/*
* This is a module which is used for logging packets.
*/
/* (C) 2001 Jan Rekorajski <baggins@pld.org.pl>
* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/spinlock.h>
#include <linux/icmpv6.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <net/ipv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6/ip6_tables.h>
MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>");
MODULE_DESCRIPTION("IP6 tables LOG target module");
MODULE_LICENSE("GPL");
static unsigned int nflog = 1;
MODULE_PARM(nflog, "i");
MODULE_PARM_DESC(nflog, "register as internal netfilter logging module");
struct in_device;
#include <net/route.h>
#include <linux/netfilter_ipv6/ip6t_LOG.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, args...)
#endif
struct esphdr {
__u32 spi;
}; /* FIXME evil kludge */
/* Use lock to serialize, so printks don't overlap */
static spinlock_t log_lock = SPIN_LOCK_UNLOCKED;
/* takes in current header and pointer to the header */
/* if another header exists, sets hdrptr to the next header
and returns the new header value, else returns 0 */
static u_int8_t ip6_nexthdr(u_int8_t currenthdr, u_int8_t **hdrptr)
{
u_int8_t hdrlen, nexthdr = 0;
switch(currenthdr){
case IPPROTO_AH:
/* whoever decided to do the length of AUTH for ipv6
in 32bit units unlike other headers should be beaten...
repeatedly...with a large stick...no, an even LARGER
stick...no, you're still not thinking big enough */
nexthdr = **hdrptr;
hdrlen = *hdrptr[1] * 4 + 8;
*hdrptr = *hdrptr + hdrlen;
break;
/*stupid rfc2402 */
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
nexthdr = **hdrptr;
hdrlen = *hdrptr[1] * 8 + 8;
*hdrptr = *hdrptr + hdrlen;
break;
case IPPROTO_FRAGMENT:
nexthdr = **hdrptr;
*hdrptr = *hdrptr + 8;
break;
}
return nexthdr;
}
/* One level of recursion won't kill us */
static void dump_packet(const struct ip6t_log_info *info,
struct ipv6hdr *ipv6h, int recurse)
{
u_int8_t currenthdr = ipv6h->nexthdr;
u_int8_t *hdrptr;
int fragment;
/* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000" */
printk("SRC=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->saddr));
printk("DST=%04x:%04x:%04x:%04x:%04x:%04x:%04x:%04x ", NIP6(ipv6h->daddr));
/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
ntohs(ipv6h->payload_len) + sizeof(struct ipv6hdr),
(ntohl(*(u_int32_t *)ipv6h) & 0x0ff00000) >> 20,
ipv6h->hop_limit,
(ntohl(*(u_int32_t *)ipv6h) & 0x000fffff));
fragment = 0;
hdrptr = (u_int8_t *)(ipv6h + 1);
while (currenthdr) {
if ((currenthdr == IPPROTO_TCP) ||
(currenthdr == IPPROTO_UDP) ||
(currenthdr == IPPROTO_ICMPV6))
break;
/* Max length: 48 "OPT (...) " */
printk("OPT ( ");
switch (currenthdr) {
case IPPROTO_FRAGMENT: {
struct frag_hdr *fhdr = (struct frag_hdr *)hdrptr;
/* Max length: 11 "FRAG:65535 " */
printk("FRAG:%u ", ntohs(fhdr->frag_off) & 0xFFF8);
/* Max length: 11 "INCOMPLETE " */
if (fhdr->frag_off & htons(0x0001))
printk("INCOMPLETE ");
printk("ID:%08x ", fhdr->identification);
if (ntohs(fhdr->frag_off) & 0xFFF8)
fragment = 1;
break;
}
case IPPROTO_DSTOPTS:
case IPPROTO_ROUTING:
case IPPROTO_HOPOPTS:
break;
/* Max Length */
case IPPROTO_AH:
case IPPROTO_ESP:
