freebsd-dev/sys/netipsec/ipsec_pcb.c
Andrey V. Elsukov fcf596178b Merge projects/ipsec into head/.
Small summary
 -------------

o Almost all IPsec releated code was moved into sys/netipsec.
o New kernel modules added: ipsec.ko and tcpmd5.ko. New kernel
  option IPSEC_SUPPORT added. It enables support for loading
  and unloading of ipsec.ko and tcpmd5.ko kernel modules.
o IPSEC_NAT_T option was removed. Now NAT-T support is enabled by
  default. The UDP_ENCAP_ESPINUDP_NON_IKE encapsulation type
  support was removed. Added TCP/UDP checksum handling for
  inbound packets that were decapsulated by transport mode SAs.
  setkey(8) modified to show run-time NAT-T configuration of SA.
o New network pseudo interface if_ipsec(4) added. For now it is
  build as part of ipsec.ko module (or with IPSEC kernel).
  It implements IPsec virtual tunnels to create route-based VPNs.
o The network stack now invokes IPsec functions using special
  methods. The only one header file <netipsec/ipsec_support.h>
  should be included to declare all the needed things to work
  with IPsec.
o All IPsec protocols handlers (ESP/AH/IPCOMP protosw) were removed.
  Now these protocols are handled directly via IPsec methods.
o TCP_SIGNATURE support was reworked to be more close to RFC.
o PF_KEY SADB was reworked:
  - now all security associations stored in the single SPI namespace,
    and all SAs MUST have unique SPI.
  - several hash tables added to speed up lookups in SADB.
  - SADB now uses rmlock to protect access, and concurrent threads
    can do SA lookups in the same time.
  - many PF_KEY message handlers were reworked to reflect changes
    in SADB.
  - SADB_UPDATE message was extended to support new PF_KEY headers:
    SADB_X_EXT_NEW_ADDRESS_SRC and SADB_X_EXT_NEW_ADDRESS_DST. They
    can be used by IKE daemon to change SA addresses.
o ipsecrequest and secpolicy structures were cardinally changed to
  avoid locking protection for ipsecrequest. Now we support
  only limited number (4) of bundled SAs, but they are supported
  for both INET and INET6.
o INPCB security policy cache was introduced. Each PCB now caches
  used security policies to avoid SP lookup for each packet.
o For inbound security policies added the mode, when the kernel does
  check for full history of applied IPsec transforms.
o References counting rules for security policies and security
  associations were changed. The proper SA locking added into xform
  code.
o xform code was also changed. Now it is possible to unregister xforms.
  tdb_xxx structures were changed and renamed to reflect changes in
  SADB/SPDB, and changed rules for locking and refcounting.

Reviewed by:	gnn, wblock
Obtained from:	Yandex LLC
Relnotes:	yes
Sponsored by:	Yandex LLC
Differential Revision:	https://reviews.freebsd.org/D9352
2017-02-06 08:49:57 +00:00

480 lines
12 KiB
C

/*-
* Copyright (c) 2016 Andrey V. Elsukov <ae@FreeBSD.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/priv.h>
#include <sys/socket.h>
#include <sys/sockopt.h>
#include <sys/syslog.h>
#include <sys/proc.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netipsec/ipsec.h>
#include <netipsec/ipsec6.h>
#include <netipsec/ipsec_support.h>
#include <netipsec/key.h>
#include <netipsec/key_debug.h>
MALLOC_DEFINE(M_IPSEC_INPCB, "inpcbpolicy", "inpcb-resident ipsec policy");
static void
ipsec_setsockaddrs_inpcb(struct inpcb *inp, union sockaddr_union *src,
union sockaddr_union *dst, u_int dir)
{
#ifdef INET6
if (inp->inp_vflag & INP_IPV6) {
struct sockaddr_in6 *sin6;
bzero(&src->sin6, sizeof(src->sin6));
