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 __rcu *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[0];
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[0];
158};
159
160#define for_nexthops(rt) {						\
161	int nhsel; struct mpls_nh *nh;  u8 *__nh;			\
162	for (nhsel = 0, nh = (rt)->rt_nh, __nh = (u8 *)((rt)->rt_nh);	\
163	     nhsel < (rt)->rt_nhn;					\
164	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)
165
166#define change_nexthops(rt) {						\
167	int nhsel; struct mpls_nh *nh; u8 *__nh;			\
168	for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh),		\
169			__nh = (u8 *)((rt)->rt_nh);			\
170	     nhsel < (rt)->rt_nhn;					\
171	     __nh += rt->rt_nh_size, nh = (struct mpls_nh *)__nh, nhsel++)
172
173#define endfor_nexthops(rt) }
174
175static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
176{
177	struct mpls_shim_hdr result;
178	result.label_stack_entry =
179		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
180			    (tc << MPLS_LS_TC_SHIFT) |
181			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
182			    (ttl << MPLS_LS_TTL_SHIFT));
183	return result;
184}
185
186static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
187{
188	struct mpls_entry_decoded result;
189	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
190
191	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
192	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
193	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
194	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
195
196	return result;
197}
198
199static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
200{
201	return rcu_dereference_rtnl(dev->mpls_ptr);
202}
203
204int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
205		   const u32 label[]);
206int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
207		   u32 label[], struct netlink_ext_ack *extack);
208bool mpls_output_possible(const struct net_device *dev);
209unsigned int mpls_dev_mtu(const struct net_device *dev);
210bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
211void mpls_stats_inc_outucastpkts(struct net_device *dev,
212				 const struct sk_buff *skb);
213
214#endif /* MPLS_INTERNAL_H */