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 static inline void lwtunnel_set_redirect(struct dst_entry *dst) 131 { 132 if (lwtunnel_output_redirect(dst->lwtstate)) { 133 dst->lwtstate->orig_output = dst->output; 134 dst->output = lwtunnel_output; 135 } 136 if (lwtunnel_input_redirect(dst->lwtstate)) { 137 dst->lwtstate->orig_input = dst->input; 138 dst->input = lwtunnel_input; 139 } 140 } 141 #else 142 143 static inline void lwtstate_free(struct lwtunnel_state *lws) 144 { 145 } 146 147 static inline struct lwtunnel_state * 148 lwtstate_get(struct lwtunnel_state *lws) 149 { 150 return lws; 151 } 152 153 static inline void lwtstate_put(struct lwtunnel_state *lws) 154 { 155 } 156 157 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) 158 { 159 return false; 160 } 161 162 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) 163 { 164 return false; 165 } 166 167 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) 168 { 169 return false; 170 } 171 172 static inline void lwtunnel_set_redirect(struct dst_entry *dst) 173 { 174 } 175 176 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, 177 unsigned int mtu) 178 { 179 return 0; 180 } 181 182 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 183 unsigned int num) 184 { 185 return -EOPNOTSUPP; 186 187 } 188 189 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 190 unsigned int num) 191 { 192 return -EOPNOTSUPP; 193 } 194 195 static inline int lwtunnel_valid_encap_type(u16 encap_type, 196 struct netlink_ext_ack *extack) 197 { 198 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel"); 199 return -EOPNOTSUPP; 200 } 201 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 202 struct netlink_ext_ack *extack) 203 { 204 /* return 0 since we are not walking attr looking for 205 * RTA_ENCAP_TYPE attribute on nexthops. 206 */ 207 return 0; 208 } 209 210 static inline int lwtunnel_build_state(u16 encap_type, 211 struct nlattr *encap, 212 unsigned int family, const void *cfg, 213 struct lwtunnel_state **lws, 214 struct netlink_ext_ack *extack) 215 { 216 return -EOPNOTSUPP; 217 } 218 219 static inline int lwtunnel_fill_encap(struct sk_buff *skb, 220 struct lwtunnel_state *lwtstate) 221 { 222 return 0; 223 } 224 225 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) 226 { 227 return 0; 228 } 229 230 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len) 231 { 232 return NULL; 233 } 234 235 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a, 236 struct lwtunnel_state *b) 237 { 238 return 0; 239 } 240 241 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) 242 { 243 return -EOPNOTSUPP; 244 } 245 246 static inline int lwtunnel_input(struct sk_buff *skb) 247 { 248 return -EOPNOTSUPP; 249 } 250 251 static inline int lwtunnel_xmit(struct sk_buff *skb) 252 { 253 return -EOPNOTSUPP; 254 } 255 256 #endif /* CONFIG_LWTUNNEL */ 257 258 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type)) 259 260 #endif /* __NET_LWTUNNEL_H */ 261