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 #define RPC_MIN_SLOT_TABLE (2U)
23 #define RPC_DEF_SLOT_TABLE (16U)
24 #define RPC_MAX_SLOT_TABLE_LIMIT (65536U)
25 #define RPC_MAX_SLOT_TABLE RPC_MAX_SLOT_TABLE_LIMIT
26
27 #define RPC_CWNDSHIFT (8U)
28 #define RPC_CWNDSCALE (1U << RPC_CWNDSHIFT)
29 #define RPC_INITCWND RPC_CWNDSCALE
30 #define RPC_MAXCWND(xprt) ((xprt)->max_reqs << RPC_CWNDSHIFT)
31 #define RPCXPRT_CONGESTED(xprt) ((xprt)->cong >= (xprt)->cwnd)
32
33 /*
34 * This describes a timeout strategy
35 */
36 struct rpc_timeout {
37 unsigned long to_initval, /* initial timeout */
38 to_maxval, /* max timeout */
39 to_increment; /* if !exponential */
40 unsigned int to_retries; /* max # of retries */
41 unsigned char to_exponential;
42 };
43
44 enum rpc_display_format_t {
45 RPC_DISPLAY_ADDR = 0,
46 RPC_DISPLAY_PORT,
47 RPC_DISPLAY_PROTO,
48 RPC_DISPLAY_HEX_ADDR,
49 RPC_DISPLAY_HEX_PORT,
50 RPC_DISPLAY_NETID,
51 RPC_DISPLAY_MAX,
52 };
53
54 struct rpc_task;
55 struct rpc_xprt;
56 struct xprt_class;
57 struct seq_file;
58 struct svc_serv;
59 struct net;
60
61 /*
62 * This describes a complete RPC request
63 */
64 struct rpc_rqst {
65 /*
66 * This is the user-visible part
67 */
68 struct rpc_xprt * rq_xprt; /* RPC client */
69 struct xdr_buf rq_snd_buf; /* send buffer */
70 struct xdr_buf rq_rcv_buf; /* recv buffer */
71
72 /*
73 * This is the private part
74 */
75 struct rpc_task * rq_task; /* RPC task data */
76 struct rpc_cred * rq_cred; /* Bound cred */
77 __be32 rq_xid; /* request XID */
78 int rq_cong; /* has incremented xprt->cong */
79 u32 rq_seqno; /* gss seq no. used on req. */
80 int rq_enc_pages_num;
81 struct page **rq_enc_pages; /* scratch pages for use by
82 gss privacy code */
83 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
84
85 union {
86 struct list_head rq_list; /* Slot allocation list */
87 struct rb_node rq_recv; /* Receive queue */
88 };
89
90 struct list_head rq_xmit; /* Send queue */
91 struct list_head rq_xmit2; /* Send queue */
92
93 void *rq_buffer; /* Call XDR encode buffer */
94 size_t rq_callsize;
95 void *rq_rbuffer; /* Reply XDR decode buffer */
96 size_t rq_rcvsize;
97 size_t rq_xmit_bytes_sent; /* total bytes sent */
98 size_t rq_reply_bytes_recvd; /* total reply bytes */
99 /* received */
100
101 struct xdr_buf rq_private_buf; /* The receive buffer
102 * used in the softirq.
103 */
104 unsigned long rq_majortimeo; /* major timeout alarm */
105 unsigned long rq_minortimeo; /* minor timeout alarm */
106 unsigned long rq_timeout; /* Current timeout value */
107 ktime_t rq_rtt; /* round-trip time */
108 unsigned int rq_retries; /* # of retries */
109 unsigned int rq_connect_cookie;
110 /* A cookie used to track the
111 state of the transport
112 connection */
113 atomic_t rq_pin;
114
115 /*
116 * Partial send handling
117 */
118 u32 rq_bytes_sent; /* Bytes we have sent */
119
120 ktime_t rq_xtime; /* transmit time stamp */
121 int rq_ntrans;
122
123 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
124 struct list_head rq_bc_list; /* Callback service list */
125 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
126 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
127 #endif /* CONFIG_SUNRPC_BACKCHANEL */
128 };
129 #define rq_svec rq_snd_buf.head
130 #define rq_slen rq_snd_buf.len
131
132 /* RPC transport layer security policies */
133 enum xprtsec_policies {
134 RPC_XPRTSEC_NONE = 0,
135 RPC_XPRTSEC_TLS_ANON,
136 RPC_XPRTSEC_TLS_X509,
137 };
138
139 struct xprtsec_parms {
140 enum xprtsec_policies policy;
141
142 /* authentication material */
143 key_serial_t cert_serial;
144 key_serial_t privkey_serial;
145 };
146
147 struct rpc_xprt_ops {
148 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
149 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
150 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
151 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
152 void (*free_slot)(struct rpc_xprt *xprt,
153 struct rpc_rqst *req);
154 void (*rpcbind)(struct rpc_task *task);
155 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
156 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
157 int (*get_srcaddr)(struct rpc_xprt *xprt, char *buf,
158 size_t buflen);
159 unsigned short (*get_srcport)(struct rpc_xprt *xprt);
160 int (*buf_alloc)(struct rpc_task *task);
161 void (*buf_free)(struct rpc_task *task);
162 int (*prepare_request)(struct rpc_rqst *req,
163 struct xdr_buf *buf);
164 int (*send_request)(struct rpc_rqst *req);
165 void (*wait_for_reply_request)(struct rpc_task *task);
