hardenedbsd/HardenedBSD
1
0
Fork 0
mirror of https://git.hardenedbsd.org/hardenedbsd/HardenedBSD.git synced 2024-12-28 22:36:24 +01:00
Code Issues Actions Packages Projects Releases Wiki Activity
cc32b2eda8
HardenedBSD/sys/netinet6/ip6_ipsec.c
Gleb Smirnoff 8f134647ca Switch the entire IPv4 stack to keep the IP packet header 
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

  After this change a packet processed by the stack isn't
modified at all[2] except for TTL.

  After this change a network stack hacker doesn't need to
scratch his head trying to figure out what is the byte order
at the given place in the stack.

[1] One exception still remains. The raw sockets convert host
byte order before pass a packet to an application. Probably
this would remain for ages for compatibility.

[2] The ip_input() still subtructs header len from ip->ip_len,
but this is planned to be fixed soon.

Reviewed by:	luigi, Maxim Dounin <mdounin mdounin.ru>
Tested by:	ray, Olivier Cochard-Labbe <olivier cochard.me>
2012-10-22 21:09:03 +00:00

386 lines
10 KiB
C
Raw Blame History

/*-
* 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mac.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 <sys/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/ip_options.h>
#include <machine/in_cksum.h>
#ifdef IPSEC
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#include <netipsec/xform.h>
#include <netipsec/key.h>
#ifdef IPSEC_DEBUG
#include <netipsec/key_debug.h>
#else
#define KEYDEBUG(lev,arg)
#endif
#endif /*IPSEC*/
#include <netinet6/ip6_ipsec.h>
#include <netinet6/ip6_var.h>
extern struct protosw inet6sw[];
#ifdef INET6
#ifdef IPSEC
#ifdef IPSEC_FILTERTUNNEL
static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 1;
#else
static VNET_DEFINE(int, ip6_ipsec6_filtertunnel) = 0;
#endif
#define V_ip6_ipsec6_filtertunnel VNET(ip6_ipsec6_filtertunnel)
SYSCTL_DECL(_net_inet6_ipsec6);
SYSCTL_VNET_INT(_net_inet6_ipsec6, OID_AUTO,
filtertunnel, CTLFLAG_RW, &VNET_NAME(ip6_ipsec6_filtertunnel), 0,
"If set filter packets from an IPsec tunnel.");
#endif /* IPSEC */
#endif /* INET6 */
/*
* Check if we have to jump over firewall processing for this packet.
* Called from ip6_input().
* 1 = jump over firewall, 0 = packet goes through firewall.
*/
int
ip6_ipsec_filtertunnel(struct mbuf *m)
{
#ifdef IPSEC
/*
* Bypass packet filtering for packets previously handled by IPsec.
*/
if (!V_ip6_ipsec6_filtertunnel &&
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 ip6_input().
* 1 = drop packet, 0 = forward packet.
*/
int
ip6_ipsec_fwd(struct mbuf *m)
{
#ifdef IPSEC
struct m_tag *mtag;
struct tdb_ident *tdbi;
struct secpolicy *sp;
int error;
mtag = m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL);
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 */
/*XXX error stat???*/
DPRINTF(("%s: no SP for forwarding\n", __func__)); /*XXX*/
return 1;
}
/*
* Check security policy against packet attributes.
*/
error = ipsec_in_reject(sp, m);
KEY_FREESP(&sp);
if (error) {
V_ip6stat.ip6s_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 ip6_input().
* 1 = drop packet, 0 = continue processing packet.
*/
int
ip6_ipsec_input(struct mbuf *m, int nxt)
{
#ifdef IPSEC
struct m_tag *mtag;
struct tdb_ident *tdbi;
struct secpolicy *sp;
int 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 ((inet6sw[ip6_protox[nxt]].pr_flags & PR_LASTHDR) != 0 &&
ipsec6_in_reject(m, NULL)) {
/*
* 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);
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(("%s: no SP, packet discarded\n", __func__));/*XXX*/
return 1;
}
if (error)
return 1;
}
#endif /* IPSEC */
return 0;
}
/*
* Called from ip6_output().
* 1 = drop packet, 0 = continue processing packet,
* -1 = packet was reinjected and stop processing packet
*/
int
ip6_ipsec_output(struct mbuf **m, struct inpcb *inp, int *flags, int *error,
struct ifnet **ifp, struct secpolicy **sp)
{
#ifdef IPSEC
struct tdb_ident *tdbi;
struct m_tag *mtag;
/* XXX int s; */
if (sp == NULL)
return 1;
mtag = m_tag_find(*m, PACKET_TAG_IPSEC_PENDING_TDB, NULL);
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 no 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;
goto done;
}
}
/*
* Do delayed checksums now because we send before
* this is done in the normal processing path.
* For IPv6 we do delayed checksums in ip6_output.c.
*/
#ifdef INET
if ((*m)->m_pkthdr.csum_flags & CSUM_DELAY_DATA) {
ipseclog((LOG_DEBUG,
"%s: we do not support IPv4 over IPv6", __func__));
in_delayed_cksum(*m);
(*m)->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
#endif
/*
* 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;
goto do_ipsec;
} else { /* sp == NULL */
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. */
}
}
done:
return 0;
do_ipsec:
return -1;
bad:
return 1;
#endif /* IPSEC */
return 0;
}
#if 0
/*
* Compute the MTU for a forwarded packet that gets IPSEC encapsulated.
* Called from ip_forward().
* Returns MTU suggestion for ICMP needfrag reply.
*/
int
ip6_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!!!
*/
#ifdef IPSEC
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 = ipsec_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->route_cache.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);
}
#endif /* IPSEC */
/* XXX else case missing. */
return mtu;
}
#endif
Reference in New Issue View Git Blame Copy Permalink