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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> | |
5976687a | 17 | #include <linux/sunrpc/addr.h> |
f7b422b1 DH |
18 | #include <linux/vfs.h> |
19 | #include <linux/inet.h> | |
20 | #include "internal.h" | |
c228fd3a | 21 | #include "nfs4_fs.h" |
7d7ea882 | 22 | #include "dns_resolve.h" |
f7b422b1 DH |
23 | |
24 | #define NFSDBG_FACILITY NFSDBG_VFS | |
25 | ||
26 | /* | |
ef95d31e TM |
27 | * 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 | |
f7b422b1 | 30 | */ |
509de811 | 31 | static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname, |
f7b422b1 DH |
32 | 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) { | |
509de811 | 42 | const struct nfs4_string *component = &pathname->components[n]; |
f7b422b1 DH |
43 | 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; | |
51 | Elong: | |
52 | return ERR_PTR(-ENAMETOOLONG); | |
53 | } | |
54 | ||
1aba1567 WAA |
55 | /* |
56 | * 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 | */ | |
61 | static 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 | ||
54ceac45 DH |
79 | /* |
80 | * Determine the mount path as a string | |
81 | */ | |
b514f872 | 82 | static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen) |
54ceac45 | 83 | { |
b514f872 | 84 | char *limit; |
97a54868 BH |
85 | char *path = nfs_path(&limit, dentry, buffer, buflen, |
86 | NFS_PATH_CANONICAL); | |
b514f872 | 87 | if (!IS_ERR(path)) { |
1aba1567 WAA |
88 | char *path_component = nfs_path_component(path, limit); |
89 | if (path_component) | |
90 | return path_component; | |
b514f872 AV |
91 | } |
92 | return path; | |
54ceac45 DH |
93 | } |
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 | */ | |
b514f872 | 99 | static int nfs4_validate_fspath(struct dentry *dentry, |
54ceac45 DH |
100 | const struct nfs4_fs_locations *locations, |
101 | char *page, char *page2) | |
102 | { | |
103 | const char *path, *fs_path; | |
104 | ||
b514f872 | 105 | path = nfs4_path(dentry, page, PAGE_SIZE); |
54ceac45 DH |
106 | 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", | |
3110ff80 | 115 | __func__, path, fs_path); |
54ceac45 DH |
116 | return -ENOENT; |
117 | } | |
118 | ||
119 | return 0; | |
120 | } | |
121 | ||
7d7ea882 | 122 | static size_t nfs_parse_server_name(char *string, size_t len, |
1b340d01 | 123 | struct sockaddr *sa, size_t salen, struct nfs_server *server) |
7d7ea882 | 124 | { |
2446ab60 | 125 | struct net *net = rpc_net_ns(server->client); |
7d7ea882 TM |
126 | ssize_t ret; |
127 | ||
33faaa38 | 128 | ret = rpc_pton(net, string, len, sa, salen); |
7d7ea882 | 129 | if (ret == 0) { |
33faaa38 | 130 | ret = nfs_dns_resolve_name(net, string, len, sa, salen); |
7d7ea882 TM |
131 | if (ret < 0) |
132 | ret = 0; | |
133 | } | |
134 | return ret; | |
135 | } | |
136 | ||
2671bfc3 BS |
137 | rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors) |
138 | { | |
139 | struct gss_api_mech *mech; | |
140 | struct xdr_netobj oid; | |
141 | int i; | |
142 | rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX; | |
143 | ||
144 | for (i = 0; i < flavors->num_flavors; i++) { | |
145 | struct nfs4_secinfo_flavor *flavor; | |
146 | flavor = &flavors->flavors[i]; | |
147 | ||
148 | if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) { | |
149 | pseudoflavor = flavor->flavor; | |
150 | break; | |
151 | } else if (flavor->flavor == RPC_AUTH_GSS) { | |
152 | oid.len = flavor->gss.sec_oid4.len; | |
153 | oid.data = flavor->gss.sec_oid4.data; | |
154 | mech = gss_mech_get_by_OID(&oid); | |
155 | if (!mech) | |
156 | continue; | |
157 | pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service); | |
158 | gss_mech_put(mech); | |
159 | break; | |
160 | } | |
161 | } | |
162 | ||
163 | return pseudoflavor; | |
164 | } | |
165 | ||
72de53ec BS |
166 | static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name) |
167 | { | |
168 | struct page *page; | |
169 | struct nfs4_secinfo_flavors *flavors; | |
170 | rpc_authflavor_t flavor; | |
