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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 | ||
4ada29d5 BF |
135 | static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, |
136 | char *page, char *page2, | |
137 | const struct nfs4_fs_location *location) | |
138 | { | |
364d015e | 139 | const size_t addr_bufsize = sizeof(struct sockaddr_storage); |
4ada29d5 BF |
140 | struct vfsmount *mnt = ERR_PTR(-ENOENT); |
141 | char *mnt_path; | |
ef95d31e | 142 | unsigned int maxbuflen; |
460cdbc8 | 143 | unsigned int s; |
4ada29d5 BF |
144 | |
145 | mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE); | |
146 | if (IS_ERR(mnt_path)) | |
517be09d | 147 | return ERR_CAST(mnt_path); |
4ada29d5 | 148 | mountdata->mnt_path = mnt_path; |
ef95d31e | 149 | maxbuflen = mnt_path - 1 - page2; |
4ada29d5 | 150 | |
364d015e TM |
151 | mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL); |
152 | if (mountdata->addr == NULL) | |
153 | return ERR_PTR(-ENOMEM); | |
154 | ||
460cdbc8 | 155 | for (s = 0; s < location->nservers; s++) { |
ea31a443 | 156 | const struct nfs4_string *buf = &location->servers[s]; |
4ada29d5 | 157 | |
ef95d31e | 158 | if (buf->len <= 0 || buf->len >= maxbuflen) |
4ada29d5 | 159 | continue; |
4ada29d5 | 160 | |
ea31a443 BF |
161 | if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len)) |
162 | continue; | |
517be09d TM |
163 | |
164 | mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len, | |
1b340d01 SK |
165 | mountdata->addr, addr_bufsize, |
166 | NFS_SB(mountdata->sb)); | |
53a0b9c4 | 167 | if (mountdata->addrlen == 0) |
ea31a443 | 168 | continue; |
517be09d | 169 | |
ec6ee612 | 170 | rpc_set_port(mountdata->addr, NFS_PORT); |
ea31a443 | 171 | |
ef95d31e TM |
172 | memcpy(page2, buf->data, buf->len); |
173 | page2[buf->len] = '\0'; | |
ea31a443 | 174 | mountdata->hostname = page2; |
4ada29d5 BF |
175 | |
176 | snprintf(page, PAGE_SIZE, "%s:%s", | |
177 | mountdata->hostname, | |
178 | mountdata->mnt_path); | |
179 | ||
180 | mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata); | |
181 | if (!IS_ERR(mnt)) | |
182 | break; | |
4ada29d5 | 183 | } |
364d015e | 184 | kfree(mountdata->addr); |
4ada29d5 BF |
185 | return mnt; |
186 | } | |
187 | ||
f7b422b1 DH |
188 | /** |
189 | * nfs_follow_referral - set up mountpoint when hitting a referral on moved error | |
f7b422b1 | 190 | * @dentry - parent directory |
3f43c666 | 191 | * @locations - array of NFSv4 server location information |
f7b422b1 DH |
192 | * |
193 | */ | |
f8ad9c4b | 194 | static struct vfsmount *nfs_follow_referral(struct dentry *dentry, |
509de811 | 195 | const struct nfs4_fs_locations *locations) |
f7b422b1 DH |
196 | { |
197 | struct vfsmount *mnt = ERR_PTR(-ENOENT); | |
198 | struct nfs_clone_mount mountdata = { | |
f8ad9c4b | 199 | .sb = dentry->d_sb, |
f7b422b1 | 200 | .dentry = dentry, |
f8ad9c4b | 201 | .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor, |
f7b422b1 | 202 | }; |
54ceac45 | 203 | char *page = NULL, *page2 = NULL; |
3f43c666 | 204 | int loc, error; |
f7b422b1 DH |
205 | |
206 | if (locations == NULL || locations->nlocations <= 0) | |
