d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
e35c28a24b
freebsd-dev/sys/netipsec/ipsec.c
Marcin Wojtas 8b7f39947c Implement anti-replay algorithm with ESN support 
As RFC 4304 describes there is anti-replay algorithm responsibility
to provide appropriate value of Extended Sequence Number.

This patch introduces anti-replay algorithm with ESN support based on
RFC 4304, however to avoid performance regressions window implementation
was based on RFC 6479, which was already implemented in FreeBSD.

To keep things clean and improve code readability, implementation of window
is kept in seperate functions.

Submitted by:           Grzegorz Jaszczyk <jaz@semihalf.com>
                        Patryk Duda <pdk@semihalf.com>
Reviewed by:            jhb
Differential revision:  https://reviews.freebsd.org/D22367
Obtained from:          Semihalf
Sponsored by:           Stormshield
2020-10-16 11:24:12 +00:00

1531 lines
41 KiB
C
Raw Blame History

/* $FreeBSD$ */
/* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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.
*/
/*
* IPsec controller part.
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/domain.h>
#include <sys/priv.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/errno.h>
#include <sys/hhook.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <net/if.h>
#include <net/if_enc.h>
#include <net/if_var.h>
#include <net/vnet.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/udp.h>
#include <netinet/udp_var.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/ip6.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#endif
#include <netinet/in_pcb.h>
#ifdef INET6
#include <netinet/icmp6.h>
#endif
#include <sys/types.h>
#include <netipsec/ipsec.h>
#ifdef INET6
#include <netipsec/ipsec6.h>
#endif
#include <netipsec/ah_var.h>
#include <netipsec/esp_var.h>
#include <netipsec/ipcomp.h> /*XXX*/
#include <netipsec/ipcomp_var.h>
#include <netipsec/ipsec_support.h>
#include <netipsec/key.h>
#include <netipsec/keydb.h>
#include <netipsec/key_debug.h>
#include <netipsec/xform.h>
#include <machine/in_cksum.h>
#include <opencrypto/cryptodev.h>
/* NB: name changed so netstat doesn't use it. */
VNET_PCPUSTAT_DEFINE(struct ipsecstat, ipsec4stat);
VNET_PCPUSTAT_SYSINIT(ipsec4stat);
#ifdef VIMAGE
VNET_PCPUSTAT_SYSUNINIT(ipsec4stat);
#endif /* VIMAGE */
/* DF bit on encap. 0: clear 1: set 2: copy */
VNET_DEFINE(int, ip4_ipsec_dfbit) = 0;
VNET_DEFINE(int, ip4_esp_trans_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip4_esp_net_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip4_ah_trans_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip4_ah_net_deflev) = IPSEC_LEVEL_USE;
/* ECN ignore(-1)/forbidden(0)/allowed(1) */
VNET_DEFINE(int, ip4_ipsec_ecn) = 0;
VNET_DEFINE_STATIC(int, ip4_filtertunnel) = 0;
#define V_ip4_filtertunnel VNET(ip4_filtertunnel)
VNET_DEFINE_STATIC(int, check_policy_history) = 0;
#define V_check_policy_history VNET(check_policy_history)
VNET_DEFINE_STATIC(struct secpolicy *, def_policy) = NULL;
#define V_def_policy VNET(def_policy)
static int
sysctl_def_policy(SYSCTL_HANDLER_ARGS)
{
int error, value;
value = V_def_policy->policy;
error = sysctl_handle_int(oidp, &value, 0, req);
if (error == 0) {
if (value != IPSEC_POLICY_DISCARD &&
value != IPSEC_POLICY_NONE)
return (EINVAL);
V_def_policy->policy = value;
}
return (error);
}
/*
* Crypto support requirements:
*
* 1 require hardware support
* -1 require software support
* 0 take anything
*/
VNET_DEFINE(int, crypto_support) = CRYPTOCAP_F_HARDWARE | CRYPTOCAP_F_SOFTWARE;
/*
* Use asynchronous mode to parallelize crypto jobs:
*
* 0 - disabled
* 1 - enabled
*/
VNET_DEFINE(int, async_crypto) = 0;
/*
* TCP/UDP checksum handling policy for transport mode NAT-T (RFC3948)
*
* 0 - auto: incrementally recompute, when checksum delta is known;
* if checksum delta isn't known, reset checksum to zero for UDP,
* and mark csum_flags as valid for TCP.
* 1 - fully recompute TCP/UDP checksum.
*/
VNET_DEFINE(int, natt_cksum_policy) = 0;
FEATURE(ipsec, "Internet Protocol Security (IPsec)");
FEATURE(ipsec_natt, "UDP Encapsulation of IPsec ESP Packets ('NAT-T')");
SYSCTL_DECL(_net_inet_ipsec);
/* net.inet.ipsec */
SYSCTL_PROC(_net_inet_ipsec, IPSECCTL_DEF_POLICY, def_policy,
CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
0, 0, sysctl_def_policy, "I",
"IPsec default policy.");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_esp_trans_deflev), 0,
"Default ESP transport mode level");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_esp_net_deflev), 0,
"Default ESP tunnel mode level.");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_trans_deflev), 0,
"AH transfer mode default level.");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ah_net_deflev), 0,
"AH tunnel mode default level.");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_AH_CLEARTOS, ah_cleartos,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0,
"If set, clear type-of-service field when doing AH computation.");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DFBIT, dfbit,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_dfbit), 0,
"Do not fragment bit on encap.");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ECN, ecn,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_ecn), 0,
"Explicit Congestion Notification handling.");
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, crypto_support,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(crypto_support), 0,
"Crypto driver selection.");
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, async_crypto,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(async_crypto), 0,
"Use asynchronous mode to parallelize crypto jobs.");
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, check_policy_history,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(check_policy_history), 0,
"Use strict check of inbound packets to security policy compliance.");
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, natt_cksum_policy,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(natt_cksum_policy), 0,
"Method to fix TCP/UDP checksum for transport mode IPsec after NAT.");
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, filtertunnel,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_filtertunnel), 0,
"If set, filter packets from an IPsec tunnel.");
SYSCTL_VNET_PCPUSTAT(_net_inet_ipsec, OID_AUTO, ipsecstats, struct ipsecstat,
ipsec4stat, "IPsec IPv4 statistics.");
#ifdef REGRESSION
/*
* When set to 1, IPsec will send packets with the same sequence number.
