Rusty Russell wrote:
> Add a IFF_VNET_HDR flag. This uses the same ABI as virtio_net (ie. prepending
> struct virtio_net_hdr to packets) to indicate GSO and checksum information.
>
> Signed-off-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> ---
> drivers/net/tun.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/if_tun.h | 2 +
> 2 files changed, 91 insertions(+), 1 deletion(-)
>
> diff -r d94590c1550a drivers/net/tun.c
> --- a/drivers/net/tun.c Thu Jun 26 00:21:11 2008 +1000
> +++ b/drivers/net/tun.c Thu Jun 26 00:21:59 2008 +1000
> @@ -63,6 +63,7 @@
> #include <linux/if_tun.h>
> #include <linux/crc32.h>
> #include <linux/nsproxy.h>
> +#include <linux/virtio_net.h>
> #include <net/net_namespace.h>
> #include <net/netns/generic.h>
>
> @@ -283,12 +284,24 @@ static __inline__ ssize_t tun_get_user(s
> struct tun_pi pi = { 0, __constant_htons(ETH_P_IP) };
> struct sk_buff *skb;
> size_t len = count, align = 0;
> + struct virtio_net_hdr gso = { 0 };
>
> if (!(tun->flags & TUN_NO_PI)) {
> if ((len -= sizeof(pi)) > count)
> return -EINVAL;
>
> if(memcpy_fromiovec((void *)&pi, iv, sizeof(pi)))
> + return -EFAULT;
> + }
> +
> + if (tun->flags & TUN_VNET_HDR) {
> + if ((len -= sizeof(gso)) > count)
> + return -EINVAL;
> +
> + if (gso.hdr_len > len)
> + return -EINVAL;
> +
> + if (memcpy_fromiovec((void *)&gso, iv, sizeof(gso)))
> return -EFAULT;
> }
Unless I'm missing something the 'if (gso.hdr_len > len)' must be after
memcpy_fromiovec().
> @@ -322,8 +335,45 @@ static __inline__ ssize_t tun_get_user(s
> break;
> };
>
> - if (tun->flags & TUN_NOCHECKSUM)
> + if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
> + if (!skb_partial_csum_set(skb, gso.csum_start,
> + gso.csum_offset)) {
> + tun->dev->stats.rx_dropped++;
> + kfree_skb(skb);
> + return -EINVAL;
> + }
> + } else if (tun->flags & TUN_NOCHECKSUM)
> skb->ip_summed = CHECKSUM_UNNECESSARY;
> +
> + if (gso.gso_type != VIRTIO_NET_HDR_GSO_NONE) {
> + pr_debug("GSO!\n");
> + switch (gso.gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
> + case VIRTIO_NET_HDR_GSO_TCPV4:
> + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV4;
> + break;
> + case VIRTIO_NET_HDR_GSO_TCPV6:
> + skb_shinfo(skb)->gso_type = SKB_GSO_TCPV6;
> + break;
> + default:
> + tun->dev->stats.rx_dropped++;
> + kfree_skb(skb);
> + return -EINVAL;
> + }
We should use stats.rx_frame_errors instead of stats.rx_dropped to indicated
that we dropped it because something was wrong with the framing (headers,
etc). Applies to both of the cases above.
> +
> + 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;
> + if (skb_shinfo(skb)->gso_size == 0) {
> + tun->dev->stats.rx_dropped++;
> + kfree_skb(skb);
> + return -EINVAL;
> + }
Same here.
Everything else looks good.
Max
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