#include <machine/rtems-bsd-kernel-space.h>
/*-
* Copyright (c) 2015-2016 Yandex LLC
* Copyright (c) 2015-2016 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/sys/param.h>
#include <sys/systm.h>
#include <sys/counter.h>
#include <sys/kernel.h>
#include <rtems/bsd/sys/lock.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/rmlock.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_pflog.h>
#include <net/pfil.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#include <netinet6/ip_fw_nat64.h>
#include <netpfil/ipfw/ip_fw_private.h>
#include <netpfil/ipfw/nat64/ip_fw_nat64.h>
#include <netpfil/ipfw/nat64/nat64_translate.h>
#include <netpfil/ipfw/nat64/nat64stl.h>
#include <netpfil/pf/pf.h>
#define NAT64_LOOKUP(chain, cmd) \
(struct nat64stl_cfg *)SRV_OBJECT((chain), (cmd)->arg1)
static void
nat64stl_log(struct pfloghdr *plog, struct mbuf *m, sa_family_t family,
uint32_t kidx)
{
static uint32_t pktid = 0;
memset(plog, 0, sizeof(plog));
plog->length = PFLOG_REAL_HDRLEN;
plog->af = family;
plog->action = PF_NAT;
plog->dir = PF_IN;
plog->rulenr = htonl(kidx);
plog->subrulenr = htonl(++pktid);
plog->ruleset[0] = '\0';
strlcpy(plog->ifname, "NAT64STL", sizeof(plog->ifname));
ipfw_bpf_mtap2(plog, PFLOG_HDRLEN, m);
}
static int
nat64stl_handle_ip4(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
struct mbuf *m, uint32_t tablearg)
{
struct pfloghdr loghdr, *logdata;
struct in6_addr saddr, daddr;
struct ip *ip;
ip = mtod(m, struct ip*);
if (nat64_check_ip4(ip->ip_src.s_addr) != 0 ||
nat64_check_ip4(ip->ip_dst.s_addr) != 0 ||
nat64_check_private_ip4(ip->ip_src.s_addr) != 0 ||
nat64_check_private_ip4(ip->ip_dst.s_addr) != 0)
return (NAT64SKIP);
daddr = TARG_VAL(chain, tablearg, nh6);
if (nat64_check_ip6(&daddr) != 0)
return (NAT64MFREE);
saddr = cfg->prefix6;
nat64_set_ip4(&saddr, ip->ip_src.s_addr);
if (cfg->flags & NAT64_LOG) {
logdata = &loghdr;
nat64stl_log(logdata, m, AF_INET, cfg->no.kidx);
} else
logdata = NULL;
return (nat64_do_handle_ip4(m, &saddr, &daddr, 0, &cfg->stats,
logdata));
}
static int
nat64stl_handle_ip6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
struct mbuf *m, uint32_t tablearg)
{
struct pfloghdr loghdr, *logdata;
struct ip6_hdr *ip6;
uint32_t aaddr;
aaddr = htonl(TARG_VAL(chain, tablearg, nh4));
/*
* NOTE: we expect ipfw_chk() did m_pullup() up to upper level
* protocol's headers. Also we skip some checks, that ip6_input(),
* ip6_forward(), ip6_fastfwd() and ipfw_chk() already did.
*/
ip6 = mtod(m, struct ip6_hdr *);
/* Check ip6_dst matches configured prefix */
if (bcmp(&ip6->ip6_dst, &cfg->prefix6, cfg->plen6 / 8) != 0)
return (NAT64SKIP);
if (cfg->flags & NAT64_LOG) {
logdata = &loghdr;
nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx);
} else
logdata = NULL;
return (nat64_do_handle_ip6(m, aaddr, 0, &cfg->stats, logdata));
}
static int
nat64stl_handle_icmp6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
struct mbuf *m)
{
struct pfloghdr loghdr, *logdata;
nat64_stats_block *stats;
struct ip6_hdr *ip6i;
struct icmp6_hdr *icmp6;
uint32_t tablearg;
int hlen, proto;
hlen = 0;
stats = &cfg->stats;
proto = nat64_getlasthdr(m, &hlen);
if (proto != IPPROTO_ICMPV6) {
NAT64STAT_INC(stats, dropped);
return (NAT64MFREE);
}
icmp6 = mtodo(m, hlen);
switch (icmp6->icmp6_type) {
case ICMP6_DST_UNREACH:
case ICMP6_PACKET_TOO_BIG:
case ICMP6_TIME_EXCEED_TRANSIT:
case ICMP6_PARAM_PROB:
break;
default:
NAT64STAT_INC(stats, dropped);
return (NAT64MFREE);
}
hlen += sizeof(struct icmp6_hdr);
if (m->m_pkthdr.len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) {
NAT64STAT_INC(stats, dropped);
return (NAT64MFREE);
}
if (m->m_len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN)
m = m_pullup(m, hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN);
if (m == NULL) {
NAT64STAT_INC(stats, nomem);
return (NAT64RETURN);
}
/*
* Use destination address from inner IPv6 header to determine
* IPv4 mapped address.
*/
ip6i = mtodo(m, hlen);
if (ipfw_lookup_table_extended(chain, cfg->map64,
sizeof(struct in6_addr), &ip6i->ip6_dst, &tablearg) == 0) {
m_freem(m);
return (NAT64RETURN);
}
if (cfg->flags & NAT64_LOG) {
logdata = &loghdr;
nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx);
} else
logdata = NULL;
return (nat64_handle_icmp6(m, 0,
htonl(TARG_VAL(chain, tablearg, nh4)), 0, stats, logdata));
}
int
ipfw_nat64stl(struct ip_fw_chain *chain, struct ip_fw_args *args,
ipfw_insn *cmd, int *done)
{
ipfw_insn *icmd;
struct nat64stl_cfg *cfg;
uint32_t tablearg;
int ret;
IPFW_RLOCK_ASSERT(chain);
*done = 0; /* try next rule if not matched */
icmd = cmd + 1;
if (cmd->opcode != O_EXTERNAL_ACTION ||
cmd->arg1 != V_nat64stl_eid ||
icmd->opcode != O_EXTERNAL_INSTANCE ||
(cfg = NAT64_LOOKUP(chain, icmd)) == NULL)
return (0);
switch (args->f_id.addr_type) {
case 4:
ret = ipfw_lookup_table(chain, cfg->map46,
htonl(args->f_id.dst_ip), &tablearg);
break;
case 6:
ret = ipfw_lookup_table_extended(chain, cfg->map64,
sizeof(struct in6_addr), &args->f_id.src_ip6, &tablearg);
break;
default:
return (0);
}
if (ret == 0) {
/*
* In case when packet is ICMPv6 message from an intermediate
* router, the source address of message will not match the
* addresses from our map64 table.
*/
if (args->f_id.proto != IPPROTO_ICMPV6)
return (0);
ret = nat64stl_handle_icmp6(chain, cfg, args->m);
} else {
if (args->f_id.addr_type == 4)
ret = nat64stl_handle_ip4(chain, cfg, args->m,
tablearg);
else
ret = nat64stl_handle_ip6(chain, cfg, args->m,
tablearg);
}
if (ret == NAT64SKIP)
return (0);
*done = 1; /* terminate the search */
if (ret == NAT64MFREE)
m_freem(args->m);
args->m = NULL;
return (IP_FW_DENY);
}
