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path: root/drivers/net/tun_vnet.h
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Diffstat (limited to 'drivers/net/tun_vnet.h')
-rw-r--r--drivers/net/tun_vnet.h269
1 files changed, 269 insertions, 0 deletions
diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h
new file mode 100644
index 000000000000..81662328b2c7
--- /dev/null
+++ b/drivers/net/tun_vnet.h
@@ -0,0 +1,269 @@
+/* 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
+
+#define TUN_VNET_TNL_SIZE sizeof(struct virtio_net_hdr_v1_hash_tunnel)
+
+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 unsigned int tun_vnet_parse_size(netdev_features_t features)
+{
+ if (!(features & NETIF_F_GSO_UDP_TUNNEL))
+ return sizeof(struct virtio_net_hdr);
+
+ return TUN_VNET_TNL_SIZE;
+}
+
+static inline int __tun_vnet_hdr_get(int sz, unsigned int flags,
+ netdev_features_t features,
+ struct iov_iter *from,
+ struct virtio_net_hdr *hdr)
+{
+ unsigned int parsed_size = tun_vnet_parse_size(features);
+ u16 hdr_len;
+
+ if (iov_iter_count(from) < sz)
+ return -EINVAL;
+
+ if (!copy_from_iter_full(hdr, parsed_size, 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 - parsed_size);
+
+ return hdr_len;
+}
+
+static inline int tun_vnet_hdr_get(int sz, unsigned int flags,
+ struct iov_iter *from,
+ struct virtio_net_hdr *hdr)
+{
+ return __tun_vnet_hdr_get(sz, flags, 0, from, hdr);
+}
+
+static inline int __tun_vnet_hdr_put(int sz, netdev_features_t features,
+ struct iov_iter *iter,
+ const struct virtio_net_hdr *hdr)
+{
+ unsigned int parsed_size = tun_vnet_parse_size(features);
+
+ if (unlikely(iov_iter_count(iter) < sz))
+ return -EINVAL;
+
+ if (unlikely(copy_to_iter(hdr, parsed_size, iter) != parsed_size))
+ return -EFAULT;
+
+ if (iov_iter_zero(sz - parsed_size, iter) != sz - parsed_size)
+ return -EFAULT;
+
+ return 0;
+}
+
+static inline int tun_vnet_hdr_put(int sz, struct iov_iter *iter,
+ const struct virtio_net_hdr *hdr)
+{
+ return __tun_vnet_hdr_put(sz, 0, iter, hdr);
+}
+
+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));
+}
+
+/*
+ * Tun is not aware of the negotiated guest features, guess them from the
+ * virtio net hdr size
+ */
+static inline netdev_features_t tun_vnet_hdr_guest_features(int vnet_hdr_sz)
+{
+ if (vnet_hdr_sz >= TUN_VNET_TNL_SIZE)
+ return NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_UDP_TUNNEL_CSUM;
+ return 0;
+}
+
+static inline int
+tun_vnet_hdr_tnl_to_skb(unsigned int flags, netdev_features_t features,
+ struct sk_buff *skb,
+ const struct virtio_net_hdr_v1_hash_tunnel *hdr)
+{
+ return virtio_net_hdr_tnl_to_skb(skb, hdr,
+ features & NETIF_F_GSO_UDP_TUNNEL,
+ features & NETIF_F_GSO_UDP_TUNNEL_CSUM,
+ 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;
+}
+
+static inline int
+tun_vnet_hdr_tnl_from_skb(unsigned int flags,
+ const struct net_device *dev,
+ const struct sk_buff *skb,
+ struct virtio_net_hdr_v1_hash_tunnel *tnl_hdr)
+{
+ bool has_tnl_offload = !!(dev->features & NETIF_F_GSO_UDP_TUNNEL);
+ int vlan_hlen = skb_vlan_tag_present(skb) ? VLAN_HLEN : 0;
+
+ if (virtio_net_hdr_tnl_from_skb(skb, tnl_hdr, has_tnl_offload,
+ tun_vnet_is_little_endian(flags),
+ vlan_hlen)) {
+ struct virtio_net_hdr_v1 *hdr = &tnl_hdr->hash_hdr.hdr;
+ struct skb_shared_info *sinfo = skb_shinfo(skb);
+
+ if (net_ratelimit()) {
+ int hdr_len = tun_vnet16_to_cpu(flags, hdr->hdr_len);
+
+ 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(hdr_len, 64),
+ true);
+ }
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+#endif /* TUN_VNET_H */
generated by cgit v1.2.3 (git 2.39.0) at 2025-08-25 14:36:00 +0300