restore/xattr.c

   1 /*
   2  * Copyright (c) 1999-2004
   3  *      Stelian Pop <stelian@popies.net>, 1999-2004
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #ifndef lint
  31 static const char rcsid[] =
  32         "$Id: xattr.c,v 1.1 2005/05/02 15:10:47 stelian Exp $";
  33 #endif /* not lint */
  34
  35 #include <config.h>
  36 #include <compatlfs.h>
  37 #include <compaterr.h>
  38 #include <sys/types.h>
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41 #include <string.h>
  42 #include <unistd.h>
  43 #include <errno.h>
  44 #include <bsdcompat.h>
  45 #include <protocols/dumprestore.h>
  46 #include "restore.h"
  47 #include "extern.h"
  48 #include "pathnames.h"
  49
  50 /*
  51  * Data structures below taken from the kernel
  52  */
  53
  54 /* Maximum number of references to one attribute block */
  55 #define EXT2_XATTR_REFCOUNT_MAX         1024
  56
  57 /* Name indexes */
  58 #define EXT2_XATTR_INDEX_MAX                    10
  59 #define EXT2_XATTR_INDEX_USER                   1
  60 #define EXT2_XATTR_INDEX_POSIX_ACL_ACCESS       2
  61 #define EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT      3
  62 #define EXT2_XATTR_INDEX_TRUSTED                4
  63 #define EXT2_XATTR_INDEX_LUSTRE                 5
  64 #define EXT2_XATTR_INDEX_SECURITY               6
  65
  66 struct ext2_xattr_header {
  67         u_int32_t       h_magic;        /* magic number for identification */
  68         u_int32_t       h_refcount;     /* reference count */
  69         u_int32_t       h_blocks;       /* number of disk blocks used */
  70         u_int32_t       h_hash;         /* hash value of all attributes */
  71         u_int32_t       h_reserved[4];  /* zero right now */
  72 };
  73
  74 struct ext3_xattr_ibody_header {
  75         u_int32_t       h_magic;        /* magic number for identification */
  76 };
  77
  78 struct ext2_xattr_entry {
  79         u_char          e_name_len;     /* length of name */
  80         u_char          e_name_index;   /* attribute name index */
  81         u_int16_t       e_value_offs;   /* offset in disk block of value */
  82         u_int32_t       e_value_block;  /* disk block attribute is stored on (n/i) */
  83         u_int32_t       e_value_size;   /* size of attribute value */
  84         u_int32_t       e_hash;         /* hash value of name and value */
  85         char            e_name[0];      /* attribute name */
  86 };
  87
  88 #define EXT2_XATTR_PAD_BITS             2
  89 #define EXT2_XATTR_PAD          (1<<EXT2_XATTR_PAD_BITS)
  90 #define EXT2_XATTR_ROUND                (EXT2_XATTR_PAD-1)
  91 #define EXT2_XATTR_LEN(name_len) \
  92         (((name_len) + EXT2_XATTR_ROUND + \
  93         sizeof(struct ext2_xattr_entry)) & ~EXT2_XATTR_ROUND)
  94 #define EXT2_XATTR_NEXT(entry) \
  95         ( (struct ext2_xattr_entry *)( \
  96           (char *)(entry) + EXT2_XATTR_LEN((entry)->e_name_len)) )
  97 #define EXT3_XATTR_SIZE(size) \
  98         (((size) + EXT2_XATTR_ROUND) & ~EXT2_XATTR_ROUND)
  99
 100 #define HDR(buffer) ((struct ext2_xattr_header *)(buffer))
 101 #define ENTRY(ptr) ((struct ext2_xattr_entry *)(ptr))
 102 #define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
 103
 104 #define BFIRST(buffer) ENTRY(HDR(buffer)+1)
 105 #define IFIRST(buffer) ENTRY(((struct ext3_xattr_ibody_header *)(buffer))+1)
 106
 107 #define FIRST_ENTRY(buffer) \
 108         ((HDR(buffer)->h_magic == EXT2_XATTR_MAGIC2) ? \
 109                 IFIRST(buffer) : \
 110                 BFIRST(buffer))
 111
 112 /*
 113  * On-block xattr value offsets start at the beginning of the block, but
 114  * on-inode xattr value offsets start after the initial header
 115  * (ext3_xattr_ibody_header).
