[thirdparty/xfsprogs-dev.git] / libxfs / xfs_symlink_remote.c

/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * Copyright (c) 2012-2013 Red Hat, Inc.
 * All rights reserved.
 *
 * 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.
 *
 * 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.  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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "libxfs_priv.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_shared.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_trace.h"
#include "xfs_cksum.h"
#include "xfs_trans.h"


/*
 * Each contiguous block has a header, so it is not just a simple pathlen
 * to FSB conversion.
 */
int
xfs_symlink_blocks(
	struct xfs_mount *mp,
	int		pathlen)
{
	int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);

	return (pathlen + buflen - 1) / buflen;
}

int
xfs_symlink_hdr_set(
	struct xfs_mount	*mp,
	xfs_ino_t		ino,
	uint32_t		offset,
	uint32_t		size,
	struct xfs_buf		*bp)
{
	struct xfs_dsymlink_hdr	*dsl = bp->b_addr;

	if (!xfs_sb_version_hascrc(&mp->m_sb))
		return 0;

	memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
	dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
	dsl->sl_offset = cpu_to_be32(offset);
	dsl->sl_bytes = cpu_to_be32(size);
	uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
	dsl->sl_owner = cpu_to_be64(ino);
	dsl->sl_blkno = cpu_to_be64(bp->b_bn);
	bp->b_ops = &xfs_symlink_buf_ops;

	return sizeof(struct xfs_dsymlink_hdr);
}

/*
 * Checking of the symlink header is split into two parts. the verifier does
 * CRC, location and bounds checking, the unpacking function checks the path
 * parameters and owner.
 */
bool
xfs_symlink_hdr_ok(
	xfs_ino_t		ino,
	uint32_t		offset,
	uint32_t		size,
	struct xfs_buf		*bp)
{
	struct xfs_dsymlink_hdr *dsl = bp->b_addr;

	if (offset != be32_to_cpu(dsl->sl_offset))
		return false;
	if (size != be32_to_cpu(dsl->sl_bytes))
		return false;
	if (ino != be64_to_cpu(dsl->sl_owner))
		return false;

	/* ok */
	return true;
}

static xfs_failaddr_t
xfs_symlink_verify(
	struct xfs_buf		*bp)
{
	struct xfs_mount	*mp = bp->b_target->bt_mount;
	struct xfs_dsymlink_hdr	*dsl = bp->b_addr;

	if (!xfs_sb_version_hascrc(&mp->m_sb))
		return __this_address;
	if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
		return __this_address;
	if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
		return __this_address;
	if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
		return __this_address;
	if (be32_to_cpu(dsl->sl_offset) +
				be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
		return __this_address;
	if (dsl->sl_owner == 0)
		return __this_address;
	if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
		return __this_address;

	return NULL;
}

static void
xfs_symlink_read_verify(
	struct xfs_buf	*bp)
{
	struct xfs_mount *mp = bp->b_target->bt_mount;
	xfs_failaddr_t	fa;

	/* no verification of non-crc buffers */
	if (!xfs_sb_version_hascrc(&mp->m_sb))
		return;

	if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
		xfs_verifier_error(bp, -EFSBADCRC, __this_address);
	else {
		fa = xfs_symlink_verify(bp);
		if (fa)
			xfs_verifier_error(bp, -EFSCORRUPTED, fa);
	}
}

static void
xfs_symlink_write_verify(
	struct xfs_buf	*bp)
{
	struct xfs_mount *mp = bp->b_target->bt_mount;
	struct xfs_buf_log_item	*bip = bp->b_fspriv;
	xfs_failaddr_t		fa;

	/* no verification of non-crc buffers */
	if (!xfs_sb_version_hascrc(&mp->m_sb))
		return;

	fa = xfs_symlink_verify(bp);
	if (fa) {
		xfs_verifier_error(bp, -EFSCORRUPTED, fa);
		return;
	}

	if (bip) {
		struct xfs_dsymlink_hdr *dsl = bp->b_addr;
		dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
	}
	xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
}

const struct xfs_buf_ops xfs_symlink_buf_ops = {
	.name = "xfs_symlink",
	.verify_read = xfs_symlink_read_verify,
	.verify_write = xfs_symlink_write_verify,
	.verify_struct = xfs_symlink_verify,
};

void
xfs_symlink_local_to_remote(
	struct xfs_trans	*tp,
	struct xfs_buf		*bp,
	struct xfs_inode	*ip,
	struct xfs_ifork	*ifp)
{
	struct xfs_mount	*mp = ip->i_mount;
	char			*buf;

	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);

	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
		bp->b_ops = NULL;
		memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
		xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
		return;
	}

	/*
	 * As this symlink fits in an inode literal area, it must also fit in
	 * the smallest buffer the filesystem supports.
	 */
	ASSERT(BBTOB(bp->b_length) >=
			ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));

	bp->b_ops = &xfs_symlink_buf_ops;

	buf = bp->b_addr;
	buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
	memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
					ifp->if_bytes - 1);
}

