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

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * Copyright (c) 2012-2013 Red Hat, Inc.
 * All rights reserved.
 */
#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_inode.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_has_crc(mp))
		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(xfs_buf_daddr(bp));
	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_mount;
	struct xfs_dsymlink_hdr	*dsl = bp->b_addr;

	if (!xfs_has_crc(mp))
		return __this_address;
	if (!xfs_verify_magic(bp, dsl->sl_magic))
		return __this_address;
	if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
		return __this_address;
	if (xfs_buf_daddr(bp) != 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_mount;
	xfs_failaddr_t	fa;

	/* no verification of non-crc buffers */
	if (!xfs_has_crc(mp))
		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_mount;
	struct xfs_buf_log_item	*bip = bp->b_log_item;
	xfs_failaddr_t		fa;

	/* no verification of non-crc buffers */
	if (!xfs_has_crc(mp))
		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",
	.magic = { 0, cpu_to_be32(XFS_SYMLINK_MAGIC) },
	.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_has_crc(mp)) {
		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 in-memory consistency of an inline symlink data fork. This
 * does not do on-disk format checks.
 */
xfs_failaddr_t
xfs_symlink_shortform_verify(
	struct xfs_inode	*ip)
{
	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
	char			*sfp = (char *)ifp->if_u1.if_data;
	int			size = ifp->if_bytes;
	char			*endp = sfp + size;

	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);

	/*
	 * Zero length symlinks should never occur in memory as they are
	 * never allowed to exist on disk.
	 */
	if (!size)
		return __this_address;

