2 * This is a module which is used for logging packets.
5 /* (C) 2001 Jan Rekorajski <baggins@pld.org.pl>
6 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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.
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/skbuff.h>
16 #include <linux/if_arp.h>
18 #include <linux/spinlock.h>
19 #include <linux/icmpv6.h>
23 #include <linux/netfilter.h>
24 #include <linux/netfilter/x_tables.h>
25 #include <linux/netfilter_ipv6/ip6_tables.h>
27 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
28 MODULE_DESCRIPTION("IP6 tables LOG target module");
29 MODULE_LICENSE("GPL");
32 #include <net/route.h>
33 #include <linux/netfilter_ipv6/ip6t_LOG.h>
38 #define DEBUGP(format, args...)
41 /* Use lock to serialize, so printks don't overlap */
42 static DEFINE_SPINLOCK(log_lock);
44 /* One level of recursion won't kill us */
45 static void dump_packet(const struct nf_loginfo *info,
46 const struct sk_buff *skb, unsigned int ip6hoff,
52 const struct ipv6hdr *ih;
54 unsigned int hdrlen = 0;
55 unsigned int logflags;
57 if (info->type == NF_LOG_TYPE_LOG)
58 logflags = info->u.log.logflags;
60 logflags = NF_LOG_MASK;
62 ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
68 /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
69 printk("SRC=" NIP6_FMT " DST=" NIP6_FMT " ", NIP6(ih->saddr), NIP6(ih->daddr));
71 /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
72 printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
73 ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
74 (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
76 (ntohl(*(__be32 *)ih) & 0x000fffff));
79 ptr = ip6hoff + sizeof(struct ipv6hdr);
80 currenthdr = ih->nexthdr;
81 while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
82 struct ipv6_opt_hdr _hdr;
83 const struct ipv6_opt_hdr *hp;
85 hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
91 /* Max length: 48 "OPT (...) " */
92 if (logflags & IP6T_LOG_IPOPT)
96 case IPPROTO_FRAGMENT: {
97 struct frag_hdr _fhdr;
98 const struct frag_hdr *fh;
101 fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
104 printk("TRUNCATED ");
108 /* Max length: 6 "65535 " */
109 printk("%u ", ntohs(fh->frag_off) & 0xFFF8);
111 /* Max length: 11 "INCOMPLETE " */
112 if (fh->frag_off & htons(0x0001))
113 printk("INCOMPLETE ");
115 printk("ID:%08x ", ntohl(fh->identification));
117 if (ntohs(fh->frag_off) & 0xFFF8)
124 case IPPROTO_DSTOPTS:
125 case IPPROTO_ROUTING:
126 case IPPROTO_HOPOPTS:
128 if (logflags & IP6T_LOG_IPOPT)
132 hdrlen = ipv6_optlen(hp);
136 if (logflags & IP6T_LOG_IPOPT) {
137 struct ip_auth_hdr _ahdr;
138 const struct ip_auth_hdr *ah;
140 /* Max length: 3 "AH " */
148 ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
152 * Max length: 26 "INCOMPLETE [65535
155 printk("INCOMPLETE [%u bytes] )",
160 /* Length: 15 "SPI=0xF1234567 */
161 printk("SPI=0x%x ", ntohl(ah->spi));
165 hdrlen = (hp->hdrlen+2)<<2;
168 if (logflags & IP6T_LOG_IPOPT) {
169 struct ip_esp_hdr _esph;
170 const struct ip_esp_hdr *eh;
172 /* Max length: 4 "ESP " */
181 * Max length: 26 "INCOMPLETE [65535 bytes] )"
183 eh = skb_header_pointer(skb, ptr, sizeof(_esph),
186 printk("INCOMPLETE [%u bytes] )",
191 /* Length: 16 "SPI=0xF1234567 )" */
192 printk("SPI=0x%x )", ntohl(eh->spi) );
197 /* Max length: 20 "Unknown Ext Hdr 255" */
198 printk("Unknown Ext Hdr %u", currenthdr);
201 if (logflags & IP6T_LOG_IPOPT)
204 currenthdr = hp->nexthdr;
208 switch (currenthdr) {
211 const struct tcphdr *th;
213 /* Max length: 10 "PROTO=TCP " */
214 printk("PROTO=TCP ");
219 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
220 th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph);
222 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
226 /* Max length: 20 "SPT=65535 DPT=65535 " */
227 printk("SPT=%u DPT=%u ",
228 ntohs(th->source), ntohs(th->dest));
229 /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
230 if (logflags & IP6T_LOG_TCPSEQ)
231 printk("SEQ=%u ACK=%u ",
232 ntohl(th->seq), ntohl(th->ack_seq));
233 /* Max length: 13 "WINDOW=65535 " */
234 printk("WINDOW=%u ", ntohs(th->window));
235 /* Max length: 9 "RES=0x3C " */
236 printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
237 /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
254 /* Max length: 11 "URGP=65535 " */
255 printk("URGP=%u ", ntohs(th->urg_ptr));
257 if ((logflags & IP6T_LOG_TCPOPT)
258 && th->doff * 4 > sizeof(struct tcphdr)) {
259 u_int8_t _opt[60 - sizeof(struct tcphdr)];
262 unsigned int optsize = th->doff * 4
263 - sizeof(struct tcphdr);
265 op = skb_header_pointer(skb,
266 ptr + sizeof(struct tcphdr),
269 printk("OPT (TRUNCATED)");
273 /* Max length: 127 "OPT (" 15*4*2chars ") " */
275 for (i =0; i < optsize; i++)
