2 * linux/net/sunrpc/clnt.c
4 * This file contains the high-level RPC interface.
5 * It is modeled as a finite state machine to support both synchronous
6 * and asynchronous requests.
8 * - RPC header generation and argument serialization.
9 * - Credential refresh.
10 * - TCP connect handling.
11 * - Retry of operation when it is suspected the operation failed because
12 * of uid squashing on the server, or when the credentials were stale
13 * and need to be refreshed, or when a packet was damaged in transit.
14 * This may be have to be moved to the VFS layer.
16 * NB: BSD uses a more intelligent approach to guessing when a request
17 * or reply has been lost by keeping the RTO estimate for each procedure.
18 * We currently make do with a constant timeout value.
20 * Copyright (C) 1992,1993 Rick Sladkey <jrs@world.std.com>
21 * Copyright (C) 1995,1996 Olaf Kirch <okir@monad.swb.de>
24 #include <asm/system.h>
26 #include <linux/module.h>
27 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/utsname.h>
31 #include <linux/workqueue.h>
33 #include <linux/sunrpc/clnt.h>
34 #include <linux/sunrpc/rpc_pipe_fs.h>
35 #include <linux/sunrpc/metrics.h>
38 #define RPC_SLACK_SPACE (1024) /* total overkill */
41 # define RPCDBG_FACILITY RPCDBG_CALL
44 static DECLARE_WAIT_QUEUE_HEAD(destroy_wait);
47 static void call_start(struct rpc_task *task);
48 static void call_reserve(struct rpc_task *task);
49 static void call_reserveresult(struct rpc_task *task);
50 static void call_allocate(struct rpc_task *task);
51 static void call_encode(struct rpc_task *task);
52 static void call_decode(struct rpc_task *task);
53 static void call_bind(struct rpc_task *task);
54 static void call_bind_status(struct rpc_task *task);
55 static void call_transmit(struct rpc_task *task);
56 static void call_status(struct rpc_task *task);
57 static void call_transmit_status(struct rpc_task *task);
58 static void call_refresh(struct rpc_task *task);
59 static void call_refreshresult(struct rpc_task *task);
60 static void call_timeout(struct rpc_task *task);
61 static void call_connect(struct rpc_task *task);
62 static void call_connect_status(struct rpc_task *task);
63 static __be32 * call_header(struct rpc_task *task);
64 static __be32 * call_verify(struct rpc_task *task);
68 rpc_setup_pipedir(struct rpc_clnt *clnt, char *dir_name)
70 static uint32_t clntid;
73 clnt->cl_vfsmnt = ERR_PTR(-ENOENT);
74 clnt->cl_dentry = ERR_PTR(-ENOENT);
78 clnt->cl_vfsmnt = rpc_get_mount();
79 if (IS_ERR(clnt->cl_vfsmnt))
80 return PTR_ERR(clnt->cl_vfsmnt);
83 snprintf(clnt->cl_pathname, sizeof(clnt->cl_pathname),
84 "%s/clnt%x", dir_name,
85 (unsigned int)clntid++);
86 clnt->cl_pathname[sizeof(clnt->cl_pathname) - 1] = '\0';
87 clnt->cl_dentry = rpc_mkdir(clnt->cl_pathname, clnt);
88 if (!IS_ERR(clnt->cl_dentry))
90 error = PTR_ERR(clnt->cl_dentry);
91 if (error != -EEXIST) {
92 printk(KERN_INFO "RPC: Couldn't create pipefs entry %s, error %d\n",
93 clnt->cl_pathname, error);
100 static struct rpc_clnt * rpc_new_client(struct rpc_xprt *xprt, char *servname, struct rpc_program *program, u32 vers, rpc_authflavor_t flavor)
102 struct rpc_version *version;
103 struct rpc_clnt *clnt = NULL;
104 struct rpc_auth *auth;
108 dprintk("RPC: creating %s client for %s (xprt %p)\n",
109 program->name, servname, xprt);
114 if (vers >= program->nrvers || !(version = program->version[vers]))
118 clnt = kzalloc(sizeof(*clnt), GFP_KERNEL);
121 atomic_set(&clnt->cl_users, 0);
122 atomic_set(&clnt->cl_count, 1);
123 clnt->cl_parent = clnt;
125 clnt->cl_server = clnt->cl_inline_name;
126 len = strlen(servname) + 1;
127 if (len > sizeof(clnt->cl_inline_name)) {
128 char *buf = kmalloc(len, GFP_KERNEL);
130 clnt->cl_server = buf;
132 len = sizeof(clnt->cl_inline_name);
134 strlcpy(clnt->cl_server, servname, len);
136 clnt->cl_xprt = xprt;
137 clnt->cl_procinfo = version->procs;
138 clnt->cl_maxproc = version->nrprocs;
139 clnt->cl_protname = program->name;
140 clnt->cl_prog = program->number;
141 clnt->cl_vers = version->number;
142 clnt->cl_stats = program->stats;
143 clnt->cl_metrics = rpc_alloc_iostats(clnt);
145 if (clnt->cl_metrics == NULL)
147 clnt->cl_program = program;
149 if (!xprt_bound(clnt->cl_xprt))
150 clnt->cl_autobind = 1;
152 clnt->cl_rtt = &clnt->cl_rtt_default;
153 rpc_init_rtt(&clnt->cl_rtt_default, xprt->timeout.to_initval);
155 err = rpc_setup_pipedir(clnt, program->pipe_dir_name);
159 auth = rpcauth_create(flavor, clnt);
161 printk(KERN_INFO "RPC: Couldn't create auth handle (flavor %u)\n",
167 /* save the nodename */
168 clnt->cl_nodelen = strlen(utsname()->nodename);
169 if (clnt->cl_nodelen > UNX_MAXNODENAME)
170 clnt->cl_nodelen = UNX_MAXNODENAME;
171 memcpy(clnt->cl_nodename, utsname()->nodename, clnt->cl_nodelen);
175 if (!IS_ERR(clnt->cl_dentry)) {
176 rpc_rmdir(clnt->cl_dentry);
180 rpc_free_iostats(clnt->cl_metrics);
182 if (clnt->cl_server != clnt->cl_inline_name)
183 kfree(clnt->cl_server);
192 * rpc_create - create an RPC client and transport with one call
193 * @args: rpc_clnt create argument structure
195 * Creates and initializes an RPC transport and an RPC client.
