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 */ 22enum { 23 LWTUNNEL_XMIT_DONE, 24 LWTUNNEL_XMIT_CONTINUE = 0x100, 25}; 26 27 28struct 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 39struct 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 58DECLARE_STATIC_KEY_FALSE(nf_hooks_lwtunnel_enabled); 59 60void lwtstate_free(struct lwtunnel_state *lws); 61 62static inline struct lwtunnel_state * 63lwtstate_get(struct lwtunnel_state *lws) 64{ 65 if (lws) 66 atomic_inc(&lws->refcnt); 67 68 return lws; 69} 70 71static 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 80static 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 88static 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 96static 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 104static 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 114int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 115 unsigned int num); 116int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 117 unsigned int num); 118int lwtunnel_valid_encap_type(u16 encap_type, 119 struct netlink_ext_ack *extack); 120int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 121 struct netlink_ext_ack *extack); 122int lwtunnel_build_state(struct net *net, u16 encap_type, 123 struct nlattr *encap, 124 unsigned int family, const void *cfg, 125 struct lwtunnel_state **lws, 126 struct netlink_ext_ack *extack); 127int lwtunnel_fill_encap(struct sk_buff *skb, struct lwtunnel_state *lwtstate, 128 int encap_attr, int encap_type_attr); 129int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate); 130struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len); 131int lwtunnel_cmp_encap(struct lwtunnel_state *a, struct lwtunnel_state *b); 132int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb); 133int lwtunnel_input(struct sk_buff *skb); 134int lwtunnel_xmit(struct sk_buff *skb); 135int bpf_lwt_push_ip_encap(struct sk_buff *skb, void *hdr, u32 len, 136 bool ingress); 137 138static inline void lwtunnel_set_redirect(struct dst_entry *dst) 139{ 140 if (lwtunnel_output_redirect(dst->lwtstate)) { 141 dst->lwtstate->orig_output = dst->output; 142 dst->output = lwtunnel_output; 143 } 144 if (lwtunnel_input_redirect(dst->lwtstate)) { 145 dst->lwtstate->orig_input = dst->input; 146 dst->input = lwtunnel_input; 147 } 148} 149#else 150 151static inline void lwtstate_free(struct lwtunnel_state *lws) 152{ 153} 154 155static inline struct lwtunnel_state * 156lwtstate_get(struct lwtunnel_state *lws) 157{ 158 return lws; 159} 160 161static inline void lwtstate_put(struct lwtunnel_state *lws) 162{ 163} 164 165static inline bool lwtunnel_output_redirect(struct lwtunnel_state *lwtstate) 166{ 167 return false; 168} 169 170static inline bool lwtunnel_input_redirect(struct lwtunnel_state *lwtstate) 171{ 172 return false; 173} 174 175static inline bool lwtunnel_xmit_redirect(struct lwtunnel_state *lwtstate) 176{ 177 return false; 178} 179 180static inline void lwtunnel_set_redirect(struct dst_entry *dst) 181{ 182} 183 184static inline unsigned int lwtunnel_headroom(struct lwtunnel_state *lwtstate, 185 unsigned int mtu) 186{ 187 return 0; 188} 189 190static inline int lwtunnel_encap_add_ops(const struct lwtunnel_encap_ops *op, 191 unsigned int num) 192{ 193 return -EOPNOTSUPP; 194 195} 196 197static inline int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op, 198 unsigned int num) 199{ 200 return -EOPNOTSUPP; 201} 202 203static inline int lwtunnel_valid_encap_type(u16 encap_type, 204 struct netlink_ext_ack *extack) 205{ 206 NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel"); 207 return -EOPNOTSUPP; 208} 209static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len, 210 struct netlink_ext_ack *extack) 211{ 212 /* return 0 since we are not walking attr looking for 213 * RTA_ENCAP_TYPE attribute on nexthops. 214 */ 215 return 0; 216} 217 218static inline int lwtunnel_build_state(struct net *net, u16 encap_type, 219 struct nlattr *encap, 220 unsigned int family, const void *cfg, 221 struct lwtunnel_state **lws, 222 struct netlink_ext_ack *extack) 223{ 224 return -EOPNOTSUPP; 225} 226 227static inline int lwtunnel_fill_encap(struct sk_buff *skb, 228 struct lwtunnel_state *lwtstate, 229 int encap_attr, int encap_type_attr) 230{ 231 return 0; 232} 233 234static inline int lwtunnel_get_encap_size(struct lwtunnel_state *lwtstate) 235{ 236 return 0; 237} 238 239static inline struct lwtunnel_state *lwtunnel_state_alloc(int hdr_len) 240{ 241 return NULL; 242} 243 244static inline int lwtunnel_cmp_encap(struct lwtunnel_state *a, 245 struct lwtunnel_state *b) 246{ 247 return 0; 248} 249 250static inline int lwtunnel_output(struct net *net, struct sock *sk, struct sk_buff *skb) 251{ 252 return -EOPNOTSUPP; 253} 254 255static inline int lwtunnel_input(struct sk_buff *skb) 256{ 257 return -EOPNOTSUPP; 258} 259 260static inline int lwtunnel_xmit(struct sk_buff *skb) 261{ 262 return -EOPNOTSUPP; 263} 264 265#endif /* CONFIG_LWTUNNEL */ 266 267#define MODULE_ALIAS_RTNL_LWT(encap_type) MODULE_ALIAS("rtnl-lwt-" __stringify(encap_type)) 268 269#endif /* __NET_LWTUNNEL_H */ 270