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freebsd-skq/sys/netipsec/ipsec.c
Warner Losh c398230b64 /* -> /*- for license, minor formatting changes
2005-01-07 01:45:51 +00:00

1932 lines
46 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/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 <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 <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>
#ifdef IPSEC_DEBUG
int ipsec_debug = 1;
#else
int ipsec_debug = 0;
#endif
/* NB: name changed so netstat doesn't use it */
struct newipsecstat newipsecstat;
int ip4_ah_offsetmask = 0; /* maybe IP_DF? */
int ip4_ipsec_dfbit = 0; /* DF bit on encap. 0: clear 1: set 2: copy */
int ip4_esp_trans_deflev = IPSEC_LEVEL_USE;
int ip4_esp_net_deflev = IPSEC_LEVEL_USE;
int ip4_ah_trans_deflev = IPSEC_LEVEL_USE;
int ip4_ah_net_deflev = IPSEC_LEVEL_USE;
struct secpolicy ip4_def_policy;
int ip4_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */
int ip4_esp_randpad = -1;
/*
* Crypto support requirements:
*
* 1 require hardware support
* -1 require software support
* 0 take anything
*/
int crypto_support = 0;
SYSCTL_DECL(_net_inet_ipsec);
/* net.inet.ipsec */
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_POLICY,
def_policy, CTLFLAG_RW, &ip4_def_policy.policy, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev,
CTLFLAG_RW, &ip4_esp_trans_deflev, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev,
CTLFLAG_RW, &ip4_esp_net_deflev, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev,
CTLFLAG_RW, &ip4_ah_trans_deflev, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev,
CTLFLAG_RW, &ip4_ah_net_deflev, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_AH_CLEARTOS,
ah_cleartos, CTLFLAG_RW, &ah_cleartos, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_AH_OFFSETMASK,
ah_offsetmask, CTLFLAG_RW, &ip4_ah_offsetmask, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DFBIT,
dfbit, CTLFLAG_RW, &ip4_ipsec_dfbit, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ECN,
ecn, CTLFLAG_RW, &ip4_ipsec_ecn, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_DEBUG,
debug, CTLFLAG_RW, &ipsec_debug, 0, "");
SYSCTL_INT(_net_inet_ipsec, IPSECCTL_ESP_RANDPAD,
esp_randpad, CTLFLAG_RW, &ip4_esp_randpad, 0, "");
SYSCTL_INT(_net_inet_ipsec, OID_AUTO,
crypto_support, CTLFLAG_RW, &crypto_support,0, "");
SYSCTL_STRUCT(_net_inet_ipsec, OID_AUTO,
ipsecstats, CTLFLAG_RD, &newipsecstat, newipsecstat, "");
#ifdef INET6
int ip6_esp_trans_deflev = IPSEC_LEVEL_USE;
int ip6_esp_net_deflev = IPSEC_LEVEL_USE;
int ip6_ah_trans_deflev = IPSEC_LEVEL_USE;
int ip6_ah_net_deflev = IPSEC_LEVEL_USE;
int ip6_ipsec_ecn = 0; /* ECN ignore(-1)/forbidden(0)/allowed(1) */
int ip6_esp_randpad = -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", "");
#endif /* COMPAT_KAME */
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_POLICY,
def_policy, CTLFLAG_RW, &ip4_def_policy.policy, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_TRANSLEV, esp_trans_deflev,
CTLFLAG_RW, &ip6_esp_trans_deflev, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_ESP_NETLEV, esp_net_deflev,
CTLFLAG_RW, &ip6_esp_net_deflev, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_TRANSLEV, ah_trans_deflev,
CTLFLAG_RW, &ip6_ah_trans_deflev, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEF_AH_NETLEV, ah_net_deflev,
CTLFLAG_RW, &ip6_ah_net_deflev, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ECN,
ecn, CTLFLAG_RW, &ip6_ipsec_ecn, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_DEBUG,
debug, CTLFLAG_RW, &ipsec_debug, 0, "");
SYSCTL_INT(_net_inet6_ipsec6, IPSECCTL_ESP_RANDPAD,
esp_randpad, CTLFLAG_RW, &ip6_esp_randpad, 0, "");
#endif /* INET6 */
static int ipsec4_setspidx_inpcb __P((struct mbuf *, struct inpcb *pcb));
#ifdef INET6
static int ipsec6_setspidx_in6pcb __P((struct mbuf *, struct in6pcb *pcb));
#endif
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 int ipsec_set_policy __P((struct secpolicy **pcb_sp,
int optname, caddr_t request, size_t len, int priv));
static int ipsec_get_policy __P((struct secpolicy *pcb_sp, struct mbuf **mp));
static void vshiftl __P((unsigned char *, int, int));
static size_t ipsec_hdrsiz __P((struct secpolicy *));
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 = &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.
