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      1 /*
      2  *  linux/include/linux/sunrpc/xprt.h
      3  *
      4  *  Declarations for the RPC transport interface.
      5  *
      6  *  Copyright (C) 1995, 1996 Olaf Kirch <okir (at) monad.swb.de>
      7  */
      8 
      9 #ifndef _LINUX_SUNRPC_XPRT_H
     10 #define _LINUX_SUNRPC_XPRT_H
     11 
     12 #include <linux/uio.h>
     13 #include <linux/socket.h>
     14 #include <linux/in.h>
     15 #include <linux/sunrpc/sched.h>
     16 #include <linux/sunrpc/xdr.h>
     17 
     18 extern unsigned int xprt_udp_slot_table_entries;
     19 extern unsigned int xprt_tcp_slot_table_entries;
     20 
     21 #define RPC_MIN_SLOT_TABLE	(2U)
     22 #define RPC_DEF_SLOT_TABLE	(16U)
     23 #define RPC_MAX_SLOT_TABLE	(128U)
     24 
     25 /*
     26  * RPC call and reply header size as number of 32bit words (verifier
     27  * size computed separately)
     28  */
     29 #define RPC_CALLHDRSIZE		6
     30 #define RPC_REPHDRSIZE		4
     31 
     32 /*
     33  * Parameters for choosing a free port
     34  */
     35 extern unsigned int xprt_min_resvport;
     36 extern unsigned int xprt_max_resvport;
     37 
     38 #define RPC_MIN_RESVPORT	(1U)
     39 #define RPC_MAX_RESVPORT	(65535U)
     40 #define RPC_DEF_MIN_RESVPORT	(665U)
     41 #define RPC_DEF_MAX_RESVPORT	(1023U)
     42 
     43 /*
     44  * This describes a timeout strategy
     45  */
     46 struct rpc_timeout {
     47 	unsigned long		to_initval,		/* initial timeout */
     48 				to_maxval,		/* max timeout */
     49 				to_increment;		/* if !exponential */
     50 	unsigned int		to_retries;		/* max # of retries */
     51 	unsigned char		to_exponential;
     52 };
     53 
     54 struct rpc_task;
     55 struct rpc_xprt;
     56 struct seq_file;
     57 
     58 /*
     59  * This describes a complete RPC request
     60  */
     61 struct rpc_rqst {
     62 	/*
     63 	 * This is the user-visible part
     64 	 */
     65 	struct rpc_xprt *	rq_xprt;		/* RPC client */
     66 	struct xdr_buf		rq_snd_buf;		/* send buffer */
     67 	struct xdr_buf		rq_rcv_buf;		/* recv buffer */
     68 
     69 	/*
     70 	 * This is the private part
     71 	 */
     72 	struct rpc_task *	rq_task;	/* RPC task data */
     73 	__u32			rq_xid;		/* request XID */
     74 	int			rq_cong;	/* has incremented xprt->cong */
     75 	int			rq_received;	/* receive completed */
     76 	u32			rq_seqno;	/* gss seq no. used on req. */
     77 	int			rq_enc_pages_num;
     78 	struct page		**rq_enc_pages;	/* scratch pages for use by
     79 						   gss privacy code */
     80 	void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
     81 	struct list_head	rq_list;
     82 
     83 	__u32 *			rq_buffer;	/* XDR encode buffer */
     84 	size_t			rq_bufsize;
     85 
     86 	struct xdr_buf		rq_private_buf;		/* The receive buffer
     87 							 * used in the softirq.
