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 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 int 120 nfsd4_create_clid_dir(struct nfs4_client *clp) 121 { 122 const struct cred *original_cred; 123 char *dname = clp->cl_recdir; 124 struct dentry *dir, *dentry; 125 int status; 126 127 dprintk("NFSD: nfsd4_create_clid_dir for \"%s\"\n", dname); 128 129 if (!rec_file || clp->cl_firststate) 130 return 0; 131 132 status = nfs4_save_creds(&original_cred); 133 if (status < 0) 134 return status; 135 136 dir = rec_file->f_path.dentry; 137 /* lock the parent */ 138 mutex_lock(&dir->d_inode->i_mutex); 139 140 dentry = lookup_one_len(dname, dir, HEXDIR_LEN-1); 141 if (IS_ERR(dentry)) { 142 status = PTR_ERR(dentry); 143 goto out_unlock; 144 } 145 status = -EEXIST; 146 if (dentry->d_inode) { 147 dprintk("NFSD: nfsd4_create_clid_dir: DIRECTORY EXISTS\n"); 148 goto out_put; 149 } 150 status = mnt_want_write(rec_file->f_path.mnt); 151 if (status) 152 goto out_put; 153 status = vfs_mkdir(dir->d_inode, dentry, S_IRWXU); 154 mnt_drop_write(rec_file->f_path.mnt); 155 out_put: 156 dput(dentry); 157 out_unlock: 158 mutex_unlock(&dir->d_inode->i_mutex); 159 if (status == 0) { 160 clp->cl_firststate = 1; 161 vfs_fsync(rec_file, 0); 162 } 163 nfs4_reset_creds(original_cred); 164 dprintk("NFSD: nfsd4_create_clid_dir returns %d\n", status); 165 return status; 166 } 167 168 typedef int (recdir_func)(struct dentry *, struct dentry *); 169 170 struct name_list { 171 char name[HEXDIR_LEN]; 172 struct list_head list; 173 }; 174 175 static int 176 nfsd4_build_namelist(void *arg, const char *name, int namlen, 177 loff_t offset, u64 ino, unsigned int d_type) 178 { 179 struct list_head *names = arg; 180 struct name_list *entry; 181 182 if (namlen != HEXDIR_LEN - 1) 183 return 0; 184 entry = kmalloc(sizeof(struct name_list), GFP_KERNEL); 185 if (entry == NULL) 186 return -ENOMEM; 187 memcpy(entry->name, name, HEXDIR_LEN - 1); 188 entry->name[HEXDIR_LEN - 1] = '\0'; 189 list_add(&entry->list, names); 190 return 0; 191 } 192 193 static int 194 nfsd4_list_rec_dir(recdir_func *f) 195 { 196 const struct cred *original_cred; 197 struct dentry *dir = rec_file->f_path.dentry; 198 LIST_HEAD(names); 199 int status; 200 201 status = nfs4_save_creds(&original_cred); 202 if (status < 0) 203 return status; 204 205 status = vfs_llseek(rec_file, 0, SEEK_SET); 206 if (status < 0) { 207 nfs4_reset_creds(original_cred); 208 return status; 209 } 210 211 status = vfs_readdir(rec_file, nfsd4_build_namelist, &names); 212 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); 213 while (!list_empty(&names)) { 214 struct name_list *entry; 215 entry = list_entry(names.next, struct name_list, list); 216 if (!status) { 217 struct dentry *dentry; 218 dentry = lookup_one_len(entry->name, dir, HEXDIR_LEN-1); 219 if (IS_ERR(dentry)) { 220 status = PTR_ERR(dentry); 221 break; 222 } 223 status = f(dir, dentry); 224 dput(dentry); 225 } 226 list_del(&entry->list); 227 kfree(entry); 228 } 229 mutex_unlock(&dir->d_inode->i_mutex); 230 nfs4_reset_creds(original_cred); 231 return status; 232 } 233 234 static int 235 nfsd4_unlink_clid_dir(char *name, int namlen) 236 { 237 struct dentry *dir, *dentry; 238 int status; 239 240 dprintk("NFSD: nfsd4_unlink_clid_dir. name %.