1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * linux/include/linux/sunrpc/xprt.h
4 *
5 * Declarations for the RPC transport interface.
6 *
7 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
8 */
9
10 #ifndef _LINUX_SUNRPC_XPRT_H
11 #define _LINUX_SUNRPC_XPRT_H
12
13 #include <linux/uio.h>
14 #include <linux/socket.h>
15 #include <linux/in.h>
16 #include <linux/ktime.h>
17 #include <linux/kref.h>
18 #include <linux/sunrpc/sched.h>
19 #include <linux/sunrpc/xdr.h>
20 #include <linux/sunrpc/msg_prot.h>
21
22 #ifdef __KERNEL__
23
24 #define RPC_MIN_SLOT_TABLE (2U)
25 #define RPC_DEF_SLOT_TABLE (16U)
26 #define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
27 #define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
28
29 #define RPC_CWNDSHIFT (8U)
30 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
31 #define RPC_INITCWND RPC_CWNDSCALE
32 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
33 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
34
35 /*
36 * This describes a timeout strategy
37 */
38 struct rpc_timeout {
39 unsigned long to_initval, /* initial timeout */
40 to_maxval, /* max timeout */
41 to_increment; /* if !exponential */
42 unsigned int to_retries; /* max # of retries */
43 unsigned char to_exponential;
44 };
45
46 enum rpc_display_format_t {
47 RPC_DISPLAY_ADDR = 0,
48 RPC_DISPLAY_PORT,
49 RPC_DISPLAY_PROTO,
50 RPC_DISPLAY_HEX_ADDR,
51 RPC_DISPLAY_HEX_PORT,
52 RPC_DISPLAY_NETID,
53 RPC_DISPLAY_MAX,
54 };
55
56 struct rpc_task;
57 struct rpc_xprt;
58 struct seq_file;
59 struct svc_serv;
60 struct net;
61
62 /*
63 * This describes a complete RPC request
64 */
65 struct rpc_rqst {
66 /*
67 * This is the user-visible part
68 */
69 struct rpc_xprt * rq_xprt; /* RPC client */
70 struct xdr_buf rq_snd_buf; /* send buffer */
71 struct xdr_buf rq_rcv_buf; /* recv buffer */
72
73 /*
74 * This is the private part
75 */
76 struct rpc_task * rq_task; /* RPC task data */
77 struct rpc_cred * rq_cred; /* Bound cred */
78 __be32 rq_xid; /* request XID */
79 int rq_cong; /* has incremented xprt->cong */
80 u32 rq_seqno; /* gss seq no. used on req. */
81 int rq_enc_pages_num;
82 struct page **rq_enc_pages; /* scratch pages for use by
83 gss privacy code */
84 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
85 struct list_head rq_list;
86
87 void *rq_buffer; /* Call XDR encode buffer */
88 size_t rq_callsize;
89 void *rq_rbuffer; /* Reply XDR decode buffer */
90 size_t rq_rcvsize;
91 size_t rq_xmit_bytes_sent; /* total bytes sent */
92 size_t rq_reply_bytes_recvd; /* total reply bytes */
93 /* received */
94
95 struct xdr_buf rq_private_buf; /* The receive buffer
96 * used in the softirq.
