xref: /linux/fs/nfs/nfs4client.c (revision 8f8d5745bb520c76b81abef4a2cb3023d0313bfd)
1 /*
2  * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
3  * Written by David Howells (dhowells@redhat.com)
4  */
5 #include <linux/module.h>
6 #include <linux/nfs_fs.h>
7 #include <linux/nfs_mount.h>
8 #include <linux/sunrpc/addr.h>
9 #include <linux/sunrpc/auth.h>
10 #include <linux/sunrpc/xprt.h>
11 #include <linux/sunrpc/bc_xprt.h>
12 #include <linux/sunrpc/rpc_pipe_fs.h>
13 #include "internal.h"
14 #include "callback.h"
15 #include "delegation.h"
16 #include "nfs4session.h"
17 #include "nfs4idmap.h"
18 #include "pnfs.h"
19 #include "netns.h"
20 
21 #define NFSDBG_FACILITY		NFSDBG_CLIENT
22 
23 /*
24  * Get a unique NFSv4.0 callback identifier which will be used
25  * by the V4.0 callback service to lookup the nfs_client struct
26  */
27 static int nfs_get_cb_ident_idr(struct nfs_client *clp, int minorversion)
28 {
29 	int ret = 0;
30 	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
31 
32 	if (clp->rpc_ops->version != 4 || minorversion != 0)
33 		return ret;
34 	idr_preload(GFP_KERNEL);
35 	spin_lock(&nn->nfs_client_lock);
36 	ret = idr_alloc(&nn->cb_ident_idr, clp, 1, 0, GFP_NOWAIT);
37 	if (ret >= 0)
38 		clp->cl_cb_ident = ret;
39 	spin_unlock(&nn->nfs_client_lock);
40 	idr_preload_end();
41 	return ret < 0 ? ret : 0;
42 }
43 
44 #ifdef CONFIG_NFS_V4_1
45 /*
46  * Per auth flavor data server rpc clients
47  */
48 struct nfs4_ds_server {
49 	struct list_head	list;   /* ds_clp->cl_ds_clients */
50 	struct rpc_clnt		*rpc_clnt;
51 };
52 
53 /**
54  * nfs4_find_ds_client - Common lookup case for DS I/O
55  * @ds_clp: pointer to the DS's nfs_client
56  * @flavor: rpc auth flavour to match
57  */
58 static struct nfs4_ds_server *
59 nfs4_find_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
60 {
61 	struct nfs4_ds_server *dss;
62 
63 	rcu_read_lock();
64 	list_for_each_entry_rcu(dss, &ds_clp->cl_ds_clients, list) {
65 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
66 			continue;
67 		goto out;
68 	}
69 	dss = NULL;
70 out:
71 	rcu_read_unlock();
72 	return dss;
73 }
74 
75 static struct nfs4_ds_server *
76 nfs4_add_ds_client(struct nfs_client *ds_clp, rpc_authflavor_t flavor,
77 			   struct nfs4_ds_server *new)
78 {
79 	struct nfs4_ds_server *dss;
80 
81 	spin_lock(&ds_clp->cl_lock);
82 	list_for_each_entry(dss, &ds_clp->cl_ds_clients, list) {
83 		if (dss->rpc_clnt->cl_auth->au_flavor != flavor)
84 			continue;
85 		goto out;
86 	}
87 	if (new)
88 		list_add_rcu(&new->list, &ds_clp->cl_ds_clients);
89 	dss = new;
90 out:
91 	spin_unlock(&ds_clp->cl_lock); /* need some lock to protect list */
92 	return dss;
93 }
94 
95 static struct nfs4_ds_server *
96 nfs4_alloc_ds_server(struct nfs_client *ds_clp, rpc_authflavor_t flavor)
97 {
98 	struct nfs4_ds_server *dss;
99 
100 	dss = kmalloc(sizeof(*dss), GFP_NOFS);
101 	if (dss == NULL)
102 		return ERR_PTR(-ENOMEM);
103 
104 	dss->rpc_clnt = rpc_clone_client_set_auth(ds_clp->cl_rpcclient, flavor);
105 	if (IS_ERR(dss->rpc_clnt)) {
106 		int err = PTR_ERR(dss->rpc_clnt);
107 		kfree (dss);
108 		return ERR_PTR(err);
109 	}
110 	INIT_LIST_HEAD(&dss->list);
111 
112 	return dss;
113 }
114 
115 static void
116 nfs4_free_ds_server(struct nfs4_ds_server *dss)
117 {
118 	rpc_release_client(dss->rpc_clnt);
119 	kfree(dss);
120 }
121 
122 /**
123  * nfs4_find_or_create_ds_client - Find or create a DS rpc client
124  * @ds_clp: pointer to the DS's nfs_client
125  * @inode: pointer to the inode
126  *
127  * Find or create a DS rpc client with th MDS server rpc client auth flavor
128  * in the nfs_client cl_ds_clients list.
