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/vfs.h>
18 #include <linux/inet.h>
21 #include "dns_resolve.h"
23 #define NFSDBG_FACILITY NFSDBG_VFS
26 * Convert the NFSv4 pathname components into a standard posix path.
28 * Note that the resulting string will be placed at the end of the buffer
30 static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
31 char *buffer, ssize_t buflen)
33 char *end = buffer + buflen;
39 n = pathname->ncomponents;
41 const struct nfs4_string *component = &pathname->components[n];
42 buflen -= component->len + 1;
45 end -= component->len;
46 memcpy(end, component->data, component->len);
51 return ERR_PTR(-ENAMETOOLONG);
55 * 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
60 static char *nfs_path_component(const char *nfspath, const char *end)
64 if (*nfspath == '[') {
65 /* parse [] escaped IPv6 addrs */
66 p = strchr(nfspath, ']');
67 if (p != NULL && ++p < end && *p == ':')
70 /* otherwise split on first colon */
71 p = strchr(nfspath, ':');
72 if (p != NULL && p < end)
79 * Determine the mount path as a string
81 static char *nfs4_path(struct dentry *dentry, char *buffer, ssize_t buflen)
84 char *path = nfs_path(&limit, dentry, buffer, buflen,
87 char *path_component = nfs_path_component(path, limit);
89 return path_component;
95 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
96 * believe to be the server path to this dentry
98 static int nfs4_validate_fspath(struct dentry *dentry,
99 const struct nfs4_fs_locations *locations,
100 char *page, char *page2)
102 const char *path, *fs_path;
104 path = nfs4_path(dentry, page, PAGE_SIZE);
106 return PTR_ERR(path);
108 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
110 return PTR_ERR(fs_path);
112 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
113 dprintk("%s: path %s does not begin with fsroot %s\n",
114 __func__, path, fs_path);
121 static size_t nfs_parse_server_name(char *string, size_t len,
122 struct sockaddr *sa, size_t salen, struct nfs_server *server)
124 struct net *net = rpc_net_ns(server->client);
127 ret = rpc_pton(net, string, len, sa, salen);
129 ret = nfs_dns_resolve_name(net, string, len, sa, salen);
136 rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *flavors)
138 struct gss_api_mech *mech;
139 struct xdr_netobj oid;
141 rpc_authflavor_t pseudoflavor = RPC_AUTH_UNIX;
143 for (i = 0; i < flavors->num_flavors; i++) {
144 struct nfs4_secinfo_flavor *flavor;
145 flavor = &flavors->flavors[i];
147 if (flavor->flavor == RPC_AUTH_NULL || flavor->flavor == RPC_AUTH_UNIX) {
148 pseudoflavor = flavor->flavor;
150 } else if (flavor->flavor == RPC_AUTH_GSS) {
151 oid.len = flavor->gss.sec_oid4.len;
152 oid.data = flavor->gss.sec_oid4.data;
153 mech = gss_mech_get_by_OID(&oid);
156 pseudoflavor = gss_svc_to_pseudoflavor(mech, flavor->gss.service);
165 static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name)
168 struct nfs4_secinfo_flavors *flavors;
169 rpc_authflavor_t flavor;
172 page = alloc_page(GFP_KERNEL);
175 flavors = page_address(page);
177 err = nfs4_proc_secinfo(inode, name, flavors);
183 flavor = nfs_find_best_sec(flavors);
191 * Please call rpc_shutdown_client() when you are done with this client.
