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#define RPC_GSS_SEQNO_ARRAY_SIZE 3U
34
35enum rpc_display_format_t {
36 RPC_DISPLAY_ADDR = 0,
37 RPC_DISPLAY_PORT,
38 RPC_DISPLAY_PROTO,
39 RPC_DISPLAY_HEX_ADDR,
40 RPC_DISPLAY_HEX_PORT,
41 RPC_DISPLAY_NETID,
42 RPC_DISPLAY_MAX,
43};
44
45struct rpc_task;
46struct rpc_xprt;
47struct xprt_class;
48struct seq_file;
49struct svc_serv;
50struct net;
51#include <linux/lwq.h>
52
53/*
54 * This describes a complete RPC request
55 */
56struct rpc_rqst {
57 /*
58 * This is the user-visible part
59 */
60 struct rpc_xprt * rq_xprt; /* RPC client */
61 struct xdr_buf rq_snd_buf; /* send buffer */
62 struct xdr_buf rq_rcv_buf; /* recv buffer */
63
64 /*
65 * This is the private part
66 */
67 struct rpc_task * rq_task; /* RPC task data */
68 struct rpc_cred * rq_cred; /* Bound cred */
69 __be32 rq_xid; /* request XID */
70 int rq_cong; /* has incremented xprt->cong */
71 u32 rq_seqnos[RPC_GSS_SEQNO_ARRAY_SIZE]; /* past gss req seq nos. */
72 unsigned int rq_seqno_count; /* number of entries in rq_seqnos */
73 int rq_enc_pages_num;
74 struct page **rq_enc_pages; /* scratch pages for use by
75 gss privacy code */
76 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
77
78 union {
79 struct list_head rq_list; /* Slot allocation list */
80 struct rb_node rq_recv; /* Receive queue */
81 };
82
83 struct list_head rq_xmit; /* Send queue */
84 struct list_head rq_xmit2; /* Send queue */
85
86 void *rq_buffer; /* Call XDR encode buffer */
87 size_t rq_callsize;
88 void *rq_rbuffer; /* Reply XDR decode buffer */
89 size_t rq_rcvsize;
90 size_t rq_xmit_bytes_sent; /* total bytes sent */
91 size_t rq_reply_bytes_recvd; /* total reply bytes */
92 /* received */
93
94 struct xdr_buf rq_private_buf; /* The receive buffer
95 * used in the softirq.
96 */
97 unsigned long rq_majortimeo; /* major timeout alarm */
98 unsigned long rq_minortimeo; /* minor 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 atomic_t rq_pin;
107
108 /*
109 * Partial send handling
110 */
111 u32 rq_bytes_sent; /* Bytes we have sent */
112
113 ktime_t rq_xtime; /* transmit time stamp */
114 int rq_ntrans;
115
116#if defined(CONFIG_SUNRPC_BACKCHANNEL)
117 struct lwq_node rq_bc_list; /* Callback service list */
118 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
119 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
120#endif /* CONFIG_SUNRPC_BACKCHANEL */
121};
122#define rq_svec rq_snd_buf.head
123#define rq_slen rq_snd_buf.len
124
125static inline int xprt_rqst_add_seqno(struct rpc_rqst *req, u32 seqno)
126{
127 if (likely(req->rq_seqno_count < RPC_GSS_SEQNO_ARRAY_SIZE))
128 req->rq_seqno_count++;
129
130 /* Shift array to make room for the newest element at the beginning */
131 memmove(dest: &req->rq_seqnos[1], src: &req->rq_seqnos[0],
132 count: (RPC_GSS_SEQNO_ARRAY_SIZE - 1) * sizeof(req->rq_seqnos[0]));
133 req->rq_seqnos[0] = seqno;
134 return 0;
135}
136
137/* RPC transport layer security policies */
138enum xprtsec_policies {
139 RPC_XPRTSEC_NONE = 0,
140 RPC_XPRTSEC_TLS_ANON,
141 RPC_XPRTSEC_TLS_X509,
142};
143
144struct xprtsec_parms {
145 enum xprtsec_policies policy;
146
147 /* authentication material */
148 key_serial_t cert_serial;
149 key_serial_t privkey_serial;
150};
151
152struct rpc_xprt_ops {
153 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
154 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
155 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
156 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
157 void (*free_slot)(struct rpc_xprt *xprt,
158 struct rpc_rqst *req);
159 void (*rpcbind)(struct rpc_task *task);
160 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
161 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
162 int (*get_srcaddr)(struct rpc_xprt *xprt, char *buf,
163 size_t buflen);
164 unsigned short (*get_srcport)(struct rpc_xprt *xprt);
165 int (*buf_alloc)(struct rpc_task *task);
166 void (*buf_free)(struct rpc_task *task);
167 int (*prepare_request)(struct rpc_rqst *req,
168 struct xdr_buf *buf);
169 int (*send_request)(struct rpc_rqst *req);
170 void (*abort_send_request)(struct rpc_rqst *req);
171 void (*wait_for_reply_request)(struct rpc_task *task);