197 * It can ping the server in order to determine if it is up, and to see if
198 * it supports this program and version. RPC_CLNT_CREATE_NOPING disables
199 * this behavior so asynchronous tasks can also use rpc_create.
201 struct rpc_clnt *rpc_create(struct rpc_create_args *args)
203 struct rpc_xprt *xprt;
204 struct rpc_clnt *clnt;
206 xprt = xprt_create_transport(args->protocol, args->address,
207 args->addrsize, args->timeout);
209 return (struct rpc_clnt *)xprt;
212 * By default, kernel RPC client connects from a reserved port.
213 * CAP_NET_BIND_SERVICE will not be set for unprivileged requesters,
214 * but it is always enabled for rpciod, which handles the connect
218 if (args->flags & RPC_CLNT_CREATE_NONPRIVPORT)
221 dprintk("RPC: creating %s client for %s (xprt %p)\n",
222 args->program->name, args->servername, xprt);
224 clnt = rpc_new_client(xprt, args->servername, args->program,
225 args->version, args->authflavor);
229 if (!(args->flags & RPC_CLNT_CREATE_NOPING)) {
230 int err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
232 rpc_shutdown_client(clnt);
237 clnt->cl_softrtry = 1;
238 if (args->flags & RPC_CLNT_CREATE_HARDRTRY)
239 clnt->cl_softrtry = 0;
241 if (args->flags & RPC_CLNT_CREATE_INTR)
243 if (args->flags & RPC_CLNT_CREATE_AUTOBIND)
244 clnt->cl_autobind = 1;
245 if (args->flags & RPC_CLNT_CREATE_ONESHOT)
246 clnt->cl_oneshot = 1;
250 EXPORT_SYMBOL_GPL(rpc_create);
253 * This function clones the RPC client structure. It allows us to share the
254 * same transport while varying parameters such as the authentication
258 rpc_clone_client(struct rpc_clnt *clnt)
260 struct rpc_clnt *new;
263 new = kmemdup(clnt, sizeof(*new), GFP_KERNEL);
266 atomic_set(&new->cl_count, 1);
267 atomic_set(&new->cl_users, 0);
268 new->cl_metrics = rpc_alloc_iostats(clnt);
269 if (new->cl_metrics == NULL)
271 err = rpc_setup_pipedir(new, clnt->cl_program->pipe_dir_name);
274 new->cl_parent = clnt;
275 atomic_inc(&clnt->cl_count);
276 new->cl_xprt = xprt_get(clnt->cl_xprt);
277 /* Turn off autobind on clones */
278 new->cl_autobind = 0;
281 rpc_init_rtt(&new->cl_rtt_default, clnt->cl_xprt->timeout.to_initval);
283 atomic_inc(&new->cl_auth->au_count);
286 rpc_free_iostats(new->cl_metrics);
290 dprintk("RPC: %s returned error %d\n", __FUNCTION__, err);
295 * Properly shut down an RPC client, terminating all outstanding
296 * requests. Note that we must be certain that cl_oneshot and
297 * cl_dead are cleared, or else the client would be destroyed
298 * when the last task releases it.
