xref: /linux/fs/afs/vlclient.c (revision 2697b79a469b68e3ad3640f55284359c1396278d)
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 	.done		= afs_vlserver_probe_result,
374 	.destructor	= afs_destroy_vl_get_capabilities,
375 };
376 
377 /*
378  * Probe a volume server for the capabilities that it supports.  This can
379  * return up to 196 words.
380  *
381  * We use this to probe for service upgrade to determine what the server at the
382  * other end supports.
383  */
384 struct afs_call *afs_vl_get_capabilities(struct afs_net *net,
385 					 struct afs_addr_list *alist,
386 					 unsigned int addr_index,
387 					 struct key *key,
388 					 struct afs_vlserver *server,
389 					 unsigned int server_index)
390 {
391 	struct afs_call *call;
392 	__be32 *bp;
393 
394 	_enter("");
395 
396 	call = afs_alloc_flat_call(net, &afs_RXVLGetCapabilities, 1 * 4, 16 * 4);
397 	if (!call)
398 		return ERR_PTR(-ENOMEM);
399 
400 	call->key = key;
401 	call->vlserver = afs_get_vlserver(server);
402 	call->server_index = server_index;
403 	call->peer = rxrpc_kernel_get_peer(alist->addrs[addr_index].peer);
404 	call->vl_probe = afs_get_addrlist(alist, afs_alist_trace_get_vlgetcaps);
405 	call->probe_index = addr_index;
406 	call->service_id = server->service_id;
407 	call->upgrade = true;
408 	call->async = true;
409 	call->max_lifespan = AFS_PROBE_MAX_LIFESPAN;
410 
411 	/* marshall the parameters */
412 	bp = call->request;
413 	*bp++ = htonl(VLGETCAPABILITIES);
414 
415 	/* Can't take a ref on server */
416 	trace_afs_make_vl_call(call);
417 	afs_make_call(call, GFP_KERNEL);
418 	return call;
419 }
420 
421 /*
422  * Deliver reply data to a YFSVL.GetEndpoints call.
423  *
424  *	GetEndpoints(IN yfsServerAttributes *attr,
425  *		     OUT opr_uuid *uuid,
426  *		     OUT afs_int32 *uniquifier,
427  *		     OUT endpoints *fsEndpoints,
428  *		     OUT endpoints *volEndpoints)
429  */
430 static int afs_deliver_yfsvl_get_endpoints(struct afs_call *call)
431 {
432 	struct afs_addr_list *alist;
433 	__be32 *bp;
434 	u32 uniquifier, size;
435 	int ret;
436 
437 	_enter("{%u,%zu,%u}",
438 	       call->unmarshall, iov_iter_count(call->iter), call->count2);
439 
440 	switch (call->unmarshall) {
441 	case 0:
442 		afs_extract_to_buf(call, sizeof(uuid_t) + 3 * sizeof(__be32));
443 		call->unmarshall = 1;
444 
445 		/* Extract the returned uuid, uniquifier, fsEndpoints count and
446 		 * either the first fsEndpoint type or the volEndpoints
447 		 * count if there are no fsEndpoints. */
448 		fallthrough;
449 	case 1:
450 		ret = afs_extract_data(call, true);
451 		if (ret < 0)
452 			return ret;
453 
454 		bp = call->buffer + sizeof(uuid_t);
455 		uniquifier	= ntohl(*bp++);
456 		call->count	= ntohl(*bp++);
457 		call->count2	= ntohl(*bp); /* Type or next count */
458 
459 		if (call->count > YFS_MAXENDPOINTS)
460 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_num);
461 
462 		alist = afs_alloc_addrlist(call->count);
463 		if (!alist)
464 			return -ENOMEM;
465 		alist->version = uniquifier;
466 		call->ret_alist = alist;
467 
468 		if (call->count == 0)
469 			goto extract_volendpoints;
470 
471 	next_fsendpoint:
472 		switch (call->count2) {
473 		case YFS_ENDPOINT_IPV4:
474 			size = sizeof(__be32) * (1 + 1 + 1);
475 			break;
476 		case YFS_ENDPOINT_IPV6:
477 			size = sizeof(__be32) * (1 + 4 + 1);
478 			break;
479 		default:
480 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_type);
481 		}
482 
483 		size += sizeof(__be32);
484 		afs_extract_to_buf(call, size);
485 		call->unmarshall = 2;
486 
487 		fallthrough;	/* and extract fsEndpoints[] entries */
488 	case 2:
489 		ret = afs_extract_data(call, true);
490 		if (ret < 0)
491 			return ret;
492 
493 		alist = call->ret_alist;
494 		bp = call->buffer;
495 		switch (call->count2) {
496 		case YFS_ENDPOINT_IPV4:
497 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
498 				return afs_protocol_error(
499 					call, afs_eproto_yvl_fsendpt4_len);
500 			ret = afs_merge_fs_addr4(call->net, alist, bp[1], ntohl(bp[2]));
501 			if (ret < 0)
502 				return ret;
503 			bp += 3;
504 			break;
505 		case YFS_ENDPOINT_IPV6:
506 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
507 				return afs_protocol_error(
508 					call, afs_eproto_yvl_fsendpt6_len);
509 			ret = afs_merge_fs_addr6(call->net, alist, bp + 1, ntohl(bp[5]));
510 			if (ret < 0)
511 				return ret;
512 			bp += 6;
513 			break;
514 		default:
515 			return afs_protocol_error(call, afs_eproto_yvl_fsendpt_type);
516 		}
517 
518 		/* Got either the type of the next entry or the count of
519 		 * volEndpoints if no more fsEndpoints.