/* Verify the consistency of an inline symlink. */
xfs_failaddr_t
xfs_symlink_shortform_verify(
	struct xfs_inode	*ip)
{
	char			*sfp;
	char			*endp;
	struct xfs_ifork	*ifp;
	int			size;

	ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
	sfp = (char *)ifp->if_u1.if_data;
	size = ifp->if_bytes;
	endp = sfp + size;

	/* Zero length symlinks can exist while we're deleting a remote one. */
	if (size == 0)
		return NULL;

	/* No negative sizes or overly long symlink targets. */
	if (size < 0 || size > XFS_SYMLINK_MAXLEN)
		return __this_address;

	/* No NULLs in the target either. */
	if (memchr(sfp, 0, size - 1))
		return __this_address;

	/* We /did/ null-terminate the buffer, right? */
	if (*endp != 0)
		return __this_address;
	return NULL;
}
Commit	Line	Data
9f76c5b5	1	/*
270b1db1 DC	2	* Copyright (c) 2000-2006 Silicon Graphics, Inc.
270b1db1 DC	3	* Copyright (c) 2012-2013 Red Hat, Inc.
9f76c5b5	4	* All rights reserved.
270b1db1 DC	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License as
	8	* published by the Free Software Foundation.
	9	*
	10	* This program is distributed in the hope that it would be useful,
	11	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	* GNU General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License
	16	* along with this program; if not, write the Free Software Foundation,
	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
9f76c5b5	18	*/
9c799827	19	#include "libxfs_priv.h"
b626fb59 DC	20	#include "xfs_fs.h"
	21	#include "xfs_format.h"
	22	#include "xfs_log_format.h"
	23	#include "xfs_shared.h"
	24	#include "xfs_trans_resv.h"
	25	#include "xfs_mount.h"
	26	#include "xfs_bmap_btree.h"
	27	#include "xfs_inode.h"
	28	#include "xfs_trace.h"
	29	#include "xfs_cksum.h"
	30	#include "xfs_trans.h"
	31
9f76c5b5 DC	32
	33	/*
	34	* Each contiguous block has a header, so it is not just a simple pathlen
	35	* to FSB conversion.
	36	*/
	37	int
	38	xfs_symlink_blocks(
	39	struct xfs_mount *mp,
	40	int pathlen)
	41	{
2019931a	42	int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
9f76c5b5	43
2019931a	44	return (pathlen + buflen - 1) / buflen;
9f76c5b5 DC	45	}
9f76c5b5 DC	46
f7b80291	47	int
9f76c5b5 DC	48	xfs_symlink_hdr_set(
	49	struct xfs_mount *mp,
	50	xfs_ino_t ino,
	51	uint32_t offset,
	52	uint32_t size,
	53	struct xfs_buf *bp)
	54	{
	55	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	56
	57	if (!xfs_sb_version_hascrc(&mp->m_sb))
	58	return 0;
	59
a65d8d29	60	memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
9f76c5b5 DC	61	dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
	62	dsl->sl_offset = cpu_to_be32(offset);
	63	dsl->sl_bytes = cpu_to_be32(size);
9c4e12fb	64	uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
9f76c5b5 DC	65	dsl->sl_owner = cpu_to_be64(ino);
	66	dsl->sl_blkno = cpu_to_be64(bp->b_bn);
	67	bp->b_ops = &xfs_symlink_buf_ops;
	68
	69	return sizeof(struct xfs_dsymlink_hdr);
	70	}
	71
	72	/*
	73	* Checking of the symlink header is split into two parts. the verifier does
	74	* CRC, location and bounds checking, the unpacking function checks the path
	75	* parameters and owner.
	76	*/
	77	bool
	78	xfs_symlink_hdr_ok(
9f76c5b5 DC	79	xfs_ino_t ino,
	80	uint32_t offset,
	81	uint32_t size,
	82	struct xfs_buf *bp)
	83	{
	84	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	85
	86	if (offset != be32_to_cpu(dsl->sl_offset))
	87	return false;
	88	if (size != be32_to_cpu(dsl->sl_bytes))
	89	return false;
	90	if (ino != be64_to_cpu(dsl->sl_owner))
	91	return false;
	92
	93	/* ok */
	94	return true;
9f76c5b5 DC	95	}
9f76c5b5 DC	96
bc01119d	97	static xfs_failaddr_t
9f76c5b5 DC	98	xfs_symlink_verify(
	99	struct xfs_buf *bp)
	100	{
	101	struct xfs_mount *mp = bp->b_target->bt_mount;
	102	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	103
	104	if (!xfs_sb_version_hascrc(&mp->m_sb))
bc01119d	105	return __this_address;
9f76c5b5	106	if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
bc01119d	107	return __this_address;
9c4e12fb	108	if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
bc01119d	109	return __this_address;
9f76c5b5	110	if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
