xref: /linux/fs/afs/vlclient.c (revision 37c12fcb3c8e356825bbffb64c0158ccf8a7de94)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* AFS Volume Location Service client
3  *
4  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/gfp.h>
9 #include <linux/init.h>
10 #include <linux/sched.h>
11 #include "afs_fs.h"
12 #include "internal.h"
13 
14 /*
15  * Deliver reply data to a VL.GetEntryByNameU call.
16  */
17 static int afs_deliver_vl_get_entry_by_name_u(struct afs_call *call)
18 {
19 	struct afs_uvldbentry__xdr *uvldb;
20 	struct afs_vldb_entry *entry;
21 	u32 nr_servers, vlflags;
22 	int i, ret;
23 
24 	_enter("");
25 
26 	ret = afs_transfer_reply(call);
27 	if (ret < 0)
28 		return ret;
29 
30 	/* unmarshall the reply once we've received all of it */
31 	uvldb = call->buffer;
32 	entry = call->ret_vldb;
33 
34 	nr_servers = ntohl(uvldb->nServers);
35 	if (nr_servers > AFS_NMAXNSERVERS)
36 		nr_servers = AFS_NMAXNSERVERS;
37 
38 	for (i = 0; i < ARRAY_SIZE(uvldb->name) - 1; i++)
39 		entry->name[i] = (u8)ntohl(uvldb->name[i]);
40 	entry->name[i] = 0;
41 	entry->name_len = strlen(entry->name);
42 
43 	vlflags = ntohl(uvldb->flags);
44 	for (i = 0; i < nr_servers; i++) {
45 		struct afs_uuid__xdr *xdr;
46 		struct afs_uuid *uuid;
47 		u32 tmp = ntohl(uvldb->serverFlags[i]);
48 		int j;
49 		int n = entry->nr_servers;
50 
51 		if (tmp & AFS_VLSF_RWVOL) {
52 			entry->fs_mask[n] |= AFS_VOL_VTM_RW;
53 			if (vlflags & AFS_VLF_BACKEXISTS)
54 				entry->fs_mask[n] |= AFS_VOL_VTM_BAK;
55 		}
56 		if (tmp & AFS_VLSF_ROVOL)
57 			entry->fs_mask[n] |= AFS_VOL_VTM_RO;
58 		if (!entry->fs_mask[n])
59 			continue;
60 
61 		xdr = &uvldb->serverNumber[i];
62 		uuid = (struct afs_uuid *)&entry->fs_server[n];
63 		uuid->time_low			= xdr->time_low;
64 		uuid->time_mid			= htons(ntohl(xdr->time_mid));
65 		uuid->time_hi_and_version	= htons(ntohl(xdr->time_hi_and_version));
66 		uuid->clock_seq_hi_and_reserved	= (u8)ntohl(xdr->clock_seq_hi_and_reserved);
67 		uuid->clock_seq_low		= (u8)ntohl(xdr->clock_seq_low);
68 		for (j = 0; j < 6; j++)
69 			uuid->node[j] = (u8)ntohl(xdr->node[j]);
70 
71 		entry->vlsf_flags[n] = tmp;
72 		entry->addr_version[n] = ntohl(uvldb->serverUnique[i]);
73 		entry->nr_servers++;
74 	}
75 
76 	for (i = 0; i < AFS_MAXTYPES; i++)
77 		entry->vid[i] = ntohl(uvldb->volumeId[i]);
78 
79 	if (vlflags & AFS_VLF_RWEXISTS)
80 		__set_bit(AFS_VLDB_HAS_RW, &entry->flags);
81 	if (vlflags & AFS_VLF_ROEXISTS)
82 		__set_bit(AFS_VLDB_HAS_RO, &entry->flags);
83 	if (vlflags & AFS_VLF_BACKEXISTS)
84 		__set_bit(AFS_VLDB_HAS_BAK, &entry->flags);
85 
86 	if (!(vlflags & (AFS_VLF_RWEXISTS | AFS_VLF_ROEXISTS | AFS_VLF_BACKEXISTS))) {
87 		entry->error = -ENOMEDIUM;
88 		__set_bit(AFS_VLDB_QUERY_ERROR, &entry->flags);
89 	}
90 
91 	__set_bit(AFS_VLDB_QUERY_VALID, &entry->flags);
92 	_leave(" = 0 [done]");
93 	return 0;
94 }
95 
96 /*
97  * VL.GetEntryByNameU operation type.
