contrib/libarchive-1.3.1/tar/util.c

   1 /*-
   2  * Copyright (c) 2003-2004 Tim Kientzle
   3  * All rights reserved.
   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  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
  16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  18  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
  19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  25  */
  26
  27 #include "bsdtar_platform.h"
  28 __FBSDID("$FreeBSD: src/usr.bin/tar/util.c,v 1.14 2006/03/21 17:03:51 kientzle Exp $");
  29
  30 #include <sys/stat.h>
  31 #include <sys/types.h>  /* Linux doesn't define mode_t, etc. in sys/stat.h. */
  32 #include <ctype.h>
  33 #include <errno.h>
  34 #include <stdarg.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 #include "bsdtar.h"
  40
  41 static void     bsdtar_vwarnc(struct bsdtar *, int code,
  42                     const char *fmt, va_list ap);
  43
  44 /*
  45  * Print a string, taking care with any non-printable characters.
  46  */
  47
  48 void
  49 safe_fprintf(FILE *f, const char *fmt, ...)
  50 {
  51         char *buff;
  52         char *buff_heap;
  53         int buff_length;
  54         int length;
  55         va_list ap;
  56         char *p;
  57         unsigned i;
  58         char buff_stack[256];
  59         char copy_buff[256];
  60
  61         /* Use a stack-allocated buffer if we can, for speed and safety. */
  62         buff_heap = NULL;
  63         buff_length = sizeof(buff_stack);
  64         buff = buff_stack;
  65
  66         va_start(ap, fmt);
  67         length = vsnprintf(buff, buff_length, fmt, ap);
  68         va_end(ap);
  69         /* If the result is too large, allocate a buffer on the heap. */
  70         if (length >= buff_length) {
  71                 buff_length = length+1;
  72                 buff_heap = malloc(buff_length);
  73                 /* Failsafe: use the truncated string if malloc fails. */
  74                 if (buff_heap != NULL) {
  75                         buff = buff_heap;
  76                         va_start(ap, fmt);
  77                         length = vsnprintf(buff, buff_length, fmt, ap);
  78                         va_end(ap);
  79                 }
  80         }
  81
  82         /* Write data, expanding unprintable characters. */
  83         p = buff;
  84         i = 0;
  85         while (*p != '\0') {
  86                 unsigned char c = *p++;
  87
  88                 if (isprint(c) && c != '\\')
  89                         copy_buff[i++] = c;
  90                 else {
  91                         copy_buff[i++] = '\\';
  92                         switch (c) {
  93                         case '\a': copy_buff[i++] = 'a'; break;
  94                         case '\b': copy_buff[i++] = 'b'; break;
  95                         case '\f': copy_buff[i++] = 'f'; break;
  96                         case '\n': copy_buff[i++] = 'n'; break;
  97 #if '\r' != '\n'
  98                         /* On some platforms, \n and \r are the same. */
  99                         case '\r': copy_buff[i++] = 'r'; break;
 100 #endif
 101                         case '\t': copy_buff[i++] = 't'; break;
 102                         case '\v': copy_buff[i++] = 'v'; break;
 103                         case '\\': copy_buff[i++] = '\\'; break;
 104                         default:
 105                                 sprintf(copy_buff + i, "%03o", c);
 106                                 i += 3;
 107                         }
 108                 }
 109
 110                 /* If our temp buffer is full, dump it and keep going. */
 111                 if (i > (sizeof(copy_buff) - 8)) {
 112                         copy_buff[i++] = '\0';
 113                         fprintf(f, "%s", copy_buff);
 114                         i = 0;
 115                 }
 116         }
 117         copy_buff[i++] = '\0';
 118         fprintf(f, "%s", copy_buff);
 119
 120         /* If we allocated a heap-based buffer, free it now. */
 121         if (buff_heap != NULL)
 122                 free(buff_heap);
 123 }
 124
 125 static void
 126 bsdtar_vwarnc(struct bsdtar *bsdtar, int code, const char *fmt, va_list ap)
 127 {
 128         fprintf(stderr, "%s: ", bsdtar->progname);
 129         vfprintf(stderr, fmt, ap);
 130         if (code != 0)
 131                 fprintf(stderr, ": %s", strerror(code));
 132         fprintf(stderr, "\n");
 133 }
 134
 135 void
 136 bsdtar_warnc(struct bsdtar *bsdtar, int code, const char *fmt, ...)
