2 * linux/fs/nfs/nfs4namespace.c
4 * Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
5 * - Modified by David Howells <dhowells@redhat.com>
10 #include <linux/dcache.h>
11 #include <linux/mount.h>
12 #include <linux/namei.h>
13 #include <linux/nfs_fs.h>
14 #include <linux/nfs_mount.h>
15 #include <linux/slab.h>
16 #include <linux/string.h>
17 #include <linux/sunrpc/clnt.h>
18 #include <linux/sunrpc/addr.h>
19 #include <linux/vfs.h>
20 #include <linux/inet.h>
23 #include "dns_resolve.h"
25 #define NFSDBG_FACILITY NFSDBG_VFS
28 * Convert the NFSv4 pathname components into a standard posix path.
30 * Note that the resulting string will be placed at the end of the buffer
32 static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
33 char *buffer, ssize_t buflen)
35 char *end = buffer + buflen;
41 n = pathname->ncomponents;
43 const struct nfs4_string *component = &pathname->components[n];
44 buflen -= component->len + 1;
47 end -= component->len;
48 memcpy(end, component->data, component->len);
53 return ERR_PTR(-ENAMETOOLONG);
57 * return the path component of "<server>:<path>"
58 * nfspath - the "<server>:<path>" string
59 * end - one past the last char that could contain "<server>:"
60 * returns NULL on failure
62 static char *nfs_path_component(const char *nfspath, const char *end)
66 if (*nfspath == '[') {
67 /* parse [] escaped IPv6 addrs */
68 p = strchr(nfspath, ']');
69 if (p != NULL && ++p < end && *p == ':')
72 /* otherwise split on first colon */
73 p = strchr(nfspath, ':');
74 if (p != NULL && p < end)
81 * Determine the mount path as a string
83 static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
86 char *path = nfs_path(&limit, dentry, buffer, buflen,
89 char *path_component = nfs_path_component(path, limit);
91 return path_component;
97 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
98 * believe to be the server path to this dentry
100 static int nfs4_validate_fspath(struct dentry *dentry,
101 const struct nfs4_fs_locations *locations,
102 char *page, char *page2)
104 const char *path, *fs_path;
106 path = nfs4_path(dentry, page, PAGE_SIZE);
108 return PTR_ERR(path);
110 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
112 return PTR_ERR(fs_path);
114 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
115 dprintk("%s: path %s does not begin with fsroot %s\n",
116 __func__, path, fs_path);
123 static size_t nfs_parse_server_name(char *string, size_t len,
124 struct sockaddr *sa, size_t salen, struct nfs_server *server)
126 struct net *net = rpc_net_ns(server->client);
129 ret = rpc_pton(net, string, len, sa, salen);
131 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
139 * nfs_find_best_sec - Find a security mechanism supported locally
140 * @server: NFS server struct
141 * @flavors: List of security tuples returned by SECINFO procedure
143 * Return the pseudoflavor of the first security mechanism in
144 * "flavors" that is locally supported. Return RPC_AUTH_UNIX if
145 * no matching flavor is found in the array. The "flavors" array
146 * is searched in the order returned from the server, per RFC 3530
149 static rpc_authflavor_t nfs_find_best_sec(struct nfs_server *server,
150 struct nfs4_secinfo_flavors *flavors)
152 rpc_authflavor_t pseudoflavor;
153 struct nfs4_secinfo4 *secinfo;
156 for (i = 0; i < flavors->num_flavors; i++) {
157 secinfo = &flavors->flavors[i];
159 switch (secinfo->flavor) {
163 pseudoflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
164 &secinfo->flavor_info);
165 /* make sure pseudoflavor matches sec= mount opt */
166 if (pseudoflavor != RPC_AUTH_MAXFLAVOR &&
167 nfs_auth_info_match(&server->auth_info,
174 /* if there were any sec= options then nothing matched */
175 if (server->auth_info.flavor_len > 0)
178 return RPC_AUTH_UNIX;
181 static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
184 struct nfs4_secinfo_flavors *flavors;
185 rpc_authflavor_t flavor;
188 page = alloc_page(GFP_KERNEL);
191 flavors = page_address(page);
193 err = nfs4_proc_secinfo(inode, name, flavors);
199 flavor = nfs_find_best_sec(NFS_SERVER(inode), flavors);
207 * Please call rpc_shutdown_client() when you are done with this client.
