1d2912cb1SThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-only */ 2fd558d18SJames Chapman /* 3fd558d18SJames Chapman * L2TP internal definitions. 4fd558d18SJames Chapman * 5fd558d18SJames Chapman * Copyright (c) 2008,2009 Katalix Systems Ltd 6fd558d18SJames Chapman */ 7fbea9e07SReshetova, Elena #include <linux/refcount.h> 8fd558d18SJames Chapman 9fd558d18SJames Chapman #ifndef _L2TP_CORE_H_ 10fd558d18SJames Chapman #define _L2TP_CORE_H_ 11fd558d18SJames Chapman 121f5cd2a0SGuillaume Nault #include <net/dst.h> 131f5cd2a0SGuillaume Nault #include <net/sock.h> 141f5cd2a0SGuillaume Nault 15d6a61ec9SGuillaume Nault #ifdef CONFIG_XFRM 16d6a61ec9SGuillaume Nault #include <net/xfrm.h> 17d6a61ec9SGuillaume Nault #endif 18d6a61ec9SGuillaume Nault 19fd558d18SJames Chapman /* Just some random numbers */ 20fd558d18SJames Chapman #define L2TP_TUNNEL_MAGIC 0x42114DDA 21fd558d18SJames Chapman #define L2TP_SESSION_MAGIC 0x0C04EB7D 22fd558d18SJames Chapman 23f7faffa3SJames Chapman /* Per tunnel, session hash table size */ 24fd558d18SJames Chapman #define L2TP_HASH_BITS 4 25fd558d18SJames Chapman #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS) 26fd558d18SJames Chapman 27f7faffa3SJames Chapman /* System-wide, session hash table size */ 28f7faffa3SJames Chapman #define L2TP_HASH_BITS_2 8 29f7faffa3SJames Chapman #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2) 30f7faffa3SJames Chapman 31fd558d18SJames Chapman struct sk_buff; 32fd558d18SJames Chapman 33fd558d18SJames Chapman struct l2tp_stats { 347b7c0719STom Parkin atomic_long_t tx_packets; 357b7c0719STom Parkin atomic_long_t tx_bytes; 367b7c0719STom Parkin atomic_long_t tx_errors; 377b7c0719STom Parkin atomic_long_t rx_packets; 387b7c0719STom Parkin atomic_long_t rx_bytes; 397b7c0719STom Parkin atomic_long_t rx_seq_discards; 407b7c0719STom Parkin atomic_long_t rx_oos_packets; 417b7c0719STom Parkin atomic_long_t rx_errors; 427b7c0719STom Parkin atomic_long_t rx_cookie_discards; 43fd558d18SJames Chapman }; 44fd558d18SJames Chapman 45fd558d18SJames Chapman struct l2tp_tunnel; 46fd558d18SJames Chapman 47fd558d18SJames Chapman /* Describes a session. Contains information to determine incoming 48fd558d18SJames Chapman * packets and transmit outgoing ones. 49fd558d18SJames Chapman */ 50fd558d18SJames Chapman struct l2tp_session_cfg { 51f7faffa3SJames Chapman enum l2tp_pwtype pw_type; 5295c96174SEric Dumazet unsigned int recv_seq:1; /* expect receive packets with 53fd558d18SJames Chapman * sequence numbers? */ 5495c96174SEric Dumazet unsigned int send_seq:1; /* send packets with sequence 55fd558d18SJames Chapman * numbers? */ 5695c96174SEric Dumazet unsigned int lns_mode:1; /* behave as LNS? LAC enables 57fd558d18SJames Chapman * sequence numbers under 58fd558d18SJames Chapman * control of LNS. */ 59fd558d18SJames Chapman int debug; /* bitmask of debug message 60fd558d18SJames Chapman * categories */ 61f7faffa3SJames Chapman u16 l2specific_type; /* Layer 2 specific type */ 62f7faffa3SJames Chapman u8 cookie[8]; /* optional cookie */ 63f7faffa3SJames Chapman int cookie_len; /* 0, 4 or 8 bytes */ 64f7faffa3SJames Chapman u8 peer_cookie[8]; /* peer's cookie */ 65f7faffa3SJames Chapman int peer_cookie_len; /* 0, 4 or 8 bytes */ 66fd558d18SJames Chapman int reorder_timeout; /* configured reorder timeout 67fd558d18SJames Chapman * (in jiffies) */ 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 */ 111f7faffa3SJames Chapman enum l2tp_pwtype pwtype; 112fd558d18SJames Chapman struct l2tp_stats stats; 113f7faffa3SJames Chapman struct hlist_node global_hlist; /* Global hash list node */ 114fd558d18SJames Chapman 115f7faffa3SJames Chapman int (*build_header)(struct l2tp_session *session, void *buf); 116fd558d18SJames Chapman void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); 117fd558d18SJames