backup.c - android_external_rsync - Gitiles

 /*
  * Backup handling code.
  *
  * Copyright (C) 1999 Andrew Tridgell
  * Copyright (C) 2003-2009 Wayne Davison
  *
  * 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 of the License, 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, visit the http://fsf.org website.
  */

 #include "rsync.h"

 extern int verbose;
 extern int am_root;
 extern int preserve_acls;
 extern int preserve_xattrs;
 extern int preserve_devices;
 extern int preserve_specials;
 extern int preserve_links;
 extern int safe_symlinks;
 extern int backup_dir_len;
 extern unsigned int backup_dir_remainder;
 extern char backup_dir_buf[MAXPATHLEN];
 extern char *backup_suffix;
 extern char *backup_dir;

 /* make a complete pathname for backup file */
 char *get_backup_name(const char *fname)
 {
 	if (backup_dir) {
 		if (stringjoin(backup_dir_buf + backup_dir_len, backup_dir_remainder,
 			       fname, backup_suffix, NULL) < backup_dir_remainder)
 			return backup_dir_buf;
 	} else {
 		if (stringjoin(backup_dir_buf, MAXPATHLEN,
 			       fname, backup_suffix, NULL) < MAXPATHLEN)
 			return backup_dir_buf;
 	}

 	rprintf(FERROR, "backup filename too long\n");
 	return NULL;
 }

 /* simple backup creates a backup with a suffix in the same directory */
 static int make_simple_backup(const char *fname)
 {
 	int rename_errno;
 	const char *fnamebak = get_backup_name(fname);

 	if (!fnamebak)
 		return 0;

 	while (1) {
 		if (do_rename(fname, fnamebak) == 0) {
 			if (verbose > 1) {
 				rprintf(FINFO, "backed up %s to %s\n",
 					fname, fnamebak);
 			}
 			break;
 		}
 		/* cygwin (at least version b19) reports EINVAL */
 		if (errno == ENOENT || errno == EINVAL)
 			break;

 		rename_errno = errno;
 		if (errno == EISDIR && do_rmdir(fnamebak) == 0)
 			continue;
 		if (errno == ENOTDIR && do_unlink(fnamebak) == 0)
 			continue;

 		rsyserr(FERROR, rename_errno, "rename %s to backup %s",
 			fname, fnamebak);
 		errno = rename_errno;
 		return 0;
 	}

 	return 1;
 }


 /****************************************************************************
 Create a directory given an absolute path, perms based upon another directory
 path
 ****************************************************************************/
 int make_bak_dir(const char *fullpath)
 {
 	char fbuf[MAXPATHLEN], *rel, *end, *p;
 	struct file_struct *file;
 	int len = backup_dir_len;
 	stat_x sx;

 	while (*fullpath == '.' && fullpath[1] == '/') {
 		fullpath += 2;
 		len -= 2;
 	}

 	if (strlcpy(fbuf, fullpath, sizeof fbuf) >= sizeof fbuf)
 		return -1;

 	rel = fbuf + len;
 	end = p = rel + strlen(rel);

 	/* Try to find an existing dir, starting from the deepest dir. */
 	while (1) {
 		if (--p == fbuf)
 			return -1;
 		if (*p == '/') {
 			*p = '\0';
 			if (mkdir_defmode(fbuf) == 0)
 				break;
 			if (errno != ENOENT) {
 				rsyserr(FERROR, errno,
 					"make_bak_dir mkdir %s failed",
 					full_fname(fbuf));
 				return -1;
 			}
 		}
 	}

 	/* Make all the dirs that we didn't find on the way here. */
 	while (1) {
 		if (p >= rel) {
 			/* Try to transfer the directory settings of the
 			 * actual dir that the files are coming from. */
 			if (x_stat(rel, &sx.st, NULL) < 0) {
 				rsyserr(FERROR, errno,
 					"make_bak_dir stat %s failed",
 					full_fname(rel));
 			} else {
 #ifdef SUPPORT_ACLS
 				sx.acc_acl = sx.def_acl = NULL;
 #endif
 #ifdef SUPPORT_XATTRS
 				sx.xattr = NULL;
 #endif
 				if (!(file = make_file(rel, NULL, NULL, 0, NO_FILTERS)))
 					continue;
 #ifdef SUPPORT_ACLS
 				if (preserve_acls && !S_ISLNK(file->mode)) {
 					get_acl(rel, &sx);
 					cache_tmp_acl(file, &sx);
 					free_acl(&sx);
 				}
 #endif
 #ifdef SUPPORT_XATTRS
 				if (preserve_xattrs) {
 					get_xattr(rel, &sx);
 					cache_tmp_xattr(file, &sx);
 					free_xattr(&sx);
 				}
 #endif
 				set_file_attrs(fbuf, file, NULL, NULL, 0);
 				unmake_file(file);
 #ifdef SUPPORT_ACLS
 				uncache_tmp_acls();
 #endif
 #ifdef SUPPORT_XATTRS
 				uncache_tmp_xattrs();
 #endif
 			}
 		}
 		*p = '/';
 		p += strlen(p);
 		if (p == end)
 			break;
 		if (mkdir_defmode(fbuf) < 0) {
 			rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
 				full_fname(fbuf));
 			return -1;
 		}
 	}

