blob: 017b4b01a69c7a747b4afab8c7591b5f2ac59a20 [file] [log] [blame]
David Howellsf7b422b2006-06-09 09:34:33 -04001/*
2 * linux/fs/nfs/nfs4namespace.c
3 *
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
David Howells54ceac42006-08-22 20:06:13 -04005 * - Modified by David Howells <dhowells@redhat.com>
David Howellsf7b422b2006-06-09 09:34:33 -04006 *
7 * NFSv4 namespace
8 */
9
David Howellsf7b422b2006-06-09 09:34:33 -040010#include <linux/dcache.h>
11#include <linux/mount.h>
12#include <linux/namei.h>
13#include <linux/nfs_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/slab.h>
David Howellsf7b422b2006-06-09 09:34:33 -040015#include <linux/string.h>
16#include <linux/sunrpc/clnt.h>
17#include <linux/vfs.h>
18#include <linux/inet.h>
19#include "internal.h"
Trond Myklebustc228fd32007-01-13 02:28:11 -050020#include "nfs4_fs.h"
Trond Myklebust7d7ea882009-08-19 18:12:34 -040021#include "dns_resolve.h"
David Howellsf7b422b2006-06-09 09:34:33 -040022
23#define NFSDBG_FACILITY NFSDBG_VFS
24
25/*
Trond Myklebustef95d312009-03-10 20:33:17 -040026 * 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
David Howellsf7b422b2006-06-09 09:34:33 -040029 */
David Howells509de812006-08-22 20:06:11 -040030static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
David Howellsf7b422b2006-06-09 09:34:33 -040031 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) {
David Howells509de812006-08-22 20:06:11 -040041 const struct nfs4_string *component = &pathname->components[n];
David Howellsf7b422b2006-06-09 09:34:33 -040042 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
David Howells54ceac42006-08-22 20:06:13 -040054/*
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040055 * 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 */
60static 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
78/*
David Howells54ceac42006-08-22 20:06:13 -040079 * Determine the mount path as a string
80 */
Al Virob514f872011-03-16 06:26:11 -040081static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
David Howells54ceac42006-08-22 20:06:13 -040082{
Al Virob514f872011-03-16 06:26:11 -040083 char *limit;
84 char *path = nfs_path(&limit, dentry, buffer, buflen);
85 if (!IS_ERR(path)) {
Weston Andros Adamson1aba1562012-04-24 16:50:37 -040086 char *path_component = nfs_path_component(path, limit);
87 if (path_component)
88 return path_component;
Al Virob514f872011-03-16 06:26:11 -040089 }
90 return path;
David Howells54ceac42006-08-22 20:06:13 -040091}
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 */
Al Virob514f872011-03-16 06:26:11 -040097static int nfs4_validate_fspath(struct dentry *dentry,
David Howells54ceac42006-08-22 20:06:13 -040098 const struct nfs4_fs_locations *locations,
99 char *page, char *page2)
100{
101 const char *path, *fs_path;
102
Al Virob514f872011-03-16 06:26:11 -0400103 path = nfs4_path(dentry, page, PAGE_SIZE);
David Howells54ceac42006-08-22 20:06:13 -0400104 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",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700113 __func__, path, fs_path);
David Howells54ceac42006-08-22 20:06:13 -0400114 return -ENOENT;
115 }
116
117 return 0;
118}
119
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400120static size_t nfs_parse_server_name(char *string, size_t len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300121 struct sockaddr *sa, size_t salen, struct nfs_server *server)
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400122{
Trond Myklebust2446ab62012-03-01 17:00:56 -0500123 struct net *net = rpc_net_ns(server->client);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400124 ssize_t ret;
125
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400126 ret = rpc_pton(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400127 if (ret == 0) {
Stanislav Kinsbursky33faaa32012-01-26 15:12:05 +0400128 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
Trond Myklebust7d7ea882009-08-19 18:12:34 -0400129 if (ret < 0)
130 ret = 0;
131 }
132 return ret;
133}
134
Bryan Schumaker2671bfc2012-04-27 13:27:44 -0400135rpc_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
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400164static 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 * Please call rpc_shutdown_client() when you are done with this client.
