[NETFILTER]: nf_nat: pass manip type instead of hook to nf_nat_setup_info
[linux-2.6.git] / net / ipv6 / netfilter / ip6t_LOG.c
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 /* Use lock to serialize, so printks don't overlap */
36 static DEFINE_SPINLOCK(log_lock);
37
38 /* One level of recursion won't kill us */
39 static 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         /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
63         printk("SRC=" NIP6_FMT " DST=" NIP6_FMT " ", NIP6(ih->saddr), NIP6(ih->daddr));
64
65         /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
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                 /* Max length: 48 "OPT (...) " */
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                         /* Max length: 6 "65535 " */
103                         printk("%u ", ntohs(fh->frag_off) & 0xFFF8);
104
105                         /* Max length: 11 "INCOMPLETE " */
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                 /* Max Length */
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                                 /* Max length: 3 "AH " */
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                                          * Max length: 26 "INCOMPLETE [65535
147                                          *  bytes] )"
148                                          */
149                                         printk("INCOMPLETE [%u bytes] )",
150                                                skb->len - ptr);
151                                         return;
152                                 }
153
154                                 /* Length: 15 "SPI=0xF1234567 */
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                                 /* Max length: 4 "ESP " */
167                                 printk("ESP ");
168
169                                 if (fragment) {
170                                         printk(")");
171                                         return;
172                                 }
173
174                                 /*
175                                  * Max length: 26 "INCOMPLETE [65535 bytes] )"
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                                 /* Length: 16 "SPI=0xF1234567 )" */
186                                 printk("SPI=0x%x )", ntohl(eh->spi) );
187
188                         }
189                         return;
190                 default:
191                         /* Max length: 20 "Unknown Ext Hdr 255" */
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                 /* 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)];
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                         /* Max length: 127 "OPT (" 15*4*2chars ") " */
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                         /* Max length: 10 "PROTO=UDP "     */
282                         printk("PROTO=UDP " );
283                 else    /* Max length: 14 "PROTO=UDPLITE " */
284                         printk("PROTO=UDPLITE ");
285
286                 if (fragment)
287                         break;
288
289                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
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                 /* Max length: 20 "SPT=65535 DPT=65535 " */
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                 /* Max length: 13 "PROTO=ICMPv6 " */
307                 printk("PROTO=ICMPv6 ");
308
309                 if (fragment)
310                         break;
311
312                 /* Max length: 25 "INCOMPLETE [65535 bytes] " */
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                 /* Max length: 18 "TYPE=255 CODE=255 " */
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                         /* Max length: 19 "ID=65535 SEQ=65535 " */
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                         /* Max length: 17 "POINTER=ffffffff " */
337                         printk("POINTER=%08x ", ntohl(ic->icmp6_pointer));
338                         /* Fall through */
339                 case ICMPV6_DEST_UNREACH:
340                 case ICMPV6_PKT_TOOBIG:
341                 case ICMPV6_TIME_EXCEED:
342                         /* Max length: 3+maxlen */
343                         if (recurse) {
344                                 printk("[");
345                                 dump_packet(info, skb, ptr + sizeof(_icmp6h),
346                                             0);
347                                 printk("] ");
348                         }
349
350                         /* Max length: 10 "MTU=65535 " */
351                         if (ic->icmp6_type == ICMPV6_PKT_TOOBIG)
352                                 printk("MTU=%u ", ntohl(ic->icmp6_mtu));
353                 }
354                 break;
355         }
356         /* Max length: 10 "PROTO=255 " */
357         default:
358                 printk("PROTO=%u ", currenthdr);
359         }
360
361         /* Max length: 15 "UID=4294967295 " */
