1 /* 2 * linux/fs/nfsd/nfs4recover.c 3 * 4 * Copyright (c) 2004 The Regents of the University of Michigan. 5 * All rights reserved. 6 * 7 * Andy Adamson <andros@citi.umich.edu> 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its 19 * contributors may be used to endorse or promote products derived 20 * from this software without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED 23 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 24 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 25 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 27 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 28 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 29 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 30 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 31 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 32 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 33 * 34 */ 35 36 37 #include <linux/sunrpc/svc.h> 38 #include <linux/nfsd/nfsd.h> 39 #include <linux/nfs4.h> 40 #include <linux/nfsd/state.h> 41 #include <linux/nfsd/xdr4.h> 42 #include <linux/param.h> 43 #include <linux/file.h> 44 #include <linux/namei.h> 45 #include <asm/uaccess.h> 46 #include <asm/scatterlist.h> 47 #include <linux/crypto.h> 48 49 50 #define NFSDDBG_FACILITY NFSDDBG_PROC 51 52 /* Globals */ 53 static struct nameidata rec_dir; 54 static int rec_dir_init = 0; 55 56 static void 57 nfs4_save_user(uid_t *saveuid, gid_t *savegid) 58 { 59 *saveuid = current->fsuid; 60 *savegid = current->fsgid; 61 current->fsuid = 0; 62 current->fsgid = 0; 63 } 64 65 static void 66 nfs4_reset_user(uid_t saveuid, gid_t savegid) 67 { 68 current->fsuid = saveuid; 69 current->fsgid = savegid; 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 int 87 nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname) 88 { 89 struct xdr_netobj cksum; 90 struct crypto_tfm *tfm; 91 struct scatterlist sg[1]; 92 int status = nfserr_resource; 93 94 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n", 95 clname->len, clname->data); 96 tfm = crypto_alloc_tfm("md5", CRYPTO_TFM_REQ_MAY_SLEEP); 97 if (tfm == NULL) 98 goto out; 99 cksum.len = crypto_tfm_alg_digestsize(tfm); 100 cksum.data = kmalloc(cksum.len, GFP_KERNEL); 101 if (cksum.data == NULL) 102 goto out; 103 crypto_digest_init(tfm); 104 105 sg[0].page = virt_to_page(clname->data); 106 sg[0].offset = offset_in_page(clname->data); 107 sg[0].length = clname->len; 108 109 crypto_digest_update(tfm, sg, 1); 110 crypto_digest_final(tfm, cksum.data); 111 112 md5_to_hex(dname, cksum.data); 113 114 kfree(cksum.data); 115 status = nfs_ok; 116 out: 117 crypto_free_tfm(tfm); 118 return status; 119 } 120 121 static void 122 nfsd4_sync_rec_dir(void) 123 { 124 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 125 nfsd_sync_dir(rec_dir.dentry); 126 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 127 } 128 129 int 130 nfsd4_create_clid_dir(struct nfs4_client *clp) 131 { 132 char *dname = clp->cl_recdir; 133 struct dentry *dentry; 134 uid_t uid; 135 gid_t gid; 136 int status; 137 138 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); 139 140 if (!rec_dir_init || clp->cl_firststate) 141 return 0; 142 143 nfs4_save_user(&uid, &gid); 144 145 /* lock the parent */ 146 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 147 148 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1); 149 if (IS_ERR(dentry)) { 150 status = PTR_ERR(dentry); 151 goto out_unlock; 152 } 153 status = -EEXIST; 154 if (dentry->d_inode) { 155 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n"); 156 goto out_put; 157 } 158 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU); 159 out_put: 160 dput(dentry); 161 out_unlock: 162 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 163 if (status == 0) { 164 clp->cl_firststate = 1; 165 nfsd4_sync_rec_dir(); 166 } 167 nfs4_reset_user(uid, gid); 168 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); 169 return status; 170 } 171 172 typedef int (recdir_func)(struct dentry *, struct dentry *); 173 174 struct dentry_list { 175 struct dentry *dentry; 176 struct list_head list; 177 }; 178 179 struct dentry_list_arg { 180 struct list_head dentries; 181 struct dentry *parent; 182 }; 183 184 static int 185 nfsd4_build_dentrylist(void *arg, const char *name, int namlen, 186 loff_t offset, ino_t ino, unsigned int d_type) 187 { 188 struct dentry_list_arg *dla = arg; 189 struct list_head *dentries = &dla->dentries; 190 struct dentry *parent = dla->parent; 191 struct dentry *dentry; 192 struct dentry_list *child; 193 194 if (name && isdotent(name, namlen)) 195 return nfs_ok; 196 dentry = lookup_one_len(name, parent, namlen); 197 if (IS_ERR(dentry)) 198 return PTR_ERR(dentry); 199 child = kmalloc(sizeof(*child), GFP_KERNEL); 200 if (child == NULL) 201 return -ENOMEM; 202 child->dentry = dentry; 203 list_add(&child->list, dentries); 204 return 0; 205 } 206 207 static int 208 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) 209 { 210 struct file *filp; 211 struct dentry_list_arg dla = { 212 .parent = dir, 213 }; 214 struct list_head *dentries = &dla.dentries; 215 struct