172 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
173 void (*release_request)(struct rpc_task *task);
174 void (*close)(struct rpc_xprt *xprt);
175 void (*destroy)(struct rpc_xprt *xprt);
176 void (*set_connect_timeout)(struct rpc_xprt *xprt,
177 unsigned long connect_timeout,
178 unsigned long reconnect_timeout);
179 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
180 int (*enable_swap)(struct rpc_xprt *xprt);
181 void (*disable_swap)(struct rpc_xprt *xprt);
182 void (*inject_disconnect)(struct rpc_xprt *xprt);
183 int (*bc_setup)(struct rpc_xprt *xprt,
184 unsigned int min_reqs);
185 size_t (*bc_maxpayload)(struct rpc_xprt *xprt);
186 unsigned int (*bc_num_slots)(struct rpc_xprt *xprt);
187 void (*bc_free_rqst)(struct rpc_rqst *rqst);
188 void (*bc_destroy)(struct rpc_xprt *xprt,
189 unsigned int max_reqs);
190};
191
192/*
193 * RPC transport identifiers
194 *
195 * To preserve compatibility with the historical use of raw IP protocol
196 * id's for transport selection, UDP and TCP identifiers are specified
197 * with the previous values. No such restriction exists for new transports,
198 * except that they may not collide with these values (17 and 6,
199 * respectively).
200 */
201#define XPRT_TRANSPORT_BC (1 << 31)
202enum xprt_transports {
203 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
204 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
205 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
206 XPRT_TRANSPORT_RDMA = 256,
207 XPRT_TRANSPORT_BC_RDMA = XPRT_TRANSPORT_RDMA | XPRT_TRANSPORT_BC,
208 XPRT_TRANSPORT_LOCAL = 257,
209 XPRT_TRANSPORT_TCP_TLS = 258,
210};
211
212struct rpc_sysfs_xprt;
213struct rpc_xprt {
214 struct kref kref; /* Reference count */
215 const struct rpc_xprt_ops *ops; /* transport methods */
216 unsigned int id; /* transport id */
217
218 const struct rpc_timeout *timeout; /* timeout parms */
219 struct sockaddr_storage addr; /* server address */
220 size_t addrlen; /* size of server address */
221 int prot; /* IP protocol */
222
223 unsigned long cong; /* current congestion */
224 unsigned long cwnd; /* congestion window */
225
226 size_t max_payload; /* largest RPC payload size,
227 in bytes */
228
229 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
230 struct rpc_wait_queue sending; /* requests waiting to send */
231 struct rpc_wait_queue pending; /* requests in flight */
232 struct rpc_wait_queue backlog; /* waiting for slot */
233 struct list_head free; /* free slots */
234 unsigned int max_reqs; /* max number of slots */
235 unsigned int min_reqs; /* min number of slots */
236 unsigned int num_reqs; /* total slots */
237 unsigned long state; /* transport state */
238 unsigned char resvport : 1, /* use a reserved port */
239 reuseport : 1; /* reuse port on reconnect */
240 atomic_t swapper; /* we're swapping over this
241 transport */
242 unsigned int bind_index; /* bind function index */
243
244 /*
245 * Multipath
246 */
247 struct list_head xprt_switch;
248
249 /*
250 * Connection of transports
251 */
252 unsigned long bind_timeout,
253 reestablish_timeout;
254 struct xprtsec_parms xprtsec;
255 unsigned int connect_cookie; /* A cookie that gets bumped
256 every time the transport
257 is reconnected */
258
259 /*
260 * Disconnection of idle transports
261 */
262 struct work_struct task_cleanup;
263 struct timer_list timer;
264 unsigned long last_used,
265 idle_timeout,
266 connect_timeout,
267 max_reconnect_timeout;
268
269 /*
270 * Send stuff
271 */
272 atomic_long_t queuelen;
273 spinlock_t transport_lock; /* lock transport info */
274 spinlock_t reserve_lock; /* lock slot table */
275 spinlock_t queue_lock; /* send/receive queue lock */
276 u32 xid; /* Next XID value to use */
277 struct rpc_task * snd_task; /* Task blocked in send */
278
279 struct list_head xmit_queue; /* Send queue */
280 atomic_long_t xmit_queuelen;
281
282 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
283#if defined(CONFIG_SUNRPC_BACKCHANNEL)
284 struct svc_serv *bc_serv; /* The RPC service which will */
285 /* process the callback */
286 unsigned int bc_alloc_max;
287 unsigned int bc_alloc_count; /* Total number of preallocs */
288 atomic_t bc_slot_count; /* Number of allocated slots */
289 spinlock_t bc_pa_lock; /* Protects the preallocated