* This allows to verify if the other side has proper replay attacks detection.
*/
VNET_DEFINE(int, ipsec_replay) = 0;
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_replay,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsec_replay), 0,
"Emulate replay attack");
/*
* When set 1, IPsec will send packets with corrupted HMAC.
* This allows to verify if the other side properly detects modified packets.
*/
VNET_DEFINE(int, ipsec_integrity) = 0;
SYSCTL_INT(_net_inet_ipsec, OID_AUTO, test_integrity,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ipsec_integrity), 0,
"Emulate man-in-the-middle attack");
#endif
#ifdef INET6
VNET_PCPUSTAT_DEFINE(struct ipsecstat, ipsec6stat);
VNET_PCPUSTAT_SYSINIT(ipsec6stat);
#ifdef VIMAGE
VNET_PCPUSTAT_SYSUNINIT(ipsec6stat);
#endif /* VIMAGE */
VNET_DEFINE(int, ip6_esp_trans_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip6_esp_net_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip6_ah_trans_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip6_ah_net_deflev) = IPSEC_LEVEL_USE;
VNET_DEFINE(int, ip6_ipsec_ecn) = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */
VNET_DEFINE_STATIC(int, ip6_filtertunnel) = 0;
#define V_ip6_filtertunnel VNET(ip6_filtertunnel)
SYSCTL_DECL(_net_inet6_ipsec6);
/* net.inet6.ipsec6 */
SYSCTL_PROC(_net_inet6_ipsec6, IPSECCTL_DEF_POLICY, def_policy,
CTLTYPE_INT | CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
0, 0, sysctl_def_policy, "I",
"IPsec default policy.");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_esp_trans_deflev), 0,
"Default ESP transport mode level.");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_esp_net_deflev), 0,
"Default ESP tunnel mode level.");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ah_trans_deflev), 0,
"AH transfer mode default level.");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ah_net_deflev), 0,
"AH tunnel mode default level.");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ECN, ecn,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_ipsec_ecn), 0,
"Explicit Congestion Notification handling.");
SYSCTL_INT(_net_inet6_ipsec6, OID_AUTO, filtertunnel,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip6_filtertunnel), 0,
"If set, filter packets from an IPsec tunnel.");
SYSCTL_VNET_PCPUSTAT(_net_inet6_ipsec6, IPSECCTL_STATS, ipsecstats,
struct ipsecstat, ipsec6stat, "IPsec IPv6 statistics.");
#endif /* INET6 */
static int ipsec_in_reject(struct secpolicy *, struct inpcb *,
const struct mbuf *);
#ifdef INET
static void ipsec4_get_ulp(const struct mbuf *, struct secpolicyindex *, int);
static void ipsec4_setspidx_ipaddr(const struct mbuf *,
struct secpolicyindex *);
#endif
#ifdef INET6
static void ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *, int);
static void ipsec6_setspidx_ipaddr(const struct mbuf *,
struct secpolicyindex *);
#endif
/*
* Return a held reference to the default SP.
*/
static struct secpolicy *
key_allocsp_default(void)
{
key_addref(V_def_policy);
return (V_def_policy);
}
static void
ipsec_invalidate_cache(struct inpcb *inp, u_int dir)
{
struct secpolicy *sp;
INP_WLOCK_ASSERT(inp);
if (dir == IPSEC_DIR_OUTBOUND) {
if (inp->inp_sp->flags & INP_INBOUND_POLICY)
return;
sp = inp->inp_sp->sp_in;
inp->inp_sp->sp_in = NULL;
} else {
if (inp->inp_sp->flags & INP_OUTBOUND_POLICY)
return;
sp = inp->inp_sp->sp_out;
inp->inp_sp->sp_out = NULL;
}
if (sp != NULL)
key_freesp(&sp); /* release extra reference */
}
static void
ipsec_cachepolicy(struct inpcb *inp, struct secpolicy *sp, u_int dir)
{
uint32_t genid;
int downgrade;
INP_LOCK_ASSERT(inp);
if (dir == IPSEC_DIR_OUTBOUND) {
/* Do we have configured PCB policy? */
if (inp->inp_sp->flags & INP_OUTBOUND_POLICY)
return;
/* Another thread has already set cached policy */
if (inp->inp_sp->sp_out != NULL)
return;
/*
* Do not cache OUTBOUND policy if PCB isn't connected,
* i.e. foreign address is INADDR_ANY/UNSPECIFIED.
*/
#ifdef INET
if ((inp->inp_vflag & INP_IPV4) != 0 &&
inp->inp_faddr.s_addr == INADDR_ANY)
return;
#endif
#ifdef INET6
if ((inp->inp_vflag & INP_IPV6) != 0 &&
IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
return;
#endif
} else {
/* Do we have configured PCB policy? */
if (inp->inp_sp->flags & INP_INBOUND_POLICY)
return;
/* Another thread has already set cached policy */
if (inp->inp_sp->sp_in != NULL)
return;
/*
* Do not cache INBOUND policy for listen socket,
* that is bound to INADDR_ANY/UNSPECIFIED address.
