1 /* System-dependent calls for tar.
3 Copyright 2003-2008, 2010, 2013-2014 Free Software Foundation, Inc.
5 This program is free software; you can redistribute it and/or modify it
6 under the terms of the GNU General Public License as published by the
7 Free Software Foundation; either version 3, or (at your option) any later
10 This program is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
13 Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program. If not, see <http://www.gnu.org/licenses/>. */
24 #include <wordsplit.h>
27 xexec (const char *cmd
)
31 ws
.ws_env
= (const char **) environ
;
32 if (wordsplit (cmd
, &ws
, (WRDSF_DEFFLAGS
| WRDSF_ENV
) & ~WRDSF_NOVAR
))
33 FATAL_ERROR ((0, 0, _("cannot split string '%s': %s"),
34 cmd
, wordsplit_strerror (&ws
)));
35 execvp (ws
.ws_wordv
[0], ws
.ws_wordv
);
42 sys_get_archive_stat (void)
48 sys_file_is_archive (struct tar_stat_info
*p
)
54 sys_save_archive_dev_ino (void)
59 sys_detect_dev_null_output (void)
61 static char const dev_null
[] = "nul";
63 dev_null_output
= (strcmp (archive_name_array
[0], dev_null
) == 0
64 || (! _isrmt (archive
)));
68 sys_wait_for_child (pid_t child_pid
, bool eof
)
73 sys_spawn_shell (void)
75 spawnl (P_WAIT
, getenv ("COMSPEC"), "-", 0);
78 /* stat() in djgpp's C library gives a constant number of 42 as the
79 uid and gid of a file. So, comparing an FTP'ed archive just after
80 unpack would fail on MSDOS. */
83 sys_compare_uid (struct stat
*a
, struct stat
*b
)
89 sys_compare_gid (struct stat
*a
, struct stat
*b
)
95 sys_compare_links (struct stat
*link_data
, struct stat
*stat_data
)
101 sys_truncate (int fd
)
103 return write (fd
, "", 0);
107 sys_write_archive_buffer (void)
109 return full_write (archive
, record_start
->buffer
, record_size
);
112 /* Set ARCHIVE for writing, then compressing an archive. */
114 sys_child_open_for_compress (void)
116 FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives")));
119 /* Set ARCHIVE for uncompressing, then reading an archive. */
121 sys_child_open_for_uncompress (void)
123 FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives")));
128 extern union block
*record_start
; /* FIXME */
130 static struct stat archive_stat
; /* stat block for archive file */
133 sys_get_archive_stat (void)
135 return fstat (archive
, &archive_stat
) == 0;
139 sys_file_is_archive (struct tar_stat_info
*p
)
141 return (ar_dev
&& p
->stat
.st_dev
== ar_dev
&& p
->stat
.st_ino
== ar_ino
);
144 /* Save archive file inode and device numbers */
146 sys_save_archive_dev_ino (void)
148 if (!_isrmt (archive
) && S_ISREG (archive_stat
.st_mode
))
150 ar_dev
= archive_stat
.st_dev
;
151 ar_ino
= archive_stat
.st_ino
;
157 /* Detect if outputting to "/dev/null". */
159 sys_detect_dev_null_output (void)
161 static char const dev_null
[] = "/dev/null";
162 struct stat dev_null_stat
;
164 dev_null_output
= (strcmp (archive_name_array
[0], dev_null
) == 0
165 || (! _isrmt (archive
)
166 && S_ISCHR (archive_stat
.st_mode
)
167 && stat (dev_null
, &dev_null_stat
) == 0
168 && archive_stat
.st_dev
== dev_null_stat
.st_dev
169 && archive_stat
.st_ino
== dev_null_stat
.st_ino
));
173 sys_wait_for_child (pid_t child_pid
, bool eof
)
179 while (waitpid (child_pid
, &wait_status
