[rsync/rsync.git] / backup.c

/*
 * Backup handling code.
 *
 * Copyright (C) 1999 Andrew Tridgell
 * Copyright (C) 2003-2007 Wayne Davison
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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 "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
****************************************************************************/
static int make_bak_dir(char *fullpath)
{
	statx sx;
	struct file_struct *file;
	char *rel = fullpath + backup_dir_len;
	char *end = rel + strlen(rel);
	char *p = end;

	while (strncmp(fullpath, "./", 2) == 0)
		fullpath += 2;

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

	/* 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_acl(file, &sx);
					free_acl(&sx);
				}
#endif
#ifdef SUPPORT_XATTRS
				if (preserve_xattrs) {
					get_xattr(rel, &sx);
					cache_xattr(file, &sx);
					free_xattr(&sx);
				}
#endif
				set_file_attrs(fullpath, file, NULL, NULL, 0);
				unmake_file(file);
			}
		}
		*p = '/';
		p += strlen(p);
		if (p == end)
			break;
		if (mkdir_defmode(fullpath) < 0) {
			rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
				full_fname(fullpath));
			goto failure;
		}
	}
	return 0;

  failure:
	while (p != end) {
		*p = '/';
		p += strlen(p);
	}
	return -1;
}

/* 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
	 && (errno != ENOENT || make_bak_dir(dst) < 0
	  || robust_rename(src, dst, NULL, 0755) < 0))
		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)
{
	statx sx;
	struct file_struct *file;
	char *buf;
	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);
		return 0;
	}

#ifdef SUPPORT_ACLS
	if (preserve_acls && !S_ISLNK(file->mode)) {
		get_acl(fname, &sx);
		cache_acl(file, &sx);
		free_acl(&sx);
	}
#endif
#ifdef SUPPORT_XATTRS
	if (preserve_xattrs) {
		get_xattr(fname, &sx);
		cache_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))) {
		uint32 *devp = F_RDEV_P(file);
		dev_t rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
		do_unlink(buf);
		if (do_mknod(buf, file->mode, rdev) < 0
		    && (errno != ENOENT || make_bak_dir(buf) < 0
		     || do_mknod(buf, file->mode, rdev) < 0)) {
			rsyserr(FERROR, errno, "mknod %s failed",
				full_fname(buf));
		} else if (verbose > 2) {
			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
		    && (errno != ENOENT || make_bak_dir(buf) < 0
		     || do_mkdir(buf, file->mode) < 0)) {
			rsyserr(FINFO, 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, buf)) {
			if (verbose) {
				rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
					full_fname(buf), sl);
			}
			kept = 1;
		} else {
			do_unlink(buf);
			if (do_symlink(sl, buf) < 0
			    && (errno != ENOENT || make_bak_dir(buf) < 0
			     || do_symlink(sl, buf) < 0)) {
				rsyserr(FERROR, 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);
		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... */
		}
	}
	set_file_attrs(buf, file, NULL, fname, 0);
	unmake_file(file);