 	return 0;
 }

 /* robustly move a file, creating new directory structures if necessary */
 static int robust_move(const char *src, char *dst)
 {
 	if (robust_rename(src, dst, NULL, 0755) < 0) {
 		int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
 		if (errno == ENOENT && make_bak_dir(dst) == 0) {
 			if (robust_rename(src, dst, NULL, 0755) < 0)
 				save_errno = errno ? errno : save_errno;
 			else
 				save_errno = 0;
 		}
 		if (save_errno) {
 			errno = save_errno;
 			return -1;
 		}
 	}
 	return 0;
 }


 /* If we have a --backup-dir, then we get here from make_backup().
  * We will move the file to be deleted into a parallel directory tree. */
 static int keep_backup(const char *fname)
 {
 	stat_x sx;
 	struct file_struct *file;
 	char *buf;
 	int save_preserve_xattrs = preserve_xattrs;
 	int kept = 0;
 	int ret_code;

 	/* return if no file to keep */
 	if (x_lstat(fname, &sx.st, NULL) < 0)
 		return 1;
 #ifdef SUPPORT_ACLS
 	sx.acc_acl = sx.def_acl = NULL;
 #endif
 #ifdef SUPPORT_XATTRS
 	sx.xattr = NULL;
 #endif

 	if (!(file = make_file(fname, NULL, NULL, 0, NO_FILTERS)))
 		return 1; /* the file could have disappeared */

 	if (!(buf = get_backup_name(fname))) {
 		unmake_file(file);
 #ifdef SUPPORT_ACLS
 		uncache_tmp_acls();
 #endif
 #ifdef SUPPORT_XATTRS
 		uncache_tmp_xattrs();
 #endif
 		return 0;
 	}

 #ifdef SUPPORT_ACLS
 	if (preserve_acls && !S_ISLNK(file->mode)) {
 		get_acl(fname, &sx);
 		cache_tmp_acl(file, &sx);
 		free_acl(&sx);
 	}
 #endif
 #ifdef SUPPORT_XATTRS
 	if (preserve_xattrs) {
 		get_xattr(fname, &sx);
 		cache_tmp_xattr(file, &sx);
 		free_xattr(&sx);
 	}
 #endif

 	/* Check to see if this is a device file, or link */
 	if ((am_root && preserve_devices && IS_DEVICE(file->mode))
 	 || (preserve_specials && IS_SPECIAL(file->mode))) {
 		int save_errno;
 		do_unlink(buf);
 		if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0) {
 			save_errno = errno ? errno : EINVAL; /* 0 paranoia */
 			if (errno == ENOENT && make_bak_dir(buf) == 0) {
 				if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0)
 					save_errno = errno ? errno : save_errno;
 				else
 					save_errno = 0;
 			}
 			if (save_errno) {
 				rsyserr(FERROR, save_errno, "mknod %s failed",
 					full_fname(buf));
 			}
 		} else
 			save_errno = 0;
 		if (verbose > 2 && save_errno == 0) {
 			rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
 				fname);
 		}
 		kept = 1;
 		do_unlink(fname);
 	}

 	if (!kept && S_ISDIR(file->mode)) {
 		/* make an empty directory */
 		if (do_mkdir(buf, file->mode) < 0) {
 			int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
 			if (errno == ENOENT && make_bak_dir(buf) == 0) {
 				if (do_mkdir(buf, file->mode) < 0)
 					save_errno = errno ? errno : save_errno;
 				else
 					save_errno = 0;
 			}
 			if (save_errno) {
 				rsyserr(FINFO, save_errno, "mkdir %s failed",
 					full_fname(buf));
 			}
 		}

 		ret_code = do_rmdir(fname);
 		if (verbose > 2) {
 			rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
 				full_fname(fname), ret_code);
 		}
 		kept = 1;
 	}