 116  */
 117 #define VALUE_OFFSET(buffer, entry) \
 118         (((HDR(buffer)->h_magic == EXT2_XATTR_MAGIC2) ? \
 119                 (entry)->e_value_offs + sizeof(struct ext3_xattr_ibody_header) : \
 120                 (entry)->e_value_offs))
 121
 122 /*
 123  * xattr syscalls do not exist yet in libc, get our own copy here,
 124  * taken from libattr.
 125  */
 126 #if defined (__i386__)
 127 # define HAVE_XATTR_SYSCALLS 1
 128 # define __NR_lsetxattr         227
 129 # define __NR_lgetxattr         230
 130 # define __NR_llistxattr        233
 131 #elif defined (__sparc__)
 132 # define HAVE_XATTR_SYSCALLS 1
 133 # define __NR_lsetxattr         170
 134 # define __NR_lgetxattr         173
 135 # define __NR_llistxattr        179
 136 #elif defined (__ia64__)
 137 # define HAVE_XATTR_SYSCALLS 1
 138 # define __NR_lsetxattr         1218
 139 # define __NR_lgetxattr         1221
 140 # define __NR_llistxattr        1224
 141 #elif defined (__powerpc__)
 142 # define HAVE_XATTR_SYSCALLS 1
 143 # define __NR_lsetxattr         210
 144 # define __NR_lgetxattr         213
 145 # define __NR_llistxattr        216
 146 #elif defined (__x86_64__)
 147 # define HAVE_XATTR_SYSCALLS 1
 148 # define __NR_lsetxattr         189
 149 # define __NR_lgetxattr         192
 150 # define __NR_llistxattr        195
 151 #elif defined (__s390__)
 152 # define HAVE_XATTR_SYSCALLS 1
 153 # define __NR_lsetxattr         225
 154 # define __NR_lgetxattr         228
 155 # define __NR_llistxattr        231
 156 #elif defined (__arm__)
 157 # define HAVE_XATTR_SYSCALLS 1
 158 # define __NR_SYSCALL_BASE 0x900000
 159 # define __NR_lsetxattr         (__NR_SYSCALL_BASE+227)
 160 # define __NR_lgetxattr         (__NR_SYSCALL_BASE+230)
 161 # define __NR_llistxattr        (__NR_SYSCALL_BASE+233)
 162 #elif defined (__mips64__)
 163 # define HAVE_XATTR_SYSCALLS 1
 164 # define __NR_Linux 5000
 165 # define __NR_lsetxattr         (__NR_Linux + 218)
 166 # define __NR_lgetxattr         (__NR_Linux + 221)
 167 # define __NR_llistxattr        (__NR_Linux + 224)
 168 #elif defined (__mips__)
 169 # define HAVE_XATTR_SYSCALLS 1
 170 # define __NR_Linux 4000
 171 # define __NR_lsetxattr         (__NR_Linux + 225)
 172 # define __NR_lgetxattr         (__NR_Linux + 228)
 173 # define __NR_llistxattr        (__NR_Linux + 231)
 174 #elif defined (__alpha__)
 175 # define HAVE_XATTR_SYSCALLS 1
 176 # define __NR_lsetxattr         383
 177 # define __NR_lgetxattr         386
 178 # define __NR_llistxattr        389
 179 #elif defined (__mc68000__)
 180 # define HAVE_XATTR_SYSCALLS 1
 181 # define __NR_lsetxattr         224
 182 # define __NR_lgetxattr         227
 183 # define __NR_llistxattr        230
 184 #else
 185 # warning "Extended attribute syscalls undefined for this architecture"
 186 # define HAVE_XATTR_SYSCALLS 0
 187 #endif
 188
 189 #if HAVE_XATTR_SYSCALLS
 190 # define SYSCALL(args...)       syscall(args)
 191 #else
 192 # define SYSCALL(args...)       ( errno = ENOSYS, -1 )
 193 #endif
 194
 195 static int lsetxattr __P((const char *, const char *, void *, size_t, int));
 196 static ssize_t lgetxattr __P((const char *, const char *, void *, size_t));
 197 static ssize_t llistxattr __P((const char *, char *, size_t));
 198 static int xattr_cb_list __P((char *, char *, int, void *));
 199 static int xattr_cb_set __P((char *, char *, int, void *));
 200 static int xattr_cb_compare __P((char *, char *, int, void *));
 201 static int xattr_verify __P((char *));
 202 static int xattr_count __P((char *, int *));
 203 static int xattr_walk __P((char *, int (*)(char *, char *, int, void *), void *));
 204
 205 static int
 206 lsetxattr(const char *path, const char *name, void *value, size_t size, int flags)
 207 {
