1 /* SPDX-License-Identifier: LGPL-2.1+
3 * libudev - interface to udev device information
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
16 #include <sys/socket.h>
20 #include "alloc-util.h"
22 #include "format-util.h"
23 #include "socket-util.h"
25 #include "udev-ctrl.h"
27 /* wire protocol magic must match */
28 #define UDEV_CTRL_MAGIC 0xdead1dea
30 enum udev_ctrl_msg_type
{
32 UDEV_CTRL_SET_LOG_LEVEL
,
33 UDEV_CTRL_STOP_EXEC_QUEUE
,
34 UDEV_CTRL_START_EXEC_QUEUE
,
37 UDEV_CTRL_SET_CHILDREN_MAX
,
42 struct udev_ctrl_msg_wire
{
45 enum udev_ctrl_msg_type type
;
52 struct udev_ctrl_msg
{
54 struct udev_ctrl_connection
*conn
;
55 struct udev_ctrl_msg_wire ctrl_msg_wire
;
61 union sockaddr_union saddr
;
68 struct udev_ctrl_connection
{
70 struct udev_ctrl
*uctrl
;
74 struct udev_ctrl
*udev_ctrl_new_from_fd(int fd
) {
75 struct udev_ctrl
*uctrl
;
78 uctrl
= new0(struct udev_ctrl
, 1);
84 uctrl
->sock
= socket(AF_LOCAL
, SOCK_SEQPACKET
|SOCK_NONBLOCK
|SOCK_CLOEXEC
, 0);
85 if (uctrl
->sock
< 0) {
86 log_error_errno(errno
, "error getting socket: %m");
87 udev_ctrl_unref(uctrl
);
96 * FIXME: remove it as soon as we can depend on this:
97 * http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=90c6bd34f884cd9cee21f1d152baf6c18bcac949
99 r
= setsockopt(uctrl
->sock
, SOL_SOCKET
, SO_PASSCRED
, &const_int_one
, sizeof(const_int_one
));
101 log_warning_errno(errno
, "could not set SO_PASSCRED: %m");
103 uctrl
->saddr
.un
= (struct sockaddr_un
) {
104 .sun_family
= AF_UNIX
,
105 .sun_path
= "/run/udev/control",
108 uctrl
->addrlen
= SOCKADDR_UN_LEN(uctrl
->saddr
.un
);
112 struct udev_ctrl
*udev_ctrl_new(void) {
113 return udev_ctrl_new_from_fd(-1);
116 int udev_ctrl_enable_receiving(struct udev_ctrl
*uctrl
) {
120 err
= bind(uctrl
->sock
, &uctrl
->saddr
.sa
, uctrl
->addrlen
);
121 if (err
< 0 && errno
== EADDRINUSE
) {
122 (void) sockaddr_un_unlink(&uctrl
->saddr
.un
);
123 err
= bind(uctrl
->sock
, &uctrl
->saddr
.sa
, uctrl
->addrlen
);
127 return log_error_errno(errno
, "bind failed: %m");
129 err
= listen(uctrl
->sock
, 0);
131 return log_error_errno(errno
, "listen failed: %m");
134 uctrl
->cleanup_socket
= true;
139 static struct udev_ctrl
*udev_ctrl_free(struct udev_ctrl
*uctrl
) {
142 safe_close(uctrl
->sock
);
146 DEFINE_PRIVATE_TRIVIAL_REF_FUNC(struct udev_ctrl
, udev_ctrl
);
147 DEFINE_TRIVIAL_UNREF_FUNC(struct udev_ctrl
, udev_ctrl
, udev_ctrl_free
);
149 int udev_ctrl_cleanup(struct udev_ctrl
*uctrl
) {
152 if (uctrl
->cleanup_socket
)
153 sockaddr_un_unlink(&uctrl
->saddr
.un
);
157 int udev_ctrl_get_fd(struct udev_ctrl
*uctrl
) {
163 struct udev_ctrl_connection
*udev_ctrl_get_connection(struct udev_ctrl
*uctrl
) {
164 struct udev_ctrl_connection
*conn
;
165 struct ucred ucred
= {};
168 conn
= new(struct udev_ctrl_connection
, 1);
174 conn
->sock
= accept4(uctrl
->sock
, NULL
, NULL
, SOCK_CLOEXEC
|SOCK_NONBLOCK
);
175 if (conn
->sock
< 0) {
177 log_error_errno(errno
, "unable to receive ctrl connection: %m");
