blob: 94b0ad0e61381a8a3664e88f0a78c37a8ea47362 [file] [log] [blame]
rjw1f884582022-01-06 17:20:42 +08001/*
2 * Copyright (c) 2007 Travis Geiselbrecht
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files
6 * (the "Software"), to deal in the Software without restriction,
7 * including without limitation the rights to use, copy, modify, merge,
8 * publish, distribute, sublicense, and/or sell copies of the Software,
9 * and to permit persons to whom the Software is furnished to do so,
10 * subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
18 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
19 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
20 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
21 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
22 */
23
24#include <stdlib.h>
25#include <string.h>
26#include <stdlib.h>
27#include <err.h>
28#include <debug.h>
29#include <trace.h>
30#include "ext2_priv.h"
31
32#define LOCAL_TRACE 0
33
34int ext2_open_file(fscookie *cookie, const char *path, filecookie **fcookie)
35{
36 ext2_t *ext2 = (ext2_t *)cookie;
37 int err;
38
39 /* do a path lookup */
40 inodenum_t inum;
41 err = ext2_lookup(ext2, path, &inum);
42 if (err < 0)
43 return err;
44
45 /* create the file object */
46 ext2_file_t *file = malloc(sizeof(ext2_file_t));
47 memset(file, 0, sizeof(ext2_file_t));
48
49 /* read in the inode */
50 err = ext2_load_inode(ext2, inum, &file->inode);
51 if (err < 0) {
52 free(file);
53 return err;
54 }
55
56 file->ext2 = ext2;
57 *fcookie = (filecookie *)file;
58
59 return 0;
60}
61
62ssize_t ext2_read_file(filecookie *fcookie, void *buf, off_t offset, size_t len)
63{
64 ext2_file_t *file = (ext2_file_t *)fcookie;
65 int err;
66
67 // test that it's a file
68 if (!S_ISREG(file->inode.i_mode)) {
69 dprintf(INFO, "ext2_read_file: not a file\n");
70 return -1;
71 }
72
73 // read from the inode
74 err = ext2_read_inode(file->ext2, &file->inode, buf, offset, len);
75
76 return err;
77}
78
79int ext2_close_file(filecookie *fcookie)
80{
81 ext2_file_t *file = (ext2_file_t *)fcookie;
82
83 // see if we need to free any of the cache blocks
84 int i;
85 for (i=0; i < 3; i++) {
86 if (file->ind_cache[i].num != 0) {
87 free(file->ind_cache[i].ptr);
88 }
89 }
90
91 free(file);
92
93 return 0;
94}
95
96off_t ext2_file_len(ext2_t *ext2, struct ext2_inode *inode)
97{
98 /* calculate the file size */
99 off_t len = inode->i_size;
100 if ((ext2->sb.s_feature_ro_compat & EXT2_FEATURE_RO_COMPAT_LARGE_FILE) && (S_ISREG(inode->i_mode))) {
101 /* can potentially be a large file */
102 len |= (off_t)inode->i_size_high << 32;
103 }
104
105 return len;
106}
107
108int ext2_stat_file(filecookie *fcookie, struct file_stat *stat)
109{
110 ext2_file_t *file = (ext2_file_t *)fcookie;
111
112 stat->size = ext2_file_len(file->ext2, &file->inode);
113
114 /* is it a dir? */
115 stat->is_dir = false;
116 if (S_ISDIR(file->inode.i_mode))
117 stat->is_dir = true;
118
119 return 0;
120}
121
122int ext2_read_link(ext2_t *ext2, struct ext2_inode *inode, char *str, size_t len)
123{
124 LTRACEF("inode %p, str %p, len %zu\n", inode, str, len);
125
126 off_t linklen = ext2_file_len(ext2, inode);
127
128 if ((linklen < 0) || (linklen + 1 > len))
129 return ERR_NO_MEMORY;
130
131 if (linklen > 60) {
132 int err = ext2_read_inode(ext2, inode, str, 0, linklen);
133 if (err < 0)
134 return err;
135 str[linklen] = 0;
136 } else {
137 memcpy(str, &inode->i_block[0], linklen);
138 str[linklen] = 0;
139 }
140
141 LTRACEF("read link '%s'\n", str);
142
143 return linklen;
144}
145