nat64stl.c revision 316446
1304046Sae/*- 2304046Sae * Copyright (c) 2015-2016 Yandex LLC 3304046Sae * Copyright (c) 2015-2016 Andrey V. Elsukov <ae@FreeBSD.org> 4304046Sae * All rights reserved. 5304046Sae * 6304046Sae * Redistribution and use in source and binary forms, with or without 7304046Sae * modification, are permitted provided that the following conditions 8304046Sae * are met: 9304046Sae * 10304046Sae * 1. Redistributions of source code must retain the above copyright 11304046Sae * notice, this list of conditions and the following disclaimer. 12304046Sae * 2. Redistributions in binary form must reproduce the above copyright 13304046Sae * notice, this list of conditions and the following disclaimer in the 14304046Sae * documentation and/or other materials provided with the distribution. 15304046Sae * 16304046Sae * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17304046Sae * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18304046Sae * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19304046Sae * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20304046Sae * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21304046Sae * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22304046Sae * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23304046Sae * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24304046Sae * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25304046Sae * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26304046Sae */ 27304046Sae 28304046Sae#include <sys/cdefs.h> 29304046Sae__FBSDID("$FreeBSD: stable/11/sys/netpfil/ipfw/nat64/nat64stl.c 316446 2017-04-03 08:50:54Z ae $"); 30304046Sae 31304046Sae#include <sys/param.h> 32304046Sae#include <sys/systm.h> 33304046Sae#include <sys/counter.h> 34304046Sae#include <sys/kernel.h> 35304046Sae#include <sys/lock.h> 36304046Sae#include <sys/mbuf.h> 37304046Sae#include <sys/module.h> 38304046Sae#include <sys/rmlock.h> 39304046Sae#include <sys/rwlock.h> 40304046Sae#include <sys/socket.h> 41304046Sae#include <sys/sysctl.h> 42304046Sae 43304046Sae#include <net/if.h> 44304046Sae#include <net/if_var.h> 45304046Sae#include <net/if_pflog.h> 46304046Sae#include <net/pfil.h> 47304046Sae 48304046Sae#include <netinet/in.h> 49304046Sae#include <netinet/ip.h> 50304046Sae#include <netinet/ip_icmp.h> 51304046Sae#include <netinet/ip_var.h> 52304046Sae#include <netinet/ip_fw.h> 53304046Sae#include <netinet/ip6.h> 54304046Sae#include <netinet/icmp6.h> 55304046Sae#include <netinet6/ip_fw_nat64.h> 56304046Sae 57304046Sae#include <netpfil/ipfw/ip_fw_private.h> 58304046Sae#include <netpfil/ipfw/nat64/ip_fw_nat64.h> 59304046Sae#include <netpfil/ipfw/nat64/nat64_translate.h> 60304046Sae#include <netpfil/ipfw/nat64/nat64stl.h> 61304046Sae#include <netpfil/pf/pf.h> 62304046Sae 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); 78304046Sae plog->subrulenr = htonl(++pktid); 79304046Sae plog->ruleset[0] = '\0'; 80304046Sae strlcpy(plog->ifname, "NAT64STL", sizeof(plog->ifname)); 81304046Sae ipfw_bpf_mtap2(plog, PFLOG_HDRLEN, m); 82304046Sae} 83304046Sae 84304046Saestatic int 85304046Saenat64stl_handle_ip4(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg, 86304046Sae struct mbuf *m, uint32_t tablearg) 87304046Sae{ 88304046Sae