1 #ifndef MPLS_INTERNAL_H
2 #define MPLS_INTERNAL_H
3
4 struct mpls_shim_hdr {
5 __be32 label_stack_entry;
6 };
7
8 struct mpls_entry_decoded {
9 u32 label;
10 u8 ttl;
11 u8 tc;
12 u8 bos;
13 };
14
15 struct mpls_dev {
16 int input_enabled;
17
18 struct ctl_table_header *sysctl;
19 struct rcu_head rcu;
20 };
21
22 struct sk_buff;
23
24 #define LABEL_NOT_SPECIFIED (1 << 20)
25 #define MAX_NEW_LABELS 2
26
27 /* This maximum ha length copied from the definition of struct neighbour */
28 #define VIA_ALEN_ALIGN sizeof(unsigned long)
29 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
30
31 enum mpls_payload_type {
32 MPT_UNSPEC, /* IPv4 or IPv6 */
33 MPT_IPV4 = 4,
34 MPT_IPV6 = 6,
35
36 /* Other types not implemented:
37 * - Pseudo-wire with or without control word (RFC4385)
38 * - GAL (RFC5586)
39 */
40 };
41
42 struct mpls_nh { /* next hop label forwarding entry */
43 struct net_device __rcu *nh_dev;
44 u32 nh_label[MAX_NEW_LABELS];
45 u8 nh_labels;
46 u8 nh_via_alen;
47 u8 nh_via_table;
48 };
49
50 /* The route, nexthops and vias are stored together in the same memory
51 * block:
52 *
53 * +----------------------+
54 * | mpls_route |
55 * +----------------------+
56 * | mpls_nh 0 |
57 * +----------------------+
58 * | ... |
59 * +----------------------+
60 * | mpls_nh n-1 |
61 * +----------------------+
62 * | alignment padding |
63 * +----------------------+
64 * | via[rt_max_alen] 0 |
65 * +----------------------+
66 * | ... |
67 * +----------------------+
68 * | via[rt_max_alen] n-1 |
69 * +----------------------+
70 */
71 struct mpls_route { /* next hop label forwarding entry */
72 struct rcu_head rt_rcu;
73 u8 rt_protocol;
74 u8 rt_payload_type;
75 u8 rt_max_alen;
76 unsigned int rt_nhn;
77 struct mpls_nh rt_nh[0];
78 };
79
80 #define for_nexthops(rt) { \
81 int nhsel; struct mpls_nh *nh; \
82 for (nhsel = 0, nh = (rt)->rt_nh; \
83 nhsel < (rt)->rt_nhn; \
84 nh++, nhsel++)
85
86 #define change_nexthops(rt) { \
87 int nhsel; struct mpls_nh *nh; \
88 for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh); \
89 nhsel < (rt)->rt_nhn; \
90 nh++, nhsel++)
91
92 #define endfor_nexthops(rt) }
93
mpls_hdr(const struct sk_buff * skb)94 static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
95 {
96 return (struct mpls_shim_hdr *)skb_network_header(skb);
97 }
98
mpls_entry_encode(u32 label,unsigned ttl,unsigned tc,bool bos)99 static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
100 {
101 struct mpls_shim_hdr result;
102 result.label_stack_entry =
103 cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
104 (tc << MPLS_LS_TC_SHIFT) |
105 (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
106 (ttl << MPLS_LS_TTL_SHIFT));
107 return result;
108 }
109
mpls_entry_decode(struct mpls_shim_hdr * hdr)110 static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
111 {
112 struct mpls_entry_decoded result;
113 unsigned entry = be32_to_cpu(hdr->label_stack_entry);
114
115 result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
116 result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
117 result.tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
118 result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
119
120 return result;
121 }
122
123 int nla_put_labels(struct sk_buff *skb, int attrtype, u8 labels,
124 const u32 label[]);
125 int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
126 u32 label[]);
127 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
128 u8 via[]);
129 bool mpls_output_possible(const struct net_device *dev);
130 unsigned int mpls_dev_mtu(const struct net_device *dev);
131 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
132
133 #endif /* MPLS_INTERNAL_H */
134