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2608aefc0b
freebsd/sys/netipsec/ipsec.c
Bjoern A. Zeeb 13a6cf24ac Announce both IPsec and UDP Encap (NAT-T) if available for 
feature_present(3) checks.

This will help to run-time detect and conditionally handle specific
optionas of either feature in user space (i.e. in libipsec).

Descriptions read by:	rwatson
MFC after:		2 weeks
2010-10-30 18:52:44 +00:00

1750 lines
44 KiB
C
Raw Blame History

/* $FreeBSD$ */
/* $KAME: ipsec.c,v 1.103 2001/05/24 07:14:18 sakane Exp $ */
/*-
* 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/time.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <sys/proc.h>
#include <net/if.h>
#include <net/route.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/key.h>
#include <netipsec/keydb.h>
#include <netipsec/key_debug.h>
#include <netipsec/xform.h>
#include <machine/in_cksum.h>
#include <opencrypto/cryptodev.h>
#ifdef IPSEC_DEBUG
VNET_DEFINE(int, ipsec_debug) = 1;
#else
VNET_DEFINE(int, ipsec_debug) = 0;
#endif
/* NB: name changed so netstat doesn't use it. */
VNET_DEFINE(struct ipsecstat, ipsec4stat);
VNET_DEFINE(int, ip4_ah_offsetmask) = 0; /* maybe IP_DF? */
/* 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;
VNET_DEFINE(struct secpolicy, ip4_def_policy);
/* ECN ignore(-1)/forbidden(0)/allowed(1) */
VNET_DEFINE(int, ip4_ipsec_ecn) = 0;
VNET_DEFINE(int, ip4_esp_randpad) = -1;
/*
* 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;
FEATURE(ipsec, "Internet Protocol Security (IPsec)");
#ifdef IPSEC_NAT_T
FEATURE(ipsec_natt, "UDP Encapsulation of IPsec ESP Packets ('NAT-T')");
#endif
SYSCTL_DECL(_net_inet_ipsec);
/* net.inet.ipsec */
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DEF_POLICY, def_policy,
CTLFLAG_RW, &VNET_NAME(ip4_def_policy).policy, 0,
"IPsec default policy.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev,
CTLFLAG_RW, &VNET_NAME(ip4_esp_trans_deflev), 0,
"Default ESP transport mode level");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev,
CTLFLAG_RW, &VNET_NAME(ip4_esp_net_deflev), 0,
"Default ESP tunnel mode level.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev,
CTLFLAG_RW, &VNET_NAME(ip4_ah_trans_deflev), 0,
"AH transfer mode default level.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev,
CTLFLAG_RW, &VNET_NAME(ip4_ah_net_deflev), 0,
"AH tunnel mode default level.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_AH_CLEARTOS, ah_cleartos,
CTLFLAG_RW, &VNET_NAME(ah_cleartos), 0,
"If set clear type-of-service field when doing AH computation.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_AH_OFFSETMASK, ah_offsetmask,
CTLFLAG_RW, &VNET_NAME(ip4_ah_offsetmask), 0,
"If not set clear offset field mask when doing AH computation.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DFBIT, dfbit,
CTLFLAG_RW, &VNET_NAME(ip4_ipsec_dfbit), 0,
"Do not fragment bit on encap.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_ECN, ecn,
CTLFLAG_RW, &VNET_NAME(ip4_ipsec_ecn), 0,
"Explicit Congestion Notification handling.");
SYSCTL_VNET_INT(_net_inet_ipsec, IPSECCTL_DEBUG, debug,
CTLFLAG_RW, &VNET_NAME(ipsec_debug), 0,
"Enable IPsec debugging output when set.");
SYSCTL_VNET_INT(_net_inet_ipsec, OID_AUTO, crypto_support,
CTLFLAG_RW, &VNET_NAME(crypto_support), 0,
"Crypto driver selection.");
SYSCTL_VNET_STRUCT(_net_inet_ipsec, OID_AUTO, ipsecstats,
CTLFLAG_RD, &VNET_NAME(ipsec4stat), ipsecstat,
"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_VNET_INT(_net_inet_ipsec, OID_AUTO, test_replay,
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_VNET_INT(_net_inet_ipsec, OID_AUTO, test_integrity,
CTLFLAG_RW, &VNET_NAME(ipsec_integrity), 0,
"Emulate man-in-the-middle attack");
#endif
#ifdef INET6
VNET_DEFINE(struct ipsecstat, ipsec6stat);
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) */
SYSCTL_DECL(_net_inet6_ipsec6);
/* net.inet6.ipsec6 */
#ifdef COMPAT_KAME
SYSCTL_OID(_net_inet6_ipsec6, IPSECCTL_STATS, stats, CTLFLAG_RD,
0, 0, compat_ipsecstats_sysctl, "S", "IPsec IPv6 statistics.");
#endif /* COMPAT_KAME */
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_DEF_POLICY, def_policy, CTLFLAG_RW,
&VNET_NAME(ip4_def_policy).policy, 0,
"IPsec default policy.");
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_TRANSLEV,
esp_trans_deflev, CTLFLAG_RW, &VNET_NAME(ip6_esp_trans_deflev), 0,
"Default ESP transport mode level.");
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_NETLEV,
esp_net_deflev, CTLFLAG_RW, &VNET_NAME(ip6_esp_net_deflev), 0,
"Default ESP tunnel mode level.");
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_TRANSLEV,
ah_trans_deflev, CTLFLAG_RW, &VNET_NAME(ip6_ah_trans_deflev), 0,
"AH transfer mode default level.");
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_NETLEV,
ah_net_deflev, CTLFLAG_RW, &VNET_NAME(ip6_ah_net_deflev), 0,
"AH tunnel mode default level.");
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_ECN,
ecn, CTLFLAG_RW, &VNET_NAME(ip6_ipsec_ecn), 0,
"Explicit Congestion Notification handling.");
SYSCTL_VNET_INT(_net_inet6_ipsec6, IPSECCTL_DEBUG, debug, CTLFLAG_RW,
&VNET_NAME(ipsec_debug), 0,
"Enable IPsec debugging output when set.");
SYSCTL_VNET_STRUCT(_net_inet6_ipsec6, IPSECCTL_STATS,
ipsecstats, CTLFLAG_RD, &VNET_NAME(ipsec6stat), ipsecstat,
"IPsec IPv6 statistics.");
#endif /* INET6 */
static int ipsec_setspidx_inpcb __P((struct mbuf *, struct inpcb *));
static int ipsec_setspidx __P((struct mbuf *, struct secpolicyindex *, int));
static void ipsec4_get_ulp __P((struct mbuf *m, struct secpolicyindex *, int));
static int ipsec4_setspidx_ipaddr __P((struct mbuf *, struct secpolicyindex *));
#ifdef INET6
static void ipsec6_get_ulp __P((struct mbuf *m, struct secpolicyindex *, int));
static int ipsec6_setspidx_ipaddr __P((struct mbuf *, struct secpolicyindex *));
#endif
static void ipsec_delpcbpolicy __P((struct inpcbpolicy *));
static struct secpolicy *ipsec_deepcopy_policy __P((struct secpolicy *src));
static void vshiftl __P((unsigned char *, int, int));
MALLOC_DEFINE(M_IPSEC_INPCB, "inpcbpolicy", "inpcb-resident ipsec policy");
/*
* Return a held reference to the default SP.
