Pileus Git - ~andy/linux/blob - net/netfilter/xt_LOG.c

   1 /*
   2  * This is a module which is used for logging packets.
   3  */
   4
   5 /* (C) 1999-2001 Paul `Rusty' Russell
   6  * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14 #include <linux/module.h>
  15 #include <linux/spinlock.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/if_arp.h>
  18 #include <linux/ip.h>
  19 #include <net/ipv6.h>
  20 #include <net/icmp.h>
  21 #include <net/udp.h>
  22 #include <net/tcp.h>
  23 #include <net/route.h>
  24
  25 #include <linux/netfilter.h>
  26 #include <linux/netfilter/x_tables.h>
  27 #include <linux/netfilter/xt_LOG.h>
  28 #include <linux/netfilter_ipv6/ip6_tables.h>
  29 #include <net/netfilter/nf_log.h>
  30 #include <net/netfilter/xt_log.h>
  31
  32 static struct nf_loginfo default_loginfo = {
  33         .type   = NF_LOG_TYPE_LOG,
  34         .u = {
  35                 .log = {
  36                         .level    = 5,
  37                         .logflags = NF_LOG_MASK,
  38                 },
  39         },
  40 };
  41
  42 static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb,
  43                            u8 proto, int fragment, unsigned int offset)
  44 {
  45         struct udphdr _udph;
  46         const struct udphdr *uh;
  47
  48         if (proto == IPPROTO_UDP)
  49                 /* Max length: 10 "PROTO=UDP "     */
  50                 sb_add(m, "PROTO=UDP ");
  51         else    /* Max length: 14 "PROTO=UDPLITE " */
  52                 sb_add(m, "PROTO=UDPLITE ");
  53
  54         if (fragment)
  55                 goto out;
  56
  57         /* Max length: 25 "INCOMPLETE [65535 bytes] " */
  58         uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
  59         if (uh == NULL) {
  60                 sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset);
  61
  62                 return 1;
  63         }
  64
  65         /* Max length: 20 "SPT=65535 DPT=65535 " */
  66         sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest),
  67                 ntohs(uh->len));
  68
  69 out:
  70         return 0;
  71 }
  72
  73 static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb,
  74                            u8 proto, int fragment, unsigned int offset,
  75                            unsigned int logflags)
  76 {
  77         struct tcphdr _tcph;
  78         const struct tcphdr *th;
  79
  80         /* Max length: 10 "PROTO=TCP " */
  81         sb_add(m, "PROTO=TCP ");
  82
  83         if (fragment)
  84                 return 0;
  85
  86         /* Max length: 25 "INCOMPLETE [65535 bytes] " */
  87         th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
  88         if (th == NULL) {
  89                 sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset);
  90                 return 1;
  91         }
  92
  93         /* Max length: 20 "SPT=65535 DPT=65535 " */
  94         sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest));
  95         /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
  96         if (logflags & XT_LOG_TCPSEQ)
  97                 sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq));
  98
  99         /* Max length: 13 "WINDOW=65535 " */
 100         sb_add(m, "WINDOW=%u ", ntohs(th->window));
 101         /* Max length: 9 "RES=0x3C " */
 102         sb_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) &
 103                                             TCP_RESERVED_BITS) >> 22));
 104         /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
 105         if (th->cwr)
 106                 sb_add(m, "CWR ");
 107         if (th->ece)
 108                 sb_add(m, "ECE ");
 109         if (th->urg)
 110                 sb_add(m, "URG ");
 111         if (th->ack)
 112                 sb_add(m, "ACK ");
 113         if (th->psh)
 114                 sb_add(m, "PSH ");
 115         if (th->rst)
 116                 sb_add(m, "RST ");
 117         if (th->syn)
 118                 sb_add(m, "SYN ");
 119         if (th->fin)
 120                 sb_add(m, "FIN ");
 121         /* Max length: 11 "URGP=65535 " */
 122         sb_add(m, "URGP=%u ", ntohs(th->urg_ptr));
 123
 124         if ((logflags & XT_LOG_TCPOPT) && th->doff*4 > sizeof(struct tcphdr)) {
 125                 u_int8_t _opt[60 - sizeof(struct tcphdr)];
 126                 const u_int8_t *op;
 127                 unsigned int i;
 128                 unsigned int optsize = th->doff*4 - sizeof(struct tcphdr);
 129
 130                 op = skb_header_pointer(skb, offset + sizeof(struct tcphdr),
 131                                         optsize, _opt);
