NetBSD-5.0.2/sys/netipsec/ipsec_output.c
/* $NetBSD: ipsec_output.c,v 1.28 2008/04/28 17:40:11 degroote Exp $ */
/*-
* Copyright (c) 2002, 2003 Sam Leffler, Errno Consulting
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD: /repoman/r/ncvs/src/sys/netipsec/ipsec_output.c,v 1.3.2.2 2003/03/28 20:32:53 sam Exp $
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: ipsec_output.c,v 1.28 2008/04/28 17:40:11 degroote Exp $");
/*
* IPsec output processing.
*/
#include "opt_inet.h"
#ifdef __FreeBSD__
#include "opt_inet6.h"
#endif
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/errno.h>
#include <sys/syslog.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_var.h>
#include <netinet/in_var.h>
#include <netinet/ip_ecn.h>
#ifdef INET6
# ifdef __FreeBSD__
# include <netinet6/ip6_ecn.h>
# endif
#endif
#include <netinet/ip6.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#endif
#include <netinet/in_pcb.h>
#ifdef INET6
#include <netinet/icmp6.h>
#endif
#ifdef IPSEC_NAT_T
#include <netinet/udp.h>
#endif
#include <netipsec/ipsec.h>
#include <netipsec/ipsec_var.h>
#include <netipsec/ipsec_private.h>
#ifdef INET6
#include <netipsec/ipsec6.h>
#endif
#include <netipsec/ah_var.h>
#include <netipsec/esp_var.h>
#include <netipsec/ipcomp_var.h>
#include <netipsec/xform.h>
#include <netipsec/key.h>
#include <netipsec/keydb.h>
#include <netipsec/key_debug.h>
#include <netipsec/ipsec_osdep.h>
#include <net/net_osdep.h> /* ovbcopy() in ipsec6_encapsulate() */
/*
* Add a IPSEC_OUT_DONE tag to mark that we have finished the ipsec processing
* It will be used by ip{,6}_output to check if we have already or not
* processed this packet.
*/
static int
ipsec_register_done(struct mbuf *m, int * error)
{
struct m_tag *mtag;
mtag = m_tag_get(PACKET_TAG_IPSEC_OUT_DONE, 0, M_NOWAIT);
if (mtag == NULL) {
DPRINTF(("ipsec_register_done: could not get packet tag\n"));
*error = ENOMEM;
return -1;
}
m_tag_prepend(m, mtag);
return 0;
}
static int
ipsec_reinject_ipstack(struct mbuf *m, int af)
{
#ifdef INET
struct ip * ip;
#endif /* INET */
switch (af) {
#ifdef INET
case AF_INET:
ip = mtod(m, struct ip *);
#ifdef __FreeBSD__
/* FreeBSD ip_output() expects ip_len, ip_off in host endian */
ip->ip_len = ntohs(ip->ip_len);
ip->ip_off = ntohs(ip->ip_off);
#endif /* __FreeBSD_ */
return ip_output(m, NULL, NULL, IP_RAWOUTPUT,
(struct ip_moptions *)NULL, (struct socket *)NULL);
#endif /* INET */
#ifdef INET6
case AF_INET6:
/*
* We don't need massage, IPv6 header fields are always in
* net endian.
