| 1 | /* |
| 2 | * Copyright (c) 2004 The Regents of the University of Michigan. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * Andy Adamson <andros@citi.umich.edu> |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * |
| 11 | * 1. Redistributions of source code must retain the above copyright |
| 12 | * notice, this list of conditions and the following disclaimer. |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * 3. Neither the name of the University nor the names of its |
| 17 | * contributors may be used to endorse or promote products derived |
| 18 | * from this software without specific prior written permission. |
| 19 | * |
| 20 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED |
| 21 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| 22 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
| 23 | * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
| 24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 25 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 26 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
| 27 | * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| 28 | * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| 29 | * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 30 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 31 | * |
| 32 | */ |
| 33 | |
| 34 | #include <linux/file.h> |
| 35 | #include <linux/slab.h> |
| 36 | #include <linux/namei.h> |
| 37 | #include <linux/crypto.h> |
| 38 | #include <linux/sched.h> |
| 39 | |
| 40 | #include "nfsd.h" |
| 41 | #include "state.h" |
| 42 | #include "vfs.h" |
| 43 | |
| 44 | #define NFSDDBG_FACILITY NFSDDBG_PROC |
| 45 | |
| 46 | /* Globals */ |
| 47 | static struct file *rec_file; |
| 48 | static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery"; |
| 49 | |
| 50 | static int |
| 51 | nfs4_save_creds(const struct cred **original_creds) |
| 52 | { |
| 53 | struct cred *new; |
| 54 | |
| 55 | new = prepare_creds(); |
| 56 | if (!new) |
| 57 | return -ENOMEM; |
| 58 | |
| 59 | new->fsuid = 0; |
| 60 | new->fsgid = 0; |
| 61 | *original_creds = override_creds(new); |
| 62 | put_cred(new); |
| 63 | return 0; |
| 64 | } |
| 65 | |
| 66 | static void |
| 67 | nfs4_reset_creds(const struct cred *original) |
| 68 | { |
| 69 | revert_creds(original); |
| 70 | } |
| 71 | |
| 72 | static void |
| 73 | md5_to_hex(char *out, char *md5) |
| 74 | { |
| 75 | int i; |
| 76 | |
| 77 | for (i=0; i<16; i++) { |
| 78 | unsigned char c = md5[i]; |
| 79 | |
| 80 | *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); |
| 81 | *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); |
| 82 | } |
| 83 | *out = '\0'; |
| 84 | } |
| 85 | |
| 86 | __be32 |
| 87 | nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname) |
| 88 | { |
| 89 | struct xdr_netobj cksum; |
| 90 | struct hash_desc desc; |
| 91 | struct scatterlist sg; |
| 92 | __be32 status = nfserr_jukebox; |
| 93 | |
| 94 | dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n", |
| 95 | clname->len, clname->data); |
| 96 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 97 | desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); |
| 98 | if (IS_ERR(desc.tfm)) |
| 99 | goto out_no_tfm; |
