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1/*
2 * linux/include/linux/sunrpc/xprt.h
3 *
4 * Declarations for the RPC transport interface.
5 *
6 * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
7 */
8
9#ifndef _LINUX_SUNRPC_XPRT_H
10#define _LINUX_SUNRPC_XPRT_H
11
12#include <linux/uio.h>
13#include <linux/socket.h>
14#include <linux/in.h>
15#include <linux/ktime.h>
16#include <linux/sunrpc/sched.h>
17#include <linux/sunrpc/xdr.h>
18#include <linux/sunrpc/msg_prot.h>
19
20#ifdef __KERNEL__
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;
57
58/*
59 * This describes a complete RPC request
60 */
61struct rpc_rqst {
62 /*
63 * This is the user-visible part
64 */
65 struct rpc_xprt * rq_xprt; /* RPC client */
66 struct xdr_buf rq_snd_buf; /* send buffer */
67 struct xdr_buf rq_rcv_buf; /* recv buffer */
68
69 /*
70 * This is the private part
71 */
72 struct rpc_task * rq_task; /* RPC task data */
73 struct rpc_cred * rq_cred; /* Bound cred */
74 __be32 rq_xid; /* request XID */
75 int rq_cong; /* has incremented xprt->cong */
76 u32 rq_seqno; /* gss seq no. used on req. */
77 int rq_enc_pages_num;
78 struct page **rq_enc_pages; /* scratch pages for use by
79 gss privacy code */
80 void (*rq_release_snd_buf)(struct rpc_rqst *); /* release rq_enc_pages */
81 struct list_head rq_list;
82
83 __u32 * rq_buffer; /* XDR encode buffer */
84 size_t rq_callsize,
85 rq_rcvsize;
86 size_t rq_xmit_bytes_sent; /* total bytes sent */
87 size_t rq_reply_bytes_recvd; /* total reply bytes */
88 /* received */
89
90 struct xdr_buf rq_private_buf; /* The receive buffer
91 * used in the softirq.
92 */
93 unsigned long rq_majortimeo; /* major timeout alarm */
94 unsigned long rq_timeout; /* Current timeout value */
95 ktime_t rq_rtt; /* round-trip time */
96 unsigned int rq_retries; /* # of retries */
97 unsigned int rq_connect_cookie;
98 /* A cookie used to track the
99 state of the transport
100 connection */
101
102 /*
103 * Partial send handling
104 */
105 u32 rq_bytes_sent; /* Bytes we have sent */
106
107 ktime_t rq_xtime; /* transmit time stamp */
108 int rq_ntrans;
109
110#if defined(CONFIG_SUNRPC_BACKCHANNEL)
111 struct list_head rq_bc_list; /* Callback service list */
112 unsigned long rq_bc_pa_state; /* Backchannel prealloc state */
113 struct list_head rq_bc_pa_list; /* Backchannel prealloc list */
114#endif /* CONFIG_SUNRPC_BACKCHANEL */
115};
116#define rq_svec rq_snd_buf.head
117#define rq_slen rq_snd_buf.len
118
119struct rpc_xprt_ops {
120 void (*set_buffer_size)(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize);
121 int (*reserve_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
122 void (*release_xprt)(struct rpc_xprt *xprt, struct rpc_task *task);
123 void (*alloc_slot)(struct rpc_xprt *xprt, struct rpc_task *task);
124 void (*rpcbind)(struct rpc_task *task);
125 void (*set_port)(struct rpc_xprt *xprt, unsigned short port);
126 void (*connect)(struct rpc_xprt *xprt, struct rpc_task *task);
127 void * (*buf_alloc)(struct rpc_task *task, size_t size);
128 void (*buf_free)(void *buffer);
129 int (*send_request)(struct rpc_task *task);
130 void (*set_retrans_timeout)(struct rpc_task *task);
131 void (*timer)(struct rpc_xprt *xprt, struct rpc_task *task);
132 void (*release_request)(struct rpc_task *task);
133 void (*close)(struct rpc_xprt *xprt);
134 void (*destroy)(struct rpc_xprt *xprt);
135 void (*print_stats)(struct rpc_xprt *xprt, struct seq_file *seq);
136 int (*enable_swap)(struct rpc_xprt *xprt);
137 void (*disable_swap)(struct rpc_xprt *xprt);
138 void (*inject_disconnect)(struct rpc_xprt *xprt);
139};
140
141/*
142 * RPC transport identifiers
143 *
144 * To preserve compatibility with the historical use of raw IP protocol
145 * id's for transport selection, UDP and TCP identifiers are specified
146 * with the previous values. No such restriction exists for new transports,
147 * except that they may not collide with these values (17 and 6,
148 * respectively).