 208         return SYSCALL(__NR_lsetxattr, path, name, value, size, flags);
 209 }
 210
 211 static ssize_t
 212 lgetxattr(const char *path, const char *name, void *value, size_t size)
 213 {
 214         return SYSCALL(__NR_lgetxattr, path, name, value, size);
 215 }
 216
 217 static ssize_t
 218 llistxattr(const char *path, char *list, size_t size)
 219 {
 220         return SYSCALL(__NR_llistxattr, path, list, size);
 221 }
 222
 223 /*
 224  * Dump code starts here :)
 225  */
 226
 227 static int
 228 xattr_cb_list(char *name, char *value, int valuelen, void *private)
 229 {
 230         value[valuelen] = '\0';
 231         printf("EA: %s:%s\n", name, value);
 232
 233         return GOOD;
 234 }
 235
 236 static int
 237 xattr_cb_set(char *name, char *value, int valuelen, void *private)
 238 {
 239         char *path = (char *)private;
 240
 241         if (lsetxattr(path, name, value, valuelen, 0) < 0) {
 242                 warn("lsetxattr %s failed", path);
 243                 return FAIL;
 244         }
 245         return GOOD;
 246 }
 247
 248 static int
 249 xattr_cb_compare(char *name, char *value, int valuelen, void *private)
 250 {
 251         char *path = (char *)private;
 252         char valuef[XATTR_MAXSIZE];
 253         int valuesz;
 254
 255         valuesz = lgetxattr(path, name, valuef, XATTR_MAXSIZE);
 256         if (valuesz < 0) {
 257                 warn("%s: lgetxattr failed\n", path);
 258                 return FAIL;
 259         }
 260
 261         if (valuesz != valuelen) {
 262                 fprintf(stderr, "%s: EA %s value changed\n", path, value);
 263                 return FAIL;
 264         }
 265
 266         if (memcmp(value, valuef, valuelen)) {
 267                 fprintf(stderr, "%s: EA %s value changed\n", path, value);
 268                 return FAIL;
 269         }
 270
 271         return GOOD;
 272 }
 273
 274 static int
 275 xattr_verify(char *buffer)
 276 {
 277         struct ext2_xattr_entry *entry;
 278         char *end;
 279
 280         end = buffer + XATTR_MAXSIZE;
 281
 282         if (Bcvt)
 283                 swabst("4i", (u_char *)buffer);
 284
 285         if (HDR(buffer)->h_magic != EXT2_XATTR_MAGIC &&
 286             HDR(buffer)->h_magic != EXT2_XATTR_MAGIC2) {
 287                 fprintf(stderr, "error in EA block 1\n");
 288                 fprintf(stderr, "magic = %x\n", HDR(buffer)->h_magic);
 289
 290                 return FAIL;
 291         }
 292
 293         /* check the on-disk data structure */
 294         entry = FIRST_ENTRY(buffer);
 295         if (Bcvt)
 296                 swabst("2b1s3i", (u_char *)entry);
 297         while (!IS_LAST_ENTRY(entry)) {
 298                 struct ext2_xattr_entry *next = EXT2_XATTR_NEXT(entry);
 299
 300                 if ((char *)next >= end) {
 301                         fprintf(stderr, "error in EA block\n");
 302                         return FAIL;
 303                 }
 304                 entry = next;
 305                 if (Bcvt)
 306                         swabst("2b1s3i", (u_char *)entry);
 307         }
 308         return GOOD;
 309 }
 310
 311 static int
 312 xattr_count(char *buffer, int *count)
 313 {
 314         struct ext2_xattr_entry *entry;
 315         int result = 0;
 316
 317         /* list the attribute names */
 318         for (entry = FIRST_ENTRY(buffer); !IS_LAST_ENTRY(entry);
 319              entry = EXT2_XATTR_NEXT(entry))
 320                 result++;
 321
 322         *count = result;
 323         return GOOD;
 324 }
 325
 326 static int
 327 xattr_walk(char *buffer, int (*xattr_cb)(char *, char *, int, void *), void *private)
 328 {
 329         struct ext2_xattr_entry *entry;
 330
 331         /* list the attribute names */
 332         for (entry = FIRST_ENTRY(buffer); !IS_LAST_ENTRY(entry);