 132                 if (op == NULL) {
 133                         sb_add(m, "OPT (TRUNCATED)");
 134                         return 1;
 135                 }
 136
 137                 /* Max length: 127 "OPT (" 15*4*2chars ") " */
 138                 sb_add(m, "OPT (");
 139                 for (i = 0; i < optsize; i++)
 140                         sb_add(m, "%02X", op[i]);
 141
 142                 sb_add(m, ") ");
 143         }
 144
 145         return 0;
 146 }
 147
 148 static void dump_sk_uid_gid(struct sbuff *m, struct sock *sk)
 149 {
 150         if (!sk || sk->sk_state == TCP_TIME_WAIT)
 151                 return;
 152
 153         read_lock_bh(&sk->sk_callback_lock);
 154         if (sk->sk_socket && sk->sk_socket->file)
 155                 sb_add(m, "UID=%u GID=%u ",
 156                         sk->sk_socket->file->f_cred->fsuid,
 157                         sk->sk_socket->file->f_cred->fsgid);
 158         read_unlock_bh(&sk->sk_callback_lock);
 159 }
 160
 161 /* One level of recursion won't kill us */
 162 static void dump_ipv4_packet(struct sbuff *m,
 163                         const struct nf_loginfo *info,
 164                         const struct sk_buff *skb,
 165                         unsigned int iphoff)
 166 {
 167         struct iphdr _iph;
 168         const struct iphdr *ih;
 169         unsigned int logflags;
 170
 171         if (info->type == NF_LOG_TYPE_LOG)
 172                 logflags = info->u.log.logflags;
 173         else
 174                 logflags = NF_LOG_MASK;
 175
 176         ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
 177         if (ih == NULL) {
 178                 sb_add(m, "TRUNCATED");
 179                 return;
 180         }
 181
 182         /* Important fields:
 183          * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
 184         /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
 185         sb_add(m, "SRC=%pI4 DST=%pI4 ",
 186                &ih->saddr, &ih->daddr);
 187
 188         /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
 189         sb_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
 190                ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
 191                ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
 192
 193         /* Max length: 6 "CE DF MF " */
 194         if (ntohs(ih->frag_off) & IP_CE)
 195                 sb_add(m, "CE ");
 196         if (ntohs(ih->frag_off) & IP_DF)
 197                 sb_add(m, "DF ");
 198         if (ntohs(ih->frag_off) & IP_MF)
 199                 sb_add(m, "MF ");
 200
 201         /* Max length: 11 "FRAG:65535 " */
 202         if (ntohs(ih->frag_off) & IP_OFFSET)
 203                 sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
 204
 205         if ((logflags & XT_LOG_IPOPT) &&
 206             ih->ihl * 4 > sizeof(struct iphdr)) {
 207                 const unsigned char *op;
 208                 unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
 209                 unsigned int i, optsize;
 210
 211                 optsize = ih->ihl * 4 - sizeof(struct iphdr);
 212                 op = skb_header_pointer(skb, iphoff+sizeof(_iph),
 213                                         optsize, _opt);
 214                 if (op == NULL) {
 215                         sb_add(m, "TRUNCATED");
 216                         return;
 217                 }
 218
 219                 /* Max length: 127 "OPT (" 15*4*2chars ") " */
 220                 sb_add(m, "OPT (");
 221                 for (i = 0; i < optsize; i++)
 222                         sb_add(m, "%02X", op[i]);
 223                 sb_add(m, ") ");
 224         }
 225
 226         switch (ih->protocol) {
 227         case IPPROTO_TCP:
 228                 if (dump_tcp_header(m, skb, ih->protocol,
 229                                     ntohs(ih->frag_off) & IP_OFFSET,
 230                                     iphoff+ih->ihl*4, logflags))
 231                         return;
 232                 break;
 233         case IPPROTO_UDP:
 234         case IPPROTO_UDPLITE:
 235                 if (dump_udp_header(m, skb, ih->protocol,
 236                                     ntohs(ih->frag_off) & IP_OFFSET,
 237                                     iphoff+ih->ihl*4))
 238                         return;
 239                 break;
 240         case IPPROTO_ICMP: {
 241                 struct icmphdr _icmph;
 242                 const struct icmphdr *ich;
 243                 static const size_t required_len[NR_ICMP_TYPES+1]
 244                         = { [ICMP_ECHOREPLY] = 4,
 245                             [ICMP_DEST_UNREACH]
