summaryrefslogtreecommitdiffstats
path: root/src/wgtpkg-install.c
blob: 8035a309df1567d826b33f94363a2fab72bd9444 (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
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
/*
 Copyright 2015, 2016 IoT.bzh

 author: José Bollo <jose.bollo@iot.bzh>

 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
 You may obtain a copy of the License at

     http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing, software
 distributed under the License is distributed on an "AS IS" BASIS,
 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
*/

#define _GNU_SOURCE

#include <limits.h>
#include <errno.h>
#include <string.h>
#include <ctype.h>
#include <assert.h>
#include <unistd.h>
#include <stdio.h>
#include <sys/stat.h>

#include "verbose.h"
#include "wgt.h"
#include "wgt-info.h"
#include "wgtpkg-files.h"
#include "wgtpkg-workdir.h"
#include "wgtpkg-zip.h"
#include "wgtpkg-permissions.h"
#include "wgtpkg-digsig.h"
#include "wgtpkg-install.h"
#include "secmgr-wrap.h"
#include "utils-dir.h"

static const char permission_required[] = "required";
static const char permission_optional[] = "optional";
static const char feature_required_permissions[] = FWK_PREFIX "required-permissions";
static const char exec_type_string[] = "application/x-executable";

static int check_defined(const void *data, const char *name)
{
	if (data)
		return 0;
	ERROR("widget has no defined '%s' (temporary constraints)", name);
	errno = EINVAL;
	return -1;
}

static int check_valid_string(const char *value, const char *name)
{
	int pos;
	char c;

	if (check_defined(value, name))
		return -1;
	pos = 0;
	c = value[pos];
	if (c == 0) {
		ERROR("empty string forbidden in '%s' (temporary constraints)", name);
		errno = EINVAL;
		return -1;			
	}
	do {
		if (!isalnum(c) && !strchr(".-_", c)) {
			ERROR("forbidden char %c in '%s' -> '%s' (temporary constraints)", c, name, value);
			errno = EINVAL;
			return -1;			
		}
		c = value[++pos];
	} while(c);
	return 0;
}

static int check_temporary_constraints(const struct wgt_desc *desc)
{
	int result = check_valid_string(desc->id, "id");
	result |= check_valid_string(desc->version, "version");
	result |= check_valid_string(desc->ver, "ver");
	result |= check_defined(desc->icons, "icon");
	result |= check_defined(desc->content_src, "content");
	if (result)
		return result;
	if (desc->icons->next) {
		ERROR("widget has more than one icon defined (temporary constraints)");
		errno = EINVAL;
		result = -1;
	}
	return 0;
}

static int set_required_permissions(struct wgt_desc_param *params, int required)
{
	int optional;

	while (params) {
		/* check the value */
		if (!strcmp(params->value, permission_required))
			optional = !required;
		else if (!strcmp(params->value, permission_optional))
			optional = 1;
		else {
			ERROR("unexpected parameter value: %s found for %s", params->value, params->name);
			errno = EPERM;
			return -1;
		}
		/* set the permission */
		if (request_permission(params->name)) {
			DEBUG("granted permission: %s", params->name);
		} else if (optional) {
			INFO("optional permission ungranted: %s", params->name);
		} else {
			ERROR("ungranted permission required: %s", params->name);
			errno = EPERM;
			return -1;
		}
		params = params->next;
	}
	return 0;
}

static int check_widget(const struct wgt_desc *desc)
{
	int result;
	const struct wgt_desc_feature *feature;

	result = check_temporary_constraints(desc);
	feature = desc->features;
	while(result >= 0 && feature) {
		if (!strcmp(feature->name, feature_required_permissions))
			result = set_required_permissions(feature->params, feature->required);
		feature = feature->next;
	}
	return result;
}

static int move_widget(const char *root, const struct wgt_desc *desc, int force)
{
	char newdir[PATH_MAX];
	int rc;

	rc = snprintf(newdir, sizeof newdir, "%s/%s/%s", root, desc->id, desc->ver);
	if (rc >= (int)sizeof newdir) {
		ERROR("path too long in move_widget");
		errno = EINVAL;
		return -1;
	}

