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 xprt_class;
57struct seq_file;
58struct svc_serv;
59struct net;
60#include <linux/lwq.h>
61
62/*
63 * This describes a complete RPC request
64 */
65struct 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
86 union {
87 struct list_head rq_list; /* Slot allocation list */
88 struct rb_node rq_recv; /* Receive queue */
89 };
90
91 struct list_head rq_xmit; /* Send queue */
92 struct list_head rq_xmit2; /* Send queue */
93
94 void *rq_buffer; /* Call XDR encode buffer */
95 size_t rq_callsize;
96 void *rq_rbuffer; /* Reply XDR decode buffer */
97 size_t rq_rcvsize;
98 size_t rq_xmit_bytes_sent; /* total bytes sent */
99 size_t rq_reply_bytes_recvd; /* total reply bytes */
100 /* received */
101
102 struct xdr_buf rq_private_buf; /* The receive buffer
103 * used in the softirq.
104 */
105 unsigned long rq_majortimeo; /* major timeout alarm */
106 unsigned long rq_minortimeo; /* minor timeout alarm */
107 unsigned long rq_timeout; /* Current timeout value */
108 ktime_t rq_rtt; /* round-trip time */
109 unsigned int rq_retries; /* # of retries */
110 unsigned int rq_connect_cookie;
111 /* A cookie used to track the
112 state of the transport
113 connection */
114 atomic_t rq_pin;
115
116 /*
117 * Partial send handling
118 */
119 u32 rq_bytes_sent; /* Bytes we have sent */
120
121 ktime_t rq_xtime; /* transmit time stamp */
122 int rq_ntrans;
123
124#if defined(CONFIG_SUNRPC_BACKCHANNEL)
125 struct lwq_node rq_bc_list; /* Callback service list */
126 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
127 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
128#endif /* CONFIG_SUNRPC_BACKCHANEL */
129};
130#define rq_svec rq_snd_buf.head
131#define rq_slen rq_snd_buf.len
132
133/* RPC transport layer security policies */
134enum xprtsec_policies {
135 RPC_XPRTSEC_NONE = 0,
136 RPC_XPRTSEC_TLS_ANON,
137 RPC_XPRTSEC_TLS_X509,
138};
139
140struct xprtsec_parms {
141 enum xprtsec_policies policy;
142
143 /* authentication material */
144 key_serial_t cert_serial;
145 key_serial_t privkey_serial;
146};
147
148struct rpc_xprt_ops {
149 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
150 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
151 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
152 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
153 void (*free_slot)(struct rpc_xprt *xprt,
154 struct rpc_rqst *req);
155 void (*rpcbind)(struct rpc_task *task);
156 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
157 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
158 int (*get_srcaddr)(struct rpc_xprt *xprt, char *buf,
159 size_t buflen);
160 unsigned short (*get_srcport)(struct rpc_xprt *xprt);
161 int (*buf_alloc)(struct rpc_task *task);
162 void (*buf_free)(struct rpc_task *task);
163 int (*prepare_request)(struct rpc_rqst *req,
164 struct xdr_buf *buf);
165 int (*send_request)(struct rpc_rqst *req);
166 void (*wait_for_reply_request)(struct rpc_task *task);
167 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
168 void (*release_request)(struct rpc_task *task);
169 void (*close)(struct rpc_xprt *xprt);
170 void (*destroy)(struct rpc_xprt *xprt);
171 void (*set_connect_timeout)(struct rpc_xprt *xprt,
172 unsigned long connect_timeout,
173 unsigned long reconnect_timeout);
174 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
175 int (*enable_swap)(struct rpc_xprt *xprt);
176 void (*disable_swap)(struct rpc_xprt *xprt);
177 void (*inject_disconnect)(struct rpc_xprt *xprt);
178 int (*bc_setup)(struct rpc_xprt *xprt,
179 unsigned int min_reqs);
180 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
181 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
182 void (*bc_free_rqst)(struct rpc_rqst *rqst);
183 void (*bc_destroy)(struct rpc_xprt *xprt,
184 unsigned int max_reqs);
185};
186
187/*
188 * RPC transport identifiers
189 *
190 * To preserve compatibility with the historical use of raw IP protocol
191 * id's for transport selection, UDP and TCP identifiers are specified
192 * with the previous values. No such restriction exists for new transports,
193 * except that they may not collide with these values (17 and 6,
194 * respectively).
