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Diffstat (limited to 'net/ipv6/exthdrs.c')
-rw-r--r--net/ipv6/exthdrs.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 8d3a0e1..50ff49e 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -49,6 +49,49 @@
#include <asm/uaccess.h>
+int ipv6_find_tlv(struct sk_buff *skb, int offset, int type)
+{
+ int packet_len = skb->tail - skb->nh.raw;
+ struct ipv6_opt_hdr *hdr;
+ int len;
+
+ if (offset + 2 > packet_len)
+ goto bad;
+ hdr = (struct ipv6_opt_hdr*)(skb->nh.raw + offset);
+ len = ((hdr->hdrlen + 1) << 3);
+
+ if (offset + len > packet_len)
+ goto bad;
+
+ offset += 2;
+ len -= 2;
+
+ while (len > 0) {
+ int opttype = skb->nh.raw[offset];
+ int optlen;
+
+ if (opttype == type)
+ return offset;
+
+ switch (opttype) {
+ case IPV6_TLV_PAD0:
+ optlen = 1;
+ break;
+ default:
+ optlen = skb->nh.raw[offset + 1] + 2;
+ if (optlen > len)
+ goto bad;
+ break;
+ }
+ offset += optlen;
+ len -= optlen;
+ }
+ /* not_found */
+ return -1;
+ bad:
+ return -1;
+}
+
/*
* Parsing tlv encoded headers.
*
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