| 100 | cksum.len = crypto_hash_digestsize(desc.tfm); |
| 101 | cksum.data = kmalloc(cksum.len, GFP_KERNEL); |
| 102 | if (cksum.data == NULL) |
| 103 | goto out; |
| 104 | |
| 105 | sg_init_one(&sg, clname->data, clname->len); |
| 106 | |
| 107 | if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data)) |
| 108 | goto out; |
| 109 | |
| 110 | md5_to_hex(dname, cksum.data); |
| 111 | |
| 112 | status = nfs_ok; |
| 113 | out: |
| 114 | kfree(cksum.data); |
| 115 | crypto_free_hash(desc.tfm); |
| 116 | out_no_tfm: |
| 117 | return status; |
| 118 | } |
| 119 | |
| 120 | int |
| 121 | nfsd4_create_clid_dir(struct nfs4_client *clp) |
| 122 | { |
| 123 | const struct cred *original_cred; |
| 124 | char *dname = clp->cl_recdir; |
| 125 | struct dentry *dir, *dentry; |
| 126 | int status; |
| 127 | |
| 128 | dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); |
| 129 | |
| 130 | if (!rec_file || clp->cl_firststate) |
| 131 | return 0; |
| 132 | |
| 133 | clp->cl_firststate = 1; |
| 134 | status = nfs4_save_creds(&original_cred); |
| 135 | if (status < 0) |
| 136 | return status; |
| 137 | |
| 138 | dir = rec_file->f_path.dentry; |
| 139 | /* lock the parent */ |
| 140 | mutex_lock(&dir->d_inode->i_mutex); |
| 141 | |
| 142 | dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1); |
| 143 | if (IS_ERR(dentry)) { |
| 144 | status = PTR_ERR(dentry); |
| 145 | goto out_unlock; |
| 146 | } |
| 147 | status = -EEXIST; |
| 148 | if (dentry->d_inode) |
| 149 | goto out_put; |
| 150 | status = mnt_want_write_file(rec_file); |
| 151 | if (status) |
| 152 | goto out_put; |
| 153 | status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU); |
| 154 | mnt_drop_write_file(rec_file); |
| 155 | out_put: |
| 156 | dput(dentry); |
| 157 | out_unlock: |
| 158 | mutex_unlock(&dir->d_inode->i_mutex); |
| 159 | if (status == 0) |
| 160 | vfs_fsync(rec_file, 0); |
| 161 | else |
| 162 | printk(KERN_ERR "NFSD: failed to write recovery record" |
| 163 | " (err %d); please check that %s exists" |
| 164 | " and is writeable", status, |
| 165 | user_recovery_dirname); |
| 166 | nfs4_reset_creds(original_cred); |
| 167 | return status; |
| 168 | } |
| 169 | |
| 170 | typedef int (recdir_func)(struct dentry *, struct dentry *); |
| 171 | |
| 172 | struct name_list { |
| 173 | char name[HEXDIR_LEN]; |
| 174 | struct list_head list; |
| 175 | }; |
| 176 | |
| 177 | static int |
| 178 | nfsd4_build_namelist(void *arg, const char *name, int namlen, |
| 179 | loff_t offset, u64 ino, unsigned int d_type) |
| 180 | { |
| 181 | struct list_head *names = arg; |
| 182 | struct name_list *entry; |
| 183 | |
| 184 | if (namlen != HEXDIR_LEN - 1) |
| 185 | return 0; |
| 186 | entry = kmalloc(sizeof(struct name_list), GFP_KERNEL); |
| 187 | if (entry == NULL) |
| 188 | return -ENOMEM; |
| 189 | memcpy(entry->name, name, HEXDIR_LEN - 1); |
| 190 | entry->name[HEXDIR_LEN - 1] = '\0'; |
| 191 | list_add(&entry->list, names); |
| 192 | return 0; |
| 193 | } |
| 194 | |
| 195 | static int |
| 196 | nfsd4_list_rec_dir(recdir_func *f) |
| 197 | { |
| 198 | const struct cred *original_cred; |
| 199 | struct dentry *dir = rec_file->f_path.dentry; |
| 200 | LIST_HEAD(names); |
| 201 | int status; |
| 202 | |
