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[NETFILTER]: nf_log: minor cleanups
[linux-2.6.22.y-op.git] / net / ipv6 / netfilter / ip6t_LOG.c
blobafaa039d0b7b51ffeff724031c82794f2eb6a644
1 /*
2 * This is a module which is used for logging packets.
3 */
4
5 /* (C) 2001 Jan Rekorajski <baggins@pld.org.pl>
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 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/skbuff.h>
16 #include <linux/if_arp.h>
17 #include <linux/ip.h>
18 #include <linux/spinlock.h>
19 #include <linux/icmpv6.h>
20 #include <net/udp.h>
21 #include <net/tcp.h>
22 #include <net/ipv6.h>
23 #include <linux/netfilter.h>
24 #include <linux/netfilter/x_tables.h>
25 #include <linux/netfilter_ipv6/ip6_tables.h>
26
27 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
28 MODULE_DESCRIPTION("IP6 tables LOG target module");
29 MODULE_LICENSE("GPL");
30
31 struct in_device;
32 #include <net/route.h>
33 #include <linux/netfilter_ipv6/ip6t_LOG.h>
34
35 #if 0
36 #define DEBUGP printk
37 #else
38 #define DEBUGP(format, args...)
39 #endif
40
41 /* Use lock to serialize, so printks don't overlap */
42 static DEFINE_SPINLOCK(log_lock);
43
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,
47 int recurse)
48 {
49 u_int8_t currenthdr;
50 int fragment;
51 struct ipv6hdr _ip6h, *ih;
52 unsigned int ptr;
53 unsigned int hdrlen = 0;
54 unsigned int logflags;
55
56 if (info->type == NF_LOG_TYPE_LOG)
57 logflags = info->u.log.logflags;
58 else
59 logflags = NF_LOG_MASK;
60
61 ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
62 if (ih == NULL) {
63 printk("TRUNCATED");
64 return;
65 }
66
67 /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
68 printk("SRC=" NIP6_FMT " DST=" NIP6_FMT " ", NIP6(ih->saddr), NIP6(ih->daddr));
69
70 /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
71 printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
72 ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
73 (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
74 ih->hop_limit,
75 (ntohl(*(__be32 *)ih) & 0x000fffff));
76
77 fragment = 0;
78 ptr = ip6hoff + sizeof(struct ipv6hdr);
79 currenthdr = ih->nexthdr;
80 while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) {
81 struct ipv6_opt_hdr _hdr, *hp;
82
83 hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
84 if (hp == NULL) {
85 printk("TRUNCATED");
86 return;
87 }
88
89 /* Max length: 48 "OPT (...) " */
90 if (logflags & IP6T_LOG_IPOPT)
91 printk("OPT ( ");
92
93 switch (currenthdr) {
94 case IPPROTO_FRAGMENT: {
95 struct frag_hdr _fhdr, *fh;
96
97 printk("FRAG:");
98 fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
99 &_fhdr);
100 if (fh == NULL) {
101 printk("TRUNCATED ");
102 return;
103 }
104
105 /* Max length: 6 "65535 " */
106 printk("%u ", ntohs(fh->frag_off) & 0xFFF8);
107
108 /* Max length: 11 "INCOMPLETE " */
109 if (fh->frag_off & htons(0x0001))
110 printk("INCOMPLETE ");
111
112 printk("ID:%08x ", ntohl(fh->identification));
113
114 if (ntohs(fh->frag_off) & 0xFFF8)
115 fragment = 1;
116
117 hdrlen = 8;
118
119 break;
120 }
121 case IPPROTO_DSTOPTS:
122 case IPPROTO_ROUTING:
123 case IPPROTO_HOPOPTS:
124 if (fragment) {
125 if (logflags & IP6T_LOG_IPOPT)
126 printk(")");
127 return;
128 }
129 hdrlen = ipv6_optlen(hp);
130 break;
131 /* Max Length */
132 case IPPROTO_AH:
133 if (logflags & IP6T_LOG_IPOPT) {
134 struct ip_auth_hdr _ahdr, *ah;
135
136 /* Max length: 3 "AH " */
137 printk("AH ");
138
139 if (fragment) {
140 printk(")");
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 printk("INCOMPLETE [%u bytes] )",
152 skb->len - ptr);
153 return;
154 }
155
156 /* Length: 15 "SPI=0xF1234567 */
157 printk("SPI=0x%x ", ntohl(ah->spi));
158
159 }
160
161 hdrlen = (hp->hdrlen+2)<<2;
162 break;
163 case IPPROTO_ESP:
164 if (logflags & IP6T_LOG_IPOPT) {
165 struct ip_esp_hdr _esph, *eh;
166
167 /* Max length: 4 "ESP " */
168 printk("ESP ");
169
170 if (fragment) {
171 printk(")");
172 return;
173 }
174
175 /*
176 * Max length: 26 "INCOMPLETE [65535 bytes] )"
