blob: cdb0b41a48109e274364e4e69150c5b222114953 [file] [log] [blame]
David Howellsf7b422b2006-06-09 09:34:33 -04001/*
2 * linux/fs/nfs/nfs4namespace.c
3 *
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
David Howells54ceac42006-08-22 20:06:13 -04005 * - Modified by David Howells <dhowells@redhat.com>
David Howellsf7b422b2006-06-09 09:34:33 -04006 *
7 * NFSv4 namespace
8 */
9
David Howellsf7b422b2006-06-09 09:34:33 -040010#include <linux/dcache.h>
11#include <linux/mount.h>
12#include <linux/namei.h>
13#include <linux/nfs_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
David Howellsf7b422b2006-06-09 09:34:33 -040015#include <linux/string.h>
16#include <linux/sunrpc/clnt.h>
Jeff Layton59766872013-02-04 12:50:00 -050017#include <linux/sunrpc/addr.h>
David Howellsf7b422b2006-06-09 09:34:33 -040018#include <linux/vfs.h>
19#include <linux/inet.h>
20#include "internal.h"
Trond Myklebustc228fd32007-01-13 02:28:11 -050021#include "nfs4_fs.h"
Trond Myklebust7d7ea882009-08-19 18:12:34 -040022#include "dns_resolve.h"
David Howellsf7b422b2006-06-09 09:34:33 -040023
24#define NFSDBG_FACILITY NFSDBG_VFS
25
26/*
Trond Myklebustef95d312009-03-10 20:33:17 -040027 * Convert the NFSv4 pathname components into a standard posix path.
28 *
29 * Note that the resulting string will be placed at the end of the buffer
David Howellsf7b422b2006-06-09 09:34:33 -040030 */
David Howells509de812006-08-22 20:06:11 -040031static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
David Howellsf7b422b2006-06-09 09:34:33 -040032 char *buffer, ssize_t buflen)
33{
34 char *end = buffer + buflen;
35 int n;
36
37 *--end = '\0';
38 buflen--;
39
40 n = pathname->ncomponents;
41 while (--n >= 0) {
David Howells509de812006-08-22 20:06:11 -040042 const struct nfs4_string *component = &pathname->components[n];
David Howellsf7b422b2006-06-09 09:34:33 -040043 buflen -= component->len + 1;
44 if (buflen < 0)
45 goto Elong;
46 end -= component->len;
47 memcpy(end, component->data, component->len);
48 *--end = '/';
49 }
50 return end;
51Elong:
52 return ERR_PTR(-ENAMETOOLONG);
53}
54
David Howells54ceac42006-08-22 20:06:13 -040055/*
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040056 * return the path component of "<server>:<path>"
57 * nfspath - the "<server>:<path>" string
58 * end - one past the last char that could contain "<server>:"
59 * returns NULL on failure
60 */
61static char *nfs_path_component(const char *nfspath, const char *end)
62{
63 char *p;
64
65 if (*nfspath == '[') {
66 /* parse [] escaped IPv6 addrs */
67 p = strchr(nfspath, ']');
68 if (p != NULL && ++p < end && *p == ':')
69 return p + 1;
70 } else {
71 /* otherwise split on first colon */
72 p = strchr(nfspath, ':');
73 if (p != NULL && p < end)
74 return p + 1;
75 }
76 return NULL;
77}
78
79/*
David Howells54ceac42006-08-22 20:06:13 -040080 * Determine the mount path as a string
81 */
Al Virob514f872011-03-16 06:26:11 -040082static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
David Howells54ceac42006-08-22 20:06:13 -040083{
Al Virob514f872011-03-16 06:26:11 -040084 char *limit;
Ben Hutchings97a54862012-10-21 19:23:52 +010085 char *path = nfs_path(&limit, dentry, buffer, buflen,
86 NFS_PATH_CANONICAL);
Al Virob514f872011-03-16 06:26:11 -040087 if (!IS_ERR(path)) {
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040088 char *path_component = nfs_path_component(path, limit);
89 if (path_component)
90 return path_component;
Al Virob514f872011-03-16 06:26:11 -040091 }
92 return path;
David Howells54ceac42006-08-22 20:06:13 -040093}
94
95/*
96 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
97 * believe to be the server path to this dentry
98 */
Al Virob514f872011-03-16 06:26:11 -040099static int nfs4_validate_fspath(struct dentry *dentry,