bzero(&dst->sin6, sizeof(dst->sin6));
src->sin6.sin6_family = AF_INET6;
src->sin6.sin6_len = sizeof(struct sockaddr_in6);
dst->sin6.sin6_family = AF_INET6;
dst->sin6.sin6_len = sizeof(struct sockaddr_in6);
if (dir == IPSEC_DIR_OUTBOUND)
sin6 = &src->sin6;
else
sin6 = &dst->sin6;
sin6->sin6_addr = inp->in6p_laddr;
sin6->sin6_port = inp->inp_lport;
if (IN6_IS_SCOPE_LINKLOCAL(&inp->in6p_laddr)) {
/* XXXAE: use in6p_zoneid */
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id = ntohs(
inp->in6p_laddr.s6_addr16[1]);
}
if (dir == IPSEC_DIR_OUTBOUND)
sin6 = &dst->sin6;
else
sin6 = &src->sin6;
sin6->sin6_addr = inp->in6p_faddr;
sin6->sin6_port = inp->inp_fport;
if (IN6_IS_SCOPE_LINKLOCAL(&inp->in6p_faddr)) {
/* XXXAE: use in6p_zoneid */
sin6->sin6_addr.s6_addr16[1] = 0;
sin6->sin6_scope_id = ntohs(
inp->in6p_faddr.s6_addr16[1]);
}
}
#endif
#ifdef INET
if (inp->inp_vflag & INP_IPV4) {
struct sockaddr_in *sin;
bzero(&src->sin, sizeof(src->sin));
bzero(&dst->sin, sizeof(dst->sin));
src->sin.sin_family = AF_INET;
src->sin.sin_len = sizeof(struct sockaddr_in);
dst->sin.sin_family = AF_INET;
dst->sin.sin_len = sizeof(struct sockaddr_in);
if (dir == IPSEC_DIR_OUTBOUND)
sin = &src->sin;
else
sin = &dst->sin;
sin->sin_addr = inp->inp_laddr;
sin->sin_port = inp->inp_lport;
if (dir == IPSEC_DIR_OUTBOUND)
sin = &dst->sin;
else
sin = &src->sin;
sin->sin_addr = inp->inp_faddr;
sin->sin_port = inp->inp_fport;
}
#endif
}
void
ipsec_setspidx_inpcb(struct inpcb *inp, struct secpolicyindex *spidx,
u_int dir)
{
ipsec_setsockaddrs_inpcb(inp, &spidx->src, &spidx->dst, dir);
#ifdef INET6
if (inp->inp_vflag & INP_IPV6) {
spidx->prefs = sizeof(struct in6_addr) << 3;
spidx->prefd = sizeof(struct in6_addr) << 3;
}
#endif
#ifdef INET
if (inp->inp_vflag & INP_IPV4) {
spidx->prefs = sizeof(struct in_addr) << 3;
spidx->prefd = sizeof(struct in_addr) << 3;
}
#endif
spidx->ul_proto = IPPROTO_TCP; /* XXX: currently only TCP uses this */
spidx->dir = dir;
KEYDBG(IPSEC_DUMP,
printf("%s: ", __func__); kdebug_secpolicyindex(spidx, NULL));
}
/* Initialize PCB policy. */
int
ipsec_init_pcbpolicy(struct inpcb *inp)
{
IPSEC_ASSERT(inp != NULL, ("null inp"));
IPSEC_ASSERT(inp->inp_sp == NULL, ("inp_sp already initialized"));
inp->inp_sp = malloc(sizeof(struct inpcbpolicy), M_IPSEC_INPCB,
M_NOWAIT | M_ZERO);
if (inp->inp_sp == NULL)
return (ENOBUFS);
return (0);
}
/* Delete PCB policy. */
int
ipsec_delete_pcbpolicy(struct inpcb *inp)
{
if (inp->inp_sp == NULL)
return (0);
if (inp->inp_sp->flags & INP_INBOUND_POLICY)
key_freesp(&inp->inp_sp->sp_in);
if (inp->inp_sp->flags & INP_OUTBOUND_POLICY)
key_freesp(&inp->inp_sp->sp_out);
free(inp->inp_sp, M_IPSEC_INPCB);
inp->inp_sp = NULL;
return (0);
}
/* Deep-copy a policy in PCB. */
static struct secpolicy *
ipsec_deepcopy_pcbpolicy(struct secpolicy *src)
{
struct secpolicy *dst;
int i;
if (src == NULL)
return (NULL);
IPSEC_ASSERT(src->state == IPSEC_SPSTATE_PCB, ("SP isn't PCB"));
dst = key_newsp();
if (dst == NULL)
return (NULL);
/* spidx is not copied here */
dst->policy = src->policy;
dst->state = src->state;
dst->priority = src->priority;
/* Do not touch the refcnt field. */
/* Copy IPsec request chain. */
for (i = 0; i < src->tcount; i++) {
dst->req[i] = ipsec_newisr();
if (dst->req[i] == NULL) {
key_freesp(&dst);
return (NULL);
}
bcopy(src->req[i], dst->req[i], sizeof(struct ipsecrequest));
dst->tcount++;
}
KEYDBG(IPSEC_DUMP,
printf("%s: copied SP(%p) -> SP(%p)\n", __func__, src, dst);
kdebug_secpolicy(dst));
return (dst);
}
/*
* Copy IPsec policy from old INPCB into new.
