nfs4namespace.c (597473720f4dc69749542bfcfed4a927a43d935e) nfs4namespace.c (f2aedb713c284429987dc66c7aaf38decfc8da2a)
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/nfs/nfs4namespace.c
4 *
5 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
6 * - Modified by David Howells <dhowells@redhat.com>
7 *
8 * NFSv4 namespace
9 */
10
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * linux/fs/nfs/nfs4namespace.c
4 *
5 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
6 * - Modified by David Howells <dhowells@redhat.com>
7 *
8 * NFSv4 namespace
9 */
10
11#include <linux/module.h>
11#include <linux/dcache.h>
12#include <linux/mount.h>
13#include <linux/namei.h>
14#include <linux/nfs_fs.h>
15#include <linux/nfs_mount.h>
16#include <linux/slab.h>
17#include <linux/string.h>
18#include <linux/sunrpc/clnt.h>
19#include <linux/sunrpc/addr.h>
20#include <linux/vfs.h>
21#include <linux/inet.h>
22#include "internal.h"
23#include "nfs4_fs.h"
12#include <linux/dcache.h>
13#include <linux/mount.h>
14#include <linux/namei.h>
15#include <linux/nfs_fs.h>
16#include <linux/nfs_mount.h>
17#include <linux/slab.h>
18#include <linux/string.h>
19#include <linux/sunrpc/clnt.h>
20#include <linux/sunrpc/addr.h>
21#include <linux/vfs.h>
22#include <linux/inet.h>
23#include "internal.h"
24#include "nfs4_fs.h"
25#include "nfs.h"
24#include "dns_resolve.h"
25
26#define NFSDBG_FACILITY NFSDBG_VFS
27
28/*
26#include "dns_resolve.h"
27
28#define NFSDBG_FACILITY NFSDBG_VFS
29
30/*
31 * Work out the length that an NFSv4 path would render to as a standard posix
32 * path, with a leading slash but no terminating slash.
33 */
34static ssize_t nfs4_pathname_len(const struct nfs4_pathname *pathname)
35{
36 ssize_t len = 0;
37 int i;
38
39 for (i = 0; i < pathname->ncomponents; i++) {
40 const struct nfs4_string *component = &pathname->components[i];
41
42 if (component->len > NAME_MAX)
43 goto too_long;
44 len += 1 + component->len; /* Adding "/foo" */
45 if (len > PATH_MAX)
46 goto too_long;
47 }
48 return len;
49
50too_long:
51 return -ENAMETOOLONG;
52}
53
54/*
29 * Convert the NFSv4 pathname components into a standard posix path.
55 * Convert the NFSv4 pathname components into a standard posix path.
30 *
31 * Note that the resulting string will be placed at the end of the buffer
32 */
56 */
33static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
34 char *buffer, ssize_t buflen)
57static char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
58 unsigned short *_len)
35{
59{
36 char *end = buffer + buflen;
37 int n;
60 ssize_t len;
61 char *buf, *p;
62 int i;
38
63
39 *--end = '\0';
40 buflen--;
64 len = nfs4_pathname_len(pathname);
65 if (len < 0)
66 return ERR_PTR(len);
67 *_len = len;
41
68
42 n = pathname->ncomponents;
43 while (--n >= 0) {
44 const struct nfs4_string *component = &pathname->components[n];
45 buflen -= component->len + 1;
46 if (buflen < 0)
47 goto Elong;
48 end -= component->len;
49 memcpy(end, component->data, component->len);
50 *--end = '/';
69 p = buf = kmalloc(len + 1, GFP_KERNEL);
70 if (!buf)
71 return ERR_PTR(-ENOMEM);
72
73 for (i = 0; i < pathname->ncomponents; i++) {
74 const struct nfs4_string *component = &pathname->components[i];
75
76 *p++ = '/';
77 memcpy(p, component->data, component->len);
78 p += component->len;
51 }
79 }
52 return end;
53Elong:
54 return ERR_PTR(-ENAMETOOLONG);
80
81 *p = 0;
82 return buf;
55}
56
57/*
58 * return the path component of "<server>:<path>"
59 * nfspath - the "<server>:<path>" string
60 * end - one past the last char that could contain "<server>:"
61 * returns NULL on failure
62 */

--- 32 unchanged lines hidden (view full) ---

95}
96
97/*
98 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
99 * believe to be the server path to this dentry
100 */
101static int nfs4_validate_fspath(struct dentry *dentry,
102 const struct nfs4_fs_locations *locations,
83}
84
85/*
86 * return the path component of "<server>:<path>"
87 * nfspath - the "<server>:<path>" string
88 * end - one past the last char that could contain "<server>:"
89 * returns NULL on failure
90 */