bc01119d	111	return __this_address;
9f76c5b5	112	if (be32_to_cpu(dsl->sl_offset) +
b8fb8c95	113	be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
bc01119d	114	return __this_address;
9f76c5b5	115	if (dsl->sl_owner == 0)
bc01119d	116	return __this_address;
a65d8d29	117	if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
bc01119d	118	return __this_address;
9f76c5b5	119
bc01119d	120	return NULL;
9f76c5b5 DC	121	}
	122
	123	static void
	124	xfs_symlink_read_verify(
	125	struct xfs_buf *bp)
	126	{
	127	struct xfs_mount *mp = bp->b_target->bt_mount;
1e697959	128	xfs_failaddr_t fa;
9f76c5b5 DC	129
	130	/* no verification of non-crc buffers */
	131	if (!xfs_sb_version_hascrc(&mp->m_sb))
	132	return;
	133
45922933	134	if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
1e697959 DW	135	xfs_verifier_error(bp, -EFSBADCRC, __this_address);
	136	else {
	137	fa = xfs_symlink_verify(bp);
	138	if (fa)
	139	xfs_verifier_error(bp, -EFSCORRUPTED, fa);
	140	}
9f76c5b5 DC	141	}
	142
	143	static void
	144	xfs_symlink_write_verify(
	145	struct xfs_buf *bp)
	146	{
	147	struct xfs_mount *mp = bp->b_target->bt_mount;
	148	struct xfs_buf_log_item *bip = bp->b_fspriv;
1e697959	149	xfs_failaddr_t fa;
9f76c5b5 DC	150
	151	/* no verification of non-crc buffers */
	152	if (!xfs_sb_version_hascrc(&mp->m_sb))
	153	return;
	154
1e697959 DW	155	fa = xfs_symlink_verify(bp);
	156	if (fa) {
	157	xfs_verifier_error(bp, -EFSCORRUPTED, fa);
9f76c5b5 DC	158	return;
	159	}
	160
	161	if (bip) {
	162	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	163	dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
	164	}
43b5aeed	165	xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
9f76c5b5 DC	166	}
	167
	168	const struct xfs_buf_ops xfs_symlink_buf_ops = {
a3fac935	169	.name = "xfs_symlink",
9f76c5b5 DC	170	.verify_read = xfs_symlink_read_verify,
9f76c5b5 DC	171	.verify_write = xfs_symlink_write_verify,
95d9582b	172	.verify_struct = xfs_symlink_verify,
9f76c5b5 DC	173	};
9f76c5b5 DC	174
88b66843 DC	175	void
	176	xfs_symlink_local_to_remote(
	177	struct xfs_trans *tp,
	178	struct xfs_buf *bp,
	179	struct xfs_inode *ip,
	180	struct xfs_ifork *ifp)
	181	{
	182	struct xfs_mount *mp = ip->i_mount;
	183	char *buf;
	184
19ebedcf DC	185	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
19ebedcf DC	186
88b66843 DC	187	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
	188	bp->b_ops = NULL;
	189	memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
f44fbde0	190	xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
88b66843 DC	191	return;
	192	}
	193
	194	/*
	195	* As this symlink fits in an inode literal area, it must also fit in
	196	* the smallest buffer the filesystem supports.
	197	*/
	198	ASSERT(BBTOB(bp->b_length) >=
	199	ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
	200
	201	bp->b_ops = &xfs_symlink_buf_ops;
	202
	203	buf = bp->b_addr;
	204	buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
	205	memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
f44fbde0 BF	206	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
f44fbde0 BF	207	ifp->if_bytes - 1);
88b66843	208	}
6db3a800 DW	209
	210	/* Verify the consistency of an inline symlink. */
	211	xfs_failaddr_t
	212	xfs_symlink_shortform_verify(
	213	struct xfs_inode *ip)
	214	{
	215	char *sfp;
	216	char *endp;
	217	struct xfs_ifork *ifp;
	218	int size;
	219
	220	ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
	221	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
	222	sfp = (char *)ifp->if_u1.if_data;
	223	size = ifp->if_bytes;
	224	endp = sfp + size;
	225
	226	/* Zero length symlinks can exist while we're deleting a remote one. */
	227	if (size == 0)
	228	return NULL;
	229
	230	/* No negative sizes or overly long symlink targets. */
	231	if (size < 0 \|\| size > XFS_SYMLINK_MAXLEN)
	232	return __this_address;
	233
	234	/* No NULLs in the target either. */
	235	if (memchr(sfp, 0, size - 1))
	236	return __this_address;
	237
	238	/* We /did/ null-terminate the buffer, right? */
	239	if (*endp != 0)
	240	return __this_address;
	241	return NULL;
	242	}