1
2
3
4
5
6
7
8
9
10
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
27MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
28MODULE_DESCRIPTION("IP6 tables LOG target module");
29MODULE_LICENSE("GPL");
30
31struct in_device;
32#include <net/route.h>
33#include <linux/netfilter_ipv6/ip6t_LOG.h>
34
35
36static DEFINE_SPINLOCK(log_lock);
37
38
39static void dump_packet(const struct nf_loginfo *info,
40 const struct sk_buff *skb, unsigned int ip6hoff,
41 int recurse)
42{
43 u_int8_t currenthdr;
44 int fragment;
45 struct ipv6hdr _ip6h;
46 const struct ipv6hdr *ih;
47 unsigned int ptr;
48 unsigned int hdrlen = 0;
49 unsigned int logflags;
50
51 if (info->type == NF_LOG_TYPE_LOG)
52 logflags = info->u.log.logflags;
53 else
54 logflags = NF_LOG_MASK;
55
56 ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
57 if (ih == NULL) {
58 printk("TRUNCATED");
59 return;
60 }
61
62
63 printk("SRC=" NIP6_FMT " DST=" NIP6_FMT " ", NIP6(ih->saddr), NIP6(ih->daddr));
64
65
66 printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
67 ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
68 (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
69 ih->hop_limit,
70 (ntohl(*(__be32 *)ih) & 0x000fffff));
71
72 fragment = 0;
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;
78
79 hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
80 if (hp == NULL) {
81 printk("TRUNCATED");
82 return;
83 }
84
85
86 if (logflags & IP6T_LOG_IPOPT)
87 printk("OPT ( ");
88
89 switch (currenthdr) {
90 case IPPROTO_FRAGMENT: {
91 struct frag_hdr _fhdr;
92 const struct frag_hdr *fh;
93
94 printk("FRAG:");
95 fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
96 &_fhdr);
97 if (fh == NULL) {
98 printk("TRUNCATED ");
99 return;
100 }
101
102
103 printk("%u ", ntohs(fh->frag_off) & 0xFFF8);
104
105
106 if (fh->frag_off & htons(0x0001))
107 printk("INCOMPLETE ");
108
109 printk("ID:%08x ", ntohl(fh->identification));
110
111 if (ntohs(fh->frag_off) & 0xFFF8)
112 fragment = 1;
113
114 hdrlen = 8;
115
116 break;
117 }
118 case IPPROTO_DSTOPTS:
119 case IPPROTO_ROUTING:
120 case IPPROTO_HOPOPTS:
121 if (fragment) {
122 if (logflags & IP6T_LOG_IPOPT)
123 printk(")");
124 return;
125 }
126 hdrlen = ipv6_optlen(hp);
127 break;
128
129 case IPPROTO_AH:
130 if (logflags & IP6T_LOG_IPOPT) {
131 struct ip_auth_hdr _ahdr;
132 const struct ip_auth_hdr *ah;
133
134
135 printk("AH ");
136
137 if (fragment) {
138 printk(")");
139 return;
140 }
141
142 ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
143 &_ahdr);
144 if (ah == NULL) {
145
146
147
148
149 printk("INCOMPLETE [%u bytes] )",
150 skb->len - ptr);
151 return;
152 }
153
154
155 printk("SPI=0x%x ", ntohl(ah->spi));
156
157 }
158
159 hdrlen = (hp->hdrlen+2)<<2;
160 break;
161 case IPPROTO_ESP:
162 if (logflags & IP6T_LOG_IPOPT) {
163 struct ip_esp_hdr _esph;
164 const struct ip_esp_hdr *eh;
165
166
167 printk("ESP ");
168
169 if (fragment) {
170 printk(")");
171 return;
172 }
173
174
175
176
177 eh = skb_header_pointer(skb, ptr, sizeof(_esph),
178 &_esph);
179 if (eh == NULL) {
180 printk("INCOMPLETE [%u bytes] )",
181 skb->len - ptr);
182 return;
183 }
184
185
186 printk("SPI=0x%x )", ntohl(eh->spi) );
187
188 }
189 return;
190 default:
