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HardenedBSD/sys/netipsec/ipsec.c
Kornel Duleba 6b66194bcb ipsec: Check PMTU before sending a frame. 
If an encapsulated frame is going to have DF bit set check its desitnitions'
PMTU and if it won't fit drop it and:

Generate ICMP 3/4 message if the packet was to be forwarded.
Return EMSGSIZE error otherwise.

Obtained from:		Semihalf
Sponsored by:		Stormshield
Differential revision:	https://reviews.freebsd.org/D30993
2021-08-13 09:22:24 +02:00

1535 lines
41 KiB
C
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/* $FreeBSD$ */
/* $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_ipsec_min_pmtu) = 576;
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_MIN_PMTU, min_pmtu,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(ip4_ipsec_min_pmtu), 0,
"Lowest acceptable PMTU value.");
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.
*/
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);
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