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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
135rpc_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
164static 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
184out:
185 put_page(page);
186 return flavor;
187}
188
189
190
191
192struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
193 struct qstr *name)
194{
195 struct rpc_clnt *clone;
196 struct rpc_auth *auth;
197 rpc_authflavor_t flavor;
198
199 flavor = nfs4_negotiate_security(inode, name);
200 if ((int)flavor < 0)
201 return ERR_PTR(flavor);
202
203 clone = rpc_clone_client(clnt);
204 if (IS_ERR(clone))
205 return clone;
206
207 auth = rpcauth_create(flavor, clone);
208 if (!auth) {
209 rpc_shutdown_client(clone);
210 clone = ERR_PTR(-EIO);
211 }
212
213 return clone;
214}
215
216static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
217 char *page, char *page2,
218 const struct nfs4_fs_location *location)
219{
220 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
221 struct vfsmount *mnt = ERR_PTR(-ENOENT);
222 char *mnt_path;
223 unsigned int maxbuflen;
224 unsigned int s;
225
226 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
227 if (IS_ERR(mnt_path))
228 return ERR_CAST(mnt_path);
229 mountdata->mnt_path = mnt_path;
230 maxbuflen = mnt_path - 1 - page2;
231
232 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
233 if (mountdata->addr == NULL)
234 return ERR_PTR(-ENOMEM);
235
236 for (s = 0; s < location->nservers; s++) {
237 const struct nfs4_string *buf = &location->servers[s];
238
239 if (buf->len <= 0 || buf->len >= maxbuflen)
240 continue;
241
242 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
243 continue;
244
245 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
246 mountdata->addr, addr_bufsize,
247 NFS_SB(mountdata->sb));
248 if (mountdata->addrlen == 0)
249 continue;
250
251 rpc_set_port(mountdata->addr, NFS_PORT);
252
253 memcpy(page2, buf->data, buf->len);
254 page2[buf->len] = '\0';
255 mountdata->hostname = page2;
256
257 snprintf(page, PAGE_SIZE, "%s:%s",
258 mountdata->hostname,
259 mountdata->mnt_path);
260
261 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
262 if (!IS_ERR(mnt))
263 break;
264 }
265 kfree(mountdata->addr);
266 return mnt;
267}
268
269
270
271
272
273
274
275static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
276 const struct nfs4_fs_locations *locations)
277{
278 struct vfsmount *mnt = ERR_PTR(-ENOENT);
279 struct nfs_clone_mount mountdata = {
280 .sb = dentry->d_sb,
281 .dentry = dentry,
282 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
283 };
284 char *page = NULL, *page2 = NULL;
285 int loc, error;
286
287 if (locations == NULL || locations->nlocations <= 0)
288 goto out;
289
290 dprintk("%s: referral at %s/%s\n", __func__,
291 dentry->d_parent->d_name.name, dentry->d_name.name);
292
293 page = (char *) __get_free_page(GFP_USER);
294 if (!page)
295 goto out;
296
297 page2 = (char *) __get_free_page(GFP_USER);
298 if (!page2)
299 goto out;
300
301
302 error = nfs4_validate_fspath(dentry, locations, page, page2);
303 if (error < 0) {
304 mnt = ERR_PTR(error);
305 goto out;
306 }
307
308 for (loc = 0; loc < locations->nlocations; loc++) {
309 const struct nfs4_fs_location *location = &locations->locations[loc];
310
311 if (location == NULL || location->nservers <= 0 ||
312 location->rootpath.ncomponents == 0)
313 continue;
314
315 mnt = try_location(&mountdata, page, page2, location);
316 if (!IS_ERR(mnt))
317 break;
318 }
319
320out:
321 free_page((unsigned long) page);
322 free_page((unsigned long) page2);
323 dprintk("%s: done\n", __func__);
324 return mnt;
325}
326
327
328
329
330
331
332static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
333{
334 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
335 struct dentry *parent;
336 struct nfs4_fs_locations *fs_locations = NULL;
337 struct page *page;
338 int err;
339
340
341 dprintk("%s: enter\n", __func__);
342
343 page = alloc_page(GFP_KERNEL);
344 if (page == NULL)
345 goto out;
346
347 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
348 if (fs_locations == NULL)
349 goto out_free;
350
351
352 mnt = ERR_PTR(-ENOENT);
353
354 parent = dget_parent(dentry);
355 dprintk("%s: getting locations for %s/%s\n",
356 __func__, parent->d_name.name, dentry->d_name.name);
357
358 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
359 dput(parent);
360 if (err != 0 ||
361 fs_locations->nlocations <= 0 ||
362 fs_locations->fs_path.ncomponents <= 0)
363 goto out_free;
364
365 mnt = nfs_follow_referral(dentry, fs_locations);
366out_free:
367 __free_page(page);
368 kfree(fs_locations);
369out:
370 dprintk("%s: done\n", __func__);
371 return mnt;
372}
373
374struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
375 struct nfs_fh *fh, struct nfs_fattr *fattr)
376{
377 struct dentry *parent = dget_parent(dentry);
378 struct rpc_clnt *client;
379 struct vfsmount *mnt;
380
381
382 client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr);
383 dput(parent);
384 if (IS_ERR(client))
385 return ERR_CAST(client);
386
387 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
388 mnt = nfs_do_refmount(client, dentry);
389 else
390 mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor);
391
392 rpc_shutdown_client(client);
393 return mnt;
394}
395