--- 32 unchanged lines hidden (view full) ---

123}
124
125/*
126 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
127 * believe to be the server path to this dentry
128 */
129static int nfs4_validate_fspath(struct dentry *dentry,
130 const struct nfs4_fs_locations *locations,
103 char *page, char *page2)
131 struct nfs_fs_context *ctx)
104{
105 const char *path, *fs_path;
132{
133 const char *path, *fs_path;
134 char *buf;
135 unsigned short len;
136 int n;
106
137
107 path = nfs4_path(dentry, page, PAGE_SIZE);
108 if (IS_ERR(path))
138 buf = kmalloc(4096, GFP_KERNEL);
139 path = nfs4_path(dentry, buf, 4096);
140 if (IS_ERR(path)) {
141 kfree(buf);
109 return PTR_ERR(path);
142 return PTR_ERR(path);
143 }
110
144
111 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
112 if (IS_ERR(fs_path))
145 fs_path = nfs4_pathname_string(&locations->fs_path, &len);
146 if (IS_ERR(fs_path)) {
147 kfree(buf);
113 return PTR_ERR(fs_path);
148 return PTR_ERR(fs_path);
149 }
114
150
115 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
151 n = strncmp(path, fs_path, len);
152 kfree(buf);
153 kfree(fs_path);
154 if (n != 0) {
116 dprintk("%s: path %s does not begin with fsroot %s\n",
155 dprintk("%s: path %s does not begin with fsroot %s\n",
117 __func__, path, fs_path);
156 __func__, path, ctx->nfs_server.export_path);
118 return -ENOENT;
119 }
120
121 return 0;
122}
123
124static size_t nfs_parse_server_name(char *string, size_t len,
125 struct sockaddr *sa, size_t salen, struct net *net)

--- 105 unchanged lines hidden (view full) ---

231
232 new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
233
234out:
235 put_page(page);
236 return new;
237}
238
157 return -ENOENT;
158 }
159
160 return 0;
161}
162
163static size_t nfs_parse_server_name(char *string, size_t len,
164 struct sockaddr *sa, size_t salen, struct net *net)