195 */
196#define XPRT_TRANSPORT_BC (1 << 31)
197enum xprt_transports {
198 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
199 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
200 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
201 XPRT_TRANSPORT_RDMA = 256,
202 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
203 XPRT_TRANSPORT_LOCAL = 257,
204 XPRT_TRANSPORT_TCP_TLS = 258,
205};
206
207struct rpc_sysfs_xprt;
208struct rpc_xprt {
209 struct kref kref; /* Reference count */
210 const struct rpc_xprt_ops *ops; /* transport methods */
211 unsigned int id; /* transport id */
212
213 const struct rpc_timeout *timeout; /* timeout parms */
214 struct sockaddr_storage addr; /* server address */
215 size_t addrlen; /* size of server address */
216 int prot; /* IP protocol */
217
218 unsigned long cong; /* current congestion */
219 unsigned long cwnd; /* congestion window */
220
221 size_t max_payload; /* largest RPC payload size,
222 in bytes */
223
224 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
225 struct rpc_wait_queue sending; /* requests waiting to send */
226 struct rpc_wait_queue pending; /* requests in flight */
227 struct rpc_wait_queue backlog; /* waiting for slot */
228 struct list_head free; /* free slots */
229 unsigned int max_reqs; /* max number of slots */
230 unsigned int min_reqs; /* min number of slots */
231 unsigned int num_reqs; /* total slots */
232 unsigned long state; /* transport state */
233 unsigned char resvport : 1, /* use a reserved port */
234 reuseport : 1; /* reuse port on reconnect */
235 atomic_t swapper; /* we're swapping over this
236 transport */
237 unsigned int bind_index; /* bind function index */
238
239 /*
240 * Multipath
241 */
242 struct list_head xprt_switch;
243
244 /*
245 * Connection of transports
246 */
247 unsigned long bind_timeout,
248 reestablish_timeout;
249 struct xprtsec_parms xprtsec;
250 unsigned int connect_cookie; /* A cookie that gets bumped
251 every time the transport
252 is reconnected */
253
254 /*
255 * Disconnection of idle transports
256 */
257 struct work_struct task_cleanup;
258 struct timer_list timer;
259 unsigned long last_used,
260 idle_timeout,
261 connect_timeout,
262 max_reconnect_timeout;
263
264 /*
265 * Send stuff
266 */
267 atomic_long_t queuelen;
268 spinlock_t transport_lock; /* lock transport info */
269 spinlock_t reserve_lock; /* lock slot table */
270 spinlock_t queue_lock; /* send/receive queue lock */
271 u32 xid; /* Next XID value to use */
272 struct rpc_task * snd_task; /* Task blocked in send */
273
274 struct list_head xmit_queue; /* Send queue */
275 atomic_long_t xmit_queuelen;
276
277 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
278#if defined(CONFIG_SUNRPC_BACKCHANNEL)
279 struct svc_serv *bc_serv; /* The RPC service which will */
280 /* process the callback */
281 unsigned int bc_alloc_max;
282 unsigned int bc_alloc_count; /* Total number of preallocs */
283 atomic_t bc_slot_count; /* Number of allocated slots */
284 spinlock_t bc_pa_lock; /* Protects the preallocated
285 * items */
286 struct list_head bc_pa_list; /* List of preallocated
287 * backchannel rpc_rqst's */
288#endif /* CONFIG_SUNRPC_BACKCHANNEL */
289
290 struct rb_root recv_queue; /* Receive queue */
291
292 struct {
293 unsigned long bind_count, /* total number of binds */
294 connect_count, /* total number of connects */
295 connect_start, /* connect start timestamp */
296 connect_time, /* jiffies waiting for connect */
297 sends, /* how many complete requests */
298 recvs, /* how many complete requests */
299 bad_xids, /* lookup_rqst didn't find XID */
300 max_slots; /* max rpc_slots used */
301
302 unsigned long long req_u, /* average requests on the wire */
303 bklog_u, /* backlog queue utilization */
304 sending_u, /* send q utilization */
