diff options
Diffstat (limited to 'include/linux/virtio_net.h')
| -rw-r--r-- | include/linux/virtio_net.h | 197 |
1 files changed, 189 insertions, 8 deletions
diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 02a9f4dc594d..20e0584db1dd 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -47,9 +47,9 @@ static inline int virtio_net_hdr_set_proto(struct sk_buff *skb, return 0; } -static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, - const struct virtio_net_hdr *hdr, - bool little_endian) +static inline int __virtio_net_hdr_to_skb(struct sk_buff *skb, + const struct virtio_net_hdr *hdr, + bool little_endian, u8 hdr_gso_type) { unsigned int nh_min_len = sizeof(struct iphdr); unsigned int gso_type = 0; @@ -57,8 +57,8 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, unsigned int p_off = 0; unsigned int ip_proto; - if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { - switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { + if (hdr_gso_type != VIRTIO_NET_HDR_GSO_NONE) { + switch (hdr_gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: gso_type = SKB_GSO_TCPV4; ip_proto = IPPROTO_TCP; @@ -84,7 +84,7 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, return -EINVAL; } - if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) + if (hdr_gso_type & VIRTIO_NET_HDR_GSO_ECN) gso_type |= SKB_GSO_TCP_ECN; if (hdr->gso_size == 0) @@ -122,7 +122,8 @@ static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, if (!protocol) virtio_net_hdr_set_proto(skb, hdr); - else if (!virtio_net_hdr_match_proto(protocol, hdr->gso_type)) + else if (!virtio_net_hdr_match_proto(protocol, + hdr_gso_type)) return -EINVAL; else skb->protocol = protocol; @@ -153,7 +154,7 @@ retry: } } - if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) { + if (hdr_gso_type != VIRTIO_NET_HDR_GSO_NONE) { u16 gso_size = __virtio16_to_cpu(little_endian, hdr->gso_size); unsigned int nh_off = p_off; struct skb_shared_info *shinfo = skb_shinfo(skb); @@ -199,6 +200,13 @@ retry: return 0; } +static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, + const struct virtio_net_hdr *hdr, + bool little_endian) +{ + return __virtio_net_hdr_to_skb(skb, hdr, little_endian, hdr->gso_type); +} + static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, struct virtio_net_hdr *hdr, bool little_endian, @@ -242,4 +250,177 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, return 0; } +static inline unsigned int virtio_l3min(bool is_ipv6) +{ + return is_ipv6 ? sizeof(struct ipv6hdr) : sizeof(struct iphdr); +} + +static inline int +virtio_net_hdr_tnl_to_skb(struct sk_buff *skb, + const struct virtio_net_hdr_v1_hash_tunnel *vhdr, + bool tnl_hdr_negotiated, + bool tnl_csum_negotiated, + bool little_endian) +{ + const struct virtio_net_hdr *hdr = (const struct virtio_net_hdr *)vhdr; + unsigned int inner_nh, outer_th, inner_th; + unsigned int inner_l3min, outer_l3min; + u8 gso_inner_type, gso_tunnel_type; + bool outer_isv6, inner_isv6; + int ret; + + gso_tunnel_type = hdr->gso_type & VIRTIO_NET_HDR_GSO_UDP_TUNNEL; + if (!gso_tunnel_type) + return virtio_net_hdr_to_skb(skb, hdr, little_endian); + + /* Tunnel not supported/negotiated, but the hdr asks for it. */ + if (!tnl_hdr_negotiated) + return -EINVAL; + + /* Either ipv4 or ipv6. */ + if (gso_tunnel_type == VIRTIO_NET_HDR_GSO_UDP_TUNNEL) + return -EINVAL; + + /* The UDP tunnel must carry a GSO packet, but no UFO. */ + gso_inner_type = hdr->gso_type & ~(VIRTIO_NET_HDR_GSO_ECN | + VIRTIO_NET_HDR_GSO_UDP_TUNNEL); + if (!gso_inner_type || gso_inner_type == VIRTIO_NET_HDR_GSO_UDP) + return -EINVAL; + + /* Rely on csum being present. */ + if (!(hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)) + return -EINVAL; + + /* Validate offsets. */ + outer_isv6 = gso_tunnel_type & VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6; + inner_isv6 = gso_inner_type == VIRTIO_NET_HDR_GSO_TCPV6; + inner_l3min = virtio_l3min(inner_isv6); + outer_l3min = ETH_HLEN + virtio_l3min(outer_isv6); + + inner_th = __virtio16_to_cpu(little_endian, hdr->csum_start); + inner_nh = le16_to_cpu(vhdr->inner_nh_offset); + outer_th = le16_to_cpu(vhdr->outer_th_offset); + if (outer_th < outer_l3min || + inner_nh < outer_th + sizeof(struct udphdr) || + inner_th < inner_nh + inner_l3min) + return -EINVAL; + + /* Let the basic parsing deal with plain GSO features. */ + ret = __virtio_net_hdr_to_skb(skb, hdr, true, + hdr->gso_type & ~gso_tunnel_type); + if (ret) + return ret; + + /* In case of USO, the inner protocol is still unknown and + * `inner_isv6` is just a guess, additional parsing is needed. + * The previous validation ensures that accessing an ipv4 inner + * network header is safe. + */ + if (gso_inner_type == VIRTIO_NET_HDR_GSO_UDP_L4) { + struct iphdr *iphdr = (struct iphdr *)(skb->data + inner_nh); + + inner_isv6 = iphdr->version == 6; + inner_l3min = virtio_l3min(inner_isv6); + if (inner_th < inner_nh + inner_l3min) + return -EINVAL; + } + + skb_set_inner_protocol(skb, inner_isv6 ? htons(ETH_P_IPV6) : + htons(ETH_P_IP)); + if (hdr->flags & VIRTIO_NET_HDR_F_UDP_TUNNEL_CSUM) { + if (!tnl_csum_negotiated) + return -EINVAL; + + skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL_CSUM; + } else { + skb_shinfo(skb)->gso_type |= SKB_GSO_UDP_TUNNEL; + } + + skb->inner_transport_header = inner_th + skb_headroom(skb); + skb->inner_network_header = inner_nh + skb_headroom(skb); + skb->inner_mac_header = inner_nh + skb_headroom(skb); + skb->transport_header = outer_th + skb_headroom(skb); + skb->encapsulation = 1; + return 0; +} + +/* Checksum-related fields validation for the driver */ +static inline int virtio_net_handle_csum_offload(struct sk_buff *skb, + struct virtio_net_hdr *hdr, + bool tnl_csum_negotiated) +{ + if (!(hdr->gso_type & VIRTIO_NET_HDR_GSO_UDP_TUNNEL)) { + if (!(hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID)) + return 0; + + skb->ip_summed = CHECKSUM_UNNECESSARY; + if (!(hdr->flags & VIRTIO_NET_HDR_F_UDP_TUNNEL_CSUM)) + return 0; + + /* tunnel csum packets are invalid when the related + * feature has not been negotiated + */ + if (!tnl_csum_negotiated) + return -EINVAL; + skb->csum_level = 1; + return 0; + } + + /* DATA_VALID is mutually exclusive with NEEDS_CSUM, and GSO + * over UDP tunnel requires the latter + */ + if (hdr->flags & VIRTIO_NET_HDR_F_DATA_VALID) + return -EINVAL; + return 0; +} + +/* + * vlan_hlen always refers to the outermost MAC header. That also + * means it refers to the only MAC header, if the packet does not carry + * any encapsulation. + */ +static inline int +virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, + struct virtio_net_hdr_v1_hash_tunnel *vhdr, + bool tnl_hdr_negotiated, + bool little_endian, + int vlan_hlen) +{ + struct virtio_net_hdr *hdr = (struct virtio_net_hdr *)vhdr; + unsigned int inner_nh, outer_th; + int tnl_gso_type; + int ret; + + tnl_gso_type = skb_shinfo(skb)->gso_type & (SKB_GSO_UDP_TUNNEL | + SKB_GSO_UDP_TUNNEL_CSUM); + if (!tnl_gso_type) + return virtio_net_hdr_from_skb(skb, hdr, little_endian, false, + vlan_hlen); + + /* Tunnel support not negotiated but skb ask for it. */ + if (!tnl_hdr_negotiated) + return -EINVAL; + + /* Let the basic parsing deal with plain GSO features. */ + skb_shinfo(skb)->gso_type &= ~tnl_gso_type; + ret = virtio_net_hdr_from_skb(skb, hdr, true, false, vlan_hlen); + skb_shinfo(skb)->gso_type |= tnl_gso_type; + if (ret) + return ret; + + if (skb->protocol == htons(ETH_P_IPV6)) + hdr->gso_type |= VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6; + else + hdr->gso_type |= VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV4; + + if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP_TUNNEL_CSUM) + hdr->flags |= VIRTIO_NET_HDR_F_UDP_TUNNEL_CSUM; + + inner_nh = skb->inner_network_header - skb_headroom(skb); + outer_th = skb->transport_header - skb_headroom(skb); + vhdr->inner_nh_offset = cpu_to_le16(inner_nh); + vhdr->outer_th_offset = cpu_to_le16(outer_th); + return 0; +} + #endif /* _LINUX_VIRTIO_NET_H */ |