/* System-dependent calls for tar. Copyright (C) 2003, 2004, 2005, 2006 Free Software Foundation, Inc. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #include #include #include #include "common.h" #include #include #if MSDOS bool sys_get_archive_stat (void) { return 0; } bool sys_file_is_archive (struct tar_stat_info *p) { return false; } void sys_save_archive_dev_ino (void) { } void sys_detect_dev_null_output (void) { static char const dev_null[] = "nul"; dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0 || (! _isrmt (archive))); } void sys_drain_input_pipe (void) { } void sys_wait_for_child (pid_t child_pid) { } void sys_spawn_shell (void) { spawnl (P_WAIT, getenv ("COMSPEC"), "-", 0); } /* stat() in djgpp's C library gives a constant number of 42 as the uid and gid of a file. So, comparing an FTP'ed archive just after unpack would fail on MSDOS. */ bool sys_compare_uid (struct stat *a, struct stat *b) { return true; } bool sys_compare_gid (struct stat *a, struct stat *b) { return true; } void sys_compare_links (struct stat *link_data, struct stat *stat_data) { return true; } int sys_truncate (int fd) { return write (fd, "", 0); } size_t sys_write_archive_buffer (void) { return full_write (archive, record_start->buffer, record_size); } /* Set ARCHIVE for writing, then compressing an archive. */ void sys_child_open_for_compress (void) { FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives"))); } /* Set ARCHIVE for uncompressing, then reading an archive. */ void sys_child_open_for_uncompress (void) { FATAL_ERROR ((0, 0, _("Cannot use compressed or remote archives"))); } #else extern union block *record_start; /* FIXME */ static struct stat archive_stat; /* stat block for archive file */ bool sys_get_archive_stat (void) { return fstat (archive, &archive_stat) == 0; } bool sys_file_is_archive (struct tar_stat_info *p) { return (ar_dev && p->stat.st_dev == ar_dev && p->stat.st_ino == ar_ino); } /* Save archive file inode and device numbers */ void sys_save_archive_dev_ino (void) { if (!_isrmt (archive) && S_ISREG (archive_stat.st_mode)) { ar_dev = archive_stat.st_dev; ar_ino = archive_stat.st_ino; } else ar_dev = 0; } /* Detect if outputting to "/dev/null". */ void sys_detect_dev_null_output (void) { static char const dev_null[] = "/dev/null"; struct stat dev_null_stat; dev_null_output = (strcmp (archive_name_array[0], dev_null) == 0 || (! _isrmt (archive) && S_ISCHR (archive_stat.st_mode) && stat (dev_null, &dev_null_stat) == 0 && archive_stat.st_dev == dev_null_stat.st_dev && archive_stat.st_ino == dev_null_stat.st_ino)); } /* Manage to fully drain a pipe we might be reading, so to not break it on the producer after the EOF block. FIXME: one of these days, GNU tar might become clever enough to just stop working, once there is no more work to do, we might have to revise this area in such time. */ void sys_drain_input_pipe (void) { size_t r; if (access_mode == ACCESS_READ && ! _isrmt (archive) && (S_ISFIFO (archive_stat.st_mode) || S_ISSOCK (archive_stat.st_mode))) while ((r = rmtread (archive, record_start->buffer, record_size)) != 0 && r != SAFE_READ_ERROR) continue; } void sys_wait_for_child (pid_t child_pid) { if (child_pid) { int wait_status; while (waitpid (child_pid, &wait_status, 0) == -1) if (errno != EINTR) { waitpid_error (use_compress_program_option); break; } if (WIFSIGNALED (wait_status)) ERROR ((0, 0, _("Child died with signal %d"), WTERMSIG (wait_status))); else if (WEXITSTATUS (wait_status) != 0) ERROR ((0, 0, _("Child returned status %d"), WEXITSTATUS (wait_status))); } } void sys_spawn_shell (void) { pid_t child; const char *shell = getenv ("SHELL"); if (! shell) shell = "/bin/sh"; child = xfork (); if (child == 0) { execlp (shell, "-sh", "-i", (char *) 0); exec_fatal (shell); } else { int wait_status; while (waitpid (child, &wait_status, 0) == -1) if (errno != EINTR) { waitpid_error (shell); break; } } } bool sys_compare_uid (struct stat *a, struct stat *b) { return a->st_uid == b->st_uid; } bool sys_compare_gid (struct stat *a, struct stat *b) { return a->st_gid == b->st_gid; } bool sys_compare_links (struct stat *link_data, struct stat *stat_data) { return stat_data->st_dev == link_data->st_dev && stat_data->st_ino == link_data->st_ino; } int sys_truncate (int fd) { struct stat st; off_t pos = lseek (fd, (off_t) 0, SEEK_CUR); if ( pos < 0) return -1; if ( ftruncate(fd, pos) && errno == EPERM ) { /* wrapper around ftruncate: * ftruncate may fail to grow the size of a file with some OS and filesystem * combinations. Linux and vfat/fat is one example. If this is the case do * a write to grow the file to the desired length. */ if( (fstat( fd, &st ) == -1) || (st.st_size >= pos) || (lseek( fd, pos - 1, SEEK_SET) == (off_t)-1) || (write( fd, "\0", 1) == -1) ) return -1; } return 0; } /* Return nonzero if NAME is the name of a regular file, or if the file does not exist (so it would be created as a regular file). */ static int is_regular_file (const char *name) { struct stat stbuf; if (stat (name, &stbuf) == 0) return S_ISREG (stbuf.st_mode); else return errno == ENOENT; } size_t sys_write_archive_buffer (void) { return rmtwrite (archive, record_start->buffer, record_size); } #define PREAD 0 /* read file descriptor from pipe() */ #define PWRITE 1 /* write file descriptor from pipe() */ /* Duplicate file descriptor FROM into becoming INTO. INTO is closed first and has to be the next available slot. */ static void xdup2 (int from, int into) { if (from != into) { int status = close (into); if (status != 0 && errno != EBADF) { int e = errno; FATAL_ERROR ((0, e, _("Cannot close"))); } status = dup (from); if (status != into) { if (status < 0) { int e = errno; FATAL_ERROR ((0, e, _("Cannot dup"))); } abort (); } xclose (from); } } /* Set ARCHIVE for writing, then compressing an archive. */ pid_t sys_child_open_for_compress (void) { int parent_pipe[2]; int child_pipe[2]; pid_t grandchild_pid; pid_t child_pid; int wait_status; xpipe (parent_pipe); child_pid = xfork (); if (child_pid > 0) { /* The parent tar is still here! Just clean up. */ archive = parent_pipe[PWRITE]; xclose (parent_pipe[PREAD]); return child_pid; } /* The new born child tar is here! */ program_name = _("tar (child)"); xdup2 (parent_pipe[PREAD], STDIN_FILENO); xclose (parent_pipe[PWRITE]); /* Check if we need a grandchild tar. This happens only if either: a) the file is to be accessed by rmt: compressor doesn't know how; b) the file is not a plain file. */ if (!_remdev (archive_name_array[0]) && is_regular_file (archive_name_array[0])) { if (backup_option) maybe_backup_file (archive_name_array[0], 1); /* We don't need a grandchild tar. Open the archive and launch the compressor. */ if (strcmp (archive_name_array[0], "-")) { archive = creat (archive_name_array[0], MODE_RW); if (archive < 0) { int saved_errno = errno; if (backup_option) undo_last_backup (); errno = saved_errno; open_fatal (archive_name_array[0]); } xdup2 (archive, STDOUT_FILENO); } execlp (use_compress_program_option, use_compress_program_option, NULL); exec_fatal (use_compress_program_option); } /* We do need a grandchild tar. */ xpipe (child_pipe); grandchild_pid = xfork (); if (grandchild_pid == 0) { /* The newborn grandchild tar is here! Launch the compressor. */ program_name = _("tar (grandchild)"); xdup2 (child_pipe[PWRITE], STDOUT_FILENO); xclose (child_pipe[PREAD]); execlp (use_compress_program_option, use_compress_program_option, (char *) 0); exec_fatal (use_compress_program_option); } /* The child tar is still here! */ /* Prepare for reblocking the data from the compressor into the archive. */ xdup2 (child_pipe[PREAD], STDIN_FILENO); xclose (child_pipe[PWRITE]); if (strcmp (archive_name_array[0], "-") == 0) archive = STDOUT_FILENO; else { archive = rmtcreat (archive_name_array[0], MODE_RW, rsh_command_option); if (archive < 0) open_fatal (archive_name_array[0]); } /* Let's read out of the stdin pipe and write an archive. */ while (1) { size_t status = 0; char *cursor; size_t length; /* Assemble a record. */ for (length = 0, cursor = record_start->buffer; length < record_size; length += status, cursor += status) { size_t size = record_size - length; status = safe_read (STDIN_FILENO, cursor, size); if (status == SAFE_READ_ERROR) read_fatal (use_compress_program_option); if (status == 0) break; } /* Copy the record. */ if (status == 0) { /* We hit the end of the file. Write last record at full length, as the only role of the grandchild is doing proper reblocking. */ if (length > 0) { memset (record_start->buffer + length, 0, record_size - length); status = sys_write_archive_buffer (); if (status != record_size) archive_write_error (status); } /* There is nothing else to read, break out. */ break; } status = sys_write_archive_buffer (); if (status != record_size) archive_write_error (status); } /* Propagate any failure of the grandchild back to the parent. */ while (waitpid (grandchild_pid, &wait_status, 0) == -1) if (errno != EINTR) { waitpid_error (use_compress_program_option); break; } if (WIFSIGNALED (wait_status)) { kill (child_pid, WTERMSIG (wait_status)); exit_status = TAREXIT_FAILURE; } else if (WEXITSTATUS (wait_status) != 0) exit_status = WEXITSTATUS (wait_status); exit (exit_status); } /* Set ARCHIVE for uncompressing, then reading an archive. */ pid_t sys_child_open_for_uncompress (void) { int parent_pipe[2]; int child_pipe[2]; pid_t grandchild_pid; pid_t child_pid; int wait_status; xpipe (parent_pipe); child_pid = xfork (); if (child_pid > 0) { /* The parent tar is still here! Just clean up. */ archive = parent_pipe[PREAD]; xclose (parent_pipe[PWRITE]); return child_pid; } /* The newborn child tar is here! */ program_name = _("tar (child)"); xdup2 (parent_pipe[PWRITE], STDOUT_FILENO); xclose (parent_pipe[PREAD]); /* Check if we need a grandchild tar. This happens only if either: a) we're reading stdin: to force unblocking; b) the file is to be accessed by rmt: compressor doesn't know how; c) the file is not a plain file. */ if (strcmp (archive_name_array[0], "-") != 0 && !_remdev (archive_name_array[0]) && is_regular_file (archive_name_array[0])) { /* We don't need a grandchild tar. Open the archive and lauch the uncompressor. */ archive = open (archive_name_array[0], O_RDONLY | O_BINARY, MODE_RW); if (archive < 0) open_fatal (archive_name_array[0]); xdup2 (archive, STDIN_FILENO); execlp (use_compress_program_option, use_compress_program_option, "-d", (char *) 0); exec_fatal (use_compress_program_option); } /* We do need a grandchild tar. */ xpipe (child_pipe); grandchild_pid = xfork (); if (grandchild_pid == 0) { /* The newborn grandchild tar is here! Launch the uncompressor. */ program_name = _("tar (grandchild)"); xdup2 (child_pipe[PREAD], STDIN_FILENO); xclose (child_pipe[PWRITE]); execlp (use_compress_program_option, use_compress_program_option, "-d", (char *) 0); exec_fatal (use_compress_program_option); } /* The child tar is still here! */ /* Prepare for unblocking the data from the archive into the uncompressor. */ xdup2 (child_pipe[PWRITE], STDOUT_FILENO); xclose (child_pipe[PREAD]); if (strcmp (archive_name_array[0], "-") == 0) archive = STDIN_FILENO; else archive = rmtopen (archive_name_array[0], O_RDONLY | O_BINARY, MODE_RW, rsh_command_option); if (archive < 0) open_fatal (archive_name_array[0]); /* Let's read the archive and pipe it into stdout. */ while (1) { char *cursor; size_t maximum; size_t count; size_t status; clear_read_error_count (); error_loop: status = rmtread (archive, record_start->buffer, record_size); if (status == SAFE_READ_ERROR) { archive_read_error (); goto error_loop; } if (status == 0) break; cursor = record_start->buffer; maximum = status; while (maximum) { count = maximum < BLOCKSIZE ? maximum : BLOCKSIZE; if (full_write (STDOUT_FILENO, cursor, count) != count) write_error (use_compress_program_option); cursor += count; maximum -= count; } } xclose (STDOUT_FILENO); /* Propagate any failure of the grandchild back to the parent. */ while (waitpid (grandchild_pid, &wait_status, 0) == -1) if (errno != EINTR) { waitpid_error (use_compress_program_option); break; } if (WIFSIGNALED (wait_status)) { kill (child_pid, WTERMSIG (wait_status)); exit_status = TAREXIT_FAILURE; } else if (WEXITSTATUS (wait_status) != 0) exit_status = WEXITSTATUS (wait_status); exit (exit_status); } static void dec_to_env (char *envar, uintmax_t num) { char buf[UINTMAX_STRSIZE_BOUND]; char *numstr; numstr = STRINGIFY_BIGINT (num, buf); if (setenv (envar, numstr, 1) != 0) xalloc_die (); } static void time_to_env (char *envar, struct timespec t) { char buf[TIMESPEC_STRSIZE_BOUND]; if (setenv (envar, code_timespec (t, buf), 1) != 0) xalloc_die (); } static void oct_to_env (char *envar, unsigned long num) { char buf[1+1+(sizeof(unsigned long)*CHAR_BIT+2)/3]; snprintf (buf, sizeof buf, "0%lo", num); if (setenv (envar, buf, 1) != 0) xalloc_die (); } static void str_to_env (char *envar, char const *str) { if (str) { if (setenv (envar, str, 1) != 0) xalloc_die (); } else unsetenv (envar); } static void chr_to_env (char *envar, char c) { char buf[2]; buf[0] = c; buf[1] = 0; if (setenv (envar, buf, 1) != 0) xalloc_die (); } static void stat_to_env (char *name, char type, struct tar_stat_info *st) { str_to_env ("TAR_VERSION", PACKAGE_VERSION); chr_to_env ("TAR_FILETYPE", type); oct_to_env ("TAR_MODE", st->stat.st_mode); str_to_env ("TAR_FILENAME", name); str_to_env ("TAR_REALNAME", st->file_name); str_to_env ("TAR_UNAME", st->uname); str_to_env ("TAR_GNAME", st->gname); time_to_env ("TAR_ATIME", st->atime); time_to_env ("TAR_MTIME", st->mtime); time_to_env ("TAR_CTIME", st->ctime); dec_to_env ("TAR_SIZE", st->stat.st_size); dec_to_env ("TAR_UID", st->stat.st_uid); dec_to_env ("TAR_GID", st->stat.st_gid); switch (type) { case 'b': case 'c': dec_to_env ("TAR_MINOR", minor (st->stat.st_rdev)); dec_to_env ("TAR_MAJOR", major (st->stat.st_rdev)); unsetenv ("TAR_LINKNAME"); break; case 'l': case 'h': unsetenv ("TAR_MINOR"); unsetenv ("TAR_MAJOR"); str_to_env ("TAR_LINKNAME", st->link_name); break; default: unsetenv ("TAR_MINOR"); unsetenv ("TAR_MAJOR"); unsetenv ("TAR_LINKNAME"); break; } } static pid_t pid; static RETSIGTYPE (*pipe_handler) (int sig); int sys_exec_command (char *file_name, int typechar, struct tar_stat_info *st) { int p[2]; char *argv[4]; xpipe (p); pipe_handler = signal (SIGPIPE, SIG_IGN); pid = xfork (); if (pid != 0) { xclose (p[PREAD]); return p[PWRITE]; } /* Child */ xdup2 (p[PREAD], STDIN_FILENO); xclose (p[PWRITE]); stat_to_env (file_name, typechar, st); argv[0] = "/bin/sh"; argv[1] = "-c"; argv[2] = to_command_option; argv[3] = NULL; execv ("/bin/sh", argv); exec_fatal (file_name); } void sys_wait_command (void) { int status; if (pid < 0) return; signal (SIGPIPE, pipe_handler); while (waitpid (pid, &status, 0) == -1) if (errno != EINTR) { pid = -1; waitpid_error (to_command_option); return; } if (WIFEXITED (status)) { if (!ignore_command_error_option && WEXITSTATUS (status)) ERROR ((0, 0, _("%lu: Child returned status %d"), (unsigned long) pid, WEXITSTATUS (status))); } else if (WIFSIGNALED (status)) { WARN ((0, 0, _("%lu: Child terminated on signal %d"), (unsigned long) pid, WTERMSIG (status))); } else ERROR ((0, 0, _("%lu: Child terminated on unknown reason"), (unsigned long) pid)); pid = -1; } int sys_exec_info_script (const char **archive_name, int volume_number) { pid_t pid; char *argv[4]; char uintbuf[UINTMAX_STRSIZE_BOUND]; int p[2]; xpipe (p); pipe_handler = signal (SIGPIPE, SIG_IGN); pid = xfork (); if (pid != 0) { /* Master */ int rc; int status; char *buf; size_t size = 0; FILE *fp; xclose (p[PWRITE]); fp = fdopen (p[PREAD], "r"); rc = getline (&buf, &size, fp); fclose (fp); if (rc > 0 && buf[rc-1] == '\n') buf[--rc] = 0; while (waitpid (pid, &status, 0) == -1) if (errno != EINTR) { waitpid_error (info_script_option); return -1; } if (WIFEXITED (status)) { if (WEXITSTATUS (status) == 0 && rc > 0) *archive_name = buf; else free (buf); return WEXITSTATUS (status); } free (buf); return -1; } /* Child */ setenv ("TAR_VERSION", PACKAGE_VERSION, 1); setenv ("TAR_ARCHIVE", *archive_name, 1); setenv ("TAR_VOLUME", STRINGIFY_BIGINT (volume_number, uintbuf), 1); setenv ("TAR_SUBCOMMAND", subcommand_string (subcommand_option), 1); setenv ("TAR_FORMAT", archive_format_string (current_format == DEFAULT_FORMAT ? archive_format : current_format), 1); setenv ("TAR_FD", STRINGIFY_BIGINT (p[PWRITE], uintbuf), 1); xclose (p[PREAD]); argv[0] = "/bin/sh"; argv[1] = "-c"; argv[2] = (char*) info_script_option; argv[3] = NULL; execv (argv[0], argv); exec_fatal (info_script_option); } #endif /* not MSDOS */