| 1 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 2 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU General Public License version 2 as |
| 6 | * published by the Free Software Foundation. |
| 7 | */ |
| 8 | |
| 9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 10 | |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/module.h> |
| 13 | #include <linux/spinlock.h> |
| 14 | #include <linux/skbuff.h> |
| 15 | #include <linux/if_arp.h> |
| 16 | #include <linux/ip.h> |
| 17 | #include <net/ipv6.h> |
| 18 | #include <net/icmp.h> |
| 19 | #include <net/udp.h> |
| 20 | #include <net/tcp.h> |
| 21 | #include <net/route.h> |
| 22 | |
| 23 | #include <linux/netfilter.h> |
| 24 | #include <linux/netfilter_ipv6/ip6_tables.h> |
| 25 | #include <linux/netfilter/xt_LOG.h> |
| 26 | #include <net/netfilter/nf_log.h> |
| 27 | |
| 28 | static struct nf_loginfo default_loginfo = { |
| 29 | .type = NF_LOG_TYPE_LOG, |
| 30 | .u = { |
| 31 | .log = { |
| 32 | .level = LOGLEVEL_NOTICE, |
| 33 | .logflags = NF_LOG_DEFAULT_MASK, |
| 34 | }, |
| 35 | }, |
| 36 | }; |
| 37 | |
| 38 | /* One level of recursion won't kill us */ |
| 39 | static void dump_ipv6_packet(struct nf_log_buf *m, |
| 40 | const struct nf_loginfo *info, |
| 41 | const struct sk_buff *skb, unsigned int ip6hoff, |
| 42 | int recurse) |
| 43 | { |
| 44 | u_int8_t currenthdr; |
| 45 | int fragment; |
| 46 | struct ipv6hdr _ip6h; |
| 47 | const struct ipv6hdr *ih; |
| 48 | unsigned int ptr; |
| 49 | unsigned int hdrlen = 0; |
| 50 | unsigned int logflags; |
| 51 | |
| 52 | if (info->type == NF_LOG_TYPE_LOG) |
| 53 | logflags = info->u.log.logflags; |
| 54 | else |
| 55 | logflags = NF_LOG_DEFAULT_MASK; |
| 56 | |
| 57 | ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h); |
| 58 | if (ih == NULL) { |
| 59 | nf_log_buf_add(m, "TRUNCATED"); |
| 60 | return; |
| 61 | } |
| 62 | |
| 63 | /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */ |
| 64 | nf_log_buf_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr); |
| 65 | |
| 66 | /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ |
| 67 | nf_log_buf_add(m, "LEN=%zu TC=%u HOPLIMIT=%u FLOWLBL=%u ", |
| 68 | ntohs(ih->payload_len) + sizeof(struct ipv6hdr), |
| 69 | (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20, |
| 70 | ih->hop_limit, |
| 71 | (ntohl(*(__be32 *)ih) & 0x000fffff)); |
| 72 | |
| 73 | fragment = 0; |
| 74 | ptr = ip6hoff + sizeof(struct ipv6hdr); |
| 75 | currenthdr = ih->nexthdr; |
| 76 | while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) { |
| 77 | struct ipv6_opt_hdr _hdr; |
| 78 | const struct ipv6_opt_hdr *hp; |
| 79 | |
| 80 | hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr); |
| 81 | if (hp == NULL) { |
| 82 | nf_log_buf_add(m, "TRUNCATED"); |
| 83 | return; |
| 84 | } |
| 85 | |
| 86 | /* Max length: 48 "OPT (...) " */ |
| 87 | if (logflags & NF_LOG_IPOPT) |
| 88 | nf_log_buf_add(m, "OPT ( "); |
| 89 | |
| 90 | switch (currenthdr) { |
| 91 | case IPPROTO_FRAGMENT: { |
| 92 | struct frag_hdr _fhdr; |
| 93 | const struct frag_hdr *fh; |
| 94 | |
| 95 | nf_log_buf_add(m, "FRAG:"); |
| 96 | fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), |
| 97 | &_fhdr); |
| 98 | if (fh == NULL) { |
| 99 | nf_log_buf_add(m, "TRUNCATED "); |
| 100 | return; |
| 101 | } |
| 102 | |