     88 							 */
     89 	unsigned long		rq_majortimeo;	/* major timeout alarm */
     90 	unsigned long		rq_timeout;	/* Current timeout value */
     91 	unsigned int		rq_retries;	/* # of retries */
     92 
     93 	/*
     94 	 * Partial send handling
     95 	 */
     96 	u32			rq_bytes_sent;	/* Bytes we have sent */
     97 
     98 	unsigned long		rq_xtime;	/* when transmitted */
     99 	int			rq_ntrans;
    100 };
    101 #define rq_svec			rq_snd_buf.head
    102 #define rq_slen			rq_snd_buf.len
    103 
    104 struct rpc_xprt_ops {
    105 	void		(*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
    106 	int		(*reserve_xprt)(struct rpc_task *task);
    107 	void		(*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
    108 	void		(*set_port)(struct rpc_xprt *xprt, unsigned short port);
    109 	void		(*connect)(struct rpc_task *task);
    110 	void *		(*buf_alloc)(struct rpc_task *task, size_t size);
    111 	void		(*buf_free)(struct rpc_task *task);
    112 	int		(*send_request)(struct rpc_task *task);
    113 	void		(*set_retrans_timeout)(struct rpc_task *task);
    114 	void		(*timer)(struct rpc_task *task);
    115 	void		(*release_request)(struct rpc_task *task);
    116 	void		(*close)(struct rpc_xprt *xprt);
    117 	void		(*destroy)(struct rpc_xprt *xprt);
    118 	void		(*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
    119 };
    120 
    121 struct rpc_xprt {
    122 	struct rpc_xprt_ops *	ops;		/* transport methods */
    123 	struct socket *		sock;		/* BSD socket layer */
    124 	struct sock *		inet;		/* INET layer */
    125 
    126 	struct rpc_timeout	timeout;	/* timeout parms */
    127 	struct sockaddr_in	addr;		/* server address */
    128 	int			prot;		/* IP protocol */
    129 
    130 	unsigned long		cong;		/* current congestion */
    131 	unsigned long		cwnd;		/* congestion window */
    132 
    133 	size_t			rcvsize,	/* transport rcv buffer size */
    134 				sndsize;	/* transport send buffer size */
    135 
    136 	size_t			max_payload;	/* largest RPC payload size,
    137 						   in bytes */
    138 	unsigned int		tsh_size;	/* size of transport specific
    139 						   header */
    140 
    141 	struct rpc_wait_queue	sending;	/* requests waiting to send */
    142 	struct rpc_wait_queue	resend;		/* requests waiting to resend */
    143 	struct rpc_wait_queue	pending;	/* requests in flight */
    144 	struct rpc_wait_queue	backlog;	/* waiting for slot */
    145 	struct list_head	free;		/* free slots */
    146 	struct rpc_rqst *	slot;		/* slot table storage */
    147 	unsigned int		max_reqs;	/* total slots */
    148 	unsigned long		state;		/* transport state */
    149 	unsigned char		shutdown   : 1,	/* being shut down */
    150 				resvport   : 1; /* use a reserved port */
    151 
    152 	/*
    153 	 * XID
    154 	 */
    155 	__u32			xid;		/* Next XID value to use */
    156 
    157 	/*
    158 	 * State of TCP reply receive stuff
    159 	 */
    160 	u32			tcp_recm,	/* Fragment header */
    161 				tcp_xid,	/* Current XID */
    162 				tcp_reclen,	/* fragment length */
    163 				tcp_offset;	/* fragment offset */
    164 	unsigned long		tcp_copied,	/* copied to request */
    165 				tcp_flags;
    166 	/*
    167 	 * Connection of transports
    168 	 */
    169 	unsigned long		connect_timeout,
    170 				bind_timeout,
    171 				reestablish_timeout;
    172 	struct work_struct	connect_worker;
    173 	unsigned short		port;
    174 
    175 	/*
    176 	 * Disconnection of idle transports
    177 	 */
    178 	struct work_struct	task_cleanup;
    179 	struct timer_list	timer;
    180 	unsigned long		last_used,
    181 				idle_timeout;
    182 
    183 	/*
    184 	 * Send stuff
    185 	 */
    186 	spinlock_t		transport_lock;	/* lock transport info */
    187 	spinlock_t		reserve_lock;	/* lock slot table */
    188 	struct rpc_task *	snd_task;	/* Task blocked in send */
    189 
    190 	struct list_head	recv;
    191 
    192 	struct {
    193 		unsigned long		bind_count,	/* total number of binds */
    194 					connect_count,	/* total number of connects */
    195 					connect_start,	/* connect start timestamp */
    196 					connect_time,	/* jiffies waiting for connect */
    197 					sends,		/* how many complete requests */
    198 					recvs,		/* how many complete requests */
