summaryrefslogtreecommitdiff
path: root/net/mpls/internal.h
blob: bde52ce88c949e76083ec704ed010493b60d6466 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
#ifndef MPLS_INTERNAL_H
#define MPLS_INTERNAL_H

struct mpls_shim_hdr {
	__be32 label_stack_entry;
};

struct mpls_entry_decoded {
	u32 label;
	u8 ttl;
	u8 tc;
	u8 bos;
};

struct mpls_dev {
	int			input_enabled;

	struct ctl_table_header *sysctl;
	struct rcu_head		rcu;
};

struct sk_buff;

#define LABEL_NOT_SPECIFIED (1 << 20)
#define MAX_NEW_LABELS 2

/* This maximum ha length copied from the definition of struct neighbour */
#define VIA_ALEN_ALIGN sizeof(unsigned long)
#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))

enum mpls_payload_type {
	MPT_UNSPEC, /* IPv4 or IPv6 */
	MPT_IPV4 = 4,
	MPT_IPV6 = 6,

	/* Other types not implemented:
	 *  - Pseudo-wire with or without control word (RFC4385)
	 *  - GAL (RFC5586)
	 */
};

struct mpls_nh { /* next hop label forwarding entry */
	struct net_device __rcu *nh_dev;
	u32			nh_label[MAX_NEW_LABELS];
	u8			nh_labels;
	u8			nh_via_alen;
	u8			nh_via_table;
};

/* The route, nexthops and vias are stored together in the same memory
 * block:
 *
 * +----------------------+
 * | mpls_route           |
 * +----------------------+
 * | mpls_nh 0            |
 * +----------------------+
 * | ...                  |
 * +----------------------+
 * | mpls_nh n-1          |
 * +----------------------+
 * | alignment padding    |
 * +----------------------+
 * | via[rt_max_alen] 0   |
 * +----------------------+
 * | ...                  |
 * +----------------------+
 * | via[rt_max_alen] n-1 |
 * +----------------------+
 */
struct mpls_route { /* next hop label forwarding entry */
	struct rcu_head		rt_rcu;
	u8			rt_protocol;
	u8			rt_payload_type;
	u8			rt_max_alen;
	unsigned int		rt_nhn;
	struct mpls_nh		rt_nh[0];
};

#define for_nexthops(rt) {						\
	int nhsel; struct mpls_nh *nh;			\
	for (nhsel = 0, nh = (rt)->rt_nh;				\
	     nhsel < (rt)->rt_nhn;					\
	     nh++, nhsel++)

#define change_nexthops(rt) {						\
	int nhsel; struct mpls_nh *nh;				\
	for (nhsel = 0,	nh = (struct mpls_nh *)((rt)->rt_nh);	\
	     nhsel < (rt)->rt_nhn;					\
	     nh++, nhsel++)

#define endfor_nexthops(rt) }

static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
{
	return (struct mpls_shim_hdr *)skb_network_header(skb);
}

static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
{
	struct mpls_shim_hdr result;
	result.label_stack_entry =
		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
			    (tc << MPLS_LS_TC_SHIFT) |
			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
			    (ttl << MPLS_LS_TTL_SHIFT));
	return result;
}

static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
{
	struct mpls_entry_decoded result;
	unsigned entry = be32_to_cpu(hdr->label_stack_entry);

	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;

	return result;
}

int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
		   const u32 label[]);
int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
		   u32 label[]);
int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
		u8 via[]);
bool mpls_output_possible(const struct net_device *dev);
unsigned int mpls_dev_mtu(const struct net_device *dev);
bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);

#endif /* MPLS_INTERNAL_H */