xfrm: ipv6: move mip6_destopt_offset into xfrm core
This helper is relatively small, just move this to the xfrm core
and call it directly.
Next patch does the same for the ROUTING type.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 6b44b6e..2995905 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -77,8 +77,65 @@ static int xfrm4_transport_output(struct xfrm_state *x, struct sk_buff *skb)
return 0;
}
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
+ u8 **nexthdr)
+{
+ u16 offset = sizeof(struct ipv6hdr);
+ struct ipv6_opt_hdr *exthdr =
+ (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
+ const unsigned char *nh = skb_network_header(skb);
+ unsigned int packet_len = skb_tail_pointer(skb) -
+ skb_network_header(skb);
+ int found_rhdr = 0;
+
+ *nexthdr = &ipv6_hdr(skb)->nexthdr;
+
+ while (offset + 1 <= packet_len) {
+ switch (**nexthdr) {
+ case NEXTHDR_HOP:
+ break;
+ case NEXTHDR_ROUTING:
+ found_rhdr = 1;
+ break;
+ case NEXTHDR_DEST:
+ /* HAO MUST NOT appear more than once.
+ * XXX: It is better to try to find by the end of
+ * XXX: packet if HAO exists.
+ */
+ if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
+ net_dbg_ratelimited("mip6: hao exists already, override\n");
+ return offset;
+ }
+
+ if (found_rhdr)
+ return offset;
+
+ break;
+ default:
+ return offset;
+ }
+
+ offset += ipv6_optlen(exthdr);
+ *nexthdr = &exthdr->nexthdr;
+ exthdr = (struct ipv6_opt_hdr *)(nh + offset);
+ }
+
+ return offset;
+}
+#endif
+
static int xfrm6_hdr_offset(struct xfrm_state *x, struct sk_buff *skb, u8 **prevhdr)
{
+ switch (x->type->proto) {
+#if IS_ENABLED(CONFIG_IPV6_MIP6)
+ case IPPROTO_DSTOPTS:
+ return mip6_destopt_offset(x, skb, prevhdr);
+#endif
+ default:
+ break;
+ }
+
return x->type->hdr_offset(x, skb, prevhdr);
}