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Commit | Line | Data |
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f7b422b1 DH |
1 | /* |
2 | * linux/fs/nfs/nfs4namespace.c | |
3 | * | |
4 | * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com> | |
54ceac45 | 5 | * - Modified by David Howells <dhowells@redhat.com> |
f7b422b1 DH |
6 | * |
7 | * NFSv4 namespace | |
8 | */ | |
9 | ||
f7b422b1 DH |
10 | #include <linux/dcache.h> |
11 | #include <linux/mount.h> | |
12 | #include <linux/namei.h> | |
13 | #include <linux/nfs_fs.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
f7b422b1 DH |
15 | #include <linux/string.h> |
16 | #include <linux/sunrpc/clnt.h> | |
17 | #include <linux/vfs.h> | |
18 | #include <linux/inet.h> | |
19 | #include "internal.h" | |
c228fd3a | 20 | #include "nfs4_fs.h" |
7d7ea882 | 21 | #include "dns_resolve.h" |
f7b422b1 DH |
22 | |
23 | #define NFSDBG_FACILITY NFSDBG_VFS | |
24 | ||
25 | /* | |
ef95d31e TM |
26 | * Convert the NFSv4 pathname components into a standard posix path. |
27 | * | |
28 | * Note that the resulting string will be placed at the end of the buffer | |
f7b422b1 | 29 | */ |
509de811 | 30 | static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname, |
f7b422b1 DH |
31 | char *buffer, ssize_t buflen) |
32 | { | |
33 | char *end = buffer + buflen; | |
34 | int n; | |
35 | ||
36 | *--end = '\0'; | |
37 | buflen--; | |
38 | ||
39 | n = pathname->ncomponents; | |
40 | while (--n >= 0) { | |
509de811 | 41 | const struct nfs4_string *component = &pathname->components[n]; |
f7b422b1 DH |
42 | buflen -= component->len + 1; |
43 | if (buflen < 0) | |
44 | goto Elong; | |
45 | end -= component->len; | |
46 | memcpy(end, component->data, component->len); | |
47 | *--end = '/'; | |
48 | } | |
49 | return end; | |
50 | Elong: | |
51 | return ERR_PTR(-ENAMETOOLONG); | |
52 | } | |
53 | ||
1aba1567 WAA |
54 | /* |
55 | * return the path component of "<server>:<path>" | |
56 | * nfspath - the "<server>:<path>" string | |
57 | * end - one past the last char that could contain "<server>:" | |
58 | * returns NULL on failure | |
59 | */ | |
60 | static char *nfs_path_component(const char *nfspath, const char *end) | |
61 | { | |
62 | char *p; | |
63 | ||
64 | if (*nfspath == '[') { | |
65 | /* parse [] escaped IPv6 addrs */ | |
66 | p = strchr(nfspath, ']'); | |
67 | if (p != NULL && ++p < end && *p == ':') | |
68 | return p + 1; | |
69 | } else { | |
70 | /* otherwise split on first colon */ | |
71 | p = strchr(nfspath, ':'); | |
72 | if (p != NULL && p < end) | |
73 | return p + 1; | |
74 | } | |
75 | return NULL; | |
76 | } | |
77 | ||
54ceac45 DH |
78 | /* |
79 | * Determine the mount path as a string | |
80 | */ | |
b514f872 | 81 | static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen) |
54ceac45 | 82 | { |
b514f872 AV |
83 | char *limit; |
84 | char *path = nfs_path(&limit, dentry, buffer, buflen); | |
85 | if (!IS_ERR(path)) { | |
1aba1567 WAA |
86 | char *path_component = nfs_path_component(path, limit); |
87 | if (path_component) | |
88 | return path_component; | |
b514f872 AV |
89 | } |
90 | return path; | |
54ceac45 DH |
91 | } |
92 | ||
93 | /* | |
94 | * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we | |
95 | * believe to be the server path to this dentry | |
96 | */ | |
b514f872 | 97 | static int nfs4_validate_fspath(struct dentry *dentry, |
54ceac45 DH |
98 | const struct nfs4_fs_locations *locations, |