177 */
178 eh = skb_header_pointer(skb, ptr, sizeof(_esph),
179 &_esph);
180 if (eh == NULL) {
181 printk("INCOMPLETE [%u bytes] )",
182 skb->len - ptr);
183 return;
184 }
185
186 /* Length: 16 "SPI=0xF1234567 )" */
187 printk("SPI=0x%x )", ntohl(eh->spi) );
188
189 }
190 return;
191 default:
192 /* Max length: 20 "Unknown Ext Hdr 255" */
193 printk("Unknown Ext Hdr %u", currenthdr);
194 return;
195 }
196 if (logflags & IP6T_LOG_IPOPT)
197 printk(") ");
198
199 currenthdr = hp->nexthdr;
200 ptr += hdrlen;
201 }
202
203 switch (currenthdr) {
204 case IPPROTO_TCP: {
205 struct tcphdr _tcph, *th;
206
207 /* Max length: 10 "PROTO=TCP " */
208 printk("PROTO=TCP ");
209
210 if (fragment)
211 break;
212
213 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
214 th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph);
215 if (th == NULL) {
216 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
217 return;
218 }
219
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 " */
232 if (th->cwr)
233 printk("CWR ");
234 if (th->ece)
235 printk("ECE ");
236 if (th->urg)
237 printk("URG ");
238 if (th->ack)
239 printk("ACK ");
240 if (th->psh)
241 printk("PSH ");
242 if (th->rst)
243 printk("RST ");
244 if (th->syn)
245 printk("SYN ");
246 if (th->fin)
247 printk("FIN ");
248 /* Max length: 11 "URGP=65535 " */
249 printk("URGP=%u ", ntohs(th->urg_ptr));
250
251 if ((logflags & IP6T_LOG_TCPOPT)
252 && th->doff * 4 > sizeof(struct tcphdr)) {
253 u_int8_t _opt[60 - sizeof(struct tcphdr)], *op;
254 unsigned int i;
255 unsigned int optsize = th->doff * 4
256 - sizeof(struct tcphdr);
257
258 op = skb_header_pointer(skb,
259 ptr + sizeof(struct tcphdr),
260 optsize, _opt);
261 if (op == NULL) {
262 printk("OPT (TRUNCATED)");
263 return;
264 }
265
266 /* Max length: 127 "OPT (" 15*4*2chars ") " */
267 printk("OPT (");
268 for (i =0; i < optsize; i++)
269 printk("%02X", op[i]);
270 printk(") ");
271 }
272 break;
273 }
274 case IPPROTO_UDP:
275 case IPPROTO_UDPLITE: {
276 struct udphdr _udph, *uh;
277
278 if (currenthdr == IPPROTO_UDP)
279 /* Max length: 10 "PROTO=UDP " */
280 printk("PROTO=UDP " );
281 else /* Max length: 14 "PROTO=UDPLITE " */
282 printk("PROTO=UDPLITE ");
283
284 if (fragment)
285 break;
286
287 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
288 uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph);
289 if (uh == NULL) {
290 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
291 return;
292 }
293
294 /* Max length: 20 "SPT=65535 DPT=65535 " */
295 printk("SPT=%u DPT=%u LEN=%u ",
296 ntohs(uh->source), ntohs(uh->dest),
297 ntohs(uh->len));
298 break;
299 }
300 case IPPROTO_ICMPV6: {
301 struct icmp6hdr _icmp6h, *ic;
302
303 /* Max length: 13 "PROTO=ICMPv6 " */
304 printk("PROTO=ICMPv6 ");
305
306 if (fragment)
307 break;
308
309 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
310 ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
311 if (ic == NULL) {
312 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
313 return;
314 }
315
316 /* Max length: 18 "TYPE=255 CODE=255 " */
317 printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
318
319 switch (ic->icmp6_type) {
320 case ICMPV6_ECHO_REQUEST:
321 case ICMPV6_ECHO_REPLY:
322 /* Max length: 19 "ID=65535 SEQ=65535 " */
323 printk("ID=%u SEQ=%u ",
324 ntohs(ic->icmp6_identifier),
325 ntohs(ic->icmp6_sequence));
326 break;
327 case ICMPV6_MGM_QUERY:
328 case ICMPV6_MGM_REPORT:
329 case ICMPV6_MGM_REDUCTION:
330 break;
331
332 case ICMPV6_PARAMPROB:
333 /* Max length: 17 "POINTER=ffffffff " */
334 printk("POINTER=%08x ", ntohl(ic->icmp6_pointer));
335 /* Fall through */
336 case ICMPV6_DEST_UNREACH:
337 case ICMPV6_PKT_TOOBIG:
338 case ICMPV6_TIME_EXCEED:
339 /* Max length: 3+maxlen */
340 if (recurse) {
341 printk("[");
342 dump_packet(info, skb, ptr + sizeof(_icmp6h),
343 0);
344 printk("] ");
345 }
346
347 /* Max length: 10 "MTU=65535 " */
348 if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
349 printk("MTU=%u ", ntohl(ic->icmp6_mtu));
350 }
351 break;
