[thirdparty/xfsprogs-dev.git] / libhandle / handle.c

/*
 * Copyright (c) 1995, 2001-2003 Silicon Graphics, Inc.  All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of version 2.1 of the GNU Lesser General Public License
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Further, this software is distributed without any warranty that it is
 * free of the rightful claim of any third person regarding infringement
 * or the like.  Any license provided herein, whether implied or
 * otherwise, applies only to this software file.  Patent licenses, if
 * any, provided herein do not apply to combinations of this program with
 * other software, or any other product whatsoever.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not, write the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307,
 * USA.
 *
 * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
 * Mountain View, CA  94043, or:
 *
 * http://www.sgi.com
 *
 * For further information regarding this notice, see:
 *
 * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
 */

#include <xfs/libxfs.h>

/* attributes.h (purposefully) unavailable to xfsprogs, make do */
struct attrlist_cursor { __u32 opaque[4]; };

#include <xfs/handle.h>

/* just pick a value we know is more than big enough */
#define	MAXHANSIZ	64

/*
 *  The actual content of a handle is supposed to be opaque here.
 *  But, to do handle_to_fshandle, we need to know what it is.  Sigh.
 *  However we can get by with knowing only that the first 8 bytes of
 *  a file handle are the file system ID, and that a file system handle
 *  consists of only those 8 bytes.
 */

#define	FSIDSIZE	8

typedef union {
	int	fd;
	char	*path;
} comarg_t;

static int obj_to_handle(char *, int, unsigned int, comarg_t, void**, size_t*);
static int handle_to_fsfd(void *, char **);


/*
 * Filesystem Handle -> Open File Descriptor Cache
 *
 * Maps filesystem handles to a corresponding open file descriptor for that
 * filesystem. We need this because we're doing handle operations via xfsctl
 * and we need to remember the open file descriptor for each filesystem.
 */

struct fdhash {
	int	fsfd;
	char	fsh[FSIDSIZE];
	struct fdhash *fnxt;
	char	fspath[MAXPATHLEN];
};

static struct fdhash *fdhash_head = NULL;

int
path_to_fshandle(
	char		*path,		/* input,  path to convert */
	void		**fshanp,	/* output, pointer to data */
	size_t		*fshlen)	/* output, size of returned data */
{
	int		result;
	int		fd;
	comarg_t	obj;
	struct fdhash	*fdhp;
	char		*tmppath;

	fd = open(path, O_RDONLY);
	if (fd < 0)
		return -1;

	obj.path = path;
	result = obj_to_handle(path, fd, XFS_IOC_PATH_TO_FSHANDLE,
				obj, fshanp, fshlen);
	if (result < 0) {
		close(fd);
		return result;
	}
		
	if (handle_to_fsfd(*fshanp, &tmppath) >= 0) {
		/* this filesystem is already in the cache */
		close(fd);
	} else {
		/* new filesystem. add it to the cache */
		fdhp = malloc(sizeof(struct fdhash));
		if (fdhp == NULL) {
			errno = ENOMEM;
			return -1;
		}

		fdhp->fsfd = fd;
		strncpy(fdhp->fspath, path, sizeof(fdhp->fspath));
		memcpy(fdhp->fsh, *fshanp, FSIDSIZE);

		fdhp->fnxt = fdhash_head;
		fdhash_head = fdhp;
	}

	return result;
}

int
path_to_handle(
	char		*path,		/* input,  path to convert */
	void		**hanp,		/* output, pointer to data */
	size_t		*hlen)		/* output, size of returned data */
{
	int		fd;
	int		result;
	comarg_t	obj;

	fd = open(path, O_RDONLY);
	if (fd < 0)
		return -1;

	obj.path = path;
	result = obj_to_handle(path, fd, XFS_IOC_PATH_TO_HANDLE,
				obj, hanp, hlen);
	close(fd);
	return result;
}

