1#ifndef MPLS_INTERNAL_H
  2#define MPLS_INTERNAL_H
  3
  4struct mpls_shim_hdr {
  5	__be32 label_stack_entry;
  6};
  7
  8struct mpls_entry_decoded {
  9	u32 label;
 10	u8 ttl;
 11	u8 tc;
 12	u8 bos;
 13};
 14
 15struct mpls_dev {
 16	int			input_enabled;
 17
 18	struct ctl_table_header *sysctl;
 19	struct rcu_head		rcu;
 20};
 21
 22struct sk_buff;
 23
 24#define LABEL_NOT_SPECIFIED (1 << 20)
 25#define MAX_NEW_LABELS 2
 26
 27/* This maximum ha length copied from the definition of struct neighbour */
 28#define VIA_ALEN_ALIGN sizeof(unsigned long)
 29#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))
 30
 31enum mpls_payload_type {
 32	MPT_UNSPEC, /* IPv4 or IPv6 */
 33	MPT_IPV4 = 4,
 34	MPT_IPV6 = 6,
 35
 36	/* Other types not implemented:
 37	 *  - Pseudo-wire with or without control word (RFC4385)
 38	 *  - GAL (RFC5586)
 39	 */
 40};
 41
 42struct mpls_nh { /* next hop label forwarding entry */
 43	struct net_device __rcu *nh_dev;
 44	unsigned int		nh_flags;
 45	u32			nh_label[MAX_NEW_LABELS];
 46	u8			nh_labels;
 47	u8			nh_via_alen;
 48	u8			nh_via_table;
 49};
 50
 51/* The route, nexthops and vias are stored together in the same memory
 52 * block:
 53 *
 54 * +----------------------+
 55 * | mpls_route           |
 56 * +----------------------+
 57 * | mpls_nh 0            |
 58 * +----------------------+
 59 * | ...                  |
 60 * +----------------------+
 61 * | mpls_nh n-1          |
 62 * +----------------------+
 63 * | alignment padding    |
 64 * +----------------------+
 65 * | via[rt_max_alen] 0   |
 66 * +----------------------+
 67 * | ...                  |
 68 * +----------------------+
 69 * | via[rt_max_alen] n-1 |
 70 * +----------------------+
 71 */
 72struct mpls_route { /* next hop label forwarding entry */
 73	struct rcu_head		rt_rcu;
 74	u8			rt_protocol;
 75	u8			rt_payload_type;
 76	u8			rt_max_alen;
 77	unsigned int		rt_nhn;
 78	unsigned int		rt_nhn_alive;
 79	struct mpls_nh		rt_nh[0];
 80};
 81
 82#define for_nexthops(rt) {						\
 83	int nhsel; struct mpls_nh *nh;			\
 84	for (nhsel = 0, nh = (rt)->rt_nh;				\
 85	     nhsel < (rt)->rt_nhn;					\
 86	     nh++, nhsel++)
 87
 88#define change_nexthops(rt) {						\
 89	int nhsel; struct mpls_nh *nh;				\
 90	for (nhsel = 0,	nh = (struct mpls_nh *)((rt)->rt_nh);	\
 91	     nhsel < (rt)->rt_nhn;					\
 92	     nh++, nhsel++)
 93
 94#define endfor_nexthops(rt) }
 95
 96static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
 97{
 98	return (struct mpls_shim_hdr *)skb_network_header(skb);
 99}
100
101static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
102{
103	struct mpls_shim_hdr result;
104	result.label_stack_entry =
105		cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
106			    (tc << MPLS_LS_TC_SHIFT) |
107			    (bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
108			    (ttl << MPLS_LS_TTL_SHIFT));
109	return result;
110}
111
112static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
113{
114	struct mpls_entry_decoded result;
115	unsigned entry = be32_to_cpu(hdr->label_stack_entry);
116
117	result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
118	result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
119	result.tc =  (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
120	result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
121
122	return result;
123}
124
125int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
126		   const u32 label[]);
127int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
128		   u32 label[]);
129int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
130		u8 via[]);
131bool mpls_output_possible(const struct net_device *dev);
132unsigned int mpls_dev_mtu(const struct net_device *dev);
133bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
134
135#endif /* MPLS_INTERNAL_H */