149 */
150#define XPRT_TRANSPORT_BC (1 << 31)
151enum xprt_transports {
152 XPRT_TRANSPORT_UDP = IPPROTO_UDP,
153 XPRT_TRANSPORT_TCP = IPPROTO_TCP,
154 XPRT_TRANSPORT_BC_TCP = IPPROTO_TCP | XPRT_TRANSPORT_BC,
155 XPRT_TRANSPORT_RDMA = 256,
156 XPRT_TRANSPORT_LOCAL = 257,
157};
158
159struct rpc_xprt {
160 atomic_t count; /* Reference count */
161 struct rpc_xprt_ops * ops; /* transport methods */
162
163 const struct rpc_timeout *timeout; /* timeout parms */
164 struct sockaddr_storage addr; /* server address */
165 size_t addrlen; /* size of server address */
166 int prot; /* IP protocol */
167
168 unsigned long cong; /* current congestion */
169 unsigned long cwnd; /* congestion window */
170
171 size_t max_payload; /* largest RPC payload size,
172 in bytes */
173 unsigned int tsh_size; /* size of transport specific
174 header */
175
176 struct rpc_wait_queue binding; /* requests waiting on rpcbind */
177 struct rpc_wait_queue sending; /* requests waiting to send */
178 struct rpc_wait_queue pending; /* requests in flight */
179 struct rpc_wait_queue backlog; /* waiting for slot */
180 struct list_head free; /* free slots */
181 unsigned int max_reqs; /* max number of slots */
182 unsigned int min_reqs; /* min number of slots */
183 atomic_t num_reqs; /* total slots */
184 unsigned long state; /* transport state */
185 unsigned char resvport : 1; /* use a reserved port */
186 atomic_t swapper; /* we're swapping over this
187 transport */
188 unsigned int bind_index; /* bind function index */
189
190 /*
191 * Connection of transports
192 */
193 unsigned long bind_timeout,
194 reestablish_timeout;
195 unsigned int connect_cookie; /* A cookie that gets bumped
196 every time the transport
197 is reconnected */
198
199 /*
200 * Disconnection of idle transports
201 */
202 struct work_struct task_cleanup;
203 struct timer_list timer;
204 unsigned long last_used,
205 idle_timeout;
206
207 /*
208 * Send stuff
209 */
210 spinlock_t transport_lock; /* lock transport info */
211 spinlock_t reserve_lock; /* lock slot table */
212 u32 xid; /* Next XID value to use */
213 struct rpc_task * snd_task; /* Task blocked in send */
214 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
215#if defined(CONFIG_SUNRPC_BACKCHANNEL)
216 struct svc_serv *bc_serv; /* The RPC service which will */
217 /* process the callback */
218 int bc_alloc_count; /* Total number of preallocs */
219 atomic_t bc_free_slots;
220 spinlock_t bc_pa_lock; /* Protects the preallocated
221 * items */
222 struct list_head bc_pa_list; /* List of preallocated
223 * backchannel rpc_rqst's */
224#endif /* CONFIG_SUNRPC_BACKCHANNEL */
225 struct list_head recv;
226
227 struct {
228 unsigned long bind_count, /* total number of binds */
229 connect_count, /* total number of connects */
230 connect_start, /* connect start timestamp */
231 connect_time, /* jiffies waiting for connect */
232 sends, /* how many complete requests */
233 recvs, /* how many complete requests */
