blob: b872779d7cd5de2d73bc50172490c2028144a910 [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>
14#include <linux/string.h>
15#include <linux/sunrpc/clnt.h>
16#include <linux/vfs.h>
17#include <linux/inet.h>
18#include "internal.h"
19
20#define NFSDBG_FACILITY NFSDBG_VFS
21
22/*
23 * Check if fs_root is valid
24 */
David Howells509de812006-08-22 20:06:11 -040025static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
David Howellsf7b422b2006-06-09 09:34:33 -040026 char *buffer, ssize_t buflen)
27{
28 char *end = buffer + buflen;
29 int n;
30
31 *--end = '\0';
32 buflen--;
33
34 n = pathname->ncomponents;
35 while (--n >= 0) {
David Howells509de812006-08-22 20:06:11 -040036 const struct nfs4_string *component = &pathname->components[n];
David Howellsf7b422b2006-06-09 09:34:33 -040037 buflen -= component->len + 1;
38 if (buflen < 0)
39 goto Elong;
40 end -= component->len;
41 memcpy(end, component->data, component->len);
42 *--end = '/';
43 }
44 return end;
45Elong:
46 return ERR_PTR(-ENAMETOOLONG);
47}
48
David Howells54ceac42006-08-22 20:06:13 -040049/*
50 * Determine the mount path as a string
51 */
52static char *nfs4_path(const struct vfsmount *mnt_parent,
53 const struct dentry *dentry,
54 char *buffer, ssize_t buflen)
55{
56 const char *srvpath;
57
58 srvpath = strchr(mnt_parent->mnt_devname, ':');
59 if (srvpath)
60 srvpath++;
61 else
62 srvpath = mnt_parent->mnt_devname;
63
64 return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
65}
66
67/*
68 * Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
69 * believe to be the server path to this dentry
70 */
71static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
72 const struct dentry *dentry,
73 const struct nfs4_fs_locations *locations,
74 char *page, char *page2)
75{
76 const char *path, *fs_path;
77
78 path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
79 if (IS_ERR(path))
80 return PTR_ERR(path);
81
82 fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
83 if (IS_ERR(fs_path))
84 return PTR_ERR(fs_path);
85
86 if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
87 dprintk("%s: path %s does not begin with fsroot %s\n",
88 __FUNCTION__, path, fs_path);
89 return -ENOENT;
90 }
91
92 return 0;
93}
94
95/*
96 * Check if the string represents a "valid" IPv4 address
97 */
98static inline int valid_ipaddr4(const char *buf)
99{
100 int rc, count, in[4];
101
102 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
103 if (rc != 4)
104 return -EINVAL;
105 for (count = 0; count < 4; count++) {
106 if (in[count] > 255)
107 return -EINVAL;
108 }
109 return 0;
110}
David Howellsf7b422b2006-06-09 09:34:33 -0400111
112/**
113 * nfs_follow_referral - set up mountpoint when hitting a referral on moved error
114 * @mnt_parent - mountpoint of parent directory
115 * @dentry - parent directory
116 * @fspath - fs path returned in fs_locations
117 * @mntpath - mount path to new server
118 * @hostname - hostname of new server
119 * @addr - host addr of new server
120 *
121 */
122static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
123 const struct dentry *dentry,
David Howells509de812006-08-22 20:06:11 -0400124 const struct nfs4_fs_locations *locations)
David Howellsf7b422b2006-06-09 09:34:33 -0400125{
126 struct vfsmount *mnt = ERR_PTR(-ENOENT);
127 struct nfs_clone_mount mountdata = {
128 .sb = mnt_parent->mnt_sb,
129 .dentry = dentry,
130 .authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
131 };
David Howells54ceac42006-08-22 20:06:13 -0400132 char *page = NULL, *page2 = NULL;
David Howellsf7b422b2006-06-09 09:34:33 -0400133 char *devname;
David Howells54ceac42006-08-22 20:06:13 -0400134 int loc, s, error;
David Howellsf7b422b2006-06-09 09:34:33 -0400135
136 if (locations == NULL || locations->nlocations <= 0)
137 goto out;
138
139 dprintk("%s: referral at %s/%s\n", __FUNCTION__,
140 dentry->d_parent->d_name.name, dentry->d_name.name);
141
David Howellsf7b422b2006-06-09 09:34:33 -0400142 page = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400143 if (!page)
