1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __LINUX_GRE_H |
3 | #define __LINUX_GRE_H |
4 | |
5 | #include <linux/skbuff.h> |
6 | #include <net/ip_tunnels.h> |
7 | |
8 | struct gre_base_hdr { |
9 | __be16 flags; |
10 | __be16 protocol; |
11 | } __packed; |
12 | |
13 | struct gre_full_hdr { |
14 | struct gre_base_hdr ; |
15 | __be16 csum; |
16 | __be16 reserved1; |
17 | __be32 key; |
18 | __be32 seq; |
19 | } __packed; |
20 | #define 4 |
21 | |
22 | #define GREPROTO_CISCO 0 |
23 | #define GREPROTO_PPTP 1 |
24 | #define GREPROTO_MAX 2 |
25 | #define GRE_IP_PROTO_MAX 2 |
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 | |
35 | struct net_device *gretap_fb_dev_create(struct net *net, const char *name, |
36 | u8 name_assign_type); |
37 | int (struct sk_buff *skb, struct tnl_ptk_info *tpi, |
38 | bool *csum_err, __be16 proto, int nhs); |
39 | |
40 | static inline bool netif_is_gretap(const struct net_device *dev) |
41 | { |
42 | return dev->rtnl_link_ops && |
43 | !strcmp(dev->rtnl_link_ops->kind, "gretap" ); |
44 | } |
45 | |
46 | static inline bool netif_is_ip6gretap(const struct net_device *dev) |
47 | { |
48 | return dev->rtnl_link_ops && |
49 | !strcmp(dev->rtnl_link_ops->kind, "ip6gretap" ); |
50 | } |
51 | |
52 | static inline int gre_calc_hlen(__be16 o_flags) |
53 | { |
54 | int addend = 4; |
55 | |
56 | if (o_flags & TUNNEL_CSUM) |
57 | addend += 4; |
58 | if (o_flags & TUNNEL_KEY) |
59 | addend += 4; |
60 | if (o_flags & TUNNEL_SEQ) |
61 | addend += 4; |
62 | return addend; |
63 | } |
64 | |
65 | static inline __be16 gre_flags_to_tnl_flags(__be16 flags) |
66 | { |
67 | __be16 tflags = 0; |
68 | |
69 | if (flags & GRE_CSUM) |
70 | tflags |= TUNNEL_CSUM; |
71 | if (flags & GRE_ROUTING) |
72 | tflags |= TUNNEL_ROUTING; |
73 | if (flags & GRE_KEY) |
74 | tflags |= TUNNEL_KEY; |
75 | if (flags & GRE_SEQ) |
76 | tflags |= TUNNEL_SEQ; |
77 | if (flags & GRE_STRICT) |
78 | tflags |= TUNNEL_STRICT; |
79 | if (flags & GRE_REC) |
80 | tflags |= TUNNEL_REC; |
81 | if (flags & GRE_VERSION) |
82 | tflags |= TUNNEL_VERSION; |
83 | |
84 | return tflags; |
85 | } |
86 | |
87 | static inline __be16 gre_tnl_flags_to_gre_flags(__be16 tflags) |
88 | { |
89 | __be16 flags = 0; |
90 | |
91 | if (tflags & TUNNEL_CSUM) |
92 | flags |= GRE_CSUM; |
93 | if (tflags & TUNNEL_ROUTING) |
94 | flags |= GRE_ROUTING; |
95 | if (tflags & TUNNEL_KEY) |
96 | flags |= GRE_KEY; |
97 | if (tflags & TUNNEL_SEQ) |
98 | flags |= GRE_SEQ; |
99 | if (tflags & TUNNEL_STRICT) |
100 | flags |= GRE_STRICT; |
101 | if (tflags & TUNNEL_REC) |
102 | flags |= GRE_REC; |
103 | if (tflags & TUNNEL_VERSION) |
104 | flags |= GRE_VERSION; |
105 | |
106 | return flags; |
107 | } |
108 | |
109 | static inline void (struct sk_buff *skb, int hdr_len, |
110 | __be16 flags, __be16 proto, |
111 | __be32 key, __be32 seq) |
112 | { |
113 | struct gre_base_hdr *greh; |
114 | |
115 | skb_push(skb, len: hdr_len); |
116 | |
117 | skb_set_inner_protocol(skb, protocol: proto); |
118 | skb_reset_transport_header(skb); |
119 | greh = (struct gre_base_hdr *)skb->data; |
120 | greh->flags = gre_tnl_flags_to_gre_flags(tflags: flags); |
121 | greh->protocol = proto; |
122 | |
123 | if (flags & (TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_SEQ)) { |
124 | __be32 *ptr = (__be32 *)(((u8 *)greh) + hdr_len - 4); |
125 | |
126 | if (flags & TUNNEL_SEQ) { |
127 | *ptr = seq; |
128 | ptr--; |
129 | } |
130 | if (flags & TUNNEL_KEY) { |
131 | *ptr = key; |
132 | ptr--; |
133 | } |
134 | if (flags & TUNNEL_CSUM && |
135 | !(skb_shinfo(skb)->gso_type & |
136 | (SKB_GSO_GRE | SKB_GSO_GRE_CSUM))) { |
137 | *ptr = 0; |
138 | if (skb->ip_summed == CHECKSUM_PARTIAL) { |
139 | *(__sum16 *)ptr = csum_fold(sum: lco_csum(skb)); |
140 | } else { |
141 | skb->ip_summed = CHECKSUM_PARTIAL; |
142 | skb->csum_start = skb_transport_header(skb) - skb->head; |
143 | skb->csum_offset = sizeof(*greh); |
144 | } |
145 | } |
146 | } |
147 | } |
148 | |
149 | #endif |
150 | |