[linux-block.git] / include / linux / virtio_net.h

/* 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 bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type)
{
	switch (gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
	case VIRTIO_NET_HDR_GSO_TCPV4:
		return protocol == cpu_to_be16(ETH_P_IP);
	case VIRTIO_NET_HDR_GSO_TCPV6:
		return protocol == cpu_to_be16(ETH_P_IPV6);
	case VIRTIO_NET_HDR_GSO_UDP:
		return protocol == cpu_to_be16(ETH_P_IP) ||
		       protocol == cpu_to_be16(ETH_P_IPV6);
	default:
		return false;
	}
}

static inline int virtio_net_hdr_set_proto(struct sk_buff *skb,
					   const struct virtio_net_hdr *hdr)
{
	if (skb->protocol)
		return 0;

	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);

				if (!protocol)
					virtio_net_hdr_set_proto(skb, hdr);
				else if (!virtio_net_hdr_match_proto(protocol, hdr->gso_type))
					return -EINVAL;
				else
					skb->protocol = protocol;
			}
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 */
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
fd2a0437 MR	2	#ifndef _LINUX_VIRTIO_NET_H
	3	#define _LINUX_VIRTIO_NET_H
	4
	5	#include <linux/if_vlan.h>
9274124f WB	6	#include <uapi/linux/tcp.h>
9274124f WB	7	#include <uapi/linux/udp.h>
fd2a0437 MR	8	#include <uapi/linux/virtio_net.h>
fd2a0437 MR	9
7e5cced9 WB	10	static inline bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type)
	11	{
	12	switch (gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
	13	case VIRTIO_NET_HDR_GSO_TCPV4:
	14	return protocol == cpu_to_be16(ETH_P_IP);
	15	case VIRTIO_NET_HDR_GSO_TCPV6:
	16	return protocol == cpu_to_be16(ETH_P_IPV6);
	17	case VIRTIO_NET_HDR_GSO_UDP:
	18	return protocol == cpu_to_be16(ETH_P_IP) \|\|
	19	protocol == cpu_to_be16(ETH_P_IPV6);
	20	default:
	21	return false;
	22	}
	23	}
	24
9d2f67e4 JT	25	static inline int virtio_net_hdr_set_proto(struct sk_buff *skb,
	26	const struct virtio_net_hdr *hdr)
	27	{
1ed1d592 WB	28	if (skb->protocol)
	29	return 0;
	30
9d2f67e4 JT	31	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
	32	case VIRTIO_NET_HDR_GSO_TCPV4:
	33	case VIRTIO_NET_HDR_GSO_UDP:
	34	skb->protocol = cpu_to_be16(ETH_P_IP);
	35	break;
	36	case VIRTIO_NET_HDR_GSO_TCPV6:
	37	skb->protocol = cpu_to_be16(ETH_P_IPV6);
	38	break;
	39	default:
	40	return -EINVAL;
	41	}
	42
	43	return 0;
	44	}
	45
fd2a0437 MR	46	static inline int virtio_net_hdr_to_skb(struct sk_buff *skb,
	47	const struct virtio_net_hdr *hdr,
	48	bool little_endian)
	49	{
0c19f846	50	unsigned int gso_type = 0;
9274124f	51	unsigned int thlen = 0;
6dd912f8	52	unsigned int p_off = 0;
9274124f	53	unsigned int ip_proto;
fd2a0437 MR	54
	55	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
	56	switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) {
	57	case VIRTIO_NET_HDR_GSO_TCPV4:
	58	gso_type = SKB_GSO_TCPV4;
9274124f WB	59	ip_proto = IPPROTO_TCP;
9274124f WB	60	thlen = sizeof(struct tcphdr);
fd2a0437 MR	61	break;
	62	case VIRTIO_NET_HDR_GSO_TCPV6:
	63	gso_type = SKB_GSO_TCPV6;
9274124f WB	64	ip_proto = IPPROTO_TCP;
9274124f WB	65	thlen = sizeof(struct tcphdr);
fd2a0437	66	break;
0c19f846 WB	67	case VIRTIO_NET_HDR_GSO_UDP:
0c19f846 WB	68	gso_type = SKB_GSO_UDP;
9274124f WB	69	ip_proto = IPPROTO_UDP;
9274124f WB	70	thlen = sizeof(struct udphdr);
0c19f846	71	break;
fd2a0437 MR	72	default:
	73	return -EINVAL;
	74	}
	75
	76	if (hdr->gso_type & VIRTIO_NET_HDR_GSO_ECN)
	77	gso_type \|= SKB_GSO_TCP_ECN;
	78
	79	if (hdr->gso_size == 0)
	80	return -EINVAL;
	81	}
	82
61431a59 ED	83	skb_reset_mac_header(skb);
61431a59 ED	84
fd2a0437	85	if (hdr->flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) {
0f6925b3 ED	86	u32 start = __virtio16_to_cpu(little_endian, hdr->csum_start);
	87	u32 off = __virtio16_to_cpu(little_endian, hdr->csum_offset);
	88	u32 needed = start + max_t(u32, thlen, off + sizeof(__sum16));
	89
	90	if (!pskb_may_pull(skb, needed))
	91	return -EINVAL;
fd2a0437 MR	92
	93	if (!skb_partial_csum_set(skb, start, off))