* It is expected that new INPCB has not configured policies.
*/
int
ipsec_copy_pcbpolicy(struct inpcb *old, struct inpcb *new)
{
struct secpolicy *sp;
/*
* old->inp_sp can be NULL if PCB was created when an IPsec
* support was unavailable. This is not an error, we don't have
* policies in this PCB, so nothing to copy.
*/
if (old->inp_sp == NULL)
return (0);
IPSEC_ASSERT(new->inp_sp != NULL, ("new inp_sp is NULL"));
IPSEC_ASSERT((new->inp_sp->flags & (
INP_INBOUND_POLICY | INP_OUTBOUND_POLICY)) == 0,
("new PCB already has configured policies"));
INP_WLOCK_ASSERT(new);
INP_LOCK_ASSERT(old);
if (old->inp_sp->flags & INP_INBOUND_POLICY) {
sp = ipsec_deepcopy_pcbpolicy(old->inp_sp->sp_in);
if (sp == NULL)
return (ENOBUFS);
ipsec_setspidx_inpcb(new, &sp->spidx, IPSEC_DIR_INBOUND);
new->inp_sp->sp_in = sp;
new->inp_sp->flags |= INP_INBOUND_POLICY;
}
if (old->inp_sp->flags & INP_OUTBOUND_POLICY) {
sp = ipsec_deepcopy_pcbpolicy(old->inp_sp->sp_out);
if (sp == NULL)
return (ENOBUFS);
ipsec_setspidx_inpcb(new, &sp->spidx, IPSEC_DIR_OUTBOUND);
new->inp_sp->sp_out = sp;
new->inp_sp->flags |= INP_OUTBOUND_POLICY;
}
return (0);
}
static int
ipsec_set_pcbpolicy(struct inpcb *inp, struct ucred *cred,
void *request, size_t len)
{
struct sadb_x_policy *xpl;
struct secpolicy **spp, *newsp;
int error, flags;
xpl = (struct sadb_x_policy *)request;
/* Select direction. */
switch (xpl->sadb_x_policy_dir) {
case IPSEC_DIR_INBOUND:
case IPSEC_DIR_OUTBOUND:
break;
default:
ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
xpl->sadb_x_policy_dir));
return (EINVAL);
}
/*
* Privileged sockets are allowed to set own security policy
* and configure IPsec bypass. Unprivileged sockets only can
* have ENTRUST policy.
*/
switch (xpl->sadb_x_policy_type) {
case IPSEC_POLICY_IPSEC:
case IPSEC_POLICY_BYPASS:
if (cred != NULL &&
priv_check_cred(cred, PRIV_NETINET_IPSEC, 0) != 0)
return (EACCES);
/* Allocate new SP entry. */
newsp = key_msg2sp(xpl, len, &error);
if (newsp == NULL)
return (error);
newsp->state = IPSEC_SPSTATE_PCB;
newsp->spidx.ul_proto = IPSEC_ULPROTO_ANY;
#ifdef INET
if (inp->inp_vflag & INP_IPV4) {
newsp->spidx.src.sin.sin_family =
newsp->spidx.dst.sin.sin_family = AF_INET;
newsp->spidx.src.sin.sin_len =
newsp->spidx.dst.sin.sin_len =
sizeof(struct sockaddr_in);
}
#endif
#ifdef INET6
if (inp->inp_vflag & INP_IPV6) {
newsp->spidx.src.sin6.sin6_family =
newsp->spidx.dst.sin6.sin6_family = AF_INET6;
newsp->spidx.src.sin6.sin6_len =
newsp->spidx.dst.sin6.sin6_len =
sizeof(struct sockaddr_in6);
}
#endif
break;
case IPSEC_POLICY_ENTRUST:
/* We just use NULL pointer for ENTRUST policy */
newsp = NULL;
break;
default:
/* Other security policy types aren't allowed for PCB */
return (EINVAL);
}
INP_WLOCK(inp);
if (xpl->sadb_x_policy_dir == IPSEC_DIR_INBOUND) {
spp = &inp->inp_sp->sp_in;
flags = INP_INBOUND_POLICY;
} else {
spp = &inp->inp_sp->sp_out;
flags = INP_OUTBOUND_POLICY;
}
/* Clear old SP and set new SP. */
if (*spp != NULL)
key_freesp(spp);
*spp = newsp;