 #ifdef SUPPORT_LINKS
 	if (!kept && preserve_links && S_ISLNK(file->mode)) {
 		const char *sl = F_SYMLINK(file);
 		if (safe_symlinks && unsafe_symlink(sl, fname)) {
 			if (verbose) {
 				rprintf(FINFO, "not backing up unsafe symlink \"%s\" -> \"%s\"\n",
 					fname, sl);
 			}
 			kept = 1;
 		} else {
 			do_unlink(buf);
 			if (do_symlink(sl, buf) < 0) {
 				int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
 				if (errno == ENOENT && make_bak_dir(buf) == 0) {
 					if (do_symlink(sl, buf) < 0)
 						save_errno = errno ? errno : save_errno;
 					else
 						save_errno = 0;
 				}
 				if (save_errno) {
 					rsyserr(FERROR, save_errno, "link %s -> \"%s\"",
 						full_fname(buf), sl);
 				}
 			}
 			do_unlink(fname);
 			kept = 1;
 		}
 	}
 #endif

 	if (!kept && !S_ISREG(file->mode)) {
 		rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
 			fname);
 		unmake_file(file);
 #ifdef SUPPORT_ACLS
 		uncache_tmp_acls();
 #endif
 #ifdef SUPPORT_XATTRS
 		uncache_tmp_xattrs();
 #endif
 		return 1;
 	}

 	/* move to keep tree if a file */
 	if (!kept) {
 		if (robust_move(fname, buf) != 0) {
 			rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
 				full_fname(fname), buf);
 		} else if (sx.st.st_nlink > 1) {
 			/* If someone has hard-linked the file into the backup
 			 * dir, rename() might return success but do nothing! */
 			robust_unlink(fname); /* Just in case... */
 		}
 	}
 	preserve_xattrs = 0;
 	set_file_attrs(buf, file, NULL, fname, 0);
 	preserve_xattrs = save_preserve_xattrs;
 	unmake_file(file);
 #ifdef SUPPORT_ACLS
 	uncache_tmp_acls();
 #endif
 #ifdef SUPPORT_XATTRS
 	uncache_tmp_xattrs();
 #endif

 	if (verbose > 1) {
 		rprintf(FINFO, "backed up %s to %s\n",
 			fname, buf);
 	}
 	return 1;
 }


 /* main backup switch routine */
 int make_backup(const char *fname)
 {
 	if (backup_dir)
 		return keep_backup(fname);
 	return make_simple_backup(fname);
 }
	/*
	* Backup handling code.
	*
	* Copyright (C) 1999 Andrew Tridgell
	* Copyright (C) 2003-2009 Wayne Davison
	*
	* 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 of the License, 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, visit the http://fsf.org website.
	*/

	#include "rsync.h"

	extern int verbose;
	extern int am_root;
	extern int preserve_acls;
	extern int preserve_xattrs;
	extern int preserve_devices;
	extern int preserve_specials;
	extern int preserve_links;
	extern int safe_symlinks;
	extern int backup_dir_len;
	extern unsigned int backup_dir_remainder;
	extern char backup_dir_buf[MAXPATHLEN];
	extern char *backup_suffix;
	extern char *backup_dir;

	/* make a complete pathname for backup file */
	char get_backup_name(const char fname)
	{
	if (backup_dir) {
	if (stringjoin(backup_dir_buf + backup_dir_len, backup_dir_remainder,
	fname, backup_suffix, NULL) < backup_dir_remainder)
	return backup_dir_buf;
	} else {
	if (stringjoin(backup_dir_buf, MAXPATHLEN,
	fname, backup_suffix, NULL) < MAXPATHLEN)
	return backup_dir_buf;
	}

	rprintf(FERROR, "backup filename too long\n");
	return NULL;
	}

	/* simple backup creates a backup with a suffix in the same directory */
	static int make_simple_backup(const char *fname)
	{
	int rename_errno;
	const char *fnamebak = get_backup_name(fname);

	if (!fnamebak)
	return 0;

	while (1) {
	if (do_rename(fname, fnamebak) == 0) {
	if (verbose > 1) {
	rprintf(FINFO, "backed up %s to %s\n",
	fname, fnamebak);
	}
	break;
	}
	/* cygwin (at least version b19) reports EINVAL */
	if (errno == ENOENT \|\| errno == EINVAL)
	break;