301 rpc_shutdown_client(struct rpc_clnt *clnt)
303 dprintk("RPC: shutting down %s client for %s, tasks=%d\n",
304 clnt->cl_protname, clnt->cl_server,
305 atomic_read(&clnt->cl_users));
307 while (atomic_read(&clnt->cl_users) > 0) {
308 /* Don't let rpc_release_client destroy us */
309 clnt->cl_oneshot = 0;
311 rpc_killall_tasks(clnt);
312 wait_event_timeout(destroy_wait,
313 !atomic_read(&clnt->cl_users), 1*HZ);
316 if (atomic_read(&clnt->cl_users) < 0) {
317 printk(KERN_ERR "RPC: rpc_shutdown_client clnt %p tasks=%d\n",
318 clnt, atomic_read(&clnt->cl_users));
325 return rpc_destroy_client(clnt);
329 * Delete an RPC client
332 rpc_destroy_client(struct rpc_clnt *clnt)
334 if (!atomic_dec_and_test(&clnt->cl_count))
336 BUG_ON(atomic_read(&clnt->cl_users) != 0);
338 dprintk("RPC: destroying %s client for %s\n",
339 clnt->cl_protname, clnt->cl_server);
341 rpcauth_destroy(clnt->cl_auth);
342 clnt->cl_auth = NULL;
344 if (!IS_ERR(clnt->cl_dentry)) {
345 rpc_rmdir(clnt->cl_dentry);
348 if (clnt->cl_parent != clnt) {
349 rpc_destroy_client(clnt->cl_parent);
352 if (clnt->cl_server != clnt->cl_inline_name)
353 kfree(clnt->cl_server);
355 rpc_free_iostats(clnt->cl_metrics);
356 clnt->cl_metrics = NULL;
357 xprt_put(clnt->cl_xprt);
363 * Release an RPC client
366 rpc_release_client(struct rpc_clnt *clnt)
368 dprintk("RPC: rpc_release_client(%p, %d)\n",
369 clnt, atomic_read(&clnt->cl_users));
371 if (!atomic_dec_and_test(&clnt->cl_users))
373 wake_up(&destroy_wait);
374 if (clnt->cl_oneshot || clnt->cl_dead)
375 rpc_destroy_client(clnt);
379 * rpc_bind_new_program - bind a new RPC program to an existing client
380 * @old - old rpc_client
381 * @program - rpc program to set
382 * @vers - rpc program version
384 * Clones the rpc client and sets up a new RPC program. This is mainly
385 * of use for enabling different RPC programs to share the same transport.
386 * The Sun NFSv2/v3 ACL protocol can do this.
388 struct rpc_clnt *rpc_bind_new_program(struct rpc_clnt *old,
389 struct rpc_program *program,
392 struct rpc_clnt *clnt;
393 struct rpc_version *version;
396 BUG_ON(vers >= program->nrvers || !program->version[vers]);
397 version = program->version[vers];
398 clnt = rpc_clone_client(old);
401 clnt->cl_procinfo = version->procs;
402 clnt->cl_maxproc = version->nrprocs;
403 clnt->cl_protname = program->name;
404 clnt->cl_prog = program->number;
405 clnt->cl_vers = version->number;
406 clnt->cl_stats = program->stats;
407 err = rpc_ping(clnt, RPC_TASK_SOFT|RPC_TASK_NOINTR);
409 rpc_shutdown_client(clnt);
417 * Default callback for async RPC calls
420 rpc_default_callback(struct rpc_task *task, void *data)
424 static const struct rpc_call_ops rpc_default_ops = {
425 .rpc_call_done = rpc_default_callback,
429 * Export the signal mask handling for synchronous code that
430 * sleeps on RPC calls
432 #define RPC_INTR_SIGNALS (sigmask(SIGHUP) | sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTERM))
434 static void rpc_save_sigmask(sigset_t *oldset, int intr)
436 unsigned long sigallow = sigmask(SIGKILL);
439 /* Block all signals except those listed in sigallow */
441 sigallow |= RPC_INTR_SIGNALS;
442 siginitsetinv(&sigmask, sigallow);
443 sigprocmask(SIG_BLOCK, &sigmask, oldset);
446 static inline void rpc_task_sigmask(struct rpc_task *task, sigset_t *oldset)
448 rpc_save_sigmask(oldset, !RPC_TASK_UNINTERRUPTIBLE(task));
451 static inline void rpc_restore_sigmask(sigset_t *oldset)
453 sigprocmask(SIG_SETMASK, oldset, NULL);
456 void rpc_clnt_sigmask(struct rpc_clnt *clnt, sigset_t *oldset)
458 rpc_save_sigmask(oldset, clnt->cl_intr);
461 void rpc_clnt_sigunmask(struct rpc_clnt *clnt, sigset_t *oldset)
463 rpc_restore_sigmask(oldset);
467 * New rpc_call implementation
469 int rpc_call_sync(struct rpc_clnt *clnt, struct rpc_message *msg, int flags)
471 struct rpc_task *task;
475 /* If this client is slain all further I/O fails */
479 BUG_ON(flags & RPC_TASK_ASYNC);
481 task = rpc_new_task(clnt, flags, &rpc_default_ops, NULL);
485 /* Mask signals on RPC calls _and_ GSS_AUTH upcalls */
486 rpc_task_sigmask(task, &oldset);
488 rpc_call_setup(task, msg, 0);
490 /* Set up the call info struct and execute the task */
491 status = task->tk_status;