129  */
130 struct rpc_clnt *
131 nfs4_find_or_create_ds_client(struct nfs_client *ds_clp, struct inode *inode)
132 {
133 	struct nfs4_ds_server *dss, *new;
134 	rpc_authflavor_t flavor = NFS_SERVER(inode)->client->cl_auth->au_flavor;
135 
136 	dss = nfs4_find_ds_client(ds_clp, flavor);
137 	if (dss != NULL)
138 		goto out;
139 	new = nfs4_alloc_ds_server(ds_clp, flavor);
140 	if (IS_ERR(new))
141 		return ERR_CAST(new);
142 	dss = nfs4_add_ds_client(ds_clp, flavor, new);
143 	if (dss != new)
144 		nfs4_free_ds_server(new);
145 out:
146 	return dss->rpc_clnt;
147 }
148 EXPORT_SYMBOL_GPL(nfs4_find_or_create_ds_client);
149 
150 static void
151 nfs4_shutdown_ds_clients(struct nfs_client *clp)
152 {
153 	struct nfs4_ds_server *dss;
154 
155 	while (!list_empty(&clp->cl_ds_clients)) {
156 		dss = list_entry(clp->cl_ds_clients.next,
157 					struct nfs4_ds_server, list);
158 		list_del(&dss->list);
159 		rpc_shutdown_client(dss->rpc_clnt);
160 		kfree (dss);
161 	}
162 }
163 
164 static void
165 nfs4_cleanup_callback(struct nfs_client *clp)
166 {
167 	struct nfs4_copy_state *cp_state;
168 
169 	while (!list_empty(&clp->pending_cb_stateids)) {
170 		cp_state = list_entry(clp->pending_cb_stateids.next,
171 					struct nfs4_copy_state, copies);
172 		list_del(&cp_state->copies);
173 		kfree(cp_state);
174 	}
175 }
176 
177 void nfs41_shutdown_client(struct nfs_client *clp)
178 {
179 	if (nfs4_has_session(clp)) {
180 		nfs4_cleanup_callback(clp);
181 		nfs4_shutdown_ds_clients(clp);
182 		nfs4_destroy_session(clp->cl_session);
183 		nfs4_destroy_clientid(clp);
184 	}
185 
186 }
187 #endif	/* CONFIG_NFS_V4_1 */
188 
189 void nfs40_shutdown_client(struct nfs_client *clp)
190 {
191 	if (clp->cl_slot_tbl) {
192 		nfs4_shutdown_slot_table(clp->cl_slot_tbl);
193 		kfree(clp->cl_slot_tbl);
194 	}
195 }
196 
197 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init)
198 {
199 	int err;
200 	struct nfs_client *clp = nfs_alloc_client(cl_init);
201 	if (IS_ERR(clp))
202 		return clp;
203 
204 	err = nfs_get_cb_ident_idr(clp, cl_init->minorversion);
205 	if (err)
206 		goto error;
207 
208 	if (cl_init->minorversion > NFS4_MAX_MINOR_VERSION) {
209 		err = -EINVAL;
210 		goto error;
211 	}
212 
213 	spin_lock_init(&clp->cl_lock);
214 	INIT_DELAYED_WORK(&clp->cl_renewd, nfs4_renew_state);
215 	INIT_LIST_HEAD(&clp->cl_ds_clients);
216 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS client");
217 	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;
218 	clp->cl_minorversion = cl_init->minorversion;
219 	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];
220 	clp->cl_mig_gen = 1;
221 #if IS_ENABLED(CONFIG_NFS_V4_1)
222 	init_waitqueue_head(&clp->cl_lock_waitq);
223 #endif
224 	INIT_LIST_HEAD(&clp->pending_cb_stateids);
225 	return clp;
226 
227 error:
228 	nfs_free_client(clp);
229 	return ERR_PTR(err);
230 }
231 
232 /*
233  * Destroy the NFS4 callback service
234  */
235 static void nfs4_destroy_callback(struct nfs_client *clp)
236 {
237 	if (__test_and_clear_bit(NFS_CS_CALLBACK, &clp->cl_res_state))
238 		nfs_callback_down(clp->cl_mvops->minor_version, clp->cl_net);
239 }
240 
241 static void nfs4_shutdown_client(struct nfs_client *clp)
242 {
243 	if (__test_and_clear_bit(NFS_CS_RENEWD, &clp->cl_res_state))
244 		nfs4_kill_renewd(clp);
245 	clp->cl_mvops->shutdown_client(clp);
246 	nfs4_destroy_callback(clp);
247 	if (__test_and_clear_bit(NFS_CS_IDMAP, &clp->cl_res_state))
248 		nfs_idmap_delete(clp);
249 
250 	rpc_destroy_wait_queue(&clp->cl_rpcwaitq);
251 	kfree(clp->cl_serverowner);
252 	kfree(clp->cl_serverscope);
253 	kfree(clp->cl_implid);
254 	kfree(clp->cl_owner_id);
255 }
256 
257 void nfs4_free_client(struct nfs_client *clp)
258 {
259 	nfs4_shutdown_client(clp);
260 	nfs_free_client(clp);
261 }
262 
263 /*
264  * Initialize the NFS4 callback service
265  */
266 static int nfs4_init_callback(struct nfs_client *clp)
267 {
268 	struct rpc_xprt *xprt;
269 	int error;
270 
271 	xprt = rcu_dereference_raw(clp->cl_rpcclient->cl_xprt);
272 
273 	if (nfs4_has_session(clp)) {
274 		error = xprt_setup_backchannel(xprt, NFS41_BC_MIN_CALLBACKS);
275 		if (error < 0)
276 			return error;
277 	}
278 
279 	error = nfs_callback_up(clp->cl_mvops->minor_version, xprt);
280 	if (error < 0) {
281 		dprintk("%s: failed to start callback. Error = %d\n",
282 			__func__, error);
283 		return error;
284 	}
285 	__set_bit(NFS_CS_CALLBACK, &clp->cl_res_state);
286 
287 	return 0;
288 }
289 
290 /**
291  * nfs40_init_client - nfs_client initialization tasks for NFSv4.0
292  * @clp: nfs_client to initialize
293  *
294  * Returns zero on success, or a negative errno if some error occurred.
295  */
296 int nfs40_init_client(struct nfs_client *clp)
297 {
298 	struct nfs4_slot_table *tbl;
299 	int ret;
300 
301 	tbl = kzalloc(sizeof(*tbl), GFP_NOFS);
302 	if (tbl == NULL)
303 		return -ENOMEM;
304 
305 	ret = nfs4_setup_slot_table(tbl, NFS4_MAX_SLOT_TABLE,
306 					"NFSv4.0 transport Slot table");
307 	if (ret) {
308 		kfree(tbl);
309 		return ret;
310 	}
311 
312 	clp->cl_slot_tbl = tbl;
313 	return 0;
314 }
315 
316 #if defined(CONFIG_NFS_V4_1)
317 
318 /**
319  * nfs41_init_client - nfs_client initialization tasks for NFSv4.1+
320  * @clp: nfs_client to initialize
321  *
322  * Returns zero on success, or a negative errno if some error occurred.
