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 #include <linux/err.h> 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 hash_desc desc; 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 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[0].page = virt_to_page(clname->data); 106 sg[0].offset = offset_in_page(clname->data); 107 sg[0].length = clname->len; 108 109 if (crypto_hash_digest(&desc, sg, sg->length, cksum.data)) 110 goto out; 111 112 md5_to_hex(dname, cksum.data); 113 114 kfree(cksum.data); 115 status = nfs_ok; 116 out: 117 crypto_free_hash(desc.tfm); 118 out_no_tfm: 119 return status; 120 } 121 122 static void 123 nfsd4_sync_rec_dir(void) 124 { 125 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 126 nfsd_sync_dir(rec_dir.dentry); 127 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 128 } 129 130 int 131 nfsd4_create_clid_dir(struct nfs4_client *clp) 132 { 133 char *dname = clp->cl_recdir; 134 struct dentry *dentry; 135 uid_t uid; 136 gid_t gid; 137 int status; 138 139 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); 140 141 if (!rec_dir_init || clp->cl_firststate) 142 return 0; 143 144 nfs4_save_user(&uid, &gid); 145 146 /* lock the parent */ 147 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 148 149 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1); 150 if (IS_ERR(dentry)) { 151 status = PTR_ERR(dentry); 152 goto out_unlock; 153 } 154 status = -EEXIST; 155 if (dentry->d_inode) { 156 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n"); 157 goto out_put; 158 } 159 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU); 160 out_put: 161 dput(dentry); 162 out_unlock: 163 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 164 if (status == 0) { 165 clp->cl_firststate = 1; 166 nfsd4_sync_rec_dir(); 167 } 168 nfs4_reset_user(uid, gid); 169 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); 170 return status; 171 } 172 173 typedef int (recdir_func)(struct dentry *, struct dentry *); 174 175 struct dentry_list { 176 struct dentry *dentry; 177 struct list_head list; 178 }; 179 180 struct dentry_list_arg { 181 struct list_head dentries; 182 struct dentry *parent; 183 }; 184 185 static int 186 nfsd4_build_dentrylist(void *arg, const char *name, int namlen, 187 loff_t offset, ino_t ino, unsigned int d_type) 188 { 189 struct dentry_list_arg *dla = arg; 190 struct list_head *dentries = &dla->dentries; 191 struct dentry *parent = dla->parent; 192 struct dentry *dentry; 193 struct dentry_list *child; 194 195 if (name && isdotent(name, namlen)) 196 return nfs_ok; 197 dentry = lookup_one_len(name, parent, namlen); 198 if (IS_ERR(dentry)) 199 return PTR_ERR(dentry); 200 child = kmalloc(sizeof(*child), GFP_KERNEL); 201 if (child == NULL) 202 return -ENOMEM; 203 child->dentry = dentry; 204 list_add(&child->list, dentries); 205 return 0; 206 } 207 208 static int 209 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) 210 { 211 struct file *filp; 212 struct dentry_list_arg dla = { 213 .parent = dir, 214 }; 215 struct list_head *dentries = &dla.dentries; 216 struct dentry_list *child; 217 uid_t uid; 218 gid_t gid; 219 int status; 220 221 if (!rec_dir_init) 222 return 0; 223 224 nfs4_save_user(&uid, &gid); 225 226 filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY); 227 status = PTR_ERR(filp); 228 if (IS_ERR(filp)) 229 goto out; 230 INIT_LIST_HEAD(dentries); 231 status = vfs_readdir(filp, nfsd4_build_dentrylist, &dla); 232 fput(filp); 233 while (!list_empty(dentries)) { 234 child = list_entry(dentries->next, struct dentry_list, list); 235 status = f(dir, child->dentry); 236 if (status) 237 goto out; 238 list_del(&child->list); 239 dput(child->dentry); 240 kfree(child); 241 } 242 out: 243 while (!list_empty(dentries)) { 244 child = list_entry(dentries->next, struct dentry_list, list); 245 list_del(&child->list); 246 dput(child->dentry); 247 kfree(child); 248 } 249 nfs4_reset_user(uid, gid); 250 return status; 251 } 252 253 static int 254 nfsd4_remove_clid_file(struct dentry *dir, struct dentry *dentry) 255 { 256 int status; 257 258 if (!S_ISREG(dir->d_inode->i_mode)) { 259 printk("nfsd4: non-file found in client recovery directory\n"); 260 return -EINVAL; 261 } 262 mutex_lock(&dir->d_inode->i_mutex); 263 status = vfs_unlink(dir->d_inode, dentry); 264 mutex_unlock(&dir->d_inode->i_mutex); 265 return status; 266 } 267 268 static int 269 nfsd4_clear_clid_dir(struct dentry *dir, struct dentry *dentry) 270 { 271 int status; 272 273 /* For now this directory should already be empty, but we empty it of 274 * any regular files anyway, just in case the directory was created by 275 * a kernel from the future.... */ 276 nfsd4_list_rec_dir(dentry, nfsd4_remove_clid_file); 277 mutex_lock(&dir->d_inode->i_mutex); 278 status = vfs_rmdir(dir->d_inode, dentry); 279 mutex_unlock(&dir->d_inode->i_mutex); 280 return status; 281 } 282 283 static int 284 nfsd4_unlink_clid_dir(char *name, int namlen) 285 { 286 struct dentry *dentry; 287 int status; 288 289 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); 290 291 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 292 dentry = lookup_one_len(name, rec_dir.dentry, namlen); 293 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 294 if (IS_ERR(dentry)) { 295 status = PTR_ERR(dentry); 296 return status; 297 } 298 status = -ENOENT; 299 if (!dentry->d_inode) 300 goto out; 301 302 status = nfsd4_clear_clid_dir(rec_dir.dentry, dentry); 303 out: 304 dput(dentry); 305 return status; 306 } 307 308 void 309 nfsd4_remove_clid_dir(struct nfs4_client *clp) 310 { 311 uid_t uid; 312 gid_t gid; 313 int status; 314 315 if (!rec_dir_init || !clp->cl_firststate) 316 return; 317 318 clp->cl_firststate = 0; 319 nfs4_save_user(&uid, &gid); 320 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); 321 nfs4_reset_user(uid, gid); 322 if (status == 0) 323 nfsd4_sync_rec_dir(); 324 if (status) 325 printk("NFSD: Failed to remove expired client state directory" 326 " %.*s\n", HEXDIR_LEN, clp->cl_recdir); 327 return; 328 } 329 330 static int 331 purge_old(struct dentry *parent, struct dentry *child) 332 { 333 int status; 334 335 if (nfs4_has_reclaimed_state(child->d_name.name)) 336 return nfs_ok; 337 338 status = nfsd4_clear_clid_dir(parent, child); 339 if (status) 340 printk("failed to remove client recovery directory %s\n", 341 child->d_name.name); 342 /* Keep trying, success or failure: */ 343 return nfs_ok; 344 } 345 346 void 347 nfsd4_recdir_purge_old(void) { 348 int status; 349 350 if (!rec_dir_init) 351 return; 352 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old); 353 if (status == 0) 354 nfsd4_sync_rec_dir(); 355 if (status) 356 printk("nfsd4: failed to purge old clients from recovery" 357 " directory %s\n", rec_dir.dentry->d_name.name); 358 return; 359 } 360 361 static int 362 load_recdir(struct dentry *parent, struct dentry *child) 363 { 364 if (child->d_name.len != HEXDIR_LEN - 1) { 365 printk("nfsd4: illegal name %s in recovery directory\n", 366 child->d_name.name); 367 /* Keep trying; maybe the others are OK: */ 368 return nfs_ok; 369 } 370 nfs4_client_to_reclaim(child->d_name.name); 371 return nfs_ok; 372 } 373 374 int 375 nfsd4_recdir_load(void) { 376 int status; 377 378 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir); 379 if (status) 380 printk("nfsd4: failed loading clients from recovery" 381 " directory %s\n", rec_dir.dentry->d_name.name); 382 return status; 383 } 384 385 /* 386 * Hold reference to the recovery directory. 387 */ 388 389 void 390 nfsd4_init_recdir(char *rec_dirname) 391 { 392 uid_t uid = 0; 393 gid_t gid = 0; 394 int status; 395 396 printk("NFSD: Using %s as the NFSv4 state recovery directory\n", 397 rec_dirname); 398 399 BUG_ON(rec_dir_init); 400 401 nfs4_save_user(&uid, &gid); 402 403 status = path_lookup(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, 404 &rec_dir); 405 if (status) 406 printk("NFSD: unable to find recovery directory %s\n", 407 rec_dirname); 408 409 if (!status) 410 rec_dir_init = 1; 411 nfs4_reset_user(uid, gid); 412 } 413 414 void 415 nfsd4_shutdown_recdir(void) 416 { 417 if (!rec_dir_init) 418 return; 419 rec_dir_init = 0; 420 path_release(&rec_dir); 421 } 422