/* Extract files from a tar archive. Copyright (C) 1988, 1992, 1993, 1994, 1996, 1997, 1998, 1999, 2000, 2001, 2003, 2004, 2005, 2006, 2007, 2010 Free Software Foundation, Inc. Written by John Gilmore, on 1985-11-19. 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 3, 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 #include #include #include "common.h" static bool we_are_root; /* true if our effective uid == 0 */ static mode_t newdir_umask; /* umask when creating new directories */ static mode_t current_umask; /* current umask (which is set to 0 if -p) */ /* Status of the permissions of a file that we are extracting. */ enum permstatus { /* This file may have existed already; its permissions are unknown. */ UNKNOWN_PERMSTATUS, /* This file was created using the permissions from the archive, except with S_IRWXG | S_IRWXO masked out if 0 < same_owner_option. */ ARCHIVED_PERMSTATUS, /* This is an intermediate directory; the archive did not specify its permissions. */ INTERDIR_PERMSTATUS }; /* List of directories whose statuses we need to extract after we've finished extracting their subsidiary files. If you consider each contiguous subsequence of elements of the form [D]?[^D]*, where [D] represents an element where AFTER_LINKS is nonzero and [^D] represents an element where AFTER_LINKS is zero, then the head of the subsequence has the longest name, and each non-head element in the prefix is an ancestor (in the directory hierarchy) of the preceding element. */ struct delayed_set_stat { struct delayed_set_stat *next; dev_t dev; ino_t ino; mode_t mode; uid_t uid; gid_t gid; struct timespec atime; struct timespec mtime; size_t file_name_len; mode_t invert_permissions; enum permstatus permstatus; bool after_links; char file_name[1]; }; static struct delayed_set_stat *delayed_set_stat_head; /* List of links whose creation we have delayed. */ struct delayed_link { /* The next delayed link in the list. */ struct delayed_link *next; /* The device, inode number and last-modified time of the placeholder. */ dev_t dev; ino_t ino; struct timespec mtime; /* True if the link is symbolic. */ bool is_symlink; /* The desired owner and group of the link, if it is a symlink. */ uid_t uid; gid_t gid; /* A list of sources for this link. The sources are all to be hard-linked together. */ struct string_list *sources; /* The desired target of the desired link. */ char target[1]; }; static struct delayed_link *delayed_link_head; struct string_list { struct string_list *next; char string[1]; }; /* Set up to extract files. */ void extr_init (void) { we_are_root = geteuid () == 0; same_permissions_option += we_are_root; same_owner_option += we_are_root; /* Option -p clears the kernel umask, so it does not affect proper restoration of file permissions. New intermediate directories will comply with umask at start of program. */ newdir_umask = umask (0); if (0 < same_permissions_option) current_umask = 0; else { umask (newdir_umask); /* restore the kernel umask */ current_umask = newdir_umask; } } /* If restoring permissions, restore the mode for FILE_NAME from information given in *STAT_INFO (where *CUR_INFO gives the current status if CUR_INFO is nonzero); otherwise invert the INVERT_PERMISSIONS bits from the file's current permissions. PERMSTATUS specifies the status of the file's permissions. TYPEFLAG specifies the type of the file. */ static void set_mode (char const *file_name, struct stat const *stat_info, struct stat const *cur_info, mode_t invert_permissions, enum permstatus permstatus, char typeflag) { mode_t mode; bool failed; if (0 < same_permissions_option && permstatus != INTERDIR_PERMSTATUS) { mode = stat_info->st_mode; /* If we created the file and it has a mode that we set already with O_CREAT, then its mode is often set correctly already. But if we are changing ownership, the mode's group and and other permission bits were omitted originally, so it's less likely that the mode is OK now. Also, on many hosts, some directories inherit the setgid bits from their parents, so we we