	rename_errno = errno;
	if (errno == EISDIR && do_rmdir(fnamebak) == 0)
	continue;
	if (errno == ENOTDIR && do_unlink(fnamebak) == 0)
	continue;

	rsyserr(FERROR, rename_errno, "rename %s to backup %s",
	fname, fnamebak);
	errno = rename_errno;
	return 0;
	}

	return 1;
	}


	/****************************************************************************
	Create a directory given an absolute path, perms based upon another directory
	path
	****************************************************************************/
	int make_bak_dir(const char *fullpath)
	{
	char fbuf[MAXPATHLEN], rel, end, *p;
	struct file_struct *file;
	int len = backup_dir_len;
	stat_x sx;

	while (*fullpath == '.' && fullpath[1] == '/') {
	fullpath += 2;
	len -= 2;
	}

	if (strlcpy(fbuf, fullpath, sizeof fbuf) >= sizeof fbuf)
	return -1;

	rel = fbuf + len;
	end = p = rel + strlen(rel);

	/* Try to find an existing dir, starting from the deepest dir. */
	while (1) {
	if (--p == fbuf)
	return -1;
	if (*p == '/') {
	*p = '\0';
	if (mkdir_defmode(fbuf) == 0)
	break;
	if (errno != ENOENT) {
	rsyserr(FERROR, errno,
	"make_bak_dir mkdir %s failed",
	full_fname(fbuf));
	return -1;
	}
	}
	}

	/* Make all the dirs that we didn't find on the way here. */
	while (1) {
	if (p >= rel) {
	/* Try to transfer the directory settings of the
	* actual dir that the files are coming from. */
	if (x_stat(rel, &sx.st, NULL) < 0) {
	rsyserr(FERROR, errno,
	"make_bak_dir stat %s failed",
	full_fname(rel));
	} else {
	#ifdef SUPPORT_ACLS
	sx.acc_acl = sx.def_acl = NULL;
	#endif
	#ifdef SUPPORT_XATTRS
	sx.xattr = NULL;
	#endif
	if (!(file = make_file(rel, NULL, NULL, 0, NO_FILTERS)))
	continue;
	#ifdef SUPPORT_ACLS
	if (preserve_acls && !S_ISLNK(file->mode)) {
	get_acl(rel, &sx);
	cache_tmp_acl(file, &sx);
	free_acl(&sx);
	}
	#endif
	#ifdef SUPPORT_XATTRS
	if (preserve_xattrs) {
	get_xattr(rel, &sx);
	cache_tmp_xattr(file, &sx);
	free_xattr(&sx);
	}
	#endif
	set_file_attrs(fbuf, file, NULL, NULL, 0);
	unmake_file(file);
	#ifdef SUPPORT_ACLS
	uncache_tmp_acls();
	#endif
	#ifdef SUPPORT_XATTRS
	uncache_tmp_xattrs();
	#endif
	}
	}
	*p = '/';
	p += strlen(p);
	if (p == end)
	break;
	if (mkdir_defmode(fbuf) < 0) {
	rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
	full_fname(fbuf));
	return -1;
	}
	}

	return 0;
	}

	/* robustly move a file, creating new directory structures if necessary */
	static int robust_move(const char src, char dst)
	{
	if (robust_rename(src, dst, NULL, 0755) < 0) {
	int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
	if (errno == ENOENT && make_bak_dir(dst) == 0) {
	if (robust_rename(src, dst, NULL, 0755) < 0)
	save_errno = errno ? errno : save_errno;
	else
	save_errno = 0;
	}
	if (save_errno) {
	errno = save_errno;
	return -1;
	}
	}
	return 0;
	}


	/* If we have a --backup-dir, then we get here from make_backup().
	* We will move the file to be deleted into a parallel directory tree. */
	static int keep_backup(const char *fname)
	{
	stat_x sx;
	struct file_struct *file;
	char *buf;
	int save_preserve_xattrs = preserve_xattrs;
	int kept = 0;
	int ret_code;

	/* return if no file to keep */
	if (x_lstat(fname, &sx.st, NULL) < 0)
	return 1;
	#ifdef SUPPORT_ACLS
	sx.acc_acl = sx.def_acl = NULL;
	#endif
	#ifdef SUPPORT_XATTRS
	sx.xattr = NULL;
	#endif

	if (!(file = make_file(fname, NULL, NULL, 0, NO_FILTERS)))
	return 1; /* the file could have disappeared */

	if (!(buf = get_backup_name(fname))) {
	unmake_file(file);
	#ifdef SUPPORT_ACLS
	uncache_tmp_acls();
	#endif
	#ifdef SUPPORT_XATTRS
	uncache_tmp_xattrs();
	#endif
	return 0;
	}