| 203 | status = nfs4_save_creds(&original_cred); |
| 204 | if (status < 0) |
| 205 | return status; |
| 206 | |
| 207 | status = vfs_llseek(rec_file, 0, SEEK_SET); |
| 208 | if (status < 0) { |
| 209 | nfs4_reset_creds(original_cred); |
| 210 | return status; |
| 211 | } |
| 212 | |
| 213 | status = vfs_readdir(rec_file, nfsd4_build_namelist, &names); |
| 214 | mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); |
| 215 | while (!list_empty(&names)) { |
| 216 | struct name_list *entry; |
| 217 | entry = list_entry(names.next, struct name_list, list); |
| 218 | if (!status) { |
| 219 | struct dentry *dentry; |
| 220 | dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1); |
| 221 | if (IS_ERR(dentry)) { |
| 222 | status = PTR_ERR(dentry); |
| 223 | break; |
| 224 | } |
| 225 | status = f(dir, dentry); |
| 226 | dput(dentry); |
| 227 | } |
| 228 | list_del(&entry->list); |
| 229 | kfree(entry); |
| 230 | } |
| 231 | mutex_unlock(&dir->d_inode->i_mutex); |
| 232 | nfs4_reset_creds(original_cred); |
| 233 | return status; |
| 234 | } |
| 235 | |
| 236 | static int |
| 237 | nfsd4_unlink_clid_dir(char *name, int namlen) |
| 238 | { |
| 239 | struct dentry *dir, *dentry; |
| 240 | int status; |
| 241 | |
| 242 | dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); |
| 243 | |
| 244 | dir = rec_file->f_path.dentry; |
| 245 | mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); |
| 246 | dentry = lookup_one_len(name, dir, namlen); |
| 247 | if (IS_ERR(dentry)) { |
| 248 | status = PTR_ERR(dentry); |
| 249 | goto out_unlock; |
| 250 | } |
| 251 | status = -ENOENT; |
| 252 | if (!dentry->d_inode) |
| 253 | goto out; |
| 254 | status = vfs_rmdir(dir->d_inode, dentry); |
| 255 | out: |
| 256 | dput(dentry); |
| 257 | out_unlock: |
| 258 | mutex_unlock(&dir->d_inode->i_mutex); |
| 259 | return status; |
| 260 | } |
| 261 | |
| 262 | void |
| 263 | nfsd4_remove_clid_dir(struct nfs4_client *clp) |
| 264 | { |
| 265 | const struct cred *original_cred; |
| 266 | int status; |
| 267 | |
| 268 | if (!rec_file || !clp->cl_firststate) |
| 269 | return; |
| 270 | |
| 271 | status = mnt_want_write_file(rec_file); |
| 272 | if (status) |
| 273 | goto out; |
| 274 | clp->cl_firststate = 0; |
| 275 | |
| 276 | status = nfs4_save_creds(&original_cred); |
| 277 | if (status < 0) |
| 278 | goto out; |
| 279 | |
| 280 | status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); |
| 281 | nfs4_reset_creds(original_cred); |
| 282 | if (status == 0) |
| 283 | vfs_fsync(rec_file, 0); |
| 284 | mnt_drop_write_file(rec_file); |
| 285 | out: |
| 286 | if (status) |
| 287 | printk("NFSD: Failed to remove expired client state directory" |
| 288 | " %.*s\n", HEXDIR_LEN, clp->cl_recdir); |
| 289 | return; |
| 290 | } |
| 291 | |
| 292 | static int |
| 293 | purge_old(struct dentry *parent, struct dentry *child) |
| 294 | { |
| 295 | int status; |
| 296 | |
| 297 | if (nfs4_has_reclaimed_state(child->d_name.name, false)) |
| 298 | return 0; |
| 299 | |
| 300 | status = vfs_rmdir(parent->d_inode, child); |
| 301 | if (status) |
| 302 | printk("failed to remove client recovery directory %s\n", |
| 303 | child->d_name.name); |
| 304 | /* Keep trying, success or failure: */ |
| 305 | return 0; |
| 306 | } |