if (info->logflags & IP6T_LOG_IPOPT) {
struct esphdr *esph = (struct esphdr *)hdrptr;
int esp = (currenthdr == IPPROTO_ESP);
/* Max length: 4 "ESP " */
printk("%s ",esp ? "ESP" : "AH");
/* Length: 15 "SPI=0xF1234567 " */
printk("SPI=0x%x ", ntohl(esph->spi) );
break;
}
default:
break;
}
printk(") ");
currenthdr = ip6_nexthdr(currenthdr, &hdrptr);
}
switch (currenthdr) {
case IPPROTO_TCP: {
struct tcphdr *tcph = (struct tcphdr *)hdrptr;
/* Max length: 10 "PROTO=TCP " */
printk("PROTO=TCP ");
if (fragment)
break;
/* Max length: 20 "SPT=65535 DPT=65535 " */
printk("SPT=%u DPT=%u ",
ntohs(tcph->source), ntohs(tcph->dest));
/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
if (info->logflags & IP6T_LOG_TCPSEQ)
printk("SEQ=%u ACK=%u ",
ntohl(tcph->seq), ntohl(tcph->ack_seq));
/* Max length: 13 "WINDOW=65535 " */
printk("WINDOW=%u ", ntohs(tcph->window));
/* Max length: 9 "RES=0x3F " */
printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(tcph) & TCP_RESERVED_BITS) >> 22));
/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
if (tcph->cwr)
printk("CWR ");
if (tcph->ece)
printk("ECE ");
if (tcph->urg)
printk("URG ");
if (tcph->ack)
printk("ACK ");
if (tcph->psh)
printk("PSH ");
if (tcph->rst)
printk("RST ");
if (tcph->syn)
printk("SYN ");
if (tcph->fin)
printk("FIN ");
/* Max length: 11 "URGP=65535 " */
printk("URGP=%u ", ntohs(tcph->urg_ptr));
if ((info->logflags & IP6T_LOG_TCPOPT)
&& tcph->doff * 4 != sizeof(struct tcphdr)) {
unsigned int i;
/* Max length: 127 "OPT (" 15*4*2chars ") " */
printk("OPT (");
for (i =sizeof(struct tcphdr); i < tcph->doff * 4; i++)
printk("%02X", ((u_int8_t *)tcph)[i]);
printk(") ");
}
break;
}
case IPPROTO_UDP: {
struct udphdr *udph = (struct udphdr *)hdrptr;
/* Max length: 10 "PROTO=UDP " */
printk("PROTO=UDP ");
if (fragment)
break;
/* Max length: 20 "SPT=65535 DPT=65535 " */
printk("SPT=%u DPT=%u LEN=%u ",
ntohs(udph->source), ntohs(udph->dest),
ntohs(udph->len));
break;
}
case IPPROTO_ICMPV6: {
struct icmp6hdr *icmp6h = (struct icmp6hdr *)hdrptr;
/* Max length: 13 "PROTO=ICMPv6 " */
printk("PROTO=ICMPv6 ");
if (fragment)
break;
/* Max length: 18 "TYPE=255 CODE=255 " */
printk("TYPE=%u CODE=%u ", icmp6h->icmp6_type, icmp6h->icmp6_code);
switch (icmp6h->icmp6_type) {
case ICMPV6_ECHO_REQUEST:
case ICMPV6_ECHO_REPLY:
/* Max length: 19 "ID=65535 SEQ=65535 " */
printk("ID=%u SEQ=%u ",
ntohs(icmp6h->icmp6_identifier),
ntohs(icmp6h->icmp6_sequence));
break;
case ICMPV6_MGM_QUERY:
case ICMPV6_MGM_REPORT:
case ICMPV6_MGM_REDUCTION:
break;
case ICMPV6_PARAMPROB:
/* Max length: 17 "POINTER=ffffffff " */
printk("POINTER=%08x ", ntohl(icmp6h->icmp6_pointer));
/* Fall through */
case ICMPV6_DEST_UNREACH:
case ICMPV6_PKT_TOOBIG:
case ICMPV6_TIME_EXCEED:
/* Max length: 3+maxlen */
if (recurse) {
printk("[");
dump_packet(info, (struct ipv6hdr *)(icmp6h + 1), 0);
printk("] ");
}
/* Max length: 10 "MTU=65535 " */
if (icmp6h->icmp6_type == ICMPV6_PKT_TOOBIG)
printk("MTU=%u ", ntohl(icmp6h->icmp6_mtu));
}
break;
}
/* Max length: 10 "PROTO 255 " */
default:
printk("PROTO=%u ", currenthdr);
}
}
static void
ip6t_log_packet(unsigned int hooknum,
