xref: /linux/fs/smb/client/cifs_swn.c (revision 91b436fc925ca58625e4230f53238e955223c385)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Witness Service client for CIFS
4  *
5  * Copyright (c) 2020 Samuel Cabrero <scabrero@suse.de>
6  */
7 
8 #include <linux/kref.h>
9 #include <net/genetlink.h>
10 #include <uapi/linux/cifs/cifs_netlink.h>
11 
12 #include "cifs_swn.h"
13 #include "cifsglob.h"
14 #include "cifsproto.h"
15 #include "fscache.h"
16 #include "cifs_debug.h"
17 #include "netlink.h"
18 
19 static DEFINE_IDR(cifs_swnreg_idr);
20 static DEFINE_MUTEX(cifs_swnreg_idr_mutex);
21 
22 struct cifs_swn_reg {
23 	int id;
24 	struct kref ref_count;
25 
26 	const char *net_name;
27 	const char *share_name;
28 	bool net_name_notify;
29 	bool share_name_notify;
30 	bool ip_notify;
31 
32 	struct cifs_tcon *tcon;
33 };
34 
cifs_swn_auth_info_krb(struct cifs_tcon * tcon,struct sk_buff * skb)35 static int cifs_swn_auth_info_krb(struct cifs_tcon *tcon, struct sk_buff *skb)
36 {
37 	int ret;
38 
39 	ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_KRB_AUTH);
40 	if (ret < 0)
41 		return ret;
42 
43 	return 0;
44 }
45 
cifs_swn_auth_info_ntlm(struct cifs_tcon * tcon,struct sk_buff * skb)46 static int cifs_swn_auth_info_ntlm(struct cifs_tcon *tcon, struct sk_buff *skb)
47 {
48 	int ret;
49 
50 	if (tcon->ses->user_name != NULL) {
51 		ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_USER_NAME, tcon->ses->user_name);
52 		if (ret < 0)
53 			return ret;
54 	}
55 
56 	if (tcon->ses->password != NULL) {
57 		ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_PASSWORD, tcon->ses->password);
58 		if (ret < 0)
59 			return ret;
60 	}
61 
62 	if (tcon->ses->domainName != NULL) {
63 		ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_DOMAIN_NAME, tcon->ses->domainName);
64 		if (ret < 0)
65 			return ret;
66 	}
67 
68 	return 0;
69 }
70 
71 /*
72  * Sends a register message to the userspace daemon based on the registration.
73  * The authentication information to connect to the witness service is bundled
74  * into the message.
75  */
cifs_swn_send_register_message(struct cifs_swn_reg * swnreg)76 static int cifs_swn_send_register_message(struct cifs_swn_reg *swnreg)
77 {
78 	struct sk_buff *skb;
79 	struct genlmsghdr *hdr;
80 	enum securityEnum authtype;
81 	struct sockaddr_storage *addr;
82 	int ret;
83 
84 	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
85 	if (!skb)
86 		return -ENOMEM;
87 
88 	hdr = genlmsg_put(skb, 0, 0, &cifs_genl_family, 0, CIFS_GENL_CMD_SWN_REGISTER);
89 	if (hdr == NULL) {
90 		ret = -ENOMEM;
91 		goto nlmsg_fail;
92 	}
93 
94 	ret = nla_put_u32(skb, CIFS_GENL_ATTR_SWN_REGISTRATION_ID, swnreg->id);
95 	if (ret < 0)
96 		goto nlmsg_fail;
97 
98 	ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_NET_NAME, swnreg->net_name);
99 	if (ret < 0)
100 		goto nlmsg_fail;
101 
102 	ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME, swnreg->share_name);
103 	if (ret < 0)
104 		goto nlmsg_fail;
105 
106 	/*
107 	 * If there is an address stored use it instead of the server address, because we are
108 	 * in the process of reconnecting to it after a share has been moved or we have been
109 	 * told to switch to it (client move message). In these cases we unregister from the
110 	 * server address and register to the new address when we receive the notification.