493 rpc_release_task(task);
496 atomic_inc(&task->tk_count);
497 status = rpc_execute(task);
499 status = task->tk_status;
502 rpc_restore_sigmask(&oldset);
507 * New rpc_call implementation
510 rpc_call_async(struct rpc_clnt *clnt, struct rpc_message *msg, int flags,
511 const struct rpc_call_ops *tk_ops, void *data)
513 struct rpc_task *task;
517 /* If this client is slain all further I/O fails */
522 flags |= RPC_TASK_ASYNC;
524 /* Create/initialize a new RPC task */
526 if (!(task = rpc_new_task(clnt, flags, tk_ops, data)))
529 /* Mask signals on GSS_AUTH upcalls */
530 rpc_task_sigmask(task, &oldset);
532 rpc_call_setup(task, msg, 0);
534 /* Set up the call info struct and execute the task */
535 status = task->tk_status;
539 rpc_release_task(task);
541 rpc_restore_sigmask(&oldset);
544 rpc_release_calldata(tk_ops, data);
550 rpc_call_setup(struct rpc_task *task, struct rpc_message *msg, int flags)
553 task->tk_flags |= flags;
554 /* Bind the user cred */
555 if (task->tk_msg.rpc_cred != NULL)
556 rpcauth_holdcred(task);
558 rpcauth_bindcred(task);
560 if (task->tk_status == 0)
561 task->tk_action = call_start;
563 task->tk_action = rpc_exit_task;
567 * rpc_peeraddr - extract remote peer address from clnt's xprt
568 * @clnt: RPC client structure
569 * @buf: target buffer
570 * @size: length of target buffer
572 * Returns the number of bytes that are actually in the stored address.
574 size_t rpc_peeraddr(struct rpc_clnt *clnt, struct sockaddr *buf, size_t bufsize)
577 struct rpc_xprt *xprt = clnt->cl_xprt;
579 bytes = sizeof(xprt->addr);
582 memcpy(buf, &clnt->cl_xprt->addr, bytes);
583 return xprt->addrlen;
585 EXPORT_SYMBOL_GPL(rpc_peeraddr);
588 * rpc_peeraddr2str - return remote peer address in printable format
589 * @clnt: RPC client structure
590 * @format: address format
593 char *rpc_peeraddr2str(struct rpc_clnt *clnt, enum rpc_display_format_t format)
595 struct rpc_xprt *xprt = clnt->cl_xprt;
596 return xprt->ops->print_addr(xprt, format);
598 EXPORT_SYMBOL_GPL(rpc_peeraddr2str);
601 rpc_setbufsize(struct rpc_clnt *clnt, unsigned int sndsize, unsigned int rcvsize)
603 struct rpc_xprt *xprt = clnt->cl_xprt;
604 if (xprt->ops->set_buffer_size)
605 xprt->ops->set_buffer_size(xprt, sndsize, rcvsize);
609 * Return size of largest payload RPC client can support, in bytes
611 * For stream transports, this is one RPC record fragment (see RFC
612 * 1831), as we don't support multi-record requests yet. For datagram
613 * transports, this is the size of an IP packet minus the IP, UDP, and
616 size_t rpc_max_payload(struct rpc_clnt *clnt)
618 return clnt->cl_xprt->max_payload;
620 EXPORT_SYMBOL_GPL(rpc_max_payload);
623 * rpc_force_rebind - force transport to check that remote port is unchanged
624 * @clnt: client to rebind
627 void rpc_force_rebind(struct rpc_clnt *clnt)
629 if (clnt->cl_autobind)
630 xprt_clear_bound(clnt->cl_xprt);
632 EXPORT_SYMBOL_GPL(rpc_force_rebind);
635 * Restart an (async) RPC call. Usually called from within the
639 rpc_restart_call(struct rpc_task *task)
641 if (RPC_ASSASSINATED(task))
644 task->tk_action = call_start;
650 * Other FSM states can be visited zero or more times, but
651 * this state is visited exactly once for each RPC.
654 call_start(struct rpc_task *task)
656 struct rpc_clnt *clnt = task->tk_client;
658 dprintk("RPC: %4d call_start %s%d proc %d (%s)\n", task->tk_pid,
659 clnt->cl_protname, clnt->cl_vers, task->tk_msg.rpc_proc->p_proc,
660 (RPC_IS_ASYNC(task) ? "async" : "sync"));
662 /* Increment call count */
663 task->tk_msg.rpc_proc->p_count++;
664 clnt->cl_stats->rpccnt++;
665 task->tk_action = call_reserve;
669 * 1. Reserve an RPC call slot
672 call_reserve(struct rpc_task *task)
674 dprintk("RPC: %4d call_reserve\n", task->tk_pid);
676 if (!rpcauth_uptodatecred(task)) {
677 task->tk_action = call_refresh;
682 task->tk_action = call_reserveresult;
687 * 1b. Grok the result of xprt_reserve()
690 call_reserveresult(struct rpc_task *task)
692 int status = task->tk_status;
694 dprintk("RPC: %4d call_reserveresult (status %d)\n",
695 task->tk_pid, task->tk_status);
698 * After a call to xprt_reserve(), we must have either
699 * a request slot or else an error status.
