263 lines
7.2 KiB
C
263 lines
7.2 KiB
C
/*-
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* Copyright (c) 2015-2016 Yandex LLC
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* Copyright (c) 2015-2016 Andrey V. Elsukov <ae@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/counter.h>
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#include <sys/kernel.h>
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#include <sys/lock.h>
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#include <sys/mbuf.h>
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#include <sys/module.h>
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#include <sys/rmlock.h>
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#include <sys/rwlock.h>
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#include <sys/socket.h>
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#include <sys/sysctl.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/if_pflog.h>
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#include <net/pfil.h>
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#include <netinet/in.h>
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#include <netinet/ip.h>
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#include <netinet/ip_icmp.h>
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#include <netinet/ip_var.h>
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#include <netinet/ip_fw.h>
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#include <netinet/ip6.h>
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#include <netinet/icmp6.h>
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#include <netinet6/ip_fw_nat64.h>
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#include <netpfil/ipfw/ip_fw_private.h>
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#include <netpfil/ipfw/nat64/ip_fw_nat64.h>
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#include <netpfil/ipfw/nat64/nat64_translate.h>
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#include <netpfil/ipfw/nat64/nat64stl.h>
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#include <netpfil/pf/pf.h>
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#define NAT64_LOOKUP(chain, cmd) \
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(struct nat64stl_cfg *)SRV_OBJECT((chain), (cmd)->arg1)
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static void
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nat64stl_log(struct pfloghdr *plog, struct mbuf *m, sa_family_t family,
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uint32_t kidx)
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{
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static uint32_t pktid = 0;
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memset(plog, 0, sizeof(plog));
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plog->length = PFLOG_REAL_HDRLEN;
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plog->af = family;
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plog->action = PF_NAT;
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plog->dir = PF_IN;
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plog->rulenr = htonl(kidx);
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plog->subrulenr = htonl(++pktid);
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plog->ruleset[0] = '\0';
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strlcpy(plog->ifname, "NAT64STL", sizeof(plog->ifname));
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ipfw_bpf_mtap2(plog, PFLOG_HDRLEN, m);
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}
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static int
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nat64stl_handle_ip4(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
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struct mbuf *m, uint32_t tablearg)
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{
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struct pfloghdr loghdr, *logdata;
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struct in6_addr saddr, daddr;
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struct ip *ip;
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ip = mtod(m, struct ip*);
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if (nat64_check_ip4(ip->ip_src.s_addr) != 0 ||
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nat64_check_ip4(ip->ip_dst.s_addr) != 0 ||
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nat64_check_private_ip4(ip->ip_src.s_addr) != 0 ||
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nat64_check_private_ip4(ip->ip_dst.s_addr) != 0)
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return (NAT64SKIP);
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daddr = TARG_VAL(chain, tablearg, nh6);
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if (nat64_check_ip6(&daddr) != 0)
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return (NAT64MFREE);
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saddr = cfg->prefix6;
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nat64_set_ip4(&saddr, ip->ip_src.s_addr);
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if (cfg->flags & NAT64_LOG) {
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logdata = &loghdr;
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nat64stl_log(logdata, m, AF_INET, cfg->no.kidx);
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} else
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logdata = NULL;
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return (nat64_do_handle_ip4(m, &saddr, &daddr, 0, &cfg->stats,
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logdata));
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}
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static int
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nat64stl_handle_ip6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
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struct mbuf *m, uint32_t tablearg)
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{
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struct pfloghdr loghdr, *logdata;
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struct ip6_hdr *ip6;
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uint32_t aaddr;
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aaddr = htonl(TARG_VAL(chain, tablearg, nh4));
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/*
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* NOTE: we expect ipfw_chk() did m_pullup() up to upper level
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* protocol's headers. Also we skip some checks, that ip6_input(),
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* ip6_forward(), ip6_fastfwd() and ipfw_chk() already did.