111 	 */
112 	if (swnreg->tcon->ses->server->use_swn_dstaddr)
113 		addr = &swnreg->tcon->ses->server->swn_dstaddr;
114 	else
115 		addr = &swnreg->tcon->ses->server->dstaddr;
116 
117 	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage), addr);
118 	if (ret < 0)
119 		goto nlmsg_fail;
120 
121 	if (swnreg->net_name_notify) {
122 		ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_NET_NAME_NOTIFY);
123 		if (ret < 0)
124 			goto nlmsg_fail;
125 	}
126 
127 	if (swnreg->share_name_notify) {
128 		ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME_NOTIFY);
129 		if (ret < 0)
130 			goto nlmsg_fail;
131 	}
132 
133 	if (swnreg->ip_notify) {
134 		ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_IP_NOTIFY);
135 		if (ret < 0)
136 			goto nlmsg_fail;
137 	}
138 
139 	authtype = cifs_select_sectype(swnreg->tcon->ses->server, swnreg->tcon->ses->sectype);
140 	switch (authtype) {
141 	case Kerberos:
142 		ret = cifs_swn_auth_info_krb(swnreg->tcon, skb);
143 		if (ret < 0) {
144 			cifs_dbg(VFS, "%s: Failed to get kerberos auth info: %d\n", __func__, ret);
145 			goto nlmsg_fail;
146 		}
147 		break;
148 	case NTLMv2:
149 	case RawNTLMSSP:
150 		ret = cifs_swn_auth_info_ntlm(swnreg->tcon, skb);
151 		if (ret < 0) {
152 			cifs_dbg(VFS, "%s: Failed to get NTLM auth info: %d\n", __func__, ret);
153 			goto nlmsg_fail;
154 		}
155 		break;
156 	default:
157 		cifs_dbg(VFS, "%s: secType %d not supported!\n", __func__, authtype);
158 		ret = -EINVAL;
159 		goto nlmsg_fail;
160 	}
161 
162 	genlmsg_end(skb, hdr);
163 	genlmsg_multicast(&cifs_genl_family, skb, 0, CIFS_GENL_MCGRP_SWN, GFP_ATOMIC);
164 
165 	cifs_dbg(FYI, "%s: Message to register for network name %s with id %d sent\n", __func__,
166 			swnreg->net_name, swnreg->id);
167 
168 	return 0;
169 
170 nlmsg_fail:
171 	genlmsg_cancel(skb, hdr);
172 	nlmsg_free(skb);
173 	return ret;
174 }
175 
176 /*
177  * Sends an uregister message to the userspace daemon based on the registration
178  */
cifs_swn_send_unregister_message(struct cifs_swn_reg * swnreg)179 static int cifs_swn_send_unregister_message(struct cifs_swn_reg *swnreg)
180 {
181 	struct sk_buff *skb;
182 	struct genlmsghdr *hdr;
183 	int ret;
184 
185 	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
186 	if (skb == NULL)
187 		return -ENOMEM;
188 
189 	hdr = genlmsg_put(skb, 0, 0, &cifs_genl_family, 0, CIFS_GENL_CMD_SWN_UNREGISTER);
190 	if (hdr == NULL) {
191 		ret = -ENOMEM;
192 		goto nlmsg_fail;
193 	}
194 
195 	ret = nla_put_u32(skb, CIFS_GENL_ATTR_SWN_REGISTRATION_ID, swnreg->id);
196 	if (ret < 0)
197 		goto nlmsg_fail;
198 
199 	ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_NET_NAME, swnreg->net_name);
200 	if (ret < 0)
201 		goto nlmsg_fail;
202 
203 	ret = nla_put_string(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME, swnreg->share_name);
204 	if (ret < 0)
205 		goto nlmsg_fail;
206 
207 	ret = nla_put(skb, CIFS_GENL_ATTR_SWN_IP, sizeof(struct sockaddr_storage),