290 * items */
291 struct list_head bc_pa_list; /* List of preallocated
292 * backchannel rpc_rqst's */
293#endif /* CONFIG_SUNRPC_BACKCHANNEL */
294
295 struct rb_root recv_queue; /* Receive queue */
296
297 struct {
298 unsigned long bind_count, /* total number of binds */
299 connect_count, /* total number of connects */
300 connect_start, /* connect start timestamp */
301 connect_time, /* jiffies waiting for connect */
302 sends, /* how many complete requests */
303 recvs, /* how many complete requests */
304 bad_xids, /* lookup_rqst didn't find XID */
305 max_slots; /* max rpc_slots used */
306
307 unsigned long long req_u, /* average requests on the wire */
308 bklog_u, /* backlog queue utilization */
309 sending_u, /* send q utilization */
310 pending_u; /* pend q utilization */
311 } stat;
312
313 struct net *xprt_net;
314 netns_tracker ns_tracker;
315 const char *servername;
316 const char *address_strings[RPC_DISPLAY_MAX];
317#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
318 struct dentry *debugfs; /* debugfs directory */
319#endif
320 struct rcu_head rcu;
321 const struct xprt_class *xprt_class;
322 struct rpc_sysfs_xprt *xprt_sysfs;
323 bool main; /*mark if this is the 1st transport */
324};
325
326#if defined(CONFIG_SUNRPC_BACKCHANNEL)
327/*
328 * Backchannel flags
329 */
330#define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
331 /* buffer in use */
332#endif /* CONFIG_SUNRPC_BACKCHANNEL */
333
334#if defined(CONFIG_SUNRPC_BACKCHANNEL)
335static inline int bc_prealloc(struct rpc_rqst *req)
336{
337 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
338}
339#else
340static inline int bc_prealloc(struct rpc_rqst *req)
341{
342 return 0;
343}
344#endif /* CONFIG_SUNRPC_BACKCHANNEL */
345
346#define XPRT_CREATE_INFINITE_SLOTS (1U)
347#define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
348
349struct xprt_create {
350 int ident; /* XPRT_TRANSPORT identifier */
351 struct net * net;
352 struct sockaddr * srcaddr; /* optional local address */
353 struct sockaddr * dstaddr; /* remote peer address */
354 size_t addrlen;
355 const char *servername;
356 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
357 struct rpc_xprt_switch *bc_xps;
358 unsigned int flags;
359 struct xprtsec_parms xprtsec;
360 unsigned long connect_timeout;
361 unsigned long reconnect_timeout;
362};
363
364struct xprt_class {
365 struct list_head list;
366 int ident; /* XPRT_TRANSPORT identifier */
367 struct rpc_xprt * (*setup)(struct xprt_create *);
368 struct module *owner;
369 char name[32];
370 const char * netid[];
371};
372
373/*
374 * Generic internal transport functions
375 */
376struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
377void xprt_connect(struct rpc_task *task);
378unsigned long xprt_reconnect_delay(const struct rpc_xprt *xprt);
379void xprt_reconnect_backoff(struct rpc_xprt *xprt,
380 unsigned long init_to);
381void xprt_reserve(struct rpc_task *task);
382void xprt_retry_reserve(struct rpc_task *task);
383int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
384int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
385void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
386void xprt_free_slot(struct rpc_xprt *xprt,
387 struct rpc_rqst *req);
388bool xprt_prepare_transmit(struct rpc_task *task);
389void xprt_request_enqueue_transmit(struct rpc_task *task);
390int xprt_request_enqueue_receive(struct rpc_task *task);
391void xprt_request_wait_receive(struct rpc_task *task);
392void xprt_request_dequeue_xprt(struct rpc_task *task);
393bool xprt_request_need_retransmit(struct rpc_task *task);
394void xprt_transmit(struct rpc_task *task);
395void xprt_end_transmit(struct rpc_task *task);
396int xprt_adjust_timeout(struct rpc_rqst *req);
397void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
398void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
399void xprt_release(struct rpc_task *task);
400struct rpc_xprt * xprt_get(struct rpc_xprt *xprt);
401void xprt_put(struct rpc_xprt *xprt);
402struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
403 unsigned int num_prealloc,
404 unsigned int max_req);
405void xprt_free(struct rpc_xprt *);
406void xprt_add_backlog(struct rpc_xprt *xprt, struct rpc_task *task);
