| /* SPDX-License-Identifier: GPL-2.0 */ |
| #ifndef _LINUX_VIRTIO_NET_H |
| #define _LINUX_VIRTIO_NET_H |
| |
| #include <linux/if_vlan.h> |
| #include <uapi/linux/tcp.h> |
| #include <uapi/linux/udp.h> |
| #include <uapi/linux/virtio_net.h> |
| |
| static inline int virtio_net_hdr_set_proto(struct sk_buff *skb, |
| const struct virtio_net_hdr *hdr) |
| { |
| switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { |
| case VIRTIO_NET_HDR_GSO_TCPV4: |
| case VIRTIO_NET_HDR_GSO_UDP: |
| skb->protocol = cpu_to_be16(ETH_P_IP); |
| break; |
| case VIRTIO_NET_HDR_GSO_TCPV6: |
| skb->protocol = cpu_to_be16(ETH_P_IPV6); |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| static inline int virtio_net_hdr_to_skb(struct sk_buff *skb, |
| const struct virtio_net_hdr *hdr, |
| bool little_endian) |
| { |
| unsigned int gso_type = 0; |
| unsigned int thlen = 0; |
| 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) { |
| case VIRTIO_NET_HDR_GSO_TCPV4: |
| gso_type = SKB_GSO_TCPV4; |
| ip_proto = IPPROTO_TCP; |
| thlen = sizeof(struct tcphdr); |
| break; |
| case VIRTIO_NET_HDR_GSO_TCPV6: |
| gso_type = SKB_GSO_TCPV6; |
| ip_proto = IPPROTO_TCP; |
| thlen = sizeof(struct tcphdr); |
| break; |
| case VIRTIO_NET_HDR_GSO_UDP: |
| gso_type = SKB_GSO_UDP; |
| ip_proto = IPPROTO_UDP; |
| thlen = sizeof(struct udphdr); |
| break; |
| default: |
| return -EINVAL; |
| } |
| |
| if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN) |
| gso_type |= SKB_GSO_TCP_ECN; |
| |
| if (hdr->gso_size == 0) |
| return -EINVAL; |
| } |
| |
| skb_reset_mac_header(skb); |
| |
| if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { |
| u32 start = __virtio16_to_cpu(little_endian, hdr->csum_start); |
| u32 off = __virtio16_to_cpu(little_endian, hdr->csum_offset); |
| u32 needed = start + max_t(u32, thlen, off + sizeof(__sum16)); |
| |
| if (!pskb_may_pull(skb, needed)) |
| return -EINVAL; |
| |
| if (!skb_partial_csum_set(skb, start, off)) |
| return -EINVAL; |
| |
| p_off = skb_transport_offset(skb) + thlen; |
| if (!pskb_may_pull(skb, p_off)) |
| return -EINVAL; |
| } else { |
| /* gso packets without NEEDS_CSUM do not set transport_offset. |
| * probe and drop if does not match one of the above types. |
| */ |
| if (gso_type && skb->network_header) { |
| struct flow_keys_basic keys; |
| |
| if (!skb->protocol) { |
| __be16 protocol = dev_parse_header_protocol(skb); |
| |
| virtio_net_hdr_set_proto(skb, hdr); |
| if (protocol && protocol != skb->protocol) |
| return -EINVAL; |
| } |
| retry: |
| if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys, |
| NULL, 0, 0, 0, |
| 0)) { |
| /* UFO does not specify ipv4 or 6: try both */ |
| if (gso_type & SKB_GSO_UDP && |
| skb->protocol == htons(ETH_P_IP)) { |
| skb->protocol = htons(ETH_P_IPV6); |
| goto retry; |
| } |
| return -EINVAL; |
| } |
| |
| p_off = keys.control.thoff + thlen; |
| if (!pskb_may_pull(skb, p_off) || |
| keys.basic.ip_proto != ip_proto) |
| return -EINVAL; |
| |
| skb_set_transport_header(skb, keys.control.thoff); |
| } else if (gso_type) { |
| p_off = thlen; |
| if (!pskb_may_pull(skb, p_off)) |
| return -EINVAL; |
| } |
| } |
| |
| 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); |
| |
| /* UFO may not include transport header in gso_size. */ |
| if (gso_type & SKB_GSO_UDP) |
| nh_off -= thlen; |
| |
| /* Too small packets are not really GSO ones. */ |
| if (skb->len - nh_off > gso_size) { |
| shinfo->gso_size = gso_size; |
| shinfo->gso_type = gso_type; |
| |
| /* Header must be checked, and gso_segs computed. */ |
| shinfo->gso_type |= SKB_GSO_DODGY; |
| shinfo->gso_segs = 0; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, |
| struct virtio_net_hdr *hdr, |
| bool little_endian, |
| bool has_data_valid, |
| int vlan_hlen) |
| { |
| memset(hdr, 0, sizeof(*hdr)); /* no info leak */ |
| |
| if (skb_is_gso(skb)) { |
| struct skb_shared_info *sinfo = skb_shinfo(skb); |
| |
| /* This is a hint as to how much should be linear. */ |
| hdr->hdr_len = __cpu_to_virtio16(little_endian, |
| skb_headlen(skb)); |
| hdr->gso_size = __cpu_to_virtio16(little_endian, |
| sinfo->gso_size); |
| if (sinfo->gso_type & SKB_GSO_TCPV4) |
| hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4; |
| else if (sinfo->gso_type & SKB_GSO_TCPV6) |
| hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6; |
| else |
| return -EINVAL; |
| if (sinfo->gso_type & SKB_GSO_TCP_ECN) |
| hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN; |
| } else |
| hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE; |
| |
| if (skb->ip_summed == CHECKSUM_PARTIAL) { |
| hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM; |
| hdr->csum_start = __cpu_to_virtio16(little_endian, |
| skb_checksum_start_offset(skb) + vlan_hlen); |
| hdr->csum_offset = __cpu_to_virtio16(little_endian, |
| skb->csum_offset); |
| } else if (has_data_valid && |
| skb->ip_summed == CHECKSUM_UNNECESSARY) { |
| hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID; |
| } /* else everything is zero */ |
| |
| return 0; |
| } |
| |
| #endif /* _LINUX_VIRTIO_NET_H */ |