208 			&swnreg->tcon->ses->server->dstaddr);
209 	if (ret < 0)
210 		goto nlmsg_fail;
211 
212 	if (swnreg->net_name_notify) {
213 		ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_NET_NAME_NOTIFY);
214 		if (ret < 0)
215 			goto nlmsg_fail;
216 	}
217 
218 	if (swnreg->share_name_notify) {
219 		ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_SHARE_NAME_NOTIFY);
220 		if (ret < 0)
221 			goto nlmsg_fail;
222 	}
223 
224 	if (swnreg->ip_notify) {
225 		ret = nla_put_flag(skb, CIFS_GENL_ATTR_SWN_IP_NOTIFY);
226 		if (ret < 0)
227 			goto nlmsg_fail;
228 	}
229 
230 	genlmsg_end(skb, hdr);
231 	genlmsg_multicast(&cifs_genl_family, skb, 0, CIFS_GENL_MCGRP_SWN, GFP_ATOMIC);
232 
233 	cifs_dbg(FYI, "%s: Message to unregister for network name %s with id %d sent\n", __func__,
234 			swnreg->net_name, swnreg->id);
235 
236 	return 0;
237 
238 nlmsg_fail:
239 	genlmsg_cancel(skb, hdr);
240 	nlmsg_free(skb);
241 	return ret;
242 }
243 
244 /*
245  * Try to find a matching registration for the tcon's server name and share name.
246  * Calls to this function must be protected by cifs_swnreg_idr_mutex.
247  * TODO Try to avoid memory allocations
248  */
cifs_find_swn_reg(struct cifs_tcon * tcon)249 static struct cifs_swn_reg *cifs_find_swn_reg(struct cifs_tcon *tcon)
250 {
251 	struct cifs_swn_reg *swnreg;
252 	int id;
253 	const char *share_name;
254 	const char *net_name;
255 
256 	net_name = extract_hostname(tcon->tree_name);
257 	if (IS_ERR(net_name)) {
258 		int ret;
259 
260 		ret = PTR_ERR(net_name);
261 		cifs_dbg(VFS, "%s: failed to extract host name from target '%s': %d\n",
262 				__func__, tcon->tree_name, ret);
263 		return ERR_PTR(-EINVAL);
264 	}
265 
266 	share_name = extract_sharename(tcon->tree_name);
267 	if (IS_ERR(share_name)) {
268 		int ret;
269 
270 		ret = PTR_ERR(share_name);
271 		cifs_dbg(VFS, "%s: failed to extract share name from target '%s': %d\n",
272 				__func__, tcon->tree_name, ret);
273 		kfree(net_name);
274 		return ERR_PTR(-EINVAL);
275 	}
276 
277 	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
278 		if (strcasecmp(swnreg->net_name, net_name) != 0
279 		    || strcasecmp(swnreg->share_name, share_name) != 0) {
280 			continue;
281 		}
282 
283 		cifs_dbg(FYI, "Existing swn registration for %s:%s found\n", swnreg->net_name,
284 				swnreg->share_name);
285 
286 		kfree(net_name);
287 		kfree(share_name);
288 
289 		return swnreg;
290 	}
291 
292 	kfree(net_name);
293 	kfree(share_name);
294 
295 	return ERR_PTR(-EEXIST);
296 }
297 
298 /*
299  * Get a registration for the tcon's server and share name, allocating a new one if it does not
300  * exists
301  */
cifs_get_swn_reg(struct cifs_tcon * tcon)302 static struct cifs_swn_reg *cifs_get_swn_reg(struct cifs_tcon *tcon)
303 {
304 	struct cifs_swn_reg *reg = NULL;
305 	int ret;
306 
307 	mutex_lock(&cifs_swnreg_idr_mutex);
308 
309 	/* Check if we are already registered for this network and share names */
