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
11struct mpls_entry_decoded {
12	u32 label;
13	u8 ttl;
14	u8 tc;
15	u8 bos;
16};
17
18struct mpls_pcpu_stats {
19	struct mpls_link_stats	stats;
20	struct u64_stats_sync	syncp;
21};
22
23struct 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
70struct 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
78enum 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
89struct 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
116enum 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 */
143struct 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
174static 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
187static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
188{
189	return rcu_dereference_rtnl(dev->mpls_ptr);
190}
191
192int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
193		   const u32 label[]);
194int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
195		   u32 label[], struct netlink_ext_ack *extack);
196bool mpls_output_possible(const struct net_device *dev);
197unsigned int mpls_dev_mtu(const struct net_device *dev);
198bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
199void mpls_stats_inc_outucastpkts(struct net_device *dev,
200				 const struct sk_buff *skb);
201
202#endif /* MPLS_INTERNAL_H */
203