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@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/ktime.h>
16 #include <linux/sunrpc/sched.h>
17 #include <linux/sunrpc/xdr.h>
18 #include <linux/sunrpc/msg_prot.h>
19 
20 #ifdef __KERNEL__
21 
22 #define RPC_MIN_SLOT_TABLE	(2U)
23 #define RPC_DEF_SLOT_TABLE	(16U)
24 #define RPC_MAX_SLOT_TABLE	(128U)
25 
26 /*
27  * This describes a timeout strategy
28  */
29 struct rpc_timeout {
30 	unsigned long		to_initval,		/* initial timeout */
31 				to_maxval,		/* max timeout */
32 				to_increment;		/* if !exponential */
33 	unsigned int		to_retries;		/* max # of retries */
34 	unsigned char		to_exponential;
35 };
36 
37 enum rpc_display_format_t {
38 	RPC_DISPLAY_ADDR = 0,
39 	RPC_DISPLAY_PORT,
40 	RPC_DISPLAY_PROTO,
41 	RPC_DISPLAY_HEX_ADDR,
42 	RPC_DISPLAY_HEX_PORT,
43 	RPC_DISPLAY_NETID,
44 	RPC_DISPLAY_MAX,
45 };
46 
47 struct rpc_task;
48 struct rpc_xprt;
49 struct seq_file;
50 
51 /*
52  * This describes a complete RPC request
53  */
54 struct rpc_rqst {
55 	/*
56 	 * This is the user-visible part
57 	 */
58 	struct rpc_xprt *	rq_xprt;		/* RPC client */
59 	struct xdr_buf		rq_snd_buf;		/* send buffer */
60 	struct xdr_buf		rq_rcv_buf;		/* recv buffer */
61 
62 	/*
63 	 * This is the private part
64 	 */
65 	struct rpc_task *	rq_task;	/* RPC task data */
66 	struct rpc_cred *	rq_cred;	/* Bound cred */
67 	__be32			rq_xid;		/* request XID */
68 	int			rq_cong;	/* has incremented xprt->cong */
69 	u32			rq_seqno;	/* gss seq no. used on req. */
70 	int			rq_enc_pages_num;
71 	struct page		**rq_enc_pages;	/* scratch pages for use by
72 						   gss privacy code */
73 	void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
74 	struct list_head	rq_list;
75 
76 	__u32 *			rq_buffer;	/* XDR encode buffer */
77 	size_t			rq_callsize,
78 				rq_rcvsize;
79 	size_t			rq_xmit_bytes_sent;	/* total bytes sent */
80 	size_t			rq_reply_bytes_recvd;	/* total reply bytes */
81 							/* received */
82 
83 	struct xdr_buf		rq_private_buf;		/* The receive buffer
84 							 * used in the softirq.
85 							 */
86 	unsigned long		rq_majortimeo;	/* major timeout alarm */
87 	unsigned long		rq_timeout;	/* Current timeout value */
88 	ktime_t			rq_rtt;		/* round-trip time */
89 	unsigned int		rq_retries;	/* # of retries */
90 	unsigned int		rq_connect_cookie;
91 						/* A cookie used to track the
92 						   state of the transport
93 						   connection */
94 
95 	/*
96 	 * Partial send handling
97 	 */
98 	u32			rq_bytes_sent;	/* Bytes we have sent */
99 
100 	ktime_t			rq_xtime;	/* transmit time stamp */
101 	int			rq_ntrans;
102 
103 #if defined(CONFIG_NFS_V4_1)
104 	struct list_head	rq_bc_list;	/* Callback service list */
105 	unsigned long		rq_bc_pa_state;	/* Backchannel prealloc state */
106 	struct list_head	rq_bc_pa_list;	/* Backchannel prealloc list */
107 #endif /* CONFIG_NFS_V4_1 */
108 };
109 #define rq_svec			rq_snd_buf.head
110 #define rq_slen			rq_snd_buf.len
111 
112 struct rpc_xprt_ops {
113 	void		(*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
114 	int		(*reserve_xprt)(struct rpc_task *task);
115 	void		(*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
116 	void		(*rpcbind)(struct rpc_task *task);
117 	void		(*set_port)(struct rpc_xprt *xprt, unsigned short port);
118 	void		(*connect)(struct rpc_task *task);
119 	void *		(*buf_alloc)(struct rpc_task *task, size_t size);
120 	void		(*buf_free)(void *buffer);
121 	int		(*send_request)(struct rpc_task *task);
122 	void		(*set_retrans_timeout)(struct rpc_task *task);
123 	void		(*timer)(struct rpc_task *task);
124 	void		(*release_request)(struct rpc_task *task);
125 	void		(*close)(struct rpc_xprt *xprt);
126 	void		(*destroy)(struct rpc_xprt *xprt);
127 	void		(*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
128 };
129 
130 /*
131  * RPC transport identifiers
132  *
133  * To preserve compatibility with the historical use of raw IP protocol
134  * id's for transport selection, UDP and TCP identifiers are specified
135  * with the previous values. No such restriction exists for new transports,
136  * except that they may not collide with these values (17 and 6,
137  * respectively).
