summaryrefslogtreecommitdiffstats
path: root/net/mpls/internal.h
blob: 4db6a59713220dcefac8be970ab06b1ae25bcd5c (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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
#ifndef MPLS_INTERNAL_H
#define MPLS_INTERNAL_H
#include <net/mpls.h>

/* put a reasonable limit on the number of labels
 * we will accept from userspace
 */
#define MAX_NEW_LABELS 30

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

struct mpls_pcpu_stats {
	struct mpls_link_stats	stats;
	struct u64_stats_sync	syncp;
};

struct mpls_dev {
	int				input_enabled;
	struct net_device		*dev;
	struct mpls_pcpu_stats __percpu	*stats;

	struct ctl_table_header		*sysctl;
	struct rcu_head			rcu;
};

#if BITS_PER_LONG == 32

#define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
	do {								\
		__typeof__(*(mdev)->stats) *ptr =			\
			raw_cpu_ptr((mdev)->stats);			\
		local_bh_disable();					\
		u64_stats_update_begin(&ptr->syncp);			\
		ptr->stats.pkts_field++;				\
		ptr->stats.bytes_field += (len);			\
		u64_stats_update_end(&ptr->syncp);			\
		local_bh_enable();					\
	} while (0)

#define MPLS_INC_STATS(mdev, field)					\
	do {								\
		__typeof__(*(mdev)->stats) *ptr =			\
			raw_cpu_ptr((mdev)->stats);			\
		local_bh_disable();					\
		u64_stats_update_begin(&ptr->syncp);			\
		ptr->stats.field++;					\
		u64_stats_update_end(&ptr->syncp);			\
		local_bh_enable();					\
	} while (0)

#else

#define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
	do {								\
		this_cpu_inc((mdev)->stats->stats.pkts_field);		\
		this_cpu_add((mdev)->stats->stats.bytes_field, (len));	\
	} while (0)

#define MPLS_INC_STATS(mdev, field)			\
	this_cpu_inc((mdev)->stats->stats.field)

#endif

struct sk_buff;

#define LABEL_NOT_SPECIFIED (1 << 20)

/* 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;

	/* nh_flags is accessed under RCU in the packet path; it is
	 * modified handling netdev events with rtnl lock held
	 */
	unsigned int		nh_flags;
	u8			nh_labels;
	u8			nh_via_alen;
	u8			nh_via_table;
	u8			nh_reserved1;

	u32			nh_label[0];
};

/* offset of via from beginning of mpls_nh */
#define MPLS_NH_VIA_OFF(num_labels) \
		ALIGN(sizeof(struct mpls_nh) + (num_labels) * sizeof(u32), \
		      VIA_ALEN_ALIGN)

/* all nexthops within a route have the same size based on the
 * max number of labels and max via length across all nexthops
 */
#define MPLS_NH_SIZE(num_labels, max_via_alen)		\
		(MPLS_NH_VIA_OFF((num_labels)) +	\
		ALIGN((max_via_alen), VIA_ALEN_ALIGN))

enum mpls_ttl_propagation {
	MPLS_TTL_PROP_DEFAULT,
	MPLS_TTL_PROP_ENABLED,
	MPLS_TTL_PROP_DISABLED,
};

/* The route, nexthops and vias are stored together in the same memory
 * block:
 *
 * +----------------------+
 * | mpls_route           |
 * +----------------------+
 * | mpls_nh 0            |
 * +----------------------+
 * | alignment padding    |   4 bytes for odd number of labels
 * +----------------------+
 * | via[rt_max_alen] 0   |
 * +----------------------+
 * | alignment padding    |   via's aligned on sizeof(unsigned long)
 * +----------------------+
 * | ...                  |
 * +----------------------+
 * | mpls_nh n-1          |
 * +----------------------+
 * | 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;
	u8			rt_ttl_propagate;
	u8			rt_nhn;
	/* rt_nhn_alive is accessed under RCU in the packet path; it
	 * is modified handling netdev events with rtnl lock held
	 */
	u8			rt_nhn_alive;
	u8			rt_nh_size;
	u8			rt_via_offset;
	u8			rt_reserved1;
	struct mpls_nh		rt_nh[0];
};

#define for_nexthops(rt) {						\
	int nhsel; struct mpls_nh *nh;  u8 *__nh;			\
	for (nhsel = 0, nh = (rt)->rt_nh, __nh = (u8 *)((rt)->rt_nh);	\
	     nhsel < (rt)->rt_nhn;					\
	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)

#define change_nexthops(rt) {						\
	int nhsel; struct mpls_nh *nh; u8 *__nh;			\
	for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh),		\
			__nh = (u8 *)((rt)->rt_nh);			\
	     nhsel < (rt)->rt_nhn;					\
	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)

#define endfor_nexthops(rt) }

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;
}

static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
{
	return rcu_dereference_rtnl(dev->mpls_ptr);
}

int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
		   const u32 label[]);
int nla_get_labels(const struct nlattr *nla, u8 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);
void mpls_stats_inc_outucastpkts(struct net_device *dev,
				 const struct sk_buff *skb);

#endif /* MPLS_INTERNAL_H */