1fd558d18SJames Chapman /* 2fd558d18SJames Chapman * L2TP internal definitions. 3fd558d18SJames Chapman * 4fd558d18SJames Chapman * Copyright (c) 2008,2009 Katalix Systems Ltd 5fd558d18SJames Chapman * 6fd558d18SJames Chapman * This program is free software; you can redistribute it and/or modify 7fd558d18SJames Chapman * it under the terms of the GNU General Public License version 2 as 8fd558d18SJames Chapman * published by the Free Software Foundation. 9fd558d18SJames Chapman */ 10fbea9e07SReshetova, Elena #include <linux/refcount.h> 11fd558d18SJames Chapman 12fd558d18SJames Chapman #ifndef _L2TP_CORE_H_ 13fd558d18SJames Chapman #define _L2TP_CORE_H_ 14fd558d18SJames Chapman 151f5cd2a0SGuillaume Nault #include <net/dst.h> 161f5cd2a0SGuillaume Nault #include <net/sock.h> 171f5cd2a0SGuillaume Nault 18d6a61ec9SGuillaume Nault #ifdef CONFIG_XFRM 19d6a61ec9SGuillaume Nault #include <net/xfrm.h> 20d6a61ec9SGuillaume Nault #endif 21d6a61ec9SGuillaume Nault 22fd558d18SJames Chapman /* Just some random numbers */ 23fd558d18SJames Chapman #define L2TP_TUNNEL_MAGIC 0x42114DDA 24fd558d18SJames Chapman #define L2TP_SESSION_MAGIC 0x0C04EB7D 25fd558d18SJames Chapman 26f7faffa3SJames Chapman /* Per tunnel, session hash table size */ 27fd558d18SJames Chapman #define L2TP_HASH_BITS 4 28fd558d18SJames Chapman #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS) 29fd558d18SJames Chapman 30f7faffa3SJames Chapman /* System-wide, session hash table size */ 31f7faffa3SJames Chapman #define L2TP_HASH_BITS_2 8 32f7faffa3SJames Chapman #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2) 33f7faffa3SJames Chapman 34fd558d18SJames Chapman struct sk_buff; 35fd558d18SJames Chapman 36fd558d18SJames Chapman struct l2tp_stats { 377b7c0719STom Parkin atomic_long_t tx_packets; 387b7c0719STom Parkin atomic_long_t tx_bytes; 397b7c0719STom Parkin atomic_long_t tx_errors; 407b7c0719STom Parkin atomic_long_t rx_packets; 417b7c0719STom Parkin atomic_long_t rx_bytes; 427b7c0719STom Parkin atomic_long_t rx_seq_discards; 437b7c0719STom Parkin atomic_long_t rx_oos_packets; 447b7c0719STom Parkin atomic_long_t rx_errors; 457b7c0719STom Parkin atomic_long_t rx_cookie_discards; 46fd558d18SJames Chapman }; 47fd558d18SJames Chapman 48fd558d18SJames Chapman struct l2tp_tunnel; 49fd558d18SJames Chapman 50fd558d18SJames Chapman /* Describes a session. Contains information to determine incoming 51fd558d18SJames Chapman * packets and transmit outgoing ones. 52fd558d18SJames Chapman */ 53fd558d18SJames Chapman struct l2tp_session_cfg { 54f7faffa3SJames Chapman enum l2tp_pwtype pw_type; 5595c96174SEric Dumazet unsigned int recv_seq:1; /* expect receive packets with 56fd558d18SJames Chapman * sequence numbers? */ 5795c96174SEric Dumazet unsigned int send_seq:1; /* send packets with sequence 58fd558d18SJames Chapman * numbers? */ 5995c96174SEric Dumazet unsigned int lns_mode:1; /* behave as LNS? LAC enables 60fd558d18SJames Chapman * sequence numbers under 61fd558d18SJames Chapman * control of LNS. */ 62fd558d18SJames Chapman int debug; /* bitmask of debug message 63fd558d18SJames Chapman * categories */ 64f7faffa3SJames Chapman u16 l2specific_type; /* Layer 2 specific type */ 65f7faffa3SJames Chapman u8 cookie[8]; /* optional cookie */ 66f7faffa3SJames Chapman int cookie_len; /* 0, 4 or 8 bytes */ 67f7faffa3SJames Chapman u8 peer_cookie[8]; /* peer's cookie */ 68f7faffa3SJames Chapman int