| /* |
| * L2TP internal definitions. |
| * |
| * Copyright (c) 2008,2009 Katalix Systems Ltd |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #ifndef _L2TP_CORE_H_ |
| #define _L2TP_CORE_H_ |
| |
| /* Just some random numbers */ |
| #define L2TP_TUNNEL_MAGIC 0x42114DDA |
| #define L2TP_SESSION_MAGIC 0x0C04EB7D |
| |
| /* Per tunnel, session hash table size */ |
| #define L2TP_HASH_BITS 4 |
| #define L2TP_HASH_SIZE (1 << L2TP_HASH_BITS) |
| |
| /* System-wide, session hash table size */ |
| #define L2TP_HASH_BITS_2 8 |
| #define L2TP_HASH_SIZE_2 (1 << L2TP_HASH_BITS_2) |
| |
| struct sk_buff; |
| |
| struct l2tp_stats { |
| atomic_long_t tx_packets; |
| atomic_long_t tx_bytes; |
| atomic_long_t tx_errors; |
| atomic_long_t rx_packets; |
| atomic_long_t rx_bytes; |
| atomic_long_t rx_seq_discards; |
| atomic_long_t rx_oos_packets; |
| atomic_long_t rx_errors; |
| atomic_long_t rx_cookie_discards; |
| }; |
| |
| struct l2tp_tunnel; |
| |
| /* Describes a session. Contains information to determine incoming |
| * packets and transmit outgoing ones. |
| */ |
| struct l2tp_session_cfg { |
| enum l2tp_pwtype pw_type; |
| unsigned int data_seq:2; /* data sequencing level |
| * 0 => none, 1 => IP only, |
| * 2 => all |
| */ |
| unsigned int recv_seq:1; /* expect receive packets with |
| * sequence numbers? */ |
| unsigned int send_seq:1; /* send packets with sequence |
| * numbers? */ |
| unsigned int lns_mode:1; /* behave as LNS? LAC enables |
| * sequence numbers under |
| * control of LNS. */ |
| int debug; /* bitmask of debug message |
| * categories */ |
| u16 vlan_id; /* VLAN pseudowire only */ |
| u16 l2specific_len; /* Layer 2 specific length */ |
| u16 l2specific_type; /* Layer 2 specific type */ |
| u8 cookie[8]; /* optional cookie */ |
| int cookie_len; /* 0, 4 or 8 bytes */ |
| u8 peer_cookie[8]; /* peer's cookie */ |
| int peer_cookie_len; /* 0, 4 or 8 bytes */ |
| int reorder_timeout; /* configured reorder timeout |
| * (in jiffies) */ |
| int mtu; |
| int mru; |
| char *ifname; |
| }; |
| |
| struct l2tp_session { |
| int magic; /* should be |
| * L2TP_SESSION_MAGIC */ |
| long dead; |
| |
| struct l2tp_tunnel *tunnel; /* back pointer to tunnel |
| * context */ |
| u32 session_id; |
| u32 peer_session_id; |
| u8 cookie[8]; |
| int cookie_len; |
| u8 peer_cookie[8]; |
| int peer_cookie_len; |
| u16 l2specific_len; |
| u16 l2specific_type; |
| u16 hdr_len; |
| u32 nr; /* session NR state (receive) */ |
| u32 ns; /* session NR state (send) */ |
| struct sk_buff_head reorder_q; /* receive reorder queue */ |
| u32 nr_max; /* max NR. Depends on tunnel */ |
| u32 nr_window_size; /* NR window size */ |
| u32 nr_oos; /* NR of last OOS packet */ |
| int nr_oos_count; /* For OOS recovery */ |
| int nr_oos_count_max; |
| struct hlist_node hlist; /* Hash list node */ |
| atomic_t ref_count; |
| |
| char name[32]; /* for logging */ |
| char ifname[IFNAMSIZ]; |
| unsigned int data_seq:2; /* data sequencing level |
| * 0 => none, 1 => IP only, |
| * 2 => all |
| */ |
| unsigned int recv_seq:1; /* expect receive packets with |
| * sequence numbers? */ |
| unsigned int send_seq:1; /* send packets with sequence |
| * numbers? */ |
| unsigned int lns_mode:1; /* behave as LNS? LAC enables |
| * sequence numbers under |
| * control of LNS. */ |
| int debug; /* bitmask of debug message |
| * categories */ |
| int reorder_timeout; /* configured reorder timeout |
| * (in jiffies) */ |
| int reorder_skip; /* set if skip to next nr */ |
| int mtu; |
| int mru; |
| enum l2tp_pwtype pwtype; |
| struct l2tp_stats stats; |
| struct hlist_node global_hlist; /* Global hash list node */ |
| |
| int (*build_header)(struct l2tp_session *session, void *buf); |
| void (*recv_skb)(struct l2tp_session *session, struct sk_buff *skb, int data_len); |
