path: root/net/rxrpc/ar-internal.h

/* AF_RXRPC internal definitions
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <rxrpc/packet.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))

#define rxrpc_queue_call(CALL)	rxrpc_queue_work(&(CALL)->processor)
#define rxrpc_queue_conn(CONN)	rxrpc_queue_work(&(CONN)->processor)

/*
 * sk_state for RxRPC sockets
 */
enum {
	RXRPC_UNCONNECTED = 0,
	RXRPC_CLIENT_BOUND,		/* client local address bound */
	RXRPC_CLIENT_CONNECTED,		/* client is connected */
	RXRPC_SERVER_BOUND,		/* server local address bound */
	RXRPC_SERVER_LISTENING,		/* server listening for connections */
	RXRPC_CLOSE,			/* socket is being closed */
};

/*
 * RxRPC socket definition
 */
struct rxrpc_sock {
	/* WARNING: sk has to be the first member */
	struct sock		sk;
	rxrpc_interceptor_t	interceptor;	/* kernel service Rx interceptor function */
	struct rxrpc_local	*local;		/* local endpoint */
	struct rxrpc_transport	*trans;		/* transport handler */
	struct rxrpc_conn_bundle *bundle;	/* virtual connection bundle */
	struct rxrpc_connection	*conn;		/* exclusive virtual connection */
	struct list_head	listen_link;	/* link in the local endpoint's listen list */
	struct list_head	secureq;	/* calls awaiting connection security clearance */
	struct list_head	acceptq;	/* calls awaiting acceptance */
	struct key		*key;		/* security for this socket */
	struct key		*securities;	/* list of server security descriptors */
	struct rb_root		calls;		/* outstanding calls on this socket */
	unsigned long		flags;
#define RXRPC_SOCK_EXCLUSIVE_CONN	1	/* exclusive connection for a client socket */
	rwlock_t		call_lock;	/* lock for calls */
	u32			min_sec_level;	/* minimum security level */
#define RXRPC_SECURITY_MAX	RXRPC_SECURITY_ENCRYPT
	struct sockaddr_rxrpc	srx;		/* local address */
	sa_family_t		proto;		/* protocol created with */
	__be16			service_id;	/* service ID of local/remote service */
};

#define rxrpc_sk(__sk) container_of((__sk), struct rxrpc_sock, sk)

/*
 * RxRPC socket buffer private variables
 * - max 48 bytes (struct sk_buff::cb)
 */
struct rxrpc_skb_priv {
	struct rxrpc_call	*call;		/* call with which associated */
	unsigned long		resend_at;	/* time in jiffies at which to resend */
	union {
		unsigned int	offset;		/* offset into buffer of next read */
		int		remain;		/* amount of space remaining for next write */
		u32		error;		/* network error code */
		bool		need_resend;	/* T if needs resending */
	};

	struct rxrpc_header	hdr;		/* RxRPC packet header from this packet */
};

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

enum rxrpc_command {
	RXRPC_CMD_SEND_DATA,		/* send data message */
	RXRPC_CMD_SEND_ABORT,		/* request abort generation */
	RXRPC_CMD_ACCEPT,		/* [server] accept incoming call */
	RXRPC_CMD_REJECT_BUSY,		/* [server] reject a call as busy */
};

/*
 * RxRPC security module interface
 */
struct rxrpc_security {
	struct module		*owner;		/* providing module */
	struct list_head	link;		/* link in master list */
	const char		*name;		/* name of this service */
	u8			security_index;	/* security type provided */

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

	/* prime a connection's packet security */
	void (*prime_packet_security)(struct rxrpc_connection *);

	/* impose security on a packet */
	int (*secure_packet)(const struct rxrpc_call *,
			     struct sk_buff *,
			     size_t,
			     void *);

	/* verify the security on a received packet */
	int (*verify_packet)(const struct rxrpc_call *, struct sk_buff *,
			     u32 *);

	/* 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 definition
 * - matched by local port, address and protocol type
 */
struct rxrpc_local {
	struct socket		*socket;	/* my UDP socket */
	struct work_struct	destroyer;	/* endpoint destroyer */
	struct work_struct	acceptor;	/* incoming call processor */
	struct work_struct	rejecter;	/* packet reject writer */
	struct work_struct	event_processor; /* endpoint event processor */
	struct list_head	services;	/* services listening on this endpoint */
	struct list_head	link;		/* link in endpoint list */
	struct rw_semaphore	defrag_sem;	/* control re-enablement of IP DF bit */
	struct sk_buff_head	accept_queue;	/* incoming calls awaiting acceptance */
	struct sk_buff_head	reject_queue;	/* packets awaiting rejection */
	struct sk_buff_head	event_queue;	/* endpoint event packets awaiting processing */
	spinlock_t		lock;		/* access lock */
	rwlock_t		services_lock;	/* lock for services list */
	atomic_t		usage;
	int			debug_id;	/* debug ID for printks */
	volatile char		error_rcvd;	/* T if received ICMP error outstanding */
	struct sockaddr_rxrpc	srx;		/* local address */
};

/*
 * RxRPC remote transport endpoint definition
 * - matched by remote port, address and protocol type
 * - holds the connection ID counter for connections between the two endpoints
 */
struct rxrpc_peer {
	struct work_struct	destroyer;	/* peer destroyer */
	struct list_head	link;		/* link in master peer list */
	struct list_head	error_targets;	/* targets for net error distribution */
	spinlock_t		lock;		/* access lock */
	atomic_t		usage;
	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 */
	int			net_error;	/* network error distributed */
	struct sockaddr_rxrpc	srx;		/* remote address */

	/* calculated RTT cache */
#define RXRPC_RTT_CACHE_SIZE 32
	suseconds_t		rtt;		/* current RTT estimate (in uS) */
	unsigned int		rtt_point;	/* next entry at which to insert */
	unsigned int		rtt_usage;	/* amount of cache actually used */
	suseconds_t		rtt_cache[RXRPC_RTT_CACHE_SIZE]; /* calculated RTT cache */
};

/*
 * RxRPC point-to-point transport / connection manager definition
 * - handles a bundle of connections between two endpoints
 * - matched by { local, peer }
 */
struct rxrpc_transport {
	struct rxrpc_local	*local;		/* local transport endpoint */
	struct rxrpc_peer	*peer;		/* remote transport endpoint */
	struct work_struct	error_handler;	/* network error distributor */
	struct rb_root		bundles;	/* client connection bundles on this transport */
	struct rb_root		client_conns;	/* clie