[net-next-2.6.git] / net / ipv4 / netfilter / ipt_LOG.c

/*
 * This is a module which is used for logging packets.
 */

/* (C) 1999-2001 Paul `Rusty' Russell
 * (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.
 */
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <net/icmp.h>
#include <net/udp.h>
#include <net/tcp.h>
#include <net/route.h>

#include <linux/netfilter.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter_ipv4/ipt_LOG.h>
#include <net/netfilter/nf_log.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
MODULE_DESCRIPTION("Xtables: IPv4 packet logging to syslog");

/* Use lock to serialize, so printks don't overlap */
static DEFINE_SPINLOCK(log_lock);

/* One level of recursion won't kill us */
static void dump_packet(const struct nf_loginfo *info,
			const struct sk_buff *skb,
			unsigned int iphoff)
{
	struct iphdr _iph;
	const struct iphdr *ih;
	unsigned int logflags;

	if (info->type == NF_LOG_TYPE_LOG)
		logflags = info->u.log.logflags;
	else
		logflags = NF_LOG_MASK;

	ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
	if (ih == NULL) {
		printk("TRUNCATED");
		return;
	}

	/* 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=%pI4 DST=%pI4 ",
	       &ih->saddr, &ih->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(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
	       ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));

	/* Max length: 6 "CE DF MF " */
	if (ntohs(ih->frag_off) & IP_CE)
		printk("CE ");
	if (ntohs(ih->frag_off) & IP_DF)
		printk("DF ");
	if (ntohs(ih->frag_off) & IP_MF)
		printk("MF ");

	/* Max length: 11 "FRAG:65535 " */
	if (ntohs(ih->frag_off) & IP_OFFSET)
		printk("FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);

	if ((logflags & IPT_LOG_IPOPT) &&
	    ih->ihl * 4 > sizeof(struct iphdr)) {
		const unsigned char *op;
		unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
		unsigned int i, optsize;

		optsize = ih->ihl * 4 - sizeof(struct iphdr);
		op = skb_header_pointer(skb, iphoff+sizeof(_iph),
					optsize, _opt);
		if (op == NULL) {
			printk("TRUNCATED");
			return;
		}

		/* Max length: 127 "OPT (" 15*4*2chars ") " */
		printk("OPT (");
		for (i = 0; i < optsize; i++)
			printk("%02X", op[i]);
		printk(") ");
	}

	switch (ih->protocol) {
	case IPPROTO_TCP: {
		struct tcphdr _tcph;
		const struct tcphdr *th;

		/* Max length: 10 "PROTO=TCP " */
		printk("PROTO=TCP ");

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
		th = skb_header_pointer(skb, iphoff + ih->ihl * 4,
					sizeof(_tcph), &_tcph);
		if (th == NULL) {
			printk("INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Max length: 20 "SPT=65535 DPT=65535 " */
		printk("SPT=%u DPT=%u ",
		       ntohs(th->source), ntohs(th->dest));
		/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
		if (logflags & IPT_LOG_TCPSEQ)
			printk("SEQ=%u ACK=%u ",
			       ntohl(th->seq), ntohl(th->ack_seq));
		/* Max length: 13 "WINDOW=65535 " */
		printk("WINDOW=%u ", ntohs(th->window));
		/* Max length: 9 "RES=0x3F " */
		printk("RES=0x%02x ", (u8)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
		/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
		if (th->cwr)
			printk("CWR ");
		if (th->ece)
			printk("ECE ");
		if (th->urg)
			printk("URG ");
		if (th->ack)
			printk("ACK ");
		if (th->psh)
			printk("PSH ");
		if (th->rst)
			printk("RST ");
		if (th->syn)
			printk("SYN ");
		if (th->fin)
			printk("FIN ");
		/* Max length: 11 "URGP=65535 " */
		printk("URGP=%u ", ntohs(th->urg_ptr));

		if ((logflags & IPT_LOG_TCPOPT) &&
		    th->doff * 4 > sizeof(struct tcphdr)) {
			unsigned char _opt[4 * 15 - sizeof(struct tcphdr)];
			const unsigned char *op;
			unsigned int i, optsize;

			optsize = th->doff * 4 - sizeof(struct tcphdr);
			op = skb_header_pointer(skb,
						iphoff+ih->ihl*4+sizeof(_tcph),
						optsize, _opt);
			if (op == NULL) {
				printk("TRUNCATED");
				return;
			}