99 | char *page, char *page2) | |
100 | { | |
101 | const char *path, *fs_path; | |
102 | ||
b514f872 | 103 | path = nfs4_path(dentry, page, PAGE_SIZE); |
54ceac45 DH |
104 | if (IS_ERR(path)) |
105 | return PTR_ERR(path); | |
106 | ||
107 | fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE); | |
108 | if (IS_ERR(fs_path)) | |
109 | return PTR_ERR(fs_path); | |
110 | ||
111 | if (strncmp(path, fs_path, strlen(fs_path)) != 0) { | |
112 | dprintk("%s: path %s does not begin with fsroot %s\n", | |
3110ff80 | 113 | __func__, path, fs_path); |
54ceac45 DH |
114 | return -ENOENT; |
115 | } | |
116 | ||
117 | return 0; | |
118 | } | |
119 | ||
7d7ea882 | 120 | static size_t nfs_parse_server_name(char *string, size_t len, |
1b340d01 | 121 | struct sockaddr *sa, size_t salen, struct nfs_server *server) |
7d7ea882 | 122 | { |
2446ab60 | 123 | struct net *net = rpc_net_ns(server->client); |
7d7ea882 TM |
124 | ssize_t ret; |
125 | ||
33faaa38 | 126 | ret = rpc_pton(net, string, len, sa, salen); |
7d7ea882 | 127 | if (ret == 0) { |
33faaa38 | 128 | ret = nfs_dns_resolve_name(net, string, len, sa, salen); |
7d7ea882 TM |
129 | if (ret < 0) |
130 | ret = 0; | |
131 | } | |
132 | return ret; | |
133 | } | |
134 | ||
2671bfc3 BS |
135 | rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors) |
136 | { | |
137 | struct gss_api_mech *mech; | |
138 | struct xdr_netobj oid; | |
139 | int i; | |
140 | rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX; | |
141 | ||
142 | for (i = 0; i < flavors->num_flavors; i++) { | |
143 | struct nfs4_secinfo_flavor *flavor; | |
144 | flavor = &flavors->flavors[i]; | |
145 | ||
146 | if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) { | |
147 | pseudoflavor = flavor->flavor; | |
148 | break; | |
149 | } else if (flavor->flavor == RPC_AUTH_GSS) { | |
150 | oid.len = flavor->gss.sec_oid4.len; | |
151 | oid.data = flavor->gss.sec_oid4.data; | |
152 | mech = gss_mech_get_by_OID(&oid); | |
153 | if (!mech) | |
154 | continue; | |
155 | pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service); | |
156 | gss_mech_put(mech); | |
157 | break; | |
158 | } | |
159 | } | |
160 | ||
161 | return pseudoflavor; | |
162 | } | |
163 | ||
72de53ec BS |
164 | static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name) |
165 | { | |
166 | struct page *page; | |
167 | struct nfs4_secinfo_flavors *flavors; | |
168 | rpc_authflavor_t flavor; | |
169 | int err; | |
170 | ||
171 | page = alloc_page(GFP_KERNEL); | |
172 | if (!page) | |
173 | return -ENOMEM; | |
174 | flavors = page_address(page); | |
175 | ||
176 | err = nfs4_proc_secinfo(inode, name, flavors); | |
177 | if (err < 0) { | |
178 | flavor = err; | |
179 | goto out; | |
180 | } | |
181 | ||
182 | flavor = nfs_find_best_sec(flavors); | |
183 | ||
184 | out: | |
185 | put_page(page); | |
186 | return flavor; | |
187 | } | |
188 | ||
189 | /* | |
190 | * Please call rpc_shutdown_client() when you are done with this client. | |
191 | */ | |
192 | struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode, | |
193 | struct qstr *name) | |
194 | { | |
72de53ec BS |
195 | rpc_authflavor_t flavor; |
196 | ||
197 | flavor = nfs4_negotiate_security(inode, name); | |
5f23eff3 | 198 | if ((int)flavor < 0) |
62d98c93 | 199 | return ERR_PTR((int)flavor); |
72de53ec | 200 | |
ba9b584c | 201 | return rpc_clone_client_set_auth(clnt, flavor); |
72de53ec BS |
202 | } |
203 | ||
4ada29d5 BF |
204 | static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, |
