/* SPDX-License-Identifier: GPL-2.0-or-later */

  /* AF_RXRPC internal definitions
   *
   * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   * Written by David Howells (dhowells@redhat.com)

   */

  #include <linux/atomic.h>

  #include <linux/seqlock.h>

  #include <linux/win_minmax.h>

  #include <net/net_namespace.h>
  #include <net/netns/generic.h>

  #include <net/sock.h>

  #include <net/af_rxrpc.h>

  #include "protocol.h"

  
  #if 0
  #define CHECK_SLAB_OKAY(X)				     \
  	BUG_ON(atomic_read((X)) >> (sizeof(atomic_t) - 2) == \
  	       (POISON_FREE << 8 | POISON_FREE))
  #else

  #define CHECK_SLAB_OKAY(X) do {} while (0)

  #endif

  #define FCRYPT_BSIZE 8
  struct rxrpc_crypt {
  	union {
  		u8	x[FCRYPT_BSIZE];

  		__be32	n[2];

  	};
  } __attribute__((aligned(8)));

  #define rxrpc_queue_work(WS)	queue_work(rxrpc_workqueue, (WS))
  #define rxrpc_queue_delayed_work(WS,D)	\
  	queue_delayed_work(rxrpc_workqueue, (WS), (D))

  struct rxrpc_connection;

  /*

   * Mark applied to socket buffers in skb->mark.  skb->priority is used
   * to pass supplementary information.

   */
  enum rxrpc_skb_mark {

  	RXRPC_SKB_MARK_REJECT_BUSY,	/* Reject with BUSY */
  	RXRPC_SKB_MARK_REJECT_ABORT,	/* Reject with ABORT (code in skb->priority) */

  };
  
  /*

   * sk_state for RxRPC sockets
   */
  enum {

  	RXRPC_UNBOUND = 0,
  	RXRPC_CLIENT_UNBOUND,		/* Unbound socket used as client */

  	RXRPC_CLIENT_BOUND,		/* client local address bound */

  	RXRPC_SERVER_BOUND,		/* server local address bound */

  	RXRPC_SERVER_BOUND2,		/* second server local address bound */

  	RXRPC_SERVER_LISTENING,		/* server listening for connections */

  	RXRPC_SERVER_LISTEN_DISABLED,	/* server listening disabled */

  	RXRPC_CLOSE,			/* socket is being closed */
  };
  
  /*

   * Per-network namespace data.
   */
  struct rxrpc_net {
  	struct proc_dir_entry	*proc_net;	/* Subdir in /proc/net */
  	u32			epoch;		/* Local epoch for detecting local-end reset */
  	struct list_head	calls;		/* List of calls active in this namespace */
  	rwlock_t		call_lock;	/* Lock for ->calls */

  	atomic_t		nr_calls;	/* Count of allocated calls */

  	atomic_t		nr_conns;

  	struct list_head	conn_proc_list;	/* List of conns in this namespace for proc */
  	struct list_head	service_conns;	/* Service conns in this namespace */
  	rwlock_t		conn_lock;	/* Lock for ->conn_proc_list, ->service_conns */

  	struct work_struct	service_conn_reaper;
  	struct timer_list	service_conn_reap_timer;

  	bool			live;

  
  	bool			kill_all_client_conns;
  	atomic_t		nr_client_conns;

  	spinlock_t		client_conn_cache_lock; /* Lock for ->*_client_conns */
  	spinlock_t		client_conn_discard_lock; /* Prevent multiple discarders */

  	struct list_head	idle_client_conns;

  	struct work_struct	client_conn_reaper;
  	struct timer_list	client_conn_reap_timer;

  
  	struct list_head	local_endpoints;
  	struct mutex		local_mutex;	/* Lock for ->local_endpoints */

  	DECLARE_HASHTABLE	(peer_hash, 10);

  	spinlock_t		peer_hash_lock;	/* Lock for ->peer_hash */
  
  #define RXRPC_KEEPALIVE_TIME 20 /* NAT keepalive time in seconds */
  	u8			peer_keepalive_cursor;

  	time64_t		peer_keepalive_base;
  	struct list_head	peer_keepalive[32];
  	struct list_head	peer_keepalive_new;

  	struct timer_list	peer_keepalive_timer;
  	struct work_struct	peer_keepalive_work;

  };
  
  /*

   * Service backlog preallocation.
   *
   * This contains circular buffers of preallocated peers, connections and calls
   * for incoming service calls and their head and tail pointers.  This allows
   * calls to be set up in the data_ready handler, thereby avoiding the need to
   * shuffle packets around so much.
   */
  struct rxrpc_backlog {
  	unsigned short		peer_backlog_head;
  	unsigned short		peer_backlog_tail;
  	unsigned short		conn_backlog_head;
  	unsigned short		conn_backlog_tail;
  	unsigned short		call_backlog_head;
  	unsigned short		call_backlog_tail;
  #define RXRPC_BACKLOG_MAX	32
  	struct rxrpc_peer	*peer_backlog[RXRPC_BACKLOG_MAX];
  	struct rxrpc_connection	*conn_backlog[RXRPC_BACKLOG_MAX];
  	struct rxrpc_call	*call_backlog[RXRPC_BACKLOG_MAX];
  };
  
  /*

   * RxRPC socket definition
   */
  struct rxrpc_sock {
  	/* WARNING: sk has to be the first member */
  	struct sock		sk;

  	rxrpc_notify_new_call_t	notify_new_call; /* Func to notify of new call */

  	rxrpc_discard_new_call_t discard_new_call; /* Func to discard a new call */

  	struct rxrpc_local	*local;		/* local endpoint */

  	struct rxrpc_backlog	*backlog;	/* Preallocation for services */

  	spinlock_t		incoming_lock;	/* Incoming call vs service shutdown lock */
  	struct list_head	sock_calls;	/* List of calls owned by this socket */
  	struct list_head	to_be_accepted;	/* calls awaiting acceptance */
  	struct list_head	recvmsg_q;	/* Calls awaiting recvmsg's attention  */
  	rwlock_t		recvmsg_lock;	/* Lock for recvmsg_q */

  	struct key		*key;		/* security for this socket */
  	struct key		*securities;	/* list of server security descriptors */

  	struct rb_root		calls;		/* User ID -> call mapping */

  	unsigned long		flags;

  #define RXRPC_SOCK_CONNECTED		0	/* connect_srx is set */

  	rwlock_t		call_lock;	/* lock for calls */
  	u32			min_sec_level;	/* minimum security level */
  #define RXRPC_SECURITY_MAX	RXRPC_SECURITY_ENCRYPT

  	bool			exclusive;	/* Exclusive connection for a client socket */

  	u16			second_service;	/* Additional service bound to the endpoint */

  	struct {
  		/* Service upgrade information */
  		u16		from;		/* Service ID to upgrade (if not 0) */
  		u16		to;		/* service ID to upgrade to */
  	} service_upgrade;

  	sa_family_t		family;		/* Protocol family created with */

  	struct sockaddr_rxrpc	srx;		/* Primary Service/local addresses */

  	struct sockaddr_rxrpc	connect_srx;	/* Default client address from connect() */

  };
  
