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11#include <linux/module.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"
26#include "dns_resolve.h"
27
28#define NFSDBG_FACILITY NFSDBG_VFS
29
30
31
32
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;
45 if (len > PATH_MAX)
46 goto too_long;
47 }
48 return len;
49
50too_long:
51 return -ENAMETOOLONG;
52}
53
54
55
56
57static char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
58 unsigned short *_len)
59{
60 ssize_t len;
61 char *buf, *p;
62 int i;
63
64 len = nfs4_pathname_len(pathname);
65 if (len < 0)
66 return ERR_PTR(len);
67 *_len = len;
68
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;
79 }
80
81 *p = 0;
82 return buf;
83}
84
85
86
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88
89
90
91static char *nfs_path_component(const char *nfspath, const char *end)
92{
93 char *p;
94
95 if (*nfspath == '[') {
96
97 p = strchr(nfspath, ']');
98 if (p != NULL && ++p < end && *p == ':')
99 return p + 1;
100 } else {
101
102 p = strchr(nfspath, ':');
103 if (p != NULL && p < end)
104 return p + 1;
105 }
106 return NULL;
107}
108
109
110
111
112static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
113{
114 char *limit;
115 char *path = nfs_path(&limit, dentry, buffer, buflen,
116 NFS_PATH_CANONICAL);
117 if (!IS_ERR(path)) {
118 char *path_component = nfs_path_component(path, limit);
119 if (path_component)
120 return path_component;
121 }
122 return path;
123}
124
125
126
127
128
129static int nfs4_validate_fspath(struct dentry *dentry,
130 const struct nfs4_fs_locations *locations,
131 struct nfs_fs_context *ctx)
132{
133 const char *path;
134 char *fs_path;
135 unsigned short len;
136 char *buf;
137 int n;
138
139 buf = kmalloc(4096, GFP_KERNEL);
140 if (!buf)
141 return -ENOMEM;
142
143 path = nfs4_path(dentry, buf, 4096);
144 if (IS_ERR(path)) {
145 kfree(buf);
146 return PTR_ERR(path);
147 }
148
149 fs_path = nfs4_pathname_string(&locations->fs_path, &len);
150 if (IS_ERR(fs_path)) {
151 kfree(buf);
152 return PTR_ERR(fs_path);
153 }
154
155 n = strncmp(path, fs_path, len);
156 kfree(buf);
157 kfree(fs_path);
158 if (n != 0) {
159 dprintk("%s: path %s does not begin with fsroot %s\n",
160 __func__, path, ctx->nfs_server.export_path);
161 return -ENOENT;
162 }
163
164 return 0;
165}
166
167static size_t nfs_parse_server_name(char *string, size_t len,
168 struct sockaddr *sa, size_t salen, struct net *net)
169{
170 ssize_t ret;
171
172 ret = rpc_pton(net, string, len, sa, salen);
173 if (ret == 0) {
174 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
175 if (ret < 0)
176 ret = 0;
177 }
178 return ret;
179}
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197
198static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt,
199 struct nfs_server *server,
200 struct nfs4_secinfo_flavors *flavors)
201{
202 rpc_authflavor_t pflavor;
203 struct nfs4_secinfo4 *secinfo;
204 unsigned int i;
205
206 for (i = 0; i < flavors->num_flavors; i++) {
207 secinfo = &flavors->flavors[i];
208
209 switch (secinfo->flavor) {
210 case RPC_AUTH_NULL:
211 case RPC_AUTH_UNIX:
212 case RPC_AUTH_GSS:
213 pflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
214 &secinfo->flavor_info);
215
216 if (pflavor != RPC_AUTH_MAXFLAVOR &&
217 nfs_auth_info_match(&server->auth_info, pflavor)) {
218 struct rpc_clnt *new;
219 struct rpc_cred *cred;
220
221
222 new = rpc_clone_client_set_auth(clnt, pflavor);
223 if (IS_ERR(new))
224 continue;
225
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228
229
230 cred = rpcauth_lookupcred(new->cl_auth, 0);
231 if (IS_ERR(cred)) {
232 rpc_shutdown_client(new);
233 continue;
234 }
235 put_rpccred(cred);
236 return new;
237 }
238 }
239 }
240 return ERR_PTR(-EPERM);
241}
