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Commit 2b11e678 authored by David S. Miller's avatar David S. Miller
Browse files

Merge branch 'tun-net' 



Herbert Xu says:

====================
tun: Fix csum_start and TUN_PKT_STRIP

The first patch fixes a serious problem that breaks checksum offload
in VMs while the second patch fixes a problem that probably affects
no one.
====================

Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 7071cf7f 2eb783c4

drivers/net/tun.c

+17 −11
Original line number Diff line number Diff line
@@ -1235,12 +1235,20 @@ 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;

	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;

		}
@@ -1250,9 +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)) {
@@ -1284,7 +1292,8 @@ 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;
@@ -1293,14 +1302,13 @@ 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;

	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 +1319,6 @@ 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);