 246                             = 8 + sizeof(struct iphdr),
 247                             [ICMP_SOURCE_QUENCH]
 248                             = 8 + sizeof(struct iphdr),
 249                             [ICMP_REDIRECT]
 250                             = 8 + sizeof(struct iphdr),
 251                             [ICMP_ECHO] = 4,
 252                             [ICMP_TIME_EXCEEDED]
 253                             = 8 + sizeof(struct iphdr),
 254                             [ICMP_PARAMETERPROB]
 255                             = 8 + sizeof(struct iphdr),
 256                             [ICMP_TIMESTAMP] = 20,
 257                             [ICMP_TIMESTAMPREPLY] = 20,
 258                             [ICMP_ADDRESS] = 12,
 259                             [ICMP_ADDRESSREPLY] = 12 };
 260
 261                 /* Max length: 11 "PROTO=ICMP " */
 262                 sb_add(m, "PROTO=ICMP ");
 263
 264                 if (ntohs(ih->frag_off) & IP_OFFSET)
 265                         break;
 266
 267                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
 268                 ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
 269                                          sizeof(_icmph), &_icmph);
 270                 if (ich == NULL) {
 271                         sb_add(m, "INCOMPLETE [%u bytes] ",
 272                                skb->len - iphoff - ih->ihl*4);
 273                         break;
 274                 }
 275
 276                 /* Max length: 18 "TYPE=255 CODE=255 " */
 277                 sb_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code);
 278
 279                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
 280                 if (ich->type <= NR_ICMP_TYPES &&
 281                     required_len[ich->type] &&
 282                     skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
 283                         sb_add(m, "INCOMPLETE [%u bytes] ",
 284                                skb->len - iphoff - ih->ihl*4);
 285                         break;
 286                 }
 287
 288                 switch (ich->type) {
 289                 case ICMP_ECHOREPLY:
 290                 case ICMP_ECHO:
 291                         /* Max length: 19 "ID=65535 SEQ=65535 " */
 292                         sb_add(m, "ID=%u SEQ=%u ",
 293                                ntohs(ich->un.echo.id),
 294                                ntohs(ich->un.echo.sequence));
 295                         break;
 296
 297                 case ICMP_PARAMETERPROB:
 298                         /* Max length: 14 "PARAMETER=255 " */
 299                         sb_add(m, "PARAMETER=%u ",
 300                                ntohl(ich->un.gateway) >> 24);
 301                         break;
 302                 case ICMP_REDIRECT:
 303                         /* Max length: 24 "GATEWAY=255.255.255.255 " */
 304                         sb_add(m, "GATEWAY=%pI4 ", &ich->un.gateway);
 305                         /* Fall through */
 306                 case ICMP_DEST_UNREACH:
 307                 case ICMP_SOURCE_QUENCH:
 308                 case ICMP_TIME_EXCEEDED:
 309                         /* Max length: 3+maxlen */
 310                         if (!iphoff) { /* Only recurse once. */
 311                                 sb_add(m, "[");
 312                                 dump_ipv4_packet(m, info, skb,
 313                                             iphoff + ih->ihl*4+sizeof(_icmph));
 314                                 sb_add(m, "] ");
 315                         }
 316
 317                         /* Max length: 10 "MTU=65535 " */
 318                         if (ich->type == ICMP_DEST_UNREACH &&
 319                             ich->code == ICMP_FRAG_NEEDED)
 320                                 sb_add(m, "MTU=%u ", ntohs(ich->un.frag.mtu));
 321                 }
 322                 break;
 323         }
 324         /* Max Length */
 325         case IPPROTO_AH: {
 326                 struct ip_auth_hdr _ahdr;
 327                 const struct ip_auth_hdr *ah;
 328
 329                 if (ntohs(ih->frag_off) & IP_OFFSET)
 330                         break;
 331
 332                 /* Max length: 9 "PROTO=AH " */
 333                 sb_add(m, "PROTO=AH ");
 334
 335                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
 336                 ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
 337                                         sizeof(_ahdr), &_ahdr);
 338                 if (ah == NULL) {
 339                         sb_add(m, "INCOMPLETE [%u bytes] ",