int
handle_to_fshandle(
	void		*hanp,
	size_t		hlen,
	void		**fshanp,
	size_t		*fshlen)
{
	if (hlen < FSIDSIZE) {
		errno = EINVAL;
		return -1;
	}
	*fshanp = malloc(FSIDSIZE);
	if (*fshanp == NULL) {
		errno = ENOMEM;
		return -1;
	}
	*fshlen = FSIDSIZE;
	memcpy(*fshanp, hanp, FSIDSIZE);
	return 0;
}

static int
handle_to_fsfd(void *hanp, char **path)
{
	struct fdhash	*fdhp;

	for (fdhp = fdhash_head; fdhp != NULL; fdhp = fdhp->fnxt) {
		if (memcmp(fdhp->fsh, hanp, FSIDSIZE) == 0) {
			*path = fdhp->fspath;
			return fdhp->fsfd;
		}
	}
	errno = EBADF;
	return -1;
}

static int
obj_to_handle(
	char		*fspath,
	int		fsfd,
	unsigned int	opcode,
	comarg_t	obj,
	void		**hanp,
	size_t		*hlen)
{
	char		hbuf [MAXHANSIZ];
	int		ret;
	__uint32_t	handlen;
	xfs_fsop_handlereq_t hreq;

	if (opcode == XFS_IOC_FD_TO_HANDLE) {
		hreq.fd      = obj.fd;
		hreq.path    = NULL;
	} else {
		hreq.fd      = 0;
		hreq.path    = obj.path;
	}

	hreq.oflags   = O_LARGEFILE;
	hreq.ihandle  = NULL;
	hreq.ihandlen = 0;
	hreq.ohandle  = hbuf;
	hreq.ohandlen = &handlen;

	ret = xfsctl(fspath, fsfd, opcode, &hreq);
	if (ret)
		return ret;

	*hanp = malloc(handlen);
	if (*hanp == NULL) {
		errno = ENOMEM;
		return -1;
	}

	memcpy(*hanp, hbuf, handlen);
	*hlen = handlen;
	return 0;
}

int
open_by_fshandle(
	void		*fshanp,
	size_t		fshlen,
	int		rw)
{
	int		fsfd;
	char		*path;
	xfs_fsop_handlereq_t hreq;

	if ((fsfd = handle_to_fsfd(fshanp, &path)) < 0)
		return -1;

	hreq.fd       = 0;
	hreq.path     = NULL;
	hreq.oflags   = rw | O_LARGEFILE;
	hreq.ihandle  = fshanp;
	hreq.ihandlen = fshlen;
	hreq.ohandle  = NULL;
	hreq.ohandlen = NULL;

	return xfsctl(path, fsfd, XFS_IOC_OPEN_BY_HANDLE, &hreq);
}

int
open_by_handle(
	void		*hanp,
	size_t		hlen,
	int		rw)
{
	int		fsfd;
	char		*path;
	void		*fshanp;
	size_t		fshlen;
	xfs_fsop_handlereq_t hreq;

	if (handle_to_fshandle(hanp, hlen, &fshanp, &fshlen) != 0)
		return -1;

	if ((fsfd = handle_to_fsfd(fshanp, &path)) < 0)
		return -1;

	hreq.fd       = 0;
	hreq.path     = NULL;
	hreq.oflags   = rw | O_LARGEFILE;
	hreq.ihandle  = hanp;
	hreq.ihandlen = hlen;
	hreq.ohandle  = NULL;
	hreq.ohandlen = NULL;

	return xfsctl(path, fsfd, XFS_IOC_OPEN_BY_HANDLE, &hreq);
}

int
readlink_by_handle(
	void		*hanp,
	size_t		hlen,
	void		*buf,
	size_t		bufsiz)
{
	int		fd;
	char		*path;
	xfs_fsop_handlereq_t hreq;

