[mirror_ubuntu-bionic-kernel.git] / include / net / gre.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_GRE_H
#define __LINUX_GRE_H

#include <linux/skbuff.h>
#include <net/ip_tunnels.h>

struct gre_base_hdr {
	__be16 flags;
	__be16 protocol;
} __packed;

struct gre_full_hdr {
	struct gre_base_hdr fixed_header;
	__be16 csum;
	__be16 reserved1;
	__be32 key;
	__be32 seq;
} __packed;
#define GRE_HEADER_SECTION 4

#define GREPROTO_CISCO		0
#define GREPROTO_PPTP		1
#define GREPROTO_MAX		2
#define GRE_IP_PROTO_MAX	2

struct gre_protocol {
	int  (*handler)(struct sk_buff *skb);
	void (*err_handler)(struct sk_buff *skb, u32 info);
};

int gre_add_protocol(const struct gre_protocol *proto, u8 version);
int gre_del_protocol(const struct gre_protocol *proto, u8 version);

struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
				       u8 name_assign_type);
int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
		     bool *csum_err, __be16 proto, int nhs);

static inline int gre_calc_hlen(__be16 o_flags)
{
	int addend = 4;

	if (o_flags & TUNNEL_CSUM)
		addend += 4;
	if (o_flags & TUNNEL_KEY)
		addend += 4;
	if (o_flags & TUNNEL_SEQ)
		addend += 4;
	return addend;
}

static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
{
	__be16 tflags = 0;

	if (flags & GRE_CSUM)
		tflags |= TUNNEL_CSUM;
	if (flags & GRE_ROUTING)
		tflags |= TUNNEL_ROUTING;
	if (flags & GRE_KEY)
		tflags |= TUNNEL_KEY;
	if (flags & GRE_SEQ)
		tflags |= TUNNEL_SEQ;
	if (flags & GRE_STRICT)
		tflags |= TUNNEL_STRICT;
	if (flags & GRE_REC)
		tflags |= TUNNEL_REC;
	if (flags & GRE_VERSION)
		tflags |= TUNNEL_VERSION;

	return tflags;
}

static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags)
{
	__be16 flags = 0;

	if (tflags & TUNNEL_CSUM)
		flags |= GRE_CSUM;
	if (tflags & TUNNEL_ROUTING)
		flags |= GRE_ROUTING;
	if (tflags & TUNNEL_KEY)
		flags |= GRE_KEY;
	if (tflags & TUNNEL_SEQ)
		flags |= GRE_SEQ;
	if (tflags & TUNNEL_STRICT)
		flags |= GRE_STRICT;
	if (tflags & TUNNEL_REC)
		flags |= GRE_REC;
	if (tflags & TUNNEL_VERSION)
		flags |= GRE_VERSION;

	return flags;
}

static inline __sum16 gre_checksum(struct sk_buff *skb)
{
	__wsum csum;

	if (skb->ip_summed == CHECKSUM_PARTIAL)
		csum = lco_csum(skb);
	else
		csum = skb_checksum(skb, 0, skb->len, 0);
	return csum_fold(csum);
}

static inline void gre_build_header(struct sk_buff *skb, int hdr_len,
				    __be16 flags, __be16 proto,
				    __be32 key, __be32 seq)
{
	struct gre_base_hdr *greh;

	skb_push(skb, hdr_len);

	skb_set_inner_protocol(skb, proto);
	skb_reset_transport_header(skb);
	greh = (struct gre_base_hdr *)skb->data;
	greh->flags = gre_tnl_flags_to_gre_flags(flags);
	greh->protocol = proto;

	if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) {
		__be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4);

		if (flags & TUNNEL_SEQ) {
			*ptr = seq;
			ptr--;
		}
		if (flags & TUNNEL_KEY) {
			*ptr = key;
			ptr--;
		}
		if (flags & TUNNEL_CSUM &&
		    !(skb_shinfo(skb)->gso_type &
		      (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) {
			*ptr = 0;
			*(__sum16 *)ptr = gre_checksum(skb);
		}
	}
}

