Commit | Line | Data |
---|---|---|
6939c33a RW |
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 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
14 | #include <linux/module.h> | |
15 | #include <linux/spinlock.h> | |
16 | #include <linux/skbuff.h> | |
17 | #include <linux/if_arp.h> | |
18 | #include <linux/ip.h> | |
19 | #include <net/ipv6.h> | |
20 | #include <net/icmp.h> | |
21 | #include <net/udp.h> | |
22 | #include <net/tcp.h> | |
23 | #include <net/route.h> | |
24 | ||
25 | #include <linux/netfilter.h> | |
26 | #include <linux/netfilter/x_tables.h> | |
27 | #include <linux/netfilter/xt_LOG.h> | |
28 | #include <linux/netfilter_ipv6/ip6_tables.h> | |
29 | #include <net/netfilter/nf_log.h> | |
30 | #include <net/netfilter/xt_log.h> | |
31 | ||
32 | static struct nf_loginfo default_loginfo = { | |
33 | .type = NF_LOG_TYPE_LOG, | |
34 | .u = { | |
35 | .log = { | |
36 | .level = 5, | |
37 | .logflags = NF_LOG_MASK, | |
38 | }, | |
39 | }, | |
40 | }; | |
41 | ||
42 | static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb, | |
43 | u8 proto, int fragment, unsigned int offset) | |
44 | { | |
45 | struct udphdr _udph; | |
46 | const struct udphdr *uh; | |
47 | ||
48 | if (proto == IPPROTO_UDP) | |
49 | /* Max length: 10 "PROTO=UDP " */ | |
50 | sb_add(m, "PROTO=UDP "); | |
51 | else /* Max length: 14 "PROTO=UDPLITE " */ | |
52 | sb_add(m, "PROTO=UDPLITE "); | |
53 | ||
54 | if (fragment) | |
55 | goto out; | |
56 | ||
57 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
58 | uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); | |
59 | if (uh == NULL) { | |
60 | sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); | |
61 | ||
62 | return 1; | |
63 | } | |
64 | ||
65 | /* Max length: 20 "SPT=65535 DPT=65535 " */ | |
66 | sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest), | |
67 | ntohs(uh->len)); | |
68 | ||
69 | out: | |
70 | return 0; | |
71 | } | |
72 | ||
73 | static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb, | |
74 | u8 proto, int fragment, unsigned int offset, | |
75 | unsigned int logflags) | |
76 | { | |
77 | struct tcphdr _tcph; | |
78 | const struct tcphdr *th; | |
79 | ||
80 | /* Max length: 10 "PROTO=TCP " */ | |
81 | sb_add(m, "PROTO=TCP "); | |
82 | ||
83 | if (fragment) | |
84 | return 0; | |
85 | ||
86 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
87 | th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); | |
88 | if (th == NULL) { | |
89 | sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); | |
90 | return 1; | |
91 | } | |
92 | ||
93 | /* Max length: 20 "SPT=65535 DPT=65535 " */ | |
94 | sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest)); | |
95 | /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ | |
96 | if (logflags & XT_LOG_TCPSEQ) | |
97 | sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq)); | |
98 | ||
99 | /* Max length: 13 "WINDOW=65535 " */ | |
100 | sb_add(m, "WINDOW=%u ", ntohs(th->window)); | |
101 | /* Max length: 9 "RES=0x3C " */ | |
102 | sb_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & | |
103 | TCP_RESERVED_BITS) >> 22)); | |
104 | /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */ | |
105 | if (th->cwr) | |
106 | sb_add(m, "CWR "); | |
107 | if (th->ece) | |
108 | sb_add(m, "ECE "); | |
109 | if (th->urg) | |
110 | sb_add(m, "URG "); | |
111 | if (th->ack) | |
112 | sb_add(m, "ACK "); | |
113 | if (th->psh) | |
114 | sb_add(m, "PSH "); | |
115 | if (th->rst) | |
116 | sb_add(m, "RST "); | |
117 | if (th->syn) | |
118 | sb_add(m, "SYN "); | |
119 | if (th->fin) | |
120 | sb_add(m, "FIN "); | |
121 | /* Max length: 11 "URGP=65535 " */ | |
122 | sb_add(m, "URGP=%u ", ntohs(th->urg_ptr)); | |
123 | ||