352 }
353 /* Max length: 10 "PROTO=255 " */
354 default:
355 printk("PROTO=%u ", currenthdr);
356 }
357
358 /* Max length: 15 "UID=4294967295 " */
359 if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) {
360 read_lock_bh(&skb->sk->sk_callback_lock);
361 if (skb->sk->sk_socket && skb->sk->sk_socket->file)
362 printk("UID=%u ", skb->sk->sk_socket->file->f_uid);
363 read_unlock_bh(&skb->sk->sk_callback_lock);
364 }
365 }
366
367 static struct nf_loginfo default_loginfo = {
368 .type = NF_LOG_TYPE_LOG,
369 .u = {
370 .log = {
371 .level = 0,
372 .logflags = NF_LOG_MASK,
373 },
374 },
375 };
376
377 static void
378 ip6t_log_packet(unsigned int pf,
379 unsigned int hooknum,
380 const struct sk_buff *skb,
381 const struct net_device *in,
382 const struct net_device *out,
383 const struct nf_loginfo *loginfo,
384 const char *prefix)
385 {
386 if (!loginfo)
387 loginfo = &default_loginfo;
388
389 spin_lock_bh(&log_lock);
390 printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
391 prefix,
392 in ? in->name : "",
393 out ? out->name : "");
394 if (in && !out) {
395 unsigned int len;
396 /* MAC logging for input chain only. */
397 printk("MAC=");
398 if (skb->dev && (len = skb->dev->hard_header_len) &&
399 skb->mac.raw != skb->nh.raw) {
400 unsigned char *p = skb->mac.raw;
401 int i;
402
403 if (skb->dev->type == ARPHRD_SIT &&
404 (p -= ETH_HLEN) < skb->head)
405 p = NULL;
406
407 if (p != NULL) {
408 for (i = 0; i < len; i++)
409 printk("%02x%s", p[i],
410 i == len - 1 ? "" : ":");
411 }
412 printk(" ");
413
414 if (skb->dev->type == ARPHRD_SIT) {
415 struct iphdr *iph = (struct iphdr *)skb->mac.raw;
416 printk("TUNNEL=%u.%u.%u.%u->%u.%u.%u.%u ",
417 NIPQUAD(iph->saddr),
418 NIPQUAD(iph->daddr));
419 }
420 } else
421 printk(" ");
422 }
423
424 dump_packet(loginfo, skb, (u8*)skb->nh.ipv6h - skb->data, 1);
425 printk("\n");
426 spin_unlock_bh(&log_lock);
427 }
428
429 static unsigned int
430 ip6t_log_target(struct sk_buff **pskb,
431 const struct net_device *in,
432 const struct net_device *out,
433 unsigned int hooknum,
434 const struct xt_target *target,
435 const void *targinfo)
436 {
437 const struct ip6t_log_info *loginfo = targinfo;
438 struct nf_loginfo li;
439
440 li.type = NF_LOG_TYPE_LOG;
441 li.u.log.level = loginfo->level;
442 li.u.log.logflags = loginfo->logflags;
443
444 ip6t_log_packet(PF_INET6, hooknum, *pskb, in, out, &li,
445 loginfo->prefix);
446 return XT_CONTINUE;
447 }
448
449
450 static int ip6t_log_checkentry(const char *tablename,
451 const void *entry,
452 const struct xt_target *target,
453 void *targinfo,
454 unsigned int hook_mask)
455 {
456 const struct ip6t_log_info *loginfo = targinfo;
457
458 if (loginfo->level >= 8) {
459 DEBUGP("LOG: level %u >= 8\n", loginfo->level);
460 return 0;
461 }
462 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
463 DEBUGP("LOG: prefix term %i\n",
464 loginfo->prefix[sizeof(loginfo->prefix)-1]);
465 return 0;
466 }
467 return 1;
468 }
469
470 static struct xt_target ip6t_log_reg = {
471 .name = "LOG",
472 .family = AF_INET6,
473 .target = ip6t_log_target,
474 .targetsize = sizeof(struct ip6t_log_info),
475 .checkentry = ip6t_log_checkentry,
476 .me = THIS_MODULE,
477 };
478
479 static struct nf_logger ip6t_logger = {
480 .name = "ip6t_LOG",
481 .logfn = &ip6t_log_packet,
482 .me = THIS_MODULE,
483 };
484
485 static int __init ip6t_log_init(void)
486 {
487 int ret;
488
489 ret = xt_register_target(&ip6t_log_reg);
490 if (ret < 0)
491 return ret;
492 if (nf_log_register(PF_INET6, &ip6t_logger) < 0) {
493 printk(KERN_WARNING "ip6t_LOG: not logging via system console "
494 "since somebody else already registered for PF_INET6\n");
495 /* we cannot make module load fail here, since otherwise
496 * ip6tables userspace would abort */
497 }
498
499 return 0;
500 }
501
502 static void __exit ip6t_log_fini(void)
503 {
504 nf_log_unregister(&ip6t_logger);
505 xt_unregister_target(&ip6t_log_reg);
506 }
507
508 module_init(ip6t_log_init);
509 module_exit(ip6t_log_fini);
linux v2.6.22.y-op