2 * This is a module which is used for logging packets.
5 /* (C) 2001 Jan Rekorajski <baggins@pld.org.pl>
6 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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.
13 #include <linux/module.h>
14 #include <linux/moduleparam.h>
15 #include <linux/skbuff.h>
17 #include <linux/spinlock.h>
18 #include <linux/icmpv6.h>
22 #include <linux/netfilter.h>
23 #include <linux/netfilter_ipv6/ip6_tables.h>
25 MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
26 MODULE_DESCRIPTION("IP6 tables LOG target module");
27 MODULE_LICENSE("GPL");
29 static unsigned int nflog
= 1;
30 module_param(nflog
, int, 0400);
31 MODULE_PARM_DESC(nflog
, "register as internal netfilter logging module");
34 #include <net/route.h>
35 #include <linux/netfilter_ipv6/ip6t_LOG.h>
40 #define DEBUGP(format, args...)
45 }; /* FIXME evil kludge */
47 /* Use lock to serialize, so printks don't overlap */
48 static spinlock_t log_lock
= SPIN_LOCK_UNLOCKED
;
50 /* takes in current header and pointer to the header */
51 /* if another header exists, sets hdrptr to the next header
52 and returns the new header value, else returns IPPROTO_NONE */
53 static u_int8_t
ip6_nexthdr(u_int8_t currenthdr
, u_int8_t
**hdrptr
)
55 u_int8_t hdrlen
, nexthdr
= IPPROTO_NONE
;
59 /* whoever decided to do the length of AUTH for ipv6
60 in 32bit units unlike other headers should be beaten...
61 repeatedly...with a large stick...no, an even LARGER
62 stick...no, you're still not thinking big enough */
64 hdrlen
= (*hdrptr
)[1] * 4 + 8;
65 *hdrptr
= *hdrptr
+ hdrlen
;
72 hdrlen
= (*hdrptr
)[1] * 8 + 8;
73 *hdrptr
= *hdrptr
+ hdrlen
;
75 case IPPROTO_FRAGMENT
:
77 *hdrptr
= *hdrptr
+ 8;
83 /* One level of recursion won't kill us */
84 static void dump_packet(const struct ip6t_log_info
*info
,
85 struct ipv6hdr
*ipv6h
, int recurse
)
87 u_int8_t currenthdr
= ipv6h
->nexthdr
;
91 /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000" */
92 printk("SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h
->saddr
));
93 printk("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h
->daddr
));
95 /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
96 printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
97 ntohs(ipv6h
->payload_len
) + sizeof(struct ipv6hdr
),
98 (ntohl(*(u_int32_t
*)ipv6h
) & 0x0ff00000) >> 20,
100 (ntohl(*(u_int32_t
*)ipv6h
) & 0x000fffff));
103 hdrptr
= (u_int8_t
*)(ipv6h
+ 1);
104 while (currenthdr
!= IPPROTO_NONE
) {
105 if ((currenthdr
== IPPROTO_TCP
) ||
106 (currenthdr
== IPPROTO_UDP
) ||
107 (currenthdr
== IPPROTO_ICMPV6
))
109 /* Max length: 48 "OPT (...) " */
111 switch (currenthdr
) {
112 case IPPROTO_FRAGMENT
: {
113 struct frag_hdr
*fhdr
= (struct frag_hdr
*)hdrptr
;
115 /* Max length: 11 "FRAG:65535 " */
116 printk("FRAG:%u ", ntohs(fhdr
->frag_off
) & 0xFFF8);
118 /* Max length: 11 "INCOMPLETE " */
119 if (fhdr
->frag_off
& htons(0x0001))
120 printk("INCOMPLETE ");
122 printk("ID:%08x ", fhdr