*/
#ifdef INET
if ((inp->inp_vflag & INP_IPV4) != 0 &&
inp->inp_faddr.s_addr == INADDR_ANY)
return;
#endif
#ifdef INET6
if ((inp->inp_vflag & INP_IPV6) != 0 &&
IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_faddr))
return;
#endif
}
downgrade = 0;
if (!INP_WLOCKED(inp)) {
if ((downgrade = INP_TRY_UPGRADE(inp)) == 0)
return;
}
if (dir == IPSEC_DIR_OUTBOUND)
inp->inp_sp->sp_out = sp;
else
inp->inp_sp->sp_in = sp;
/*
* SP is already referenced by the lookup code.
* We take extra reference here to avoid race in the
* ipsec_getpcbpolicy() function - SP will not be freed in the
* time between we take SP pointer from the cache and key_addref()
* call.
*/
key_addref(sp);
genid = key_getspgen();
if (genid != inp->inp_sp->genid) {
ipsec_invalidate_cache(inp, dir);
inp->inp_sp->genid = genid;
}
KEYDBG(IPSEC_STAMP,
printf("%s: PCB(%p): cached %s SP(%p)\n",
__func__, inp, dir == IPSEC_DIR_OUTBOUND ? "OUTBOUND":
"INBOUND", sp));
if (downgrade != 0)
INP_DOWNGRADE(inp);
}
static struct secpolicy *
ipsec_checkpolicy(struct secpolicy *sp, struct inpcb *inp, int *error)
{
/* Save found OUTBOUND policy into PCB SP cache. */
if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_out == NULL)
ipsec_cachepolicy(inp, sp, IPSEC_DIR_OUTBOUND);
switch (sp->policy) {
default:
printf("%s: invalid policy %u\n", __func__, sp->policy);
/* FALLTHROUGH */
case IPSEC_POLICY_DISCARD:
*error = -EINVAL; /* Packet is discarded by caller. */
/* FALLTHROUGH */
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_NONE:
key_freesp(&sp);
sp = NULL; /* NB: force NULL result. */
break;
case IPSEC_POLICY_IPSEC:
/* XXXAE: handle LARVAL SP */
break;
}
KEYDBG(IPSEC_DUMP,
printf("%s: get SP(%p), error %d\n", __func__, sp, *error));
return (sp);
}
static struct secpolicy *
ipsec_getpcbpolicy(struct inpcb *inp, u_int dir)
{
struct secpolicy *sp;
int flags, downgrade;
if (inp == NULL || inp->inp_sp == NULL)
return (NULL);
INP_LOCK_ASSERT(inp);
flags = inp->inp_sp->flags;
if (dir == IPSEC_DIR_OUTBOUND) {
sp = inp->inp_sp->sp_out;
flags &= INP_OUTBOUND_POLICY;
} else {
sp = inp->inp_sp->sp_in;
flags &= INP_INBOUND_POLICY;
}
/*
* Check flags. If we have PCB SP, just return it.
* Otherwise we need to check that cached SP entry isn't stale.
*/
if (flags == 0) {
if (sp == NULL)
return (NULL);
if (inp->inp_sp->genid != key_getspgen()) {
/* Invalidate the cache. */
downgrade = 0;
if (!INP_WLOCKED(inp)) {
if ((downgrade = INP_TRY_UPGRADE(inp)) == 0)
return (NULL);
}
ipsec_invalidate_cache(inp, IPSEC_DIR_OUTBOUND);
ipsec_invalidate_cache(inp, IPSEC_DIR_INBOUND);
if (downgrade != 0)
INP_DOWNGRADE(inp);
return (NULL);
}
KEYDBG(IPSEC_STAMP,
printf("%s: PCB(%p): cache hit SP(%p)\n",
__func__, inp, sp));
/* Return referenced cached policy */
}
key_addref(sp);
return (sp);
}
#ifdef INET
static void
ipsec4_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx,
int needport)
{
uint8_t nxt;
int off;
/* Sanity check. */
IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip),
("packet too short"));
if (m->m_len >= sizeof (struct ip)) {
const struct ip *ip = mtod(m, const struct ip *);
if (ip->ip_off & htons(IP_MF | IP_OFFMASK))
goto done;
off = ip->ip_hl << 2;
nxt = ip->ip_p;
} else {
struct ip ih;
m_copydata(m, 0, sizeof (struct ip), (caddr_t) &ih);
if (ih.ip_off & htons(IP_MF | IP_OFFMASK))
goto done;
off = ih.ip_hl << 2;
nxt = ih.ip_p;
}
while (off < m->m_pkthdr.len) {
struct ip6_ext ip6e;
struct tcphdr th;
struct udphdr uh;
switch (nxt) {
case IPPROTO_TCP:
spidx->ul_proto = nxt;
if (!needport)
goto done_proto;
if (off + sizeof(struct tcphdr) > m->m_pkthdr.len)
goto done;
m_copydata(m, off, sizeof (th), (caddr_t) &th);
spidx->src.sin.sin_port = th.th_sport;
spidx->dst.sin.sin_port = th.th_dport;
return;
case IPPROTO_UDP:
spidx->ul_proto = nxt;
if (!needport)
goto done_proto;
if (off + sizeof(struct udphdr) > m->m_pkthdr.len)
goto done;
m_copydata(m, off, sizeof (uh), (caddr_t) &uh);
spidx->src.sin.sin_port = uh.uh_sport;
spidx->dst.sin.sin_port = uh.uh_dport;
return;
case IPPROTO_AH:
if (off + sizeof(ip6e) > m->m_pkthdr.len)
goto done;
/* XXX Sigh, this works but is totally bogus. */
m_copydata(m, off, sizeof(ip6e), (caddr_t) &ip6e);
off += (ip6e.ip6e_len + 2) << 2;
nxt = ip6e.ip6e_nxt;
break;
case IPPROTO_ICMP:
default:
/* XXX Intermediate headers??? */
spidx->ul_proto = nxt;
goto done_proto;
}
}
done:
spidx->ul_proto = IPSEC_ULPROTO_ANY;
done_proto:
spidx->src.sin.sin_port = IPSEC_PORT_ANY;
spidx->dst.sin.sin_port = IPSEC_PORT_ANY;
KEYDBG(IPSEC_DUMP,
printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL));
}
static void
ipsec4_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx)
{
ipsec4_setsockaddrs(m, &spidx->src, &spidx->dst);
spidx->prefs = sizeof(struct in_addr) << 3;
spidx->prefd = sizeof(struct in_addr) << 3;
}
static struct secpolicy *
ipsec4_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir,
int needport)
{
struct secpolicyindex spidx;
struct secpolicy *sp;
sp = ipsec_getpcbpolicy(inp, dir);
if (sp == NULL && key_havesp(dir)) {
/* Make an index to look for a policy. */
ipsec4_setspidx_ipaddr(m, &spidx);
ipsec4_get_ulp(m, &spidx, needport);
spidx.dir = dir;
sp = key_allocsp(&spidx, dir);
}
if (sp == NULL) /* No SP found, use system default. */
sp = key_allocsp_default();
return (sp);
}
/*
* Check security policy for *OUTBOUND* IPv4 packet.
