1304046Sae/*- 2346211Sae * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3304046Sae * 4346211Sae * Copyright (c) 2015-2019 Yandex LLC 5346211Sae * Copyright (c) 2015-2019 Andrey V. Elsukov <ae@FreeBSD.org> 6346211Sae * 7304046Sae * Redistribution and use in source and binary forms, with or without 8304046Sae * modification, are permitted provided that the following conditions 9304046Sae * are met: 10304046Sae * 11304046Sae * 1. Redistributions of source code must retain the above copyright 12304046Sae * notice, this list of conditions and the following disclaimer. 13304046Sae * 2. Redistributions in binary form must reproduce the above copyright 14304046Sae * notice, this list of conditions and the following disclaimer in the 15304046Sae * documentation and/or other materials provided with the distribution. 16304046Sae * 17304046Sae * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18304046Sae * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19304046Sae * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20304046Sae * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21304046Sae * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22304046Sae * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23304046Sae * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24304046Sae * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25304046Sae * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26304046Sae * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27304046Sae */ 28304046Sae 29304046Sae#include <sys/cdefs.h> 30304046Sae__FBSDID("$FreeBSD: stable/11/sys/netpfil/ipfw/nat64/nat64stl.c 346211 2019-04-14 12:35:58Z ae $"); 31304046Sae 32304046Sae#include <sys/param.h> 33304046Sae#include <sys/systm.h> 34304046Sae#include <sys/counter.h> 35304046Sae#include <sys/kernel.h> 36304046Sae#include <sys/lock.h> 37304046Sae#include <sys/mbuf.h> 38304046Sae#include <sys/module.h> 39304046Sae#include <sys/rmlock.h> 40304046Sae#include <sys/rwlock.h> 41304046Sae#include <sys/socket.h> 42304046Sae#include <sys/sysctl.h> 43304046Sae 44304046Sae#include <net/if.h> 45304046Sae#include <net/if_var.h> 46304046Sae#include <net/if_pflog.h> 47304046Sae#include <net/pfil.h> 48304046Sae 49304046Sae#include <netinet/in.h> 50304046Sae#include <netinet/ip.h> 51304046Sae#include <netinet/ip_icmp.h> 52304046Sae#include <netinet/ip_var.h> 53304046Sae#include <netinet/ip_fw.h> 54304046Sae#include <netinet/ip6.h> 55304046Sae#include <netinet/icmp6.h> 56304046Sae#include <netinet6/ip_fw_nat64.h> 57304046Sae 58304046Sae#include <netpfil/ipfw/ip_fw_private.h> 59304046Sae#include <netpfil/pf/pf.h> 60304046Sae 61334836Sae#include "nat64stl.h" 62334836Sae 63304046Sae#define NAT64_LOOKUP(chain, cmd) \ 64304046Sae (struct nat64stl_cfg *)SRV_OBJECT((chain), (cmd)->arg1) 65304046Sae 66304046Saestatic void 67304046Saenat64stl_log(struct pfloghdr *plog, struct mbuf *m, sa_family_t family, 68304046Sae uint32_t kidx) 69304046Sae{ 70304046Sae static uint32_t pktid = 0; 71304046Sae 72316446Sae memset(plog, 0, sizeof(*plog)); 73304046Sae plog->length = PFLOG_REAL_HDRLEN; 74304046Sae plog->af = family; 75304046Sae plog->action = PF_NAT; 76304046Sae plog->dir = PF_IN; 77304046Sae plog->rulenr = htonl(kidx); 78332765Sae pktid++; 79332765Sae plog->subrulenr = htonl(pktid); 80304046Sae plog->ruleset[0] = '\0'; 81304046Sae strlcpy(plog->ifname, "NAT64STL", sizeof(plog->ifname)); 82304046Sae ipfw_bpf_mtap2(plog, PFLOG_HDRLEN, m); 83304046Sae} 84304046Sae 