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00959ade DK |
1 | #ifndef __LINUX_GRE_H |
2 | #define __LINUX_GRE_H | |
3 | ||
4 | #include <linux/skbuff.h> | |
c5441932 | 5 | #include <net/ip_tunnels.h> |
00959ade | 6 | |
9f57c67c PS |
7 | struct gre_base_hdr { |
8 | __be16 flags; | |
9 | __be16 protocol; | |
ab10dccb GF |
10 | } __packed; |
11 | ||
12 | struct gre_full_hdr { | |
13 | struct gre_base_hdr fixed_header; | |
14 | __be16 csum; | |
15 | __be16 reserved1; | |
16 | __be32 key; | |
17 | __be32 seq; | |
18 | } __packed; | |
9f57c67c PS |
19 | #define GRE_HEADER_SECTION 4 |
20 | ||
00959ade DK |
21 | #define GREPROTO_CISCO 0 |
22 | #define GREPROTO_PPTP 1 | |
23 | #define GREPROTO_MAX 2 | |
bda7bb46 | 24 | #define GRE_IP_PROTO_MAX 2 |
00959ade DK |
25 | |
26 | struct gre_protocol { | |
27 | int (*handler)(struct sk_buff *skb); | |
28 | void (*err_handler)(struct sk_buff *skb, u32 info); | |
29 | }; | |
30 | ||
31 | int gre_add_protocol(const struct gre_protocol *proto, u8 version); | |
32 | int gre_del_protocol(const struct gre_protocol *proto, u8 version); | |
33 | ||
b2acd1dc PS |
34 | struct net_device *gretap_fb_dev_create(struct net *net, const char *name, |
35 | u8 name_assign_type); | |
95f5c64c | 36 | int gre_parse_header(struct sk_buff *skb, struct tnl_ptk_info *tpi, |
e582615a | 37 | bool *csum_err, __be16 proto, int nhs); |
95f5c64c TH |
38 | |
39 | static 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 | ||
52 | static 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 | ||
74 | static 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 | ||
182a352d TH |
96 | static 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 | ||
107 | static 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 | ||
3d7b3320 | 115 | skb_set_inner_protocol(skb, proto); |
182a352d TH |
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 | ||
00959ade | 141 | #endif |