debugfs/dump.c

   1 /*
   2  * dump.c --- dump the contents of an inode out to a file
   3  *
   4  * Copyright (C) 1994 Theodore Ts'o.  This file may be redistributed
   5  * under the terms of the GNU Public License.
   6  */
   7
   8 #ifndef _GNU_SOURCE
   9 #define _GNU_SOURCE /* for O_LARGEFILE */
  10 #endif
  11
  12 #include "config.h"
  13 #include <stdio.h>
  14 #include <unistd.h>
  15 #include <stdlib.h>
  16 #include <ctype.h>
  17 #include <string.h>
  18 #include <time.h>
  19 #ifdef HAVE_ERRNO_H
  20 #include <errno.h>
  21 #endif
  22 #include <sys/types.h>
  23 #include <sys/stat.h>
  24 #include <fcntl.h>
  25 #include <utime.h>
  26 #ifdef HAVE_GETOPT_H
  27 #include <getopt.h>
  28 #else
  29 extern int optind;
  30 extern char *optarg;
  31 #endif
  32
  33 #include "debugfs.h"
  34
  35 #ifndef O_LARGEFILE
  36 #define O_LARGEFILE 0
  37 #endif
  38
  39 /*
  40  * The mode_xlate function translates a linux mode into a native-OS mode_t.
  41  */
  42 static struct {
  43         __u16 lmask;
  44         mode_t mask;
  45 } mode_table[] = {
  46         { LINUX_S_IRUSR, S_IRUSR },
  47         { LINUX_S_IWUSR, S_IWUSR },
  48         { LINUX_S_IXUSR, S_IXUSR },
  49         { LINUX_S_IRGRP, S_IRGRP },
  50         { LINUX_S_IWGRP, S_IWGRP },
  51         { LINUX_S_IXGRP, S_IXGRP },
  52         { LINUX_S_IROTH, S_IROTH },
  53         { LINUX_S_IWOTH, S_IWOTH },
  54         { LINUX_S_IXOTH, S_IXOTH },
  55         { 0, 0 }
  56 };
  57
  58 static mode_t mode_xlate(__u16 lmode)
  59 {
  60         mode_t  mode = 0;
  61         int     i;
  62
  63         for (i=0; mode_table[i].lmask; i++) {
  64                 if (lmode & mode_table[i].lmask)
  65                         mode |= mode_table[i].mask;
  66         }
  67         return mode;
  68 }
  69
  70 static void fix_perms(const char *cmd, const struct ext2_inode *inode,
  71                       int fd, const char *name)
  72 {
  73         struct utimbuf ut;
  74         int i;
  75
  76         if (fd != -1)
  77                 i = fchmod(fd, mode_xlate(inode->i_mode));
  78         else
  79                 i = chmod(name, mode_xlate(inode->i_mode));
  80         if (i == -1)
  81                 com_err(cmd, errno, "while setting permissions of %s", name);
  82
  83 #ifndef HAVE_FCHOWN
  84         i = chown(name, inode->i_uid, inode->i_gid);
  85 #else
  86         if (fd != -1)
  87                 i = fchown(fd, inode->i_uid, inode->i_gid);
  88         else
  89                 i = chown(name, inode->i_uid, inode->i_gid);
  90 #endif
  91         if (i == -1)
  92                 com_err(cmd, errno, "while changing ownership of %s", name);
  93
  94         if (fd != -1)
  95                 close(fd);
  96
  97         ut.actime = inode->i_atime;
  98         ut.modtime = inode->i_mtime;
  99         if (utime(name, &ut) == -1)
 100                 com_err(cmd, errno, "while setting times of %s", name);
 101 }
 102
 103 static void dump_file(const char *cmdname, ext2_ino_t ino, int fd,
 104                       int preserve, char *outname)
 105 {
 106         errcode_t retval;
 107         struct ext2_inode       inode;
 108         char            *buf = 0;
 109         ext2_file_t     e2_file;
 110         int             nbytes;
 111         unsigned int    got, blocksize = current_fs->blocksize;
 112
 113         if (debugfs_read_inode(ino, &inode, cmdname))
 114                 return;
 115
 116         retval = ext2fs_file_open(current_fs, ino, 0, &e2_file);
 117         if (retval) {
 118                 com_err(cmdname, retval, "while opening ext2 file");
 119                 return;
 120         }
 121         retval = ext2fs_get_mem(blocksize, &buf);
 122         if (retval) {
 123                 com_err(cmdname, retval, "while allocating memory");
 124                 return;
 125         }
 126         while (1) {
 127                 retval = ext2fs_file_read(e2_file, buf, blocksize, &got);
 128                 if (retval)
 129                         com_err(cmdname, retval, "while reading ext2 file");
 130                 if (got == 0)
 131                         break;
 132                 nbytes = write(fd, buf, got);
 133                 if ((unsigned) nbytes != got)
 134                         com_err(cmdname, errno, "while writing file");
 135         }
 136         if (buf)
 137                 ext2fs_free_mem(&buf);
