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/namei.h> 36 #include <linux/crypto.h> 37 #include <linux/sched.h> 38 39 #include "nfsd.h" 40 #include "state.h" 41 #include "vfs.h" 42 43 #define NFSDDBG_FACILITY NFSDDBG_PROC 44 45 /* Globals */ 46 static struct path rec_dir; 47 static int rec_dir_init = 0; 48 49 static int 50 nfs4_save_creds(const struct cred **original_creds) 51 { 52 struct cred *new; 53 54 new = prepare_creds(); 55 if (!new) 56 return -ENOMEM; 57 58 new->fsuid = 0; 59 new->fsgid = 0; 60 *original_creds = override_creds(new); 61 put_cred(new); 62 return 0; 63 } 64 65 static void 66 nfs4_reset_creds(const struct cred *original) 67 { 68 revert_creds(original); 69 } 70 71 static void 72 md5_to_hex(char *out, char *md5) 73 { 74 int i; 75 76 for (i=0; i<16; i++) { 77 unsigned char c = md5[i]; 78 79 *out++ = '0' + ((c&0xf0)>>4) + (c>=0xa0)*('a'-'9'-1); 80 *out++ = '0' + (c&0x0f) + ((c&0x0f)>=0x0a)*('a'-'9'-1); 81 } 82 *out = '\0'; 83 } 84 85 __be32 86 nfs4_make_rec_clidname(char *dname, struct xdr_netobj *clname) 87 { 88 struct xdr_netobj cksum; 89 struct hash_desc desc; 90 struct scatterlist sg; 91 __be32 status = nfserr_resource; 92 93 dprintk("NFSD: nfs4_make_rec_clidname for %.*s\n", 94 clname->len, clname->data); 95 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; 96 desc.tfm = crypto_alloc_hash("md5", 0, CRYPTO_ALG_ASYNC); 97 if (IS_ERR(desc.tfm)) 98 goto out_no_tfm; 99 cksum.len = crypto_hash_digestsize(desc.tfm); 100 cksum.data = kmalloc(cksum.len, GFP_KERNEL); 101 if (cksum.data == NULL) 102 goto out; 103 104 sg_init_one(&sg, clname->data, clname->len); 105 106 if (crypto_hash_digest(&desc, &sg, sg.length, cksum.data)) 107 goto out; 108 109 md5_to_hex(dname, cksum.data); 110 111 status = nfs_ok; 112 out: 113 kfree(cksum.data); 114 crypto_free_hash(desc.tfm); 115 out_no_tfm: 116 return status; 117 } 118 119 static void 120 nfsd4_sync_rec_dir(void) 121 { 122 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 123 nfsd_sync_dir(rec_dir.dentry); 124 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 125 } 126 127 int 128 nfsd4_create_clid_dir(struct nfs4_client *clp) 129 { 130 const struct cred *original_cred; 131 char *dname = clp->cl_recdir; 132 struct dentry *dentry; 133 int status; 134 135 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); 136 137 if (!rec_dir_init || clp->cl_firststate) 138 return 0; 139 140 status = nfs4_save_creds(&original_cred); 141 if (status < 0) 142 return status; 143 144 /* lock the parent */ 145 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 146 147 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1); 148 if (IS_ERR(dentry)) { 149 status = PTR_ERR(dentry); 150 goto out_unlock; 151 } 152 status = -EEXIST; 153 if (dentry->d_inode) { 154 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n"); 155 goto out_put; 156 } 157 status = mnt_want_write(rec_dir.mnt); 158 if (status) 159 goto out_put; 160 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU); 161 mnt_drop_write(rec_dir.mnt); 162 out_put: 163 dput(dentry); 164 out_unlock: 165 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 166 if (status == 0) { 167 clp->cl_firststate = 1; 168 nfsd4_sync_rec_dir(); 169 } 170 nfs4_reset_creds(original_cred); 171 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); 172 return status; 173 } 174 175 typedef int (recdir_func)(struct dentry *, struct dentry *); 176 177 struct name_list { 178 char name[HEXDIR_LEN]; 179 struct list_head list; 180 }; 181 182 static int 183 nfsd4_build_namelist(void *arg, const char *name, int namlen, 184 loff_t offset, u64 ino, unsigned int d_type) 185 { 186 struct list_head *names = arg; 187 struct name_list *entry; 188 189 if (namlen != HEXDIR_LEN - 1) 190 return 0; 191 entry = kmalloc(sizeof(struct name_list), GFP_KERNEL); 192 if (entry == NULL) 193 return -ENOMEM; 194 memcpy(entry->name, name, HEXDIR_LEN - 1); 195 entry->name[HEXDIR_LEN - 1] = '\0'; 196 list_add(&entry->list, names); 197 return 0; 198 } 199 200 static int 201 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) 202 { 203 const struct cred *original_cred; 204 struct file *filp; 205 LIST_HEAD(names); 206 struct name_list *entry; 207 struct dentry *dentry; 208 int status; 209 210 if (!rec_dir_init) 211 return 0; 212 213 status = nfs4_save_creds(&original_cred); 214 if (status < 0) 215 return status; 216 217 filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY, 218 current_cred()); 219 status = PTR_ERR(filp); 220 if (IS_ERR(filp)) 221 goto out; 222 status = vfs_readdir(filp, nfsd4_build_namelist, &names); 