#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
00959ade DK	2	#ifndef __LINUX_GRE_H
	3	#define __LINUX_GRE_H
	4
	5	#include <linux/skbuff.h>
c5441932	6	#include <net/ip_tunnels.h>
00959ade	7
9f57c67c PS	8	struct gre_base_hdr {
	9	__be16 flags;
	10	__be16 protocol;
ab10dccb GF	11	} __packed;
	12
	13	struct gre_full_hdr {
	14	struct gre_base_hdr fixed_header;
	15	__be16 csum;
	16	__be16 reserved1;
	17	__be32 key;
	18	__be32 seq;
	19	} __packed;
9f57c67c PS	20	#define GRE_HEADER_SECTION 4
9f57c67c PS	21
00959ade DK	22	#define GREPROTO_CISCO 0
	23	#define GREPROTO_PPTP 1
	24	#define GREPROTO_MAX 2
bda7bb46	25	#define GRE_IP_PROTO_MAX 2
00959ade DK	26
	27	struct gre_protocol {
	28	int (handler)(struct sk_buff skb);
	29	void (err_handler)(struct sk_buff skb, u32 info);
	30	};
	31
	32	int gre_add_protocol(const struct gre_protocol *proto, u8 version);
	33	int gre_del_protocol(const struct gre_protocol *proto, u8 version);
	34
b2acd1dc PS	35	struct net_device gretap_fb_dev_create(struct net net, const char *name,
b2acd1dc PS	36	u8 name_assign_type);
95f5c64c	37	int gre_parse_header(struct sk_buff skb, struct tnl_ptk_info tpi,
e582615a	38	bool *csum_err, __be16 proto, int nhs);
95f5c64c TH	39
	40	static inline int gre_calc_hlen(__be16 o_flags)
	41	{
	42	int addend = 4;
	43
	44	if (o_flags & TUNNEL_CSUM)
	45	addend += 4;
	46	if (o_flags & TUNNEL_KEY)
	47	addend += 4;
	48	if (o_flags & TUNNEL_SEQ)
	49	addend += 4;
	50	return addend;
	51	}
	52
	53	static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
	54	{
	55	__be16 tflags = 0;
	56
	57	if (flags & GRE_CSUM)
	58	tflags \|= TUNNEL_CSUM;
	59	if (flags & GRE_ROUTING)
	60	tflags \|= TUNNEL_ROUTING;
	61	if (flags & GRE_KEY)
	62	tflags \|= TUNNEL_KEY;
	63	if (flags & GRE_SEQ)
	64	tflags \|= TUNNEL_SEQ;
	65	if (flags & GRE_STRICT)
	66	tflags \|= TUNNEL_STRICT;
	67	if (flags & GRE_REC)
	68	tflags \|= TUNNEL_REC;
	69	if (flags & GRE_VERSION)
	70	tflags \|= TUNNEL_VERSION;
	71
	72	return tflags;
	73	}
	74
	75	static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags)
	76	{
	77	__be16 flags = 0;
	78
	79	if (tflags & TUNNEL_CSUM)
	80	flags \|= GRE_CSUM;
	81	if (tflags & TUNNEL_ROUTING)
	82	flags \|= GRE_ROUTING;
	83	if (tflags & TUNNEL_KEY)
	84	flags \|= GRE_KEY;
	85	if (tflags & TUNNEL_SEQ)
	86	flags \|= GRE_SEQ;
	87	if (tflags & TUNNEL_STRICT)
	88	flags \|= GRE_STRICT;
	89	if (tflags & TUNNEL_REC)
	90	flags \|= GRE_REC;
	91	if (tflags & TUNNEL_VERSION)
	92	flags \|= GRE_VERSION;
	93
	94	return flags;
	95	}
	96
182a352d TH	97	static inline __sum16 gre_checksum(struct sk_buff *skb)
	98	{
	99	__wsum csum;
	100
	101	if (skb->ip_summed == CHECKSUM_PARTIAL)
	102	csum = lco_csum(skb);
	103	else
	104	csum = skb_checksum(skb, 0, skb->len, 0);
	105	return csum_fold(csum);
	106	}
	107
	108	static inline void gre_build_header(struct sk_buff *skb, int hdr_len,
	109	__be16 flags, __be16 proto,
	110	__be32 key, __be32 seq)
	111	{
	112	struct gre_base_hdr *greh;
	113
	114	skb_push(skb, hdr_len);
	115
3d7b3320	116	skb_set_inner_protocol(skb, proto);
182a352d TH	117	skb_reset_transport_header(skb);
	118	greh = (struct gre_base_hdr *)skb->data;
	119	greh->flags = gre_tnl_flags_to_gre_flags(flags);
	120	greh->protocol = proto;
	121
	122	if (flags & (TUNNEL_KEY \| TUNNEL_CSUM \| TUNNEL_SEQ)) {
	123	__be32 ptr = (__be32 )(((u8 *)greh) + hdr_len - 4);
	124
	125	if (flags & TUNNEL_SEQ) {
	126	*ptr = seq;
	127	ptr--;
	128	}
	129	if (flags & TUNNEL_KEY) {
	130	*ptr = key;
	131	ptr--;
	132	}
	133	if (flags & TUNNEL_CSUM &&
	134	!(skb_shinfo(skb)->gso_type &
	135	(SKB_GSO_GRE \| SKB_GSO_GRE_CSUM))) {
	136	*ptr = 0;
	137	(__sum16 )ptr = gre_checksum(skb);
	138	}
	139	}
	140	}
	141
00959ade	142	#endif