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         atomic_t        refcnt;
  28         int             (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb);
  29         int             (*orig_input)(struct sk_buff *);
  30         int             len;
  31         __u16           headroom;
  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         int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
  40         int (*input)(struct sk_buff *skb);
  41         int (*fill_encap)(struct sk_buff *skb,
  42                           struct lwtunnel_state *lwtstate);
  43         int (*get_encap_size)(struct lwtunnel_state *lwtstate);
  44         int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
  45         int (*xmit)(struct sk_buff *skb);
  46 };
  47
  48 #ifdef CONFIG_LWTUNNEL
  49 static inline void lwtstate_free(struct lwtunnel_state *lws)
  50 {
  51         kfree(lws);
  52 }
  53
  54 static inline struct lwtunnel_state *
  55 lwtstate_get(struct lwtunnel_state *lws)
  56 {
  57         if (lws)
  58                 atomic_inc(&lws->refcnt);
  59
  60         return lws;
  61 }
  62
  63 static inline void lwtstate_put(struct lwtunnel_state *lws)
  64 {
  65         if (!lws)
  66                 return;
  67
  68         if (atomic_dec_and_test(&lws->refcnt))
  69                 lwtstate_free(lws);
  70 }
  71
  72 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
  73 {
  74         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
  75                 return true;
  76
  77         return false;
  78 }
  79
  80 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
  81 {
  82         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
  83                 return true;
  84
  85         return false;
  86 }
  87
  88 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
  89 {
  90         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
  91                 return true;
  92
  93         return false;
  94 }
  95
  96 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
  97                                              unsigned int mtu)
  98 {
  99         if (lwtunnel_xmit_redirect(lwtstate) && lwtstate->headroom < mtu)
 100                 return lwtstate->headroom;
 101
 102         return 0;
 103 }
 104
 105 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 106                            unsigned int num);
 107 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 108                            unsigned int num);
 109 int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 110                          struct nlattr *encap,
 111                          unsigned int family, const void *cfg,
 112                          struct lwtunnel_state **lws);
 113 int lwtunnel_fill_encap(struct sk_buff *skb,
 114                         struct lwtunnel_state *lwtstate);
 115 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
 116 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
 117 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
 118 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 119 int lwtunnel_input(struct sk_buff *skb);
 120 int lwtunnel_xmit(struct sk_buff *skb);
 121
 122 #else
 123
 124 static inline void lwtstate_free(struct lwtunnel_state *lws)
 125 {
 126 }
 127
 128 static inline struct lwtunnel_state *
 129 lwtstate_get(struct lwtunnel_state *lws)
 130 {
 131         return lws;
 132 }
 133
 134 static inline void lwtstate_put(struct lwtunnel_state *lws)
 135 {
 136 }
 137
 138 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 139 {
 140         return false;
 141 }
 142
 143 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 144 {
 145         return false;
 146 }
 147
 148 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 149 {
 150         return false;
 151 }
 152
 153 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 154                                              unsigned int mtu)
 155 {
 156         return 0;
 157 }
 158
 159 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 160                                          unsigned int num)
 161 {
 162         return -EOPNOTSUPP;
 163
 164 }
 165
 166 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 167                                          unsigned int num)
 168 {
 169         return -EOPNOTSUPP;
 170 }
 171
 172 static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 173                                        struct nlattr *encap,
 174                                        unsigned int family, const void *cfg,
 175                                        struct lwtunnel_state **lws)
 176 {
 177         return -EOPNOTSUPP;
 178 }
 179
 180 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
 181                                       struct lwtunnel_state *lwtstate)
 182 {
 183         return 0;
 184 }
 185
 186 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
 187 {
 188         return 0;
 189 }
 190
 191 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
 192 {
 193         return NULL;
 194 }
 195
 196 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
 197                                      struct lwtunnel_state *b)
 198 {
 199         return 0;
 200 }
 201
 202 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 203 {
 204         return -EOPNOTSUPP;
 205 }
 206
 207 static inline int lwtunnel_input(struct sk_buff *skb)
 208 {
 209         return -EOPNOTSUPP;
 210 }
 211
 212 static inline int lwtunnel_xmit(struct sk_buff *skb)
 213 {
 214         return -EOPNOTSUPP;
 215 }
 216
 217 #endif /* CONFIG_LWTUNNEL */
 218
 219 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
 220
 221 #endif /* __NET_LWTUNNEL_H */