 340                                skb->len - iphoff - ih->ihl*4);
 341                         break;
 342                 }
 343
 344                 /* Length: 15 "SPI=0xF1234567 " */
 345                 sb_add(m, "SPI=0x%x ", ntohl(ah->spi));
 346                 break;
 347         }
 348         case IPPROTO_ESP: {
 349                 struct ip_esp_hdr _esph;
 350                 const struct ip_esp_hdr *eh;
 351
 352                 /* Max length: 10 "PROTO=ESP " */
 353                 sb_add(m, "PROTO=ESP ");
 354
 355                 if (ntohs(ih->frag_off) & IP_OFFSET)
 356                         break;
 357
 358                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
 359                 eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
 360                                         sizeof(_esph), &_esph);
 361                 if (eh == NULL) {
 362                         sb_add(m, "INCOMPLETE [%u bytes] ",
 363                                skb->len - iphoff - ih->ihl*4);
 364                         break;
 365                 }
 366
 367                 /* Length: 15 "SPI=0xF1234567 " */
 368                 sb_add(m, "SPI=0x%x ", ntohl(eh->spi));
 369                 break;
 370         }
 371         /* Max length: 10 "PROTO 255 " */
 372         default:
 373                 sb_add(m, "PROTO=%u ", ih->protocol);
 374         }
 375
 376         /* Max length: 15 "UID=4294967295 " */
 377         if ((logflags & XT_LOG_UID) && !iphoff)
 378                 dump_sk_uid_gid(m, skb->sk);
 379
 380         /* Max length: 16 "MARK=0xFFFFFFFF " */
 381         if (!iphoff && skb->mark)
 382                 sb_add(m, "MARK=0x%x ", skb->mark);
 383
 384         /* Proto    Max log string length */
 385         /* IP:      40+46+6+11+127 = 230 */
 386         /* TCP:     10+max(25,20+30+13+9+32+11+127) = 252 */
 387         /* UDP:     10+max(25,20) = 35 */
 388         /* UDPLITE: 14+max(25,20) = 39 */
 389         /* ICMP:    11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
 390         /* ESP:     10+max(25)+15 = 50 */
 391         /* AH:      9+max(25)+15 = 49 */
 392         /* unknown: 10 */
 393
 394         /* (ICMP allows recursion one level deep) */
 395         /* maxlen =  IP + ICMP +  IP + max(TCP,UDP,ICMP,unknown) */
 396         /* maxlen = 230+   91  + 230 + 252 = 803 */
 397 }
 398
 399 static void dump_ipv4_mac_header(struct sbuff *m,
 400                             const struct nf_loginfo *info,
 401                             const struct sk_buff *skb)
 402 {
 403         struct net_device *dev = skb->dev;
 404         unsigned int logflags = 0;
 405
 406         if (info->type == NF_LOG_TYPE_LOG)
 407                 logflags = info->u.log.logflags;
 408
 409         if (!(logflags & XT_LOG_MACDECODE))
 410                 goto fallback;
 411
 412         switch (dev->type) {
 413         case ARPHRD_ETHER:
 414                 sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ",
 415                        eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
 416                        ntohs(eth_hdr(skb)->h_proto));
 417                 return;
 418         default:
 419                 break;
 420         }
 421
 422 fallback:
 423         sb_add(m, "MAC=");
 424         if (dev->hard_header_len &&
 425             skb->mac_header != skb->network_header) {
 426                 const unsigned char *p = skb_mac_header(skb);
 427                 unsigned int i;
 428
 429                 sb_add(m, "%02x", *p++);
 430                 for (i = 1; i < dev->hard_header_len; i++, p++)
 431                         sb_add(m, ":%02x", *p);
 432         }
 433         sb_add(m, " ");
 434 }
 435
 436 static void
 437 log_packet_common(struct sbuff *m,
 438                   u_int8_t pf,
 439                   unsigned int hooknum,
 440                   const struct sk_buff *skb,
 441                   const struct net_device *in,
 442                   const struct net_device *out,
 443                   const struct nf_loginfo *loginfo,
 444                   const char *prefix)
 445 {
 446         sb_add(m, KERN_SOH "%c%sIN=%s OUT=%s ",
 447                '0' + loginfo->u.log.level, prefix,
 448                in ? in->name : "",
 449                out ? out->name : "");
 450 #ifdef CONFIG_BRIDGE_NETFILTER
 451         if (skb->nf_bridge) {
 452                 const struct net_device *physindev;
 453                 const struct net_device *physoutdev;
 454
 455                 physindev = skb->nf_bridge->physindev;
 456                 if (physindev && in != physindev)
 457                         sb_add(m, "PHYSIN=%s ", physindev->name);