	#ifdef SUPPORT_ACLS
	if (preserve_acls && !S_ISLNK(file->mode)) {
	get_acl(fname, &sx);
	cache_tmp_acl(file, &sx);
	free_acl(&sx);
	}
	#endif
	#ifdef SUPPORT_XATTRS
	if (preserve_xattrs) {
	get_xattr(fname, &sx);
	cache_tmp_xattr(file, &sx);
	free_xattr(&sx);
	}
	#endif

	/* Check to see if this is a device file, or link */
	if ((am_root && preserve_devices && IS_DEVICE(file->mode))
	\|\| (preserve_specials && IS_SPECIAL(file->mode))) {
	int save_errno;
	do_unlink(buf);
	if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0) {
	save_errno = errno ? errno : EINVAL; /* 0 paranoia */
	if (errno == ENOENT && make_bak_dir(buf) == 0) {
	if (do_mknod(buf, file->mode, sx.st.st_rdev) < 0)
	save_errno = errno ? errno : save_errno;
	else
	save_errno = 0;
	}
	if (save_errno) {
	rsyserr(FERROR, save_errno, "mknod %s failed",
	full_fname(buf));
	}
	} else
	save_errno = 0;
	if (verbose > 2 && save_errno == 0) {
	rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
	fname);
	}
	kept = 1;
	do_unlink(fname);
	}

	if (!kept && S_ISDIR(file->mode)) {
	/* make an empty directory */
	if (do_mkdir(buf, file->mode) < 0) {
	int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
	if (errno == ENOENT && make_bak_dir(buf) == 0) {
	if (do_mkdir(buf, file->mode) < 0)
	save_errno = errno ? errno : save_errno;
	else
	save_errno = 0;
	}
	if (save_errno) {
	rsyserr(FINFO, save_errno, "mkdir %s failed",
	full_fname(buf));
	}
	}

	ret_code = do_rmdir(fname);
	if (verbose > 2) {
	rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
	full_fname(fname), ret_code);
	}
	kept = 1;
	}

	#ifdef SUPPORT_LINKS
	if (!kept && preserve_links && S_ISLNK(file->mode)) {
	const char *sl = F_SYMLINK(file);
	if (safe_symlinks && unsafe_symlink(sl, fname)) {
	if (verbose) {
	rprintf(FINFO, "not backing up unsafe symlink \"%s\" -> \"%s\"\n",
	fname, sl);
	}
	kept = 1;
	} else {
	do_unlink(buf);
	if (do_symlink(sl, buf) < 0) {
	int save_errno = errno ? errno : EINVAL; /* 0 paranoia */
	if (errno == ENOENT && make_bak_dir(buf) == 0) {
	if (do_symlink(sl, buf) < 0)
	save_errno = errno ? errno : save_errno;
	else
	save_errno = 0;
	}
	if (save_errno) {
	rsyserr(FERROR, save_errno, "link %s -> \"%s\"",
	full_fname(buf), sl);
	}
	}
	do_unlink(fname);
	kept = 1;
	}
	}
	#endif

	if (!kept && !S_ISREG(file->mode)) {
	rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
	fname);
	unmake_file(file);
	#ifdef SUPPORT_ACLS
	uncache_tmp_acls();
	#endif
	#ifdef SUPPORT_XATTRS
	uncache_tmp_xattrs();
	#endif
	return 1;
	}

	/* move to keep tree if a file */
	if (!kept) {
	if (robust_move(fname, buf) != 0) {
	rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
	full_fname(fname), buf);
	} else if (sx.st.st_nlink > 1) {
	/* If someone has hard-linked the file into the backup
	* dir, rename() might return success but do nothing! */
	robust_unlink(fname); /* Just in case... */
	}
	}
	preserve_xattrs = 0;
	set_file_attrs(buf, file, NULL, fname, 0);
	preserve_xattrs = save_preserve_xattrs;
	unmake_file(file);
	#ifdef SUPPORT_ACLS
	uncache_tmp_acls();
	#endif
	#ifdef SUPPORT_XATTRS
	uncache_tmp_xattrs();
	#endif

	if (verbose > 1) {
	rprintf(FINFO, "backed up %s to %s\n",
	fname, buf);
	}
	return 1;
	}


	/* main backup switch routine */
	int make_backup(const char *fname)
	{
	if (backup_dir)
	return keep_backup(fname);
	return make_simple_backup(fname);
	}