must set directories' modes explicitly. */ if ((permstatus == ARCHIVED_PERMSTATUS && ! (mode & ~ (0 < same_owner_option ? S_IRWXU : MODE_RWX))) && typeflag != DIRTYPE && typeflag != GNUTYPE_DUMPDIR) return; } else if (! invert_permissions) return; else { /* We must inspect a directory's current permissions, since the directory may have inherited its setgid bit from its parent. INVERT_PERMISSIONS happens to be nonzero only for directories that we created, so there's no point optimizing this code for other cases. */ struct stat st; if (! cur_info) { if (stat (file_name, &st) != 0) { stat_error (file_name); return; } cur_info = &st; } mode = cur_info->st_mode ^ invert_permissions; } failed = chmod (file_name, mode) != 0; if (failed && errno == EPERM) { /* On Solaris, chmod may fail if we don't have PRIV_ALL. */ if (priv_set_restore_linkdir () == 0) { failed = chmod (file_name, mode) != 0; priv_set_remove_linkdir (); } } if (failed) chmod_error_details (file_name, mode); } /* Check time after successfully setting FILE_NAME's time stamp to T. */ static void check_time (char const *file_name, struct timespec t) { if (t.tv_sec <= 0) WARNOPT (WARN_TIMESTAMP, (0, 0, _("%s: implausibly old time stamp %s"), file_name, tartime (t, true))); else if (timespec_cmp (volume_start_time, t) < 0) { struct timespec now; gettime (&now); if (timespec_cmp (now, t) < 0) { char buf[TIMESPEC_STRSIZE_BOUND]; struct timespec diff; diff.tv_sec = t.tv_sec - now.tv_sec; diff.tv_nsec = t.tv_nsec - now.tv_nsec; if (diff.tv_nsec < 0) { diff.tv_nsec += BILLION; diff.tv_sec--; } WARNOPT (WARN_TIMESTAMP, (0, 0, _("%s: time stamp %s is %s s in the future"), file_name, tartime (t, true), code_timespec (diff, buf))); } } } /* Restore stat attributes (owner, group, mode and times) for FILE_NAME, using information given in *ST. If CUR_INFO is nonzero, *CUR_INFO is the file's current status. If not restoring permissions, invert the INVERT_PERMISSIONS bits from the file's current permissions. PERMSTATUS specifies the status of the file's permissions. TYPEFLAG specifies the type of the file. */ /* FIXME: About proper restoration of symbolic link attributes, we still do not have it right. Pretesters' reports tell us we need further study and probably more configuration. For now, just use lchown if it exists, and punt for the rest. Sigh! */ static void set_stat (char const *file_name, struct tar_stat_info const *st, struct stat const *cur_info, mode_t invert_permissions, enum permstatus permstatus, char typeflag) { if (typeflag != SYMTYPE) { /* We do the utime before the chmod because some versions of utime are broken and trash the modes of the file. */ if (! touch_option && permstatus != INTERDIR_PERMSTATUS) { /* We set the accessed time to `now', which is really the time we started extracting files, unless incremental_option is used, in which case .st_atime is used. */ /* FIXME: incremental_option should set ctime too, but how? */ struct timespec ts[2]; if (incremental_option) ts[0] = st->atime; else ts[0] = start_time; ts[1] = st->mtime; if (utimens (file_name, ts) != 0) utime_error (file_name); else { check_time (file_name, ts[0]); check_time (file_name, ts[1]); } } /* Some systems allow non-root users to give files away. Once this done, it is not possible anymore to change file permissions. However, setting file permissions now would be incorrect, since they would apply to the wrong user, and there would be a race condition. So, don't use systems that allow non-root users to give files away. */ } if (0 < same_owner_option && permstatus != INTERDIR_PERMSTATUS) { /* When lchown exists, it should be used to change the attributes of the symbolic link itself. In this case, a mere chown would change the attributes of the file the symbolic link is pointing to, and should be avoided. */ int chown_result = 1; if (typeflag == SYMTYPE) { #if HAVE_LCHOWN chown_result = lchown (file_name, st->stat.st_uid, st->stat.st_gid); #endif } else { chown_result = chown (file_name, st->stat.st_uid, st->stat.st_gid); } if (chown_result == 