703 if (task->tk_rqstp) {
704 task->tk_action = call_allocate;
708 printk(KERN_ERR "%s: status=%d, but no request slot, exiting\n",
709 __FUNCTION__, status);
710 rpc_exit(task, -EIO);
715 * Even though there was an error, we may have acquired
716 * a request slot somehow. Make sure not to leak it.
718 if (task->tk_rqstp) {
719 printk(KERN_ERR "%s: status=%d, request allocated anyway\n",
720 __FUNCTION__, status);
725 case -EAGAIN: /* woken up; retry */
726 task->tk_action = call_reserve;
728 case -EIO: /* probably a shutdown */
731 printk(KERN_ERR "%s: unrecognized error %d, exiting\n",
732 __FUNCTION__, status);
735 rpc_exit(task, status);
739 * 2. Allocate the buffer. For details, see sched.c:rpc_malloc.
740 * (Note: buffer memory is freed in xprt_release).
743 call_allocate(struct rpc_task *task)
745 struct rpc_rqst *req = task->tk_rqstp;
746 struct rpc_xprt *xprt = task->tk_xprt;
749 dprintk("RPC: %4d call_allocate (status %d)\n",
750 task->tk_pid, task->tk_status);
751 task->tk_action = call_bind;
755 /* FIXME: compute buffer requirements more exactly using
757 bufsiz = task->tk_msg.rpc_proc->p_bufsiz + RPC_SLACK_SPACE;
759 if (xprt->ops->buf_alloc(task, bufsiz << 1) != NULL)
761 printk(KERN_INFO "RPC: buffer allocation failed for task %p\n", task);
763 if (RPC_IS_ASYNC(task) || !signalled()) {
765 task->tk_action = call_reserve;
766 rpc_delay(task, HZ>>4);
770 rpc_exit(task, -ERESTARTSYS);
774 rpc_task_need_encode(struct rpc_task *task)
776 return task->tk_rqstp->rq_snd_buf.len == 0;
780 rpc_task_force_reencode(struct rpc_task *task)
782 task->tk_rqstp->rq_snd_buf.len = 0;
786 * 3. Encode arguments of an RPC call
789 call_encode(struct rpc_task *task)
791 struct rpc_rqst *req = task->tk_rqstp;
792 struct xdr_buf *sndbuf = &req->rq_snd_buf;
793 struct xdr_buf *rcvbuf = &req->rq_rcv_buf;
798 dprintk("RPC: %4d call_encode (status %d)\n",
799 task->tk_pid, task->tk_status);
801 /* Default buffer setup */
802 bufsiz = req->rq_bufsize >> 1;
803 sndbuf->head[0].iov_base = (void *)req->rq_buffer;
804 sndbuf->head[0].iov_len = bufsiz;
805 sndbuf->tail[0].iov_len = 0;
806 sndbuf->page_len = 0;
808 sndbuf->buflen = bufsiz;
809 rcvbuf->head[0].iov_base = (void *)((char *)req->rq_buffer + bufsiz);
810 rcvbuf->head[0].iov_len = bufsiz;
811 rcvbuf->tail[0].iov_len = 0;
812 rcvbuf->page_len = 0;
814 rcvbuf->buflen = bufsiz;
816 /* Encode header and provided arguments */
817 encode = task->tk_msg.rpc_proc->p_encode;
818 if (!(p = call_header(task))) {
819 printk(KERN_INFO "RPC: call_header failed, exit EIO\n");
820 rpc_exit(task, -EIO);
826 task->tk_status = rpcauth_wrap_req(task, encode, req, p,
827 task->tk_msg.rpc_argp);
828 if (task->tk_status == -ENOMEM) {
829 /* XXX: Is this sane? */
830 rpc_delay(task, 3*HZ);
831 task->tk_status = -EAGAIN;
836 * 4. Get the server port number if not yet set
839 call_bind(struct rpc_task *task)
841 struct rpc_xprt *xprt = task->tk_xprt;
843 dprintk("RPC: %4d call_bind (status %d)\n",
844 task->tk_pid, task->tk_status);
846 task->tk_action = call_connect;
847 if (!xprt_bound(xprt)) {
848 task->tk_action = call_bind_status;
849 task->tk_timeout = xprt->bind_timeout;
850 xprt->ops->rpcbind(task);
855 * 4a. Sort out bind result
858 call_bind_status(struct rpc_task *task)
860 int status = -EACCES;
862 if (task->tk_status >= 0) {
863 dprintk("RPC: %4d call_bind_status (status %d)\n",
864 task->tk_pid, task->tk_status);
866 task->tk_action = call_connect;
870 switch (task->tk_status) {
872 dprintk("RPC: %4d remote rpcbind: RPC program/version unavailable\n",
874 rpc_delay(task, 3*HZ);
