sit: update dev->needed_headroom in ipip6_tunnel_bind_dev()

When a tunnel device is bound with the underlying device, its
dev->needed_headroom needs to be updated properly. IPv4 tunnels
already do the same in ip_tunnel_bind_dev(). Otherwise we may
not have enough header room for skb, especially after commit
b17f709a24 ("gue: TX support for using remote checksum offload option").

Fixes: 32b8a8e59c ("sit: add IPv4 over IPv4 support")
Reported-by: Palash Oswal <oswalpalash@gmail.com>
Link: https://lore.kernel.org/netdev/CAGyP=7fDcSPKu6nttbGwt7RXzE3uyYxLjCSE97J64pRxJP8jPA@mail.gmail.com/
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2023-04-26 23:00:06 -07:00 committed by David S. Miller
parent da94a7781f
commit c88f8d5cd9

View file

@ -1095,12 +1095,13 @@ static netdev_tx_t sit_tunnel_xmit(struct sk_buff *skb,
static void ipip6_tunnel_bind_dev(struct net_device *dev)
{
struct ip_tunnel *tunnel = netdev_priv(dev);
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
struct net_device *tdev = NULL;
struct ip_tunnel *tunnel;
int hlen = LL_MAX_HEADER;
const struct iphdr *iph;
struct flowi4 fl4;
tunnel = netdev_priv(dev);
iph = &tunnel->parms.iph;
if (iph->daddr) {
@ -1123,14 +1124,15 @@ static void ipip6_tunnel_bind_dev(struct net_device *dev)
tdev = __dev_get_by_index(tunnel->net, tunnel->parms.link);
if (tdev && !netif_is_l3_master(tdev)) {
int t_hlen = tunnel->hlen + sizeof(struct iphdr);
int mtu;
mtu = tdev->mtu - t_hlen;
if (mtu < IPV6_MIN_MTU)
mtu = IPV6_MIN_MTU;
WRITE_ONCE(dev->mtu, mtu);
hlen = tdev->hard_header_len + tdev->needed_headroom;
}
dev->needed_headroom = t_hlen + hlen;
}
static void ipip6_tunnel_update(struct ip_tunnel *t, struct ip_tunnel_parm *p,