181 /* check peer credential of connection */
182 r
= getpeercred(conn
->sock
, &ucred
);
184 log_error_errno(r
, "unable to receive credentials of ctrl connection: %m");
188 log_error("sender uid="UID_FMT
", message ignored", ucred
.uid
);
192 /* enable receiving of the sender credentials in the messages */
193 r
= setsockopt(conn
->sock
, SOL_SOCKET
, SO_PASSCRED
, &const_int_one
, sizeof(const_int_one
));
195 log_warning_errno(errno
, "could not set SO_PASSCRED: %m");
197 udev_ctrl_ref(uctrl
);
205 static struct udev_ctrl_connection
*udev_ctrl_connection_free(struct udev_ctrl_connection
*conn
) {
208 safe_close(conn
->sock
);
209 udev_ctrl_unref(conn
->uctrl
);
213 DEFINE_TRIVIAL_REF_UNREF_FUNC(struct udev_ctrl_connection
, udev_ctrl_connection
, udev_ctrl_connection_free
);
215 static int ctrl_send(struct udev_ctrl
*uctrl
, enum udev_ctrl_msg_type type
, int intval
, const char *buf
, int timeout
) {
216 struct udev_ctrl_msg_wire ctrl_msg_wire
;
219 memzero(&ctrl_msg_wire
, sizeof(struct udev_ctrl_msg_wire
));
220 strcpy(ctrl_msg_wire
.version
, "udev-" PACKAGE_VERSION
);
221 ctrl_msg_wire
.magic
= UDEV_CTRL_MAGIC
;
222 ctrl_msg_wire
.type
= type
;
225 strscpy(ctrl_msg_wire
.buf
, sizeof(ctrl_msg_wire
.buf
), buf
);
227 ctrl_msg_wire
.intval
= intval
;
229 if (!uctrl
->connected
) {
230 if (connect(uctrl
->sock
, &uctrl
->saddr
.sa
, uctrl
->addrlen
) < 0) {
234 uctrl
->connected
= true;
236 if (send(uctrl
->sock
, &ctrl_msg_wire
, sizeof(ctrl_msg_wire
), 0) < 0) {
241 /* wait for peer message handling or disconnect */
243 struct pollfd pfd
[1];
246 pfd
[0].fd
= uctrl
->sock
;
247 pfd
[0].events
= POLLIN
;
248 r
= poll(pfd
, 1, timeout
* MSEC_PER_SEC
);
256 if (r
> 0 && pfd
[0].revents
& POLLERR
) {
269 int udev_ctrl_send_set_log_level(struct udev_ctrl
*uctrl
, int priority
, int timeout
) {
270 return ctrl_send(uctrl
, UDEV_CTRL_SET_LOG_LEVEL
, priority
, NULL
, timeout
);
273 int udev_ctrl_send_stop_exec_queue(struct udev_ctrl
*uctrl
, int timeout
) {
274 return ctrl_send(uctrl
, UDEV_CTRL_STOP_EXEC_QUEUE
, 0, NULL
, timeout
);
277 int udev_ctrl_send_start_exec_queue(struct udev_ctrl
*uctrl
, int timeout
) {
278 return ctrl_send(uctrl
, UDEV_CTRL_START_EXEC_QUEUE
, 0, NULL
, timeout
);
281 int udev_ctrl_send_reload(struct udev_ctrl
*uctrl
, int timeout
) {
282 return ctrl_send(uctrl
, UDEV_CTRL_RELOAD
, 0, NULL
, timeout
);
285 int udev_ctrl_send_set_env(struct udev_ctrl
*uctrl
, const char *key
, int timeout
) {
286 return ctrl_send(uctrl
, UDEV_CTRL_SET_ENV
, 0, key
, timeout
);
289 int udev_ctrl_send_set_children_max(struct udev_ctrl
*uctrl
, int count
, int timeout
) {
290 return ctrl_send(uctrl
, UDEV_CTRL_SET_CHILDREN_MAX
, count
, NULL
, timeout
);
293 int udev_ctrl_send_ping(struct udev_ctrl
*uctrl
, int timeout
) {
294 return ctrl_send(uctrl
, UDEV_CTRL_PING
, 0, NULL
, timeout
);
297 int udev_ctrl_send_exit(struct udev_ctrl
*uctrl
, int timeout
) {
298 return ctrl_send(uctrl
, UDEV_CTRL_EXIT
, 0, NULL
, timeout
);
301 struct udev_ctrl_msg
