summaryrefslogtreecommitdiff
path: root/udev/lib/libudev-ctrl.c
blob: 2e15db0be0ba1e6e210cb18a3857a1043beafb41 (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
313
314
315
316
317
318
319
/*
 * libudev - interface to udev device information
 *
 * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>

#include "libudev.h"
#include "libudev-private.h"

/* last known version with this wire protocol */
#define UDEV_CTRL_MAGIC				0xdead1dea

enum udev_ctrl_msg_type {
	UDEV_CTRL_UNKNOWN,
	UDEV_CTRL_SET_LOG_LEVEL,
	UDEV_CTRL_STOP_EXEC_QUEUE,
	UDEV_CTRL_START_EXEC_QUEUE,
	UDEV_CTRL_RELOAD_RULES,
	UDEV_CTRL_SET_ENV,
	UDEV_CTRL_SET_MAX_CHILDS,
	UDEV_CTRL_SET_MAX_CHILDS_RUNNING,
};

struct udev_ctrl_msg_wire {
	char version[16];
	unsigned int magic;
	enum udev_ctrl_msg_type type;
	union {
		int intval;
		char buf[256];
	};
};

struct udev_ctrl_msg {
	int refcount;
	struct udev_ctrl *uctrl;
	struct udev_ctrl_msg_wire ctrl_msg_wire;
};

struct udev_ctrl {
	int refcount;
	struct udev *udev;
	int sock;
	struct sockaddr_un saddr;
	socklen_t addrlen;
};

struct udev_ctrl *udev_ctrl_new_from_socket(struct udev *udev, const char *socket_path)
{
	struct udev_ctrl *uctrl;

	uctrl = calloc(1, sizeof(struct udev_ctrl));
	if (uctrl == NULL)
		return NULL;
	uctrl->refcount = 1;
	uctrl->udev = udev;

	uctrl->sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
	if (uctrl->sock < 0) {
		err(udev, "error getting socket: %m\n");
		udev_ctrl_unref(uctrl);
		return NULL;
	}

	uctrl->saddr.sun_family = AF_LOCAL;
	strcpy(uctrl->saddr.sun_path, socket_path);
	uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.sun_path);
	/* translate leading '@' to abstract namespace */
	if (uctrl->saddr.sun_path[0] == '@')
		uctrl->saddr.sun_path[0] = '\0';

	return uctrl;
}

int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl)
{
	int err;
	const int feature_on = 1;

	err= bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
	if (err < 0) {
		err(uctrl->udev, "bind failed: %m\n");
		return err;
	}

	/* enable receiving of the sender credentials */
	setsockopt(uctrl->sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
	return 0;
}

struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl)
{
	return uctrl->udev;
}

struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl)
{
	if (uctrl == NULL)
		return NULL;
	uctrl->refcount++;
	return uctrl;
}

void udev_ctrl_unref(struct udev_ctrl *uctrl)
{
	if (uctrl == NULL)
		return;
	uctrl->refcount--;
	if (uctrl->refcount > 0)
		return;
	if (uctrl->sock >= 0)
		close(uctrl->sock);
	free(uctrl);
}

int udev_ctrl_get_fd(struct udev_ctrl *uctrl)
{
	if (uctrl == NULL)
		return -1;
	return uctrl->sock;
}

static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf)
{
	struct udev_ctrl_msg_wire ctrl_msg_wire;
	int err;

	memset(&ctrl_msg_wire, 0x00, sizeof(struct udev_ctrl_msg_wire));
	strcpy(ctrl_msg_wire.version, "udev-" VERSION);
	ctrl_msg_wire.magic = UDEV_CTRL_MAGIC;
	ctrl_msg_wire.type = type;

	if (buf != NULL)
		util_strlcpy(ctrl_msg_wire.buf, buf, sizeof(ctrl_msg_wire.buf));
	else
		ctrl_msg_wire.intval = intval;