166 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
167 void (*release_request)(struct rpc_task *task);
168 void (*close)(struct rpc_xprt *xprt);
169 void (*destroy)(struct rpc_xprt *xprt);
170 void (*set_connect_timeout)(struct rpc_xprt *xprt,
171 unsigned long connect_timeout,
172 unsigned long reconnect_timeout);
173 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
174 int (*enable_swap)(struct rpc_xprt *xprt);
175 void (*disable_swap)(struct rpc_xprt *xprt);
176 void (*inject_disconnect)(struct rpc_xprt *xprt);
177 int (*bc_setup)(struct rpc_xprt *xprt,
178 unsigned int min_reqs);
179 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
180 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
181 void (*bc_free_rqst)(struct rpc_rqst *rqst);
182 void (*bc_destroy)(struct rpc_xprt *xprt,
183 unsigned int max_reqs);
184 };
185
186 /*
187 * RPC transport identifiers
188 *
189 * To preserve compatibility with the historical use of raw IP protocol
190 * id's for transport selection, UDP and TCP identifiers are specified
191 * with the previous values. No such restriction exists for new transports,
192 * except that they may not collide with these values (17 and 6,
193 * respectively).
194 */
195 #define XPRT_TRANSPORT_BC (1 << 31)
196 enum xprt_transports {
197 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
198 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
199 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
200 XPRT_TRANSPORT_RDMA = 256,
201 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
202 XPRT_TRANSPORT_LOCAL = 257,
203 XPRT_TRANSPORT_TCP_TLS = 258,
204 };
205
206 struct rpc_sysfs_xprt;
207 struct rpc_xprt {
208 struct kref kref; /* Reference count */
209 const struct rpc_xprt_ops *ops; /* transport methods */
210 unsigned int id; /* transport id */
211
212 const struct rpc_timeout *timeout; /* timeout parms */
213 struct sockaddr_storage addr; /* server address */
214 size_t addrlen; /* size of server address */
215 int prot; /* IP protocol */
216
217 unsigned long cong; /* current congestion */
218 unsigned long cwnd; /* congestion window */
219
220 size_t max_payload; /* largest RPC payload size,
221 in bytes */
222
223 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
224 struct rpc_wait_queue sending; /* requests waiting to send */
225 struct rpc_wait_queue pending; /* requests in flight */
226 struct rpc_wait_queue backlog; /* waiting for slot */
227 struct list_head free; /* free slots */
228 unsigned int max_reqs; /* max number of slots */
229 unsigned int min_reqs; /* min number of slots */
230 unsigned int num_reqs; /* total slots */
231 unsigned long state; /* transport state */
232 unsigned char resvport : 1, /* use a reserved port */
233 reuseport : 1; /* reuse port on reconnect */
234 atomic_t swapper; /* we're swapping over this
235 transport */
236 unsigned int bind_index; /* bind function index */
237
238 /*
239 * Multipath
240 */
241 struct list_head xprt_switch;
242
243 /*
244 * Connection of transports
245 */
246 unsigned long bind_timeout,
247 reestablish_timeout;
248 struct xprtsec_parms xprtsec;
249 unsigned int connect_cookie; /* A cookie that gets bumped
250 every time the transport
251 is reconnected */
252
253 /*
254 * Disconnection of idle transports
255 */
256 struct work_struct task_cleanup;
257 struct timer_list timer;
258 unsigned long last_used,
259 idle_timeout,
260 connect_timeout,
261 max_reconnect_timeout;
262
263 /*
264 * Send stuff
265 */
266 atomic_long_t queuelen;
267 spinlock_t transport_lock; /* lock transport info */
268 spinlock_t reserve_lock; /* lock slot table */
269 spinlock_t queue_lock; /* send/receive queue lock */
270 u32 xid; /* Next XID value to use */
271 struct rpc_task * snd_task; /* Task blocked in send */
272
273 struct list_head xmit_queue; /* Send queue */
274 atomic_long_t xmit_queuelen;
275
276 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
277 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
278 struct svc_serv *bc_serv; /* The RPC service which will */
279 /* process the callback */
280 unsigned int bc_alloc_max;
281 unsigned int bc_alloc_count; /* Total number of preallocs */
282 atomic_t bc_slot_count; /* Number of allocated slots */
283 spinlock_t bc_pa_lock; /* Protects the preallocated
284 * items */
285 struct list_head bc_pa_list; /* List of preallocated
286 * backchannel rpc_rqst's */
287 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
288
289 struct rb_root recv_queue; /* Receive queue */