			/* Max length: 127 "OPT (" 15*4*2chars ") " */
			printk("OPT (");
			for (i = 0; i < optsize; i++)
				printk("%02X", op[i]);
			printk(") ");
		}
		break;
	}
	case IPPROTO_UDP:
	case IPPROTO_UDPLITE: {
		struct udphdr _udph;
		const struct udphdr *uh;

		if (ih->protocol == IPPROTO_UDP)
			/* Max length: 10 "PROTO=UDP "     */
			printk("PROTO=UDP " );
		else	/* Max length: 14 "PROTO=UDPLITE " */
			printk("PROTO=UDPLITE ");

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
		uh = skb_header_pointer(skb, iphoff+ih->ihl*4,
					sizeof(_udph), &_udph);
		if (uh == NULL) {
			printk("INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Max length: 20 "SPT=65535 DPT=65535 " */
		printk("SPT=%u DPT=%u LEN=%u ",
		       ntohs(uh->source), ntohs(uh->dest),
		       ntohs(uh->len));
		break;
	}
	case IPPROTO_ICMP: {
		struct icmphdr _icmph;
		const struct icmphdr *ich;
		static const size_t required_len[NR_ICMP_TYPES+1]
			= { [ICMP_ECHOREPLY] = 4,
			    [ICMP_DEST_UNREACH]
			    = 8 + sizeof(struct iphdr),
			    [ICMP_SOURCE_QUENCH]
			    = 8 + sizeof(struct iphdr),
			    [ICMP_REDIRECT]
			    = 8 + sizeof(struct iphdr),
			    [ICMP_ECHO] = 4,
			    [ICMP_TIME_EXCEEDED]
			    = 8 + sizeof(struct iphdr),
			    [ICMP_PARAMETERPROB]
			    = 8 + sizeof(struct iphdr),
			    [ICMP_TIMESTAMP] = 20,
			    [ICMP_TIMESTAMPREPLY] = 20,
			    [ICMP_ADDRESS] = 12,
			    [ICMP_ADDRESSREPLY] = 12 };

		/* Max length: 11 "PROTO=ICMP " */
		printk("PROTO=ICMP ");

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
		ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
					 sizeof(_icmph), &_icmph);
		if (ich == NULL) {
			printk("INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Max length: 18 "TYPE=255 CODE=255 " */
		printk("TYPE=%u CODE=%u ", ich->type, ich->code);

		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
		if (ich->type <= NR_ICMP_TYPES &&
		    required_len[ich->type] &&
		    skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
			printk("INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		switch (ich->type) {
		case ICMP_ECHOREPLY:
		case ICMP_ECHO:
			/* Max length: 19 "ID=65535 SEQ=65535 " */
			printk("ID=%u SEQ=%u ",
			       ntohs(ich->un.echo.id),
			       ntohs(ich->un.echo.sequence));
			break;

		case ICMP_PARAMETERPROB:
			/* Max length: 14 "PARAMETER=255 " */
			printk("PARAMETER=%u ",
			       ntohl(ich->un.gateway) >> 24);
			break;
		case ICMP_REDIRECT:
			/* Max length: 24 "GATEWAY=255.255.255.255 " */
			printk("GATEWAY=%pI4 ", &ich->un.gateway);
			/* Fall through */
		case ICMP_DEST_UNREACH:
		case ICMP_SOURCE_QUENCH:
		case ICMP_TIME_EXCEEDED:
			/* Max length: 3+maxlen */
			if (!iphoff) { /* Only recurse once. */
				printk("[");
				dump_packet(info, skb,
					    iphoff + ih->ihl*4+sizeof(_icmph));
				printk("] ");
			}

			/* Max length: 10 "MTU=65535 " */
			if (ich->type == ICMP_DEST_UNREACH &&
			    ich->code == ICMP_FRAG_NEEDED)
				printk("MTU=%u ", ntohs(ich->un.frag.mtu));
		}
		break;
	}
	/* Max Length */
	case IPPROTO_AH: {
		struct ip_auth_hdr _ahdr;
		const struct ip_auth_hdr *ah;

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		/* Max length: 9 "PROTO=AH " */
		printk("PROTO=AH ");

		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
		ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
					sizeof(_ahdr), &_ahdr);
		if (ah == NULL) {
			printk("INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Length: 15 "SPI=0xF1234567 " */
		printk("SPI=0x%x ", ntohl(ah->spi));
		break;
	}
	case IPPROTO_ESP: {
		struct ip_esp_hdr _esph;
		const struct ip_esp_hdr *eh;

