/* Extract files from a tar archive. Copyright 1988, 1992-1994, 1996-2001, 2003-2007, 2010, 2012-2013 Free Software Foundation, Inc. This file is part of GNU tar. GNU tar 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 of the License, or (at your option) any later version. GNU tar 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, see . Written by John Gilmore, on 1985-11-19. */ /* Modified to print checksums by Paul Klamer (LoC) 07/17/2014 */ #include #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) */ #define ALL_MODE_BITS ((mode_t) ~ (mode_t) 0) #if ! HAVE_FCHMOD && ! defined fchmod # define fchmod(fd, mode) (errno = ENOSYS, -1) #endif #if ! HAVE_FCHOWN && ! defined fchown # define fchown(fd, uid, gid) (errno = ENOSYS, -1) #endif /* Return true if an error number ERR means the system call is supported in this case. */ static bool implemented (int err) { return ! (err == ENOSYS || err == ENOTSUP || (EOPNOTSUPP != ENOTSUP && err == EOPNOTSUPP)); } /* 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 { /* Next directory in list. */ struct delayed_set_stat *next; /* Metadata for this directory. */ dev_t dev; ino_t ino; mode_t mode; /* The desired mode is MODE & ~ current_umask. */ uid_t uid; gid_t gid; struct timespec atime; struct timespec mtime; /* An estimate of the directory's current mode, along with a mask specifying which bits of this estimate are known to be correct. If CURRENT_MODE_MASK is zero, CURRENT_MODE's value doesn't matter. */ mode_t current_mode; mode_t current_mode_mask; /* This directory is an intermediate directory that was created as an ancestor of some other directory; it was not mentioned in the archive, so do not set its uid, gid, atime, or mtime, and don't alter its mode outside of MODE_RWX. */ bool interdir; /* Whether symbolic links should be followed when accessing the directory. */ int atflag; /* Do not set the status of this directory until after delayed links are created. */ bool after_links; /* Directory that the name is relative to. */ int change_dir; /* extended attributes*/ char *cntx_name; char *acls_a_ptr; size_t acls_a_len; char *acls_d_ptr; size_t acls_d_len; size_t xattr_map_size; struct xattr_array *xattr_map; /* Length and contents of name. */ size_t file_name_len; 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 birthtime of the placeholder. birthtime.tv_nsec is negative if the birthtime is not available. Don't use mtime as this would allow for false matches if some other process removes the placeholder. Don't use ctime as this would cause race conditions and other screwups, e.g., when restoring hard-linked symlinks. */ dev_t dev; ino_t ino; struct timespec birthtime; /* True if the link is symbolic. */ bool is_symlink; /* The desired metadata, valid only the link is symbolic. */ mode_t mode; uid_t uid; gid_t gid; struct timespec atime; struct timespec mtime; /* The directory that the sources and target are relative to. */ int change_dir; /* A list of sources for this link. The sources are all to be hard-linked together. */ struct string_list *sources; /* SELinux context */ char *cntx_name; /* ACLs */ char *acls_a_ptr; size_t acls_a_len; char *acls_d_ptr; size_t acls_d_len; size_t xattr_map_size; struct xattr_array *xattr_map; /* 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 () == ROOT_UID; 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; } } /* Use fchmod if possible, fchmodat otherwise. */ static int fd_chmod (int fd, char const *file, mode_t mode, int atflag) { if (0 <= fd) { int result = fchmod (fd, mode); if (result == 0 || implemented (errno)) return result; } return fchmodat (chdir_fd, file, mode, atflag); } /* Use fchown if possible, fchownat otherwise. */ static int fd_chown (int fd, char const *file, uid_t uid, gid_t gid, int atflag) { if (0 <= fd) { int result = fchown (fd, uid, gid); if (result == 0 || implemented (errno)) return result; } return fchownat (chdir_fd, file, uid, gid, atflag); } /* Use