struct pfloghdr loghdr, *logdata; 89304046Sae struct in6_addr saddr, daddr; 90304046Sae struct ip *ip; 91304046Sae 92304046Sae ip = mtod(m, struct ip*); 93304046Sae if (nat64_check_ip4(ip->ip_src.s_addr) != 0 || 94304046Sae nat64_check_ip4(ip->ip_dst.s_addr) != 0 || 95304046Sae nat64_check_private_ip4(ip->ip_src.s_addr) != 0 || 96304046Sae nat64_check_private_ip4(ip->ip_dst.s_addr) != 0) 97304046Sae return (NAT64SKIP); 98304046Sae 99304046Sae daddr = TARG_VAL(chain, tablearg, nh6); 100304046Sae if (nat64_check_ip6(&daddr) != 0) 101304046Sae return (NAT64MFREE); 102304046Sae saddr = cfg->prefix6; 103304046Sae nat64_set_ip4(&saddr, ip->ip_src.s_addr); 104304046Sae 105304046Sae if (cfg->flags & NAT64_LOG) { 106304046Sae logdata = &loghdr; 107304046Sae nat64stl_log(logdata, m, AF_INET, cfg->no.kidx); 108304046Sae } else 109304046Sae logdata = NULL; 110304046Sae return (nat64_do_handle_ip4(m, &saddr, &daddr, 0, &cfg->stats, 111304046Sae logdata)); 112304046Sae} 113304046Sae 114304046Saestatic int 115304046Saenat64stl_handle_ip6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg, 116304046Sae struct mbuf *m, uint32_t tablearg) 117304046Sae{ 118304046Sae struct pfloghdr loghdr, *logdata; 119304046Sae struct ip6_hdr *ip6; 120304046Sae uint32_t aaddr; 121304046Sae 122304046Sae aaddr = htonl(TARG_VAL(chain, tablearg, nh4)); 123304046Sae 124304046Sae /* 125304046Sae * NOTE: we expect ipfw_chk() did m_pullup() up to upper level 126304046Sae * protocol's headers. Also we skip some checks, that ip6_input(), 127304046Sae * ip6_forward(), ip6_fastfwd() and ipfw_chk() already did. 128304046Sae */ 129304046Sae ip6 = mtod(m, struct ip6_hdr *); 130304046Sae /* Check ip6_dst matches configured prefix */ 131304046Sae if (bcmp(&ip6->ip6_dst, &cfg->prefix6, cfg->plen6 / 8) != 0) 132304046Sae return (NAT64SKIP); 133304046Sae 134304046Sae if (cfg->flags & NAT64_LOG) { 135304046Sae logdata = &loghdr; 136304046Sae nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx); 137304046Sae } else 138304046Sae logdata = NULL; 139304046Sae return (nat64_do_handle_ip6(m, aaddr, 0, &cfg->stats, logdata)); 140304046Sae} 141304046Sae 142304046Saestatic int 143304046Saenat64stl_handle_icmp6(struct ip_fw_chain *chain, struct nat64stl_cfg *cfg, 144304046Sae struct mbuf *m) 145304046Sae{ 146304046Sae struct pfloghdr loghdr, *logdata; 147304046Sae nat64_stats_block *stats; 148304046Sae struct ip6_hdr *ip6i; 149304046Sae struct icmp6_hdr *icmp6; 150304046Sae uint32_t tablearg; 151304046Sae int hlen, proto; 152304046Sae 153304046Sae hlen = 0; 154304046Sae stats = &cfg->stats; 155304046Sae proto = nat64_getlasthdr(m, &hlen); 156304046Sae if (proto != IPPROTO_ICMPV6) { 157304046Sae NAT64STAT_INC(stats, dropped); 158304046Sae return (NAT64MFREE); 159304046Sae } 160304046Sae icmp6 = mtodo(m, hlen); 161304046Sae switch (icmp6->icmp6_type) { 162304046Sae case ICMP6_DST_UNREACH: 163304046Sae case ICMP6_PACKET_TOO_BIG: 164304046Sae case ICMP6_TIME_EXCEED_TRANSIT: 165304046Sae case ICMP6_PARAM_PROB: 166304046Sae break; 167304046Sae default: 168304046Sae NAT64STAT_INC(stats, dropped); 169304046Sae return (NAT64MFREE); 170304046Sae } 171304046Sae hlen += sizeof(struct icmp6_hdr); 172304046Sae if (m->m_pkthdr.len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) { 