97 */
98 unsigned long rq_majortimeo; /* major timeout alarm */
99 unsigned long rq_timeout; /* Current timeout value */
100 ktime_t rq_rtt; /* round-trip time */
101 unsigned int rq_retries; /* # of retries */
102 unsigned int rq_connect_cookie;
103 /* A cookie used to track the
104 state of the transport
105 connection */
106
107 /*
108 * Partial send handling
109 */
110 u32 rq_bytes_sent; /* Bytes we have sent */
111
112 ktime_t rq_xtime; /* transmit time stamp */
113 int rq_ntrans;
114
115 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
116 struct list_head rq_bc_list; /* Callback service list */
117 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
118 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
119 #endif /* CONFIG_SUNRPC_BACKCHANEL */
120 };
121 #define rq_svec rq_snd_buf.head
122 #define rq_slen rq_snd_buf.len
123
124 struct rpc_xprt_ops {
125 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
126 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
127 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
128 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
129 void (*free_slot)(struct rpc_xprt *xprt,
130 struct rpc_rqst *req);
131 void (*rpcbind)(struct rpc_task *task);
132 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
133 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
134 int (*buf_alloc)(struct rpc_task *task);
135 void (*buf_free)(struct rpc_task *task);
136 int (*send_request)(struct rpc_task *task);
137 void (*set_retrans_timeout)(struct rpc_task *task);
138 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
139 void (*release_request)(struct rpc_task *task);
140 void (*close)(struct rpc_xprt *xprt);
141 void (*destroy)(struct rpc_xprt *xprt);
142 void (*set_connect_timeout)(struct rpc_xprt *xprt,
143 unsigned long connect_timeout,
144 unsigned long reconnect_timeout);
145 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
146 int (*enable_swap)(struct rpc_xprt *xprt);
147 void (*disable_swap)(struct rpc_xprt *xprt);
148 void (*inject_disconnect)(struct rpc_xprt *xprt);
149 int (*bc_setup)(struct rpc_xprt *xprt,
150 unsigned int min_reqs);
151 int (*bc_up)(struct svc_serv *serv, struct net *net);
152 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
153 void (*bc_free_rqst)(struct rpc_rqst *rqst);
154 void (*bc_destroy)(struct rpc_xprt *xprt,
155 unsigned int max_reqs);
156 };
157
158 /*
159 * RPC transport identifiers
160 *
161 * To preserve compatibility with the historical use of raw IP protocol
162 * id's for transport selection, UDP and TCP identifiers are specified
163 * with the previous values. No such restriction exists for new transports,
164 * except that they may not collide with these values (17 and 6,
165 * respectively).
166 */
167 #define XPRT_TRANSPORT_BC (1 << 31)
168 enum xprt_transports {
169 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
170 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
171 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
172 XPRT_TRANSPORT_RDMA = 256,
173 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
174 XPRT_TRANSPORT_LOCAL = 257,
175 };
176
177 struct rpc_xprt {
178 struct kref kref; /* Reference count */
179 const struct rpc_xprt_ops *ops; /* transport methods */
180
181 const struct rpc_timeout *timeout; /* timeout parms */
182 struct sockaddr_storage addr; /* server address */
183 size_t addrlen; /* size of server address */
184 int prot; /* IP protocol */
185
186 unsigned long cong; /* current congestion */
187 unsigned long cwnd; /* congestion window */
188
189 size_t max_payload; /* largest RPC payload size,
190 in bytes */
191 unsigned int tsh_size; /* size of transport specific
192 header */
193
194 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
195 struct rpc_wait_queue sending; /* requests waiting to send */
196 struct rpc_wait_queue pending; /* requests in flight */
197 struct rpc_wait_queue backlog; /* waiting for slot */
198 struct list_head free; /* free slots */
199 unsigned int max_reqs; /* max number of slots */
200 unsigned int min_reqs; /* min number of slots */
201 unsigned int num_reqs; /* total slots */
202 unsigned long state; /* transport state */
203 unsigned char resvport : 1; /* use a reserved port */
204 atomic_t swapper; /* we're swapping over this
205 transport */
206 unsigned int bind_index; /* bind function index */
207
208 /*
209 * Multipath
210 */
211 struct list_head xprt_switch;
212
213 /*
214 * Connection of transports
215 */
216 unsigned long bind_timeout,
217 reestablish_timeout;
218 unsigned int connect_cookie; /* A cookie that gets bumped
219 every time the transport
220 is reconnected */
221
222 /*
223 * Disconnection of idle transports
