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/* $OpenBSD: ip_ip4.c,v 1.10 1997/07/01 22:12:49 provos Exp $ */
/*
* The author of this code is John Ioannidis, ji@tla.org,
* (except when noted otherwise).
*
* This code was written for BSD/OS in Athens, Greece, in November 1995.
*
* Ported to OpenBSD and NetBSD, with additional transforms, in December 1996,
* by Angelos D. Keromytis, kermit@forthnet.gr.
*
* Copyright (C) 1995, 1996, 1997 by John Ioannidis and Angelos D. Keromytis.
*
* Permission to use, copy, and modify this software without fee
* is hereby granted, provided that this entire notice is included in
* all copies of any software which is or includes a copy or
* modification of this software.
*
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTY. IN PARTICULAR, NEITHER AUTHOR MAKES ANY
* REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
* MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
* PURPOSE.
*/
/*
* IP-inside-IP processing
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <machine/cpu.h>
#include <net/if.h>
#include <net/route.h>
#include <net/netisr.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/ip_icmp.h>
#include <sys/socketvar.h>
#include <net/raw_cb.h>
#include <net/encap.h>
#include <netinet/ip_ipsp.h>
#include <netinet/ip_ip4.h>
#include <dev/rndvar.h>
void ip4_input __P((struct mbuf *, int));
/*
* ip4_input gets called when we receive an encapsulated packet,
* either because we got it at a real interface, or because AH or ESP
* were being used in tunnel mode (in which case the rcvif element will
* contain the address of the encapX interface associated with the tunnel.
*/
void
ip4_input(register struct mbuf *m, int iphlen)
{
struct ip *ipo, *ipi;
struct ifqueue *ifq = NULL;
int s;
ip4stat.ip4s_ipackets++;
/*
* Strip IP options, if any.
*/
if (iphlen > sizeof (struct ip))
{
ip_stripoptions(m, (struct mbuf *)0);
iphlen = sizeof (struct ip);
}
/*
* Make sure next IP header is in the first mbuf.
*
* Careful here! we are receiving the packet from ipintr;
* this means that the ip_len field has been adjusted to
* not count the ip header, and is also in host order.
*/
ipo = mtod(m, struct ip *);
if (m->m_len < iphlen + sizeof (struct ip))
{
if ((m = m_pullup(m, iphlen + sizeof (struct ip))) == 0)
{
ip4stat.ip4s_hdrops++;
return;
}
ipo = mtod(m, struct ip *);
}
ipi = (struct ip *)((caddr_t)ipo + iphlen);
/*
* RFC 1853 specifies that the inner TTL should not be touched on
* decapsulation.
*/
if (ipi->ip_v != IPVERSION)
{
ip4stat.ip4s_notip4++;
return;
}
/*
* Interface pointer is already in first mbuf; chop off the
* `outer' header and reschedule.
*/
m->m_len -= iphlen;
m->m_pkthdr.len -= iphlen;
m->m_data += iphlen;
/*
* Interface pointer stays the same; if no IPsec processing has
* been done (or will be done), this will point to a normal
* interface. Otherwise, it'll point to an encap interface, which
* will allow a packet filter to distinguish between secure and
* untrusted packets.
*/
ifq = &ipintrq;
s = splimp(); /* isn't it already? */
if (IF_QFULL(ifq))
{
IF_DROP(ifq);
m_freem(m);
ip4stat.ip4s_qfull++;
splx(s);
return;
}
IF_ENQUEUE(ifq, m);
schednetisr(NETISR_IP);
splx(s);
return;
}
int
ipe4_output(struct mbuf *m, struct sockaddr_encap *gw, struct tdb *tdb,
struct mbuf **mp)
{
struct ip *ipo, *ipi;
ushort ilen;
ip4stat.ip4s_opackets++;
ipi = mtod(m, struct ip *);
ilen = ntohs(ipi->ip_len);
M_PREPEND(m, sizeof (struct ip), M_DONTWAIT);
if (m == 0)
return ENOBUFS;
ipo = mtod(m, struct ip *);
ipo->ip_v = IPVERSION;
ipo->ip_hl = 5;
ipo->ip_tos = ipi->ip_tos;
ipo->ip_len = htons(ilen + sizeof (struct ip));
/* ipo->ip_id = htons(ip_id++); */
get_random_bytes((void *)&(ipo->ip_id), sizeof(ipo->ip_id));
ipo->ip_off = ipi->ip_off & ~(IP_MF | IP_OFFMASK); /* keep C and DF */
if (tdb->tdb_flags & TDBF_SAME_TTL)
ipo->ip_ttl = ipi->ip_ttl;
else
if (tdb->tdb_ttl == 0)
ipo->ip_ttl = ip_defttl;
else
ipi->ip_ttl = tdb->tdb_ttl;
ipo->ip_p = IPPROTO_IPIP;
ipo->ip_sum = 0;
ipo->ip_src = tdb->tdb_osrc;
ipo->ip_dst = tdb->tdb_odst;
/*
* printf("ip4_output: [%x->%x](l=%d, p=%d)",
* ntohl(ipi->ip_src.s_addr), ntohl(ipi->ip_dst.s_addr),
* ilen, ipi->ip_p);
* printf(" through [%x->%x](l=%d, p=%d)\n",
* ntohl(ipo->ip_src.s_addr), ntohl(ipo->ip_dst.s_addr),
* ipo->ip_len, ipo->ip_p);
*/
*mp = m;
/* Update the counters */
if (tdb->tdb_xform->xf_type == XF_IP4)
{
tdb->tdb_cur_packets++;
tdb->tdb_cur_bytes += ntohs(ipo->ip_len) - (ipo->ip_hl << 2);
}
return 0;
/* return ip_output(m, NULL, NULL, IP_ENCAPSULATED, NULL);*/
}
int
ipe4_attach()
{
return 0;
}
int
ipe4_init(struct tdb *tdbp, struct xformsw *xsp, struct mbuf *m)
{
#ifdef ENCDEBUG
if (encdebug)
printf("ipe4_init: setting up\n");
#endif
tdbp->tdb_xform = xsp;
return 0;
}
int
ipe4_zeroize(struct tdb *tdbp)
{
return 0;
}
void
ipe4_input(struct mbuf *m, ...)
{
printf("ipe4_input: should never be called\n");
if (m)
m_freem(m);
}
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