  #define rxrpc_sk(__sk) container_of((__sk), struct rxrpc_sock, sk)
  
  /*

   * CPU-byteorder normalised Rx packet header.
   */
  struct rxrpc_host_header {
  	u32		epoch;		/* client boot timestamp */
  	u32		cid;		/* connection and channel ID */
  	u32		callNumber;	/* call ID (0 for connection-level packets) */
  	u32		seq;		/* sequence number of pkt in call stream */
  	u32		serial;		/* serial number of pkt sent to network */
  	u8		type;		/* packet type */
  	u8		flags;		/* packet flags */
  	u8		userStatus;	/* app-layer defined status */
  	u8		securityIndex;	/* security protocol ID */
  	union {
  		u16	_rsvd;		/* reserved */
  		u16	cksum;		/* kerberos security checksum */
  	};
  	u16		serviceId;	/* service ID */
  } __packed;
  
  /*

   * RxRPC socket buffer private variables
   * - max 48 bytes (struct sk_buff::cb)
   */
  struct rxrpc_skb_priv {

  	atomic_t	nr_ring_pins;		/* Number of rxtx ring pins */

  	u8		nr_subpackets;		/* Number of subpackets */
  	u8		rx_flags;		/* Received packet flags */
  #define RXRPC_SKB_INCL_LAST	0x01		/* - Includes last packet */

  #define RXRPC_SKB_TX_BUFFER	0x02		/* - Is transmit buffer */

  	union {

  		int		remain;		/* amount of space remaining for next write */

  
  		/* List of requested ACKs on subpackets */
  		unsigned long	rx_req_ack[(RXRPC_MAX_NR_JUMBO + BITS_PER_LONG - 1) /
  					   BITS_PER_LONG];

  	};

  	struct rxrpc_host_header hdr;		/* RxRPC packet header from this packet */

  };
  
  #define rxrpc_skb(__skb) ((struct rxrpc_skb_priv *) &(__skb)->cb)

  /*
   * RxRPC security module interface
   */
  struct rxrpc_security {

  	const char		*name;		/* name of this service */
  	u8			security_index;	/* security type provided */

  	u32			no_key_abort;	/* Abort code indicating no key */

  	/* Initialise a security service */
  	int (*init)(void);
  
  	/* Clean up a security service */
  	void (*exit)(void);

  	/* initialise a connection's security */
  	int (*init_connection_security)(struct rxrpc_connection *);
  
  	/* prime a connection's packet security */

  	int (*prime_packet_security)(struct rxrpc_connection *);

  
  	/* impose security on a packet */

  	int (*secure_packet)(struct rxrpc_call *,

  			     struct sk_buff *,
  			     size_t,
  			     void *);
  
  	/* verify the security on a received packet */

  	int (*verify_packet)(struct rxrpc_call *, struct sk_buff *,

  			     unsigned int, unsigned int, rxrpc_seq_t, u16);

  	/* Free crypto request on a call */
  	void (*free_call_crypto)(struct rxrpc_call *);

  	/* Locate the data in a received packet that has been verified. */
  	void (*locate_data)(struct rxrpc_call *, struct sk_buff *,
  			    unsigned int *, unsigned int *);

  
  	/* issue a challenge */
  	int (*issue_challenge)(struct rxrpc_connection *);
  
  	/* respond to a challenge */
  	int (*respond_to_challenge)(struct rxrpc_connection *,
  				    struct sk_buff *,
  				    u32 *);
  
  	/* verify a response */
  	int (*verify_response)(struct rxrpc_connection *,
  			       struct sk_buff *,
  			       u32 *);
  
  	/* clear connection security */
  	void (*clear)(struct rxrpc_connection *);
  };
  
  /*

   * RxRPC local transport endpoint description
   * - owned by a single AF_RXRPC socket
   * - pointed to by transport socket struct sk_user_data

   */
  struct rxrpc_local {

  	struct rcu_head		rcu;

  	atomic_t		active_users;	/* Number of users of the local endpoint */
  	atomic_t		usage;		/* Number of references to the structure */

  	struct rxrpc_net	*rxnet;		/* The network ns in which this resides */

  	struct list_head	link;

  	struct socket		*socket;	/* my UDP socket */

  	struct work_struct	processor;

  	struct rxrpc_sock __rcu	*service;	/* Service(s) listening on this endpoint */

  	struct rw_semaphore	defrag_sem;	/* control re-enablement of IP DF bit */

  	struct sk_buff_head	reject_queue;	/* packets awaiting rejection */

  	struct sk_buff_head	event_queue;	/* endpoint event packets awaiting processing */

  	struct rb_root		client_bundles;	/* Client connection bundles by socket params */
  	spinlock_t		client_bundles_lock; /* Lock for client_bundles */

  	spinlock_t		lock;		/* access lock */
  	rwlock_t		services_lock;	/* lock for services list */

  	int			debug_id;	/* debug ID for printks */

  	bool			dead;

  	bool			service_closed;	/* Service socket closed */

  	struct sockaddr_rxrpc	srx;		/* local address */
  };
  
  /*
   * RxRPC remote transport endpoint definition

   * - matched by local endpoint, remote port, address and protocol type

   */
  struct rxrpc_peer {

  	struct rcu_head		rcu;		/* This must be first */
  	atomic_t		usage;
  	unsigned long		hash_key;
  	struct hlist_node	hash_link;
  	struct rxrpc_local	*local;

  	struct hlist_head	error_targets;	/* targets for net error distribution */

  	struct rb_root		service_conns;	/* Service connections */

  	struct list_head	keepalive_link;	/* Link in net->peer_keepalive[] */

  	time64_t		last_tx_at;	/* Last time packet sent here */

  	seqlock_t		service_conn_lock;

  	spinlock_t		lock;		/* access lock */

  	unsigned int		if_mtu;		/* interface MTU for this peer */
  	unsigned int		mtu;		/* network MTU for this peer */
  	unsigned int		maxdata;	/* data size (MTU - hdrsize) */

  	unsigned short		hdrsize;	/* header size (IP + UDP + RxRPC) */
  	int			debug_id;	/* debug ID for printks */

  	struct sockaddr_rxrpc	srx;		/* remote address */
  
  	/* calculated RTT cache */
  #define RXRPC_RTT_CACHE_SIZE 32

  	spinlock_t		rtt_input_lock;	/* RTT lock for input routine */

  	ktime_t			rtt_last_req;	/* Time of last RTT request */

  	unsigned int		rtt_count;	/* Number of samples we've got */
  
  	u32			srtt_us;	/* smoothed round trip time << 3 in usecs */
  	u32			mdev_us;	/* medium deviation			*/
  	u32			mdev_max_us;	/* maximal mdev for the last rtt period	*/
  	u32			rttvar_us;	/* smoothed mdev_max			*/
  	u32			rto_j;		/* Retransmission timeout in jiffies */
  	u8			backoff;	/* Backoff timeout */

  
  	u8			cong_cwnd;	/* Congestion window size */

  };
  