| void (*session_close)(struct l2tp_session *session); |
| void (*ref)(struct l2tp_session *session); |
| void (*deref)(struct l2tp_session *session); |
| #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) |
| void (*show)(struct seq_file *m, void *priv); |
| #endif |
| uint8_t priv[0]; /* private data */ |
| }; |
| |
| /* Describes the tunnel. It contains info to track all the associated |
| * sessions so incoming packets can be sorted out |
| */ |
| struct l2tp_tunnel_cfg { |
| int debug; /* bitmask of debug message |
| * categories */ |
| enum l2tp_encap_type encap; |
| |
| /* Used only for kernel-created sockets */ |
| struct in_addr local_ip; |
| struct in_addr peer_ip; |
| #if IS_ENABLED(CONFIG_IPV6) |
| struct in6_addr *local_ip6; |
| struct in6_addr *peer_ip6; |
| #endif |
| u16 local_udp_port; |
| u16 peer_udp_port; |
| unsigned int use_udp_checksums:1, |
| udp6_zero_tx_checksums:1, |
| udp6_zero_rx_checksums:1; |
| }; |
| |
| struct l2tp_tunnel { |
| int magic; /* Should be L2TP_TUNNEL_MAGIC */ |
| |
| unsigned long dead; |
| |
| struct rcu_head rcu; |
| rwlock_t hlist_lock; /* protect session_hlist */ |
| struct hlist_head session_hlist[L2TP_HASH_SIZE]; |
| /* hashed list of sessions, |
| * hashed by id */ |
| u32 tunnel_id; |
| u32 peer_tunnel_id; |
| int version; /* 2=>L2TPv2, 3=>L2TPv3 */ |
| |
| char name[20]; /* for logging */ |
| int debug; /* bitmask of debug message |
| * categories */ |
| enum l2tp_encap_type encap; |
| struct l2tp_stats stats; |
| |
| struct list_head list; /* Keep a list of all tunnels */ |
| struct net *l2tp_net; /* the net we belong to */ |
| |
| atomic_t ref_count; |
| #ifdef CONFIG_DEBUG_FS |
| void (*show)(struct seq_file *m, void *arg); |
| #endif |
| int (*recv_payload_hook)(struct sk_buff *skb); |
| void (*old_sk_destruct)(struct sock *); |
| struct sock *sock; /* Parent socket */ |
| int fd; /* Parent fd, if tunnel socket |
| * was created by userspace */ |
| #if IS_ENABLED(CONFIG_IPV6) |
| bool v4mapped; |
| #endif |
| |
| struct work_struct del_work; |
| |
| uint8_t priv[0]; /* private data */ |
| }; |
| |
| struct l2tp_nl_cmd_ops { |
| int (*session_create)(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg); |
| int (*session_delete)(struct l2tp_session *session); |
| }; |
| |
| static inline void *l2tp_tunnel_priv(struct l2tp_tunnel *tunnel) |
| { |
| return &tunnel->priv[0]; |
| } |
| |
| static inline void *l2tp_session_priv(struct l2tp_session *session) |
| { |
| return &session->priv[0]; |
| } |
| |
| static inline struct l2tp_tunnel *l2tp_sock_to_tunnel(struct sock *sk) |
| { |
| struct l2tp_tunnel *tunnel; |
| |
| if (sk == NULL) |
| return NULL; |
| |
| sock_hold(sk); |
| tunnel = (struct l2tp_tunnel *)(sk->sk_user_data); |
| if (tunnel == NULL) { |
| sock_put(sk); |
| goto out; |
| } |
| |
| BUG_ON(tunnel->magic != L2TP_TUNNEL_MAGIC); |
| |
| out: |
| return tunnel; |
| } |
| |
| struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); |
| |
| struct l2tp_session *l2tp_session_get(const struct net *net, |
| struct l2tp_tunnel *tunnel, |
| u32 session_id, bool do_ref); |
| struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth, |
| bool do_ref); |
| struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net, |
| const char *ifname, |
| bool do_ref); |
| struct l2tp_tunnel *l2tp_tunnel_find(const struct net *net, u32 tunnel_id); |
| struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth); |
| |
| int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id, |
| u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg, |
| struct l2tp_tunnel **tunnelp); |
| void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel); |
| void l2tp_tunnel_delete(struct l2tp_tunnel *tunnel); |
