aeca69ded5
option is now deprecated, as well as the KAME IPsec code. What was FAST_IPSEC is now IPSEC. Approved by: re Sponsored by: Secure Computing
387 lines
10 KiB
C
387 lines
10 KiB
C
/*-
|
|
* 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.
|
|
* 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.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#include "opt_ipsec.h"
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/route.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/in_var.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/in_pcb.h>
|
|
#include <netinet/ip_var.h>
|
|
#include <netinet/ip_options.h>
|
|
#include <netinet/ip_ipsec.h>
|
|
|
|
#include <machine/in_cksum.h>
|
|
|
|
#ifdef IPSEC
|
|
#include <netipsec/ipsec.h>
|
|
#include <netipsec/xform.h>
|
|
#include <netipsec/key.h>
|
|
#endif /*IPSEC*/
|
|
|
|
extern struct protosw inetsw[];
|
|
|
|
/*
|
|
* Check if we have to jump over firewall processing for this packet.
|
|
* Called from ip_input().
|
|
* 1 = jump over firewall, 0 = packet goes through firewall.
|
|
*/
|
|
int
|
|
ip_ipsec_filtergif(struct mbuf *m)
|
|
{
|
|
#if defined(IPSEC) && !defined(IPSEC_FILTERGIF)
|
|
/*
|
|
* Bypass packet filtering for packets from a tunnel (gif).
|
|
*/
|
|
if (m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
|
|
return 1;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Check if this packet has an active SA and needs to be dropped instead
|
|
* of forwarded.
|
|
* Called from ip_input().
|
|
* 1 = drop packet, 0 = forward packet.
|
|
*/
|
|
int
|
|
ip_ipsec_fwd(struct mbuf *m)
|
|
{
|
|
#ifdef IPSEC
|
|
struct m_tag *mtag;
|
|
struct tdb_ident *tdbi;
|
|
struct secpolicy *sp;
|
|
int s, error;
|
|
|
|
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
|
|
s = splnet();
|
|
if (mtag != NULL) {
|
|
tdbi = (struct tdb_ident *)(mtag + 1);
|
|
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
|
|
} else {
|
|
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
|
|
IP_FORWARDING, &error);
|
|
}
|
|
if (sp == NULL) { /* NB: can happen if error */
|
|
splx(s);
|
|
/*XXX error stat???*/
|
|
DPRINTF(("ip_input: no SP for forwarding\n")); /*XXX*/
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Check security policy against packet attributes.
|
|
*/
|
|
error = ipsec_in_reject(sp, m);
|
|
KEY_FREESP(&sp);
|
|
splx(s);
|
|
if (error) {
|
|
ipstat.ips_cantforward++;
|
|
return 1;
|
|
}
|
|
#endif /* IPSEC */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Check if protocol type doesn't have a further header and do IPSEC
|
|
* decryption or reject right now. Protocols with further headers get
|
|
* their IPSEC treatment within the protocol specific processing.
|
|
* Called from ip_input().
|
|
* 1 = drop packet, 0 = continue processing packet.
|
|
*/
|
|
int
|
|
ip_ipsec_input(struct mbuf *m)
|
|
{
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
#ifdef IPSEC
|
|
struct m_tag *mtag;
|
|
struct tdb_ident *tdbi;
|
|
struct secpolicy *sp;
|
|
int s, error;
|
|
/*
|
|
* enforce IPsec policy checking if we are seeing last header.
|
|
* note that we do not visit this with protocols with pcb layer
|
|
* code - like udp/tcp/raw ip.
|
|
*/
|
|
if ((inetsw[ip_protox[ip->ip_p]].pr_flags & PR_LASTHDR) != 0) {
|
|
/*
|
|
* Check if the packet has already had IPsec processing
|
|
* done. If so, then just pass it along. This tag gets
|
|
* set during AH, ESP, etc. input handling, before the
|
|
* packet is returned to the ip input queue for delivery.
|
|
*/
|
|
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
|
|
s = splnet();
|
|
if (mtag != NULL) {
|
|
tdbi = (struct tdb_ident *)(mtag + 1);
|
|
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_INBOUND);
|
|
} else {
|
|
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND,
|
|
IP_FORWARDING, &error);
|
|
}
|
|
if (sp != NULL) {
|
|
/*
|
|
* Check security policy against packet attributes.