  /*

   * Keys for matching a connection.
   */
  struct rxrpc_conn_proto {

  	union {
  		struct {
  			u32	epoch;		/* epoch of this connection */
  			u32	cid;		/* connection ID */
  		};
  		u64		index_key;

  	};
  };
  
  struct rxrpc_conn_parameters {
  	struct rxrpc_local	*local;		/* Representation of local endpoint */
  	struct rxrpc_peer	*peer;		/* Remote endpoint */
  	struct key		*key;		/* Security details */
  	bool			exclusive;	/* T if conn is exclusive */

  	bool			upgrade;	/* T if service ID can be upgraded */

  	u16			service_id;	/* Service ID for this connection */
  	u32			security_level;	/* Security level selected */
  };
  
  /*

   * Bits in the connection flags.
   */
  enum rxrpc_conn_flag {
  	RXRPC_CONN_HAS_IDR,		/* Has a client conn ID assigned */

  	RXRPC_CONN_IN_SERVICE_CONNS,	/* Conn is in peer->service_conns */

  	RXRPC_CONN_DONT_REUSE,		/* Don't reuse this connection */

  	RXRPC_CONN_PROBING_FOR_UPGRADE,	/* Probing for service upgrade */

  	RXRPC_CONN_FINAL_ACK_0,		/* Need final ACK for channel 0 */
  	RXRPC_CONN_FINAL_ACK_1,		/* Need final ACK for channel 1 */
  	RXRPC_CONN_FINAL_ACK_2,		/* Need final ACK for channel 2 */
  	RXRPC_CONN_FINAL_ACK_3,		/* Need final ACK for channel 3 */

  };

  #define RXRPC_CONN_FINAL_ACK_MASK ((1UL << RXRPC_CONN_FINAL_ACK_0) |	\
  				   (1UL << RXRPC_CONN_FINAL_ACK_1) |	\
  				   (1UL << RXRPC_CONN_FINAL_ACK_2) |	\
  				   (1UL << RXRPC_CONN_FINAL_ACK_3))

  /*
   * Events that can be raised upon a connection.
   */
  enum rxrpc_conn_event {
  	RXRPC_CONN_EV_CHALLENGE,	/* Send challenge packet */
  };
  
  /*
   * The connection protocol state.
   */
  enum rxrpc_conn_proto_state {
  	RXRPC_CONN_UNUSED,		/* Connection not yet attempted */
  	RXRPC_CONN_CLIENT,		/* Client connection */

  	RXRPC_CONN_SERVICE_PREALLOC,	/* Service connection preallocation */

  	RXRPC_CONN_SERVICE_UNSECURED,	/* Service unsecured connection */
  	RXRPC_CONN_SERVICE_CHALLENGING,	/* Service challenging for security */
  	RXRPC_CONN_SERVICE,		/* Service secured connection */
  	RXRPC_CONN_REMOTELY_ABORTED,	/* Conn aborted by peer */
  	RXRPC_CONN_LOCALLY_ABORTED,	/* Conn aborted locally */

  	RXRPC_CONN__NR_STATES
  };
  
  /*

   * RxRPC client connection bundle.
   */
  struct rxrpc_bundle {
  	struct rxrpc_conn_parameters params;
  	atomic_t		usage;
  	unsigned int		debug_id;
  	bool			try_upgrade;	/* True if the bundle is attempting upgrade */
  	bool			alloc_conn;	/* True if someone's getting a conn */

  	short			alloc_error;	/* Error from last conn allocation */

  	spinlock_t		channel_lock;
  	struct rb_node		local_node;	/* Node in local->client_conns */
  	struct list_head	waiting_calls;	/* Calls waiting for channels */
  	unsigned long		avail_chans;	/* Mask of available channels */
  	struct rxrpc_connection	*conns[4];	/* The connections in the bundle (max 4) */
  };
  
  /*

   * RxRPC connection definition

   * - matched by { local, peer, epoch, conn_id, direction }

   * - each connection can only handle four simultaneous calls
   */
  struct rxrpc_connection {

  	struct rxrpc_conn_proto	proto;
  	struct rxrpc_conn_parameters params;

  	atomic_t		usage;
  	struct rcu_head		rcu;
  	struct list_head	cache_link;

  	unsigned char		act_chans;	/* Mask of active channels */

  	struct rxrpc_channel {

  		unsigned long		final_ack_at;	/* Time at which to issue final ACK */

  		struct rxrpc_call __rcu	*call;		/* Active call */

  		unsigned int		call_debug_id;	/* call->debug_id */

  		u32			call_id;	/* ID of current call */
  		u32			call_counter;	/* Call ID counter */
  		u32			last_call;	/* ID of last call */

  		u8			last_type;	/* Type of last packet */

  		union {
  			u32		last_seq;
  			u32		last_abort;
  		};

  	} channels[RXRPC_MAXCALLS];

  	struct timer_list	timer;		/* Conn event timer */

  	struct work_struct	processor;	/* connection event processor */

  	struct rxrpc_bundle	*bundle;	/* Client connection bundle */
  	struct rb_node		service_node;	/* Node in peer->service_conns */

  	struct list_head	proc_link;	/* link in procfs list */

  	struct list_head	link;		/* link in master connection list */

  	struct sk_buff_head	rx_queue;	/* received conn-level packets */

  	const struct rxrpc_security *security;	/* applied security module */

  	struct key		*server_key;	/* security for this service */

  	struct crypto_sync_skcipher *cipher;	/* encryption handle */

  	struct rxrpc_crypt	csum_iv;	/* packet checksum base */

  	unsigned long		flags;

  	unsigned long		events;

  	unsigned long		idle_timestamp;	/* Time at which last became idle */

  	spinlock_t		state_lock;	/* state-change lock */

  	enum rxrpc_conn_proto_state state;	/* current state of connection */

  	u32			abort_code;	/* Abort code of connection abort */

  	int			debug_id;	/* debug ID for printks */

  	atomic_t		serial;		/* packet serial number counter */

  	unsigned int		hi_serial;	/* highest serial number received */

  	u32			security_nonce;	/* response re-use preventer */

  	u32			service_id;	/* Service ID, possibly upgraded */

  	u8			size_align;	/* data size alignment (for security) */

  	u8			security_size;	/* security header size */

  	u8			security_ix;	/* security type */

  	u8			out_clientflag;	/* RXRPC_CLIENT_INITIATED if we are client */

  	u8			bundle_shift;	/* Index into bundle->avail_chans */

  	short			error;		/* Local error code */

  };

  static inline bool rxrpc_to_server(const struct rxrpc_skb_priv *sp)
  {
  	return sp->hdr.flags & RXRPC_CLIENT_INITIATED;
  }
  
  static inline bool rxrpc_to_client(const struct rxrpc_skb_priv *sp)
  {
  	return !rxrpc_to_server(sp);
  }

  /*

   * Flags in call->flags.
   */
  enum rxrpc_call_flag {
  	RXRPC_CALL_RELEASED,		/* call has been released - no more message to userspace */