*/
static struct secpolicy *
key_allocsp_default(const char* where, int tag)
{
struct secpolicy *sp;
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP key_allocsp_default from %s:%u\n", where, tag));
sp = &V_ip4_def_policy;
if (sp->policy != IPSEC_POLICY_DISCARD &&
sp->policy != IPSEC_POLICY_NONE) {
ipseclog((LOG_INFO, "fixed system default policy: %d->%d\n",
sp->policy, IPSEC_POLICY_NONE));
sp->policy = IPSEC_POLICY_NONE;
}
key_addref(sp);
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP key_allocsp_default returns SP:%p (%u)\n",
sp, sp->refcnt));
return (sp);
}
#define KEY_ALLOCSP_DEFAULT() \
key_allocsp_default(__FILE__, __LINE__)
/*
* For OUTBOUND packet having a socket. Searching SPD for packet,
* and return a pointer to SP.
* OUT: NULL: no apropreate SP found, the following value is set to error.
* 0 : bypass
* EACCES : discard packet.
* ENOENT : ipsec_acquire() in progress, maybe.
* others : error occured.
* others: a pointer to SP
*
* NOTE: IPv6 mapped adddress concern is implemented here.
*/
struct secpolicy *
ipsec_getpolicy(struct tdb_ident *tdbi, u_int dir)
{
struct secpolicy *sp;
IPSEC_ASSERT(tdbi != NULL, ("null tdbi"));
IPSEC_ASSERT(dir == IPSEC_DIR_INBOUND || dir == IPSEC_DIR_OUTBOUND,
("invalid direction %u", dir));
sp = KEY_ALLOCSP2(tdbi->spi, &tdbi->dst, tdbi->proto, dir);
if (sp == NULL) /*XXX????*/
sp = KEY_ALLOCSP_DEFAULT();
IPSEC_ASSERT(sp != NULL, ("null SP"));
return (sp);
}
/*
* For OUTBOUND packet having a socket. Searching SPD for packet,
* and return a pointer to SP.
* OUT: NULL: no apropreate SP found, the following value is set to error.
* 0 : bypass
* EACCES : discard packet.
* ENOENT : ipsec_acquire() in progress, maybe.
* others : error occured.
* others: a pointer to SP
*
* NOTE: IPv6 mapped adddress concern is implemented here.
*/
static struct secpolicy *
ipsec_getpolicybysock(struct mbuf *m, u_int dir, struct inpcb *inp, int *error)
{
struct inpcbpolicy *pcbsp;
struct secpolicy *currsp = NULL; /* Policy on socket. */
struct secpolicy *sp;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
IPSEC_ASSERT(inp != NULL, ("null inpcb"));
IPSEC_ASSERT(error != NULL, ("null error"));
IPSEC_ASSERT(dir == IPSEC_DIR_INBOUND || dir == IPSEC_DIR_OUTBOUND,
("invalid direction %u", dir));
/* Set spidx in pcb. */
*error = ipsec_setspidx_inpcb(m, inp);
if (*error)
return (NULL);
pcbsp = inp->inp_sp;
IPSEC_ASSERT(pcbsp != NULL, ("null pcbsp"));
switch (dir) {
case IPSEC_DIR_INBOUND:
currsp = pcbsp->sp_in;
break;
case IPSEC_DIR_OUTBOUND:
currsp = pcbsp->sp_out;
break;
}
IPSEC_ASSERT(currsp != NULL, ("null currsp"));
if (pcbsp->priv) { /* When privilieged socket. */
switch (currsp->policy) {
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_IPSEC:
key_addref(currsp);
sp = currsp;
break;
case IPSEC_POLICY_ENTRUST:
/* Look for a policy in SPD. */
sp = KEY_ALLOCSP(&currsp->spidx, dir);
if (sp == NULL) /* No SP found. */
sp = KEY_ALLOCSP_DEFAULT();
break;
default:
ipseclog((LOG_ERR, "%s: Invalid policy for PCB %d\n",
__func__, currsp->policy));
*error = EINVAL;
return (NULL);
}
} else { /* Unpriv, SPD has policy. */
sp = KEY_ALLOCSP(&currsp->spidx, dir);
if (sp == NULL) { /* No SP found. */
switch (currsp->policy) {
case IPSEC_POLICY_BYPASS:
ipseclog((LOG_ERR, "%s: Illegal policy for "
"non-priviliged defined %d\n",
__func__, currsp->policy));
*error = EINVAL;
return (NULL);
case IPSEC_POLICY_ENTRUST:
sp = KEY_ALLOCSP_DEFAULT();
break;
case IPSEC_POLICY_IPSEC:
key_addref(currsp);
sp = currsp;
break;
default:
ipseclog((LOG_ERR, "%s: Invalid policy for "
"PCB %d\n", __func__, currsp->policy));
*error = EINVAL;
return (NULL);
}
}
}
IPSEC_ASSERT(sp != NULL,
("null SP (priv %u policy %u", pcbsp->priv, currsp->policy));
KEYDEBUG(KEYDEBUG_IPSEC_STAMP,
printf("DP %s (priv %u policy %u) allocate SP:%p (refcnt %u)\n",
__func__, pcbsp->priv, currsp->policy, sp, sp->refcnt));
return (sp);
}
/*
* For FORWADING packet or OUTBOUND without a socket. Searching SPD for packet,
* and return a pointer to SP.