124 | if ((logflags & XT_LOG_TCPOPT) && th->doff*4 > sizeof(struct tcphdr)) { | |
125 | u_int8_t _opt[60 - sizeof(struct tcphdr)]; | |
126 | const u_int8_t *op; | |
127 | unsigned int i; | |
128 | unsigned int optsize = th->doff*4 - sizeof(struct tcphdr); | |
129 | ||
130 | op = skb_header_pointer(skb, offset + sizeof(struct tcphdr), | |
131 | optsize, _opt); | |
132 | if (op == NULL) { | |
133 | sb_add(m, "OPT (TRUNCATED)"); | |
134 | return 1; | |
135 | } | |
136 | ||
137 | /* Max length: 127 "OPT (" 15*4*2chars ") " */ | |
138 | sb_add(m, "OPT ("); | |
139 | for (i = 0; i < optsize; i++) | |
140 | sb_add(m, "%02X", op[i]); | |
141 | ||
142 | sb_add(m, ") "); | |
143 | } | |
144 | ||
145 | return 0; | |
146 | } | |
147 | ||
148 | /* One level of recursion won't kill us */ | |
149 | static void dump_ipv4_packet(struct sbuff *m, | |
150 | const struct nf_loginfo *info, | |
151 | const struct sk_buff *skb, | |
152 | unsigned int iphoff) | |
153 | { | |
154 | struct iphdr _iph; | |
155 | const struct iphdr *ih; | |
156 | unsigned int logflags; | |
157 | ||
158 | if (info->type == NF_LOG_TYPE_LOG) | |
159 | logflags = info->u.log.logflags; | |
160 | else | |
161 | logflags = NF_LOG_MASK; | |
162 | ||
163 | ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); | |
164 | if (ih == NULL) { | |
165 | sb_add(m, "TRUNCATED"); | |
166 | return; | |
167 | } | |
168 | ||
169 | /* Important fields: | |
170 | * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */ | |
171 | /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */ | |
172 | sb_add(m, "SRC=%pI4 DST=%pI4 ", | |
173 | &ih->saddr, &ih->daddr); | |
174 | ||
175 | /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ | |
176 | sb_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", | |
177 | ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, | |
178 | ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); | |
179 | ||
180 | /* Max length: 6 "CE DF MF " */ | |
181 | if (ntohs(ih->frag_off) & IP_CE) | |
182 | sb_add(m, "CE "); | |
183 | if (ntohs(ih->frag_off) & IP_DF) | |
184 | sb_add(m, "DF "); | |
185 | if (ntohs(ih->frag_off) & IP_MF) | |
186 | sb_add(m, "MF "); | |
187 | ||
188 | /* Max length: 11 "FRAG:65535 " */ | |
189 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
190 | sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); | |
191 | ||
192 | if ((logflags & XT_LOG_IPOPT) && | |
193 | ih->ihl * 4 > sizeof(struct iphdr)) { | |
194 | const unsigned char *op; | |
195 | unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; | |
196 | unsigned int i, optsize; | |
197 | ||
198 | optsize = ih->ihl * 4 - sizeof(struct iphdr); | |
199 | op = skb_header_pointer(skb, iphoff+sizeof(_iph), | |
200 | optsize, _opt); | |
201 | if (op == NULL) { | |
202 | sb_add(m, "TRUNCATED"); | |
203 | return; | |
204 | } | |
205 | ||
206 | /* Max length: 127 "OPT (" 15*4*2chars ") " */ | |
207 | sb_add(m, "OPT ("); | |
208 | for (i = 0; i < optsize; i++) | |
209 | sb_add(m, "%02X", op[i]); | |
210 | sb_add(m, ") "); | |
211 | } | |
212 | ||
213 | switch (ih->protocol) { | |
214 | case IPPROTO_TCP: | |
215 | if (dump_tcp_header(m, skb, ih->protocol, | |
216 | ntohs(ih->frag_off) & IP_OFFSET, | |
217 | iphoff+ih->ihl*4, logflags)) | |
218 | return; | |
417e02bf | 219 | break; |
6939c33a RW |
220 | case IPPROTO_UDP: |
221 | case IPPROTO_UDPLITE: | |
222 | if (dump_udp_header(m, skb, ih->protocol, | |
223 | ntohs(ih->frag_off) & IP_OFFSET, | |
224 | iphoff+ih->ihl*4)) | |
225 | return; | |
417e02bf | 226 | break; |
6939c33a RW |
227 | case IPPROTO_ICMP: { |
228 | struct icmphdr _icmph; | |
229 | const struct icmphdr *ich; | |
230 | static const size_t required_len[NR_ICMP_TYPES+1] | |
231 | = { [ICMP_ECHOREPLY] = 4, | |