, 0) == -1)
182 waitpid_error (use_compress_program_option
);
186 if (WIFSIGNALED (wait_status
))
188 int sig
= WTERMSIG (wait_status
);
189 if (!(!eof
&& sig
== SIGPIPE
))
190 FATAL_ERROR ((0, 0, _("Child died with signal %d"), sig
));
192 else if (WEXITSTATUS (wait_status
) != 0)
193 FATAL_ERROR ((0, 0, _("Child returned status %d"),
194 WEXITSTATUS (wait_status
)));
199 sys_spawn_shell (void)
202 const char *shell
= getenv ("SHELL");
208 priv_set_restore_linkdir ();
209 execlp (shell
, "-sh", "-i", NULL
);
215 while (waitpid (child
, &wait_status
, 0) == -1)
218 waitpid_error (shell
);
225 sys_compare_uid (struct stat
*a
, struct stat
*b
)
227 return a
->st_uid
== b
->st_uid
;
231 sys_compare_gid (struct stat
*a
, struct stat
*b
)
233 return a
->st_gid
== b
->st_gid
;
237 sys_compare_links (struct stat
*link_data
, struct stat
*stat_data
)
239 return stat_data
->st_dev
== link_data
->st_dev
240 && stat_data
->st_ino
== link_data
->st_ino
;
244 sys_truncate (int fd
)
246 off_t pos
= lseek (fd
, (off_t
) 0, SEEK_CUR
);
247 return pos
< 0 ? -1 : ftruncate (fd
, pos
);
250 /* Return nonzero if NAME is the name of a regular file, or if the file
251 does not exist (so it would be created as a regular file). */
253 is_regular_file (const char *name
)
257 if (stat (name
, &stbuf
) == 0)
258 return S_ISREG (stbuf
.st_mode
);
260 return errno
== ENOENT
;
264 sys_write_archive_buffer (void)
266 return rmtwrite (archive
, record_start
->buffer
, record_size
);
269 #define PREAD 0 /* read file descriptor from pipe() */
270 #define PWRITE 1 /* write file descriptor from pipe() */
272 /* Duplicate file descriptor FROM into becoming INTO.
273 INTO is closed first and has to be the next available slot. */
275 xdup2 (int from
, int into
)
279 int status
= close (into
);
281 if (status
!= 0 && errno
!= EBADF
)
284 FATAL_ERROR ((0, e
, _("Cannot close")));
292 FATAL_ERROR ((0, e
, _("Cannot dup")));
300 static void wait_for_grandchild (pid_t pid
) __attribute__ ((__noreturn__
));
302 /* Propagate any failure of the grandchild back to the parent. */
304 wait_for_grandchild (pid_t pid
)
309 while (waitpid (pid
, &wait_status
, 0) == -1)
312 waitpid_error (use_compress_program_option
);
316 if (WIFSIGNALED (wait_status
))
317 raise (WTERMSIG (wait_status
));
318 else if (WEXITSTATUS (wait_status
) != 0)
319 exit_code
= WEXITSTATUS (wait_status
);
324 /* Set ARCHIVE for writing, then compressing an archive. */
326 sys_child_open_for_compress (void)
330 pid_t grandchild_pid
;
334 child_pid
= xfork ();
338 /* The parent tar is still here! Just clean up. */
340 archive
= parent_pipe
[PWRITE
];
341 xclose (parent_pipe
[PREAD
]);
345 /* The new born child tar is here! */
347 set_program_name (_("tar (child)"));
348 signal (SIGPIPE
, SIG_DFL
);
350 xdup2 (parent_pipe
[PREAD
], STDIN_FILENO
);
351 xclose (parent_pipe
[PWRITE
]);
353 /* Check if we need a grandchild tar. This happens only if either:
354 a) the file is to be accessed by rmt: compressor doesn't know how;
355 b) the file is not a plain file. */
357 if (!_remdev (archive_name_array
[0])
358 && is_regular_file (archive_name_array
[0]))
361 maybe_backup_file (archive_name_array
[0], 1);
363 /* We don't need a grandchild tar. Open the archive and launch the