85304046Saestatic int 86304046Saenat64stl_handle_ip4(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg, 87304046Sae struct mbuf *m, uint32_t tablearg) 88304046Sae{ 89304046Sae struct pfloghdr loghdr, *logdata; 90304046Sae struct in6_addr saddr, daddr; 91304046Sae struct ip *ip; 92304046Sae 93304046Sae ip = mtod(m, struct ip*); 94304046Sae if (nat64_check_ip4(ip->ip_src.s_addr) != 0 || 95304046Sae nat64_check_ip4(ip->ip_dst.s_addr) != 0 || 96334836Sae nat64_check_private_ip4(&cfg->base, ip->ip_src.s_addr) != 0 || 97334836Sae nat64_check_private_ip4(&cfg->base, ip->ip_dst.s_addr) != 0) 98304046Sae return (NAT64SKIP); 99304046Sae 100304046Sae daddr = TARG_VAL(chain, tablearg, nh6); 101304046Sae if (nat64_check_ip6(&daddr) != 0) 102304046Sae return (NAT64MFREE); 103346210Sae 104346210Sae saddr = cfg->base.plat_prefix; 105346210Sae nat64_embed_ip4(&saddr, cfg->base.plat_plen, ip->ip_src.s_addr); 106334836Sae if (cfg->base.flags & NAT64_LOG) { 107304046Sae logdata = &loghdr; 108304046Sae nat64stl_log(logdata, m, AF_INET, cfg->no.kidx); 109304046Sae } else 110304046Sae logdata = NULL; 111334836Sae return (nat64_do_handle_ip4(m, &saddr, &daddr, 0, &cfg->base, 112304046Sae logdata)); 113304046Sae} 114304046Sae 115304046Saestatic int 116304046Saenat64stl_handle_ip6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg, 117304046Sae struct mbuf *m, uint32_t tablearg) 118304046Sae{ 119304046Sae struct pfloghdr loghdr, *logdata; 120304046Sae struct ip6_hdr *ip6; 121304046Sae uint32_t aaddr; 122304046Sae 123304046Sae aaddr = htonl(TARG_VAL(chain, tablearg, nh4)); 124346210Sae if (nat64_check_private_ip4(&cfg->base, aaddr) != 0) { 125346210Sae NAT64STAT_INC(&cfg->base.stats, dropped); 126346210Sae return (NAT64MFREE); 127346210Sae } 128304046Sae /* 129304046Sae * NOTE: we expect ipfw_chk() did m_pullup() up to upper level 130304046Sae * protocol's headers. Also we skip some checks, that ip6_input(), 131304046Sae * ip6_forward(), ip6_fastfwd() and ipfw_chk() already did. 132304046Sae */ 133304046Sae ip6 = mtod(m, struct ip6_hdr *); 134304046Sae /* Check ip6_dst matches configured prefix */ 135346210Sae if (memcmp(&ip6->ip6_dst, &cfg->base.plat_prefix, 136346210Sae cfg->base.plat_plen / 8) != 0) 137304046Sae return (NAT64SKIP); 138304046Sae 139334836Sae if (cfg->base.flags & NAT64_LOG) { 140304046Sae logdata = &loghdr; 141304046Sae nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx); 142304046Sae } else 143304046Sae logdata = NULL; 144334836Sae return (nat64_do_handle_ip6(m, aaddr, 0, &cfg->base, logdata)); 145304046Sae} 146304046Sae 147304046Saestatic int 148304046Saenat64stl_handle_icmp6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg, 149304046Sae struct mbuf *m) 150304046Sae{ 151304046Sae struct pfloghdr loghdr, *logdata; 152334836Sae struct nat64_counters *stats; 153304046Sae struct ip6_hdr *ip6i; 154304046Sae struct icmp6_hdr *icmp6; 155304046Sae uint32_t tablearg; 156304046Sae int hlen, proto; 157304046Sae 158304046Sae hlen = 0; 159334836Sae stats = &cfg->base.stats; 160304046Sae proto = nat64_getlasthdr(m, &hlen); 161304046Sae if (proto != IPPROTO_ICMPV6) { 162304046Sae NAT64STAT_INC(stats, dropped); 163304046Sae return (NAT64MFREE); 164304046Sae } 165304046Sae icmp6 = mtodo(m, hlen); 166304046Sae switch (icmp6->icmp6_type) { 167304046Sae case ICMP6_DST_UNREACH: 168304046Sae case ICMP6_PACKET_TOO_BIG: 169304046Sae case ICMP6_TIME_EXCEED_TRANSIT: 170304046Sae case ICMP6_PARAM_PROB: 171304046Sae break; 172304046Sae