Line data Source code
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 "xfs.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_error.h"
16 : #include "xfs_trans.h"
17 : #include "xfs_buf_item.h"
18 : #include "xfs_log.h"
19 :
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 240353456 : xfs_symlink_blocks(
27 : struct xfs_mount *mp,
28 : int pathlen)
29 : {
30 240353456 : int buflen = XFS_SYMLINK_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
31 :
32 240353456 : return (pathlen + buflen - 1) / buflen;
33 : }
34 :
35 : int
36 18316506 : 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 18316506 : struct xfs_dsymlink_hdr *dsl = bp->b_addr;
44 :
45 18316506 : if (!xfs_has_crc(mp))
46 : return 0;
47 :
48 18316506 : memset(dsl, 0, sizeof(struct xfs_dsymlink_hdr));
49 18316506 : dsl->sl_magic = cpu_to_be32(XFS_SYMLINK_MAGIC);
50 18316506 : dsl->sl_offset = cpu_to_be32(offset);
51 18316506 : dsl->sl_bytes = cpu_to_be32(size);
52 18316506 : uuid_copy(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid);
53 18316800 : dsl->sl_owner = cpu_to_be64(ino);
54 18316800 : dsl->sl_blkno = cpu_to_be64(xfs_buf_daddr(bp));
55 18316800 : bp->b_ops = &xfs_symlink_buf_ops;
56 :
57 18316800 : 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 203945244 : xfs_symlink_hdr_ok(
67 : xfs_ino_t ino,
68 : uint32_t offset,
69 : uint32_t size,
70 : struct xfs_buf *bp)
71 : {
72 203945244 : struct xfs_dsymlink_hdr *dsl = bp->b_addr;
73 :
74 407890488 : if (offset != be32_to_cpu(dsl->sl_offset))
75 : return false;
76 408436870 : if (size != be32_to_cpu(dsl->sl_bytes))
77 : return false;
78 204254907 : if (ino != be64_to_cpu(dsl->sl_owner))
79 0 : return false;
80 :
81 : /* ok */
82 : return true;
83 : }
84 :
85 : static xfs_failaddr_t
86 3403678 : xfs_symlink_verify(
87 : struct xfs_buf *bp)
88 : {
89 3403678 : struct xfs_mount *mp = bp->b_mount;
90 3403678 : struct xfs_dsymlink_hdr *dsl = bp->b_addr;
91 :
92 3403678 : if (!xfs_has_crc(mp))
93 0 : return __this_address;
94 3403678 : if (!xfs_verify_magic(bp, dsl->sl_magic))
95 0 : return __this_address;
96 3403678 : if (!uuid_equal(&dsl->sl_uuid, &mp->m_sb.sb_meta_uuid))
97 0 : return __this_address;
98 3403678 : if (xfs_buf_daddr(bp) != be64_to_cpu(dsl->sl_blkno))
99 0 : return __this_address;
100 6807356 : if (be32_to_cpu(dsl->sl_offset) +
101 3403678 : be32_to_cpu(dsl->sl_bytes) >= XFS_SYMLINK_MAXLEN)
102 0 : return __this_address;
103 3403678 : if (dsl->sl_owner == 0)
104 0 : return __this_address;
105 3403678 : if (!xfs_log_check_lsn(mp, be64_to_cpu(dsl->sl_lsn)))
106 0 : return __this_address;
107 :
108 : return NULL;
109 : }
110 :
111 : static void
112 562830 : xfs_symlink_read_verify(
113 : struct xfs_buf *bp)
114 : {
115 562830 : struct xfs_mount *mp = bp->b_mount;
116 562830 : xfs_failaddr_t fa;
117 :
118 : /* no verification of non-crc buffers */
119 562830 : if (!xfs_has_crc(mp))
120 : return;
121 :
122 562830 : if (!xfs_buf_verify_cksum(bp, XFS_SYMLINK_CRC_OFF))
123 2 : xfs_verifier_error(bp, -EFSBADCRC, __this_address);
124 : else {
125 562828 : fa = xfs_symlink_verify(bp);
126 562828 : if (fa)
127 0 : xfs_verifier_error(bp, -EFSCORRUPTED, fa);
128 : }
129 : }
130 :
131 : static void
132 2840850 : xfs_symlink_write_verify(