520 		 */
521 		call->count2 = ntohl(*bp++);
522 
523 		call->count--;
524 		if (call->count > 0)
525 			goto next_fsendpoint;
526 
527 	extract_volendpoints:
528 		/* Extract the list of volEndpoints. */
529 		call->count = call->count2;
530 		if (!call->count)
531 			goto end;
532 		if (call->count > YFS_MAXENDPOINTS)
533 			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
534 
535 		afs_extract_to_buf(call, 1 * sizeof(__be32));
536 		call->unmarshall = 3;
537 
538 		/* Extract the type of volEndpoints[0].  Normally we would
539 		 * extract the type of the next endpoint when we extract the
540 		 * data of the current one, but this is the first...
541 		 */
542 		fallthrough;
543 	case 3:
544 		ret = afs_extract_data(call, true);
545 		if (ret < 0)
546 			return ret;
547 
548 		bp = call->buffer;
549 
550 	next_volendpoint:
551 		call->count2 = ntohl(*bp++);
552 		switch (call->count2) {
553 		case YFS_ENDPOINT_IPV4:
554 			size = sizeof(__be32) * (1 + 1 + 1);
555 			break;
556 		case YFS_ENDPOINT_IPV6:
557 			size = sizeof(__be32) * (1 + 4 + 1);
558 			break;
559 		default:
560 			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
561 		}
562 
563 		if (call->count > 1)
564 			size += sizeof(__be32); /* Get next type too */
565 		afs_extract_to_buf(call, size);
566 		call->unmarshall = 4;
567 
568 		fallthrough;	/* and extract volEndpoints[] entries */
569 	case 4:
570 		ret = afs_extract_data(call, true);
571 		if (ret < 0)
572 			return ret;
573 
574 		bp = call->buffer;
575 		switch (call->count2) {
576 		case YFS_ENDPOINT_IPV4:
577 			if (ntohl(bp[0]) != sizeof(__be32) * 2)
578 				return afs_protocol_error(
579 					call, afs_eproto_yvl_vlendpt4_len);
580 			bp += 3;
581 			break;
582 		case YFS_ENDPOINT_IPV6:
583 			if (ntohl(bp[0]) != sizeof(__be32) * 5)
584 				return afs_protocol_error(
585 					call, afs_eproto_yvl_vlendpt6_len);
586 			bp += 6;
587 			break;
588 		default:
589 			return afs_protocol_error(call, afs_eproto_yvl_vlendpt_type);
590 		}
591 
592 		/* Got either the type of the next entry or the count of
593 		 * volEndpoints if no more fsEndpoints.
594 		 */
595 		call->count--;
596 		if (call->count > 0)
597 			goto next_volendpoint;
598 
599 	end:
600 		afs_extract_discard(call, 0);
601 		call->unmarshall = 5;
602 
603 		fallthrough;	/* Done */
604 	case 5:
605 		ret = afs_extract_data(call, false);
606 		if (ret < 0)
607 			return ret;
608 		call->unmarshall = 6;
609 		fallthrough;
610 
611 	case 6:
612 		break;
613 	}
614 
615 	_leave(" = 0 [done]");
616 	return 0;
617 }
618 
619 /*
620  * YFSVL.GetEndpoints operation type.
621  */
622 static const struct afs_call_type afs_YFSVLGetEndpoints = {
623 	.name		= "YFSVL.GetEndpoints",
624 	.op		= afs_YFSVL_GetEndpoints,
625 	.deliver	= afs_deliver_yfsvl_get_endpoints,
626 	.destructor	= afs_flat_call_destructor,
627 };
628 
629 /*
630  * Dispatch an operation to get the addresses for a server, where the server is
631  * nominated by UUID.