 137 {
 138         va_list ap;
 139
 140         va_start(ap, fmt);
 141         bsdtar_vwarnc(bsdtar, code, fmt, ap);
 142         va_end(ap);
 143 }
 144
 145 void
 146 bsdtar_errc(struct bsdtar *bsdtar, int eval, int code, const char *fmt, ...)
 147 {
 148         va_list ap;
 149
 150         va_start(ap, fmt);
 151         bsdtar_vwarnc(bsdtar, code, fmt, ap);
 152         va_end(ap);
 153         exit(eval);
 154 }
 155
 156 int
 157 yes(const char *fmt, ...)
 158 {
 159         char buff[32];
 160         char *p;
 161         ssize_t l;
 162
 163         va_list ap;
 164         va_start(ap, fmt);
 165         vfprintf(stderr, fmt, ap);
 166         va_end(ap);
 167         fprintf(stderr, " (y/N)? ");
 168         fflush(stderr);
 169
 170         l = read(2, buff, sizeof(buff));
 171         if (l <= 0)
 172                 return (0);
 173         buff[l] = 0;
 174
 175         for (p = buff; *p != '\0'; p++) {
 176                 if (isspace(0xff & (int)*p))
 177                         continue;
 178                 switch(*p) {
 179                 case 'y': case 'Y':
 180                         return (1);
 181                 case 'n': case 'N':
 182                         return (0);
 183                 default:
 184                         return (0);
 185                 }
 186         }
 187
 188         return (0);
 189 }
 190
 191 void
 192 bsdtar_strmode(struct archive_entry *entry, char *bp)
 193 {
 194         static const char *perms = "?rwxrwxrwx ";
 195         static const mode_t permbits[] =
 196             { S_IRUSR, S_IWUSR, S_IXUSR, S_IRGRP, S_IWGRP, S_IXGRP,
 197               S_IROTH, S_IWOTH, S_IXOTH };
 198         mode_t mode;
 199         int i;
 200
 201         /* Fill in a default string, then selectively override. */
 202         strcpy(bp, perms);
 203
 204         mode = archive_entry_mode(entry);
 205         switch (mode & S_IFMT) {
 206         case S_IFREG:  bp[0] = '-'; break;
 207         case S_IFBLK:  bp[0] = 'b'; break;
 208         case S_IFCHR:  bp[0] = 'c'; break;
 209         case S_IFDIR:  bp[0] = 'd'; break;
 210         case S_IFLNK:  bp[0] = 'l'; break;
 211         case S_IFSOCK: bp[0] = 's'; break;
 212 #ifdef S_IFIFO
 213         case S_IFIFO:  bp[0] = 'p'; break;
 214 #endif
 215 #ifdef S_IFWHT
 216         case S_IFWHT:  bp[0] = 'w'; break;
 217 #endif
 218         }
 219
 220         for (i = 0; i < 9; i++)
 221                 if (!(mode & permbits[i]))
 222                         bp[i+1] = '-';
 223
 224         if (mode & S_ISUID) {
 225                 if (mode & S_IXUSR) bp[3] = 's';
 226                 else bp[3] = 'S';
 227         }
 228         if (mode & S_ISGID) {
 229                 if (mode & S_IXGRP) bp[6] = 's';
 230                 else bp[6] = 'S';
 231         }
 232         if (mode & S_ISVTX) {
 233                 if (mode & S_IXOTH) bp[9] = 't';
 234                 else bp[9] = 'T';
 235         }
 236         if (archive_entry_acl_count(entry, ARCHIVE_ENTRY_ACL_TYPE_ACCESS))
 237                 bp[10] = '+';
 238 }
 239
 240
 241 /*
 242  * Read lines from file and do something with each one.  If option_null
 243  * is set, lines are terminated with zero bytes; otherwise, they're
 244  * terminated with newlines.
