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Merge branches 'pxa' and 'orion-fixes1'
[deliverable/linux.git] / net / ipv4 / netfilter / ipt_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 #include <linux/module.h>
14 #include <linux/spinlock.h>
15 #include <linux/skbuff.h>
16 #include <linux/ip.h>
17 #include <net/icmp.h>
18 #include <net/udp.h>
19 #include <net/tcp.h>
20 #include <net/route.h>
21
22 #include <linux/netfilter.h>
23 #include <linux/netfilter/x_tables.h>
24 #include <linux/netfilter_ipv4/ipt_LOG.h>
25 #include <net/netfilter/nf_log.h>
26
27 MODULE_LICENSE("GPL");
28 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
29 MODULE_DESCRIPTION("Xtables: IPv4 packet logging to syslog");
30
31 /* Use lock to serialize, so printks don't overlap */
32 static DEFINE_SPINLOCK(log_lock);
33
34 /* One level of recursion won't kill us */
35 static void dump_packet(const struct nf_loginfo *info,
36 const struct sk_buff *skb,
37 unsigned int iphoff)
38 {
39 struct iphdr _iph;
40 const struct iphdr *ih;
41 unsigned int logflags;
42
43 if (info->type == NF_LOG_TYPE_LOG)
44 logflags = info->u.log.logflags;
45 else
46 logflags = NF_LOG_MASK;
47
48 ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
49 if (ih == NULL) {
50 printk("TRUNCATED");
51 return;
52 }
53
54 /* Important fields:
55 * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
56 /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
57 printk("SRC=%u.%u.%u.%u DST=%u.%u.%u.%u ",
58 NIPQUAD(ih->saddr), NIPQUAD(ih->daddr));
59
60 /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
61 printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
62 ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
63 ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
64
65 /* Max length: 6 "CE DF MF " */
66 if (ntohs(ih->frag_off) & IP_CE)
67 printk("CE ");
68 if (ntohs(ih->frag_off) & IP_DF)
69 printk("DF ");
70 if (ntohs(ih->frag_off) & IP_MF)
71 printk("MF ");
72
73 /* Max length: 11 "FRAG:65535 " */
74 if (ntohs(ih->frag_off) & IP_OFFSET)
75 printk("FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
76
77 if ((logflags & IPT_LOG_IPOPT)
78 && ih->ihl * 4 > sizeof(struct iphdr)) {
79 const unsigned char *op;
80 unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
81 unsigned int i, optsize;
82
83 optsize = ih->ihl * 4 - sizeof(struct iphdr);
84 op = skb_header_pointer(skb, iphoff+sizeof(_iph),
85 optsize, _opt);
86 if (op == NULL) {
87 printk("TRUNCATED");
88 return;
89 }
90
91 /* Max length: 127 "OPT (" 15*4*2chars ") " */
92 printk("OPT (");
93 for (i = 0; i < optsize; i++)
94 printk("%02X", op[i]);
95 printk(") ");
96 }
97
98 switch (ih->protocol) {
99 case IPPROTO_TCP: {
100 struct tcphdr _tcph;
101 const struct tcphdr *th;
102
103 /* Max length: 10 "PROTO=TCP " */
104 printk("PROTO=TCP ");
105
106 if (ntohs(ih->frag_off) & IP_OFFSET)
107 break;
108
109 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
110 th = skb_header_pointer(skb, iphoff + ih->ihl * 4,
111 sizeof(_tcph), &_tcph);
112 if (th == NULL) {
113 printk("INCOMPLETE [%u bytes] ",
114 skb->len - iphoff - ih->ihl*4);
115 break;
116 }
117
118 /* Max length: 20 "SPT=65535 DPT=65535 " */
119 printk("SPT=%u DPT=%u ",