234 bad_xids, /* lookup_rqst didn't find XID */
235 max_slots; /* max rpc_slots used */
236
237 unsigned long long req_u, /* average requests on the wire */
238 bklog_u, /* backlog queue utilization */
239 sending_u, /* send q utilization */
240 pending_u; /* pend q utilization */
241 } stat;
242
243 struct net *xprt_net;
244 const char *servername;
245 const char *address_strings[RPC_DISPLAY_MAX];
246#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
247 struct dentry *debugfs; /* debugfs directory */
248 atomic_t inject_disconnect;
249#endif
250};
251
252#if defined(CONFIG_SUNRPC_BACKCHANNEL)
253/*
254 * Backchannel flags
255 */
256#define RPC_BC_PA_IN_USE 0x0001 /* Preallocated backchannel */
257 /* buffer in use */
258#endif /* CONFIG_SUNRPC_BACKCHANNEL */
259
260#if defined(CONFIG_SUNRPC_BACKCHANNEL)
261static inline int bc_prealloc(struct rpc_rqst *req)
262{
263 return test_bit(RPC_BC_PA_IN_USE, &req->rq_bc_pa_state);
264}
265#else
266static inline int bc_prealloc(struct rpc_rqst *req)
267{
268 return 0;
269}
270#endif /* CONFIG_SUNRPC_BACKCHANNEL */
271
272#define XPRT_CREATE_INFINITE_SLOTS (1U)
273#define XPRT_CREATE_NO_IDLE_TIMEOUT (1U << 1)
274
275struct xprt_create {
276 int ident; /* XPRT_TRANSPORT identifier */
277 struct net * net;
278 struct sockaddr * srcaddr; /* optional local address */
279 struct sockaddr * dstaddr; /* remote peer address */
280 size_t addrlen;
281 const char *servername;
282 struct svc_xprt *bc_xprt; /* NFSv4.1 backchannel */
283 unsigned int flags;
284};
285
286struct xprt_class {
287 struct list_head list;
288 int ident; /* XPRT_TRANSPORT identifier */
289 struct rpc_xprt * (*setup)(struct xprt_create *);
290 struct module *owner;
291 char name[32];
292};
293
294/*
295 * Generic internal transport functions
296 */
297struct rpc_xprt *xprt_create_transport(struct xprt_create *args);
298void xprt_connect(struct rpc_task *task);
299void xprt_reserve(struct rpc_task *task);
300void xprt_retry_reserve(struct rpc_task *task);
301int xprt_reserve_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
302int xprt_reserve_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
303void xprt_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
304void xprt_lock_and_alloc_slot(struct rpc_xprt *xprt, struct rpc_task *task);
305bool xprt_prepare_transmit(struct rpc_task *task);
306void xprt_transmit(struct rpc_task *task);
307void xprt_end_transmit(struct rpc_task *task);
308int xprt_adjust_timeout(struct rpc_rqst *req);
309void xprt_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task);
310void xprt_release_xprt_cong(struct rpc_xprt *xprt, struct rpc_task *task);
311void xprt_release(struct rpc_task *task);
312void xprt_put(struct rpc_xprt *xprt);
313struct rpc_xprt * xprt_alloc(struct net *net, size_t size,
314 unsigned int num_prealloc,
315 unsigned int max_req);
316void xprt_free(struct rpc_xprt *);
317
318/**
319 * xprt_get - return a reference to an RPC transport.