--- 105 unchanged lines hidden (view full) ---

270
271 new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
272
273out:
274 put_page(page);
275 return new;
276}
277
239static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
240 char *page, char *page2,
241 const struct nfs4_fs_location *location)
278static int try_location(struct fs_context *fc,
279 const struct nfs4_fs_location *location)
242{
243 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
280{
281 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
244 struct net *net = rpc_net_ns(NFS_SB(mountdata->sb)->client);
245 struct vfsmount *mnt = ERR_PTR(-ENOENT);
246 char *mnt_path;
247 unsigned int maxbuflen;
248 unsigned int s;
282 struct nfs_fs_context *ctx = nfs_fc2context(fc);
283 unsigned int len, s;
284 char *export_path, *source, *p;
285 int ret = -ENOENT;
249
286
250 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
251 if (IS_ERR(mnt_path))
252 return ERR_CAST(mnt_path);
253 mountdata->mnt_path = mnt_path;
254 maxbuflen = mnt_path - 1 - page2;
287 /* Allocate a buffer big enough to hold any of the hostnames plus a
288 * terminating char and also a buffer big enough to hold the hostname
289 * plus a colon plus the path.
290 */
291 len = 0;
292 for (s = 0; s < location->nservers; s++) {
293 const struct nfs4_string *buf = &location->servers[s];
294 if (buf->len > len)
295 len = buf->len;
296 }
255
297
256 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
257 if (mountdata->addr == NULL)
258 return ERR_PTR(-ENOMEM);
298 kfree(ctx->nfs_server.hostname);
299 ctx->nfs_server.hostname = kmalloc(len + 1, GFP_KERNEL);
300 if (!ctx->nfs_server.hostname)
301 return -ENOMEM;
259
302
303 export_path = nfs4_pathname_string(&location->rootpath,
304 &ctx->nfs_server.export_path_len);
305 if (IS_ERR(export_path))
306 return PTR_ERR(export_path);
307
308 ctx->nfs_server.export_path = export_path;
309
310 source = kmalloc(len + 1 + ctx->nfs_server.export_path_len + 1,
311 GFP_KERNEL);
312 if (!source)
313 return -ENOMEM;
314
315 kfree(fc->source);
316 fc->source = source;
317
318 ctx->clone_data.addr = kmalloc(addr_bufsize, GFP_KERNEL);
319 if (ctx->clone_data.addr == NULL)
320 return -ENOMEM;
260 for (s = 0; s < location->nservers; s++) {
261 const struct nfs4_string *buf = &location->servers[s];
262
321 for (s = 0; s < location->nservers; s++) {
322 const struct nfs4_string *buf = &location->servers[s];
323
263 if (buf->len <= 0 || buf->len >= maxbuflen)
264 continue;
265
266 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
267 continue;
268
324 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
325 continue;
326
269 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
270 mountdata->addr, addr_bufsize, net);
271 if (mountdata->addrlen == 0)
327 ctx->clone_data.addrlen =
328 nfs_parse_server_name(buf->data, buf->len,
329 ctx->clone_data.addr,
330 addr_bufsize,
331 fc->net_ns);
332 if (ctx->clone_data.addrlen == 0)
272 continue;
273
333 continue;
334
274 memcpy(page2, buf->data, buf->len);
275 page2[buf->len] = '\0';
276 mountdata->hostname = page2;
335 rpc_set_port(ctx->clone_data.addr, NFS_PORT);
277
336
278 snprintf(page, PAGE_SIZE, "%s:%s",
279 mountdata->hostname,
280 mountdata->mnt_path);
337 memcpy(ctx->nfs_server.hostname, buf->data, buf->len);
338 ctx->nfs_server.hostname[buf->len] = '\0';
339 ctx->clone_data.hostname = ctx->nfs_server.hostname;
281
340
282 mnt = vfs_submount(mountdata->dentry, &nfs4_referral_fs_type, page, mountdata);
283 if (!IS_ERR(mnt))
284 break;
341 p = source;
342 memcpy(p, buf->data, buf->len);
343 p += buf->len;
344 *p++ = ':';
345 memcpy(p, ctx->nfs_server.export_path, ctx->nfs_server.export_path_len);
346 p += ctx->nfs_server.export_path_len;
347 *p = 0;
348
349 ret = nfs4_get_referral_tree(fc);
350 if (ret == 0)
351 return 0;
285 }
352 }
286 kfree(mountdata->addr);
287 return mnt;
353
354 return ret;
288}
289
290/**
291 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
292 * @dentry: parent directory
293 * @locations: array of NFSv4 server location information
294 *
295 */
355}
356
357/**
358 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
359 * @dentry: parent directory
360 * @locations: array of NFSv4 server location information
361 *
362 */
296static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
297 const struct nfs4_fs_locations *locations)
363static int nfs_follow_referral(struct fs_context *fc,
364 const struct nfs4_fs_locations *locations)
298{
365{
299 struct vfsmount *mnt = ERR_PTR(-ENOENT);
300 struct nfs_clone_mount mountdata = {
301 .sb = dentry->d_sb,
302 .dentry = dentry,
303 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
304 };
305 char *page = NULL, *page2 = NULL;
366 struct nfs_fs_context *ctx = nfs_fc2context(fc);
306 int loc, error;
307
308 if (locations == NULL || locations->nlocations <= 0)
367 int loc, error;
368
369 if (locations == NULL || locations->nlocations <= 0)
309 goto out;
370 return -ENOENT;
310
371
311 dprintk("%s: referral at %pd2\n", __func__, dentry);
372 dprintk("%s: referral at %pd2\n", __func__, ctx->clone_data.dentry);
312
373
313 page = (char *) __get_free_page(GFP_USER);
314 if (!page)
315 goto out;
316
317 page2 = (char *) __get_free_page(GFP_USER);
318 if (!page2)
319 goto out;
320
321 /* Ensure fs path is a prefix of current dentry path */
374 /* Ensure fs path is a prefix of current dentry path */
322 error = nfs4_validate_fspath(dentry, locations, page, page2);
323 if (error < 0) {
324 mnt = ERR_PTR(error);
325 goto out;
