#include <machine/rtems-bsd-kernel-space.h>
/*-
* 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 <rtems/bsd/local/opt_inet.h>
#include <rtems/bsd/local/opt_ipsec.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/sockopt.h>
#include <sys/sysctl.h>
#include <netinet/in.h>
#include <netinet/in_pcb.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/ip_var.h>
#include <netinet/tcp.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <net/vnet.h>
#include <netipsec/ipsec.h>
#include <netipsec/esp.h>
#include <netipsec/esp_var.h>
#include <netipsec/xform.h>
#include <netipsec/key.h>
#include <netipsec/key_debug.h>
#include <netipsec/ipsec_support.h>
#include <machine/in_cksum.h>
/*
* Handle UDP_ENCAP socket option. Always return with released INP_WLOCK.
*/
int
udp_ipsec_pcbctl(struct inpcb *inp, struct sockopt *sopt)
{
struct udpcb *up;
int error, optval;
INP_WLOCK_ASSERT(inp);
if (sopt->sopt_name != UDP_ENCAP) {
INP_WUNLOCK(inp);
return (ENOPROTOOPT);
}
up = intoudpcb(inp);
if (sopt->sopt_dir == SOPT_GET) {
if (up->u_flags & UF_ESPINUDP)
optval = UDP_ENCAP_ESPINUDP;
else
optval = 0;
INP_WUNLOCK(inp);
return (sooptcopyout(sopt, &optval, sizeof(optval)));
}
INP_WUNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof(optval), sizeof(optval));
if (error != 0)
return (error);
INP_WLOCK(inp);
switch (optval) {
case 0:
up->u_flags &= ~UF_ESPINUDP;
break;
case UDP_ENCAP_ESPINUDP:
up->u_flags |= UF_ESPINUDP;
break;
default:
error = EINVAL;
}
INP_WUNLOCK(inp);
return (error);
}
/*
* Potentially decap ESP in UDP frame. Check for an ESP header.
* If present, strip the UDP header and push the result through IPSec.
*
* Returns error if mbuf consumed and/or processed, otherwise 0.
*/
int
udp_ipsec_input(struct mbuf *m, int off, int af)
{
union sockaddr_union dst;
struct secasvar *sav;
struct udphdr *udp;
struct ip *ip;
uint32_t spi;
int hlen;
/*
* Just return if packet doesn't have enough data.
* We need at least [IP header + UDP header + ESP header].
* NAT-Keepalive packet has only one byte of payload, so it
* by default will not be processed.
*/
if (m->m_pkthdr.len < off + sizeof(struct esp))
return (0);
m_copydata(m, off, sizeof(uint32_t), (caddr_t)&spi);
if (spi == 0) /* Non-ESP marker. */
return (0);
/*
* Find SA and check that it is configured for UDP
* encapsulation.
*/
bzero(&dst, sizeof(dst));
dst.sa.sa_family = af;
switch (af) {
#ifdef INET
case AF_INET:
dst.sin.sin_len = sizeof(struct sockaddr_in);
ip = mtod(m, struct ip *);
ip->ip_p = IPPROTO_ESP;
off = offsetof(struct ip, ip_p);
hlen = ip->ip_hl << 2;
dst.sin.sin_addr = ip->ip_dst;
break;
#endif
#ifdef INET6
case AF_INET6:
/* Not yet */
/* FALLTHROUGH */
#endif
default:
ESPSTAT_INC(esps_nopf);
m_freem(m);
return (EPFNOSUPPORT);
}
sav = key_allocsa(&dst, IPPROTO_ESP, spi);
if (sav == NULL) {
ESPSTAT_INC(esps_notdb);
m_freem(m);
return (ENOENT);
}
udp = mtodo(m, hlen);
if (sav->natt == NULL ||
sav->natt->sport != udp->uh_sport ||
sav->natt->dport != udp->uh_dport) {
/* XXXAE: should we check source address? */
ESPSTAT_INC(esps_notdb);
key_freesav(&sav);
m_freem(m);
return (ENOENT);
}
/*
* Remove the UDP header
* Before:
* <--- off --->
* +----+------+-----+
* | IP | UDP | ESP |
* +----+------+-----+
* <-skip->
* After:
* +----+-----+
* | IP | ESP |
* +----+-----+
* <-skip->
*/
m_striphdr(m, hlen, sizeof(*udp));
/*
* We cannot yet update the cksums so clear any h/w cksum flags
* as they are no longer valid.