*/
struct secpolicy *
ipsec_getpolicybysock(m, dir, inp, error)
struct mbuf *m;
u_int dir;
struct inpcb *inp;
int *error;
{
struct inpcbpolicy *pcbsp = NULL;
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 */
if (inp->inp_vflag & INP_IPV6PROTO) {
#ifdef INET6
*error = ipsec6_setspidx_in6pcb(m, inp);
pcbsp = inp->in6p_sp;
#else
*error = EINVAL; /* should not happen */
#endif
} else {
*error = ipsec4_setspidx_inpcb(m, inp);
pcbsp = inp->inp_sp;
}
if (*error)
return NULL;
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(m, dir, flag, error)
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(m, dir, flag, error, inp)
struct mbuf *m;
u_int dir, 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"));
newipsecstat.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);
/* fall thru... */
case IPSEC_POLICY_DISCARD:
newipsecstat.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 an SA */
*error = key_spdacquire(sp);
break;
}
if (*error != 0) {
KEY_FREESP(&sp);
sp = NULL;
}
return sp;
}
static int
ipsec4_setspidx_inpcb(m, pcb)
struct mbuf *m;
struct inpcb *pcb;
{
int error;
IPSEC_ASSERT(pcb != NULL, ("null pcb"));
IPSEC_ASSERT(pcb->inp_sp != NULL, ("null inp_sp"));
IPSEC_ASSERT(pcb->inp_sp->sp_out != NULL && pcb->inp_sp->sp_in != NULL,
("null sp_in || sp_out"));
error = ipsec_setspidx(m, &pcb->inp_sp->sp_in->spidx, 1);
if (error == 0) {
pcb->inp_sp->sp_in->spidx.dir = IPSEC_DIR_INBOUND;
pcb->inp_sp->sp_out->spidx = pcb->inp_sp->sp_in->spidx;
pcb->inp_sp->sp_out->spidx.dir = IPSEC_DIR_OUTBOUND;
} else {
bzero(&pcb->inp_sp->sp_in->spidx,
sizeof (pcb->inp_sp->sp_in->spidx));
bzero(&pcb->inp_sp->sp_out->spidx,
sizeof (pcb->inp_sp->sp_in->spidx));
}
return error;
}
#ifdef INET6
static int
ipsec6_setspidx_in6pcb(m, pcb)
struct mbuf *m;
struct in6pcb *pcb;
{
struct secpolicyindex *spidx;
int error;
IPSEC_ASSERT(pcb != NULL, ("null pcb"));
IPSEC_ASSERT(pcb->in6p_sp != NULL, ("null inp_sp"));
IPSEC_ASSERT(pcb->in6p_sp->sp_out != NULL && pcb->in6p_sp->sp_in != NULL,
("null sp_in || sp_out"));
bzero(&pcb->in6p_sp->sp_in->spidx, sizeof(*spidx));
bzero(&pcb->in6p_sp->sp_out->spidx, sizeof(*spidx));
spidx = &pcb->in6p_sp->sp_in->spidx;
error = ipsec_setspidx(m, spidx, 1);
if (error)
goto bad;
spidx->dir = IPSEC_DIR_INBOUND;
spidx = &pcb->in6p_sp->sp_out->spidx;
error = ipsec_setspidx(m, spidx, 1);
if (error)
goto bad;
spidx->dir = IPSEC_DIR_OUTBOUND;
return 0;
bad:
bzero(&pcb->in6p_sp->sp_in->spidx, sizeof(*spidx));
bzero(&pcb->in6p_sp->sp_out->spidx, sizeof(*spidx));
return error;
}
#endif
/*
* 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(m, spidx, needport)
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 (m->m_pkthdr.len > off + sizeof(ip6e))
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(m, spidx, needport)
struct mbuf *m;
struct secpolicyindex *spidx;
int needport;
{
int off, nxt;
struct tcphdr th;
struct udphdr uh;
/* 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:
default:
/* XXX intermediate headers??? */
spidx->ul_proto = nxt;