David Howellsf7b422b2006-06-09 09:34:33 -0400144 goto out;
David Howells54ceac42006-08-22 20:06:13 -0400145
David Howellsf7b422b2006-06-09 09:34:33 -0400146 page2 = (char *) __get_free_page(GFP_USER);
David Howells54ceac42006-08-22 20:06:13 -0400147 if (!page2)
David Howellsf7b422b2006-06-09 09:34:33 -0400148 goto out;
149
David Howells54ceac42006-08-22 20:06:13 -0400150 /* Ensure fs path is a prefix of current dentry path */
151 error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
152 if (error < 0) {
153 mnt = ERR_PTR(error);
154 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400155 }
156
157 devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
158 if (IS_ERR(devname)) {
159 mnt = (struct vfsmount *)devname;
David Howells54ceac42006-08-22 20:06:13 -0400160 goto out;
David Howellsf7b422b2006-06-09 09:34:33 -0400161 }
162
163 loc = 0;
164 while (loc < locations->nlocations && IS_ERR(mnt)) {
David Howells509de812006-08-22 20:06:11 -0400165 const struct nfs4_fs_location *location = &locations->locations[loc];
David Howellsf7b422b2006-06-09 09:34:33 -0400166 char *mnt_path;
167
168 if (location == NULL || location->nservers <= 0 ||
169 location->rootpath.ncomponents == 0) {
170 loc++;
171 continue;
172 }
173
174 mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
175 if (IS_ERR(mnt_path)) {
176 loc++;
177 continue;
178 }
179 mountdata.mnt_path = mnt_path;
180
181 s = 0;
182 while (s < location->nservers) {
183 struct sockaddr_in addr = {};
184
185 if (location->servers[s].len <= 0 ||
186 valid_ipaddr4(location->servers[s].data) < 0) {
187 s++;
188 continue;
189 }
190
191 mountdata.hostname = location->servers[s].data;
192 addr.sin_addr.s_addr = in_aton(mountdata.hostname);
193 addr.sin_family = AF_INET;
194 addr.sin_port = htons(NFS_PORT);
195 mountdata.addr = &addr;
196
David Howells54ceac42006-08-22 20:06:13 -0400197 mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, devname, &mountdata);
David Howellsf7b422b2006-06-09 09:34:33 -0400198 if (!IS_ERR(mnt)) {
199 break;
200 }
201 s++;
202 }
203 loc++;
204 }
205
David Howellsf7b422b2006-06-09 09:34:33 -0400206out:
David Howells54ceac42006-08-22 20:06:13 -0400207 free_page((unsigned long) page);
208 free_page((unsigned long) page2);
David Howellsf7b422b2006-06-09 09:34:33 -0400209 dprintk("%s: done\n", __FUNCTION__);
210 return mnt;
211}
212
213/*
214 * nfs_do_refmount - handle crossing a referral on server
215 * @dentry - dentry of referral
216 * @nd - nameidata info
217 *
218 */
219struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
220{
David Howells54ceac42006-08-22 20:06:13 -0400221 struct vfsmount *mnt = ERR_PTR(-ENOMEM);
David Howellsf7b422b2006-06-09 09:34:33 -0400222 struct dentry *parent;
223 struct nfs4_fs_locations *fs_locations = NULL;
224 struct page *page;
225 int err;
226
227 /* BUG_ON(IS_ROOT(dentry)); */
228 dprintk("%s: enter\n", __FUNCTION__);
229
230 page = alloc_page(GFP_KERNEL);
231 if (page == NULL)
232 goto out;
233
234 fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
235 if (fs_locations == NULL)
236 goto out_free;
237
238 /* Get locations */
David Howells54ceac42006-08-22 20:06:13 -0400239 mnt = ERR_PTR(-ENOENT);
240
David Howellsf7b422b2006-06-09 09:34:33 -0400241 parent = dget_parent(dentry);
David Howells54ceac42006-08-22 20:06:13 -0400242 dprintk("%s: getting locations for %s/%s\n",
243 __FUNCTION__, parent->d_name.name, dentry->d_name.name);
244
David Howellsf7b422b2006-06-09 09:34:33 -0400245 err = nfs4_proc_fs_locations(parent->d_inode, dentry, fs_locations, page);
246 dput(parent);
David Howells54ceac42006-08-22 20:06:13 -0400247 if (err != 0 ||
248 fs_locations->nlocations <= 0 ||
David Howellsf7b422b2006-06-09 09:34:33 -0400249 fs_locations->fs_path.ncomponents <= 0)
250 goto out_free;
251
252 mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
253out_free:
254 __free_page(page);
255 kfree(fs_locations);
256out:
257 dprintk("%s: done\n", __FUNCTION__);
258 return mnt;
259}