98  */
99 static const struct afs_call_type afs_RXVLGetEntryByNameU = {
100 	.name		= "VL.GetEntryByNameU",
101 	.op		= afs_VL_GetEntryByNameU,
102 	.deliver	= afs_deliver_vl_get_entry_by_name_u,
103 	.destructor	= afs_flat_call_destructor,
104 };
105 
106 /*
107  * Dispatch a get volume entry by name or ID operation (uuid variant).  If the
108  * volname is a decimal number then it's a volume ID not a volume name.
109  */
110 struct afs_vldb_entry *afs_vl_get_entry_by_name_u(struct afs_vl_cursor *vc,
111 						  const char *volname,
112 						  int volnamesz)
113 {
114 	struct afs_vldb_entry *entry;
115 	struct afs_call *call;
116 	struct afs_net *net = vc->cell->net;
117 	size_t reqsz, padsz;
118 	__be32 *bp;
119 
120 	_enter("");
121 
122 	padsz = (4 - (volnamesz & 3)) & 3;
123 	reqsz = 8 + volnamesz + padsz;
124 
125 	entry = kzalloc(sizeof(struct afs_vldb_entry), GFP_KERNEL);
126 	if (!entry)
127 		return ERR_PTR(-ENOMEM);
128 
129 	call = afs_alloc_flat_call(net, &afs_RXVLGetEntryByNameU, reqsz,
130 				   sizeof(struct afs_uvldbentry__xdr));
131 	if (!call) {
132 		kfree(entry);
133 		return ERR_PTR(-ENOMEM);
134 	}
135 
136 	call->key = vc->key;
137 	call->ret_vldb = entry;
138 	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
139 	call->peer = rxrpc_kernel_get_peer(vc->alist->addrs[vc->addr_index].peer);
140 	call->service_id = vc->server->service_id;
141 
142 	/* Marshall the parameters */
143 	bp = call->request;
144 	*bp++ = htonl(VLGETENTRYBYNAMEU);
145 	*bp++ = htonl(volnamesz);
146 	memcpy(bp, volname, volnamesz);
147 	if (padsz > 0)
148 		memset((void *)bp + volnamesz, 0, padsz);
149 
150 	trace_afs_make_vl_call(call);
151 	afs_make_call(call, GFP_KERNEL);
152 	afs_wait_for_call_to_complete(call);
153 	vc->call_abort_code	= call->abort_code;
154 	vc->call_error		= call->error;
155 	vc->call_responded	= call->responded;
156 	afs_put_call(call);
157 	if (vc->call_error) {
158 		kfree(entry);
159 		return ERR_PTR(vc->call_error);
160 	}
161 	return entry;
162 }
163 
164 /*
165  * Deliver reply data to a VL.GetAddrsU call.
166  *
167  *	GetAddrsU(IN ListAddrByAttributes *inaddr,
168  *		  OUT afsUUID *uuidp1,
169  *		  OUT uint32_t *uniquifier,
170  *		  OUT uint32_t *nentries,
171  *		  OUT bulkaddrs *blkaddrs);
172  */
173 static int afs_deliver_vl_get_addrs_u(struct afs_call *call)
174 {
175 	struct afs_addr_list *alist;
176 	__be32 *bp;
177 	u32 uniquifier, nentries, count;
178 	int i, ret;
179 
180 	_enter("{%u,%zu/%u}",
181 	       call->unmarshall, iov_iter_count(call->iter), call->count);
182 
183 	switch (call->unmarshall) {
184 	case 0:
185 		afs_extract_to_buf(call,
186 				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
187 		call->unmarshall++;
188 
189 		/* Extract the returned uuid, uniquifier, nentries and
190 		 * blkaddrs size */
191 		fallthrough;
192 	case 1:
193 		ret = afs_extract_data(call, true);
194 		if (ret < 0)
195 			return ret;
196 
197 		bp = call->buffer + sizeof(struct afs_uuid__xdr);
198 		uniquifier	= ntohl(*bp++);
199 		nentries	= ntohl(*bp++);
200 		count		= ntohl(*bp);
201 
202 		nentries = min(nentries, count);
203 		alist = afs_alloc_addrlist(nentries);
204 		if (!alist)
205 			return -ENOMEM;
206 		alist->version = uniquifier;
207 		call->ret_alist = alist;
