/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2009-2010 Ana Kukec <anchie@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 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/priv.h>
#include <sys/protosw.h>
#include <sys/sdt.h>
#include <sys/systm.h>
#include <sys/socket.h>
#include <sys/sockbuf.h>
#include <sys/socketvar.h>
#include <sys/types.h>
#include <net/route.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_private.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <netinet/ip_var.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/scope6_var.h>
#include <netinet6/send.h>
static MALLOC_DEFINE(M_SEND, "send", "Secure Neighbour Discovery");
/*
* The socket used to communicate with the SeND daemon.
*/
VNET_DEFINE_STATIC(struct socket *, send_so);
#define V_send_so VNET(send_so)
u_long send_sendspace = 8 * (1024 + sizeof(struct sockaddr_send));
u_long send_recvspace = 9216;
struct mtx send_mtx;
#define SEND_LOCK_INIT() mtx_init(&send_mtx, "send_mtx", NULL, MTX_DEF)
#define SEND_LOCK() mtx_lock(&send_mtx)
#define SEND_UNLOCK() mtx_unlock(&send_mtx)
#define SEND_LOCK_DESTROY() mtx_destroy(&send_mtx)
static int
send_attach(struct socket *so, int proto, struct thread *td)
{
int error;
SEND_LOCK();
if (V_send_so != NULL) {
SEND_UNLOCK();
return (EEXIST);
}
error = priv_check(td, PRIV_NETINET_RAW);
if (error) {
SEND_UNLOCK();
return(error);
}
if (proto != IPPROTO_SEND) {
SEND_UNLOCK();
return (EPROTONOSUPPORT);
}
error = soreserve(so, send_sendspace, send_recvspace);
if (error) {
SEND_UNLOCK();
return(error);
}
V_send_so = so;
SEND_UNLOCK();
return (0);
}
static int
send_output(struct mbuf *m, struct ifnet *ifp, int direction)
{
struct ip6_hdr *ip6;
struct sockaddr_in6 dst;
struct icmp6_hdr *icmp6;
struct epoch_tracker et;
int icmp6len;
int error;
/*
* Receive incoming (SeND-protected) or outgoing traffic
* (SeND-validated) from the SeND user space application.
*/
switch (direction) {
case SND_IN:
if (m->m_len < (sizeof(struct ip6_hdr) +
sizeof(struct icmp6_hdr))) {
m = m_pullup(m, sizeof(struct ip6_hdr) +
sizeof(struct icmp6_hdr));
if (!m)
return (ENOBUFS);
}
/* Before passing off the mbuf record the proper interface. */
m->m_pkthdr.rcvif = ifp;
if (m->m_flags & M_PKTHDR)
icmp6len = m->m_pkthdr.len - sizeof(struct ip6_hdr);
else
panic("Doh! not the first mbuf.");
ip6 = mtod(m, struct ip6_hdr *);
icmp6 = (struct icmp6_hdr *)(ip6 + 1);
error = 0;
/*
* Output the packet as icmp6.c:icpm6_input() would do.
* The mbuf is always consumed, so we do not have to
* care about that.
*/
NET_EPOCH_ENTER(et);
switch (icmp6->icmp6_type) {
case ND_NEIGHBOR_SOLICIT:
nd6_ns_input(m, sizeof(struct ip6_hdr), icmp6len);
break;
case ND_NEIGHBOR_ADVERT:
nd6_na_input(m, sizeof(struct ip6_hdr), icmp6len);
break;
case ND_REDIRECT:
icmp6_redirect_input(m, sizeof(struct ip6_hdr));
break;
case ND_ROUTER_SOLICIT:
nd6_rs_input(m, sizeof(struct ip6_hdr), icmp6len);
break;
case ND_ROUTER_ADVERT:
nd6_ra_input(m, sizeof(struct ip6_hdr), icmp6len);
break;
default:
m_freem(m);
error = ENOSYS;
}
NET_EPOCH_EXIT(et);
return (error);
case SND_OUT:
if (m->m_len < sizeof(struct ip6_hdr)) {
m = m_pullup(m, sizeof(struct ip6_hdr));
if (!m)
return (ENOBUFS);
}
ip6 = mtod(m, struct ip6_hdr *);
if (IN6_IS_ADDR_MULTICAST(&ip6->ip6_dst))
m->m_flags |= M_MCAST;
bzero(&dst, sizeof(dst));
dst.sin6_family = AF_INET6;
dst.sin6_len = sizeof(dst);
dst.sin6_addr = ip6->ip6_dst;
m_clrprotoflags(m); /* Avoid confusing lower layers. */
IP_PROBE(send, NULL, NULL, ip6, ifp, NULL, ip6);
/*
* Output the packet as nd6.c:nd6_output_lle() would do.
* The mbuf is always consumed, so we do not have to care
* about that.
* XXX-BZ as we added data, what about fragmenting,
* if now needed?