		/* Max length: 10 "PROTO=ESP " */
		printk("PROTO=ESP ");

		if (ntohs(ih->frag_off) & IP_OFFSET)
			break;

		/* Max length: 25 "INCOMPLETE [65535 bytes] " */
		eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
					sizeof(_esph), &_esph);
		if (eh == NULL) {
			printk("INCOMPLETE [%u bytes] ",
			       skb->len - iphoff - ih->ihl*4);
			break;
		}

		/* Length: 15 "SPI=0xF1234567 " */
		printk("SPI=0x%x ", ntohl(eh->spi));
		break;
	}
	/* Max length: 10 "PROTO 255 " */
	default:
		printk("PROTO=%u ", ih->protocol);
	}

	/* Max length: 15 "UID=4294967295 " */
	if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
		read_lock_bh(&skb->sk->sk_callback_lock);
		if (skb->sk->sk_socket && skb->sk->sk_socket->file)
			printk("UID=%u GID=%u ",
				skb->sk->sk_socket->file->f_cred->fsuid,
				skb->sk->sk_socket->file->f_cred->fsgid);
		read_unlock_bh(&skb->sk->sk_callback_lock);
	}

	/* Max length: 16 "MARK=0xFFFFFFFF " */
	if (!iphoff && skb->mark)
		printk("MARK=0x%x ", skb->mark);

	/* 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 */
	/* UDPLITE: 14+max(25,20) = 39 */
	/* 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 struct nf_loginfo default_loginfo = {
	.type	= NF_LOG_TYPE_LOG,
	.u = {
		.log = {
			.level    = 5,
			.logflags = NF_LOG_MASK,
		},
	},
};

static void
ipt_log_packet(u_int8_t pf,
	       unsigned int hooknum,
	       const struct sk_buff *skb,
	       const struct net_device *in,
	       const struct net_device *out,
	       const struct nf_loginfo *loginfo,
	       const char *prefix)
{
	if (!loginfo)
		loginfo = &default_loginfo;

	spin_lock_bh(&log_lock);
	printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
	       prefix,
	       in ? in->name : "",
	       out ? out->name : "");
#ifdef CONFIG_BRIDGE_NETFILTER
	if (skb->nf_bridge) {
		const struct net_device *physindev;
		const struct net_device *physoutdev;

		physindev = skb->nf_bridge->physindev;
		if (physindev && in != physindev)
			printk("PHYSIN=%s ", physindev->name);
		physoutdev = skb->nf_bridge->physoutdev;
		if (physoutdev && out != physoutdev)
			printk("PHYSOUT=%s ", physoutdev->name);
	}
#endif

	if (in && !out) {
		/* MAC logging for input chain only. */
		printk("MAC=");
		if (skb->dev && skb->dev->hard_header_len &&
		    skb->mac_header != skb->network_header) {
			int i;
			const unsigned char *p = skb_mac_header(skb);
			for (i = 0; i < skb->dev->hard_header_len; i++,p++)
				printk("%02x%c", *p,
				       i==skb->dev->hard_header_len - 1
				       ? ' ':':');
		} else
			printk(" ");
	}

	dump_packet(loginfo, skb, 0);
	printk("\n");
	spin_unlock_bh(&log_lock);
}

static unsigned int
log_tg(struct sk_buff *skb, const struct xt_action_param *par)
{
	const struct ipt_log_info *loginfo = par->targinfo;
	struct nf_loginfo li;

	li.type = NF_LOG_TYPE_LOG;
	li.u.log.level = loginfo->level;
	li.u.log.logflags = loginfo->logflags;

	ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, par->out, &li,
		       loginfo->prefix);
	return XT_CONTINUE;
}

static int log_tg_check(const struct xt_tgchk_param *par)
{
	const struct ipt_log_info *loginfo = par->targinfo;

	if (loginfo->level >= 8) {
		pr_debug("level %u >= 8\n", loginfo->level);
		return -EINVAL;
	}
	if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
		pr_debug("prefix is not null-terminated\n");
		return -EINVAL;
	}
	return 0;
}

static struct xt_target log_tg_reg __read_mostly = {
	.name		= "LOG",
	.family		= NFPROTO_IPV4,
	.target		= log_tg,
	.targetsize	= sizeof(struct ipt_log_info),
	.checkentry	= log_tg_check,
	.me		= THIS_MODULE,
};