 245  *
 246  * This uses a self-sizing buffer to handle arbitrarily-long lines.
 247  * If the "process" function returns non-zero for any line, this
 248  * function will return non-zero after attempting to process all
 249  * remaining lines.
 250  */
 251 int
 252 process_lines(struct bsdtar *bsdtar, const char *pathname,
 253     int (*process)(struct bsdtar *, const char *))
 254 {
 255         FILE *f;
 256         char *buff, *buff_end, *line_start, *line_end, *p;
 257         size_t buff_length, bytes_read, bytes_wanted;
 258         int separator;
 259         int ret;
 260
 261         separator = bsdtar->option_null ? '\0' : '\n';
 262         ret = 0;
 263
 264         if (strcmp(pathname, "-") == 0)
 265                 f = stdin;
 266         else
 267                 f = fopen(pathname, "r");
 268         if (f == NULL)
 269                 bsdtar_errc(bsdtar, 1, errno, "Couldn't open %s", pathname);
 270         buff_length = 8192;
 271         buff = malloc(buff_length);
 272         if (buff == NULL)
 273                 bsdtar_errc(bsdtar, 1, ENOMEM, "Can't read %s", pathname);
 274         line_start = line_end = buff_end = buff;
 275         for (;;) {
 276                 /* Get some more data into the buffer. */
 277                 bytes_wanted = buff + buff_length - buff_end;
 278                 bytes_read = fread(buff_end, 1, bytes_wanted, f);
 279                 buff_end += bytes_read;
 280                 /* Process all complete lines in the buffer. */
 281                 while (line_end < buff_end) {
 282                         if (*line_end == separator) {
 283                                 *line_end = '\0';
 284                                 if ((*process)(bsdtar, line_start) != 0)
 285                                         ret = -1;
 286                                 line_start = line_end + 1;
 287                                 line_end = line_start;
 288                         } else
 289                                 line_end++;
 290                 }
 291                 if (feof(f))
 292                         break;
 293                 if (ferror(f))
 294                         bsdtar_errc(bsdtar, 1, errno,
 295                             "Can't read %s", pathname);
 296                 if (line_start > buff) {
 297                         /* Move a leftover fractional line to the beginning. */
 298                         memmove(buff, line_start, buff_end - line_start);
 299                         buff_end -= line_start - buff;
 300                         line_end -= line_start - buff;
 301                         line_start = buff;
 302                 } else {
 303                         /* Line is too big; enlarge the buffer. */
 304                         p = realloc(buff, buff_length *= 2);
 305                         if (p == NULL)
 306                                 bsdtar_errc(bsdtar, 1, ENOMEM,
 307                                     "Line too long in %s", pathname);
 308                         buff_end = p + (buff_end - buff);
 309                         line_end = p + (line_end - buff);
 310                         line_start = buff = p;
 311                 }
 312         }
 313         /* At end-of-file, handle the final line. */
 314         if (line_end > line_start) {
 315                 *line_end = '\0';
 316                 if ((*process)(bsdtar, line_start) != 0)
 317                         ret = -1;
 318         }
 319         free(buff);
 320         if (f != stdin)
 321                 fclose(f);
 322         return (ret);
 323 }
 324
 325 /*-
 326  * The logic here for -C <dir> attempts to avoid
 327  * chdir() as long as possible.  For example:
 328  * "-C /foo -C /bar file"          needs chdir("/bar") but not chdir("/foo")
 329  * "-C /foo -C bar file"           needs chdir("/foo/bar")
 330  * "-C /foo -C bar /file1"         does not need chdir()
 331  * "-C /foo -C bar /file1 file2"   needs chdir("/foo/bar") before file2
 332  *
 333  * The only correct way to handle this is to record a "pending" chdir
 334  * request and combine multiple requests intelligently until we
 335  * need to process a non-absolute file.  set_chdir() adds the new dir
 336  * to the pending list; do_chdir() actually executes any pending chdir.