| 307 | |
| 308 | void |
| 309 | nfsd4_recdir_purge_old(void) { |
| 310 | int status; |
| 311 | |
| 312 | if (!rec_file) |
| 313 | return; |
| 314 | status = mnt_want_write_file(rec_file); |
| 315 | if (status) |
| 316 | goto out; |
| 317 | status = nfsd4_list_rec_dir(purge_old); |
| 318 | if (status == 0) |
| 319 | vfs_fsync(rec_file, 0); |
| 320 | mnt_drop_write_file(rec_file); |
| 321 | out: |
| 322 | if (status) |
| 323 | printk("nfsd4: failed to purge old clients from recovery" |
| 324 | " directory %s\n", rec_file->f_path.dentry->d_name.name); |
| 325 | } |
| 326 | |
| 327 | static int |
| 328 | load_recdir(struct dentry *parent, struct dentry *child) |
| 329 | { |
| 330 | if (child->d_name.len != HEXDIR_LEN - 1) { |
| 331 | printk("nfsd4: illegal name %s in recovery directory\n", |
| 332 | child->d_name.name); |
| 333 | /* Keep trying; maybe the others are OK: */ |
| 334 | return 0; |
| 335 | } |
| 336 | nfs4_client_to_reclaim(child->d_name.name); |
| 337 | return 0; |
| 338 | } |
| 339 | |
| 340 | int |
| 341 | nfsd4_recdir_load(void) { |
| 342 | int status; |
| 343 | |
| 344 | if (!rec_file) |
| 345 | return 0; |
| 346 | |
| 347 | status = nfsd4_list_rec_dir(load_recdir); |
| 348 | if (status) |
| 349 | printk("nfsd4: failed loading clients from recovery" |
| 350 | " directory %s\n", rec_file->f_path.dentry->d_name.name); |
| 351 | return status; |
| 352 | } |
| 353 | |
| 354 | /* |
| 355 | * Hold reference to the recovery directory. |
| 356 | */ |
| 357 | |
| 358 | void |
| 359 | nfsd4_init_recdir() |
| 360 | { |
| 361 | const struct cred *original_cred; |
| 362 | int status; |
| 363 | |
| 364 | printk("NFSD: Using %s as the NFSv4 state recovery directory\n", |
| 365 | user_recovery_dirname); |
| 366 | |
| 367 | BUG_ON(rec_file); |
| 368 | |
| 369 | status = nfs4_save_creds(&original_cred); |
| 370 | if (status < 0) { |
| 371 | printk("NFSD: Unable to change credentials to find recovery" |
| 372 | " directory: error %d\n", |
| 373 | status); |
| 374 | return; |
| 375 | } |
| 376 | |
| 377 | rec_file = filp_open(user_recovery_dirname, O_RDONLY | O_DIRECTORY, 0); |
| 378 | if (IS_ERR(rec_file)) { |
| 379 | printk("NFSD: unable to find recovery directory %s\n", |
| 380 | user_recovery_dirname); |
| 381 | rec_file = NULL; |
| 382 | } |
| 383 | |
| 384 | nfs4_reset_creds(original_cred); |
| 385 | } |
| 386 | |
| 387 | void |
| 388 | nfsd4_shutdown_recdir(void) |
| 389 | { |
| 390 | if (!rec_file) |
| 391 | return; |
| 392 | fput(rec_file); |
| 393 | rec_file = NULL; |
| 394 | } |
| 395 | |
| 396 | /* |
| 397 | * Change the NFSv4 recovery directory to recdir. |
| 398 | */ |
| 399 | int |
| 400 | nfs4_reset_recoverydir(char *recdir) |
| 401 | { |
| 402 | int status; |
| 403 | struct path path; |
| 404 | |
| 405 | status = kern_path(recdir, LOOKUP_FOLLOW, &path); |
| 406 | if (status) |
| 407 | return status; |
| 408 | status = -ENOTDIR; |
| 409 | if (S_ISDIR(path.dentry->d_inode->i_mode)) { |
| 410 | strcpy(user_recovery_dirname, recdir); |
| 411 | status = 0; |
| 412 | } |
| 413 | path_put(&path); |
| 414 | return status; |
| 415 | } |
| 416 | |
| 417 | char * |
| 418 | nfs4_recoverydir(void) |
| 419 | { |
| 420 | return user_recovery_dirname; |
| 421 | } |