Decouple the vnet handling code so that we can reuse it for tap.
Signed-off-by: Akihiko Odaki akihiko.odaki@daynix.com Reviewed-by: Willem de Bruijn willemb@google.com --- drivers/net/tun.c | 237 ++++++++++++++++++++++++++++++++---------------------- 1 file changed, 139 insertions(+), 98 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 28a1af1de9d704ed5cc51aac3d99bc095cb28ba5..a52c5d00e75c28bb1574f07f59be9f96702a6f0a 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -352,6 +352,127 @@ static inline __virtio16 cpu_to_tun16(unsigned int flags, u16 val) return __cpu_to_virtio16(tun_is_little_endian(flags), val); }
+static long tun_vnet_ioctl(int *vnet_hdr_sz, unsigned int *flags, + unsigned int cmd, int __user *sp) +{ + int s; + + switch (cmd) { + case TUNGETVNETHDRSZ: + s = *vnet_hdr_sz; + if (put_user(s, sp)) + return -EFAULT; + return 0; + + case TUNSETVNETHDRSZ: + if (get_user(s, sp)) + return -EFAULT; + if (s < (int)sizeof(struct virtio_net_hdr)) + return -EINVAL; + + *vnet_hdr_sz = s; + return 0; + + case TUNGETVNETLE: + s = !!(*flags & TUN_VNET_LE); + if (put_user(s, sp)) + return -EFAULT; + return 0; + + case TUNSETVNETLE: + if (get_user(s, sp)) + return -EFAULT; + if (s) + *flags |= TUN_VNET_LE; + else + *flags &= ~TUN_VNET_LE; + return 0; + + case TUNGETVNETBE: + return tun_get_vnet_be(*flags, sp); + + case TUNSETVNETBE: + return tun_set_vnet_be(flags, sp); + + default: + return -EINVAL; + } +} + +static int tun_vnet_hdr_get(int sz, unsigned int flags, struct iov_iter *from, + struct virtio_net_hdr *hdr) +{ + u16 hdr_len; + + if (iov_iter_count(from) < sz) + return -EINVAL; + + if (!copy_from_iter_full(hdr, sizeof(*hdr), from)) + return -EFAULT; + + hdr_len = tun16_to_cpu(flags, hdr->hdr_len); + + if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + hdr_len = max(tun16_to_cpu(flags, hdr->csum_start) + tun16_to_cpu(flags, hdr->csum_offset) + 2, hdr_len); + hdr->hdr_len = cpu_to_tun16(flags, hdr_len); + } + + if (hdr_len > iov_iter_count(from)) + return -EINVAL; + + iov_iter_advance(from, sz - sizeof(*hdr)); + + return hdr_len; +} + +static int tun_vnet_hdr_put(int sz, struct iov_iter *iter, + const struct virtio_net_hdr *hdr) +{ + if (unlikely(iov_iter_count(iter) < sz)) + return -EINVAL; + + if (unlikely(copy_to_iter(hdr, sizeof(*hdr), iter) != sizeof(*hdr))) + return -EFAULT; + + iov_iter_advance(iter, sz - sizeof(*hdr)); + + return 0; +} + +static int tun_vnet_hdr_to_skb(unsigned int flags, struct sk_buff *skb, + const struct virtio_net_hdr *hdr) +{ + return virtio_net_hdr_to_skb(skb, hdr, tun_is_little_endian(flags)); +} + +static int tun_vnet_hdr_from_skb(unsigned int flags, + const struct net_device *dev, + const struct sk_buff *skb, + struct virtio_net_hdr *hdr) +{ + int vlan_hlen = skb_vlan_tag_present(skb) ? VLAN_HLEN : 0; + + if (virtio_net_hdr_from_skb(skb, hdr, + tun_is_little_endian(flags), true, + vlan_hlen)) { + struct skb_shared_info *sinfo = skb_shinfo(skb); + + if (net_ratelimit()) { + netdev_err(dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len %d\n", + sinfo->gso_type, tun16_to_cpu(flags, hdr->gso_size), + tun16_to_cpu(flags, hdr->hdr_len)); + print_hex_dump(KERN_ERR, "tun: ", + DUMP_PREFIX_NONE, + 16, 1, skb->head, + min(tun16_to_cpu(flags, hdr->hdr_len), 64), true); + } + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + static inline u32 tun_hashfn(u32 rxhash) { return rxhash & TUN_MASK_FLOW_ENTRIES; @@ -1765,25 +1886,12 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile,
if (tun->flags & IFF_VNET_HDR) { int vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); - int flags = tun->flags; - - if (len < vnet_hdr_sz) - return -EINVAL; - len -= vnet_hdr_sz; - - if (!copy_from_iter_full(&gso, sizeof(gso), from)) - return -EFAULT; - - hdr_len = tun16_to_cpu(flags, gso.hdr_len);
- if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { - hdr_len = max(tun16_to_cpu(flags, gso.csum_start) + tun16_to_cpu(flags, gso.csum_offset) + 2, hdr_len); - gso.hdr_len = cpu_to_tun16(flags, hdr_len); - } + hdr_len = tun_vnet_hdr_get(vnet_hdr_sz, tun->flags, from, &gso); + if (hdr_len < 0) + return hdr_len;
