net: Revert macvtap/tun truncation signalling changes.

Jason Wang and Michael S. Tsirkin are still discussing how
to properly fix this.

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 24 insertions, 26 deletions

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 7544a0c686b4..957cc5c3653d 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -767,14 +767,10 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
                                 const struct sk_buff *skb,
                                 const struct iovec *iv, int len)
 {
-        int ret, off;
+        int ret;
         int vnet_hdr_len = 0;
         int vlan_offset = 0;
         int copied;
-        struct {
-                __be16 h_vlan_proto;
-                __be16 h_vlan_TCI;
-        } veth;
 
         if (q->flags & IFF_VNET_HDR) {
                 struct virtio_net_hdr vnet_hdr;
@@ -789,13 +785,16 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
                 if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
                         return -EFAULT;
         }
-        off = copied = vnet_hdr_len;
+        copied = vnet_hdr_len;
 
         if (!vlan_tx_tag_present(skb))
                 len = min_t(int, skb->len, len);
         else {
                 int copy;
-
+                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));
 
@@ -803,22 +802,22 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
                 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, off, copy);
+                ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
                 len -= copy;
-                off += copy;
+                copied += copy;
                 if (ret || !len)
                         goto done;
 
                 copy = min_t(int, sizeof(veth), len);
-                ret = memcpy_toiovecend(iv, (void *)&veth, off, copy);
+                ret = memcpy_toiovecend(iv, (void *)&veth, copied, copy);
                 len -= copy;
-                off += copy;
+                copied += copy;
                 if (ret || !len)
                         goto done;
         }
 
-        ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, off, len);
-        copied += skb->len + (vlan_offset ? sizeof(veth) : 0);
+        ret = skb_copy_datagram_const_iovec(skb, vlan_offset, iv, copied, len);
+        copied += len;
 
 done:
         return ret ? ret : copied;
@@ -876,7 +875,7 @@ static ssize_t macvtap_aio_read(struct kiocb *iocb, const struct iovec *iv,
         }
 
         ret = macvtap_do_read(q, iocb, iv, len, file->f_flags & O_NONBLOCK);
-        ret = min_t(ssize_t, ret, len);
+        ret = min_t(ssize_t, ret, len); /* XXX copied from tun.c. Why? */
         if (ret > 0)
                 iocb->ki_pos = ret;
 out:
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index dd1bd7aedc3c..e26cbea1ce68 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1183,11 +1183,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
                             const struct iovec *iv, int len)
 {
         struct tun_pi pi = { 0, skb->protocol };
-        struct {
-                __be16 h_vlan_proto;
-                __be16 h_vlan_TCI;
-        } veth;
-        ssize_t total = 0, off = 0;
+        ssize_t total = 0;
         int vlan_offset = 0;
 
         if (!(tun->flags & TUN_NO_PI)) {
@@ -1252,11 +1248,14 @@ 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));
@@ -1265,22 +1264,22 @@ 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, off, copy);
+                ret = skb_copy_datagram_const_iovec(skb, 0, iv, total, copy);
                 len -= copy;
-                off += copy;
+                total += copy;
                 if (ret || !len)
                         goto done;
 
                 copy = min_t(int, sizeof(veth), len);
-                ret = memcpy_toiovecend(iv, (void *)&veth, off, copy);
+                ret = memcpy_toiovecend(iv, (void *)&veth, total, copy);
                 len -= copy;
-                off += copy;
+                total += copy;
                 if (ret || !len)
                         goto done;
         }
 
-        skb_copy_datagram_const_iovec(skb, vlan_offset, iv, off, len);
-        total += skb->len + (vlan_offset ? sizeof(veth) : 0);
+        skb_copy_datagram_const_iovec(skb, vlan_offset, iv, total, len);
+        total += len;
 
 done:
         tun->dev->stats.tx_packets++;