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/slab.h>
15 #include <linux/string.h>
16 #include <linux/sunrpc/clnt.h>
17 #include <linux/sunrpc/addr.h>
18 #include <linux/vfs.h>
19 #include <linux/inet.h>
22 #include "dns_resolve.h"
24 #define NFSDBG_FACILITY NFSDBG_VFS
27 * Convert the NFSv4 pathname components into a standard posix path.
29 * Note that the resulting string will be placed at the end of the buffer
31 static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
32 char *buffer, ssize_t buflen)
34 char *end = buffer + buflen;
40 n = pathname->ncomponents;
42 const struct nfs4_string *component = &pathname->components[n];
43 buflen -= component->len + 1;
46 end -= component->len;
47 memcpy(end, component->data, component->len);
52 return ERR_PTR(-ENAMETOOLONG);
56 * return the path component of "<server>:<path>"
57 * nfspath - the "<server>:<path>" string
58 * end - one past the last char that could contain "<server>:"
59 * returns NULL on failure
61 static char *nfs_path_component(const char *nfspath, const char *end)
65 if (*nfspath == '[') {
66 /* parse [] escaped IPv6 addrs */
67 p = strchr(nfspath, ']');
68 if (p != NULL && ++p < end && *p == ':')
71 /* otherwise split on first colon */
72 p = strchr(nfspath, ':');
73 if (p != NULL && p < end)
80 * Determine the mount path as a string
82 static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
85 char *path = nfs_path(&limit, dentry, buffer, buflen,
88 char *path_component = nfs_path_component(path, limit);
90 return path_component;
96 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
97 * believe to be the server path to this dentry
99 static int nfs4_validate_fspath(struct dentry *dentry,
100 const struct nfs4_fs_locations *locations,
101 char *page, char *page2)
103 const char *path, *fs_path;
105 path = nfs4_path(dentry, page, PAGE_SIZE);
107 return PTR_ERR(path);
109 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
111 return PTR_ERR(fs_path);
113 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
114 dprintk("%s: path %s does not begin with fsroot %s\n",
115 __func__, path, fs_path);
122 static size_t nfs_parse_server_name(char *string, size_t len,
123 struct sockaddr *sa, size_t salen, struct nfs_server *server)
125 struct net *net = rpc_net_ns(server->client);
128 ret = rpc_pton(net, string, len, sa, salen);
130 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
138 * nfs_find_best_sec - Find a security mechanism supported locally
139 * @flavors: List of security tuples returned by SECINFO procedure
141 * Return the pseudoflavor of the first security mechanism in
142 * "flavors" that is locally supported. Return RPC_AUTH_UNIX if
143 * no matching flavor is found in the array. The "flavors" array
144 * is searched in the order returned from the server, per RFC 3530
147 rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors)
149 rpc_authflavor_t pseudoflavor;
150 struct nfs4_secinfo4 *secinfo;
153 for (i = 0; i < flavors->num_flavors; i++) {
154 secinfo = &flavors->flavors[i];
156 switch (secinfo->flavor) {
160 pseudoflavor = rpcauth_get_pseudoflavor(secinfo->flavor,
161 &secinfo->flavor_info);
162 if (pseudoflavor != RPC_AUTH_MAXFLAVOR)
168 return RPC_AUTH_UNIX;
171 static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
174 struct nfs4_secinfo_flavors *flavors;
175 rpc_authflavor_t flavor;
178 page = alloc_page(GFP_KERNEL);
181 flavors = page_address(page);
183 err = nfs4_proc_secinfo(inode, name, flavors);
189 flavor = nfs_find_best_sec(flavors);
197 * Please call rpc_shutdown_client() when you are done with this client.
199 struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
202 rpc_authflavor_t flavor;
204 flavor = nfs4_negotiate_security(inode, name);
206 return ERR_PTR((int)flavor);
208 return rpc_clone_client_set_auth(clnt, flavor);
211 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
212 char *page, char *page2,
213 const struct nfs4_fs_location *location)
215 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
216 struct vfsmount *mnt = ERR_PTR(-ENOENT);
218 unsigned int maxbuflen;
221 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
222 if (IS_ERR(mnt_path))
223 return ERR_CAST(mnt_path);
224 mountdata->mnt_path = mnt_path;
225 maxbuflen = mnt_path - 1 - page2;
227 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
228 if (mountdata->addr == NULL)
229 return ERR_PTR(-ENOMEM);
231 for (s = 0; s < location->nservers; s++) {
232 const struct nfs4_string *buf = &location->servers[s];
234 if (buf->len <= 0 || buf->len >= maxbuflen)
237 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
240 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
241 mountdata->addr, addr_bufsize,
242 NFS_SB(mountdata->sb));
243 if (mountdata->addrlen == 0)
246 rpc_set_port(mountdata->addr, NFS_PORT);
248 memcpy(page2, buf->data, buf->len);
249 page2[buf->len] = '\0';
250 mountdata->hostname = page2;
252 snprintf(page, PAGE_SIZE, "%s:%s",
254 mountdata->mnt_path);
256 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
260 kfree(mountdata->addr);
265 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
266 * @dentry - parent directory
267 * @locations - array of NFSv4 server location information
270 static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
271 const struct nfs4_fs_locations *locations)
273 struct vfsmount *mnt = ERR_PTR(-ENOENT);
274 struct nfs_clone_mount mountdata = {
277 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
279 char *page = NULL, *page2 = NULL;
282 if (locations == NULL || locations->nlocations <= 0)
285 dprintk("%s: referral at %s/%s\n", __func__,
286 dentry->d_parent->d_name.name, dentry->d_name.name);
288 page = (char *) __get_free_page(GFP_USER);
292 page2 = (char *) __get_free_page(GFP_USER);
296 /* Ensure fs path is a prefix of current dentry path */
297 error = nfs4_validate_fspath(dentry, locations, page, page2);
299 mnt = ERR_PTR(error);
303 for (loc = 0; loc < locations->nlocations; loc++) {
304 const struct nfs4_fs_location *location = &locations->locations[loc];
306 if (location == NULL || location->nservers <= 0 ||
307 location->rootpath.ncomponents == 0)
310 mnt = try_location(&mountdata, page, page2, location);
316 free_page((unsigned long) page);
317 free_page((unsigned long) page2);
318 dprintk("%s: done\n", __func__);
323 * nfs_do_refmount - handle crossing a referral on server
324 * @dentry - dentry of referral
327 static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
329 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
330 struct dentry *parent;
331 struct nfs4_fs_locations *fs_locations = NULL;
335 /* BUG_ON(IS_ROOT(dentry)); */
336 dprintk("%s: enter\n", __func__);
338 page = alloc_page(GFP_KERNEL);
342 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
343 if (fs_locations == NULL)
347 mnt = ERR_PTR(-ENOENT);
349 parent = dget_parent(dentry);
350 dprintk("%s: getting locations for %s/%s\n",
351 __func__, parent->d_name.name, dentry->d_name.name);
353 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
356 fs_locations->nlocations <= 0 ||
357 fs_locations->fs_path.ncomponents <= 0)
360 mnt = nfs_follow_referral(dentry, fs_locations);
365 dprintk("%s: done\n", __func__);
369 struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
370 struct nfs_fh *fh, struct nfs_fattr *fattr)
372 struct dentry *parent = dget_parent(dentry);
373 struct rpc_clnt *client;
374 struct vfsmount *mnt;
376 /* Look it up again to get its attributes and sec flavor */
377 client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr);
380 return ERR_CAST(client);
382 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
383 mnt = nfs_do_refmount(client, dentry);
385 mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor);
387 rpc_shutdown_client(client);