KEYDBG(IPSEC_DUMP,
printf("%s: new SP(%p)\n", __func__, newsp));
if (newsp == NULL)
inp->inp_sp->flags &= ~flags;
else {
inp->inp_sp->flags |= flags;
KEYDBG(IPSEC_DUMP, kdebug_secpolicy(newsp));
}
INP_WUNLOCK(inp);
return (0);
}
static int
ipsec_get_pcbpolicy(struct inpcb *inp, void *request, size_t *len)
{
struct sadb_x_policy *xpl;
struct secpolicy *sp;
int error, flags;
xpl = (struct sadb_x_policy *)request;
INP_RLOCK(inp);
flags = inp->inp_sp->flags;
/* Select direction. */
switch (xpl->sadb_x_policy_dir) {
case IPSEC_DIR_INBOUND:
sp = inp->inp_sp->sp_in;
flags &= INP_INBOUND_POLICY;
break;
case IPSEC_DIR_OUTBOUND:
sp = inp->inp_sp->sp_out;
flags &= INP_OUTBOUND_POLICY;
break;
default:
INP_RUNLOCK(inp);
ipseclog((LOG_ERR, "%s: invalid direction=%u\n", __func__,
xpl->sadb_x_policy_dir));
return (EINVAL);
}
if (flags == 0) {
/* Return ENTRUST policy */
INP_RUNLOCK(inp);
xpl->sadb_x_policy_exttype = SADB_X_EXT_POLICY;
xpl->sadb_x_policy_type = IPSEC_POLICY_ENTRUST;
xpl->sadb_x_policy_id = 0;
xpl->sadb_x_policy_priority = 0;
xpl->sadb_x_policy_len = PFKEY_UNIT64(sizeof(*xpl));
*len = sizeof(*xpl);
return (0);
}
IPSEC_ASSERT(sp != NULL,
("sp is NULL, but flags is 0x%04x", inp->inp_sp->flags));
key_addref(sp);
INP_RUNLOCK(inp);
error = key_sp2msg(sp, request, len);
key_freesp(&sp);
if (error == EINVAL)
return (error);
/*
* We return "success", but user should check *len.
* *len will be set to size of valid data and
* sadb_x_policy_len will contain needed size.
*/
return (0);
}
/* Handle socket option control request for PCB */
static int
ipsec_control_pcbpolicy(struct inpcb *inp, struct sockopt *sopt)
{
void *optdata;
size_t optlen;
int error;
if (inp->inp_sp == NULL)
return (ENOPROTOOPT);
/* Limit maximum request size to PAGE_SIZE */
optlen = sopt->sopt_valsize;
if (optlen < sizeof(struct sadb_x_policy) || optlen > PAGE_SIZE)
return (EINVAL);
optdata = malloc(optlen, M_TEMP, sopt->sopt_td ? M_WAITOK: M_NOWAIT);
if (optdata == NULL)
return (ENOBUFS);
/*
* We need a hint from the user, what policy is requested - input
* or output? User should specify it in the buffer, even for
* setsockopt().
*/
error = sooptcopyin(sopt, optdata, optlen, optlen);
if (error == 0) {
if (sopt->sopt_dir == SOPT_SET)
error = ipsec_set_pcbpolicy(inp,
sopt->sopt_td ? sopt->sopt_td->td_ucred: NULL,
optdata, optlen);
else {
error = ipsec_get_pcbpolicy(inp, optdata, &optlen);
if (error == 0)
error = sooptcopyout(sopt, optdata, optlen);
}
}
free(optdata, M_TEMP);
return (error);
}
#ifdef INET
/*
* IPSEC_PCBCTL() method implementation for IPv4.
*/
int
ipsec4_pcbctl(struct inpcb *inp, struct sockopt *sopt)
{
if (sopt->sopt_name != IP_IPSEC_POLICY)
return (ENOPROTOOPT);
return (ipsec_control_pcbpolicy(inp, sopt));
}
#endif
#ifdef INET6
/*
* IPSEC_PCBCTL() method implementation for IPv6.
*/
int
ipsec6_pcbctl(struct inpcb *inp, struct sockopt *sopt)
{
if (sopt->sopt_name != IPV6_IPSEC_POLICY)
return (ENOPROTOOPT);
return (ipsec_control_pcbpolicy(inp, sopt));
}
#endif