138  */
139 #define XPRT_TRANSPORT_BC       (1 << 31)
140 enum xprt_transports {
141 	XPRT_TRANSPORT_UDP	= IPPROTO_UDP,
142 	XPRT_TRANSPORT_TCP	= IPPROTO_TCP,
143 	XPRT_TRANSPORT_BC_TCP	= IPPROTO_TCP | XPRT_TRANSPORT_BC,
144 	XPRT_TRANSPORT_RDMA	= 256
145 };
146 
147 struct rpc_xprt {
148 	atomic_t		count;		/* Reference count */
149 	struct rpc_xprt_ops *	ops;		/* transport methods */
150 
151 	const struct rpc_timeout *timeout;	/* timeout parms */
152 	struct sockaddr_storage	addr;		/* server address */
153 	size_t			addrlen;	/* size of server address */
154 	int			prot;		/* IP protocol */
155 
156 	unsigned long		cong;		/* current congestion */
157 	unsigned long		cwnd;		/* congestion window */
158 
159 	size_t			max_payload;	/* largest RPC payload size,
160 						   in bytes */
161 	unsigned int		tsh_size;	/* size of transport specific
162 						   header */
163 
164 	struct rpc_wait_queue	binding;	/* requests waiting on rpcbind */
165 	struct rpc_wait_queue	sending;	/* requests waiting to send */
166 	struct rpc_wait_queue	resend;		/* requests waiting to resend */
167 	struct rpc_wait_queue	pending;	/* requests in flight */
168 	struct rpc_wait_queue	backlog;	/* waiting for slot */
169 	struct list_head	free;		/* free slots */
170 	struct rpc_rqst *	slot;		/* slot table storage */
171 	unsigned int		max_reqs;	/* total slots */
172 	unsigned long		state;		/* transport state */
173 	unsigned char		shutdown   : 1,	/* being shut down */
174 				resvport   : 1; /* use a reserved port */
175 	unsigned int		bind_index;	/* bind function index */
176 
177 	/*
178 	 * Connection of transports
179 	 */
180 	unsigned long		bind_timeout,
181 				reestablish_timeout;
182 	unsigned int		connect_cookie;	/* A cookie that gets bumped
183 						   every time the transport
184 						   is reconnected */
185 
186 	/*
187 	 * Disconnection of idle transports
188 	 */
189 	struct work_struct	task_cleanup;
190 	struct timer_list	timer;
191 	unsigned long		last_used,
192 				idle_timeout;
193 
194 	/*
195 	 * Send stuff
196 	 */
197 	spinlock_t		transport_lock;	/* lock transport info */
198 	spinlock_t		reserve_lock;	/* lock slot table */
199 	u32			xid;		/* Next XID value to use */
200 	struct rpc_task *	snd_task;	/* Task blocked in send */
201 	struct svc_xprt		*bc_xprt;	/* NFSv4.1 backchannel */
202 #if defined(CONFIG_NFS_V4_1)
203 	struct svc_serv		*bc_serv;       /* The RPC service which will */
204 						/* process the callback */
205 	unsigned int		bc_alloc_count;	/* Total number of preallocs */
206 	spinlock_t		bc_pa_lock;	/* Protects the preallocated
207 						 * items */
208 	struct list_head	bc_pa_list;	/* List of preallocated
209 						 * backchannel rpc_rqst's */
210 #endif /* CONFIG_NFS_V4_1 */
211 	struct list_head	recv;
212 
213 	struct {
214 		unsigned long		bind_count,	/* total number of binds */
215 					connect_count,	/* total number of connects */
216 					connect_start,	/* connect start timestamp */
217 					connect_time,	/* jiffies waiting for connect */
218 					sends,		/* how many complete requests */
219 					recvs,		/* how many complete requests */
220 					bad_xids;	/* lookup_rqst didn't find XID */