133 : struct xfs_buf *bp)
134 : {
135 2840850 : struct xfs_mount *mp = bp->b_mount;
136 2840850 : struct xfs_buf_log_item *bip = bp->b_log_item;
137 2840850 : xfs_failaddr_t fa;
138 :
139 : /* no verification of non-crc buffers */
140 2840850 : if (!xfs_has_crc(mp))
141 : return;
142 :
143 2840850 : fa = xfs_symlink_verify(bp);
144 2840850 : if (fa) {
145 0 : xfs_verifier_error(bp, -EFSCORRUPTED, fa);
146 0 : return;
147 : }
148 :
149 2840850 : if (bip) {
150 2840850 : struct xfs_dsymlink_hdr *dsl = bp->b_addr;
151 2840850 : dsl->sl_lsn = cpu_to_be64(bip->bli_item.li_lsn);
152 : }
153 2840850 : xfs_buf_update_cksum(bp, XFS_SYMLINK_CRC_OFF);
154 : }
155 :
156 : const struct xfs_buf_ops xfs_symlink_buf_ops = {
157 : .name = "xfs_symlink",
158 : .magic = { 0, cpu_to_be32(XFS_SYMLINK_MAGIC) },
159 : .verify_read = xfs_symlink_read_verify,
160 : .verify_write = xfs_symlink_write_verify,
161 : .verify_struct = xfs_symlink_verify,
162 : };
163 :
164 : void
165 4 : xfs_symlink_local_to_remote(
166 : struct xfs_trans *tp,
167 : struct xfs_buf *bp,
168 : struct xfs_inode *ip,
169 : struct xfs_ifork *ifp)
170 : {
171 4 : struct xfs_mount *mp = ip->i_mount;
172 4 : char *buf;
173 :
174 4 : xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SYMLINK_BUF);
175 :
176 4 : if (!xfs_has_crc(mp)) {
177 0 : bp->b_ops = NULL;
178 0 : memcpy(bp->b_addr, ifp->if_u1.if_data, ifp->if_bytes);
179 0 : xfs_trans_log_buf(tp, bp, 0, ifp->if_bytes - 1);
180 0 : return;
181 : }
182 :
183 : /*
184 : * As this symlink fits in an inode literal area, it must also fit in
185 : * the smallest buffer the filesystem supports.
186 : */
187 4 : ASSERT(BBTOB(bp->b_length) >=
188 : ifp->if_bytes + sizeof(struct xfs_dsymlink_hdr));
189 :
190 4 : bp->b_ops = &xfs_symlink_buf_ops;
191 :
192 4 : buf = bp->b_addr;
193 4 : buf += xfs_symlink_hdr_set(mp, ip->i_ino, 0, ifp->if_bytes, bp);
194 8 : memcpy(buf, ifp->if_u1.if_data, ifp->if_bytes);
195 4 : xfs_trans_log_buf(tp, bp, 0, sizeof(struct xfs_dsymlink_hdr) +
196 4 : ifp->if_bytes - 1);
197 : }
198 :
199 : /*
200 : * Verify the in-memory consistency of an inline symlink data fork. This
201 : * does not do on-disk format checks.
202 : */
203 : xfs_failaddr_t
204 8714754 : xfs_symlink_shortform_verify(
205 : struct xfs_inode *ip)
206 : {
207 8714754 : struct xfs_ifork *ifp = xfs_ifork_ptr(ip, XFS_DATA_FORK);
208 8714754 : char *sfp = (char *)ifp->if_u1.if_data;
209 8714754 : int size = ifp->if_bytes;
210 8714754 : char *endp = sfp + size;
211 :
212 8714754 : ASSERT(ifp->if_format == XFS_DINODE_FMT_LOCAL);
213 :
214 : /*
215 : * Zero length symlinks should never occur in memory as they are
216 : * never allowed to exist on disk.
217 : */
218 8714754 : if (!size)
219 0 : return __this_address;
220 :
221 : /* No negative sizes or overly long symlink targets. */
222 8714754 : if (size < 0 || size > XFS_SYMLINK_MAXLEN)
223 0 : return __this_address;
224 :
225 : /* No NULLs in the target either. */
226 17429508 : if (memchr(sfp, 0, size - 1))
227 2 : return __this_address;
228 :
229 : /* We /did/ null-terminate the buffer, right? */
230 8714752 : if (*endp != 0)
231 0 : return __this_address;
232 : return NULL;
233 : }
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