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authorJason Wang <jasowang@redhat.com>2013-12-09 18:25:16 +0800
committerDavid S. Miller <davem@davemloft.net>2013-12-10 22:06:49 -0500
commit923347bb83c67c3a572b04decb5875c3adb0d306 (patch)
tree90c725a751b4f1a964685cf73d486d53ae88d7e4
parentfffc15a5012e9052d3b236efc56840841a125416 (diff)
downloadop-kernel-dev-923347bb83c67c3a572b04decb5875c3adb0d306.zip
op-kernel-dev-923347bb83c67c3a572b04decb5875c3adb0d306.tar.gz
tun: unbreak truncated packet signalling
Commit 6680ec68eff47d36f67b4351bc9836fd6cba9532 (tuntap: hardware vlan tx support) breaks the truncated packet signal by never return a length greater than iov length in tun_put_user(). This patch fixes this by always return the length of packet plus possible vlan header. Caller can detect the truncated packet by comparing the return value and the size of iov length. Reported-by: Vlad Yasevich <vyasevich@gmail.com> Cc: Vlad Yasevich <vyasevich@gmail.com> Cc: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/tun.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index e26cbea..dd1bd7a 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1183,7 +1183,11 @@ static ssize_t tun_put_user(struct tun_struct *tun,
const struct iovec *iv, int len)
{
struct tun_pi pi = { 0, skb->protocol };
- ssize_t total = 0;
+ struct {
+ __be16 h_vlan_proto;
+ __be16 h_vlan_TCI;
+ } veth;
+ ssize_t total = 0, off = 0;
int vlan_offset = 0;
if (!(tun->flags & TUN_NO_PI)) {
@@ -1248,14 +1252,11 @@ static ssize_t tun_put_user(struct tun_struct *tun,
total += tun->vnet_hdr_sz;
}
+ off = total;
if (!vlan_tx_tag_present(skb)) {
len = min_t(int, skb->len, len);
} else {
int copy, ret;
- struct {
- __be16 h_vlan_proto;
- __be16 h_vlan_TCI;
- } veth;
veth.h_vlan_proto = skb->vlan_proto;
veth.h_vlan_TCI = htons(vlan_tx_tag_get(skb));
@@ -1264,22 +1265,22 @@ static ssize_t tun_put_user(struct tun_struct *tun,
len = min_t(int, skb->len + VLAN_HLEN, len);
copy = min_t(int, vlan_offset, len);
- ret = skb_copy_datagram_const_iovec(skb, 0, iv, total, copy);
+ ret = skb_copy_datagram_const_iovec(skb, 0, iv, off, copy);
len -= copy;
- total += copy;
+ off += copy;
if (ret || !len)
goto done;
copy = min_t(int, sizeof(veth), len);
- ret = memcpy_toiovecend(iv, (void *)&veth, total, copy);
+ ret = memcpy_toiovecend(iv, (void *)&veth, off, copy);
len -= copy;
- total += copy;
+ off += copy;
if (ret || !len)
goto done;
}
- skb_copy_datagram_const_iovec(skb, vlan_offset, iv, total, len);
- total += len;
+ skb_copy_datagram_const_iovec(skb, vlan_offset, iv, off, len);
+ total += skb->len + (vlan_offset ? sizeof(veth) : 0);
done:
tun->dev->stats.tx_packets++;
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