[PATCH net-next v10 03/10] ipv6: Add case for IPV6_TLV_TNL_ENCAP_LIMIT in EH TLV switch

Tom Herbert
2026-05-04T18:52:53Z

IPV6_TLV_TNL_ENCAP_LIMIT is a recognized Destination option that is
processed in ip6_tunnel.c. Add a case for it in the switch in
ip6_parse_tlv so that it is recognized as a known option.

Also remove the unlikely around the check for max_count < 0 since the
default limits for HBH and Destination options can be less than zero.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Reviewed-by: Justin Iurman <justin.iurman@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
---
net/ipv6/exthdrs.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index 64e85189489c..b50f4b3bf59d 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -122,7 +122,7 @@ static bool ip6_parse_tlv(bool hopbyhop,
int tlv_count = 0;
int padlen = 0;

- if (unlikely(max_count < 0)) {
+ if (max_count < 0) {
disallow_unknowns = true;
max_count = -max_count;
}
@@ -202,6 +202,16 @@ static bool ip6_parse_tlv(bool hopbyhop,
if (!ipv6_dest_hao(skb, off))
return false;
break;
+#endif
+#if IS_ENABLED(CONFIG_IPV6_TUNNEL)
+ case IPV6_TLV_TNL_ENCAP_LIMIT:
+ /* The tunnel encapsulation option.
+ * This is handled in ip6_tunnel.c so
+ * we don't need to do anything here
+ * except to accept it as a recognized
+ * option
+ */
+ break;
#endif
default:
if (!ip6_tlvopt_unknown(skb, off,
--
2.43.0