0) { /* Changing the owner can flip st_mode bits in some cases, so ignore cur_info if it might be obsolete now. */ if (cur_info && cur_info->st_mode & S_IXUGO && cur_info->st_mode & (S_ISUID | S_ISGID)) cur_info = NULL; } else if (chown_result < 0) chown_error_details (file_name, st->stat.st_uid, st->stat.st_gid); } if (typeflag != SYMTYPE) set_mode (file_name, &st->stat, cur_info, invert_permissions, permstatus, typeflag); } /* Remember to restore stat attributes (owner, group, mode and times) for the directory FILE_NAME, using information given in *ST, once we stop extracting files into that directory. If not restoring permissions, remember to invert the INVERT_PERMISSIONS bits from the file's current permissions. PERMSTATUS specifies the status of the file's permissions. NOTICE: this works only if the archive has usual member order, i.e. directory, then the files in that directory. Incremental archive have somewhat reversed order: first go subdirectories, then all other members. To help cope with this case the variable delay_directory_restore_option is set by prepare_to_extract. If an archive was explicitely created so that its member order is reversed, some directory timestamps can be restored incorrectly, e.g.: tar --no-recursion -cf archive dir dir/file1 foo dir/file2 */ static void delay_set_stat (char const *file_name, struct tar_stat_info const *st, mode_t invert_permissions, enum permstatus permstatus) { size_t file_name_len = strlen (file_name); struct delayed_set_stat *data = xmalloc (offsetof (struct delayed_set_stat, file_name) + file_name_len + 1); data->next = delayed_set_stat_head; data->dev = st->stat.st_dev; data->ino = st->stat.st_ino; data->mode = st->stat.st_mode; data->uid = st->stat.st_uid; data->gid = st->stat.st_gid; data->atime = st->atime; data->mtime = st->mtime; data->file_name_len = file_name_len; data->invert_permissions = invert_permissions; data->permstatus = permstatus; data->after_links = 0; strcpy (data->file_name, file_name); delayed_set_stat_head = data; } /* Update the delayed_set_stat info for an intermediate directory created within the file name of DIR. The intermediate directory turned out to be the same as this directory, e.g. due to ".." or symbolic links. *DIR_STAT_INFO is the status of the directory. */ static void repair_delayed_set_stat (char const *dir, struct stat const *dir_stat_info) { struct delayed_set_stat *data; for (data = delayed_set_stat_head; data; data = data->next) { struct stat st; if (stat (data->file_name, &st) != 0) { stat_error (data->file_name); return; } if (st.st_dev == dir_stat_info->st_dev && st.st_ino == dir_stat_info->st_ino) { data->dev = current_stat_info.stat.st_dev; data->ino = current_stat_info.stat.st_ino; data->mode = current_stat_info.stat.st_mode; data->uid = current_stat_info.stat.st_uid; data->gid = current_stat_info.stat.st_gid; data->atime = current_stat_info.atime; data->mtime = current_stat_info.mtime; data->invert_permissions = ((current_stat_info.stat.st_mode ^ st.st_mode) & MODE_RWX & ~ current_umask); data->permstatus = ARCHIVED_PERMSTATUS; return; } } ERROR ((0, 0, _("%s: Unexpected inconsistency when making directory"), quotearg_colon (dir))); } /* After a file/link/directory creation has failed, see if it's because some required directory was not present, and if so, create all required directories. Return non-zero if a directory was created. */ static int make_directories (char *file_name) { char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name); char *cursor; /* points into the file name */ int did_something = 0; /* did we do anything yet? */ int mode; int invert_permissions; int status; for (cursor = cursor0; *cursor; cursor++) { if (! ISSLASH (*cursor)) continue; /* Avoid mkdir of empty string, if leading or double '/'. */ if (cursor == cursor0 || ISSLASH (cursor[-1])) continue; /* Avoid mkdir where last part of file name is "." or "..". */ if (cursor[-1] == '.' && (cursor == cursor0 + 1 || ISSLASH (cursor[-2]) || (cursor[-2] == '.' && (cursor == cursor0 + 2 || ISSLASH (cursor[-3]))))) continue; *cursor = '\0'; /* truncate the name there */ mode = MODE_RWX & ~ newdir_umask; invert_permissions = we_are_root ? 