	return move_workdir(newdir, 1, force);
}

static int install_icon(const struct wgt_desc *desc)
{
	char link[PATH_MAX];
	char target[PATH_MAX];
	int rc;

	create_directory(FWK_ICON_DIR, 0755, 1);
	rc = snprintf(link, sizeof link, "%s/%s", FWK_ICON_DIR, desc->idaver);
	if (rc >= (int)sizeof link) {
		ERROR("link too long in install_icon");
		errno = EINVAL;
		return -1;
	}

	rc = snprintf(target, sizeof target, "%s/%s", workdir, desc->icons->src);
	if (rc >= (int)sizeof target) {
		ERROR("target too long in install_icon");
		errno = EINVAL;
		return -1;
	}

	unlink(link);
	rc = symlink(target, link);
	if (rc)
		ERROR("can't create link %s -> %s", link, target);
	return rc;
}

static int install_exec_flag(const struct wgt_desc *desc)
{
	return desc->content_type != NULL && !strcmp(desc->content_type, exec_type_string)
		? fchmodat(workdirfd, desc->content_src, 0755, 0) : 0;
}

static int install_security(const struct wgt_desc *desc)
{
	char path[PATH_MAX], *head;
	const char *icon, *perm;
	int rc;
	unsigned int i, n, len, lic, lf;
	struct filedesc *f;

	rc = secmgr_init(desc->id);
	if (rc)
		goto error;

	rc = secmgr_path_public_read_only(workdir);
	if (rc)
		goto error2;

	/* instal the files */
	head = stpcpy(path, workdir);
	assert(head < path + sizeof path);
	len = (unsigned)((path + sizeof path) - head);
	if (!len) {
		ERROR("root path too long in install_security");
		errno = ENAMETOOLONG;
		goto error2;
	}
	len--;
	*head++ = '/';
	icon = desc->icons->src;
	lic = (unsigned)strlen(icon);
	n = file_count();
	i = 0;
	while(i < n) {
		f = file_of_index(i++);
		lf = (unsigned)strlen(f->name);
		if (lf >= len) {
			ERROR("path too long in install_security");
			errno = ENAMETOOLONG;
			goto error2;
		}
		strcpy(head, f->name);
		if (lf <= lic && !memcmp(f->name, icon, lf) && (!f->name[lf] || f->name[lf] == '/'))
			rc = secmgr_path_public_read_only(path);
		else
			rc = secmgr_path_read_only(path);
		if (rc)
			goto error2;
	}

	/* install the permissions */
	perm = first_usable_permission();
	while(perm) {
		rc = secmgr_permit(perm);
		if (rc)
			goto error2;
		perm = next_usable_permission();
	}

	rc = secmgr_install();
	return rc;
error2:
	secmgr_cancel();
error:
	return -1;
}

/* install the widget of the file */
struct wgt_info *install_widget(const char *wgtfile, const char *root, int force)
{
	struct wgt_info *ifo;
	const struct wgt_desc *desc;

	NOTICE("-- INSTALLING widget %s to %s --", wgtfile, root);

	/* workdir */
	create_directory(root, 0755, 1);
	if (make_workdir(root, "TMP", 0)) {
		ERROR("failed to create a working directory");
		goto error1;
	}

	if (zread(wgtfile, 0))
		goto error2;

	if (check_all_signatures())
		goto error2;

	ifo = wgt_info_createat(workdirfd, NULL, 1, 1, 1);
	if (!ifo)
		goto error2;

	reset_requested_permissions();
	desc = wgt_info_desc(ifo);
	if (check_widget(desc))
		goto error3;

	if (move_widget(root, desc, force))
		goto error3;

	if (install_icon(desc))
		goto error3;

	if (install_exec_flag(desc))
		goto error3;

	if (install_security(desc))
		goto error3;

	file_reset();
	return ifo;

error3:
	wgt_info_unref(ifo);

error2:
	remove_workdir();

error1:
	file_reset();
	return NULL;
}