173304046Sae NAT64STAT_INC(stats, dropped); 174304046Sae return (NAT64MFREE); 175304046Sae } 176304046Sae if (m->m_len < hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN) 177304046Sae m = m_pullup(m, hlen + sizeof(struct ip6_hdr) + ICMP_MINLEN); 178304046Sae if (m == NULL) { 179304046Sae NAT64STAT_INC(stats, nomem); 180304046Sae return (NAT64RETURN); 181304046Sae } 182304046Sae /* 183304046Sae * Use destination address from inner IPv6 header to determine 184304046Sae * IPv4 mapped address. 185304046Sae */ 186304046Sae ip6i = mtodo(m, hlen); 187316446Sae if (ipfw_lookup_table(chain, cfg->map64, 188304046Sae sizeof(struct in6_addr), &ip6i->ip6_dst, &tablearg) == 0) { 189304046Sae m_freem(m); 190304046Sae return (NAT64RETURN); 191304046Sae } 192304046Sae if (cfg->flags & NAT64_LOG) { 193304046Sae logdata = &loghdr; 194304046Sae nat64stl_log(logdata, m, AF_INET6, cfg->no.kidx); 195304046Sae } else 196304046Sae logdata = NULL; 197304046Sae return (nat64_handle_icmp6(m, 0, 198304046Sae htonl(TARG_VAL(chain, tablearg, nh4)), 0, stats, logdata)); 199304046Sae} 200304046Sae 201304046Saeint 202304046Saeipfw_nat64stl(struct ip_fw_chain *chain, struct ip_fw_args *args, 203304046Sae ipfw_insn *cmd, int *done) 204304046Sae{ 205304046Sae ipfw_insn *icmd; 206304046Sae struct nat64stl_cfg *cfg; 207316446Sae in_addr_t dst4; 208304046Sae uint32_t tablearg; 209304046Sae int ret; 210304046Sae 211304046Sae IPFW_RLOCK_ASSERT(chain); 212304046Sae 213304046Sae *done = 0; /* try next rule if not matched */ 214304046Sae icmd = cmd + 1; 215304046Sae if (cmd->opcode != O_EXTERNAL_ACTION || 216304046Sae cmd->arg1 != V_nat64stl_eid || 217304046Sae icmd->opcode != O_EXTERNAL_INSTANCE || 218304046Sae (cfg = NAT64_LOOKUP(chain, icmd)) == NULL) 219304046Sae return (0); 220304046Sae 221304046Sae switch (args->f_id.addr_type) { 222304046Sae case 4: 223316446Sae dst4 = htonl(args->f_id.dst_ip); 224316446Sae ret = ipfw_lookup_table(chain, cfg->map46, sizeof(in_addr_t), 225316446Sae &dst4, &tablearg); 226304046Sae break; 227304046Sae case 6: 228316446Sae ret = ipfw_lookup_table(chain, cfg->map64, 229304046Sae sizeof(struct in6_addr), &args->f_id.src_ip6, &tablearg); 230304046Sae break; 231304046Sae default: 232304046Sae return (0); 233304046Sae } 234304046Sae if (ret == 0) { 235304046Sae /* 236304046Sae * In case when packet is ICMPv6 message from an intermediate 237304046Sae * router, the source address of message will not match the 238304046Sae * addresses from our map64 table. 239304046Sae */ 240304046Sae if (args->f_id.proto != IPPROTO_ICMPV6) 241304046Sae return (0); 242304046Sae 243304046Sae ret = nat64stl_handle_icmp6(chain, cfg, args->m); 244304046Sae } else { 245304046Sae if (args->f_id.addr_type == 4) 246304046Sae ret = nat64stl_handle_ip4(chain, cfg, args->m, 247304046Sae tablearg); 248304046Sae else 249304046Sae ret = nat64stl_handle_ip6(chain, cfg, args->m, 250304046Sae tablearg); 251304046Sae } 252304046Sae if (ret == NAT64SKIP) 253304046Sae return (0); 254304046Sae 255304046Sae *done = 1; /* terminate the search */ 256304046Sae if (ret == NAT64MFREE) 257304046Sae m_freem(args->m); 258304046Sae args->m = NULL; 259304046Sae return (IP_FW_DENY); 260304046Sae} 261304046Sae 262304046Sae 263