    199 					bad_xids;	/* lookup_rqst didn't find XID */
    200 
    201 		unsigned long long	req_u,		/* average requests on the wire */
    202 					bklog_u;	/* backlog queue utilization */
    203 	} stat;
    204 
    205 	void			(*old_data_ready)(struct sock *, int);
    206 	void			(*old_state_change)(struct sock *);
    207 	void			(*old_write_space)(struct sock *);
    208 };
    209 
    210 #define XPRT_LAST_FRAG		(1 << 0)
    211 #define XPRT_COPY_RECM		(1 << 1)
    212 #define XPRT_COPY_XID		(1 << 2)
    213 #define XPRT_COPY_DATA		(1 << 3)
    214 
    215 #ifdef __KERNEL__
    216 
    217 /*
    218  * Transport operations used by ULPs
    219  */
    220 struct rpc_xprt *	xprt_create_proto(int proto, struct sockaddr_in *addr, struct rpc_timeout *to);
    221 void			xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr);
    222 
    223 /*
    224  * Generic internal transport functions
    225  */
    226 void			xprt_connect(struct rpc_task *task);
    227 void			xprt_reserve(struct rpc_task *task);
    228 int			xprt_reserve_xprt(struct rpc_task *task);
    229 int			xprt_reserve_xprt_cong(struct rpc_task *task);
    230 int			xprt_prepare_transmit(struct rpc_task *task);
    231 void			xprt_transmit(struct rpc_task *task);
    232 void			xprt_end_transmit(struct rpc_task *task);
    233 int			xprt_adjust_timeout(struct rpc_rqst *req);
    234 void			xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
    235 void			xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
    236 void			xprt_release(struct rpc_task *task);
    237 int			xprt_destroy(struct rpc_xprt *xprt);
    238 
    239 static inline u32 *xprt_skip_transport_header(struct rpc_xprt *xprt, u32 *p)
    240 {
    241 	return p + xprt->tsh_size;
    242 }
    243 
    244 /*
    245  * Transport switch helper functions
    246  */
    247 void			xprt_set_retrans_timeout_def(struct rpc_task *task);
    248 void			xprt_set_retrans_timeout_rtt(struct rpc_task *task);
    249 void			xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
    250 void			xprt_wait_for_buffer_space(struct rpc_task *task);
    251 void			xprt_write_space(struct rpc_xprt *xprt);
    252 void			xprt_update_rtt(struct rpc_task *task);
    253 void			xprt_adjust_cwnd(struct rpc_task *task, int result);
    254 struct rpc_rqst *	xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid);
    255 void			xprt_complete_rqst(struct rpc_task *task, int copied);
    256 void			xprt_release_rqst_cong(struct rpc_task *task);
    257 void			xprt_disconnect(struct rpc_xprt *xprt);
    258 
    259 /*
    260  * Socket transport setup operations
    261  */
    262 int			xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to);
    263 int			xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to);
    264 
    265 /*
    266  * Reserved bit positions in xprt->state
    267  */
    268 #define XPRT_LOCKED		(0)
    269 #define XPRT_CONNECTED		(1)
    270 #define XPRT_CONNECTING		(2)
    271 #define XPRT_CLOSE_WAIT		(3)
    272 
    273 static inline void xprt_set_connected(struct rpc_xprt *xprt)
    274 {
    275 	set_bit(XPRT_CONNECTED, &xprt->state);
    276 }
    277 
    278 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
    279 {
    280 	clear_bit(XPRT_CONNECTED, &xprt->state);
    281 }
    282 
    283 static inline int xprt_connected(struct rpc_xprt *xprt)
    284 {
    285 	return test_bit(XPRT_CONNECTED, &xprt->state);
    286 }
    287 
    288 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
    289 {
    290 	return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
    291 }
    292 
    293 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
    294 {
    295 	return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
    296 }
    297 
    298 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
    299 {
    300 	smp_mb__before_clear_bit();
    301 	clear_bit(XPRT_CONNECTING, &xprt->state);
    302 	smp_mb__after_clear_bit();
    303 }
    304 
    305 static inline int xprt_connecting(struct rpc_xprt *xprt)
    306 {
    307 	return test_bit(XPRT_CONNECTING, &xprt->state);
    308 }
    309 
    310 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
    311 {
    312 	return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
    313 }
    314 
    315 #endif /* __KERNEL__*/
    316 
    317 #endif /* _LINUX_SUNRPC_XPRT_H */
    318