223 fput(filp); 224 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); 225 while (!list_empty(&names)) { 226 entry = list_entry(names.next, struct name_list, list); 227 228 dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1); 229 if (IS_ERR(dentry)) { 230 status = PTR_ERR(dentry); 231 break; 232 } 233 status = f(dir, dentry); 234 dput(dentry); 235 if (status) 236 break; 237 list_del(&entry->list); 238 kfree(entry); 239 } 240 mutex_unlock(&dir->d_inode->i_mutex); 241 out: 242 while (!list_empty(&names)) { 243 entry = list_entry(names.next, struct name_list, list); 244 list_del(&entry->list); 245 kfree(entry); 246 } 247 nfs4_reset_creds(original_cred); 248 return status; 249 } 250 251 static int 252 nfsd4_unlink_clid_dir(char *name, int namlen) 253 { 254 struct dentry *dentry; 255 int status; 256 257 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); 258 259 mutex_lock_nested(&rec_dir.dentry->d_inode->i_mutex, I_MUTEX_PARENT); 260 dentry = lookup_one_len(name, rec_dir.dentry, namlen); 261 if (IS_ERR(dentry)) { 262 status = PTR_ERR(dentry); 263 goto out_unlock; 264 } 265 status = -ENOENT; 266 if (!dentry->d_inode) 267 goto out; 268 status = vfs_rmdir(rec_dir.dentry->d_inode, dentry); 269 out: 270 dput(dentry); 271 out_unlock: 272 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 273 return status; 274 } 275 276 void 277 nfsd4_remove_clid_dir(struct nfs4_client *clp) 278 { 279 const struct cred *original_cred; 280 int status; 281 282 if (!rec_dir_init || !clp->cl_firststate) 283 return; 284 285 status = mnt_want_write(rec_dir.mnt); 286 if (status) 287 goto out; 288 clp->cl_firststate = 0; 289 290 status = nfs4_save_creds(&original_cred); 291 if (status < 0) 292 goto out; 293 294 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); 295 nfs4_reset_creds(original_cred); 296 if (status == 0) 297 nfsd4_sync_rec_dir(); 298 mnt_drop_write(rec_dir.mnt); 299 out: 300 if (status) 301 printk("NFSD: Failed to remove expired client state directory" 302 " %.*s\n", HEXDIR_LEN, clp->cl_recdir); 303 return; 304 } 305 306 static int 307 purge_old(struct dentry *parent, struct dentry *child) 308 { 309 int status; 310 311 /* note: we currently use this path only for minorversion 0 */ 312 if (nfs4_has_reclaimed_state(child->d_name.name, false)) 313 return 0; 314 315 status = vfs_rmdir(parent->d_inode, child); 316 if (status) 317 printk("failed to remove client recovery directory %s\n", 318 child->d_name.name); 319 /* Keep trying, success or failure: */ 320 return 0; 321 } 322 323 void 324 nfsd4_recdir_purge_old(void) { 325 int status; 326 327 if (!rec_dir_init) 328 return; 329 status = mnt_want_write(rec_dir.mnt); 330 if (status) 331 goto out; 332 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old); 333 if (status == 0) 334 nfsd4_sync_rec_dir(); 335 mnt_drop_write(rec_dir.mnt); 336 out: 337 if (status) 338 printk("nfsd4: failed to purge old clients from recovery" 339 " directory %s\n", rec_dir.dentry->d_name.name); 340 } 341 342 static int 343 load_recdir(struct dentry *parent, struct dentry *child) 344 { 345 if (child->d_name.len != HEXDIR_LEN - 1) { 346 printk("nfsd4: illegal name %s in recovery directory\n", 347 child->d_name.name); 348 /* Keep trying; maybe the others are OK: */ 349 return 0; 350 } 351 nfs4_client_to_reclaim(child->d_name.name); 352 return 0; 353 } 354 355 int 356 nfsd4_recdir_load(void) { 357 int status; 358 359 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir); 360 if (status) 361 printk("nfsd4: failed loading clients from recovery" 362 " directory %s\n", rec_dir.dentry->d_name.name); 363 return status; 364 } 365 366 /* 367 * Hold reference to the recovery directory. 368 */ 369 370 void 371 nfsd4_init_recdir(char *rec_dirname) 372 { 373 const struct cred *original_cred; 374 int status; 375 376 printk("NFSD: Using %s as the NFSv4 state recovery directory\n", 377 rec_dirname); 378 379 BUG_ON(rec_dir_init); 380 381 status = nfs4_save_creds(&original_cred); 382 if (status < 0) { 383 printk("NFSD: Unable to change credentials to find recovery" 384 " directory: error %d\n", 385 status); 386 return; 387 } 388 389 status = kern_path(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, 390 &rec_dir); 391 if (status) 392 printk("NFSD: unable to find recovery directory %s\n", 393 rec_dirname); 394 395 if (!status) 396 rec_dir_init = 1; 397 nfs4_reset_creds(original_cred); 398 } 399 400 void 401 nfsd4_shutdown_recdir(void) 402 { 403 if (!rec_dir_init) 404 return; 405 rec_dir_init = 0; 406 path_put(&rec_dir); 407 } 408