patch-2.4.21 linux-2.4.21/net/ipv6/netfilter/ip6t_rt.c

• Lines: 295
• Date: 2003-06-13 07:51:39.000000000 -0700
• Orig file: linux-2.4.20/net/ipv6/netfilter/ip6t_rt.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.20/net/ipv6/netfilter/ip6t_rt.c linux-2.4.21/net/ipv6/netfilter/ip6t_rt.c
@@ -0,0 +1,294 @@
+/* Kernel module to match ROUTING parameters. */
+#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 <asm/byteorder.h>
+
+#include <linux/netfilter_ipv6/ip6_tables.h>
+#include <linux/netfilter_ipv6/ip6t_rt.h>
+
+EXPORT_NO_SYMBOLS;
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("IPv6 RT match");
+MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
+
+#if 0
+#define DEBUGP printk
+#else
+#define DEBUGP(format, args...)
+#endif
+
+/* Returns 1 if the id is matched by the range, 0 otherwise */
+static inline int
+segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, int invert)
+{
+       int r=0;
+       DEBUGP("rt segsleft_match:%c 0x%x <= 0x%x <= 0x%x",invert? '!':' ',
+              min,id,max);
+       r=(id >= min && id <= max) ^ invert;
+       DEBUGP(" result %s\n",r? "PASS" : "FAILED");
+       return r;
+}
+
+static int
+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)
+{
+       struct ipv6_rt_hdr *route = NULL;
+       const struct ip6t_rt *rtinfo = matchinfo;
+       unsigned int temp;
+       unsigned int len;
+       u8 nexthdr;
+       unsigned int ptr;
+       unsigned int hdrlen = 0;
+       unsigned int ret = 0;
+
+       /* 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;
+
+        while (ip6t_ext_hdr(nexthdr)) {
+               struct ipv6_opt_hdr *hdr;
+
+              DEBUGP("ipv6_rt 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) {
+                     break;
+              }
+              /* ESP -> evaluate */
+                if (nexthdr == NEXTHDR_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);
+
+              /* ROUTING -> evaluate */
+                if (nexthdr == NEXTHDR_ROUTING) {
+                     temp |= MASK_ROUTING;
+                     break;
+              }
+
+
+              /* set the flag */
+              switch (nexthdr){
+                     case NEXTHDR_HOP:
+                     case NEXTHDR_ROUTING:
+                     case NEXTHDR_FRAGMENT:
+                     case NEXTHDR_AUTH:
+                     case NEXTHDR_DEST:
+                            break;
+                     default:
+                            DEBUGP("ipv6_rt match: unknown nextheader %u\n",nexthdr);
+                            return 0;
+                            break;
+              }
+
+                nexthdr = hdr->nexthdr;
+                len -= hdrlen;
+                ptr += hdrlen;
+		if ( ptr > skb->len ) {
+			DEBUGP("ipv6_rt: new pointer is too large! \n");
+			break;
+		}
+        }
+
+       /* ROUTING header not found */
+       if ( temp != MASK_ROUTING ) return 0;
+
+       if (len < (int)sizeof(struct ipv6_rt_hdr)){
+	       *hotdrop = 1;
+       		return 0;
+       }
+
+       if (len < hdrlen){
+	       /* Pcket smaller than its length field */
+       		return 0;
+       }
+
+       route=skb->data+ptr;
+
+       DEBUGP("IPv6 RT LEN %u %u ", hdrlen, route->hdrlen);
+       DEBUGP("TYPE %04X ", route->type);
+       DEBUGP("SGS_LEFT %u %08X\n", ntohl(route->segments_left), ntohl(route->segments_left));
+
+       DEBUGP("IPv6 RT segsleft %02X ",
+       		(segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
+                           ntohl(route->segments_left),
+                           !!(rtinfo->invflags & IP6T_RT_INV_SGS))));
+       DEBUGP("type %02X %02X %02X ",
+       		rtinfo->rt_type, route->type, 
+       		(!(rtinfo->flags & IP6T_RT_TYP) ||
+                           ((rtinfo->rt_type == route->type) ^
+                           !!(rtinfo->invflags & IP6T_RT_INV_TYP))));
+       DEBUGP("len %02X %04X %02X ",
+       		rtinfo->hdrlen, hdrlen,
+       		(!(rtinfo->flags & IP6T_RT_LEN) ||
+                           ((rtinfo->hdrlen == hdrlen) ^
+                           !!(rtinfo->invflags & IP6T_RT_INV_LEN))));
+       DEBUGP("res %02X %02X %02X ", 
+       		(rtinfo->flags & IP6T_RT_RES), ((struct rt0_hdr *)route)->bitmap,
+       		!((rtinfo->flags & IP6T_RT_RES) && (((struct rt0_hdr *)route)->bitmap)));