* OUT: positive: a pointer to the entry for security policy leaf matched.
* NULL: no apropreate SP found, the following value is set to error.
* 0 : bypass
* EACCES : discard packet.
* ENOENT : ipsec_acquire() in progress, maybe.
* others : error occured.
*/
struct secpolicy *
ipsec_getpolicybyaddr(struct mbuf *m, u_int dir, int flag, int *error)
{
struct secpolicyindex spidx;
struct secpolicy *sp;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
IPSEC_ASSERT(error != NULL, ("null error"));
IPSEC_ASSERT(dir == IPSEC_DIR_INBOUND || dir == IPSEC_DIR_OUTBOUND,
("invalid direction %u", dir));
sp = NULL;
if (key_havesp(dir)) {
/* Make an index to look for a policy. */
*error = ipsec_setspidx(m, &spidx,
(flag & IP_FORWARDING) ? 0 : 1);
if (*error != 0) {
DPRINTF(("%s: setpidx failed, dir %u flag %u\n",
__func__, dir, flag));
return (NULL);
}
spidx.dir = dir;
sp = KEY_ALLOCSP(&spidx, dir);
}
if (sp == NULL) /* No SP found, use system default. */
sp = KEY_ALLOCSP_DEFAULT();
IPSEC_ASSERT(sp != NULL, ("null SP"));
return (sp);
}
struct secpolicy *
ipsec4_checkpolicy(struct mbuf *m, u_int dir, u_int flag, int *error,
struct inpcb *inp)
{
struct secpolicy *sp;
*error = 0;
if (inp == NULL)
sp = ipsec_getpolicybyaddr(m, dir, flag, error);
else
sp = ipsec_getpolicybysock(m, dir, inp, error);
if (sp == NULL) {
IPSEC_ASSERT(*error != 0, ("getpolicy failed w/o error"));
V_ipsec4stat.ips_out_inval++;
return (NULL);
}
IPSEC_ASSERT(*error == 0, ("sp w/ error set to %u", *error));
switch (sp->policy) {
case IPSEC_POLICY_ENTRUST:
default:
printf("%s: invalid policy %u\n", __func__, sp->policy);
/* FALLTHROUGH */
case IPSEC_POLICY_DISCARD:
V_ipsec4stat.ips_out_polvio++;
*error = -EINVAL; /* Packet is discarded by caller. */
break;
case IPSEC_POLICY_BYPASS:
case IPSEC_POLICY_NONE:
KEY_FREESP(&sp);
sp = NULL; /* NB: force NULL result. */
break;
case IPSEC_POLICY_IPSEC:
if (sp->req == NULL) /* Acquire a SA. */
*error = key_spdacquire(sp);
break;
}
if (*error != 0) {
KEY_FREESP(&sp);
sp = NULL;
}
return (sp);
}
static int
ipsec_setspidx_inpcb(struct mbuf *m, struct inpcb *inp)
{
int error;
IPSEC_ASSERT(inp != NULL, ("null inp"));
IPSEC_ASSERT(inp->inp_sp != NULL, ("null inp_sp"));
IPSEC_ASSERT(inp->inp_sp->sp_out != NULL && inp->inp_sp->sp_in != NULL,
("null sp_in || sp_out"));
error = ipsec_setspidx(m, &inp->inp_sp->sp_in->spidx, 1);
if (error == 0) {
inp->inp_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND;
inp->inp_sp->sp_out->spidx = inp->inp_sp->sp_in->spidx;
inp->inp_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND;
} else {
bzero(&inp->inp_sp->sp_in->spidx,
sizeof (inp->inp_sp->sp_in->spidx));
bzero(&inp->inp_sp->sp_out->spidx,
sizeof (inp->inp_sp->sp_in->spidx));
}
return (error);
}
/*
* Configure security policy index (src/dst/proto/sport/dport)
* by looking at the content of mbuf.
* The caller is responsible for error recovery (like clearing up spidx).
*/
static int
ipsec_setspidx(struct mbuf *m, struct secpolicyindex *spidx, int needport)
{
struct ip *ip = NULL;
struct ip ipbuf;
u_int v;
struct mbuf *n;
int len;
int error;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
/*
* Validate m->m_pkthdr.len. We see incorrect length if we
* mistakenly call this function with inconsistent mbuf chain
* (like 4.4BSD tcp/udp processing). XXX Should we panic here?