877 dprintk("RPC: %4d rpcbind request timed out\n",
881 dprintk("RPC: %4d remote rpcbind service unavailable\n",
884 case -EPROTONOSUPPORT:
885 dprintk("RPC: %4d remote rpcbind version 2 unavailable\n",
889 dprintk("RPC: %4d unrecognized rpcbind error (%d)\n",
890 task->tk_pid, -task->tk_status);
894 rpc_exit(task, status);
898 task->tk_action = call_timeout;
902 * 4b. Connect to the RPC server
905 call_connect(struct rpc_task *task)
907 struct rpc_xprt *xprt = task->tk_xprt;
909 dprintk("RPC: %4d call_connect xprt %p %s connected\n",
911 (xprt_connected(xprt) ? "is" : "is not"));
913 task->tk_action = call_transmit;
914 if (!xprt_connected(xprt)) {
915 task->tk_action = call_connect_status;
916 if (task->tk_status < 0)
923 * 4c. Sort out connect result
926 call_connect_status(struct rpc_task *task)
928 struct rpc_clnt *clnt = task->tk_client;
929 int status = task->tk_status;
931 dprintk("RPC: %5u call_connect_status (status %d)\n",
932 task->tk_pid, task->tk_status);
936 clnt->cl_stats->netreconn++;
937 task->tk_action = call_transmit;
941 /* Something failed: remote service port may have changed */
942 rpc_force_rebind(clnt);
947 task->tk_action = call_bind;
948 if (!RPC_IS_SOFT(task))
950 /* if soft mounted, test if we've timed out */
952 task->tk_action = call_timeout;
955 rpc_exit(task, -EIO);
959 * 5. Transmit the RPC request, and wait for reply
962 call_transmit(struct rpc_task *task)
964 dprintk("RPC: %4d call_transmit (status %d)\n",
965 task->tk_pid, task->tk_status);
967 task->tk_action = call_status;
968 if (task->tk_status < 0)
970 task->tk_status = xprt_prepare_transmit(task);
971 if (task->tk_status != 0)
973 task->tk_action = call_transmit_status;
974 /* Encode here so that rpcsec_gss can use correct sequence number. */
975 if (rpc_task_need_encode(task)) {
976 BUG_ON(task->tk_rqstp->rq_bytes_sent != 0);
978 /* Did the encode result in an error condition? */
979 if (task->tk_status != 0)
983 if (task->tk_status < 0)
986 * On success, ensure that we call xprt_end_transmit() before sleeping
987 * in order to allow access to the socket to other RPC requests.
989 call_transmit_status(task);
990 if (task->tk_msg.rpc_proc->p_decode != NULL)
992 task->tk_action = rpc_exit_task;
993 rpc_wake_up_task(task);
997 * 5a. Handle cleanup after a transmission
1000 call_transmit_status(struct rpc_task *task)
1002 task->tk_action = call_status;
1004 * Special case: if we've been waiting on the socket's write_space()
1005 * callback, then don't call xprt_end_transmit().
1007 if (task->tk_status == -EAGAIN)
1009 xprt_end_transmit(task);
1010 rpc_task_force_reencode(task);
1014 * 6. Sort out the RPC call status
1017 call_status(struct rpc_task *task)
1019 struct rpc_clnt *clnt = task->tk_client;
1020 struct rpc_rqst *req = task->tk_rqstp;
1023 if (req->rq_received > 0 && !req->rq_bytes_sent)
1024 task->tk_status = req->rq_received;
1026 dprintk("RPC: %4d call_status (status %d)\n",
1027 task->tk_pid, task->tk_status);
1029 status = task->tk_status;
1031 task->tk_action = call_decode;
1035 task->tk_status = 0;
1041 * Delay any retries for 3 seconds, then handle as if it
1044 rpc_delay(task, 3*HZ);
1046 task->tk_action = call_timeout;
1050 rpc_force_rebind(clnt);
1051 task->tk_action = call_bind;
1054 task->tk_action = call_transmit;
1057 /* shutdown or soft timeout */
1058 rpc_exit(task, status);
1061 printk("%s: RPC call returned error %d\n",
1062 clnt->cl_protname, -status);
1063 rpc_exit(task, status);
1068 * 6a. Handle RPC timeout
1069 * We do not release the request slot, so we keep using the
1070 * same XID for all retransmits.