  	RXRPC_CALL_HAS_USERID,		/* has a user ID attached */

  	RXRPC_CALL_IS_SERVICE,		/* Call is service call */

  	RXRPC_CALL_EXPOSED,		/* The call was exposed to the world */

  	RXRPC_CALL_RX_LAST,		/* Received the last packet (at rxtx_top) */
  	RXRPC_CALL_TX_LAST,		/* Last packet in Tx buffer (at rxtx_top) */

  	RXRPC_CALL_SEND_PING,		/* A ping will need to be sent */

  	RXRPC_CALL_RETRANS_TIMEOUT,	/* Retransmission due to timeout occurred */

  	RXRPC_CALL_BEGAN_RX_TIMER,	/* We began the expect_rx_by timer */

  	RXRPC_CALL_RX_HEARD,		/* The peer responded at least once to this call */

  	RXRPC_CALL_RX_UNDERRUN,		/* Got data underrun */

  	RXRPC_CALL_DISCONNECTED,	/* The call has been disconnected */

  	RXRPC_CALL_KERNEL,		/* The call was made by the kernel */

  	RXRPC_CALL_UPGRADE,		/* Service upgrade was requested for the call */

  };
  
  /*
   * Events that can be raised on a call.
   */
  enum rxrpc_call_event {

  	RXRPC_CALL_EV_ACK,		/* need to generate ACK */

  	RXRPC_CALL_EV_ABORT,		/* need to generate abort */

  	RXRPC_CALL_EV_RESEND,		/* Tx resend required */

  	RXRPC_CALL_EV_PING,		/* Ping send required */

  	RXRPC_CALL_EV_EXPIRED,		/* Expiry occurred */

  	RXRPC_CALL_EV_ACK_LOST,		/* ACK may be lost, send ping */

  };
  
  /*
   * The states that a call can be in.
   */
  enum rxrpc_call_state {

  	RXRPC_CALL_UNINITIALISED,
  	RXRPC_CALL_CLIENT_AWAIT_CONN,	/* - client waiting for connection to become available */

  	RXRPC_CALL_CLIENT_SEND_REQUEST,	/* - client sending request phase */
  	RXRPC_CALL_CLIENT_AWAIT_REPLY,	/* - client awaiting reply */
  	RXRPC_CALL_CLIENT_RECV_REPLY,	/* - client receiving reply phase */

  	RXRPC_CALL_SERVER_PREALLOC,	/* - service preallocation */

  	RXRPC_CALL_SERVER_SECURING,	/* - server securing request connection */

  	RXRPC_CALL_SERVER_RECV_REQUEST,	/* - server receiving request */
  	RXRPC_CALL_SERVER_ACK_REQUEST,	/* - server pending ACK of request */
  	RXRPC_CALL_SERVER_SEND_REPLY,	/* - server sending reply */
  	RXRPC_CALL_SERVER_AWAIT_ACK,	/* - server awaiting final ACK */

  	RXRPC_CALL_COMPLETE,		/* - call complete */

  	NR__RXRPC_CALL_STATES
  };
  
  /*

   * Call completion condition (state == RXRPC_CALL_COMPLETE).
   */
  enum rxrpc_call_completion {
  	RXRPC_CALL_SUCCEEDED,		/* - Normal termination */
  	RXRPC_CALL_REMOTELY_ABORTED,	/* - call aborted by peer */
  	RXRPC_CALL_LOCALLY_ABORTED,	/* - call aborted locally on error or close */
  	RXRPC_CALL_LOCAL_ERROR,		/* - call failed due to local error */
  	RXRPC_CALL_NETWORK_ERROR,	/* - call terminated by network error */
  	NR__RXRPC_CALL_COMPLETIONS
  };
  
  /*

   * Call Tx congestion management modes.
   */
  enum rxrpc_congest_mode {
  	RXRPC_CALL_SLOW_START,
  	RXRPC_CALL_CONGEST_AVOIDANCE,
  	RXRPC_CALL_PACKET_LOSS,
  	RXRPC_CALL_FAST_RETRANSMIT,
  	NR__RXRPC_CONGEST_MODES
  };
  
  /*

   * RxRPC call definition
   * - matched by { connection, call_id }
   */
  struct rxrpc_call {

  	struct rcu_head		rcu;

  	struct rxrpc_connection	*conn;		/* connection carrying call */

  	struct rxrpc_peer	*peer;		/* Peer record for remote address */

  	struct rxrpc_sock __rcu	*socket;	/* socket responsible */

  	struct rxrpc_net	*rxnet;		/* Network namespace to which call belongs */

  	const struct rxrpc_security *security;	/* applied security module */

  	struct mutex		user_mutex;	/* User access mutex */

  	unsigned long		ack_at;		/* When deferred ACK needs to happen */

  	unsigned long		ack_lost_at;	/* When ACK is figured as lost */

  	unsigned long		resend_at;	/* When next resend needs to happen */
  	unsigned long		ping_at;	/* When next to send a ping */

  	unsigned long		keepalive_at;	/* When next to send a keepalive ping */

  	unsigned long		expect_rx_by;	/* When we expect to get a packet by */
  	unsigned long		expect_req_by;	/* When we expect to get a request DATA packet by */
  	unsigned long		expect_term_by;	/* When we expect call termination by */
  	u32			next_rx_timo;	/* Timeout for next Rx packet (jif) */
  	u32			next_req_timo;	/* Timeout for next Rx request packet (jif) */

  	struct skcipher_request	*cipher_req;	/* Packet cipher request buffer */

  	struct timer_list	timer;		/* Combined event timer */
  	struct work_struct	processor;	/* Event processor */

  	rxrpc_notify_rx_t	notify_rx;	/* kernel service Rx notification function */

  	struct list_head	link;		/* link in master call list */

  	struct list_head	chan_wait_link;	/* Link in conn->bundle->waiting_calls */

  	struct hlist_node	error_link;	/* link in error distribution list */

  	struct list_head	accept_link;	/* Link in rx->acceptq */
  	struct list_head	recvmsg_link;	/* Link in rx->recvmsg_q */
  	struct list_head	sock_link;	/* Link in rx->sock_calls */
  	struct rb_node		sock_node;	/* Node in rx->calls */

  	struct sk_buff		*tx_pending;	/* Tx socket buffer being filled */

  	wait_queue_head_t	waitq;		/* Wait queue for channel or Tx */

  	s64			tx_total_len;	/* Total length left to be transmitted (or -1) */

  	__be32			crypto_buf[2];	/* Temporary packet crypto buffer */

  	unsigned long		user_call_ID;	/* user-defined call ID */

  	unsigned long		flags;

  	unsigned long		events;

  	spinlock_t		lock;

  	spinlock_t		notify_lock;	/* Kernel notification lock */

  	rwlock_t		state_lock;	/* lock for state transition */

  	u32			abort_code;	/* Local/remote abort code */
  	int			error;		/* Local error incurred */

  	enum rxrpc_call_state	state;		/* current state of call */
  	enum rxrpc_call_completion completion;	/* Call completion condition */