 458                 physoutdev = skb->nf_bridge->physoutdev;
 459                 if (physoutdev && out != physoutdev)
 460                         sb_add(m, "PHYSOUT=%s ", physoutdev->name);
 461         }
 462 #endif
 463 }
 464
 465
 466 static void
 467 ipt_log_packet(u_int8_t pf,
 468                unsigned int hooknum,
 469                const struct sk_buff *skb,
 470                const struct net_device *in,
 471                const struct net_device *out,
 472                const struct nf_loginfo *loginfo,
 473                const char *prefix)
 474 {
 475         struct sbuff *m = sb_open();
 476
 477         if (!loginfo)
 478                 loginfo = &default_loginfo;
 479
 480         log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix);
 481
 482         if (in != NULL)
 483                 dump_ipv4_mac_header(m, loginfo, skb);
 484
 485         dump_ipv4_packet(m, loginfo, skb, 0);
 486
 487         sb_close(m);
 488 }
 489
 490 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 491 /* One level of recursion won't kill us */
 492 static void dump_ipv6_packet(struct sbuff *m,
 493                         const struct nf_loginfo *info,
 494                         const struct sk_buff *skb, unsigned int ip6hoff,
 495                         int recurse)
 496 {
 497         u_int8_t currenthdr;
 498         int fragment;
 499         struct ipv6hdr _ip6h;
 500         const struct ipv6hdr *ih;
 501         unsigned int ptr;
 502         unsigned int hdrlen = 0;
 503         unsigned int logflags;
 504
 505         if (info->type == NF_LOG_TYPE_LOG)
 506                 logflags = info->u.log.logflags;
 507         else
 508                 logflags = NF_LOG_MASK;
 509
 510         ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
 511         if (ih == NULL) {
 512                 sb_add(m, "TRUNCATED");
 513                 return;
 514         }
 515
 516         /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
 517         sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
 518
 519         /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
 520         sb_add(m, "LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
 521                ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
 522                (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
 523                ih->hop_limit,
 524                (ntohl(*(__be32 *)ih) & 0x000fffff));
 525
 526         fragment = 0;
 527         ptr = ip6hoff + sizeof(struct ipv6hdr);
 528         currenthdr = ih->nexthdr;
 529         while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
 530                 struct ipv6_opt_hdr _hdr;
 531                 const struct ipv6_opt_hdr *hp;
 532
 533                 hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
 534                 if (hp == NULL) {
 535                         sb_add(m, "TRUNCATED");
 536                         return;
 537                 }
 538
 539                 /* Max length: 48 "OPT (...) " */
 540                 if (logflags & XT_LOG_IPOPT)
 541                         sb_add(m, "OPT ( ");
 542
 543                 switch (currenthdr) {
 544                 case IPPROTO_FRAGMENT: {
 545                         struct frag_hdr _fhdr;
 546                         const struct frag_hdr *fh;
 547
 548                         sb_add(m, "FRAG:");
 549                         fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
 550                                                 &_fhdr);
 551                         if (fh == NULL) {
 552                                 sb_add(m, "TRUNCATED ");
 553                                 return;
 554                         }
 555
 556                         /* Max length: 6 "65535 " */
 557                         sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8);
 558
 559                         /* Max length: 11 "INCOMPLETE " */
 560                         if (fh->frag_off & htons(0x0001))
 561                                 sb_add(m, "INCOMPLETE ");
 562
 563                         sb_add(m, "ID:%08x ", ntohl(fh->identification));
 564
 565                         if (ntohs(fh->frag_off) & 0xFFF8)
 566                                 fragment = 1;
 567
 568                         hdrlen = 8;
 569
 570                         break;
 571                 }
 572                 case IPPROTO_DSTOPTS:
 573                 case IPPROTO_ROUTING:
 574                 case IPPROTO_HOPOPTS:
 575                         if (fragment) {
 576                                 if (logflags & XT_LOG_IPOPT)
