struct sk_buff *skb;
size_t len = total_len, align = NET_SKB_PAD, linear;
struct virtio_net_hdr gso = { 0 };
+ int good_linear;
int offset = 0;
int copylen;
bool zerocopy = false;
return -EINVAL;
}
+ good_linear = SKB_MAX_HEAD(align);
+
if (msg_control) {
/* There are 256 bytes to be copied in skb, so there is
* enough room for skb expand head in case it is used.
* The rest of the buffer is mapped from userspace.
*/
copylen = gso.hdr_len ? gso.hdr_len : GOODCOPY_LEN;
+ if (copylen > good_linear)
+ copylen = good_linear;
linear = copylen;
if (iov_pages(iv, offset + copylen, count) <= MAX_SKB_FRAGS)
zerocopy = true;
if (!zerocopy) {
copylen = len;
- linear = gso.hdr_len;
+ if (gso.hdr_len > good_linear)
+ linear = good_linear;
+ else
+ linear = gso.hdr_len;
}
skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
{
struct tun_pi pi = { 0, skb->protocol };
ssize_t total = 0;
- int vlan_offset = 0;
+ int vlan_offset = 0, copied;
if (!(tun->flags & TUN_NO_PI)) {
if ((len -= sizeof(pi)) < 0)
total += tun->vnet_hdr_sz;
}
+ copied = total;
+ total += skb->len;
if (!vlan_tx_tag_present(skb)) {
len = min_t(int, skb->len, len);
} else {
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, total, copy);
+ ret = skb_copy_datagram_const_iovec(skb, 0, iv, copied, copy);
len -= copy;
- total += copy;
+ copied += 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, copied, copy);
len -= copy;
- total += copy;
+ copied += 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, copied, len);
done:
tun->dev->stats.tx_packets++;
ret = tun_do_read(tun, tfile, iocb, iv, len,
file->f_flags & O_NONBLOCK);
ret = min_t(ssize_t, ret, len);
+ if (ret > 0)
+ iocb->ki_pos = ret;
out:
tun_put(tun);
return ret;