323  */
324 int nfs41_init_client(struct nfs_client *clp)
325 {
326 	struct nfs4_session *session = NULL;
327 
328 	/*
329 	 * Create the session and mark it expired.
330 	 * When a SEQUENCE operation encounters the expired session
331 	 * it will do session recovery to initialize it.
332 	 */
333 	session = nfs4_alloc_session(clp);
334 	if (!session)
335 		return -ENOMEM;
336 
337 	clp->cl_session = session;
338 
339 	/*
340 	 * The create session reply races with the server back
341 	 * channel probe. Mark the client NFS_CS_SESSION_INITING
342 	 * so that the client back channel can find the
343 	 * nfs_client struct
344 	 */
345 	nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING);
346 	return 0;
347 }
348 
349 #endif	/* CONFIG_NFS_V4_1 */
350 
351 /*
352  * Initialize the minor version specific parts of an NFS4 client record
353  */
354 static int nfs4_init_client_minor_version(struct nfs_client *clp)
355 {
356 	int ret;
357 
358 	ret = clp->cl_mvops->init_client(clp);
359 	if (ret)
360 		return ret;
361 	return nfs4_init_callback(clp);
362 }
363 
364 /**
365  * nfs4_init_client - Initialise an NFS4 client record
366  *
367  * @clp: nfs_client to initialise
368  * @cl_init: pointer to nfs_client_initdata
369  *
370  * Returns pointer to an NFS client, or an ERR_PTR value.
371  */
372 struct nfs_client *nfs4_init_client(struct nfs_client *clp,
373 				    const struct nfs_client_initdata *cl_init)
374 {
375 	char buf[INET6_ADDRSTRLEN + 1];
376 	const char *ip_addr = cl_init->ip_addr;
377 	struct nfs_client *old;
378 	int error;
379 
380 	if (clp->cl_cons_state == NFS_CS_READY)
381 		/* the client is initialised already */
382 		return clp;
383 
384 	/* Check NFS protocol revision and initialize RPC op vector */
385 	clp->rpc_ops = &nfs_v4_clientops;
386 
387 	if (clp->cl_minorversion != 0)
388 		__set_bit(NFS_CS_INFINITE_SLOTS, &clp->cl_flags);
389 	__set_bit(NFS_CS_DISCRTRY, &clp->cl_flags);
390 	__set_bit(NFS_CS_NO_RETRANS_TIMEOUT, &clp->cl_flags);
391 
392 	error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_GSS_KRB5I);
393 	if (error == -EINVAL)
394 		error = nfs_create_rpc_client(clp, cl_init, RPC_AUTH_UNIX);
395 	if (error < 0)
396 		goto error;
397 
398 	/* If no clientaddr= option was specified, find a usable cb address */
399 	if (ip_addr == NULL) {
400 		struct sockaddr_storage cb_addr;
401 		struct sockaddr *sap = (struct sockaddr *)&cb_addr;
402 
403 		error = rpc_localaddr(clp->cl_rpcclient, sap, sizeof(cb_addr));
404 		if (error < 0)
405 			goto error;
406 		error = rpc_ntop(sap, buf, sizeof(buf));
407 		if (error < 0)
408 			goto error;
409 		ip_addr = (const char *)buf;
410 	}
411 	strlcpy(clp->cl_ipaddr, ip_addr, sizeof(clp->cl_ipaddr));
412 
413 	error = nfs_idmap_new(clp);
414 	if (error < 0) {
415 		dprintk("%s: failed to create idmapper. Error = %d\n",
416 			__func__, error);
417 		goto error;
418 	}
419 	__set_bit(NFS_CS_IDMAP, &clp->cl_res_state);
420 
421 	error = nfs4_init_client_minor_version(clp);
422 	if (error < 0)
423 		goto error;
424 
425 	error = nfs4_discover_server_trunking(clp, &old);
426 	if (error < 0)
427 		goto error;
428 
429 	if (clp != old) {
430 		clp->cl_preserve_clid = true;
431 		/*
432 		 * Mark the client as having failed initialization so other
433 		 * processes walking the nfs_client_list in nfs_match_client()
434 		 * won't try to use it.
435 		 */
436 		nfs_mark_client_ready(clp, -EPERM);
437 	}
438 	nfs_put_client(clp);
439 	clear_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags);
440 	return old;
441 
442 error:
443 	nfs_mark_client_ready(clp, error);
444 	nfs_put_client(clp);
445 	return ERR_PTR(error);
446 }
447 
448 /*
449  * SETCLIENTID just did a callback update with the callback ident in
450  * "drop," but server trunking discovery claims "drop" and "keep" are
451  * actually the same server.  Swap the callback IDs so that "keep"
452  * will continue to use the callback ident the server now knows about,
453  * and so that "keep"'s original callback ident is destroyed when
454  * "drop" is freed.
