[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_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_log_item;
	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 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)
{
	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 should never occur in memory as they are
	 * never alllowed 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
37b3b4d6	1	// SPDX-License-Identifier: GPL-2.0
9f76c5b5	2	/*
270b1db1 DC	3	* Copyright (c) 2000-2006 Silicon Graphics, Inc.
270b1db1 DC	4	* Copyright (c) 2012-2013 Red Hat, Inc.
9f76c5b5 DC	5	* All rights reserved.
9f76c5b5 DC	6	*/
9c799827	7	#include "libxfs_priv.h"
b626fb59 DC	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_bmap_btree.h"
	15	#include "xfs_inode.h"
	16	#include "xfs_trace.h"
	17	#include "xfs_cksum.h"
	18	#include "xfs_trans.h"
	19
9f76c5b5 DC	20
	21	/*
	22	* Each contiguous block has a header, so it is not just a simple pathlen
	23	* to FSB conversion.
	24	*/
	25	int
	26	xfs_symlink_blocks(
	27	struct xfs_mount *mp,
	28	int pathlen)
	29	{
2019931a	30	int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
9f76c5b5	31
2019931a	32	return (pathlen + buflen - 1) / buflen;
9f76c5b5 DC	33	}
9f76c5b5 DC	34
f7b80291	35	int
9f76c5b5 DC	36	xfs_symlink_hdr_set(
	37	struct xfs_mount *mp,
	38	xfs_ino_t ino,
	39	uint32_t offset,
	40	uint32_t size,
	41	struct xfs_buf *bp)
	42	{
	43	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	44
	45	if (!xfs_sb_version_hascrc(&mp->m_sb))
	46	return 0;
	47
a65d8d29	48	memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
9f76c5b5 DC	49	dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
	50	dsl->sl_offset = cpu_to_be32(offset);
	51	dsl->sl_bytes = cpu_to_be32(size);
9c4e12fb	52	uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
9f76c5b5 DC	53	dsl->sl_owner = cpu_to_be64(ino);
	54	dsl->sl_blkno = cpu_to_be64(bp->b_bn);
	55	bp->b_ops = &xfs_symlink_buf_ops;
	56
	57	return sizeof(struct xfs_dsymlink_hdr);
	58	}
	59
	60	/*
	61	* Checking of the symlink header is split into two parts. the verifier does
	62	* CRC, location and bounds checking, the unpacking function checks the path
	63	* parameters and owner.
	64	*/
	65	bool
	66	xfs_symlink_hdr_ok(
9f76c5b5 DC	67	xfs_ino_t ino,
	68	uint32_t offset,
	69	uint32_t size,
	70	struct xfs_buf *bp)
	71	{
	72	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	73
	74	if (offset != be32_to_cpu(dsl->sl_offset))
	75	return false;
	76	if (size != be32_to_cpu(dsl->sl_bytes))
	77	return false;
	78	if (ino != be64_to_cpu(dsl->sl_owner))
	79	return false;
	80
	81	/* ok */
	82	return true;
9f76c5b5 DC	83	}
9f76c5b5 DC	84
bc01119d	85	static xfs_failaddr_t
9f76c5b5 DC	86	xfs_symlink_verify(
	87	struct xfs_buf *bp)
	88	{
	89	struct xfs_mount *mp = bp->b_target->bt_mount;
	90	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	91
	92	if (!xfs_sb_version_hascrc(&mp->m_sb))
bc01119d	93	return __this_address;
9f76c5b5	94	if (dsl->sl_magic != cpu_to_be32(XFS_SYMLINK_MAGIC))
bc01119d	95	return __this_address;
9c4e12fb	96	if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
bc01119d	97	return __this_address;
9f76c5b5	98	if (bp->b_bn != be64_to_cpu(dsl->sl_blkno))
bc01119d	99	return __this_address;
9f76c5b5	100	if (be32_to_cpu(dsl->sl_offset) +
b8fb8c95	101	be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
bc01119d	102	return __this_address;
9f76c5b5	103	if (dsl->sl_owner == 0)
bc01119d	104	return __this_address;
a65d8d29	105	if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
bc01119d	106	return __this_address;
9f76c5b5	107
bc01119d	108	return NULL;
9f76c5b5 DC	109	}
	110
	111	static void
	112	xfs_symlink_read_verify(
	113	struct xfs_buf *bp)
	114	{