	94	return -EINVAL;
9274124f	95
6dd912f8	96	p_off = skb_transport_offset(skb) + thlen;
0f6925b3	97	if (!pskb_may_pull(skb, p_off))
9274124f	98	return -EINVAL;
d5be7f63 WB	99	} else {
	100	/* gso packets without NEEDS_CSUM do not set transport_offset.
	101	* probe and drop if does not match one of the above types.
	102	*/
9e8db591	103	if (gso_type && skb->network_header) {
9274124f WB	104	struct flow_keys_basic keys;
9274124f WB	105
924a9bc3 BN	106	if (!skb->protocol) {
	107	__be16 protocol = dev_parse_header_protocol(skb);
	108
7e5cced9 WB	109	if (!protocol)
	110	virtio_net_hdr_set_proto(skb, hdr);
	111	else if (!virtio_net_hdr_match_proto(protocol, hdr->gso_type))
924a9bc3	112	return -EINVAL;
7e5cced9 WB	113	else
7e5cced9 WB	114	skb->protocol = protocol;
924a9bc3	115	}
9e8db591	116	retry:
9274124f WB	117	if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
	118	NULL, 0, 0, 0,
	119	0)) {
9e8db591 WB	120	/* UFO does not specify ipv4 or 6: try both */
	121	if (gso_type & SKB_GSO_UDP &&
	122	skb->protocol == htons(ETH_P_IP)) {
	123	skb->protocol = htons(ETH_P_IPV6);
	124	goto retry;
	125	}
d5be7f63	126	return -EINVAL;
9e8db591	127	}
9274124f	128
6dd912f8	129	p_off = keys.control.thoff + thlen;
0f6925b3	130	if (!pskb_may_pull(skb, p_off) \|\|
9274124f WB	131	keys.basic.ip_proto != ip_proto)
	132	return -EINVAL;
	133
	134	skb_set_transport_header(skb, keys.control.thoff);
6dd912f8 WB	135	} else if (gso_type) {
6dd912f8 WB	136	p_off = thlen;
0f6925b3	137	if (!pskb_may_pull(skb, p_off))
6dd912f8	138	return -EINVAL;
d5be7f63	139	}
fd2a0437 MR	140	}
	141
	142	if (hdr->gso_type != VIRTIO_NET_HDR_GSO_NONE) {
	143	u16 gso_size = __virtio16_to_cpu(little_endian, hdr->gso_size);
cf9acc90	144	unsigned int nh_off = p_off;
7c6d2ecb	145	struct skb_shared_info *shinfo = skb_shinfo(skb);
fd2a0437	146
cf9acc90 JD	147	/* UFO may not include transport header in gso_size. */
	148	if (gso_type & SKB_GSO_UDP)
	149	nh_off -= thlen;
	150
7c6d2ecb	151	/* Too small packets are not really GSO ones. */
cf9acc90	152	if (skb->len - nh_off > gso_size) {
7c6d2ecb ED	153	shinfo->gso_size = gso_size;
7c6d2ecb ED	154	shinfo->gso_type = gso_type;
fd2a0437	155
7c6d2ecb ED	156	/* Header must be checked, and gso_segs computed. */
	157	shinfo->gso_type \|= SKB_GSO_DODGY;
	158	shinfo->gso_segs = 0;
	159	}
fd2a0437 MR	160	}
	161
	162	return 0;
	163	}
	164
	165	static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
	166	struct virtio_net_hdr *hdr,
6391a448	167	bool little_endian,
fd3a8862 WB	168	bool has_data_valid,
fd3a8862 WB	169	int vlan_hlen)
fd2a0437	170	{
9403cd7c	171	memset(hdr, 0, sizeof(hdr)); / no info leak */
fd2a0437 MR	172
	173	if (skb_is_gso(skb)) {
	174	struct skb_shared_info *sinfo = skb_shinfo(skb);
	175
	176	/* This is a hint as to how much should be linear. */
	177	hdr->hdr_len = __cpu_to_virtio16(little_endian,
	178	skb_headlen(skb));
	179	hdr->gso_size = __cpu_to_virtio16(little_endian,
	180	sinfo->gso_size);
	181	if (sinfo->gso_type & SKB_GSO_TCPV4)
	182	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
	183	else if (sinfo->gso_type & SKB_GSO_TCPV6)
	184	hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
fd2a0437 MR	185	else
	186	return -EINVAL;
	187	if (sinfo->gso_type & SKB_GSO_TCP_ECN)
	188	hdr->gso_type \|= VIRTIO_NET_HDR_GSO_ECN;
	189	} else
	190	hdr->gso_type = VIRTIO_NET_HDR_GSO_NONE;
	191
	192	if (skb->ip_summed == CHECKSUM_PARTIAL) {
	193	hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
fd3a8862 WB	194	hdr->csum_start = __cpu_to_virtio16(little_endian,
fd3a8862 WB	195	skb_checksum_start_offset(skb) + vlan_hlen);
fd2a0437 MR	196	hdr->csum_offset = __cpu_to_virtio16(little_endian,
fd2a0437 MR	197	skb->csum_offset);
6391a448 JW	198	} else if (has_data_valid &&
	199	skb->ip_summed == CHECKSUM_UNNECESSARY) {
	200	hdr->flags = VIRTIO_NET_HDR_F_DATA_VALID;
fd2a0437 MR	201	} /* else everything is zero */
	202
	203	return 0;
	204	}
	205
d66016a7	206	#endif /* _LINUX_VIRTIO_NET_H */