 577                                         sb_add(m, ")");
 578                                 return;
 579                         }
 580                         hdrlen = ipv6_optlen(hp);
 581                         break;
 582                 /* Max Length */
 583                 case IPPROTO_AH:
 584                         if (logflags & XT_LOG_IPOPT) {
 585                                 struct ip_auth_hdr _ahdr;
 586                                 const struct ip_auth_hdr *ah;
 587
 588                                 /* Max length: 3 "AH " */
 589                                 sb_add(m, "AH ");
 590
 591                                 if (fragment) {
 592                                         sb_add(m, ")");
 593                                         return;
 594                                 }
 595
 596                                 ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
 597                                                         &_ahdr);
 598                                 if (ah == NULL) {
 599                                         /*
 600                                          * Max length: 26 "INCOMPLETE [65535
 601                                          *  bytes] )"
 602                                          */
 603                                         sb_add(m, "INCOMPLETE [%u bytes] )",
 604                                                skb->len - ptr);
 605                                         return;
 606                                 }
 607
 608                                 /* Length: 15 "SPI=0xF1234567 */
 609                                 sb_add(m, "SPI=0x%x ", ntohl(ah->spi));
 610
 611                         }
 612
 613                         hdrlen = (hp->hdrlen+2)<<2;
 614                         break;
 615                 case IPPROTO_ESP:
 616                         if (logflags & XT_LOG_IPOPT) {
 617                                 struct ip_esp_hdr _esph;
 618                                 const struct ip_esp_hdr *eh;
 619
 620                                 /* Max length: 4 "ESP " */
 621                                 sb_add(m, "ESP ");
 622
 623                                 if (fragment) {
 624                                         sb_add(m, ")");
 625                                         return;
 626                                 }
 627
 628                                 /*
 629                                  * Max length: 26 "INCOMPLETE [65535 bytes] )"
 630                                  */
 631                                 eh = skb_header_pointer(skb, ptr, sizeof(_esph),
 632                                                         &_esph);
 633                                 if (eh == NULL) {
 634                                         sb_add(m, "INCOMPLETE [%u bytes] )",
 635                                                skb->len - ptr);
 636                                         return;
 637                                 }
 638
 639                                 /* Length: 16 "SPI=0xF1234567 )" */
 640                                 sb_add(m, "SPI=0x%x )", ntohl(eh->spi));
 641
 642                         }
 643                         return;
 644                 default:
 645                         /* Max length: 20 "Unknown Ext Hdr 255" */
 646                         sb_add(m, "Unknown Ext Hdr %u", currenthdr);
 647                         return;
 648                 }
 649                 if (logflags & XT_LOG_IPOPT)
 650                         sb_add(m, ") ");
 651
 652                 currenthdr = hp->nexthdr;
 653                 ptr += hdrlen;
 654         }
 655
 656         switch (currenthdr) {
 657         case IPPROTO_TCP:
 658                 if (dump_tcp_header(m, skb, currenthdr, fragment, ptr,
 659                     logflags))
 660                         return;
 661                 break;
 662         case IPPROTO_UDP:
 663         case IPPROTO_UDPLITE:
 664                 if (dump_udp_header(m, skb, currenthdr, fragment, ptr))
 665                         return;
 666                 break;
 667         case IPPROTO_ICMPV6: {
 668                 struct icmp6hdr _icmp6h;
 669                 const struct icmp6hdr *ic;
 670
 671                 /* Max length: 13 "PROTO=ICMPv6 " */
 672                 sb_add(m, "PROTO=ICMPv6 ");
 673
 674                 if (fragment)
 675                         break;
 676
 677                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
 678                 ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
 679                 if (ic == NULL) {