	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);
}
Commit	Line	Data
addf0c4a	1	/*
0f78b815 WD	2	* Backup handling code.
	3	*
	4	* Copyright (C) 1999 Andrew Tridgell
ba2133d6	5	* Copyright (C) 2003-2007 Wayne Davison
0f78b815 WD	6	*
0f78b815 WD	7	* This program is free software; you can redistribute it and/or modify
ba2133d6 WD	8	* it under the terms of the GNU General Public License version 2 as
ba2133d6 WD	9	* published by the Free Software Foundation.
0f78b815 WD	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*
e7c67065 WD	16	* You should have received a copy of the GNU General Public License along
	17	* with this program; if not, write to the Free Software Foundation, Inc.,
	18	* 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
0f78b815	19	*/
3d19b4c8 AT	20
	21	#include "rsync.h"
	22
	23	extern int verbose;
378a074c	24	extern int am_root;
1c3344a1	25	extern int preserve_acls;
16edf865	26	extern int preserve_xattrs;
378a074c	27	extern int preserve_devices;
b5c6a6ae	28	extern int preserve_specials;
378a074c	29	extern int preserve_links;
377dbd20	30	extern int safe_symlinks;
6b2a3d5d	31	extern int backup_dir_len;
82ad07c4 WD	32	extern unsigned int backup_dir_remainder;
	33	extern char backup_dir_buf[MAXPATHLEN];
	34	extern char *backup_suffix;
	35	extern char *backup_dir;
378a074c	36
c94e4afb	37	/* make a complete pathname for backup file */
45d8bfe0	38	char get_backup_name(const char fname)
c94e4afb	39	{
c94e4afb WD	40	if (backup_dir) {
	41	if (stringjoin(backup_dir_buf + backup_dir_len, backup_dir_remainder,
	42	fname, backup_suffix, NULL) < backup_dir_remainder)
	43	return backup_dir_buf;
	44	} else {
fb22c277 WD	45	if (stringjoin(backup_dir_buf, MAXPATHLEN,
	46	fname, backup_suffix, NULL) < MAXPATHLEN)
	47	return backup_dir_buf;
c94e4afb WD	48	}
	49
	50	rprintf(FERROR, "backup filename too long\n");
	51	return NULL;
	52	}
	53
66203a98	54	/* simple backup creates a backup with a suffix in the same directory */
45d8bfe0	55	static int make_simple_backup(const char *fname)
3d19b4c8	56	{
ba679d51	57	int rename_errno;
45d8bfe0	58	const char *fnamebak = get_backup_name(fname);
5d2a7071	59
c94e4afb	60	if (!fnamebak)
3d19b4c8	61	return 0;
3d19b4c8	62
ba679d51 WD	63	while (1) {
	64	if (do_rename(fname, fnamebak) == 0) {
	65	if (verbose > 1) {
	66	rprintf(FINFO, "backed up %s to %s\n",
45c49b52	67	fname, fnamebak);
ba679d51 WD	68	}
ba679d51 WD	69	break;
3d19b4c8	70	}
ba679d51 WD	71	/* cygwin (at least version b19) reports EINVAL */
	72	if (errno == ENOENT \|\| errno == EINVAL)
	73	break;
	74
	75	rename_errno = errno;
	76	if (errno == EISDIR && do_rmdir(fnamebak) == 0)
	77	continue;
	78	if (errno == ENOTDIR && do_unlink(fnamebak) == 0)
	79	continue;
	80
	81	rsyserr(FERROR, rename_errno, "rename %s to backup %s",
45c49b52	82	fname, fnamebak);
ba679d51 WD	83	errno = rename_errno;
ba679d51 WD	84	return 0;
3d19b4c8	85	}
ba679d51	86
3d19b4c8 AT	87	return 1;
3d19b4c8 AT	88	}
66203a98 AT	89
66203a98 AT	90
378a074c AT	91	/****************************************************************************
	92	Create a directory given an absolute path, perms based upon another directory
	93	path
	94	****************************************************************************/
de0e2250	95	static int make_bak_dir(char *fullpath)
378a074c	96	{
1c3344a1 WD	97	statx sx;
1c3344a1 WD	98	struct file_struct *file;
de0e2250 WD	99	char *rel = fullpath + backup_dir_len;
	100	char *end = rel + strlen(rel);
	101	char *p = end;
	102
	103	while (strncmp(fullpath, "./", 2) == 0)
	104	fullpath += 2;
	105
	106	/* Try to find an existing dir, starting from the deepest dir. */
