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 /* LWTUNNEL_XMIT_CONTINUE should be distinguishable from dst_output return 20 * values (NET_XMIT_xxx and NETDEV_TX_xxx in linux/netdevice.h) for safety. 21 */ 22 enum { 23 LWTUNNEL_XMIT_DONE, 24 LWTUNNEL_XMIT_CONTINUE = 0x100, 25 }; 26 27 28 struct lwtunnel_state { 29 __u16 type; 30 __u16 flags; 31 __u16 headroom; 32 atomic_t refcnt; 33 int (*orig_output)(struct net *net, struct sock *sk, struct sk_buff *skb); 34 int (*orig_input)(struct sk_buff *); 35 struct rcu_head rcu; 36 __u8 data[]; 37 }; 38 39 struct lwtunnel_encap_ops { 40 int (*build_state)(struct net *net, struct nlattr *encap, 41 unsigned int family, const void *cfg, 42 struct lwtunnel_state **ts, 43 struct netlink_ext_ack *extack); 44 void (*destroy_state)(struct lwtunnel_state *lws); 45 int (*output)(struct net *net, struct sock *sk, struct sk_buff *skb); 46 int (*input)(struct sk_buff *skb); 47 int (*fill_encap)(struct sk_buff *skb, 48 struct lwtunnel_state *lwtstate); 49 int (*get_encap_size)(struct lwtunnel_state *lwtstate); 50 int (*cmp_encap)(struct lwtunnel_state *a, struct lwtunnel_state *b); 51 int (*xmit)(struct sk_buff *skb); 52 53 struct module *owner; 54 }; 55 56 #ifdef CONFIG_LWTUNNEL 57 58 DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled); 59 60 void lwtstate_free(struct lwtunnel_state *lws); 61 62 static inline struct lwtunnel_state * 63 lwtstate_get(struct lwtunnel_state *lws) 64 { 65 if (lws) 66 atomic_inc(&lws->refcnt); 67 68 return lws; 69 } 70 71 static inline void lwtstate_put(struct lwtunnel_state *lws) 72 { 73 if (!lws) 74 return; 75 76 if (atomic_dec_and_test(&lws->refcnt)) 77 lwtstate_free(lws); 78 } 79 80 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) 81 { 82 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_OUTPUT_REDIRECT)) 83 return true; 84 85 return false; 86 } 87 88 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) 89 { 90 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_INPUT_REDIRECT)) 91 return true; 92 93 return false; 94 } 95 96 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) 97 { 98 if (lwtstate && (lwtstate->flags & LWTUNNEL_STATE_XMIT_REDIRECT)) 99 return true; 100 101 return false; 102 } 103 104 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, 105 unsigned int mtu) 106 { 107 if ((lwtunnel_xmit_redirect(lwtstate) || 108 lwtunnel_output_redirect(lwtstate)) && lwtstate->headroom < mtu) 109 return lwtstate->headroom; 110 111 return 0; 112 } 113 114 int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 115 unsigned int num); 116 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 117 unsigned int num); 118 int lwtunnel_valid_encap_type(u16 encap_type, 119 struct netlink_ext_ack *extack, 120 bool rtnl_is_held); 121 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 122 struct netlink_ext_ack *extack, 123 bool rtnl_is_held); 124 int lwtunnel_build_state(struct net *net, u16 encap_type, 125 struct nlattr *encap, 126 unsigned int family, const void *cfg, 127 struct lwtunnel_state **lws, 128 struct netlink_ext_ack *extack); 129 int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, 130 int encap_attr, int encap_type_attr); 131 int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate); 132 struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len); 133 int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b); 134 int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb); 135 int lwtunnel_input(struct sk_buff *skb); 136 int lwtunnel_xmit(struct sk_buff *skb); 137 int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, 138 bool ingress); 139 140 static inline void lwtunnel_set_redirect(struct dst_entry *dst) 141 { 142 if (lwtunnel_output_redirect(dst->lwtstate)) { 143 dst->lwtstate->orig_output = dst->output; 144 dst->output = lwtunnel_output; 145 } 146 if (lwtunnel_input_redirect(dst->lwtstate)) { 147 dst->lwtstate->orig_input = dst->input; 148 dst->input = lwtunnel_input; 149 } 150 } 151 #else 152 153 static inline void lwtstate_free(struct lwtunnel_state *lws) 154 { 155 } 156 157 static inline struct lwtunnel_state * 158 lwtstate_get(struct lwtunnel_state *lws) 159 { 160 return lws; 161 } 162 163 static inline void lwtstate_put(struct lwtunnel_state *lws) 164 { 165 } 166 167 static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) 168 { 169 return false; 170 } 171 172 static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) 173 { 174 return false; 175 } 176 177 static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) 178 { 179 return false; 180 } 181 182 static inline void lwtunnel_set_redirect(struct dst_entry *dst) 183 { 184 } 185 186 static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, 187 unsigned int mtu) 188 { 189 return 0; 190 } 191 192 static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 193 unsigned int num) 194 { 195 return -EOPNOTSUPP; 196 197 } 198 199 static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 200 unsigned int num) 201 { 202 return -EOPNOTSUPP; 203 } 204 205 static inline int lwtunnel_valid_encap_type(u16 encap_type, 206 struct netlink_ext_ack *extack, 207 bool rtnl_is_held) 208 { 209 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel"); 210 return -EOPNOTSUPP; 211 } 212 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 213 struct netlink_ext_ack *extack, 214 bool rtnl_is_held) 215 { 216 /* return 0 since we are not walking attr looking for 217 * RTA_ENCAP_TYPE attribute on nexthops. 218 */ 219 return 0; 220 } 221 222 static inline int lwtunnel_build_state(struct net *net, u16 encap_type, 223 struct nlattr *encap, 224 unsigned int family, const void *cfg, 225 struct lwtunnel_state **lws, 226 struct netlink_ext_ack *extack) 227 { 228 return -EOPNOTSUPP; 229 } 230 231 static inline int lwtunnel_fill_encap(struct sk_buff *skb, 232 struct lwtunnel_state *lwtstate, 233 int encap_attr, int encap_type_attr) 234 { 235 return 0; 236 } 237 238 static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) 239 { 240 return 0; 241 } 242 243 static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len) 244 { 245 return NULL; 246 } 247 248 static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a, 249 struct lwtunnel_state *b) 250 { 251 return 0; 252 } 253 254 static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) 255 { 256 return -EOPNOTSUPP; 257 } 258 259 static inline int lwtunnel_input(struct sk_buff *skb) 260 { 261 return -EOPNOTSUPP; 262 } 263 264 static inline int lwtunnel_xmit(struct sk_buff *skb) 265 { 266 return -EOPNOTSUPP; 267 } 268 269 #endif /* CONFIG_LWTUNNEL */ 270 271 #define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type)) 272 273 #endif /* __NET_LWTUNNEL_H */ 274