*/
return ip6_output(m, NULL, NULL, 0, NULL, NULL, NULL);
#endif /* INET6 */
}
panic("ipsec_reinject_ipstack : iunknown protocol family %u\n", af);
return -1; /* NOTREACHED */
}
int
ipsec_process_done(struct mbuf *m, struct ipsecrequest *isr)
{
struct secasvar *sav;
struct secasindex *saidx;
int error;
#ifdef INET
struct ip * ip;
#endif /* INET */
#ifdef INET6
struct ip6_hdr * ip6;
#endif /* INET6 */
#ifdef IPSEC_NAT_T
struct mbuf * mo;
struct udphdr *udp = NULL;
uint64_t * data = NULL;
int hlen, roff;
#endif /* IPSEC_NAT_T */
IPSEC_SPLASSERT_SOFTNET("ipsec_process_done");
IPSEC_ASSERT(m != NULL, ("ipsec_process_done: null mbuf"));
IPSEC_ASSERT(isr != NULL, ("ipsec_process_done: null ISR"));
sav = isr->sav;
IPSEC_ASSERT(sav != NULL, ("ipsec_process_done: null SA"));
IPSEC_ASSERT(sav->sah != NULL, ("ipsec_process_done: null SAH"));
saidx = &sav->sah->saidx;
#ifdef IPSEC_NAT_T
if(sav->natt_type != 0) {
ip = mtod(m, struct ip *);
hlen = sizeof(struct udphdr);
if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
hlen += sizeof(uint64_t);
mo = m_makespace(m, sizeof(struct ip), hlen, &roff);
if (mo == NULL) {
DPRINTF(("ipsec_process_done : failed to inject"
"%u byte UDP for SA %s/%08lx\n",
hlen, ipsec_address(&saidx->dst),
(u_long) ntohl(sav->spi)));
error = ENOBUFS;
goto bad;
}
udp = (struct udphdr*) (mtod(mo, char*) + roff);
data = (uint64_t*) (udp + 1);
if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
*data = 0; /* NON-IKE Marker */
if (sav->natt_type == UDP_ENCAP_ESPINUDP_NON_IKE)
udp->uh_sport = htons(UDP_ENCAP_ESPINUDP_PORT);
else
udp->uh_sport = key_portfromsaddr(&saidx->src);
udp->uh_dport = key_portfromsaddr(&saidx->dst);
udp->uh_sum = 0;
udp->uh_ulen = htons(m->m_pkthdr.len - (ip->ip_hl << 2));
}
#endif /* IPSEC_NAT_T */
switch (saidx->dst.sa.sa_family) {
#ifdef INET
case AF_INET:
/* Fix the header length, for AH processing. */
ip = mtod(m, struct ip *);
ip->ip_len = htons(m->m_pkthdr.len);
#ifdef IPSEC_NAT_T
if (sav->natt_type != 0)
ip->ip_p = IPPROTO_UDP;
#endif /* IPSEC_NAT_T */
break;
#endif /* INET */
#ifdef INET6
case AF_INET6:
/* Fix the header length, for AH processing. */
if (m->m_pkthdr.len < sizeof (struct ip6_hdr)) {
error = ENXIO;
goto bad;
}
if (m->m_pkthdr.len - sizeof (struct ip6_hdr) > IPV6_MAXPACKET) {
/* No jumbogram support. */
error = ENXIO; /*?*/
goto bad;
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(struct ip6_hdr));
#ifdef IPSEC_NAT_T
if (sav->natt_type != 0)
ip6->ip6_nxt = IPPROTO_UDP;
#endif /* IPSEC_NAT_T */
break;
#endif /* INET6 */
default:
DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
saidx->dst.sa.sa_family));
error = ENXIO;
goto bad;
}
/*
* If there's another (bundled) SA to apply, do so.
* Note that this puts a burden on the kernel stack size.
* If this is a problem we'll need to introduce a queue
* to set the packet on so we can unwind the stack before
* doing further processing.
*/
if (isr->next) {
IPSEC_STATINC(IPSEC_STAT_OUT_BUNDLESA);
switch ( saidx->dst.sa.sa_family ) {
#ifdef INET
case AF_INET:
return ipsec4_process_packet(m, isr->next, 0,0);
#endif /* INET */
#ifdef INET6
case AF_INET6:
return ipsec6_process_packet(m,isr->next);
#endif /* INET6 */
default :
DPRINTF(("ipsec_process_done: unknown protocol family %u\n",
saidx->dst.sa.sa_family));
error = ENXIO;
goto bad;
}
}
/*
* We're done with IPsec processing,
* mark that we have already processed the packet
* transmit it packet using the appropriate network protocol (IP or IPv6).
