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