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253
254struct rpc_clnt *
255nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode,
256 const struct qstr *name)
257{
258 struct page *page;
259 struct nfs4_secinfo_flavors *flavors;
260 struct rpc_clnt *new;
261 int err;
262
263 page = alloc_page(GFP_KERNEL);
264 if (!page)
265 return ERR_PTR(-ENOMEM);
266
267 flavors = page_address(page);
268
269 err = nfs4_proc_secinfo(inode, name, flavors);
270 if (err < 0) {
271 new = ERR_PTR(err);
272 goto out;
273 }
274
275 new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors);
276
277out:
278 put_page(page);
279 return new;
280}
281
282static int try_location(struct fs_context *fc,
283 const struct nfs4_fs_location *location)
284{
285 struct nfs_fs_context *ctx = nfs_fc2context(fc);
286 unsigned int len, s;
287 char *export_path, *source, *p;
288 int ret = -ENOENT;
289
290
291
292
293
294 len = 0;
295 for (s = 0; s < location->nservers; s++) {
296 const struct nfs4_string *buf = &location->servers[s];
297 if (buf->len > len)
298 len = buf->len;
299 }
300
301 kfree(ctx->nfs_server.hostname);
302 ctx->nfs_server.hostname = kmalloc(len + 1, GFP_KERNEL);
303 if (!ctx->nfs_server.hostname)
304 return -ENOMEM;
305
306 export_path = nfs4_pathname_string(&location->rootpath,
307 &ctx->nfs_server.export_path_len);
308 if (IS_ERR(export_path))
309 return PTR_ERR(export_path);
310
311 kfree(ctx->nfs_server.export_path);
312 ctx->nfs_server.export_path = export_path;
313
314 source = kmalloc(len + 1 + ctx->nfs_server.export_path_len + 1,
315 GFP_KERNEL);
316 if (!source)
317 return -ENOMEM;
318
319 kfree(fc->source);
320 fc->source = source;
321 for (s = 0; s < location->nservers; s++) {
322 const struct nfs4_string *buf = &location->servers[s];
323
324 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
325 continue;
326
327 ctx->nfs_server.addrlen =
328 nfs_parse_server_name(buf->data, buf->len,
329 &ctx->nfs_server.address,
330 sizeof(ctx->nfs_server._address),
331 fc->net_ns);
332 if (ctx->nfs_server.addrlen == 0)
333 continue;
334
335 rpc_set_port(&ctx->nfs_server.address, NFS_PORT);
336
337 memcpy(ctx->nfs_server.hostname, buf->data, buf->len);
338 ctx->nfs_server.hostname[buf->len] = '\0';
339
340 p = source;
341 memcpy(p, buf->data, buf->len);
342 p += buf->len;
343 *p++ = ':';
344 memcpy(p, ctx->nfs_server.export_path, ctx->nfs_server.export_path_len);
345 p += ctx->nfs_server.export_path_len;
346 *p = 0;
347
348 ret = nfs4_get_referral_tree(fc);
349 if (ret == 0)
350 return 0;
351 }
352
353 return ret;
354}
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359
360
361
362static int nfs_follow_referral(struct fs_context *fc,
363 const struct nfs4_fs_locations *locations)
364{
365 struct nfs_fs_context *ctx = nfs_fc2context(fc);
366 int loc, error;
367
368 if (locations == NULL || locations->nlocations <= 0)
369 return -ENOENT;
370
371 dprintk("%s: referral at %pd2\n", __func__, ctx->clone_data.dentry);
372
373
374 error = nfs4_validate_fspath(ctx->clone_data.dentry, locations, ctx);
375 if (error < 0)
376 return error;
377
378 error = -ENOENT;
379 for (loc = 0; loc < locations->nlocations; loc++) {
380 const struct nfs4_fs_location *location = &locations->locations[loc];
381
382 if (location == NULL || location->nservers <= 0 ||
383 location->rootpath.ncomponents == 0)
384 continue;
385
386 error = try_location(fc, location);
387 if (error == 0)
388 return 0;
389 }
390
391 return error;
392}
393
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397
398
399static int nfs_do_refmount(struct fs_context *fc, struct rpc_clnt *client)
400{
401 struct nfs_fs_context *ctx = nfs_fc2context(fc);
402 struct dentry *dentry, *parent;
403 struct nfs4_fs_locations *fs_locations = NULL;
404 struct page *page;
405 int err = -ENOMEM;
