[PATCH net-next 1/2] tun: remove unnecessary tun_xdp_hdr structure

[Jason Wang]

With f95f0f95cfb7("net, xdp: Introduce xdp_init_buff utility routine"),
buffer length could be stored as frame size so there's no need to have
a dedicated tun_xdp_hdr structure. We can simply store virtio net
header instead.

Signed-off-by: Jason Wang <jasow...@redhat.com>
---
 drivers/net/tap.c      | 5 ++---
 drivers/net/tun.c      | 5 ++---
 drivers/vhost/net.c    | 8 ++------
 include/linux/if_tun.h | 5 -----
 4 files changed, 6 insertions(+), 17 deletions(-)

diff --git a/drivers/net/tap.c b/drivers/net/tap.c
index bdf0788d8e66..d82eb7276a8b 100644
--- a/drivers/net/tap.c
+++ b/drivers/net/tap.c
@@ -1044,9 +1044,8 @@ static const struct file_operations tap_fops = {
 
 static int tap_get_user_xdp(struct tap_queue *q, struct xdp_buff *xdp)
 {
-       struct tun_xdp_hdr *hdr = xdp->data_hard_start;
-       struct virtio_net_hdr *gso = &hdr->gso;
-       int buflen = hdr->buflen;
+       struct virtio_net_hdr *gso = xdp->data_hard_start;
+       int buflen = xdp->frame_sz;
        int vnet_hdr_len = 0;
        struct tap_dev *tap;
        struct sk_buff *skb;
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 1207196cbbed..90055947a54b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2356,13 +2356,12 @@ static int tun_xdp_one(struct tun_struct *tun,
                       struct tun_page *tpage)
 {
        unsigned int datasize = xdp->data_end - xdp->data;
-       struct tun_xdp_hdr *hdr = xdp->data_hard_start;
-       struct virtio_net_hdr *gso = &hdr->gso;
+       struct virtio_net_hdr *gso = xdp->data_hard_start;
        struct bpf_prog *xdp_prog;
        struct sk_buff *skb = NULL;
        struct sk_buff_head *queue;
        u32 rxhash = 0, act;
-       int buflen = hdr->buflen;
+       int buflen = xdp->frame_sz;
        int metasize = 0;
        int ret = 0;
        bool skb_xdp = false;
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
index 7cbfc7d718b3..777eb6193985 100644
--- a/drivers/vhost/net.c
+++ b/drivers/vhost/net.c
@@ -668,7 +668,6 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue 
*nvq,
        struct socket *sock = vhost_vq_get_backend(vq);
        struct virtio_net_hdr *gso;
        struct xdp_buff *xdp = &nvq->xdp[nvq->batched_xdp];
-       struct tun_xdp_hdr *hdr;
        size_t len = iov_iter_count(from);
        int headroom = vhost_sock_xdp(sock) ? XDP_PACKET_HEADROOM : 0;
        int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
@@ -691,15 +690,13 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue 
*nvq,
        if (unlikely(!buf))
                return -ENOMEM;
 
-       copied = copy_from_iter(buf + offsetof(struct tun_xdp_hdr, gso),
-                               sock_hlen, from);
+       copied = copy_from_iter(buf, sock_hlen, from);
        if (copied != sock_hlen) {
                ret = -EFAULT;
                goto err;
        }
 
-       hdr = buf;
-       gso = &hdr->gso;
+       gso = buf;
 
        if (!sock_hlen)
                memset(buf, 0, pad);
@@ -727,7 +724,6 @@ static int vhost_net_build_xdp(struct vhost_net_virtqueue 
*nvq,
 
        xdp_init_buff(xdp, buflen, NULL);
        xdp_prepare_buff(xdp, buf, pad, len, true);
-       hdr->buflen = buflen;
 
        ++nvq->batched_xdp;
 
diff --git a/include/linux/if_tun.h b/include/linux/if_tun.h
index 043d442994b0..80166eb62f41 100644
--- a/include/linux/if_tun.h
+++ b/include/linux/if_tun.h
@@ -19,11 +19,6 @@ struct tun_msg_ctl {
        void *ptr;
 };
 
-struct tun_xdp_hdr {
-       int buflen;
-       struct virtio_net_hdr gso;
-};
-
 #if defined(CONFIG_TUN) || defined(CONFIG_TUN_MODULE)
 struct socket *tun_get_socket(struct file *);
 struct ptr_ring *tun_get_tx_ring(struct file *file);
-- 
2.34.1