diff --git a/drivers/net/tun.c b/drivers/net/tun.c index f8c5e2fd04df..abc91f28dac4 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -186,7 +186,8 @@ struct tun_struct { struct net_device *dev; netdev_features_t set_features; #define TUN_USER_FEATURES (NETIF_F_HW_CSUM|NETIF_F_TSO_ECN|NETIF_F_TSO| \ - NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4) + NETIF_F_TSO6 | NETIF_F_GSO_UDP_L4 | \ + NETIF_F_GSO_UDP_TUNNEL | NETIF_F_GSO_UDP_TUNNEL_CSUM) int align; int vnet_hdr_sz; @@ -925,6 +926,7 @@ static int tun_net_init(struct net_device *dev) dev->hw_features = NETIF_F_SG | NETIF_F_FRAGLIST | TUN_USER_FEATURES | NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_HW_VLAN_STAG_TX; + dev->hw_enc_features = dev->hw_features; dev->features = dev->hw_features; dev->vlan_features = dev->features & ~(NETIF_F_HW_VLAN_CTAG_TX | @@ -1698,7 +1700,8 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, struct sk_buff *skb; size_t total_len = iov_iter_count(from); size_t len = total_len, align = tun->align, linear; - struct virtio_net_hdr gso = { 0 }; + struct virtio_net_hdr_v1_hash_tunnel hdr; + struct virtio_net_hdr *gso; int good_linear; int copylen; int hdr_len = 0; @@ -1708,6 +1711,15 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, int skb_xdp = 1; bool frags = tun_napi_frags_enabled(tfile); enum skb_drop_reason drop_reason = SKB_DROP_REASON_NOT_SPECIFIED; + netdev_features_t features = 0; + + /* + * Keep it easy and always zero the whole buffer, even if the + * tunnel-related field will be touched only when the feature + * is enabled and the hdr size id compatible. + */ + memset(&hdr, 0, sizeof(hdr)); + gso = (struct virtio_net_hdr *)&hdr; if (!(tun->flags & IFF_NO_PI)) { if (len < sizeof(pi)) @@ -1721,7 +1733,9 @@ 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); - hdr_len = tun_vnet_hdr_get(vnet_hdr_sz, tun->flags, from, &gso); + features = tun_vnet_hdr_guest_features(vnet_hdr_sz); + hdr_len = __tun_vnet_hdr_get(vnet_hdr_sz, tun->flags, + features, from, gso); if (hdr_len < 0) return hdr_len; @@ -1755,7 +1769,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, * (e.g gso or jumbo packet), we will do it at after * skb was created with generic XDP routine. */ - skb = tun_build_skb(tun, tfile, from, &gso, len, &skb_xdp); + skb = tun_build_skb(tun, tfile, from, gso, len, &skb_xdp); err = PTR_ERR_OR_ZERO(skb); if (err) goto drop; @@ -1799,7 +1813,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, } } - if (tun_vnet_hdr_to_skb(tun->flags, skb, &gso)) { + if (tun_vnet_hdr_tnl_to_skb(tun->flags, features, skb, &hdr)) { atomic_long_inc(&tun->rx_frame_errors); err = -EINVAL; goto free_skb; @@ -2050,13 +2064,21 @@ static ssize_t tun_put_user(struct tun_struct *tun, } if (vnet_hdr_sz) { - struct virtio_net_hdr gso; + struct virtio_net_hdr_v1_hash_tunnel hdr; + struct virtio_net_hdr *gso; - ret = tun_vnet_hdr_from_skb(tun->flags, tun->dev, skb, &gso); + ret = tun_vnet_hdr_tnl_from_skb(tun->flags, tun->dev, skb, + &hdr); if (ret) return ret; - ret = tun_vnet_hdr_put(vnet_hdr_sz, iter, &gso); + /* + * Drop the packet if the configured header size is too small + * WRT the enabled offloads. + */ + gso = (struct virtio_net_hdr *)&hdr; + ret = __tun_vnet_hdr_put(vnet_hdr_sz, tun->dev->features, + iter, gso); if (ret) return ret; } @@ -2357,10 +2379,12 @@ static int tun_xdp_one(struct tun_struct *tun, { unsigned int datasize = xdp->data_end - xdp->data; struct tun_xdp_hdr *hdr = xdp->data_hard_start; + struct virtio_net_hdr_v1_hash_tunnel *tnl_hdr; struct virtio_net_hdr *gso = &hdr->gso; struct bpf_prog *xdp_prog; struct sk_buff *skb = NULL; struct sk_buff_head *queue; + netdev_features_t features; u32 rxhash = 0, act; int buflen = hdr->buflen; int metasize = 0; @@ -2426,7 +2450,9 @@ static int tun_xdp_one(struct tun_struct *tun, if (metasize > 0) skb_metadata_set(skb, metasize); - if (tun_vnet_hdr_to_skb(tun->flags, skb, gso)) { + features = tun_vnet_hdr_guest_features(READ_ONCE(tun->vnet_hdr_sz)); + tnl_hdr = (struct virtio_net_hdr_v1_hash_tunnel *)gso; + if (tun_vnet_hdr_tnl_to_skb(tun->flags, features, skb, tnl_hdr)) { atomic_long_inc(&tun->rx_frame_errors); kfree_skb(skb); ret = -EINVAL; @@ -2812,6 +2838,8 @@ static void tun_get_iff(struct tun_struct *tun, struct ifreq *ifr) } +#define PLAIN_GSO (NETIF_F_GSO_UDP_L4 | NETIF_F_TSO | NETIF_F_TSO6) + /* This is like a cut-down ethtool ops, except done via tun fd so no * privs required. */ static int set_offload(struct tun_struct *tun, unsigned long arg) @@ -2841,6 +2869,18 @@ static int set_offload(struct tun_struct *tun, unsigned long arg) features |= NETIF_F_GSO_UDP_L4; arg &= ~(TUN_F_USO4 | TUN_F_USO6); } + + /* + * Tunnel offload is allowed only if some plain offload is + * available, too. + */ + if (features & PLAIN_GSO && arg & TUN_F_UDP_TUNNEL_GSO) { + features |= NETIF_F_GSO_UDP_TUNNEL; + if (arg & TUN_F_UDP_TUNNEL_GSO_CSUM) + features |= NETIF_F_GSO_UDP_TUNNEL_CSUM; + arg &= ~(TUN_F_UDP_TUNNEL_GSO | + TUN_F_UDP_TUNNEL_GSO_CSUM); + } } /* This gives the user a way to test for new features in future by diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h index 58b9ac7a5fc4..81662328b2c7 100644 --- a/drivers/net/tun_vnet.h +++ b/drivers/net/tun_vnet.h @@ -6,6 +6,8 @@ #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) && @@ -107,16 +109,26 @@ static inline long tun_vnet_ioctl(int *vnet_hdr_sz, unsigned int *flags, } } -static inline int tun_vnet_hdr_get(int sz, unsigned int flags, - struct iov_iter *from, - struct virtio_net_hdr *hdr) +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, sizeof(*hdr), from)) + if (!copy_from_iter_full(hdr, parsed_size, from)) return -EFAULT; hdr_len = tun_vnet16_to_cpu(flags, hdr->hdr_len); @@ -129,24 +141,40 @@ static inline int tun_vnet_hdr_get(int sz, unsigned int flags, if (hdr_len > iov_iter_count(from)) return -EINVAL; - iov_iter_advance(from, sz - sizeof(*hdr)); + 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) { - 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; + return __tun_vnet_hdr_put(sz, 0, iter, hdr); } static inline int tun_vnet_hdr_to_skb(unsigned int flags, struct sk_buff *skb, @@ -155,6 +183,28 @@ static inline int tun_vnet_hdr_to_skb(unsigned int flags, struct sk_buff *skb, 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, @@ -183,4 +233,37 @@ static inline int tun_vnet_hdr_from_skb(unsigned int flags, 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 */ diff --git a/include/uapi/linux/if_tun.h b/include/uapi/linux/if_tun.h index 287cdc81c939..79d53c7a1ebd 100644 --- a/include/uapi/linux/if_tun.h +++ b/include/uapi/linux/if_tun.h @@ -93,6 +93,15 @@ #define TUN_F_USO4 0x20 /* I can handle USO for IPv4 packets */ #define TUN_F_USO6 0x40 /* I can handle USO for IPv6 packets */ +/* I can handle TSO/USO for UDP tunneled packets */ +#define TUN_F_UDP_TUNNEL_GSO 0x080 + +/* + * I can handle TSO/USO for UDP tunneled packets requiring csum offload for + * the outer header + */ +#define TUN_F_UDP_TUNNEL_GSO_CSUM 0x100 + /* Protocol info prepended to the packets (when IFF_NO_PI is not set) */ #define TUN_PKT_STRIP 0x0001 struct tun_pi {