->identification
);
124 if (ntohs(fhdr
->frag_off
) & 0xFFF8)
129 case IPPROTO_DSTOPTS
:
130 case IPPROTO_ROUTING
:
131 case IPPROTO_HOPOPTS
:
136 if (info
->logflags
& IP6T_LOG_IPOPT
) {
137 struct esphdr
*esph
= (struct esphdr
*)hdrptr
;
138 int esp
= (currenthdr
== IPPROTO_ESP
);
140 /* Max length: 4 "ESP " */
141 printk("%s ",esp
? "ESP" : "AH");
143 /* Length: 15 "SPI=0xF1234567 " */
144 printk("SPI=0x%x ", ntohl(esph
->spi
) );
151 currenthdr
= ip6_nexthdr(currenthdr
, &hdrptr
);
154 switch (currenthdr
) {
156 struct tcphdr
*tcph
= (struct tcphdr
*)hdrptr
;
158 /* Max length: 10 "PROTO=TCP " */
159 printk("PROTO=TCP ");
164 /* Max length: 20 "SPT=65535 DPT=65535 " */
165 printk("SPT=%u DPT=%u ",
166 ntohs(tcph
->source
), ntohs(tcph
->dest
));
167 /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
168 if (info
->logflags
& IP6T_LOG_TCPSEQ
)
169 printk("SEQ=%u ACK=%u ",
170 ntohl(tcph
->seq
), ntohl(tcph
->ack_seq
));
171 /* Max length: 13 "WINDOW=65535 " */
172 printk("WINDOW=%u ", ntohs(tcph
->window
));
173 /* Max length: 9 "RES=0x3F " */
174 printk("RES=0x%02x ", (u_int8_t
)(ntohl(tcp_flag_word(tcph
) & TCP_RESERVED_BITS
) >> 22));
175 /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
192 /* Max length: 11 "URGP=65535 " */
193 printk("URGP=%u ", ntohs(tcph
->urg_ptr
));
195 if ((info
->logflags
& IP6T_LOG_TCPOPT
)
196 && tcph
->doff
* 4 != sizeof(struct tcphdr
)) {
199 /* Max length: 127 "OPT (" 15*4*2chars ") " */
201 for (i
=sizeof(struct tcphdr
); i
< tcph
->doff
* 4; i
++)
202 printk("%02X", ((u_int8_t
*)tcph
)[i
]);
208 struct udphdr
*udph
= (struct udphdr
*)hdrptr
;
210 /* Max length: 10 "PROTO=UDP " */
211 printk("PROTO=UDP ");
216 /* Max length: 20 "SPT=65535 DPT=65535 " */
217 printk("SPT=%u DPT=%u LEN=%u ",
218 ntohs(udph
->source
), ntohs(udph
->dest
),
222 case IPPROTO_ICMPV6
: {
223 struct icmp6hdr
*icmp6h
= (struct icmp6hdr
*)hdrptr
;
225 /* Max length: 13 "PROTO=ICMPv6 " */
226 printk("PROTO=ICMPv6 ");
231 /* Max length: 18 "TYPE=255 CODE=255 " */
232 printk("TYPE=%u CODE=%u ", icmp6h
->icmp6_type
, icmp6h
->icmp6_code
);
234 switch (icmp6h
->icmp6_type
) {
235 case ICMPV6_ECHO_REQUEST
:
236 case ICMPV6_ECHO_REPLY
:
237 /* Max length: 19 "ID=65535 SEQ=65535 " */
238 printk("ID=%u SEQ=%u ",
239 ntohs(icmp6h
->icmp6_identifier
),
240 ntohs(icmp6h
->icmp6_sequence
));
242 case ICMPV6_MGM_QUERY
:
243 case ICMPV6_MGM_REPORT
:
244 case ICMPV6_MGM_REDUCTION
:
247 case ICMPV6_PARAMPROB
:
248 /* Max length: 17 "POINTER=ffffffff " */
249 printk("POINTER=%08x ", ntohl(icmp6h
->icmp6_pointer
));
251 case ICMPV6_DEST_UNREACH
:
252 case ICMPV6_PKT_TOOBIG
:
253 case ICMPV6_TIME_EXCEED
:
254 /* Max length: 3+maxlen */
257 dump_packet(info
, (struct ipv6hdr
*)(icmp6h
+ 1), 0);
261 /* Max length: 10 "MTU=65535 " */
262 if (icmp6h
->icmp6_type
== ICMPV6_PKT_TOOBIG
)
263 printk("MTU=%u ", ntohl(icmp6h
->icmp6_mtu
));
267 /* Max length: 10 "PROTO=255 " */
269 printk("PROTO=%u ", currenthdr
