[PATCH net-next v4 03/12] net: tunnel: add skb_vlan_inet_prepare_reason() helper

From: Menglong Dong
Date: Tue Oct 01 2024 - 03:35:36 EST


Introduce the function skb_vlan_inet_prepare_reason() and make
skb_vlan_inet_prepare an inline call to it. The drop reasons of it just
come from pskb_may_pull_reason.

Signed-off-by: Menglong Dong <dongml2@xxxxxxxxxxxxxxx>
---
v3:
- fix some format problems, as Alexander advised
---
include/net/ip_tunnels.h | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/include/net/ip_tunnels.h b/include/net/ip_tunnels.h
index 7fc2f7bf837a..d00d8835e789 100644
--- a/include/net/ip_tunnels.h
+++ b/include/net/ip_tunnels.h
@@ -465,13 +465,14 @@ static inline bool pskb_inet_may_pull(struct sk_buff *skb)
return pskb_inet_may_pull_reason(skb) == SKB_NOT_DROPPED_YET;
}

-/* Variant of pskb_inet_may_pull().
+/* Variant of pskb_inet_may_pull_reason().
*/
-static inline bool skb_vlan_inet_prepare(struct sk_buff *skb,
- bool inner_proto_inherit)
+static inline enum skb_drop_reason
+skb_vlan_inet_prepare_reason(struct sk_buff *skb, bool inner_proto_inherit)
{
int nhlen = 0, maclen = inner_proto_inherit ? 0 : ETH_HLEN;
__be16 type = skb->protocol;
+ enum skb_drop_reason reason;

/* Essentially this is skb_protocol(skb, true)
* And we get MAC len.
@@ -492,11 +493,20 @@ static inline bool skb_vlan_inet_prepare(struct sk_buff *skb,
/* For ETH_P_IPV6/ETH_P_IP we make sure to pull
* a base network header in skb->head.
*/
- if (!pskb_may_pull(skb, maclen + nhlen))
- return false;
+ reason = pskb_may_pull_reason(skb, maclen + nhlen);
+ if (reason)
+ return reason;

skb_set_network_header(skb, maclen);
- return true;
+
+ return SKB_NOT_DROPPED_YET;
+}
+
+static inline bool skb_vlan_inet_prepare(struct sk_buff *skb,
+ bool inner_proto_inherit)
+{
+ return skb_vlan_inet_prepare_reason(skb, inner_proto_inherit) ==
+ SKB_NOT_DROPPED_YET;
}

static inline int ip_encap_hlen(struct ip_tunnel_encap *e)
--
2.39.5