290
291 struct {
292 unsigned long bind_count, /* total number of binds */
293 connect_count, /* total number of connects */
294 connect_start, /* connect start timestamp */
295 connect_time, /* jiffies waiting for connect */
296 sends, /* how many complete requests */
297 recvs, /* how many complete requests */
298 bad_xids, /* lookup_rqst didn't find XID */
299 max_slots; /* max rpc_slots used */
300
301 unsigned long long req_u, /* average requests on the wire */
302 bklog_u, /* backlog queue utilization */
303 sending_u, /* send q utilization */
304 pending_u; /* pend q utilization */
305 } stat;
306
307 struct net *xprt_net;
308 netns_tracker ns_tracker;
309 const char *servername;
310 const char *address_strings[RPC_DISPLAY_MAX];
311 #if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
312 struct dentry *debugfs; /* debugfs directory */
313 #endif
314 struct rcu_head rcu;
315 const struct xprt_class *xprt_class;
316 struct rpc_sysfs_xprt *xprt_sysfs;
317 bool main; /*mark if this is the 1st transport */
318 };
319
320 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
321 /*
322 * Backchannel flags
323 */
324 #define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
325 /* buffer in use */
326 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
327
328 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
bc_prealloc(struct rpc_rqst * req)329 static inline int bc_prealloc(struct rpc_rqst *req)
330 {
331 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
332 }
333 #else
bc_prealloc(struct rpc_rqst * req)334 static inline int bc_prealloc(struct rpc_rqst *req)
335 {
336 return 0;
337 }
338 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
339
340 #define XPRT_CREATE_INFINITE_SLOTS (1U)
341 #define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
342
343 struct xprt_create {
344 int ident; /* XPRT_TRANSPORT identifier */
345 struct net * net;
346 struct sockaddr * srcaddr; /* optional local address */
347 struct sockaddr * dstaddr; /* remote peer address */
348 size_t addrlen;
349 const char *servername;
350 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
351 struct rpc_xprt_switch *bc_xps;
352 unsigned int flags;
353 struct xprtsec_parms xprtsec;
354 unsigned long connect_timeout;
355 unsigned long reconnect_timeout;
356 };
357
358 struct xprt_class {
359 struct list_head list;
360 int ident; /* XPRT_TRANSPORT identifier */
361 struct rpc_xprt * (*setup)(struct xprt_create *);
362 struct module *owner;
363 char name[32];
364 const char * netid[];
365 };
366
367 /*
368 * Generic internal transport functions
369 */
370 struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
371 void xprt_connect(struct rpc_task *task);
372 unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
373 void xprt_reconnect_backoff(struct rpc_xprt *xprt,
374 unsigned long init_to);
375 void xprt_reserve(struct rpc_task *task);
376 void xprt_retry_reserve(struct rpc_task *task);
377 int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
378 int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
379 void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
380 void xprt_free_slot(struct rpc_xprt *xprt,
381 struct rpc_rqst *req);
382 bool xprt_prepare_transmit(struct rpc_task *task);
383 void xprt_request_enqueue_transmit(struct rpc_task *task);
384 int xprt_request_enqueue_receive(struct rpc_task *task);
385 void xprt_request_wait_receive(struct rpc_task *task);
386 void xprt_request_dequeue_xprt(struct rpc_task *task);
387 bool xprt_request_need_retransmit(struct rpc_task *task);
388 void xprt_transmit(struct rpc_task *task);
389 void xprt_end_transmit(struct rpc_task *task);
390 int xprt_adjust_timeout(struct rpc_rqst *req);
391 void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
392 void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
393 void xprt_release(struct rpc_task *task);
394 struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
395 void xprt_put(struct rpc_xprt *xprt);
396 struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
397 unsigned int num_prealloc,
398 unsigned int max_req);
399 void xprt_free(struct rpc_xprt *);
400 void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
401 bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
402 void xprt_cleanup_ids(void);
403
404 static inline int
xprt_enable_swap(struct rpc_xprt * xprt)405 xprt_enable_swap(struct rpc_xprt *xprt)
406 {
407 return xprt->ops->enable_swap(xprt);
408 }
409
410 static inline void