*/
if (m->m_pkthdr.csum_flags & CSUM_DATA_VALID)
m->m_pkthdr.csum_flags &= ~(CSUM_DATA_VALID | CSUM_PSEUDO_HDR);
/*
* We can update ip_len and ip_sum here, but ipsec4_input_cb()
* will do this anyway, so don't touch them here.
*/
ESPSTAT_INC(esps_input);
(*sav->tdb_xform->xf_input)(m, sav, hlen, off);
return (EINPROGRESS); /* Consumed by IPsec. */
}
int
udp_ipsec_output(struct mbuf *m, struct secasvar *sav)
{
struct udphdr *udp;
struct mbuf *n;
struct ip *ip;
int hlen, off;
IPSEC_ASSERT(sav->natt != NULL, ("UDP encapsulation isn't required."));
if (sav->sah->saidx.dst.sa.sa_family == AF_INET6)
return (EAFNOSUPPORT);
ip = mtod(m, struct ip *);
hlen = ip->ip_hl << 2;
n = m_makespace(m, hlen, sizeof(*udp), &off);
if (n == NULL) {
DPRINTF(("%s: m_makespace for udphdr failed\n", __func__));
return (ENOBUFS);
}
udp = mtodo(n, off);
udp->uh_dport = sav->natt->dport;
udp->uh_sport = sav->natt->sport;
udp->uh_sum = 0;
udp->uh_ulen = htons(m->m_pkthdr.len - hlen);
ip = mtod(m, struct ip *);
ip->ip_len = htons(m->m_pkthdr.len);
ip->ip_p = IPPROTO_UDP;
return (0);
}
void
udp_ipsec_adjust_cksum(struct mbuf *m, struct secasvar *sav, int proto,
int skip)
{
struct ip *ip;
uint16_t cksum, off;
IPSEC_ASSERT(sav->natt != NULL, ("NAT-T isn't required"));
IPSEC_ASSERT(proto == IPPROTO_UDP || proto == IPPROTO_TCP,
("unexpected protocol %u", proto));
if (proto == IPPROTO_UDP)
off = offsetof(struct udphdr, uh_sum);
else
off = offsetof(struct tcphdr, th_sum);
if (V_natt_cksum_policy == 0) { /* auto */
if (sav->natt->cksum != 0) {
/* Incrementally recompute. */
m_copydata(m, skip + off, sizeof(cksum),
(caddr_t)&cksum);
/* Do not adjust UDP checksum if it is zero. */
if (proto == IPPROTO_UDP && cksum == 0)
return;
cksum = in_addword(cksum, sav->natt->cksum);
} else {
/* No OA from IKEd. */
if (proto == IPPROTO_TCP) {
/* Ignore for TCP. */
m->m_pkthdr.csum_data = 0xffff;
m->m_pkthdr.csum_flags |= (CSUM_DATA_VALID |
CSUM_PSEUDO_HDR);
return;
}
cksum = 0; /* Reset for UDP. */
}
m_copyback(m, skip + off, sizeof(cksum), (caddr_t)&cksum);
} else { /* Fully recompute */
ip = mtod(m, struct ip *);
cksum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
htons(m->m_pkthdr.len - skip + proto));
m_copyback(m, skip + off, sizeof(cksum), (caddr_t)&cksum);
m->m_pkthdr.csum_flags =
(proto == IPPROTO_UDP) ? CSUM_UDP: CSUM_TCP;
m->m_pkthdr.csum_data = off;
in_delayed_cksum(m);
m->m_pkthdr.csum_flags &= ~CSUM_DELAY_DATA;
}
}