break;
}
}
/* assumes that m is sane */
static int
ipsec6_setspidx_ipaddr(m, spidx)
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(p)
struct inpcbpolicy *p;
{
free(p, M_IPSEC_INPCB);
}
/* initialize policy in PCB */
int
ipsec_init_policy(so, pcb_sp)
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(old, new)
struct inpcbpolicy *old, *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(src)
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(pcb_sp, optname, request, len, priv)
struct secpolicy **pcb_sp;
int optname;
caddr_t request;
size_t len;
int priv;
{
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() 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 (priv == 0 && xpl->sadb_x_policy_type == IPSEC_POLICY_BYPASS)
return EACCES;
/* allocation 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;
}
static int
ipsec_get_policy(pcb_sp, mp)
struct secpolicy *pcb_sp;
struct mbuf **mp;
{
/* sanity check. */
if (pcb_sp == NULL || mp == 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;
}
int
ipsec4_set_policy(inp, optname, request, len, priv)
struct inpcb *inp;
int optname;
caddr_t request;
size_t len;
int priv;
{
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(pcb_sp, optname, request, len, priv);
}
int
ipsec4_get_policy(inp, request, len, mp)
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;
}
return ipsec_get_policy(pcb_sp, mp);
}
/* delete policy in PCB */
int
ipsec4_delete_pcbpolicy(inp)
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;
}
#ifdef INET6
int
ipsec6_set_policy(in6p, optname, request, len, priv)
struct in6pcb *in6p;
int optname;
caddr_t request;
size_t len;
int priv;
{
struct sadb_x_policy *xpl;
struct secpolicy **pcb_sp;
/* sanity check. */
if (in6p == 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 = &in6p->in6p_sp->sp_in;
break;
case IPSEC_DIR_OUTBOUND:
pcb_sp = &in6p->in6p_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(pcb_sp, optname, request, len, priv);
}
int
ipsec6_get_policy(in6p, request, len, mp)
struct in6pcb *in6p;
caddr_t request;
size_t len;
struct mbuf **mp;
{
struct sadb_x_policy *xpl;
struct secpolicy *pcb_sp;
/* sanity check. */
if (in6p == NULL || request == NULL || mp == NULL)
return EINVAL;
IPSEC_ASSERT(in6p->in6p_sp != NULL, ("null in6p_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 = in6p->in6p_sp->sp_in;
break;
case IPSEC_DIR_OUTBOUND:
pcb_sp = in6p->in6p_sp->sp_out;
break;
default:
ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
xpl->sadb_x_policy_dir));
return EINVAL;
}
return ipsec_get_policy(pcb_sp, mp);
}
int
ipsec6_delete_pcbpolicy(in6p)
struct in6pcb *in6p;
{
IPSEC_ASSERT(in6p != NULL, ("null in6p"));
if (in6p->in6p_sp == NULL)
return 0;
if (in6p->in6p_sp->sp_in != NULL)
KEY_FREESP(&in6p->in6p_sp->sp_in);
if (in6p->in6p_sp->sp_out != NULL)
KEY_FREESP(&in6p->in6p_sp->sp_out);
ipsec_delpcbpolicy(in6p->in6p_sp);
in6p->in6p_sp = NULL;
return 0;
}
#endif
/*
* return current level.
* Either IPSEC_LEVEL_USE or IPSEC_LEVEL_REQUIRE are always returned.
