xref: /linux-6.15/include/linux/sunrpc/xprt.h (revision e11da5b4)
1 /*
2  *  linux/include/linux/sunrpc/xprt.h
3  *
4  *  Declarations for the RPC transport interface.
5  *
6  *  Copyright (C) 1995, 1996 Olaf Kirch <[email protected]>
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/kref.h>
16 #include <linux/ktime.h>
17 #include <linux/sunrpc/sched.h>
18 #include <linux/sunrpc/xdr.h>
19 #include <linux/sunrpc/msg_prot.h>
20 
21 #ifdef __KERNEL__
22 
23 #define RPC_MIN_SLOT_TABLE	(2U)
24 #define RPC_DEF_SLOT_TABLE	(16U)
25 #define RPC_MAX_SLOT_TABLE	(128U)
26 
27 /*
28  * This describes a timeout strategy
29  */
30 struct rpc_timeout {
31 	unsigned long		to_initval,		/* initial timeout */
32 				to_maxval,		/* max timeout */
33 				to_increment;		/* if !exponential */
34 	unsigned int		to_retries;		/* max # of retries */
35 	unsigned char		to_exponential;
36 };
37 
38 enum rpc_display_format_t {
39 	RPC_DISPLAY_ADDR = 0,
40 	RPC_DISPLAY_PORT,
41 	RPC_DISPLAY_PROTO,
42 	RPC_DISPLAY_HEX_ADDR,
43 	RPC_DISPLAY_HEX_PORT,
44 	RPC_DISPLAY_NETID,
45 	RPC_DISPLAY_MAX,
46 };
47 
48 struct rpc_task;
49 struct rpc_xprt;
50 struct seq_file;
51 
52 /*
53  * This describes a complete RPC request
54  */
55 struct rpc_rqst {
56 	/*
57 	 * This is the user-visible part
58 	 */
59 	struct rpc_xprt *	rq_xprt;		/* RPC client */
60 	struct xdr_buf		rq_snd_buf;		/* send buffer */
61 	struct xdr_buf		rq_rcv_buf;		/* recv buffer */
62 
63 	/*
64 	 * This is the private part
65 	 */
66 	struct rpc_task *	rq_task;	/* RPC task data */
67 	struct rpc_cred *	rq_cred;	/* Bound cred */
68 	__be32			rq_xid;		/* request XID */
69 	int			rq_cong;	/* has incremented xprt->cong */
70 	u32			rq_seqno;	/* gss seq no. used on req. */
71 	int			rq_enc_pages_num;
72 	struct page		**rq_enc_pages;	/* scratch pages for use by
73 						   gss privacy code */
74 	void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
75 	struct list_head	rq_list;
76 
77 	__u32 *			rq_buffer;	/* XDR encode buffer */
78 	size_t			rq_callsize,
79 				rq_rcvsize;
80 	size_t			rq_xmit_bytes_sent;	/* total bytes sent */
81 	size_t			rq_reply_bytes_recvd;	/* total reply bytes */
82 							/* received */
83 
84 	struct xdr_buf		rq_private_buf;		/* The receive buffer
85 							 * used in the softirq.
86 							 */
87 	unsigned long		rq_majortimeo;	/* major timeout alarm */
88 	unsigned long		rq_timeout;	/* Current timeout value */
89 	ktime_t			rq_rtt;		/* round-trip time */
90 	unsigned int		rq_retries;	/* # of retries */
91 	unsigned int		rq_connect_cookie;
92 						/* A cookie used to track the
93 						   state of the transport
94 						   connection */
95 
96 	/*
97 	 * Partial send handling
98 	 */
99 	u32			rq_bytes_sent;	/* Bytes we have sent */
100 
101 	ktime_t			rq_xtime;	/* transmit time stamp */
102 	int			rq_ntrans;
103 
104 #if defined(CONFIG_NFS_V4_1)
105 	struct list_head	rq_bc_list;	/* Callback service list */
106 	unsigned long		rq_bc_pa_state;	/* Backchannel prealloc state */
107 	struct list_head	rq_bc_pa_list;	/* Backchannel prealloc list */
108 #endif /* CONFIG_NFS_V4_1 */
109 };
110 #define rq_svec			rq_snd_buf.head
111 #define rq_slen			rq_snd_buf.len
112 
113 struct rpc_xprt_ops {
114 	void		(*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
115 	int		(*reserve_xprt)(struct rpc_task *task);
116 	void		(*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
117 	void		(*rpcbind)(struct rpc_task *task);
118 	void		(*set_port)(struct rpc_xprt *xprt, unsigned short port);
119 	void		(*connect)(struct rpc_task *task);
120 	void *		(*buf_alloc)(struct rpc_task *task, size_t size);
121 	void		(*buf_free)(void *buffer);
122 	int		(*send_request)(struct rpc_task *task);
123 	void		(*set_retrans_timeout)(struct rpc_task *task);
124 	void		(*timer)(struct rpc_task *task);
125 	void		(*release_request)(struct rpc_task *task);
126 	void		(*close)(struct rpc_xprt *xprt);
127 	void		(*destroy)(struct rpc_xprt *xprt);
128 	void		(*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
129 };
130 
131 /*
132  * RPC transport identifiers
133  *
134  * To preserve compatibility with the historical use of raw IP protocol
135  * id's for transport selection, UDP and TCP identifiers are specified
136  * with the previous values. No such restriction exists for new transports,
137  * except that they may not collide with these values (17 and 6,
138  * respectively).