|
|
*/
|
|
error = ipsec_in_reject(sp, m);
|
|
KEY_FREESP(&sp);
|
|
} else {
|
|
/* XXX error stat??? */
|
|
error = EINVAL;
|
|
DPRINTF(("ip_input: no SP, packet discarded\n"));/*XXX*/
|
|
return 1;
|
|
}
|
|
splx(s);
|
|
if (error)
|
|
return 1;
|
|
}
|
|
#endif /* IPSEC */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
|
|
* Called from ip_forward().
|
|
* Returns MTU suggestion for ICMP needfrag reply.
|
|
*/
|
|
int
|
|
ip_ipsec_mtu(struct mbuf *m)
|
|
{
|
|
int mtu = 0;
|
|
/*
|
|
* If the packet is routed over IPsec tunnel, tell the
|
|
* originator the tunnel MTU.
|
|
* tunnel MTU = if MTU - sizeof(IP) - ESP/AH hdrsiz
|
|
* XXX quickhack!!!
|
|
*/
|
|
struct secpolicy *sp = NULL;
|
|
int ipsecerror;
|
|
int ipsechdr;
|
|
struct route *ro;
|
|
sp = ipsec_getpolicybyaddr(m,
|
|
IPSEC_DIR_OUTBOUND,
|
|
IP_FORWARDING,
|
|
&ipsecerror);
|
|
if (sp != NULL) {
|
|
/* count IPsec header size */
|
|
ipsechdr = ipsec4_hdrsiz(m,
|
|
IPSEC_DIR_OUTBOUND,
|
|
NULL);
|
|
|
|
/*
|
|
* find the correct route for outer IPv4
|
|
* header, compute tunnel MTU.
|
|
*/
|
|
if (sp->req != NULL &&
|
|
sp->req->sav != NULL &&
|
|
sp->req->sav->sah != NULL) {
|
|
ro = &sp->req->sav->sah->sa_route;
|
|
if (ro->ro_rt && ro->ro_rt->rt_ifp) {
|
|
mtu =
|
|
ro->ro_rt->rt_rmx.rmx_mtu ?
|
|
ro->ro_rt->rt_rmx.rmx_mtu :
|
|
ro->ro_rt->rt_ifp->if_mtu;
|
|
mtu -= ipsechdr;
|
|
}
|
|
}
|
|
KEY_FREESP(&sp);
|
|
}
|
|
return mtu;
|
|
}
|
|
|
|
/*
|
|
*
|
|
* Called from ip_output().
|
|
* 1 = drop packet, 0 = continue processing packet,
|
|
* -1 = packet was reinjected and stop processing packet
|
|
*/
|
|
int
|
|
ip_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
|
|
struct route **ro, struct route *iproute, struct sockaddr_in **dst,
|
|
struct in_ifaddr **ia, struct ifnet **ifp)
|
|
{
|
|
#ifdef IPSEC
|
|
struct secpolicy *sp = NULL;
|
|
struct ip *ip = mtod(*m, struct ip *);
|
|
struct tdb_ident *tdbi;
|
|
struct m_tag *mtag;
|
|
int s;
|
|
/*
|
|
* Check the security policy (SP) for the packet and, if
|
|
* required, do IPsec-related processing. There are two
|
|
* cases here; the first time a packet is sent through
|
|
* it will be untagged and handled by ipsec4_checkpolicy.
|
|
* If the packet is resubmitted to ip_output (e.g. after
|
|
* AH, ESP, etc. processing), there will be a tag to bypass
|
|
* the lookup and related policy checking.