| 103 | /* Max length: 6 "65535 " */ |
| 104 | nf_log_buf_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8); |
| 105 | |
| 106 | /* Max length: 11 "INCOMPLETE " */ |
| 107 | if (fh->frag_off & htons(0x0001)) |
| 108 | nf_log_buf_add(m, "INCOMPLETE "); |
| 109 | |
| 110 | nf_log_buf_add(m, "ID:%08x ", |
| 111 | ntohl(fh->identification)); |
| 112 | |
| 113 | if (ntohs(fh->frag_off) & 0xFFF8) |
| 114 | fragment = 1; |
| 115 | |
| 116 | hdrlen = 8; |
| 117 | |
| 118 | break; |
| 119 | } |
| 120 | case IPPROTO_DSTOPTS: |
| 121 | case IPPROTO_ROUTING: |
| 122 | case IPPROTO_HOPOPTS: |
| 123 | if (fragment) { |
| 124 | if (logflags & NF_LOG_IPOPT) |
| 125 | nf_log_buf_add(m, ")"); |
| 126 | return; |
| 127 | } |
| 128 | hdrlen = ipv6_optlen(hp); |
| 129 | break; |
| 130 | /* Max Length */ |
| 131 | case IPPROTO_AH: |
| 132 | if (logflags & NF_LOG_IPOPT) { |
| 133 | struct ip_auth_hdr _ahdr; |
| 134 | const struct ip_auth_hdr *ah; |
| 135 | |
| 136 | /* Max length: 3 "AH " */ |
| 137 | nf_log_buf_add(m, "AH "); |
| 138 | |
| 139 | if (fragment) { |
| 140 | nf_log_buf_add(m, ")"); |
| 141 | return; |
| 142 | } |
| 143 | |
| 144 | ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), |
| 145 | &_ahdr); |
| 146 | if (ah == NULL) { |
| 147 | /* |
| 148 | * Max length: 26 "INCOMPLETE [65535 |
| 149 | * bytes] )" |
| 150 | */ |
| 151 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] )", |
| 152 | skb->len - ptr); |
| 153 | return; |
| 154 | } |
| 155 | |
| 156 | /* Length: 15 "SPI=0xF1234567 */ |
| 157 | nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi)); |
| 158 | |
| 159 | } |
| 160 | |
| 161 | hdrlen = (hp->hdrlen+2)<<2; |
| 162 | break; |
| 163 | case IPPROTO_ESP: |
| 164 | if (logflags & NF_LOG_IPOPT) { |
| 165 | struct ip_esp_hdr _esph; |
| 166 | const struct ip_esp_hdr *eh; |
| 167 | |
| 168 | /* Max length: 4 "ESP " */ |
| 169 | nf_log_buf_add(m, "ESP "); |
| 170 | |
| 171 | if (fragment) { |
| 172 | nf_log_buf_add(m, ")"); |
| 173 | return; |
| 174 | } |
| 175 | |
| 176 | /* |
| 177 | * Max length: 26 "INCOMPLETE [65535 bytes] )" |
| 178 | */ |
| 179 | eh = skb_header_pointer(skb, ptr, sizeof(_esph), |
| 180 | &_esph); |
| 181 | if (eh == NULL) { |
| 182 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] )", |
| 183 | skb->len - ptr); |
| 184 | return; |
| 185 | } |
| 186 | |
| 187 | /* Length: 16 "SPI=0xF1234567 )" */ |
| 188 | nf_log_buf_add(m, "SPI=0x%x )", |
| 189 | ntohl(eh->spi)); |
| 190 | } |
| 191 | return; |
| 192 | default: |
| 193 | /* Max length: 20 "Unknown Ext Hdr 255" */ |
| 194 | nf_log_buf_add(m, "Unknown Ext Hdr %u", currenthdr); |
| 195 | return; |
| 196 | } |
| 197 | if (logflags & NF_LOG_IPOPT) |
| 198 | nf_log_buf_add(m, ") "); |
| 199 | |
| 200 | currenthdr = hp->nexthdr; |
| 201 | ptr += hdrlen; |
| 202 | } |
| 203 | |
| 204 | switch (currenthdr) { |
| 205 | case IPPROTO_TCP: |
| 206 | if (nf_log_dump_tcp_header(m, skb, currenthdr, fragment, |
| 207 | ptr, logflags)) |
| 208 | return; |
| 209 | break; |
| 210 | case IPPROTO_UDP: |
| 211 | case IPPROTO_UDPLITE: |
| 212 | if (nf_log_dump_udp_header(m, skb, currenthdr, fragment, ptr)) |
| 213 | return; |
| 214 | break; |
| 215 | case IPPROTO_ICMPV6: { |
| 216 | struct icmp6hdr _icmp6h; |
| 217 | const struct icmp6hdr *ic; |
| 218 | |