171 | int err; | |
172 | ||
173 | page = alloc_page(GFP_KERNEL); | |
174 | if (!page) | |
175 | return -ENOMEM; | |
176 | flavors = page_address(page); | |
177 | ||
178 | err = nfs4_proc_secinfo(inode, name, flavors); | |
179 | if (err < 0) { | |
180 | flavor = err; | |
181 | goto out; | |
182 | } | |
183 | ||
184 | flavor = nfs_find_best_sec(flavors); | |
185 | ||
186 | out: | |
187 | put_page(page); | |
188 | return flavor; | |
189 | } | |
190 | ||
191 | /* | |
192 | * Please call rpc_shutdown_client() when you are done with this client. | |
193 | */ | |
194 | struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode, | |
195 | struct qstr *name) | |
196 | { | |
72de53ec BS |
197 | rpc_authflavor_t flavor; |
198 | ||
199 | flavor = nfs4_negotiate_security(inode, name); | |
5f23eff3 | 200 | if ((int)flavor < 0) |
62d98c93 | 201 | return ERR_PTR((int)flavor); |
72de53ec | 202 | |
ba9b584c | 203 | return rpc_clone_client_set_auth(clnt, flavor); |
72de53ec BS |
204 | } |
205 | ||
4ada29d5 BF |
206 | static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, |
207 | char *page, char *page2, | |
208 | const struct nfs4_fs_location *location) | |
209 | { | |
364d015e | 210 | const size_t addr_bufsize = sizeof(struct sockaddr_storage); |
4ada29d5 BF |
211 | struct vfsmount *mnt = ERR_PTR(-ENOENT); |
212 | char *mnt_path; | |
ef95d31e | 213 | unsigned int maxbuflen; |
460cdbc8 | 214 | unsigned int s; |
4ada29d5 BF |
215 | |
216 | mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); | |
217 | if (IS_ERR(mnt_path)) | |
517be09d | 218 | return ERR_CAST(mnt_path); |
4ada29d5 | 219 | mountdata->mnt_path = mnt_path; |
ef95d31e | 220 | maxbuflen = mnt_path - 1 - page2; |
4ada29d5 | 221 | |
364d015e TM |
222 | mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL); |
223 | if (mountdata->addr == NULL) | |
224 | return ERR_PTR(-ENOMEM); | |
225 | ||
460cdbc8 | 226 | for (s = 0; s < location->nservers; s++) { |
ea31a443 | 227 | const struct nfs4_string *buf = &location->servers[s]; |
4ada29d5 | 228 | |
ef95d31e | 229 | if (buf->len <= 0 || buf->len >= maxbuflen) |
4ada29d5 | 230 | continue; |
4ada29d5 | 231 | |
ea31a443 BF |
232 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) |
233 | continue; | |
517be09d TM |
234 | |
235 | mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len, | |
1b340d01 SK |
236 | mountdata->addr, addr_bufsize, |
237 | NFS_SB(mountdata->sb)); | |
53a0b9c4 | 238 | if (mountdata->addrlen == 0) |
ea31a443 | 239 | continue; |
517be09d | 240 | |
ec6ee612 | 241 | rpc_set_port(mountdata->addr, NFS_PORT); |
ea31a443 | 242 | |
ef95d31e TM |
243 | memcpy(page2, buf->data, buf->len); |
244 | page2[buf->len] = '\0'; | |
ea31a443 | 245 | mountdata->hostname = page2; |
4ada29d5 BF |
246 | |
247 | snprintf(page, PAGE_SIZE, "%s:%s", | |
248 | mountdata->hostname, | |
249 | mountdata->mnt_path); | |
250 | ||
251 | mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata); | |
252 | if (!IS_ERR(mnt)) | |
253 | break; | |
4ada29d5 | 254 | } |
364d015e | 255 | kfree(mountdata->addr); |
4ada29d5 BF |
256 | return mnt; |
257 | } | |
258 | ||
f7b422b1 DH |
259 | /** |
260 | * nfs_follow_referral - set up mountpoint when hitting a referral on moved error | |
f7b422b1 | 261 | * @dentry - parent directory |
3f43c666 | 262 | * @locations - array of NFSv4 server location information |
f7b422b1 DH |
263 | * |
264 | */ | |
f8ad9c4b | 265 | static struct vfsmount *nfs_follow_referral(struct dentry *dentry, |
509de811 | 266 | const struct nfs4_fs_locations *locations) |
f7b422b1 DH |
267 | { |
268 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
269 | struct nfs_clone_mount mountdata = { | |
f8ad9c4b | 270 | .sb = dentry->d_sb, |
f7b422b1 | 271 | .dentry = dentry, |
f8ad9c4b | 272 | .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor, |
f7b422b1 | 273 | }; |
54ceac45 | 274 | char *page = NULL, *page2 = NULL; |
3f43c666 | 275 | int loc, error; |
f7b422b1 DH |
276 | |
277 | if (locations == NULL || locations->nlocations <= 0) | |
