Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_VIRTIO_NET_H
3#define _LINUX_VIRTIO_NET_H
4
5#include <linux/if_vlan.h>
6#include <uapi/linux/virtio_net.h>
7
8static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
9 const struct virtio_net_hdr *hdr,
10 bool little_endian)
11{
12 unsigned short gso_type = 0;
13
14 if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
15 switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
16 case VIRTIO_NET_HDR_GSO_TCPV4:
17 gso_type = SKB_GSO_TCPV4;
18 break;
19 case VIRTIO_NET_HDR_GSO_TCPV6:
20 gso_type = SKB_GSO_TCPV6;
21 break;
22 default:
23 return -EINVAL;
24 }
25
26 if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
27 gso_type |= SKB_GSO_TCP_ECN;
28
29 if (hdr->gso_size == 0)
30 return -EINVAL;
31 }
32
33 if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
34 u16 start = __virtio16_to_cpu(little_endian, hdr->csum_start);
35 u16 off = __virtio16_to_cpu(little_endian, hdr->csum_offset);
36
37 if (!skb_partial_csum_set(skb, start, off))
38 return -EINVAL;
39 }
40
41 if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
42 u16 gso_size = __virtio16_to_cpu(little_endian, hdr->gso_size);
43
44 skb_shinfo(skb)->gso_size = gso_size;
45 skb_shinfo(skb)->gso_type = gso_type;
46
47 /* Header must be checked, and gso_segs computed. */
48 skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
49 skb_shinfo(skb)->gso_segs = 0;
50 }
51
52 return 0;
53}
54
55static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
56 struct virtio_net_hdr *hdr,
57 bool little_endian,
58 bool has_data_valid)
59{
60 memset(hdr, 0, sizeof(*hdr)); /* no info leak */
61
62 if (skb_is_gso(skb)) {
63 struct skb_shared_info *sinfo = skb_shinfo(skb);
64
65 /* This is a hint as to how much should be linear. */
66 hdr->hdr_len = __cpu_to_virtio16(little_endian,
67 skb_headlen(skb));
68 hdr->gso_size = __cpu_to_virtio16(little_endian,
69 sinfo->gso_size);
70 if (sinfo->gso_type & SKB_GSO_TCPV4)
71 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
72 else if (sinfo->gso_type & SKB_GSO_TCPV6)
73 hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
74 else
75 return -EINVAL;
76 if (sinfo->gso_type & SKB_GSO_TCP_ECN)
77 hdr->gso_type |= VIRTIO_NET_HDR_GSO_ECN;
78 } else
79 hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
80
81 if (skb->ip_summed == CHECKSUM_PARTIAL) {
82 hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
83 if (skb_vlan_tag_present(skb))
84 hdr->csum_start = __cpu_to_virtio16(little_endian,
85 skb_checksum_start_offset(skb) + VLAN_HLEN);
86 else
87 hdr->csum_start = __cpu_to_virtio16(little_endian,
88 skb_checksum_start_offset(skb));
89 hdr->csum_offset = __cpu_to_virtio16(little_endian,
90 skb->csum_offset);
91 } else if (has_data_valid &&
92 skb->ip_summed == CHECKSUM_UNNECESSARY) {
93 hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
94 } /* else everything is zero */
95
96 return 0;
97}
98
99#endif /* _LINUX_VIRTIO_NET_H */