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*/
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ip6 = mtod(m, struct ip6_hdr *);
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/* Check ip6_dst matches configured prefix */
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if (bcmp(&ip6->ip6_dst, &cfg->prefix6, cfg->plen6 / 8) != 0)
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return (NAT64SKIP);
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if (cfg->flags & NAT64_LOG) {
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logdata = &loghdr;
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nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx);
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} else
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logdata = NULL;
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return (nat64_do_handle_ip6(m, aaddr, 0, &cfg->stats, logdata));
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}
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static int
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nat64stl_handle_icmp6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg,
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struct mbuf *m)
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{
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struct pfloghdr loghdr, *logdata;
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nat64_stats_block *stats;
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struct ip6_hdr *ip6i;
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struct icmp6_hdr *icmp6;
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uint32_t tablearg;
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int hlen, proto;
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hlen = 0;
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stats = &cfg->stats;
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proto = nat64_getlasthdr(m, &hlen);
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if (proto != IPPROTO_ICMPV6) {
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NAT64STAT_INC(stats, dropped);
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return (NAT64MFREE);
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}
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icmp6 = mtodo(m, hlen);
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switch (icmp6->icmp6_type) {
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case ICMP6_DST_UNREACH:
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case ICMP6_PACKET_TOO_BIG:
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case ICMP6_TIME_EXCEED_TRANSIT:
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case ICMP6_PARAM_PROB:
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break;
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default:
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NAT64STAT_INC(stats, dropped);
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return (NAT64MFREE);
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}
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hlen += sizeof(struct icmp6_hdr);
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if (m->m_pkthdr.len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) {
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NAT64STAT_INC(stats, dropped);
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return (NAT64MFREE);
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}
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if (m->m_len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN)
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m = m_pullup(m, hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN);
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if (m == NULL) {
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NAT64STAT_INC(stats, nomem);
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return (NAT64RETURN);
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}
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/*
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* Use destination address from inner IPv6 header to determine
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* IPv4 mapped address.
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*/
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ip6i = mtodo(m, hlen);
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if (ipfw_lookup_table(chain, cfg->map64,
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sizeof(struct in6_addr), &ip6i->ip6_dst, &tablearg) == 0) {
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m_freem(m);
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return (NAT64RETURN);
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}
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if (cfg->flags & NAT64_LOG) {
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logdata = &loghdr;
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nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx);
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} else
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logdata = NULL;
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return (nat64_handle_icmp6(m, 0,
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htonl(TARG_VAL(chain, tablearg, nh4)), 0, stats, logdata));
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}
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int
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ipfw_nat64stl(struct ip_fw_chain *chain, struct ip_fw_args *args,
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ipfw_insn *cmd, int *done)
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{
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ipfw_insn *icmd;
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struct nat64stl_cfg *cfg;
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in_addr_t dst4;
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uint32_t tablearg;
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int ret;
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IPFW_RLOCK_ASSERT(chain);
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*done = 0; /* try next rule if not matched */
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icmd = cmd + 1;
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if (cmd->opcode != O_EXTERNAL_ACTION ||
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cmd->arg1 != V_nat64stl_eid ||
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icmd->opcode != O_EXTERNAL_INSTANCE ||
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(cfg = NAT64_LOOKUP(chain, icmd)) == NULL)
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return (0);
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switch (args->f_id.addr_type) {
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case 4:
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dst4 = htonl(args->f_id.dst_ip);
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ret = ipfw_lookup_table(chain, cfg->map46, sizeof(in_addr_t),
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&dst4, &tablearg);
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break;
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case 6:
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ret = ipfw_lookup_table(chain, cfg->map64,
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sizeof(struct in6_addr), &args->f_id.src_ip6, &tablearg);
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break;
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default:
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return (0);
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}
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if (ret == 0) {
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/*
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* In case when packet is ICMPv6 message from an intermediate
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* router, the source address of message will not match the
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* addresses from our map64 table.
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*/
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if (args->f_id.proto != IPPROTO_ICMPV6)
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return (0);
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ret = nat64stl_handle_icmp6(chain, cfg, args->m);
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} else {
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if (args->f_id.addr_type == 4)
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ret = nat64stl_handle_ip4(chain, cfg, args->m,
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tablearg);
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else
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ret = nat64stl_handle_ip6(chain, cfg, args->m,
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tablearg);
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}
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if (ret == NAT64SKIP)
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return (0);
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*done = 1; /* terminate the search */
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if (ret == NAT64MFREE)
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m_freem(args->m);
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args->m = NULL;
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return (IP_FW_DENY);
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}
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