	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
		return -1;

	hreq.fd       = 0;
	hreq.path     = NULL;
	hreq.oflags   = O_LARGEFILE;
	hreq.ihandle  = hanp;
	hreq.ihandlen = hlen;
	hreq.ohandle  = buf;
	hreq.ohandlen = (__u32 *)&bufsiz;

	return xfsctl(path, fd, XFS_IOC_READLINK_BY_HANDLE, &hreq);
}

int
attr_multi_by_handle(
	void		*hanp,
	size_t		hlen,
	void		*buf,
	int		rtrvcnt,
	int		flags)
{
	int		fd;
	char		*path;
	xfs_fsop_attrmulti_handlereq_t amhreq;

	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
		return -1;

	amhreq.hreq.fd       = 0;
	amhreq.hreq.path     = NULL;
	amhreq.hreq.oflags   = O_LARGEFILE;
	amhreq.hreq.ihandle  = hanp;
	amhreq.hreq.ihandlen = hlen;
	amhreq.hreq.ohandle  = NULL;
	amhreq.hreq.ohandlen = NULL;

	amhreq.opcount = rtrvcnt;
	amhreq.ops = buf;

	return xfsctl(path, fd, XFS_IOC_ATTRMULTI_BY_HANDLE, &amhreq);
}

int
attr_list_by_handle(
	void		*hanp,
	size_t		hlen,
	void		*buf,
	size_t		bufsize,
	int		flags,
	struct attrlist_cursor *cursor)
{
	int		fd;
	char		*path;
	xfs_fsop_attrlist_handlereq_t alhreq;

	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
		return -1;

	alhreq.hreq.fd       = 0;
	alhreq.hreq.path     = NULL;
	alhreq.hreq.oflags   = O_LARGEFILE;
	alhreq.hreq.ihandle  = hanp;
	alhreq.hreq.ihandlen = hlen;
	alhreq.hreq.ohandle  = NULL;
	alhreq.hreq.ohandlen = NULL;

	memcpy(&alhreq.pos, cursor, sizeof(alhreq.pos));
	alhreq.flags = flags;
	alhreq.buflen = bufsize;
	alhreq.buffer = buf;

	return xfsctl(path, fd, XFS_IOC_ATTRLIST_BY_HANDLE, &alhreq);
}

int
fssetdm_by_handle(
	void		*hanp,
	size_t		hlen,
	struct fsdmidata *fsdmidata)
{
	int		fd;
	char		*path;
	xfs_fsop_setdm_handlereq_t dmhreq;

	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
		return -1;

	dmhreq.hreq.fd       = 0;
	dmhreq.hreq.path     = NULL;
	dmhreq.hreq.oflags   = O_LARGEFILE;
	dmhreq.hreq.ihandle  = hanp;
	dmhreq.hreq.ihandlen = hlen;
	dmhreq.hreq.ohandle  = NULL;
	dmhreq.hreq.ohandlen = NULL;

	dmhreq.data = fsdmidata;

