[PATCH v7 40/46] tun: TUN_VNET_LE support, fix sparse warnings for virtio headers

Michael S. Tsirkin
2014-11-30T15:14:49Z

Pretty straight-forward: convert all fields to/from
virtio endian-ness.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>
---
drivers/net/tun.c | 48 +++++++++++++++++++++++++++++-------------------
1 file changed, 29 insertions(+), 19 deletions(-)

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 36be4fd..c052bd6b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -111,7 +111,7 @@ do { \
#define TUN_FASYNC IFF_ATTACH_QUEUE

#define TUN_FEATURES (IFF_NO_PI | IFF_ONE_QUEUE | IFF_VNET_HDR | \
- IFF_MULTI_QUEUE)
+ IFF_VNET_LE | IFF_MULTI_QUEUE)
#define GOODCOPY_LEN 128

#define FLT_EXACT_COUNT 8
@@ -205,6 +205,16 @@ struct tun_struct {
u32 flow_count;
};

+static inline u16 tun16_to_cpu(struct tun_struct *tun, __virtio16 val)
+{
+ return __virtio16_to_cpu(tun->flags & IFF_VNET_LE, val);
+}
+
+static inline __virtio16 cpu_to_tun16(struct tun_struct *tun, u16 val)
+{
+ return __cpu_to_virtio16(tun->flags & IFF_VNET_LE, val);
+}
+
static inline u32 tun_hashfn(u32 rxhash)
{
return rxhash & 0x3ff;
@@ -1053,10 +1063,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
return -EFAULT;

if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
- gso.csum_start + gso.csum_offset + 2 > gso.hdr_len)
- gso.hdr_len = gso.csum_start + gso.csum_offset + 2;
+ tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2 > tun16_to_cpu(tun, gso.hdr_len))
+ gso.hdr_len = cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offset) + 2);

- if (gso.hdr_len > len)
+ if (tun16_to_cpu(tun, gso.hdr_len) > len)
return -EINVAL;
offset += tun->vnet_hdr_sz;
}
@@ -1064,7 +1074,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) {
align += NET_IP_ALIGN;
if (unlikely(len < ETH_HLEN ||
- (gso.hdr_len && gso.hdr_len < ETH_HLEN)))
+ (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN)))
return -EINVAL;
}

@@ -1075,7 +1085,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
* 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;
+ copylen = gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN;
if (copylen > good_linear)
copylen = good_linear;
linear = copylen;
@@ -1085,10 +1095,10 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,

if (!zerocopy) {
copylen = len;
- if (gso.hdr_len > good_linear)
+ if (tun16_to_cpu(tun, gso.hdr_len) > good_linear)
linear = good_linear;
else
- linear = gso.hdr_len;
+ linear = tun16_to_cpu(tun, gso.hdr_len);
}

skb = tun_alloc_skb(tfile, align, copylen, linear, noblock);
@@ -1115,8 +1125,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
}

if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
- if (!skb_partial_csum_set(skb, gso.csum_start,
- gso.csum_offset)) {
+ if (!skb_partial_csum_set(skb, tun16_to_cpu(tun, gso.csum_start),
+ tun16_to_cpu(tun, gso.csum_offset))) {
tun->dev->stats.rx_frame_errors++;
kfree_skb(skb);
return -EINVAL;
@@ -1184,7 +1194,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
if (gso.gso_type & VIRTIO_NET_HDR_GSO_ECN)
skb_shinfo(skb)->gso_type |= SKB_GSO_TCP_ECN;

- skb_shinfo(skb)->gso_size = gso.gso_size;
+ skb_shinfo(skb)->gso_size = tun16_to_cpu(tun, gso.gso_size);
if (skb_shinfo(skb)->gso_size == 0) {
tun->dev->stats.rx_frame_errors++;
kfree_skb(skb);
@@ -1276,8 +1286,8 @@ static ssize_t tun_put_user(struct tun_struct *tun,
struct skb_shared_info *sinfo = skb_shinfo(skb);

/* This is a hint as to how much should be linear. */
- gso.hdr_len = skb_headlen(skb);
- gso.gso_size = sinfo->gso_size;
+ gso.hdr_len = cpu_to_tun16(tun, skb_headlen(skb));
+ gso.gso_size = cpu_to_tun16(tun, sinfo->gso_size);
if (sinfo->gso_type & SKB_GSO_TCPV4)
gso.gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
else if (sinfo->gso_type & SKB_GSO_TCPV6)
@@ -1285,12 +1295,12 @@ static ssize_t tun_put_user(struct tun_struct *tun,
else {
pr_err("unexpected GSO type: "
"0x%x, gso_size %d, hdr_len %d\n",
- sinfo->gso_type, gso.gso_size,
- gso.hdr_len);
+ sinfo->gso_type, tun16_to_cpu(tun, gso.gso_size),
+ tun16_to_cpu(tun, gso.hdr_len));
print_hex_dump(KERN_ERR, "tun: ",
DUMP_PREFIX_NONE,
16, 1, skb->head,
- min((int)gso.hdr_len, 64), true);
+ min((int)tun16_to_cpu(tun, gso.hdr_len), 64), true);
WARN_ON_ONCE(1);
return -EINVAL;
}
@@ -1301,9 +1311,9 @@ 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) +
- vlan_hlen;
- gso.csum_offset = skb->csum_offset;
+ gso.csum_start = cpu_to_tun16(tun, skb_checksum_start_offset(skb) +
+ vlan_hlen);
+ gso.csum_offset = cpu_to_tun16(tun, skb->csum_offset);
} else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
gso.flags = VIRTIO_NET_HDR_F_DATA_VALID;
} /* else everything is zero */
--
MST