1073 call_timeout(struct rpc_task *task)
1075 struct rpc_clnt *clnt = task->tk_client;
1077 if (xprt_adjust_timeout(task->tk_rqstp) == 0) {
1078 dprintk("RPC: %4d call_timeout (minor)\n", task->tk_pid);
1082 dprintk("RPC: %4d call_timeout (major)\n", task->tk_pid);
1083 task->tk_timeouts++;
1085 if (RPC_IS_SOFT(task)) {
1086 printk(KERN_NOTICE "%s: server %s not responding, timed out\n",
1087 clnt->cl_protname, clnt->cl_server);
1088 rpc_exit(task, -EIO);
1092 if (!(task->tk_flags & RPC_CALL_MAJORSEEN)) {
1093 task->tk_flags |= RPC_CALL_MAJORSEEN;
1094 printk(KERN_NOTICE "%s: server %s not responding, still trying\n",
1095 clnt->cl_protname, clnt->cl_server);
1097 rpc_force_rebind(clnt);
1100 clnt->cl_stats->rpcretrans++;
1101 task->tk_action = call_bind;
1102 task->tk_status = 0;
1106 * 7. Decode the RPC reply
1109 call_decode(struct rpc_task *task)
1111 struct rpc_clnt *clnt = task->tk_client;
1112 struct rpc_rqst *req = task->tk_rqstp;
1113 kxdrproc_t decode = task->tk_msg.rpc_proc->p_decode;
1116 dprintk("RPC: %4d call_decode (status %d)\n",
1117 task->tk_pid, task->tk_status);
1119 if (task->tk_flags & RPC_CALL_MAJORSEEN) {
1120 printk(KERN_NOTICE "%s: server %s OK\n",
1121 clnt->cl_protname, clnt->cl_server);
1122 task->tk_flags &= ~RPC_CALL_MAJORSEEN;
1125 if (task->tk_status < 12) {
1126 if (!RPC_IS_SOFT(task)) {
1127 task->tk_action = call_bind;
1128 clnt->cl_stats->rpcretrans++;
1131 dprintk("%s: too small RPC reply size (%d bytes)\n",
1132 clnt->cl_protname, task->tk_status);
1133 task->tk_action = call_timeout;
1138 * Ensure that we see all writes made by xprt_complete_rqst()
1139 * before it changed req->rq_received.
1142 req->rq_rcv_buf.len = req->rq_private_buf.len;
1144 /* Check that the softirq receive buffer is valid */
1145 WARN_ON(memcmp(&req->rq_rcv_buf, &req->rq_private_buf,
1146 sizeof(req->rq_rcv_buf)) != 0);
1148 /* Verify the RPC header */
1149 p = call_verify(task);
1151 if (p == ERR_PTR(-EAGAIN))
1156 task->tk_action = rpc_exit_task;
1159 task->tk_status = rpcauth_unwrap_resp(task, decode, req, p,
1160 task->tk_msg.rpc_resp);
1161 dprintk("RPC: %4d call_decode result %d\n", task->tk_pid,
1165 req->rq_received = req->rq_private_buf.len = 0;
1166 task->tk_status = 0;
1170 * 8. Refresh the credentials if rejected by the server
1173 call_refresh(struct rpc_task *task)
1175 dprintk("RPC: %4d call_refresh\n", task->tk_pid);
1177 xprt_release(task); /* Must do to obtain new XID */
1178 task->tk_action = call_refreshresult;
1179 task->tk_status = 0;
1180 task->tk_client->cl_stats->rpcauthrefresh++;
1181 rpcauth_refreshcred(task);
1185 * 8a. Process the results of a credential refresh
1188 call_refreshresult(struct rpc_task *task)
1190 int status = task->tk_status;
1191 dprintk("RPC: %4d call_refreshresult (status %d)\n",
1192 task->tk_pid, task->tk_status);
1194 task->tk_status = 0;
1195 task->tk_action = call_reserve;
1196 if (status >= 0 && rpcauth_uptodatecred(task))
1198 if (status == -EACCES) {
1199 rpc_exit(task, -EACCES);
1202 task->tk_action = call_refresh;
1203 if (status != -ETIMEDOUT)
1204 rpc_delay(task, 3*HZ);
1209 * Call header serialization
1212 call_header(struct rpc_task *task)
1214 struct rpc_clnt *clnt = task->tk_client;
1215 struct rpc_rqst *req = task->tk_rqstp;
1216 __be32 *p = req->rq_svec[0].iov_base;
1218 /* FIXME: check buffer size? */
1220 p = xprt_skip_transport_header(task->tk_xprt, p);
1221 *p++ = req->rq_xid; /* XID */
1222 *p++ = htonl(RPC_CALL); /* CALL */
1223 *p++ = htonl(RPC_VERSION); /* RPC version */
1224 *p++ = htonl(clnt->cl_prog); /* program number */
1225 *p++ = htonl(clnt->cl_vers); /* program version */
1226 *p++ = htonl(task->tk_msg.rpc_proc->p_proc); /* procedure */
1227 p = rpcauth_marshcred(task, p);
1228 req->rq_slen = xdr_adjust_iovec(&req->rq_svec[0], p);
1233 * Reply header verification
1236 call_verify(struct rpc_task *task)
1238 struct kvec *iov = &task->tk_rqstp->rq_rcv_buf.head[0];