	return xfsctl(path, fd, XFS_IOC_FSSETDM_BY_HANDLE, &dmhreq);
}

void
free_handle(
	void		*hanp,
	size_t		hlen)
{
	free(hanp);
}
Commit	Line	Data
	1	/*
	2	* Copyright (c) 1995, 2001-2003 Silicon Graphics, Inc. All Rights Reserved.
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of version 2.1 of the GNU Lesser General Public License
	6	* as published by the Free Software Foundation.
	7	*
	8	* This program is distributed in the hope that it would be useful, but
	9	* WITHOUT ANY WARRANTY; without even the implied warranty of
	10	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
	11	*
	12	* Further, this software is distributed without any warranty that it is
	13	* free of the rightful claim of any third person regarding infringement
	14	* or the like. Any license provided herein, whether implied or
	15	* otherwise, applies only to this software file. Patent licenses, if
	16	* any, provided herein do not apply to combinations of this program with
	17	* other software, or any other product whatsoever.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this program; if not, write the Free Software
	21	* Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307,
	22	* USA.
	23	*
	24	* Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
	25	* Mountain View, CA 94043, or:
	26	*
	27	* http://www.sgi.com
	28	*
	29	* For further information regarding this notice, see:
	30	*
	31	* http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
	32	*/
	33
	34	#include <xfs/libxfs.h>
	35
	36	/* attributes.h (purposefully) unavailable to xfsprogs, make do */
	37	struct attrlist_cursor { __u32 opaque[4]; };
	38
	39	#include <xfs/handle.h>
	40
	41	/* just pick a value we know is more than big enough */
	42	#define MAXHANSIZ 64
	43
	44	/*
	45	* The actual content of a handle is supposed to be opaque here.
	46	* But, to do handle_to_fshandle, we need to know what it is. Sigh.
	47	* However we can get by with knowing only that the first 8 bytes of
	48	* a file handle are the file system ID, and that a file system handle
	49	* consists of only those 8 bytes.
	50	*/
	51
	52	#define FSIDSIZE 8
	53
	54	typedef union {
	55	int fd;
	56	char *path;
	57	} comarg_t;
	58
	59	static int obj_to_handle(char , int, unsigned int, comarg_t, void, size_t);
	60	static int handle_to_fsfd(void , char *);
	61
	62
	63	/*
	64	* Filesystem Handle -> Open File Descriptor Cache
	65	*
	66	* Maps filesystem handles to a corresponding open file descriptor for that
	67	* filesystem. We need this because we're doing handle operations via xfsctl
	68	* and we need to remember the open file descriptor for each filesystem.
	69	*/
	70
	71	struct fdhash {
	72	int fsfd;
	73	char fsh[FSIDSIZE];
	74	struct fdhash *fnxt;
	75	char fspath[MAXPATHLEN];
	76	};
	77
	78	static struct fdhash *fdhash_head = NULL;
	79
	80	int
	81	path_to_fshandle(
	82	char path, / input, path to convert */
	83	void *fshanp, / output, pointer to data */
	84	size_t fshlen) / output, size of returned data */
	85	{
	86	int result;
	87	int fd;
	88	comarg_t obj;
	89	struct fdhash *fdhp;
	90	char *tmppath;
	91
	92	fd = open(path, O_RDONLY);
	93	if (fd < 0)
	94	return -1;
	95
	96	obj.path = path;
	97	result = obj_to_handle(path, fd, XFS_IOC_PATH_TO_FSHANDLE,