*s\n", namlen, name); 241 242 dir = rec_file->f_path.dentry; 243 mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); 244 dentry = lookup_one_len(name, dir, namlen); 245 if (IS_ERR(dentry)) { 246 status = PTR_ERR(dentry); 247 goto out_unlock; 248 } 249 status = -ENOENT; 250 if (!dentry->d_inode) 251 goto out; 252 status = vfs_rmdir(dir->d_inode, dentry); 253 out: 254 dput(dentry); 255 out_unlock: 256 mutex_unlock(&dir->d_inode->i_mutex); 257 return status; 258 } 259 260 void 261 nfsd4_remove_clid_dir(struct nfs4_client *clp) 262 { 263 const struct cred *original_cred; 264 int status; 265 266 if (!rec_file || !clp->cl_firststate) 267 return; 268 269 status = mnt_want_write(rec_file->f_path.mnt); 270 if (status) 271 goto out; 272 clp->cl_firststate = 0; 273 274 status = nfs4_save_creds(&original_cred); 275 if (status < 0) 276 goto out; 277 278 status = nfsd4_unlink_clid_dir(clp->cl_recdir, HEXDIR_LEN-1); 279 nfs4_reset_creds(original_cred); 280 if (status == 0) 281 vfs_fsync(rec_file, 0); 282 mnt_drop_write(rec_file->f_path.mnt); 283 out: 284 if (status) 285 printk("NFSD: Failed to remove expired client state directory" 286 " %.*s\n", HEXDIR_LEN, clp->cl_recdir); 287 return; 288 } 289 290 static int 291 purge_old(struct dentry *parent, struct dentry *child) 292 { 293 int status; 294 295 if (nfs4_has_reclaimed_state(child->d_name.name, false)) 296 return 0; 297 298 status = vfs_rmdir(parent->d_inode, child); 299 if (status) 300 printk("failed to remove client recovery directory %s\n", 301 child->d_name.name); 302 /* Keep trying, success or failure: */ 303 return 0; 304 } 305 306 void 307 nfsd4_recdir_purge_old(void) { 308 int status; 309 310 if (!rec_file) 311 return; 312 status = mnt_want_write(rec_file->f_path.mnt); 313 if (status) 314 goto out; 315 status = nfsd4_list_rec_dir(purge_old); 316 if (status == 0) 317 vfs_fsync(rec_file, 0); 318 mnt_drop_write(rec_file->f_path.mnt); 319 out: 320 if (status) 321 printk("nfsd4: failed to purge old clients from recovery" 322 " directory %s\n", rec_file->f_path.dentry->d_name.name); 323 } 324 325 static int 326 load_recdir(struct dentry *parent, struct dentry *child) 327 { 328 if (child->d_name.len != HEXDIR_LEN - 1) { 329 printk("nfsd4: illegal name %s in recovery directory\n", 330 child->d_name.name); 331 /* Keep trying; maybe the others are OK: */ 332 return 0; 333 } 334 nfs4_client_to_reclaim(child->d_name.name); 335 return 0; 336 } 337 338 int 339 nfsd4_recdir_load(void) { 340 int status; 341 342 if (!rec_file) 343 return 0; 344 345 status = nfsd4_list_rec_dir(load_recdir); 346 if (status) 347 printk("nfsd4: failed loading clients from recovery" 348 " directory %s\n", rec_file->f_path.dentry->d_name.name); 349 return status; 350 } 351 352 /* 353 * Hold reference to the recovery directory. 354 */ 355 356 void 357 nfsd4_init_recdir(char *rec_dirname) 358 { 359 const struct cred *original_cred; 360 int status; 361 362 printk("NFSD: Using %s as the NFSv4 state recovery directory\n", 363 rec_dirname); 364 365 BUG_ON(rec_file); 366 367 status = nfs4_save_creds(&original_cred); 368 if (status < 0) { 369 printk("NFSD: Unable to change credentials to find recovery" 370 " directory: error %d\n", 371 status); 372 return; 373 } 374 375 rec_file = filp_open(rec_dirname, O_RDONLY | O_DIRECTORY, 0); 376 if (IS_ERR(rec_file)) { 377 printk("NFSD: unable to find recovery directory %s\n", 378 rec_dirname); 379 rec_file = NULL; 380 } 381 382 nfs4_reset_creds(original_cred); 383 } 384 385 void 386 nfsd4_shutdown_recdir(void) 387 { 388 if (!rec_file) 389 return; 390 fput(rec_file); 391 rec_file = NULL; 392 } 393