xref: /linux/net/mpls/internal.h (revision 6c373ca89399c5a3f7ef210ad8f63dc3437da345)
1 #ifndef MPLS_INTERNAL_H
2 #define MPLS_INTERNAL_H
3 
4 #define LABEL_IPV4_EXPLICIT_NULL	0 /* RFC3032 */
5 #define LABEL_ROUTER_ALERT_LABEL	1 /* RFC3032 */
6 #define LABEL_IPV6_EXPLICIT_NULL	2 /* RFC3032 */
7 #define LABEL_IMPLICIT_NULL		3 /* RFC3032 */
8 #define LABEL_ENTROPY_INDICATOR		7 /* RFC6790 */
9 #define LABEL_GAL			13 /* RFC5586 */
10 #define LABEL_OAM_ALERT			14 /* RFC3429 */
11 #define LABEL_EXTENSION			15 /* RFC7274 */
12 
13 
14 struct mpls_shim_hdr {
15 	__be32 label_stack_entry;
16 };
17 
18 struct mpls_entry_decoded {
19 	u32 label;
20 	u8 ttl;
21 	u8 tc;
22 	u8 bos;
23 };
24 
25 struct sk_buff;
26 
27 static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
28 {
29 	return (struct mpls_shim_hdr *)skb_network_header(skb);
30 }
31 
32 static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
33 {
34 	struct mpls_shim_hdr result;
35 	result.label_stack_entry =
36 		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
37 			    (tc << MPLS_LS_TC_SHIFT) |
38 			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
39 			    (ttl << MPLS_LS_TTL_SHIFT));
40 	return result;
41 }
42 
43 static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
44 {
45 	struct mpls_entry_decoded result;
46 	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
47 
48 	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
49 	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
50 	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
51 	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
52 
53 	return result;
54 }
55 
56 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels, const u32 label[]);
57 int nla_get_labels(const struct nlattr *nla, u32 max_labels, u32 *labels, u32 label[]);
58 
59 #endif /* MPLS_INTERNAL_H */
60