365 if (strcmp (archive_name_array
[0], "-"))
367 archive
= creat (archive_name_array
[0], MODE_RW
);
370 int saved_errno
= errno
;
375 open_fatal (archive_name_array
[0]);
377 xdup2 (archive
, STDOUT_FILENO
);
379 priv_set_restore_linkdir ();
380 xexec (use_compress_program_option
);
383 /* We do need a grandchild tar. */
386 grandchild_pid
= xfork ();
388 if (grandchild_pid
== 0)
390 /* The newborn grandchild tar is here! Launch the compressor. */
392 set_program_name (_("tar (grandchild)"));
394 xdup2 (child_pipe
[PWRITE
], STDOUT_FILENO
);
395 xclose (child_pipe
[PREAD
]);
396 priv_set_restore_linkdir ();
397 xexec (use_compress_program_option
);
400 /* The child tar is still here! */
402 /* Prepare for reblocking the data from the compressor into the archive. */
404 xdup2 (child_pipe
[PREAD
], STDIN_FILENO
);
405 xclose (child_pipe
[PWRITE
]);
407 if (strcmp (archive_name_array
[0], "-") == 0)
408 archive
= STDOUT_FILENO
;
411 archive
= rmtcreat (archive_name_array
[0], MODE_RW
, rsh_command_option
);
413 open_fatal (archive_name_array
[0]);
416 /* Let's read out of the stdin pipe and write an archive. */
424 /* Assemble a record. */
426 for (length
= 0, cursor
= record_start
->buffer
;
427 length
< record_size
;
428 length
+= status
, cursor
+= status
)
430 size_t size
= record_size
- length
;
432 status
= safe_read (STDIN_FILENO
, cursor
, size
);
433 if (status
== SAFE_READ_ERROR
)
434 read_fatal (use_compress_program_option
);
439 /* Copy the record. */
443 /* We hit the end of the file. Write last record at
444 full length, as the only role of the grandchild is
445 doing proper reblocking. */
449 memset (record_start
->buffer
+ length
, 0, record_size
- length
);
450 status
= sys_write_archive_buffer ();
451 if (status
!= record_size
)
452 archive_write_error (status
);
455 /* There is nothing else to read, break out. */
459 status
= sys_write_archive_buffer ();
460 if (status
!= record_size
)
461 archive_write_error (status
);
464 wait_for_grandchild (grandchild_pid
);
468 run_decompress_program (void)
471 const char *p
, *prog
= NULL
;
473 int wsflags
= (WRDSF_DEFFLAGS
| WRDSF_ENV
| WRDSF_DOOFFS
) & ~WRDSF_NOVAR
;
475 ws
.ws_env
= (const char **) environ
;
478 for (p
= first_decompress_program (&i
); p
; p
= next_decompress_program (&i
))
482 WARNOPT (WARN_DECOMPRESS_PROGRAM
,
483 (0, errno
, _("cannot run %s"), prog
));
484 WARNOPT (WARN_DECOMPRESS_PROGRAM
,
485 (0, 0, _("trying %s"), p
));
487 if (wordsplit (p
, &ws
, wsflags
))
488 FATAL_ERROR ((0, 0, _("cannot split string '%s': %s"),
489 p
, wordsplit_strerror (&ws
)));
490 wsflags
|= WRDSF_REUSE
;
491 memmove(ws
.ws_wordv
, ws
.ws_wordv
+ ws
.ws_offs
,
492 sizeof(ws
.ws_wordv
[0])*ws
.ws_wordc
);
493 ws
.ws_wordv
[ws
.ws_wordc
] = (char *) "-d";
495 execvp (ws
.ws_wordv
[0], ws
.ws_wordv
);
496 ws
.ws_wordv
[ws
.ws_wordc
] = NULL
;
499 FATAL_ERROR ((0, 0, _("unable to run decompression program")));
503 /* Set ARCHIVE for uncompressing, then reading an archive. */
505 sys_child_open_for_uncompress (void)
509 pid_t grandchild_pid
;
513 child_pid
= xfork ();
517 /* The parent tar is still here! Just clean up. */
519 archive
= parent_pipe
[PREAD
];
520 xclose (parent_pipe
[PWRITE
]);