static struct nf_logger ipt_log_logger __read_mostly = {
	.name		= "ipt_LOG",
	.logfn		= &ipt_log_packet,
	.me		= THIS_MODULE,
};

static int __init log_tg_init(void)
{
	int ret;

	ret = xt_register_target(&log_tg_reg);
	if (ret < 0)
		return ret;
	nf_log_register(NFPROTO_IPV4, &ipt_log_logger);
	return 0;
}

static void __exit log_tg_exit(void)
{
	nf_log_unregister(&ipt_log_logger);
	xt_unregister_target(&log_tg_reg);
}

module_init(log_tg_init);
module_exit(log_tg_exit);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This is a module which is used for logging packets.
	3	*/
	4
	5	/* (C) 1999-2001 Paul `Rusty' Russell
	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	*/
ff67e4e4	12	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
1da177e4 LT	13	#include <linux/module.h>
	14	#include <linux/spinlock.h>
	15	#include <linux/skbuff.h>
	16	#include <linux/ip.h>
	17	#include <net/icmp.h>
	18	#include <net/udp.h>
	19	#include <net/tcp.h>
	20	#include <net/route.h>
	21
	22	#include <linux/netfilter.h>
6709dbbb	23	#include <linux/netfilter/x_tables.h>
1da177e4	24	#include <linux/netfilter_ipv4/ipt_LOG.h>
f01ffbd6	25	#include <net/netfilter/nf_log.h>
1da177e4 LT	26
	27	MODULE_LICENSE("GPL");
	28	MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
2ae15b64	29	MODULE_DESCRIPTION("Xtables: IPv4 packet logging to syslog");
1da177e4	30
1da177e4 LT	31	/* Use lock to serialize, so printks don't overlap */
	32	static DEFINE_SPINLOCK(log_lock);
	33
	34	/* One level of recursion won't kill us */
608c8e4f	35	static void dump_packet(const struct nf_loginfo *info,
1da177e4 LT	36	const struct sk_buff *skb,
	37	unsigned int iphoff)
	38	{
a47362a2 JE	39	struct iphdr _iph;
a47362a2 JE	40	const struct iphdr *ih;
608c8e4f HW	41	unsigned int logflags;
	42
	43	if (info->type == NF_LOG_TYPE_LOG)
	44	logflags = info->u.log.logflags;
	45	else
	46	logflags = NF_LOG_MASK;
1da177e4 LT	47
	48	ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph);
	49	if (ih == NULL) {
	50	printk("TRUNCATED");
	51	return;
	52	}
	53
	54	/* Important fields:
	55	* TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */
	56	/* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */
cffee385 HH	57	printk("SRC=%pI4 DST=%pI4 ",
cffee385 HH	58	&ih->saddr, &ih->daddr);
1da177e4 LT	59
	60	/* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */
	61	printk("LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ",
	62	ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK,
	63	ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id));
	64
	65	/* Max length: 6 "CE DF MF " */
	66	if (ntohs(ih->frag_off) & IP_CE)
	67	printk("CE ");
	68	if (ntohs(ih->frag_off) & IP_DF)
	69	printk("DF ");
	70	if (ntohs(ih->frag_off) & IP_MF)
	71	printk("MF ");
	72
	73	/* Max length: 11 "FRAG:65535 " */
	74	if (ntohs(ih->frag_off) & IP_OFFSET)
	75	printk("FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET);
	76
3666ed1c JP	77	if ((logflags & IPT_LOG_IPOPT) &&
3666ed1c JP	78	ih->ihl * 4 > sizeof(struct iphdr)) {
3cf93c96 JE	79	const unsigned char *op;
3cf93c96 JE	80	unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
1da177e4 LT	81	unsigned int i, optsize;
