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12#include <linux/dcache.h>
13#include <linux/mount.h>
14#include <linux/namei.h>
15#include <linux/slab.h>
16#include <linux/vfs.h>
17#include <linux/fs.h>
18#include <linux/inet.h>
19#include "cifsglob.h"
20#include "cifsproto.h"
21#include "cifsfs.h"
22#include "dns_resolve.h"
23#include "cifs_debug.h"
24#include "cifs_unicode.h"
25#include "dfs_cache.h"
26#include "fs_context.h"
27
28static LIST_HEAD(cifs_dfs_automount_list);
29
30static void cifs_dfs_expire_automounts(struct work_struct *work);
31static DECLARE_DELAYED_WORK(cifs_dfs_automount_task,
32 cifs_dfs_expire_automounts);
33static int cifs_dfs_mountpoint_expiry_timeout = 500 * HZ;
34
35static void cifs_dfs_expire_automounts(struct work_struct *work)
36{
37 struct list_head *list = &cifs_dfs_automount_list;
38
39 mark_mounts_for_expiry(list);
40 if (!list_empty(list))
41 schedule_delayed_work(&cifs_dfs_automount_task,
42 cifs_dfs_mountpoint_expiry_timeout);
43}
44
45void cifs_dfs_release_automount_timer(void)
46{
47 BUG_ON(!list_empty(&cifs_dfs_automount_list));
48 cancel_delayed_work_sync(&cifs_dfs_automount_task);
49}
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61
62
63static char *
64cifs_build_devname(char *nodename, const char *prepath)
65{
66 size_t pplen;
67 size_t unclen;
68 char *dev;
69 char *pos;
70
71
72 nodename += strspn(nodename, "\\");
73 if (!*nodename)
74 return ERR_PTR(-EINVAL);
75
76
77 unclen = strlen(nodename);
78 pos = nodename + unclen - 1;
79
80
81 while (*pos == '\\') {
82 --pos;
83 --unclen;
84 }
85
86
87
88
89
90
91 pplen = prepath ? strlen(prepath) : 0;
92 dev = kmalloc(2 + unclen + 1 + pplen + 1, GFP_KERNEL);
93 if (!dev)
94 return ERR_PTR(-ENOMEM);
95
96 pos = dev;
97
98 *pos = '/';
99 ++pos;
100 *pos = '/';
101 ++pos;
102
103
104 memcpy(pos, nodename, unclen);
105 pos += unclen;
106
107
108 if (pplen) {
109 *pos = '/';
110 ++pos;
111 memcpy(pos, prepath, pplen);
112 pos += pplen;
113 }
114
115
116 *pos = '\0';
117
118 convert_delimiter(dev, '/');
119 return dev;
120}
121
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126
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132
133
134
135char *cifs_compose_mount_options(const char *sb_mountdata,
136 const char *fullpath,
137 const struct dfs_info3_param *ref,
138 char **devname)
139{
140 int rc;
141 char *name;
142 char *mountdata = NULL;
143 const char *prepath = NULL;
144 int md_len;
145 char *tkn_e;
146 char *srvIP = NULL;
147 char sep = ',';
148 int off, noff;
149
150 if (sb_mountdata == NULL)
151 return ERR_PTR(-EINVAL);
152
153 if (ref) {
154 if (WARN_ON_ONCE(!ref->node_name || ref->path_consumed < 0))
155 return ERR_PTR(-EINVAL);
156
157 if (strlen(fullpath) - ref->path_consumed) {
158 prepath = fullpath + ref->path_consumed;
159
160 if (*prepath == '/' || *prepath == '\\')
161 prepath++;
162 }
163
164 name = cifs_build_devname(ref->node_name, prepath);
165 if (IS_ERR(name)) {
166 rc = PTR_ERR(name);
167 name = NULL;
168 goto compose_mount_options_err;
169 }
170 } else {
171 name = cifs_build_devname((char *)fullpath, NULL);
172 if (IS_ERR(name)) {
173 rc = PTR_ERR(name);
174 name = NULL;
175 goto compose_mount_options_err;
176 }
177 }
178
179 rc = dns_resolve_server_name_to_ip(name, &srvIP, NULL);
180 if (rc < 0) {
181 cifs_dbg(FYI, "%s: Failed to resolve server part of %s to IP: %d\n",
182 __func__, name, rc);
183 goto compose_mount_options_err;
184 }
185
186
187
188
189
190
191
192 md_len = strlen(sb_mountdata) + INET6_ADDRSTRLEN;
193 mountdata = kzalloc(md_len + sizeof("ip=") + 1, GFP_KERNEL);
194 if (mountdata == NULL) {
195 rc = -ENOMEM;
196 goto compose_mount_options_err;
197 }
198
199
200 off = 0;
201 if (strncmp(sb_mountdata, "sep=", 4) == 0) {
202 sep = sb_mountdata[4];
203 strncpy(mountdata, sb_mountdata, 5);
204 off += 5;
205 }
206
207 do {
208 tkn_e = strchr(sb_mountdata + off, sep);
209 if (tkn_e == NULL)
210 noff = strlen(sb_mountdata + off);
211 else
212 noff = tkn_e - (sb_mountdata + off) + 1;
213
214 if (strncasecmp(sb_mountdata + off, "cruid=", 6) == 0) {
215 off += noff;
216 continue;
217 }
218 if (strncasecmp(sb_mountdata + off, "unc=", 4) == 0) {
219 off += noff;
220 continue;
221 }
222 if (strncasecmp(sb_mountdata + off, "ip=", 3) == 0) {
223 off += noff;