1239 int len = task->tk_rqstp->rq_rcv_buf.len >> 2;
1240 __be32 *p = iov->iov_base;
1242 int error = -EACCES;
1244 if ((task->tk_rqstp->rq_rcv_buf.len & 3) != 0) {
1245 /* RFC-1014 says that the representation of XDR data must be a
1246 * multiple of four bytes
1247 * - if it isn't pointer subtraction in the NFS client may give
1251 "call_verify: XDR representation not a multiple of"
1252 " 4 bytes: 0x%x\n", task->tk_rqstp->rq_rcv_buf.len);
1257 p += 1; /* skip XID */
1259 if ((n = ntohl(*p++)) != RPC_REPLY) {
1260 printk(KERN_WARNING "call_verify: not an RPC reply: %x\n", n);
1263 if ((n = ntohl(*p++)) != RPC_MSG_ACCEPTED) {
1266 switch ((n = ntohl(*p++))) {
1267 case RPC_AUTH_ERROR:
1270 dprintk("%s: RPC call version mismatch!\n", __FUNCTION__);
1271 error = -EPROTONOSUPPORT;
1274 dprintk("%s: RPC call rejected, unknown error: %x\n", __FUNCTION__, n);
1279 switch ((n = ntohl(*p++))) {
1280 case RPC_AUTH_REJECTEDCRED:
1281 case RPC_AUTH_REJECTEDVERF:
1282 case RPCSEC_GSS_CREDPROBLEM:
1283 case RPCSEC_GSS_CTXPROBLEM:
1284 if (!task->tk_cred_retry)
1286 task->tk_cred_retry--;
1287 dprintk("RPC: %4d call_verify: retry stale creds\n",
1289 rpcauth_invalcred(task);
1290 task->tk_action = call_refresh;
1292 case RPC_AUTH_BADCRED:
1293 case RPC_AUTH_BADVERF:
1294 /* possibly garbled cred/verf? */
1295 if (!task->tk_garb_retry)
1297 task->tk_garb_retry--;
1298 dprintk("RPC: %4d call_verify: retry garbled creds\n",
1300 task->tk_action = call_bind;
1302 case RPC_AUTH_TOOWEAK:
1303 printk(KERN_NOTICE "call_verify: server %s requires stronger "
1304 "authentication.\n", task->tk_client->cl_server);
1307 printk(KERN_WARNING "call_verify: unknown auth error: %x\n", n);
1310 dprintk("RPC: %4d call_verify: call rejected %d\n",
1314 if (!(p = rpcauth_checkverf(task, p))) {
1315 printk(KERN_WARNING "call_verify: auth check failed\n");
1316 goto out_garbage; /* bad verifier, retry */
1318 len = p - (__be32 *)iov->iov_base - 1;
1321 switch ((n = ntohl(*p++))) {
1324 case RPC_PROG_UNAVAIL:
1325 dprintk("RPC: call_verify: program %u is unsupported by server %s\n",
1326 (unsigned int)task->tk_client->cl_prog,
1327 task->tk_client->cl_server);
1328 error = -EPFNOSUPPORT;
1330 case RPC_PROG_MISMATCH:
1331 dprintk("RPC: call_verify: program %u, version %u unsupported by server %s\n",
1332 (unsigned int)task->tk_client->cl_prog,
1333 (unsigned int)task->tk_client->cl_vers,
1334 task->tk_client->cl_server);
1335 error = -EPROTONOSUPPORT;
1337 case RPC_PROC_UNAVAIL:
1338 dprintk("RPC: call_verify: proc %p unsupported by program %u, version %u on server %s\n",
1339 task->tk_msg.rpc_proc,
1340 task->tk_client->cl_prog,
1341 task->tk_client->cl_vers,
1342 task->tk_client->cl_server);
1343 error = -EOPNOTSUPP;
1345 case RPC_GARBAGE_ARGS:
1346 dprintk("RPC: %4d %s: server saw garbage\n", task->tk_pid, __FUNCTION__);
1349 printk(KERN_WARNING "call_verify: server accept status: %x\n", n);
1354 task->tk_client->cl_stats->rpcgarbage++;
1355 if (task->tk_garb_retry) {
1356 task->tk_garb_retry--;
1357 dprintk("RPC %s: retrying %4d\n", __FUNCTION__, task->tk_pid);
1358 task->tk_action = call_bind;
1360 return ERR_PTR(-EAGAIN);
1362 printk(KERN_WARNING "RPC %s: retry failed, exit EIO\n", __FUNCTION__);
1366 rpc_exit(task, error);
1367 return ERR_PTR(error);
1369 printk(KERN_WARNING "RPC %s: server reply was truncated.\n", __FUNCTION__);
1373 static int rpcproc_encode_null(void *rqstp, __be32 *data, void *obj)
1378 static int rpcproc_decode_null(void *rqstp, __be32 *data, void *obj)
1383 static struct rpc_procinfo rpcproc_null = {
1384 .p_encode = rpcproc_encode_null,
1385 .p_decode = rpcproc_decode_null,
1388 int rpc_ping(struct rpc_clnt *clnt, int flags)
1390 struct rpc_message msg = {
1391 .rpc_proc = &rpcproc_null,
1394 msg.rpc_cred = authnull_ops.lookup_cred(NULL, NULL, 0);
1395 err = rpc_call_sync(clnt, &msg, flags);
1396 put_rpccred(msg.rpc_cred);