*/
len = 0;
for (n = m; n; n = n->m_next)
len += n->m_len;
if (m->m_pkthdr.len != len) {
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: pkthdr len(%d) mismatch (%d), ignored.\n",
__func__, len, m->m_pkthdr.len));
return (EINVAL);
}
if (m->m_pkthdr.len < sizeof(struct ip)) {
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: pkthdr len(%d) too small (v4), ignored.\n",
__func__, m->m_pkthdr.len));
return (EINVAL);
}
if (m->m_len >= sizeof(*ip))
ip = mtod(m, struct ip *);
else {
m_copydata(m, 0, sizeof(ipbuf), (caddr_t)&ipbuf);
ip = &ipbuf;
}
#ifdef _IP_VHL
v = _IP_VHL_V(ip->ip_vhl);
#else
v = ip->ip_v;
#endif
switch (v) {
case 4:
error = ipsec4_setspidx_ipaddr(m, spidx);
if (error)
return (error);
ipsec4_get_ulp(m, spidx, needport);
return (0);
#ifdef INET6
case 6:
if (m->m_pkthdr.len < sizeof(struct ip6_hdr)) {
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: pkthdr len(%d) too small (v6), "
"ignored\n", __func__, m->m_pkthdr.len));
return (EINVAL);
}
error = ipsec6_setspidx_ipaddr(m, spidx);
if (error)
return (error);
ipsec6_get_ulp(m, spidx, needport);
return (0);
#endif
default:
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: " "unknown IP version %u, ignored.\n",
__func__, v));
return (EINVAL);
}
}
static void
ipsec4_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport)
{
u_int8_t nxt;
int off;
/* Sanity check. */
IPSEC_ASSERT(m != NULL, ("null mbuf"));
IPSEC_ASSERT(m->m_pkthdr.len >= sizeof(struct ip),("packet too short"));
/* NB: ip_input() flips it into host endian. XXX Need more checking. */
if (m->m_len >= sizeof (struct ip)) {
struct ip *ip = mtod(m, struct ip *);
if (ip->ip_off & (IP_MF | IP_OFFMASK))
goto done;
#ifdef _IP_VHL
off = _IP_VHL_HL(ip->ip_vhl) << 2;
#else
off = ip->ip_hl << 2;
#endif
nxt = ip->ip_p;
} else {
struct ip ih;
m_copydata(m, 0, sizeof (struct ip), (caddr_t) &ih);
if (ih.ip_off & (IP_MF | IP_OFFMASK))
goto done;
#ifdef _IP_VHL
off = _IP_VHL_HL(ih.ip_vhl) << 2;
#else
off = ih.ip_hl << 2;
#endif
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;
}
/* Assumes that m is sane. */
static int
ipsec4_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx)
{
static const struct sockaddr_in template = {
sizeof (struct sockaddr_in),
AF_INET,
0, { 0 }, { 0, 0, 0, 0, 0, 0, 0, 0 }
};
spidx->src.sin = template;
spidx->dst.sin = template;
if (m->m_len < sizeof (struct ip)) {
m_copydata(m, offsetof(struct ip, ip_src),
sizeof (struct in_addr),
(caddr_t) &spidx->src.sin.sin_addr);
m_copydata(m, offsetof(struct ip, ip_dst),
sizeof (struct in_addr),
(caddr_t) &spidx->dst.sin.sin_addr);
} else {
struct ip *ip = mtod(m, struct ip *);
spidx->src.sin.sin_addr = ip->ip_src;
spidx->dst.sin.sin_addr = ip->ip_dst;
}
spidx->prefs = sizeof(struct in_addr) << 3;
spidx->prefd = sizeof(struct in_addr) << 3;
return (0);
}
#ifdef INET6
static void
ipsec6_get_ulp(struct mbuf *m, struct secpolicyindex *spidx, int needport)
{
int off, nxt;
struct tcphdr th;
struct udphdr uh;
struct icmp6_hdr ih;
/* Sanity check. */
if (m == NULL)
panic("%s: NULL pointer was passed.\n", __func__);
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s:\n", __func__); kdebug_mbuf(m));
/* Set default. */
spidx->ul_proto = IPSEC_ULPROTO_ANY;
((struct sockaddr_in6 *)&spidx->src)->sin6_port = IPSEC_PORT_ANY;
((struct sockaddr_in6 *)&spidx->dst)->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);
((struct sockaddr_in6 *)&spidx->src)->sin6_port = th.th_sport;
((struct sockaddr_in6 *)&spidx->dst)->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);
((struct sockaddr_in6 *)&spidx->src)->sin6_port = uh.uh_sport;
((struct sockaddr_in6 *)&spidx->dst)->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);
((struct sockaddr_in6 *)&spidx->src)->sin6_port =
htons((uint16_t)ih.icmp6_type);
((struct sockaddr_in6 *)&spidx->dst)->sin6_port =
htons((uint16_t)ih.icmp6_code);
break;
default:
/* XXX Intermediate headers??? */
spidx->ul_proto = nxt;
break;
}
}
/* Assumes that m is sane. */
static int
ipsec6_setspidx_ipaddr(struct mbuf *m, struct secpolicyindex *spidx)
{
struct ip6_hdr *ip6 = NULL;
struct ip6_hdr ip6buf;
struct sockaddr_in6 *sin6;
if (m->m_len >= sizeof(*ip6))
ip6 = mtod(m, struct ip6_hdr *);
else {
m_copydata(m, 0, sizeof(ip6buf), (caddr_t)&ip6buf);
ip6 = &ip6buf;
}
sin6 = (struct sockaddr_in6 *)&spidx->src;
bzero(sin6, sizeof(*sin6));
sin6->sin6_family = AF_INET6;
sin6->sin6_len = sizeof(struct sockaddr_in6);
bcopy(&ip6->ip6_src, &sin6->sin6_addr, sizeof(ip6->ip6_src));