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 GID=%u",
366                                 skb->sk->sk_socket->file->f_uid,
367                                 skb->sk->sk_socket->file->f_gid);
368                 read_unlock_bh(&skb->sk->sk_callback_lock);
369         }
370 }
371
372 static struct nf_loginfo default_loginfo = {
373         .type   = NF_LOG_TYPE_LOG,
374         .u = {
375                 .log = {
376                         .level    = 0,
377                         .logflags = NF_LOG_MASK,
378                 },
379         },
380 };
381
382 static void
383 ip6t_log_packet(unsigned int pf,
384                 unsigned int hooknum,
385                 const struct sk_buff *skb,
386                 const struct net_device *in,
387                 const struct net_device *out,
388                 const struct nf_loginfo *loginfo,
389                 const char *prefix)
390 {
391         if (!loginfo)
392                 loginfo = &default_loginfo;
393
394         spin_lock_bh(&log_lock);
395         printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
396                 prefix,
397                 in ? in->name : "",
398                 out ? out->name : "");
399         if (in && !out) {
400                 unsigned int len;
401                 /* MAC logging for input chain only. */
402                 printk("MAC=");
403                 if (skb->dev && (len = skb->dev->hard_header_len) &&
404                     skb->mac_header != skb->network_header) {
405                         const unsigned char *p = skb_mac_header(skb);
406                         int i;
407
408                         if (skb->dev->type == ARPHRD_SIT &&
409                             (p -= ETH_HLEN) < skb->head)
410                                 p = NULL;
411
412                         if (p != NULL) {
413                                 for (i = 0; i < len; i++)
414                                         printk("%02x%s", p[i],
415                                                i == len - 1 ? "" : ":");
416                         }
417                         printk(" ");
418
419                         if (skb->dev->type == ARPHRD_SIT) {
420                                 const struct iphdr *iph =
421                                         (struct iphdr *)skb_mac_header(skb);
422                                 printk("TUNNEL=%u.%u.%u.%u->%u.%u.%u.%u ",
423                                        NIPQUAD(iph->saddr),
424                                        NIPQUAD(iph->daddr));
425                         }
426                 } else
427                         printk(" ");
428         }
429
430         dump_packet(loginfo, skb, skb_network_offset(skb), 1);
431         printk("\n");
432         spin_unlock_bh(&log_lock);
433 }
434
435 static unsigned int
436 log_tg6(struct sk_buff *skb, const struct net_device *in,
437         const struct net_device *out, unsigned int hooknum,
438         const struct xt_target *target, const void *targinfo)
439 {
440         const struct ip6t_log_info *loginfo = targinfo;
441         struct nf_loginfo li;
442
443         li.type = NF_LOG_TYPE_LOG;
444         li.u.log.level = loginfo->level;
445         li.u.log.logflags = loginfo->logflags;
446
447         ip6t_log_packet(PF_INET6, hooknum, skb, in, out, &li, loginfo->prefix);
448         return XT_CONTINUE;
449 }
450
451
452 static bool
453 log_tg6_check(const char *tablename, const void *entry,
454               const struct xt_target *target, void *targinfo,
455               unsigned int hook_mask)
456 {
457         const struct ip6t_log_info *loginfo = targinfo;
458
459         if (loginfo->level >= 8) {
460                 pr_debug("LOG: level %u >= 8\n", loginfo->level);
461                 return false;
462         }
463         if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
464                 pr_debug("LOG: prefix term %i\n",
465                          loginfo->prefix[sizeof(loginfo->prefix)-1]);
466                 return false;
467         }
468         return true;
469 }
470
471 static struct xt_target log_tg6_reg __read_mostly = {
472         .name           = "LOG",
473         .family         = AF_INET6,
474         .target         = log_tg6,
475         .targetsize     = sizeof(struct ip6t_log_info),
476         .checkentry     = log_tg6_check,
477         .me             = THIS_MODULE,
478 };
479
480 static struct nf_logger ip6t_logger = {
481         .name           = "ip6t_LOG",
482         .logfn          = &ip6t_log_packet,
483         .me             = THIS_MODULE,
484 };
485
486 static int __init log_tg6_init(void)
487 {
488         int ret;
489
490         ret = xt_register_target(&log_tg6_reg);
491         if (ret < 0)
492                 return ret;
493         nf_log_register(PF_INET6, &ip6t_logger);
494         return 0;
495 }
496
497 static void __exit log_tg6_exit(void)
498 {
499         nf_log_unregister(&ip6t_logger);
500         xt_unregister_target(&log_tg6_reg);
501 }
502
503 module_init(log_tg6_init);
504 module_exit(log_tg6_exit);