*/
if (ipsec_register_done(m, &error) < 0)
goto bad;
return ipsec_reinject_ipstack(m, saidx->dst.sa.sa_family);
bad:
m_freem(m);
KEY_FREESAV(&sav);
return (error);
}
/*
* ipsec_nextisr can return :
* - isr == NULL and error != 0 => something is bad : the packet must be
* discarded
* - isr == NULL and error == 0 => no more rules to apply, ipsec processing
* is done, reinject it in ip stack
* - isr != NULL (error == 0) => we need to apply one rule to the packet
*/
static struct ipsecrequest *
ipsec_nextisr(
struct mbuf *m,
struct ipsecrequest *isr,
int af,
struct secasindex *saidx,
int *error
)
{
#define IPSEC_OSTAT(x, y, z) \
do { \
switch (isr->saidx.proto) { \
case IPPROTO_ESP: \
ESP_STATINC(x); \
break; \
case IPPROTO_AH: \
AH_STATINC(y); \
break; \
default: \
IPCOMP_STATINC(z); \
break; \
} \
} while (/*CONSTCOND*/0)
struct secasvar *sav;
IPSEC_SPLASSERT_SOFTNET("ipsec_nextisr");
IPSEC_ASSERT(af == AF_INET || af == AF_INET6,
("ipsec_nextisr: invalid address family %u", af));
again:
/*
* Craft SA index to search for proper SA. Note that
* we only fillin unspecified SA peers for transport
* mode; for tunnel mode they must already be filled in.
*/
*saidx = isr->saidx;
if (isr->saidx.mode == IPSEC_MODE_TRANSPORT) {
/* Fillin unspecified SA peers only for transport mode */
if (af == AF_INET) {
struct sockaddr_in *sin;
struct ip *ip = mtod(m, struct ip *);
if (saidx->src.sa.sa_len == 0) {
sin = &saidx->src.sin;
sin->sin_len = sizeof(*sin);
sin->sin_family = AF_INET;
sin->sin_port = IPSEC_PORT_ANY;
sin->sin_addr = ip->ip_src;
}
if (saidx->dst.sa.sa_len == 0) {
sin = &saidx->dst.sin;
sin->sin_len = sizeof(*sin);
sin->sin_family = AF_INET;
sin->sin_port = IPSEC_PORT_ANY;
sin->sin_addr = ip->ip_dst;
}
} else {
struct sockaddr_in6 *sin6;
struct ip6_hdr *ip6 = mtod(m, struct ip6_hdr *);
if (saidx->src.sin6.sin6_len == 0) {
sin6 = (struct sockaddr_in6 *)&saidx->src;
sin6->sin6_len = sizeof(*sin6);
sin6->sin6_family = AF_INET6;
sin6->sin6_port = IPSEC_PORT_ANY;
sin6->sin6_addr = ip6->ip6_src;
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
/* fix scope id for comparing SPD */
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id =
ntohs(ip6->ip6_src.s6_addr16[1]);
}
}
if (saidx->dst.sin6.sin6_len == 0) {
sin6 = (struct sockaddr_in6 *)&saidx->dst;
sin6->sin6_len = sizeof(*sin6);
sin6->sin6_family = AF_INET6;
sin6->sin6_port = IPSEC_PORT_ANY;
sin6->sin6_addr = ip6->ip6_dst;
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
/* fix scope id for comparing SPD */
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id =
ntohs(ip6->ip6_dst.s6_addr16[1]);
}
}
}
}
/*
* Lookup SA and validate it.
*/
*error = key_checkrequest(isr, saidx);
if (*error != 0) {
/*
* IPsec processing is required, but no SA found.
* I assume that key_acquire() had been called
* to get/establish the SA. Here I discard
* this packet because it is responsibility for
* upper layer to retransmit the packet.
*/
IPSEC_STATINC(IPSEC_STAT_OUT_NOSA);
goto bad;
}
sav = isr->sav;
/* sav may be NULL here if we have an USE rule */
if (sav == NULL) {
IPSEC_ASSERT(ipsec_get_reqlevel(isr) == IPSEC_LEVEL_USE,
("ipsec_nextisr: no SA found, but required; level %u",
ipsec_get_reqlevel(isr)));
isr = isr->next;
/*
* No more rules to apply, return NULL isr and no error
* It can happen when the last rules are USE rules
* */
if (isr == NULL) {
*error = 0;
return isr;
}
goto again;
}
/*
* Check system global policy controls.
*/
if ((isr->saidx.proto == IPPROTO_ESP && !esp_enable) ||
(isr->saidx.proto == IPPROTO_AH && !ah_enable) ||
(isr->saidx.proto == IPPROTO_IPCOMP && !ipcomp_enable)) {
DPRINTF(("ipsec_nextisr: IPsec outbound packet dropped due"
" to policy (check your sysctls)\n"));
IPSEC_OSTAT(ESP_STAT_PDROPS, AH_STAT_PDROPS,
IPCOMP_STAT_PDROPS);
*error = EHOSTUNREACH;
goto bad;
}
/*
* Sanity check the SA contents for the caller
* before they invoke the xform output method.