David Howells54ceac42006-08-22 20:06:13 -0400100 const struct nfs4_fs_locations *locations,
101 char *page, char *page2)
102{
103 const char *path, *fs_path;
104
Al Virob514f872011-03-16 06:26:11 -0400105 path = nfs4_path(dentry, page, PAGE_SIZE);
David Howells54ceac42006-08-22 20:06:13 -0400106 if (IS_ERR(path))
107 return PTR_ERR(path);
108
109 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
110 if (IS_ERR(fs_path))
111 return PTR_ERR(fs_path);
112
113 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
114 dprintk("%s: path %s does not begin with fsroot %s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700115 __func__, path, fs_path);
David Howells54ceac42006-08-22 20:06:13 -0400116 return -ENOENT;
117 }
118
119 return 0;
120}
121
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400122static size_t nfs_parse_server_name(char *string, size_t len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300123 struct sockaddr *sa, size_t salen, struct nfs_server *server)
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400124{
Trond Myklebust2446ab62012-03-01 17:00:56 -0500125 struct net *net = rpc_net_ns(server->client);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400126 ssize_t ret;
127
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400128 ret = rpc_pton(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400129 if (ret == 0) {
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400130 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400131 if (ret < 0)
132 ret = 0;
133 }
134 return ret;
135}
136
Chuck Lever9568c5e2013-03-16 15:54:43 -0400137/**
138 * nfs_find_best_sec - Find a security mechanism supported locally
139 * @flavors: List of security tuples returned by SECINFO procedure
140 *
141 * Return the pseudoflavor of the first security mechanism in
142 * "flavors" that is locally supported. Return RPC_AUTH_UNIX if
143 * no matching flavor is found in the array. The "flavors" array
144 * is searched in the order returned from the server, per RFC 3530
145 * recommendation.
146 */
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400147rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors)
148{
Chuck Lever9568c5e2013-03-16 15:54:43 -0400149 rpc_authflavor_t pseudoflavor;
150 struct nfs4_secinfo4 *secinfo;
Chuck Leverfb15b262013-03-16 15:54:34 -0400151 unsigned int i;
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400152
153 for (i = 0; i < flavors->num_flavors; i++) {
Chuck Lever9568c5e2013-03-16 15:54:43 -0400154 secinfo = &flavors->flavors[i];
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400155
Chuck Lever9568c5e2013-03-16 15:54:43 -0400156 switch (secinfo->flavor) {
157 case RPC_AUTH_NULL:
158 case RPC_AUTH_UNIX:
159 case RPC_AUTH_GSS:
160 pseudoflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
161 &secinfo->flavor_info);
162 if (pseudoflavor != RPC_AUTH_MAXFLAVOR)
163 return pseudoflavor;
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400164 break;
165 }
166 }
167
Chuck Lever9568c5e2013-03-16 15:54:43 -0400168 return RPC_AUTH_UNIX;
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400169}
170
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400171static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
172{
173 struct page *page;
174 struct nfs4_secinfo_flavors *flavors;
175 rpc_authflavor_t flavor;
176 int err;
177
178 page = alloc_page(GFP_KERNEL);
179 if (!page)
180 return -ENOMEM;
181 flavors = page_address(page);
182
183 err = nfs4_proc_secinfo(inode, name, flavors);
184 if (err < 0) {
185 flavor = err;
186 goto out;
187 }
188
189 flavor = nfs_find_best_sec(flavors);
190
191out:
192 put_page(page);
193 return flavor;
194}
195
196/*
197 * Please call rpc_shutdown_client() when you are done with this client.
