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