*/
if (sav->tdb_xform == NULL) {
DPRINTF(("ipsec_nextisr: no transform for SA\n"));
IPSEC_OSTAT(ESP_STAT_NOXFORM, AH_STAT_NOXFORM,
IPCOMP_STAT_NOXFORM);
*error = EHOSTUNREACH;
goto bad;
}
return isr;
bad:
IPSEC_ASSERT(*error != 0, ("ipsec_nextisr: error return w/ no error code"));
return NULL;
#undef IPSEC_OSTAT
}
#ifdef INET
/*
* IPsec output logic for IPv4.
*/
int
ipsec4_process_packet(
struct mbuf *m,
struct ipsecrequest *isr,
int flags,
int tunalready
)
{
struct secasindex saidx;
struct secasvar *sav;
struct ip *ip;
int s, error, i, off;
IPSEC_ASSERT(m != NULL, ("ipsec4_process_packet: null mbuf"));
IPSEC_ASSERT(isr != NULL, ("ipsec4_process_packet: null isr"));
s = splsoftnet(); /* insure SA contents don't change */
isr = ipsec_nextisr(m, isr, AF_INET, &saidx, &error);
if (isr == NULL) {
if (error != 0) {
goto bad;
} else {
if (ipsec_register_done(m, &error) < 0)
goto bad;
splx(s);
return ipsec_reinject_ipstack(m, AF_INET);
}
}
sav = isr->sav;
if (!tunalready) {
union sockaddr_union *dst = &sav->sah->saidx.dst;
int setdf;
/*
* Collect IP_DF state from the outer header.
*/
if (dst->sa.sa_family == AF_INET) {
if (m->m_len < sizeof (struct ip) &&
(m = m_pullup(m, sizeof (struct ip))) == NULL) {
error = ENOBUFS;
goto bad;
}
ip = mtod(m, struct ip *);
/* Honor system-wide control of how to handle IP_DF */
switch (ip4_ipsec_dfbit) {
case 0: /* clear in outer header */
case 1: /* set in outer header */
setdf = ip4_ipsec_dfbit;
break;
default: /* propagate to outer header */
setdf = ip->ip_off;
#ifndef __FreeBSD__
/* On FreeBSD, ip_off and ip_len assumed in host endian. */
setdf = ntohs(setdf);
#endif
setdf = htons(setdf & IP_DF);
break;
}
} else {
ip = NULL; /* keep compiler happy */
setdf = 0;
}
/* Do the appropriate encapsulation, if necessary */
if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
dst->sa.sa_family != AF_INET || /* PF mismatch */
#if 0
(sav->flags & SADB_X_SAFLAGS_TUNNEL) || /* Tunnel requ'd */
sav->tdb_xform->xf_type == XF_IP4 || /* ditto */
#endif
(dst->sa.sa_family == AF_INET && /* Proxy */
dst->sin.sin_addr.s_addr != INADDR_ANY &&
dst->sin.sin_addr.s_addr != ip->ip_dst.s_addr)) {
struct mbuf *mp;
/* Fix IPv4 header checksum and length */
if (m->m_len < sizeof (struct ip) &&
(m = m_pullup(m, sizeof (struct ip))) == NULL) {
error = ENOBUFS;
goto bad;
}
ip = mtod(m, struct ip *);
ip->ip_len = htons(m->m_pkthdr.len);
ip->ip_sum = 0;
ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
/* Encapsulate the packet */
error = ipip_output(m, isr, &mp, 0, 0);
if (mp == NULL && !error) {
/* Should never happen. */
DPRINTF(("ipsec4_process_packet: ipip_output "
"returns no mbuf and no error!"));
error = EFAULT;
}
if (error) {
if (mp) {
/* XXX: Should never happen! */
m_freem(mp);
}
m = NULL; /* ipip_output() already freed it */
goto bad;
}
m = mp, mp = NULL;
/*
* ipip_output clears IP_DF in the new header. If
* we need to propagate IP_DF from the outer header,
* then we have to do it here.