224 */
225 struct work_struct task_cleanup;
226 struct timer_list timer;
227 unsigned long last_used,
228 idle_timeout,
229 connect_timeout,
230 max_reconnect_timeout;
231
232 /*
233 * Send stuff
234 */
235 spinlock_t transport_lock; /* lock transport info */
236 spinlock_t reserve_lock; /* lock slot table */
237 spinlock_t recv_lock; /* lock receive list */
238 u32 xid; /* Next XID value to use */
239 struct rpc_task * snd_task; /* Task blocked in send */
240 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
241 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
242 struct svc_serv *bc_serv; /* The RPC service which will */
243 /* process the callback */
244 int bc_alloc_count; /* Total number of preallocs */
245 atomic_t bc_free_slots;
246 spinlock_t bc_pa_lock; /* Protects the preallocated
247 * items */
248 struct list_head bc_pa_list; /* List of preallocated
249 * backchannel rpc_rqst's */
250 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
251 struct list_head recv;
252
253 struct {
254 unsigned long bind_count, /* total number of binds */
255 connect_count, /* total number of connects */
256 connect_start, /* connect start timestamp */
257 connect_time, /* jiffies waiting for connect */
258 sends, /* how many complete requests */
259 recvs, /* how many complete requests */
260 bad_xids, /* lookup_rqst didn't find XID */
261 max_slots; /* max rpc_slots used */
262
263 unsigned long long req_u, /* average requests on the wire */
264 bklog_u, /* backlog queue utilization */
265 sending_u, /* send q utilization */
266 pending_u; /* pend q utilization */
267 } stat;
268
269 struct net *xprt_net;
270 const char *servername;
271 const char *address_strings[RPC_DISPLAY_MAX];
272 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
273 struct dentry *debugfs; /* debugfs directory */
274 atomic_t inject_disconnect;
275 #endif
276 struct rcu_head rcu;
277 };
278
279 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
280 /*
281 * Backchannel flags
282 */
283 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
284 /* buffer in use */
285 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
286
287 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)288 static inline int bc_prealloc(struct rpc_rqst *req)
289 {
290 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
291 }
292 #else
bc_prealloc(struct rpc_rqst * req)293 static inline int bc_prealloc(struct rpc_rqst *req)
294 {
295 return 0;
296 }
297 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
298
299 #define XPRT_CREATE_INFINITE_SLOTS (1U)
300 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
301
302 struct xprt_create {
303 int ident; /* XPRT_TRANSPORT identifier */
304 struct net * net;
305 struct sockaddr * srcaddr; /* optional local address */
306 struct sockaddr * dstaddr; /* remote peer address */
307 size_t addrlen;
308 const char *servername;
309 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
310 struct rpc_xprt_switch *bc_xps;
311 unsigned int flags;
312 };
313
314 struct xprt_class {
315 struct list_head list;
316 int ident; /* XPRT_TRANSPORT identifier */
317 struct rpc_xprt * (*setup)(struct xprt_create *);
318 struct module *owner;
319 char name[32];
320 };
321
322 /*
323 * Generic internal transport functions
324 */
325 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
326 void xprt_connect(struct rpc_task *task);
327 void xprt_reserve(struct rpc_task *task);
328 void xprt_request_init(struct rpc_task *task);
329 void xprt_retry_reserve(struct rpc_task *task);
330 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
331 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
332 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
333 void xprt_free_slot(struct rpc_xprt *xprt,
334 struct rpc_rqst *req);
335 void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
336 bool xprt_prepare_transmit(struct rpc_task *task);
337 void xprt_transmit(struct rpc_task *task);
338 void xprt_end_transmit(struct rpc_task *task);
339 int xprt_adjust_timeout(struct rpc_rqst *req);
340 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
341 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
342 void xprt_release(struct rpc_task *task);
343 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
344 void xprt_put(struct rpc_xprt *xprt);
345 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
346 unsigned int num_prealloc,
347 unsigned int max_req);
348 void xprt_free(struct rpc_xprt *);
349
xprt_skip_transport_header(struct rpc_xprt * xprt,__be32 * p)350 static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
351 {
352 return p + xprt->tsh_size;
353 }
354
355 static inline int
