macvtap: TUN_VNET_LE support

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Jason Wang <jasowang@redhat.com>

1 files changed, 43 insertions, 25 deletions

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 880cc090dc44..af90ab5e5768 100644
--- a/drivers/net/macvtap.c
+++ b/drivers/net/macvtap.c
@@ -45,6 +45,18 @@ struct macvtap_queue {
         struct list_head next;
 };
 
+#define MACVTAP_FEATURES (IFF_VNET_HDR | IFF_VNET_LE | IFF_MULTI_QUEUE)
+
+static inline u16 macvtap16_to_cpu(struct macvtap_queue *q, __virtio16 val)
+{
+        return __virtio16_to_cpu(q->flags & IFF_VNET_LE, val);
+}
+
+static inline __virtio16 cpu_to_macvtap16(struct macvtap_queue *q, u16 val)
+{
+        return __cpu_to_virtio16(q->flags & IFF_VNET_LE, val);
+}
+
 static struct proto macvtap_proto = {
         .name = "macvtap",
         .owner = THIS_MODULE,
@@ -557,7 +569,8 @@ static inline struct sk_buff *macvtap_alloc_skb(struct sock *sk, size_t prepad,
  * macvtap_skb_from_vnet_hdr and macvtap_skb_to_vnet_hdr should
  * be shared with the tun/tap driver.
  */
-static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
+static int macvtap_skb_from_vnet_hdr(struct macvtap_queue *q,
+                                     struct sk_buff *skb,
                                      struct virtio_net_hdr *vnet_hdr)
 {
         unsigned short gso_type = 0;
@@ -588,13 +601,13 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
         }
 
         if (vnet_hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
-                if (!skb_partial_csum_set(skb, vnet_hdr->csum_start,
-                                          vnet_hdr->csum_offset))
+                if (!skb_partial_csum_set(skb, macvtap16_to_cpu(q, vnet_hdr->csum_start),
+                                          macvtap16_to_cpu(q, vnet_hdr->csum_offset)))
                         return -EINVAL;
         }
 
         if (vnet_hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
-                skb_shinfo(skb)->gso_size = vnet_hdr->gso_size;
+                skb_shinfo(skb)->gso_size = macvtap16_to_cpu(q, vnet_hdr->gso_size);
                 skb_shinfo(skb)->gso_type = gso_type;
 
                 /* Header must be checked, and gso_segs computed. */
@@ -604,8 +617,9 @@ static int macvtap_skb_from_vnet_hdr(struct sk_buff *skb,
         return 0;
 }
 
-static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
-                                   struct virtio_net_hdr *vnet_hdr)
+static void macvtap_skb_to_vnet_hdr(struct macvtap_queue *q,
+                                    const struct sk_buff *skb,
+                                    struct virtio_net_hdr *vnet_hdr)
 {
         memset(vnet_hdr, 0, sizeof(*vnet_hdr));
 
@@ -613,8 +627,8 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
                 struct skb_shared_info *sinfo = skb_shinfo(skb);
 
                 /* This is a hint as to how much should be linear. */
-                vnet_hdr->hdr_len = skb_headlen(skb);
-                vnet_hdr->gso_size = sinfo->gso_size;
+                vnet_hdr->hdr_len = cpu_to_macvtap16(q, skb_headlen(skb));
+                vnet_hdr->gso_size = cpu_to_macvtap16(q, sinfo->gso_size);
                 if (sinfo->gso_type & SKB_GSO_TCPV4)
                         vnet_hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
                 else if (sinfo->gso_type & SKB_GSO_TCPV6)
@@ -628,10 +642,13 @@ static void macvtap_skb_to_vnet_hdr(const struct sk_buff *skb,
 
