include/net/lwtunnel.h

   1 #ifndef __NET_LWTUNNEL_H
   2 #define __NET_LWTUNNEL_H 1
   3
   4 #include <linux/lwtunnel.h>
   5 #include <linux/netdevice.h>
   6 #include <linux/skbuff.h>
   7 #include <linux/types.h>
   8 #include <net/route.h>
   9
  10 #define LWTUNNEL_HASH_BITS   7
  11 #define LWTUNNEL_HASH_SIZE   (1 << LWTUNNEL_HASH_BITS)
  12
  13 /* lw tunnel state flags */
  14 #define LWTUNNEL_STATE_OUTPUT_REDIRECT  BIT(0)
  15 #define LWTUNNEL_STATE_INPUT_REDIRECT   BIT(1)
  16 #define LWTUNNEL_STATE_XMIT_REDIRECT    BIT(2)
  17
  18 enum {
  19         LWTUNNEL_XMIT_DONE,
  20         LWTUNNEL_XMIT_CONTINUE,
  21 };
  22
  23
  24 struct lwtunnel_state {
  25         __u16           type;
  26         __u16           flags;
  27         __u16           headroom;
  28         atomic_t        refcnt;
  29         int             (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
  30         int             (*orig_input)(struct sk_buff *);
  31         struct          rcu_head rcu;
  32         __u8            data[0];
  33 };
  34
  35 struct lwtunnel_encap_ops {
  36         int (*build_state)(struct net_device *dev, struct nlattr *encap,
  37                            unsigned int family, const void *cfg,
  38                            struct lwtunnel_state **ts);
  39         void (*destroy_state)(struct lwtunnel_state *lws);
  40         int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
  41         int (*input)(struct sk_buff *skb);
  42         int (*fill_encap)(struct sk_buff *skb,
  43                           struct lwtunnel_state *lwtstate);
  44         int (*get_encap_size)(struct lwtunnel_state *lwtstate);
  45         int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
  46         int (*xmit)(struct sk_buff *skb);
  47 };
  48
  49 #ifdef CONFIG_LWTUNNEL
  50 void lwtstate_free(struct lwtunnel_state *lws);
  51
  52 static inline struct lwtunnel_state *
  53 lwtstate_get(struct lwtunnel_state *lws)
  54 {
  55         if (lws)
  56                 atomic_inc(&lws->refcnt);
  57
  58         return lws;
  59 }
  60
  61 static inline void lwtstate_put(struct lwtunnel_state *lws)
  62 {
  63         if (!lws)
  64                 return;
  65
  66         if (atomic_dec_and_test(&lws->refcnt))
  67                 lwtstate_free(lws);
  68 }
  69
  70 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
  71 {
  72         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
  73                 return true;
  74
  75         return false;
  76 }
  77
  78 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
  79 {
  80         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
  81                 return true;
  82
  83         return false;
  84 }
  85
  86 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
  87 {
  88         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
  89                 return true;
  90
  91         return false;
  92 }
  93
  94 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
  95                                              unsigned int mtu)
  96 {
  97         if (lwtunnel_xmit_redirect(lwtstate) && lwtstate->headroom < mtu)
  98                 return lwtstate->headroom;
  99
 100         return 0;
 101 }
 102
 103 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 104                            unsigned int num);
 105 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 106                            unsigned int num);
 107 int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 108                          struct nlattr *encap,
 109                          unsigned int family, const void *cfg,
 110                          struct lwtunnel_state **lws);
 111 int lwtunnel_fill_encap(struct sk_buff *skb,
 112                         struct lwtunnel_state *lwtstate);
 113 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
 114 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
 115 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
 116 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 117 int lwtunnel_input(struct sk_buff *skb);
 118 int lwtunnel_xmit(struct sk_buff *skb);
 119
 120 #else
 121
 122 static inline void lwtstate_free(struct lwtunnel_state *lws)
 123 {
 124 }
 125
 126 static inline struct lwtunnel_state *
 127 lwtstate_get(struct lwtunnel_state *lws)
 128 {
 129         return lws;
 130 }
 131
 132 static inline void lwtstate_put(struct lwtunnel_state *lws)
 133 {
 134 }
 135
 136 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 137 {
 138         return false;
 139 }
 140
 141 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 142 {
 143         return false;
 144 }
 145
 146 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 147 {
 148         return false;
 149 }
 150
 151 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 152                                              unsigned int mtu)
 153 {
 154         return 0;
 155 }
 156
 157 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 158                                          unsigned int num)
 159 {
 160         return -EOPNOTSUPP;
 161
 162 }
 163
 164 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 165                                          unsigned int num)
 166 {
 167         return -EOPNOTSUPP;
 168 }
 169
 170 static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 171                                        struct nlattr *encap,
 172                                        unsigned int family, const void *cfg,
 173                                        struct lwtunnel_state **lws)
 174 {
 175         return -EOPNOTSUPP;
 176 }
 177
 178 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
 179                                       struct lwtunnel_state *lwtstate)
 180 {
 181         return 0;
 182 }
 183
 184 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
 185 {
 186         return 0;
 187 }
 188
 189 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
 190 {
 191         return NULL;
 192 }
 193
 194 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
 195                                      struct lwtunnel_state *b)
 196 {
 197         return 0;
 198 }
 199
 200 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 201 {
 202         return -EOPNOTSUPP;
 203 }
 204
 205 static inline int lwtunnel_input(struct sk_buff *skb)
 206 {
 207         return -EOPNOTSUPP;
 208 }
 209
 210 static inline int lwtunnel_xmit(struct sk_buff *skb)
 211 {
 212         return -EOPNOTSUPP;
 213 }
 214
 215 #endif /* CONFIG_LWTUNNEL */
 216
 217 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
 218
 219 #endif /* __NET_LWTUNNEL_H */