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 18fd558d18SJames Chapman /* Just some random numbers */ 19fd558d18SJames Chapman #define L2TP_TUNNEL_MAGIC 0x42114DDA 20fd558d18SJames Chapman #define L2TP_SESSION_MAGIC 0x0C04EB7D 21fd558d18SJames Chapman 22f7faffa3SJames Chapman /* Per tunnel, session hash table size */ 23fd558d18SJames Chapman #define L2TP_HASH_BITS 4 24fd558d18SJames Chapman #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS) 25fd558d18SJames Chapman 26f7faffa3SJames Chapman /* System-wide, session hash table size */ 27f7faffa3SJames Chapman #define L2TP_HASH_BITS_2 8 28f7faffa3SJames Chapman #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2) 29f7faffa3SJames Chapman 30fd558d18SJames Chapman struct sk_buff; 31fd558d18SJames Chapman 32fd558d18SJames Chapman struct l2tp_stats { 337b7c0719STom Parkin atomic_long_t tx_packets; 347b7c0719STom Parkin atomic_long_t tx_bytes; 357b7c0719STom Parkin atomic_long_t tx_errors; 367b7c0719STom Parkin atomic_long_t rx_packets; 377b7c0719STom Parkin atomic_long_t rx_bytes; 387b7c0719STom Parkin atomic_long_t rx_seq_discards; 397b7c0719STom Parkin atomic_long_t rx_oos_packets; 407b7c0719STom Parkin atomic_long_t rx_errors; 417b7c0719STom Parkin atomic_long_t rx_cookie_discards; 42fd558d18SJames Chapman }; 43fd558d18SJames Chapman 44fd558d18SJames Chapman struct l2tp_tunnel; 45fd558d18SJames Chapman 46fd558d18SJames Chapman /* Describes a session. Contains information to determine incoming 47fd558d18SJames Chapman * packets and transmit outgoing ones. 48fd558d18SJames Chapman */ 49fd558d18SJames Chapman struct l2tp_session_cfg { 50f7faffa3SJames Chapman enum l2tp_pwtype pw_type; 5195c96174SEric Dumazet unsigned int recv_seq:1; /* expect receive packets with 52fd558d18SJames Chapman * sequence numbers? */ 5395c96174SEric Dumazet unsigned int send_seq:1; /* send packets with sequence 54fd558d18SJames Chapman * numbers? */ 5595c96174SEric Dumazet unsigned int lns_mode:1; /* behave as LNS? LAC enables 56fd558d18SJames Chapman * sequence numbers under 57fd558d18SJames Chapman * control of LNS. */ 58fd558d18SJames Chapman int debug; /* bitmask of debug message 59fd558d18SJames Chapman * categories */ 60f7faffa3SJames Chapman u16 l2specific_type; /* Layer 2 specific type */ 61f7faffa3SJames Chapman u8 cookie[8]; /* optional cookie */ 62f7faffa3SJames Chapman int cookie_len; /* 0, 4 or 8 bytes */ 63f7faffa3SJames Chapman u8 peer_cookie[8]; /* peer's cookie */ 64f7faffa3SJames Chapman int peer_cookie_len; /* 0, 4 or 8 bytes */ 65fd558d18SJames Chapman int reorder_timeout; /* configured reorder timeout 66fd558d18SJames Chapman * (in jiffies) */ 67fd558d18SJames Chapman int mtu; 68309795f4SJames Chapman char *ifname; 69fd558d18SJames Chapman }; 70fd558d18SJames Chapman 71fd558d18SJames Chapman struct l2tp_session { 72fd558d18SJames Chapman int magic; /* should be 73fd558d18SJames Chapman * L2TP_SESSION_MAGIC */ 74b228a940SGuillaume Nault long dead; 75fd558d18SJames Chapman 76fd558d18SJames Chapman struct l2tp_tunnel *tunnel; /* back pointer to tunnel 77fd558d18SJames Chapman * context */ 78fd558d18SJames Chapman u32 session_id; 79fd558d18SJames Chapman u32 peer_session_id; 80f7faffa3SJames Chapman u8 cookie[8]; 81f7faffa3SJames Chapman int cookie_len; 82f7faffa3SJames Chapman u8 peer_cookie[8]; 83f7faffa3SJames Chapman int peer_cookie_len; 84f7faffa3SJames Chapman u16 l2specific_type; 85f7faffa3SJames Chapman u16 hdr_len; 86f7faffa3SJames Chapman u32 nr; /* session NR state (receive) */ 87f7faffa3SJames Chapman u32 ns; /* session NR state (send) */ 88fd558d18SJames Chapman struct sk_buff_head reorder_q; /* receive reorder queue */ 898a1631d5SJames Chapman u32 nr_max; /* max NR. Depends on tunnel */ 908a1631d5SJames Chapman u32 nr_window_size; /* NR window size */ 91a0dbd822SJames Chapman u32 nr_oos; /* NR of last OOS packet */ 