*udev_ctrl_receive_msg(struct udev_ctrl_connection
*conn
) {
302 struct udev_ctrl_msg
*uctrl_msg
;
304 struct cmsghdr
*cmsg
;
306 char cred_msg
[CMSG_SPACE(sizeof(struct ucred
))];
307 struct msghdr smsg
= {
310 .msg_control
= cred_msg
,
311 .msg_controllen
= sizeof(cred_msg
),
315 uctrl_msg
= new0(struct udev_ctrl_msg
, 1);
316 if (uctrl_msg
== NULL
)
318 uctrl_msg
->n_ref
= 1;
319 uctrl_msg
->conn
= conn
;
320 udev_ctrl_connection_ref(conn
);
322 /* wait for the incoming message */
324 struct pollfd pfd
[1];
327 pfd
[0].fd
= conn
->sock
;
328 pfd
[0].events
= POLLIN
;
330 r
= poll(pfd
, 1, 10000);
336 log_error("timeout waiting for ctrl message");
339 if (!(pfd
[0].revents
& POLLIN
)) {
340 log_error_errno(errno
, "ctrl connection error: %m");
348 iov
.iov_base
= &uctrl_msg
->ctrl_msg_wire
;
349 iov
.iov_len
= sizeof(struct udev_ctrl_msg_wire
);
351 size
= recvmsg(conn
->sock
, &smsg
, 0);
353 log_error_errno(errno
, "unable to receive ctrl message: %m");
357 cmsg_close_all(&smsg
);
359 cmsg
= CMSG_FIRSTHDR(&smsg
);
361 if (cmsg
== NULL
|| cmsg
->cmsg_type
!= SCM_CREDENTIALS
) {
362 log_error("no sender credentials received, message ignored");
366 cred
= (struct ucred
*) CMSG_DATA(cmsg
);
368 if (cred
->uid
!= 0) {
369 log_error("sender uid="UID_FMT
", message ignored", cred
->uid
);
373 if (uctrl_msg
->ctrl_msg_wire
.magic
!= UDEV_CTRL_MAGIC
) {
374 log_error("message magic 0x%08x doesn't match, ignore it", uctrl_msg
->ctrl_msg_wire
.magic
);
380 udev_ctrl_msg_unref(uctrl_msg
);
384 static struct udev_ctrl_msg
*udev_ctrl_msg_free(struct udev_ctrl_msg
*ctrl_msg
) {
387 udev_ctrl_connection_unref(ctrl_msg
->conn
);
388 return mfree(ctrl_msg
);
391 DEFINE_TRIVIAL_UNREF_FUNC(struct udev_ctrl_msg
, udev_ctrl_msg
, udev_ctrl_msg_free
);
393 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg
*ctrl_msg
) {
394 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_LOG_LEVEL
)
395 return ctrl_msg
->ctrl_msg_wire
.intval
;
399 int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg
*ctrl_msg
) {
400 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_STOP_EXEC_QUEUE
)
405 int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg
*ctrl_msg
) {
406 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_START_EXEC_QUEUE
)
411 int udev_ctrl_get_reload(struct udev_ctrl_msg
*ctrl_msg
) {
412 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_RELOAD
)
417 const char *udev_ctrl_get_set_env(struct udev_ctrl_msg
*ctrl_msg
) {
418 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_ENV
)
419 return ctrl_msg
->ctrl_msg_wire
.buf
;
423 int udev_ctrl_get_set_children_max(struct udev_ctrl_msg
*ctrl_msg
) {
424 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_CHILDREN_MAX
)
425 return ctrl_msg
->ctrl_msg_wire
.intval
;
429 int udev_ctrl_get_ping(struct udev_ctrl_msg
*ctrl_msg
) {
430 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_PING
)
435 int udev_ctrl_get_exit(struct udev_ctrl_msg
*ctrl_msg
) {
436 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_EXIT
)