120 ntohs(th->source), ntohs(th->dest));
121 /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
122 if (logflags & IPT_LOG_TCPSEQ)
123 printk("SEQ=%u ACK=%u ",
124 ntohl(th->seq), ntohl(th->ack_seq));
125 /* Max length: 13 "WINDOW=65535 " */
126 printk("WINDOW=%u ", ntohs(th->window));
127 /* Max length: 9 "RES=0x3F " */
128 printk("RES=0x%02x ", (u8)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
129 /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
130 if (th->cwr)
131 printk("CWR ");
132 if (th->ece)
133 printk("ECE ");
134 if (th->urg)
135 printk("URG ");
136 if (th->ack)
137 printk("ACK ");
138 if (th->psh)
139 printk("PSH ");
140 if (th->rst)
141 printk("RST ");
142 if (th->syn)
143 printk("SYN ");
144 if (th->fin)
145 printk("FIN ");
146 /* Max length: 11 "URGP=65535 " */
147 printk("URGP=%u ", ntohs(th->urg_ptr));
148
149 if ((logflags & IPT_LOG_TCPOPT)
150 && th->doff * 4 > sizeof(struct tcphdr)) {
151 unsigned char _opt[4 * 15 - sizeof(struct tcphdr)];
152 const unsigned char *op;
153 unsigned int i, optsize;
154
155 optsize = th->doff * 4 - sizeof(struct tcphdr);
156 op = skb_header_pointer(skb,
157 iphoff+ih->ihl*4+sizeof(_tcph),
158 optsize, _opt);
159 if (op == NULL) {
160 printk("TRUNCATED");
161 return;
162 }
163
164 /* Max length: 127 "OPT (" 15*4*2chars ") " */
165 printk("OPT (");
166 for (i = 0; i < optsize; i++)
167 printk("%02X", op[i]);
168 printk(") ");
169 }
170 break;
171 }
172 case IPPROTO_UDP:
173 case IPPROTO_UDPLITE: {
174 struct udphdr _udph;
175 const struct udphdr *uh;
176
177 if (ih->protocol == IPPROTO_UDP)
178 /* Max length: 10 "PROTO=UDP " */
179 printk("PROTO=UDP " );
180 else /* Max length: 14 "PROTO=UDPLITE " */
181 printk("PROTO=UDPLITE ");
182
183 if (ntohs(ih->frag_off) & IP_OFFSET)
184 break;
185
186 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
187 uh = skb_header_pointer(skb, iphoff+ih->ihl*4,
188 sizeof(_udph), &_udph);
189 if (uh == NULL) {
190 printk("INCOMPLETE [%u bytes] ",
191 skb->len - iphoff - ih->ihl*4);
192 break;
193 }
194
195 /* Max length: 20 "SPT=65535 DPT=65535 " */
196 printk("SPT=%u DPT=%u LEN=%u ",
197 ntohs(uh->source), ntohs(uh->dest),
198 ntohs(uh->len));
199 break;
200 }
201 case IPPROTO_ICMP: {
202 struct icmphdr _icmph;
203 const struct icmphdr *ich;
204 static const size_t required_len[NR_ICMP_TYPES+1]
205 = { [ICMP_ECHOREPLY] = 4,
206 [ICMP_DEST_UNREACH]
207 = 8 + sizeof(struct iphdr),
208 [ICMP_SOURCE_QUENCH]
209 = 8 + sizeof(struct iphdr),
210 [ICMP_REDIRECT]
211 = 8 + sizeof(struct iphdr),
212 [ICMP_ECHO] = 4,
213 [ICMP_TIME_EXCEEDED]
214 = 8 + sizeof(struct iphdr),
215 [ICMP_PARAMETERPROB]
216 = 8 + sizeof(struct iphdr),
217 [ICMP_TIMESTAMP] = 20,
218 [ICMP_TIMESTAMPREPLY] = 20,
219 [ICMP_ADDRESS] = 12,
220 [ICMP_ADDRESSREPLY] = 12 };
221
222 /* Max length: 11 "PROTO=ICMP " */
223 printk("PROTO=ICMP ");
224
225 if (ntohs(ih->frag_off) & IP_OFFSET)
226 break;
227
228 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
229 ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
230 sizeof(_icmph), &_icmph);
231 if (ich == NULL) {
232 printk("INCOMPLETE [%u bytes] ",
233 skb->len - iphoff - ih->ihl*4);
234 break;
235 }
236
237 /* Max length: 18 "TYPE=255 CODE=255 " */