| struct l2tp_session *l2tp_session_create(int priv_size, |
| struct l2tp_tunnel *tunnel, |
| u32 session_id, u32 peer_session_id, |
| struct l2tp_session_cfg *cfg); |
| void __l2tp_session_unhash(struct l2tp_session *session); |
| int l2tp_session_delete(struct l2tp_session *session); |
| void l2tp_session_free(struct l2tp_session *session); |
| void l2tp_recv_common(struct l2tp_session *session, struct sk_buff *skb, |
| unsigned char *ptr, unsigned char *optr, u16 hdrflags, |
| int length, int (*payload_hook)(struct sk_buff *skb)); |
| int l2tp_session_queue_purge(struct l2tp_session *session); |
| int l2tp_udp_encap_recv(struct sock *sk, struct sk_buff *skb); |
| void l2tp_session_set_header_len(struct l2tp_session *session, int version); |
| |
| int l2tp_xmit_skb(struct l2tp_session *session, struct sk_buff *skb, |
| int hdr_len); |
| |
| int l2tp_nl_register_ops(enum l2tp_pwtype pw_type, |
| const struct l2tp_nl_cmd_ops *ops); |
| void l2tp_nl_unregister_ops(enum l2tp_pwtype pw_type); |
| int l2tp_ioctl(struct sock *sk, int cmd, unsigned long arg); |
| |
| static inline void l2tp_tunnel_inc_refcount(struct l2tp_tunnel *tunnel) |
| { |
| atomic_inc(&tunnel->ref_count); |
| } |
| |
| static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel) |
| { |
| if (atomic_dec_and_test(&tunnel->ref_count)) |
| kfree_rcu(tunnel, rcu); |
| } |
| |
| /* Session reference counts. Incremented when code obtains a reference |
| * to a session. |
| */ |
| static inline void l2tp_session_inc_refcount_1(struct l2tp_session *session) |
| { |
| atomic_inc(&session->ref_count); |
| } |
| |
| static inline void l2tp_session_dec_refcount_1(struct l2tp_session *session) |
| { |
| if (atomic_dec_and_test(&session->ref_count)) |
| l2tp_session_free(session); |
| } |
| |
| #ifdef L2TP_REFCNT_DEBUG |
| #define l2tp_session_inc_refcount(_s) \ |
| do { \ |
| pr_debug("l2tp_session_inc_refcount: %s:%d %s: cnt=%d\n", \ |
| __func__, __LINE__, (_s)->name, \ |
| atomic_read(&_s->ref_count)); \ |
| l2tp_session_inc_refcount_1(_s); \ |
| } while (0) |
| #define l2tp_session_dec_refcount(_s) \ |
| do { \ |
| pr_debug("l2tp_session_dec_refcount: %s:%d %s: cnt=%d\n", \ |
| __func__, __LINE__, (_s)->name, \ |
| atomic_read(&_s->ref_count)); \ |
| l2tp_session_dec_refcount_1(_s); \ |
| } while (0) |
| #else |
| #define l2tp_session_inc_refcount(s) l2tp_session_inc_refcount_1(s) |
| #define l2tp_session_dec_refcount(s) l2tp_session_dec_refcount_1(s) |
| #endif |
| |
| static inline int l2tp_get_l2specific_len(struct l2tp_session *session) |
| { |
| switch (session->l2specific_type) { |
| case L2TP_L2SPECTYPE_DEFAULT: |
| return 4; |
| case L2TP_L2SPECTYPE_NONE: |
| default: |
| return 0; |
| } |
| } |
| |
| static inline int l2tp_v3_ensure_opt_in_linear(struct l2tp_session *session, struct sk_buff *skb, |
| unsigned char **ptr, unsigned char **optr) |
| { |
| int opt_len = session->peer_cookie_len + l2tp_get_l2specific_len(session); |
| |
| if (opt_len > 0) { |
| int off = *ptr - *optr; |
| |
| if (!pskb_may_pull(skb, off + opt_len)) |
| return -1; |
| |
| if (skb->data != *optr) { |
| *optr = skb->data; |
| *ptr = skb->data + off; |
| } |
| } |
| |
| return 0; |
| } |
| |
| #define l2tp_printk(ptr, type, func, fmt, ...) \ |
| do { \ |
| if (((ptr)->debug) & (type)) \ |
| func(fmt, ##__VA_ARGS__); \ |
| } while (0) |
| |
| #define l2tp_warn(ptr, type, fmt, ...) \ |
| l2tp_printk(ptr, type, pr_warn, fmt, ##__VA_ARGS__) |
| #define l2tp_info(ptr, type, fmt, ...) \ |
| l2tp_printk(ptr, type, pr_info, fmt, ##__VA_ARGS__) |
| #define l2tp_dbg(ptr, type, fmt, ...) \ |
| l2tp_printk(ptr, type, pr_debug, fmt, ##__VA_ARGS__) |
| |
| #define MODULE_ALIAS_L2TP_PWTYPE(type) \ |
| MODULE_ALIAS("net-l2tp-type-" __stringify(type)) |
| |
| #endif /* _L2TP_CORE_H_ */ |