139  */
140 #define XPRT_TRANSPORT_BC       (1 << 31)
141 enum xprt_transports {
142 	XPRT_TRANSPORT_UDP	= IPPROTO_UDP,
143 	XPRT_TRANSPORT_TCP	= IPPROTO_TCP,
144 	XPRT_TRANSPORT_BC_TCP	= IPPROTO_TCP | XPRT_TRANSPORT_BC,
145 	XPRT_TRANSPORT_RDMA	= 256
146 };
147 
148 struct rpc_xprt {
149 	struct kref		kref;		/* Reference count */
150 	struct rpc_xprt_ops *	ops;		/* transport methods */
151 
152 	const struct rpc_timeout *timeout;	/* timeout parms */
153 	struct sockaddr_storage	addr;		/* server address */
154 	size_t			addrlen;	/* size of server address */
155 	int			prot;		/* IP protocol */
156 
157 	unsigned long		cong;		/* current congestion */
158 	unsigned long		cwnd;		/* congestion window */
159 
160 	size_t			max_payload;	/* largest RPC payload size,
161 						   in bytes */
162 	unsigned int		tsh_size;	/* size of transport specific
163 						   header */
164 
165 	struct rpc_wait_queue	binding;	/* requests waiting on rpcbind */
166 	struct rpc_wait_queue	sending;	/* requests waiting to send */
167 	struct rpc_wait_queue	resend;		/* requests waiting to resend */
168 	struct rpc_wait_queue	pending;	/* requests in flight */
169 	struct rpc_wait_queue	backlog;	/* waiting for slot */
170 	struct list_head	free;		/* free slots */
171 	struct rpc_rqst *	slot;		/* slot table storage */
172 	unsigned int		max_reqs;	/* total slots */
173 	unsigned long		state;		/* transport state */
174 	unsigned char		shutdown   : 1,	/* being shut down */
175 				resvport   : 1; /* use a reserved port */
176 	unsigned int		bind_index;	/* bind function index */
177 
178 	/*
179 	 * Connection of transports
180 	 */
181 	unsigned long		bind_timeout,
182 				reestablish_timeout;
183 	unsigned int		connect_cookie;	/* A cookie that gets bumped
184 						   every time the transport
185 						   is reconnected */
186 
187 	/*
188 	 * Disconnection of idle transports
189 	 */
190 	struct work_struct	task_cleanup;
191 	struct timer_list	timer;
192 	unsigned long		last_used,
193 				idle_timeout;
194 
195 	/*
196 	 * Send stuff
197 	 */
198 	spinlock_t		transport_lock;	/* lock transport info */
199 	spinlock_t		reserve_lock;	/* lock slot table */
200 	u32			xid;		/* Next XID value to use */
201 	struct rpc_task *	snd_task;	/* Task blocked in send */
202 	struct svc_xprt		*bc_xprt;	/* NFSv4.1 backchannel */
203 #if defined(CONFIG_NFS_V4_1)
204 	struct svc_serv		*bc_serv;       /* The RPC service which will */
205 						/* process the callback */
206 	unsigned int		bc_alloc_count;	/* Total number of preallocs */
207 	spinlock_t		bc_pa_lock;	/* Protects the preallocated
208 						 * items */
209 	struct list_head	bc_pa_list;	/* List of preallocated
210 						 * backchannel rpc_rqst's */
211 #endif /* CONFIG_NFS_V4_1 */
212 	struct list_head	recv;
213 
214 	struct {
215 		unsigned long		bind_count,	/* total number of binds */
216 					connect_count,	/* total number of connects */
217 					connect_start,	/* connect start timestamp */
218 					connect_time,	/* jiffies waiting for connect */
219 					sends,		/* how many complete requests */
220 					recvs,		/* how many complete requests */
221 					bad_xids;	/* lookup_rqst didn't find XID */
222 
223 		unsigned long long	req_u,		/* average requests on the wire */
224 					bklog_u;	/* backlog queue utilization */
225 	} stat;
226 
227 	struct net		*xprt_net;
228 	const char		*address_strings[RPC_DISPLAY_MAX];
229 };
230 
231 #if defined(CONFIG_NFS_V4_1)
232 /*
233  * Backchannel flags
234  */
235 #define	RPC_BC_PA_IN_USE	0x0001		/* Preallocated backchannel */
236 						/* buffer in use */
237 #endif /* CONFIG_NFS_V4_1 */
238 
239 #if defined(CONFIG_NFS_V4_1)
240 static inline int bc_prealloc(struct rpc_rqst *req)
241 {
242 	return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
243 }
244 #else
245 static inline int bc_prealloc(struct rpc_rqst *req)
246 {
247 	return 0;
248 }
249 #endif /* CONFIG_NFS_V4_1 */
250 
251 struct xprt_create {
252 	int			ident;		/* XPRT_TRANSPORT identifier */
253 	struct net *		net;