455  */
456 static void nfs4_swap_callback_idents(struct nfs_client *keep,
457 				      struct nfs_client *drop)
458 {
459 	struct nfs_net *nn = net_generic(keep->cl_net, nfs_net_id);
460 	unsigned int save = keep->cl_cb_ident;
461 
462 	if (keep->cl_cb_ident == drop->cl_cb_ident)
463 		return;
464 
465 	dprintk("%s: keeping callback ident %u and dropping ident %u\n",
466 		__func__, keep->cl_cb_ident, drop->cl_cb_ident);
467 
468 	spin_lock(&nn->nfs_client_lock);
469 
470 	idr_replace(&nn->cb_ident_idr, keep, drop->cl_cb_ident);
471 	keep->cl_cb_ident = drop->cl_cb_ident;
472 
473 	idr_replace(&nn->cb_ident_idr, drop, save);
474 	drop->cl_cb_ident = save;
475 
476 	spin_unlock(&nn->nfs_client_lock);
477 }
478 
479 static bool nfs4_match_client_owner_id(const struct nfs_client *clp1,
480 		const struct nfs_client *clp2)
481 {
482 	if (clp1->cl_owner_id == NULL || clp2->cl_owner_id == NULL)
483 		return true;
484 	return strcmp(clp1->cl_owner_id, clp2->cl_owner_id) == 0;
485 }
486 
487 static bool nfs4_same_verifier(nfs4_verifier *v1, nfs4_verifier *v2)
488 {
489 	return memcmp(v1->data, v2->data, sizeof(v1->data)) == 0;
490 }
491 
492 static int nfs4_match_client(struct nfs_client  *pos,  struct nfs_client *new,
493 			     struct nfs_client **prev, struct nfs_net *nn)
494 {
495 	int status;
496 
497 	if (pos->rpc_ops != new->rpc_ops)
498 		return 1;
499 
500 	if (pos->cl_minorversion != new->cl_minorversion)
501 		return 1;
502 
503 	/* If "pos" isn't marked ready, we can't trust the
504 	 * remaining fields in "pos", especially the client
505 	 * ID and serverowner fields.  Wait for CREATE_SESSION
506 	 * to finish. */
507 	if (pos->cl_cons_state > NFS_CS_READY) {
508 		refcount_inc(&pos->cl_count);
509 		spin_unlock(&nn->nfs_client_lock);
510 
511 		nfs_put_client(*prev);
512 		*prev = pos;
513 
514 		status = nfs_wait_client_init_complete(pos);
515 		spin_lock(&nn->nfs_client_lock);
516 
517 		if (status < 0)
518 			return status;
519 	}
520 
521 	if (pos->cl_cons_state != NFS_CS_READY)
522 		return 1;
523 
524 	if (pos->cl_clientid != new->cl_clientid)
525 		return 1;
526 
527 	/* NFSv4.1 always uses the uniform string, however someone
528 	 * might switch the uniquifier string on us.
529 	 */
530 	if (!nfs4_match_client_owner_id(pos, new))
531 		return 1;
532 
533 	return 0;
534 }
535 
536 /**
537  * nfs40_walk_client_list - Find server that recognizes a client ID
538  *
539  * @new: nfs_client with client ID to test
540  * @result: OUT: found nfs_client, or new
541  * @cred: credential to use for trunking test
542  *
543  * Returns zero, a negative errno, or a negative NFS4ERR status.
544  * If zero is returned, an nfs_client pointer is planted in "result."
545  *
546  * NB: nfs40_walk_client_list() relies on the new nfs_client being
547  *     the last nfs_client on the list.
548  */
549 int nfs40_walk_client_list(struct nfs_client *new,
550 			   struct nfs_client **result,
551 			   const struct cred *cred)
552 {
553 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
554 	struct nfs_client *pos, *prev = NULL;
555 	struct nfs4_setclientid_res clid = {
556 		.clientid	= new->cl_clientid,
557 		.confirm	= new->cl_confirm,
558 	};
559 	int status = -NFS4ERR_STALE_CLIENTID;
560 
561 	spin_lock(&nn->nfs_client_lock);
562 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
563 
564 		if (pos == new)
565 			goto found;
566 
567 		status = nfs4_match_client(pos, new, &prev, nn);
568 		if (status < 0)
569 			goto out_unlock;
570 		if (status != 0)
571 			continue;
572 		/*
573 		 * We just sent a new SETCLIENTID, which should have
574 		 * caused the server to return a new cl_confirm.  So if
575 		 * cl_confirm is the same, then this is a different
576 		 * server that just returned the same cl_confirm by
577 		 * coincidence:
578 		 */
579 		if ((new != pos) && nfs4_same_verifier(&pos->cl_confirm,
580 						       &new->cl_confirm))
581 			continue;
582 		/*
583 		 * But if the cl_confirm's are different, then the only
584 		 * way that a SETCLIENTID_CONFIRM to pos can succeed is
585 		 * if new and pos point to the same server:
586 		 */
587 found:
588 		refcount_inc(&pos->cl_count);
589 		spin_unlock(&nn->nfs_client_lock);
590 
591 		nfs_put_client(prev);
592 		prev = pos;
593 
594 		status = nfs4_proc_setclientid_confirm(pos, &clid, cred);
595 		switch (status) {
596 		case -NFS4ERR_STALE_CLIENTID:
597 			break;
598 		case 0:
599 			nfs4_swap_callback_idents(pos, new);
600 			pos->cl_confirm = new->cl_confirm;
601 			nfs_mark_client_ready(pos, NFS_CS_READY);
602 
603 			prev = NULL;
604 			*result = pos;
605 			goto out;
606 		case -ERESTARTSYS:
607 		case -ETIMEDOUT:
608 			/* The callback path may have been inadvertently
609 			 * changed. Schedule recovery!
610 			 */
611 			nfs4_schedule_path_down_recovery(pos);
612 		default:
613 			goto out;
614 		}
615 
616 		spin_lock(&nn->nfs_client_lock);
617 	}
618 out_unlock:
619 	spin_unlock(&nn->nfs_client_lock);
620 
621 	/* No match found. The server lost our clientid */
622 out:
623 	nfs_put_client(prev);
624 	return status;
625 }
626 
627 #ifdef CONFIG_NFS_V4_1
628 /*
629  * Returns true if the server major ids match
630  */
631 static bool
632 nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
633 				struct nfs41_server_owner *o2)
634 {
635 	if (o1->major_id_sz != o2->major_id_sz)
636 		return false;
637 	return memcmp(o1->major_id, o2->major_id, o1->major_id_sz) == 0;
638 }
639 
640 /*
641  * Returns true if the server scopes match
642  */
643 static bool
644 nfs4_check_server_scope(struct nfs41_server_scope *s1,
645 			struct nfs41_server_scope *s2)
646 {
647 	if (s1->server_scope_sz != s2->server_scope_sz)
648 		return false;
649 	return memcmp(s1->server_scope, s2->server_scope,
650 					s1->server_scope_sz) == 0;
651 }
652 
653 /**
654  * nfs4_detect_session_trunking - Checks for session trunking.