310 	reg = cifs_find_swn_reg(tcon);
311 	if (!IS_ERR(reg)) {
312 		kref_get(&reg->ref_count);
313 		goto unlock;
314 	} else if (PTR_ERR(reg) != -EEXIST) {
315 		goto unlock;
316 	}
317 
318 	reg = kmalloc(sizeof(struct cifs_swn_reg), GFP_ATOMIC);
319 	if (reg == NULL) {
320 		ret = -ENOMEM;
321 		goto fail_unlock;
322 	}
323 
324 	kref_init(&reg->ref_count);
325 
326 	reg->id = idr_alloc(&cifs_swnreg_idr, reg, 1, 0, GFP_ATOMIC);
327 	if (reg->id < 0) {
328 		cifs_dbg(FYI, "%s: failed to allocate registration id\n", __func__);
329 		ret = reg->id;
330 		goto fail;
331 	}
332 
333 	reg->net_name = extract_hostname(tcon->tree_name);
334 	if (IS_ERR(reg->net_name)) {
335 		ret = PTR_ERR(reg->net_name);
336 		cifs_dbg(VFS, "%s: failed to extract host name from target: %d\n", __func__, ret);
337 		goto fail_idr;
338 	}
339 
340 	reg->share_name = extract_sharename(tcon->tree_name);
341 	if (IS_ERR(reg->share_name)) {
342 		ret = PTR_ERR(reg->share_name);
343 		cifs_dbg(VFS, "%s: failed to extract share name from target: %d\n", __func__, ret);
344 		goto fail_net_name;
345 	}
346 
347 	reg->net_name_notify = true;
348 	reg->share_name_notify = true;
349 	reg->ip_notify = (tcon->capabilities & SMB2_SHARE_CAP_SCALEOUT);
350 
351 	reg->tcon = tcon;
352 unlock:
353 	mutex_unlock(&cifs_swnreg_idr_mutex);
354 
355 	return reg;
356 
357 fail_net_name:
358 	kfree(reg->net_name);
359 fail_idr:
360 	idr_remove(&cifs_swnreg_idr, reg->id);
361 fail:
362 	kfree(reg);
363 fail_unlock:
364 	mutex_unlock(&cifs_swnreg_idr_mutex);
365 	return ERR_PTR(ret);
366 }
367 
cifs_swn_reg_release(struct kref * ref)368 static void cifs_swn_reg_release(struct kref *ref)
369 {
370 	struct cifs_swn_reg *swnreg = container_of(ref, struct cifs_swn_reg, ref_count);
371 	int ret;
372 
373 	ret = cifs_swn_send_unregister_message(swnreg);
374 	if (ret < 0)
375 		cifs_dbg(VFS, "%s: Failed to send unregister message: %d\n", __func__, ret);
376 
377 	idr_remove(&cifs_swnreg_idr, swnreg->id);
378 	kfree(swnreg->net_name);
379 	kfree(swnreg->share_name);
380 	kfree(swnreg);
381 }
382 
cifs_put_swn_reg(struct cifs_swn_reg * swnreg)383 static void cifs_put_swn_reg(struct cifs_swn_reg *swnreg)
384 {
385 	mutex_lock(&cifs_swnreg_idr_mutex);
386 	kref_put(&swnreg->ref_count, cifs_swn_reg_release);
387 	mutex_unlock(&cifs_swnreg_idr_mutex);
388 }
389 
cifs_swn_resource_state_changed(struct cifs_swn_reg * swnreg,const char * name,int state)390 static int cifs_swn_resource_state_changed(struct cifs_swn_reg *swnreg, const char *name, int state)
391 {
392 	switch (state) {
393 	case CIFS_SWN_RESOURCE_STATE_UNAVAILABLE:
394 		cifs_dbg(FYI, "%s: resource name '%s' become unavailable\n", __func__, name);
395 		cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true);
396 		break;
397 	case CIFS_SWN_RESOURCE_STATE_AVAILABLE:
398 		cifs_dbg(FYI, "%s: resource name '%s' become available\n", __func__, name);
399 		cifs_signal_cifsd_for_reconnect(swnreg->tcon->ses->server, true);
