1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_VIRTIO_NET_H
3 #define _LINUX_VIRTIO_NET_H
5 #include <linux/if_vlan.h>
6 #include <uapi/linux/tcp.h>
7 #include <uapi/linux/udp.h>
8 #include <uapi/linux/virtio_net.h>
10 static inline int virtio_net_hdr_set_proto(struct sk_buff
*skb
,
11 const struct virtio_net_hdr
*hdr
)
13 switch (hdr
->gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
14 case VIRTIO_NET_HDR_GSO_TCPV4
:
15 case VIRTIO_NET_HDR_GSO_UDP
:
16 skb
->protocol
= cpu_to_be16(ETH_P_IP
);
18 case VIRTIO_NET_HDR_GSO_TCPV6
:
19 skb
->protocol
= cpu_to_be16(ETH_P_IPV6
);
28 static inline int virtio_net_hdr_to_skb(struct sk_buff
*skb
,
29 const struct virtio_net_hdr
*hdr
,
32 unsigned int gso_type
= 0;
33 unsigned int thlen
= 0;
34 unsigned int p_off
= 0;
35 unsigned int ip_proto
;
37 if (hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
38 switch (hdr
->gso_type
& ~VIRTIO_NET_HDR_GSO_ECN
) {
39 case VIRTIO_NET_HDR_GSO_TCPV4
:
40 gso_type
= SKB_GSO_TCPV4
;
41 ip_proto
= IPPROTO_TCP
;
42 thlen
= sizeof(struct tcphdr
);
44 case VIRTIO_NET_HDR_GSO_TCPV6
:
45 gso_type
= SKB_GSO_TCPV6
;
46 ip_proto
= IPPROTO_TCP
;
47 thlen
= sizeof(struct tcphdr
);
49 case VIRTIO_NET_HDR_GSO_UDP
:
50 gso_type
= SKB_GSO_UDP
;
51 ip_proto
= IPPROTO_UDP
;
52 thlen
= sizeof(struct udphdr
);
58 if (hdr
->gso_type
& VIRTIO_NET_HDR_GSO_ECN
)
59 gso_type
|= SKB_GSO_TCP_ECN
;
61 if (hdr
->gso_size
== 0)
65 skb_reset_mac_header(skb
);
67 if (hdr
->flags
& VIRTIO_NET_HDR_F_NEEDS_CSUM
) {
68 u32 start
= __virtio16_to_cpu(little_endian
, hdr
->csum_start
);
69 u32 off
= __virtio16_to_cpu(little_endian
, hdr
->csum_offset
);
70 u32 needed
= start
+ max_t(u32
, thlen
, off
+ sizeof(__sum16
));
72 if (!pskb_may_pull(skb
, needed
))
75 if (!skb_partial_csum_set(skb
, start
, off
))
78 p_off
= skb_transport_offset(skb
) + thlen
;
79 if (!pskb_may_pull(skb
, p_off
))
82 /* gso packets without NEEDS_CSUM do not set transport_offset.
83 * probe and drop if does not match one of the above types.
85 if (gso_type
&& skb
->network_header
) {
86 struct flow_keys_basic keys
;
89 __be16 protocol
= dev_parse_header_protocol(skb
);
91 virtio_net_hdr_set_proto(skb
, hdr
);
92 if (protocol
&& protocol
!= skb
->protocol
)
96 if (!skb_flow_dissect_flow_keys_basic(NULL
, skb
, &keys
,
99 /* UFO does not specify ipv4 or 6: try both */
100 if (gso_type
& SKB_GSO_UDP
&&
101 skb
->protocol
== htons(ETH_P_IP
)) {
102 skb
->protocol
= htons(ETH_P_IPV6
);
108 p_off
= keys
.control
.thoff
+ thlen
;
109 if (!pskb_may_pull(skb
, p_off
) ||
110 keys
.basic
.ip_proto
!= ip_proto
)
113 skb_set_transport_header(skb
, keys
.control
.thoff
);
114 } else if (gso_type
) {
116 if (!pskb_may_pull(skb
, p_off
))
121 if (hdr
->gso_type
!= VIRTIO_NET_HDR_GSO_NONE
) {
122 u16 gso_size
= __virtio16_to_cpu(little_endian
, hdr
->gso_size
);
123 struct skb_shared_info
*shinfo
= skb_shinfo(skb
);
125 /* Too small packets are not really GSO ones. */
126 if (skb
->len
- p_off
> gso_size
) {
127 shinfo
->gso_size
= gso_size
;
128 shinfo
->gso_type
= gso_type
;
130 /* Header must be checked, and gso_segs computed. */
131 shinfo
->gso_type
|= SKB_GSO_DODGY
;
132 shinfo
->gso_segs
= 0;
139 static inline int virtio_net_hdr_from_skb(const struct sk_buff
*skb
,
140 struct virtio_net_hdr
*hdr
,
145 memset(hdr
, 0, sizeof(*hdr
)); /* no info leak */
147 if (skb_is_gso(skb
)) {
148 struct skb_shared_info
*sinfo
= skb_shinfo(skb
);
150 /* This is a hint as to how much should be linear. */
151 hdr
->hdr_len
= __cpu_to_virtio16(little_endian
,
153 hdr
->gso_size
= __cpu_to_virtio16(little_endian
,
155 if (sinfo
->gso_type
& SKB_GSO_TCPV4
)
156 hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV4
;
157 else if (sinfo
->gso_type
& SKB_GSO_TCPV6
)
158 hdr
->gso_type
= VIRTIO_NET_HDR_GSO_TCPV6
;
161 if (sinfo
->gso_type
& SKB_GSO_TCP_ECN
)
162 hdr
->gso_type
|= VIRTIO_NET_HDR_GSO_ECN
;
164 hdr
->gso_type
= VIRTIO_NET_HDR_GSO_NONE
;
166 if (skb
->ip_summed
== CHECKSUM_PARTIAL
) {
167 hdr
->flags
= VIRTIO_NET_HDR_F_NEEDS_CSUM
;
168 hdr
->csum_start
= __cpu_to_virtio16(little_endian
,
169 skb_checksum_start_offset(skb
) + vlan_hlen
);
170 hdr
->csum_offset
= __cpu_to_virtio16(little_endian
,
172 } else if (has_data_valid
&&
173 skb
->ip_summed
== CHECKSUM_UNNECESSARY
) {
174 hdr
->flags
= VIRTIO_NET_HDR_F_DATA_VALID
;
175 } /* else everything is zero */
180 #endif /* _LINUX_VIRTIO_NET_H */