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_src)) {
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id = ntohs(ip6->ip6_src.s6_addr16[1]);
}
spidx->prefs = sizeof(struct in6_addr) << 3;
sin6 = (struct sockaddr_in6 *)&spidx->dst;
bzero(sin6, sizeof(*sin6));
sin6->sin6_family = AF_INET6;
sin6->sin6_len = sizeof(struct sockaddr_in6);
bcopy(&ip6->ip6_dst, &sin6->sin6_addr, sizeof(ip6->ip6_dst));
if (IN6_IS_SCOPE_LINKLOCAL(&ip6->ip6_dst)) {
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id = ntohs(ip6->ip6_dst.s6_addr16[1]);
}
spidx->prefd = sizeof(struct in6_addr) << 3;
return (0);
}
#endif
static void
ipsec_delpcbpolicy(struct inpcbpolicy *p)
{
free(p, M_IPSEC_INPCB);
}
/* Initialize policy in PCB. */
int
ipsec_init_policy(struct socket *so, struct inpcbpolicy **pcb_sp)
{
struct inpcbpolicy *new;
/* Sanity check. */
if (so == NULL || pcb_sp == NULL)
panic("%s: NULL pointer was passed.\n", __func__);
new = (struct inpcbpolicy *) malloc(sizeof(struct inpcbpolicy),
M_IPSEC_INPCB, M_NOWAIT|M_ZERO);
if (new == NULL) {
ipseclog((LOG_DEBUG, "%s: No more memory.\n", __func__));
return (ENOBUFS);
}
new->priv = IPSEC_IS_PRIVILEGED_SO(so);
if ((new->sp_in = KEY_NEWSP()) == NULL) {
ipsec_delpcbpolicy(new);
return (ENOBUFS);
}
new->sp_in->state = IPSEC_SPSTATE_ALIVE;
new->sp_in->policy = IPSEC_POLICY_ENTRUST;
if ((new->sp_out = KEY_NEWSP()) == NULL) {
KEY_FREESP(&new->sp_in);
ipsec_delpcbpolicy(new);
return (ENOBUFS);
}
new->sp_out->state = IPSEC_SPSTATE_ALIVE;
new->sp_out->policy = IPSEC_POLICY_ENTRUST;
*pcb_sp = new;
return (0);
}
/* Copy old IPsec policy into new. */
int
ipsec_copy_policy(struct inpcbpolicy *old, struct inpcbpolicy *new)
{
struct secpolicy *sp;
sp = ipsec_deepcopy_policy(old->sp_in);
if (sp) {
KEY_FREESP(&new->sp_in);
new->sp_in = sp;
} else
return (ENOBUFS);
sp = ipsec_deepcopy_policy(old->sp_out);
if (sp) {
KEY_FREESP(&new->sp_out);
new->sp_out = sp;
} else
return (ENOBUFS);
new->priv = old->priv;
return (0);
}
struct ipsecrequest *
ipsec_newisr(void)
{
struct ipsecrequest *p;
p = malloc(sizeof(struct ipsecrequest), M_IPSEC_SR, M_NOWAIT|M_ZERO);
if (p != NULL)
IPSECREQUEST_LOCK_INIT(p);
return (p);
}
void
ipsec_delisr(struct ipsecrequest *p)
{
IPSECREQUEST_LOCK_DESTROY(p);
free(p, M_IPSEC_SR);
}
/* Deep-copy a policy in PCB. */
static struct secpolicy *
ipsec_deepcopy_policy(struct secpolicy *src)
{
struct ipsecrequest *newchain = NULL;
struct ipsecrequest *p;
struct ipsecrequest **q;
struct ipsecrequest *r;
struct secpolicy *dst;
if (src == NULL)
return (NULL);
dst = KEY_NEWSP();
if (dst == NULL)
return (NULL);
/*
* Deep-copy IPsec request chain. This is required since struct
* ipsecrequest is not reference counted.
*/
q = &newchain;
for (p = src->req; p; p = p->next) {
*q = ipsec_newisr();
if (*q == NULL)
goto fail;
(*q)->saidx.proto = p->saidx.proto;
(*q)->saidx.mode = p->saidx.mode;
(*q)->level = p->level;
(*q)->saidx.reqid = p->saidx.reqid;
bcopy(&p->saidx.src, &(*q)->saidx.src, sizeof((*q)->saidx.src));
bcopy(&p->saidx.dst, &(*q)->saidx.dst, sizeof((*q)->saidx.dst));
(*q)->sp = dst;
q = &((*q)->next);
}
dst->req = newchain;
dst->state = src->state;
dst->policy = src->policy;
/* Do not touch the refcnt fields. */
return (dst);
fail:
for (p = newchain; p; p = r) {
r = p->next;
ipsec_delisr(p);
p = NULL;
}
return (NULL);
}
/* Set policy and IPsec request if present. */
static int
ipsec_set_policy_internal(struct secpolicy **pcb_sp, int optname,
caddr_t request, size_t len, struct ucred *cred)
{
struct sadb_x_policy *xpl;
struct secpolicy *newsp = NULL;
int error;
/* Sanity check. */
if (pcb_sp == NULL || *pcb_sp == NULL || request == NULL)
return (EINVAL);
if (len < sizeof(*xpl))
return (EINVAL);
xpl = (struct sadb_x_policy *)request;
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: passed policy\n", __func__);
kdebug_sadb_x_policy((struct sadb_ext *)xpl));
/* Check policy type. */
/* ipsec_set_policy_internal() accepts IPSEC, ENTRUST and BYPASS. */
if (xpl->sadb_x_policy_type == IPSEC_POLICY_DISCARD
|| xpl->sadb_x_policy_type == IPSEC_POLICY_NONE)
return (EINVAL);
/* Check privileged socket. */
if (cred != NULL && xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS) {
error = priv_check_cred(cred, PRIV_NETINET_IPSEC, 0);
if (error)
return (EACCES);
}
/* Allocating new SP entry. */
if ((newsp = key_msg2sp(xpl, len, &error)) == NULL)
return (error);
newsp->state = IPSEC_SPSTATE_ALIVE;
/* Clear old SP and set new SP. */
KEY_FREESP(pcb_sp);
*pcb_sp = newsp;