326 }
375 error = nfs4_validate_fspath(ctx->clone_data.dentry, locations, ctx);
376 if (error < 0)
377 return error;
327
378
379 error = -ENOENT;
328 for (loc = 0; loc < locations->nlocations; loc++) {
329 const struct nfs4_fs_location *location = &locations->locations[loc];
330
331 if (location == NULL || location->nservers <= 0 ||
332 location->rootpath.ncomponents == 0)
333 continue;
334
380 for (loc = 0; loc < locations->nlocations; loc++) {
381 const struct nfs4_fs_location *location = &locations->locations[loc];
382
383 if (location == NULL || location->nservers <= 0 ||
384 location->rootpath.ncomponents == 0)
385 continue;
386
335 mnt = try_location(&mountdata, page, page2, location);
336 if (!IS_ERR(mnt))
337 break;
387 error = try_location(fc, location);
388 if (error == 0)
389 return 0;
338 }
339
390 }
391
340out:
341 free_page((unsigned long) page);
342 free_page((unsigned long) page2);
343 return mnt;
392 return error;
344}
345
346/*
347 * nfs_do_refmount - handle crossing a referral on server
348 * @dentry - dentry of referral
349 *
350 */
393}
394
395/*
396 * nfs_do_refmount - handle crossing a referral on server
397 * @dentry - dentry of referral
398 *
399 */
351static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
400static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client)
352{
401{
353 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
354 struct dentry *parent;
402 struct nfs_fs_context *ctx = nfs_fc2context(fc);
403 struct dentry *dentry, *parent;
355 struct nfs4_fs_locations *fs_locations = NULL;
356 struct page *page;
404 struct nfs4_fs_locations *fs_locations = NULL;
405 struct page *page;
357 int err;
406 int err = -ENOMEM;
358
359 /* BUG_ON(IS_ROOT(dentry)); */
360 page = alloc_page(GFP_KERNEL);
407
408 /* BUG_ON(IS_ROOT(dentry)); */
409 page = alloc_page(GFP_KERNEL);
361 if (page == NULL)
362 return mnt;
410 if (!page)
411 return -ENOMEM;
363
364 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
412
413 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
365 if (fs_locations == NULL)
414 if (!fs_locations)
366 goto out_free;
367
368 /* Get locations */
415 goto out_free;
416
417 /* Get locations */
369 mnt = ERR_PTR(-ENOENT);
370
418 dentry = ctx->clone_data.dentry;
371 parent = dget_parent(dentry);
372 dprintk("%s: getting locations for %pd2\n",
373 __func__, dentry);
374
375 err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page);
376 dput(parent);
419 parent = dget_parent(dentry);
420 dprintk("%s: getting locations for %pd2\n",
421 __func__, dentry);
422
423 err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page);
424 dput(parent);
377 if (err != 0 ||
378 fs_locations->nlocations <= 0 ||
425 if (err != 0)
426 goto out_free_2;
427
428 err = -ENOENT;
429 if (fs_locations->nlocations <= 0 ||
379 fs_locations->fs_path.ncomponents <= 0)
430 fs_locations->fs_path.ncomponents <= 0)
380 goto out_free;
431 goto out_free_2;
381
432
382 mnt = nfs_follow_referral(dentry, fs_locations);
433 err = nfs_follow_referral(fc, fs_locations);
434out_free_2:
435 kfree(fs_locations);
383out_free:
384 __free_page(page);
436out_free:
437 __free_page(page);
385 kfree(fs_locations);
386 return mnt;
438 return err;
387}
388
439}
440
389struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
390 struct nfs_fh *fh, struct nfs_fattr *fattr)
441int nfs4_submount(struct fs_context *fc, struct nfs_server *server)
391{
442{
392 rpc_authflavor_t flavor = server->client->cl_auth->au_flavor;
443 struct nfs_fs_context *ctx = nfs_fc2context(fc);
444 struct dentry *dentry = ctx->clone_data.dentry;
393 struct dentry *parent = dget_parent(dentry);
394 struct inode *dir = d_inode(parent);
395 const struct qstr *name = &dentry->d_name;
396 struct rpc_clnt *client;
445 struct dentry *parent = dget_parent(dentry);
446 struct inode *dir = d_inode(parent);
447 const struct qstr *name = &dentry->d_name;
448 struct rpc_clnt *client;
397 struct vfsmount *mnt;
449 int ret;
398
399 /* Look it up again to get its attributes and sec flavor */
450
451 /* Look it up again to get its attributes and sec flavor */
400 client = nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
452 client = nfs4_proc_lookup_mountpoint(dir, name, ctx->mount_info.mntfh,
453 ctx->clone_data.fattr);
401 dput(parent);
402 if (IS_ERR(client))
454 dput(parent);
455 if (IS_ERR(client))
403 return ERR_CAST(client);
456 return PTR_ERR(client);
404
457
405 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
406 mnt = nfs_do_refmount(client, dentry);
407 goto out;
458 ctx->selected_flavor = client->cl_auth->au_flavor;
459 if (ctx->clone_data.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
460 ret = nfs_do_refmount(fc, client);
461 } else {
462 ret = nfs_do_submount(fc);
408 }
409
463 }
464
410 if (client->cl_auth->au_flavor != flavor)
411 flavor = client->cl_auth->au_flavor;
412 mnt = nfs_do_submount(dentry, fh, fattr, flavor);
413out:
414 rpc_shutdown_client(client);
465 rpc_shutdown_client(client);
415 return mnt;
466 return ret;
416}
417
418/*
419 * Try one location from the fs_locations array.
420 *
421 * Returns zero on success, or a negative errno value.
422 */
423static int nfs4_try_replacing_one_location(struct nfs_server *server,

--- 95 unchanged lines hidden --- 		467}
468
469/*
470 * Try one location from the fs_locations array.
471 *
472 * Returns zero on success, or a negative errno value.
473 */
474static int nfs4_try_replacing_one_location(struct nfs_server *server,

--- 95 unchanged lines hidden ---