191
192 printk("Unknown Ext Hdr %u", currenthdr);
193 return;
194 }
195 if (logflags & IP6T_LOG_IPOPT)
196 printk(") ");
197
198 currenthdr = hp->nexthdr;
199 ptr += hdrlen;
200 }
201
202 switch (currenthdr) {
203 case IPPROTO_TCP: {
204 struct tcphdr _tcph;
205 const struct tcphdr *th;
206
207
208 printk("PROTO=TCP ");
209
210 if (fragment)
211 break;
212
213
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
221 printk("SPT=%u DPT=%u ",
222 ntohs(th->source), ntohs(th->dest));
223
224 if (logflags & IP6T_LOG_TCPSEQ)
225 printk("SEQ=%u ACK=%u ",
226 ntohl(th->seq), ntohl(th->ack_seq));
227
228 printk("WINDOW=%u ", ntohs(th->window));
229
230 printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
231
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
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)];
254 const u_int8_t *op;
255 unsigned int i;
256 unsigned int optsize = th->doff * 4
257 - sizeof(struct tcphdr);
258
259 op = skb_header_pointer(skb,
260 ptr + sizeof(struct tcphdr),
261 optsize, _opt);
262 if (op == NULL) {
263 printk("OPT (TRUNCATED)");
264 return;
265 }
266
267
268 printk("OPT (");
269 for (i =0; i < optsize; i++)
270 printk("%02X", op[i]);
271 printk(") ");
272 }
273 break;
274 }
275 case IPPROTO_UDP:
276 case IPPROTO_UDPLITE: {
277 struct udphdr _udph;
278 const struct udphdr *uh;
279
280 if (currenthdr == IPPROTO_UDP)
281
282 printk("PROTO=UDP " );
283 else
284 printk("PROTO=UDPLITE ");
285
286 if (fragment)
287 break;
288
289
290 uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph);
291 if (uh == NULL) {
292 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
293 return;
294 }
295
296
297 printk("SPT=%u DPT=%u LEN=%u ",
298 ntohs(uh->source), ntohs(uh->dest),
299 ntohs(uh->len));
300 break;
301 }
302 case IPPROTO_ICMPV6: {
303 struct icmp6hdr _icmp6h;
304 const struct icmp6hdr *ic;
305
306
307 printk("PROTO=ICMPv6 ");
308
309 if (fragment)
310 break;
311
312
313 ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
314 if (ic == NULL) {
315 printk("INCOMPLETE [%u bytes] ", skb->len - ptr);
316 return;
317 }
318
319
320 printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code);
321
322 switch (ic->icmp6_type) {
323 case ICMPV6_ECHO_REQUEST:
324 case ICMPV6_ECHO_REPLY:
325
326 printk("ID=%u SEQ=%u ",
327 ntohs(ic->icmp6_identifier),
328 ntohs(ic->icmp6_sequence));
329 break;
330 case ICMPV6_MGM_QUERY:
331 case ICMPV6_MGM_REPORT:
332 case ICMPV6_MGM_REDUCTION:
333 break;
334
335 case ICMPV6_PARAMPROB:
336
337 printk("POINTER=%08x ", ntohl(ic->icmp6_pointer));
338
339 case ICMPV6_DEST_UNREACH:
340 case ICMPV6_PKT_TOOBIG:
341 case ICMPV6_TIME_EXCEED:
342
343 if (recurse) {
344 printk("[");
345 dump_packet(info, skb, ptr + sizeof(_icmp6h),
346 0);
347 printk("] ");
348 }
349
350
351 if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
352 printk("MTU=%u ", ntohl(ic->icmp6_mtu));
353 }
354 break;
355 }
356
357 default:
358 printk("PROTO=%u ", currenthdr);
359 }
360
361
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 ", skb->sk->sk_socket->file->f_uid);
366 read_unlock_bh(&skb->sk->sk_callback_lock);
367 }
368}
369
370static struct nf_loginfo default_loginfo = {
371 .type = NF_LOG_TYPE_LOG,
372 .u = {