xprt_disable_swap(struct rpc_xprt * xprt)411 xprt_disable_swap(struct rpc_xprt *xprt)
412 {
413 xprt->ops->disable_swap(xprt);
414 }
415
416 /*
417 * Transport switch helper functions
418 */
419 int xprt_register_transport(struct xprt_class *type);
420 int xprt_unregister_transport(struct xprt_class *type);
421 int xprt_find_transport_ident(const char *);
422 void xprt_wait_for_reply_request_def(struct rpc_task *task);
423 void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
424 void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
425 void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
426 bool xprt_write_space(struct rpc_xprt *xprt);
427 void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
428 struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
429 void xprt_update_rtt(struct rpc_task *task);
430 void xprt_complete_rqst(struct rpc_task *task, int copied);
431 void xprt_pin_rqst(struct rpc_rqst *req);
432 void xprt_unpin_rqst(struct rpc_rqst *req);
433 void xprt_release_rqst_cong(struct rpc_task *task);
434 bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
435 void xprt_disconnect_done(struct rpc_xprt *xprt);
436 void xprt_force_disconnect(struct rpc_xprt *xprt);
437 void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
438
439 bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
440 void xprt_unlock_connect(struct rpc_xprt *, void *);
441 void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
442
443 /*
444 * Reserved bit positions in xprt->state
445 */
446 #define XPRT_LOCKED (0)
447 #define XPRT_CONNECTED (1)
448 #define XPRT_CONNECTING (2)
449 #define XPRT_CLOSE_WAIT (3)
450 #define XPRT_BOUND (4)
451 #define XPRT_BINDING (5)
452 #define XPRT_CLOSING (6)
453 #define XPRT_OFFLINE (7)
454 #define XPRT_REMOVE (8)
455 #define XPRT_CONGESTED (9)
456 #define XPRT_CWND_WAIT (10)
457 #define XPRT_WRITE_SPACE (11)
458 #define XPRT_SND_IS_COOKIE (12)
459
xprt_set_connected(struct rpc_xprt * xprt)460 static inline void xprt_set_connected(struct rpc_xprt *xprt)
461 {
462 set_bit(XPRT_CONNECTED, &xprt->state);
463 }
464
xprt_clear_connected(struct rpc_xprt * xprt)465 static inline void xprt_clear_connected(struct rpc_xprt *xprt)
466 {
467 clear_bit(XPRT_CONNECTED, &xprt->state);
468 }
469
xprt_connected(struct rpc_xprt * xprt)470 static inline int xprt_connected(struct rpc_xprt *xprt)
471 {
472 return test_bit(XPRT_CONNECTED, &xprt->state);
473 }
474
xprt_test_and_set_connected(struct rpc_xprt * xprt)475 static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
476 {
477 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
478 }
479
xprt_test_and_clear_connected(struct rpc_xprt * xprt)480 static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
481 {
482 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
483 }
484
xprt_clear_connecting(struct rpc_xprt * xprt)485 static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
486 {
487 smp_mb__before_atomic();
488 clear_bit(XPRT_CONNECTING, &xprt->state);
489 smp_mb__after_atomic();
490 }
491
xprt_connecting(struct rpc_xprt * xprt)492 static inline int xprt_connecting(struct rpc_xprt *xprt)
493 {
494 return test_bit(XPRT_CONNECTING, &xprt->state);
495 }
496
xprt_test_and_set_connecting(struct rpc_xprt * xprt)497 static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
498 {
499 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
500 }
501
xprt_set_bound(struct rpc_xprt * xprt)502 static inline void xprt_set_bound(struct rpc_xprt *xprt)
503 {
504 test_and_set_bit(XPRT_BOUND, &xprt->state);
505 }
506
xprt_bound(struct rpc_xprt * xprt)507 static inline int xprt_bound(struct rpc_xprt *xprt)
508 {
509 return test_bit(XPRT_BOUND, &xprt->state);
510 }
511
xprt_clear_bound(struct rpc_xprt * xprt)512 static inline void xprt_clear_bound(struct rpc_xprt *xprt)
513 {
514 clear_bit(XPRT_BOUND, &xprt->state);
515 }
516
xprt_clear_binding(struct rpc_xprt * xprt)517 static inline void xprt_clear_binding(struct rpc_xprt *xprt)
518 {
519 smp_mb__before_atomic();
520 clear_bit(XPRT_BINDING, &xprt->state);
521 smp_mb__after_atomic();
522 }
523
xprt_test_and_set_binding(struct rpc_xprt * xprt)524 static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
525 {
526 return test_and_set_bit(XPRT_BINDING, &xprt->state);
527 }
528
529 void xprt_set_offline_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
530 void xprt_set_online_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
531 void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
532 #endif /* _LINUX_SUNRPC_XPRT_H */
533