 */
	case PRU_SHUTDOWN:
		socantsendmore(so);
		break;

	/*
	 * Ship a packet out.  The appropriate raw output
	 * routine handles any massaging necessary.
	 */
	case PRU_SEND:
	    {
		register u_int32_t dst;

		if (so->so_state & SS_ISCONNECTED) {
			if (nam) {
				error = EISCONN;
				break;
			}
			dst = inp->inp_faddr.s_addr;
		} else {
			if (nam == NULL) {
				error = ENOTCONN;
				break;
			}
			dst = mtod(nam, struct sockaddr_in *)->sin_addr.s_addr;
		}
#ifdef IPSEC
		if (!(error = check_ipsec_policy(inp, dst)))
#endif
		error = rip_output(m, so, dst);
		m = NULL;
		break;
	    }

	case PRU_SENSE:
		/*
		 * stat: don't bother with a blocksize.
		 */
		return (0);

	/*
	 * Not supported.
	 */
	case PRU_RCVOOB:
	case PRU_RCVD:
	case PRU_LISTEN:
	case PRU_ACCEPT:
	case PRU_SENDOOB:
		error = EOPNOTSUPP;
		break;

	case PRU_SOCKADDR:
		in_setsockaddr(inp, nam);
		break;

	case PRU_PEERADDR:
		in_setpeeraddr(inp, nam);
		break;

	default:
		panic("rip_usrreq");
	}
release:
	if (m != NULL)
		m_freem(m);
	return (error);
}