0 : MODE_WXUSR & ~ mode; status = mkdir (file_name, mode ^ invert_permissions); if (status == 0) { /* Create a struct delayed_set_stat even if invert_permissions is zero, because repair_delayed_set_stat may need to update the struct. */ delay_set_stat (file_name, ¤t_stat_info, invert_permissions, INTERDIR_PERMSTATUS); print_for_mkdir (file_name, cursor - file_name, mode); did_something = 1; *cursor = '/'; continue; } *cursor = '/'; if (errno == EEXIST) continue; /* Directory already exists. */ else if ((errno == ENOSYS /* Automounted dirs on Solaris return this. Reported by Warren Hyde */ || ERRNO_IS_EACCES) /* Turbo C mkdir gives a funny errno. */ && access (file_name, W_OK) == 0) continue; /* Some other error in the mkdir. We return to the caller. */ break; } return did_something; /* tell them to retry if we made one */ } static bool file_newer_p (const char *file_name, struct tar_stat_info *tar_stat) { struct stat st; if (stat (file_name, &st)) { if (errno != ENOENT) { stat_warn (file_name); /* Be on the safe side: if the file does exist assume it is newer */ return true; } return false; } if (!S_ISDIR (st.st_mode) && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (&st)) <= 0) { return true; } return false; } #define RECOVER_NO 0 #define RECOVER_OK 1 #define RECOVER_SKIP 2 /* Attempt repairing what went wrong with the extraction. Delete an already existing file or create missing intermediate directories. Return RECOVER_OK if we somewhat increased our chances at a successful extraction, RECOVER_NO if there are no chances, and RECOVER_SKIP if the caller should skip extraction of that member. The value of errno is properly restored on returning RECOVER_NO. */ static int maybe_recoverable (char *file_name, int *interdir_made) { int e = errno; if (*interdir_made) return RECOVER_NO; switch (errno) { case EEXIST: /* Remove an old file, if the options allow this. */ switch (old_files_option) { case KEEP_OLD_FILES: return RECOVER_SKIP; case KEEP_NEWER_FILES: if (file_newer_p (file_name, ¤t_stat_info)) { errno = e; return RECOVER_NO; } /* FALL THROUGH */ case DEFAULT_OLD_FILES: case NO_OVERWRITE_DIR_OLD_FILES: case OVERWRITE_OLD_FILES: { int r = remove_any_file (file_name, ORDINARY_REMOVE_OPTION); errno = EEXIST; return r > 0 ? RECOVER_OK : RECOVER_NO; } case UNLINK_FIRST_OLD_FILES: break; } case ENOENT: /* Attempt creating missing intermediate directories. */ if (! make_directories (file_name)) { errno = ENOENT; return RECOVER_NO; } *interdir_made = 1; return RECOVER_OK; default: /* Just say we can't do anything about it... */ return RECOVER_NO; } } /* Fix the statuses of all directories whose statuses need fixing, and which are not ancestors of FILE_NAME. If AFTER_LINKS is nonzero, do this for all such directories; otherwise, stop at the first directory that is marked to be fixed up only after delayed links are applied. */ static void apply_nonancestor_delayed_set_stat (char const *file_name, bool after_links) { size_t file_name_len = strlen (file_name); bool check_for_renamed_directories = 0; while (delayed_set_stat_head) { struct delayed_set_stat *data = delayed_set_stat_head; bool skip_this_one = 0; struct stat st; struct stat const *cur_info = 0; check_for_renamed_directories |= data->after_links; if (after_links < data->after_links || (data->file_name_len < file_name_len && file_name[data->file_name_len] && (ISSLASH (file_name[data->file_name_len]) || ISSLASH (file_name[data->file_name_len - 1])) && memcmp (file_name, data->file_name, data->file_name_len) == 0)) break; if (check_for_renamed_directories) { cur_info = &st; if (stat (data->file_name, &st) != 0) { stat_error (data->file_name); skip_this_one = 1; } else if (! (st.st_dev == data->dev && st.st_ino == data->ino)) { ERROR ((0, 0, _("%s: Directory renamed before its status could be extracted"), quotearg_colon (data->file_name))); skip_this_one = 1; } } if (! skip_this_one) { struct tar_stat_info sb; sb.stat.st_mode = data->mode; sb.stat.st_uid = data->uid; sb.stat.st_gid = data->gid; sb.atime = data->atime; sb.mtime = data->mtime; set_stat (data->file_name, &sb, cur_info, data->invert_permissions, data->permstatus, DIRTYPE); } delayed_set_stat_head = data->next; free (data); } } /* Extractor functions for various member types */ static int extract_dir (char *file_name, int typeflag) { int status; mode_t mode; int interdir_made = 0; /* Save 'root device' to avoid purging mount points. */ if (one_file_system_option && root_device == 0) { struct stat st; char *dir = xgetcwd (); if (deref_stat (true, dir, &st)) stat_diag (dir); else root_device = st.st_dev; free (dir); } if (incremental_option) /* Read the entry and delete files that aren't listed in the archive. */ purge_directory (file_name); else if (typeflag == GNUTYPE_DUMPDIR) skip_member (); mode = current_stat_info.stat.st_mode | (we_are_root ? 0 : MODE_WXUSR); if (0 < same_owner_option || current_stat_info.stat.st_mode & ~ MODE_RWX) mode &= S_IRWXU; while ((status = mkdir (file_name, mode))) { if (errno == EEXIST && (interdir_made || old_files_option == DEFAULT_OLD_FILES || old_files_option == OVERWRITE_OLD_FILES)) { struct stat st; if (stat (file_name, &st) == 0) { if (interdir_made) { repair_delayed_set_stat (file_name, &st); return 0; } if (S_ISDIR (st.st_mode)) { status = 0; mode = st.st_mode; break; } } errno = EEXIST; } switch (maybe_recoverable (file_name, &interdir_made)) { case RECOVER_OK: continue; case RECOVER_SKIP: break; case RECOVER_NO: if (errno != EEXIST) { mkdir_error (file_name); return 1; } break; } break; } if (status == 0 || old_files_option == DEFAULT_OLD_FILES || old_files_option == OVERWRITE_OLD_FILES) { if (status == 0) delay_set_stat (file_name, ¤t_stat_info, ((mode ^ current_stat_info.stat.st_mode) & MODE_RWX & ~ current_umask), ARCHIVED_PERMSTATUS); else /* For an already existing directory, invert_perms must be 0 */ delay_set_stat (file_name, ¤t_stat_info, 0, UNKNOWN_PERMSTATUS); } return status; } static int open_output_file (char *file_name, int typeflag, mode_t mode) { int fd; int openflag = (O_WRONLY | O_BINARY | O_CREAT | (old_files_option == OVERWRITE_OLD_FILES ? O_TRUNC : O_EXCL)); #if O_CTG /* Contiguous files (on the Masscomp) have to specify the size in the open call that creates them. */ if (typeflag == CONTTYPE) fd = open (file_name, openflag | O_CTG, mode, current_stat_info.stat.st_size); else fd = open (file_name, openflag, mode); #else /* not O_CTG */ if (typeflag == CONTTYPE) { static int conttype_diagnosed; if (!conttype_diagnosed) { conttype_diagnosed = 1; WARNOPT (WARN_CONTIGUOUS_CAST, (0, 0, _("Extracting contiguous files as regular files"))); } } fd = open (file_name, openflag, mode); #endif /* not O_CTG */ return fd; } static int extract_file (char *file_name, int typeflag) { int fd; off_t size; union block *data_block; int status; size_t count; size_t written; int interdir_made = 0; mode_t mode = current_stat_info.stat.st_mode & MODE_RWX & ~ current_umask; mode_t invert_permissions = 0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO) : 0; /* FIXME: deal with protection issues. */ if (to_stdout_option) fd = STDOUT_FILENO; else if (to_command_option) { fd = sys_exec_command (file_name, 'f', ¤t_stat_info); if (fd < 0) { skip_member (); return 0; } } else { int recover = RECOVER_NO; do fd = open_output_file (file_name, typeflag, mode ^ invert_permissions); while (fd < 0 && (recover = maybe_recoverable (file_name, &interdir_made)) == RECOVER_OK); if (fd < 0) { skip_member (); if (recover == RECOVER_SKIP) return 0; open_error (file_name); return 1; } } mv_begin (¤t_stat_info); if (current_stat_info.is_sparse) sparse_extract_file (fd, ¤t_stat_info, &size); else for (size = current_stat_info.stat.st_size; size > 0; ) { mv_size_left (size); /* Locate data, determine max length writeable, write it, block that we have used the data, then check if the write worked. */ data_block = find_next_block (); if (! data_block) { ERROR ((0, 