*
* XXX shouldn't assume what ipip_output does.
*/
if (dst->sa.sa_family == AF_INET && setdf) {
if (m->m_len < sizeof (struct ip) &&
(m = m_pullup(m, sizeof (struct ip))) == NULL) {
error = ENOBUFS;
goto bad;
}
ip = mtod(m, struct ip *);
ip->ip_off |= IP_OFF_CONVERT(IP_DF);
}
}
}
/*
* Dispatch to the appropriate IPsec transform logic. The
* packet will be returned for transmission after crypto
* processing, etc. are completed. For encapsulation we
* bypass this call because of the explicit call done above
* (necessary to deal with IP_DF handling for IPv4).
*
* NB: m & sav are ``passed to caller'' who's reponsible for
* for reclaiming their resources.
*/
if (sav->tdb_xform->xf_type != XF_IP4) {
ip = mtod(m, struct ip *);
i = ip->ip_hl << 2;
off = offsetof(struct ip, ip_p);
error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
} else {
error = ipsec_process_done(m, isr);
}
splx(s);
return error;
bad:
splx(s);
if (m)
m_freem(m);
return error;
}
#endif
#ifdef INET6
int
ipsec6_process_packet(
struct mbuf *m,
struct ipsecrequest *isr
)
{
struct secasindex saidx;
struct secasvar *sav;
struct ip6_hdr *ip6;
int s, error, i, off;
IPSEC_ASSERT(m != NULL, ("ipsec6_process_packet: null mbuf"));
IPSEC_ASSERT(isr != NULL, ("ipsec6_process_packet: null isr"));
s = splsoftnet(); /* insure SA contents don't change */
isr = ipsec_nextisr(m, isr, AF_INET6, &saidx, &error);
if (isr == NULL) {
if (error != 0) {
// XXX Should we send a notification ?
goto bad;
} else {
if (ipsec_register_done(m, &error) < 0)
goto bad;
splx(s);
return ipsec_reinject_ipstack(m, AF_INET6);
}
}
sav = isr->sav;
if (sav->tdb_xform->xf_type != XF_IP4) {
i = sizeof(struct ip6_hdr);
off = offsetof(struct ip6_hdr, ip6_nxt);
error = (*sav->tdb_xform->xf_output)(m, isr, NULL, i, off);
} else {
union sockaddr_union *dst = &sav->sah->saidx.dst;
ip6 = mtod(m, struct ip6_hdr *);
/* Do the appropriate encapsulation, if necessary */
if (isr->saidx.mode == IPSEC_MODE_TUNNEL || /* Tunnel requ'd */
dst->sa.sa_family != AF_INET6 || /* PF mismatch */
((dst->sa.sa_family == AF_INET6) &&
(!IN6_IS_ADDR_UNSPECIFIED(&dst->sin6.sin6_addr)) &&
(!IN6_ARE_ADDR_EQUAL(&dst->sin6.sin6_addr,
&ip6->ip6_dst)))
)
{
struct mbuf *mp;
/* Fix IPv6 header payload length. */
if (m->m_len < sizeof(struct ip6_hdr))
if ((m = m_pullup(m,sizeof(struct ip6_hdr))) == NULL)
return ENOBUFS;
if (m->m_pkthdr.len - sizeof(*ip6) > IPV6_MAXPACKET) {
/* No jumbogram support. */
m_freem(m);
return ENXIO; /*XXX*/
}
ip6 = mtod(m, struct ip6_hdr *);
ip6->ip6_plen = htons(m->m_pkthdr.len - sizeof(*ip6));
/* Encapsulate the packet */
error = ipip_output(m, isr, &mp, 0, 0);
if (mp == NULL && !error) {
/* Should never happen. */
DPRINTF(("ipsec6_process_packet: ipip_output "
"returns no mbuf and no error!"));
error = EFAULT;
}
if (error) {
if (mp) {
/* XXX: Should never happen! */
m_freem(mp);
}
m = NULL; /* ipip_output() already freed it */
goto bad;
}
m = mp;
mp = NULL;
}
error = ipsec_process_done(m,isr);
}
splx(s);
return error;
bad:
splx(s);
if (m)
m_freem(m);
return error;
}
#endif /*INET6*/