221 
222 		unsigned long long	req_u,		/* average requests on the wire */
223 					bklog_u;	/* backlog queue utilization */
224 	} stat;
225 
226 	struct net		*xprt_net;
227 	const char		*address_strings[RPC_DISPLAY_MAX];
228 };
229 
230 #if defined(CONFIG_NFS_V4_1)
231 /*
232  * Backchannel flags
233  */
234 #define	RPC_BC_PA_IN_USE	0x0001		/* Preallocated backchannel */
235 						/* buffer in use */
236 #endif /* CONFIG_NFS_V4_1 */
237 
238 #if defined(CONFIG_NFS_V4_1)
bc_prealloc(struct rpc_rqst * req)239 static inline int bc_prealloc(struct rpc_rqst *req)
240 {
241 	return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
242 }
243 #else
bc_prealloc(struct rpc_rqst * req)244 static inline int bc_prealloc(struct rpc_rqst *req)
245 {
246 	return 0;
247 }
248 #endif /* CONFIG_NFS_V4_1 */
249 
250 struct xprt_create {
251 	int			ident;		/* XPRT_TRANSPORT identifier */
252 	struct net *		net;
253 	struct sockaddr *	srcaddr;	/* optional local address */
254 	struct sockaddr *	dstaddr;	/* remote peer address */
255 	size_t			addrlen;
256 	struct svc_xprt		*bc_xprt;	/* NFSv4.1 backchannel */
257 };
258 
259 struct xprt_class {
260 	struct list_head	list;
261 	int			ident;		/* XPRT_TRANSPORT identifier */
262 	struct rpc_xprt *	(*setup)(struct xprt_create *);
263 	struct module		*owner;
264 	char			name[32];
265 };
266 
267 /*
268  * Generic internal transport functions
269  */
270 struct rpc_xprt		*xprt_create_transport(struct xprt_create *args);
271 void			xprt_connect(struct rpc_task *task);
272 void			xprt_reserve(struct rpc_task *task);
273 int			xprt_reserve_xprt(struct rpc_task *task);
274 int			xprt_reserve_xprt_cong(struct rpc_task *task);
275 int			xprt_prepare_transmit(struct rpc_task *task);
276 void			xprt_transmit(struct rpc_task *task);
277 void			xprt_end_transmit(struct rpc_task *task);
278 int			xprt_adjust_timeout(struct rpc_rqst *req);
279 void			xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
280 void			xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
281 void			xprt_release(struct rpc_task *task);
282 struct rpc_xprt *	xprt_get(struct rpc_xprt *xprt);
283 void			xprt_put(struct rpc_xprt *xprt);
284 struct rpc_xprt *	xprt_alloc(struct net *net, int size, int max_req);
285 void			xprt_free(struct rpc_xprt *);
286 
xprt_skip_transport_header(struct rpc_xprt * xprt,__be32 * p)287 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
288 {
289 	return p + xprt->tsh_size;
290 }
291 
292 /*
293  * Transport switch helper functions
294  */
295 int			xprt_register_transport(struct xprt_class *type);
296 int			xprt_unregister_transport(struct xprt_class *type);
297 int			xprt_load_transport(const char *);
298 void			xprt_set_retrans_timeout_def(struct rpc_task *task);
299 void			xprt_set_retrans_timeout_rtt(struct rpc_task *task);
300 void			xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
301 void			xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
302 void			xprt_write_space(struct rpc_xprt *xprt);
303 void			xprt_adjust_cwnd(struct rpc_task *task, int result);
304 struct rpc_rqst *	xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