193 struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode,
196 rpc_authflavor_t flavor;
198 flavor = nfs4_negotiate_security(inode, name);
200 return ERR_PTR((int)flavor);
202 return rpc_clone_client_set_auth(clnt, flavor);
205 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
206 char *page, char *page2,
207 const struct nfs4_fs_location *location)
209 const size_t addr_bufsize = sizeof(struct sockaddr_storage);
210 struct vfsmount *mnt = ERR_PTR(-ENOENT);
212 unsigned int maxbuflen;
215 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
216 if (IS_ERR(mnt_path))
217 return ERR_CAST(mnt_path);
218 mountdata->mnt_path = mnt_path;
219 maxbuflen = mnt_path - 1 - page2;
221 mountdata->addr = kmalloc(addr_bufsize, GFP_KERNEL);
222 if (mountdata->addr == NULL)
223 return ERR_PTR(-ENOMEM);
225 for (s = 0; s < location->nservers; s++) {
226 const struct nfs4_string *buf = &location->servers[s];
228 if (buf->len <= 0 || buf->len >= maxbuflen)
231 if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
234 mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
235 mountdata->addr, addr_bufsize,
236 NFS_SB(mountdata->sb));
237 if (mountdata->addrlen == 0)
240 rpc_set_port(mountdata->addr, NFS_PORT);
242 memcpy(page2, buf->data, buf->len);
243 page2[buf->len] = '\0';
244 mountdata->hostname = page2;
246 snprintf(page, PAGE_SIZE, "%s:%s",
248 mountdata->mnt_path);
250 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
254 kfree(mountdata->addr);
259 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
260 * @dentry - parent directory
261 * @locations - array of NFSv4 server location information
264 static struct vfsmount *nfs_follow_referral(struct dentry *dentry,
265 const struct nfs4_fs_locations *locations)
267 struct vfsmount *mnt = ERR_PTR(-ENOENT);
268 struct nfs_clone_mount mountdata = {
271 .authflavor = NFS_SB(dentry->d_sb)->client->cl_auth->au_flavor,
273 char *page = NULL, *page2 = NULL;
276 if (locations == NULL || locations->nlocations <= 0)
279 dprintk("%s: referral at %s/%s\n", __func__,
280 dentry->d_parent->d_name.name, dentry->d_name.name);
282 page = (char *) __get_free_page(GFP_USER);
286 page2 = (char *) __get_free_page(GFP_USER);
290 /* Ensure fs path is a prefix of current dentry path */
291 error = nfs4_validate_fspath(dentry, locations, page, page2);
293 mnt = ERR_PTR(error);
297 for (loc = 0; loc < locations->nlocations; loc++) {
298 const struct nfs4_fs_location *location = &locations->locations[loc];
300 if (location == NULL || location->nservers <= 0 ||
301 location->rootpath.ncomponents == 0)
304 mnt = try_location(&mountdata, page, page2, location);
310 free_page((unsigned long) page);
311 free_page((unsigned long) page2);
312 dprintk("%s: done\n", __func__);
317 * nfs_do_refmount - handle crossing a referral on server
318 * @dentry - dentry of referral
321 static struct vfsmount *nfs_do_refmount(struct rpc_clnt *client, struct dentry *dentry)
323 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
324 struct dentry *parent;
325 struct nfs4_fs_locations *fs_locations = NULL;
329 /* BUG_ON(IS_ROOT(dentry)); */
330 dprintk("%s: enter\n", __func__);
332 page = alloc_page(GFP_KERNEL);
336 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
337 if (fs_locations == NULL)
341 mnt = ERR_PTR(-ENOENT);
343 parent = dget_parent(dentry);
344 dprintk("%s: getting locations for %s/%s\n",
345 __func__, parent->d_name.name, dentry->d_name.name);
347 err = nfs4_proc_fs_locations(client, parent->d_inode, &dentry->d_name, fs_locations, page);
350 fs_locations->nlocations <= 0 ||
351 fs_locations->fs_path.ncomponents <= 0)
354 mnt = nfs_follow_referral(dentry, fs_locations);
359 dprintk("%s: done\n", __func__);
363 struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
364 struct nfs_fh *fh, struct nfs_fattr *fattr)
366 struct dentry *parent = dget_parent(dentry);
367 struct rpc_clnt *client;
368 struct vfsmount *mnt;
370 /* Look it up again to get its attributes and sec flavor */
371 client = nfs4_proc_lookup_mountpoint(parent->d_inode, &dentry->d_name, fh, fattr);
374 return ERR_CAST(client);
376 if (fattr->valid & NFS_ATTR_FATTR_V4_REFERRAL)
377 mnt = nfs_do_refmount(client, dentry);
379 mnt = nfs_do_submount(dentry, fh, fattr, client->cl_auth->au_flavor);
381 rpc_shutdown_client(client);