320 * @xprt: pointer to the transport
321 *
322 */
323static inline struct rpc_xprt *xprt_get(struct rpc_xprt *xprt)
324{
325 if (atomic_inc_not_zero(&xprt->count))
326 return xprt;
327 return NULL;
328}
329
330static inline __be32 *xprt_skip_transport_header(struct rpc_xprt *xprt, __be32 *p)
331{
332 return p + xprt->tsh_size;
333}
334
335static inline int
336xprt_enable_swap(struct rpc_xprt *xprt)
337{
338 return xprt->ops->enable_swap(xprt);
339}
340
341static inline void
342xprt_disable_swap(struct rpc_xprt *xprt)
343{
344 xprt->ops->disable_swap(xprt);
345}
346
347/*
348 * Transport switch helper functions
349 */
350int xprt_register_transport(struct xprt_class *type);
351int xprt_unregister_transport(struct xprt_class *type);
352int xprt_load_transport(const char *);
353void xprt_set_retrans_timeout_def(struct rpc_task *task);
354void xprt_set_retrans_timeout_rtt(struct rpc_task *task);
355void xprt_wake_pending_tasks(struct rpc_xprt *xprt, int status);
356void xprt_wait_for_buffer_space(struct rpc_task *task, rpc_action action);
357void xprt_write_space(struct rpc_xprt *xprt);
358void xprt_adjust_cwnd(struct rpc_xprt *xprt, struct rpc_task *task, int result);
359struct rpc_rqst * xprt_lookup_rqst(struct rpc_xprt *xprt, __be32 xid);
360void xprt_complete_rqst(struct rpc_task *task, int copied);
361void xprt_release_rqst_cong(struct rpc_task *task);
362void xprt_disconnect_done(struct rpc_xprt *xprt);
363void xprt_force_disconnect(struct rpc_xprt *xprt);
364void xprt_conditional_disconnect(struct rpc_xprt *xprt, unsigned int cookie);
365
366bool xprt_lock_connect(struct rpc_xprt *, struct rpc_task *, void *);
367void xprt_unlock_connect(struct rpc_xprt *, void *);
368
369/*
370 * Reserved bit positions in xprt->state
371 */
372#define XPRT_LOCKED (0)
373#define XPRT_CONNECTED (1)
374#define XPRT_CONNECTING (2)
375#define XPRT_CLOSE_WAIT (3)
376#define XPRT_BOUND (4)
377#define XPRT_BINDING (5)
378#define XPRT_CLOSING (6)
379#define XPRT_CONGESTED (9)
380
381static inline void xprt_set_connected(struct rpc_xprt *xprt)
382{
383 set_bit(XPRT_CONNECTED, &xprt->state);
384}
385
386static inline void xprt_clear_connected(struct rpc_xprt *xprt)
387{
388 clear_bit(XPRT_CONNECTED, &xprt->state);
389}
390
391static inline int xprt_connected(struct rpc_xprt *xprt)
392{
393 return test_bit(XPRT_CONNECTED, &xprt->state);
394}
395
396static inline int xprt_test_and_set_connected(struct rpc_xprt *xprt)
397{
398 return test_and_set_bit(XPRT_CONNECTED, &xprt->state);
399}
400
401static inline int xprt_test_and_clear_connected(struct rpc_xprt *xprt)
402{
403 return test_and_clear_bit(XPRT_CONNECTED, &xprt->state);
404}
405
406static inline void xprt_clear_connecting(struct rpc_xprt *xprt)
407{
408 smp_mb__before_atomic();
409 clear_bit(XPRT_CONNECTING, &xprt->state);
410 smp_mb__after_atomic();
411}
412
413static inline int xprt_connecting(struct rpc_xprt *xprt)
414{
415 return test_bit(XPRT_CONNECTING, &xprt->state);
416}
417
418static inline int xprt_test_and_set_connecting(struct rpc_xprt *xprt)
419{
420 return test_and_set_bit(XPRT_CONNECTING, &xprt->state);
421}
422
423static inline void xprt_set_bound(struct rpc_xprt *xprt)
424{
425 test_and_set_bit(XPRT_BOUND, &xprt->state);
426}
427
428static inline int xprt_bound(struct rpc_xprt *xprt)
429{
430 return test_bit(XPRT_BOUND, &xprt->state);
431}
432
433static inline void xprt_clear_bound(struct rpc_xprt *xprt)
434{
435 clear_bit(XPRT_BOUND, &xprt->state);
436}
437
438static inline void xprt_clear_binding(struct rpc_xprt *xprt)
439{
440 smp_mb__before_atomic();
441 clear_bit(XPRT_BINDING, &xprt->state);
442 smp_mb__after_atomic();
443}
444
445static inline int xprt_test_and_set_binding(struct rpc_xprt *xprt)
446{
447 return test_and_set_bit(XPRT_BINDING, &xprt->state);
448}
449
450#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
451extern unsigned int rpc_inject_disconnect;
452static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
453{
454 if (!rpc_inject_disconnect)
455 return;
456 if (atomic_dec_return(&xprt->inject_disconnect))
457 return;
458 atomic_set(&xprt->inject_disconnect, rpc_inject_disconnect);
459 xprt->ops->inject_disconnect(xprt);
460}
461#else
462static inline void xprt_inject_disconnect(struct rpc_xprt *xprt)
463{
464}
465#endif
466
467#endif /* __KERNEL__*/
468
469#endif /* _LINUX_SUNRPC_XPRT_H */