aboutsummaryrefslogtreecommitdiff
path: root/bin/gensquashfs/dirscan_xattr.c
blob: 3995a198639000f27407e4cf236d4bd01ef7b991 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
/* SPDX-License-Identifier: GPL-3.0-or-later */
/*
 * dirscan_xattr.c
 *
 * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
 */
#include "mkfs.h"

#ifdef HAVE_SYS_XATTR_H
static char *get_full_path(const char *prefix, tree_node_t *node)
{
	char *path = NULL, *new = NULL;
	size_t path_len, prefix_len;
	int ret;

	path = fstree_get_path(node);
	if (path == NULL)
		goto fail;

	ret = canonicalize_name(path);
	assert(ret == 0);

	path_len = strlen(path);
	prefix_len = strlen(prefix);

	while (prefix_len > 0 && prefix[prefix_len - 1] == '/')
		--prefix_len;

	if (prefix_len > 0) {
		new = realloc(path, path_len + prefix_len + 2);
		if (new == NULL)
			goto fail;

		path = new;

		memmove(path + prefix_len + 1, path, path_len + 1);
		memcpy(path, prefix, prefix_len);
		path[prefix_len] = '/';
	}

	return path;
fail:
	perror("getting full path for xattr scan");
	free(path);
	return NULL;
}

static int xattr_from_path(sqfs_xattr_writer_t *xwr, const char *path)
{
	char *key, *value = NULL, *buffer = NULL;
	ssize_t buflen, vallen, keylen;
	int ret;

	buflen = llistxattr(path, NULL, 0);
	if (buflen < 0) {
		fprintf(stderr, "llistxattr %s: %s", path, strerror(errno));
		return -1;
	}

	if (buflen == 0)
		return 0;

	buffer = malloc(buflen);
	if (buffer == NULL) {
		perror("xattr name buffer");
		return -1;
	}

	buflen = llistxattr(path, buffer, buflen);
	if (buflen == -1) {
		fprintf(stderr, "llistxattr %s: %s", path, strerror(errno));
		goto fail;
	}

	key = buffer;
	while (buflen > 0) {
		vallen = lgetxattr(path, key, NULL, 0);
		if (vallen == -1) {
			fprintf(stderr, "lgetxattr %s: %s",
				path, strerror(errno));
			goto fail;
		}

		if (vallen > 0) {
			value = calloc(1, vallen);
			if (value == NULL) {
				perror("allocating xattr value buffer");
				goto fail;
			}

			vallen = lgetxattr(path, key, value, vallen);
			if (vallen == -1) {
				fprintf(stderr, "lgetxattr %s: %s\n",
					path, strerror(errno));
				goto fail;
			}

			ret = sqfs_xattr_writer_add(xwr, key, value, vallen);
			if (ret) {
				sqfs_perror(path,
					    "storing xattr key-value pairs",
					    ret);
				goto fail;
			}

			free(value);
			value = NULL;
		}

		keylen = strlen(key) + 1;
		buflen -= keylen;
		key += keylen;
	}

	free(buffer);
	return 0;
fail:
	free(value);
	free(buffer);
	return -1;
}
#endif

static int xattr_xcan_dfs(const char *path_prefix, void *selinux_handle,
			  sqfs_xattr_writer_t *xwr, unsigned int flags,
			  tree_node_t *node)
{
	char *path;
	int ret;

	ret = sqfs_xattr_writer_begin(xwr);
	if (ret) {
		sqfs_perror(node->name, "recoding xattr key-value pairs\n",
			    ret);
		return -1;
	}

#ifdef HAVE_SYS_XATTR_H
	if (flags & DIR_SCAN_READ_XATTR) {
		path = get_full_path(path_prefix, node);
		if (path == NULL)
			return -1;

		ret = xattr_from_path(xwr, path);
		free(path);

		if (ret)
			return -1;
	}
#else
	(void)path_prefix;
#endif

	if (selinux_handle != NULL) {
		path = fstree_get_path(node);
		if (path == NULL) {
			perror("reconstructing absolute path");
			return -1;
		}

		ret = selinux_relable_node(selinux_handle, xwr, node, path);
		free(path);

		if (ret)
			return -1;
	}

	if (sqfs_xattr_writer_end(xwr, &node->xattr_idx)) {
		sqfs_perror(node->name, "completing xattr key-value pairs",
			    ret);
		return -1;
	}

	if (S_ISDIR(node->mode)) {
		node = node->data.dir.children;

		while (node != NULL) {
			if (xattr_xcan_dfs(path_prefix, selinux_handle, xwr,
					   flags, node)) {
				return -1;
			}

			node = node->next;
		}
	}

	return 0;
}

int xattrs_from_dir(fstree_t *fs, const char *path, void *selinux_handle,
		    sqfs_xattr_writer_t *xwr, unsigned int flags)
{
	if (xwr == NULL)
		return 0;

	if (selinux_handle == NULL && !(flags & DIR_SCAN_READ_XATTR))
		return 0;

	return xattr_xcan_dfs(path, selinux_handle, xwr, flags, fs->root);
}