232 | [ICMP_DEST_UNREACH] | |
233 | = 8 + sizeof(struct iphdr), | |
234 | [ICMP_SOURCE_QUENCH] | |
235 | = 8 + sizeof(struct iphdr), | |
236 | [ICMP_REDIRECT] | |
237 | = 8 + sizeof(struct iphdr), | |
238 | [ICMP_ECHO] = 4, | |
239 | [ICMP_TIME_EXCEEDED] | |
240 | = 8 + sizeof(struct iphdr), | |
241 | [ICMP_PARAMETERPROB] | |
242 | = 8 + sizeof(struct iphdr), | |
243 | [ICMP_TIMESTAMP] = 20, | |
244 | [ICMP_TIMESTAMPREPLY] = 20, | |
245 | [ICMP_ADDRESS] = 12, | |
246 | [ICMP_ADDRESSREPLY] = 12 }; | |
247 | ||
248 | /* Max length: 11 "PROTO=ICMP " */ | |
249 | sb_add(m, "PROTO=ICMP "); | |
250 | ||
251 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
252 | break; | |
253 | ||
254 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
255 | ich = skb_header_pointer(skb, iphoff + ih->ihl * 4, | |
256 | sizeof(_icmph), &_icmph); | |
257 | if (ich == NULL) { | |
258 | sb_add(m, "INCOMPLETE [%u bytes] ", | |
259 | skb->len - iphoff - ih->ihl*4); | |
260 | break; | |
261 | } | |
262 | ||
263 | /* Max length: 18 "TYPE=255 CODE=255 " */ | |
264 | sb_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code); | |
265 | ||
266 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
267 | if (ich->type <= NR_ICMP_TYPES && | |
268 | required_len[ich->type] && | |
269 | skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) { | |
270 | sb_add(m, "INCOMPLETE [%u bytes] ", | |
271 | skb->len - iphoff - ih->ihl*4); | |
272 | break; | |
273 | } | |
274 | ||
275 | switch (ich->type) { | |
276 | case ICMP_ECHOREPLY: | |
277 | case ICMP_ECHO: | |
278 | /* Max length: 19 "ID=65535 SEQ=65535 " */ | |
279 | sb_add(m, "ID=%u SEQ=%u ", | |
280 | ntohs(ich->un.echo.id), | |
281 | ntohs(ich->un.echo.sequence)); | |
282 | break; | |
283 | ||
284 | case ICMP_PARAMETERPROB: | |
285 | /* Max length: 14 "PARAMETER=255 " */ | |
286 | sb_add(m, "PARAMETER=%u ", | |
287 | ntohl(ich->un.gateway) >> 24); | |
288 | break; | |
289 | case ICMP_REDIRECT: | |
290 | /* Max length: 24 "GATEWAY=255.255.255.255 " */ | |
291 | sb_add(m, "GATEWAY=%pI4 ", &ich->un.gateway); | |
292 | /* Fall through */ | |
293 | case ICMP_DEST_UNREACH: | |
294 | case ICMP_SOURCE_QUENCH: | |
295 | case ICMP_TIME_EXCEEDED: | |
296 | /* Max length: 3+maxlen */ | |
297 | if (!iphoff) { /* Only recurse once. */ | |
298 | sb_add(m, "["); | |
299 | dump_ipv4_packet(m, info, skb, | |
300 | iphoff + ih->ihl*4+sizeof(_icmph)); | |
301 | sb_add(m, "] "); | |
302 | } | |
303 | ||
304 | /* Max length: 10 "MTU=65535 " */ | |
305 | if (ich->type == ICMP_DEST_UNREACH && | |
306 | ich->code == ICMP_FRAG_NEEDED) | |
307 | sb_add(m, "MTU=%u ", ntohs(ich->un.frag.mtu)); | |
308 | } | |
309 | break; | |
310 | } | |
311 | /* Max Length */ | |
312 | case IPPROTO_AH: { | |
313 | struct ip_auth_hdr _ahdr; | |
314 | const struct ip_auth_hdr *ah; | |
315 | ||
316 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
317 | break; | |
318 | ||
319 | /* Max length: 9 "PROTO=AH " */ | |
320 | sb_add(m, "PROTO=AH "); | |
321 | ||
322 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
323 | ah = skb_header_pointer(skb, iphoff+ih->ihl*4, | |
324 | sizeof(_ahdr), &_ahdr); | |
325 | if (ah == NULL) { | |
326 | sb_add(m, "INCOMPLETE [%u bytes] ", | |
327 | skb->len - iphoff - ih->ihl*4); | |
328 | break; | |
329 | } | |
330 | ||
331 | /* Length: 15 "SPI=0xF1234567 " */ | |
332 | sb_add(m, "SPI=0x%x ", ntohl(ah->spi)); | |
333 | break; | |
334 | } | |
335 | case IPPROTO_ESP: { | |
336 | struct ip_esp_hdr _esph; | |
337 | const struct ip_esp_hdr *eh; | |
338 | ||
339 | /* Max length: 10 "PROTO=ESP " */ | |
340 | sb_add(m, "PROTO=ESP "); | |
341 | ||
342 | if (ntohs(ih->frag_off) & IP_OFFSET) | |
343 | break; | |
344 | ||