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: new policy\n", __func__);
kdebug_secpolicy(newsp));
return (0);
}
int
ipsec_set_policy(struct inpcb *inp, int optname, caddr_t request,
size_t len, struct ucred *cred)
{
struct sadb_x_policy *xpl;
struct secpolicy **pcb_sp;
/* Sanity check. */
if (inp == NULL || request == NULL)
return (EINVAL);
if (len < sizeof(*xpl))
return (EINVAL);
xpl = (struct sadb_x_policy *)request;
/* Select direction. */
switch (xpl->sadb_x_policy_dir) {
case IPSEC_DIR_INBOUND:
pcb_sp = &inp->inp_sp->sp_in;
break;
case IPSEC_DIR_OUTBOUND:
pcb_sp = &inp->inp_sp->sp_out;
break;
default:
ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
xpl->sadb_x_policy_dir));
return (EINVAL);
}
return (ipsec_set_policy_internal(pcb_sp, optname, request, len, cred));
}
int
ipsec_get_policy(struct inpcb *inp, caddr_t request, size_t len,
struct mbuf **mp)
{
struct sadb_x_policy *xpl;
struct secpolicy *pcb_sp;
/* Sanity check. */
if (inp == NULL || request == NULL || mp == NULL)
return (EINVAL);
IPSEC_ASSERT(inp->inp_sp != NULL, ("null inp_sp"));
if (len < sizeof(*xpl))
return (EINVAL);
xpl = (struct sadb_x_policy *)request;
/* Select direction. */
switch (xpl->sadb_x_policy_dir) {
case IPSEC_DIR_INBOUND:
pcb_sp = inp->inp_sp->sp_in;
break;
case IPSEC_DIR_OUTBOUND:
pcb_sp = inp->inp_sp->sp_out;
break;
default:
ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
xpl->sadb_x_policy_dir));
return (EINVAL);
}
/* Sanity check. Should be an IPSEC_ASSERT. */
if (pcb_sp == NULL)
return (EINVAL);
*mp = key_sp2msg(pcb_sp);
if (!*mp) {
ipseclog((LOG_DEBUG, "%s: No more memory.\n", __func__));
return (ENOBUFS);
}
(*mp)->m_type = MT_DATA;
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s:\n", __func__); kdebug_mbuf(*mp));
return (0);
}
/* Delete policy in PCB. */
int
ipsec_delete_pcbpolicy(struct inpcb *inp)
{
IPSEC_ASSERT(inp != NULL, ("null inp"));
if (inp->inp_sp == NULL)
return (0);
if (inp->inp_sp->sp_in != NULL)
KEY_FREESP(&inp->inp_sp->sp_in);
if (inp->inp_sp->sp_out != NULL)
KEY_FREESP(&inp->inp_sp->sp_out);
ipsec_delpcbpolicy(inp->inp_sp);
inp->inp_sp = NULL;
return (0);
}
/*
* Return current level.
* Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned.
*/
u_int
ipsec_get_reqlevel(struct ipsecrequest *isr)
{
u_int level = 0;
u_int esp_trans_deflev, esp_net_deflev;
u_int ah_trans_deflev, ah_net_deflev;
IPSEC_ASSERT(isr != NULL && isr->sp != NULL, ("null argument"));
IPSEC_ASSERT(isr->sp->spidx.src.sa.sa_family == isr->sp->spidx.dst.sa.sa_family,
("af family mismatch, src %u, dst %u",
isr->sp->spidx.src.sa.sa_family,
isr->sp->spidx.dst.sa.sa_family));
/* 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))
/* Set default level. */
switch (((struct sockaddr *)&isr->sp->spidx.src)->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__, isr->sp->spidx.src.sa.sa_family);
}
#undef IPSEC_CHECK_DEFAULT
/* 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);
}
/*
* 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
*/
int
ipsec_in_reject(struct secpolicy *sp, struct mbuf *m)
{
struct ipsecrequest *isr;
int need_auth;
KEYDEBUG(KEYDEBUG_IPSEC_DATA,
printf("%s: using SP\n", __func__); kdebug_secpolicy(sp));
/* 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));
/* XXX Should compare policy against IPsec header history. */
need_auth = 0;
for (isr = sp->req; isr != NULL; isr = isr->next) {
if (ipsec_get_reqlevel(isr) != IPSEC_LEVEL_REQUIRE)
continue;
switch (isr->saidx.proto) {
case IPPROTO_ESP:
if ((m->m_flags & M_DECRYPTED) == 0) {
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: ESP m_flags:%x\n", __func__,
m->m_flags));
return (1);
}
if (!need_auth &&
isr->sav != NULL &&
isr->sav->tdb_authalgxform != NULL &&
(m->m_flags & M_AUTHIPDGM) == 0) {
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: ESP/AH m_flags:%x\n", __func__,
m->m_flags));
return (1);
}
break;
case IPPROTO_AH:
need_auth = 1;
if ((m->m_flags & M_AUTHIPHDR) == 0) {
KEYDEBUG(KEYDEBUG_IPSEC_DUMP,
printf("%s: AH m_flags:%x\n", __func__,
m->m_flags));
return (1);
}
break;
case IPPROTO_IPCOMP:
/*
* We don't really care, as IPcomp document
* says that we shouldn't compress small
* packets. IPComp policy should always be
* treated as being in "use" level.
*/
break;
}
}
return (0); /* Valid. */
}
static int
ipsec46_in_reject(struct mbuf *m, struct inpcb *inp)
{
struct secpolicy *sp;
int error;
int result;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
/*
* Get SP for this packet.