198 */
199struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
200 struct qstr *name)
201{
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400202 rpc_authflavor_t flavor;
203
204 flavor = nfs4_negotiate_security(inode, name);
Benny Halevy5f23eff32012-05-16 11:35:36 +0300205 if ((int)flavor < 0)
NeilBrown62d98c92012-09-17 16:46:34 +1000206 return ERR_PTR((int)flavor);
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400207
Chuck Leverba9b5842012-09-14 17:24:02 -0400208 return rpc_clone_client_set_auth(clnt, flavor);
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400209}
210
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400211static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
212 char *page, char *page2,
213 const struct nfs4_fs_location *location)
214{
Trond Myklebust364d015e52010-04-16 16:22:46 -0400215 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400216 struct vfsmount *mnt = ERR_PTR(-ENOENT);
217 char *mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400218 unsigned int maxbuflen;
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400219 unsigned int s;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400220
221 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
222 if (IS_ERR(mnt_path))
Trond Myklebust517be092009-10-06 15:42:20 -0400223 return ERR_CAST(mnt_path);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400224 mountdata->mnt_path = mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400225 maxbuflen = mnt_path - 1 - page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400226
Trond Myklebust364d015e52010-04-16 16:22:46 -0400227 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
228 if (mountdata->addr == NULL)
229 return ERR_PTR(-ENOMEM);
230
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400231 for (s = 0; s < location->nservers; s++) {
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400232 const struct nfs4_string *buf = &location->servers[s];
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400233
Trond Myklebustef95d312009-03-10 20:33:17 -0400234 if (buf->len <= 0 || buf->len >= maxbuflen)
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400235 continue;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400236
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400237 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
238 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400239
240 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300241 mountdata->addr, addr_bufsize,
242 NFS_SB(mountdata->sb));
Chuck Lever53a0b9c2009-08-09 15:09:36 -0400243 if (mountdata->addrlen == 0)
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400244 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400245
Chuck Leverec6ee612009-08-09 15:09:37 -0400246 rpc_set_port(mountdata->addr, NFS_PORT);
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400247
Trond Myklebustef95d312009-03-10 20:33:17 -0400248 memcpy(page2, buf->data, buf->len);
249 page2[buf->len] = '\0';
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400250 mountdata->hostname = page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400251
252 snprintf(page, PAGE_SIZE, "%s:%s",
253 mountdata->hostname,
254 mountdata->mnt_path);
255
256 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
257 if (!IS_ERR(mnt))
258 break;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400259 }
Trond Myklebust364d015e52010-04-16 16:22:46 -0400260 kfree(mountdata->addr);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400261 return mnt;
262}
263
David Howellsf7b422b2006-06-09 09:34:33 -0400264/**
265 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
David Howellsf7b422b2006-06-09 09:34:33 -0400266 * @dentry - parent directory
Chuck Lever3f43c662007-12-10 14:57:31 -0500267 * @locations - array of NFSv4 server location information
David Howellsf7b422b2006-06-09 09:34:33 -0400268 *
269 */
Al Virof8ad9c42011-03-16 06:32:07 -0400270static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400271 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400272{
273 struct vfsmount *mnt = ERR_PTR(-ENOENT);
274 struct nfs_clone_mount mountdata = {
Al Virof8ad9c42011-03-16 06:32:07 -0400275 .sb = dentry->d_sb,
David Howellsf7b422b2006-06-09 09:34:33 -0400276 .dentry = dentry,
Al Virof8ad9c42011-03-16 06:32:07 -0400277 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
David Howellsf7b422b2006-06-09 09:34:33 -0400278 };
David Howells54ceac42006-08-22 20:06:13 -0400279 char *page = NULL, *page2 = NULL;
Chuck Lever3f43c662007-12-10 14:57:31 -0500280 int loc, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400281
282 if (locations == NULL || locations->nlocations <= 0)
