1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef MPLS_INTERNAL_H
3 #define MPLS_INTERNAL_H
4 #include <net/mpls.h>
5 
6 /* put a reasonable limit on the number of labels
7  * we will accept from userspace
8  */
9 #define MAX_NEW_LABELS 30
10 
11 struct mpls_entry_decoded {
12 	u32 label;
13 	u8 ttl;
14 	u8 tc;
15 	u8 bos;
16 };
17 
18 struct mpls_pcpu_stats {
19 	struct mpls_link_stats	stats;
20 	struct u64_stats_sync	syncp;
21 };
22 
23 struct mpls_dev {
24 	int				input_enabled;
25 	struct net_device		*dev;
26 	struct mpls_pcpu_stats __percpu	*stats;
27 
28 	struct ctl_table_header		*sysctl;
29 	struct rcu_head			rcu;
30 };
31 
32 #if BITS_PER_LONG == 32
33 
34 #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
35 	do {								\
36 		__typeof__(*(mdev)->stats) *ptr =			\
37 			raw_cpu_ptr((mdev)->stats);			\
38 		local_bh_disable();					\
39 		u64_stats_update_begin(&ptr->syncp);			\
40 		ptr->stats.pkts_field++;				\
41 		ptr->stats.bytes_field += (len);			\
42 		u64_stats_update_end(&ptr->syncp);			\
43 		local_bh_enable();					\
44 	} while (0)
45 
46 #define MPLS_INC_STATS(mdev, field)					\
47 	do {								\
48 		__typeof__(*(mdev)->stats) *ptr =			\
49 			raw_cpu_ptr((mdev)->stats);			\
50 		local_bh_disable();					\
51 		u64_stats_update_begin(&ptr->syncp);			\
52 		ptr->stats.field++;					\
53 		u64_stats_update_end(&ptr->syncp);			\
54 		local_bh_enable();					\
55 	} while (0)
56 
57 #else
58 
59 #define MPLS_INC_STATS_LEN(mdev, len, pkts_field, bytes_field)		\
60 	do {								\
61 		this_cpu_inc((mdev)->stats->stats.pkts_field);		\
62 		this_cpu_add((mdev)->stats->stats.bytes_field, (len));	\
63 	} while (0)
64 
65 #define MPLS_INC_STATS(mdev, field)			\
66 	this_cpu_inc((mdev)->stats->stats.field)
67 
68 #endif
69 
70 struct sk_buff;
71 
72 #define LABEL_NOT_SPECIFIED (1 << 20)
73 
74 /* This maximum ha length copied from the definition of struct neighbour */
75 #define VIA_ALEN_ALIGN sizeof(unsigned long)
76 #define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
77 
78 enum mpls_payload_type {
79 	MPT_UNSPEC, /* IPv4 or IPv6 */
80 	MPT_IPV4 = 4,
81 	MPT_IPV6 = 6,
82 
83 	/* Other types not implemented:
84 	 *  - Pseudo-wire with or without control word (RFC4385)
85 	 *  - GAL (RFC5586)
86 	 */
87 };
88 
89 struct mpls_nh { /* next hop label forwarding entry */
90 	struct net_device	*nh_dev;
91 
92 	/* nh_flags is accessed under RCU in the packet path; it is
93 	 * modified handling netdev events with rtnl lock held
94 	 */
95 	unsigned int		nh_flags;
96 	u8			nh_labels;
97 	u8			nh_via_alen;
98 	u8			nh_via_table;
99 	u8			nh_reserved1;
100 
101 	u32			nh_label[];
102 };
103 
104 /* offset of via from beginning of mpls_nh */
105 #define MPLS_NH_VIA_OFF(num_labels) \
106 		ALIGN(sizeof(struct mpls_nh) + (num_labels) * sizeof(u32), \
107 		      VIA_ALEN_ALIGN)
108 
109 /* all nexthops within a route have the same size based on the
110  * max number of labels and max via length across all nexthops
111  */
112 #define MPLS_NH_SIZE(num_labels, max_via_alen)		\
113 		(MPLS_NH_VIA_OFF((num_labels)) +	\
114 		ALIGN((max_via_alen), VIA_ALEN_ALIGN))
115 
116 enum mpls_ttl_propagation {
117 	MPLS_TTL_PROP_DEFAULT,
118 	MPLS_TTL_PROP_ENABLED,
119 	MPLS_TTL_PROP_DISABLED,
120 };
121 
122 /* The route, nexthops and vias are stored together in the same memory
123  * block:
124  *
125  * +----------------------+
126  * | mpls_route           |
127  * +----------------------+
128  * | mpls_nh 0            |
129  * +----------------------+
130  * | alignment padding    |   4 bytes for odd number of labels
131  * +----------------------+
132  * | via[rt_max_alen] 0   |
133  * +----------------------+
134  * | alignment padding    |   via's aligned on sizeof(unsigned long)
135  * +----------------------+
136  * | ...                  |
137  * +----------------------+
138  * | mpls_nh n-1          |
139  * +----------------------+
140  * | via[rt_max_alen] n-1 |
141  * +----------------------+
142  */
143 struct mpls_route { /* next hop label forwarding entry */
144 	struct rcu_head		rt_rcu;
145 	u8			rt_protocol;
146 	u8			rt_payload_type;
147 	u8			rt_max_alen;
148 	u8			rt_ttl_propagate;
149 	u8			rt_nhn;
150 	/* rt_nhn_alive is accessed under RCU in the packet path; it
151 	 * is modified handling netdev events with rtnl lock held
152 	 */
153 	u8			rt_nhn_alive;
154 	u8			rt_nh_size;
155 	u8			rt_via_offset;
156 	u8			rt_reserved1;
157 	struct mpls_nh		rt_nh[];
158 };
159 
160 #define for_nexthops(rt) {						\
161 	int nhsel; const struct mpls_nh *nh;				\
162 	for (nhsel = 0, nh = (rt)->rt_nh;				\
163 	     nhsel < (rt)->rt_nhn;					\
164 	     nh = (void *)nh + (rt)->rt_nh_size, nhsel++)
165 
166 #define change_nexthops(rt) {						\
167 	int nhsel; struct mpls_nh *nh;					\
168 	for (nhsel = 0, nh = (rt)->rt_nh;				\
169 	     nhsel < (rt)->rt_nhn;					\
170 	     nh = (void *)nh + (rt)->rt_nh_size, nhsel++)
171 
172 #define endfor_nexthops(rt) }
173 
mpls_entry_decode(struct mpls_shim_hdr * hdr)174 static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
175 {
176 	struct mpls_entry_decoded result;
177 	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
178 
179 	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
180 	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
181 	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
182 	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
183 
184 	return result;
185 }
186 
mpls_dev_get(const struct net_device * dev)187 static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
188 {
189 	return rcu_dereference_rtnl(dev->mpls_ptr);
190 }
191 
192 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
193 		   const u32 label[]);
194 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
195 		   u32 label[], struct netlink_ext_ack *extack);
196 bool mpls_output_possible(const struct net_device *dev);
197 unsigned int mpls_dev_mtu(const struct net_device *dev);
198 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
199 void mpls_stats_inc_outucastpkts(struct net_device *dev,
200 				 const struct sk_buff *skb);
201 
202 #endif /* MPLS_INTERNAL_H */
203