	82
	83	optsize = ih->ihl * 4 - sizeof(struct iphdr);
	84	op = skb_header_pointer(skb, iphoff+sizeof(_iph),
	85	optsize, _opt);
	86	if (op == NULL) {
	87	printk("TRUNCATED");
	88	return;
	89	}
	90
	91	/* Max length: 127 "OPT (" 1542chars ") " */
	92	printk("OPT (");
	93	for (i = 0; i < optsize; i++)
	94	printk("%02X", op[i]);
	95	printk(") ");
	96	}
	97
	98	switch (ih->protocol) {
	99	case IPPROTO_TCP: {
a47362a2 JE	100	struct tcphdr _tcph;
a47362a2 JE	101	const struct tcphdr *th;
1da177e4 LT	102
	103	/* Max length: 10 "PROTO=TCP " */
	104	printk("PROTO=TCP ");
	105
	106	if (ntohs(ih->frag_off) & IP_OFFSET)
	107	break;
	108
	109	/* Max length: 25 "INCOMPLETE [65535 bytes] " */
	110	th = skb_header_pointer(skb, iphoff + ih->ihl * 4,
	111	sizeof(_tcph), &_tcph);
	112	if (th == NULL) {
	113	printk("INCOMPLETE [%u bytes] ",
	114	skb->len - iphoff - ih->ihl*4);
	115	break;
	116	}
	117
	118	/* Max length: 20 "SPT=65535 DPT=65535 " */
	119	printk("SPT=%u DPT=%u ",
	120	ntohs(th->source), ntohs(th->dest));
	121	/* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */
608c8e4f	122	if (logflags & IPT_LOG_TCPSEQ)
1da177e4 LT	123	printk("SEQ=%u ACK=%u ",
	124	ntohl(th->seq), ntohl(th->ack_seq));
	125	/* Max length: 13 "WINDOW=65535 " */
	126	printk("WINDOW=%u ", ntohs(th->window));
	127	/* Max length: 9 "RES=0x3F " */
	128	printk("RES=0x%02x ", (u8)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22));
	129	/* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */
	130	if (th->cwr)
	131	printk("CWR ");
	132	if (th->ece)
	133	printk("ECE ");
	134	if (th->urg)
	135	printk("URG ");
	136	if (th->ack)
	137	printk("ACK ");
	138	if (th->psh)
	139	printk("PSH ");
	140	if (th->rst)
	141	printk("RST ");
	142	if (th->syn)
	143	printk("SYN ");
	144	if (th->fin)
	145	printk("FIN ");
	146	/* Max length: 11 "URGP=65535 " */
	147	printk("URGP=%u ", ntohs(th->urg_ptr));
	148
3666ed1c JP	149	if ((logflags & IPT_LOG_TCPOPT) &&
3666ed1c JP	150	th->doff * 4 > sizeof(struct tcphdr)) {
1da177e4	151	unsigned char _opt[4 * 15 - sizeof(struct tcphdr)];
a47362a2	152	const unsigned char *op;
1da177e4 LT	153	unsigned int i, optsize;
	154
	155	optsize = th->doff * 4 - sizeof(struct tcphdr);
	156	op = skb_header_pointer(skb,
	157	iphoff+ih->ihl*4+sizeof(_tcph),
	158	optsize, _opt);
	159	if (op == NULL) {
	160	printk("TRUNCATED");
	161	return;
	162	}
	163
	164	/* Max length: 127 "OPT (" 1542chars ") " */
	165	printk("OPT (");
	166	for (i = 0; i < optsize; i++)
	167	printk("%02X", op[i]);
	168	printk(") ");
	169	}
	170	break;
	171	}
ba4e58ec GR	172	case IPPROTO_UDP:
ba4e58ec GR	173	case IPPROTO_UDPLITE: {
a47362a2 JE	174	struct udphdr _udph;
a47362a2 JE	175	const struct udphdr *uh;
1da177e4	176
ba4e58ec GR	177	if (ih->protocol == IPPROTO_UDP)
	178	/* Max length: 10 "PROTO=UDP " */
	179	printk("PROTO=UDP " );
	180	else /* Max length: 14 "PROTO=UDPLITE " */
	181	printk("PROTO=UDPLITE ");
1da177e4 LT	182
	183	if (ntohs(ih->frag_off) & IP_OFFSET)
	184	break;
	185
	186	/* Max length: 25 "INCOMPLETE [65535 bytes] " */
	187	uh = skb_header_pointer(skb, iphoff+ih->ihl*4,
	188	sizeof(_udph), &_udph);