92a0dbd822SJames Chapman int nr_oos_count; /* For OOS recovery */ 93a0dbd822SJames Chapman int nr_oos_count_max; 94fd558d18SJames Chapman struct hlist_node hlist; /* Hash list node */ 95f00c854cSReshetova, Elena refcount_t ref_count; 96fd558d18SJames Chapman 97fd558d18SJames Chapman char name[32]; /* for logging */ 98309795f4SJames Chapman char ifname[IFNAMSIZ]; 9995c96174SEric Dumazet unsigned int recv_seq:1; /* expect receive packets with 100fd558d18SJames Chapman * sequence numbers? */ 10195c96174SEric Dumazet unsigned int send_seq:1; /* send packets with sequence 102fd558d18SJames Chapman * numbers? */ 10395c96174SEric Dumazet unsigned int lns_mode:1; /* behave as LNS? LAC enables 104fd558d18SJames Chapman * sequence numbers under 105fd558d18SJames Chapman * control of LNS. */ 106fd558d18SJames Chapman int debug; /* bitmask of debug message 107fd558d18SJames Chapman * categories */ 108fd558d18SJames Chapman int reorder_timeout; /* configured reorder timeout 109fd558d18SJames Chapman * (in jiffies) */ 11038d40b3fSJames Chapman int reorder_skip; /* set if skip to next nr */ 111fd558d18SJames Chapman int mtu; 112f7faffa3SJames Chapman enum l2tp_pwtype pwtype; 113fd558d18SJames Chapman struct l2tp_stats stats; 114f7faffa3SJames Chapman struct hlist_node global_hlist; /* Global hash list node */ 115fd558d18SJames Chapman 116f7faffa3SJames Chapman int (*build_header)(struct l2tp_session *session, void *buf); 117fd558d18SJames Chapman void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); 118fd558d18SJames Chapman void (*session_close)(struct l2tp_session *session); 1199dd79945SJavier Martinez Canillas #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 1200ad66140SJames Chapman void (*show)(struct seq_file *m, void *priv); 1210ad66140SJames Chapman #endif 122fd558d18SJames Chapman uint8_t priv[0]; /* private data */ 123fd558d18SJames Chapman }; 124fd558d18SJames Chapman 125fd558d18SJames Chapman /* Describes the tunnel. It contains info to track all the associated 126fd558d18SJames Chapman * sessions so incoming packets can be sorted out 127fd558d18SJames Chapman */ 128fd558d18SJames Chapman struct l2tp_tunnel_cfg { 129fd558d18SJames Chapman int debug; /* bitmask of debug message 130fd558d18SJames Chapman * categories */ 1310d76751fSJames Chapman enum l2tp_encap_type encap; 132789a4a2cSJames Chapman 133789a4a2cSJames Chapman /* Used only for kernel-created sockets */ 134789a4a2cSJames Chapman struct in_addr local_ip; 135789a4a2cSJames Chapman struct in_addr peer_ip; 136f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 137f9bac8dfSChris Elston struct in6_addr *local_ip6; 138f9bac8dfSChris Elston struct in6_addr *peer_ip6; 139f9bac8dfSChris Elston #endif 140789a4a2cSJames Chapman u16 local_udp_port; 141789a4a2cSJames Chapman u16 peer_udp_port; 1426b649feaSTom Herbert unsigned int use_udp_checksums:1, 1436b649feaSTom Herbert udp6_zero_tx_checksums:1, 1446b649feaSTom Herbert udp6_zero_rx_checksums:1; 145fd558d18SJames Chapman }; 146fd558d18SJames Chapman 147fd558d18SJames Chapman struct l2tp_tunnel { 148fd558d18SJames Chapman int magic; /* Should be L2TP_TUNNEL_MAGIC */ 14962b982eeSSabrina Dubroca 15062b982eeSSabrina Dubroca unsigned long dead; 15162b982eeSSabrina Dubroca 15299469c32Sxeb@mail.ru struct rcu_head rcu; 153fd558d18SJames Chapman rwlock_t hlist_lock; /* protect session_hlist */ 154f3c66d4eSGuillaume Nault bool acpt_newsess; /* Indicates whether this 155f3c66d4eSGuillaume Nault * tunnel accepts new sessions. 