diff options
Diffstat (limited to 'drivers/net/tun_vnet.h')
| -rw-r--r-- | drivers/net/tun_vnet.h | 186 |
1 files changed, 186 insertions, 0 deletions
diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h new file mode 100644 index 000000000000..58b9ac7a5fc4 --- /dev/null +++ b/drivers/net/tun_vnet.h @@ -0,0 +1,186 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +#ifndef TUN_VNET_H +#define TUN_VNET_H + +/* High bits in flags field are unused. */ +#define TUN_VNET_LE 0x80000000 +#define TUN_VNET_BE 0x40000000 + +static inline bool tun_vnet_legacy_is_little_endian(unsigned int flags) +{ + bool be = IS_ENABLED(CONFIG_TUN_VNET_CROSS_LE) && + (flags & TUN_VNET_BE); + + return !be && virtio_legacy_is_little_endian(); +} + +static inline long tun_get_vnet_be(unsigned int flags, int __user *argp) +{ + int be = !!(flags & TUN_VNET_BE); + + if (!IS_ENABLED(CONFIG_TUN_VNET_CROSS_LE)) + return -EINVAL; + + if (put_user(be, argp)) + return -EFAULT; + + return 0; +} + +static inline long tun_set_vnet_be(unsigned int *flags, int __user *argp) +{ + int be; + + if (!IS_ENABLED(CONFIG_TUN_VNET_CROSS_LE)) + return -EINVAL; + + if (get_user(be, argp)) + return -EFAULT; + + if (be) + *flags |= TUN_VNET_BE; + else + *flags &= ~TUN_VNET_BE; + + return 0; +} + +static inline bool tun_vnet_is_little_endian(unsigned int flags) +{ + return flags & TUN_VNET_LE || tun_vnet_legacy_is_little_endian(flags); +} + +static inline u16 tun_vnet16_to_cpu(unsigned int flags, __virtio16 val) +{ + return __virtio16_to_cpu(tun_vnet_is_little_endian(flags), val); +} + +static inline __virtio16 cpu_to_tun_vnet16(unsigned int flags, u16 val) +{ + return __cpu_to_virtio16(tun_vnet_is_little_endian(flags), val); +} + +static inline 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 inline 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 = tun_vnet16_to_cpu(flags, hdr->hdr_len); + + if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + hdr_len = max(tun_vnet16_to_cpu(flags, hdr->csum_start) + tun_vnet16_to_cpu(flags, hdr->csum_offset) + 2, hdr_len); + hdr->hdr_len = cpu_to_tun_vnet16(flags, hdr_len); + } + + if (hdr_len > iov_iter_count(from)) + return -EINVAL; + + iov_iter_advance(from, sz - sizeof(*hdr)); + + return hdr_len; +} + +static inline 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; + + if (iov_iter_zero(sz - sizeof(*hdr), iter) != sz - sizeof(*hdr)) + return -EFAULT; + + return 0; +} + +static inline 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_vnet_is_little_endian(flags)); +} + +static inline 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_vnet_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, tun_vnet16_to_cpu(flags, hdr->gso_size), + tun_vnet16_to_cpu(flags, hdr->hdr_len)); + print_hex_dump(KERN_ERR, "tun: ", + DUMP_PREFIX_NONE, + 16, 1, skb->head, + min(tun_vnet16_to_cpu(flags, hdr->hdr_len), 64), true); + } + WARN_ON_ONCE(1); + return -EINVAL; + } + + return 0; +} + +#endif /* TUN_VNET_H */ |