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         struct module *owner;
  48 };
  49
  50 #ifdef CONFIG_LWTUNNEL
  51 void lwtstate_free(struct lwtunnel_state *lws);
  52
  53 static inline struct lwtunnel_state *
  54 lwtstate_get(struct lwtunnel_state *lws)
  55 {
  56         if (lws)
  57                 atomic_inc(&lws->refcnt);
  58
  59         return lws;
  60 }
  61
  62 static inline void lwtstate_put(struct lwtunnel_state *lws)
  63 {
  64         if (!lws)
  65                 return;
  66
  67         if (atomic_dec_and_test(&lws->refcnt))
  68                 lwtstate_free(lws);
  69 }
  70
  71 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
  72 {
  73         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
  74                 return true;
  75
  76         return false;
  77 }
  78
  79 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
  80 {
  81         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
  82                 return true;
  83
  84         return false;
  85 }
  86
  87 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
  88 {
  89         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
  90                 return true;
  91
  92         return false;
  93 }
  94
  95 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
  96                                              unsigned int mtu)
  97 {
  98         if (lwtunnel_xmit_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_valid_encap_type(u16 encap_type);
 109 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len);
 110 int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 111                          struct nlattr *encap,
 112                          unsigned int family, const void *cfg,
 113                          struct lwtunnel_state **lws);
 114 int lwtunnel_fill_encap(struct sk_buff *skb,
 115                         struct lwtunnel_state *lwtstate);
 116 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
 117 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
 118 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
 119 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 120 int lwtunnel_input(struct sk_buff *skb);
 121 int lwtunnel_xmit(struct sk_buff *skb);
 122
 123 #else
 124
 125 static inline void lwtstate_free(struct lwtunnel_state *lws)
 126 {
 127 }
 128
 129 static inline struct lwtunnel_state *
 130 lwtstate_get(struct lwtunnel_state *lws)
 131 {
 132         return lws;
 133 }
 134
 135 static inline void lwtstate_put(struct lwtunnel_state *lws)
 136 {
 137 }
 138
 139 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 140 {
 141         return false;
 142 }
 143
 144 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 145 {
 146         return false;
 147 }
 148
 149 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 150 {
 151         return false;
 152 }
 153
 154 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 155                                              unsigned int mtu)
 156 {
 157         return 0;
 158 }
 159
 160 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 161                                          unsigned int num)
 162 {
 163         return -EOPNOTSUPP;
 164
 165 }
 166
 167 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 168                                          unsigned int num)
 169 {
 170         return -EOPNOTSUPP;
 171 }
 172
 173 static inline int lwtunnel_valid_encap_type(u16 encap_type)
 174 {
 175         return -EOPNOTSUPP;
 176 }
 177 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len)
 178 {
 179         /* return 0 since we are not walking attr looking for
 180          * RTA_ENCAP_TYPE attribute on nexthops.
 181          */
 182         return 0;
 183 }
 184
 185 static inline int lwtunnel_build_state(struct net_device *dev, u16 encap_type,
 186                                        struct nlattr *encap,
 187                                        unsigned int family, const void *cfg,
 188                                        struct lwtunnel_state **lws)
 189 {
 190         return -EOPNOTSUPP;
 191 }
 192
 193 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
 194                                       struct lwtunnel_state *lwtstate)
 195 {
 196         return 0;
 197 }
 198
 199 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
 200 {
 201         return 0;
 202 }
 203
 204 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
 205 {
 206         return NULL;
 207 }
 208
 209 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
 210                                      struct lwtunnel_state *b)
 211 {
 212         return 0;
 213 }
 214
 215 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 216 {
 217         return -EOPNOTSUPP;
 218 }
 219
 220 static inline int lwtunnel_input(struct sk_buff *skb)
 221 {
 222         return -EOPNOTSUPP;
 223 }
 224
 225 static inline int lwtunnel_xmit(struct sk_buff *skb)
 226 {
 227         return -EOPNOTSUPP;
 228 }
 229
 230 #endif /* CONFIG_LWTUNNEL */
 231
 232 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
 233
 234 #endif /* __NET_LWTUNNEL_H */