	189	if (uh == NULL) {
	190	printk("INCOMPLETE [%u bytes] ",
	191	skb->len - iphoff - ih->ihl*4);
	192	break;
	193	}
	194
	195	/* Max length: 20 "SPT=65535 DPT=65535 " */
	196	printk("SPT=%u DPT=%u LEN=%u ",
	197	ntohs(uh->source), ntohs(uh->dest),
	198	ntohs(uh->len));
	199	break;
	200	}
	201	case IPPROTO_ICMP: {
a47362a2 JE	202	struct icmphdr _icmph;
a47362a2 JE	203	const struct icmphdr *ich;
9b5b5cff	204	static const size_t required_len[NR_ICMP_TYPES+1]
1da177e4 LT	205	= { [ICMP_ECHOREPLY] = 4,
	206	[ICMP_DEST_UNREACH]
	207	= 8 + sizeof(struct iphdr),
	208	[ICMP_SOURCE_QUENCH]
	209	= 8 + sizeof(struct iphdr),
	210	[ICMP_REDIRECT]
	211	= 8 + sizeof(struct iphdr),
	212	[ICMP_ECHO] = 4,
	213	[ICMP_TIME_EXCEEDED]
	214	= 8 + sizeof(struct iphdr),
	215	[ICMP_PARAMETERPROB]
	216	= 8 + sizeof(struct iphdr),
	217	[ICMP_TIMESTAMP] = 20,
	218	[ICMP_TIMESTAMPREPLY] = 20,
	219	[ICMP_ADDRESS] = 12,
	220	[ICMP_ADDRESSREPLY] = 12 };
	221
	222	/* Max length: 11 "PROTO=ICMP " */
	223	printk("PROTO=ICMP ");
	224
	225	if (ntohs(ih->frag_off) & IP_OFFSET)
	226	break;
	227
	228	/* Max length: 25 "INCOMPLETE [65535 bytes] " */
	229	ich = skb_header_pointer(skb, iphoff + ih->ihl * 4,
	230	sizeof(_icmph), &_icmph);
	231	if (ich == NULL) {
	232	printk("INCOMPLETE [%u bytes] ",
	233	skb->len - iphoff - ih->ihl*4);
	234	break;
	235	}
	236
	237	/* Max length: 18 "TYPE=255 CODE=255 " */
	238	printk("TYPE=%u CODE=%u ", ich->type, ich->code);
	239
	240	/* Max length: 25 "INCOMPLETE [65535 bytes] " */
3666ed1c JP	241	if (ich->type <= NR_ICMP_TYPES &&
	242	required_len[ich->type] &&
	243	skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) {
1da177e4 LT	244	printk("INCOMPLETE [%u bytes] ",
	245	skb->len - iphoff - ih->ihl*4);
	246	break;
	247	}
	248
	249	switch (ich->type) {
	250	case ICMP_ECHOREPLY:
	251	case ICMP_ECHO:
	252	/* Max length: 19 "ID=65535 SEQ=65535 " */
	253	printk("ID=%u SEQ=%u ",
	254	ntohs(ich->un.echo.id),
	255	ntohs(ich->un.echo.sequence));
	256	break;
	257
	258	case ICMP_PARAMETERPROB:
	259	/* Max length: 14 "PARAMETER=255 " */
	260	printk("PARAMETER=%u ",
	261	ntohl(ich->un.gateway) >> 24);
	262	break;
	263	case ICMP_REDIRECT:
	264	/* Max length: 24 "GATEWAY=255.255.255.255 " */
cffee385	265	printk("GATEWAY=%pI4 ", &ich->un.gateway);
1da177e4 LT	266	/* Fall through */
	267	case ICMP_DEST_UNREACH:
	268	case ICMP_SOURCE_QUENCH:
	269	case ICMP_TIME_EXCEEDED:
	270	/* Max length: 3+maxlen */
	271	if (!iphoff) { /* Only recurse once. */
	272	printk("[");
	273	dump_packet(info, skb,
	274	iphoff + ih->ihl*4+sizeof(_icmph));
	275	printk("] ");
	276	}
	277
	278	/* Max length: 10 "MTU=65535 " */
3666ed1c JP	279	if (ich->type == ICMP_DEST_UNREACH &&
3666ed1c JP	280	ich->code == ICMP_FRAG_NEEDED)
1da177e4 LT	281	printk("MTU=%u ", ntohs(ich->un.frag.mtu));
	282	}
	283	break;
	284	}
	285	/* Max Length */
	286	case IPPROTO_AH: {
a47362a2 JE	287	struct ip_auth_hdr _ahdr;
a47362a2 JE	288	const struct ip_auth_hdr *ah;
1da177e4 LT	289
	290	if (ntohs(ih->frag_off) & IP_OFFSET)
	291	break;
e905a9ed	292
1da177e4 LT	293	/* Max length: 9 "PROTO=AH " */
	294	printk("PROTO=AH ");
	295
	296	/* Max length: 25 "INCOMPLETE [65535 bytes] " */
