xref: /linux/net/mpls/internal.h (revision a4ac8c986d3f72ccbaf6d6782511fb645e568306)
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_pcpu_stats {
13 	struct mpls_link_stats	stats;
14 	struct u64_stats_sync	syncp;
15 };
16 
17 struct mpls_dev {
18 	int				input_enabled;
19 	struct net_device		*dev;
20 	struct mpls_pcpu_stats __percpu	*stats;
21 
22 	struct ctl_table_header		*sysctl;
23 	struct rcu_head			rcu;
24 };
25 
26 #if BITS_PER_LONG == 32
27 
28 #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
29 	do {								\
30 		__typeof__(*(mdev)->stats) *ptr =			\
31 			raw_cpu_ptr((mdev)->stats);			\
32 		local_bh_disable();					\
33 		u64_stats_update_begin(&ptr->syncp);			\
34 		ptr->stats.pkts_field++;				\
35 		ptr->stats.bytes_field += (len);			\
36 		u64_stats_update_end(&ptr->syncp);			\
37 		local_bh_enable();					\
38 	} while (0)
39 
40 #define MPLS_INC_STATS(mdev, field)					\
41 	do {								\
42 		__typeof__(*(mdev)->stats) *ptr =			\
43 			raw_cpu_ptr((mdev)->stats);			\
44 		local_bh_disable();					\
45 		u64_stats_update_begin(&ptr->syncp);			\
46 		ptr->stats.field++;					\
47 		u64_stats_update_end(&ptr->syncp);			\
48 		local_bh_enable();					\
49 	} while (0)
50 
51 #else
52 
53 #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
54 	do {								\
55 		this_cpu_inc((mdev)->stats->stats.pkts_field);		\
56 		this_cpu_add((mdev)->stats->stats.bytes_field, (len));	\
57 	} while (0)
58 
59 #define MPLS_INC_STATS(mdev, field)			\
60 	this_cpu_inc((mdev)->stats->stats.field)
61 
62 #endif
63 
64 struct sk_buff;
65 
66 #define LABEL_NOT_SPECIFIED (1 << 20)
67 
68 /* This maximum ha length copied from the definition of struct neighbour */
69 #define VIA_ALEN_ALIGN sizeof(unsigned long)
70 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
71 
72 enum mpls_payload_type {
73 	MPT_UNSPEC, /* IPv4 or IPv6 */
74 	MPT_IPV4 = 4,
75 	MPT_IPV6 = 6,
76 
77 	/* Other types not implemented:
78 	 *  - Pseudo-wire with or without control word (RFC4385)
79 	 *  - GAL (RFC5586)
80 	 */
81 };
82 
83 struct mpls_nh { /* next hop label forwarding entry */
84 	struct net_device __rcu *nh_dev;
85 
86 	/* nh_flags is accessed under RCU in the packet path; it is
87 	 * modified handling netdev events with rtnl lock held
88 	 */
89 	unsigned int		nh_flags;
90 	u8			nh_labels;
91 	u8			nh_via_alen;
92 	u8			nh_via_table;
93 	u8			nh_reserved1;
94 
95 	u32			nh_label[0];
96 };
97 
98 /* offset of via from beginning of mpls_nh */
99 #define MPLS_NH_VIA_OFF(num_labels) \
100 		ALIGN(sizeof(struct mpls_nh) + (num_labels) * sizeof(u32), \
101 		      VIA_ALEN_ALIGN)
102 
103 /* all nexthops within a route have the same size based on the
104  * max number of labels and max via length across all nexthops
105  */
106 #define MPLS_NH_SIZE(num_labels, max_via_alen)		\
107 		(MPLS_NH_VIA_OFF((num_labels)) +	\
108 		ALIGN((max_via_alen), VIA_ALEN_ALIGN))
109 
110 enum mpls_ttl_propagation {
111 	MPLS_TTL_PROP_DEFAULT,
112 	MPLS_TTL_PROP_ENABLED,
113 	MPLS_TTL_PROP_DISABLED,
114 };
115 
116 /* The route, nexthops and vias are stored together in the same memory
117  * block:
118  *
119  * +----------------------+
120  * | mpls_route           |
121  * +----------------------+
122  * | mpls_nh 0            |
123  * +----------------------+
124  * | alignment padding    |   4 bytes for odd number of labels
125  * +----------------------+
126  * | via[rt_max_alen] 0   |
127  * +----------------------+
128  * | alignment padding    |   via's aligned on sizeof(unsigned long)
129  * +----------------------+
130  * | ...                  |
131  * +----------------------+
132  * | mpls_nh n-1          |
133  * +----------------------+
134  * | via[rt_max_alen] n-1 |
135  * +----------------------+
136  */
137 struct mpls_route { /* next hop label forwarding entry */
138 	struct rcu_head		rt_rcu;
139 	u8			rt_protocol;
140 	u8			rt_payload_type;
141 	u8			rt_max_alen;
142 	u8			rt_ttl_propagate;
143 	u8			rt_nhn;
144 	/* rt_nhn_alive is accessed under RCU in the packet path; it
145 	 * is modified handling netdev events with rtnl lock held
146 	 */
147 	u8			rt_nhn_alive;
148 	u8			rt_nh_size;
149 	u8			rt_via_offset;
150 	u8			rt_reserved1;
151 	struct mpls_nh		rt_nh[0];
152 };
153 
154 #define for_nexthops(rt) {						\
155 	int nhsel; struct mpls_nh *nh;  u8 *__nh;			\
156 	for (nhsel = 0, nh = (rt)->rt_nh, __nh = (u8 *)((rt)->rt_nh);	\
157 	     nhsel < (rt)->rt_nhn;					\
158 	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)
159 
160 #define change_nexthops(rt) {						\
161 	int nhsel; struct mpls_nh *nh; u8 *__nh;			\
162 	for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh),		\
163 			__nh = (u8 *)((rt)->rt_nh);			\
164 	     nhsel < (rt)->rt_nhn;					\
165 	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)
166 
167 #define endfor_nexthops(rt) }
168 
169 static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
170 {
171 	struct mpls_shim_hdr result;
172 	result.label_stack_entry =
173 		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
174 			    (tc << MPLS_LS_TC_SHIFT) |
175 			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
176 			    (ttl << MPLS_LS_TTL_SHIFT));
177 	return result;
178 }
179 
180 static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
181 {
182 	struct mpls_entry_decoded result;
183 	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
184 
185 	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
186 	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
187 	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
188 	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
189 
190 	return result;
191 }
192 
193 static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
194 {
195 	return rcu_dereference_rtnl(dev->mpls_ptr);
196 }
197 
198 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
199 		   const u32 label[]);
200 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
201 		   u32 label[]);
202 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
203 		u8 via[]);
204 bool mpls_output_possible(const struct net_device *dev);
205 unsigned int mpls_dev_mtu(const struct net_device *dev);
206 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
207 void mpls_stats_inc_outucastpkts(struct net_device *dev,
208 				 const struct sk_buff *skb);
209 
210 #endif /* MPLS_INTERNAL_H */
211