 680                         sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr);
 681                         return;
 682                 }
 683
 684                 /* Max length: 18 "TYPE=255 CODE=255 " */
 685                 sb_add(m, "TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
 686
 687                 switch (ic->icmp6_type) {
 688                 case ICMPV6_ECHO_REQUEST:
 689                 case ICMPV6_ECHO_REPLY:
 690                         /* Max length: 19 "ID=65535 SEQ=65535 " */
 691                         sb_add(m, "ID=%u SEQ=%u ",
 692                                 ntohs(ic->icmp6_identifier),
 693                                 ntohs(ic->icmp6_sequence));
 694                         break;
 695                 case ICMPV6_MGM_QUERY:
 696                 case ICMPV6_MGM_REPORT:
 697                 case ICMPV6_MGM_REDUCTION:
 698                         break;
 699
 700                 case ICMPV6_PARAMPROB:
 701                         /* Max length: 17 "POINTER=ffffffff " */
 702                         sb_add(m, "POINTER=%08x ", ntohl(ic->icmp6_pointer));
 703                         /* Fall through */
 704                 case ICMPV6_DEST_UNREACH:
 705                 case ICMPV6_PKT_TOOBIG:
 706                 case ICMPV6_TIME_EXCEED:
 707                         /* Max length: 3+maxlen */
 708                         if (recurse) {
 709                                 sb_add(m, "[");
 710                                 dump_ipv6_packet(m, info, skb,
 711                                             ptr + sizeof(_icmp6h), 0);
 712                                 sb_add(m, "] ");
 713                         }
 714
 715                         /* Max length: 10 "MTU=65535 " */
 716                         if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
 717                                 sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu));
 718                 }
 719                 break;
 720         }
 721         /* Max length: 10 "PROTO=255 " */
 722         default:
 723                 sb_add(m, "PROTO=%u ", currenthdr);
 724         }
 725
 726         /* Max length: 15 "UID=4294967295 " */
 727         if ((logflags & XT_LOG_UID) && recurse)
 728                 dump_sk_uid_gid(m, skb->sk);
 729
 730         /* Max length: 16 "MARK=0xFFFFFFFF " */
 731         if (!recurse && skb->mark)
 732                 sb_add(m, "MARK=0x%x ", skb->mark);
 733 }
 734
 735 static void dump_ipv6_mac_header(struct sbuff *m,
 736                             const struct nf_loginfo *info,
 737                             const struct sk_buff *skb)
 738 {
 739         struct net_device *dev = skb->dev;
 740         unsigned int logflags = 0;
 741
 742         if (info->type == NF_LOG_TYPE_LOG)
 743                 logflags = info->u.log.logflags;
 744
 745         if (!(logflags & XT_LOG_MACDECODE))
 746                 goto fallback;
 747
 748         switch (dev->type) {
 749         case ARPHRD_ETHER:
 750                 sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ",
 751                        eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
 752                        ntohs(eth_hdr(skb)->h_proto));
 753                 return;
 754         default:
 755                 break;
 756         }
 757
 758 fallback:
 759         sb_add(m, "MAC=");
 760         if (dev->hard_header_len &&
 761             skb->mac_header != skb->network_header) {
 762                 const unsigned char *p = skb_mac_header(skb);
 763                 unsigned int len = dev->hard_header_len;
 764                 unsigned int i;
 765
 766                 if (dev->type == ARPHRD_SIT) {
 767                         p -= ETH_HLEN;
 768
 769                         if (p < skb->head)
 770                                 p = NULL;
 771                 }
 772
 773                 if (p != NULL) {
 774                         sb_add(m, "%02x", *p++);
 775                         for (i = 1; i < len; i++)
 776                                 sb_add(m, ":%02x", *p++);
 777                 }
 778                 sb_add(m, " ");
 779
 780                 if (dev->type == ARPHRD_SIT) {
 781                         const struct iphdr *iph =
 782                                 (struct iphdr *)skb_mac_header(skb);
 783                         sb_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr,
 784                                &iph->daddr);
 785                 }
 786         } else
 787                 sb_add(m, " ");
 788 }
 789
 790 static void
 791 ip6t_log_packet(u_int8_t pf,
 792                 unsigned int hooknum,
