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1 #ifndef MPLS_INTERNAL_H
2 #define MPLS_INTERNAL_H
3 #include <net/mpls.h>
4 
5 struct mpls_entry_decoded {
6 	u32 label;
7 	u8 ttl;
8 	u8 tc;
9 	u8 bos;
10 };
11 
12 struct mpls_dev {
13 	int			input_enabled;
14 
15 	struct ctl_table_header *sysctl;
16 	struct rcu_head		rcu;
17 };
18 
19 struct sk_buff;
20 
21 #define LABEL_NOT_SPECIFIED (1 << 20)
22 #define MAX_NEW_LABELS 2
23 
24 /* This maximum ha length copied from the definition of struct neighbour */
25 #define VIA_ALEN_ALIGN sizeof(unsigned long)
26 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
27 
28 enum mpls_payload_type {
29 	MPT_UNSPEC, /* IPv4 or IPv6 */
30 	MPT_IPV4 = 4,
31 	MPT_IPV6 = 6,
32 
33 	/* Other types not implemented:
34 	 *  - Pseudo-wire with or without control word (RFC4385)
35 	 *  - GAL (RFC5586)
36 	 */
37 };
38 
39 struct mpls_nh { /* next hop label forwarding entry */
40 	struct net_device __rcu *nh_dev;
41 	unsigned int		nh_flags;
42 	u32			nh_label[MAX_NEW_LABELS];
43 	u8			nh_labels;
44 	u8			nh_via_alen;
45 	u8			nh_via_table;
46 };
47 
48 /* The route, nexthops and vias are stored together in the same memory
49  * block:
50  *
51  * +----------------------+
52  * | mpls_route           |
53  * +----------------------+
54  * | mpls_nh 0            |
55  * +----------------------+
56  * | ...                  |
57  * +----------------------+
58  * | mpls_nh n-1          |
59  * +----------------------+
60  * | alignment padding    |
61  * +----------------------+
62  * | via[rt_max_alen] 0   |
63  * +----------------------+
64  * | ...                  |
65  * +----------------------+
66  * | via[rt_max_alen] n-1 |
67  * +----------------------+
68  */
69 struct mpls_route { /* next hop label forwarding entry */
70 	struct rcu_head		rt_rcu;
71 	u8			rt_protocol;
72 	u8			rt_payload_type;
73 	u8			rt_max_alen;
74 	unsigned int		rt_nhn;
75 	unsigned int		rt_nhn_alive;
76 	struct mpls_nh		rt_nh[0];
77 };
78 
79 #define for_nexthops(rt) {						\
80 	int nhsel; struct mpls_nh *nh;			\
81 	for (nhsel = 0, nh = (rt)->rt_nh;				\
82 	     nhsel < (rt)->rt_nhn;					\
83 	     nh++, nhsel++)
84 
85 #define change_nexthops(rt) {						\
86 	int nhsel; struct mpls_nh *nh;				\
87 	for (nhsel = 0,	nh = (struct mpls_nh *)((rt)->rt_nh);	\
88 	     nhsel < (rt)->rt_nhn;					\
89 	     nh++, nhsel++)
90 
91 #define endfor_nexthops(rt) }
92 
mpls_entry_encode(u32 label,unsigned ttl,unsigned tc,bool bos)93 static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
94 {
95 	struct mpls_shim_hdr result;
96 	result.label_stack_entry =
97 		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
98 			    (tc << MPLS_LS_TC_SHIFT) |
99 			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
100 			    (ttl << MPLS_LS_TTL_SHIFT));
101 	return result;
102 }
103 
mpls_entry_decode(struct mpls_shim_hdr * hdr)104 static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
105 {
106 	struct mpls_entry_decoded result;
107 	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
108 
109 	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
110 	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
111 	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
112 	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
113 
114 	return result;
115 }
116 
117 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
118 		   const u32 label[]);
119 int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
120 		   u32 label[]);
121 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
122 		u8 via[]);
123 bool mpls_output_possible(const struct net_device *dev);
124 unsigned int mpls_dev_mtu(const struct net_device *dev);
125 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
126 
127 #endif /* MPLS_INTERNAL_H */
128