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);
Benny Halevy5f23eff32012-05-16 11:35:36 +0300200 if ((int)flavor < 0)
Bryan Schumaker72de53e2012-04-27 13:27:40 -0400201 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
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400216static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
217 char *page, char *page2,
218 const struct nfs4_fs_location *location)
219{
Trond Myklebust364d015e52010-04-16 16:22:46 -0400220 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400221 struct vfsmount *mnt = ERR_PTR(-ENOENT);
222 char *mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400223 unsigned int maxbuflen;
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400224 unsigned int s;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400225
226 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
227 if (IS_ERR(mnt_path))
Trond Myklebust517be092009-10-06 15:42:20 -0400228 return ERR_CAST(mnt_path);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400229 mountdata->mnt_path = mnt_path;
Trond Myklebustef95d312009-03-10 20:33:17 -0400230 maxbuflen = mnt_path - 1 - page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400231
Trond Myklebust364d015e52010-04-16 16:22:46 -0400232 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
233 if (mountdata->addr == NULL)
234 return ERR_PTR(-ENOMEM);
235
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400236 for (s = 0; s < location->nservers; s++) {
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400237 const struct nfs4_string *buf = &location->servers[s];
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400238
Trond Myklebustef95d312009-03-10 20:33:17 -0400239 if (buf->len <= 0 || buf->len >= maxbuflen)
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400240 continue;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400241
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400242 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
243 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400244
245 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
Stanislav Kinsbursky1b340d02011-11-25 17:13:04 +0300246 mountdata->addr, addr_bufsize,
247 NFS_SB(mountdata->sb));
Chuck Lever53a0b9c2009-08-09 15:09:36 -0400248 if (mountdata->addrlen == 0)
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400249 continue;
Trond Myklebust517be092009-10-06 15:42:20 -0400250
Chuck Leverec6ee612009-08-09 15:09:37 -0400251 rpc_set_port(mountdata->addr, NFS_PORT);
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400252
Trond Myklebustef95d312009-03-10 20:33:17 -0400253 memcpy(page2, buf->data, buf->len);
254 page2[buf->len] = '\0';
J. Bruce Fieldsea31a4432008-08-20 16:10:23 -0400255 mountdata->hostname = page2;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400256
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;
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400264 }
Trond Myklebust364d015e52010-04-16 16:22:46 -0400265 kfree(mountdata->addr);
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400266 return mnt;
267}
268
David Howellsf7b422b2006-06-09 09:34:33 -0400269/**
270 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
David Howellsf7b422b2006-06-09 09:34:33 -0400271 * @dentry - parent directory
Chuck Lever3f43c662007-12-10 14:57:31 -0500272 * @locations - array of NFSv4 server location information
David Howellsf7b422b2006-06-09 09:34:33 -0400273 *
274 */
Al Virof8ad9c42011-03-16 06:32:07 -0400275static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400276 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400277{
278 struct vfsmount *mnt = ERR_PTR(-ENOENT);
279 struct nfs_clone_mount mountdata = {
Al Virof8ad9c42011-03-16 06:32:07 -0400280 .sb = dentry->d_sb,
David Howellsf7b422b2006-06-09 09:34:33 -0400281 .dentry = dentry,
Al Virof8ad9c42011-03-16 06:32:07 -0400282 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
David Howellsf7b422b2006-06-09 09:34:33 -0400283 };
David Howells54ceac42006-08-22 20:06:13 -0400284 char *page = NULL, *page2 = NULL;
Chuck Lever3f43c662007-12-10 14:57:31 -0500285 int loc, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400286