373 .log = {
374 .level = 0,
375 .logflags = NF_LOG_MASK,
376 },
377 },
378};
379
380static void
381ip6t_log_packet(unsigned int pf,
382 unsigned int hooknum,
383 const struct sk_buff *skb,
384 const struct net_device *in,
385 const struct net_device *out,
386 const struct nf_loginfo *loginfo,
387 const char *prefix)
388{
389 if (!loginfo)
390 loginfo = &default_loginfo;
391
392 spin_lock_bh(&log_lock);
393 printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
394 prefix,
395 in ? in->name : "",
396 out ? out->name : "");
397 if (in && !out) {
398 unsigned int len;
399
400 printk("MAC=");
401 if (skb->dev && (len = skb->dev->hard_header_len) &&
402 skb->mac_header != skb->network_header) {
403 const unsigned char *p = skb_mac_header(skb);
404 int i;
405
406 if (skb->dev->type == ARPHRD_SIT &&
407 (p -= ETH_HLEN) < skb->head)
408 p = NULL;
409
410 if (p != NULL) {
411 for (i = 0; i < len; i++)
412 printk("%02x%s", p[i],
413 i == len - 1 ? "" : ":");
414 }
415 printk(" ");
416
417 if (skb->dev->type == ARPHRD_SIT) {
418 const struct iphdr *iph =
419 (struct iphdr *)skb_mac_header(skb);
420 printk("TUNNEL=%u.%u.%u.%u->%u.%u.%u.%u ",
421 NIPQUAD(iph->saddr),
422 NIPQUAD(iph->daddr));
423 }
424 } else
425 printk(" ");
426 }
427
428 dump_packet(loginfo, skb, skb_network_offset(skb), 1);
429 printk("\n");
430 spin_unlock_bh(&log_lock);
431}
432
433static unsigned int
434ip6t_log_target(struct sk_buff *skb,
435 const struct net_device *in,
436 const struct net_device *out,
437 unsigned int hooknum,
438 const struct xt_target *target,
439 const void *targinfo)
440{
441 const struct ip6t_log_info *loginfo = targinfo;
442 struct nf_loginfo li;
443
444 li.type = NF_LOG_TYPE_LOG;
445 li.u.log.level = loginfo->level;
446 li.u.log.logflags = loginfo->logflags;
447
448 ip6t_log_packet(PF_INET6, hooknum, skb, in, out, &li, loginfo->prefix);
449 return XT_CONTINUE;
450}
451
452
453static bool ip6t_log_checkentry(const char *tablename,
454 const void *entry,
455 const struct xt_target *target,
456 void *targinfo,
457 unsigned int hook_mask)
458{
459 const struct ip6t_log_info *loginfo = targinfo;
460
461 if (loginfo->level >= 8) {
462 pr_debug("LOG: level %u >= 8\n", loginfo->level);
463 return false;
464 }
465 if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
466 pr_debug("LOG: prefix term %i\n",
467 loginfo->prefix[sizeof(loginfo->prefix)-1]);
468 return false;
469 }
470 return true;
471}
472
473static struct xt_target ip6t_log_reg __read_mostly = {
474 .name = "LOG",
475 .family = AF_INET6,
476 .target = ip6t_log_target,
477 .targetsize = sizeof(struct ip6t_log_info),
478 .checkentry = ip6t_log_checkentry,
479 .me = THIS_MODULE,
480};
481
482static struct nf_logger ip6t_logger = {
483 .name = "ip6t_LOG",
484 .logfn = &ip6t_log_packet,
485 .me = THIS_MODULE,
486};
487
488static int __init ip6t_log_init(void)
489{
490 int ret;
491
492 ret = xt_register_target(&ip6t_log_reg);
493 if (ret < 0)
494 return ret;
495 nf_log_register(PF_INET6, &ip6t_logger);
496 return 0;
497}
498
499static void __exit ip6t_log_fini(void)
500{
501 nf_log_unregister(&ip6t_logger);
502 xt_unregister_target(&ip6t_log_reg);
503}
504
505module_init(ip6t_log_init);
506module_exit(ip6t_log_fini);
507