207 | goto out; | |
208 | ||
3110ff80 | 209 | dprintk("%s: referral at %s/%s\n", __func__, |
f7b422b1 DH |
210 | dentry->d_parent->d_name.name, dentry->d_name.name); |
211 | ||
f7b422b1 | 212 | page = (char *) __get_free_page(GFP_USER); |
54ceac45 | 213 | if (!page) |
f7b422b1 | 214 | goto out; |
54ceac45 | 215 | |
f7b422b1 | 216 | page2 = (char *) __get_free_page(GFP_USER); |
54ceac45 | 217 | if (!page2) |
f7b422b1 DH |
218 | goto out; |
219 | ||
54ceac45 | 220 | /* Ensure fs path is a prefix of current dentry path */ |
b514f872 | 221 | error = nfs4_validate_fspath(dentry, locations, page, page2); |
54ceac45 DH |
222 | if (error < 0) { |
223 | mnt = ERR_PTR(error); | |
224 | goto out; | |
f7b422b1 DH |
225 | } |
226 | ||
460cdbc8 | 227 | for (loc = 0; loc < locations->nlocations; loc++) { |
509de811 | 228 | const struct nfs4_fs_location *location = &locations->locations[loc]; |
f7b422b1 DH |
229 | |
230 | if (location == NULL || location->nservers <= 0 || | |
460cdbc8 | 231 | location->rootpath.ncomponents == 0) |
f7b422b1 | 232 | continue; |
f7b422b1 | 233 | |
4ada29d5 BF |
234 | mnt = try_location(&mountdata, page, page2, location); |
235 | if (!IS_ERR(mnt)) | |
236 | break; | |
f7b422b1 DH |
237 | } |
238 | ||
f7b422b1 | 239 | out: |
54ceac45 DH |
240 | free_page((unsigned long) page); |
241 | free_page((unsigned long) page2); | |
3110ff80 | 242 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
243 | return mnt; |
244 | } | |
245 | ||
246 | /* | |
247 | * nfs_do_refmount - handle crossing a referral on server | |
248 | * @dentry - dentry of referral | |
f7b422b1 DH |
249 | * |
250 | */ | |
f8ad9c4b | 251 | struct vfsmount *nfs_do_refmount(struct dentry *dentry) |
f7b422b1 | 252 | { |
54ceac45 | 253 | struct vfsmount *mnt = ERR_PTR(-ENOMEM); |
f7b422b1 DH |
254 | struct dentry *parent; |
255 | struct nfs4_fs_locations *fs_locations = NULL; | |
256 | struct page *page; | |
257 | int err; | |
258 | ||
259 | /* BUG_ON(IS_ROOT(dentry)); */ | |
3110ff80 | 260 | dprintk("%s: enter\n", __func__); |
f7b422b1 DH |
261 | |
262 | page = alloc_page(GFP_KERNEL); | |
263 | if (page == NULL) | |
264 | goto out; | |
265 | ||
266 | fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL); | |
267 | if (fs_locations == NULL) | |
268 | goto out_free; | |
269 | ||
270 | /* Get locations */ | |
54ceac45 DH |
271 | mnt = ERR_PTR(-ENOENT); |
272 | ||
f7b422b1 | 273 | parent = dget_parent(dentry); |
54ceac45 | 274 | dprintk("%s: getting locations for %s/%s\n", |
3110ff80 | 275 | __func__, parent->d_name.name, dentry->d_name.name); |
54ceac45 | 276 | |
c228fd3a | 277 | err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page); |
f7b422b1 | 278 | dput(parent); |
54ceac45 DH |
279 | if (err != 0 || |
280 | fs_locations->nlocations <= 0 || | |
f7b422b1 DH |
281 | fs_locations->fs_path.ncomponents <= 0) |
282 | goto out_free; | |
283 | ||
f8ad9c4b | 284 | mnt = nfs_follow_referral(dentry, fs_locations); |
f7b422b1 DH |
285 | out_free: |
286 | __free_page(page); | |
287 | kfree(fs_locations); | |
288 | out: | |
3110ff80 | 289 | dprintk("%s: done\n", __func__); |
f7b422b1 DH |
290 | return mnt; |
291 | } |