);
274 ip6t_log_packet(unsigned int hooknum
,
275 const struct sk_buff
*skb
,
276 const struct net_device
*in
,
277 const struct net_device
*out
,
278 const struct ip6t_log_info
*loginfo
,
279 const char *level_string
,
282 struct ipv6hdr
*ipv6h
= skb
->nh
.ipv6h
;
284 spin_lock_bh(&log_lock
);
285 printk(level_string
);
286 printk("%sIN=%s OUT=%s ",
287 prefix
== NULL
? loginfo
->prefix
: prefix
,
289 out
? out
->name
: "");
291 /* MAC logging for input chain only. */
293 if (skb
->dev
&& skb
->dev
->hard_header_len
&& skb
->mac
.raw
!= (void*)ipv6h
) {
294 if (skb
->dev
->type
!= ARPHRD_SIT
){
296 unsigned char *p
= skb
->mac
.raw
;
297 for (i
= 0; i
< skb
->dev
->hard_header_len
; i
++,p
++)
299 i
==skb
->dev
->hard_header_len
- 1
303 unsigned char *p
= skb
->mac
.raw
;
304 if ( p
- (ETH_ALEN
*2+2) > skb
->head
){
306 for (i
= 0; i
< (ETH_ALEN
); i
++,p
++)
308 i
== ETH_ALEN
-1 ? "->" : ":");
310 for (i
= 0; i
< (ETH_ALEN
); i
++,p
++)
312 i
== ETH_ALEN
-1 ? ' ' : ':');
315 if ((skb
->dev
->addr_len
== 4) &&
316 skb
->dev
->hard_header_len
> 20){
318 p
= skb
->mac
.raw
+ 12;
319 for (i
= 0; i
< 4; i
++,p
++)
321 i
== 3 ? "->" : ".");
322 for (i
= 0; i
< 4; i
++,p
++)
331 dump_packet(loginfo
, ipv6h
, 1);
333 spin_unlock_bh(&log_lock
);
337 ip6t_log_target(struct sk_buff
**pskb
,
338 unsigned int hooknum
,
339 const struct net_device
*in
,
340 const struct net_device
*out
,
341 const void *targinfo
,
344 const struct ip6t_log_info
*loginfo
= targinfo
;
345 char level_string
[4] = "< >";
347 level_string
[1] = '0' + (loginfo
->level
% 8);
348 ip6t_log_packet(hooknum
, *pskb
, in
, out
, loginfo
, level_string
, NULL
);
350 return IP6T_CONTINUE
;
354 ip6t_logfn(unsigned int hooknum
,
355 const struct sk_buff
*skb
,
356 const struct net_device
*in
,
357 const struct net_device
*out
,
360 struct ip6t_log_info loginfo
= {
362 .logflags
= IP6T_LOG_MASK
,
366 ip6t_log_packet(hooknum
, skb
, in
, out
, &loginfo
, KERN_WARNING
, prefix
);
369 static int ip6t_log_checkentry(const char *tablename
,
370 const struct ip6t_entry
*e
,
372 unsigned int targinfosize
,
373 unsigned int hook_mask
)
375 const struct ip6t_log_info
*loginfo
= targinfo
;
377 if (targinfosize
!= IP6T_ALIGN(sizeof(struct ip6t_log_info
))) {
378 DEBUGP("LOG: targinfosize %u != %u\n",
379 targinfosize
, IP6T_ALIGN(sizeof(struct ip6t_log_info
)));
383 if (loginfo
->level
>= 8) {
384 DEBUGP("LOG: level %u >= 8\n", loginfo
->level
);
388 if (loginfo
->prefix
[sizeof(loginfo
->prefix
)-1] != '\0') {
389 DEBUGP("LOG: prefix term %i\n",
390 loginfo
->prefix
[sizeof(loginfo
->prefix
)-1]);
397 static struct ip6t_target ip6t_log_reg
= {
399 .target
= ip6t_log_target
,
400 .checkentry
= ip6t_log_checkentry
,
404 static int __init
init(void)
406 if (ip6t_register_target(&ip6t_log_reg
))
409 nf_log_register(PF_INET6
, &ip6t_logfn
);
414 static void __exit
fini(void)
417 nf_log_unregister(PF_INET6
, &ip6t_logfn
);
418 ip6t_unregister_target(&ip6t_log_reg
);