209 struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
212 rpc_authflavor_t flavor;
214 flavor = nfs4_negotiate_security(inode, name);
216 return ERR_PTR((int)flavor);
218 return rpc_clone_client_set_auth(clnt, flavor);
221 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
222 char *page, char *page2,
223 const struct nfs4_fs_location *location)
225 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
226 struct vfsmount *mnt = ERR_PTR(-ENOENT);
228 unsigned int maxbuflen;
231 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
232 if (IS_ERR(mnt_path))
233 return ERR_CAST(mnt_path);
234 mountdata->mnt_path = mnt_path;
235 maxbuflen = mnt_path - 1 - page2;
237 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
238 if (mountdata->addr == NULL)
239 return ERR_PTR(-ENOMEM);
241 for (s = 0; s < location->nservers; s++) {
242 const struct nfs4_string *buf = &location->servers[s];
244 if (buf->len <= 0 || buf->len >= maxbuflen)
247 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
250 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
251 mountdata->addr, addr_bufsize,
252 NFS_SB(mountdata->sb));
253 if (mountdata->addrlen == 0)
256 rpc_set_port(mountdata->addr, NFS_PORT);
258 memcpy(page2, buf->data, buf->len);
259 page2[buf->len] = '\0';
260 mountdata->hostname = page2;
262 snprintf(page, PAGE_SIZE, "%s:%s",
264 mountdata->mnt_path);
266 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
270 kfree(mountdata->addr);
275 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
276 * @dentry - parent directory
277 * @locations - array of NFSv4 server location information
280 static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
281 const struct nfs4_fs_locations *locations)
283 struct vfsmount *mnt = ERR_PTR(-ENOENT);
284 struct nfs_clone_mount mountdata = {
287 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
289 char *page = NULL, *page2 = NULL;
292 if (locations == NULL || locations->nlocations <= 0)
295 dprintk("%s: referral at %pd2\n", __func__, dentry);
297 page = (char *) __get_free_page(GFP_USER);
301 page2 = (char *) __get_free_page(GFP_USER);
305 /* Ensure fs path is a prefix of current dentry path */
306 error = nfs4_validate_fspath(dentry, locations, page, page2);
308 mnt = ERR_PTR(error);
312 for (loc = 0; loc < locations->nlocations; loc++) {
313 const struct nfs4_fs_location *location = &locations->locations[loc];
315 if (location == NULL || location->nservers <= 0 ||
316 location->rootpath.ncomponents == 0)
319 mnt = try_location(&mountdata, page, page2, location);
325 free_page((unsigned long) page);
326 free_page((unsigned long) page2);
327 dprintk("%s: done\n", __func__);
332 * nfs_do_refmount - handle crossing a referral on server
333 * @dentry - dentry of referral
336 static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
338 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
339 struct dentry *parent;
340 struct nfs4_fs_locations *fs_locations = NULL;
344 /* BUG_ON(IS_ROOT(dentry)); */
345 dprintk("%s: enter\n", __func__);
347 page = alloc_page(GFP_KERNEL);
351 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
352 if (fs_locations == NULL)
356 mnt = ERR_PTR(-ENOENT);
358 parent = dget_parent(dentry);
359 dprintk("%s: getting locations for %pd2\n",
362 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
365 fs_locations->nlocations <= 0 ||
366 fs_locations->fs_path.ncomponents <= 0)
369 mnt = nfs_follow_referral(dentry, fs_locations);
374 dprintk("%s: done\n", __func__);
378 struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
379 struct nfs_fh *fh, struct nfs_fattr *fattr)
381 rpc_authflavor_t flavor = server->client->cl_auth->au_flavor;
382 struct dentry *parent = dget_parent(dentry);
383 struct inode *dir = parent->d_inode;
384 struct qstr *name = &dentry->d_name;
385 struct rpc_clnt *client;
386 struct vfsmount *mnt;
388 /* Look it up again to get its attributes and sec flavor */
389 client = nfs4_proc_lookup_mountpoint(dir, name, fh, fattr);
392 return ERR_CAST(client);
394 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL) {
395 mnt = nfs_do_refmount(client, dentry);
399 if (client->cl_auth->au_flavor != flavor)
400 flavor = client->cl_auth->au_flavor;
402 rpc_authflavor_t new = nfs4_negotiate_security(dir, name);
406 mnt = nfs_do_submount(dentry, fh, fattr, flavor);
408 rpc_shutdown_client(client);
413 * Try one location from the fs_locations array.
415 * Returns zero on success, or a negative errno value.
417 static int nfs4_try_replacing_one_location(struct nfs_server *server,
418 char *page, char *page2,
419 const struct nfs4_fs_location *location)
421 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
422 struct sockaddr *sap;
427 sap = kmalloc(addr_bufsize, GFP_KERNEL);
432 for (s = 0; s < location->nservers; s++) {
433 const struct nfs4_string *buf = &location->servers[s];
436 if (buf->len <= 0 || buf->len > PAGE_SIZE)
439 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL)
442 salen = nfs_parse_server_name(buf->data, buf->len,
443 sap, addr_bufsize, server);
446 rpc_set_port(sap, NFS_PORT);
449 hostname = kstrndup(buf->data, buf->len, GFP_KERNEL);
450 if (hostname == NULL)
453 error = nfs4_update_server(server, hostname, sap, salen);
464 * nfs4_replace_transport - set up transport to destination server
466 * @server: export being migrated
467 * @locations: fs_locations array
469 * Returns zero on success, or a negative errno value.
471 * The client tries all the entries in the "locations" array, in the
472 * order returned by the server, until one works or the end of the
475 int nfs4_replace_transport(struct nfs_server *server,
476 const struct nfs4_fs_locations *locations)
478 char *page = NULL, *page2 = NULL;
482 if (locations == NULL || locations->nlocations <= 0)
486 page = (char *) __get_free_page(GFP_USER);
489 page2 = (char *) __get_free_page(GFP_USER);
493 for (loc = 0; loc < locations->nlocations; loc++) {
494 const struct nfs4_fs_location *location =
495 &locations->locations[loc];
497 if (location == NULL || location->nservers <= 0 ||
498 location->rootpath.ncomponents == 0)
501 error = nfs4_try_replacing_one_location(server, page,
508 free_page((unsigned long)page);
509 free_page((unsigned long)page2);