305 pending_u; /* pend q utilization */
306 } stat;
307
308 struct net *xprt_net;
309 netns_tracker ns_tracker;
310 const char *servername;
311 const char *address_strings[RPC_DISPLAY_MAX];
312#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
313 struct dentry *debugfs; /* debugfs directory */
314#endif
315 struct rcu_head rcu;
316 const struct xprt_class *xprt_class;
317 struct rpc_sysfs_xprt *xprt_sysfs;
318 bool main; /*mark if this is the 1st transport */
319};
320
321#if defined(CONFIG_SUNRPC_BACKCHANNEL)
322/*
323 * Backchannel flags
324 */
325#define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
326 /* buffer in use */
327#endif /* CONFIG_SUNRPC_BACKCHANNEL */
328
329#if defined(CONFIG_SUNRPC_BACKCHANNEL)
330static inline int bc_prealloc(struct rpc_rqst *req)
331{
332 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
333}
334#else
335static inline int bc_prealloc(struct rpc_rqst *req)
336{
337 return 0;
338}
339#endif /* CONFIG_SUNRPC_BACKCHANNEL */
340
341#define XPRT_CREATE_INFINITE_SLOTS (1U)
342#define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
343
344struct xprt_create {
345 int ident; /* XPRT_TRANSPORT identifier */
346 struct net * net;
347 struct sockaddr * srcaddr; /* optional local address */
348 struct sockaddr * dstaddr; /* remote peer address */
349 size_t addrlen;
350 const char *servername;
351 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
352 struct rpc_xprt_switch *bc_xps;
353 unsigned int flags;
354 struct xprtsec_parms xprtsec;
355 unsigned long connect_timeout;
356 unsigned long reconnect_timeout;
357};
358
359struct xprt_class {
360 struct list_head list;
361 int ident; /* XPRT_TRANSPORT identifier */
362 struct rpc_xprt * (*setup)(struct xprt_create *);
363 struct module *owner;
364 char name[32];
365 const char * netid[];
366};
367
368/*
369 * Generic internal transport functions
370 */
371struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
372void xprt_connect(struct rpc_task *task);
373unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
374void xprt_reconnect_backoff(struct rpc_xprt *xprt,
375 unsigned long init_to);
376void xprt_reserve(struct rpc_task *task);
377void xprt_retry_reserve(struct rpc_task *task);
378int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
379int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
380void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
381void xprt_free_slot(struct rpc_xprt *xprt,
382 struct rpc_rqst *req);
383bool xprt_prepare_transmit(struct rpc_task *task);
384void xprt_request_enqueue_transmit(struct rpc_task *task);
385int xprt_request_enqueue_receive(struct rpc_task *task);
386void xprt_request_wait_receive(struct rpc_task *task);
387void xprt_request_dequeue_xprt(struct rpc_task *task);
388bool xprt_request_need_retransmit(struct rpc_task *task);
389void xprt_transmit(struct rpc_task *task);
390void xprt_end_transmit(struct rpc_task *task);
391int xprt_adjust_timeout(struct rpc_rqst *req);
392void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
393void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
394void xprt_release(struct rpc_task *task);
395struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
396void xprt_put(struct rpc_xprt *xprt);
397struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
398 unsigned int num_prealloc,
399 unsigned int max_req);
400void xprt_free(struct rpc_xprt *);
401void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
402bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
403void xprt_cleanup_ids(void);
404
405static inline int
406xprt_enable_swap(struct rpc_xprt *xprt)
407{
408 return xprt->ops->enable_swap(xprt);
409}
410
411static inline void
412xprt_disable_swap(struct rpc_xprt *xprt)
413{
414 xprt->ops->disable_swap(xprt);
415}
416
417/*
418 * Transport switch helper functions