*/
error = ((*ifp->if_output)(ifp, m, (struct sockaddr *)&dst,
NULL));
if (error)
error = ENOENT;
return (error);
default:
panic("%s: direction %d neither SND_IN nor SND_OUT.",
__func__, direction);
}
}
/*
* Receive a SeND message from user space to be either send out by the kernel
* or, with SeND ICMPv6 options removed, to be further processed by the icmp6
* input path.
*/
static int
send_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *nam,
struct mbuf *control, struct thread *td)
{
struct sockaddr_send *sendsrc;
struct ifnet *ifp;
int error;
KASSERT(V_send_so == so, ("%s: socket %p not send socket %p",
__func__, so, V_send_so));
sendsrc = (struct sockaddr_send *)nam;
if (sendsrc->send_family != AF_INET6) {
error = EAFNOSUPPORT;
goto err;
}
if (sendsrc->send_len != sizeof(*sendsrc)) {
error = EINVAL;
goto err;
}
ifp = ifnet_byindex_ref(sendsrc->send_ifidx);
if (ifp == NULL) {
error = ENETUNREACH;
goto err;
}
error = send_output(m, ifp, sendsrc->send_direction);
if_rele(ifp);
m = NULL;
err:
if (control != NULL)
m_freem(control);
if (m != NULL)
m_freem(m);
return (error);
}
static void
send_close(struct socket *so)
{
SEND_LOCK();
if (V_send_so)
V_send_so = NULL;
SEND_UNLOCK();
}
/*
* Send a SeND message to user space, that was either received and has to be
* validated or was about to be send out and has to be handled by the SEND
* daemon adding SeND ICMPv6 options.
*/
static int
send_input(struct mbuf *m, struct ifnet *ifp, int direction, int msglen __unused)
{
struct ip6_hdr *ip6;
struct sockaddr_send sendsrc;
SEND_LOCK();
if (V_send_so == NULL) {
SEND_UNLOCK();
return (-1);
}
/*
* Make sure to clear any possible internally embedded scope before
* passing the packet to user space for SeND cryptographic signature
* validation to succeed.
*/
ip6 = mtod(m, struct ip6_hdr *);
in6_clearscope(&ip6->ip6_src);
in6_clearscope(&ip6->ip6_dst);
bzero(&sendsrc, sizeof(sendsrc));
sendsrc.send_len = sizeof(sendsrc);
sendsrc.send_family = AF_INET6;
sendsrc.send_direction = direction;
sendsrc.send_ifidx = ifp->if_index;
/*
* Send incoming or outgoing traffic to user space either to be
* protected (outgoing) or validated (incoming) according to rfc3971.
*/
SOCKBUF_LOCK(&V_send_so->so_rcv);
if (sbappendaddr_locked(&V_send_so->so_rcv,
(struct sockaddr *)&sendsrc, m, NULL) == 0) {
soroverflow_locked(V_send_so);
/* XXX stats. */
m_freem(m);
} else {
sorwakeup_locked(V_send_so);
}
SEND_UNLOCK();
return (0);
}
static struct protosw send_protosw = {
.pr_type = SOCK_RAW,
.pr_flags = PR_ATOMIC|PR_ADDR,
.pr_protocol = IPPROTO_SEND,
.pr_attach = send_attach,
.pr_send = send_send,
.pr_detach = send_close
};
static int
send_modevent(module_t mod, int type, void *unused)
{
#ifdef __notyet__
VNET_ITERATOR_DECL(vnet_iter);
#endif
int error;
switch (type) {
case MOD_LOAD:
SEND_LOCK_INIT();
error = protosw_register(&inet6domain, &send_protosw);
if (error != 0) {
printf("%s:%d: MOD_LOAD pf_proto_register(): %d\n",
__func__, __LINE__, error);
SEND_LOCK_DESTROY();
break;
}
send_sendso_input_hook = send_input;
break;
case MOD_UNLOAD:
/* Do not allow unloading w/o locking. */
return (EBUSY);
#ifdef __notyet__
VNET_LIST_RLOCK_NOSLEEP();
SEND_LOCK();
VNET_FOREACH(vnet_iter) {
CURVNET_SET(vnet_iter);
if (V_send_so != NULL) {
CURVNET_RESTORE();
SEND_UNLOCK();
VNET_LIST_RUNLOCK_NOSLEEP();
return (EBUSY);
}
CURVNET_RESTORE();
}
SEND_UNLOCK();
VNET_LIST_RUNLOCK_NOSLEEP();
error = protosw_unregister(&send_protosw);
if (error == 0)
SEND_LOCK_DESTROY();
send_sendso_input_hook = NULL;
break;
#endif
default:
error = 0;
break;
}
return (error);
}
static moduledata_t sendmod = {
"send",
send_modevent,
0
};
DECLARE_MODULE(send, sendmod, SI_SUB_PROTO_DOMAIN, SI_ORDER_ANY);
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