407bool xprt_wake_up_backlog(struct rpc_xprt *xprt, struct rpc_rqst *req);
408void xprt_cleanup_ids(void);
409
410static inline int
411xprt_enable_swap(struct rpc_xprt *xprt)
412{
413 return xprt->ops->enable_swap(xprt);
414}
415
416static inline void
417xprt_disable_swap(struct rpc_xprt *xprt)
418{
419 xprt->ops->disable_swap(xprt);
420}
421
422/*
423 * Transport switch helper functions
424 */
425int xprt_register_transport(struct xprt_class *type);
426int xprt_unregister_transport(struct xprt_class *type);
427int xprt_find_transport_ident(const char *);
428void xprt_wait_for_reply_request_def(struct rpc_task *task);
429void xprt_wait_for_reply_request_rtt(struct rpc_task *task);
430void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
431void xprt_wait_for_buffer_space(struct rpc_xprt *xprt);
432bool xprt_write_space(struct rpc_xprt *xprt);
433void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
434struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
435void xprt_update_rtt(struct rpc_task *task);
436void xprt_complete_rqst(struct rpc_task *task, int copied);
437void xprt_pin_rqst(struct rpc_rqst *req);
438void xprt_unpin_rqst(struct rpc_rqst *req);
439void xprt_release_rqst_cong(struct rpc_task *task);
440bool xprt_request_get_cong(struct rpc_xprt *xprt, struct rpc_rqst *req);
441void xprt_disconnect_done(struct rpc_xprt *xprt);
442void xprt_force_disconnect(struct rpc_xprt *xprt);
443void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
444
445bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
446void xprt_unlock_connect(struct rpc_xprt *, void *);
447void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
448
449/*
450 * Reserved bit positions in xprt->state
451 */
452#define XPRT_LOCKED (0)
453#define XPRT_CONNECTED (1)
454#define XPRT_CONNECTING (2)
455#define XPRT_CLOSE_WAIT (3)
456#define XPRT_BOUND (4)
457#define XPRT_BINDING (5)
458#define XPRT_CLOSING (6)
459#define XPRT_OFFLINE (7)
460#define XPRT_REMOVE (8)
461#define XPRT_CONGESTED (9)
462#define XPRT_CWND_WAIT (10)
463#define XPRT_WRITE_SPACE (11)
464#define XPRT_SND_IS_COOKIE (12)
465
466static inline void xprt_set_connected(struct rpc_xprt *xprt)
467{
468 set_bit(XPRT_CONNECTED, addr: &xprt->state);
469}
470
471static inline void xprt_clear_connected(struct rpc_xprt *xprt)
472{
473 clear_bit(XPRT_CONNECTED, addr: &xprt->state);
474}
475
476static inline int xprt_connected(struct rpc_xprt *xprt)
477{
478 return test_bit(XPRT_CONNECTED, &xprt->state);
479}
480
481static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
482{
483 return test_and_set_bit(XPRT_CONNECTED, addr: &xprt->state);
484}
485
486static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
487{
488 return test_and_clear_bit(XPRT_CONNECTED, addr: &xprt->state);
489}
490
491static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
492{
493 smp_mb__before_atomic();
494 clear_bit(XPRT_CONNECTING, addr: &xprt->state);
495 smp_mb__after_atomic();
496}
497
498static inline int xprt_connecting(struct rpc_xprt *xprt)
499{
500 return test_bit(XPRT_CONNECTING, &xprt->state);
501}
502
503static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
504{
505 return test_and_set_bit(XPRT_CONNECTING, addr: &xprt->state);
506}
507
508static inline void xprt_set_bound(struct rpc_xprt *xprt)
509{
510 test_and_set_bit(XPRT_BOUND, addr: &xprt->state);
511}
512
513static inline int xprt_bound(struct rpc_xprt *xprt)
514{
515 return test_bit(XPRT_BOUND, &xprt->state);
516}
517
518static inline void xprt_clear_bound(struct rpc_xprt *xprt)
519{
520 clear_bit(XPRT_BOUND, addr: &xprt->state);
521}
522
523static inline void xprt_clear_binding(struct rpc_xprt *xprt)
524{
525 smp_mb__before_atomic();
526 clear_bit(XPRT_BINDING, addr: &xprt->state);
527 smp_mb__after_atomic();
528}
529
530static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
531{
532 return test_and_set_bit(XPRT_BINDING, addr: &xprt->state);
533}
534
535void xprt_set_offline_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
536void xprt_set_online_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
537void xprt_delete_locked(struct rpc_xprt *xprt, struct rpc_xprt_switch *xps);
538#endif /* _LINUX_SUNRPC_XPRT_H */
539