208 		call->count = count;
209 		call->count2 = nentries;
210 		call->unmarshall++;
211 
212 	more_entries:
213 		count = min(call->count, 4U);
214 		afs_extract_to_buf(call, count * sizeof(__be32));
215 
216 		fallthrough;	/* and extract entries */
217 	case 2:
218 		ret = afs_extract_data(call, call->count > 4);
219 		if (ret < 0)
220 			return ret;
221 
222 		alist = call->ret_alist;
223 		bp = call->buffer;
224 		count = min(call->count, 4U);
225 		for (i = 0; i < count; i++) {
226 			if (alist->nr_addrs < call->count2) {
227 				ret = afs_merge_fs_addr4(call->net, alist, *bp++, AFS_FS_PORT);
228 				if (ret < 0)
229 					return ret;
230 			}
231 		}
232 
233 		call->count -= count;
234 		if (call->count > 0)
235 			goto more_entries;
236 		call->unmarshall++;
237 		break;
238 	}
239 
240 	_leave(" = 0 [done]");
241 	return 0;
242 }
243 
244 /*
245  * VL.GetAddrsU operation type.
246  */
247 static const struct afs_call_type afs_RXVLGetAddrsU = {
248 	.name		= "VL.GetAddrsU",
249 	.op		= afs_VL_GetAddrsU,
250 	.deliver	= afs_deliver_vl_get_addrs_u,
251 	.destructor	= afs_flat_call_destructor,
252 };
253 
254 /*
255  * Dispatch an operation to get the addresses for a server, where the server is
256  * nominated by UUID.
257  */
258 struct afs_addr_list *afs_vl_get_addrs_u(struct afs_vl_cursor *vc,
259 					 const uuid_t *uuid)
260 {
261 	struct afs_ListAddrByAttributes__xdr *r;
262 	struct afs_addr_list *alist;
263 	const struct afs_uuid *u = (const struct afs_uuid *)uuid;
264 	struct afs_call *call;
265 	struct afs_net *net = vc->cell->net;
266 	__be32 *bp;
267 	int i;
268 
269 	_enter("");
270 
271 	call = afs_alloc_flat_call(net, &afs_RXVLGetAddrsU,
272 				   sizeof(__be32) + sizeof(struct afs_ListAddrByAttributes__xdr),
273 				   sizeof(struct afs_uuid__xdr) + 3 * sizeof(__be32));
274 	if (!call)
275 		return ERR_PTR(-ENOMEM);
276 
277 	call->key = vc->key;
278 	call->ret_alist = NULL;
279 	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
280 	call->peer = rxrpc_kernel_get_peer(vc->alist->addrs[vc->addr_index].peer);
281 	call->service_id = vc->server->service_id;
282 
283 	/* Marshall the parameters */
284 	bp = call->request;
285 	*bp++ = htonl(VLGETADDRSU);
286 	r = (struct afs_ListAddrByAttributes__xdr *)bp;
287 	r->Mask		= htonl(AFS_VLADDR_UUID);
288 	r->ipaddr	= 0;
289 	r->index	= 0;
290 	r->spare	= 0;
291 	r->uuid.time_low			= u->time_low;
292 	r->uuid.time_mid			= htonl(ntohs(u->time_mid));
293 	r->uuid.time_hi_and_version		= htonl(ntohs(u->time_hi_and_version));
294 	r->uuid.clock_seq_hi_and_reserved 	= htonl(u->clock_seq_hi_and_reserved);
295 	r->uuid.clock_seq_low			= htonl(u->clock_seq_low);
296 	for (i = 0; i < 6; i++)
297 		r->uuid.node[i] = htonl(u->node[i]);
298 
299 	trace_afs_make_vl_call(call);
300 	afs_make_call(call, GFP_KERNEL);
301 	afs_wait_for_call_to_complete(call);
302 	vc->call_abort_code	= call->abort_code;
303 	vc->call_error		= call->error;
304 	vc->call_responded	= call->responded;
305 	alist			= call->ret_alist;
306 	afs_put_call(call);
307 	if (vc->call_error) {
308 		afs_put_addrlist(alist, afs_alist_trace_put_getaddru);
309 		return ERR_PTR(vc->call_error);
310 	}
311 	return alist;
312 }
313 
314 /*
315  * Deliver reply data to an VL.GetCapabilities operation.