238 printk("TYPE=%u CODE=%u ", ich->type, ich->code);
239
240 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
241 if (ich->type <= NR_ICMP_TYPES
242 && required_len[ich->type]
243 && skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
244 printk("INCOMPLETE [%u bytes] ",
245 skb->len - iphoff - ih->ihl*4);
246 break;
247 }
248
249 switch (ich->type) {
250 case ICMP_ECHOREPLY:
251 case ICMP_ECHO:
252 /* Max length: 19 "ID=65535 SEQ=65535 " */
253 printk("ID=%u SEQ=%u ",
254 ntohs(ich->un.echo.id),
255 ntohs(ich->un.echo.sequence));
256 break;
257
258 case ICMP_PARAMETERPROB:
259 /* Max length: 14 "PARAMETER=255 " */
260 printk("PARAMETER=%u ",
261 ntohl(ich->un.gateway) >> 24);
262 break;
263 case ICMP_REDIRECT:
264 /* Max length: 24 "GATEWAY=255.255.255.255 " */
265 printk("GATEWAY=%u.%u.%u.%u ",
266 NIPQUAD(ich->un.gateway));
267 /* Fall through */
268 case ICMP_DEST_UNREACH:
269 case ICMP_SOURCE_QUENCH:
270 case ICMP_TIME_EXCEEDED:
271 /* Max length: 3+maxlen */
272 if (!iphoff) { /* Only recurse once. */
273 printk("[");
274 dump_packet(info, skb,
275 iphoff + ih->ihl*4+sizeof(_icmph));
276 printk("] ");
277 }
278
279 /* Max length: 10 "MTU=65535 " */
280 if (ich->type == ICMP_DEST_UNREACH
281 && ich->code == ICMP_FRAG_NEEDED)
282 printk("MTU=%u ", ntohs(ich->un.frag.mtu));
283 }
284 break;
285 }
286 /* Max Length */
287 case IPPROTO_AH: {
288 struct ip_auth_hdr _ahdr;
289 const struct ip_auth_hdr *ah;
290
291 if (ntohs(ih->frag_off) & IP_OFFSET)
292 break;
293
294 /* Max length: 9 "PROTO=AH " */
295 printk("PROTO=AH ");
296
297 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
298 ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
299 sizeof(_ahdr), &_ahdr);
300 if (ah == NULL) {
301 printk("INCOMPLETE [%u bytes] ",
302 skb->len - iphoff - ih->ihl*4);
303 break;
304 }
305
306 /* Length: 15 "SPI=0xF1234567 " */
307 printk("SPI=0x%x ", ntohl(ah->spi));
308 break;
309 }
310 case IPPROTO_ESP: {
311 struct ip_esp_hdr _esph;
312 const struct ip_esp_hdr *eh;
313
314 /* Max length: 10 "PROTO=ESP " */
315 printk("PROTO=ESP ");
316
317 if (ntohs(ih->frag_off) & IP_OFFSET)
318 break;
319
320 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
321 eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
322 sizeof(_esph), &_esph);
323 if (eh == NULL) {
324 printk("INCOMPLETE [%u bytes] ",
325 skb->len - iphoff - ih->ihl*4);
326 break;
327 }
328
329 /* Length: 15 "SPI=0xF1234567 " */
330 printk("SPI=0x%x ", ntohl(eh->spi));
331 break;
332 }
333 /* Max length: 10 "PROTO 255 " */
334 default:
335 printk("PROTO=%u ", ih->protocol);
336 }
337
338 /* Max length: 15 "UID=4294967295 " */
339 if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
340 read_lock_bh(&skb->sk->sk_callback_lock);
341 if (skb->sk->sk_socket && skb->sk->sk_socket->file)
342 printk("UID=%u GID=%u ",
343 skb->sk->sk_socket->file->f_uid,
344 skb->sk->sk_socket->file->f_gid);
345 read_unlock_bh(&skb->sk->sk_callback_lock);
346 }
347
348 /* Max length: 16 "MARK=0xFFFFFFFF " */
349 if (!iphoff && skb->mark)
350 printk("MARK=0x%x ", skb->mark);
351
352 /* Proto Max log string length */
353 /* IP: 40+46+6+11+127 = 230 */
354 /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */
355 /* UDP: 10+max(25,20) = 35 */