fstat if possible, fstatat otherwise. */ static int fd_stat (int fd, char const *file, struct stat *st, int atflag) { return (0 <= fd ? fstat (fd, st) : fstatat (chdir_fd, file, st, atflag)); } /* Set the mode for FILE_NAME to MODE. MODE_MASK specifies the bits of MODE that we care about; thus if MODE_MASK is zero, do nothing. If FD is nonnegative, it is a file descriptor for the file. CURRENT_MODE and CURRENT_MODE_MASK specify information known about the file's current mode, using the style of struct delayed_set_stat. TYPEFLAG specifies the type of the file. ATFLAG specifies the flag to use when statting the file. */ static void set_mode (char const *file_name, mode_t mode, mode_t mode_mask, int fd, mode_t current_mode, mode_t current_mode_mask, char typeflag, int atflag) { if (((current_mode ^ mode) | ~ current_mode_mask) & mode_mask) { if (MODE_ALL & ~ mode_mask & ~ current_mode_mask) { struct stat st; if (fd_stat (fd, file_name, &st, atflag) != 0) { stat_error (file_name); return; } current_mode = st.st_mode; } current_mode &= MODE_ALL; mode = (current_mode & ~ mode_mask) | (mode & mode_mask); if (current_mode != mode) { int chmod_errno = fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno; /* On Solaris, chmod may fail if we don't have PRIV_ALL, because setuid-root files would otherwise be a backdoor. See http://opensolaris.org/jive/thread.jspa?threadID=95826 (2009-09-03). */ if (chmod_errno == EPERM && (mode & S_ISUID) && priv_set_restore_linkdir () == 0) { chmod_errno = fd_chmod (fd, file_name, mode, atflag) == 0 ? 0 : errno; priv_set_remove_linkdir (); } /* Linux fchmodat does not support AT_SYMLINK_NOFOLLOW, and returns ENOTSUP even when operating on non-symlinks, try again with the flag disabled if it does not appear to be supported and if the file is not a symlink. This introduces a race, alas. */ if (atflag && typeflag != SYMTYPE && ! implemented (chmod_errno)) chmod_errno = fd_chmod (fd, file_name, mode, 0) == 0 ? 0 : errno; if (chmod_errno && (typeflag != SYMTYPE || implemented (chmod_errno))) { errno = chmod_errno; 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 FD is nonnegative, it is a file descriptor for the file. CURRENT_MODE and CURRENT_MODE_MASK specify information known about the file's current mode, using the style of struct delayed_set_stat. TYPEFLAG specifies the type of the file. If INTERDIR, this is an intermediate directory. ATFLAG specifies the flag to use when statting the file. */ static void set_stat (char const *file_name, struct tar_stat_info const *st, int fd, mode_t current_mode, mode_t current_mode_mask, char typeflag, bool interdir, int atflag) { /* Do the utime before the chmod because some versions of utime are broken and trash the modes of the file. */ if (! touch_option && ! interdir) { struct timespec ts[2]; if (incremental_option) ts[0] = st->atime; else ts[0].tv_nsec = UTIME_OMIT; ts[1] = st->mtime; if (fdutimensat (fd, chdir_fd, file_name, ts, atflag) == 0) { if (incremental_option) check_time (file_name, ts[0]); check_time (file_name, ts[1]); } else if (typeflag != SYMTYPE || implemented (errno)) utime_error (file_name); } if (0 < same_owner_option && ! interdir) { /* 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. */ uid_t uid = st->stat.st_uid; gid_t gid = st->stat.st_gid; if (fd_chown (fd, file_name, uid, gid, atflag) == 0) { /* Changing the owner can clear st_mode bits in some cases. */ if ((current_mode | ~ current_mode_mask) & S_IXUGO) current_mode_mask &= ~ (current_mode & (S_ISUID | S_ISGID)); } else if (typeflag != SYMTYPE || implemented (errno)) chown_error_details (file_name, uid, gid); } set_mode (file_name, st->stat.st_mode & ~ current_umask, 0 < same_permissions_option && ! interdir ? MODE_ALL : MODE_RWX, fd, current_mode, current_mode_mask, typeflag, atflag); /* these three calls must be done *after* fd_chown() call because fd_chown causes that linux capabilities becomes cleared. */ xattrs_xattrs_set (st, file_name, typeflag, 1); xattrs_acls_set (st, file_name, typeflag); xattrs_selinux_set (st, file_name, typeflag); } /* For each entry H in the leading prefix of entries in HEAD that do not have after_links marked, mark H and fill in its dev and ino members. Assume HEAD && ! HEAD->after_links. */ static void mark_after_links (struct delayed_set_stat *head) { struct delayed_set_stat *h = head; do { struct stat st; h->after_links = 1; if (deref_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); } /* 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 ST is null, merely create a placeholder node for an intermediate directory that was created by make_directories. 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 current_mode, mode_t current_mode_mask, mode_t mode, int atflag) { 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->mode = mode; if (st) { data->dev = st->stat.st_dev; data->ino = st->stat.st_ino; 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->current_mode = current_mode; data->current_mode_mask = current_mode_mask; data->interdir = ! st; data->atflag = atflag; data->after_links = 0; data->change_dir = chdir_current; data->cntx_name = NULL; if (st) assign_string (&data->cntx_name, st->cntx_name); if (st && st->acls_a_ptr) { data->acls_a_ptr = xmemdup (st->acls_a_ptr, st->acls_a_len + 1); data->acls_a_len = st->acls_a_len; } else { data->acls_a_ptr = NULL; data->acls_a_len = 0; } if (st && st->acls_d_ptr) { data->acls_d_ptr = xmemdup (st->acls_d_ptr, st->acls_d_len + 1); data->acls_d_len = st->acls_d_len; } else { data->acls_d_ptr = NULL; data->acls_d_len = 0; } if (st) xheader_xattr_copy (st, &data->xattr_map, &data->xattr_map_size); else { data->xattr_map = NULL; data->xattr_map_size = 0; } strcpy (data->file_name, file_name); delayed_set_stat_head = data; if (must_be_dot_or_slash (file_name)) mark_after_links (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 (fstatat (chdir_fd, data->file_name, &st, data->atflag) != 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->current_mode = st.st_mode; data->current_mode_mask = ALL_MODE_BITS; data->interdir = false; 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 zero if all the required directories were created, nonzero (issuing a diagnostic) otherwise. Set *INTERDIR_MADE if at least one directory was created. */ static int make_directories (char *file_name, bool *interdir_made) { char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name); char *cursor; /* points into the file name */ for (cursor = cursor0; *cursor; cursor++) { mode_t mode; mode_t desired_mode; int status; 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 */ desired_mode = MODE_RWX & ~ newdir_umask; mode = desired_mode | (we_are_root ? 0 : MODE_WXUSR); status = mkdirat (chdir_fd, file_name, mode); if (status == 0) { /* Create a struct delayed_set_stat even if mode == desired_mode, because repair_delayed_set_stat may need to update the struct. */ delay_set_stat (file_name, 0, mode & ~ current_umask, MODE_RWX, desired_mode, AT_SYMLINK_NOFOLLOW); print_for_mkdir (file_name, cursor - file_name, desired_mode); *interdir_made = true; } else if (errno == EEXIST) status = 0; else { /* Check whether the desired file exists. Even when the file exists, mkdir can fail with some errno value E other than EEXIST, so long as E describes an error condition that also applies. */ int e = errno; struct stat st; status = fstatat (chdir_fd, file_name, &st, 0); if (status) { errno = e; mkdir_error (file_name); } } *cursor = '/'; if (status) return status; } return 0; } /* Return true if FILE_NAME (with status *STP, if STP) is not a directory, and has a time stamp newer than (or equal to) that of TAR_STAT. */ static bool file_newer_p (const char *file_name, struct stat const *stp, struct tar_stat_info *tar_stat) { struct stat st; if (!stp) { if (deref_stat (file_name, &st) != 0) { if (errno != ENOENT) { stat_warn (file_name); /* Be safer: if the file exists, assume