*/
struct secpolicy *
ipsec4_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error,
int needport)
{
struct secpolicy *sp;
*error = 0;
sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_OUTBOUND, needport);
if (sp != NULL)
sp = ipsec_checkpolicy(sp, inp, error);
if (sp == NULL) {
switch (*error) {
case 0: /* No IPsec required: BYPASS or NONE */
break;
case -EINVAL:
IPSECSTAT_INC(ips_out_polvio);
break;
default:
IPSECSTAT_INC(ips_out_inval);
}
}
KEYDBG(IPSEC_STAMP,
printf("%s: using SP(%p), error %d\n", __func__, sp, *error));
if (sp != NULL)
KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp));
return (sp);
}
/*
* Check IPv4 packet against *INBOUND* security policy.
* This function is called from tcp_input(), udp_input(),
* rip_input() and sctp_input().
*/
int
ipsec4_in_reject(const struct mbuf *m, struct inpcb *inp)
{
struct secpolicy *sp;
int result;
sp = ipsec4_getpolicy(m, inp, IPSEC_DIR_INBOUND, 0);
result = ipsec_in_reject(sp, inp, m);
key_freesp(&sp);
if (result != 0)
IPSECSTAT_INC(ips_in_polvio);
return (result);
}
/*
* IPSEC_CAP() method implementation for IPv4.
*/
int
ipsec4_capability(struct mbuf *m, u_int cap)
{
switch (cap) {
case IPSEC_CAP_BYPASS_FILTER:
/*
* Bypass packet filtering for packets previously handled
* by IPsec.
*/
if (!V_ip4_filtertunnel &&
m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
return (1);
return (0);
case IPSEC_CAP_OPERABLE:
/* Do we have active security policies? */
if (key_havesp(IPSEC_DIR_INBOUND) != 0 ||
key_havesp(IPSEC_DIR_OUTBOUND) != 0)
return (1);
return (0);
};
return (EOPNOTSUPP);
}
#endif /* INET */
#ifdef INET6
static void
ipsec6_get_ulp(const struct mbuf *m, struct secpolicyindex *spidx,
int needport)
{
struct tcphdr th;
struct udphdr uh;
struct icmp6_hdr ih;
int off, nxt;
IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip6_hdr),
("packet too short"));
/* Set default. */
spidx->ul_proto = IPSEC_ULPROTO_ANY;
spidx->src.sin6.sin6_port = IPSEC_PORT_ANY;
spidx->dst.sin6.sin6_port = IPSEC_PORT_ANY;
nxt = -1;
off = ip6_lasthdr(m, 0, IPPROTO_IPV6, &nxt);
if (off < 0 || m->m_pkthdr.len < off)
return;
switch (nxt) {
case IPPROTO_TCP:
spidx->ul_proto = nxt;
if (!needport)
break;
if (off + sizeof(struct tcphdr) > m->m_pkthdr.len)
break;
m_copydata(m, off, sizeof(th), (caddr_t)&th);
spidx->src.sin6.sin6_port = th.th_sport;
spidx->dst.sin6.sin6_port = th.th_dport;
break;
case IPPROTO_UDP:
spidx->ul_proto = nxt;
if (!needport)
break;
if (off + sizeof(struct udphdr) > m->m_pkthdr.len)
break;
m_copydata(m, off, sizeof(uh), (caddr_t)&uh);
spidx->src.sin6.sin6_port = uh.uh_sport;
spidx->dst.sin6.sin6_port = uh.uh_dport;
break;
case IPPROTO_ICMPV6:
spidx->ul_proto = nxt;
if (off + sizeof(struct icmp6_hdr) > m->m_pkthdr.len)
break;
m_copydata(m, off, sizeof(ih), (caddr_t)&ih);
spidx->src.sin6.sin6_port = htons((uint16_t)ih.icmp6_type);
spidx->dst.sin6.sin6_port = htons((uint16_t)ih.icmp6_code);
break;
default:
/* XXX Intermediate headers??? */
spidx->ul_proto = nxt;
break;
}
KEYDBG(IPSEC_DUMP,
printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL));
}
static void
ipsec6_setspidx_ipaddr(const struct mbuf *m, struct secpolicyindex *spidx)
{
ipsec6_setsockaddrs(m, &spidx->src, &spidx->dst);
spidx->prefs = sizeof(struct in6_addr) << 3;
spidx->prefd = sizeof(struct in6_addr) << 3;
}
static struct secpolicy *
ipsec6_getpolicy(const struct mbuf *m, struct inpcb *inp, u_int dir,
int needport)
{
struct secpolicyindex spidx;
struct secpolicy *sp;
sp = ipsec_getpcbpolicy(inp, dir);
if (sp == NULL && key_havesp(dir)) {
/* Make an index to look for a policy. */
ipsec6_setspidx_ipaddr(m, &spidx);
ipsec6_get_ulp(m, &spidx, needport);
spidx.dir = dir;
sp = key_allocsp(&spidx, dir);
}
if (sp == NULL) /* No SP found, use system default. */
sp = key_allocsp_default();
return (sp);
}
/*
* Check security policy for *OUTBOUND* IPv6 packet.