316  */
317 static int afs_deliver_vl_get_capabilities(struct afs_call *call)
318 {
319 	u32 count;
320 	int ret;
321 
322 	_enter("{%u,%zu/%u}",
323 	       call->unmarshall, iov_iter_count(call->iter), call->count);
324 
325 	switch (call->unmarshall) {
326 	case 0:
327 		afs_extract_to_tmp(call);
328 		call->unmarshall++;
329 
330 		fallthrough;	/* and extract the capabilities word count */
331 	case 1:
332 		ret = afs_extract_data(call, true);
333 		if (ret < 0)
334 			return ret;
335 
336 		count = ntohl(call->tmp);
337 		call->count = count;
338 		call->count2 = count;
339 
340 		call->unmarshall++;
341 		afs_extract_discard(call, count * sizeof(__be32));
342 
343 		fallthrough;	/* and extract capabilities words */
344 	case 2:
345 		ret = afs_extract_data(call, false);
346 		if (ret < 0)
347 			return ret;
348 
349 		/* TODO: Examine capabilities */
350 
351 		call->unmarshall++;
352 		break;
353 	}
354 
355 	_leave(" = 0 [done]");
356 	return 0;
357 }
358 
359 static void afs_destroy_vl_get_capabilities(struct afs_call *call)
360 {
361 	afs_put_addrlist(call->vl_probe, afs_alist_trace_put_vlgetcaps);
362 	afs_put_vlserver(call->net, call->vlserver);
363 	afs_flat_call_destructor(call);
364 }
365 
366 /*
367  * VL.GetCapabilities operation type
368  */
369 static const struct afs_call_type afs_RXVLGetCapabilities = {
370 	.name		= "VL.GetCapabilities",
371 	.op		= afs_VL_GetCapabilities,
372 	.deliver	= afs_deliver_vl_get_capabilities,
373 	.immediate_cancel = afs_vlserver_probe_result,
374 	.done		= afs_vlserver_probe_result,
375 	.destructor	= afs_destroy_vl_get_capabilities,
376 };
377 
378 /*
379  * Probe a volume server for the capabilities that it supports.  This can
380  * return up to 196 words.
381  *
382  * We use this to probe for service upgrade to determine what the server at the
383  * other end supports.
384  */
385 struct afs_call *afs_vl_get_capabilities(struct afs_net *net,
386 					 struct afs_addr_list *alist,
387 					 unsigned int addr_index,
388 					 struct key *key,
389 					 struct afs_vlserver *server,
390 					 unsigned int server_index)
391 {
392 	struct afs_call *call;
393 	__be32 *bp;
394 
395 	_enter("");
396 
397 	call = afs_alloc_flat_call(net, &afs_RXVLGetCapabilities, 1 * 4, 16 * 4);
398 	if (!call)
399 		return ERR_PTR(-ENOMEM);
400 
401 	call->key = key;
402 	call->vlserver = afs_get_vlserver(server);
403 	call->server_index = server_index;
404 	call->peer = rxrpc_kernel_get_peer(alist->addrs[addr_index].peer);
405 	call->vl_probe = afs_get_addrlist(alist, afs_alist_trace_get_vlgetcaps);
406 	call->probe_index = addr_index;
407 	call->service_id = server->service_id;
408 	call->upgrade = true;
409 	call->async = true;
410 	call->max_lifespan = AFS_PROBE_MAX_LIFESPAN;
411 
412 	/* marshall the parameters */
413 	bp = call->request;
414 	*bp++ = htonl(VLGETCAPABILITIES);
415 
416 	/* Can't take a ref on server */
417 	trace_afs_make_vl_call(call);
418 	afs_make_call(call, GFP_KERNEL);
419 	return call;
420 }
421 
422 /*
423  * Deliver reply data to a YFSVL.GetEndpoints call.
