* [PATCH 1/2] tun: Fix csum_start with VLAN acceleration
2014-11-02 20:29 [0/2] tun: Fix csum_start and TUN_PKT_STRIP Herbert Xu
@ 2014-11-02 20:30 ` Herbert Xu
2014-11-02 20:30 ` [PATCH 2/2] tun: Fix TUN_PKT_STRIP setting Herbert Xu
2014-11-03 19:28 ` [0/2] tun: Fix csum_start and TUN_PKT_STRIP David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Herbert Xu @ 2014-11-02 20:30 UTC (permalink / raw)
To: David S. Miller, netdev
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: 6680ec68eff4 ("tuntap: hardware vlan tx support")
Cc: stable@vger.kernel.org
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
drivers/net/tun.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 7302398..57e6bf7 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1235,6 +1235,10 @@ static ssize_t tun_put_user(struct tun_struct *tun,
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
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 ((len -= sizeof(pi)) < 0)
@@ -1284,7 +1288,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
if (skb->ip_summed == CHECKSUM_PARTIAL) {
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;
} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
@@ -1297,10 +1302,9 @@ static ssize_t tun_put_user(struct tun_struct *tun,
}
copied = total;
- total += skb->len;
- if (!vlan_tx_tag_present(skb)) {
- len = min_t(int, skb->len, len);
- } else {
+ len = min_t(int, skb->len + vlan_hlen, len);
+ total += skb->len + vlan_hlen;
+ if (vlan_hlen) {
int copy, ret;
struct {
__be16 h_vlan_proto;
@@ -1311,8 +1315,6 @@ static ssize_t tun_put_user(struct tun_struct *tun,
veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
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);
ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] tun: Fix TUN_PKT_STRIP setting
2014-11-02 20:29 [0/2] tun: Fix csum_start and TUN_PKT_STRIP Herbert Xu
2014-11-02 20:30 ` [PATCH 1/2] tun: Fix csum_start with VLAN acceleration Herbert Xu
@ 2014-11-02 20:30 ` Herbert Xu
2014-11-03 19:28 ` [0/2] tun: Fix csum_start and TUN_PKT_STRIP David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Herbert Xu @ 2014-11-02 20:30 UTC (permalink / raw)
To: David S. Miller, netdev
We set the flag TUN_PKT_STRIP if the user buffer provided is too
small to contain the entire packet plus meta-data. However, this
has been broken ever since we added GSO meta-data. VLAN acceleration
also has the same problem.
This patch fixes this by taking both into account when setting the
TUN_PKT_STRIP flag.
The fact that this has been broken for six years without anyone
realising means that nobody actually uses this flag.
Fixes: f43798c27684 ("tun: Allow GSO using virtio_net_hdr")
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
drivers/net/tun.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 57e6bf7..9dd3746 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1236,15 +1236,19 @@ static ssize_t tun_put_user(struct tun_struct *tun,
ssize_t total = 0;
int vlan_offset = 0, copied;
int vlan_hlen = 0;
+ int vnet_hdr_sz = 0;
if (vlan_tx_tag_present(skb))
vlan_hlen = VLAN_HLEN;
+ if (tun->flags & TUN_VNET_HDR)
+ vnet_hdr_sz = tun->vnet_hdr_sz;
+
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
return -EINVAL;
- if (len < skb->len) {
+ if (len < skb->len + vlan_hlen + vnet_hdr_sz) {
/* Packet will be striped */
pi.flags |= TUN_PKT_STRIP;
}
@@ -1254,9 +1258,9 @@ static ssize_t tun_put_user(struct tun_struct *tun,
total += sizeof(pi);
}
- if (tun->flags & TUN_VNET_HDR) {
+ if (vnet_hdr_sz) {
struct virtio_net_hdr gso = { 0 }; /* no info leak */
- if ((len -= tun->vnet_hdr_sz) < 0)
+ if ((len -= vnet_hdr_sz) < 0)
return -EINVAL;
if (skb_is_gso(skb)) {
@@ -1298,7 +1302,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
if (unlikely(memcpy_toiovecend(iv, (void *)&gso, total,
sizeof(gso))))
return -EFAULT;
- total += tun->vnet_hdr_sz;
+ total += vnet_hdr_sz;
}
copied = total;
^ permalink raw reply related [flat|nested] 4+ messages in thread