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[NETFILTER]: x_tables: consistent and unique symbol names
[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
26 MODULE_LICENSE("GPL");
27 MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
28 MODULE_DESCRIPTION("iptables syslog logging module");
29
30 /* Use lock to serialize, so printks don't overlap */
31 static DEFINE_SPINLOCK(log_lock);
32
33 /* One level of recursion won't kill us */
34 static void dump_packet(const struct nf_loginfo *info,
35 const struct sk_buff *skb,
36 unsigned int iphoff)
37 {
38 struct iphdr _iph;
39 const struct iphdr *ih;
40 unsigned int logflags;
41
42 if (info->type == NF_LOG_TYPE_LOG)
43 logflags = info->u.log.logflags;
44 else
45 logflags = NF_LOG_MASK;
46
47 ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
48 if (ih == NULL) {
49 printk("TRUNCATED");
50 return;
51 }
52
53 /* Important fields:
54 * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
55 /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
56 printk("SRC=%u.%u.%u.%u DST=%u.%u.%u.%u ",
57 NIPQUAD(ih->saddr), NIPQUAD(ih->daddr));
58
59 /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
60 printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
61 ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
62 ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
63
64 /* Max length: 6 "CE DF MF " */
65 if (ntohs(ih->frag_off) & IP_CE)
66 printk("CE ");
67 if (ntohs(ih->frag_off) & IP_DF)
68 printk("DF ");
69 if (ntohs(ih->frag_off) & IP_MF)
70 printk("MF ");
71
72 /* Max length: 11 "FRAG:65535 " */
73 if (ntohs(ih->frag_off) & IP_OFFSET)
74 printk("FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
75
76 if ((logflags & IPT_LOG_IPOPT)
77 && ih->ihl * 4 > sizeof(struct iphdr)) {
78 unsigned char _opt[4 * 15 - sizeof(struct iphdr)], *op;
79 unsigned int i, optsize;
80
81 optsize = ih->ihl * 4 - sizeof(struct iphdr);
82 op = skb_header_pointer(skb, iphoff+sizeof(_iph),
83 optsize, _opt);
84 if (op == NULL) {
85 printk("TRUNCATED");
86 return;
87 }
88
89 /* Max length: 127 "OPT (" 15*4*2chars ") " */
90 printk("OPT (");
91 for (i = 0; i < optsize; i++)
92 printk("%02X", op[i]);
93 printk(") ");
94 }
95
96 switch (ih->protocol) {
97 case IPPROTO_TCP: {
98 struct tcphdr _tcph;
99 const struct tcphdr *th;
100
101 /* Max length: 10 "PROTO=TCP " */
102 printk("PROTO=TCP ");
103
104 if (ntohs(ih->frag_off) & IP_OFFSET)
105 break;
106
107 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
108 th = skb_header_pointer(skb, iphoff + ih->ihl * 4,
109 sizeof(_tcph), &_tcph);
110 if (th == NULL) {
111 printk("INCOMPLETE [%u bytes] ",
112 skb->len - iphoff - ih->ihl*4);
113 break;
114 }
115
116 /* Max length: 20 "SPT=65535 DPT=65535 " */
117 printk("SPT=%u DPT=%u ",
118 ntohs(th->source), ntohs(th->dest));
119 /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
120 if (logflags & IPT_LOG_TCPSEQ)
121 printk("SEQ=%u ACK=%u ",
122 ntohl(th->seq), ntohl(th->ack_seq));
123 /* Max length: 13 "WINDOW=65535 " */
124 printk("WINDOW=%u ", ntohs(th->window));
125 /* Max length: 9 "RES=0x3F " */
126 printk("RES=0x%02x ", (u8)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
127 /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
128 if (th->cwr)
129 printk("CWR ");
130 if (th->ece)
131 printk("ECE ");
132 if (th->urg)
133 printk("URG ");
134 if (th->ack)
135 printk("ACK ");
136 if (th->psh)
137 printk("PSH ");
138 if (th->rst)
139 printk("RST ");
140 if (th->syn)
141 printk("SYN ");
142 if (th->fin)
143 printk("FIN ");
144 /* Max length: 11 "URGP=65535 " */
145 printk("URGP=%u ", ntohs(th->urg_ptr));
146
147 if ((logflags & IPT_LOG_TCPOPT)
148 && th->doff * 4 > sizeof(struct tcphdr)) {
149 unsigned char _opt[4 * 15 - sizeof(struct tcphdr)];
150 const unsigned char *op;
151 unsigned int i, optsize;
152
153 optsize = th->doff * 4 - sizeof(struct tcphdr);
154 op = skb_header_pointer(skb,
155 iphoff+ih->ihl*4+sizeof(_tcph),
156 optsize, _opt);
157 if (op == NULL) {
158 printk("TRUNCATED");
159 return;
160 }
161
162 /* Max length: 127 "OPT (" 15*4*2chars ") " */
163 printk("OPT (");
164 for (i = 0; i < optsize; i++)
165 printk("%02X", op[i]);
166 printk(") ");
167 }
168 break;
169 }
170 case IPPROTO_UDP:
171 case IPPROTO_UDPLITE: {
172 struct udphdr _udph;
173 const struct udphdr *uh;
174
175 if (ih->protocol == IPPROTO_UDP)
176 /* Max length: 10 "PROTO=UDP " */
177 printk("PROTO=UDP " );
178 else /* Max length: 14 "PROTO=UDPLITE " */
179 printk("PROTO=UDPLITE ");
180
181 if (ntohs(ih->frag_off) & IP_OFFSET)
182 break;
183
184 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
185 uh = skb_header_pointer(skb, iphoff+ih->ihl*4,
186 sizeof(_udph), &_udph);
187 if (uh == NULL) {
188 printk("INCOMPLETE [%u bytes] ",
189 skb->len - iphoff - ih->ihl*4);
190 break;
191 }
192
193 /* Max length: 20 "SPT=65535 DPT=65535 " */
194 printk("SPT=%u DPT=%u LEN=%u ",
195 ntohs(uh->source), ntohs(uh->dest),
196 ntohs(uh->len));
197 break;
198 }
199 case IPPROTO_ICMP: {
200 struct icmphdr _icmph;
201 const struct icmphdr *ich;
202 static const size_t required_len[NR_ICMP_TYPES+1]
203 = { [ICMP_ECHOREPLY] = 4,
204 [ICMP_DEST_UNREACH]
205 = 8 + sizeof(struct iphdr),
206 [ICMP_SOURCE_QUENCH]
207 = 8 + sizeof(struct iphdr),
208 [ICMP_REDIRECT]
209 = 8 + sizeof(struct iphdr),
210 [ICMP_ECHO] = 4,
211 [ICMP_TIME_EXCEEDED]
212 = 8 + sizeof(struct iphdr),
213 [ICMP_PARAMETERPROB]
214 = 8 + sizeof(struct iphdr),
215 [ICMP_TIMESTAMP] = 20,
216 [ICMP_TIMESTAMPREPLY] = 20,
217 [ICMP_ADDRESS] = 12,
218 [ICMP_ADDRESSREPLY] = 12 };
219
220 /* Max length: 11 "PROTO=ICMP " */
221 printk("PROTO=ICMP ");
222
223 if (ntohs(ih->frag_off) & IP_OFFSET)
224 break;
225
226 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
227 ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
228 sizeof(_icmph), &_icmph);
229 if (ich == NULL) {
230 printk("INCOMPLETE [%u bytes] ",
231 skb->len - iphoff - ih->ihl*4);
232 break;
233 }
234
235 /* Max length: 18 "TYPE=255 CODE=255 " */
236 printk("TYPE=%u CODE=%u ", ich->type, ich->code);
237
238 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
239 if (ich->type <= NR_ICMP_TYPES
240 && required_len[ich->type]
241 && skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
242 printk("INCOMPLETE [%u bytes] ",
243 skb->len - iphoff - ih->ihl*4);
244 break;
245 }
246
247 switch (ich->type) {
248 case ICMP_ECHOREPLY:
249 case ICMP_ECHO:
