1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __NET_LWTUNNEL_H 3 #define __NET_LWTUNNEL_H 1 4 5 #include <linux/lwtunnel.h> 6 #include <linux/netdevice.h> 7 #include <linux/skbuff.h> 8 #include <linux/types.h> 9 #include <net/route.h> 10 11 #define LWTUNNEL_HASH_BITS 7 12 #define LWTUNNEL_HASH_SIZE (1 << LWTUNNEL_HASH_BITS) 13 14 /* lw tunnel state flags */ 15 #define LWTUNNEL_STATE_OUTPUT_REDIRECT BIT(0) 16 #define LWTUNNEL_STATE_INPUT_REDIRECT BIT(1) 17 #define LWTUNNEL_STATE_XMIT_REDIRECT BIT(2) 18 19 enum { 20 LWTUNNEL_XMIT_DONE, 21 LWTUNNEL_XMIT_CONTINUE, 22 }; 23 24 25 struct lwtunnel_state { 26 __u16 type; 27 __u16 flags; 28 __u16 headroom; 29 atomic_t refcnt; 30 int (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb); 31 int (*orig_input)(struct sk_buff *); 32 struct rcu_head rcu; 33 __u8 data[0]; 34 }; 35 36 struct lwtunnel_encap_ops { 37 int (*build_state)(struct nlattr *encap, 38 unsigned int family, const void *cfg, 39 struct lwtunnel_state **ts, 40 struct netlink_ext_ack *extack); 41 void (*destroy_state)(struct lwtunnel_state *lws); 42 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb); 43 int (*input)(struct sk_buff *skb); 44 int (*fill_encap)(struct sk_buff *skb, 45 struct lwtunnel_state *lwtstate); 46 int (*get_encap_size)(struct lwtunnel_state *lwtstate); 47 int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b); 48 int (*xmit)(struct sk_buff *skb); 49 50 struct module *owner; 51 }; 52 53 #ifdef CONFIG_LWTUNNEL 54 void lwtstate_free(struct lwtunnel_state *lws); 55 56 static inline struct lwtunnel_state * 57 lwtstate_get(struct lwtunnel_state *lws) 58 { 59 if (lws) 60 atomic_inc(&lws->refcnt); 61 62 return lws; 63 } 64 65 static inline void lwtstate_put(struct lwtunnel_state *lws) 66 { 67 if (!lws) 68 return; 69 70 if (atomic_dec_and_test(&lws->refcnt)) 71 lwtstate_free(lws); 72 } 73 74 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) 75 { 76 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT)) 77 return true; 78 79 return false; 80 } 81 82 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) 83 { 84 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT)) 85 return true; 86 87 return false; 88 } 89 90 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) 91 { 92 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT)) 93 return true; 94 95 return false; 96 } 97 98 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, 99 unsigned int mtu) 100 { 101 if ((lwtunnel_xmit_redirect(lwtstate) || 102 lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu) 103 return lwtstate->headroom; 104 105 return 0; 106 } 107 108 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 109 unsigned int num); 110 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 111 unsigned int num); 112 int lwtunnel_valid_encap_type(u16 encap_type, 113 struct netlink_ext_ack *extack); 114 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 115 struct netlink_ext_ack *extack); 116 int lwtunnel_build_state(u16 encap_type, 117 struct nlattr *encap, 118 unsigned int family, const void *cfg, 119 struct lwtunnel_state **lws, 120 struct netlink_ext_ack *extack); 121 int lwtunnel_fill_encap(struct sk_buff *skb, 122 struct lwtunnel_state *lwtstate); 123 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate); 124 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len); 125 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b); 126 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb); 127 int lwtunnel_input(struct sk_buff *skb); 128 int lwtunnel_xmit(struct sk_buff *skb); 129 130 #else 131 132 static inline void lwtstate_free(struct lwtunnel_state *lws) 133 { 134 } 135 136 static inline struct lwtunnel_state * 137 lwtstate_get(struct lwtunnel_state *lws) 138 { 139 return lws; 140 } 141 142 static inline void lwtstate_put(struct lwtunnel_state *lws) 143 { 144 } 145 146 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) 147 { 148 return false; 149 } 150 151 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) 152 { 153 return false; 154 } 155 156 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) 157 { 158 return false; 159 } 160 161 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, 162 unsigned int mtu) 163 { 164 return 0; 165 } 166 167 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 168 unsigned int num) 169 { 170 return -EOPNOTSUPP; 171 172 } 173 174 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 175 unsigned int num) 176 { 177 return -EOPNOTSUPP; 178 } 179 180 static inline int lwtunnel_valid_encap_type(u16 encap_type, 181 struct netlink_ext_ack *extack) 182 { 183 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel"); 184 return -EOPNOTSUPP; 185 } 186 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 187 struct netlink_ext_ack *extack) 188 { 189 /* return 0 since we are not walking attr looking for 190 * RTA_ENCAP_TYPE attribute on nexthops. 191 */ 192 return 0; 193 } 194 195 static inline int lwtunnel_build_state(u16 encap_type, 196 struct nlattr *encap, 197 unsigned int family, const void *cfg, 198 struct lwtunnel_state **lws, 199 struct netlink_ext_ack *extack) 200 { 201 return -EOPNOTSUPP; 202 } 203 204 static inline int lwtunnel_fill_encap(struct sk_buff *skb, 205 struct lwtunnel_state *lwtstate) 206 { 207 return 0; 208 } 209 210 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) 211 { 212 return 0; 213 } 214 215 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len) 216 { 217 return NULL; 218 } 219 220 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a, 221 struct lwtunnel_state *b) 222 { 223 return 0; 224 } 225 226 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) 227 { 228 return -EOPNOTSUPP; 229 } 230 231 static inline int lwtunnel_input(struct sk_buff *skb) 232 { 233 return -EOPNOTSUPP; 234 } 235 236 static inline int lwtunnel_xmit(struct sk_buff *skb) 237 { 238 return -EOPNOTSUPP; 239 } 240 241 #endif /* CONFIG_LWTUNNEL */ 242 243 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type)) 244 245 #endif /* __NET_LWTUNNEL_H */ 246