524 /* The newborn child tar is here! */
526 set_program_name (_("tar (child)"));
527 signal (SIGPIPE
, SIG_DFL
);
529 xdup2 (parent_pipe
[PWRITE
], STDOUT_FILENO
);
530 xclose (parent_pipe
[PREAD
]);
532 /* Check if we need a grandchild tar. This happens only if either:
533 a) we're reading stdin: to force unblocking;
534 b) the file is to be accessed by rmt: compressor doesn't know how;
535 c) the file is not a plain file. */
537 if (strcmp (archive_name_array
[0], "-") != 0
538 && !_remdev (archive_name_array
[0])
539 && is_regular_file (archive_name_array
[0]))
541 /* We don't need a grandchild tar. Open the archive and lauch the
544 archive
= open (archive_name_array
[0], O_RDONLY
| O_BINARY
, MODE_RW
);
546 open_fatal (archive_name_array
[0]);
547 xdup2 (archive
, STDIN_FILENO
);
548 priv_set_restore_linkdir ();
549 run_decompress_program ();
552 /* We do need a grandchild tar. */
555 grandchild_pid
= xfork ();
557 if (grandchild_pid
== 0)
559 /* The newborn grandchild tar is here! Launch the uncompressor. */
561 set_program_name (_("tar (grandchild)"));
563 xdup2 (child_pipe
[PREAD
], STDIN_FILENO
);
564 xclose (child_pipe
[PWRITE
]);
565 priv_set_restore_linkdir ();
566 run_decompress_program ();
569 /* The child tar is still here! */
571 /* Prepare for unblocking the data from the archive into the
574 xdup2 (child_pipe
[PWRITE
], STDOUT_FILENO
);
575 xclose (child_pipe
[PREAD
]);
577 if (strcmp (archive_name_array
[0], "-") == 0)
578 archive
= STDIN_FILENO
;
580 archive
= rmtopen (archive_name_array
[0], O_RDONLY
| O_BINARY
,
581 MODE_RW
, rsh_command_option
);
583 open_fatal (archive_name_array
[0]);
585 /* Let's read the archive and pipe it into stdout. */
594 clear_read_error_count ();
597 status
= rmtread (archive
, record_start
->buffer
, record_size
);
598 if (status
== SAFE_READ_ERROR
)
600 archive_read_error ();
605 cursor
= record_start
->buffer
;
609 count
= maximum
< BLOCKSIZE
? maximum
: BLOCKSIZE
;
610 if (full_write (STDOUT_FILENO
, cursor
, count
) != count
)
611 write_error (use_compress_program_option
);
617 xclose (STDOUT_FILENO
);
619 wait_for_grandchild (grandchild_pid
);
625 dec_to_env (char const *envar
, uintmax_t num
)
627 char buf
[UINTMAX_STRSIZE_BOUND
];
630 numstr
= STRINGIFY_BIGINT (num
, buf
);
631 if (setenv (envar
, numstr
, 1) != 0)
636 time_to_env (char const *envar
, struct timespec t
)
638 char buf
[TIMESPEC_STRSIZE_BOUND
];
639 if (setenv (envar
, code_timespec (t
, buf
), 1) != 0)
644 oct_to_env (char const *envar
, unsigned long num
)
646 char buf
[1+1+(sizeof(unsigned long)*CHAR_BIT
+2)/3];
648 snprintf (buf
, sizeof buf
, "0%lo", num
);
649 if (setenv (envar
, buf
, 1) != 0)
654 str_to_env (char const *envar
, char const *str
)
658 if (setenv (envar
, str
, 1) != 0)
666 chr_to_env (char const *envar
, char c
)
671 if (setenv (envar
, buf
, 1) != 0)
676 stat_to_env (char *name
, char type
, struct tar_stat_info
*st
)
678 str_to_env ("TAR_VERSION", PACKAGE_VERSION
);
679 str_to_env ("TAR_ARCHIVE", *archive_name_cursor
);
680 dec_to_env ("TAR_VOLUME", archive_name_cursor
- archive_name_array
+ 1);
681 dec_to_env ("TAR_BLOCKING_FACTOR", blocking_factor
);
682 str_to_env ("TAR_FORMAT",
683 archive_format_string (current_format
== DEFAULT_FORMAT
?