| 219 | /* Max length: 13 "PROTO=ICMPv6 " */ |
| 220 | nf_log_buf_add(m, "PROTO=ICMPv6 "); |
| 221 | |
| 222 | if (fragment) |
| 223 | break; |
| 224 | |
| 225 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| 226 | ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h); |
| 227 | if (ic == NULL) { |
| 228 | nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", |
| 229 | skb->len - ptr); |
| 230 | return; |
| 231 | } |
| 232 | |
| 233 | /* Max length: 18 "TYPE=255 CODE=255 " */ |
| 234 | nf_log_buf_add(m, "TYPE=%u CODE=%u ", |
| 235 | ic->icmp6_type, ic->icmp6_code); |
| 236 | |
| 237 | switch (ic->icmp6_type) { |
| 238 | case ICMPV6_ECHO_REQUEST: |
| 239 | case ICMPV6_ECHO_REPLY: |
| 240 | /* Max length: 19 "ID=65535 SEQ=65535 " */ |
| 241 | nf_log_buf_add(m, "ID=%u SEQ=%u ", |
| 242 | ntohs(ic->icmp6_identifier), |
| 243 | ntohs(ic->icmp6_sequence)); |
| 244 | break; |
| 245 | case ICMPV6_MGM_QUERY: |
| 246 | case ICMPV6_MGM_REPORT: |
| 247 | case ICMPV6_MGM_REDUCTION: |
| 248 | break; |
| 249 | |
| 250 | case ICMPV6_PARAMPROB: |
| 251 | /* Max length: 17 "POINTER=ffffffff " */ |
| 252 | nf_log_buf_add(m, "POINTER=%08x ", |
| 253 | ntohl(ic->icmp6_pointer)); |
| 254 | /* Fall through */ |
| 255 | case ICMPV6_DEST_UNREACH: |
| 256 | case ICMPV6_PKT_TOOBIG: |
| 257 | case ICMPV6_TIME_EXCEED: |
| 258 | /* Max length: 3+maxlen */ |
| 259 | if (recurse) { |
| 260 | nf_log_buf_add(m, "["); |
| 261 | dump_ipv6_packet(m, info, skb, |
| 262 | ptr + sizeof(_icmp6h), 0); |
| 263 | nf_log_buf_add(m, "] "); |
| 264 | } |
| 265 | |
| 266 | /* Max length: 10 "MTU=65535 " */ |
| 267 | if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) { |
| 268 | nf_log_buf_add(m, "MTU=%u ", |
| 269 | ntohl(ic->icmp6_mtu)); |
| 270 | } |
| 271 | } |
| 272 | break; |
| 273 | } |
| 274 | /* Max length: 10 "PROTO=255 " */ |
| 275 | default: |
| 276 | nf_log_buf_add(m, "PROTO=%u ", currenthdr); |
| 277 | } |
| 278 | |
| 279 | /* Max length: 15 "UID=4294967295 " */ |
| 280 | if ((logflags & NF_LOG_UID) && recurse) |
| 281 | nf_log_dump_sk_uid_gid(m, skb->sk); |
| 282 | |
| 283 | /* Max length: 16 "MARK=0xFFFFFFFF " */ |
| 284 | if (recurse && skb->mark) |
| 285 | nf_log_buf_add(m, "MARK=0x%x ", skb->mark); |
| 286 | } |
| 287 | |
| 288 | static void dump_ipv6_mac_header(struct nf_log_buf *m, |
| 289 | const struct nf_loginfo *info, |
| 290 | const struct sk_buff *skb) |
| 291 | { |
| 292 | struct net_device *dev = skb->dev; |
| 293 | unsigned int logflags = 0; |
| 294 | |
| 295 | if (info->type == NF_LOG_TYPE_LOG) |
| 296 | logflags = info->u.log.logflags; |
| 297 | |
| 298 | if (!(logflags & NF_LOG_MACDECODE)) |
| 299 | goto fallback; |
| 300 | |
| 301 | switch (dev->type) { |
| 302 | case ARPHRD_ETHER: |
| 303 | nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", |
| 304 | eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, |
| 305 | ntohs(eth_hdr(skb)->h_proto)); |
| 306 | return; |
| 307 | default: |
| 308 | break; |
| 309 | } |
| 310 | |
| 311 | fallback: |
| 312 | nf_log_buf_add(m, "MAC="); |
| 313 | if (dev->hard_header_len && |
| 314 | skb->mac_header != skb->network_header) { |
| 315 | const unsigned char *p = skb_mac_header(skb); |
| 316 | unsigned int len = dev->hard_header_len; |
| 317 | unsigned int i; |
| 318 | |
| 319 | if (dev->type == ARPHRD_SIT) { |