156f3c66d4eSGuillaume Nault * Protected by hlist_lock. 157f3c66d4eSGuillaume Nault */ 158fd558d18SJames Chapman struct hlist_head session_hlist[L2TP_HASH_SIZE]; 159fd558d18SJames Chapman /* hashed list of sessions, 160fd558d18SJames Chapman * hashed by id */ 161fd558d18SJames Chapman u32 tunnel_id; 162fd558d18SJames Chapman u32 peer_tunnel_id; 163fd558d18SJames Chapman int version; /* 2=>L2TPv2, 3=>L2TPv3 */ 164fd558d18SJames Chapman 165fd558d18SJames Chapman char name[20]; /* for logging */ 166fd558d18SJames Chapman int debug; /* bitmask of debug message 167fd558d18SJames Chapman * categories */ 1680d76751fSJames Chapman enum l2tp_encap_type encap; 169fd558d18SJames Chapman struct l2tp_stats stats; 170fd558d18SJames Chapman 171fd558d18SJames Chapman struct list_head list; /* Keep a list of all tunnels */ 172fd558d18SJames Chapman struct net *l2tp_net; /* the net we belong to */ 173fd558d18SJames Chapman 174fbea9e07SReshetova, Elena refcount_t ref_count; 175fd558d18SJames Chapman void (*old_sk_destruct)(struct sock *); 176fd558d18SJames Chapman struct sock *sock; /* Parent socket */ 17780d84ef3STom Parkin int fd; /* Parent fd, if tunnel socket 17880d84ef3STom Parkin * was created by userspace */ 179fd558d18SJames Chapman 180f8ccac0eSTom Parkin struct work_struct del_work; 181fd558d18SJames Chapman }; 182fd558d18SJames Chapman 183309795f4SJames Chapman struct l2tp_nl_cmd_ops { 184f026bc29SGuillaume Nault int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel, 185f026bc29SGuillaume Nault u32 session_id, u32 peer_session_id, 186f026bc29SGuillaume Nault struct l2tp_session_cfg *cfg); 187309795f4SJames Chapman int (*session_delete)(struct l2tp_session *session); 188309795f4SJames Chapman }; 189309795f4SJames Chapman 190fd558d18SJames Chapman static inline void *l2tp_session_priv(struct l2tp_session *session) 191fd558d18SJames Chapman { 192fd558d18SJames Chapman return &session->priv[0]; 193fd558d18SJames Chapman } 194fd558d18SJames Chapman 19554652eb1SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); 1965846c131SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth); 1975846c131SGuillaume Nault 198d00fa9adSJames Chapman void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); 19954652eb1SGuillaume Nault 2009aaef50cSGuillaume Nault struct l2tp_session *l2tp_session_get(const struct net *net, 20161b9a047SGuillaume Nault struct l2tp_tunnel *tunnel, 202a4346210SGuillaume Nault u32 session_id); 203a4346210SGuillaume Nault struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth); 2049aaef50cSGuillaume Nault struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, 205a4346210SGuillaume Nault const char *ifname); 206fd558d18SJames Chapman 207c1b1203dSJoe Perches int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, 208c1b1203dSJoe Perches u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, 209c1b1203dSJoe Perches struct l2tp_tunnel **tunnelp); 2106b9f3423SGuillaume Nault int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, 2116b9f3423SGuillaume Nault struct l2tp_tunnel_cfg *cfg); 2126b9f3423SGuillaume Nault 21362b982eeSSabrina Dubroca void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel); 214c1b1203dSJoe Perches struct l2tp_session *l2tp_session_create(int priv_size, 215c1b1203dSJoe Perches struct l2tp_tunnel *tunnel, 216c1b1203dSJoe Perches u32 session_id, u32 peer_session_id, 217c1b1203dSJoe Perches struct l2tp_session_cfg *cfg); 2183953ae7bSGuillaume Nault int l2tp_session_register(struct l2tp_session *session, 2193953ae7bSGuillaume Nault struct l2tp_tunnel *tunnel); 2203953ae7bSGuillaume Nault 221c1b1203dSJoe Perches void __l2tp_session_unhash(struct l2tp_session *session); 222c1b1203dSJoe Perches int l2tp_session_delete(struct l2tp_session *session); 223c1b1203dSJoe Perches void l2tp_session_free(struct l2tp_session *session); 224c1b1203dSJoe Perches void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 225c1b1203dSJoe Perches unsigned char *ptr, unsigned char *optr, u16 hdrflags, 2262b139e6bSGuillaume Nault int length); 227c1b1203dSJoe Perches int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); 228bb5016eaSGuillaume Nault void l2tp_session_set_header_len(struct l2tp_session *session, int version); 