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 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         struct module *owner;
  49 };
  50
  51 #ifdef CONFIG_LWTUNNEL
  52 void lwtstate_free(struct lwtunnel_state *lws);
  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) ||
 100              lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
 101                 return lwtstate->headroom;
 102
 103         return 0;
 104 }
 105
 106 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 107                            unsigned int num);
 108 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 109                            unsigned int num);
 110 int lwtunnel_valid_encap_type(u16 encap_type);
 111 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len);
 112 int lwtunnel_build_state(u16 encap_type,
 113                          struct nlattr *encap,
 114                          unsigned int family, const void *cfg,
 115                          struct lwtunnel_state **lws);
 116 int lwtunnel_fill_encap(struct sk_buff *skb,
 117                         struct lwtunnel_state *lwtstate);
 118 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
 119 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
 120 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
 121 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 122 int lwtunnel_input(struct sk_buff *skb);
 123 int lwtunnel_xmit(struct sk_buff *skb);
 124
 125 #else
 126
 127 static inline void lwtstate_free(struct lwtunnel_state *lws)
 128 {
 129 }
 130
 131 static inline struct lwtunnel_state *
 132 lwtstate_get(struct lwtunnel_state *lws)
 133 {
 134         return lws;
 135 }
 136
 137 static inline void lwtstate_put(struct lwtunnel_state *lws)
 138 {
 139 }
 140
 141 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 142 {
 143         return false;
 144 }
 145
 146 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 147 {
 148         return false;
 149 }
 150
 151 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 152 {
 153         return false;
 154 }
 155
 156 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 157                                              unsigned int mtu)
 158 {
 159         return 0;
 160 }
 161
 162 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 163                                          unsigned int num)
 164 {
 165         return -EOPNOTSUPP;
 166
 167 }
 168
 169 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 170                                          unsigned int num)
 171 {
 172         return -EOPNOTSUPP;
 173 }
 174
 175 static inline int lwtunnel_valid_encap_type(u16 encap_type)
 176 {
 177         return -EOPNOTSUPP;
 178 }
 179 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len)
 180 {
 181         /* return 0 since we are not walking attr looking for
 182          * RTA_ENCAP_TYPE attribute on nexthops.
 183          */
 184         return 0;
 185 }
 186
 187 static inline int lwtunnel_build_state(u16 encap_type,
 188                                        struct nlattr *encap,
 189                                        unsigned int family, const void *cfg,
 190                                        struct lwtunnel_state **lws)
 191 {
 192         return -EOPNOTSUPP;
 193 }
 194
 195 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
 196                                       struct lwtunnel_state *lwtstate)
 197 {
 198         return 0;
 199 }
 200
 201 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
 202 {
 203         return 0;
 204 }
 205
 206 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
 207 {
 208         return NULL;
 209 }
 210
 211 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
 212                                      struct lwtunnel_state *b)
 213 {
 214         return 0;
 215 }
 216
 217 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 218 {
 219         return -EOPNOTSUPP;
 220 }
 221
 222 static inline int lwtunnel_input(struct sk_buff *skb)
 223 {
 224         return -EOPNOTSUPP;
 225 }
 226
 227 static inline int lwtunnel_xmit(struct sk_buff *skb)
 228 {
 229         return -EOPNOTSUPP;
 230 }
 231
 232 #endif /* CONFIG_LWTUNNEL */
 233
 234 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
 235
 236 #endif /* __NET_LWTUNNEL_H */