 793                 const struct sk_buff *skb,
 794                 const struct net_device *in,
 795                 const struct net_device *out,
 796                 const struct nf_loginfo *loginfo,
 797                 const char *prefix)
 798 {
 799         struct sbuff *m = sb_open();
 800
 801         if (!loginfo)
 802                 loginfo = &default_loginfo;
 803
 804         log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix);
 805
 806         if (in != NULL)
 807                 dump_ipv6_mac_header(m, loginfo, skb);
 808
 809         dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1);
 810
 811         sb_close(m);
 812 }
 813 #endif
 814
 815 static unsigned int
 816 log_tg(struct sk_buff *skb, const struct xt_action_param *par)
 817 {
 818         const struct xt_log_info *loginfo = par->targinfo;
 819         struct nf_loginfo li;
 820
 821         li.type = NF_LOG_TYPE_LOG;
 822         li.u.log.level = loginfo->level;
 823         li.u.log.logflags = loginfo->logflags;
 824
 825         if (par->family == NFPROTO_IPV4)
 826                 ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in,
 827                                par->out, &li, loginfo->prefix);
 828 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 829         else if (par->family == NFPROTO_IPV6)
 830                 ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in,
 831                                 par->out, &li, loginfo->prefix);
 832 #endif
 833         else
 834                 WARN_ON_ONCE(1);
 835
 836         return XT_CONTINUE;
 837 }
 838
 839 static int log_tg_check(const struct xt_tgchk_param *par)
 840 {
 841         const struct xt_log_info *loginfo = par->targinfo;
 842
 843         if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6)
 844                 return -EINVAL;
 845
 846         if (loginfo->level >= 8) {
 847                 pr_debug("level %u >= 8\n", loginfo->level);
 848                 return -EINVAL;
 849         }
 850
 851         if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
 852                 pr_debug("prefix is not null-terminated\n");
 853                 return -EINVAL;
 854         }
 855
 856         return 0;
 857 }
 858
 859 static struct xt_target log_tg_regs[] __read_mostly = {
 860         {
 861                 .name           = "LOG",
 862                 .family         = NFPROTO_IPV4,
 863                 .target         = log_tg,
 864                 .targetsize     = sizeof(struct xt_log_info),
 865                 .checkentry     = log_tg_check,
 866                 .me             = THIS_MODULE,
 867         },
 868 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 869         {
 870                 .name           = "LOG",
 871                 .family         = NFPROTO_IPV6,
 872                 .target         = log_tg,
 873                 .targetsize     = sizeof(struct xt_log_info),
 874                 .checkentry     = log_tg_check,
 875                 .me             = THIS_MODULE,
 876         },
 877 #endif
 878 };
 879
 880 static struct nf_logger ipt_log_logger __read_mostly = {
 881         .name           = "ipt_LOG",
 882         .logfn          = &ipt_log_packet,
 883         .me             = THIS_MODULE,
 884 };
 885
 886 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 887 static struct nf_logger ip6t_log_logger __read_mostly = {
 888         .name           = "ip6t_LOG",
 889         .logfn          = &ip6t_log_packet,
 890         .me             = THIS_MODULE,
 891 };
 892 #endif
 893
 894 static int __init log_tg_init(void)
 895 {
 896         int ret;
 897
 898         ret = xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
 899         if (ret < 0)
 900                 return ret;
 901
 902         nf_log_register(NFPROTO_IPV4, &ipt_log_logger);
 903 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 904         nf_log_register(NFPROTO_IPV6, &ip6t_log_logger);
 905 #endif
 906         return 0;
 907 }
 908
 909 static void __exit log_tg_exit(void)
 910 {
 911         nf_log_unregister(&ipt_log_logger);
 912 #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
 913         nf_log_unregister(&ip6t_log_logger);
 914 #endif
 915         xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs));
 916 }
 917
 918 module_init(log_tg_init);
 919 module_exit(log_tg_exit);
 920
 921 MODULE_LICENSE("GPL");
 922 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
 923 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
 924 MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging");
 925 MODULE_ALIAS("ipt_LOG");
 926 MODULE_ALIAS("ip6t_LOG");