345 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
346 | eh = skb_header_pointer(skb, iphoff+ih->ihl*4, | |
347 | sizeof(_esph), &_esph); | |
348 | if (eh == NULL) { | |
349 | sb_add(m, "INCOMPLETE [%u bytes] ", | |
350 | skb->len - iphoff - ih->ihl*4); | |
351 | break; | |
352 | } | |
353 | ||
354 | /* Length: 15 "SPI=0xF1234567 " */ | |
355 | sb_add(m, "SPI=0x%x ", ntohl(eh->spi)); | |
356 | break; | |
357 | } | |
358 | /* Max length: 10 "PROTO 255 " */ | |
359 | default: | |
360 | sb_add(m, "PROTO=%u ", ih->protocol); | |
361 | } | |
362 | ||
363 | /* Max length: 15 "UID=4294967295 " */ | |
364 | if ((logflags & XT_LOG_UID) && !iphoff && skb->sk) { | |
365 | read_lock_bh(&skb->sk->sk_callback_lock); | |
366 | if (skb->sk->sk_socket && skb->sk->sk_socket->file) | |
367 | sb_add(m, "UID=%u GID=%u ", | |
368 | skb->sk->sk_socket->file->f_cred->fsuid, | |
369 | skb->sk->sk_socket->file->f_cred->fsgid); | |
370 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
371 | } | |
372 | ||
373 | /* Max length: 16 "MARK=0xFFFFFFFF " */ | |
374 | if (!iphoff && skb->mark) | |
375 | sb_add(m, "MARK=0x%x ", skb->mark); | |
376 | ||
377 | /* Proto Max log string length */ | |
378 | /* IP: 40+46+6+11+127 = 230 */ | |
379 | /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */ | |
380 | /* UDP: 10+max(25,20) = 35 */ | |
381 | /* UDPLITE: 14+max(25,20) = 39 */ | |
382 | /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */ | |
383 | /* ESP: 10+max(25)+15 = 50 */ | |
384 | /* AH: 9+max(25)+15 = 49 */ | |
385 | /* unknown: 10 */ | |
386 | ||
387 | /* (ICMP allows recursion one level deep) */ | |
388 | /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */ | |
389 | /* maxlen = 230+ 91 + 230 + 252 = 803 */ | |
390 | } | |
391 | ||
392 | static void dump_ipv4_mac_header(struct sbuff *m, | |
393 | const struct nf_loginfo *info, | |
394 | const struct sk_buff *skb) | |
395 | { | |
396 | struct net_device *dev = skb->dev; | |
397 | unsigned int logflags = 0; | |
398 | ||
399 | if (info->type == NF_LOG_TYPE_LOG) | |
400 | logflags = info->u.log.logflags; | |
401 | ||
402 | if (!(logflags & XT_LOG_MACDECODE)) | |
403 | goto fallback; | |
404 | ||
405 | switch (dev->type) { | |
406 | case ARPHRD_ETHER: | |
407 | sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", | |
408 | eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, | |
409 | ntohs(eth_hdr(skb)->h_proto)); | |
410 | return; | |
411 | default: | |
412 | break; | |
413 | } | |
414 | ||
415 | fallback: | |
416 | sb_add(m, "MAC="); | |
417 | if (dev->hard_header_len && | |
418 | skb->mac_header != skb->network_header) { | |
419 | const unsigned char *p = skb_mac_header(skb); | |
420 | unsigned int i; | |
421 | ||
422 | sb_add(m, "%02x", *p++); | |
423 | for (i = 1; i < dev->hard_header_len; i++, p++) | |
424 | sb_add(m, ":%02x", *p); | |
425 | } | |
426 | sb_add(m, " "); | |
427 | } | |
428 | ||
429 | static void | |
430 | log_packet_common(struct sbuff *m, | |
431 | u_int8_t pf, | |
432 | unsigned int hooknum, | |
433 | const struct sk_buff *skb, | |
434 | const struct net_device *in, | |
435 | const struct net_device *out, | |
436 | const struct nf_loginfo *loginfo, | |
437 | const char *prefix) | |
438 | { | |
439 | sb_add(m, "<%d>%sIN=%s OUT=%s ", loginfo->u.log.level, | |
440 | prefix, | |
441 | in ? in->name : "", | |
442 | out ? out->name : ""); | |
443 | #ifdef CONFIG_BRIDGE_NETFILTER | |
444 | if (skb->nf_bridge) { | |
445 | const struct net_device *physindev; | |
446 | const struct net_device *physoutdev; | |
447 | ||
448 | physindev = skb->nf_bridge->physindev; | |
449 | if (physindev && in != physindev) | |
450 | sb_add(m, "PHYSIN=%s ", physindev->name); | |