655  * @clp:    original mount nfs_client
656  * @res:    result structure from an exchange_id using the original mount
657  *          nfs_client with a new multi_addr transport
658  * @xprt:   pointer to the transport to add.
659  *
660  * Called after a successful EXCHANGE_ID on a multi-addr connection.
661  * Upon success, add the transport.
662  *
663  * Returns zero on success, otherwise -EINVAL
664  *
665  * Note: since the exchange_id for the new multi_addr transport uses the
666  * same nfs_client from the original mount, the cl_owner_id is reused,
667  * so eir_clientowner is the same.
668  */
669 int nfs4_detect_session_trunking(struct nfs_client *clp,
670 				 struct nfs41_exchange_id_res *res,
671 				 struct rpc_xprt *xprt)
672 {
673 	/* Check eir_clientid */
674 	if (clp->cl_clientid != res->clientid)
675 		goto out_err;
676 
677 	/* Check eir_server_owner so_major_id */
678 	if (!nfs4_check_serverowner_major_id(clp->cl_serverowner,
679 					     res->server_owner))
680 		goto out_err;
681 
682 	/* Check eir_server_owner so_minor_id */
683 	if (clp->cl_serverowner->minor_id != res->server_owner->minor_id)
684 		goto out_err;
685 
686 	/* Check eir_server_scope */
687 	if (!nfs4_check_server_scope(clp->cl_serverscope, res->server_scope))
688 		goto out_err;
689 
690 	pr_info("NFS:  %s: Session trunking succeeded for %s\n",
691 		clp->cl_hostname,
692 		xprt->address_strings[RPC_DISPLAY_ADDR]);
693 
694 	return 0;
695 out_err:
696 	pr_info("NFS:  %s: Session trunking failed for %s\n", clp->cl_hostname,
697 		xprt->address_strings[RPC_DISPLAY_ADDR]);
698 
699 	return -EINVAL;
700 }
701 
702 /**
703  * nfs41_walk_client_list - Find nfs_client that matches a client/server owner
704  *
705  * @new: nfs_client with client ID to test
706  * @result: OUT: found nfs_client, or new
707  * @cred: credential to use for trunking test
708  *
709  * Returns zero, a negative errno, or a negative NFS4ERR status.
710  * If zero is returned, an nfs_client pointer is planted in "result."
711  *
712  * NB: nfs41_walk_client_list() relies on the new nfs_client being
713  *     the last nfs_client on the list.
714  */
715 int nfs41_walk_client_list(struct nfs_client *new,
716 			   struct nfs_client **result,
717 			   const struct cred *cred)
718 {
719 	struct nfs_net *nn = net_generic(new->cl_net, nfs_net_id);
720 	struct nfs_client *pos, *prev = NULL;
721 	int status = -NFS4ERR_STALE_CLIENTID;
722 
723 	spin_lock(&nn->nfs_client_lock);
724 	list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
725 
726 		if (pos == new)
727 			goto found;
728 
729 		status = nfs4_match_client(pos, new, &prev, nn);
730 		if (status < 0)
731 			goto out;
732 		if (status != 0)
733 			continue;
734 
735 		/*
736 		 * Note that session trunking is just a special subcase of
737 		 * client id trunking. In either case, we want to fall back
738 		 * to using the existing nfs_client.
739 		 */
740 		if (!nfs4_check_serverowner_major_id(pos->cl_serverowner,
741 						     new->cl_serverowner))
742 			continue;
743 
744 found:
745 		refcount_inc(&pos->cl_count);
746 		*result = pos;
747 		status = 0;
748 		break;
749 	}
750 
751 out:
752 	spin_unlock(&nn->nfs_client_lock);
753 	nfs_put_client(prev);
754 	return status;
755 }
756 #endif	/* CONFIG_NFS_V4_1 */
757 
758 static void nfs4_destroy_server(struct nfs_server *server)
759 {
760 	nfs_server_return_all_delegations(server);
761 	unset_pnfs_layoutdriver(server);
762 	nfs4_purge_state_owners(server);
763 }
764 
765 /*
766  * NFSv4.0 callback thread helper
767  *
768  * Find a client by callback identifier
769  */
770 struct nfs_client *
771 nfs4_find_client_ident(struct net *net, int cb_ident)
772 {
773 	struct nfs_client *clp;
774 	struct nfs_net *nn = net_generic(net, nfs_net_id);
775 
776 	spin_lock(&nn->nfs_client_lock);
777 	clp = idr_find(&nn->cb_ident_idr, cb_ident);
778 	if (clp)
779 		refcount_inc(&clp->cl_count);
780 	spin_unlock(&nn->nfs_client_lock);
781 	return clp;
782 }
783 
784 #if defined(CONFIG_NFS_V4_1)
785 /* Common match routine for v4.0 and v4.1 callback services */
786 static bool nfs4_cb_match_client(const struct sockaddr *addr,
787 		struct nfs_client *clp, u32 minorversion)
788 {
789 	struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
790 
791 	/* Don't match clients that failed to initialise */
792 	if (!(clp->cl_cons_state == NFS_CS_READY ||
793 	    clp->cl_cons_state == NFS_CS_SESSION_INITING))
794 		return false;
795 
796 	smp_rmb();
797 
798 	/* Match the version and minorversion */
799 	if (clp->rpc_ops->version != 4 ||
800 	    clp->cl_minorversion != minorversion)
801 		return false;
802 
803 	/* Match only the IP address, not the port number */
804 	return rpc_cmp_addr(addr, clap);