it is newer. */ return true; } return false; } stp = &st; } return (! S_ISDIR (stp->st_mode) && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (stp)) <= 0); } #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. If REGULAR, the caller was trying to extract onto a regular file. Set *INTERDIR_MADE if an intermediate directory is made as part of the recovery process. */ static int maybe_recoverable (char *file_name, bool regular, bool *interdir_made) { int e = errno; struct stat st; struct stat const *stp = 0; if (*interdir_made) return RECOVER_NO; switch (e) { case ELOOP: /* With open ("symlink", O_NOFOLLOW|...), POSIX says errno == ELOOP, but some operating systems do not conform to the standard. */ #ifdef EFTYPE /* NetBSD uses errno == EFTYPE; see . */ case EFTYPE: #endif /* FreeBSD 8.1 uses errno == EMLINK. */ case EMLINK: /* Tru64 5.1B uses errno == ENOTSUP. */ case ENOTSUP: if (! regular || old_files_option != OVERWRITE_OLD_FILES || dereference_option) break; if (strchr (file_name, '/')) { if (deref_stat (file_name, &st) != 0) break; stp = &st; } /* The caller tried to open a symbolic link with O_NOFOLLOW. Fall through, treating it as an already-existing file. */ case EEXIST: /* Remove an old file, if the options allow this. */ switch (old_files_option) { case SKIP_OLD_FILES: WARNOPT (WARN_EXISTING_FILE, (0, 0, _("%s: skipping existing file"), file_name)); return RECOVER_SKIP; case KEEP_OLD_FILES: return RECOVER_NO; case KEEP_NEWER_FILES: if (file_newer_p (file_name, stp, ¤t_stat_info)) break; /* FALL THROUGH */ case DEFAULT_OLD_FILES: case NO_OVERWRITE_DIR_OLD_FILES: case OVERWRITE_OLD_FILES: if (0 < remove_any_file (file_name, ORDINARY_REMOVE_OPTION)) return RECOVER_OK; break; case UNLINK_FIRST_OLD_FILES: break; } case ENOENT: /* Attempt creating missing intermediate directories. */ if (make_directories (file_name, interdir_made) == 0 && *interdir_made) return RECOVER_OK; break; default: /* Just say we can't do anything about it... */ break; } errno = e; return RECOVER_NO; } /* Restore stat extended attributes (xattr) for FILE_NAME, using information given in *ST. Restore before extraction because they may affect file layout (e.g. on Lustre distributed parallel filesystem - setting info about how many servers is this file striped over, stripe size, mirror copies, etc. in advance dramatically improves the following performance of reading and writing a file). If not restoring permissions, invert the INVERT_PERMISSIONS bits from the file's current permissions. TYPEFLAG specifies the type of the file. FILE_CREATED indicates set_xattr has created the file */ static int set_xattr (char const *file_name, struct tar_stat_info const *st, mode_t invert_permissions, char typeflag, int *file_created) { int status = 0; #ifdef HAVE_XATTRS bool interdir_made = false; if ((xattrs_option > 0) && st->xattr_map_size) { mode_t mode = current_stat_info.stat.st_mode & MODE_RWX & ~ current_umask; do status = mknodat (chdir_fd, file_name, mode ^ invert_permissions, 0); while (status && maybe_recoverable ((char *)file_name, false, &interdir_made)); xattrs_xattrs_set (st, file_name, typeflag, 0); *file_created = 1; } #endif return(status); } /* 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; mode_t current_mode = data->current_mode; mode_t current_mode_mask = data->current_mode_mask; 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; chdir_do (data->change_dir); if (check_for_renamed_directories) { if (fstatat (chdir_fd, data->file_name, &st, data->atflag) != 0) { stat_error (data->file_name); skip_this_one = 1; } else { current_mode = st.st_mode; current_mode_mask = ALL_MODE_BITS; 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; sb.cntx_name = data->cntx_name; sb.acls_a_ptr = data->acls_a_ptr; sb.acls_a_len = data->acls_a_len; sb.acls_d_ptr = data->acls_d_ptr; sb.acls_d_len = data->acls_d_len; sb.xattr_map = data->xattr_map; sb.xattr_map_size = data->xattr_map_size; set_stat (data->file_name, &sb, -1, current_mode, current_mode_mask, DIRTYPE, data->interdir, data->atflag); } delayed_set_stat_head = data->next; xheader_xattr_free (data->xattr_map, data->xattr_map_size); free (data->cntx_name); free (data->acls_a_ptr); free (data->acls_d_ptr); free (data); } } static bool is_directory_link (const char *file_name) { struct stat st; int e = errno; int res; res = (fstatat (chdir_fd, file_name, &st, AT_SYMLINK_NOFOLLOW) == 0 && S_ISLNK (st.st_mode) && fstatat (chdir_fd, file_name, &st, 0) == 0 && S_ISDIR (st.st_mode)); errno = e; return res; } /* Extractor functions for various member types */ static int extract_dir (char *file_name, int typeflag) { int status; mode_t mode; mode_t current_mode = 0; mode_t current_mode_mask = 0; int atflag = 0; bool interdir_made = false; /* Save 'root device' to avoid purging mount points. */ if (one_file_system_option && root_device == 0) { struct stat st; if (fstatat (chdir_fd, ".", &st, 0) != 0) stat_diag ("."); else root_device = st.st_dev; } 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 (); /* If ownership or permissions will be restored later, create the directory with restrictive permissions at first, so that in the meantime processes owned by other users do not inadvertently create files under this directory that inherit the wrong owner, group, or permissions from the directory. If not root, though, make the directory writeable and searchable at first, so that files can be created under it. */ mode = ((current_stat_info.stat.st_mode & (0 < same_owner_option || 0 < same_permissions_option ? S_IRWXU : MODE_RWX)) | (we_are_root ? 0 : MODE_WXUSR)); for (;;) { status = mkdirat (chdir_fd, file_name, mode); if (status == 0) { current_mode = mode & ~ current_umask; current_mode_mask = MODE_RWX; atflag = AT_SYMLINK_NOFOLLOW; break; } if (errno == EEXIST && (interdir_made || keep_directory_symlink_option || old_files_option == DEFAULT_OLD_FILES || old_files_option == OVERWRITE_OLD_FILES)) { struct stat st; if (keep_directory_symlink_option && is_directory_link (file_name)) return 0; if (deref_stat (file_name, &st) == 0) { current_mode = st.st_mode; current_mode_mask = ALL_MODE_BITS; if (S_ISDIR (current_mode)) { if (interdir_made) { repair_delayed_set_stat (file_name, &st); return 0; } break; } } errno = EEXIST; } switch (maybe_recoverable (file_name, false, &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) delay_set_stat (file_name, ¤t_stat_info, current_mode, current_mode_mask, current_stat_info.stat.st_mode, atflag); return status; } static int open_output_file (char const *file_name, int typeflag, mode_t mode, int file_created, mode_t *current_mode, mode_t *current_mode_mask) { int fd; bool overwriting_old_files = old_files_option == OVERWRITE_OLD_FILES; int openflag = (O_WRONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK | O_CREAT | (overwriting_old_files ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW) : O_EXCL)); /* File might be created in set_xattr. So clear O_EXCL to avoid open() fail */ if (file_created) openflag = openflag & ~O_EXCL; 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"))); } } /* If O_NOFOLLOW is needed but does not work, check for a symlink separately. There's a race condition, but that cannot be avoided on hosts lacking O_NOFOLLOW. */ if (! HAVE_WORKING_O_NOFOLLOW && overwriting_old_files && ! dereference_option) { struct stat st; if (fstatat (chdir_fd, file_name, &st, AT_SYMLINK_NOFOLLOW) == 0 && S_ISLNK (st.st_mode)) { errno = ELOOP; return -1; } } fd = openat (chdir_fd, file_name, openflag, mode); if (0 <= fd) { if (overwriting_old_files) { struct stat st; if (fstat (fd, &st) != 0) { int e = errno; close (fd); errno = e; return -1; } if (! S_ISREG (st.st_mode)) { close (fd); errno = EEXIST; return -1; } *current_mode = st.st_mode; *current_mode_mask = ALL_MODE_BITS; } else { *current_mode = mode & ~ current_umask; *current_mode_mask = MODE_RWX; } } 