 138         retval = ext2fs_file_close(e2_file);
 139         if (retval) {
 140                 com_err(cmdname, retval, "while closing ext2 file");
 141                 return;
 142         }
 143
 144         if (preserve)
 145                 fix_perms("dump_file", &inode, fd, outname);
 146
 147         return;
 148 }
 149
 150 void do_dump(int argc, char **argv)
 151 {
 152         ext2_ino_t      inode;
 153         int             fd;
 154         int             c;
 155         int             preserve = 0;
 156         char            *in_fn, *out_fn;
 157
 158         reset_getopt();
 159         while ((c = getopt (argc, argv, "p")) != EOF) {
 160                 switch (c) {
 161                 case 'p':
 162                         preserve++;
 163                         break;
 164                 default:
 165                 print_usage:
 166                         com_err(argv[0], 0, "Usage: dump_inode [-p] "
 167                                 "<file> <output_file>");
 168                         return;
 169                 }
 170         }
 171         if (optind != argc-2)
 172                 goto print_usage;
 173
 174         if (check_fs_open(argv[0]))
 175                 return;
 176
 177         in_fn = argv[optind];
 178         out_fn = argv[optind+1];
 179
 180         inode = string_to_inode(in_fn);
 181         if (!inode)
 182                 return;
 183
 184         fd = open(out_fn, O_CREAT | O_WRONLY | O_TRUNC | O_LARGEFILE, 0666);
 185         if (fd < 0) {
 186                 com_err(argv[0], errno, "while opening %s for dump_inode",
 187                         out_fn);
 188                 return;
 189         }
 190
 191         dump_file(argv[0], inode, fd, preserve, out_fn);
 192         if (close(fd) != 0) {
 193                 com_err(argv[0], errno, "while closing %s for dump_inode",
 194                         out_fn);
 195                 return;
 196         }
 197
 198         return;
 199 }
 200
 201 static void rdump_symlink(ext2_ino_t ino, struct ext2_inode *inode,
 202                           const char *fullname)
 203 {
 204         ext2_file_t e2_file;
 205         char *buf;
 206         errcode_t retval;
 207
 208         buf = malloc(inode->i_size + 1);
 209         if (!buf) {
 210                 com_err("rdump", errno, "while allocating for symlink");
 211                 goto errout;
 212         }
 213
 214         /* Apparently, this is the right way to detect and handle fast
 215          * symlinks; see do_stat() in debugfs.c. */
 216         if (inode->i_blocks == 0)
 217                 strcpy(buf, (char *) inode->i_block);
 218         else {
 219                 unsigned bytes = inode->i_size;
 220                 char *p = buf;
 221                 retval = ext2fs_file_open(current_fs, ino, 0, &e2_file);
 222                 if (retval) {
 223                         com_err("rdump", retval, "while opening symlink");
 224                         goto errout;
 225                 }
 226                 for (;;) {
 227                         unsigned int got;
 228                         retval = ext2fs_file_read(e2_file, p, bytes, &got);
 229                         if (retval) {
 230                                 com_err("rdump", retval, "while reading symlink");
 231                                 goto errout;
 232                         }
 233                         bytes -= got;
 234                         p += got;
 235                         if (got == 0 || bytes == 0)
 236                                 break;
 237                 }
 238                 buf[inode->i_size] = 0;
 239                 retval = ext2fs_file_close(e2_file);
 240                 if (retval)
 241                         com_err("rdump", retval, "while closing symlink");
 242         }
 243
 244         if (symlink(buf, fullname) == -1) {
 245                 com_err("rdump", errno, "while creating symlink %s -> %s", buf, fullname);
 246                 goto errout;
 247         }
 248
 249 errout:
 250         free(buf);
 251 }
 252
 253 static int rdump_dirent(struct ext2_dir_entry *, int, int, char *, void *);
 254
 255 static void rdump_inode(ext2_ino_t ino, struct ext2_inode *inode,
 256                         const char *name, const char *dumproot)
 257 {
 258         char *fullname;
 259
 260         /* There are more efficient ways to do this, but this method