805 }
806 
807 /*
808  * NFSv4.1 callback thread helper
809  * For CB_COMPOUND calls, find a client by IP address, protocol version,
810  * minorversion, and sessionID
811  *
812  * Returns NULL if no such client
813  */
814 struct nfs_client *
815 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
816 			   struct nfs4_sessionid *sid, u32 minorversion)
817 {
818 	struct nfs_client *clp;
819 	struct nfs_net *nn = net_generic(net, nfs_net_id);
820 
821 	spin_lock(&nn->nfs_client_lock);
822 	list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) {
823 		if (!nfs4_cb_match_client(addr, clp, minorversion))
824 			continue;
825 
826 		if (!nfs4_has_session(clp))
827 			continue;
828 
829 		/* Match sessionid*/
830 		if (memcmp(clp->cl_session->sess_id.data,
831 		    sid->data, NFS4_MAX_SESSIONID_LEN) != 0)
832 			continue;
833 
834 		refcount_inc(&clp->cl_count);
835 		spin_unlock(&nn->nfs_client_lock);
836 		return clp;
837 	}
838 	spin_unlock(&nn->nfs_client_lock);
839 	return NULL;
840 }
841 
842 #else /* CONFIG_NFS_V4_1 */
843 
844 struct nfs_client *
845 nfs4_find_client_sessionid(struct net *net, const struct sockaddr *addr,
846 			   struct nfs4_sessionid *sid, u32 minorversion)
847 {
848 	return NULL;
849 }
850 #endif /* CONFIG_NFS_V4_1 */
851 
852 /*
853  * Set up an NFS4 client
854  */
855 static int nfs4_set_client(struct nfs_server *server,
856 		const char *hostname,
857 		const struct sockaddr *addr,
858 		const size_t addrlen,
859 		const char *ip_addr,
860 		int proto, const struct rpc_timeout *timeparms,
861 		u32 minorversion, struct net *net)
862 {
863 	struct nfs_client_initdata cl_init = {
864 		.hostname = hostname,
865 		.addr = addr,
866 		.addrlen = addrlen,
867 		.ip_addr = ip_addr,
868 		.nfs_mod = &nfs_v4,
869 		.proto = proto,
870 		.minorversion = minorversion,
871 		.net = net,
872 		.timeparms = timeparms,
873 	};
874 	struct nfs_client *clp;
875 
876 	if (server->flags & NFS_MOUNT_NORESVPORT)
877 		set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
878 	if (server->options & NFS_OPTION_MIGRATION)
879 		set_bit(NFS_CS_MIGRATION, &cl_init.init_flags);
880 	if (test_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status))
881 		set_bit(NFS_CS_TSM_POSSIBLE, &cl_init.init_flags);
882 	server->port = rpc_get_port(addr);
883 
884 	/* Allocate or find a client reference we can use */
885 	clp = nfs_get_client(&cl_init);
886 	if (IS_ERR(clp))
887 		return PTR_ERR(clp);
888 
889 	if (server->nfs_client == clp) {
890 		nfs_put_client(clp);
891 		return -ELOOP;
892 	}
893 
894 	/*
895 	 * Query for the lease time on clientid setup or renewal
896 	 *
897 	 * Note that this will be set on nfs_clients that were created
898 	 * only for the DS role and did not set this bit, but now will
899 	 * serve a dual role.
900 	 */
901 	set_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state);
902 
903 	server->nfs_client = clp;
904 	return 0;
905 }
906 
907 /*
908  * Set up a pNFS Data Server client.
909  *
910  * Return any existing nfs_client that matches server address,port,version
911  * and minorversion.
912  *
913  * For a new nfs_client, use a soft mount (default), a low retrans and a
914  * low timeout interval so that if a connection is lost, we retry through
915  * the MDS.
916  */
917 struct nfs_client *nfs4_set_ds_client(struct nfs_server *mds_srv,
918 		const struct sockaddr *ds_addr, int ds_addrlen,
919 		int ds_proto, unsigned int ds_timeo, unsigned int ds_retrans,
920 		u32 minor_version)
921 {
922 	struct rpc_timeout ds_timeout;
923 	struct nfs_client *mds_clp = mds_srv->nfs_client;
924 	struct nfs_client_initdata cl_init = {
925 		.addr = ds_addr,
926 		.addrlen = ds_addrlen,
927 		.nodename = mds_clp->cl_rpcclient->cl_nodename,
928 		.ip_addr = mds_clp->cl_ipaddr,
929 		.nfs_mod = &nfs_v4,
930 		.proto = ds_proto,
931 		.minorversion = minor_version,
932 		.net = mds_clp->cl_net,
933 		.timeparms = &ds_timeout,
934 	};
935 	char buf[INET6_ADDRSTRLEN + 1];
936 
937 	if (rpc_ntop(ds_addr, buf, sizeof(buf)) <= 0)
938 		return ERR_PTR(-EINVAL);
939 	cl_init.hostname = buf;
940 
941 	if (mds_srv->flags & NFS_MOUNT_NORESVPORT)
942 		__set_bit(NFS_CS_NORESVPORT, &cl_init.init_flags);
943 
944 	/*
945 	 * Set an authflavor equual to the MDS value. Use the MDS nfs_client
946 	 * cl_ipaddr so as to use the same EXCHANGE_ID co_ownerid as the MDS
947 	 * (section 13.1 RFC 5661).
948 	 */
949 	nfs_init_timeout_values(&ds_timeout, ds_proto, ds_timeo, ds_retrans);
950 	return nfs_get_client(&cl_init);
951 }
952 EXPORT_SYMBOL_GPL(nfs4_set_ds_client);
953 
954 /*
955  * Session has been established, and the client marked ready.
956  * Limit the mount rsize, wsize and dtsize using negotiated fore
957  * channel attributes.