Chapman void (*session_close)(struct l2tp_session *session); 1180ad66140SJames Chapman void (*show)(struct seq_file *m, void *priv); 119af71b090SGustavo A. R. Silva u8 priv[]; /* private data */ 120fd558d18SJames Chapman }; 121fd558d18SJames Chapman 122fd558d18SJames Chapman /* Describes the tunnel. It contains info to track all the associated 123fd558d18SJames Chapman * sessions so incoming packets can be sorted out 124fd558d18SJames Chapman */ 125fd558d18SJames Chapman struct l2tp_tunnel_cfg { 126fd558d18SJames Chapman int debug; /* bitmask of debug message 127fd558d18SJames Chapman * categories */ 1280d76751fSJames Chapman enum l2tp_encap_type encap; 129789a4a2cSJames Chapman 130789a4a2cSJames Chapman /* Used only for kernel-created sockets */ 131789a4a2cSJames Chapman struct in_addr local_ip; 132789a4a2cSJames Chapman struct in_addr peer_ip; 133f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 134f9bac8dfSChris Elston struct in6_addr *local_ip6; 135f9bac8dfSChris Elston struct in6_addr *peer_ip6; 136f9bac8dfSChris Elston #endif 137789a4a2cSJames Chapman u16 local_udp_port; 138789a4a2cSJames Chapman u16 peer_udp_port; 1396b649feaSTom Herbert unsigned int use_udp_checksums:1, 1406b649feaSTom Herbert udp6_zero_tx_checksums:1, 1416b649feaSTom Herbert udp6_zero_rx_checksums:1; 142fd558d18SJames Chapman }; 143fd558d18SJames Chapman 144fd558d18SJames Chapman struct l2tp_tunnel { 145fd558d18SJames Chapman int magic; /* Should be L2TP_TUNNEL_MAGIC */ 14662b982eeSSabrina Dubroca 14762b982eeSSabrina Dubroca unsigned long dead; 14862b982eeSSabrina Dubroca 14999469c32Sxeb@mail.ru struct rcu_head rcu; 150fd558d18SJames Chapman rwlock_t hlist_lock; /* protect session_hlist */ 151f3c66d4eSGuillaume Nault bool acpt_newsess; /* Indicates whether this 152f3c66d4eSGuillaume Nault * tunnel accepts new sessions. 153f3c66d4eSGuillaume Nault * Protected by hlist_lock. 154f3c66d4eSGuillaume Nault */ 155fd558d18SJames Chapman struct hlist_head session_hlist[L2TP_HASH_SIZE]; 156fd558d18SJames Chapman /* hashed list of sessions, 157fd558d18SJames Chapman * hashed by id */ 158fd558d18SJames Chapman u32 tunnel_id; 159fd558d18SJames Chapman u32 peer_tunnel_id; 160fd558d18SJames Chapman int version; /* 2=>L2TPv2, 3=>L2TPv3 */ 161fd558d18SJames Chapman 162fd558d18SJames Chapman char name[20]; /* for logging */ 163fd558d18SJames Chapman int debug; /* bitmask of debug message 164fd558d18SJames Chapman * categories */ 1650d76751fSJames Chapman enum l2tp_encap_type encap; 166fd558d18SJames Chapman struct l2tp_stats stats; 167fd558d18SJames Chapman 168fd558d18SJames Chapman struct list_head list; /* Keep a list of all tunnels */ 169fd558d18SJames Chapman struct net *l2tp_net; /* the net we belong to */ 170fd558d18SJames Chapman 171fbea9e07SReshetova, Elena refcount_t ref_count; 172fd558d18SJames Chapman void (*old_sk_destruct)(struct sock *); 173fd558d18SJames Chapman struct sock *sock; /* Parent socket */ 17480d84ef3STom Parkin int fd; /* Parent fd, if tunnel socket 17580d84ef3STom Parkin * was created by userspace */ 176fd558d18SJames Chapman 177f8ccac0eSTom Parkin struct work_struct del_work; 178fd558d18SJames Chapman }; 179fd558d18SJames Chapman 180309795f4SJames Chapman struct l2tp_nl_cmd_ops { 181f026bc29SGuillaume Nault int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel, 182f026bc29SGuillaume Nault u32 session_id, u32 peer_session_id, 183f026bc29SGuillaume Nault struct l2tp_session_cfg *cfg); 184309795f4SJames Chapman int (*session_delete)(struct l2tp_session *session); 185309795f4SJames Chapman }; 186309795f4SJames Chapman 187fd558d18SJames Chapman static inline void *l2tp_session_priv(struct l2tp_session *session) 188fd558d18SJames Chapman { 189fd558d18SJames Chapman return &session->priv[0]; 190fd558d18SJames Chapman } 191fd558d18SJames Chapman 