*/
struct secpolicy *
ipsec6_checkpolicy(const struct mbuf *m, struct inpcb *inp, int *error,
int needport)
{
struct secpolicy *sp;
*error = 0;
sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_OUTBOUND, needport);
if (sp != NULL)
sp = ipsec_checkpolicy(sp, inp, error);
if (sp == NULL) {
switch (*error) {
case 0: /* No IPsec required: BYPASS or NONE */
break;
case -EINVAL:
IPSEC6STAT_INC(ips_out_polvio);
break;
default:
IPSEC6STAT_INC(ips_out_inval);
}
}
KEYDBG(IPSEC_STAMP,
printf("%s: using SP(%p), error %d\n", __func__, sp, *error));
if (sp != NULL)
KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp));
return (sp);
}
/*
* Check IPv6 packet against inbound security policy.
* This function is called from tcp6_input(), udp6_input(),
* rip6_input() and sctp_input().
*/
int
ipsec6_in_reject(const struct mbuf *m, struct inpcb *inp)
{
struct secpolicy *sp;
int result;
sp = ipsec6_getpolicy(m, inp, IPSEC_DIR_INBOUND, 0);
result = ipsec_in_reject(sp, inp, m);
key_freesp(&sp);
if (result)
IPSEC6STAT_INC(ips_in_polvio);
return (result);
}
/*
* IPSEC_CAP() method implementation for IPv6.
*/
int
ipsec6_capability(struct mbuf *m, u_int cap)
{
switch (cap) {
case IPSEC_CAP_BYPASS_FILTER:
/*
* Bypass packet filtering for packets previously handled
* by IPsec.
*/
if (!V_ip6_filtertunnel &&
m_tag_find(m, PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL)
return (1);
return (0);
case IPSEC_CAP_OPERABLE:
/* Do we have active security policies? */
if (key_havesp(IPSEC_DIR_INBOUND) != 0 ||
key_havesp(IPSEC_DIR_OUTBOUND) != 0)
return (1);
return (0);
};
return (EOPNOTSUPP);
}
#endif /* INET6 */
int
ipsec_run_hhooks(struct ipsec_ctx_data *ctx, int type)
{
int idx;
switch (ctx->af) {
#ifdef INET
case AF_INET:
idx = HHOOK_IPSEC_INET;
break;
#endif
#ifdef INET6
case AF_INET6:
idx = HHOOK_IPSEC_INET6;
break;
#endif
default:
return (EPFNOSUPPORT);
}
if (type == HHOOK_TYPE_IPSEC_IN)
HHOOKS_RUN_IF(V_ipsec_hhh_in[idx], ctx, NULL);
else
HHOOKS_RUN_IF(V_ipsec_hhh_out[idx], ctx, NULL);
if (*ctx->mp == NULL)
return (EACCES);
return (0);
}
/*
* Return current level.
* Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned.
*/
u_int
ipsec_get_reqlevel(struct secpolicy *sp, u_int idx)
{
struct ipsecrequest *isr;
u_int esp_trans_deflev, esp_net_deflev;
u_int ah_trans_deflev, ah_net_deflev;
u_int level = 0;
IPSEC_ASSERT(idx < sp->tcount, ("Wrong IPsec request index %d", idx));
/* XXX Note that we have ipseclog() expanded here - code sync issue. */
#define IPSEC_CHECK_DEFAULT(lev) \
(((lev) != IPSEC_LEVEL_USE && (lev) != IPSEC_LEVEL_REQUIRE && \
(lev) != IPSEC_LEVEL_UNIQUE) \
? (V_ipsec_debug ? \
log(LOG_INFO, "fixed system default level " #lev ":%d->%d\n",\
(lev), IPSEC_LEVEL_REQUIRE) : 0), \
(lev) = IPSEC_LEVEL_REQUIRE, (lev) : (lev))
/*
* IPsec VTI uses unique security policy with fake spidx filled
* with zeroes. Just return IPSEC_LEVEL_REQUIRE instead of doing
* full level lookup for such policies.
*/
if (sp->state == IPSEC_SPSTATE_IFNET) {
IPSEC_ASSERT(sp->req[idx]->level == IPSEC_LEVEL_UNIQUE,
("Wrong IPsec request level %d", sp->req[idx]->level));
return (IPSEC_LEVEL_REQUIRE);
}
/* Set default level. */
switch (sp->spidx.src.sa.sa_family) {
#ifdef INET
case AF_INET:
esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_trans_deflev);
esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_esp_net_deflev);
ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_trans_deflev);
ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip4_ah_net_deflev);
break;
#endif
#ifdef INET6
case AF_INET6:
esp_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_trans_deflev);
esp_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_esp_net_deflev);
ah_trans_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_trans_deflev);
ah_net_deflev = IPSEC_CHECK_DEFAULT(V_ip6_ah_net_deflev);
break;
#endif /* INET6 */
default:
panic("%s: unknown af %u",
__func__, sp->spidx.src.sa.sa_family);
}
#undef IPSEC_CHECK_DEFAULT
isr = sp->req[idx];
/* Set level. */
switch (isr->level) {
case IPSEC_LEVEL_DEFAULT:
switch (isr->saidx.proto) {
case IPPROTO_ESP:
if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
level = esp_net_deflev;
else
level = esp_trans_deflev;
break;
case IPPROTO_AH:
if (isr->saidx.mode == IPSEC_MODE_TUNNEL)
level = ah_net_deflev;
else
level = ah_trans_deflev;
break;
case IPPROTO_IPCOMP:
/*
* We don't really care, as IPcomp document says that
* we shouldn't compress small packets.