424  *
425  *	GetEndpoints(IN yfsServerAttributes *attr,
426  *		     OUT opr_uuid *uuid,
427  *		     OUT afs_int32 *uniquifier,
428  *		     OUT endpoints *fsEndpoints,
429  *		     OUT endpoints *volEndpoints)
430  */
431 static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
432 {
433 	struct afs_addr_list *alist;
434 	__be32 *bp;
435 	u32 uniquifier, size;
436 	int ret;
437 
438 	_enter("{%u,%zu,%u}",
439 	       call->unmarshall, iov_iter_count(call->iter), call->count2);
440 
441 	switch (call->unmarshall) {
442 	case 0:
443 		afs_extract_to_buf(call, sizeof(uuid_t) + 3 * sizeof(__be32));
444 		call->unmarshall = 1;
445 
446 		/* Extract the returned uuid, uniquifier, fsEndpoints count and
447 		 * either the first fsEndpoint type or the volEndpoints
448 		 * count if there are no fsEndpoints. */
449 		fallthrough;
450 	case 1:
451 		ret = afs_extract_data(call, true);
452 		if (ret < 0)
453 			return ret;
454 
455 		bp = call->buffer + sizeof(uuid_t);
456 		uniquifier	= ntohl(*bp++);
457 		call->count	= ntohl(*bp++);
458 		call->count2	= ntohl(*bp); /* Type or next count */
459 
460 		if (call->count > YFS_MAXENDPOINTS)
461 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_num);
462 
463 		alist = afs_alloc_addrlist(call->count);
464 		if (!alist)
465 			return -ENOMEM;
466 		alist->version = uniquifier;
467 		call->ret_alist = alist;
468 
469 		if (call->count == 0)
470 			goto extract_volendpoints;
471 
472 	next_fsendpoint:
473 		switch (call->count2) {
474 		case YFS_ENDPOINT_IPV4:
475 			size = sizeof(__be32) * (1 + 1 + 1);
476 			break;
477 		case YFS_ENDPOINT_IPV6:
478 			size = sizeof(__be32) * (1 + 4 + 1);
479 			break;
480 		default:
481 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_type);
482 		}
483 
484 		size += sizeof(__be32);
485 		afs_extract_to_buf(call, size);
486 		call->unmarshall = 2;
487 
488 		fallthrough;	/* and extract fsEndpoints[] entries */
489 	case 2:
490 		ret = afs_extract_data(call, true);
491 		if (ret < 0)
492 			return ret;
493 
494 		alist = call->ret_alist;
495 		bp = call->buffer;
496 		switch (call->count2) {
497 		case YFS_ENDPOINT_IPV4:
498 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
499 				return afs_protocol_error(
500 					call, afs_eproto_yvl_fsendpt4_len);
501 			ret = afs_merge_fs_addr4(call->net, alist, bp[1], ntohl(bp[2]));
502 			if (ret < 0)
503 				return ret;
504 			bp += 3;
505 			break;
506 		case YFS_ENDPOINT_IPV6:
507 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
508 				return afs_protocol_error(
509 					call, afs_eproto_yvl_fsendpt6_len);
510 			ret = afs_merge_fs_addr6(call->net, alist, bp + 1, ntohl(bp[5]));
511 			if (ret < 0)
512 				return ret;
513 			bp += 6;
514 			break;
515 		default:
516 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_type);
517 		}
518 
519 		/* Got either the type of the next entry or the count of
520 		 * volEndpoints if no more fsEndpoints.
521 		 */
522 		call->count2 = ntohl(*bp++);
523 
524 		call->count--;
525 		if (call->count > 0)
526 			goto next_fsendpoint;
527 
528 	extract_volendpoints:
529 		/* Extract the list of volEndpoints. */
530 		call->count = call->count2;
531 		if (!call->count)
532 			goto end;
533 		if (call->count > YFS_MAXENDPOINTS)
534 			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
535 
536 		afs_extract_to_buf(call, 1 * sizeof(__be32));
537 		call->unmarshall = 3;
538 
539 		/* Extract the type of volEndpoints[0].  Normally we would
540 		 * extract the type of the next endpoint when we extract the
541 		 * data of the current one, but this is the first...
