1d2912cb1SThomas Gleixner /* SPDX-License-Identifier: GPL-2.0-only */ 220dcb110STom Parkin /* L2TP internal definitions. 3fd558d18SJames Chapman * 4fd558d18SJames Chapman * Copyright (c) 2008,2009 Katalix Systems Ltd 5fd558d18SJames Chapman */ 6fbea9e07SReshetova, Elena #include <linux/refcount.h> 7fd558d18SJames Chapman 8fd558d18SJames Chapman #ifndef _L2TP_CORE_H_ 9fd558d18SJames Chapman #define _L2TP_CORE_H_ 10fd558d18SJames Chapman 111f5cd2a0SGuillaume Nault #include <net/dst.h> 121f5cd2a0SGuillaume Nault #include <net/sock.h> 131f5cd2a0SGuillaume Nault 14d6a61ec9SGuillaume Nault #ifdef CONFIG_XFRM 15d6a61ec9SGuillaume Nault #include <net/xfrm.h> 16d6a61ec9SGuillaume Nault #endif 17d6a61ec9SGuillaume 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; 5120dcb110STom Parkin unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */ 5220dcb110STom Parkin unsigned int send_seq:1; /* send packets with sequence numbers? */ 5320dcb110STom Parkin unsigned int lns_mode:1; /* behave as LNS? 5420dcb110STom Parkin * LAC enables sequence numbers under LNS control. 5520dcb110STom Parkin */ 5620dcb110STom Parkin int debug; /* bitmask of debug message categories */ 57f7faffa3SJames Chapman u16 l2specific_type; /* Layer 2 specific type */ 58f7faffa3SJames Chapman u8 cookie[8]; /* optional cookie */ 59f7faffa3SJames Chapman int cookie_len; /* 0, 4 or 8 bytes */ 60f7faffa3SJames Chapman u8 peer_cookie[8]; /* peer's cookie */ 61f7faffa3SJames Chapman int peer_cookie_len; /* 0, 4 or 8 bytes */ 6220dcb110STom Parkin int reorder_timeout; /* configured reorder timeout (in jiffies) */ 63309795f4SJames Chapman char *ifname; 64fd558d18SJames Chapman }; 65fd558d18SJames Chapman 66fd558d18SJames Chapman struct l2tp_session { 6720dcb110STom Parkin int magic; /* should be L2TP_SESSION_MAGIC */ 68b228a940SGuillaume Nault long dead; 69fd558d18SJames Chapman 7020dcb110STom Parkin struct l2tp_tunnel *tunnel; /* back pointer to tunnel context */ 71fd558d18SJames Chapman u32 session_id; 72fd558d18SJames Chapman u32 peer_session_id; 73f7faffa3SJames Chapman u8 cookie[8]; 74f7faffa3SJames Chapman int cookie_len; 75f7faffa3SJames Chapman u8 peer_cookie[8]; 76f7faffa3SJames Chapman int peer_cookie_len; 77f7faffa3SJames Chapman u16 l2specific_type; 78f7faffa3SJames Chapman u16 hdr_len; 79f7faffa3SJames Chapman u32 nr; /* session NR state (receive) */ 80f7faffa3SJames Chapman u32 ns; /* session NR state (send) */ 81fd558d18SJames Chapman struct sk_buff_head reorder_q; /* receive reorder queue */ 828a1631d5SJames Chapman u32 nr_max; /* max NR. Depends on tunnel */ 838a1631d5SJames Chapman u32 nr_window_size; /* NR window size */ 84a0dbd822SJames Chapman u32 nr_oos; /* NR of last OOS packet */ 8520dcb110STom Parkin int nr_oos_count; /* for OOS recovery */ 86a0dbd822SJames Chapman int nr_oos_count_max; 8720dcb110STom Parkin struct hlist_node hlist; /* hash list node */ 88f00c854cSReshetova, Elena refcount_t ref_count; 89fd558d18SJames Chapman 90fd558d18SJames Chapman char name[32]; /* for logging */ 91309795f4SJames Chapman char ifname[IFNAMSIZ]; 9220dcb110STom Parkin unsigned int recv_seq:1; /* expect receive packets with sequence numbers? */ 9320dcb110STom Parkin unsigned int send_seq:1; /* send packets with sequence numbers? */ 9420dcb110STom Parkin unsigned int lns_mode:1; /* behave as LNS? 9520dcb110STom Parkin * LAC enables sequence numbers under LNS control. 