Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 340 insertions, 0 deletions

diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
new file mode 100644
index 000000000..b2ce90260
--- /dev/null
+++ b/net/l2tp/l2tp_core.h
@@ -0,0 +1,340 @@
+/*
+ * 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.
+ */
+#include <linux/refcount.h>
+
+#ifndef _L2TP_CORE_H_
+#define _L2TP_CORE_H_
+
+#include <net/dst.h>
+#include <net/sock.h>
+
+#ifdef CONFIG_XFRM
+#include <net/xfrm.h>
+#endif
+
+/* 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		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			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) */
+	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_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 */
+	refcount_t		ref_count;
+
+	char			name[32];	/* for logging */
+	char			ifname[IFNAMSIZ];
+	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 */
+	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 (*show)(struct seq_file *m, void *priv);
+	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 */
+	bool			acpt_newsess;	/* Indicates whether this
+						 * tunnel accepts new sessions.
+						 * Protected by hlist_lock.
+						 */
+	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 */
+
+	refcount_t		ref_count;
+	void (*old_sk_destruct)(struct sock *);
+	struct sock		*sock;		/* Parent socket */
+	int			fd;		/* Parent fd, if tunnel socket
+						 * was created by userspace */
+
+	struct work_struct	del_work;
+};
+
+struct l2tp_nl_cmd_ops {
+	int (*session_create)(struct net *net, struct l2tp_tunnel *tunnel,
+			      u32 session_id, u32 peer_session_id,
+			      struct l2tp_session_cfg *cfg);
+	int (*session_delete)(struct l2tp_session *session);
+};
+
+static inline void *l2tp_session_priv(struct l2tp_session *session)
+{
+	return &session->priv[0];
+}
+
+struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id);
+struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth);
+struct l2tp_session *l2tp_tunnel_get_session(struct l2tp_tunnel *tunnel,
+					     u32 session_id);
+
+void l2tp_tunnel_free(struct l2tp_tunnel *tunnel);
+
+struct l2tp_session *l2tp_session_get(const struct net *net, u32 session_id);
+struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
+struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
+						const char *ifname);
+
+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);
+int l2tp_tunnel_register(struct l2tp_tunnel *tunnel, struct net *net,
+			 struct l2tp_tunnel_cfg *cfg);
+
+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);
+int l2tp_session_register(struct l2tp_session *session,
+			  struct l2tp_tunnel *tunnel);
+
+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 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)
+{
+	refcount_inc(&tunnel->ref_count);
+}
+
+static inline void l2tp_tunnel_dec_refcount(struct l2tp_tunnel *tunnel)
+{
+	if (refcount_dec_and_test(&tunnel->ref_count))
+		l2tp_tunnel_free(tunnel);
+}
+
+/* Session reference counts. Incremented when code obtains a reference
+ * to a session.
+ */
+static inline void l2tp_session_inc_refcount(struct l2tp_session *session)
+{
+	refcount_inc(&session->ref_count);
+}
+
+static inline void l2tp_session_dec_refcount(struct l2tp_session *session)
+{
+	if (refcount_dec_and_test(&session->ref_count))
+		l2tp_session_free(session);
+}
+
+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 u32 l2tp_tunnel_dst_mtu(const struct l2tp_tunnel *tunnel)
+{
+	struct dst_entry *dst;
+	u32 mtu;
+
+	dst = sk_dst_get(tunnel->sock);
+	if (!dst)
+		return 0;
+
+	mtu = dst_mtu(dst);
+	dst_release(dst);
+
+	return mtu;
+}
+
+#ifdef CONFIG_XFRM
+static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
+{
+	struct sock *sk = tunnel->sock;
+
+	return sk && (rcu_access_pointer(sk->sk_policy[0]) ||
+		      rcu_access_pointer(sk->sk_policy[1]));
+}
+#else
+static inline bool l2tp_tunnel_uses_xfrm(const struct l2tp_tunnel *tunnel)
+{
+	return false;
+}
+#endif
+
+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_ */