250 /* Max length: 19 "ID=65535 SEQ=65535 " */
251 printk("ID=%u SEQ=%u ",
252 ntohs(ich->un.echo.id),
253 ntohs(ich->un.echo.sequence));
254 break;
255
256 case ICMP_PARAMETERPROB:
257 /* Max length: 14 "PARAMETER=255 " */
258 printk("PARAMETER=%u ",
259 ntohl(ich->un.gateway) >> 24);
260 break;
261 case ICMP_REDIRECT:
262 /* Max length: 24 "GATEWAY=255.255.255.255 " */
263 printk("GATEWAY=%u.%u.%u.%u ",
264 NIPQUAD(ich->un.gateway));
265 /* Fall through */
266 case ICMP_DEST_UNREACH:
267 case ICMP_SOURCE_QUENCH:
268 case ICMP_TIME_EXCEEDED:
269 /* Max length: 3+maxlen */
270 if (!iphoff) { /* Only recurse once. */
271 printk("[");
272 dump_packet(info, skb,
273 iphoff + ih->ihl*4+sizeof(_icmph));
274 printk("] ");
275 }
276
277 /* Max length: 10 "MTU=65535 " */
278 if (ich->type == ICMP_DEST_UNREACH
279 && ich->code == ICMP_FRAG_NEEDED)
280 printk("MTU=%u ", ntohs(ich->un.frag.mtu));
281 }
282 break;
283 }
284 /* Max Length */
285 case IPPROTO_AH: {
286 struct ip_auth_hdr _ahdr;
287 const struct ip_auth_hdr *ah;
288
289 if (ntohs(ih->frag_off) & IP_OFFSET)
290 break;
291
292 /* Max length: 9 "PROTO=AH " */
293 printk("PROTO=AH ");
294
295 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
296 ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
297 sizeof(_ahdr), &_ahdr);
298 if (ah == NULL) {
299 printk("INCOMPLETE [%u bytes] ",
300 skb->len - iphoff - ih->ihl*4);
301 break;
302 }
303
304 /* Length: 15 "SPI=0xF1234567 " */
305 printk("SPI=0x%x ", ntohl(ah->spi));
306 break;
307 }
308 case IPPROTO_ESP: {
309 struct ip_esp_hdr _esph;
310 const struct ip_esp_hdr *eh;
311
312 /* Max length: 10 "PROTO=ESP " */
313 printk("PROTO=ESP ");
314
315 if (ntohs(ih->frag_off) & IP_OFFSET)
316 break;
317
318 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
319 eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
320 sizeof(_esph), &_esph);
321 if (eh == NULL) {
322 printk("INCOMPLETE [%u bytes] ",
323 skb->len - iphoff - ih->ihl*4);
324 break;
325 }
326
327 /* Length: 15 "SPI=0xF1234567 " */
328 printk("SPI=0x%x ", ntohl(eh->spi));
329 break;
330 }
331 /* Max length: 10 "PROTO 255 " */
332 default:
333 printk("PROTO=%u ", ih->protocol);
334 }
335
336 /* Max length: 15 "UID=4294967295 " */
337 if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
338 read_lock_bh(&skb->sk->sk_callback_lock);
339 if (skb->sk->sk_socket && skb->sk->sk_socket->file)
340 printk("UID=%u ", skb->sk->sk_socket->file->f_uid);
341 read_unlock_bh(&skb->sk->sk_callback_lock);
342 }
343
344 /* Proto Max log string length */
345 /* IP: 40+46+6+11+127 = 230 */
346 /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */
347 /* UDP: 10+max(25,20) = 35 */
348 /* UDPLITE: 14+max(25,20) = 39 */
349 /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
350 /* ESP: 10+max(25)+15 = 50 */
351 /* AH: 9+max(25)+15 = 49 */
352 /* unknown: 10 */
353
354 /* (ICMP allows recursion one level deep) */
355 /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */
356 /* maxlen = 230+ 91 + 230 + 252 = 803 */
357 }
358
359 static struct nf_loginfo default_loginfo = {
360 .type = NF_LOG_TYPE_LOG,
361 .u = {
362 .log = {
363 .level = 0,
364 .logflags = NF_LOG_MASK,
365 },
366 },
367 };
368
369 static void