	115	struct xfs_mount *mp = bp->b_target->bt_mount;
1e697959	116	xfs_failaddr_t fa;
9f76c5b5 DC	117
	118	/* no verification of non-crc buffers */
	119	if (!xfs_sb_version_hascrc(&mp->m_sb))
	120	return;
	121
45922933	122	if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
1e697959 DW	123	xfs_verifier_error(bp, -EFSBADCRC, __this_address);
	124	else {
	125	fa = xfs_symlink_verify(bp);
	126	if (fa)
	127	xfs_verifier_error(bp, -EFSCORRUPTED, fa);
	128	}
9f76c5b5 DC	129	}
	130
	131	static void
	132	xfs_symlink_write_verify(
	133	struct xfs_buf *bp)
	134	{
	135	struct xfs_mount *mp = bp->b_target->bt_mount;
37d086ca	136	struct xfs_buf_log_item *bip = bp->b_log_item;
1e697959	137	xfs_failaddr_t fa;
9f76c5b5 DC	138
	139	/* no verification of non-crc buffers */
	140	if (!xfs_sb_version_hascrc(&mp->m_sb))
	141	return;
	142
1e697959 DW	143	fa = xfs_symlink_verify(bp);
	144	if (fa) {
	145	xfs_verifier_error(bp, -EFSCORRUPTED, fa);
9f76c5b5 DC	146	return;
	147	}
	148
	149	if (bip) {
	150	struct xfs_dsymlink_hdr *dsl = bp->b_addr;
	151	dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
	152	}
43b5aeed	153	xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
9f76c5b5 DC	154	}
	155
	156	const struct xfs_buf_ops xfs_symlink_buf_ops = {
a3fac935	157	.name = "xfs_symlink",
9f76c5b5 DC	158	.verify_read = xfs_symlink_read_verify,
9f76c5b5 DC	159	.verify_write = xfs_symlink_write_verify,
95d9582b	160	.verify_struct = xfs_symlink_verify,
9f76c5b5 DC	161	};
9f76c5b5 DC	162
88b66843 DC	163	void
	164	xfs_symlink_local_to_remote(
	165	struct xfs_trans *tp,
	166	struct xfs_buf *bp,
	167	struct xfs_inode *ip,
	168	struct xfs_ifork *ifp)
	169	{
	170	struct xfs_mount *mp = ip->i_mount;
	171	char *buf;
	172
19ebedcf DC	173	xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
19ebedcf DC	174
88b66843 DC	175	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
	176	bp->b_ops = NULL;
	177	memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
f44fbde0	178	xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
88b66843 DC	179	return;
	180	}
	181
	182	/*
	183	* As this symlink fits in an inode literal area, it must also fit in
	184	* the smallest buffer the filesystem supports.
	185	*/
	186	ASSERT(BBTOB(bp->b_length) >=
	187	ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
	188
	189	bp->b_ops = &xfs_symlink_buf_ops;
	190
	191	buf = bp->b_addr;
	192	buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
	193	memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
f44fbde0 BF	194	xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
f44fbde0 BF	195	ifp->if_bytes - 1);
88b66843	196	}
6db3a800	197
bf64a47a DC	198	/*
	199	* Verify the in-memory consistency of an inline symlink data fork. This
	200	* does not do on-disk format checks.
	201	*/
6db3a800 DW	202	xfs_failaddr_t
	203	xfs_symlink_shortform_verify(
	204	struct xfs_inode *ip)
	205	{
	206	char *sfp;
	207	char *endp;
	208	struct xfs_ifork *ifp;
	209	int size;
	210
	211	ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
	212	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
	213	sfp = (char *)ifp->if_u1.if_data;
	214	size = ifp->if_bytes;
	215	endp = sfp + size;
	216
bf64a47a DC	217	/*
	218	* Zero length symlinks should never occur in memory as they are
	219	* never alllowed to exist on disk.
	220	*/
	221	if (!size)
	222	return __this_address;
6db3a800 DW	223
	224	/* No negative sizes or overly long symlink targets. */
	225	if (size < 0 \|\| size > XFS_SYMLINK_MAXLEN)
	226	return __this_address;
	227
	228	/* No NULLs in the target either. */
	229	if (memchr(sfp, 0, size - 1))
	230	return __this_address;
	231
	232	/* We /did/ null-terminate the buffer, right? */
	233	if (*endp != 0)
	234	return __this_address;
	235	return NULL;
	236	}