	107	while (1) {
	108	if (--p == fullpath) {
	109	p += strlen(p);
	110	goto failure;
	111	}
	112	if (*p == '/') {
	113	*p = '\0';
a56cdef9	114	if (mkdir_defmode(fullpath) == 0)
de0e2250 WD	115	break;
de0e2250 WD	116	if (errno != ENOENT) {
d62bcc17 WD	117	rsyserr(FERROR, errno,
	118	"make_bak_dir mkdir %s failed",
	119	full_fname(fullpath));
de0e2250 WD	120	goto failure;
	121	}
	122	}
47d6a60c	123	}
de0e2250 WD	124
	125	/* Make all the dirs that we didn't find on the way here. */
	126	while (1) {
	127	if (p >= rel) {
	128	/* Try to transfer the directory settings of the
	129	* actual dir that the files are coming from. */
9439c0cb	130	if (x_stat(rel, &sx.st, NULL) < 0) {
d62bcc17 WD	131	rsyserr(FERROR, errno,
	132	"make_bak_dir stat %s failed",
	133	full_fname(rel));
de0e2250	134	} else {
1c3344a1 WD	135	#ifdef SUPPORT_ACLS
1c3344a1 WD	136	sx.acc_acl = sx.def_acl = NULL;
16edf865 WD	137	#endif
	138	#ifdef SUPPORT_XATTRS
	139	sx.xattr = NULL;
1c3344a1 WD	140	#endif
	141	if (!(file = make_file(rel, NULL, NULL, 0, NO_FILTERS)))
	142	continue;
	143	#ifdef SUPPORT_ACLS
	144	if (preserve_acls && !S_ISLNK(file->mode)) {
	145	get_acl(rel, &sx);
	146	cache_acl(file, &sx);
	147	free_acl(&sx);
	148	}
1e999f9f	149	#endif
16edf865 WD	150	#ifdef SUPPORT_XATTRS
	151	if (preserve_xattrs) {
	152	get_xattr(rel, &sx);
	153	cache_xattr(file, &sx);
	154	free_xattr(&sx);
	155	}
	156	#endif
	157	set_file_attrs(fullpath, file, NULL, NULL, 0);
b13505da	158	unmake_file(file);
47d6a60c S	159	}
47d6a60c S	160	}
de0e2250 WD	161	*p = '/';
	162	p += strlen(p);
	163	if (p == end)
	164	break;
a56cdef9	165	if (mkdir_defmode(fullpath) < 0) {
d62bcc17 WD	166	rsyserr(FERROR, errno, "make_bak_dir mkdir %s failed",
d62bcc17 WD	167	full_fname(fullpath));
de0e2250 WD	168	goto failure;
de0e2250 WD	169	}
47d6a60c S	170	}
47d6a60c S	171	return 0;
de0e2250	172
b2e6caa0	173	failure:
de0e2250 WD	174	while (p != end) {
	175	*p = '/';
	176	p += strlen(p);
	177	}
	178	return -1;
378a074c AT	179	}
378a074c AT	180
66203a98	181	/* robustly move a file, creating new directory structures if necessary */
45d8bfe0	182	static int robust_move(const char src, char dst)
66203a98	183	{
21955d9c WD	184	if (robust_rename(src, dst, NULL, 0755) < 0
	185	&& (errno != ENOENT \|\| make_bak_dir(dst) < 0
	186	\|\| robust_rename(src, dst, NULL, 0755) < 0))
62c9e6b3 WD	187	return -1;
62c9e6b3 WD	188	return 0;
de0e2250	189	}
66203a98 AT	190
66203a98 AT	191
de0e2250 WD	192	/* If we have a --backup-dir, then we get here from make_backup().
de0e2250 WD	193	* We will move the file to be deleted into a parallel directory tree. */
45d8bfe0	194	static int keep_backup(const char *fname)
66203a98	195	{
1c3344a1	196	statx sx;
66203a98	197	struct file_struct *file;
c94e4afb	198	char *buf;
47d6a60c	199	int kept = 0;
378a074c AT	200	int ret_code;
378a074c AT	201
66203a98	202	/* return if no file to keep */
9439c0cb	203	if (x_lstat(fname, &sx.st, NULL) < 0)
9fd62d15	204	return 1;
1c3344a1 WD	205	#ifdef SUPPORT_ACLS
	206	sx.acc_acl = sx.def_acl = NULL;
	207	#endif
16edf865 WD	208	#ifdef SUPPORT_XATTRS
	209	sx.xattr = NULL;
	210	#endif
66203a98	211
3de73827	212	if (!(file = make_file(fname, NULL, NULL, 0, NO_FILTERS)))
c94e4afb	213	return 1; /* the file could have disappeared */
66203a98	214
82ad07c4 WD	215	if (!(buf = get_backup_name(fname))) {
82ad07c4 WD	216	unmake_file(file);
47d6a60c	217	return 0;
82ad07c4	218	}
378a074c	219
1c3344a1 WD	220	#ifdef SUPPORT_ACLS
	221	if (preserve_acls && !S_ISLNK(file->mode)) {
	222	get_acl(fname, &sx);
	223	cache_acl(file, &sx);
	224	free_acl(&sx);
	225	}
	226	#endif
16edf865 WD	227	#ifdef SUPPORT_XATTRS