406
407
408 page = alloc_page(GFP_KERNEL);
409 if (!page)
410 return -ENOMEM;
411
412 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
413 if (!fs_locations)
414 goto out_free;
415
416
417 dentry = ctx->clone_data.dentry;
418 parent = dget_parent(dentry);
419 dprintk("%s: getting locations for %pd2\n",
420 __func__, dentry);
421
422 err = nfs4_proc_fs_locations(client, d_inode(parent), &dentry->d_name, fs_locations, page);
423 dput(parent);
424 if (err != 0)
425 goto out_free_2;
426
427 err = -ENOENT;
428 if (fs_locations->nlocations <= 0 ||
429 fs_locations->fs_path.ncomponents <= 0)
430 goto out_free_2;
431
432 err = nfs_follow_referral(fc, fs_locations);
433out_free_2:
434 kfree(fs_locations);
435out_free:
436 __free_page(page);
437 return err;
438}
439
440int nfs4_submount(struct fs_context *fc, struct nfs_server *server)
441{
442 struct nfs_fs_context *ctx = nfs_fc2context(fc);
443 struct dentry *dentry = ctx->clone_data.dentry;
444 struct dentry *parent = dget_parent(dentry);
445 struct inode *dir = d_inode(parent);
446 struct rpc_clnt *client;
447 int ret;
448
449
450 client = nfs4_proc_lookup_mountpoint(dir, dentry, ctx->mntfh,
451 ctx->clone_data.fattr);
452 dput(parent);
453 if (IS_ERR(client))
454 return PTR_ERR(client);
455
456 ctx->selected_flavor = client->cl_auth->au_flavor;
457 if (ctx->clone_data.fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
458 ret = nfs_do_refmount(fc, client);
459 } else {
460 ret = nfs_do_submount(fc);
461 }
462
463 rpc_shutdown_client(client);
464 return ret;
465}
466
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470
471
472static int nfs4_try_replacing_one_location(struct nfs_server *server,
473 char *page, char *page2,
474 const struct nfs4_fs_location *location)
475{
476 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
477 struct net *net = rpc_net_ns(server->client);
478 struct sockaddr *sap;
479 unsigned int s;
480 size_t salen;
481 int error;
482
483 sap = kmalloc(addr_bufsize, GFP_KERNEL);
484 if (sap == NULL)
485 return -ENOMEM;
486
487 error = -ENOENT;
488 for (s = 0; s < location->nservers; s++) {
489 const struct nfs4_string *buf = &location->servers[s];
490 char *hostname;
491
492 if (buf->len <= 0 || buf->len > PAGE_SIZE)
493 continue;
494
495 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL)
496 continue;
497
498 salen = nfs_parse_server_name(buf->data, buf->len,
499 sap, addr_bufsize, net);
500 if (salen == 0)
501 continue;
502 rpc_set_port(sap, NFS_PORT);
503
504 error = -ENOMEM;
505 hostname = kmemdup_nul(buf->data, buf->len, GFP_KERNEL);
506 if (hostname == NULL)
507 break;
508
509 error = nfs4_update_server(server, hostname, sap, salen, net);
510 kfree(hostname);
511 if (error == 0)
512 break;
513 }
514
515 kfree(sap);
516 return error;
517}
518
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530
531int nfs4_replace_transport(struct nfs_server *server,
532 const struct nfs4_fs_locations *locations)
533{
534 char *page = NULL, *page2 = NULL;
535 int loc, error;
536
537 error = -ENOENT;
538 if (locations == NULL || locations->nlocations <= 0)
539 goto out;
540
541 error = -ENOMEM;
542 page = (char *) __get_free_page(GFP_USER);
543 if (!page)
544 goto out;
545 page2 = (char *) __get_free_page(GFP_USER);
546 if (!page2)
547 goto out;
548
549 for (loc = 0; loc < locations->nlocations; loc++) {
550 const struct nfs4_fs_location *location =
551 &locations->locations[loc];
552
553 if (location == NULL || location->nservers <= 0 ||
554 location->rootpath.ncomponents == 0)
555 continue;
556
557 error = nfs4_try_replacing_one_location(server, page,
558 page2, location);
559 if (error == 0)
560 break;
561 }
562
563out:
564 free_page((unsigned long)page);
565 free_page((unsigned long)page2);
566 return error;
567}
568