287 if (locations == NULL || locations->nlocations <= 0)
288 goto out;
289
Harvey Harrison3110ff82008-05-02 13:42:44 -0700290 dprintk("%s: referral at %s/%s\n", __func__,
David Howellsf7b422b2006-06-09 09:34:33 -0400291 dentry->d_parent->d_name.name, dentry->d_name.name);
292
David Howellsf7b422b2006-06-09 09:34:33 -0400293 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400294 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400295 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400296
David Howellsf7b422b2006-06-09 09:34:33 -0400297 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400298 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400299 goto out;
300
David Howells54ceac42006-08-22 20:06:13 -0400301 /* Ensure fs path is a prefix of current dentry path */
Al Virob514f872011-03-16 06:26:11 -0400302 error = nfs4_validate_fspath(dentry, locations, page, page2);
David Howells54ceac42006-08-22 20:06:13 -0400303 if (error < 0) {
304 mnt = ERR_PTR(error);
305 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400306 }
307
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400308 for (loc = 0; loc < locations->nlocations; loc++) {
David Howells509de812006-08-22 20:06:11 -0400309 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400310
311 if (location == NULL || location->nservers <= 0 ||
J. Bruce Fields460cdbc2008-08-20 16:10:21 -0400312 location->rootpath.ncomponents == 0)
David Howellsf7b422b2006-06-09 09:34:33 -0400313 continue;
David Howellsf7b422b2006-06-09 09:34:33 -0400314
J. Bruce Fields4ada29d2008-08-20 16:10:20 -0400315 mnt = try_location(&mountdata, page, page2, location);
316 if (!IS_ERR(mnt))
317 break;
David Howellsf7b422b2006-06-09 09:34:33 -0400318 }
319
David Howellsf7b422b2006-06-09 09:34:33 -0400320out:
David Howells54ceac42006-08-22 20:06:13 -0400321 free_page((unsigned long) page);
322 free_page((unsigned long) page2);
Harvey Harrison3110ff82008-05-02 13:42:44 -0700323 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400324 return mnt;
325}
326
327/*
328 * nfs_do_refmount - handle crossing a referral on server
329 * @dentry - dentry of referral
David Howellsf7b422b2006-06-09 09:34:33 -0400330 *
331 */
Bryan Schumaker281cad42012-04-27 13:27:45 -0400332static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
David Howellsf7b422b2006-06-09 09:34:33 -0400333{
David Howells54ceac42006-08-22 20:06:13 -0400334 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400335 struct dentry *parent;
336 struct nfs4_fs_locations *fs_locations = NULL;
337 struct page *page;
338 int err;
339
340 /* BUG_ON(IS_ROOT(dentry)); */
Harvey Harrison3110ff82008-05-02 13:42:44 -0700341 dprintk("%s: enter\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400342
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 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400352 mnt = ERR_PTR(-ENOENT);
353
David Howellsf7b422b2006-06-09 09:34:33 -0400354 parent = dget_parent(dentry);
David Howells54ceac42006-08-22 20:06:13 -0400355 dprintk("%s: getting locations for %s/%s\n",
Harvey Harrison3110ff82008-05-02 13:42:44 -0700356 __func__, parent->d_name.name, dentry->d_name.name);
David Howells54ceac42006-08-22 20:06:13 -0400357
Bryan Schumakerf05d1472012-04-27 13:27:41 -0400358 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
David Howellsf7b422b2006-06-09 09:34:33 -0400359 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400360 if (err != 0 ||
361 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400362 fs_locations->fs_path.ncomponents <= 0)
363 goto out_free;
364
Al Virof8ad9c42011-03-16 06:32:07 -0400365 mnt = nfs_follow_referral(dentry, fs_locations);
David Howellsf7b422b2006-06-09 09:34:33 -0400366out_free:
367 __free_page(page);
368 kfree(fs_locations);
369out:
Harvey Harrison3110ff82008-05-02 13:42:44 -0700370 dprintk("%s: done\n", __func__);
David Howellsf7b422b2006-06-09 09:34:33 -0400371 return mnt;
372}
Bryan Schumaker281cad42012-04-27 13:27:45 -0400373
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 /* Look it up again to get its attributes and sec flavor */
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}