const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const struct ip6t_log_info *loginfo,
const char *level_string,
const char *prefix)
{
struct ipv6hdr *ipv6h = skb->nh.ipv6h;
spin_lock_bh(&log_lock);
printk(level_string);
printk("%sIN=%s OUT=%s ",
prefix == NULL ? loginfo->prefix : prefix,
in ? in->name : "",
out ? out->name : "");
if (in && !out) {
/* MAC logging for input chain only. */
printk("MAC=");
if (skb->dev && skb->dev->hard_header_len && skb->mac.raw != (void*)ipv6h) {
if (skb->dev->type != ARPHRD_SIT){
int i;
unsigned char *p = skb->mac.raw;
for (i = 0; i < skb->dev->hard_header_len; i++,p++)
printk("%02x%c", *p,
i==skb->dev->hard_header_len - 1
? ' ':':');
} else {
int i;
unsigned char *p = skb->mac.raw;
if ( p - (ETH_ALEN*2+2) > skb->head ){
p -= (ETH_ALEN+2);
for (i = 0; i < (ETH_ALEN); i++,p++)
printk("%02x%s", *p,
i == ETH_ALEN-1 ? "->" : ":");
p -= (ETH_ALEN*2);
for (i = 0; i < (ETH_ALEN); i++,p++)
printk("%02x%c", *p,
i == ETH_ALEN-1 ? ' ' : ':');
}
if ((skb->dev->addr_len == 4) &&
skb->dev->hard_header_len > 20){
printk("TUNNEL=");
p = skb->mac.raw + 12;
for (i = 0; i < 4; i++,p++)
printk("%3d%s", *p,
i == 3 ? "->" : ".");
for (i = 0; i < 4; i++,p++)
printk("%3d%c", *p,
i == 3 ? ' ' : '.');
}
}
} else
printk(" ");
}
dump_packet(loginfo, ipv6h, 1);
printk("\n");
spin_unlock_bh(&log_lock);
}
static unsigned int
ip6t_log_target(struct sk_buff **pskb,
unsigned int hooknum,
const struct net_device *in,
const struct net_device *out,
const void *targinfo,
void *userinfo)
{
const struct ip6t_log_info *loginfo = targinfo;
char level_string[4] = "< >";
level_string[1] = '0' + (loginfo->level % 8);
ip6t_log_packet(hooknum, *pskb, in, out, loginfo, level_string, NULL);
return IP6T_CONTINUE;
}
static void
ip6t_logfn(unsigned int hooknum,
const struct sk_buff *skb,
const struct net_device *in,
const struct net_device *out,
const char *prefix)
{
struct ip6t_log_info loginfo = {
.level = 0,
.logflags = IP6T_LOG_MASK,
.prefix = ""
};
ip6t_log_packet(hooknum, skb, in, out, &loginfo, KERN_WARNING, prefix);
}
static int ip6t_log_checkentry(const char *tablename,
const struct ip6t_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
const struct ip6t_log_info *loginfo = targinfo;
if (targinfosize != IP6T_ALIGN(sizeof(struct ip6t_log_info))) {
DEBUGP("LOG: targinfosize %u != %u\n",
targinfosize, IP6T_ALIGN(sizeof(struct ip6t_log_info)));
return 0;
}
if (loginfo->level >= 8) {
DEBUGP("LOG: level %u >= 8\n", loginfo->level);
return 0;
}
if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
DEBUGP("LOG: prefix term %i\n",
loginfo->prefix[sizeof(loginfo->prefix)-1]);
return 0;
}
return 1;
}
static struct ip6t_target ip6t_log_reg = {
.name = "LOG",
.target = ip6t_log_target,
.checkentry = ip6t_log_checkentry,
.me = THIS_MODULE,
};
static int __init init(void)
{
if (ip6t_register_target(&ip6t_log_reg))
return -EINVAL;
if (nflog)
nf_log_register(PF_INET6, &ip6t_logfn);
return 0;
}
static void __exit fini(void)
{
if (nflog)
nf_log_unregister(PF_INET6, &ip6t_logfn);
ip6t_unregister_target(&ip6t_log_reg);
}
module_init(init);
module_exit(fini);
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