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authorJason A. Donenfeld <Jason@zx2c4.com>2020-06-29 19:06:18 -0600
committerDavid S. Miller <davem@davemloft.net>2020-06-30 12:29:39 -0700
commit2606aff916854b61234bf85001be9777bab2d5f8 (patch)
tree333affa90c05bb0a59116ca6304f3b7321e767aa /net/ipv4
parentbf64ff4c2aac65d680dc639a511c781cf6b6ec08 (diff)
net: ip_tunnel: add header_ops for layer 3 devices
Some devices that take straight up layer 3 packets benefit from having a shared header_ops so that AF_PACKET sockets can inject packets that are recognized. This shared infrastructure will be used by other drivers that currently can't inject packets using AF_PACKET. It also exposes the parser function, as it is useful in standalone form too. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/ip_tunnel_core.c18
1 files changed, 18 insertions, 0 deletions
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 181b7a2a0247..f8b419e2475c 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -844,3 +844,21 @@ void ip_tunnel_unneed_metadata(void)
static_branch_dec(&ip_tunnel_metadata_cnt);
}
EXPORT_SYMBOL_GPL(ip_tunnel_unneed_metadata);
+
+/* Returns either the correct skb->protocol value, or 0 if invalid. */
+__be16 ip_tunnel_parse_protocol(const struct sk_buff *skb)
+{
+ if (skb_network_header(skb) >= skb->head &&
+ (skb_network_header(skb) + sizeof(struct iphdr)) <= skb_tail_pointer(skb) &&
+ ip_hdr(skb)->version == 4)
+ return htons(ETH_P_IP);
+ if (skb_network_header(skb) >= skb->head &&
+ (skb_network_header(skb) + sizeof(struct ipv6hdr)) <= skb_tail_pointer(skb) &&
+ ipv6_hdr(skb)->version == 6)
+ return htons(ETH_P_IPV6);
+ return 0;
+}
+EXPORT_SYMBOL(ip_tunnel_parse_protocol);
+
+const struct header_ops ip_tunnel_header_ops = { .parse_protocol = ip_tunnel_parse_protocol };
+EXPORT_SYMBOL(ip_tunnel_header_ops);