File: [Development] / linux-2.4-xfs / net / ipv4 / netfilter / ipt_LOG.c (download)
Revision 1.2, Wed Apr 13 15:13:51 2005 UTC (12 years, 6 months ago) by nathans.longdrop.melbourne.sgi.com
Branch: MAIN
CVS Tags: HEAD
Changes since 1.1: +4 -3
lines
Merge up to 2.4.30
Merge of 2.4.x-xfs-melb:linux:22159a by kenmcd.
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/*
* This is a module which is used for logging packets.
*/
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <net/route.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_LOG.h>
#if 0
#define DEBUGP printk
#else
#define DEBUGP(format, args...)
#endif
/* FIXME: move to ip.h like in 2.5 */
struct ahhdr {
__u8 nexthdr;
__u8 hdrlen;
__u16 reserved;
__u32 spi;
__u32 seq_no;
};
struct esphdr {
__u32 spi;
__u32 seq_no;
};
/* Use lock to serialize, so printks don't overlap */
static spinlock_t log_lock = SPIN_LOCK_UNLOCKED;
/* One level of recursion won't kill us */
static void dump_packet(const struct ipt_log_info *info,
struct iphdr *iph, unsigned int len, int recurse)
{
void *protoh = (u_int32_t *)iph + iph->ihl;
unsigned int datalen = len - iph->ihl * 4;
/* Important fields:
* TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
printk("SRC=%u.%u.%u.%u DST=%u.%u.%u.%u ",
NIPQUAD(iph->saddr), NIPQUAD(iph->daddr));
/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
ntohs(iph->tot_len), iph->tos & IPTOS_TOS_MASK,
iph->tos & IPTOS_PREC_MASK, iph->ttl, ntohs(iph->id));
/* Max length: 6 "CE DF MF " */
if (ntohs(iph->frag_off) & IP_CE)
printk("CE ");
if (ntohs(iph->frag_off) & IP_DF)
printk("DF ");
if (ntohs(iph->frag_off) & IP_MF)
printk("MF ");
/* Max length: 11 "FRAG:65535 " */
if (ntohs(iph->frag_off) & IP_OFFSET)
printk("FRAG:%u ", ntohs(iph->frag_off) & IP_OFFSET);
if ((info->logflags & IPT_LOG_IPOPT)
&& iph->ihl * 4 > sizeof(struct iphdr)
&& iph->ihl * 4 <= len) {
unsigned int i;
/* Max length: 127 "OPT (" 15*4*2chars ") " */
printk("OPT (");
for (i = sizeof(struct iphdr); i < iph->ihl * 4; i++)
printk("%02X", ((u_int8_t *)iph)[i]);
printk(") ");
}
switch (iph->protocol) {
case IPPROTO_TCP: {
struct tcphdr *tcph = protoh;
/* Max length: 10 "PROTO=TCP " */
printk("PROTO=TCP ");
if (ntohs(iph->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (datalen < sizeof (*tcph)) {
printk("INCOMPLETE [%u bytes] ", datalen);
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 & IPT_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 & IPT_LOG_TCPOPT)
&& tcph->doff * 4 > sizeof(struct tcphdr)
&& tcph->doff * 4 <= datalen) {
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 = protoh;
/* Max length: 10 "PROTO=UDP " */
printk("PROTO=UDP ");
if (ntohs(iph->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (datalen < sizeof (*udph)) {
printk("INCOMPLETE [%u bytes] ", datalen);
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_ICMP: {
struct icmphdr *icmph = protoh;
static size_t required_len[NR_ICMP_TYPES+1]
= { [ICMP_ECHOREPLY] = 4,
[ICMP_DEST_UNREACH]
= 8 + sizeof(struct iphdr) + 8,
[ICMP_SOURCE_QUENCH]
= 8 + sizeof(struct iphdr) + 8,
[ICMP_REDIRECT]
= 8 + sizeof(struct iphdr) + 8,
[ICMP_ECHO] = 4,
[ICMP_TIME_EXCEEDED]
= 8 + sizeof(struct iphdr) + 8,
[ICMP_PARAMETERPROB]
= 8 + sizeof(struct iphdr) + 8,
[ICMP_TIMESTAMP] = 20,
[ICMP_TIMESTAMPREPLY] = 20,
[ICMP_ADDRESS] = 12,
[ICMP_ADDRESSREPLY] = 12 };
/* Max length: 11 "PROTO=ICMP " */
printk("PROTO=ICMP ");
if (ntohs(iph->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (datalen < 4) {
printk("INCOMPLETE [%u bytes] ", datalen);
break;
}
/* Max length: 18 "TYPE=255 CODE=255 " */
printk("TYPE=%u CODE=%u ", icmph->type, icmph->code);
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (icmph->type <= NR_ICMP_TYPES
&& required_len[icmph->type]
&& datalen < required_len[icmph->type]) {
printk("INCOMPLETE [%u bytes] ", datalen);