	98	obj, fshanp, fshlen);
	99	if (result < 0) {
	100	close(fd);
	101	return result;
	102	}
	103
	104	if (handle_to_fsfd(*fshanp, &tmppath) >= 0) {
	105	/* this filesystem is already in the cache */
	106	close(fd);
	107	} else {
	108	/* new filesystem. add it to the cache */
	109	fdhp = malloc(sizeof(struct fdhash));
	110	if (fdhp == NULL) {
	111	errno = ENOMEM;
	112	return -1;
	113	}
	114
	115	fdhp->fsfd = fd;
	116	strncpy(fdhp->fspath, path, sizeof(fdhp->fspath));
	117	memcpy(fdhp->fsh, *fshanp, FSIDSIZE);
	118
	119	fdhp->fnxt = fdhash_head;
	120	fdhash_head = fdhp;
	121	}
	122
	123	return result;
	124	}
	125
	126	int
	127	path_to_handle(
	128	char path, / input, path to convert */
	129	void *hanp, / output, pointer to data */
	130	size_t hlen) / output, size of returned data */
	131	{
	132	int fd;
	133	int result;
	134	comarg_t obj;
	135
	136	fd = open(path, O_RDONLY);
	137	if (fd < 0)
	138	return -1;
	139
	140	obj.path = path;
	141	result = obj_to_handle(path, fd, XFS_IOC_PATH_TO_HANDLE,
	142	obj, hanp, hlen);
	143	close(fd);
	144	return result;
	145	}
	146
	147	int
	148	handle_to_fshandle(
	149	void *hanp,
	150	size_t hlen,
	151	void **fshanp,
	152	size_t *fshlen)
	153	{
	154	if (hlen < FSIDSIZE) {
	155	errno = EINVAL;
	156	return -1;
	157	}
	158	*fshanp = malloc(FSIDSIZE);
	159	if (*fshanp == NULL) {
	160	errno = ENOMEM;
	161	return -1;
	162	}
	163	*fshlen = FSIDSIZE;
	164	memcpy(*fshanp, hanp, FSIDSIZE);
	165	return 0;
	166	}
	167
	168	static int
	169	handle_to_fsfd(void hanp, char *path)
	170	{
	171	struct fdhash *fdhp;
	172
	173	for (fdhp = fdhash_head; fdhp != NULL; fdhp = fdhp->fnxt) {
	174	if (memcmp(fdhp->fsh, hanp, FSIDSIZE) == 0) {
	175	*path = fdhp->fspath;
	176	return fdhp->fsfd;
	177	}
	178	}
	179	errno = EBADF;
	180	return -1;
	181	}
	182
	183	static int
	184	obj_to_handle(
	185	char *fspath,
	186	int fsfd,
	187	unsigned int opcode,
	188	comarg_t obj,
	189	void **hanp,
	190	size_t *hlen)
	191	{
	192	char hbuf [MAXHANSIZ];
	193	int ret;
	194	__uint32_t handlen;
	195	xfs_fsop_handlereq_t hreq;
	196
	197	if (opcode == XFS_IOC_FD_TO_HANDLE) {
	198	hreq.fd = obj.fd;
	199	hreq.path = NULL;
	200	} else {
	201	hreq.fd = 0;
	202	hreq.path = obj.path;
	203	}
	204
	205	hreq.oflags = O_LARGEFILE;
	206	hreq.ihandle = NULL;
	207	hreq.ihandlen = 0;
	208	hreq.ohandle = hbuf;
	209	hreq.ohandlen = &handlen;
	210
	211	ret = xfsctl(fspath, fsfd, opcode, &hreq);
	212	if (ret)
	213	return ret;
	214
	215	*hanp = malloc(handlen);
	216	if (*hanp == NULL) {
	217	errno = ENOMEM;
	218	return -1;
	219	}
	220
	221	memcpy(*hanp, hbuf, handlen);
	222	*hlen = handlen;
	223	return 0;
	224	}
	225
	226	int
	227	open_by_fshandle(
	228	void *fshanp,
	229	size_t fshlen,
	230	int rw)
	231	{
	232	int fsfd;
	233	char *path;
	234	xfs_fsop_handlereq_t hreq;
	235
	236	if ((fsfd = handle_to_fsfd(fshanp, &path)) < 0)
	237	return -1;
	238
	239	hreq.fd = 0;
	240	hreq.path = NULL;
	241	hreq.oflags = rw \| O_LARGEFILE;
	242	hreq.ihandle = fshanp;
	243	hreq.ihandlen = fshlen;
	244	hreq.ohandle = NULL;
	245	hreq.ohandlen = NULL;
	246
	247	return xfsctl(path, fsfd, XFS_IOC_OPEN_BY_HANDLE, &hreq);
	248	}
	249
	250	int
	251	open_by_handle(
	252	void *hanp,
	253	size_t hlen,