*/
level = IPSEC_LEVEL_USE;
break;
default:
panic("%s: Illegal protocol defined %u\n", __func__,
isr->saidx.proto);
}
break;
case IPSEC_LEVEL_USE:
case IPSEC_LEVEL_REQUIRE:
level = isr->level;
break;
case IPSEC_LEVEL_UNIQUE:
level = IPSEC_LEVEL_REQUIRE;
break;
default:
panic("%s: Illegal IPsec level %u\n", __func__, isr->level);
}
return (level);
}
static int
ipsec_check_history(const struct mbuf *m, struct secpolicy *sp, u_int idx)
{
struct xform_history *xh;
struct m_tag *mtag;
mtag = NULL;
while ((mtag = m_tag_find(__DECONST(struct mbuf *, m),
PACKET_TAG_IPSEC_IN_DONE, mtag)) != NULL) {
xh = (struct xform_history *)(mtag + 1);
KEYDBG(IPSEC_DATA,
char buf[IPSEC_ADDRSTRLEN];
printf("%s: mode %s proto %u dst %s\n", __func__,
kdebug_secasindex_mode(xh->mode), xh->proto,
ipsec_address(&xh->dst, buf, sizeof(buf))));
if (xh->proto != sp->req[idx]->saidx.proto)
continue;
/* If SA had IPSEC_MODE_ANY, consider this as match. */
if (xh->mode != sp->req[idx]->saidx.mode &&
xh->mode != IPSEC_MODE_ANY)
continue;
/*
* For transport mode IPsec request doesn't contain
* addresses. We need to use address from spidx.
*/
if (sp->req[idx]->saidx.mode == IPSEC_MODE_TRANSPORT) {
if (key_sockaddrcmp_withmask(&xh->dst.sa,
&sp->spidx.dst.sa, sp->spidx.prefd) != 0)
continue;
} else {
if (key_sockaddrcmp(&xh->dst.sa,
&sp->req[idx]->saidx.dst.sa, 0) != 0)
continue;
}
return (0); /* matched */
}
return (1);
}
/*
* Check security policy requirements against the actual
* packet contents. Return one if the packet should be
* reject as "invalid"; otherwiser return zero to have the
* packet treated as "valid".
*
* OUT:
* 0: valid
* 1: invalid
*/
static int
ipsec_in_reject(struct secpolicy *sp, struct inpcb *inp, const struct mbuf *m)
{
int i;
KEYDBG(IPSEC_STAMP,
printf("%s: PCB(%p): using SP(%p)\n", __func__, inp, sp));
KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp));
if (inp != NULL && inp->inp_sp != NULL && inp->inp_sp->sp_in == NULL)
ipsec_cachepolicy(inp, sp, IPSEC_DIR_INBOUND);
/* Check policy. */
switch (sp->policy) {
case IPSEC_POLICY_DISCARD:
return (1);
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_NONE:
return (0);
}
IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC,
("invalid policy %u", sp->policy));
/*
* ipsec[46]_common_input_cb after each transform adds
* PACKET_TAG_IPSEC_IN_DONE mbuf tag. It contains SPI, proto, mode
* and destination address from saidx. We can compare info from
* these tags with requirements in SP.
*/
for (i = 0; i < sp->tcount; i++) {
/*
* Do not check IPcomp, since IPcomp document
* says that we shouldn't compress small packets.
* IPComp policy should always be treated as being
* in "use" level.
*/
if (sp->req[i]->saidx.proto == IPPROTO_IPCOMP ||
ipsec_get_reqlevel(sp, i) != IPSEC_LEVEL_REQUIRE)
continue;
if (V_check_policy_history != 0 &&
ipsec_check_history(m, sp, i) != 0)
return (1);
else switch (sp->req[i]->saidx.proto) {
case IPPROTO_ESP:
if ((m->m_flags & M_DECRYPTED) == 0) {
KEYDBG(IPSEC_DUMP,
printf("%s: ESP m_flags:%x\n", __func__,
m->m_flags));
return (1);
}
break;
case IPPROTO_AH:
if ((m->m_flags & M_AUTHIPHDR) == 0) {
KEYDBG(IPSEC_DUMP,
printf("%s: AH m_flags:%x\n", __func__,
m->m_flags));
return (1);
}
break;
}
}
return (0); /* Valid. */
}
/*
* Compute the byte size to be occupied by IPsec header.
* In case it is tunnelled, it includes the size of outer IP header.
*/
static size_t
ipsec_hdrsiz_internal(struct secpolicy *sp)
{
size_t size;
int i;
KEYDBG(IPSEC_STAMP, printf("%s: using SP(%p)\n", __func__, sp));
KEYDBG(IPSEC_DATA, kdebug_secpolicy(sp));
switch (sp->policy) {
case IPSEC_POLICY_DISCARD:
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_NONE:
return (0);
}
IPSEC_ASSERT(sp->policy == IPSEC_POLICY_IPSEC,
("invalid policy %u", sp->policy));
/*
* XXX: for each transform we need to lookup suitable SA
* and use info from SA to calculate headers size.
* XXX: for NAT-T we need to cosider UDP header size.