	297	ah = skb_header_pointer(skb, iphoff+ih->ihl*4,
	298	sizeof(_ahdr), &_ahdr);
	299	if (ah == NULL) {
	300	printk("INCOMPLETE [%u bytes] ",
	301	skb->len - iphoff - ih->ihl*4);
	302	break;
	303	}
	304
	305	/* Length: 15 "SPI=0xF1234567 " */
	306	printk("SPI=0x%x ", ntohl(ah->spi));
	307	break;
	308	}
	309	case IPPROTO_ESP: {
a47362a2 JE	310	struct ip_esp_hdr _esph;
a47362a2 JE	311	const struct ip_esp_hdr *eh;
1da177e4 LT	312
	313	/* Max length: 10 "PROTO=ESP " */
	314	printk("PROTO=ESP ");
	315
	316	if (ntohs(ih->frag_off) & IP_OFFSET)
	317	break;
	318
	319	/* Max length: 25 "INCOMPLETE [65535 bytes] " */
	320	eh = skb_header_pointer(skb, iphoff+ih->ihl*4,
	321	sizeof(_esph), &_esph);
	322	if (eh == NULL) {
	323	printk("INCOMPLETE [%u bytes] ",
	324	skb->len - iphoff - ih->ihl*4);
	325	break;
	326	}
	327
	328	/* Length: 15 "SPI=0xF1234567 " */
	329	printk("SPI=0x%x ", ntohl(eh->spi));
	330	break;
	331	}
	332	/* Max length: 10 "PROTO 255 " */
	333	default:
	334	printk("PROTO=%u ", ih->protocol);
	335	}
	336
	337	/* Max length: 15 "UID=4294967295 " */
e905a9ed	338	if ((logflags & IPT_LOG_UID) && !iphoff && skb->sk) {
1da177e4 LT	339	read_lock_bh(&skb->sk->sk_callback_lock);
1da177e4 LT	340	if (skb->sk->sk_socket && skb->sk->sk_socket->file)
36e2a1b0	341	printk("UID=%u GID=%u ",
d76b0d9b DH	342	skb->sk->sk_socket->file->f_cred->fsuid,
d76b0d9b DH	343	skb->sk->sk_socket->file->f_cred->fsgid);
1da177e4 LT	344	read_unlock_bh(&skb->sk->sk_callback_lock);
	345	}
	346
36e2a1b0 PM	347	/* Max length: 16 "MARK=0xFFFFFFFF " */
	348	if (!iphoff && skb->mark)
	349	printk("MARK=0x%x ", skb->mark);
	350
1da177e4 LT	351	/* Proto Max log string length */
	352	/* IP: 40+46+6+11+127 = 230 */
	353	/* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */
	354	/* UDP: 10+max(25,20) = 35 */
ba4e58ec	355	/* UDPLITE: 14+max(25,20) = 39 */
1da177e4 LT	356	/* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */
	357	/* ESP: 10+max(25)+15 = 50 */
	358	/* AH: 9+max(25)+15 = 49 */
	359	/* unknown: 10 */
	360
	361	/* (ICMP allows recursion one level deep) */
	362	/* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */
	363	/* maxlen = 230+ 91 + 230 + 252 = 803 */
	364	}
	365
d127e94a	366	static struct nf_loginfo default_loginfo = {
608c8e4f HW	367	.type = NF_LOG_TYPE_LOG,
	368	.u = {
	369	.log = {
f0d57a54	370	.level = 5,
608c8e4f HW	371	.logflags = NF_LOG_MASK,
	372	},
	373	},
	374	};
	375
1da177e4	376	static void
76108cea	377	ipt_log_packet(u_int8_t pf,
608c8e4f	378	unsigned int hooknum,
1da177e4 LT	379	const struct sk_buff *skb,
	380	const struct net_device *in,
	381	const struct net_device *out,
608c8e4f	382	const struct nf_loginfo *loginfo,
1da177e4 LT	383	const char *prefix)
1da177e4 LT	384	{
608c8e4f HW	385	if (!loginfo)
	386	loginfo = &default_loginfo;
	387
1da177e4	388	spin_lock_bh(&log_lock);
608c8e4f HW	389	printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level,
608c8e4f HW	390	prefix,
1da177e4 LT	391	in ? in->name : "",
	392	out ? out->name : "");
	393	#ifdef CONFIG_BRIDGE_NETFILTER
	394	if (skb->nf_bridge) {
a47362a2 JE	395	const struct net_device *physindev;
