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 path rec_dir; 48 static int rec_dir_init = 0; 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_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_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 static void 121 nfsd4_sync_rec_dir(void) 122 { 123 vfs_fsync(NULL, rec_dir.dentry, 0); 124 } 125 126 int 127 nfsd4_create_clid_dir(struct nfs4_client *clp) 128 { 129 const struct cred *original_cred; 130 char *dname = clp->cl_recdir; 131 struct dentry *dentry; 132 int status; 133 134 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); 135 136 if (!rec_dir_init || clp->cl_firststate) 137 return 0; 138 139 status = nfs4_save_creds(&original_cred); 140 if (status < 0) 141 return status; 142 143 /* lock the parent */ 144 mutex_lock(&rec_dir.dentry->d_inode->i_mutex); 145 146 dentry = lookup_one_len(dname, rec_dir.dentry, HEXDIR_LEN-1); 147 if (IS_ERR(dentry)) { 148 status = PTR_ERR(dentry); 149 goto out_unlock; 150 } 151 status = -EEXIST; 152 if (dentry->d_inode) { 153 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n"); 154 goto out_put; 155 } 156 status = mnt_want_write(rec_dir.mnt); 157 if (status) 158 goto out_put; 159 status = vfs_mkdir(rec_dir.dentry->d_inode, dentry, S_IRWXU); 160 mnt_drop_write(rec_dir.mnt); 161 out_put: 162 dput(dentry); 163 out_unlock: 164 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 165 if (status == 0) { 166 clp->cl_firststate = 1; 167 nfsd4_sync_rec_dir(); 168 } 169 nfs4_reset_creds(original_cred); 170 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); 171 return status; 172 } 173 174 typedef int (recdir_func)(struct dentry *, struct dentry *); 175 176 struct name_list { 177 char name[HEXDIR_LEN]; 178 struct list_head list; 179 }; 180 181 static int 182 nfsd4_build_namelist(void *arg, const char *name, int namlen, 183 loff_t offset, u64 ino, unsigned int d_type) 184 { 185 struct list_head *names = arg; 186 struct name_list *entry; 187 188 if (namlen != HEXDIR_LEN - 1) 189 return 0; 190 entry = kmalloc(sizeof(struct name_list), GFP_KERNEL); 191 if (entry == NULL) 192 return -ENOMEM; 193 memcpy(entry->name, name, HEXDIR_LEN - 1); 194 entry->name[HEXDIR_LEN - 1] = '\0'; 195 list_add(&entry->list, names); 196 return 0; 197 } 198 199 static int 200 nfsd4_list_rec_dir(struct dentry *dir, recdir_func *f) 201 { 202 const struct cred *original_cred; 203 struct file *filp; 204 LIST_HEAD(names); 205 struct name_list *entry; 206 struct dentry *dentry; 207 int status; 208 209 if (!rec_dir_init) 210 return 0; 211 212 status = nfs4_save_creds(&original_cred); 213 if (status < 0) 214 return status; 215 216 filp = dentry_open(dget(dir), mntget(rec_dir.mnt), O_RDONLY, 217 current_cred()); 218 status = PTR_ERR(filp); 219 if (IS_ERR(filp)) 220 goto out; 221 status = vfs_readdir(filp, nfsd4_build_namelist, &names); 222 fput(filp); 223 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); 224 while (!list_empty(&names)) { 225 entry = list_entry(names.next, struct name_list, list); 226 227 dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1); 228 if (IS_ERR(dentry)) { 229 status = PTR_ERR(dentry); 230 break; 231 } 232 status = f(dir, dentry); 233 dput(dentry); 234 if (status) 235 break; 236 list_del(&entry->list); 237 kfree(entry); 238 } 239 mutex_unlock(&dir->d_inode->i_mutex); 240 out: 241 while (!list_empty(&names)) { 242 entry = list_entry(names.next, struct name_list, list); 243 list_del(&entry->list); 244 kfree(entry); 245 } 246 nfs4_reset_creds(original_cred); 247 return status; 248 } 249 250 static int 251 nfsd4_unlink_clid_dir(char *name, int namlen) 252 { 253 struct dentry *dentry; 254 int status; 255 256 