 261          * requires only minimal debugging. */
 262         fullname = malloc(strlen(dumproot) + strlen(name) + 2);
 263         if (!fullname) {
 264                 com_err("rdump", errno, "while allocating memory");
 265                 return;
 266         }
 267         sprintf(fullname, "%s/%s", dumproot, name);
 268
 269         if (LINUX_S_ISLNK(inode->i_mode))
 270                 rdump_symlink(ino, inode, fullname);
 271         else if (LINUX_S_ISREG(inode->i_mode)) {
 272                 int fd;
 273                 fd = open(fullname, O_WRONLY | O_CREAT | O_TRUNC | O_LARGEFILE, S_IRWXU);
 274                 if (fd == -1) {
 275                         com_err("rdump", errno, "while dumping %s", fullname);
 276                         goto errout;
 277                 }
 278                 dump_file("rdump", ino, fd, 1, fullname);
 279                 if (close(fd) != 0) {
 280                         com_err("rdump", errno, "while dumping %s", fullname);
 281                         goto errout;
 282                 }
 283         }
 284         else if (LINUX_S_ISDIR(inode->i_mode) && strcmp(name, ".") && strcmp(name, "..")) {
 285                 errcode_t retval;
 286
 287                 /* Create the directory with 0700 permissions, because we
 288                  * expect to have to create entries it.  Then fix its perms
 289                  * once we've done the traversal. */
 290                 if (mkdir(fullname, S_IRWXU) == -1) {
 291                         com_err("rdump", errno, "while making directory %s", fullname);
 292                         goto errout;
 293                 }
 294
 295                 retval = ext2fs_dir_iterate(current_fs, ino, 0, 0,
 296                                             rdump_dirent, (void *) fullname);
 297                 if (retval)
 298                         com_err("rdump", retval, "while dumping %s", fullname);
 299
 300                 fix_perms("rdump", inode, -1, fullname);
 301         }
 302         /* else do nothing (don't dump device files, sockets, fifos, etc.) */
 303
 304 errout:
 305         free(fullname);
 306 }
 307
 308 static int rdump_dirent(struct ext2_dir_entry *dirent,
 309                         int offset EXT2FS_ATTR((unused)),
 310                         int blocksize EXT2FS_ATTR((unused)),
 311                         char *buf EXT2FS_ATTR((unused)), void *private)
 312 {
 313         char name[EXT2_NAME_LEN + 1];
 314         int thislen;
 315         const char *dumproot = private;
 316         struct ext2_inode inode;
 317
 318         thislen = dirent->name_len & 0xFF;
 319         strncpy(name, dirent->name, thislen);
 320         name[thislen] = 0;
 321
 322         if (debugfs_read_inode(dirent->inode, &inode, name))
 323                 return 0;
 324
 325         rdump_inode(dirent->inode, &inode, name, dumproot);
 326
 327         return 0;
 328 }
 329
 330 void do_rdump(int argc, char **argv)
 331 {
 332         ext2_ino_t ino;
 333         struct ext2_inode inode;
 334         struct stat st;
 335         int i;
 336         char *p;
 337
 338         if (common_args_process(argc, argv, 3, 3, "rdump",
 339                                 "<directory> <native directory>", 0))
 340                 return;
 341
 342         ino = string_to_inode(argv[1]);
 343         if (!ino)
 344                 return;
 345
 346         /* Ensure ARGV[2] is a directory. */
 347         i = stat(argv[2], &st);
 348         if (i == -1) {
 349                 com_err("rdump", errno, "while statting %s", argv[2]);
 350                 return;
 351         }
 352         if (!S_ISDIR(st.st_mode)) {
 353                 com_err("rdump", 0, "%s is not a directory", argv[2]);
 354                 return;
 355         }
 356
 357         if (debugfs_read_inode(ino, &inode, argv[1]))
 358                 return;
 359
 360         p = strrchr(argv[1], '/');
 361         if (p)
 362                 p++;
 363         else
 364                 p = argv[1];
 365
 366         rdump_inode(ino, &inode, p, argv[2]);
 367 }
 368
 369 void do_cat(int argc, char **argv)
 370 {
 371         ext2_ino_t      inode;
 372
 373         if (common_inode_args_process(argc, argv, &inode, 0))
 374                 return;
 375
 376         fflush(stdout);
 377         fflush(stderr);
 378         dump_file(argv[0], inode, 1, 0, argv[2]);
 379
 380         return;
 381 }
 382