542 		 */
543 		fallthrough;
544 	case 3:
545 		ret = afs_extract_data(call, true);
546 		if (ret < 0)
547 			return ret;
548 
549 		bp = call->buffer;
550 
551 	next_volendpoint:
552 		call->count2 = ntohl(*bp++);
553 		switch (call->count2) {
554 		case YFS_ENDPOINT_IPV4:
555 			size = sizeof(__be32) * (1 + 1 + 1);
556 			break;
557 		case YFS_ENDPOINT_IPV6:
558 			size = sizeof(__be32) * (1 + 4 + 1);
559 			break;
560 		default:
561 			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
562 		}
563 
564 		if (call->count > 1)
565 			size += sizeof(__be32); /* Get next type too */
566 		afs_extract_to_buf(call, size);
567 		call->unmarshall = 4;
568 
569 		fallthrough;	/* and extract volEndpoints[] entries */
570 	case 4:
571 		ret = afs_extract_data(call, true);
572 		if (ret < 0)
573 			return ret;
574 
575 		bp = call->buffer;
576 		switch (call->count2) {
577 		case YFS_ENDPOINT_IPV4:
578 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
579 				return afs_protocol_error(
580 					call, afs_eproto_yvl_vlendpt4_len);
581 			bp += 3;
582 			break;
583 		case YFS_ENDPOINT_IPV6:
584 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
585 				return afs_protocol_error(
586 					call, afs_eproto_yvl_vlendpt6_len);
587 			bp += 6;
588 			break;
589 		default:
590 			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
591 		}
592 
593 		/* Got either the type of the next entry or the count of
594 		 * volEndpoints if no more fsEndpoints.
595 		 */
596 		call->count--;
597 		if (call->count > 0)
598 			goto next_volendpoint;
599 
600 	end:
601 		afs_extract_discard(call, 0);
602 		call->unmarshall = 5;
603 
604 		fallthrough;	/* Done */
605 	case 5:
606 		ret = afs_extract_data(call, false);
607 		if (ret < 0)
608 			return ret;
609 		call->unmarshall = 6;
610 		fallthrough;
611 
612 	case 6:
613 		break;
614 	}
615 
616 	_leave(" = 0 [done]");
617 	return 0;
618 }
619 
620 /*
621  * YFSVL.GetEndpoints operation type.
622  */
623 static const struct afs_call_type afs_YFSVLGetEndpoints = {
624 	.name		= "YFSVL.GetEndpoints",
625 	.op		= afs_YFSVL_GetEndpoints,
626 	.deliver	= afs_deliver_yfsvl_get_endpoints,
627 	.destructor	= afs_flat_call_destructor,
628 };
629 
630 /*
631  * Dispatch an operation to get the addresses for a server, where the server is
632  * nominated by UUID.
633  */
634 struct afs_addr_list *afs_yfsvl_get_endpoints(struct afs_vl_cursor *vc,
635 					      const uuid_t *uuid)
636 {
637 	struct afs_addr_list *alist;
638 	struct afs_call *call;
639 	struct afs_net *net = vc->cell->net;
640 	__be32 *bp;
641 
642 	_enter("");
643 
644 	call = afs_alloc_flat_call(net, &afs_YFSVLGetEndpoints,
645 				   sizeof(__be32) * 2 + sizeof(*uuid),
646 				   sizeof(struct in6_addr) + sizeof(__be32) * 3);
647 	if (!call)
648 		return ERR_PTR(-ENOMEM);
649 
650 	call->key = vc->key;
651 	call->ret_alist = NULL;
652 	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
653 	call->peer = rxrpc_kernel_get_peer(vc->alist->addrs[vc->addr_index].peer);
654 	call->service_id = vc->server->service_id;
655 
656 	/* Marshall the parameters */
657 	bp = call->request;
658 	*bp++ = htonl(YVLGETENDPOINTS);
659 	*bp++ = htonl(YFS_SERVER_UUID);
660 	memcpy(bp, uuid, sizeof(*uuid)); /* Type opr_uuid */
661 
662 	trace_afs_make_vl_call(call);
663 	afs_make_call(call, GFP_KERNEL);
664 	afs_wait_for_call_to_complete(call);
665 	vc->call_abort_code	= call->abort_code;
666 	vc->call_error		= call->error;
667 	vc->call_responded	= call->responded;
668 	alist			= call->ret_alist;
669 	afs_put_call(call);
670 	if (vc->call_error) {
671 		afs_put_addrlist(alist, afs_alist_trace_put_getaddru);
672 		return ERR_PTR(vc->call_error);
673 	}
674 	return alist;
675 }
676 
677 /*
678  * Deliver reply data to a YFSVL.GetCellName operation.