*/
size = 0;
for (i = 0; i < sp->tcount; i++) {
switch (sp->req[i]->saidx.proto) {
case IPPROTO_ESP:
size += esp_hdrsiz(NULL);
break;
case IPPROTO_AH:
size += ah_hdrsiz(NULL);
break;
case IPPROTO_IPCOMP:
size += sizeof(struct ipcomp);
break;
}
if (sp->req[i]->saidx.mode == IPSEC_MODE_TUNNEL) {
switch (sp->req[i]->saidx.dst.sa.sa_family) {
#ifdef INET
case AF_INET:
size += sizeof(struct ip);
break;
#endif
#ifdef INET6
case AF_INET6:
size += sizeof(struct ip6_hdr);
break;
#endif
default:
ipseclog((LOG_ERR, "%s: unknown AF %d in "
"IPsec tunnel SA\n", __func__,
sp->req[i]->saidx.dst.sa.sa_family));
break;
}
}
}
return (size);
}
/*
* Compute ESP/AH header size for protocols with PCB, including
* outer IP header. Currently only tcp_output() uses it.
*/
size_t
ipsec_hdrsiz_inpcb(struct inpcb *inp)
{
struct secpolicyindex spidx;
struct secpolicy *sp;
size_t sz;
sp = ipsec_getpcbpolicy(inp, IPSEC_DIR_OUTBOUND);
if (sp == NULL && key_havesp(IPSEC_DIR_OUTBOUND)) {
ipsec_setspidx_inpcb(inp, &spidx, IPSEC_DIR_OUTBOUND);
sp = key_allocsp(&spidx, IPSEC_DIR_OUTBOUND);
}
if (sp == NULL)
sp = key_allocsp_default();
sz = ipsec_hdrsiz_internal(sp);
key_freesp(&sp);
return (sz);
}
#define IPSEC_BITMAP_INDEX_MASK(w) (w - 1)
#define IPSEC_REDUNDANT_BIT_SHIFTS 5
#define IPSEC_REDUNDANT_BITS (1 << IPSEC_REDUNDANT_BIT_SHIFTS)
#define IPSEC_BITMAP_LOC_MASK (IPSEC_REDUNDANT_BITS - 1)
/*
* Functions below are responsible for checking and updating bitmap.
* These are used to separate ipsec_chkreplay() and ipsec_updatereplay()
* from window implementation
*
* Based on RFC 6479. Blocks are 32 bits unsigned integers
*/
static inline int
check_window(const struct secreplay *replay, uint64_t seq)
{
int index, bit_location;
bit_location = seq & IPSEC_BITMAP_LOC_MASK;
index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS)
& IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size);
/* This packet already seen? */
return ((replay->bitmap)[index] & (1 << bit_location));
}
static inline void
advance_window(const struct secreplay *replay, uint64_t seq)
{
int i;
uint64_t index, index_cur, diff;
index_cur = replay->last >> IPSEC_REDUNDANT_BIT_SHIFTS;
index = seq >> IPSEC_REDUNDANT_BIT_SHIFTS;
diff = index - index_cur;
if (diff > replay->bitmap_size) {
/* something unusual in this case */
diff = replay->bitmap_size;
}
for (i = 0; i < diff; i++) {
replay->bitmap[(i + index_cur + 1)
& IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size)] = 0;
}
}
static inline void
set_window(const struct secreplay *replay, uint64_t seq)
{
int index, bit_location;
bit_location = seq & IPSEC_BITMAP_LOC_MASK;
index = (seq >> IPSEC_REDUNDANT_BIT_SHIFTS)
& IPSEC_BITMAP_INDEX_MASK(replay->bitmap_size);
replay->bitmap[index] |= (1 << bit_location);
}
/*
* Check the variable replay window.
* ipsec_chkreplay() performs replay check before ICV verification.
* ipsec_updatereplay() updates replay bitmap. This must be called after
* ICV verification (it also performs replay check, which is usually done
* beforehand).
* 0 (zero) is returned if packet disallowed, 1 if packet permitted.
*
* Based on RFC 4303
*/
int
ipsec_chkreplay(uint32_t seq, uint32_t *seqhigh, struct secasvar *sav)
{
char buf[128];
struct secreplay *replay;
uint32_t window;
uint32_t tl, th, bl;
uint32_t seqh;
IPSEC_ASSERT(sav != NULL, ("Null SA"));
IPSEC_ASSERT(sav->replay != NULL, ("Null replay state"));
replay = sav->replay;
/* No need to check replay if disabled. */
if (replay->wsize == 0)
return (1);
/* Zero sequence number is not allowed. */
if (seq == 0 && replay->last == 0)
return (0);
window = replay->wsize << 3; /* Size of window */
tl = (uint32_t)replay->last; /* Top of window, lower part */
th = (uint32_t)(replay->last >> 32); /* Top of window, high part */
bl = tl - window + 1; /* Bottom of window, lower part */
/*
* We keep the high part intact when:
* 1) the seq is within [bl, 0xffffffff] and the whole window is
* within one subspace;
* 2) the seq is within [0, bl) and window spans two subspaces.
*/
if ((tl >= window - 1 && seq >= bl) ||
(tl < window - 1 && seq < bl)) {
*seqhigh = th;
if (seq <= tl) {
/* Sequence number inside window - check against replay */
if (check_window(replay, seq))
return (0);
}
/* Sequence number above top of window or not found in bitmap */
return (1);
}
/*
* If ESN is not enabled and packet with highest sequence number
* was received we should report overflow
*/
if (tl == 0xffffffff && !(sav->flags & SADB_X_SAFLAGS_ESN)) {
/* Set overflow flag. */
replay->overflow++;
if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
if (sav->sah->saidx.proto == IPPROTO_ESP)
ESPSTAT_INC(esps_wrap);
else if (sav->sah->saidx.proto == IPPROTO_AH)
AHSTAT_INC(ahs_wrap);
return (0);
}
ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n",
__func__, replay->overflow,
ipsec_sa2str(sav, buf, sizeof(buf))));
}
/*
* Seq is within [bl, 0xffffffff] and bl is within
* [0xffffffff-window, 0xffffffff]. This means we got a seq
* which is within our replay window, but in the previous
* subspace.