*/
u_int
ipsec_get_reqlevel(isr)
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) \
? (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(ip4_esp_trans_deflev);
esp_net_deflev = IPSEC_CHECK_DEFAULT(ip4_esp_net_deflev);
ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_trans_deflev);
ah_net_deflev = IPSEC_CHECK_DEFAULT(ip4_ah_net_deflev);
break;
#endif
#ifdef INET6
case AF_INET6:
esp_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_trans_deflev);
esp_net_deflev = IPSEC_CHECK_DEFAULT(ip6_esp_net_deflev);
ah_trans_deflev = IPSEC_CHECK_DEFAULT(ip6_ah_trans_deflev);
ah_net_deflev = IPSEC_CHECK_DEFAULT(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 */
}
/*
* 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(m, inp)
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);
if (result)
newipsecstat.ips_in_polvio++;
KEY_FREESP(&sp);
} else {
result = 0; /* XXX should be panic ?
* -> No, there may be error. */
}
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(m, inp)
struct mbuf *m;
struct inpcb *inp;
{
struct secpolicy *sp = NULL;
int error;
int result;
/* sanity check */
if (m == NULL)
return 0; /* XXX should be panic ? */
/* 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);
if (result)
newipsecstat.ips_in_polvio++;
KEY_FREESP(&sp);
} else {
result = 0;
}
return result;
}
#endif
/*
* compute the byte size to be occupied by IPsec header.
* in case it is tunneled, it includes the size of outer IP header.
* NOTE: SP passed is free in this function.
*/
static size_t
ipsec_hdrsiz(struct secpolicy *sp)
{
struct ipsecrequest *isr;
size_t siz;
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));
siz = 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;
}
}
siz += clen;
}
return siz;
}
/* This function is called from ip_forward() and ipsec4_hdrsize_tcp(). */
size_t
ipsec4_hdrsiz(m, dir, inp)
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(sp);
KEYDEBUG(KEYDEBUG_IPSEC_DATA,
printf("%s: size:%lu.\n", __func__,
(unsigned long)size));
KEY_FREESP(&sp);
} else {
size = 0; /* XXX should be panic ? */
}
return size;
}
#ifdef INET6
/* This function is called from ipsec6_hdrsize_tcp(),
* and maybe from ip6_forward.()
*/
size_t
ipsec6_hdrsiz(m, dir, in6p)
struct mbuf *m;
u_int dir;
struct in6pcb *in6p;
{
struct secpolicy *sp;
int error;
size_t size;
IPSEC_ASSERT(m != NULL, ("null mbuf"));
IPSEC_ASSERT(in6p == NULL || in6p->in6p_socket != NULL,
("socket w/o inpcb"));
/* get SP for this packet */
/* XXX Is it right to call with IP_FORWARDING. */
if (in6p == NULL)
sp = ipsec_getpolicybyaddr(m, dir, IP_FORWARDING, &error);
else
sp = ipsec_getpolicybysock(m, dir, in6p, &error);
if (sp == NULL)
return 0;
size = ipsec_hdrsiz(sp);
KEYDEBUG(KEYDEBUG_IPSEC_DATA,
printf("%s: size:%lu.\n", __func__, (unsigned long)size));
KEY_FREESP(&sp);
return size;
}
#endif /*INET6*/
/*
* 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(seq, sav)
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_SPLASSERT_SOFTNET(__func__);
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(seq, sav)
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_SPLASSERT_SOFTNET(__func__);
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 bunffer to left.
* IN: bitmap: pointer to the buffer
* nbit: the number of to shift.
* wsize: buffer size (bytes).
*/
static void
vshiftl(bitmap, nbit, wsize)
unsigned char *bitmap;
int nbit, 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;
}
}
return;
}
/* 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;
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]);
}
/* Return a printable string for the address. */
char *
ipsec_address(union sockaddr_union* sa)
{
switch (sa->sa.sa_family) {
#if INET
case AF_INET:
return inet_ntoa4(sa->sin.sin_addr);
#endif /* INET */
#if INET6
case AF_INET6:
return ip6_sprintf(&sa->sin6.sin6_addr);
#endif /* INET6 */
default:
return "(unknown address family)";
}
}
const char *
ipsec_logsastr(sav)
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(m)
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_attach(void)
{
SECPOLICY_LOCK_INIT(&ip4_def_policy);
ip4_def_policy.refcnt = 1; /* NB: disallow free */
}
SYSINIT(ipsec, SI_SUB_PROTO_DOMAIN, SI_ORDER_FIRST, ipsec_attach, 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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