278 | goto out; | |
279 | ||
3110ff80 | 280 | dprintk("%s: referral at %s/%s\n", __func__, |
f7b422b1 DH |
281 | dentry->d_parent->d_name.name, dentry->d_name.name); |
282 | ||
f7b422b1 | 283 | page = (char *) __get_free_page(GFP_USER); |
54ceac45 | 284 | if (!page) |
f7b422b1 | 285 | goto out; |
54ceac45 | 286 | |
f7b422b1 | 287 | page2 = (char *) __get_free_page(GFP_USER); |
54ceac45 | 288 | if (!page2) |
f7b422b1 DH |
289 | goto out; |
290 | ||
54ceac45 | 291 | /* Ensure fs path is a prefix of current dentry path */ |
b514f872 | 292 | error = nfs4_validate_fspath(dentry, locations, page, page2); |
54ceac45 DH |
293 | if (error < 0) { |
294 | mnt = ERR_PTR(error); | |
295 | goto out; | |
f7b422b1 DH |
296 | } |
297 | ||
460cdbc8 | 298 | for (loc = 0; loc < locations->nlocations; loc++) { |
509de811 | 299 | const struct nfs4_fs_location *location = &locations->locations[loc]; |
f7b422b1 DH |
300 | |
301 | if (location == NULL || location->nservers <= 0 || | |
460cdbc8 | 302 | location->rootpath.ncomponents == 0) |
f7b422b1 | 303 | continue; |
f7b422b1 | 304 | |
4ada29d5 BF |
305 | mnt = try_location(&mountdata, page, page2, location); |
306 | if (!IS_ERR(mnt)) | |
307 | break; | |
f7b422b1 DH |
308 | } |
309 | ||
f7b422b1 | 310 | out: |
54ceac45 DH |
311 | free_page((unsigned long) page); |
312 | free_page((unsigned long) page2); | |
3110ff80 | 313 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
314 | return mnt; |
315 | } | |
316 | ||
317 | /* | |
318 | * nfs_do_refmount - handle crossing a referral on server | |
319 | * @dentry - dentry of referral | |
f7b422b1 DH |
320 | * |
321 | */ | |
281cad46 | 322 | static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry) |
f7b422b1 | 323 | { |
54ceac45 | 324 | struct vfsmount *mnt = ERR_PTR(-ENOMEM); |
f7b422b1 DH |
325 | struct dentry *parent; |
326 | struct nfs4_fs_locations *fs_locations = NULL; | |
327 | struct page *page; | |
328 | int err; | |
329 | ||
330 | /* BUG_ON(IS_ROOT(dentry)); */ | |
3110ff80 | 331 | dprintk("%s: enter\n", __func__); |
f7b422b1 DH |
332 | |
333 | page = alloc_page(GFP_KERNEL); | |
334 | if (page == NULL) | |
335 | goto out; | |
336 | ||
337 | fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); | |
338 | if (fs_locations == NULL) | |
339 | goto out_free; | |
340 | ||
341 | /* Get locations */ | |
54ceac45 DH |
342 | mnt = ERR_PTR(-ENOENT); |
343 | ||
f7b422b1 | 344 | parent = dget_parent(dentry); |
54ceac45 | 345 | dprintk("%s: getting locations for %s/%s\n", |
3110ff80 | 346 | __func__, parent->d_name.name, dentry->d_name.name); |
54ceac45 | 347 | |
f05d147f | 348 | err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page); |
f7b422b1 | 349 | dput(parent); |
54ceac45 DH |
350 | if (err != 0 || |
351 | fs_locations->nlocations <= 0 || | |
f7b422b1 DH |
352 | fs_locations->fs_path.ncomponents <= 0) |
353 | goto out_free; | |
354 | ||
f8ad9c4b | 355 | mnt = nfs_follow_referral(dentry, fs_locations); |
f7b422b1 DH |
356 | out_free: |
357 | __free_page(page); | |
358 | kfree(fs_locations); | |
359 | out: | |
3110ff80 | 360 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
361 | return mnt; |
362 | } | |
281cad46 BS |
363 | |
364 | struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry, | |
365 | struct nfs_fh *fh, struct nfs_fattr *fattr) | |
366 | { | |
367 | struct dentry *parent = dget_parent(dentry); | |
368 | struct rpc_clnt *client; | |
369 | struct vfsmount *mnt; | |
370 | ||
371 | /* Look it up again to get its attributes and sec flavor */ | |
372 | client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr); | |
373 | dput(parent); | |
374 | if (IS_ERR(client)) | |
375 | return ERR_CAST(client); | |
376 | ||
377 | if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) | |
378 | mnt = nfs_do_refmount(client, dentry); | |
379 | else | |
380 | mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor); | |
381 | ||
382 | rpc_shutdown_client(client); | |
383 | return mnt; | |
384 | } |