205 | char *page, char *page2, | |
206 | const struct nfs4_fs_location *location) | |
207 | { | |
364d015e | 208 | const size_t addr_bufsize = sizeof(struct sockaddr_storage); |
4ada29d5 BF |
209 | struct vfsmount *mnt = ERR_PTR(-ENOENT); |
210 | char *mnt_path; | |
ef95d31e | 211 | unsigned int maxbuflen; |
460cdbc8 | 212 | unsigned int s; |
4ada29d5 BF |
213 | |
214 | mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); | |
215 | if (IS_ERR(mnt_path)) | |
517be09d | 216 | return ERR_CAST(mnt_path); |
4ada29d5 | 217 | mountdata->mnt_path = mnt_path; |
ef95d31e | 218 | maxbuflen = mnt_path - 1 - page2; |
4ada29d5 | 219 | |
364d015e TM |
220 | mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL); |
221 | if (mountdata->addr == NULL) | |
222 | return ERR_PTR(-ENOMEM); | |
223 | ||
460cdbc8 | 224 | for (s = 0; s < location->nservers; s++) { |
ea31a443 | 225 | const struct nfs4_string *buf = &location->servers[s]; |
4ada29d5 | 226 | |
ef95d31e | 227 | if (buf->len <= 0 || buf->len >= maxbuflen) |
4ada29d5 | 228 | continue; |
4ada29d5 | 229 | |
ea31a443 BF |
230 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) |
231 | continue; | |
517be09d TM |
232 | |
233 | mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len, | |
1b340d01 SK |
234 | mountdata->addr, addr_bufsize, |
235 | NFS_SB(mountdata->sb)); | |
53a0b9c4 | 236 | if (mountdata->addrlen == 0) |
ea31a443 | 237 | continue; |
517be09d | 238 | |
ec6ee612 | 239 | rpc_set_port(mountdata->addr, NFS_PORT); |
ea31a443 | 240 | |
ef95d31e TM |
241 | memcpy(page2, buf->data, buf->len); |
242 | page2[buf->len] = '\0'; | |
ea31a443 | 243 | mountdata->hostname = page2; |
4ada29d5 BF |
244 | |
245 | snprintf(page, PAGE_SIZE, "%s:%s", | |
246 | mountdata->hostname, | |
247 | mountdata->mnt_path); | |
248 | ||
249 | mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata); | |
250 | if (!IS_ERR(mnt)) | |
251 | break; | |
4ada29d5 | 252 | } |
364d015e | 253 | kfree(mountdata->addr); |
4ada29d5 BF |
254 | return mnt; |
255 | } | |
256 | ||
f7b422b1 DH |
257 | /** |
258 | * nfs_follow_referral - set up mountpoint when hitting a referral on moved error | |
f7b422b1 | 259 | * @dentry - parent directory |
3f43c666 | 260 | * @locations - array of NFSv4 server location information |
f7b422b1 DH |
261 | * |
262 | */ | |
f8ad9c4b | 263 | static struct vfsmount *nfs_follow_referral(struct dentry *dentry, |
509de811 | 264 | const struct nfs4_fs_locations *locations) |
f7b422b1 DH |
265 | { |
266 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
267 | struct nfs_clone_mount mountdata = { | |
f8ad9c4b | 268 | .sb = dentry->d_sb, |
f7b422b1 | 269 | .dentry = dentry, |
f8ad9c4b | 270 | .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor, |
f7b422b1 | 271 | }; |
54ceac45 | 272 | char *page = NULL, *page2 = NULL; |
3f43c666 | 273 | int loc, error; |
f7b422b1 DH |
274 | |
275 | if (locations == NULL || locations->nlocations <= 0) | |
276 | goto out; | |
277 | ||
3110ff80 | 278 | dprintk("%s: referral at %s/%s\n", __func__, |
f7b422b1 DH |
279 | dentry->d_parent->d_name.name, dentry->d_name.name); |
280 | ||
f7b422b1 | 281 | page = (char *) __get_free_page(GFP_USER); |
54ceac45 | 282 | if (!page) |
f7b422b1 | 283 | goto out; |
54ceac45 | 284 | |
f7b422b1 | 285 | page2 = (char *) __get_free_page(GFP_USER); |
54ceac45 | 286 | if (!page2) |
f7b422b1 DH |
287 | goto out; |
288 | ||
54ceac45 | 289 | /* Ensure fs path is a prefix of current dentry path */ |