	err = sendto(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0,
		     (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
	if (err == -1) {
		err(uctrl->udev, "error sending message: %m\n");
	}
	return err;
}

int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority)
{
	ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL);
	return 0;
}

int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl)
{
	ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL);
	return 0;
}

int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl)
{
	ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL);
	return 0;
}

int udev_ctrl_send_reload_rules(struct udev_ctrl *uctrl)
{
	ctrl_send(uctrl, UDEV_CTRL_RELOAD_RULES, 0, NULL);
	return 0;
}

int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key)
{
	ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key);
	return 0;
}

int udev_ctrl_send_set_max_childs(struct udev_ctrl *uctrl, int count)
{
	ctrl_send(uctrl, UDEV_CTRL_SET_MAX_CHILDS, count, NULL);
	return 0;
}

struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl *uctrl)
{
	struct udev_ctrl_msg *uctrl_msg;
	ssize_t size;
	struct msghdr smsg;
	struct cmsghdr *cmsg;
	struct iovec iov;
	struct ucred *cred;
	char cred_msg[CMSG_SPACE(sizeof(struct ucred))];

	uctrl_msg = calloc(1, sizeof(struct udev_ctrl_msg));
	if (uctrl_msg == NULL)
		return NULL;
	uctrl_msg->refcount = 1;
	uctrl_msg->uctrl = uctrl;

	iov.iov_base = &uctrl_msg->ctrl_msg_wire;
	iov.iov_len = sizeof(struct udev_ctrl_msg_wire);

	memset(&smsg, 0x00, sizeof(struct msghdr));
	smsg.msg_iov = &iov;
	smsg.msg_iovlen = 1;
	smsg.msg_control = cred_msg;
	smsg.msg_controllen = sizeof(cred_msg);

	size = recvmsg(uctrl->sock, &smsg, 0);
	if (size <  0) {
		err(uctrl->udev, "unable to receive user udevd message: %m\n");
		goto err;
	}
	cmsg = CMSG_FIRSTHDR(&smsg);
	cred = (struct ucred *) CMSG_DATA(cmsg);

	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
		err(uctrl->udev, "no sender credentials received, message ignored\n");
		goto err;
	}

	if (cred->uid != 0) {
		err(uctrl->udev, "sender uid=%i, message ignored\n", cred->uid);
		goto err;
	}

	if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
		err(uctrl->udev, "message magic 0x%08x doesn't match, ignore it\n", uctrl_msg->ctrl_msg_wire.magic);
		goto err;
	}

	info(uctrl->udev, "created ctrl_msg %p (%i)\n", uctrl_msg, uctrl_msg->ctrl_msg_wire.type);
	return uctrl_msg;
err:
	udev_ctrl_msg_unref(uctrl_msg);
	return NULL;
}

struct udev_ctrl_msg *udev_ctrl_msg_ref(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg == NULL)
		return NULL;
	ctrl_msg->refcount++;
	return ctrl_msg;
}

void udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg == NULL)
		return;
	ctrl_msg->refcount--;
	if (ctrl_msg->refcount > 0)
		return;
	info(ctrl_msg->uctrl->udev, "release ctrl_msg %p\n", ctrl_msg);
	free(ctrl_msg);
}

int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_LOG_LEVEL)
		return ctrl_msg->ctrl_msg_wire.intval;
	return -1;
}

int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_STOP_EXEC_QUEUE)
		return 1;
	return -1;
}

int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_START_EXEC_QUEUE)
		return 1;
	return -1;
}

int udev_ctrl_get_reload_rules(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_RELOAD_RULES)
		return 1;
	return -1;
}

const char *udev_ctrl_get_set_env(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_ENV)
		return ctrl_msg->ctrl_msg_wire.buf;
	return NULL;
}

int udev_ctrl_get_set_max_childs(struct udev_ctrl_msg *ctrl_msg)
{
	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_MAX_CHILDS)
		return ctrl_msg->ctrl_msg_wire.intval;
	return -1;
}