224 continue;
225 }
226 if (strncasecmp(sb_mountdata + off, "prefixpath=", 11) == 0) {
227 off += noff;
228 continue;
229 }
230 strncat(mountdata, sb_mountdata + off, noff);
231 off += noff;
232 } while (tkn_e);
233 strcat(mountdata, sb_mountdata + off);
234 mountdata[md_len] = '\0';
235
236
237 if (mountdata[strlen(mountdata) - 1] != sep)
238 strncat(mountdata, &sep, 1);
239 strcat(mountdata, "ip=");
240 strcat(mountdata, srvIP);
241
242 if (devname)
243 *devname = name;
244 else
245 kfree(name);
246
247
248
249
250compose_mount_options_out:
251 kfree(srvIP);
252 return mountdata;
253
254compose_mount_options_err:
255 kfree(mountdata);
256 mountdata = ERR_PTR(rc);
257 kfree(name);
258 goto compose_mount_options_out;
259}
260
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270
271
272static struct vfsmount *cifs_dfs_do_mount(struct dentry *mntpt,
273 struct cifs_sb_info *cifs_sb,
274 const char *fullpath)
275{
276 struct vfsmount *mnt;
277 char *mountdata;
278 char *devname;
279
280 devname = kstrdup(fullpath, GFP_KERNEL);
281 if (!devname)
282 return ERR_PTR(-ENOMEM);
283
284 convert_delimiter(devname, '/');
285
286
287
288
289
290
291 mountdata = cifs_compose_mount_options(cifs_sb->ctx->mount_options,
292 fullpath + 1, NULL, NULL);
293 if (IS_ERR(mountdata)) {
294 kfree(devname);
295 return (struct vfsmount *)mountdata;
296 }
297
298 mnt = vfs_submount(mntpt, &cifs_fs_type, devname, mountdata);
299 kfree(mountdata);
300 kfree(devname);
301 return mnt;
302}
303
304
305
306
307static struct vfsmount *cifs_dfs_do_automount(struct dentry *mntpt)
308{
309 struct cifs_sb_info *cifs_sb;
310 struct cifs_ses *ses;
311 struct cifs_tcon *tcon;
312 void *page;
313 char *full_path, *root_path;
314 unsigned int xid;
315 int rc;
316 struct vfsmount *mnt;
317
318 cifs_dbg(FYI, "in %s\n", __func__);
319 BUG_ON(IS_ROOT(mntpt));
320
321
322
323
324
325
326
327 mnt = ERR_PTR(-ENOMEM);
328
329 cifs_sb = CIFS_SB(mntpt->d_sb);
330 if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_DFS) {
331 mnt = ERR_PTR(-EREMOTE);
332 goto cdda_exit;
333 }
334
335 page = alloc_dentry_path();
336
337 full_path = build_path_from_dentry_optional_prefix(mntpt, page, true);
338 if (IS_ERR(full_path)) {
339 mnt = ERR_CAST(full_path);
340 goto free_full_path;
341 }
342
343 convert_delimiter(full_path, '\\');
344
345 cifs_dbg(FYI, "%s: full_path: %s\n", __func__, full_path);
346
347 if (!cifs_sb_master_tlink(cifs_sb)) {
348 cifs_dbg(FYI, "%s: master tlink is NULL\n", __func__);
349 goto free_full_path;
350 }
351
352 tcon = cifs_sb_master_tcon(cifs_sb);
353 if (!tcon) {
354 cifs_dbg(FYI, "%s: master tcon is NULL\n", __func__);
355 goto free_full_path;
356 }
357
358 root_path = kstrdup(tcon->treeName, GFP_KERNEL);
359 if (!root_path) {
360 mnt = ERR_PTR(-ENOMEM);
361 goto free_full_path;
362 }
363 cifs_dbg(FYI, "%s: root path: %s\n", __func__, root_path);
364
365 ses = tcon->ses;
366 xid = get_xid();
367
368
369
370
371
372 rc = dfs_cache_find(xid, ses, cifs_sb->local_nls, cifs_remap(cifs_sb),
373 root_path + 1, NULL, NULL);
374 if (!rc) {
375 rc = dfs_cache_find(xid, ses, cifs_sb->local_nls,
376 cifs_remap(cifs_sb), full_path + 1,
377 NULL, NULL);
378 }
379
380 free_xid(xid);
381
382 if (rc) {
383 mnt = ERR_PTR(rc);
384 goto free_root_path;
385 }
386
387
388
389
390
391
392 mnt = cifs_dfs_do_mount(mntpt, cifs_sb, full_path);
393 cifs_dbg(FYI, "%s: cifs_dfs_do_mount:%s , mnt:%p\n", __func__,
394 full_path + 1, mnt);
395
396free_root_path:
397 kfree(root_path);
398free_full_path:
399 free_dentry_path(page);
400cdda_exit:
401 cifs_dbg(FYI, "leaving %s\n" , __func__);
402 return mnt;
403}
404
405
406
407
408struct vfsmount *cifs_dfs_d_automount(struct path *path)
409{
410 struct vfsmount *newmnt;
411
412 cifs_dbg(FYI, "in %s\n", __func__);
413
414 newmnt = cifs_dfs_do_automount(path->dentry);
415 if (IS_ERR(newmnt)) {
416 cifs_dbg(FYI, "leaving %s [automount failed]\n" , __func__);
417 return newmnt;
418 }
419
420 mntget(newmnt);
421 mnt_set_expiry(newmnt, &cifs_dfs_automount_list);
422 schedule_delayed_work(&cifs_dfs_automount_task,
423 cifs_dfs_mountpoint_expiry_timeout);
424 cifs_dbg(FYI, "leaving %s [ok]\n" , __func__);
425 return newmnt;
426}
427
428const struct inode_operations cifs_dfs_referral_inode_operations = {
429};
430