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.
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/if_arp.h>
17 #include <linux/spinlock.h>
18 #include <linux/icmpv6.h>
22 #include <linux/netfilter.h>
23 #include <linux/netfilter/x_tables.h>
24 #include <linux/netfilter_ipv6/ip6_tables.h>
25 #include <net/netfilter/nf_log.h>
27 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
28 MODULE_DESCRIPTION("Xtables: IPv6 packet logging to syslog");
29 MODULE_LICENSE("GPL");
32 #include <net/route.h>
33 #include <linux/netfilter_ipv6/ip6t_LOG.h>
35 /* Use lock to serialize, so printks don't overlap */
36 static DEFINE_SPINLOCK(log_lock);
38 /* One level of recursion won't kill us */
39 static void dump_packet(const struct nf_loginfo *info,
40 const struct sk_buff *skb, unsigned int ip6hoff,
46 const struct ipv6hdr *ih;
48 unsigned int hdrlen = 0;
49 unsigned int logflags;
51 if (info->type == NF_LOG_TYPE_LOG)
52 logflags = info->u.log.logflags;
54 logflags = NF_LOG_MASK;
56 ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
62 /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
63 printk("SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
65 /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
66 printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
67 ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
68 (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
70 (ntohl(*(__be32 *)ih) & 0x000fffff));
73 ptr = ip6hoff + sizeof(struct ipv6hdr);
74 currenthdr = ih->nexthdr;
75 while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
76 struct ipv6_opt_hdr _hdr;
77 const struct ipv6_opt_hdr *hp;
79 hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
85 /* Max length: 48 "OPT (...) " */
86 if (logflags & IP6T_LOG_IPOPT)
90 case IPPROTO_FRAGMENT: {
91 struct frag_hdr _fhdr;
92 const struct frag_hdr *fh;
95 fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
102 /* Max length: 6 "65535 " */
103 printk("%u ", ntohs(fh->frag_off) & 0xFFF8);
105 /* Max length: 11 "INCOMPLETE " */
106 if (fh->frag_off & htons(0x0001))
107 printk("INCOMPLETE ");
109 printk("ID:%08x ", ntohl(fh->identification));
111 if (ntohs(fh->frag_off) & 0xFFF8)
118 case IPPROTO_DSTOPTS:
119 case IPPROTO_ROUTING:
120 case IPPROTO_HOPOPTS:
122 if (logflags & IP6T_LOG_IPOPT)
126 hdrlen = ipv6_optlen(hp);
130 if (logflags & IP6T_LOG_IPOPT) {
131 struct ip_auth_hdr _ahdr;
132 const struct ip_auth_hdr *ah;
134 /* Max length: 3 "AH " */
142 ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
146 * Max length: 26 "INCOMPLETE [65535
149 printk("INCOMPLETE [%u bytes] )",
154 /* Length: 15 "SPI=0xF1234567 */
155 printk("SPI=0x%x ", ntohl(ah->spi));
159 hdrlen = (hp->hdrlen+2)<<2;
162 if (logflags & IP6T_LOG_IPOPT) {
163 struct ip_esp_hdr _esph;
164 const struct ip_esp_hdr *eh;
166 /* Max length: 4 "ESP " */
175 * Max length: 26 "INCOMPLETE [65535 bytes] )"
177 eh = skb_header_pointer(skb, ptr, sizeof(_esph),
180 printk("INCOMPLETE [%u bytes] )",
185 /* Length: 16 "SPI=0xF1234567 )" */
186 printk("SPI=0x%x )", ntohl(eh->spi) );
191 /* Max length: 20 "Unknown Ext Hdr 255" */
192 printk("Unknown Ext Hdr %u", currenthdr);
195 if (logflags & IP6T_LOG_IPOPT)
198 currenthdr = hp->nexthdr;
202 switch (currenthdr) {
205 const struct tcphdr *th;
207 /* Max length: 10 "PROTO=TCP " */
208 printk("PROTO=TCP ");
213 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
214 th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph);
216 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
220 /* Max length: 20 "SPT=65535 DPT=65535 " */
221 printk("SPT=%u DPT=%u ",
222 ntohs(th->source), ntohs(th->dest));
223 /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
224 if (logflags & IP6T_LOG_TCPSEQ)
225 printk("SEQ=%u ACK=%u ",
226 ntohl(th->seq), ntohl(th->ack_seq));
227 /* Max length: 13 "WINDOW=65535 " */
228 printk("WINDOW=%u ", ntohs(th->window));
229 /* Max length: 9 "RES=0x3C " */
230 printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
231 /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
248 /* Max length: 11 "URGP=65535 " */
249 printk("URGP=%u ", ntohs(th->urg_ptr));
251 if ((logflags & IP6T_LOG_TCPOPT) &&
252 th->doff * 4 > sizeof(struct tcphdr)) {
253 u_int8_t _opt[60 - sizeof(struct tcphdr)];
256 unsigned int optsize = th->doff * 4
257 - sizeof(struct tcphdr);
259 op = skb_header_pointer(skb,
260 ptr + sizeof(struct tcphdr),
263 printk("OPT (TRUNCATED)");
267 /* Max length: 127 "OPT (" 15*4*2chars ") " */
269 for (i =0; i < optsize; i++)
270 printk("%02X", op[i]);
276 case IPPROTO_UDPLITE: {
278 const struct udphdr *uh;
280 if (currenthdr == IPPROTO_UDP)
281 /* Max length: 10 "PROTO=UDP " */
282 printk("PROTO=UDP " );
283 else /* Max length: 14 "PROTO=UDPLITE " */
284 printk("PROTO=UDPLITE ");