	/* 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
	1	// SPDX-License-Identifier: GPL-2.0
	2	/*
	3	* Copyright (c) 2000-2006 Silicon Graphics, Inc.
	4	* Copyright (c) 2012-2013 Red Hat, Inc.
	5	* All rights reserved.
	6	*/
	7	#include "libxfs_priv.h"
	8	#include "xfs_fs.h"
	9	#include "xfs_format.h"
	10	#include "xfs_log_format.h"
	11	#include "xfs_shared.h"
	12	#include "xfs_trans_resv.h"
	13	#include "xfs_mount.h"
	14	#include "xfs_inode.h"
	15	#include "xfs_trans.h"
	16
	17
	18	/*
	19	* Each contiguous block has a header, so it is not just a simple pathlen
	20	* to FSB conversion.
	21	*/
	22	int
	23	xfs_symlink_blocks(
	24	struct xfs_mount *mp,
	25	int pathlen)
	26	{
	27	int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
	28
	29	return (pathlen + buflen - 1) / buflen;
	30	}
	31
	32	int
	33	xfs_symlink_hdr_set(
	34	struct xfs_mount *mp,
	35	xfs_ino_t ino,
	36	uint32_t offset,
	37	uint32_t size,
	38	struct xfs_buf *bp)
	39	{
	40	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	41
	42	if (!xfs_has_crc(mp))
	43	return 0;
	44
	45	memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
	46	dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
	47	dsl->sl_offset = cpu_to_be32(offset);
	48	dsl->sl_bytes = cpu_to_be32(size);
	49	uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
	50	dsl->sl_owner = cpu_to_be64(ino);
	51	dsl->sl_blkno = cpu_to_be64(xfs_buf_daddr(bp));
	52	bp->b_ops = &xfs_symlink_buf_ops;
	53
	54	return sizeof(struct xfs_dsymlink_hdr);
	55	}
	56
	57	/*
	58	* Checking of the symlink header is split into two parts. the verifier does
	59	* CRC, location and bounds checking, the unpacking function checks the path
	60	* parameters and owner.
	61	*/
	62	bool
	63	xfs_symlink_hdr_ok(
	64	xfs_ino_t ino,
	65	uint32_t offset,
	66	uint32_t size,
	67	struct xfs_buf *bp)
	68	{
	69	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	70
	71	if (offset != be32_to_cpu(dsl->sl_offset))
	72	return false;
	73	if (size != be32_to_cpu(dsl->sl_bytes))
	74	return false;
	75	if (ino != be64_to_cpu(dsl->sl_owner))
	76	return false;
	77
	78	/* ok */
	79	return true;
	80	}
	81
	82	static xfs_failaddr_t
	83	xfs_symlink_verify(
	84	struct xfs_buf *bp)
	85	{
	86	struct xfs_mount *mp = bp->b_mount;
	87	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	88
	89	if (!xfs_has_crc(mp))
	90	return __this_address;
	91	if (!xfs_verify_magic(bp, dsl->sl_magic))
	92	return __this_address;
	93	if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
	94	return __this_address;
	95	if (xfs_buf_daddr(bp) != be64_to_cpu(dsl->sl_blkno))
	96	return __this_address;
	97	if (be32_to_cpu(dsl->sl_offset) +
	98	be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
	99	return __this_address;
	100	if (dsl->sl_owner == 0)
	101	return __this_address;
	102	if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
	103	return __this_address;
	104
	105	return NULL;
	106	}
	107
	108	static void
	109	xfs_symlink_read_verify(
	110	struct xfs_buf *bp)
	111	{
	112	struct xfs_mount *mp = bp->b_mount;
	113	xfs_failaddr_t fa;
	114
	115	/* no verification of non-crc buffers */
	116	if (!xfs_has_crc(mp))
	117	return;
	118
	119	if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
	120	xfs_verifier_error(bp, -EFSBADCRC, __this_address);
	121	else {
	122	fa = xfs_symlink_verify(bp);
	123	if (fa)
	124	xfs_verifier_error(bp, -EFSCORRUPTED, fa);
	125	}
	126	}
	127
	128	static void
	129	xfs_symlink_write_verify(
	130	struct xfs_buf *bp)
	131	{
	132	struct xfs_mount *mp = bp->b_mount;
	133	struct xfs_buf_log_item *bip = bp->b_log_item;
	134	xfs_failaddr_t fa;
	135
	136	/* no verification of non-crc buffers */
	137	if (!xfs_has_crc(mp))
	138	return;
	139
	140	fa = xfs_symlink_verify(bp);
	141	if (fa) {
	142	xfs_verifier_error(bp, -EFSCORRUPTED, fa);
	143	return;
	144	}
	145
	146	if (bip) {
	147	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	148	dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
	149	}
	150	xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
	151	}
	152
	153	const struct xfs_buf_ops xfs_symlink_buf_ops = {
	154	.name = "xfs_symlink",
	155	.magic = { 0, cpu_to_be32(XFS_SYMLINK_MAGIC) },
	156	.verify_read = xfs_symlink_read_verify,
	157	.verify_write = xfs_symlink_write_verify,
	158	.verify_struct = xfs_symlink_verify,
	159	};
	160
	161	void
	162	xfs_symlink_local_to_remote(
	163	struct xfs_trans *tp,
	164	struct xfs_buf *bp,
	165	struct xfs_inode *ip,
	166	struct xfs_ifork *ifp)
	167	{
	168	struct xfs_mount *mp = ip->i_mount;
	169	char *buf;
	170
	171	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
	172
	173	if (!xfs_has_crc(mp)) {
	174	bp->b_ops = NULL;
	175	memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
	176	xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
	177	return;
	178	}
	179
	180	/*
	181	* As this symlink fits in an inode literal area, it must also fit in
	182	* the smallest buffer the filesystem supports.
	183	*/
	184	ASSERT(BBTOB(bp->b_length) >=
	185	ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
	186
	187	bp->b_ops = &xfs_symlink_buf_ops;
	188
	189	buf = bp->b_addr;
	190	buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
	191	memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
	192	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
	193	ifp->if_bytes - 1);
	194	}
	195
	196	/*
	197	* Verify the in-memory consistency of an inline symlink data fork. This
	198	* does not do on-disk format checks.
	199	*/
	200	xfs_failaddr_t
	201	xfs_symlink_shortform_verify(
	202	struct xfs_inode *ip)
	203	{
	204	struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
	205	char sfp = (char )ifp->if_u1.if_data;
	206	int size = ifp->if_bytes;
	207	char *endp = sfp + size;
	208
	209	ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
	210
	211	/*
	212	* Zero length symlinks should never occur in memory as they are
	213	* never allowed to exist on disk.
	214	*/
	215	if (!size)
	216	return __this_address;
	217
	218	/* No negative sizes or overly long symlink targets. */
	219	if (size < 0 \|\| size > XFS_SYMLINK_MAXLEN)
	220	return __this_address;
	221
	222	/* No NULLs in the target either. */
	223	if (memchr(sfp, 0, size - 1))
	224	return __this_address;
	225
	226	/* We /did/ null-terminate the buffer, right? */
	227	if (*endp != 0)
	228	return __this_address;
	229	return NULL;
	230	}