400 		break;
401 	case CIFS_SWN_RESOURCE_STATE_UNKNOWN:
402 		cifs_dbg(FYI, "%s: resource name '%s' changed to unknown state\n", __func__, name);
403 		break;
404 	}
405 	return 0;
406 }
407 
cifs_sockaddr_equal(struct sockaddr_storage * addr1,struct sockaddr_storage * addr2)408 static bool cifs_sockaddr_equal(struct sockaddr_storage *addr1, struct sockaddr_storage *addr2)
409 {
410 	if (addr1->ss_family != addr2->ss_family)
411 		return false;
412 
413 	if (addr1->ss_family == AF_INET) {
414 		return (memcmp(&((const struct sockaddr_in *)addr1)->sin_addr,
415 				&((const struct sockaddr_in *)addr2)->sin_addr,
416 				sizeof(struct in_addr)) == 0);
417 	}
418 
419 	if (addr1->ss_family == AF_INET6) {
420 		return (memcmp(&((const struct sockaddr_in6 *)addr1)->sin6_addr,
421 				&((const struct sockaddr_in6 *)addr2)->sin6_addr,
422 				sizeof(struct in6_addr)) == 0);
423 	}
424 
425 	return false;
426 }
427 
cifs_swn_store_swn_addr(const struct sockaddr_storage * new,const struct sockaddr_storage * old,struct sockaddr_storage * dst)428 static int cifs_swn_store_swn_addr(const struct sockaddr_storage *new,
429 				   const struct sockaddr_storage *old,
430 				   struct sockaddr_storage *dst)
431 {
432 	__be16 port = cpu_to_be16(CIFS_PORT);
433 
434 	if (old->ss_family == AF_INET) {
435 		struct sockaddr_in *ipv4 = (struct sockaddr_in *)old;
436 
437 		port = ipv4->sin_port;
438 	} else if (old->ss_family == AF_INET6) {
439 		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)old;
440 
441 		port = ipv6->sin6_port;
442 	}
443 
444 	if (new->ss_family == AF_INET) {
445 		struct sockaddr_in *ipv4 = (struct sockaddr_in *)new;
446 
447 		ipv4->sin_port = port;
448 	} else if (new->ss_family == AF_INET6) {
449 		struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)new;
450 
451 		ipv6->sin6_port = port;
452 	}
453 
454 	*dst = *new;
455 
456 	return 0;
457 }
458 
cifs_swn_reconnect(struct cifs_tcon * tcon,struct sockaddr_storage * addr)459 static int cifs_swn_reconnect(struct cifs_tcon *tcon, struct sockaddr_storage *addr)
460 {
461 	int ret = 0;
462 
463 	/* Store the reconnect address */
464 	cifs_server_lock(tcon->ses->server);
465 	if (cifs_sockaddr_equal(&tcon->ses->server->dstaddr, addr))
466 		goto unlock;
467 
468 	ret = cifs_swn_store_swn_addr(addr, &tcon->ses->server->dstaddr,
469 				      &tcon->ses->server->swn_dstaddr);
470 	if (ret < 0) {
471 		cifs_dbg(VFS, "%s: failed to store address: %d\n", __func__, ret);
472 		goto unlock;
473 	}
474 	tcon->ses->server->use_swn_dstaddr = true;
475 
476 	/*
477 	 * Unregister to stop receiving notifications for the old IP address.
478 	 */
479 	ret = cifs_swn_unregister(tcon);
480 	if (ret < 0) {
481 		cifs_dbg(VFS, "%s: Failed to unregister for witness notifications: %d\n",
482 			 __func__, ret);
483 		goto unlock;
484 	}
485 
486 	/*
487 	 * And register to receive notifications for the new IP address now that we have
488 	 * stored the new address.