a47362a2 JE	396	const struct net_device *physoutdev;
1da177e4	397
a47362a2	398	physindev = skb->nf_bridge->physindev;
1da177e4 LT	399	if (physindev && in != physindev)
1da177e4 LT	400	printk("PHYSIN=%s ", physindev->name);
a47362a2	401	physoutdev = skb->nf_bridge->physoutdev;
1da177e4 LT	402	if (physoutdev && out != physoutdev)
	403	printk("PHYSOUT=%s ", physoutdev->name);
	404	}
	405	#endif
	406
	407	if (in && !out) {
	408	/* MAC logging for input chain only. */
	409	printk("MAC=");
3666ed1c JP	410	if (skb->dev && skb->dev->hard_header_len &&
3666ed1c JP	411	skb->mac_header != skb->network_header) {
1da177e4	412	int i;
98e399f8	413	const unsigned char *p = skb_mac_header(skb);
1da177e4 LT	414	for (i = 0; i < skb->dev->hard_header_len; i++,p++)
	415	printk("%02x%c", *p,
	416	i==skb->dev->hard_header_len - 1
	417	? ' ':':');
	418	} else
	419	printk(" ");
	420	}
	421
	422	dump_packet(loginfo, skb, 0);
	423	printk("\n");
	424	spin_unlock_bh(&log_lock);
	425	}
	426
	427	static unsigned int
4b560b44	428	log_tg(struct sk_buff skb, const struct xt_action_param par)
1da177e4	429	{
7eb35586	430	const struct ipt_log_info *loginfo = par->targinfo;
608c8e4f	431	struct nf_loginfo li;
1da177e4	432
608c8e4f HW	433	li.type = NF_LOG_TYPE_LOG;
	434	li.u.log.level = loginfo->level;
	435	li.u.log.logflags = loginfo->logflags;
1da177e4	436
7eb35586	437	ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, par->out, &li,
e905a9ed	438	loginfo->prefix);
6709dbbb	439	return XT_CONTINUE;
1da177e4 LT	440	}
1da177e4 LT	441
135367b8	442	static int log_tg_check(const struct xt_tgchk_param *par)
1da177e4	443	{
af5d6dc2	444	const struct ipt_log_info *loginfo = par->targinfo;
1da177e4	445
1da177e4	446	if (loginfo->level >= 8) {
ff67e4e4	447	pr_debug("level %u >= 8\n", loginfo->level);
d6b00a53	448	return -EINVAL;
1da177e4	449	}
1da177e4	450	if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') {
ff67e4e4	451	pr_debug("prefix is not null-terminated\n");
d6b00a53	452	return -EINVAL;
1da177e4	453	}
d6b00a53	454	return 0;
1da177e4 LT	455	}
1da177e4 LT	456
d3c5ee6d	457	static struct xt_target log_tg_reg __read_mostly = {
1da177e4	458	.name = "LOG",
ee999d8b	459	.family = NFPROTO_IPV4,
d3c5ee6d	460	.target = log_tg,
1d5cd909	461	.targetsize = sizeof(struct ipt_log_info),
d3c5ee6d	462	.checkentry = log_tg_check,
1da177e4 LT	463	.me = THIS_MODULE,
	464	};
	465
ca735b3a	466	static struct nf_logger ipt_log_logger __read_mostly = {
608c8e4f HW	467	.name = "ipt_LOG",
	468	.logfn = &ipt_log_packet,
	469	.me = THIS_MODULE,
	470	};
	471
d3c5ee6d	472	static int __init log_tg_init(void)
1da177e4	473	{
e1fd0586 JE	474	int ret;
e1fd0586 JE	475
d3c5ee6d	476	ret = xt_register_target(&log_tg_reg);
e1fd0586 JE	477	if (ret < 0)
e1fd0586 JE	478	return ret;
ee999d8b	479	nf_log_register(NFPROTO_IPV4, &ipt_log_logger);
7e2acc7e	480	return 0;
1da177e4 LT	481	}
1da177e4 LT	482
d3c5ee6d	483	static void __exit log_tg_exit(void)
1da177e4	484	{
e92ad99c	485	nf_log_unregister(&ipt_log_logger);
d3c5ee6d	486	xt_unregister_target(&log_tg_reg);
1da177e4 LT	487	}
1da177e4 LT	488
d3c5ee6d JE	489	module_init(log_tg_init);
d3c5ee6d JE	490	module_exit(log_tg_exit);