peer_cookie_len; /* 0, 4 or 8 bytes */ 69fd558d18SJames Chapman int reorder_timeout; /* configured reorder timeout 70fd558d18SJames Chapman * (in jiffies) */ 71309795f4SJames Chapman char *ifname; 72fd558d18SJames Chapman }; 73fd558d18SJames Chapman 74fd558d18SJames Chapman struct l2tp_session { 75fd558d18SJames Chapman int magic; /* should be 76fd558d18SJames Chapman * L2TP_SESSION_MAGIC */ 77b228a940SGuillaume Nault long dead; 78fd558d18SJames Chapman 79fd558d18SJames Chapman struct l2tp_tunnel *tunnel; /* back pointer to tunnel 80fd558d18SJames Chapman * context */ 81fd558d18SJames Chapman u32 session_id; 82fd558d18SJames Chapman u32 peer_session_id; 83f7faffa3SJames Chapman u8 cookie[8]; 84f7faffa3SJames Chapman int cookie_len; 85f7faffa3SJames Chapman u8 peer_cookie[8]; 86f7faffa3SJames Chapman int peer_cookie_len; 87f7faffa3SJames Chapman u16 l2specific_type; 88f7faffa3SJames Chapman u16 hdr_len; 89f7faffa3SJames Chapman u32 nr; /* session NR state (receive) */ 90f7faffa3SJames Chapman u32 ns; /* session NR state (send) */ 91fd558d18SJames Chapman struct sk_buff_head reorder_q; /* receive reorder queue */ 928a1631d5SJames Chapman u32 nr_max; /* max NR. Depends on tunnel */ 938a1631d5SJames Chapman u32 nr_window_size; /* NR window size */ 94a0dbd822SJames Chapman u32 nr_oos; /* NR of last OOS packet */ 95a0dbd822SJames Chapman int nr_oos_count; /* For OOS recovery */ 96a0dbd822SJames Chapman int nr_oos_count_max; 97fd558d18SJames Chapman struct hlist_node hlist; /* Hash list node */ 98f00c854cSReshetova, Elena refcount_t ref_count; 99fd558d18SJames Chapman 100fd558d18SJames Chapman char name[32]; /* for logging */ 101309795f4SJames Chapman char ifname[IFNAMSIZ]; 10295c96174SEric Dumazet unsigned int recv_seq:1; /* expect receive packets with 103fd558d18SJames Chapman * sequence numbers? */ 10495c96174SEric Dumazet unsigned int send_seq:1; /* send packets with sequence 105fd558d18SJames Chapman * numbers? */ 10695c96174SEric Dumazet unsigned int lns_mode:1; /* behave as LNS? LAC enables 107fd558d18SJames Chapman * sequence numbers under 108fd558d18SJames Chapman * control of LNS. */ 109fd558d18SJames Chapman int debug; /* bitmask of debug message 110fd558d18SJames Chapman * categories */ 111fd558d18SJames Chapman int reorder_timeout; /* configured reorder timeout 112fd558d18SJames Chapman * (in jiffies) */ 11338d40b3fSJames Chapman int reorder_skip; /* set if skip to next nr */ 114f7faffa3SJames Chapman enum l2tp_pwtype pwtype; 115fd558d18SJames Chapman struct l2tp_stats stats; 116f7faffa3SJames Chapman struct hlist_node global_hlist; /* Global hash list node */ 117fd558d18SJames Chapman 118f7faffa3SJames Chapman int (*build_header)(struct l2tp_session *session, void *buf); 119fd558d18SJames Chapman void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); 120fd558d18SJames Chapman void (*session_close)(struct l2tp_session *session); 1219dd79945SJavier Martinez Canillas #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 1220ad66140SJames Chapman void (*show)(struct seq_file *m, void *priv); 1230ad66140SJames Chapman #endif 124fd558d18SJames Chapman uint8_t priv[0]; /* private data */ 125fd558d18SJames Chapman }; 126fd558d18SJames Chapman 127fd558d18SJames Chapman /* Describes the tunnel. It contains info to track all the associated 128fd558d18SJames Chapman * sessions so incoming packets can be sorted out 129fd558d18SJames Chapman */ 130fd558d18SJames Chapman struct l2tp_tunnel_cfg { 131fd558d18SJames Chapman int debug; /* bitmask of debug message 132fd558d18SJames Chapman * categories */ 1330d76751fSJames Chapman enum l2tp_encap_type encap; 134789a4a2cSJames Chapman 135789a4a2cSJames Chapman /* Used only for kernel-created sockets */ 136789a4a2cSJames Chapman struct in_addr local_ip; 137789a4a2cSJames Chapman struct in_addr peer_ip; 138f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 139f9bac8dfSChris Elston struct in6_addr *local_ip6; 140f9bac8dfSChris Elston struct in6_addr *peer_ip6; 141f9bac8dfSChris Elston #endif 142789a4a2cSJames Chapman u16 local_udp_port; 143789a4a2cSJames Chapman u16 peer_udp_port; 1446b649feaSTom Herbert unsigned int use_udp_checksums:1, 1456b649feaSTom Herbert udp6_zero_tx_checksums:1, 1466b649feaSTom Herbert udp6_zero_rx_checksums:1; 147fd558d18SJames Chapman }; 148fd558d18SJames Chapman 149fd558d18SJames Chapman struct l2tp_tunnel { 150fd558d18SJames Chapman int magic; /* Should be L2TP_TUNNEL_MAGIC */ 15162b982eeSSabrina Dubroca 15262b982eeSSabrina Dubroca unsigned long dead; 15362b982eeSSabrina Dubroca 15499469c32Sxeb@mail.ru struct rcu_head rcu; 155fd558d18SJames Chapman rwlock_t hlist_lock; /* protect session_hlist */ 156f3c66d4eSGuillaume Nault bool acpt_newsess; /* Indicates whether this 157f3c66d4eSGuillaume Nault * tunnel accepts new sessions. 158f3c66d4eSGuillaume Nault * Protected by hlist_lock. 159f3c66d4eSGuillaume Nault */ 160fd558d18SJames Chapman struct hlist_head session_hlist[L2TP_HASH_SIZE]; 161fd558d18SJames Chapman /* hashed list of sessions, 162fd558d18SJames Chapman * hashed by id */ 163fd558d18SJames Chapman u32 tunnel_id; 164fd558d18SJames Chapman u32 peer_tunnel_id; 165fd558d18SJames Chapman int version; /* 2=>L2TPv2, 3=>L2TPv3 */ 166fd558d18SJames Chapman 167fd558d18SJames Chapman char name[20]; /* for logging */ 168fd558d18SJames Chapman int debug; /* bitmask of debug message 169fd558d18SJames Chapman * categories */ 1700d76751fSJames Chapman enum l2tp_encap_type encap; 171fd558d18SJames Chapman struct l2tp_stats stats; 172fd558d18SJames Chapman 173fd558d18SJames Chapman struct list_head list; /* Keep a list of all tunnels */ 174fd558d18SJames Chapman struct net *l2tp_net; /* the net we belong to */ 175fd558d18SJames Chapman 176fbea9e07SReshetova, Elena refcount_t ref_count; 177fd558d18SJames Chapman void (*old_sk_destruct)(struct sock *); 178fd558d18SJames Chapman struct sock *sock; /* Parent socket */ 17980d84ef3STom Parkin int fd; /* Parent fd, if tunnel socket 18080d84ef3STom Parkin * was created by userspace */ 181fd558d18SJames Chapman 182f8ccac0eSTom Parkin struct work_struct del_work; 183fd558d18SJames Chapman }; 184fd558d18SJames Chapman 185309795f4SJames Chapman struct l2tp_nl_cmd_ops { 186f026bc29SGuillaume Nault int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel, 187f026bc29SGuillaume Nault u32 session_id, u32 peer_session_id, 188f026bc29SGuillaume Nault struct l2tp_session_cfg *cfg); 189309795f4SJames Chapman int (*session_delete)(struct l2tp_session *session); 190309795f4SJames Chapman }; 191309795f4SJames Chapman 192fd558d18SJames Chapman static inline void *l2tp_session_priv(struct l2tp_session *session) 193fd558d18SJames Chapman { 194fd558d18SJames Chapman return &session->priv[0]; 195fd558d18SJames Chapman } 196fd558d18SJames Chapman 19754652eb1SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); 