305 void			xprt_complete_rqst(struct rpc_task *task, int copied);
306 void			xprt_release_rqst_cong(struct rpc_task *task);
307 void			xprt_disconnect_done(struct rpc_xprt *xprt);
308 void			xprt_force_disconnect(struct rpc_xprt *xprt);
309 void			xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
310 
311 /*
312  * Reserved bit positions in xprt->state
313  */
314 #define XPRT_LOCKED		(0)
315 #define XPRT_CONNECTED		(1)
316 #define XPRT_CONNECTING		(2)
317 #define XPRT_CLOSE_WAIT		(3)
318 #define XPRT_BOUND		(4)
319 #define XPRT_BINDING		(5)
320 #define XPRT_CLOSING		(6)
321 #define XPRT_CONNECTION_ABORT	(7)
322 #define XPRT_CONNECTION_CLOSE	(8)
323 #define XPRT_INITIALIZED	(9)
324 
xprt_set_connected(struct rpc_xprt * xprt)325 static inline void xprt_set_connected(struct rpc_xprt *xprt)
326 {
327 	set_bit(XPRT_CONNECTED, &xprt->state);
328 }
329 
xprt_clear_connected(struct rpc_xprt * xprt)330 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
331 {
332 	clear_bit(XPRT_CONNECTED, &xprt->state);
333 }
334 
xprt_connected(struct rpc_xprt * xprt)335 static inline int xprt_connected(struct rpc_xprt *xprt)
336 {
337 	return test_bit(XPRT_CONNECTED, &xprt->state);
338 }
339 
xprt_test_and_set_connected(struct rpc_xprt * xprt)340 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
341 {
342 	return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
343 }
344 
xprt_test_and_clear_connected(struct rpc_xprt * xprt)345 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
346 {
347 	return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
348 }
349 
xprt_clear_connecting(struct rpc_xprt * xprt)350 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
351 {
352 	smp_mb__before_clear_bit();
353 	clear_bit(XPRT_CONNECTING, &xprt->state);
354 	smp_mb__after_clear_bit();
355 }
356 
xprt_connecting(struct rpc_xprt * xprt)357 static inline int xprt_connecting(struct rpc_xprt *xprt)
358 {
359 	return test_bit(XPRT_CONNECTING, &xprt->state);
360 }
361 
xprt_test_and_set_connecting(struct rpc_xprt * xprt)362 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
363 {
364 	return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
365 }
366 
xprt_set_bound(struct rpc_xprt * xprt)367 static inline void xprt_set_bound(struct rpc_xprt *xprt)
368 {
369 	test_and_set_bit(XPRT_BOUND, &xprt->state);
370 }
371 
xprt_bound(struct rpc_xprt * xprt)372 static inline int xprt_bound(struct rpc_xprt *xprt)
373 {
374 	return test_bit(XPRT_BOUND, &xprt->state);
375 }
376 
xprt_clear_bound(struct rpc_xprt * xprt)377 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
378 {
379 	clear_bit(XPRT_BOUND, &xprt->state);
380 }
381 
xprt_clear_binding(struct rpc_xprt * xprt)382 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
383 {
384 	smp_mb__before_clear_bit();
385 	clear_bit(XPRT_BINDING, &xprt->state);
386 	smp_mb__after_clear_bit();
387 }
388 
xprt_test_and_set_binding(struct rpc_xprt * xprt)389 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
390 {
391 	return test_and_set_bit(XPRT_BINDING, &xprt->state);
392 }
393 
394 #endif /* __KERNEL__*/
395 
396 #endif /* _LINUX_SUNRPC_XPRT_H */
397