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; bool interdir_made = false; EVP_MD_CTX shatx; //this is the handle that passes the SHA1 data EVP_MD_CTX mdctx; // and this passes the md5 data EVP_MD_CTX sha256tx; //this is the handle that passes the SHA1 data EVP_MD_CTX sha512tx; // and this passes the md5 data char sha1ChkSum[128], md5ChkSum[128],sha256ChkSum[128],sha512ChkSum[128]; // these are the strings that get the printable values unsigned int sha1_len,md_len,sha256_len,sha512_len,i; unsigned char sha1_value[EVP_MAX_MD_SIZE]; // this receives the SHA1 hex value unsigned char md_value[EVP_MAX_MD_SIZE]; // and the md5 value unsigned char sha256_value[EVP_MAX_MD_SIZE]; // this receives the SHA256 hex value unsigned char sha512_value[EVP_MAX_MD_SIZE]; // and the sha512 value mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); mode_t invert_permissions = 0 < same_owner_option ? mode & (S_IRWXG | S_IRWXO) : 0; mode_t current_mode = 0; mode_t current_mode_mask = 0; //printf("right here Bub, extract.c\n"); if(sha1_option) EVP_DigestInit(&shatx, EVP_sha1()); if (md5_option) EVP_DigestInit(&mdctx, EVP_md5()); if(sha256_option) EVP_DigestInit(&sha256tx, EVP_sha256()); if (sha512_option) EVP_DigestInit(&sha512tx, EVP_sha512()); 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 file_created = 0; if (set_xattr (file_name, ¤t_stat_info, invert_permissions, typeflag, &file_created)) { skip_member (); open_error (file_name); return 1; } while ((fd = open_output_file (file_name, typeflag, mode, file_created, ¤t_mode, ¤t_mode_mask)) < 0) { int recover = maybe_recoverable (file_name, true, &interdir_made); if (recover != RECOVER_OK) { skip_member (); if (recover == RECOVER_SKIP) return 0; open_error (file_name); return 1; } } } mv_begin_read (¤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 = blocking_write (fd, data_block->buffer, written); size -= written; //printf("Write Block\n"); if (sha1_option) EVP_DigestUpdate(&shatx, data_block,written); if (md5_option) EVP_DigestUpdate(&mdctx, data_block,written); if (sha256_option) EVP_DigestUpdate(&sha256tx, data_block,written); if (sha512_option) EVP_DigestUpdate(&sha512tx, data_block,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; if (! to_command_option) set_stat (file_name, ¤t_stat_info, fd, current_mode, current_mode_mask, typeflag, false, (old_files_option == OVERWRITE_OLD_FILES ? 0 : AT_SYMLINK_NOFOLLOW)); if (sha1_option) { EVP_DigestFinal(&shatx, sha1_value, &sha1_len); EVP_MD_CTX_cleanup(&shatx); for (i=0;inext = delayed_link_head; delayed_link_head = p; p->dev = st.st_dev; p->ino = st.st_ino; p->birthtime = get_stat_birthtime (&st); p->is_symlink = is_symlink; if (is_symlink) { p->mode = current_stat_info.stat.st_mode; p->uid = current_stat_info.stat.st_uid; p->gid = current_stat_info.stat.st_gid; p->atime = current_stat_info.atime; p->mtime = current_stat_info.mtime; } p->change_dir = chdir_current; p->sources = xmalloc (offsetof (struct string_list, string) + strlen (file_name) + 1); p->sources->next = 0; strcpy (p->sources->string, file_name); p->cntx_name = NULL; assign_string (&p->cntx_name, current_stat_info.cntx_name); p->acls_a_ptr = NULL; p->acls_a_len = 0; p->acls_d_ptr = NULL; p->acls_d_len = 0; xheader_xattr_copy (¤t_stat_info, &p->xattr_map, &p->xattr_map_size); 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)) mark_after_links (h); return 0; } return -1; } static int extract_link (char *file_name, int typeflag) { bool interdir_made = false; 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 = linkat (chdir_fd, link_name, chdir_fd, file_name, 0); e = errno; if (status == 0) { struct delayed_link *ds = delayed_link_head; if (ds && fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW) == 0) for (; ds; ds = ds->next) if (ds->change_dir == chdir_current && ds->dev == st1.st_dev && ds->ino == st1.st_ino && (timespec_cmp (ds->birthtime, get_stat_birthtime (&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) || ((fstatat (chdir_fd, link_name, &st1, AT_SYMLINK_NOFOLLOW) == 0) && (fstatat (chdir_fd, file_name, &st2, AT_SYMLINK_NOFOLLOW) == 0) && st1.st_dev == st2.st_dev && st1.st_ino == st2.st_ino)) return 0; errno = e; } while ((rc = maybe_recoverable (file_name, false, &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 bool interdir_made = false; 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 (symlinkat (current_stat_info.link_name, chdir_fd, file_name) != 0) switch (maybe_recoverable (file_name, false, &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, -1, 0, 0, SYMTYPE, false, AT_SYMLINK_NOFOLLOW); return 0; #else static int warned_once; if (!warned_once) { warned_once = 1; WARNOPT (WARN_SYMLINK_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) { bool interdir_made = false; mode_t mode = (current_stat_info.stat.st_mode & (MODE_RWX | S_IFBLK | S_IFCHR) & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); while (mknodat (chdir_fd, file_name, mode, current_stat_info.stat.st_rdev) != 0) switch (maybe_recoverable (file_name, false, &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, -1, mode & ~ current_umask, MODE_RWX, typeflag, false, AT_SYMLINK_NOFOLLOW); return 0; } #endif #if HAVE_MKFIFO || defined mkfifo static int extract_fifo (char *file_name, int typeflag) { bool interdir_made = false; mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); while (mkfifoat (chdir_fd, file_name, mode) != 0) switch (maybe_recoverable (file_name, false, &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, -1, mode & ~ current_umask, MODE_RWX, typeflag, false, AT_SYMLINK_NOFOLLOW); 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; } static int extract_skip (char *file_name, int typeflag) { skip_member (); return 0; } 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_skip; 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, 0, ¤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; set_next_block_after (current_header); 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) { int dir = chdir_current; apply_nonancestor_delayed_set_stat (current_stat_info.file_name, 0); chdir_do (dir); } /* 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 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; chdir_do (ds->change_dir); 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 (fstatat (chdir_fd, source, &st, AT_SYMLINK_NOFOLLOW) == 0 && st.st_dev == ds->dev && st.st_ino == ds->ino && timespec_cmp (get_stat_birthtime (&st), ds->birthtime) == 0) { /* Unlink the placeholder, then create a hard link if possible, a symbolic link otherwise. */ if (unlinkat (chdir_fd, source, 0) != 0) unlink_error (source); else if (valid_source && (linkat (chdir_fd, valid_source, chdir_fd, source, 0) == 0)) ; else if (!ds->is_symlink) { if (linkat (chdir_fd, ds->target, chdir_fd, source, 0) != 0) link_error (ds->target, source); } else if (symlinkat (ds->target, chdir_fd, source) != 0) symlink_error (ds->target, source); else { struct tar_stat_info st1; st1.stat.st_mode = ds->mode; st1.stat.st_uid = ds->uid; st1.stat.st_gid = ds->gid; st1.atime = ds->atime; st1.mtime = ds->mtime; st1.cntx_name = ds->cntx_name; st1.acls_a_ptr = ds->acls_a_ptr; st1.acls_a_len = ds->acls_a_len; st1.acls_d_ptr = ds->acls_d_ptr; st1.acls_d_len = ds->acls_d_len; st1.xattr_map = ds->xattr_map; st1.xattr_map_size = ds->xattr_map_size; set_stat (source, &st1, -1, 0, 0, SYMTYPE, false, AT_SYMLINK_NOFOLLOW); valid_source = source; } } } for (sources = ds->sources; sources; ) { struct string_list *next = sources->next; free (sources); sources = next; } xheader_xattr_free (ds->xattr_map, ds->xattr_map_size); free (ds->cntx_name); { 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 (renameat (chdir_fd, src, chdir_fd, dst) != 0) { int e = errno; bool interdir_made; switch (e) { case ENOENT: if (make_directories (dst, &interdir_made) == 0) { if (renameat (chdir_fd, src, chdir_fd, 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; }