macvtap: TUN_VNET_LE support

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

diff --git a/drivers/net/macvtap.c b/drivers/net/macvtap.c
index 880cc09..af90ab5 100644 (file)
--- 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;