default: 173304046Sae NAT64STAT_INC(stats, dropped); 174304046Sae return (NAT64MFREE); 175304046Sae } 176304046Sae hlen += sizeof(struct icmp6_hdr); 177304046Sae if (m->m_pkthdr.len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) { 178304046Sae NAT64STAT_INC(stats, dropped); 179304046Sae return (NAT64MFREE); 180304046Sae } 181304046Sae if (m->m_len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) 182304046Sae m = m_pullup(m, hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN); 183304046Sae if (m == NULL) { 184304046Sae NAT64STAT_INC(stats, nomem); 185304046Sae return (NAT64RETURN); 186304046Sae } 187304046Sae /* 188304046Sae * Use destination address from inner IPv6 header to determine 189304046Sae * IPv4 mapped address. 190304046Sae */ 191304046Sae ip6i = mtodo(m, hlen); 192316446Sae if (ipfw_lookup_table(chain, cfg->map64, 193304046Sae sizeof(struct in6_addr), &ip6i->ip6_dst, &tablearg) == 0) { 194304046Sae m_freem(m); 195304046Sae return (NAT64RETURN); 196304046Sae } 197334836Sae if (cfg->base.flags & NAT64_LOG) { 198304046Sae logdata = &loghdr; 199304046Sae nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx); 200304046Sae } else 201304046Sae logdata = NULL; 202304046Sae return (nat64_handle_icmp6(m, 0, 203334836Sae htonl(TARG_VAL(chain, tablearg, nh4)), 0, &cfg->base, logdata)); 204304046Sae} 205304046Sae 206304046Saeint 207304046Saeipfw_nat64stl(struct ip_fw_chain *chain, struct ip_fw_args *args, 208304046Sae ipfw_insn *cmd, int *done) 209304046Sae{ 210304046Sae ipfw_insn *icmd; 211304046Sae struct nat64stl_cfg *cfg; 212316446Sae in_addr_t dst4; 213304046Sae uint32_t tablearg; 214304046Sae int ret; 215304046Sae 216304046Sae IPFW_RLOCK_ASSERT(chain); 217304046Sae 218304046Sae *done = 0; /* try next rule if not matched */ 219304046Sae icmd = cmd + 1; 220304046Sae if (cmd->opcode != O_EXTERNAL_ACTION || 221304046Sae cmd->arg1 != V_nat64stl_eid || 222304046Sae icmd->opcode != O_EXTERNAL_INSTANCE || 223304046Sae (cfg = NAT64_LOOKUP(chain, icmd)) == NULL) 224304046Sae return (0); 225304046Sae 226304046Sae switch (args->f_id.addr_type) { 227304046Sae case 4: 228316446Sae dst4 = htonl(args->f_id.dst_ip); 229316446Sae ret = ipfw_lookup_table(chain, cfg->map46, sizeof(in_addr_t), 230316446Sae &dst4, &tablearg); 231304046Sae break; 232304046Sae case 6: 233316446Sae ret = ipfw_lookup_table(chain, cfg->map64, 234304046Sae sizeof(struct in6_addr), &args->f_id.src_ip6, &tablearg); 235304046Sae break; 236304046Sae default: 237304046Sae return (0); 238304046Sae } 239304046Sae if (ret == 0) { 240304046Sae /* 241304046Sae * In case when packet is ICMPv6 message from an intermediate 242304046Sae * router, the source address of message will not match the 243304046Sae * addresses from our map64 table. 244304046Sae */ 245304046Sae if (args->f_id.proto != IPPROTO_ICMPV6) 246304046Sae return (0); 247304046Sae 248304046Sae ret = nat64stl_handle_icmp6(chain, cfg, args->m); 249304046Sae } else { 250304046Sae if (args->f_id.addr_type == 4) 251304046Sae ret = nat64stl_handle_ip4(chain, cfg, args->m, 252304046Sae tablearg); 253304046Sae else 254304046Sae ret = nat64stl_handle_ip6(chain, cfg, args->m, 255304046Sae tablearg); 256304046Sae } 257304046Sae if (ret == NAT64SKIP) 258304046Sae return (0); 259304046Sae 260304046Sae *done = 1; /* terminate the search */ 261304046Sae if (ret == NAT64MFREE) 262304046Sae m_freem(args->m); 263304046Sae args->m = NULL; 264346210Sae return (IP_FW_NAT64); 265304046Sae} 266304046Sae 267304046Sae 268