0, _("Unexpected EOF in archive"))); break; /* FIXME: What happens, then? */ } written = available_space_after (data_block); if (written > size) written = size; errno = 0; count = full_write (fd, data_block->buffer, written); size -= written; set_next_block_after ((union block *) (data_block->buffer + written - 1)); if (count != written) { if (!to_command_option) write_error_details (file_name, count, written); /* FIXME: shouldn't we restore from backup? */ break; } } skip_file (size); mv_end (); /* If writing to stdout, don't try to do anything to the filename; it doesn't exist, or we don't want to touch it anyway. */ if (to_stdout_option) return 0; status = close (fd); if (status < 0) close_error (file_name); if (to_command_option) sys_wait_command (); else set_stat (file_name, ¤t_stat_info, NULL, invert_permissions, (old_files_option == OVERWRITE_OLD_FILES ? UNKNOWN_PERMSTATUS : ARCHIVED_PERMSTATUS), typeflag); return status; } /* Create a placeholder file with name FILE_NAME, which will be replaced after other extraction is done by a symbolic link if IS_SYMLINK is true, and by a hard link otherwise. Set *INTERDIR_MADE if an intermediate directory is made in the process. */ static int create_placeholder_file (char *file_name, bool is_symlink, int *interdir_made) { int fd; struct stat st; while ((fd = open (file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0) { switch (maybe_recoverable (file_name, interdir_made)) { case RECOVER_OK: continue; case RECOVER_SKIP: return 0; case RECOVER_NO: open_error (file_name); return -1; } } if (fstat (fd, &st) != 0) { stat_error (file_name); close (fd); } else if (close (fd) != 0) close_error (file_name); else { struct delayed_set_stat *h; struct delayed_link *p = xmalloc (offsetof (struct delayed_link, target) + strlen (current_stat_info.link_name) + 1); p->next = delayed_link_head; delayed_link_head = p; p->dev = st.st_dev; p->ino = st.st_ino; p->mtime = get_stat_mtime (&st); p->is_symlink = is_symlink; if (is_symlink) { p->uid = current_stat_info.stat.st_uid; p->gid = current_stat_info.stat.st_gid; } p->sources = xmalloc (offsetof (struct string_list, string) + strlen (file_name) + 1); p->sources->next = 0; strcpy (p->sources->string, file_name); strcpy (p->target, current_stat_info.link_name); h = delayed_set_stat_head; if (h && ! h->after_links && strncmp (file_name, h->file_name, h->file_name_len) == 0 && ISSLASH (file_name[h->file_name_len]) && (last_component (file_name) == file_name + h->file_name_len + 1)) { do { h->after_links = 1; if (stat (h->file_name, &st) != 0) stat_error (h->file_name); else { h->dev = st.st_dev; h->ino = st.st_ino; } } while ((h = h->next) && ! h->after_links); } return 0; } return -1; } static int extract_link (char *file_name, int typeflag) { int interdir_made = 0; char const *link_name; int rc; link_name = current_stat_info.link_name; if (! absolute_names_option && contains_dot_dot (link_name)) return create_placeholder_file (file_name, false, &interdir_made); do { struct stat st1, st2; int e; int status = link (link_name, file_name); e = errno; if (status == 0) { struct delayed_link *ds = delayed_link_head; if (ds && lstat (link_name, &st1) == 0) for (; ds; ds = ds->next) if (ds->dev == st1.st_dev && ds->ino == st1.st_ino && timespec_cmp (ds->mtime, get_stat_mtime (&st1)) == 0) { struct string_list *p = xmalloc (offsetof (struct string_list, string) + strlen (file_name) + 1); strcpy (p->string, file_name); p->next = ds->sources; ds->sources = p; break; } return 0; } else if ((e == EEXIST && strcmp (link_name, file_name) == 0) || (lstat (link_name, &st1) == 0 && lstat (file_name, &st2) == 0 && st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino)) return 0; errno = e; } while ((rc = maybe_recoverable (file_name, &interdir_made)) == RECOVER_OK); if (rc == RECOVER_SKIP) return 0; if (!