dentry_list *child; 216 uid_t uid; 217 gid_t gid; 218 int status; 219 220 if (!rec_dir_init) 221 return 0; 222 223 nfs4_save_user(&uid, &gid); 224 225 filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY); 226 status = PTR_ERR(filp); 227 if (IS_ERR(filp)) 228 goto out; 229 INIT_LIST_HEAD(dentries); 230 status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla); 231 fput(filp); 232 while (!list_empty(dentries)) { 233 child = list_entry(dentries->next, struct dentry_list, list); 234 status = f(dir, child->dentry); 235 if (status) 236 goto out; 237 list_del(&child->list); 238 dput(child->dentry); 239 kfree(child); 240 } 241 out: 242 while (!list_empty(dentries)) { 243 child = list_entry(dentries->next, struct dentry_list, list); 244 list_del(&child->list); 245 dput(child->dentry); 246 kfree(child); 247 } 248 nfs4_reset_user(uid, gid); 249 return status; 250 } 251 252 static int 253 nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry) 254 { 255 int status; 256 257 if (!S_ISREG(dir->d_inode->i_mode)) { 258 printk("nfsd4: non-file found in client recovery directory\n"); 259 return -EINVAL; 260 } 261 mutex_lock(&dir->d_inode->i_mutex); 262 status = vfs_unlink(dir->d_inode, dentry); 263 mutex_unlock(&dir->d_inode->i_mutex); 264 return status; 265 } 266 267 static int 268 nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry) 269 { 270 int status; 271 272 /* For now this directory should already be empty, but we empty it of 273 * any regular files anyway, just in case the directory was created by 274 * a kernel from the future.... */ 275 nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file); 276 mutex_lock(&dir->d_inode->i_mutex); 277 status = vfs_rmdir(dir->d_inode, dentry); 278 mutex_unlock(&dir->d_inode->i_mutex); 279 return status; 280 } 281 282 static int 283 nfsd4_unlink_clid_dir(char *name, int namlen) 284 { 285 struct dentry *dentry; 286 int status; 287 288 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); 289 290 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 291 dentry = lookup_one_len(name, rec_dir.dentry, namlen); 292 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 293 if (IS_ERR(dentry)) { 294 status = PTR_ERR(dentry); 295 return status; 296 } 297 status = -ENOENT; 298 if (!dentry->d_inode) 299 goto out; 300 301 status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry); 302 out: 303 dput(dentry); 304 return status; 305 } 306 307 void 308 nfsd4_remove_clid_dir(struct nfs4_client *clp) 309 { 310 uid_t uid; 311 gid_t gid; 312 int status; 313 314 if (!rec_dir_init || !clp->cl_firststate) 315 return; 316 317 clp->cl_firststate = 0; 318 nfs4_save_user(&uid, &gid); 319 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); 320 nfs4_reset_user(uid, gid); 321 if (status == 0) 322 nfsd4_sync_rec_dir(); 323 if (status) 324 printk("NFSD: Failed to remove expired client state directory" 325 " %.*s\n", HEXDIR_LEN, clp->cl_recdir); 326 return; 327 } 328 329 static int 330 purge_old(struct dentry *parent, struct dentry *child) 331 { 332 int status; 333 334 if (nfs4_has_reclaimed_state(child->d_name.name)) 335 return nfs_ok; 336 337 status = nfsd4_clear_clid_dir(parent, child); 338 if (status) 339 printk("failed to remove client recovery directory %s\n", 340 child->d_name.name); 341 /* Keep trying, success or failure: */ 342 return nfs_ok; 343 } 344 345 void 346 nfsd4_recdir_purge_old(void) { 347 int status; 348 349 if (!rec_dir_init) 350 return; 351 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old); 352 if (status == 0) 353 nfsd4_sync_rec_dir(); 354 if (status) 355 printk("nfsd4: failed to purge old clients from recovery" 356 " directory %s\n", rec_dir.dentry->d_name.name); 357 return; 358 } 359 360 static int 361 load_recdir(struct dentry *parent, struct dentry *child) 362 { 363 if (child->d_name.len != HEXDIR_LEN - 1) { 364 printk("nfsd4: illegal name %s in recovery directory\n", 365 child->d_name.name); 366 /* Keep trying; maybe the others are OK: */ 367 return nfs_ok; 368 } 369 nfs4_client_to_reclaim(child->d_name.name); 370 return nfs_ok; 371 } 372 373 int 374 nfsd4_recdir_load(void) { 375 int status; 376 377 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir); 378 if (status) 379 printk("nfsd4: failed loading clients from recovery" 380 " directory %s\n", rec_dir.dentry->d_name.name); 381 return status; 382 } 383 384 /* 385 * Hold reference to the recovery directory. 386 */ 387 388 void 389 nfsd4_init_recdir(char *rec_dirname) 390 { 391 uid_t uid = 0; 392 gid_t gid = 0; 393 int status; 394 395 printk("NFSD: Using %s as the NFSv4 state recovery directory\n", 396 rec_dirname); 397 398 BUG_ON(rec_dir_init); 399 400 nfs4_save_user(&uid, &gid); 401 402 status = path_lookup(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, 403 &rec_dir); 404 if (status) 405 printk("NFSD: unable to find recovery directory %s\n", 406 rec_dirname); 407 408 if (!status) 409 rec_dir_init = 1; 410 nfs4_reset_user(uid, gid); 411 } 412 413 void 414 nfsd4_shutdown_recdir(void) 415 { 416 if (!rec_dir_init) 417 return; 418 rec_dir_init = 0; 419 path_release(&rec_dir); 420 } 421