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