  	atomic_t		usage;

  	u16			service_id;	/* service ID */

  	u8			security_ix;	/* Security type */

  	enum rxrpc_interruptibility interruptibility; /* At what point call may be interrupted */

  	u32			call_id;	/* call ID on connection  */
  	u32			cid;		/* connection ID plus channel index */
  	int			debug_id;	/* debug ID for printks */

  	unsigned short		rx_pkt_offset;	/* Current recvmsg packet offset */
  	unsigned short		rx_pkt_len;	/* Current recvmsg packet len */

  	bool			rx_pkt_last;	/* Current recvmsg packet is last */

  	/* Rx/Tx circular buffer, depending on phase.
  	 *
  	 * In the Rx phase, packets are annotated with 0 or the number of the
  	 * segment of a jumbo packet each buffer refers to.  There can be up to
  	 * 47 segments in a maximum-size UDP packet.
  	 *
  	 * In the Tx phase, packets are annotated with which buffers have been
  	 * acked.
  	 */
  #define RXRPC_RXTX_BUFF_SIZE	64
  #define RXRPC_RXTX_BUFF_MASK	(RXRPC_RXTX_BUFF_SIZE - 1)

  #define RXRPC_INIT_RX_WINDOW_SIZE 63

  	struct sk_buff		**rxtx_buffer;
  	u8			*rxtx_annotations;
  #define RXRPC_TX_ANNO_ACK	0
  #define RXRPC_TX_ANNO_UNACK	1
  #define RXRPC_TX_ANNO_NAK	2
  #define RXRPC_TX_ANNO_RETRANS	3

  #define RXRPC_TX_ANNO_MASK	0x03

  #define RXRPC_TX_ANNO_LAST	0x04
  #define RXRPC_TX_ANNO_RESENT	0x08

  #define RXRPC_RX_ANNO_SUBPACKET	0x3f		/* Subpacket number in jumbogram */

  #define RXRPC_RX_ANNO_VERIFIED	0x80		/* Set if verified and decrypted */
  	rxrpc_seq_t		tx_hard_ack;	/* Dead slot in buffer; the first transmitted but
  						 * not hard-ACK'd packet follows this.
  						 */
  	rxrpc_seq_t		tx_top;		/* Highest Tx slot allocated. */

  	u16			tx_backoff;	/* Delay to insert due to Tx failure */

  
  	/* TCP-style slow-start congestion control [RFC5681].  Since the SMSS
  	 * is fixed, we keep these numbers in terms of segments (ie. DATA
  	 * packets) rather than bytes.
  	 */
  #define RXRPC_TX_SMSS		RXRPC_JUMBO_DATALEN
  	u8			cong_cwnd;	/* Congestion window size */
  	u8			cong_extra;	/* Extra to send for congestion management */
  	u8			cong_ssthresh;	/* Slow-start threshold */
  	enum rxrpc_congest_mode	cong_mode:8;	/* Congestion management mode */
  	u8			cong_dup_acks;	/* Count of ACKs showing missing packets */
  	u8			cong_cumul_acks; /* Cumulative ACK count */
  	ktime_t			cong_tstamp;	/* Last time cwnd was changed */

  	rxrpc_seq_t		rx_hard_ack;	/* Dead slot in buffer; the first received but not
  						 * consumed packet follows this.

  						 */

  	rxrpc_seq_t		rx_top;		/* Highest Rx slot allocated. */
  	rxrpc_seq_t		rx_expect_next;	/* Expected next packet sequence number */

  	rxrpc_serial_t		rx_serial;	/* Highest serial received for this call */

  	u8			rx_winsize;	/* Size of Rx window */
  	u8			tx_winsize;	/* Maximum size of Tx window */

  	bool			tx_phase;	/* T if transmission phase, F if receive phase */

  	u8			nr_jumbo_bad;	/* Number of jumbo dups/exceeds-windows */

  	spinlock_t		input_lock;	/* Lock for packet input to this call */

  	/* receive-phase ACK management */

  	u8			ackr_reason;	/* reason to ACK */

  	rxrpc_serial_t		ackr_serial;	/* serial of packet being ACK'd */

  	rxrpc_serial_t		ackr_first_seq;	/* first sequence number received */

  	rxrpc_seq_t		ackr_prev_seq;	/* previous sequence number received */

  	rxrpc_seq_t		ackr_consumed;	/* Highest packet shown consumed */
  	rxrpc_seq_t		ackr_seen;	/* Highest packet shown seen */

  	/* RTT management */
  	rxrpc_serial_t		rtt_serial[4];	/* Serial number of DATA or PING sent */
  	ktime_t			rtt_sent_at[4];	/* Time packet sent */
  	unsigned long		rtt_avail;	/* Mask of available slots in bits 0-3,
  						 * Mask of pending samples in 8-11 */
  #define RXRPC_CALL_RTT_AVAIL_MASK	0xf
  #define RXRPC_CALL_RTT_PEND_SHIFT	8

  	/* transmission-phase ACK management */

  	ktime_t			acks_latest_ts;	/* Timestamp of latest ACK received */

  	rxrpc_seq_t		acks_lowest_nak; /* Lowest NACK in the buffer (or ==tx_hard_ack) */

  	rxrpc_seq_t		acks_lost_top;	/* tx_top at the time lost-ack ping sent */
  	rxrpc_serial_t		acks_lost_ping;	/* Serial number of probe ACK */

  };
  
  /*

   * Summary of a new ACK and the changes it made to the Tx buffer packet states.

   */
  struct rxrpc_ack_summary {
  	u8			ack_reason;
  	u8			nr_acks;		/* Number of ACKs in packet */
  	u8			nr_nacks;		/* Number of NACKs in packet */
  	u8			nr_new_acks;		/* Number of new ACKs in packet */
  	u8			nr_new_nacks;		/* Number of new NACKs in packet */
  	u8			nr_rot_new_acks;	/* Number of rotated new ACKs */
  	bool			new_low_nack;		/* T if new low NACK found */

  	bool			retrans_timeo;		/* T if reTx due to timeout happened */
  	u8			flight_size;		/* Number of unreceived transmissions */
  	/* Place to stash values for tracing */
  	enum rxrpc_congest_mode	mode:8;
  	u8			cwnd;
  	u8			ssthresh;
  	u8			dup_acks;
  	u8			cumulative_acks;

  };

  /*
   * sendmsg() cmsg-specified parameters.
   */
  enum rxrpc_command {
  	RXRPC_CMD_SEND_DATA,		/* send data message */
  	RXRPC_CMD_SEND_ABORT,		/* request abort generation */

  	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */

  	RXRPC_CMD_CHARGE_ACCEPT,	/* [server] charge accept preallocation */

  };
  
  struct rxrpc_call_params {
  	s64			tx_total_len;	/* Total Tx data length (if send data) */
  	unsigned long		user_call_ID;	/* User's call ID */
  	struct {
  		u32		hard;		/* Maximum lifetime (sec) */
  		u32		idle;		/* Max time since last data packet (msec) */
  		u32		normal;		/* Max time since last call packet (msec) */
  	} timeouts;
  	u8			nr_timeouts;	/* Number of timeouts specified */

  	bool			kernel;		/* T if kernel is making the call */

  	enum rxrpc_interruptibility interruptibility; /* How is interruptible is the call? */