(incremental_option && errno == EEXIST)) { link_error (link_name, file_name); return 1; } return 0; } static int extract_symlink (char *file_name, int typeflag) { #ifdef HAVE_SYMLINK int interdir_made = 0; if (! absolute_names_option && (IS_ABSOLUTE_FILE_NAME (current_stat_info.link_name) || contains_dot_dot (current_stat_info.link_name))) return create_placeholder_file (file_name, true, &interdir_made); while (symlink (current_stat_info.link_name, file_name)) switch (maybe_recoverable (file_name, &interdir_made)) { case RECOVER_OK: continue; case RECOVER_SKIP: return 0; case RECOVER_NO: symlink_error (current_stat_info.link_name, file_name); return -1; } set_stat (file_name, ¤t_stat_info, NULL, 0, 0, SYMTYPE); return 0; #else static int warned_once; if (!warned_once) { warned_once = 1; WARNOPT (WARN_SYMBOLIC_CAST, (0, 0, _("Attempting extraction of symbolic links as hard links"))); } return extract_link (file_name, typeflag); #endif } #if S_IFCHR || S_IFBLK static int extract_node (char *file_name, int typeflag) { int interdir_made = 0; mode_t mode = current_stat_info.stat.st_mode & ~ current_umask; mode_t invert_permissions = 0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO) : 0; while (mknod (file_name, mode ^ invert_permissions, current_stat_info.stat.st_rdev)) switch (maybe_recoverable (file_name, &interdir_made)) { case RECOVER_OK: continue; case RECOVER_SKIP: return 0; case RECOVER_NO: mknod_error (file_name); return -1; } set_stat (file_name, ¤t_stat_info, NULL, invert_permissions, ARCHIVED_PERMSTATUS, typeflag); return 0; } #endif #if HAVE_MKFIFO || defined mkfifo static int extract_fifo (char *file_name, int typeflag) { int status; int interdir_made = 0; mode_t mode = current_stat_info.stat.st_mode & ~ current_umask; mode_t invert_permissions = 0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO) : 0; while ((status = mkfifo (file_name, mode)) != 0) switch (maybe_recoverable (file_name, &interdir_made)) { case RECOVER_OK: continue; case RECOVER_SKIP: return 0; case RECOVER_NO: mkfifo_error (file_name); return -1; } set_stat (file_name, ¤t_stat_info, NULL, invert_permissions, ARCHIVED_PERMSTATUS, typeflag); return 0; } #endif static int extract_volhdr (char *file_name, int typeflag) { skip_member (); return 0; } static int extract_failure (char *file_name, int typeflag) { return 1; } typedef int (*tar_extractor_t) (char *file_name, int typeflag); /* Prepare to extract a file. Find extractor function. Return zero if extraction should not proceed. */ static int prepare_to_extract (char const *file_name, int typeflag, tar_extractor_t *fun) { int rc = 1; if (EXTRACT_OVER_PIPE) rc = 0; /* Select the extractor */ switch (typeflag) { case GNUTYPE_SPARSE: *fun = extract_file; rc = 1; break; case AREGTYPE: case REGTYPE: case CONTTYPE: /* Appears to be a file. But BSD tar uses the convention that a slash suffix means a directory. */ if (current_stat_info.had_trailing_slash) *fun = extract_dir; else { *fun = extract_file; rc = 1; } break; case SYMTYPE: *fun = extract_symlink; break; case LNKTYPE: *fun = extract_link; break; #if S_IFCHR case CHRTYPE: current_stat_info.stat.st_mode |= S_IFCHR; *fun = extract_node; break; #endif #if S_IFBLK case BLKTYPE: current_stat_info.stat.st_mode |= S_IFBLK; *fun = extract_node; break; #endif #if HAVE_MKFIFO || defined mkfifo case FIFOTYPE: *fun = extract_fifo; break; #endif case DIRTYPE: case GNUTYPE_DUMPDIR: *fun = extract_dir; if (current_stat_info.is_dumpdir) delay_directory_restore_option = true; break; case GNUTYPE_VOLHDR: *fun = extract_volhdr; break; case GNUTYPE_MULTIVOL: ERROR ((0, 0, _("%s: Cannot extract -- file is continued from another volume"), quotearg_colon (current_stat_info.file_name))); *fun = extract_failure; break; case GNUTYPE_LONGNAME: case GNUTYPE_LONGLINK: ERROR ((0, 0, _("Unexpected long name header"))); *fun = extract_failure; break; default: WARNOPT (WARN_UNKNOWN_CAST, (0, 0, _("%s: Unknown file type `%c', extracted as normal file"), quotearg_colon (file_name), typeflag)); *fun = extract_file; } /* Determine whether the extraction should proceed */ if (rc == 0) return 0; switch (old_files_option) { case UNLINK_FIRST_OLD_FILES: if (!remove_any_file (file_name, recursive_unlink_option ? RECURSIVE_REMOVE_OPTION : ORDINARY_REMOVE_OPTION) && errno && errno != ENOENT) { unlink_error (file_name); return 0; } break; case KEEP_NEWER_FILES: if (file_newer_p (file_name, ¤t_stat_info)) { WARNOPT (WARN_IGNORE_NEWER, (0, 0, _("Current %s is newer or same age"), quote (file_name))); return 0; } break; default: break; } return 1; } /* Extract a file from the archive. */ void extract_archive (void) { char typeflag; tar_extractor_t fun; fatal_exit_hook = extract_finish; /* Try to disable the ability to unlink a directory. */ priv_set_remove_linkdir (); set_next_block_after (current_header); decode_header (current_header, ¤t_stat_info, ¤t_format, 1); if (!current_stat_info.file_name[0] || (interactive_option && !confirm ("extract", current_stat_info.file_name))) { skip_member (); return; } /* Print the block from current_header and current_stat. */ if (verbose_option) print_header (¤t_stat_info, current_header, -1); /* Restore stats for all non-ancestor directories, unless it is an incremental archive. (see NOTICE in the comment to delay_set_stat above) */ if (!delay_directory_restore_option) apply_nonancestor_delayed_set_stat (current_stat_info.file_name, 0); /* Take a safety backup of a previously existing file. */ if (backup_option) if (!maybe_backup_file (current_stat_info.file_name, 0)) { int e = errno; ERROR ((0, e, _("%s: Was unable to backup this file"), quotearg_colon (current_stat_info.file_name))); skip_member (); return; } /* Extract the archive entry according to its type. */ /* KLUDGE */ typeflag = sparse_member_p (¤t_stat_info) ? GNUTYPE_SPARSE : current_header->header.typeflag; if (prepare_to_extract (current_stat_info.file_name, typeflag, &fun)) { if (fun && (*fun) (current_stat_info.file_name, typeflag) && backup_option) undo_last_backup (); } else skip_member (); } /* Extract the symbolic links whose final extraction were delayed. */ static void apply_delayed_links (void) { struct delayed_link *ds; for (ds = delayed_link_head; ds; ) { struct string_list *sources = ds->sources; char const *valid_source = 0; for (sources = ds->sources; sources; sources = sources->next) { char const *source = sources->string; struct stat st; /* Make sure the placeholder file is still there. If not, don't create a link, as the placeholder was probably removed by a later extraction. */ if (lstat (source, &st) == 0 && st.st_dev == ds->dev && st.st_ino == ds->ino && timespec_cmp (get_stat_mtime (&st), ds->mtime) == 0) { /* Unlink the placeholder, then create a hard link if possible, a symbolic link otherwise. */ if (unlink (source) != 0) unlink_error (source); else if (valid_source && link (valid_source, source) == 0) ; else if (!ds->is_symlink) { if (link (ds->target, source) != 0) link_error (ds->target, source); } else if (symlink (ds->target, source) != 0) symlink_error (ds->target, source); else { struct tar_stat_info st1; st1.stat.st_uid = ds->uid; st1.stat.st_gid = ds->gid; set_stat (source, &st1, NULL, 0, 0, SYMTYPE); valid_source = source; } } } for (sources = ds->sources; sources; ) { struct string_list *next = sources->next; free (sources); sources = next; } { struct delayed_link *next = ds->next; free (ds); ds = next; } } delayed_link_head = 0; } /* Finish the extraction of an archive. */ void extract_finish (void) { /* First, fix the status of ordinary directories that need fixing. */ apply_nonancestor_delayed_set_stat ("", 0); /* Then, apply delayed links, so that they don't affect delayed directory status-setting for ordinary directories. */ apply_delayed_links (); /* Finally, fix the status of directories that are ancestors of delayed links. */ apply_nonancestor_delayed_set_stat ("", 1); } bool rename_directory (char *src, char *dst) { if (rename (src, dst)) { int e = errno; switch (e) { case ENOENT: if (make_directories (dst)) { if (rename (src, dst) == 0) return true; e = errno; } break; case EXDEV: /* FIXME: Fall back to recursive copying */ default: break; } ERROR ((0, e, _("Cannot rename %s to %s"), quote_n (0, src), quote_n (1, dst))); return false; } return true; }