1985846c131SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth); 19901e28b92SGuillaume Nault struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, 20001e28b92SGuillaume Nault u32 session_id); 2015846c131SGuillaume Nault 202d00fa9adSJames Chapman void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); 20354652eb1SGuillaume Nault 20401e28b92SGuillaume Nault struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id); 205a4346210SGuillaume Nault struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth); 2069aaef50cSGuillaume Nault struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, 207a4346210SGuillaume Nault const char *ifname); 208fd558d18SJames Chapman 209c1b1203dSJoe Perches int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, 210c1b1203dSJoe Perches u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, 211c1b1203dSJoe Perches struct l2tp_tunnel **tunnelp); 2126b9f3423SGuillaume Nault int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, 2136b9f3423SGuillaume Nault struct l2tp_tunnel_cfg *cfg); 2146b9f3423SGuillaume Nault 21562b982eeSSabrina Dubroca void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel); 216c1b1203dSJoe Perches struct l2tp_session *l2tp_session_create(int priv_size, 217c1b1203dSJoe Perches struct l2tp_tunnel *tunnel, 218c1b1203dSJoe Perches u32 session_id, u32 peer_session_id, 219c1b1203dSJoe Perches struct l2tp_session_cfg *cfg); 2203953ae7bSGuillaume Nault int l2tp_session_register(struct l2tp_session *session, 2213953ae7bSGuillaume Nault struct l2tp_tunnel *tunnel); 2223953ae7bSGuillaume Nault 223c1b1203dSJoe Perches void __l2tp_session_unhash(struct l2tp_session *session); 224c1b1203dSJoe Perches int l2tp_session_delete(struct l2tp_session *session); 225c1b1203dSJoe Perches void l2tp_session_free(struct l2tp_session *session); 226c1b1203dSJoe Perches void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 227c1b1203dSJoe Perches unsigned char *ptr, unsigned char *optr, u16 hdrflags, 2282b139e6bSGuillaume Nault int length); 229c1b1203dSJoe Perches int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); 230bb5016eaSGuillaume Nault void l2tp_session_set_header_len(struct l2tp_session *session, int version); 231fd558d18SJames Chapman 232c1b1203dSJoe Perches int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, 233c1b1203dSJoe Perches int hdr_len); 234fd558d18SJames Chapman 235c1b1203dSJoe Perches int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, 236c1b1203dSJoe Perches const struct l2tp_nl_cmd_ops *ops); 237c1b1203dSJoe Perches void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); 23872fb96e7SEric Dumazet int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); 239309795f4SJames Chapman 24054652eb1SGuillaume Nault static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) 24154652eb1SGuillaume Nault { 24254652eb1SGuillaume Nault refcount_inc(&tunnel->ref_count); 24354652eb1SGuillaume Nault } 24454652eb1SGuillaume Nault 24554652eb1SGuillaume Nault static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) 24654652eb1SGuillaume Nault { 24754652eb1SGuillaume Nault if (refcount_dec_and_test(&tunnel->ref_count)) 248d00fa9adSJames Chapman l2tp_tunnel_free(tunnel); 24954652eb1SGuillaume Nault } 25054652eb1SGuillaume Nault 251fd558d18SJames Chapman /* Session reference counts. Incremented when code obtains a reference 252fd558d18SJames Chapman * to a session. 