451 | physoutdev = skb->nf_bridge->physoutdev; | |
452 | if (physoutdev && out != physoutdev) | |
453 | sb_add(m, "PHYSOUT=%s ", physoutdev->name); | |
454 | } | |
455 | #endif | |
456 | } | |
457 | ||
458 | ||
459 | static void | |
460 | ipt_log_packet(u_int8_t pf, | |
461 | unsigned int hooknum, | |
462 | const struct sk_buff *skb, | |
463 | const struct net_device *in, | |
464 | const struct net_device *out, | |
465 | const struct nf_loginfo *loginfo, | |
466 | const char *prefix) | |
467 | { | |
468 | struct sbuff *m = sb_open(); | |
469 | ||
470 | if (!loginfo) | |
471 | loginfo = &default_loginfo; | |
472 | ||
473 | log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); | |
474 | ||
475 | if (in != NULL) | |
476 | dump_ipv4_mac_header(m, loginfo, skb); | |
477 | ||
478 | dump_ipv4_packet(m, loginfo, skb, 0); | |
479 | ||
480 | sb_close(m); | |
481 | } | |
482 | ||
a0f65a26 | 483 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
6939c33a RW |
484 | /* One level of recursion won't kill us */ |
485 | static void dump_ipv6_packet(struct sbuff *m, | |
486 | const struct nf_loginfo *info, | |
487 | const struct sk_buff *skb, unsigned int ip6hoff, | |
488 | int recurse) | |
489 | { | |
490 | u_int8_t currenthdr; | |
491 | int fragment; | |
492 | struct ipv6hdr _ip6h; | |
493 | const struct ipv6hdr *ih; | |
494 | unsigned int ptr; | |
495 | unsigned int hdrlen = 0; | |
496 | unsigned int logflags; | |
497 | ||
498 | if (info->type == NF_LOG_TYPE_LOG) | |
499 | logflags = info->u.log.logflags; | |
500 | else | |
501 | logflags = NF_LOG_MASK; | |
502 | ||
503 | ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h); | |
504 | if (ih == NULL) { | |
505 | sb_add(m, "TRUNCATED"); | |
506 | return; | |
507 | } | |
508 | ||
509 | /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */ | |
510 | sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr); | |
511 | ||
512 | /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ | |
513 | sb_add(m, "LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ", | |
514 | ntohs(ih->payload_len) + sizeof(struct ipv6hdr), | |
515 | (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20, | |
516 | ih->hop_limit, | |
517 | (ntohl(*(__be32 *)ih) & 0x000fffff)); | |
518 | ||
519 | fragment = 0; | |
520 | ptr = ip6hoff + sizeof(struct ipv6hdr); | |
521 | currenthdr = ih->nexthdr; | |
522 | while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) { | |
523 | struct ipv6_opt_hdr _hdr; | |
524 | const struct ipv6_opt_hdr *hp; | |
525 | ||
526 | hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr); | |
527 | if (hp == NULL) { | |
528 | sb_add(m, "TRUNCATED"); | |
529 | return; | |
530 | } | |
531 | ||
532 | /* Max length: 48 "OPT (...) " */ | |
533 | if (logflags & XT_LOG_IPOPT) | |
534 | sb_add(m, "OPT ( "); | |
535 | ||
536 | switch (currenthdr) { | |
537 | case IPPROTO_FRAGMENT: { | |
538 | struct frag_hdr _fhdr; | |
539 | const struct frag_hdr *fh; | |
540 | ||
541 | sb_add(m, "FRAG:"); | |
542 | fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), | |
543 | &_fhdr); | |
544 | if (fh == NULL) { | |
545 | sb_add(m, "TRUNCATED "); | |
546 | return; | |
547 | } | |
548 | ||
549 | /* Max length: 6 "65535 " */ | |
550 | sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8); | |
551 | ||
552 | /* Max length: 11 "INCOMPLETE " */ | |
553 | if (fh->frag_off & htons(0x0001)) | |
554 | sb_add(m, "INCOMPLETE "); | |
555 | ||
556 | sb_add(m, "ID:%08x ", ntohl(fh->identification)); | |
557 | ||
558 | if (ntohs(fh->frag_off) & 0xFFF8) | |
559 | fragment = 1; | |
560 | ||
561 | hdrlen = 8; | |
562 | ||
563 | break; | |
564 | } | |
565 | case IPPROTO_DSTOPTS: | |
566 | case IPPROTO_ROUTING: | |
567 | case IPPROTO_HOPOPTS: | |