b514f872 | 290 | error = nfs4_validate_fspath(dentry, locations, page, page2); |
54ceac45 DH |
291 | if (error < 0) { |
292 | mnt = ERR_PTR(error); | |
293 | goto out; | |
f7b422b1 DH |
294 | } |
295 | ||
460cdbc8 | 296 | for (loc = 0; loc < locations->nlocations; loc++) { |
509de811 | 297 | const struct nfs4_fs_location *location = &locations->locations[loc]; |
f7b422b1 DH |
298 | |
299 | if (location == NULL || location->nservers <= 0 || | |
460cdbc8 | 300 | location->rootpath.ncomponents == 0) |
f7b422b1 | 301 | continue; |
f7b422b1 | 302 | |
4ada29d5 BF |
303 | mnt = try_location(&mountdata, page, page2, location); |
304 | if (!IS_ERR(mnt)) | |
305 | break; | |
f7b422b1 DH |
306 | } |
307 | ||
f7b422b1 | 308 | out: |
54ceac45 DH |
309 | free_page((unsigned long) page); |
310 | free_page((unsigned long) page2); | |
3110ff80 | 311 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
312 | return mnt; |
313 | } | |
314 | ||
315 | /* | |
316 | * nfs_do_refmount - handle crossing a referral on server | |
317 | * @dentry - dentry of referral | |
f7b422b1 DH |
318 | * |
319 | */ | |
281cad46 | 320 | static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry) |
f7b422b1 | 321 | { |
54ceac45 | 322 | struct vfsmount *mnt = ERR_PTR(-ENOMEM); |
f7b422b1 DH |
323 | struct dentry *parent; |
324 | struct nfs4_fs_locations *fs_locations = NULL; | |
325 | struct page *page; | |
326 | int err; | |
327 | ||
328 | /* BUG_ON(IS_ROOT(dentry)); */ | |
3110ff80 | 329 | dprintk("%s: enter\n", __func__); |
f7b422b1 DH |
330 | |
331 | page = alloc_page(GFP_KERNEL); | |
332 | if (page == NULL) | |
333 | goto out; | |
334 | ||
335 | fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); | |
336 | if (fs_locations == NULL) | |
337 | goto out_free; | |
338 | ||
339 | /* Get locations */ | |
54ceac45 DH |
340 | mnt = ERR_PTR(-ENOENT); |
341 | ||
f7b422b1 | 342 | parent = dget_parent(dentry); |
54ceac45 | 343 | dprintk("%s: getting locations for %s/%s\n", |
3110ff80 | 344 | __func__, parent->d_name.name, dentry->d_name.name); |
54ceac45 | 345 | |
f05d147f | 346 | err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page); |
f7b422b1 | 347 | dput(parent); |
54ceac45 DH |
348 | if (err != 0 || |
349 | fs_locations->nlocations <= 0 || | |
f7b422b1 DH |
350 | fs_locations->fs_path.ncomponents <= 0) |
351 | goto out_free; | |
352 | ||
f8ad9c4b | 353 | mnt = nfs_follow_referral(dentry, fs_locations); |
f7b422b1 DH |
354 | out_free: |
355 | __free_page(page); | |
356 | kfree(fs_locations); | |
357 | out: | |
3110ff80 | 358 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
359 | return mnt; |
360 | } | |
281cad46 BS |
361 | |
362 | struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry, | |
363 | struct nfs_fh *fh, struct nfs_fattr *fattr) | |
364 | { | |
365 | struct dentry *parent = dget_parent(dentry); | |
366 | struct rpc_clnt *client; | |
367 | struct vfsmount *mnt; | |
368 | ||
369 | /* Look it up again to get its attributes and sec flavor */ | |
370 | client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr); | |
371 | dput(parent); | |
372 | if (IS_ERR(client)) | |
373 | return ERR_CAST(client); | |
374 | ||
375 | if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) | |
376 | mnt = nfs_do_refmount(client, dentry); | |
377 | else | |
378 | mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor); | |
379 | ||
380 | rpc_shutdown_client(client); | |
381 | return mnt; | |
382 | } |