 333              entry = EXT2_XATTR_NEXT(entry)) {
 334                 char name[XATTR_MAXSIZE], value[XATTR_MAXSIZE];
 335                 int off;
 336
 337                 switch (entry->e_name_index) {
 338                 case EXT2_XATTR_INDEX_USER:
 339                         strcpy(name, "user.");
 340                         break;
 341                 case EXT2_XATTR_INDEX_POSIX_ACL_ACCESS:
 342                 case EXT2_XATTR_INDEX_POSIX_ACL_DEFAULT:
 343                         strcpy(name, "system.");
 344                         break;
 345                 case EXT2_XATTR_INDEX_TRUSTED:
 346                         strcpy(name, "trusted.");
 347                         break;
 348                 case EXT2_XATTR_INDEX_LUSTRE:
 349                         strcpy(name, "lustre.");
 350                         break;
 351                 case EXT2_XATTR_INDEX_SECURITY:
 352                         strcpy(name, "security.");
 353                         break;
 354                 default:
 355                         fprintf(stderr, "Unknown EA index\n");
 356                         return FAIL;
 357                 }
 358
 359                 off = strlen(name);
 360                 memcpy(name + off, entry->e_name, entry->e_name_len);
 361                 name[off + entry->e_name_len] = '\0';
 362
 363
 364                 memcpy(value, buffer + VALUE_OFFSET(buffer, entry), entry->e_value_size);
 365
 366                 if (xattr_cb(name, value, entry->e_value_size, private) != GOOD)
 367                         return FAIL;
 368         }
 369
 370         return GOOD;
 371 }
 372
 373 int
 374 xattr_compare(char *path, char *buffer)
 375 {
 376         int countf, countt;
 377         char *names = NULL, *end_names, *name;
 378
 379         countf = llistxattr(path, NULL, 0);
 380         if (countf < 0) {
 381                 warn("%s: llistxattr failed", path);
 382                 return FAIL;
 383         }
 384
 385         names = malloc(countf + 1);
 386         if (!names) {
 387                 warn("%s: llistxattr failed", path);
 388                 return FAIL;
 389         }
 390
 391         countf = llistxattr(path, names, countf);
 392         if (countf < 0) {
 393                 warn("%s: llistxattr failed", path);
 394                 free(names);
 395                 return FAIL;
 396         }
 397
 398         names[countf] = '\0';
 399         end_names = names + countf;
 400
 401         countf = 0;
 402         for (name = names; name != end_names; name = strchr(name, '\0') + 1) {
 403                 if (!*name)
 404                         continue;
 405                 countf++;
 406         }
 407
 408         free(names);
 409
 410         if (buffer) {
 411                 if (xattr_verify(buffer) == FAIL)
 412                         return FAIL;
 413
 414                 if (xattr_count(buffer, &countt) == FAIL)
 415                         return FAIL;
 416         }
 417         else
 418                 countt = 0;
 419
 420         if (countf != countt) {
 421                 fprintf(stderr, "%s: EA count changed from %d to %d\n", path, countt, countf);
 422                 return FAIL;
 423         }
 424
 425         if (!buffer)
 426                 return GOOD;
 427
 428         return xattr_walk(buffer, xattr_cb_compare, path);
 429 }
 430
 431 int
 432 xattr_extract(char *path, char *buffer)
 433 {
 434         if (dflag) {
 435                 fprintf(stderr, "xattr_extract(%s)\n", path);
 436                 xattr_walk(buffer, xattr_cb_list, NULL);
 437         }
 438
 439         if (xattr_verify(buffer) == FAIL)
 440                 return FAIL;
 441
 442         return xattr_walk(buffer, xattr_cb_set, path);
 443 }
 444