632  */
633 struct afs_addr_list *afs_yfsvl_get_endpoints(struct afs_vl_cursor *vc,
634 					      const uuid_t *uuid)
635 {
636 	struct afs_addr_list *alist;
637 	struct afs_call *call;
638 	struct afs_net *net = vc->cell->net;
639 	__be32 *bp;
640 
641 	_enter("");
642 
643 	call = afs_alloc_flat_call(net, &afs_YFSVLGetEndpoints,
644 				   sizeof(__be32) * 2 + sizeof(*uuid),
645 				   sizeof(struct in6_addr) + sizeof(__be32) * 3);
646 	if (!call)
647 		return ERR_PTR(-ENOMEM);
648 
649 	call->key = vc->key;
650 	call->ret_alist = NULL;
651 	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
652 	call->peer = rxrpc_kernel_get_peer(vc->alist->addrs[vc->addr_index].peer);
653 	call->service_id = vc->server->service_id;
654 
655 	/* Marshall the parameters */
656 	bp = call->request;
657 	*bp++ = htonl(YVLGETENDPOINTS);
658 	*bp++ = htonl(YFS_SERVER_UUID);
659 	memcpy(bp, uuid, sizeof(*uuid)); /* Type opr_uuid */
660 
661 	trace_afs_make_vl_call(call);
662 	afs_make_call(call, GFP_KERNEL);
663 	afs_wait_for_call_to_complete(call);
664 	vc->call_abort_code	= call->abort_code;
665 	vc->call_error		= call->error;
666 	vc->call_responded	= call->responded;
667 	alist			= call->ret_alist;
668 	afs_put_call(call);
669 	if (vc->call_error) {
670 		afs_put_addrlist(alist, afs_alist_trace_put_getaddru);
671 		return ERR_PTR(vc->call_error);
672 	}
673 	return alist;
674 }
675 
676 /*
677  * Deliver reply data to a YFSVL.GetCellName operation.
678  */
679 static int afs_deliver_yfsvl_get_cell_name(struct afs_call *call)
680 {
681 	char *cell_name;
682 	u32 namesz, paddedsz;
683 	int ret;
684 
685 	_enter("{%u,%zu/%u}",
686 	       call->unmarshall, iov_iter_count(call->iter), call->count);
687 
688 	switch (call->unmarshall) {
689 	case 0:
690 		afs_extract_to_tmp(call);
691 		call->unmarshall++;
692 
693 		fallthrough;	/* and extract the cell name length */
694 	case 1:
695 		ret = afs_extract_data(call, true);
696 		if (ret < 0)
697 			return ret;
698 
699 		namesz = ntohl(call->tmp);
700 		if (namesz > AFS_MAXCELLNAME)
701 			return afs_protocol_error(call, afs_eproto_cellname_len);
702 		paddedsz = (namesz + 3) & ~3;
703 		call->count = namesz;
704 		call->count2 = paddedsz - namesz;
705 
706 		cell_name = kmalloc(namesz + 1, GFP_KERNEL);
707 		if (!cell_name)
708 			return -ENOMEM;
709 		cell_name[namesz] = 0;
710 		call->ret_str = cell_name;
711 
712 		afs_extract_begin(call, cell_name, namesz);
713 		call->unmarshall++;
714 
715 		fallthrough;	/* and extract cell name */
716 	case 2:
717 		ret = afs_extract_data(call, true);
718 		if (ret < 0)
719 			return ret;
720 
721 		afs_extract_discard(call, call->count2);
722 		call->unmarshall++;
723 
724 		fallthrough;	/* and extract padding */
725 	case 3:
726 		ret = afs_extract_data(call, false);
727 		if (ret < 0)
728 			return ret;
729 
730 		call->unmarshall++;
731 		break;
732 	}
733 
734 	_leave(" = 0 [done]");
735 	return 0;
736 }
737 
738 /*
739  * VL.GetCapabilities operation type
740  */
741 static const struct afs_call_type afs_YFSVLGetCellName = {
742 	.name		= "YFSVL.GetCellName",
743 	.op		= afs_YFSVL_GetCellName,
744 	.deliver	= afs_deliver_yfsvl_get_cell_name,
745 	.destructor	= afs_flat_call_destructor,
746 };
747 
748 /*
749  * Probe a volume server for the capabilities that it supports.  This can
750  * return up to 196 words.
751  *
752  * We use this to probe for service upgrade to determine what the server at the
753  * other end supports.
754  */
755 char *afs_yfsvl_get_cell_name(struct afs_vl_cursor *vc)
756 {
757 	struct afs_call *call;
758 	struct afs_net *net = vc->cell->net;
759 	__be32 *bp;
760 	char *cellname;
761 
762 	_enter("");
763 
764 	call = afs_alloc_flat_call(net, &afs_YFSVLGetCellName, 1 * 4, 0);
765 	if (!call)
766 		return ERR_PTR(-ENOMEM);
767 
768 	call->key = vc->key;
769 	call->ret_str = NULL;
770 	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
771 	call->peer = rxrpc_kernel_get_peer(vc->alist->addrs[vc->addr_index].peer);
772 	call->service_id = vc->server->service_id;
773 
774 	/* marshall the parameters */
775 	bp = call->request;
776 	*bp++ = htonl(YVLGETCELLNAME);
777 
778 	/* Can't take a ref on server */
779 	trace_afs_make_vl_call(call);
780 	afs_make_call(call, GFP_KERNEL);
781 	afs_wait_for_call_to_complete(call);
782 	vc->call_abort_code	= call->abort_code;
783 	vc->call_error		= call->error;
784 	vc->call_responded	= call->responded;
785 	cellname		= call->ret_str;
786 	afs_put_call(call);
787 	if (vc->call_error) {
788 		kfree(cellname);
789 		return ERR_PTR(vc->call_error);
790 	}
791 	return cellname;
792 }
793