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10#include <linux/dcache.h>
11#include <linux/mount.h>
12#include <linux/namei.h>
13#include <linux/nfs_fs.h>
14#include <linux/slab.h>
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"
20#include "nfs4_fs.h"
21#include "dns_resolve.h"
22
23#define NFSDBG_FACILITY NFSDBG_VFS
24
25
26
27
28
29
30static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
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) {
41 const struct nfs4_string *component = &pathname->components[n];
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;
50Elong:
51 return ERR_PTR(-ENAMETOOLONG);
52}
53
54
55
56
57
58
59
60static char *nfs_path_component(const char *nfspath, const char *end)
61{
62 char *p;
63
64 if (*nfspath == '[') {
65
66 p = strchr(nfspath, ']');
67 if (p != NULL && ++p < end && *p == ':')
68 return p + 1;
69 } else {
70
71 p = strchr(nfspath, ':');
72 if (p != NULL && p < end)
73 return p + 1;
74 }
75 return NULL;
76}
77
78
79
80
81static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
82{
83 char *limit;
84 char *path = nfs_path(&limit, dentry, buffer, buflen);
85 if (!IS_ERR(path)) {
86 char *path_component = nfs_path_component(path, limit);
87 if (path_component)
88 return path_component;
89 }
90 return path;
91}
92
93
94
95
96
97static int nfs4_validate_fspath(struct dentry *dentry,
98 const struct nfs4_fs_locations *locations,
99 char *page, char *page2)
100{
101 const char *path, *fs_path;
102
103 path = nfs4_path(dentry, page, PAGE_SIZE);
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",
113 __func__, path, fs_path);
114 return -ENOENT;
115 }
116
117 return 0;
118}
119
120static size_t nfs_parse_server_name(char *string, size_t len,
121 struct sockaddr *sa, size_t salen, struct nfs_server *server)
122{
123 struct net *net = rpc_net_ns(server->client);
124 ssize_t ret;
125
126 ret = rpc_pton(net, string, len, sa, salen);
127 if (ret == 0) {
128 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
129 if (ret < 0)
130 ret = 0;
131 }
132 return ret;
133}
134
135static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
136{
137 struct page *page;
138 struct nfs4_secinfo_flavors *flavors;
139 rpc_authflavor_t flavor;
140 int err;
141
142 page = alloc_page(GFP_KERNEL);
143 if (!page)
144 return -ENOMEM;
145 flavors = page_address(page);
146
147 err = nfs4_proc_secinfo(inode, name, flavors);
148 if (err < 0) {
149 flavor = err;
150 goto out;
151 }
152
153 flavor = nfs_find_best_sec(flavors);
154
155out:
156 put_page(page);
157 return flavor;
158}
159
160
161
162
163struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
164 struct qstr *name)
165{
166 struct rpc_clnt *clone;
167 struct rpc_auth *auth;
168 rpc_authflavor_t flavor;
169
170 flavor = nfs4_negotiate_security(inode, name);
171 if (flavor < 0)
172 return ERR_PTR(flavor);
173
174 clone = rpc_clone_client(clnt);
175 if (IS_ERR(clone))
176 return clone;
177
178 auth = rpcauth_create(flavor, clone);
179 if (!auth) {
180 rpc_shutdown_client(clone);
181 clone = ERR_PTR(-EIO);
182 }
183
184 return clone;
185}
186
187static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
188 char *page, char *page2,
189 const struct nfs4_fs_location *location)
190{
191 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
192 struct vfsmount *mnt = ERR_PTR(-ENOENT);
193 char *mnt_path;
194 unsigned int maxbuflen;
195 unsigned int s;
196
197 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
198 if (IS_ERR(mnt_path))
199 return ERR_CAST(mnt_path);
200 mountdata->mnt_path = mnt_path;
201 maxbuflen = mnt_path - 1 - page2;
202
203 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
204 if (mountdata->addr == NULL)
205 return ERR_PTR(-ENOMEM);
206
207 for (s = 0; s < location->nservers; s++) {
208 const struct nfs4_string *buf = &location->servers[s];
209
210 if (buf->len <= 0 || buf->len >= maxbuflen)
211 continue;
212
213 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
214 continue;
215
216 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
217 mountdata->addr, addr_bufsize,
218 NFS_SB(mountdata->sb));
219 if (mountdata->addrlen == 0)
220 continue;
221
222 rpc_set_port(mountdata->addr, NFS_PORT);
223
224 memcpy(page2, buf->data, buf->len);
225 page2[buf->len] = '\0';
226 mountdata->hostname = page2;
227
228 snprintf(page, PAGE_SIZE, "%s:%s",
229 mountdata->hostname,
230 mountdata->mnt_path);
231
232 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
233 if (!IS_ERR(mnt))
234 break;
235 }
236 kfree(mountdata->addr);
237 return mnt;
238}
239
240
241
242
243
244
245
246static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
247 const struct nfs4_fs_locations *locations)
248{
249 struct vfsmount *mnt = ERR_PTR(-ENOENT);
250 struct nfs_clone_mount mountdata = {
251 .sb = dentry->d_sb,
252 .dentry = dentry,
253 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
254 };
255 char *page = NULL, *page2 = NULL;
256 int loc, error;
257
258 if (locations == NULL || locations->nlocations <= 0)
259 goto out;
260
261 dprintk("%s: referral at %s/%s\n", __func__,
262 dentry->d_parent->d_name.name, dentry->d_name.name);
263
264 page = (char *) __get_free_page(GFP_USER);
265 if (!page)
266 goto out;
267
268 page2 = (char *) __get_free_page(GFP_USER);
269 if (!page2)
270 goto out;
271
272
273 error = nfs4_validate_fspath(dentry, locations, page, page2);
274 if (error < 0) {
275 mnt = ERR_PTR(error);
276 goto out;
277 }
278
279 for (loc = 0; loc < locations->nlocations; loc++) {
280 const struct nfs4_fs_location *location = &locations->locations[loc];
281
282 if (location == NULL || location->nservers <= 0 ||
283 location->rootpath.ncomponents == 0)
284 continue;
285
286 mnt = try_location(&mountdata, page, page2, location);
287 if (!IS_ERR(mnt))
288 break;
289 }
290
291out:
292 free_page((unsigned long) page);
293 free_page((unsigned long) page2);
294 dprintk("%s: done\n", __func__);
295 return mnt;
296}
297
298
299
300
301
302
303struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
304{
305 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
306 struct dentry *parent;
307 struct nfs4_fs_locations *fs_locations = NULL;
308 struct page *page;
309 int err;
310
311
312 dprintk("%s: enter\n", __func__);
313
314 page = alloc_page(GFP_KERNEL);
315 if (page == NULL)
316 goto out;
317
318 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
319 if (fs_locations == NULL)
320 goto out_free;
321
322
323 mnt = ERR_PTR(-ENOENT);
324
325 parent = dget_parent(dentry);
326 dprintk("%s: getting locations for %s/%s\n",
327 __func__, parent->d_name.name, dentry->d_name.name);
328
329 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
330 dput(parent);
331 if (err != 0 ||
332 fs_locations->nlocations <= 0 ||
333 fs_locations->fs_path.ncomponents <= 0)
334 goto out_free;
335
336 mnt = nfs_follow_referral(dentry, fs_locations);
337out_free:
338 __free_page(page);
339 kfree(fs_locations);
340out:
341 dprintk("%s: done\n", __func__);
342 return mnt;
343}
344