+
+       ret = (route != NULL)
+       		&&
+       		(segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
+                           ntohl(route->segments_left),
+                           !!(rtinfo->invflags & IP6T_RT_INV_SGS)))
+		&&
+	      	(!(rtinfo->flags & IP6T_RT_LEN) ||
+                           ((rtinfo->hdrlen == hdrlen) ^
+                           !!(rtinfo->invflags & IP6T_RT_INV_LEN)))
+		&&
+       		(!(rtinfo->flags & IP6T_RT_TYP) ||
+                           ((rtinfo->rt_type == route->type) ^
+                           !!(rtinfo->invflags & IP6T_RT_INV_TYP)))
+		&&
+       		!((rtinfo->flags & IP6T_RT_RES) && (((struct rt0_hdr *)route)->bitmap));
+
+	DEBUGP("#%d ",rtinfo->addrnr);
+       temp = len = ptr = 0;
+       if ( !(rtinfo->flags & IP6T_RT_FST) ){
+	       return ret;
+	} else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) {
+		DEBUGP("Not strict ");
+		if ( rtinfo->addrnr > (unsigned int)((hdrlen-8)/16) ){
+			DEBUGP("There isn't enough space\n");
+			return 0;
+		} else {
+			DEBUGP("#%d ",rtinfo->addrnr);
+			ptr = 0;
+			for(temp=0; temp<(unsigned int)((hdrlen-8)/16); temp++){
+				len = 0;
+				while ((u8)(((struct rt0_hdr *)route)->
+						addr[temp].s6_addr[len]) ==
+					(u8)(rtinfo->addrs[ptr].s6_addr[len])){
+					DEBUGP("%02X?%02X ",
+		(u8)(((struct rt0_hdr *)route)->addr[temp].s6_addr[len]),
+					(u8)(rtinfo->addrs[ptr].s6_addr[len]));
+					len++;
+					if ( len == 16 ) break;
+				}
+				if (len==16) {
+					DEBUGP("ptr=%d temp=%d;\n",ptr,temp);
+					ptr++;
+				} else {
+					DEBUGP("%02X?%02X ",
+		(u8)(((struct rt0_hdr *)route)->addr[temp].s6_addr[len]),
+					(u8)(rtinfo->addrs[ptr].s6_addr[len]));
+					DEBUGP("!ptr=%d temp=%d;\n",ptr,temp);
+				}
+				if (ptr==rtinfo->addrnr) break;
+			}
+			DEBUGP("ptr=%d len=%d #%d\n",ptr,len, rtinfo->addrnr);
+			if ( (len == 16) && (ptr == rtinfo->addrnr))
+				return ret;
+			else return 0;
+		}
+	} else {
+		DEBUGP("Strict ");
+		if ( rtinfo->addrnr > (unsigned int)((hdrlen-8)/16) ){
+			DEBUGP("There isn't enough space\n");
+			return 0;
+		} else {
+			DEBUGP("#%d ",rtinfo->addrnr);
+			for(temp=0; temp<rtinfo->addrnr; temp++){
+				len = 0;
+				while ((u8)(((struct rt0_hdr *)route)->
+						addr[temp].s6_addr[len]) ==
+					(u8)(rtinfo->addrs[temp].s6_addr[len])){
+					DEBUGP("%02X?%02X ",
+		(u8)(((struct rt0_hdr *)route)->addr[temp].s6_addr[len]),
+					(u8)(rtinfo->addrs[temp].s6_addr[len]));
+					len++;
+					if ( len == 16 ) break;
+				}
+				if (len!=16) {
+					DEBUGP("%02X?%02X ",
+		(u8)(((struct rt0_hdr *)route)->addr[temp].s6_addr[len]),
+					(u8)(rtinfo->addrs[temp].s6_addr[len]));
+					DEBUGP("!len=%d temp=%d;\n",len,temp);
+					break;
+				}
+			}
+			DEBUGP("temp=%d len=%d #%d\n",temp,len,rtinfo->addrnr);
+			if ( (len == 16) && (temp == rtinfo->addrnr) && (temp == (unsigned int)((hdrlen-8)/16)))
+				return ret;
+			else return 0;
+		}
+	}
+
+	return 0;
+}
+
+/* Called when user tries to insert an entry of this type. */
+static int
+checkentry(const char *tablename,
+          const struct ip6t_ip6 *ip,
+          void *matchinfo,
+          unsigned int matchinfosize,
+          unsigned int hook_mask)
+{
+       const struct ip6t_rt *rtinfo = matchinfo;
+
+       if (matchinfosize != IP6T_ALIGN(sizeof(struct ip6t_rt))) {
+              DEBUGP("ip6t_rt: matchsize %u != %u\n",
+                      matchinfosize, IP6T_ALIGN(sizeof(struct ip6t_rt)));
+              return 0;
+       }
+       if (rtinfo->invflags & ~IP6T_RT_INV_MASK) {
+              DEBUGP("ip6t_rt: unknown flags %X\n",
+                      rtinfo->invflags);
+              return 0;
+       }
+       if ( (rtinfo->flags & (IP6T_RT_RES|IP6T_RT_FST_MASK)) && 
+		       (!(rtinfo->flags & IP6T_RT_TYP) || 
+		       (rtinfo->rt_type != 0) || 
+		       (rtinfo->invflags & IP6T_RT_INV_TYP)) ) {
+	      DEBUGP("`--rt-type 0' required before `--rt-0-*'");
+              return 0;
+       }
+
+       return 1;
+}
+
+static struct ip6t_match rt_match
+= { { NULL, NULL }, "rt", &match, &checkentry, NULL, THIS_MODULE };
+
+static int __init init(void)
+{
+       return ip6t_register_match(&rt_match);
+}
+
+static void __exit cleanup(void)
+{
+       ip6t_unregister_match(&rt_match);
+}
+
+module_init(init);
+module_exit(cleanup);