* When we are called from ip_forward(), we call
* ipsec_getpolicybyaddr() with IP_FORWARDING flag.
*/
if (inp == NULL)
sp = ipsec_getpolicybyaddr(m, IPSEC_DIR_INBOUND, IP_FORWARDING, &error);
else
sp = ipsec_getpolicybysock(m, IPSEC_DIR_INBOUND, inp, &error);
if (sp != NULL) {
result = ipsec_in_reject(sp, m);
KEY_FREESP(&sp);
} else {
result = 0; /* XXX Should be panic?
* -> No, there may be error. */
}
return (result);
}
/*
* Check AH/ESP integrity.
* This function is called from tcp_input(), udp_input(),
* and {ah,esp}4_input for tunnel mode.
*/
int
ipsec4_in_reject(struct mbuf *m, struct inpcb *inp)
{
int result;
result = ipsec46_in_reject(m, inp);
if (result)
V_ipsec4stat.ips_in_polvio++;
return (result);
}
#ifdef INET6
/*
* Check AH/ESP integrity.
* This function is called from tcp6_input(), udp6_input(),
* and {ah,esp}6_input for tunnel mode.
*/
int
ipsec6_in_reject(struct mbuf *m, struct inpcb *inp)
{
int result;
result = ipsec46_in_reject(m, inp);
if (result)
V_ipsec6stat.ips_in_polvio++;
return (result);
}
#endif
/*
* Compute the byte size to be occupied by IPsec header.
* In case it is tunnelled, it includes the size of outer IP header.
* NOTE: SP passed is freed in this function.
*/
static size_t
ipsec_hdrsiz_internal(struct secpolicy *sp)
{
struct ipsecrequest *isr;
size_t size;
KEYDEBUG(KEYDEBUG_IPSEC_DATA,
printf("%s: using SP\n", __func__); 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));
size = 0;
for (isr = sp->req; isr != NULL; isr = isr->next) {
size_t clen = 0;
switch (isr->saidx.proto) {
case IPPROTO_ESP:
clen = esp_hdrsiz(isr->sav);
break;
case IPPROTO_AH:
clen = ah_hdrsiz(isr->sav);
break;
case IPPROTO_IPCOMP:
clen = sizeof(struct ipcomp);
break;
}
if (isr->saidx.mode == IPSEC_MODE_TUNNEL) {
switch (isr->saidx.dst.sa.sa_family) {
case AF_INET:
clen += sizeof(struct ip);
break;
#ifdef INET6
case AF_INET6:
clen += sizeof(struct ip6_hdr);
break;
#endif
default:
ipseclog((LOG_ERR, "%s: unknown AF %d in "
"IPsec tunnel SA\n", __func__,
((struct sockaddr *)&isr->saidx.dst)->sa_family));
break;
}
}
size += clen;
}
return (size);
}
/*
* This function is called from ipsec_hdrsiz_tcp(), ip_ipsec_mtu(),
* disabled ip6_ipsec_mtu() and ip6_forward().
*/
size_t
ipsec_hdrsiz(struct mbuf *m, u_int dir, struct inpcb *inp)
{
struct secpolicy *sp;
int error;
size_t size;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
/* Get SP for this packet.
* When we are called from ip_forward(), we call
* ipsec_getpolicybyaddr() with IP_FORWARDING flag.
*/
if (inp == NULL)
sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error);
else
sp = ipsec_getpolicybysock(m, dir, inp, &error);
if (sp != NULL) {
size = ipsec_hdrsiz_internal(sp);
KEYDEBUG(KEYDEBUG_IPSEC_DATA,
printf("%s: size:%lu.\n", __func__,
(unsigned long)size));
KEY_FREESP(&sp);
} else {
size = 0; /* XXX Should be panic?
* -> No, we are called w/o knowing if
* IPsec processing is needed. */
}
return (size);
}
/*
* 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 2401.
*/
int
ipsec_chkreplay(u_int32_t seq, struct secasvar *sav)
{
const struct secreplay *replay;
u_int32_t diff;
int fr;
u_int32_t wsizeb; /* Constant: bits of window size. */
int frlast; /* Constant: last frame. */
IPSEC_ASSERT(sav != NULL, ("Null SA"));
IPSEC_ASSERT(sav->replay != NULL, ("Null replay state"));
replay = sav->replay;
if (replay->wsize == 0)
return (1); /* No need to check replay. */
/* Constant. */
frlast = replay->wsize - 1;
wsizeb = replay->wsize << 3;
/* Sequence number of 0 is invalid. */
if (seq == 0)
return (0);
/* First time is always okay. */
if (replay->count == 0)
return (1);
if (seq > replay->lastseq) {
/* Larger sequences are okay. */
return (1);
} else {
/* seq is equal or less than lastseq. */
diff = replay->lastseq - seq;
/* Over range to check, i.e. too old or wrapped. */
if (diff >= wsizeb)
return (0);
fr = frlast - diff / 8;
/* This packet already seen? */
if ((replay->bitmap)[fr] & (1 << (diff % 8)))
return (0);
/* Out of order but good. */
return (1);
}
}
/*
* Check replay counter whether to update or not.