	254	int rw)
	255	{
	256	int fsfd;
	257	char *path;
	258	void *fshanp;
	259	size_t fshlen;
	260	xfs_fsop_handlereq_t hreq;
	261
	262	if (handle_to_fshandle(hanp, hlen, &fshanp, &fshlen) != 0)
	263	return -1;
	264
	265	if ((fsfd = handle_to_fsfd(fshanp, &path)) < 0)
	266	return -1;
	267
	268	hreq.fd = 0;
	269	hreq.path = NULL;
	270	hreq.oflags = rw \| O_LARGEFILE;
	271	hreq.ihandle = hanp;
	272	hreq.ihandlen = hlen;
	273	hreq.ohandle = NULL;
	274	hreq.ohandlen = NULL;
	275
	276	return xfsctl(path, fsfd, XFS_IOC_OPEN_BY_HANDLE, &hreq);
	277	}
	278
	279	int
	280	readlink_by_handle(
	281	void *hanp,
	282	size_t hlen,
	283	void *buf,
	284	size_t bufsiz)
	285	{
	286	int fd;
	287	char *path;
	288	xfs_fsop_handlereq_t hreq;
	289
	290	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
	291	return -1;
	292
	293	hreq.fd = 0;
	294	hreq.path = NULL;
	295	hreq.oflags = O_LARGEFILE;
	296	hreq.ihandle = hanp;
	297	hreq.ihandlen = hlen;
	298	hreq.ohandle = buf;
	299	hreq.ohandlen = (__u32 *)&bufsiz;
	300
	301	return xfsctl(path, fd, XFS_IOC_READLINK_BY_HANDLE, &hreq);
	302	}
	303
	304	int
	305	attr_multi_by_handle(
	306	void *hanp,
	307	size_t hlen,
	308	void *buf,
	309	int rtrvcnt,
	310	int flags)
	311	{
	312	int fd;
	313	char *path;
	314	xfs_fsop_attrmulti_handlereq_t amhreq;
	315
	316	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
	317	return -1;
	318
	319	amhreq.hreq.fd = 0;
	320	amhreq.hreq.path = NULL;
	321	amhreq.hreq.oflags = O_LARGEFILE;
	322	amhreq.hreq.ihandle = hanp;
	323	amhreq.hreq.ihandlen = hlen;
	324	amhreq.hreq.ohandle = NULL;
	325	amhreq.hreq.ohandlen = NULL;
	326
	327	amhreq.opcount = rtrvcnt;
	328	amhreq.ops = buf;
	329
	330	return xfsctl(path, fd, XFS_IOC_ATTRMULTI_BY_HANDLE, &amhreq);
	331	}
	332
	333	int
	334	attr_list_by_handle(
	335	void *hanp,
	336	size_t hlen,
	337	void *buf,
	338	size_t bufsize,
	339	int flags,
	340	struct attrlist_cursor *cursor)
	341	{
	342	int fd;
	343	char *path;
	344	xfs_fsop_attrlist_handlereq_t alhreq;
	345
	346	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
	347	return -1;
	348
	349	alhreq.hreq.fd = 0;
	350	alhreq.hreq.path = NULL;
	351	alhreq.hreq.oflags = O_LARGEFILE;
	352	alhreq.hreq.ihandle = hanp;
	353	alhreq.hreq.ihandlen = hlen;
	354	alhreq.hreq.ohandle = NULL;
	355	alhreq.hreq.ohandlen = NULL;
	356
	357	memcpy(&alhreq.pos, cursor, sizeof(alhreq.pos));
	358	alhreq.flags = flags;
	359	alhreq.buflen = bufsize;
	360	alhreq.buffer = buf;
	361
	362	return xfsctl(path, fd, XFS_IOC_ATTRLIST_BY_HANDLE, &alhreq);
	363	}
	364
	365	int
	366	fssetdm_by_handle(
	367	void *hanp,
	368	size_t hlen,
	369	struct fsdmidata *fsdmidata)
	370	{
	371	int fd;
	372	char *path;
	373	xfs_fsop_setdm_handlereq_t dmhreq;
	374
	375	if ((fd = handle_to_fsfd(hanp, &path)) < 0)
	376	return -1;
	377
	378	dmhreq.hreq.fd = 0;
	379	dmhreq.hreq.path = NULL;
	380	dmhreq.hreq.oflags = O_LARGEFILE;
	381	dmhreq.hreq.ihandle = hanp;
	382	dmhreq.hreq.ihandlen = hlen;
	383	dmhreq.hreq.ohandle = NULL;
	384	dmhreq.hreq.ohandlen = NULL;
	385
	386	dmhreq.data = fsdmidata;
	387
	388	return xfsctl(path, fd, XFS_IOC_FSSETDM_BY_HANDLE, &dmhreq);
	389	}
	390
	391	void
	392	free_handle(
	393	void *hanp,
	394	size_t hlen)
	395	{
	396	free(hanp);
	397	}