489 	 */
490 	ret = cifs_swn_register(tcon);
491 	if (ret < 0) {
492 		cifs_dbg(VFS, "%s: Failed to register for witness notifications: %d\n",
493 			 __func__, ret);
494 		goto unlock;
495 	}
496 
497 	cifs_signal_cifsd_for_reconnect(tcon->ses->server, false);
498 
499 unlock:
500 	cifs_server_unlock(tcon->ses->server);
501 
502 	return ret;
503 }
504 
cifs_swn_client_move(struct cifs_swn_reg * swnreg,struct sockaddr_storage * addr)505 static int cifs_swn_client_move(struct cifs_swn_reg *swnreg, struct sockaddr_storage *addr)
506 {
507 	struct sockaddr_in *ipv4 = (struct sockaddr_in *)addr;
508 	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)addr;
509 
510 	if (addr->ss_family == AF_INET)
511 		cifs_dbg(FYI, "%s: move to %pI4\n", __func__, &ipv4->sin_addr);
512 	else if (addr->ss_family == AF_INET6)
513 		cifs_dbg(FYI, "%s: move to %pI6\n", __func__, &ipv6->sin6_addr);
514 
515 	return cifs_swn_reconnect(swnreg->tcon, addr);
516 }
517 
cifs_swn_notify(struct sk_buff * skb,struct genl_info * info)518 int cifs_swn_notify(struct sk_buff *skb, struct genl_info *info)
519 {
520 	struct cifs_swn_reg *swnreg;
521 	char name[256];
522 	int type;
523 
524 	if (info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]) {
525 		int swnreg_id;
526 
527 		swnreg_id = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_REGISTRATION_ID]);
528 		mutex_lock(&cifs_swnreg_idr_mutex);
529 		swnreg = idr_find(&cifs_swnreg_idr, swnreg_id);
530 		mutex_unlock(&cifs_swnreg_idr_mutex);
531 		if (swnreg == NULL) {
532 			cifs_dbg(FYI, "%s: registration id %d not found\n", __func__, swnreg_id);
533 			return -EINVAL;
534 		}
535 	} else {
536 		cifs_dbg(FYI, "%s: missing registration id attribute\n", __func__);
537 		return -EINVAL;
538 	}
539 
540 	if (info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]) {
541 		type = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_NOTIFICATION_TYPE]);
542 	} else {
543 		cifs_dbg(FYI, "%s: missing notification type attribute\n", __func__);
544 		return -EINVAL;
545 	}
546 
547 	switch (type) {
548 	case CIFS_SWN_NOTIFICATION_RESOURCE_CHANGE: {
549 		int state;
550 
551 		if (info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_NAME]) {
552 			nla_strscpy(name, info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_NAME],
553 					sizeof(name));
554 		} else {
555 			cifs_dbg(FYI, "%s: missing resource name attribute\n", __func__);
556 			return -EINVAL;
557 		}
558 		if (info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]) {
559 			state = nla_get_u32(info->attrs[CIFS_GENL_ATTR_SWN_RESOURCE_STATE]);
560 		} else {
561 			cifs_dbg(FYI, "%s: missing resource state attribute\n", __func__);
562 			return -EINVAL;
563 		}
564 		return cifs_swn_resource_state_changed(swnreg, name, state);
565 	}
566 	case CIFS_SWN_NOTIFICATION_CLIENT_MOVE: {
567 		struct sockaddr_storage addr;
568 
569 		if (info->attrs[CIFS_GENL_ATTR_SWN_IP]) {
570 			nla_memcpy(&addr, info->attrs[CIFS_GENL_ATTR_SWN_IP], sizeof(addr));