679  */
680 static int afs_deliver_yfsvl_get_cell_name(struct afs_call *call)
681 {
682 	char *cell_name;
683 	u32 namesz, paddedsz;
684 	int ret;
685 
686 	_enter("{%u,%zu/%u}",
687 	       call->unmarshall, iov_iter_count(call->iter), call->count);
688 
689 	switch (call->unmarshall) {
690 	case 0:
691 		afs_extract_to_tmp(call);
692 		call->unmarshall++;
693 
694 		fallthrough;	/* and extract the cell name length */
695 	case 1:
696 		ret = afs_extract_data(call, true);
697 		if (ret < 0)
698 			return ret;
699 
700 		namesz = ntohl(call->tmp);
701 		if (namesz > YFS_VL_MAXCELLNAME)
702 			return afs_protocol_error(call, afs_eproto_cellname_len);
703 		paddedsz = (namesz + 3) & ~3;
704 		call->count = namesz;
705 		call->count2 = paddedsz - namesz;
706 
707 		cell_name = kmalloc(namesz + 1, GFP_KERNEL);
708 		if (!cell_name)
709 			return -ENOMEM;
710 		cell_name[namesz] = 0;
711 		call->ret_str = cell_name;
712 
713 		afs_extract_begin(call, cell_name, namesz);
714 		call->unmarshall++;
715 
716 		fallthrough;	/* and extract cell name */
717 	case 2:
718 		ret = afs_extract_data(call, true);
719 		if (ret < 0)
720 			return ret;
721 
722 		afs_extract_discard(call, call->count2);
723 		call->unmarshall++;
724 
725 		fallthrough;	/* and extract padding */
726 	case 3:
727 		ret = afs_extract_data(call, false);
728 		if (ret < 0)
729 			return ret;
730 
731 		call->unmarshall++;
732 		break;
733 	}
734 
735 	_leave(" = 0 [done]");
736 	return 0;
737 }
738 
739 /*
740  * VL.GetCapabilities operation type
741  */
742 static const struct afs_call_type afs_YFSVLGetCellName = {
743 	.name		= "YFSVL.GetCellName",
744 	.op		= afs_YFSVL_GetCellName,
745 	.deliver	= afs_deliver_yfsvl_get_cell_name,
746 	.destructor	= afs_flat_call_destructor,
747 };
748 
749 /*
750  * Probe a volume server for the capabilities that it supports.  This can
751  * return up to 196 words.
752  *
753  * We use this to probe for service upgrade to determine what the server at the
754  * other end supports.
755  */
756 char *afs_yfsvl_get_cell_name(struct afs_vl_cursor *vc)
757 {
758 	struct afs_call *call;
759 	struct afs_net *net = vc->cell->net;
760 	__be32 *bp;
761 	char *cellname;
762 
763 	_enter("");
764 
765 	call = afs_alloc_flat_call(net, &afs_YFSVLGetCellName, 1 * 4, 0);
766 	if (!call)
767 		return ERR_PTR(-ENOMEM);
768 
769 	call->key = vc->key;
770 	call->ret_str = NULL;
771 	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
772 	call->peer = rxrpc_kernel_get_peer(vc->alist->addrs[vc->addr_index].peer);
773 	call->service_id = vc->server->service_id;
774 
775 	/* marshall the parameters */
776 	bp = call->request;
777 	*bp++ = htonl(YVLGETCELLNAME);
778 
779 	/* Can't take a ref on server */
780 	trace_afs_make_vl_call(call);
781 	afs_make_call(call, GFP_KERNEL);
782 	afs_wait_for_call_to_complete(call);
783 	vc->call_abort_code	= call->abort_code;
784 	vc->call_error		= call->error;
785 	vc->call_responded	= call->responded;
786 	cellname		= call->ret_str;
787 	afs_put_call(call);
788 	if (vc->call_error) {
789 		kfree(cellname);
790 		return ERR_PTR(vc->call_error);
791 	}
792 	return cellname;
793 }
794