	228	if (preserve_xattrs) {
	229	get_xattr(fname, &sx);
	230	cache_xattr(file, &sx);
	231	free_xattr(&sx);
	232	}
	233	#endif
1c3344a1	234
378a074c	235	/* Check to see if this is a device file, or link */
b5c6a6ae WD	236	if ((am_root && preserve_devices && IS_DEVICE(file->mode))
b5c6a6ae WD	237	\|\| (preserve_specials && IS_SPECIAL(file->mode))) {
e238c997 WD	238	uint32 *devp = F_RDEV_P(file);
e238c997 WD	239	dev_t rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
93e28fbd	240	do_unlink(buf);
82ad07c4	241	if (do_mknod(buf, file->mode, rdev) < 0
93e28fbd	242	&& (errno != ENOENT \|\| make_bak_dir(buf) < 0
82ad07c4	243	\|\| do_mknod(buf, file->mode, rdev) < 0)) {
93e28fbd WD	244	rsyserr(FERROR, errno, "mknod %s failed",
	245	full_fname(buf));
	246	} else if (verbose > 2) {
	247	rprintf(FINFO, "make_backup: DEVICE %s successful.\n",
45c49b52	248	fname);
47d6a60c S	249	}
	250	kept = 1;
	251	do_unlink(fname);
	252	}
378a074c	253
addf0c4a	254	if (!kept && S_ISDIR(file->mode)) {
378a074c	255	/* make an empty directory */
c94e4afb WD	256	if (do_mkdir(buf, file->mode) < 0
	257	&& (errno != ENOENT \|\| make_bak_dir(buf) < 0
	258	\|\| do_mkdir(buf, file->mode) < 0)) {
d62bcc17	259	rsyserr(FINFO, errno, "mkdir %s failed",
c94e4afb	260	full_fname(buf));
377dbd20	261	}
47d6a60c	262
377dbd20	263	ret_code = do_rmdir(fname);
addf0c4a	264	if (verbose > 2) {
ea42541f WD	265	rprintf(FINFO, "make_backup: RMDIR %s returns %i\n",
ea42541f WD	266	full_fname(fname), ret_code);
47d6a60c S	267	}
	268	kept = 1;
	269	}
378a074c	270
4f5b0756	271	#ifdef SUPPORT_LINKS
addf0c4a	272	if (!kept && preserve_links && S_ISLNK(file->mode)) {
82ad07c4 WD	273	const char *sl = F_SYMLINK(file);
82ad07c4 WD	274	if (safe_symlinks && unsafe_symlink(sl, buf)) {
47d6a60c S	275	if (verbose) {
47d6a60c S	276	rprintf(FINFO, "ignoring unsafe symlink %s -> %s\n",
82ad07c4	277	full_fname(buf), sl);
47d6a60c S	278	}
47d6a60c S	279	kept = 1;
93e28fbd WD	280	} else {
93e28fbd WD	281	do_unlink(buf);
82ad07c4	282	if (do_symlink(sl, buf) < 0
93e28fbd	283	&& (errno != ENOENT \|\| make_bak_dir(buf) < 0
82ad07c4	284	\|\| do_symlink(sl, buf) < 0)) {
93e28fbd	285	rsyserr(FERROR, errno, "link %s -> \"%s\"",
82ad07c4	286	full_fname(buf), sl);
93e28fbd WD	287	}
	288	do_unlink(fname);
	289	kept = 1;
47d6a60c	290	}
47d6a60c	291	}
378a074c	292	#endif
378a074c	293
addf0c4a	294	if (!kept && !S_ISREG(file->mode)) {
47d6a60c	295	rprintf(FINFO, "make_bak: skipping non-regular file %s\n",
45c49b52	296	fname);
82ad07c4	297	unmake_file(file);
f8c8ef9e	298	return 1;
47d6a60c	299	}
66203a98	300
66203a98	301	/* move to keep tree if a file */
addf0c4a	302	if (!kept) {
c94e4afb	303	if (robust_move(fname, buf) != 0) {
d62bcc17	304	rsyserr(FERROR, errno, "keep_backup failed: %s -> \"%s\"",
45c49b52	305	full_fname(fname), buf);
1c3344a1	306	} else if (sx.st.st_nlink > 1) {
394bcdb5	307	/* If someone has hard-linked the file into the backup
3cb22c20	308	* dir, rename() might return success but do nothing! */
394bcdb5	309	robust_unlink(fname); /* Just in case... */
47d6a60c S	310	}
47d6a60c S	311	}
16edf865	312	set_file_attrs(buf, file, NULL, fname, 0);
82ad07c4	313	unmake_file(file);
378a074c	314
4875d6b6 WD	315	if (verbose > 1) {
4875d6b6 WD	316	rprintf(FINFO, "backed up %s to %s\n",
45c49b52	317	fname, buf);
4875d6b6	318	}
66203a98	319	return 1;
de0e2250	320	}
66203a98 AT	321
	322
	323	/* main backup switch routine */
45d8bfe0	324	int make_backup(const char *fname)
66203a98 AT	325	{
66203a98 AT	326	if (backup_dir)
addf0c4a WD	327	return keep_backup(fname);
addf0c4a WD	328	return make_simple_backup(fname);
66203a98	329	}