571 		} else {
572 			cifs_dbg(FYI, "%s: missing IP address attribute\n", __func__);
573 			return -EINVAL;
574 		}
575 		return cifs_swn_client_move(swnreg, &addr);
576 	}
577 	default:
578 		cifs_dbg(FYI, "%s: unknown notification type %d\n", __func__, type);
579 		break;
580 	}
581 
582 	return 0;
583 }
584 
cifs_swn_register(struct cifs_tcon * tcon)585 int cifs_swn_register(struct cifs_tcon *tcon)
586 {
587 	struct cifs_swn_reg *swnreg;
588 	int ret;
589 
590 	swnreg = cifs_get_swn_reg(tcon);
591 	if (IS_ERR(swnreg))
592 		return PTR_ERR(swnreg);
593 
594 	ret = cifs_swn_send_register_message(swnreg);
595 	if (ret < 0) {
596 		cifs_dbg(VFS, "%s: Failed to send swn register message: %d\n", __func__, ret);
597 		/* Do not put the swnreg or return error, the echo task will retry */
598 	}
599 
600 	return 0;
601 }
602 
cifs_swn_unregister(struct cifs_tcon * tcon)603 int cifs_swn_unregister(struct cifs_tcon *tcon)
604 {
605 	struct cifs_swn_reg *swnreg;
606 
607 	mutex_lock(&cifs_swnreg_idr_mutex);
608 
609 	swnreg = cifs_find_swn_reg(tcon);
610 	if (IS_ERR(swnreg)) {
611 		mutex_unlock(&cifs_swnreg_idr_mutex);
612 		return PTR_ERR(swnreg);
613 	}
614 
615 	mutex_unlock(&cifs_swnreg_idr_mutex);
616 
617 	cifs_put_swn_reg(swnreg);
618 
619 	return 0;
620 }
621 
cifs_swn_dump(struct seq_file * m)622 void cifs_swn_dump(struct seq_file *m)
623 {
624 	struct cifs_swn_reg *swnreg;
625 	struct sockaddr_in *sa;
626 	struct sockaddr_in6 *sa6;
627 	int id;
628 
629 	seq_puts(m, "Witness registrations:");
630 
631 	mutex_lock(&cifs_swnreg_idr_mutex);
632 	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
633 		seq_printf(m, "\nId: %u Refs: %u Network name: '%s'%s Share name: '%s'%s Ip address: ",
634 				id, kref_read(&swnreg->ref_count),
635 				swnreg->net_name, swnreg->net_name_notify ? "(y)" : "(n)",
636 				swnreg->share_name, swnreg->share_name_notify ? "(y)" : "(n)");
637 		switch (swnreg->tcon->ses->server->dstaddr.ss_family) {
638 		case AF_INET:
639 			sa = (struct sockaddr_in *) &swnreg->tcon->ses->server->dstaddr;
640 			seq_printf(m, "%pI4", &sa->sin_addr.s_addr);
641 			break;
642 		case AF_INET6:
643 			sa6 = (struct sockaddr_in6 *) &swnreg->tcon->ses->server->dstaddr;
644 			seq_printf(m, "%pI6", &sa6->sin6_addr.s6_addr);
645 			if (sa6->sin6_scope_id)
646 				seq_printf(m, "%%%u", sa6->sin6_scope_id);
647 			break;
648 		default:
649 			seq_puts(m, "(unknown)");
650 		}
651 		seq_printf(m, "%s", swnreg->ip_notify ? "(y)" : "(n)");
652 	}
653 	mutex_unlock(&cifs_swnreg_idr_mutex);
654 	seq_puts(m, "\n");
655 }
656 
cifs_swn_check(void)657 void cifs_swn_check(void)
658 {
659 	struct cifs_swn_reg *swnreg;
660 	int id;
661 	int ret;
662 
663 	mutex_lock(&cifs_swnreg_idr_mutex);
664 	idr_for_each_entry(&cifs_swnreg_idr, swnreg, id) {
665 		ret = cifs_swn_send_register_message(swnreg);
666 		if (ret < 0)
667 			cifs_dbg(FYI, "%s: Failed to send register message: %d\n", __func__, ret);
668 	}
669 	mutex_unlock(&cifs_swnreg_idr_mutex);
670 }
671