  };
  
  struct rxrpc_send_params {
  	struct rxrpc_call_params call;
  	u32			abort_code;	/* Abort code to Tx (if abort) */
  	enum rxrpc_command	command : 8;	/* The command to implement */
  	bool			exclusive;	/* Shared or exclusive call */
  	bool			upgrade;	/* If the connection is upgradeable */
  };

  #include <trace/events/rxrpc.h>

  /*

   * af_rxrpc.c

   */

  extern atomic_t rxrpc_n_tx_skbs, rxrpc_n_rx_skbs;

  extern struct workqueue_struct *rxrpc_workqueue;

  
  /*

   * call_accept.c

   */

  int rxrpc_service_prealloc(struct rxrpc_sock *, gfp_t);
  void rxrpc_discard_prealloc(struct rxrpc_sock *);

  struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *,

  					   struct rxrpc_sock *,

  					   struct sk_buff *);

  void rxrpc_accept_incoming_calls(struct rxrpc_local *);

  int rxrpc_user_charge_accept(struct rxrpc_sock *, unsigned long);

  
  /*

   * call_event.c

   */

  void rxrpc_propose_ACK(struct rxrpc_call *, u8, u32, bool, bool,

  		       enum rxrpc_propose_ack_trace);

  void rxrpc_process_call(struct work_struct *);

  static inline void rxrpc_reduce_call_timer(struct rxrpc_call *call,
  					   unsigned long expire_at,
  					   unsigned long now,
  					   enum rxrpc_timer_trace why)
  {
  	trace_rxrpc_timer(call, why, now);
  	timer_reduce(&call->timer, expire_at);
  }

  /*

   * call_object.c

   */

  extern const char *const rxrpc_call_states[];
  extern const char *const rxrpc_call_completions[];

  extern unsigned int rxrpc_max_call_lifetime;

  extern struct kmem_cache *rxrpc_call_jar;

  struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *, unsigned long);

  struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *, gfp_t, unsigned int);

  struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *,

  					 struct rxrpc_conn_parameters *,

  					 struct sockaddr_rxrpc *,

  					 struct rxrpc_call_params *, gfp_t,
  					 unsigned int);

  void rxrpc_incoming_call(struct rxrpc_sock *, struct rxrpc_call *,
  			 struct sk_buff *);

  void rxrpc_release_call(struct rxrpc_sock *, struct rxrpc_call *);

  void rxrpc_release_calls_on_socket(struct rxrpc_sock *);

  bool __rxrpc_queue_call(struct rxrpc_call *);
  bool rxrpc_queue_call(struct rxrpc_call *);

  void rxrpc_see_call(struct rxrpc_call *);

  void rxrpc_get_call(struct rxrpc_call *, enum rxrpc_call_trace);
  void rxrpc_put_call(struct rxrpc_call *, enum rxrpc_call_trace);

  void rxrpc_cleanup_call(struct rxrpc_call *);

  void rxrpc_destroy_all_calls(struct rxrpc_net *);

  static inline bool rxrpc_is_service_call(const struct rxrpc_call *call)
  {
  	return test_bit(RXRPC_CALL_IS_SERVICE, &call->flags);
  }
  
  static inline bool rxrpc_is_client_call(const struct rxrpc_call *call)
  {
  	return !rxrpc_is_service_call(call);
  }

  /*

   * conn_client.c
   */

  extern unsigned int rxrpc_reap_client_connections;

  extern unsigned long rxrpc_conn_idle_client_expiry;
  extern unsigned long rxrpc_conn_idle_client_fast_expiry;

  extern struct idr rxrpc_client_conn_ids;

  void rxrpc_destroy_client_conn_ids(void);

  struct rxrpc_bundle *rxrpc_get_bundle(struct rxrpc_bundle *);
  void rxrpc_put_bundle(struct rxrpc_bundle *);

  int rxrpc_connect_call(struct rxrpc_sock *, struct rxrpc_call *,
  		       struct rxrpc_conn_parameters *, struct sockaddr_rxrpc *,
  		       gfp_t);

  void rxrpc_expose_client_call(struct rxrpc_call *);

  void rxrpc_disconnect_client_call(struct rxrpc_bundle *, struct rxrpc_call *);

  void rxrpc_put_client_conn(struct rxrpc_connection *);

  void rxrpc_discard_expired_client_conns(struct work_struct *);
  void rxrpc_destroy_all_client_connections(struct rxrpc_net *);

  void rxrpc_clean_up_local_conns(struct rxrpc_local *);

  
  /*

   * conn_event.c
   */
  void rxrpc_process_connection(struct work_struct *);

  void rxrpc_process_delayed_final_acks(struct rxrpc_connection *, bool);

  
  /*
   * conn_object.c

   */

  extern unsigned int rxrpc_connection_expiry;

  extern unsigned int rxrpc_closed_conn_expiry;

  struct rxrpc_connection *rxrpc_alloc_connection(gfp_t);

  struct rxrpc_connection *rxrpc_find_connection_rcu(struct rxrpc_local *,

  						   struct sk_buff *,
  						   struct rxrpc_peer **);

  void __rxrpc_disconnect_call(struct rxrpc_connection *, struct rxrpc_call *);

  void rxrpc_disconnect_call(struct rxrpc_call *);

  void rxrpc_kill_connection(struct rxrpc_connection *);

  bool rxrpc_queue_conn(struct rxrpc_connection *);
  void rxrpc_see_connection(struct rxrpc_connection *);

  struct rxrpc_connection *rxrpc_get_connection(struct rxrpc_connection *);

  struct rxrpc_connection *rxrpc_get_connection_maybe(struct rxrpc_connection *);
  void rxrpc_put_service_conn(struct rxrpc_connection *);

  void rxrpc_service_connection_reaper(struct work_struct *);
  void rxrpc_destroy_all_connections(struct rxrpc_net *);

  static inline bool rxrpc_conn_is_client(const struct rxrpc_connection *conn)
  {
  	return conn->out_clientflag;
  }
  
  static inline bool rxrpc_conn_is_service(const struct rxrpc_connection *conn)
  {

  	return !rxrpc_conn_is_client(conn);

  }

  static inline void rxrpc_put_connection(struct rxrpc_connection *conn)
  {

  	if (!conn)
  		return;

  	if (rxrpc_conn_is_client(conn))
  		rxrpc_put_client_conn(conn);
  	else
  		rxrpc_put_service_conn(conn);

  }

  static inline void rxrpc_reduce_conn_timer(struct rxrpc_connection *conn,
  					   unsigned long expire_at)
  {
  	timer_reduce(&conn->timer, expire_at);
  }