|
|
*/
|
|
mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
|
|
s = splnet();
|
|
if (mtag != NULL) {
|
|
tdbi = (struct tdb_ident *)(mtag + 1);
|
|
sp = ipsec_getpolicy(tdbi, IPSEC_DIR_OUTBOUND);
|
|
if (sp == NULL)
|
|
*error = -EINVAL; /* force silent drop */
|
|
m_tag_delete(*m, mtag);
|
|
} else {
|
|
sp = ipsec4_checkpolicy(*m, IPSEC_DIR_OUTBOUND, *flags,
|
|
error, inp);
|
|
}
|
|
/*
|
|
* There are four return cases:
|
|
* sp != NULL apply IPsec policy
|
|
* sp == NULL, error == 0 no IPsec handling needed
|
|
* sp == NULL, error == -EINVAL discard packet w/o error
|
|
* sp == NULL, error != 0 discard packet, report error
|
|
*/
|
|
if (sp != NULL) {
|
|
/* Loop detection, check if ipsec processing already done */
|
|
KASSERT(sp->req != NULL, ("ip_output: no ipsec request"));
|
|
for (mtag = m_tag_first(*m); mtag != NULL;
|
|
mtag = m_tag_next(*m, mtag)) {
|
|
if (mtag->m_tag_cookie != MTAG_ABI_COMPAT)
|
|
continue;
|
|
if (mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_DONE &&
|
|
mtag->m_tag_id != PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED)
|
|
continue;
|
|
/*
|
|
* Check if policy has an SA associated with it.
|
|
* This can happen when an SP has yet to acquire
|
|
* an SA; e.g. on first reference. If it occurs,
|
|
* then we let ipsec4_process_packet do its thing.
|
|
*/
|
|
if (sp->req->sav == NULL)
|
|
break;
|
|
tdbi = (struct tdb_ident *)(mtag + 1);
|
|
if (tdbi->spi == sp->req->sav->spi &&
|
|
tdbi->proto == sp->req->sav->sah->saidx.proto &&
|
|
bcmp(&tdbi->dst, &sp->req->sav->sah->saidx.dst,
|
|
sizeof (union sockaddr_union)) == 0) {
|
|
/*
|
|
* No IPsec processing is needed, free
|
|
* reference to SP.
|
|
*
|
|
* NB: null pointer to avoid free at
|
|
* done: below.
|
|
*/
|
|
KEY_FREESP(&sp), sp = NULL;
|
|
splx(s);
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Do delayed checksums now because we send before
|
|
* this is done in the normal processing path.
|
|
*/
|
|
if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
|
|
in_delayed_cksum(*m);
|
|
(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
|
|
}
|
|
|
|
ip->ip_len = htons(ip->ip_len);
|
|
ip->ip_off = htons(ip->ip_off);
|
|
|
|
/* NB: callee frees mbuf */
|
|
*error = ipsec4_process_packet(*m, sp->req, *flags, 0);
|
|
/*
|
|
* Preserve KAME behaviour: ENOENT can be returned
|
|
* when an SA acquire is in progress. Don't propagate
|
|
* this to user-level; it confuses applications.
|
|
*
|
|
* XXX this will go away when the SADB is redone.
|
|
*/
|
|
if (*error == ENOENT)
|
|
*error = 0;
|
|
splx(s);
|
|
goto reinjected;
|
|
} else { /* sp == NULL */
|
|
splx(s);
|
|
|
|
if (*error != 0) {
|
|
/*
|
|
* Hack: -EINVAL is used to signal that a packet
|
|
* should be silently discarded. This is typically
|
|
* because we asked key management for an SA and
|
|
* it was delayed (e.g. kicked up to IKE).
|
|
*/
|
|
if (*error == -EINVAL)
|
|
*error = 0;
|
|
goto bad;
|
|
} else {
|
|
/* No IPsec processing for this packet. */
|
|
}
|
|
#ifdef notyet
|
|
/*
|
|
* If deferred crypto processing is needed, check that
|
|
* the interface supports it.
|
|
*/
|
|
mtag = m_tag_find(*m, PACKET_TAG_IPSEC_OUT_CRYPTO_NEEDED, NULL);
|
|
if (mtag != NULL && ((*ifp)->if_capenable & IFCAP_IPSEC) == 0) {
|
|
/* notify IPsec to do its own crypto */
|
|
ipsp_skipcrypto_unmark((struct tdb_ident *)(mtag + 1));
|
|
*error = EHOSTUNREACH;
|
|
goto bad;
|
|
}
|
|
#endif
|
|
}
|
|
done:
|
|
if (sp != NULL)
|
|
KEY_FREESP(&sp);
|
|
return 0;
|
|
reinjected:
|
|
if (sp != NULL)
|
|
KEY_FREESP(&sp);
|
|
return -1;
|
|
bad:
|
|
if (sp != NULL)
|
|
KEY_FREESP(&sp);
|
|
return 1;
|
|
#endif /* IPSEC */
|
|
return 0;
|
|
}
|