370 ipt_log_packet(unsigned int pf,
371 unsigned int hooknum,
372 const struct sk_buff *skb,
373 const struct net_device *in,
374 const struct net_device *out,
375 const struct nf_loginfo *loginfo,
376 const char *prefix)
377 {
378 if (!loginfo)
379 loginfo = &default_loginfo;
380
381 spin_lock_bh(&log_lock);
382 printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
383 prefix,
384 in ? in->name : "",
385 out ? out->name : "");
386 #ifdef CONFIG_BRIDGE_NETFILTER
387 if (skb->nf_bridge) {
388 const struct net_device *physindev;
389 const struct net_device *physoutdev;
390
391 physindev = skb->nf_bridge->physindev;
392 if (physindev && in != physindev)
393 printk("PHYSIN=%s ", physindev->name);
394 physoutdev = skb->nf_bridge->physoutdev;
395 if (physoutdev && out != physoutdev)
396 printk("PHYSOUT=%s ", physoutdev->name);
397 }
398 #endif
399
400 if (in && !out) {
401 /* MAC logging for input chain only. */
402 printk("MAC=");
403 if (skb->dev && skb->dev->hard_header_len
404 && skb->mac_header != skb->network_header) {
405 int i;
406 const unsigned char *p = skb_mac_header(skb);
407 for (i = 0; i < skb->dev->hard_header_len; i++,p++)
408 printk("%02x%c", *p,
409 i==skb->dev->hard_header_len - 1
410 ? ' ':':');
411 } else
412 printk(" ");
413 }
414
415 dump_packet(loginfo, skb, 0);
416 printk("\n");
417 spin_unlock_bh(&log_lock);
418 }
419
420 static unsigned int
421 log_tg(struct sk_buff *skb, const struct net_device *in,
422 const struct net_device *out, unsigned int hooknum,
423 const struct xt_target *target, const void *targinfo)
424 {
425 const struct ipt_log_info *loginfo = targinfo;
426 struct nf_loginfo li;
427
428 li.type = NF_LOG_TYPE_LOG;
429 li.u.log.level = loginfo->level;
430 li.u.log.logflags = loginfo->logflags;
431
432 ipt_log_packet(PF_INET, hooknum, skb, in, out, &li,
433 loginfo->prefix);
434 return XT_CONTINUE;
435 }
436
437 static bool
438 log_tg_check(const char *tablename, const void *e,
439 const struct xt_target *target, void *targinfo,
440 unsigned int hook_mask)
441 {
442 const struct ipt_log_info *loginfo = targinfo;
443
444 if (loginfo->level >= 8) {
445 pr_debug("LOG: level %u >= 8\n", loginfo->level);
446 return false;
447 }
448 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
449 pr_debug("LOG: prefix term %i\n",
450 loginfo->prefix[sizeof(loginfo->prefix)-1]);
451 return false;
452 }
453 return true;
454 }
455
456 static struct xt_target log_tg_reg __read_mostly = {
457 .name = "LOG",
458 .family = AF_INET,
459 .target = log_tg,
460 .targetsize = sizeof(struct ipt_log_info),
461 .checkentry = log_tg_check,
462 .me = THIS_MODULE,
463 };
464
465 static struct nf_logger ipt_log_logger ={
466 .name = "ipt_LOG",
467 .logfn = &ipt_log_packet,
468 .me = THIS_MODULE,
469 };
470
471 static int __init log_tg_init(void)
472 {
473 int ret;
474
475 ret = xt_register_target(&log_tg_reg);
476 if (ret < 0)
477 return ret;
478 nf_log_register(PF_INET, &ipt_log_logger);
479 return 0;
480 }
481
482 static void __exit log_tg_exit(void)
483 {
484 nf_log_unregister(&ipt_log_logger);
485 xt_unregister_target(&log_tg_reg);
486 }
487
488 module_init(log_tg_init);
489 module_exit(log_tg_exit);
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