Commit a8f9bfdf authored by Herbert Xu's avatar Herbert Xu Committed by David S. Miller

tun: Fix csum_start with VLAN acceleration

When VLAN acceleration is in use on the xmit path, we end up
setting csum_start to the wrong place.  The result is that the
whoever ends up doing the checksum setting will corrupt the packet
instead of writing the checksum to the expected location, usually
this means writing the checksum with an offset of -4.

This patch fixes this by adjusting csum_start when VLAN acceleration
is detected.

Fixes: 6680ec68 ("tuntap: hardware vlan tx support")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7071cf7f
...@@ -1235,6 +1235,10 @@ static ssize_t tun_put_user(struct tun_struct *tun, ...@@ -1235,6 +1235,10 @@ static ssize_t tun_put_user(struct tun_struct *tun,
struct tun_pi pi = { 0, skb->protocol }; struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0; ssize_t total = 0;
int vlan_offset = 0, copied; int vlan_offset = 0, copied;
int vlan_hlen = 0;
if (vlan_tx_tag_present(skb))
vlan_hlen = VLAN_HLEN;
if (!(tun->flags & TUN_NO_PI)) { if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0) if ((len -= sizeof(pi)) < 0)
...@@ -1284,7 +1288,8 @@ static ssize_t tun_put_user(struct tun_struct *tun, ...@@ -1284,7 +1288,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
if (skb->ip_summed == CHECKSUM_PARTIAL) { if (skb->ip_summed == CHECKSUM_PARTIAL) {
gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; gso.flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
gso.csum_start = skb_checksum_start_offset(skb); gso.csum_start = skb_checksum_start_offset(skb) +
vlan_hlen;
gso.csum_offset = skb->csum_offset; gso.csum_offset = skb->csum_offset;
} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) { } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
gso.flags = VIRTIO_NET_HDR_F_DATA_VALID; gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
...@@ -1297,10 +1302,9 @@ static ssize_t tun_put_user(struct tun_struct *tun, ...@@ -1297,10 +1302,9 @@ static ssize_t tun_put_user(struct tun_struct *tun,
} }
copied = total; copied = total;
total += skb->len; len = min_t(int, skb->len + vlan_hlen, len);
if (!vlan_tx_tag_present(skb)) { total += skb->len + vlan_hlen;
len = min_t(int, skb->len, len); if (vlan_hlen) {
} else {
int copy, ret; int copy, ret;
struct { struct {
__be16 h_vlan_proto; __be16 h_vlan_proto;
...@@ -1311,8 +1315,6 @@ static ssize_t tun_put_user(struct tun_struct *tun, ...@@ -1311,8 +1315,6 @@ static ssize_t tun_put_user(struct tun_struct *tun,
veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb)); veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto); vlan_offset = offsetof(struct vlan_ethhdr, h_vlan_proto);
len = min_t(int, skb->len + VLAN_HLEN, len);
total += VLAN_HLEN;
copy = min_t(int, vlan_offset, len); copy = min_t(int, vlan_offset, len);
ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy); ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment