1#ifndef MPLS_INTERNAL_H
  2#define MPLS_INTERNAL_H
  3#include <net/mpls.h>
  4
  5struct mpls_entry_decoded {
  6	u32 label;
  7	u8 ttl;
  8	u8 tc;
  9	u8 bos;
 10};
 11
 12struct mpls_dev {
 13	int			input_enabled;
 14
 15	struct ctl_table_header *sysctl;
 16	struct rcu_head		rcu;
 17};
 18
 19struct sk_buff;
 20
 21#define LABEL_NOT_SPECIFIED (1 << 20)
 22#define MAX_NEW_LABELS 2
 23
 24/* This maximum ha length copied from the definition of struct neighbour */
 25#define VIA_ALEN_ALIGN sizeof(unsigned long)
 26#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
 27
 28enum mpls_payload_type {
 29	MPT_UNSPEC, /* IPv4 or IPv6 */
 30	MPT_IPV4 = 4,
 31	MPT_IPV6 = 6,
 32
 33	/* Other types not implemented:
 34	 *  - Pseudo-wire with or without control word (RFC4385)
 35	 *  - GAL (RFC5586)
 36	 */
 37};
 38
 39struct mpls_nh { /* next hop label forwarding entry */
 40	struct net_device __rcu *nh_dev;
 41	unsigned int		nh_flags;
 42	u32			nh_label[MAX_NEW_LABELS];
 43	u8			nh_labels;
 44	u8			nh_via_alen;
 45	u8			nh_via_table;
 46};
 47
 48/* The route, nexthops and vias are stored together in the same memory
 49 * block:
 50 *
 51 * +----------------------+
 52 * | mpls_route           |
 53 * +----------------------+
 54 * | mpls_nh 0            |
 55 * +----------------------+
 56 * | ...                  |
 57 * +----------------------+
 58 * | mpls_nh n-1          |
 59 * +----------------------+
 60 * | alignment padding    |
 61 * +----------------------+
 62 * | via[rt_max_alen] 0   |
 63 * +----------------------+
 64 * | ...                  |
 65 * +----------------------+
 66 * | via[rt_max_alen] n-1 |
 67 * +----------------------+
 68 */
 69struct mpls_route { /* next hop label forwarding entry */
 70	struct rcu_head		rt_rcu;
 71	u8			rt_protocol;
 72	u8			rt_payload_type;
 73	u8			rt_max_alen;
 74	unsigned int		rt_nhn;
 75	unsigned int		rt_nhn_alive;
 76	struct mpls_nh		rt_nh[0];
 77};
 78
 79#define for_nexthops(rt) {						\
 80	int nhsel; struct mpls_nh *nh;			\
 81	for (nhsel = 0, nh = (rt)->rt_nh;				\
 82	     nhsel < (rt)->rt_nhn;					\
 83	     nh++, nhsel++)
 84
 85#define change_nexthops(rt) {						\
 86	int nhsel; struct mpls_nh *nh;				\
 87	for (nhsel = 0,	nh = (struct mpls_nh *)((rt)->rt_nh);	\
 88	     nhsel < (rt)->rt_nhn;					\
 89	     nh++, nhsel++)
 90
 91#define endfor_nexthops(rt) }
 92
 93static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
 94{
 95	struct mpls_shim_hdr result;
 96	result.label_stack_entry =
 97		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
 98			    (tc << MPLS_LS_TC_SHIFT) |
 99			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
100			    (ttl << MPLS_LS_TTL_SHIFT));
101	return result;
102}
103
104static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
105{
106	struct mpls_entry_decoded result;
107	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
108
109	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
110	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
111	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
112	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
113
114	return result;
115}
116
117int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
118		   const u32 label[]);
119int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
120		   u32 label[]);
121int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
122		u8 via[]);
123bool mpls_output_possible(const struct net_device *dev);
124unsigned int mpls_dev_mtu(const struct net_device *dev);
125bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
126
127#endif /* MPLS_INTERNAL_H */