229fd558d18SJames Chapman 230c1b1203dSJoe Perches int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, 231c1b1203dSJoe Perches int hdr_len); 232fd558d18SJames Chapman 233c1b1203dSJoe Perches int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, 234c1b1203dSJoe Perches const struct l2tp_nl_cmd_ops *ops); 235c1b1203dSJoe Perches void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); 23672fb96e7SEric Dumazet int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); 237309795f4SJames Chapman 23854652eb1SGuillaume Nault static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) 23954652eb1SGuillaume Nault { 24054652eb1SGuillaume Nault refcount_inc(&tunnel->ref_count); 24154652eb1SGuillaume Nault } 24254652eb1SGuillaume Nault 24354652eb1SGuillaume Nault static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) 24454652eb1SGuillaume Nault { 24554652eb1SGuillaume Nault if (refcount_dec_and_test(&tunnel->ref_count)) 246d00fa9adSJames Chapman l2tp_tunnel_free(tunnel); 24754652eb1SGuillaume Nault } 24854652eb1SGuillaume Nault 249fd558d18SJames Chapman /* Session reference counts. Incremented when code obtains a reference 250fd558d18SJames Chapman * to a session. 251fd558d18SJames Chapman */ 2529ff672baSGuillaume Nault static inline void l2tp_session_inc_refcount(struct l2tp_session *session) 253fd558d18SJames Chapman { 254f00c854cSReshetova, Elena refcount_inc(&session->ref_count); 255fd558d18SJames Chapman } 256fd558d18SJames Chapman 2579ff672baSGuillaume Nault static inline void l2tp_session_dec_refcount(struct l2tp_session *session) 258fd558d18SJames Chapman { 259f00c854cSReshetova, Elena if (refcount_dec_and_test(&session->ref_count)) 260fd558d18SJames Chapman l2tp_session_free(session); 261fd558d18SJames Chapman } 262fd558d18SJames Chapman 26362e7b6a5SLorenzo Bianconi static inline int l2tp_get_l2specific_len(struct l2tp_session *session) 26462e7b6a5SLorenzo Bianconi { 26562e7b6a5SLorenzo Bianconi switch (session->l2specific_type) { 26662e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_DEFAULT: 26762e7b6a5SLorenzo Bianconi return 4; 26862e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_NONE: 26962e7b6a5SLorenzo Bianconi default: 27062e7b6a5SLorenzo Bianconi return 0; 27162e7b6a5SLorenzo Bianconi } 27262e7b6a5SLorenzo Bianconi } 27362e7b6a5SLorenzo Bianconi 2741f5cd2a0SGuillaume Nault static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel) 2751f5cd2a0SGuillaume Nault { 2761f5cd2a0SGuillaume Nault struct dst_entry *dst; 2771f5cd2a0SGuillaume Nault u32 mtu; 2781f5cd2a0SGuillaume Nault 2791f5cd2a0SGuillaume Nault dst = sk_dst_get(tunnel->sock); 2801f5cd2a0SGuillaume Nault if (!dst) 2811f5cd2a0SGuillaume Nault return 0; 2821f5cd2a0SGuillaume Nault 2831f5cd2a0SGuillaume Nault mtu = dst_mtu(dst); 2841f5cd2a0SGuillaume Nault dst_release(dst); 2851f5cd2a0SGuillaume Nault 2861f5cd2a0SGuillaume Nault return mtu; 2871f5cd2a0SGuillaume Nault } 2881f5cd2a0SGuillaume Nault 289a4ca44faSJoe Perches #define l2tp_printk(ptr, type, func, fmt, ...) \ 290a4ca44faSJoe Perches do { \ 291a4ca44faSJoe Perches if (((ptr)->debug) & (type)) \ 292a4ca44faSJoe Perches func(fmt, ##__VA_ARGS__); \ 293a4ca44faSJoe Perches } while (0) 294a4ca44faSJoe Perches 295a4ca44faSJoe Perches #define l2tp_warn(ptr, type, fmt, ...) \ 296a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__) 297a4ca44faSJoe Perches #define l2tp_info(ptr, type, fmt, ...) \ 298a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__) 299a4ca44faSJoe Perches #define l2tp_dbg(ptr, type, fmt, ...) \ 300a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__) 301a4ca44faSJoe Perches 302f1f39f91Sstephen hemminger #define MODULE_ALIAS_L2TP_PWTYPE(type) \ 303f1f39f91Sstephen hemminger MODULE_ALIAS("net-l2tp-type-" __stringify(type)) 304f1f39f91Sstephen hemminger 305fd558d18SJames Chapman #endif /* _L2TP_CORE_H_ */ 306