break;
}
switch (icmph->type) {
case ICMP_ECHOREPLY:
case ICMP_ECHO:
/* Max length: 19 "ID=65535 SEQ=65535 " */
printk("ID=%u SEQ=%u ",
ntohs(icmph->un.echo.id),
ntohs(icmph->un.echo.sequence));
break;
case ICMP_PARAMETERPROB:
/* Max length: 14 "PARAMETER=255 " */
printk("PARAMETER=%u ",
ntohl(icmph->un.gateway) >> 24);
break;
case ICMP_REDIRECT:
/* Max length: 24 "GATEWAY=255.255.255.255 " */
printk("GATEWAY=%u.%u.%u.%u ", NIPQUAD(icmph->un.gateway));
/* Fall through */
case ICMP_DEST_UNREACH:
case ICMP_SOURCE_QUENCH:
case ICMP_TIME_EXCEEDED:
/* Max length: 3+maxlen */
if (recurse) {
printk("[");
dump_packet(info,
(struct iphdr *)(icmph + 1),
datalen-sizeof(struct icmphdr),
0);
printk("] ");
}
/* Max length: 10 "MTU=65535 " */
if (icmph->type == ICMP_DEST_UNREACH
&& icmph->code == ICMP_FRAG_NEEDED)
printk("MTU=%u ", ntohs(icmph->un.frag.mtu));
}
break;
}
/* Max Length */
case IPPROTO_AH: {
struct ahhdr *ah = protoh;
/* Max length: 9 "PROTO=AH " */
printk("PROTO=AH ");
if (ntohs(iph->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (datalen < sizeof (*ah)) {
printk("INCOMPLETE [%u bytes] ", datalen);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
printk("SPI=0x%x ", ntohl(ah->spi) );
break;
}
case IPPROTO_ESP: {
struct esphdr *esph = protoh;
/* Max length: 10 "PROTO=ESP " */
printk("PROTO=ESP ");
if (ntohs(iph->frag_off) & IP_OFFSET)
break;
/* Max length: 25 "INCOMPLETE [65535 bytes] " */
if (datalen < sizeof (*esph)) {
printk("INCOMPLETE [%u bytes] ", datalen);
break;
}
/* Length: 15 "SPI=0xF1234567 " */
printk("SPI=0x%x ", ntohl(esph->spi) );
break;
}
/* Max length: 10 "PROTO 255 " */
default:
printk("PROTO=%u ", iph->protocol);
}
/* Proto Max log string length */
/* IP: 40+46+6+11+127 = 230 */
/* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */
/* UDP: 10+max(25,20) = 35 */
/* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
/* ESP: 10+max(25)+15 = 50 */
/* AH: 9+max(25)+15 = 49 */
/* unknown: 10 */
/* (ICMP allows recursion one level deep) */
/* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */
/* maxlen = 230+ 91 + 230 + 252 = 803 */
}
static unsigned int
ipt_log_target(struct sk_buff **pskb,
unsigned int hooknum,
const struct net_device *in,
const struct net_device *out,
const void *targinfo,
void *userinfo)
{
struct iphdr *iph = (*pskb)->nh.iph;
const struct ipt_log_info *loginfo = targinfo;
char level_string[4] = "< >";
level_string[1] = '0' + (loginfo->level % 8);
spin_lock_bh(&log_lock);
printk(level_string);
printk("%sIN=%s OUT=%s ",
loginfo->prefix,
in ? in->name : "",
out ? out->name : "");
if (in && !out) {
/* MAC logging for input chain only. */
printk("MAC=");
if ((*pskb)->dev && (*pskb)->dev->hard_header_len && (*pskb)->mac.raw != (void*)iph) {
int i;
unsigned char *p = (*pskb)->mac.raw;
for (i = 0; i < (*pskb)->dev->hard_header_len; i++,p++)
printk("%02x%c", *p,
i==(*pskb)->dev->hard_header_len - 1
? ' ':':');
} else
printk(" ");
}
dump_packet(loginfo, iph, (*pskb)->len, 1);
printk("\n");
spin_unlock_bh(&log_lock);
return IPT_CONTINUE;
}
static int ipt_log_checkentry(const char *tablename,
const struct ipt_entry *e,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
const struct ipt_log_info *loginfo = targinfo;
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_log_info))) {
DEBUGP("LOG: targinfosize %u != %u\n",
targinfosize, IPT_ALIGN(sizeof(struct ipt_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 ipt_target ipt_log_reg
= { { NULL, NULL }, "LOG", ipt_log_target, ipt_log_checkentry, NULL,
THIS_MODULE };
static int __init init(void)
{
if (ipt_register_target(&ipt_log_reg))
return -EINVAL;
return 0;
}
static void __exit fini(void)
{
ipt_unregister_target(&ipt_log_reg);
}
module_init(init);
module_exit(fini);
MODULE_LICENSE("GPL");
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