| 320 | p -= ETH_HLEN; |
| 321 | |
| 322 | if (p < skb->head) |
| 323 | p = NULL; |
| 324 | } |
| 325 | |
| 326 | if (p != NULL) { |
| 327 | nf_log_buf_add(m, "%02x", *p++); |
| 328 | for (i = 1; i < len; i++) |
| 329 | nf_log_buf_add(m, ":%02x", *p++); |
| 330 | } |
| 331 | nf_log_buf_add(m, " "); |
| 332 | |
| 333 | if (dev->type == ARPHRD_SIT) { |
| 334 | const struct iphdr *iph = |
| 335 | (struct iphdr *)skb_mac_header(skb); |
| 336 | nf_log_buf_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr, |
| 337 | &iph->daddr); |
| 338 | } |
| 339 | } else { |
| 340 | nf_log_buf_add(m, " "); |
| 341 | } |
| 342 | } |
| 343 | |
| 344 | static void nf_log_ip6_packet(struct net *net, u_int8_t pf, |
| 345 | unsigned int hooknum, const struct sk_buff *skb, |
| 346 | const struct net_device *in, |
| 347 | const struct net_device *out, |
| 348 | const struct nf_loginfo *loginfo, |
| 349 | const char *prefix) |
| 350 | { |
| 351 | struct nf_log_buf *m; |
| 352 | |
| 353 | /* FIXME: Disabled from containers until syslog ns is supported */ |
| 354 | if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) |
| 355 | return; |
| 356 | |
| 357 | m = nf_log_buf_open(); |
| 358 | |
| 359 | if (!loginfo) |
| 360 | loginfo = &default_loginfo; |
| 361 | |
| 362 | nf_log_dump_packet_common(m, pf, hooknum, skb, in, out, |
| 363 | loginfo, prefix); |
| 364 | |
| 365 | if (in != NULL) |
| 366 | dump_ipv6_mac_header(m, loginfo, skb); |
| 367 | |
| 368 | dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1); |
| 369 | |
| 370 | nf_log_buf_close(m); |
| 371 | } |
| 372 | |
| 373 | static struct nf_logger nf_ip6_logger __read_mostly = { |
| 374 | .name = "nf_log_ipv6", |
| 375 | .type = NF_LOG_TYPE_LOG, |
| 376 | .logfn = nf_log_ip6_packet, |
| 377 | .me = THIS_MODULE, |
| 378 | }; |
| 379 | |
| 380 | static int __net_init nf_log_ipv6_net_init(struct net *net) |
| 381 | { |
| 382 | return nf_log_set(net, NFPROTO_IPV6, &nf_ip6_logger); |
| 383 | } |
| 384 | |
| 385 | static void __net_exit nf_log_ipv6_net_exit(struct net *net) |
| 386 | { |
| 387 | nf_log_unset(net, &nf_ip6_logger); |
| 388 | } |
| 389 | |
| 390 | static struct pernet_operations nf_log_ipv6_net_ops = { |
| 391 | .init = nf_log_ipv6_net_init, |
| 392 | .exit = nf_log_ipv6_net_exit, |
| 393 | }; |
| 394 | |
| 395 | static int __init nf_log_ipv6_init(void) |
| 396 | { |
| 397 | int ret; |
| 398 | |
| 399 | ret = register_pernet_subsys(&nf_log_ipv6_net_ops); |
| 400 | if (ret < 0) |
| 401 | return ret; |
| 402 | |
| 403 | ret = nf_log_register(NFPROTO_IPV6, &nf_ip6_logger); |
| 404 | if (ret < 0) { |
| 405 | pr_err("failed to register logger\n"); |
| 406 | goto err1; |
| 407 | } |
| 408 | |
| 409 | return 0; |
| 410 | |
| 411 | err1: |
| 412 | unregister_pernet_subsys(&nf_log_ipv6_net_ops); |
| 413 | return ret; |
| 414 | } |
| 415 | |
| 416 | static void __exit nf_log_ipv6_exit(void) |
| 417 | { |
| 418 | unregister_pernet_subsys(&nf_log_ipv6_net_ops); |
| 419 | nf_log_unregister(&nf_ip6_logger); |
| 420 | } |
| 421 | |
| 422 | module_init(nf_log_ipv6_init); |
| 423 | module_exit(nf_log_ipv6_exit); |
| 424 | |
| 425 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| 426 | MODULE_DESCRIPTION("Netfilter IPv6 packet logging"); |
| 427 | MODULE_LICENSE("GPL"); |
| 428 | MODULE_ALIAS_NF_LOGGER(AF_INET6, 0); |