9620dcb110STom Parkin */ 9720dcb110STom Parkin int debug; /* bitmask of debug message categories */ 9820dcb110STom Parkin int reorder_timeout; /* configured reorder timeout (in jiffies) */ 9938d40b3fSJames Chapman int reorder_skip; /* set if skip to next nr */ 100f7faffa3SJames Chapman enum l2tp_pwtype pwtype; 101fd558d18SJames Chapman struct l2tp_stats stats; 10220dcb110STom Parkin struct hlist_node global_hlist; /* global hash list node */ 103fd558d18SJames Chapman 104f7faffa3SJames Chapman int (*build_header)(struct l2tp_session *session, void *buf); 105fd558d18SJames Chapman void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); 106fd558d18SJames Chapman void (*session_close)(struct l2tp_session *session); 1070ad66140SJames Chapman void (*show)(struct seq_file *m, void *priv); 108af71b090SGustavo A. R. Silva u8 priv[]; /* private data */ 109fd558d18SJames Chapman }; 110fd558d18SJames Chapman 111fd558d18SJames Chapman /* Describes the tunnel. It contains info to track all the associated 112fd558d18SJames Chapman * sessions so incoming packets can be sorted out 113fd558d18SJames Chapman */ 114fd558d18SJames Chapman struct l2tp_tunnel_cfg { 11520dcb110STom Parkin int debug; /* bitmask of debug message categories */ 1160d76751fSJames Chapman enum l2tp_encap_type encap; 117789a4a2cSJames Chapman 118789a4a2cSJames Chapman /* Used only for kernel-created sockets */ 119789a4a2cSJames Chapman struct in_addr local_ip; 120789a4a2cSJames Chapman struct in_addr peer_ip; 121f9bac8dfSChris Elston #if IS_ENABLED(CONFIG_IPV6) 122f9bac8dfSChris Elston struct in6_addr *local_ip6; 123f9bac8dfSChris Elston struct in6_addr *peer_ip6; 124f9bac8dfSChris Elston #endif 125789a4a2cSJames Chapman u16 local_udp_port; 126789a4a2cSJames Chapman u16 peer_udp_port; 1276b649feaSTom Herbert unsigned int use_udp_checksums:1, 1286b649feaSTom Herbert udp6_zero_tx_checksums:1, 1296b649feaSTom Herbert udp6_zero_rx_checksums:1; 130fd558d18SJames Chapman }; 131fd558d18SJames Chapman 132fd558d18SJames Chapman struct l2tp_tunnel { 133fd558d18SJames Chapman int magic; /* Should be L2TP_TUNNEL_MAGIC */ 13462b982eeSSabrina Dubroca 13562b982eeSSabrina Dubroca unsigned long dead; 13662b982eeSSabrina Dubroca 13799469c32Sxeb@mail.ru struct rcu_head rcu; 138fd558d18SJames Chapman rwlock_t hlist_lock; /* protect session_hlist */ 13920dcb110STom Parkin bool acpt_newsess; /* indicates whether this tunnel accepts 14020dcb110STom Parkin * new sessions. Protected by hlist_lock. 141f3c66d4eSGuillaume Nault */ 142fd558d18SJames Chapman struct hlist_head session_hlist[L2TP_HASH_SIZE]; 14320dcb110STom Parkin /* hashed list of sessions, hashed by id */ 144fd558d18SJames Chapman u32 tunnel_id; 145fd558d18SJames Chapman u32 peer_tunnel_id; 146fd558d18SJames Chapman int version; /* 2=>L2TPv2, 3=>L2TPv3 */ 147fd558d18SJames Chapman 148fd558d18SJames Chapman char name[20]; /* for logging */ 14920dcb110STom Parkin int debug; /* bitmask of debug message categories */ 1500d76751fSJames Chapman enum l2tp_encap_type encap; 151fd558d18SJames Chapman struct l2tp_stats stats; 152fd558d18SJames Chapman 15320dcb110STom Parkin struct list_head list; /* list node on per-namespace list of tunnels */ 154fd558d18SJames Chapman struct net *l2tp_net; /* the net we belong to */ 155fd558d18SJames Chapman 156fbea9e07SReshetova, Elena refcount_t ref_count; 157fd558d18SJames Chapman void (*old_sk_destruct)(struct sock *); 15820dcb110STom Parkin struct sock *sock; /* parent socket */ 15920dcb110STom Parkin int fd; /* parent fd, if tunnel socket was created 16020dcb110STom Parkin * by userspace 16120dcb110STom Parkin */ 162fd558d18SJames Chapman 163f8ccac0eSTom Parkin struct work_struct del_work; 164fd558d18SJames Chapman }; 165fd558d18SJames Chapman 166309795f4SJames Chapman struct l2tp_nl_cmd_ops { 167f026bc29SGuillaume Nault int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel, 168f026bc29SGuillaume Nault u32 session_id, u32 peer_session_id, 169f026bc29SGuillaume Nault struct l2tp_session_cfg *cfg); 170309795f4SJames Chapman int (*session_delete)(struct l2tp_session *session); 171309795f4SJames Chapman }; 172309795f4SJames Chapman 173fd558d18SJames Chapman static inline void *l2tp_session_priv(struct l2tp_session *session) 174fd558d18SJames Chapman { 175fd558d18SJames Chapman return &session->priv[0]; 176fd558d18SJames Chapman } 177fd558d18SJames Chapman 17854652eb1SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); 1795846c131SGuillaume Nault struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth); 18001e28b92SGuillaume Nault struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel, 18101e28b92SGuillaume Nault u32 session_id); 1825846c131SGuillaume Nault 183d00fa9adSJames Chapman void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); 18454652eb1SGuillaume Nault 18501e28b92SGuillaume Nault struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id); 186a4346210SGuillaume Nault struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth); 1879aaef50cSGuillaume Nault struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, 188a4346210SGuillaume Nault const char *ifname); 189fd558d18SJames Chapman 190c1b1203dSJoe Perches int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, 191c1b1203dSJoe Perches u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, 192c1b1203dSJoe Perches struct l2tp_tunnel **tunnelp); 1936b9f3423SGuillaume Nault int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net, 1946b9f3423SGuillaume Nault struct l2tp_tunnel_cfg *cfg); 1956b9f3423SGuillaume Nault 19662b982eeSSabrina Dubroca void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel); 197c1b1203dSJoe Perches struct l2tp_session *l2tp_session_create(int priv_size, 198c1b1203dSJoe Perches struct l2tp_tunnel *tunnel, 199c1b1203dSJoe Perches u32 session_id, u32 peer_session_id, 200c1b1203dSJoe Perches struct l2tp_session_cfg *cfg); 2013953ae7bSGuillaume Nault int l2tp_session_register(struct l2tp_session *session, 2023953ae7bSGuillaume Nault struct l2tp_tunnel *tunnel); 2033953ae7bSGuillaume Nault 204c1b1203dSJoe Perches void __l2tp_session_unhash(struct l2tp_session *session); 205c1b1203dSJoe Perches int l2tp_session_delete(struct l2tp_session *session); 206c1b1203dSJoe Perches void l2tp_session_free(struct l2tp_session *session); 207c1b1203dSJoe Perches void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, 208c1b1203dSJoe Perches unsigned char *ptr, unsigned char *optr, u16 hdrflags, 2092b139e6bSGuillaume Nault int length); 210c1b1203dSJoe Perches int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); 211bb5016eaSGuillaume Nault void l2tp_session_set_header_len(struct l2tp_session *session, int version); 212fd558d18SJames Chapman 213c1b1203dSJoe Perches int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, 214c1b1203dSJoe Perches int hdr_len); 215fd558d18SJames Chapman 216c1b1203dSJoe Perches int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, 217c1b1203dSJoe Perches const struct l2tp_nl_cmd_ops *ops); 218c1b1203dSJoe Perches void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); 21972fb96e7SEric Dumazet int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); 220309795f4SJames Chapman 22154652eb1SGuillaume Nault static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) 22254652eb1SGuillaume Nault { 22354652eb1SGuillaume Nault refcount_inc(&tunnel->ref_count); 22454652eb1SGuillaume Nault } 22554652eb1SGuillaume Nault 22654652eb1SGuillaume Nault static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) 22754652eb1SGuillaume Nault { 22854652eb1SGuillaume Nault if (refcount_dec_and_test(&tunnel->ref_count)) 229d00fa9adSJames Chapman l2tp_tunnel_free(tunnel); 23054652eb1SGuillaume Nault } 23154652eb1SGuillaume Nault 232fd558d18SJames Chapman /* Session reference counts. Incremented when code obtains a reference 233fd558d18SJames Chapman * to a session. 