- if (hdr_len > len) - return -EINVAL; - iov_iter_advance(from, vnet_hdr_sz - sizeof(gso)); + len -= vnet_hdr_sz; }
if ((tun->flags & TUN_TYPE_MASK) == IFF_TAP) { @@ -1857,7 +1965,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } }
- if (virtio_net_hdr_to_skb(skb, &gso, tun_is_little_endian(tun->flags))) { + if (tun_vnet_hdr_to_skb(tun->flags, skb, &gso)) { atomic_long_inc(&tun->rx_frame_errors); err = -EINVAL; goto free_skb; @@ -2052,18 +2160,15 @@ static ssize_t tun_put_user_xdp(struct tun_struct *tun, { int vnet_hdr_sz = 0; size_t size = xdp_frame->len; - size_t ret; + ssize_t ret;
if (tun->flags & IFF_VNET_HDR) { struct virtio_net_hdr gso = { 0 };
vnet_hdr_sz = READ_ONCE(tun->vnet_hdr_sz); - if (unlikely(iov_iter_count(iter) < vnet_hdr_sz)) - return -EINVAL; - if (unlikely(copy_to_iter(&gso, sizeof(gso), iter) != - sizeof(gso))) - return -EFAULT; - iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + ret = tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + if (ret) + return ret; }
ret = copy_to_iter(xdp_frame->data, size, iter) + vnet_hdr_sz; @@ -2086,6 +2191,7 @@ static ssize_t tun_put_user(struct tun_struct *tun, int vlan_offset = 0; int vlan_hlen = 0; int vnet_hdr_sz = 0; + int ret;
if (skb_vlan_tag_present(skb)) vlan_hlen = VLAN_HLEN; @@ -2111,33 +2217,14 @@ static ssize_t tun_put_user(struct tun_struct *tun,
if (vnet_hdr_sz) { struct virtio_net_hdr gso; - int flags = tun->flags; - - if (iov_iter_count(iter) < vnet_hdr_sz) - return -EINVAL; - - if (virtio_net_hdr_from_skb(skb, &gso, - tun_is_little_endian(flags), true, - vlan_hlen)) { - struct skb_shared_info *sinfo = skb_shinfo(skb); - - if (net_ratelimit()) { - netdev_err(tun->dev, "unexpected GSO type: 0x%x, gso_size %d, hdr_len %d\n", - sinfo->gso_type, tun16_to_cpu(flags, gso.gso_size), - tun16_to_cpu(flags, gso.hdr_len)); - print_hex_dump(KERN_ERR, "tun: ", - DUMP_PREFIX_NONE, - 16, 1, skb->head, - min((int)tun16_to_cpu(flags, gso.hdr_len), 64), true); - } - WARN_ON_ONCE(1); - return -EINVAL; - }
- if (copy_to_iter(&gso, sizeof(gso), iter) != sizeof(gso)) - return -EFAULT; + ret = tun_vnet_hdr_from_skb(tun->flags, tun->dev, skb, &gso); + if (ret) + return ret;
- iov_iter_advance(iter, vnet_hdr_sz - sizeof(gso)); + ret = tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + if (ret) + return ret; }
if (vlan_hlen) { @@ -2497,7 +2584,7 @@ static int tun_xdp_one(struct tun_struct *tun, skb_reserve(skb, xdp->data - xdp->data_hard_start); skb_put(skb, xdp->data_end - xdp->data);
- if (virtio_net_hdr_to_skb(skb, gso, tun_is_little_endian(tun->flags))) { + if (tun_vnet_hdr_to_skb(tun->flags, skb, gso)) { atomic_long_inc(&tun->rx_frame_errors); kfree_skb(skb); ret = -EINVAL; @@ -3081,8 +3168,6 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, kgid_t group; int ifindex; int sndbuf; - int vnet_hdr_sz; - int le; int ret; bool do_notify = false;
@@ -3289,50 +3374,6 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, tun_set_sndbuf(tun); break;
- case TUNGETVNETHDRSZ: - vnet_hdr_sz = tun->vnet_hdr_sz; - if (copy_to_user(argp, &vnet_hdr_sz, sizeof(vnet_hdr_sz))) - ret = -EFAULT; - break; - - case TUNSETVNETHDRSZ: - if (copy_from_user(&vnet_hdr_sz, argp, sizeof(vnet_hdr_sz))) { - ret = -EFAULT; - break; - } - if (vnet_hdr_sz < (int)sizeof(struct virtio_net_hdr)) { - ret = -EINVAL; - break; - } - - tun->vnet_hdr_sz = vnet_hdr_sz; - break; - - case TUNGETVNETLE: - le = !!(tun->flags & TUN_VNET_LE); - if (put_user(le, (int __user *)argp)) - ret = -EFAULT; - break; - - case TUNSETVNETLE: - if (get_user(le, (int __user *)argp)) { - ret = -EFAULT; - break; - } - if (le) - tun->flags |= TUN_VNET_LE; - else - tun->flags &= ~TUN_VNET_LE; - break; - - case TUNGETVNETBE: - ret = tun_get_vnet_be(tun->flags, argp); - break; - - case TUNSETVNETBE: - ret = tun_set_vnet_be(&tun->flags, argp); - break; - case TUNATTACHFILTER: /* Can be set only for TAPs */ ret = -EINVAL; @@ -3388,7 +3429,7 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, break;
default: - ret = -EINVAL; + ret = tun_vnet_ioctl(&tun->vnet_hdr_sz, &tun->flags, cmd, argp); break; }