356 /* UDPLITE: 14+max(25,20) = 39 */
357 /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
358 /* ESP: 10+max(25)+15 = 50 */
359 /* AH: 9+max(25)+15 = 49 */
360 /* unknown: 10 */
361
362 /* (ICMP allows recursion one level deep) */
363 /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */
364 /* maxlen = 230+ 91 + 230 + 252 = 803 */
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 ipt_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 #ifdef CONFIG_BRIDGE_NETFILTER
395 if (skb->nf_bridge) {
396 const struct net_device *physindev;
397 const struct net_device *physoutdev;
398
399 physindev = skb->nf_bridge->physindev;
400 if (physindev && in != physindev)
401 printk("PHYSIN=%s ", physindev->name);
402 physoutdev = skb->nf_bridge->physoutdev;
403 if (physoutdev && out != physoutdev)
404 printk("PHYSOUT=%s ", physoutdev->name);
405 }
406 #endif
407
408 if (in && !out) {
409 /* MAC logging for input chain only. */
410 printk("MAC=");
411 if (skb->dev && skb->dev->hard_header_len
412 && skb->mac_header != skb->network_header) {
413 int i;
414 const unsigned char *p = skb_mac_header(skb);
415 for (i = 0; i < skb->dev->hard_header_len; i++,p++)
416 printk("%02x%c", *p,
417 i==skb->dev->hard_header_len - 1
418 ? ' ':':');
419 } else
420 printk(" ");
421 }
422
423 dump_packet(loginfo, skb, 0);
424 printk("\n");
425 spin_unlock_bh(&log_lock);
426 }
427
428 static unsigned int
429 log_tg(struct sk_buff *skb, const struct net_device *in,
430 const struct net_device *out, unsigned int hooknum,
431 const struct xt_target *target, const void *targinfo)
432 {
433 const struct ipt_log_info *loginfo = targinfo;
434 struct nf_loginfo li;
435
436 li.type = NF_LOG_TYPE_LOG;
437 li.u.log.level = loginfo->level;
438 li.u.log.logflags = loginfo->logflags;
439
440 ipt_log_packet(PF_INET, hooknum, skb, in, out, &li,
441 loginfo->prefix);
442 return XT_CONTINUE;
443 }
444
445 static bool
446 log_tg_check(const char *tablename, const void *e,
447 const struct xt_target *target, void *targinfo,
448 unsigned int hook_mask)
449 {
450 const struct ipt_log_info *loginfo = targinfo;
451
452 if (loginfo->level >= 8) {
453 pr_debug("LOG: level %u >= 8\n", loginfo->level);
454 return false;
455 }
456 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
457 pr_debug("LOG: prefix term %i\n",
458 loginfo->prefix[sizeof(loginfo->prefix)-1]);
459 return false;
460 }
461 return true;
462 }
463
464 static struct xt_target log_tg_reg __read_mostly = {
465 .name = "LOG",
466 .family = AF_INET,
467 .target = log_tg,
468 .targetsize = sizeof(struct ipt_log_info),
469 .checkentry = log_tg_check,
470 .me = THIS_MODULE,
471 };
472
473 static const struct nf_logger ipt_log_logger ={
474 .name = "ipt_LOG",
475 .logfn = &ipt_log_packet,
476 .me = THIS_MODULE,
477 };
478
479 static int __init log_tg_init(void)
480 {
481 int ret;
482
483 ret = xt_register_target(&log_tg_reg);
484 if (ret < 0)
485 return ret;
486 nf_log_register(PF_INET, &ipt_log_logger);
487 return 0;
488 }
489
490 static void __exit log_tg_exit(void)
491 {
492 nf_log_unregister(&ipt_log_logger);
493 xt_unregister_target(&log_tg_reg);
494 }
495
496 module_init(log_tg_init);
497 module_exit(log_tg_exit);
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