19254652eb1SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); 1935846c131SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth); 19401e28b92SGuillaume Nault struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, 19501e28b92SGuillaume Nault u32 session_id); 1965846c131SGuillaume Nault 197d00fa9adSJames Chapman void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); 19854652eb1SGuillaume Nault 19901e28b92SGuillaume Nault struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id); 200a4346210SGuillaume Nault struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth); 2019aaef50cSGuillaume Nault struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, 202a4346210SGuillaume Nault const char *ifname); 203fd558d18SJames Chapman 204c1b1203dSJoe Perches int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, 205c1b1203dSJoe Perches u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, 206c1b1203dSJoe Perches struct l2tp_tunnel **tunnelp); 2076b9f3423SGuillaume Nault int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, 2086b9f3423SGuillaume Nault struct l2tp_tunnel_cfg *cfg); 2096b9f3423SGuillaume Nault 21062b982eeSSabrina Dubroca void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel); 211c1b1203dSJoe Perches struct l2tp_session *l2tp_session_create(int priv_size, 212c1b1203dSJoe Perches struct l2tp_tunnel *tunnel, 213c1b1203dSJoe Perches u32 session_id, u32 peer_session_id, 214c1b1203dSJoe Perches struct l2tp_session_cfg *cfg); 2153953ae7bSGuillaume Nault int l2tp_session_register(struct l2tp_session *session, 2163953ae7bSGuillaume Nault struct l2tp_tunnel *tunnel); 2173953ae7bSGuillaume Nault 218c1b1203dSJoe Perches void __l2tp_session_unhash(struct l2tp_session *session); 219c1b1203dSJoe Perches int l2tp_session_delete(struct l2tp_session *session); 220c1b1203dSJoe Perches void l2tp_session_free(struct l2tp_session *session); 221c1b1203dSJoe Perches void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 222c1b1203dSJoe Perches unsigned char *ptr, unsigned char *optr, u16 hdrflags, 2232b139e6bSGuillaume Nault int length); 224c1b1203dSJoe Perches int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); 225bb5016eaSGuillaume Nault void l2tp_session_set_header_len(struct l2tp_session *session, int version); 226fd558d18SJames Chapman 227c1b1203dSJoe Perches int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, 228c1b1203dSJoe Perches int hdr_len); 229fd558d18SJames Chapman 230c1b1203dSJoe Perches int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, 231c1b1203dSJoe Perches const struct l2tp_nl_cmd_ops *ops); 232c1b1203dSJoe Perches void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); 23372fb96e7SEric Dumazet int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); 234309795f4SJames Chapman 23554652eb1SGuillaume Nault static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) 23654652eb1SGuillaume Nault { 23754652eb1SGuillaume Nault refcount_inc(&tunnel->ref_count); 23854652eb1SGuillaume Nault } 23954652eb1SGuillaume Nault 24054652eb1SGuillaume Nault static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) 24154652eb1SGuillaume Nault { 24254652eb1SGuillaume Nault if (refcount_dec_and_test(&tunnel->ref_count)) 243d00fa9adSJames Chapman l2tp_tunnel_free(tunnel); 24454652eb1SGuillaume Nault } 24554652eb1SGuillaume Nault 246fd558d18SJames Chapman /* Session reference counts. Incremented when code obtains a reference 247fd558d18SJames Chapman * to a session. 