253fd558d18SJames Chapman */ 2549ff672baSGuillaume Nault static inline void l2tp_session_inc_refcount(struct l2tp_session *session) 255fd558d18SJames Chapman { 256f00c854cSReshetova, Elena refcount_inc(&session->ref_count); 257fd558d18SJames Chapman } 258fd558d18SJames Chapman 2599ff672baSGuillaume Nault static inline void l2tp_session_dec_refcount(struct l2tp_session *session) 260fd558d18SJames Chapman { 261f00c854cSReshetova, Elena if (refcount_dec_and_test(&session->ref_count)) 262fd558d18SJames Chapman l2tp_session_free(session); 263fd558d18SJames Chapman } 264fd558d18SJames Chapman 26562e7b6a5SLorenzo Bianconi static inline int l2tp_get_l2specific_len(struct l2tp_session *session) 26662e7b6a5SLorenzo Bianconi { 26762e7b6a5SLorenzo Bianconi switch (session->l2specific_type) { 26862e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_DEFAULT: 26962e7b6a5SLorenzo Bianconi return 4; 27062e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_NONE: 27162e7b6a5SLorenzo Bianconi default: 27262e7b6a5SLorenzo Bianconi return 0; 27362e7b6a5SLorenzo Bianconi } 27462e7b6a5SLorenzo Bianconi } 27562e7b6a5SLorenzo Bianconi 2761f5cd2a0SGuillaume Nault static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel) 2771f5cd2a0SGuillaume Nault { 2781f5cd2a0SGuillaume Nault struct dst_entry *dst; 2791f5cd2a0SGuillaume Nault u32 mtu; 2801f5cd2a0SGuillaume Nault 2811f5cd2a0SGuillaume Nault dst = sk_dst_get(tunnel->sock); 2821f5cd2a0SGuillaume Nault if (!dst) 2831f5cd2a0SGuillaume Nault return 0; 2841f5cd2a0SGuillaume Nault 2851f5cd2a0SGuillaume Nault mtu = dst_mtu(dst); 2861f5cd2a0SGuillaume Nault dst_release(dst); 2871f5cd2a0SGuillaume Nault 2881f5cd2a0SGuillaume Nault return mtu; 2891f5cd2a0SGuillaume Nault } 2901f5cd2a0SGuillaume Nault 291d6a61ec9SGuillaume Nault #ifdef CONFIG_XFRM 292d6a61ec9SGuillaume Nault static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) 293d6a61ec9SGuillaume Nault { 294d6a61ec9SGuillaume Nault struct sock *sk = tunnel->sock; 295d6a61ec9SGuillaume Nault 296d6a61ec9SGuillaume Nault return sk && (rcu_access_pointer(sk->sk_policy[0]) || 297d6a61ec9SGuillaume Nault rcu_access_pointer(sk->sk_policy[1])); 298d6a61ec9SGuillaume Nault } 299d6a61ec9SGuillaume Nault #else 300d6a61ec9SGuillaume Nault static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) 301d6a61ec9SGuillaume Nault { 302d6a61ec9SGuillaume Nault return false; 303d6a61ec9SGuillaume Nault } 304d6a61ec9SGuillaume Nault #endif 305d6a61ec9SGuillaume Nault 306a4ca44faSJoe Perches #define l2tp_printk(ptr, type, func, fmt, ...) \ 307a4ca44faSJoe Perches do { \ 308a4ca44faSJoe Perches if (((ptr)->debug) & (type)) \ 309a4ca44faSJoe Perches func(fmt, ##__VA_ARGS__); \ 310a4ca44faSJoe Perches } while (0) 311a4ca44faSJoe Perches 312a4ca44faSJoe Perches #define l2tp_warn(ptr, type, fmt, ...) \ 313a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__) 314a4ca44faSJoe Perches #define l2tp_info(ptr, type, fmt, ...) \ 315a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__) 316a4ca44faSJoe Perches #define l2tp_dbg(ptr, type, fmt, ...) \ 317a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__) 318a4ca44faSJoe Perches 319f1f39f91Sstephen hemminger #define MODULE_ALIAS_L2TP_PWTYPE(type) \ 320f1f39f91Sstephen hemminger MODULE_ALIAS("net-l2tp-type-" __stringify(type)) 321f1f39f91Sstephen hemminger 322fd558d18SJames Chapman #endif /* _L2TP_CORE_H_ */ 323