* OUT: 0: OK
* 1: NG
*/
int
ipsec_updatereplay(u_int32_t seq, struct secasvar *sav)
{
struct secreplay *replay;
u_int32_t diff;
int fr;
u_int32_t wsizeb; /* Constant: bits of window size. */
int frlast; /* Constant: last frame. */
IPSEC_ASSERT(sav != NULL, ("Null SA"));
IPSEC_ASSERT(sav->replay != NULL, ("Null replay state"));
replay = sav->replay;
if (replay->wsize == 0)
goto ok; /* No need to check replay. */
/* Constant. */
frlast = replay->wsize - 1;
wsizeb = replay->wsize << 3;
/* Sequence number of 0 is invalid. */
if (seq == 0)
return (1);
/* First time. */
if (replay->count == 0) {
replay->lastseq = seq;
bzero(replay->bitmap, replay->wsize);
(replay->bitmap)[frlast] = 1;
goto ok;
}
if (seq > replay->lastseq) {
/* seq is larger than lastseq. */
diff = seq - replay->lastseq;
/* New larger sequence number. */
if (diff < wsizeb) {
/* In window. */
/* Set bit for this packet. */
vshiftl(replay->bitmap, diff, replay->wsize);
(replay->bitmap)[frlast] |= 1;
} else {
/* This packet has a "way larger". */
bzero(replay->bitmap, replay->wsize);
(replay->bitmap)[frlast] = 1;
}
replay->lastseq = seq;
/* Larger is good. */
} else {
/* seq is equal or less than lastseq. */
diff = replay->lastseq - seq;
/* Over range to check, i.e. too old or wrapped. */
if (diff >= wsizeb)
return (1);
fr = frlast - diff / 8;
/* This packet already seen? */
if ((replay->bitmap)[fr] & (1 << (diff % 8)))
return (1);
/* Mark as seen. */
(replay->bitmap)[fr] |= (1 << (diff % 8));
/* Out of order but good. */
}
ok:
if (replay->count == ~0) {
/* Set overflow flag. */
replay->overflow++;
/* Don't increment, no more packets accepted. */
if ((sav->flags & SADB_X_EXT_CYCSEQ) == 0)
return (1);
ipseclog((LOG_WARNING, "%s: replay counter made %d cycle. %s\n",
__func__, replay->overflow, ipsec_logsastr(sav)));
}
replay->count++;
return (0);
}
/*
* Shift variable length buffer to left.
* IN: bitmap: pointer to the buffer
* nbit: the number of to shift.
* wsize: buffer size (bytes).
*/
static void
vshiftl(unsigned char *bitmap, int nbit, int wsize)
{
int s, j, i;
unsigned char over;
for (j = 0; j < nbit; j += 8) {
s = (nbit - j < 8) ? (nbit - j): 8;
bitmap[0] <<= s;
for (i = 1; i < wsize; i++) {
over = (bitmap[i] >> (8 - s));
bitmap[i] <<= s;
bitmap[i-1] |= over;
}
}
}
#ifdef INET
/* Return a printable string for the IPv4 address. */
static char *
inet_ntoa4(struct in_addr ina)
{
static char buf[4][4 * sizeof "123" + 4];
unsigned char *ucp = (unsigned char *) &ina;
static int i = 3;
/* XXX-BZ Returns static buffer. */
i = (i + 1) % 4;
sprintf(buf[i], "%d.%d.%d.%d", ucp[0] & 0xff, ucp[1] & 0xff,
ucp[2] & 0xff, ucp[3] & 0xff);
return (buf[i]);
}
#endif
/* Return a printable string for the address. */
char *
ipsec_address(union sockaddr_union* sa)
{
#ifdef INET6
char ip6buf[INET6_ADDRSTRLEN];
#endif
switch (sa->sa.sa_family) {
#ifdef INET
case AF_INET:
return (inet_ntoa4(sa->sin.sin_addr));
#endif /* INET */
#ifdef INET6
case AF_INET6:
return (ip6_sprintf(ip6buf, &sa->sin6.sin6_addr));
#endif /* INET6 */
default:
return ("(unknown address family)");
}
}
const char *
ipsec_logsastr(struct secasvar *sav)
{
static char buf[256];
char *p;
struct secasindex *saidx = &sav->sah->saidx;
IPSEC_ASSERT(saidx->src.sa.sa_family == saidx->dst.sa.sa_family,
("address family mismatch"));
p = buf;
snprintf(buf, sizeof(buf), "SA(SPI=%u ", (u_int32_t)ntohl(sav->spi));
while (p && *p)
p++;
/* NB: only use ipsec_address on one address at a time. */
snprintf(p, sizeof (buf) - (p - buf), "src=%s ",
ipsec_address(&saidx->src));
while (p && *p)
p++;
snprintf(p, sizeof (buf) - (p - buf), "dst=%s)",
ipsec_address(&saidx->dst));
return (buf);
}
void
ipsec_dumpmbuf(struct mbuf *m)
{
int totlen;
int i;
u_char *p;
totlen = 0;
printf("---\n");
while (m) {
p = mtod(m, u_char *);
for (i = 0; i < m->m_len; i++) {
printf("%02x ", p[i]);
totlen++;
if (totlen % 16 == 0)
printf("\n");
}
m = m->m_next;
}
if (totlen % 16 != 0)
printf("\n");
printf("---\n");
}
static void
ipsec_init(const void *unused __unused)
{
SECPOLICY_LOCK_INIT(&V_ip4_def_policy);
V_ip4_def_policy.refcnt = 1; /* NB: disallow free. */
}
VNET_SYSINIT(ipsec_init, SI_SUB_PROTO_DOMAININIT, SI_ORDER_ANY, ipsec_init,
NULL);
/* XXX This stuff doesn't belong here... */
static struct xformsw* xforms = NULL;
/*
* Register a transform; typically at system startup.
*/
void
xform_register(struct xformsw* xsp)
{
xsp->xf_next = xforms;
xforms = xsp;
}
/*
* Initialize transform support in an sav.
*/
int
xform_init(struct secasvar *sav, int xftype)
{
struct xformsw *xsp;
if (sav->tdb_xform != NULL) /* Previously initialized. */
return (0);
for (xsp = xforms; xsp; xsp = xsp->xf_next)
if (xsp->xf_type == xftype)
return ((*xsp->xf_init)(sav, xsp));
return (EINVAL);
}
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