248fd558d18SJames Chapman */ 2499ff672baSGuillaume Nault static inline void l2tp_session_inc_refcount(struct l2tp_session *session) 250fd558d18SJames Chapman { 251f00c854cSReshetova, Elena refcount_inc(&session->ref_count); 252fd558d18SJames Chapman } 253fd558d18SJames Chapman 2549ff672baSGuillaume Nault static inline void l2tp_session_dec_refcount(struct l2tp_session *session) 255fd558d18SJames Chapman { 256f00c854cSReshetova, Elena if (refcount_dec_and_test(&session->ref_count)) 257fd558d18SJames Chapman l2tp_session_free(session); 258fd558d18SJames Chapman } 259fd558d18SJames Chapman 26062e7b6a5SLorenzo Bianconi static inline int l2tp_get_l2specific_len(struct l2tp_session *session) 26162e7b6a5SLorenzo Bianconi { 26262e7b6a5SLorenzo Bianconi switch (session->l2specific_type) { 26362e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_DEFAULT: 26462e7b6a5SLorenzo Bianconi return 4; 26562e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_NONE: 26662e7b6a5SLorenzo Bianconi default: 26762e7b6a5SLorenzo Bianconi return 0; 26862e7b6a5SLorenzo Bianconi } 26962e7b6a5SLorenzo Bianconi } 27062e7b6a5SLorenzo Bianconi 2711f5cd2a0SGuillaume Nault static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel) 2721f5cd2a0SGuillaume Nault { 2731f5cd2a0SGuillaume Nault struct dst_entry *dst; 2741f5cd2a0SGuillaume Nault u32 mtu; 2751f5cd2a0SGuillaume Nault 2761f5cd2a0SGuillaume Nault dst = sk_dst_get(tunnel->sock); 2771f5cd2a0SGuillaume Nault if (!dst) 2781f5cd2a0SGuillaume Nault return 0; 2791f5cd2a0SGuillaume Nault 2801f5cd2a0SGuillaume Nault mtu = dst_mtu(dst); 2811f5cd2a0SGuillaume Nault dst_release(dst); 2821f5cd2a0SGuillaume Nault 2831f5cd2a0SGuillaume Nault return mtu; 2841f5cd2a0SGuillaume Nault } 2851f5cd2a0SGuillaume Nault 286d6a61ec9SGuillaume Nault #ifdef CONFIG_XFRM 287d6a61ec9SGuillaume Nault static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) 288d6a61ec9SGuillaume Nault { 289d6a61ec9SGuillaume Nault struct sock *sk = tunnel->sock; 290d6a61ec9SGuillaume Nault 291d6a61ec9SGuillaume Nault return sk && (rcu_access_pointer(sk->sk_policy[0]) || 292d6a61ec9SGuillaume Nault rcu_access_pointer(sk->sk_policy[1])); 293d6a61ec9SGuillaume Nault } 294d6a61ec9SGuillaume Nault #else 295d6a61ec9SGuillaume Nault static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) 296d6a61ec9SGuillaume Nault { 297d6a61ec9SGuillaume Nault return false; 298d6a61ec9SGuillaume Nault } 299d6a61ec9SGuillaume Nault #endif 300d6a61ec9SGuillaume Nault 3014522a70dSJacob Wen static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb, 3024522a70dSJacob Wen unsigned char **ptr, unsigned char **optr) 3034522a70dSJacob Wen { 3044522a70dSJacob Wen int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session); 3054522a70dSJacob Wen 3064522a70dSJacob Wen if (opt_len > 0) { 3074522a70dSJacob Wen int off = *ptr - *optr; 3084522a70dSJacob Wen 3094522a70dSJacob Wen if (!pskb_may_pull(skb, off + opt_len)) 3104522a70dSJacob Wen return -1; 3114522a70dSJacob Wen 3124522a70dSJacob Wen if (skb->data != *optr) { 3134522a70dSJacob Wen *optr = skb->data; 3144522a70dSJacob Wen *ptr = skb->data + off; 3154522a70dSJacob Wen } 3164522a70dSJacob Wen } 3174522a70dSJacob Wen 3184522a70dSJacob Wen return 0; 3194522a70dSJacob Wen } 3204522a70dSJacob Wen 321a4ca44faSJoe Perches #define l2tp_printk(ptr, type, func, fmt, ...) \ 322a4ca44faSJoe Perches do { \ 323a4ca44faSJoe Perches if (((ptr)->debug) & (type)) \ 324a4ca44faSJoe Perches func(fmt, ##__VA_ARGS__); \ 325a4ca44faSJoe Perches } while (0) 326a4ca44faSJoe Perches 327a4ca44faSJoe Perches #define l2tp_warn(ptr, type, fmt, ...) \ 328a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__) 329a4ca44faSJoe Perches #define l2tp_info(ptr, type, fmt, ...) \ 330a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__) 331a4ca44faSJoe Perches #define l2tp_dbg(ptr, type, fmt, ...) \ 332a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__) 333a4ca44faSJoe Perches 334f1f39f91Sstephen hemminger #define MODULE_ALIAS_L2TP_PWTYPE(type) \ 335f1f39f91Sstephen hemminger MODULE_ALIAS("net-l2tp-type-" __stringify(type)) 336f1f39f91Sstephen hemminger 337fd558d18SJames Chapman #endif /* _L2TP_CORE_H_ */ 338