ipv6: Add fragment reporting to ipv6_skip_exthdr().

[~andy/linux] / net / ipv6 / exthdrs_core.c

diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c
index 37f548b7f6dc73c4489107a59ee48e4928efa8f1..72957f4a7c6c9f6c24056a5c3eb6046b61c7a3ea 100644 (file)
--- a/net/ipv6/exthdrs_core.c
+++ b/net/ipv6/exthdrs_core.c
@@ -57,6 +57,9 @@ int ipv6_ext_hdr(u8 nexthdr)
  *         it returns NULL.
  *       - First fragment header is skipped, not-first ones
  *         are considered as unparsable.
+ *       - Reports the offset field of the final fragment header so it is
+ *         possible to tell whether this is a first fragment, later fragment,
+ *         or not fragmented.
  *       - ESP is unparsable for now and considered like
  *         normal payload protocol.
  *       - Note also special handling of AUTH header. Thanks to IPsec wizards.
@@ -64,10 +67,13 @@ int ipv6_ext_hdr(u8 nexthdr)
  * --ANK (980726)
  */
 
-int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp)
+int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp,
+                    __be16 *frag_offp)
 {
        u8 nexthdr = *nexthdrp;
 
+       *frag_offp = 0;
+
        while (ipv6_ext_hdr(nexthdr)) {
                struct ipv6_opt_hdr _hdr, *hp;
                int hdrlen;
@@ -87,7 +93,8 @@ int ipv6_skip_exthdr(const struct sk_buff *skb, int start, u8 *nexthdrp)
                        if (fp == NULL)
                                return -1;
 
-                       if (ntohs(*fp) & ~0x7)
+                       *frag_offp = *fp;
+                       if (ntohs(*frag_offp) & ~0x7)
                                break;
                        hdrlen = 8;
                } else if (nexthdr == NEXTHDR_AUTH)