net/mpls/internal.h

   1 #ifndef MPLS_INTERNAL_H
   2 #define MPLS_INTERNAL_H
   3 #include <net/mpls.h>
   4
   5 struct mpls_entry_decoded {
   6         u32 label;
   7         u8 ttl;
   8         u8 tc;
   9         u8 bos;
  10 };
  11
  12 struct mpls_dev {
  13         int                     input_enabled;
  14
  15         struct ctl_table_header *sysctl;
  16         struct rcu_head         rcu;
  17 };
  18
  19 struct 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
  28 enum 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
  39 struct 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  */
  69 struct 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
  93 static 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
 104 static 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
 117 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
 118                    const u32 label[]);
 119 int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
 120                    u32 label[]);
 121 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
 122                 u8 via[]);
 123 bool mpls_output_possible(const struct net_device *dev);
 124 unsigned int mpls_dev_mtu(const struct net_device *dev);
 125 bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
 126
 127 #endif /* MPLS_INTERNAL_H */