684 archive_format
: current_format
));
685 chr_to_env ("TAR_FILETYPE", type
);
686 oct_to_env ("TAR_MODE", st
->stat
.st_mode
);
687 str_to_env ("TAR_FILENAME", name
);
688 str_to_env ("TAR_REALNAME", st
->file_name
);
689 str_to_env ("TAR_UNAME", st
->uname
);
690 str_to_env ("TAR_GNAME", st
->gname
);
691 time_to_env ("TAR_ATIME", st
->atime
);
692 time_to_env ("TAR_MTIME", st
->mtime
);
693 time_to_env ("TAR_CTIME", st
->ctime
);
694 dec_to_env ("TAR_SIZE", st
->stat
.st_size
);
695 dec_to_env ("TAR_UID", st
->stat
.st_uid
);
696 dec_to_env ("TAR_GID", st
->stat
.st_gid
);
702 dec_to_env ("TAR_MINOR", minor (st
->stat
.st_rdev
));
703 dec_to_env ("TAR_MAJOR", major (st
->stat
.st_rdev
));
704 unsetenv ("TAR_LINKNAME");
709 unsetenv ("TAR_MINOR");
710 unsetenv ("TAR_MAJOR");
711 str_to_env ("TAR_LINKNAME", st
->link_name
);
715 unsetenv ("TAR_MINOR");
716 unsetenv ("TAR_MAJOR");
717 unsetenv ("TAR_LINKNAME");
722 static pid_t global_pid
;
723 static void (*pipe_handler
) (int sig
);
726 sys_exec_command (char *file_name
, int typechar
, struct tar_stat_info
*st
)
731 pipe_handler
= signal (SIGPIPE
, SIG_IGN
);
732 global_pid
= xfork ();
741 xdup2 (p
[PREAD
], STDIN_FILENO
);
744 stat_to_env (file_name
, typechar
, st
);
746 priv_set_restore_linkdir ();
747 xexec (to_command_option
);
751 sys_wait_command (void)
758 signal (SIGPIPE
, pipe_handler
);
759 while (waitpid (global_pid
, &status
, 0) == -1)
763 waitpid_error (to_command_option
);
767 if (WIFEXITED (status
))
769 if (!ignore_command_error_option
&& WEXITSTATUS (status
))
770 ERROR ((0, 0, _("%lu: Child returned status %d"),
771 (unsigned long) global_pid
, WEXITSTATUS (status
)));
773 else if (WIFSIGNALED (status
))
775 WARN ((0, 0, _("%lu: Child terminated on signal %d"),
776 (unsigned long) global_pid
, WTERMSIG (status
)));
779 ERROR ((0, 0, _("%lu: Child terminated on unknown reason"),
780 (unsigned long) global_pid
));
786 sys_exec_info_script (const char **archive_name
, int volume_number
)
789 char uintbuf
[UINTMAX_STRSIZE_BOUND
];
791 static void (*saved_handler
) (int sig
);
794 saved_handler
= signal (SIGPIPE
, SIG_IGN
);
809 fp
= fdopen (p
[PREAD
], "r");
810 rc
= getline (&buf
, &size
, fp
);
813 if (rc
> 0 && buf
[rc
-1] == '\n')
816 while (waitpid (pid
, &status
, 0) == -1)
819 signal (SIGPIPE
, saved_handler
);
820 waitpid_error (info_script_option
);
824 signal (SIGPIPE
, saved_handler
);
826 if (WIFEXITED (status
))
828 if (WEXITSTATUS (status
) == 0 && rc
> 0)
832 return WEXITSTATUS (status
);
840 setenv ("TAR_VERSION", PACKAGE_VERSION
, 1);
841 setenv ("TAR_ARCHIVE", *archive_name
, 1);
842 setenv ("TAR_VOLUME", STRINGIFY_BIGINT (volume_number
, uintbuf
), 1);
843 setenv ("TAR_BLOCKING_FACTOR",
844 STRINGIFY_BIGINT (blocking_factor
, uintbuf
), 1);
845 setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option
), 1);
846 setenv ("TAR_FORMAT",
847 archive_format_string (current_format
== DEFAULT_FORMAT
?
848 archive_format
: current_format
), 1);
849 setenv ("TAR_FD", STRINGIFY_BIGINT (p
[PWRITE
], uintbuf
), 1);
853 priv_set_restore_linkdir ();
854 xexec (info_script_option
);
858 sys_exec_checkpoint_script (const char *script_name
,
859 const char *archive_name
,
860 int checkpoint_number
)
863 char uintbuf
[UINTMAX_STRSIZE_BOUND
];
873 while (waitpid (pid
, &status
, 0) == -1)
876 waitpid_error (script_name
);
884 setenv ("TAR_VERSION", PACKAGE_VERSION
, 1);
885 setenv ("TAR_ARCHIVE", archive_name
, 1);
886 setenv ("TAR_CHECKPOINT", STRINGIFY_BIGINT (checkpoint_number
, uintbuf
), 1);
887 setenv ("TAR_BLOCKING_FACTOR",
888 STRINGIFY_BIGINT (blocking_factor
, uintbuf
), 1);
889 setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option
), 1);
890 setenv ("TAR_FORMAT",
891 archive_format_string (current_format
== DEFAULT_FORMAT
?
892 archive_format
: current_format
), 1);
893 priv_set_restore_linkdir ();
897 #endif /* not MSDOS */