         if (skb->ip_summed == CHECKSUM_PARTIAL) {
                 vnet_hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-                vnet_hdr->csum_start = skb_checksum_start_offset(skb);
                 if (vlan_tx_tag_present(skb))
-                        vnet_hdr->csum_start += VLAN_HLEN;
-                vnet_hdr->csum_offset = skb->csum_offset;
+                        vnet_hdr->csum_start = cpu_to_macvtap16(q,
+                                skb_checksum_start_offset(skb) + VLAN_HLEN);
+                else
+                        vnet_hdr->csum_start = cpu_to_macvtap16(q,
+                                skb_checksum_start_offset(skb));
+                vnet_hdr->csum_offset = cpu_to_macvtap16(q, skb->csum_offset);
         } else if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
                 vnet_hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
         } /* else everything is zero */
@@ -666,12 +683,14 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
                 if (err < 0)
                         goto err;
                 if ((vnet_hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) &&
-                     vnet_hdr.csum_start + vnet_hdr.csum_offset + 2 >
-                                                        vnet_hdr.hdr_len)
-                        vnet_hdr.hdr_len = vnet_hdr.csum_start +
-                                                vnet_hdr.csum_offset + 2;
+                     macvtap16_to_cpu(q, vnet_hdr.csum_start) +
+                     macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2 >
+                             macvtap16_to_cpu(q, vnet_hdr.hdr_len))
+                        vnet_hdr.hdr_len = cpu_to_macvtap16(q,
+                                 macvtap16_to_cpu(q, vnet_hdr.csum_start) +
+                                 macvtap16_to_cpu(q, vnet_hdr.csum_offset) + 2);
                 err = -EINVAL;
-                if (vnet_hdr.hdr_len > len)
+                if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > len)
                         goto err;
         }
 
@@ -684,7 +703,8 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
                 goto err;
 
         if (m && m->msg_control && sock_flag(&q->sk, SOCK_ZEROCOPY)) {
-                copylen = vnet_hdr.hdr_len ? vnet_hdr.hdr_len : GOODCOPY_LEN;
+                copylen = vnet_hdr.hdr_len ?
+                        macvtap16_to_cpu(q, vnet_hdr.hdr_len) : GOODCOPY_LEN;
                 if (copylen > good_linear)
                         copylen = good_linear;
                 linear = copylen;
@@ -695,10 +715,10 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
 
         if (!zerocopy) {
                 copylen = len;
-                if (vnet_hdr.hdr_len > good_linear)
+                if (macvtap16_to_cpu(q, vnet_hdr.hdr_len) > good_linear)
                         linear = good_linear;
                 else
-                        linear = vnet_hdr.hdr_len;
+                        linear = macvtap16_to_cpu(q, vnet_hdr.hdr_len);
         }
 
         skb = macvtap_alloc_skb(&q->sk, NET_IP_ALIGN, copylen,
@@ -725,7 +745,7 @@ static ssize_t macvtap_get_user(struct macvtap_queue *q, struct msghdr *m,
         skb->protocol = eth_hdr(skb)->h_proto;
 
         if (vnet_hdr_len) {
-                err = macvtap_skb_from_vnet_hdr(skb, &vnet_hdr);
+                err = macvtap_skb_from_vnet_hdr(q, skb, &vnet_hdr);
                 if (err)
                         goto err_kfree;
         }
@@ -791,7 +811,7 @@ static ssize_t macvtap_put_user(struct macvtap_queue *q,
                 if ((len -= vnet_hdr_len) < 0)
                         return -EINVAL;
 
-                macvtap_skb_to_vnet_hdr(skb, &vnet_hdr);
+                macvtap_skb_to_vnet_hdr(q, skb, &vnet_hdr);
 
                 if (memcpy_toiovecend(iv, (void *)&vnet_hdr, 0, sizeof(vnet_hdr)))
                         return -EFAULT;
@@ -1003,8 +1023,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
                         return -EFAULT;
 
                 ret = 0;
-                if ((u & ~(IFF_VNET_HDR | IFF_MULTI_QUEUE)) !=
-                    (IFF_NO_PI | IFF_TAP))
+                if ((u & ~MACVTAP_FEATURES) != (IFF_NO_PI | IFF_TAP))
                         ret = -EINVAL;
                 else
                         q->flags = u;
@@ -1036,8 +1055,7 @@ static long macvtap_ioctl(struct file *file, unsigned int cmd,
                 return ret;
 
         case TUNGETFEATURES:
-                if (put_user(IFF_TAP | IFF_NO_PI | IFF_VNET_HDR |
-                             IFF_MULTI_QUEUE, up))
+                if (put_user(IFF_TAP | IFF_NO_PI | MACVTAP_FEATURES, up))
                         return -EFAULT;
                 return 0;