--- /dev/null	Tue May  5 22:32:27 1998
+++ linux/net/ipv6/netfilter/ip6t_LOG.c	Wed Feb 14 01:36:32 2001
@@ -0,0 +1,347 @@
+/*
+ * This is a module which is used for logging packets.
+ */
+#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_ipv6/ip6_tables.h>
+
+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
+
+#define NIP6(addr) \
+	ntohs((addr).s6_addr16[0]), \
+	ntohs((addr).s6_addr16[1]), \
+	ntohs((addr).s6_addr16[2]), \
+	ntohs((addr).s6_addr16[3]), \
+	ntohs((addr).s6_addr16[4]), \
+	ntohs((addr).s6_addr16[5]), \
+	ntohs((addr).s6_addr16[6]), \
+	ntohs((addr).s6_addr16[7])
+
+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=%u 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 & __constant_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: 36 "URG ACK PSH RST SYN FIN " */
+		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 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)
+{
+	struct ipv6hdr *ipv6h = (*pskb)->nh.ipv6h;
+	const struct ip6t_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*)ipv6h) {
+			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, ipv6h, 1);
+	printk("\n");
+	spin_unlock_bh(&log_lock);
+
+	return IP6T_CONTINUE;
+}
+
+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
+= { { NULL, NULL }, "LOG", ip6t_log_target, ip6t_log_checkentry, NULL, 
+    THIS_MODULE };
+
+static int __init init(void)
+{
+	if (ip6t_register_target(&ip6t_log_reg))
+		return -EINVAL;
+
+	return 0;
+}
+
+static void __exit fini(void)
+{
+	ip6t_unregister_target(&ip6t_log_reg);
+}
+
+module_init(init);
+module_exit(fini);