254 	struct sockaddr *	srcaddr;	/* optional local address */
255 	struct sockaddr *	dstaddr;	/* remote peer address */
256 	size_t			addrlen;
257 	struct svc_xprt		*bc_xprt;	/* NFSv4.1 backchannel */
258 };
259 
260 struct xprt_class {
261 	struct list_head	list;
262 	int			ident;		/* XPRT_TRANSPORT identifier */
263 	struct rpc_xprt *	(*setup)(struct xprt_create *);
264 	struct module		*owner;
265 	char			name[32];
266 };
267 
268 /*
269  * Generic internal transport functions
270  */
271 struct rpc_xprt		*xprt_create_transport(struct xprt_create *args);
272 void			xprt_connect(struct rpc_task *task);
273 void			xprt_reserve(struct rpc_task *task);
274 int			xprt_reserve_xprt(struct rpc_task *task);
275 int			xprt_reserve_xprt_cong(struct rpc_task *task);
276 int			xprt_prepare_transmit(struct rpc_task *task);
277 void			xprt_transmit(struct rpc_task *task);
278 void			xprt_end_transmit(struct rpc_task *task);
279 int			xprt_adjust_timeout(struct rpc_rqst *req);
280 void			xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
281 void			xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
282 void			xprt_release(struct rpc_task *task);
283 struct rpc_xprt *	xprt_get(struct rpc_xprt *xprt);
284 void			xprt_put(struct rpc_xprt *xprt);
285 struct rpc_xprt *	xprt_alloc(struct net *net, int size, int max_req);
286 void			xprt_free(struct rpc_xprt *);
287 
288 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
289 {
290 	return p + xprt->tsh_size;
291 }
292 
293 /*
294  * Transport switch helper functions
295  */
296 int			xprt_register_transport(struct xprt_class *type);
297 int			xprt_unregister_transport(struct xprt_class *type);
298 int			xprt_load_transport(const char *);
299 void			xprt_set_retrans_timeout_def(struct rpc_task *task);
300 void			xprt_set_retrans_timeout_rtt(struct rpc_task *task);
301 void			xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
302 void			xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
303 void			xprt_write_space(struct rpc_xprt *xprt);
304 void			xprt_adjust_cwnd(struct rpc_task *task, int result);
305 struct rpc_rqst *	xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
306 void			xprt_complete_rqst(struct rpc_task *task, int copied);
307 void			xprt_release_rqst_cong(struct rpc_task *task);
308 void			xprt_disconnect_done(struct rpc_xprt *xprt);
309 void			xprt_force_disconnect(struct rpc_xprt *xprt);
310 void			xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
311 
312 /*
313  * Reserved bit positions in xprt->state
314  */
315 #define XPRT_LOCKED		(0)
316 #define XPRT_CONNECTED		(1)
317 #define XPRT_CONNECTING		(2)
318 #define XPRT_CLOSE_WAIT		(3)
319 #define XPRT_BOUND		(4)
320 #define XPRT_BINDING		(5)
321 #define XPRT_CLOSING		(6)
322 #define XPRT_CONNECTION_ABORT	(7)
323 #define XPRT_CONNECTION_CLOSE	(8)
324 
325 static inline void xprt_set_connected(struct rpc_xprt *xprt)
326 {
327 	set_bit(XPRT_CONNECTED, &xprt->state);
328 }
329 
330 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
331 {
332 	clear_bit(XPRT_CONNECTED, &xprt->state);
333 }
334 
335 static inline int xprt_connected(struct rpc_xprt *xprt)
336 {
337 	return test_bit(XPRT_CONNECTED, &xprt->state);
338 }
339 
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 
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 
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 
357 static inline int xprt_connecting(struct rpc_xprt *xprt)
358 {
359 	return test_bit(XPRT_CONNECTING, &xprt->state);
360 }
361 
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 
367 static inline void xprt_set_bound(struct rpc_xprt *xprt)
368 {
369 	test_and_set_bit(XPRT_BOUND, &xprt->state);
370 }
371 
372 static inline int xprt_bound(struct rpc_xprt *xprt)
373 {
374 	return test_bit(XPRT_BOUND, &xprt->state);
375 }
376 
377 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
378 {
379 	clear_bit(XPRT_BOUND, &xprt->state);
380 }
381 
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 
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