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                            struct netlink_ext_ack *extack);
  40         void (*destroy_state)(struct lwtunnel_state *lws);
  41         int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb);
  42         int (*input)(struct sk_buff *skb);
  43         int (*fill_encap)(struct sk_buff *skb,
  44                           struct lwtunnel_state *lwtstate);
  45         int (*get_encap_size)(struct lwtunnel_state *lwtstate);
  46         int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b);
  47         int (*xmit)(struct sk_buff *skb);
  48
  49         struct module *owner;
  50 };
  51
  52 #ifdef CONFIG_LWTUNNEL
  53 void lwtstate_free(struct lwtunnel_state *lws);
  54
  55 static inline struct lwtunnel_state *
  56 lwtstate_get(struct lwtunnel_state *lws)
  57 {
  58         if (lws)
  59                 atomic_inc(&lws->refcnt);
  60
  61         return lws;
  62 }
  63
  64 static inline void lwtstate_put(struct lwtunnel_state *lws)
  65 {
  66         if (!lws)
  67                 return;
  68
  69         if (atomic_dec_and_test(&lws->refcnt))
  70                 lwtstate_free(lws);
  71 }
  72
  73 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
  74 {
  75         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT))
  76                 return true;
  77
  78         return false;
  79 }
  80
  81 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
  82 {
  83         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT))
  84                 return true;
  85
  86         return false;
  87 }
  88
  89 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
  90 {
  91         if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT))
  92                 return true;
  93
  94         return false;
  95 }
  96
  97 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
  98                                              unsigned int mtu)
  99 {
 100         if ((lwtunnel_xmit_redirect(lwtstate) ||
 101              lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu)
 102                 return lwtstate->headroom;
 103
 104         return 0;
 105 }
 106
 107 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 108                            unsigned int num);
 109 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 110                            unsigned int num);
 111 int lwtunnel_valid_encap_type(u16 encap_type,
 112                               struct netlink_ext_ack *extack);
 113 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
 114                                    struct netlink_ext_ack *extack);
 115 int lwtunnel_build_state(u16 encap_type,
 116                          struct nlattr *encap,
 117                          unsigned int family, const void *cfg,
 118                          struct lwtunnel_state **lws,
 119                          struct netlink_ext_ack *extack);
 120 int lwtunnel_fill_encap(struct sk_buff *skb,
 121                         struct lwtunnel_state *lwtstate);
 122 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate);
 123 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len);
 124 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b);
 125 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb);
 126 int lwtunnel_input(struct sk_buff *skb);
 127 int lwtunnel_xmit(struct sk_buff *skb);
 128
 129 #else
 130
 131 static inline void lwtstate_free(struct lwtunnel_state *lws)
 132 {
 133 }
 134
 135 static inline struct lwtunnel_state *
 136 lwtstate_get(struct lwtunnel_state *lws)
 137 {
 138         return lws;
 139 }
 140
 141 static inline void lwtstate_put(struct lwtunnel_state *lws)
 142 {
 143 }
 144
 145 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate)
 146 {
 147         return false;
 148 }
 149
 150 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate)
 151 {
 152         return false;
 153 }
 154
 155 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate)
 156 {
 157         return false;
 158 }
 159
 160 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate,
 161                                              unsigned int mtu)
 162 {
 163         return 0;
 164 }
 165
 166 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op,
 167                                          unsigned int num)
 168 {
 169         return -EOPNOTSUPP;
 170
 171 }
 172
 173 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 174                                          unsigned int num)
 175 {
 176         return -EOPNOTSUPP;
 177 }
 178
 179 static inline int lwtunnel_valid_encap_type(u16 encap_type,
 180                                             struct netlink_ext_ack *extack)
 181 {
 182         NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
 183         return -EOPNOTSUPP;
 184 }
 185 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
 186                                                  struct netlink_ext_ack *extack)
 187 {
 188         /* return 0 since we are not walking attr looking for
 189          * RTA_ENCAP_TYPE attribute on nexthops.
 190          */
 191         return 0;
 192 }
 193
 194 static inline int lwtunnel_build_state(u16 encap_type,
 195                                        struct nlattr *encap,
 196                                        unsigned int family, const void *cfg,
 197                                        struct lwtunnel_state **lws,
 198                                        struct netlink_ext_ack *extack)
 199 {
 200         return -EOPNOTSUPP;
 201 }
 202
 203 static inline int lwtunnel_fill_encap(struct sk_buff *skb,
 204                                       struct lwtunnel_state *lwtstate)
 205 {
 206         return 0;
 207 }
 208
 209 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate)
 210 {
 211         return 0;
 212 }
 213
 214 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len)
 215 {
 216         return NULL;
 217 }
 218
 219 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a,
 220                                      struct lwtunnel_state *b)
 221 {
 222         return 0;
 223 }
 224
 225 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb)
 226 {
 227         return -EOPNOTSUPP;
 228 }
 229
 230 static inline int lwtunnel_input(struct sk_buff *skb)
 231 {
 232         return -EOPNOTSUPP;
 233 }
 234
 235 static inline int lwtunnel_xmit(struct sk_buff *skb)
 236 {
 237         return -EOPNOTSUPP;
 238 }
 239
 240 #endif /* CONFIG_LWTUNNEL */
 241
 242 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type))
 243
 244 #endif /* __NET_LWTUNNEL_H */