419 */
420int xprt_register_transport(struct xprt_class *type);
421int xprt_unregister_transport(struct xprt_class *type);
422int xprt_find_transport_ident(const char *);
423void xprt_wait_for_reply_request_def(struct rpc_task *task);
424void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
425void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
426void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
427bool xprt_write_space(struct rpc_xprt *xprt);
428void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
429struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
430void xprt_update_rtt(struct rpc_task *task);
431void xprt_complete_rqst(struct rpc_task *task, int copied);
432void xprt_pin_rqst(struct rpc_rqst *req);
433void xprt_unpin_rqst(struct rpc_rqst *req);
434void xprt_release_rqst_cong(struct rpc_task *task);
435bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
436void xprt_disconnect_done(struct rpc_xprt *xprt);
437void xprt_force_disconnect(struct rpc_xprt *xprt);
438void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
439
440bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
441void xprt_unlock_connect(struct rpc_xprt *, void *);
442void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
443
444/*
445 * Reserved bit positions in xprt->state
446 */
447#define XPRT_LOCKED (0)
448#define XPRT_CONNECTED (1)
449#define XPRT_CONNECTING (2)
450#define XPRT_CLOSE_WAIT (3)
451#define XPRT_BOUND (4)
452#define XPRT_BINDING (5)
453#define XPRT_CLOSING (6)
454#define XPRT_OFFLINE (7)
455#define XPRT_REMOVE (8)
456#define XPRT_CONGESTED (9)
457#define XPRT_CWND_WAIT (10)
458#define XPRT_WRITE_SPACE (11)
459#define XPRT_SND_IS_COOKIE (12)
460
461static inline void xprt_set_connected(struct rpc_xprt *xprt)
462{
463 set_bit(XPRT_CONNECTED, addr: &xprt->state);
464}
465
466static inline void xprt_clear_connected(struct rpc_xprt *xprt)
467{
468 clear_bit(XPRT_CONNECTED, addr: &xprt->state);
469}
470
471static inline int xprt_connected(struct rpc_xprt *xprt)
472{
473 return test_bit(XPRT_CONNECTED, &xprt->state);
474}
475
476static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
477{
478 return test_and_set_bit(XPRT_CONNECTED, addr: &xprt->state);
479}
480
481static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
482{
483 return test_and_clear_bit(XPRT_CONNECTED, addr: &xprt->state);
484}
485
486static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
487{
488 smp_mb__before_atomic();
489 clear_bit(XPRT_CONNECTING, addr: &xprt->state);
490 smp_mb__after_atomic();
491}
492
493static inline int xprt_connecting(struct rpc_xprt *xprt)
494{
495 return test_bit(XPRT_CONNECTING, &xprt->state);
496}
497
498static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
499{
500 return test_and_set_bit(XPRT_CONNECTING, addr: &xprt->state);
501}
502
503static inline void xprt_set_bound(struct rpc_xprt *xprt)
504{
505 test_and_set_bit(XPRT_BOUND, addr: &xprt->state);
506}
507
508static inline int xprt_bound(struct rpc_xprt *xprt)
509{
510 return test_bit(XPRT_BOUND, &xprt->state);
511}
512
513static inline void xprt_clear_bound(struct rpc_xprt *xprt)
514{
515 clear_bit(XPRT_BOUND, addr: &xprt->state);
516}
517
518static inline void xprt_clear_binding(struct rpc_xprt *xprt)
519{
520 smp_mb__before_atomic();
521 clear_bit(XPRT_BINDING, addr: &xprt->state);
522 smp_mb__after_atomic();
523}
524
525static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
526{
527 return test_and_set_bit(XPRT_BINDING, addr: &xprt->state);
528}
529
530void xprt_set_offline_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
531void xprt_set_online_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
532void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
533#endif /* _LINUX_SUNRPC_XPRT_H */
534

source code of linux/include/linux/sunrpc/xprt.h