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) ||
  98              lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
  99                 return lwtstate->headroom;
 100
 101         return 0;
 102 }
 103
 104 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 105                            unsigned int num);
 106 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 107                            unsigned int num);
 108 int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 109                          struct nlattr *encap,
 110                          unsigned int family, const void *cfg,
 111                          struct lwtunnel_state **lws);
 112 int lwtunnel_fill_encap(struct sk_buff *skb,
 113                         struct lwtunnel_state *lwtstate);
 114 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
 115 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
 116 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
 117 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 118 int lwtunnel_input(struct sk_buff *skb);
 119 int lwtunnel_xmit(struct sk_buff *skb);
 120
 121 #else
 122
 123 static inline void lwtstate_free(struct lwtunnel_state *lws)
 124 {
 125 }
 126
 127 static inline struct lwtunnel_state *
 128 lwtstate_get(struct lwtunnel_state *lws)
 129 {
 130         return lws;
 131 }
 132
 133 static inline void lwtstate_put(struct lwtunnel_state *lws)
 134 {
 135 }
 136
 137 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 138 {
 139         return false;
 140 }
 141
 142 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 143 {
 144         return false;
 145 }
 146
 147 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 148 {
 149         return false;
 150 }
 151
 152 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 153                                              unsigned int mtu)
 154 {
 155         return 0;
 156 }
 157
 158 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 159                                          unsigned int num)
 160 {
 161         return -EOPNOTSUPP;
 162
 163 }
 164
 165 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 166                                          unsigned int num)
 167 {
 168         return -EOPNOTSUPP;
 169 }
 170
 171 static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 172                                        struct nlattr *encap,
 173                                        unsigned int family, const void *cfg,
 174                                        struct lwtunnel_state **lws)
 175 {
 176         return -EOPNOTSUPP;
 177 }
 178
 179 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
 180                                       struct lwtunnel_state *lwtstate)
 181 {
 182         return 0;
 183 }
 184
 185 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
 186 {
 187         return 0;
 188 }
 189
 190 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
 191 {
 192         return NULL;
 193 }
 194
 195 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
 196                                      struct lwtunnel_state *b)
 197 {
 198         return 0;
 199 }
 200
 201 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 202 {
 203         return -EOPNOTSUPP;
 204 }
 205
 206 static inline int lwtunnel_input(struct sk_buff *skb)
 207 {
 208         return -EOPNOTSUPP;
 209 }
 210
 211 static inline int lwtunnel_xmit(struct sk_buff *skb)
 212 {
 213         return -EOPNOTSUPP;
 214 }
 215
 216 #endif /* CONFIG_LWTUNNEL */
 217
 218 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
 219
 220 #endif /* __NET_LWTUNNEL_H */