568 | if (fragment) { | |
569 | if (logflags & XT_LOG_IPOPT) | |
570 | sb_add(m, ")"); | |
571 | return; | |
572 | } | |
573 | hdrlen = ipv6_optlen(hp); | |
574 | break; | |
575 | /* Max Length */ | |
576 | case IPPROTO_AH: | |
577 | if (logflags & XT_LOG_IPOPT) { | |
578 | struct ip_auth_hdr _ahdr; | |
579 | const struct ip_auth_hdr *ah; | |
580 | ||
581 | /* Max length: 3 "AH " */ | |
582 | sb_add(m, "AH "); | |
583 | ||
584 | if (fragment) { | |
585 | sb_add(m, ")"); | |
586 | return; | |
587 | } | |
588 | ||
589 | ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), | |
590 | &_ahdr); | |
591 | if (ah == NULL) { | |
592 | /* | |
593 | * Max length: 26 "INCOMPLETE [65535 | |
594 | * bytes] )" | |
595 | */ | |
596 | sb_add(m, "INCOMPLETE [%u bytes] )", | |
597 | skb->len - ptr); | |
598 | return; | |
599 | } | |
600 | ||
601 | /* Length: 15 "SPI=0xF1234567 */ | |
602 | sb_add(m, "SPI=0x%x ", ntohl(ah->spi)); | |
603 | ||
604 | } | |
605 | ||
606 | hdrlen = (hp->hdrlen+2)<<2; | |
607 | break; | |
608 | case IPPROTO_ESP: | |
609 | if (logflags & XT_LOG_IPOPT) { | |
610 | struct ip_esp_hdr _esph; | |
611 | const struct ip_esp_hdr *eh; | |
612 | ||
613 | /* Max length: 4 "ESP " */ | |
614 | sb_add(m, "ESP "); | |
615 | ||
616 | if (fragment) { | |
617 | sb_add(m, ")"); | |
618 | return; | |
619 | } | |
620 | ||
621 | /* | |
622 | * Max length: 26 "INCOMPLETE [65535 bytes] )" | |
623 | */ | |
624 | eh = skb_header_pointer(skb, ptr, sizeof(_esph), | |
625 | &_esph); | |
626 | if (eh == NULL) { | |
627 | sb_add(m, "INCOMPLETE [%u bytes] )", | |
628 | skb->len - ptr); | |
629 | return; | |
630 | } | |
631 | ||
632 | /* Length: 16 "SPI=0xF1234567 )" */ | |
633 | sb_add(m, "SPI=0x%x )", ntohl(eh->spi)); | |
634 | ||
635 | } | |
636 | return; | |
637 | default: | |
638 | /* Max length: 20 "Unknown Ext Hdr 255" */ | |
639 | sb_add(m, "Unknown Ext Hdr %u", currenthdr); | |
640 | return; | |
641 | } | |
642 | if (logflags & XT_LOG_IPOPT) | |
643 | sb_add(m, ") "); | |
644 | ||
645 | currenthdr = hp->nexthdr; | |
646 | ptr += hdrlen; | |
647 | } | |
648 | ||
649 | switch (currenthdr) { | |
650 | case IPPROTO_TCP: | |
651 | if (dump_tcp_header(m, skb, currenthdr, fragment, ptr, | |
652 | logflags)) | |
653 | return; | |
417e02bf | 654 | break; |
6939c33a RW |
655 | case IPPROTO_UDP: |
656 | case IPPROTO_UDPLITE: | |
657 | if (dump_udp_header(m, skb, currenthdr, fragment, ptr)) | |
658 | return; | |
417e02bf | 659 | break; |
6939c33a RW |
660 | case IPPROTO_ICMPV6: { |
661 | struct icmp6hdr _icmp6h; | |
662 | const struct icmp6hdr *ic; | |
663 | ||
664 | /* Max length: 13 "PROTO=ICMPv6 " */ | |
665 | sb_add(m, "PROTO=ICMPv6 "); | |
666 | ||
667 | if (fragment) | |
668 | break; | |
669 | ||
670 | /* Max length: 25 "INCOMPLETE [65535 bytes] " */ | |
671 | ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h); | |
672 | if (ic == NULL) { | |
673 | sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr); | |
674 | return; | |
675 | } | |
676 | ||
677 | /* Max length: 18 "TYPE=255 CODE=255 " */ | |
678 | sb_add(m, "TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code); | |
679 | ||
680 | switch (ic->icmp6_type) { | |
681 | case ICMPV6_ECHO_REQUEST: | |
682 | case ICMPV6_ECHO_REPLY: | |
683 | /* Max length: 19 "ID=65535 SEQ=65535 " */ | |
684 | sb_add(m, "ID=%u SEQ=%u ", | |
685 | ntohs(ic->icmp6_identifier), | |
686 | ntohs(ic->icmp6_sequence)); | |
687 | break; | |
688 | case ICMPV6_MGM_QUERY: | |
689 | case ICMPV6_MGM_REPORT: | |
690 | case ICMPV6_MGM_REDUCTION: | |
691 | break; | |
692 | ||
693 | case ICMPV6_PARAMPROB: | |
694 | /* Max length: 17 "POINTER=ffffffff " */ | |
695 | sb_add(m, "POINTER=%08x ", ntohl(ic->icmp6_pointer)); | |