  /*

   * conn_service.c
   */

  struct rxrpc_connection *rxrpc_find_service_conn_rcu(struct rxrpc_peer *,
  						     struct sk_buff *);

  struct rxrpc_connection *rxrpc_prealloc_service_connection(struct rxrpc_net *, gfp_t);

  void rxrpc_new_incoming_connection(struct rxrpc_sock *, struct rxrpc_connection *,
  				   const struct rxrpc_security *, struct key *,
  				   struct sk_buff *);

  void rxrpc_unpublish_service_conn(struct rxrpc_connection *);

  
  /*

   * input.c

   */

  int rxrpc_input_packet(struct sock *, struct sk_buff *);

  
  /*

   * insecure.c

   */

  extern const struct rxrpc_security rxrpc_no_security;

  
  /*

   * key.c

   */

  extern struct key_type key_type_rxrpc;
  extern struct key_type key_type_rxrpc_s;

  int rxrpc_request_key(struct rxrpc_sock *, sockptr_t , int);
  int rxrpc_server_keyring(struct rxrpc_sock *, sockptr_t, int);

  int rxrpc_get_server_data_key(struct rxrpc_connection *, const void *, time64_t,

  			      u32);

  
  /*

   * local_event.c
   */

  extern void rxrpc_process_local_events(struct rxrpc_local *);

  
  /*

   * local_object.c

   */

  struct rxrpc_local *rxrpc_lookup_local(struct net *, const struct sockaddr_rxrpc *);

  struct rxrpc_local *rxrpc_get_local(struct rxrpc_local *);
  struct rxrpc_local *rxrpc_get_local_maybe(struct rxrpc_local *);
  void rxrpc_put_local(struct rxrpc_local *);

  struct rxrpc_local *rxrpc_use_local(struct rxrpc_local *);
  void rxrpc_unuse_local(struct rxrpc_local *);

  void rxrpc_queue_local(struct rxrpc_local *);

  void rxrpc_destroy_all_locals(struct rxrpc_net *);

  static inline bool __rxrpc_unuse_local(struct rxrpc_local *local)
  {
  	return atomic_dec_return(&local->active_users) == 0;
  }
  
  static inline bool __rxrpc_use_local(struct rxrpc_local *local)
  {
  	return atomic_fetch_add_unless(&local->active_users, 1, 0) != 0;
  }

  /*

   * misc.c

   */

  extern unsigned int rxrpc_max_backlog __read_mostly;

  extern unsigned long rxrpc_requested_ack_delay;
  extern unsigned long rxrpc_soft_ack_delay;
  extern unsigned long rxrpc_idle_ack_delay;

  extern unsigned int rxrpc_rx_window_size;
  extern unsigned int rxrpc_rx_mtu;
  extern unsigned int rxrpc_rx_jumbo_max;

  extern const s8 rxrpc_ack_priority[];

  /*

   * net_ns.c
   */
  extern unsigned int rxrpc_net_id;
  extern struct pernet_operations rxrpc_net_ops;
  
  static inline struct rxrpc_net *rxrpc_net(struct net *net)
  {
  	return net_generic(net, rxrpc_net_id);
  }
  
  /*

   * output.c

   */

  int rxrpc_send_ack_packet(struct rxrpc_call *, bool, rxrpc_serial_t *);

  int rxrpc_send_abort_packet(struct rxrpc_call *);

  int rxrpc_send_data_packet(struct rxrpc_call *, struct sk_buff *, bool);

  void rxrpc_reject_packets(struct rxrpc_local *);

  void rxrpc_send_keepalive(struct rxrpc_peer *);

  
  /*

   * peer_event.c

   */

  void rxrpc_error_report(struct sock *);

  void rxrpc_peer_keepalive_worker(struct work_struct *);

  
  /*
   * peer_object.c

   */

  struct rxrpc_peer *rxrpc_lookup_peer_rcu(struct rxrpc_local *,
  					 const struct sockaddr_rxrpc *);

  struct rxrpc_peer *rxrpc_lookup_peer(struct rxrpc_sock *, struct rxrpc_local *,

  				     struct sockaddr_rxrpc *, gfp_t);
  struct rxrpc_peer *rxrpc_alloc_peer(struct rxrpc_local *, gfp_t);

  void rxrpc_new_incoming_peer(struct rxrpc_sock *, struct rxrpc_local *,
  			     struct rxrpc_peer *);

  void rxrpc_destroy_all_peers(struct rxrpc_net *);

  struct rxrpc_peer *rxrpc_get_peer(struct rxrpc_peer *);
  struct rxrpc_peer *rxrpc_get_peer_maybe(struct rxrpc_peer *);
  void rxrpc_put_peer(struct rxrpc_peer *);

  void rxrpc_put_peer_locked(struct rxrpc_peer *);

  
  /*

   * proc.c

   */

  extern const struct seq_operations rxrpc_call_seq_ops;
  extern const struct seq_operations rxrpc_connection_seq_ops;

  extern const struct seq_operations rxrpc_peer_seq_ops;

  
  /*

   * recvmsg.c

   */

  void rxrpc_notify_socket(struct rxrpc_call *);

  bool __rxrpc_set_call_completion(struct rxrpc_call *, enum rxrpc_call_completion, u32, int);
  bool rxrpc_set_call_completion(struct rxrpc_call *, enum rxrpc_call_completion, u32, int);
  bool __rxrpc_call_completed(struct rxrpc_call *);
  bool rxrpc_call_completed(struct rxrpc_call *);
  bool __rxrpc_abort_call(const char *, struct rxrpc_call *, rxrpc_seq_t, u32, int);
  bool rxrpc_abort_call(const char *, struct rxrpc_call *, rxrpc_seq_t, u32, int);

  int rxrpc_recvmsg(struct socket *, struct msghdr *, size_t, int);

  
  /*

   * Abort a call due to a protocol error.
   */
  static inline bool __rxrpc_abort_eproto(struct rxrpc_call *call,
  					struct sk_buff *skb,
  					const char *eproto_why,
  					const char *why,
  					u32 abort_code)
  {
  	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
  
  	trace_rxrpc_rx_eproto(call, sp->hdr.serial, eproto_why);
  	return rxrpc_abort_call(why, call, sp->hdr.seq, abort_code, -EPROTO);
  }
  
  #define rxrpc_abort_eproto(call, skb, eproto_why, abort_why, abort_code) \
  	__rxrpc_abort_eproto((call), (skb), tracepoint_string(eproto_why), \
  			     (abort_why), (abort_code))
  
  /*

   * rtt.c
   */

  void rxrpc_peer_add_rtt(struct rxrpc_call *, enum rxrpc_rtt_rx_trace, int,

  			rxrpc_serial_t, rxrpc_serial_t, ktime_t, ktime_t);
  unsigned long rxrpc_get_rto_backoff(struct rxrpc_peer *, bool);
  void rxrpc_peer_init_rtt(struct rxrpc_peer *);
  
  /*

   * rxkad.c
   */
  #ifdef CONFIG_RXKAD
  extern const struct rxrpc_security rxkad;
  #endif
  
