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freebsd-skq/sys/netipsec/ipsec.c
Gleb Smirnoff 8f134647ca Switch the entire IPv4 stack to keep the IP packet header 
in network byte order. Any host byte order processing is
done in local variables and host byte order values are
never[1] written to a packet.

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

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

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

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

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

1749 lines
44 KiB
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/* $FreeBSD$ */
/* $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"));
if (m->m_len >= sizeof (struct ip)) {
struct ip *ip = mtod(m, struct ip *);
if (ip->ip_off & htons(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 & htons(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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