958  */
959 static void nfs4_session_limit_rwsize(struct nfs_server *server)
960 {
961 #ifdef CONFIG_NFS_V4_1
962 	struct nfs4_session *sess;
963 	u32 server_resp_sz;
964 	u32 server_rqst_sz;
965 
966 	if (!nfs4_has_session(server->nfs_client))
967 		return;
968 	sess = server->nfs_client->cl_session;
969 	server_resp_sz = sess->fc_attrs.max_resp_sz - nfs41_maxread_overhead;
970 	server_rqst_sz = sess->fc_attrs.max_rqst_sz - nfs41_maxwrite_overhead;
971 
972 	if (server->dtsize > server_resp_sz)
973 		server->dtsize = server_resp_sz;
974 	if (server->rsize > server_resp_sz)
975 		server->rsize = server_resp_sz;
976 	if (server->wsize > server_rqst_sz)
977 		server->wsize = server_rqst_sz;
978 #endif /* CONFIG_NFS_V4_1 */
979 }
980 
981 static int nfs4_server_common_setup(struct nfs_server *server,
982 		struct nfs_fh *mntfh, bool auth_probe)
983 {
984 	struct nfs_fattr *fattr;
985 	int error;
986 
987 	/* data servers support only a subset of NFSv4.1 */
988 	if (is_ds_only_client(server->nfs_client))
989 		return -EPROTONOSUPPORT;
990 
991 	fattr = nfs_alloc_fattr();
992 	if (fattr == NULL)
993 		return -ENOMEM;
994 
995 	/* We must ensure the session is initialised first */
996 	error = nfs4_init_session(server->nfs_client);
997 	if (error < 0)
998 		goto out;
999 
1000 	/* Set the basic capabilities */
1001 	server->caps |= server->nfs_client->cl_mvops->init_caps;
1002 	if (server->flags & NFS_MOUNT_NORDIRPLUS)
1003 			server->caps &= ~NFS_CAP_READDIRPLUS;
1004 	/*
1005 	 * Don't use NFS uid/gid mapping if we're using AUTH_SYS or lower
1006 	 * authentication.
1007 	 */
1008 	if (nfs4_disable_idmapping &&
1009 			server->client->cl_auth->au_flavor == RPC_AUTH_UNIX)
1010 		server->caps |= NFS_CAP_UIDGID_NOMAP;
1011 
1012 
1013 	/* Probe the root fh to retrieve its FSID and filehandle */
1014 	error = nfs4_get_rootfh(server, mntfh, auth_probe);
1015 	if (error < 0)
1016 		goto out;
1017 
1018 	dprintk("Server FSID: %llx:%llx\n",
1019 			(unsigned long long) server->fsid.major,
1020 			(unsigned long long) server->fsid.minor);
1021 	nfs_display_fhandle(mntfh, "Pseudo-fs root FH");
1022 
1023 	error = nfs_probe_fsinfo(server, mntfh, fattr);
1024 	if (error < 0)
1025 		goto out;
1026 
1027 	nfs4_session_limit_rwsize(server);
1028 
1029 	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
1030 		server->namelen = NFS4_MAXNAMLEN;
1031 
1032 	nfs_server_insert_lists(server);
1033 	server->mount_time = jiffies;
1034 	server->destroy = nfs4_destroy_server;
1035 out:
1036 	nfs_free_fattr(fattr);
1037 	return error;
1038 }
1039 
1040 /*
1041  * Create a version 4 volume record
1042  */
1043 static int nfs4_init_server(struct nfs_server *server,
1044 		struct nfs_parsed_mount_data *data)
1045 {
1046 	struct rpc_timeout timeparms;
1047 	int error;
1048 
1049 	nfs_init_timeout_values(&timeparms, data->nfs_server.protocol,
1050 			data->timeo, data->retrans);
1051 
1052 	/* Initialise the client representation from the mount data */
1053 	server->flags = data->flags;
1054 	server->options = data->options;
1055 	server->auth_info = data->auth_info;
1056 
1057 	/* Use the first specified auth flavor. If this flavor isn't
1058 	 * allowed by the server, use the SECINFO path to try the
1059 	 * other specified flavors */
1060 	if (data->auth_info.flavor_len >= 1)
1061 		data->selected_flavor = data->auth_info.flavors[0];
1062 	else
1063 		data->selected_flavor = RPC_AUTH_UNIX;
1064 
1065 	/* Get a client record */
1066 	error = nfs4_set_client(server,
1067 			data->nfs_server.hostname,
1068 			(const struct sockaddr *)&data->nfs_server.address,
1069 			data->nfs_server.addrlen,
1070 			data->client_address,
1071 			data->nfs_server.protocol,
1072 			&timeparms,
1073 			data->minorversion,
1074 			data->net);
1075 	if (error < 0)
1076 		return error;
1077 
1078 	if (data->rsize)
1079 		server->rsize = nfs_block_size(data->rsize, NULL);
1080 	if (data->wsize)
1081 		server->wsize = nfs_block_size(data->wsize, NULL);
1082 
1083 	server->acregmin = data->acregmin * HZ;
1084 	server->acregmax = data->acregmax * HZ;
1085 	server->acdirmin = data->acdirmin * HZ;
1086 	server->acdirmax = data->acdirmax * HZ;
1087 	server->port     = data->nfs_server.port;
1088 
1089 	return nfs_init_server_rpcclient(server, &timeparms,
1090 					 data->selected_flavor);
1091 }
1092 
1093 /*
1094  * Create a version 4 volume record
1095  * - keyed on server and FSID
1096  */
1097 /*struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
1098 				      struct nfs_fh *mntfh)*/
1099 struct nfs_server *nfs4_create_server(struct nfs_mount_info *mount_info,
1100 				      struct nfs_subversion *nfs_mod)
1101 {
1102 	struct nfs_server *server;
1103 	bool auth_probe;
1104 	int error;
1105 
1106 	server = nfs_alloc_server();
1107 	if (!server)
1108 		return ERR_PTR(-ENOMEM);
1109 
1110 	auth_probe = mount_info->parsed->auth_info.flavor_len < 1;
1111 
1112 	/* set up the general RPC client */
1113 	error = nfs4_init_server(server, mount_info->parsed);
1114 	if (error < 0)
1115 		goto error;
1116 
1117 	error = nfs4_server_common_setup(server, mount_info->mntfh, auth_probe);