276 printk("%02X", op[i]);
282 case IPPROTO_UDPLITE: {
284 const struct udphdr *uh;
286 if (currenthdr == IPPROTO_UDP)
287 /* Max length: 10 "PROTO=UDP " */
288 printk("PROTO=UDP " );
289 else /* Max length: 14 "PROTO=UDPLITE " */
290 printk("PROTO=UDPLITE ");
295 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
296 uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph);
298 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
302 /* Max length: 20 "SPT=65535 DPT=65535 " */
303 printk("SPT=%u DPT=%u LEN=%u ",
304 ntohs(uh->source), ntohs(uh->dest),
308 case IPPROTO_ICMPV6: {
309 struct icmp6hdr _icmp6h;
310 const struct icmp6hdr *ic;
312 /* Max length: 13 "PROTO=ICMPv6 " */
313 printk("PROTO=ICMPv6 ");
318 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
319 ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
321 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
325 /* Max length: 18 "TYPE=255 CODE=255 " */
326 printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
328 switch (ic->icmp6_type) {
329 case ICMPV6_ECHO_REQUEST:
330 case ICMPV6_ECHO_REPLY:
331 /* Max length: 19 "ID=65535 SEQ=65535 " */
332 printk("ID=%u SEQ=%u ",
333 ntohs(ic->icmp6_identifier),
334 ntohs(ic->icmp6_sequence));
336 case ICMPV6_MGM_QUERY:
337 case ICMPV6_MGM_REPORT:
338 case ICMPV6_MGM_REDUCTION:
341 case ICMPV6_PARAMPROB:
342 /* Max length: 17 "POINTER=ffffffff " */
343 printk("POINTER=%08x ", ntohl(ic->icmp6_pointer));
345 case ICMPV6_DEST_UNREACH:
346 case ICMPV6_PKT_TOOBIG:
347 case ICMPV6_TIME_EXCEED:
348 /* Max length: 3+maxlen */
351 dump_packet(info, skb, ptr + sizeof(_icmp6h),
356 /* Max length: 10 "MTU=65535 " */
357 if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
358 printk("MTU=%u ", ntohl(ic->icmp6_mtu));
362 /* Max length: 10 "PROTO=255 " */
364 printk("PROTO=%u ", currenthdr);
367 /* Max length: 15 "UID=4294967295 " */
368 if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) {
369 read_lock_bh(&skb->sk->sk_callback_lock);
370 if (skb->sk->sk_socket && skb->sk->sk_socket->file)
371 printk("UID=%u ", skb->sk->sk_socket->file->f_uid);
372 read_unlock_bh(&skb->sk->sk_callback_lock);
376 static struct nf_loginfo default_loginfo = {
377 .type = NF_LOG_TYPE_LOG,
381 .logflags = NF_LOG_MASK,
387 ip6t_log_packet(unsigned int pf,
388 unsigned int hooknum,
389 const struct sk_buff *skb,
390 const struct net_device *in,
391 const struct net_device *out,
392 const struct nf_loginfo *loginfo,
396 loginfo = &default_loginfo;
398 spin_lock_bh(&log_lock);
399 printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
402 out ? out->name : "");
405 /* MAC logging for input chain only. */
407 if (skb->dev && (len = skb->dev->hard_header_len) &&
408 skb->mac_header != skb->network_header) {
409 const unsigned char *p = skb_mac_header(skb);
412 if (skb->dev->type == ARPHRD_SIT &&
413 (p -= ETH_HLEN) < skb->head)
417 for (i = 0; i < len; i++)
418 printk("%02x%s", p[i],
419 i == len - 1 ? "" : ":");
423 if (skb->dev->type == ARPHRD_SIT) {
424 const struct iphdr *iph =
425 (struct iphdr *)skb_mac_header(skb);
426 printk("TUNNEL=%u.%u.%u.%u->%u.%u.%u.%u ",
428 NIPQUAD(iph->daddr));
434 dump_packet(loginfo, skb, skb_network_offset(skb), 1);
436 spin_unlock_bh(&log_lock);
440 ip6t_log_target(struct sk_buff **pskb,
441 const struct net_device *in,
442 const struct net_device *out,
443 unsigned int hooknum,
444 const struct xt_target *target,
445 const void *targinfo)
447 const struct ip6t_log_info *loginfo = targinfo;
448 struct nf_loginfo li;
450 li.type = NF_LOG_TYPE_LOG;
451 li.u.log.level = loginfo->level;
452 li.u.log.logflags = loginfo->logflags;
454 ip6t_log_packet(PF_INET6, hooknum, *pskb, in, out, &li,
460 static bool ip6t_log_checkentry(const char *tablename,
462 const struct xt_target *target,
464 unsigned int hook_mask)
466 const struct ip6t_log_info *loginfo = targinfo;
468 if (loginfo->level >= 8) {
469 DEBUGP("LOG: level %u >= 8\n", loginfo->level);
472 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
473 DEBUGP("LOG: prefix term %i\n",
474 loginfo->prefix[sizeof(loginfo->prefix)-1]);
480 static struct xt_target ip6t_log_reg = {
483 .target = ip6t_log_target,
484 .targetsize = sizeof(struct ip6t_log_info),
485 .checkentry = ip6t_log_checkentry,
489 static struct nf_logger ip6t_logger = {
491 .logfn = &ip6t_log_packet,
495 static int __init ip6t_log_init(void)
499 ret = xt_register_target(&ip6t_log_reg);
502 ret = nf_log_register(PF_INET6, &ip6t_logger);
503 if (ret < 0 && ret != -EEXIST)
504 xt_unregister_target(&ip6t_log_reg);
508 static void __exit ip6t_log_fini(void)
510 nf_log_unregister(&ip6t_logger);
511 xt_unregister_target(&ip6t_log_reg);
514 module_init(ip6t_log_init);
515 module_exit(ip6t_log_fini);