696 | /* Fall through */ | |
697 | case ICMPV6_DEST_UNREACH: | |
698 | case ICMPV6_PKT_TOOBIG: | |
699 | case ICMPV6_TIME_EXCEED: | |
700 | /* Max length: 3+maxlen */ | |
701 | if (recurse) { | |
702 | sb_add(m, "["); | |
703 | dump_ipv6_packet(m, info, skb, | |
704 | ptr + sizeof(_icmp6h), 0); | |
705 | sb_add(m, "] "); | |
706 | } | |
707 | ||
708 | /* Max length: 10 "MTU=65535 " */ | |
709 | if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) | |
710 | sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu)); | |
711 | } | |
712 | break; | |
713 | } | |
714 | /* Max length: 10 "PROTO=255 " */ | |
715 | default: | |
716 | sb_add(m, "PROTO=%u ", currenthdr); | |
717 | } | |
718 | ||
719 | /* Max length: 15 "UID=4294967295 " */ | |
720 | if ((logflags & XT_LOG_UID) && recurse && skb->sk) { | |
721 | read_lock_bh(&skb->sk->sk_callback_lock); | |
722 | if (skb->sk->sk_socket && skb->sk->sk_socket->file) | |
723 | sb_add(m, "UID=%u GID=%u ", | |
724 | skb->sk->sk_socket->file->f_cred->fsuid, | |
725 | skb->sk->sk_socket->file->f_cred->fsgid); | |
726 | read_unlock_bh(&skb->sk->sk_callback_lock); | |
727 | } | |
728 | ||
729 | /* Max length: 16 "MARK=0xFFFFFFFF " */ | |
730 | if (!recurse && skb->mark) | |
731 | sb_add(m, "MARK=0x%x ", skb->mark); | |
732 | } | |
733 | ||
734 | static void dump_ipv6_mac_header(struct sbuff *m, | |
735 | const struct nf_loginfo *info, | |
736 | const struct sk_buff *skb) | |
737 | { | |
738 | struct net_device *dev = skb->dev; | |
739 | unsigned int logflags = 0; | |
740 | ||
741 | if (info->type == NF_LOG_TYPE_LOG) | |
742 | logflags = info->u.log.logflags; | |
743 | ||
744 | if (!(logflags & XT_LOG_MACDECODE)) | |
745 | goto fallback; | |
746 | ||
747 | switch (dev->type) { | |
748 | case ARPHRD_ETHER: | |
749 | sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", | |
750 | eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, | |
751 | ntohs(eth_hdr(skb)->h_proto)); | |
752 | return; | |
753 | default: | |
754 | break; | |
755 | } | |
756 | ||
757 | fallback: | |
758 | sb_add(m, "MAC="); | |
759 | if (dev->hard_header_len && | |
760 | skb->mac_header != skb->network_header) { | |
761 | const unsigned char *p = skb_mac_header(skb); | |
762 | unsigned int len = dev->hard_header_len; | |
763 | unsigned int i; | |
764 | ||
765 | if (dev->type == ARPHRD_SIT) { | |
766 | p -= ETH_HLEN; | |
767 | ||
768 | if (p < skb->head) | |
769 | p = NULL; | |
770 | } | |
771 | ||
772 | if (p != NULL) { | |
773 | sb_add(m, "%02x", *p++); | |
774 | for (i = 1; i < len; i++) | |
775 | sb_add(m, ":%02x", *p++); | |
776 | } | |
777 | sb_add(m, " "); | |
778 | ||
779 | if (dev->type == ARPHRD_SIT) { | |
780 | const struct iphdr *iph = | |
781 | (struct iphdr *)skb_mac_header(skb); | |
782 | sb_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr, | |
783 | &iph->daddr); | |
784 | } | |
785 | } else | |
786 | sb_add(m, " "); | |
787 | } | |
788 | ||
789 | static void | |
790 | ip6t_log_packet(u_int8_t pf, | |
791 | unsigned int hooknum, | |
792 | const struct sk_buff *skb, | |
793 | const struct net_device *in, | |
794 | const struct net_device *out, | |
795 | const struct nf_loginfo *loginfo, | |
796 | const char *prefix) | |
797 | { | |
798 | struct sbuff *m = sb_open(); | |
799 | ||
800 | if (!loginfo) | |
801 | loginfo = &default_loginfo; | |
802 | ||
803 | log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); | |
804 | ||
805 | if (in != NULL) | |
806 | dump_ipv6_mac_header(m, loginfo, skb); | |
807 | ||
808 | dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1); | |
809 | ||
810 | sb_close(m); | |
811 | } | |
812 | #endif | |
813 | ||
814 | static unsigned int | |
815 | log_tg(struct sk_buff *skb, const struct xt_action_param *par) | |