1118 	if (error < 0)
1119 		goto error;
1120 
1121 	return server;
1122 
1123 error:
1124 	nfs_free_server(server);
1125 	return ERR_PTR(error);
1126 }
1127 
1128 /*
1129  * Create an NFS4 referral server record
1130  */
1131 struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
1132 					       struct nfs_fh *mntfh)
1133 {
1134 	struct nfs_client *parent_client;
1135 	struct nfs_server *server, *parent_server;
1136 	bool auth_probe;
1137 	int error;
1138 
1139 	server = nfs_alloc_server();
1140 	if (!server)
1141 		return ERR_PTR(-ENOMEM);
1142 
1143 	parent_server = NFS_SB(data->sb);
1144 	parent_client = parent_server->nfs_client;
1145 
1146 	/* Initialise the client representation from the parent server */
1147 	nfs_server_copy_userdata(server, parent_server);
1148 
1149 	/* Get a client representation */
1150 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1151 	rpc_set_port(data->addr, NFS_RDMA_PORT);
1152 	error = nfs4_set_client(server, data->hostname,
1153 				data->addr,
1154 				data->addrlen,
1155 				parent_client->cl_ipaddr,
1156 				XPRT_TRANSPORT_RDMA,
1157 				parent_server->client->cl_timeout,
1158 				parent_client->cl_mvops->minor_version,
1159 				parent_client->cl_net);
1160 	if (!error)
1161 		goto init_server;
1162 #endif	/* IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA) */
1163 
1164 	rpc_set_port(data->addr, NFS_PORT);
1165 	error = nfs4_set_client(server, data->hostname,
1166 				data->addr,
1167 				data->addrlen,
1168 				parent_client->cl_ipaddr,
1169 				XPRT_TRANSPORT_TCP,
1170 				parent_server->client->cl_timeout,
1171 				parent_client->cl_mvops->minor_version,
1172 				parent_client->cl_net);
1173 	if (error < 0)
1174 		goto error;
1175 
1176 #if IS_ENABLED(CONFIG_SUNRPC_XPRT_RDMA)
1177 init_server:
1178 #endif
1179 	error = nfs_init_server_rpcclient(server, parent_server->client->cl_timeout, data->authflavor);
1180 	if (error < 0)
1181 		goto error;
1182 
1183 	auth_probe = parent_server->auth_info.flavor_len < 1;
1184 
1185 	error = nfs4_server_common_setup(server, mntfh, auth_probe);
1186 	if (error < 0)
1187 		goto error;
1188 
1189 	return server;
1190 
1191 error:
1192 	nfs_free_server(server);
1193 	return ERR_PTR(error);
1194 }
1195 
1196 /*
1197  * Grab the destination's particulars, including lease expiry time.
1198  *
1199  * Returns zero if probe succeeded and retrieved FSID matches the FSID
1200  * we have cached.
1201  */
1202 static int nfs_probe_destination(struct nfs_server *server)
1203 {
1204 	struct inode *inode = d_inode(server->super->s_root);
1205 	struct nfs_fattr *fattr;
1206 	int error;
1207 
1208 	fattr = nfs_alloc_fattr();
1209 	if (fattr == NULL)
1210 		return -ENOMEM;
1211 
1212 	/* Sanity: the probe won't work if the destination server
1213 	 * does not recognize the migrated FH. */
1214 	error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
1215 
1216 	nfs_free_fattr(fattr);
1217 	return error;
1218 }
1219 
1220 /**
1221  * nfs4_update_server - Move an nfs_server to a different nfs_client
1222  *
1223  * @server: represents FSID to be moved
1224  * @hostname: new end-point's hostname
1225  * @sap: new end-point's socket address
1226  * @salen: size of "sap"
1227  * @net: net namespace
1228  *
1229  * The nfs_server must be quiescent before this function is invoked.
1230  * Either its session is drained (NFSv4.1+), or its transport is
1231  * plugged and drained (NFSv4.0).
1232  *
1233  * Returns zero on success, or a negative errno value.
1234  */
1235 int nfs4_update_server(struct nfs_server *server, const char *hostname,
1236 		       struct sockaddr *sap, size_t salen, struct net *net)
1237 {
1238 	struct nfs_client *clp = server->nfs_client;
1239 	struct rpc_clnt *clnt = server->client;
1240 	struct xprt_create xargs = {
1241 		.ident		= clp->cl_proto,
1242 		.net		= net,
1243 		.dstaddr	= sap,
1244 		.addrlen	= salen,
1245 		.servername	= hostname,
1246 	};
1247 	char buf[INET6_ADDRSTRLEN + 1];
1248 	struct sockaddr_storage address;
1249 	struct sockaddr *localaddr = (struct sockaddr *)&address;
1250 	int error;
1251 
1252 	error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
1253 	if (error != 0)
1254 		return error;
1255 
1256 	error = rpc_localaddr(clnt, localaddr, sizeof(address));
1257 	if (error != 0)
1258 		return error;
1259 
1260 	if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0)
1261 		return -EAFNOSUPPORT;
1262 
1263 	nfs_server_remove_lists(server);
1264 	set_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1265 	error = nfs4_set_client(server, hostname, sap, salen, buf,
1266 				clp->cl_proto, clnt->cl_timeout,
1267 				clp->cl_minorversion, net);
1268 	clear_bit(NFS_MIG_TSM_POSSIBLE, &server->mig_status);
1269 	if (error != 0) {
1270 		nfs_server_insert_lists(server);
1271 		return error;
1272 	}
1273 	nfs_put_client(clp);
1274 
1275 	if (server->nfs_client->cl_hostname == NULL)
1276 		server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
1277 	nfs_server_insert_lists(server);
1278 
1279 	return nfs_probe_destination(server);
1280 }
1281