*/
if (tl < window - 1 && seq >= bl) {
if (th == 0)
return (0);
*seqhigh = th - 1;
seqh = th - 1;
if (check_window(replay, seq))
return (0);
return (1);
}
/*
* Seq is within [0, bl) but the whole window is within one subspace.
* This means that seq has wrapped and is in next subspace
*/
*seqhigh = th + 1;
seqh = th + 1;
/* Don't let high part wrap. */
if (seqh == 0) {
/* Set overflow flag. */
replay->overflow++;
if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0) {
if (sav->sah->saidx.proto == IPPROTO_ESP)
ESPSTAT_INC(esps_wrap);
else if (sav->sah->saidx.proto == IPPROTO_AH)
AHSTAT_INC(ahs_wrap);
return (0);
}
ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n",
__func__, replay->overflow,
ipsec_sa2str(sav, buf, sizeof(buf))));
}
return (1);
}
/*
* Check replay counter whether to update or not.
* OUT: 0: OK
* 1: NG
*/
int
ipsec_updatereplay(uint32_t seq, struct secasvar *sav)
{
struct secreplay *replay;
uint32_t window;
uint32_t tl, th, bl;
uint32_t seqh;
IPSEC_ASSERT(sav != NULL, ("Null SA"));
IPSEC_ASSERT(sav->replay != NULL, ("Null replay state"));
replay = sav->replay;
/* No need to check replay if disabled. */
if (replay->wsize == 0)
return (0);
/* Zero sequence number is not allowed. */
if (seq == 0 && replay->last == 0)
return (1);
window = replay->wsize << 3; /* Size of window */
tl = (uint32_t)replay->last; /* Top of window, lower part */
th = (uint32_t)(replay->last >> 32); /* Top of window, high part */
bl = tl - window + 1; /* Bottom of window, lower part */
/*
* We keep the high part intact when:
* 1) the seq is within [bl, 0xffffffff] and the whole window is
* within one subspace;
* 2) the seq is within [0, bl) and window spans two subspaces.
*/
if ((tl >= window - 1 && seq >= bl) ||
(tl < window - 1 && seq < bl)) {
seqh = th;
if (seq <= tl) {
/* Sequence number inside window - check against replay */
if (check_window(replay, seq))
return (1);
set_window(replay, seq);
} else {
advance_window(replay, ((uint64_t)seqh << 32) | seq);
set_window(replay, seq);
replay->last = ((uint64_t)seqh << 32) | seq;
}
/* Sequence number above top of window or not found in bitmap */
replay->count++;
return (0);
}
if (!(sav->flags & SADB_X_SAFLAGS_ESN))
return (1);
/*
* Seq is within [bl, 0xffffffff] and bl is within
* [0xffffffff-window, 0xffffffff]. This means we got a seq
* which is within our replay window, but in the previous
* subspace.
*/
if (tl < window - 1 && seq >= bl) {
if (th == 0)
return (1);
if (check_window(replay, seq))
return (1);
set_window(replay, seq);
replay->count++;
return (0);
}
/*
* Seq is within [0, bl) but the whole window is within one subspace.
* This means that seq has wrapped and is in next subspace
*/
seqh = th + 1;
/* Don't let high part wrap. */
if (seqh == 0)
return (1);
advance_window(replay, ((uint64_t)seqh << 32) | seq);
set_window(replay, seq);
replay->last = ((uint64_t)seqh << 32) | seq;
replay->count++;
return (0);
}
int
ipsec_updateid(struct secasvar *sav, crypto_session_t *new,
crypto_session_t *old)
{
crypto_session_t tmp;
/*
* tdb_cryptoid is initialized by xform_init().
* Then it can be changed only when some crypto error occurred or
* when SA is deleted. We stored used cryptoid in the xform_data
* structure. In case when crypto error occurred and crypto
* subsystem has reinited the session, it returns new cryptoid
* and EAGAIN error code.
*
* This function will be called when we got EAGAIN from crypto
* subsystem.
* *new is cryptoid that was returned by crypto subsystem in
* the crp_sid.
* *old is the original cryptoid that we stored in xform_data.
*
* For first failed request *old == sav->tdb_cryptoid, then
* we update sav->tdb_cryptoid and redo crypto_dispatch().
* For next failed request *old != sav->tdb_cryptoid, then
* we store cryptoid from first request into the *new variable
* and crp_sid from this second session will be returned via
* *old pointer, so caller can release second session.
*
* XXXAE: check this more carefully.
*/
KEYDBG(IPSEC_STAMP,
printf("%s: SA(%p) moves cryptoid %p -> %p\n",
__func__, sav, *old, *new));
KEYDBG(IPSEC_DATA, kdebug_secasv(sav));
SECASVAR_LOCK(sav);
if (sav->tdb_cryptoid != *old) {
/* cryptoid was already updated */
tmp = *new;
*new = sav->tdb_cryptoid;
*old = tmp;
SECASVAR_UNLOCK(sav);
return (1);
}
sav->tdb_cryptoid = *new;
SECASVAR_UNLOCK(sav);
return (0);
}
int
ipsec_initialized(void)
{
return (V_def_policy != NULL);
}
static void
def_policy_init(const void *unused __unused)
{
V_def_policy = key_newsp();
if (V_def_policy != NULL) {
V_def_policy->policy = IPSEC_POLICY_NONE;
/* Force INPCB SP cache invalidation */
key_bumpspgen();
} else
printf("%s: failed to initialize default policy\n", __func__);
}
static void
def_policy_uninit(const void *unused __unused)
{
if (V_def_policy != NULL) {
key_freesp(&V_def_policy);
key_bumpspgen();
}
}
VNET_SYSINIT(def_policy_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST,
def_policy_init, NULL);
VNET_SYSUNINIT(def_policy_uninit, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST,
def_policy_uninit, NULL);
Reference in New Issue View Git Blame Copy Permalink