289 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
290 uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph);
292 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
296 /* Max length: 20 "SPT=65535 DPT=65535 " */
297 printk("SPT=%u DPT=%u LEN=%u ",
298 ntohs(uh->source), ntohs(uh->dest),
302 case IPPROTO_ICMPV6: {
303 struct icmp6hdr _icmp6h;
304 const struct icmp6hdr *ic;
306 /* Max length: 13 "PROTO=ICMPv6 " */
307 printk("PROTO=ICMPv6 ");
312 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
313 ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
315 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
319 /* Max length: 18 "TYPE=255 CODE=255 " */
320 printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
322 switch (ic->icmp6_type) {
323 case ICMPV6_ECHO_REQUEST:
324 case ICMPV6_ECHO_REPLY:
325 /* Max length: 19 "ID=65535 SEQ=65535 " */
326 printk("ID=%u SEQ=%u ",
327 ntohs(ic->icmp6_identifier),
328 ntohs(ic->icmp6_sequence));
330 case ICMPV6_MGM_QUERY:
331 case ICMPV6_MGM_REPORT:
332 case ICMPV6_MGM_REDUCTION:
335 case ICMPV6_PARAMPROB:
336 /* Max length: 17 "POINTER=ffffffff " */
337 printk("POINTER=%08x ", ntohl(ic->icmp6_pointer));
339 case ICMPV6_DEST_UNREACH:
340 case ICMPV6_PKT_TOOBIG:
341 case ICMPV6_TIME_EXCEED:
342 /* Max length: 3+maxlen */
345 dump_packet(info, skb, ptr + sizeof(_icmp6h),
350 /* Max length: 10 "MTU=65535 " */
351 if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
352 printk("MTU=%u ", ntohl(ic->icmp6_mtu));
356 /* Max length: 10 "PROTO=255 " */
358 printk("PROTO=%u ", currenthdr);
361 /* Max length: 15 "UID=4294967295 " */
362 if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) {
363 read_lock_bh(&skb->sk->sk_callback_lock);
364 if (skb->sk->sk_socket && skb->sk->sk_socket->file)
365 printk("UID=%u GID=%u ",
366 skb->sk->sk_socket->file->f_cred->fsuid,
367 skb->sk->sk_socket->file->f_cred->fsgid);
368 read_unlock_bh(&skb->sk->sk_callback_lock);
371 /* Max length: 16 "MARK=0xFFFFFFFF " */
372 if (!recurse && skb->mark)
373 printk("MARK=0x%x ", skb->mark);
376 static void dump_mac_header(const struct nf_loginfo *info,
377 const struct sk_buff *skb)
379 struct net_device *dev = skb->dev;
380 unsigned int logflags = 0;
382 if (info->type == NF_LOG_TYPE_LOG)
383 logflags = info->u.log.logflags;
385 if (!(logflags & IP6T_LOG_MACDECODE))
390 printk("MACSRC=%pM MACDST=%pM MACPROTO=%04x ",
391 eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest,
392 ntohs(eth_hdr(skb)->h_proto));
400 if (dev->hard_header_len &&
401 skb->mac_header != skb->network_header) {
402 const unsigned char *p = skb_mac_header(skb);
403 unsigned int len = dev->hard_header_len;
406 if (dev->type == ARPHRD_SIT &&
407 (p -= ETH_HLEN) < skb->head)
411 printk("%02x", *p++);
412 for (i = 1; i < len; i++)
413 printk(":%02x", p[i]);
417 if (dev->type == ARPHRD_SIT) {
418 const struct iphdr *iph =
419 (struct iphdr *)skb_mac_header(skb);
420 printk("TUNNEL=%pI4->%pI4 ", &iph->saddr, &iph->daddr);
426 static struct nf_loginfo default_loginfo = {
427 .type = NF_LOG_TYPE_LOG,
431 .logflags = NF_LOG_MASK,
437 ip6t_log_packet(u_int8_t pf,
438 unsigned int hooknum,
439 const struct sk_buff *skb,
440 const struct net_device *in,
441 const struct net_device *out,
442 const struct nf_loginfo *loginfo,
446 loginfo = &default_loginfo;
448 spin_lock_bh(&log_lock);
449 printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
452 out ? out->name : "");
454 /* MAC logging for input path only. */
456 dump_mac_header(loginfo, skb);
458 dump_packet(loginfo, skb, skb_network_offset(skb), 1);
460 spin_unlock_bh(&log_lock);
464 log_tg6(struct sk_buff *skb, const struct xt_action_param *par)
466 const struct ip6t_log_info *loginfo = par->targinfo;
467 struct nf_loginfo li;
469 li.type = NF_LOG_TYPE_LOG;
470 li.u.log.level = loginfo->level;
471 li.u.log.logflags = loginfo->logflags;
473 ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, par->out,
474 &li, loginfo->prefix);
479 static int log_tg6_check(const struct xt_tgchk_param *par)
481 const struct ip6t_log_info *loginfo = par->targinfo;
483 if (loginfo->level >= 8) {
484 pr_debug("level %u >= 8\n", loginfo->level);
487 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
488 pr_debug("prefix not null-terminated\n");
494 static struct xt_target log_tg6_reg __read_mostly = {
496 .family = NFPROTO_IPV6,
498 .targetsize = sizeof(struct ip6t_log_info),
499 .checkentry = log_tg6_check,
503 static struct nf_logger ip6t_logger __read_mostly = {
505 .logfn = &ip6t_log_packet,
509 static int __init log_tg6_init(void)
513 ret = xt_register_target(&log_tg6_reg);
516 nf_log_register(NFPROTO_IPV6, &ip6t_logger);
520 static void __exit log_tg6_exit(void)
522 nf_log_unregister(&ip6t_logger);
523 xt_unregister_target(&log_tg6_reg);
526 module_init(log_tg6_init);
527 module_exit(log_tg6_exit);