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); 257 258 mutex_lock_nested(&rec_dir.dentry->d_inode->i_mutex, I_MUTEX_PARENT); 259 dentry = lookup_one_len(name, rec_dir.dentry, namlen); 260 if (IS_ERR(dentry)) { 261 status = PTR_ERR(dentry); 262 goto out_unlock; 263 } 264 status = -ENOENT; 265 if (!dentry->d_inode) 266 goto out; 267 status = vfs_rmdir(rec_dir.dentry->d_inode, dentry); 268 out: 269 dput(dentry); 270 out_unlock: 271 mutex_unlock(&rec_dir.dentry->d_inode->i_mutex); 272 return status; 273 } 274 275 void 276 nfsd4_remove_clid_dir(struct nfs4_client *clp) 277 { 278 const struct cred *original_cred; 279 int status; 280 281 if (!rec_dir_init || !clp->cl_firststate) 282 return; 283 284 status = mnt_want_write(rec_dir.mnt); 285 if (status) 286 goto out; 287 clp->cl_firststate = 0; 288 289 status = nfs4_save_creds(&original_cred); 290 if (status < 0) 291 goto out; 292 293 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); 294 nfs4_reset_creds(original_cred); 295 if (status == 0) 296 nfsd4_sync_rec_dir(); 297 mnt_drop_write(rec_dir.mnt); 298 out: 299 if (status) 300 printk("NFSD: Failed to remove expired client state directory" 301 " %.*s\n", HEXDIR_LEN, clp->cl_recdir); 302 return; 303 } 304 305 static int 306 purge_old(struct dentry *parent, struct dentry *child) 307 { 308 int status; 309 310 /* note: we currently use this path only for minorversion 0 */ 311 if (nfs4_has_reclaimed_state(child->d_name.name, false)) 312 return 0; 313 314 status = vfs_rmdir(parent->d_inode, child); 315 if (status) 316 printk("failed to remove client recovery directory %s\n", 317 child->d_name.name); 318 /* Keep trying, success or failure: */ 319 return 0; 320 } 321 322 void 323 nfsd4_recdir_purge_old(void) { 324 int status; 325 326 if (!rec_dir_init) 327 return; 328 status = mnt_want_write(rec_dir.mnt); 329 if (status) 330 goto out; 331 status = nfsd4_list_rec_dir(rec_dir.dentry, purge_old); 332 if (status == 0) 333 nfsd4_sync_rec_dir(); 334 mnt_drop_write(rec_dir.mnt); 335 out: 336 if (status) 337 printk("nfsd4: failed to purge old clients from recovery" 338 " directory %s\n", rec_dir.dentry->d_name.name); 339 } 340 341 static int 342 load_recdir(struct dentry *parent, struct dentry *child) 343 { 344 if (child->d_name.len != HEXDIR_LEN - 1) { 345 printk("nfsd4: illegal name %s in recovery directory\n", 346 child->d_name.name); 347 /* Keep trying; maybe the others are OK: */ 348 return 0; 349 } 350 nfs4_client_to_reclaim(child->d_name.name); 351 return 0; 352 } 353 354 int 355 nfsd4_recdir_load(void) { 356 int status; 357 358 status = nfsd4_list_rec_dir(rec_dir.dentry, load_recdir); 359 if (status) 360 printk("nfsd4: failed loading clients from recovery" 361 " directory %s\n", rec_dir.dentry->d_name.name); 362 return status; 363 } 364 365 /* 366 * Hold reference to the recovery directory. 367 */ 368 369 void 370 nfsd4_init_recdir(char *rec_dirname) 371 { 372 const struct cred *original_cred; 373 int status; 374 375 printk("NFSD: Using %s as the NFSv4 state recovery directory\n", 376 rec_dirname); 377 378 BUG_ON(rec_dir_init); 379 380 status = nfs4_save_creds(&original_cred); 381 if (status < 0) { 382 printk("NFSD: Unable to change credentials to find recovery" 383 " directory: error %d\n", 384 status); 385 return; 386 } 387 388 status = kern_path(rec_dirname, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, 389 &rec_dir); 390 if (status) 391 printk("NFSD: unable to find recovery directory %s\n", 392 rec_dirname); 393 394 if (!status) 395 rec_dir_init = 1; 396 nfs4_reset_creds(original_cred); 397 } 398 399 void 400 nfsd4_shutdown_recdir(void) 401 { 402 if (!rec_dir_init) 403 return; 404 rec_dir_init = 0; 405 path_put(&rec_dir); 406 } 407