The current code allows to inherit the TOS, TTL, DF from the payload
when skb->protocol is ETH_P_IP or ETH_P_IPV6.
However when the payload is VLAN encapsulated (e.g because the tunnel
is of type GRETAP), then this inheriting does not work, because the
visible skb->protocol is of type ETH_P_8021Q or ETH_P_8021AD.
Instead of skb->protocol, use skb_protocol().
Signed-off-by: Matthias May <[email protected]>
---
v2 -> v3:
- Instead of manual parsing, use skb_protocol() as suggested by Eyal Birger
v1 -> v2:
- Add support for ETH_P_8021AD as suggested by Jakub Kicinski.
---
net/ipv4/ip_tunnel.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)
diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 94017a8c3994..dbe18c16b9f6 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -641,6 +641,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
const struct iphdr *inner_iph;
unsigned int max_headroom; /* The extra header space needed */
struct rtable *rt = NULL; /* Route to the other host */
+ __be16 payload_protocol;
bool use_cache = false;
struct flowi4 fl4;
bool md = false;
@@ -651,6 +652,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
inner_iph = (const struct iphdr *)skb_inner_network_header(skb);
connected = (tunnel->parms.iph.daddr != 0);
+ payload_protocol = skb_protocol(skb, true);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
@@ -670,13 +672,12 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
dst = tun_info->key.u.ipv4.dst;
md = true;
connected = true;
- }
- else if (skb->protocol == htons(ETH_P_IP)) {
+ } else if (payload_protocol == htons(ETH_P_IP)) {
rt = skb_rtable(skb);
dst = rt_nexthop(rt, inner_iph->daddr);
}
#if IS_ENABLED(CONFIG_IPV6)
- else if (skb->protocol == htons(ETH_P_IPV6)) {
+ else if (payload_protocol == htons(ETH_P_IPV6)) {
const struct in6_addr *addr6;
struct neighbour *neigh;
bool do_tx_error_icmp;
@@ -716,10 +717,10 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
tos = tnl_params->tos;
if (tos & 0x1) {
tos &= ~0x1;
- if (skb->protocol == htons(ETH_P_IP)) {
+ if (payload_protocol == htons(ETH_P_IP)) {
tos = inner_iph->tos;
connected = false;
- } else if (skb->protocol == htons(ETH_P_IPV6)) {
+ } else if (payload_protocol == htons(ETH_P_IPV6)) {
tos = ipv6_get_dsfield((const struct ipv6hdr *)inner_iph);
connected = false;
}
@@ -765,7 +766,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
}
df = tnl_params->frag_off;
- if (skb->protocol == htons(ETH_P_IP) && !tunnel->ignore_df)
+ if (payload_protocol == htons(ETH_P_IP) && !tunnel->ignore_df)
df |= (inner_iph->frag_off & htons(IP_DF));
if (tnl_update_pmtu(dev, skb, rt, df, inner_iph, 0, 0, false)) {
@@ -786,10 +787,10 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
tos = ip_tunnel_ecn_encap(tos, inner_iph, skb);
ttl = tnl_params->ttl;
if (ttl == 0) {
- if (skb->protocol == htons(ETH_P_IP))
+ if (payload_protocol == htons(ETH_P_IP))
ttl = inner_iph->ttl;
#if IS_ENABLED(CONFIG_IPV6)
- else if (skb->protocol == htons(ETH_P_IPV6))
+ else if (payload_protocol == htons(ETH_P_IPV6))
ttl = ((const struct ipv6hdr *)inner_iph)->hop_limit;
#endif
else
--
2.35.1