234fd558d18SJames Chapman */ 2359ff672baSGuillaume Nault static inline void l2tp_session_inc_refcount(struct l2tp_session *session) 236fd558d18SJames Chapman { 237f00c854cSReshetova, Elena refcount_inc(&session->ref_count); 238fd558d18SJames Chapman } 239fd558d18SJames Chapman 2409ff672baSGuillaume Nault static inline void l2tp_session_dec_refcount(struct l2tp_session *session) 241fd558d18SJames Chapman { 242f00c854cSReshetova, Elena if (refcount_dec_and_test(&session->ref_count)) 243fd558d18SJames Chapman l2tp_session_free(session); 244fd558d18SJames Chapman } 245fd558d18SJames Chapman 24662e7b6a5SLorenzo Bianconi static inline int l2tp_get_l2specific_len(struct l2tp_session *session) 24762e7b6a5SLorenzo Bianconi { 24862e7b6a5SLorenzo Bianconi switch (session->l2specific_type) { 24962e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_DEFAULT: 25062e7b6a5SLorenzo Bianconi return 4; 25162e7b6a5SLorenzo Bianconi case L2TP_L2SPECTYPE_NONE: 25262e7b6a5SLorenzo Bianconi default: 25362e7b6a5SLorenzo Bianconi return 0; 25462e7b6a5SLorenzo Bianconi } 25562e7b6a5SLorenzo Bianconi } 25662e7b6a5SLorenzo Bianconi 2571f5cd2a0SGuillaume Nault static inline u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel) 2581f5cd2a0SGuillaume Nault { 2591f5cd2a0SGuillaume Nault struct dst_entry *dst; 2601f5cd2a0SGuillaume Nault u32 mtu; 2611f5cd2a0SGuillaume Nault 2621f5cd2a0SGuillaume Nault dst = sk_dst_get(tunnel->sock); 2631f5cd2a0SGuillaume Nault if (!dst) 2641f5cd2a0SGuillaume Nault return 0; 2651f5cd2a0SGuillaume Nault 2661f5cd2a0SGuillaume Nault mtu = dst_mtu(dst); 2671f5cd2a0SGuillaume Nault dst_release(dst); 2681f5cd2a0SGuillaume Nault 2691f5cd2a0SGuillaume Nault return mtu; 2701f5cd2a0SGuillaume Nault } 2711f5cd2a0SGuillaume Nault 272d6a61ec9SGuillaume Nault #ifdef CONFIG_XFRM 273d6a61ec9SGuillaume Nault static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) 274d6a61ec9SGuillaume Nault { 275d6a61ec9SGuillaume Nault struct sock *sk = tunnel->sock; 276d6a61ec9SGuillaume Nault 277d6a61ec9SGuillaume Nault return sk && (rcu_access_pointer(sk->sk_policy[0]) || 278d6a61ec9SGuillaume Nault rcu_access_pointer(sk->sk_policy[1])); 279d6a61ec9SGuillaume Nault } 280d6a61ec9SGuillaume Nault #else 281d6a61ec9SGuillaume Nault static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel) 282d6a61ec9SGuillaume Nault { 283d6a61ec9SGuillaume Nault return false; 284d6a61ec9SGuillaume Nault } 285d6a61ec9SGuillaume Nault #endif 286d6a61ec9SGuillaume Nault 2874522a70dSJacob Wen static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb, 2884522a70dSJacob Wen unsigned char **ptr, unsigned char **optr) 2894522a70dSJacob Wen { 2904522a70dSJacob Wen int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session); 2914522a70dSJacob Wen 2924522a70dSJacob Wen if (opt_len > 0) { 2934522a70dSJacob Wen int off = *ptr - *optr; 2944522a70dSJacob Wen 2954522a70dSJacob Wen if (!pskb_may_pull(skb, off + opt_len)) 2964522a70dSJacob Wen return -1; 2974522a70dSJacob Wen 2984522a70dSJacob Wen if (skb->data != *optr) { 2994522a70dSJacob Wen *optr = skb->data; 3004522a70dSJacob Wen *ptr = skb->data + off; 3014522a70dSJacob Wen } 3024522a70dSJacob Wen } 3034522a70dSJacob Wen 3044522a70dSJacob Wen return 0; 3054522a70dSJacob Wen } 3064522a70dSJacob Wen 307a4ca44faSJoe Perches #define l2tp_printk(ptr, type, func, fmt, ...) \ 308a4ca44faSJoe Perches do { \ 309a4ca44faSJoe Perches if (((ptr)->debug) & (type)) \ 310a4ca44faSJoe Perches func(fmt, ##__VA_ARGS__); \ 311a4ca44faSJoe Perches } while (0) 312a4ca44faSJoe Perches 313a4ca44faSJoe Perches #define l2tp_warn(ptr, type, fmt, ...) \ 314a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__) 315a4ca44faSJoe Perches #define l2tp_info(ptr, type, fmt, ...) \ 316a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__) 317a4ca44faSJoe Perches #define l2tp_dbg(ptr, type, fmt, ...) \ 318a4ca44faSJoe Perches l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__) 319a4ca44faSJoe Perches 320f1f39f91Sstephen hemminger #define MODULE_ALIAS_L2TP_PWTYPE(type) \ 321f1f39f91Sstephen hemminger MODULE_ALIAS("net-l2tp-type-" __stringify(type)) 322f1f39f91Sstephen hemminger 323fd558d18SJames Chapman #endif /* _L2TP_CORE_H_ */ 324