816 | { | |
817 | const struct xt_log_info *loginfo = par->targinfo; | |
818 | struct nf_loginfo li; | |
819 | ||
820 | li.type = NF_LOG_TYPE_LOG; | |
821 | li.u.log.level = loginfo->level; | |
822 | li.u.log.logflags = loginfo->logflags; | |
823 | ||
824 | if (par->family == NFPROTO_IPV4) | |
825 | ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, | |
826 | par->out, &li, loginfo->prefix); | |
a0f65a26 | 827 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
6939c33a RW |
828 | else if (par->family == NFPROTO_IPV6) |
829 | ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, | |
830 | par->out, &li, loginfo->prefix); | |
831 | #endif | |
832 | else | |
833 | WARN_ON_ONCE(1); | |
834 | ||
835 | return XT_CONTINUE; | |
836 | } | |
837 | ||
838 | static int log_tg_check(const struct xt_tgchk_param *par) | |
839 | { | |
840 | const struct xt_log_info *loginfo = par->targinfo; | |
841 | ||
842 | if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6) | |
843 | return -EINVAL; | |
844 | ||
845 | if (loginfo->level >= 8) { | |
846 | pr_debug("level %u >= 8\n", loginfo->level); | |
847 | return -EINVAL; | |
848 | } | |
849 | ||
850 | if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') { | |
851 | pr_debug("prefix is not null-terminated\n"); | |
852 | return -EINVAL; | |
853 | } | |
854 | ||
855 | return 0; | |
856 | } | |
857 | ||
858 | static struct xt_target log_tg_regs[] __read_mostly = { | |
859 | { | |
860 | .name = "LOG", | |
861 | .family = NFPROTO_IPV4, | |
862 | .target = log_tg, | |
863 | .targetsize = sizeof(struct xt_log_info), | |
864 | .checkentry = log_tg_check, | |
865 | .me = THIS_MODULE, | |
866 | }, | |
a0f65a26 | 867 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
6939c33a RW |
868 | { |
869 | .name = "LOG", | |
870 | .family = NFPROTO_IPV6, | |
871 | .target = log_tg, | |
872 | .targetsize = sizeof(struct xt_log_info), | |
873 | .checkentry = log_tg_check, | |
874 | .me = THIS_MODULE, | |
875 | }, | |
876 | #endif | |
877 | }; | |
878 | ||
879 | static struct nf_logger ipt_log_logger __read_mostly = { | |
880 | .name = "ipt_LOG", | |
881 | .logfn = &ipt_log_packet, | |
882 | .me = THIS_MODULE, | |
883 | }; | |
884 | ||
a0f65a26 | 885 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
6939c33a RW |
886 | static struct nf_logger ip6t_log_logger __read_mostly = { |
887 | .name = "ip6t_LOG", | |
888 | .logfn = &ip6t_log_packet, | |
889 | .me = THIS_MODULE, | |
890 | }; | |
891 | #endif | |
892 | ||
893 | static int __init log_tg_init(void) | |
894 | { | |
895 | int ret; | |
896 | ||
897 | ret = xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); | |
898 | if (ret < 0) | |
899 | return ret; | |
900 | ||
901 | nf_log_register(NFPROTO_IPV4, &ipt_log_logger); | |
a0f65a26 | 902 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
6939c33a RW |
903 | nf_log_register(NFPROTO_IPV6, &ip6t_log_logger); |
904 | #endif | |
905 | return 0; | |
906 | } | |
907 | ||
908 | static void __exit log_tg_exit(void) | |
909 | { | |
910 | nf_log_unregister(&ipt_log_logger); | |
a0f65a26 | 911 | #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) |
6939c33a RW |
912 | nf_log_unregister(&ip6t_log_logger); |
913 | #endif | |
914 | xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); | |
915 | } | |
916 | ||
917 | module_init(log_tg_init); | |
918 | module_exit(log_tg_exit); | |
919 | ||
920 | MODULE_LICENSE("GPL"); | |
921 | MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); | |
922 | MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>"); | |
923 | MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging"); | |
924 | MODULE_ALIAS("ipt_LOG"); | |
925 | MODULE_ALIAS("ip6t_LOG"); |