283 goto out;
284
Harvey Harrison3110ff82008-05-02 13:42:44 -0700285 dprintk("%s: referral at %s/%s\n", __func__,
David Howellsf7b422b2006-06-09 09:34:33 -0400286 dentry->d_parent->d_name.name, dentry->d_name.name);
287
David Howellsf7b422b2006-06-09 09:34:33 -0400288 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400289 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400290 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400291
David Howellsf7b422b2006-06-09 09:34:33 -0400292 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400293 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400294 goto out;
295
David Howells54ceac42006-08-22 20:06:13 -0400296 /* Ensure fs path is a prefix of current dentry path */
Al Virob514f872011-03-16 06:26:11 -0400297 error = nfs4_validate_fspath(dentry, locations, page, page2);
David Howells54ceac42006-08-22 20:06:13 -0400298 if (error < 0) {
299 mnt = ERR_PTR(error);
300 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400301 }
302
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400303 for (loc = 0; loc < locations->nlocations; loc++) {
David Howells509de812006-08-22 20:06:11 -0400304 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400305
306 if (location == NULL || location->nservers <= 0 ||
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400307 location->rootpath.ncomponents == 0)
David Howellsf7b422b2006-06-09 09:34:33 -0400308 continue;
David Howellsf7b422b2006-06-09 09:34:33 -0400309
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400310 mnt = try_location(&mountdata, page, page2, location);
311 if (!IS_ERR(mnt))
312 break;
David Howellsf7b422b2006-06-09 09:34:33 -0400313 }
314
David Howellsf7b422b2006-06-09 09:34:33 -0400315out:
David Howells54ceac42006-08-22 20:06:13 -0400316 free_page((unsigned long) page);
317 free_page((unsigned long) page2);
Harvey Harrison3110ff82008-05-02 13:42:44 -0700318 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400319 return mnt;
320}
321
322/*
323 * nfs_do_refmount - handle crossing a referral on server
324 * @dentry - dentry of referral
David Howellsf7b422b2006-06-09 09:34:33 -0400325 *
326 */
Bryan Schumaker281cad42012-04-27 13:27:45 -0400327static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
David Howellsf7b422b2006-06-09 09:34:33 -0400328{
David Howells54ceac42006-08-22 20:06:13 -0400329 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400330 struct dentry *parent;
331 struct nfs4_fs_locations *fs_locations = NULL;
332 struct page *page;
333 int err;
334
335 /* BUG_ON(IS_ROOT(dentry)); */
Harvey Harrison3110ff82008-05-02 13:42:44 -0700336 dprintk("%s: enter\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400337
338 page = alloc_page(GFP_KERNEL);
339 if (page == NULL)
340 goto out;
341
342 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
343 if (fs_locations == NULL)
344 goto out_free;
345
346 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400347 mnt = ERR_PTR(-ENOENT);
348
David Howellsf7b422b2006-06-09 09:34:33 -0400349 parent = dget_parent(dentry);
David Howells54ceac42006-08-22 20:06:13 -0400350 dprintk("%s: getting locations for %s/%s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700351 __func__, parent->d_name.name, dentry->d_name.name);
David Howells54ceac42006-08-22 20:06:13 -0400352
Bryan Schumakerf05d1472012-04-27 13:27:41 -0400353 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
David Howellsf7b422b2006-06-09 09:34:33 -0400354 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400355 if (err != 0 ||
356 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400357 fs_locations->fs_path.ncomponents <= 0)
358 goto out_free;
359
Al Virof8ad9c42011-03-16 06:32:07 -0400360 mnt = nfs_follow_referral(dentry, fs_locations);
David Howellsf7b422b2006-06-09 09:34:33 -0400361out_free:
362 __free_page(page);
363 kfree(fs_locations);
364out:
Harvey Harrison3110ff82008-05-02 13:42:44 -0700365 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400366 return mnt;
367}
Bryan Schumaker281cad42012-04-27 13:27:45 -0400368
369struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
370 struct nfs_fh *fh, struct nfs_fattr *fattr)
371{
372 struct dentry *parent = dget_parent(dentry);
373 struct rpc_clnt *client;
374 struct vfsmount *mnt;
375
376 /* Look it up again to get its attributes and sec flavor */
377 client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr);
378 dput(parent);
379 if (IS_ERR(client))
380 return ERR_CAST(client);
381
382 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
383 mnt = nfs_do_refmount(client, dentry);
384 else
385 mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor);
386
387 rpc_shutdown_client(client);
388 return mnt;
389}