  /*
   * security.c

   */

  int __init rxrpc_init_security(void);
  void rxrpc_exit_security(void);

  int rxrpc_init_client_conn_security(struct rxrpc_connection *);

  bool rxrpc_look_up_server_security(struct rxrpc_local *, struct rxrpc_sock *,
  				   const struct rxrpc_security **, struct key **,
  				   struct sk_buff *);

  /*
   * sendmsg.c
   */
  int rxrpc_do_sendmsg(struct rxrpc_sock *, struct msghdr *, size_t);

  
  /*

   * skbuff.c

   */

  void rxrpc_kernel_data_consumed(struct rxrpc_call *, struct sk_buff *);

  void rxrpc_packet_destructor(struct sk_buff *);

  void rxrpc_new_skb(struct sk_buff *, enum rxrpc_skb_trace);
  void rxrpc_see_skb(struct sk_buff *, enum rxrpc_skb_trace);

  void rxrpc_eaten_skb(struct sk_buff *, enum rxrpc_skb_trace);

  void rxrpc_get_skb(struct sk_buff *, enum rxrpc_skb_trace);
  void rxrpc_free_skb(struct sk_buff *, enum rxrpc_skb_trace);

  void rxrpc_purge_queue(struct sk_buff_head *);

  
  /*

   * sysctl.c
   */
  #ifdef CONFIG_SYSCTL
  extern int __init rxrpc_sysctl_init(void);
  extern void rxrpc_sysctl_exit(void);
  #else
  static inline int __init rxrpc_sysctl_init(void) { return 0; }
  static inline void rxrpc_sysctl_exit(void) {}
  #endif
  
  /*

   * utils.c
   */

  int rxrpc_extract_addr_from_skb(struct sockaddr_rxrpc *, struct sk_buff *);

  static inline bool before(u32 seq1, u32 seq2)
  {
          return (s32)(seq1 - seq2) < 0;
  }
  static inline bool before_eq(u32 seq1, u32 seq2)
  {
          return (s32)(seq1 - seq2) <= 0;
  }
  static inline bool after(u32 seq1, u32 seq2)
  {
          return (s32)(seq1 - seq2) > 0;
  }
  static inline bool after_eq(u32 seq1, u32 seq2)
  {
          return (s32)(seq1 - seq2) >= 0;
  }

  /*

   * debug tracing
   */

  extern unsigned int rxrpc_debug;

  
  #define dbgprintk(FMT,...) \

  	printk("[%-6.6s] "FMT"
  ", current->comm ,##__VA_ARGS__)

  #define kenter(FMT,...)	dbgprintk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
  #define kleave(FMT,...)	dbgprintk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)

  #define kdebug(FMT,...)	dbgprintk("    "FMT ,##__VA_ARGS__)
  #define kproto(FMT,...)	dbgprintk("### "FMT ,##__VA_ARGS__)
  #define knet(FMT,...)	dbgprintk("@@@ "FMT ,##__VA_ARGS__)
  
  
  #if defined(__KDEBUG)
  #define _enter(FMT,...)	kenter(FMT,##__VA_ARGS__)
  #define _leave(FMT,...)	kleave(FMT,##__VA_ARGS__)
  #define _debug(FMT,...)	kdebug(FMT,##__VA_ARGS__)
  #define _proto(FMT,...)	kproto(FMT,##__VA_ARGS__)
  #define _net(FMT,...)	knet(FMT,##__VA_ARGS__)
  
  #elif defined(CONFIG_AF_RXRPC_DEBUG)
  #define RXRPC_DEBUG_KENTER	0x01
  #define RXRPC_DEBUG_KLEAVE	0x02
  #define RXRPC_DEBUG_KDEBUG	0x04
  #define RXRPC_DEBUG_KPROTO	0x08
  #define RXRPC_DEBUG_KNET	0x10
  
  #define _enter(FMT,...)					\
  do {							\
  	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KENTER))	\
  		kenter(FMT,##__VA_ARGS__);		\
  } while (0)
  
  #define _leave(FMT,...)					\
  do {							\
  	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KLEAVE))	\
  		kleave(FMT,##__VA_ARGS__);		\
  } while (0)
  
  #define _debug(FMT,...)					\
  do {							\
  	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KDEBUG))	\
  		kdebug(FMT,##__VA_ARGS__);		\
  } while (0)
  
  #define _proto(FMT,...)					\
  do {							\
  	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KPROTO))	\
  		kproto(FMT,##__VA_ARGS__);		\
  } while (0)
  
  #define _net(FMT,...)					\
  do {							\
  	if (unlikely(rxrpc_debug & RXRPC_DEBUG_KNET))	\
  		knet(FMT,##__VA_ARGS__);		\
  } while (0)
  
  #else

  #define _enter(FMT,...)	no_printk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
  #define _leave(FMT,...)	no_printk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
  #define _debug(FMT,...)	no_printk("    "FMT ,##__VA_ARGS__)
  #define _proto(FMT,...)	no_printk("### "FMT ,##__VA_ARGS__)
  #define _net(FMT,...)	no_printk("@@@ "FMT ,##__VA_ARGS__)

  #endif
  
  /*
   * debug assertion checking
   */
  #if 1 // defined(__KDEBUGALL)
  
  #define ASSERT(X)						\
  do {								\
  	if (unlikely(!(X))) {					\

  		pr_err("Assertion failed
  ");			\

  		BUG();						\
  	}							\

  } while (0)

  
  #define ASSERTCMP(X, OP, Y)						\
  do {									\

  	__typeof__(X) _x = (X);						\
  	__typeof__(Y) _y = (__typeof__(X))(Y);				\

  	if (unlikely(!(_x OP _y))) {					\

  		pr_err("Assertion failed - %lu(0x%lx) %s %lu(0x%lx) is false
  ", \
  		       (unsigned long)_x, (unsigned long)_x, #OP,	\
  		       (unsigned long)_y, (unsigned long)_y);		\

  		BUG();							\
  	}								\

  } while (0)

  
  #define ASSERTIF(C, X)						\
  do {								\
  	if (unlikely((C) && !(X))) {				\

  		pr_err("Assertion failed
  ");			\

  		BUG();						\
  	}							\

  } while (0)

  
  #define ASSERTIFCMP(C, X, OP, Y)					\
  do {									\

  	__typeof__(X) _x = (X);						\
  	__typeof__(Y) _y = (__typeof__(X))(Y);				\

  	if (unlikely((C) && !(_x OP _y))) {				\
  		pr_err("Assertion failed - %lu(0x%lx) %s %lu(0x%lx) is false
  ", \

  		       (unsigned long)_x, (unsigned long)_x, #OP,	\
  		       (unsigned long)_y, (unsigned long)_y);		\

  		BUG();							\
  	}								\

  } while (0)

  
  #else
  
  #define ASSERT(X)				\
  do {						\

  } while (0)

  
  #define ASSERTCMP(X, OP, Y)			\
  do {						\

  } while (0)

  
  #define ASSERTIF(C, X)				\
  do {						\

  } while (0)

  
  #define ASSERTIFCMP(C, X, OP, Y)		\
  do {						\

  } while (0)

  
  #endif /* __KDEBUGALL */