 337  *
 338  * This way, programs that build tar command lines don't have to worry
 339  * about -C with non-existent directories; such requests will only
 340  * fail if the directory must be accessed.
 341  */
 342 void
 343 set_chdir(struct bsdtar *bsdtar, const char *newdir)
 344 {
 345         if (newdir[0] == '/') {
 346                 /* The -C /foo -C /bar case; dump first one. */
 347                 free(bsdtar->pending_chdir);
 348                 bsdtar->pending_chdir = NULL;
 349         }
 350         if (bsdtar->pending_chdir == NULL)
 351                 /* Easy case: no previously-saved dir. */
 352                 bsdtar->pending_chdir = strdup(newdir);
 353         else {
 354                 /* The -C /foo -C bar case; concatenate */
 355                 char *old_pending = bsdtar->pending_chdir;
 356                 size_t old_len = strlen(old_pending);
 357                 bsdtar->pending_chdir = malloc(old_len + strlen(newdir) + 2);
 358                 if (old_pending[old_len - 1] == '/')
 359                         old_pending[old_len - 1] = '\0';
 360                 if (bsdtar->pending_chdir != NULL)
 361                         sprintf(bsdtar->pending_chdir, "%s/%s",
 362                             old_pending, newdir);
 363                 free(old_pending);
 364         }
 365         if (bsdtar->pending_chdir == NULL)
 366                 bsdtar_errc(bsdtar, 1, errno, "No memory");
 367 }
 368
 369 void
 370 do_chdir(struct bsdtar *bsdtar)
 371 {
 372         if (bsdtar->pending_chdir == NULL)
 373                 return;
 374
 375         if (chdir(bsdtar->pending_chdir) != 0) {
 376                 bsdtar_errc(bsdtar, 1, 0, "could not chdir to '%s'\n",
 377                     bsdtar->pending_chdir);
 378         }
 379         free(bsdtar->pending_chdir);
 380         bsdtar->pending_chdir = NULL;
 381 }
 382
 383 /*
 384  * Handle --strip-components and any future path-rewriting options.
 385  * Returns non-zero if the pathname should not be extracted.
 386  */
 387 int
 388 edit_pathname(struct bsdtar *bsdtar, struct archive_entry *entry)
 389 {
 390         const char *name = archive_entry_pathname(entry);
 391
 392         /* Strip leading dir names as per --strip-components option. */
 393         if (bsdtar->strip_components > 0) {
 394                 int r = bsdtar->strip_components;
 395                 const char *p = name;
 396
 397                 while (r > 0) {
 398                         switch (*p++) {
 399                         case '/':
 400                                 r--;
 401                                 name = p;
 402                                 break;
 403                         case '\0':
 404                                 /* Path is too short, skip it. */
 405                                 return (1);
 406                         }
 407                 }
 408         }
 409
 410         /* Strip redundant "./" from start of filename. */
 411         if (name[0] == '.' && name[1] == '/' && name[2] != '\0')
 412                 name += 2;
 413
 414         /* Strip redundant leading '/' characters. */
 415         while (name[0] == '/' && name[1] == '/')
 416                 name++;
 417
 418         /* Strip leading '/' unless user has asked us not to. */
 419         if (name[0] == '/' && !bsdtar->option_absolute_paths) {
 420                 /* Generate a warning the first time this happens. */
 421                 if (!bsdtar->warned_lead_slash) {
 422                         bsdtar_warnc(bsdtar, 0,
 423                             "Removing leading '/' from member names");
 424                         bsdtar->warned_lead_slash = 1;
 425                 }
 426                 name++;
 427                 /* Special case: Stripping leading '/' from "/" yields ".". */
 428                 if (*name == '\0')
 429                         name = ".";
 430         }
 431
 432         /* Safely replace name in archive_entry. */
 433         if (name != archive_entry_pathname(entry)) {
 434                 char *q = strdup(name);
 435                 archive_entry_copy_pathname(entry, q);
 436                 free(q);
 437         }
 438         return (0);
 439 }