xprt_enable_swap(struct rpc_xprt * xprt)356 xprt_enable_swap(struct rpc_xprt *xprt)
357 {
358 return xprt->ops->enable_swap(xprt);
359 }
360
361 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)362 xprt_disable_swap(struct rpc_xprt *xprt)
363 {
364 xprt->ops->disable_swap(xprt);
365 }
366
367 /*
368 * Transport switch helper functions
369 */
370 int xprt_register_transport(struct xprt_class *type);
371 int xprt_unregister_transport(struct xprt_class *type);
372 int xprt_load_transport(const char *);
373 void xprt_set_retrans_timeout_def(struct rpc_task *task);
374 void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
375 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
376 void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
377 void xprt_write_space(struct rpc_xprt *xprt);
378 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
379 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
380 void xprt_update_rtt(struct rpc_task *task);
381 void xprt_complete_rqst(struct rpc_task *task, int copied);
382 void xprt_pin_rqst(struct rpc_rqst *req);
383 void xprt_unpin_rqst(struct rpc_rqst *req);
384 void xprt_release_rqst_cong(struct rpc_task *task);
385 void xprt_disconnect_done(struct rpc_xprt *xprt);
386 void xprt_force_disconnect(struct rpc_xprt *xprt);
387 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
388
389 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
390 void xprt_unlock_connect(struct rpc_xprt *, void *);
391
392 /*
393 * Reserved bit positions in xprt->state
394 */
395 #define XPRT_LOCKED (0)
396 #define XPRT_CONNECTED (1)
397 #define XPRT_CONNECTING (2)
398 #define XPRT_CLOSE_WAIT (3)
399 #define XPRT_BOUND (4)
400 #define XPRT_BINDING (5)
401 #define XPRT_CLOSING (6)
402 #define XPRT_CONGESTED (9)
403
xprt_set_connected(struct rpc_xprt * xprt)404 static inline void xprt_set_connected(struct rpc_xprt *xprt)
405 {
406 set_bit(XPRT_CONNECTED, &xprt->state);
407 }
408
xprt_clear_connected(struct rpc_xprt * xprt)409 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
410 {
411 clear_bit(XPRT_CONNECTED, &xprt->state);
412 }
413
xprt_connected(struct rpc_xprt * xprt)414 static inline int xprt_connected(struct rpc_xprt *xprt)
415 {
416 return test_bit(XPRT_CONNECTED, &xprt->state);
417 }
418
xprt_test_and_set_connected(struct rpc_xprt * xprt)419 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
420 {
421 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
422 }
423
xprt_test_and_clear_connected(struct rpc_xprt * xprt)424 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
425 {
426 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
427 }
428
xprt_clear_connecting(struct rpc_xprt * xprt)429 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
430 {
431 smp_mb__before_atomic();
432 clear_bit(XPRT_CONNECTING, &xprt->state);
433 smp_mb__after_atomic();
434 }
435
xprt_connecting(struct rpc_xprt * xprt)436 static inline int xprt_connecting(struct rpc_xprt *xprt)
437 {
438 return test_bit(XPRT_CONNECTING, &xprt->state);
439 }
440
xprt_test_and_set_connecting(struct rpc_xprt * xprt)441 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
442 {
443 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
444 }
445
xprt_set_bound(struct rpc_xprt * xprt)446 static inline void xprt_set_bound(struct rpc_xprt *xprt)
447 {
448 test_and_set_bit(XPRT_BOUND, &xprt->state);
449 }
450
xprt_bound(struct rpc_xprt * xprt)451 static inline int xprt_bound(struct rpc_xprt *xprt)
452 {
453 return test_bit(XPRT_BOUND, &xprt->state);
454 }
455
xprt_clear_bound(struct rpc_xprt * xprt)456 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
457 {
458 clear_bit(XPRT_BOUND, &xprt->state);
459 }
460
xprt_clear_binding(struct rpc_xprt * xprt)461 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
462 {
463 smp_mb__before_atomic();
464 clear_bit(XPRT_BINDING, &xprt->state);
465 smp_mb__after_atomic();
466 }
467
xprt_test_and_set_binding(struct rpc_xprt * xprt)468 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
469 {
470 return test_and_set_bit(XPRT_BINDING, &xprt->state);
471 }
472
473 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
474 extern unsigned int rpc_inject_disconnect;
xprt_inject_disconnect(struct rpc_xprt * xprt)475 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
476 {
477 if (!rpc_inject_disconnect)
478 return;
479 if (atomic_dec_return(&xprt->inject_disconnect))
480 return;
481 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
482 xprt->ops->inject_disconnect(xprt);
483 }
484 #else
xprt_inject_disconnect(struct rpc_xprt * xprt)485 static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
486 {
487 }
488 #endif
489
490 #endif /* __KERNEL__*/
491
492 #endif /* _LINUX_SUNRPC_XPRT_H */
493
