patch-2.4.21 linux-2.4.21/net/ipv6/netfilter/ip6t_ipv6header.c

• Lines: 212
• Date: 2003-06-13 07:51:39.000000000 -0700
• Orig file: linux-2.4.20/net/ipv6/netfilter/ip6t_ipv6header.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/net/ipv6/netfilter/ip6t_ipv6header.c linux-2.4.21/net/ipv6/netfilter/ip6t_ipv6header.c
@@ -0,0 +1,211 @@
+/* ipv6header match - matches IPv6 packets based
+on whether they contain certain headers */
+
+/* Original idea: Brad Chapman 
+ * Rewritten by: Andras Kis-Szabo <kisza@sch.bme.hu> */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/ipv6.h>
+#include <linux/types.h>
+#include <net/checksum.h>
+#include <net/ipv6.h>
+
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter_ipv6/ip6t_ipv6header.h>
+
+EXPORT_NO_SYMBOLS;
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IPv6 headers match");
+MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+static int
+ipv6header_match(const struct sk_buff *skb,
+		 const struct net_device *in,
+		 const struct net_device *out,
+		 const void *matchinfo,
+		 int offset,
+		 const void *protohdr,
+		 u_int16_t datalen,
+		 int *hotdrop)
+{
+	const struct ip6t_ipv6header_info *info = matchinfo;
+	unsigned int temp;
+	int len;
+	u8 nexthdr;
+	unsigned int ptr;
+        struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
+
+	/* Make sure this isn't an evil packet */
+	DEBUGP("ipv6_header entered \n");
+
+	/* type of the 1st exthdr */
+	nexthdr = skb->nh.ipv6h->nexthdr;
+	/* pointer to the 1st exthdr */
+	ptr = sizeof(struct ipv6hdr);
+	/* available length */
+	len = skb->len - ptr;
+	temp = 0;
+
+	DEBUGP("ipv6_header nexthdr %02X \n",nexthdr);
+	DEBUGP("ipv6_header ptr %08X \n",ptr);
+	DEBUGP("ipv6_header skblen %04X \n",skb->len);
+	DEBUGP("ipv6_header skbdatalen %04X \n",skb->data_len);
+	DEBUGP("ipv6_header len %04X \n",len);
+#if 0
+	for (temp=0;temp<skb->len;temp++){
+		if (!(temp % 16 )) DEBUGP("\nipv6_header data ");
+		DEBUGP("%02X ",skb->data[temp]);
+	}
+#endif
+	DEBUGP("\nipv6_header h.raw %02X %02X %02X %02X \n",
+			skb->h.raw[0],
+			skb->h.raw[1],
+			skb->h.raw[2],
+			skb->h.raw[3]);
+	DEBUGP("ipv6_header nh.raw %02X %02X %02X %02X \n",
+			skb->nh.raw[0],
+			skb->nh.raw[1],
+			skb->nh.raw[2],
+			skb->nh.raw[3]);
+	DEBUGP("ipv6_header CB %02X %02X %02X %02X %02X %02X %02X \n",
+			opt->iif,
+			opt->ra,
+			opt->hop,
+			opt->auth,
+			opt->dst0,
+			opt->srcrt,
+			opt->dst1);
+
+	temp = 0;
+
+        while (ip6t_ext_hdr(nexthdr)) {
+        	struct ipv6_opt_hdr *hdr;
+        	int hdrlen;
+
+		DEBUGP("ipv6_header header iteration \n");
+
+		/* Is there enough space for the next ext header? */
+                if (len < (int)sizeof(struct ipv6_opt_hdr))
+                        return 0;
+		/* No more exthdr -> evaluate */
+                if (nexthdr == NEXTHDR_NONE) {
+			temp |= MASK_NONE;
+			break;
+		}
+		/* ESP -> evaluate */
+                if (nexthdr == NEXTHDR_ESP) {
+			temp |= MASK_ESP;
+			break;
+		}
+
+		hdr=(struct ipv6_opt_hdr *)skb->data+ptr;
+
+		/* Calculate the header length */
+                if (nexthdr == NEXTHDR_FRAGMENT) {
+                        hdrlen = 8;
+                } else if (nexthdr == NEXTHDR_AUTH)
+                        hdrlen = (hdr->hdrlen+2)<<2;
+                else
+                        hdrlen = ipv6_optlen(hdr);
+
+		DEBUGP("ipv6_header hdrlen %04X \n",hdrlen);
+
+		/* set the flag */
+		switch (nexthdr){
+			case NEXTHDR_HOP:
+				temp |= MASK_HOPOPTS;
+				break;
+			case NEXTHDR_ROUTING:
+				temp |= MASK_ROUTING;
+				break;
+			case NEXTHDR_FRAGMENT:
+				temp |= MASK_FRAGMENT;
+				break;
+			case NEXTHDR_AUTH:
+				temp |= MASK_AH;
+				break;
+			case NEXTHDR_DEST:
+				temp |= MASK_DSTOPTS;
+				break;
+			default:
+				DEBUGP("IPV6HEADER match: unknown nextheader %u\n",nexthdr);
+				return 0;
+				break;
+		}
+
+                nexthdr = hdr->nexthdr;
+                len -= hdrlen;
+                ptr += hdrlen;
+		if ( ptr > skb->len ) {
+			DEBUGP("ipv6_header new ptr %04X \n",ptr);
+			break;
+		}
+        }
+
+	if ( (nexthdr != NEXTHDR_NONE ) && (nexthdr != NEXTHDR_ESP) )
+		temp |= MASK_PROTO;
+
+	DEBUGP ("ipv6header: %02X %02X \n", temp, info->matchflags);
+
+	if (info->modeflag)
+		return (!( (temp & info->matchflags)
+			^ info->matchflags) ^ info->invflags);
+	else
+		return (!( temp ^ info->matchflags) ^ info->invflags);
+}
+
+static int
+ipv6header_checkentry(const char *tablename,
+		      const struct ip6t_ip6 *ip,
+		      void *matchinfo,
+		      unsigned int matchsize,
+		      unsigned int hook_mask)
+{
+	/* Check for obvious errors */
+	/* This match is valid in all hooks! */
+	if (matchsize != IP6T_ALIGN(sizeof(struct ip6t_ipv6header_info))) {
+		DEBUGP("ip6t_ipv6header: matchsize != %u\n",
+			 IP6T_ALIGN(sizeof(struct ip6t_ipv6header_info)));
+		return 0;
+	}
+
+	return 1;
+}
+
+static void
+ipv6header_destroy(void *matchinfo,
+		   unsigned int matchinfosize)
+{
+	return;
+}
+
+static struct ip6t_match
+ip6t_ipv6header_match = {
+	{ NULL, NULL },
+	"ipv6header",
+	&ipv6header_match,
+	&ipv6header_checkentry,
+	&ipv6header_destroy,
+	THIS_MODULE
+};
+
+static int  __init ipv6header_init(void)
+{
+	return ip6t_register_match(&ip6t_ipv6header_match);
+}
+
+static void __exit ipv6header_exit(void)
+{
+	ip6t_unregister_match(&ip6t_ipv6header_match);
+}
+
+module_init(ipv6header_init);
+module_exit(ipv6header_exit);
+