2 * libudev - interface to udev device information
4 * Copyright (C) 2008 Kay Sievers <kay@vrfy.org>
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
18 #include <sys/types.h>
20 #include <sys/socket.h>
25 /* wire protocol magic must match */
26 #define UDEV_CTRL_MAGIC 0xdead1dea
28 enum udev_ctrl_msg_type
{
30 UDEV_CTRL_SET_LOG_LEVEL
,
31 UDEV_CTRL_STOP_EXEC_QUEUE
,
32 UDEV_CTRL_START_EXEC_QUEUE
,
35 UDEV_CTRL_SET_CHILDREN_MAX
,
40 struct udev_ctrl_msg_wire
{
43 enum udev_ctrl_msg_type type
;
50 struct udev_ctrl_msg
{
52 struct udev_ctrl_connection
*conn
;
53 struct udev_ctrl_msg_wire ctrl_msg_wire
;
60 struct sockaddr_un saddr
;
67 struct udev_ctrl_connection
{
69 struct udev_ctrl
*uctrl
;
73 struct udev_ctrl
*udev_ctrl_new_from_fd(struct udev
*udev
, int fd
) {
74 struct udev_ctrl
*uctrl
;
78 uctrl
= new0(struct udev_ctrl
, 1);
85 uctrl
->sock
= socket(AF_LOCAL
, SOCK_SEQPACKET
|SOCK_NONBLOCK
|SOCK_CLOEXEC
, 0);
86 if (uctrl
->sock
< 0) {
87 log_error_errno(errno
, "error getting socket: %m");
88 udev_ctrl_unref(uctrl
);
95 r
= setsockopt(uctrl
->sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
97 log_warning_errno(errno
, "could not set SO_PASSCRED: %m");
99 uctrl
->saddr
.sun_family
= AF_LOCAL
;
100 strscpy(uctrl
->saddr
.sun_path
, sizeof(uctrl
->saddr
.sun_path
), "/run/udev/control");
101 uctrl
->addrlen
= offsetof(struct sockaddr_un
, sun_path
) + strlen(uctrl
->saddr
.sun_path
);
105 struct udev_ctrl
*udev_ctrl_new(struct udev
*udev
) {
106 return udev_ctrl_new_from_fd(udev
, -1);
109 int udev_ctrl_enable_receiving(struct udev_ctrl
*uctrl
) {
113 err
= bind(uctrl
->sock
, (struct sockaddr
*)&uctrl
->saddr
, uctrl
->addrlen
);
114 if (err
< 0 && errno
== EADDRINUSE
) {
115 unlink(uctrl
->saddr
.sun_path
);
116 err
= bind(uctrl
->sock
, (struct sockaddr
*)&uctrl
->saddr
, uctrl
->addrlen
);
121 log_error_errno(errno
, "bind failed: %m");
125 err
= listen(uctrl
->sock
, 0);
128 log_error_errno(errno
, "listen failed: %m");
133 uctrl
->cleanup_socket
= true;
138 struct udev
*udev_ctrl_get_udev(struct udev_ctrl
*uctrl
) {
142 static struct udev_ctrl
*udev_ctrl_ref(struct udev_ctrl
*uctrl
) {
149 struct udev_ctrl
*udev_ctrl_unref(struct udev_ctrl
*uctrl
) {
153 if (uctrl
->refcount
> 0)
155 if (uctrl
->sock
>= 0)
161 int udev_ctrl_cleanup(struct udev_ctrl
*uctrl
) {
164 if (uctrl
->cleanup_socket
)
165 unlink(uctrl
->saddr
.sun_path
);
169 int udev_ctrl_get_fd(struct udev_ctrl
*uctrl
) {
175 struct udev_ctrl_connection
*udev_ctrl_get_connection(struct udev_ctrl
*uctrl
) {
176 struct udev_ctrl_connection
*conn
;
177 struct ucred ucred
= {};
181 conn
= new(struct udev_ctrl_connection
, 1);
187 conn
->sock
= accept4(uctrl
->sock
, NULL
, NULL
, SOCK_CLOEXEC
|SOCK_NONBLOCK
);
188 if (conn
->sock
< 0) {
190 log_error_errno(errno
, "unable to receive ctrl connection: %m");
194 /* check peer credential of connection */
195 r
= getpeercred(conn
->sock
, &ucred
);
197 log_error_errno(r
, "unable to receive credentials of ctrl connection: %m");
201 log_error("sender uid="UID_FMT
", message ignored", ucred
.uid
);
205 /* enable receiving of the sender credentials in the messages */
206 r
= setsockopt(conn
->sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
208 log_warning_errno(errno
, "could not set SO_PASSCRED: %m");
210 udev_ctrl_ref(uctrl
);
219 struct udev_ctrl_connection
*udev_ctrl_connection_ref(struct udev_ctrl_connection
*conn
) {
226 struct udev_ctrl_connection
*udev_ctrl_connection_unref(struct udev_ctrl_connection
*conn
) {
230 if (conn
->refcount
> 0)
234 udev_ctrl_unref(conn
->uctrl
);
239 static int ctrl_send(struct udev_ctrl
*uctrl
, enum udev_ctrl_msg_type type
, int intval
, const char *buf
, int timeout
) {
240 struct udev_ctrl_msg_wire ctrl_msg_wire
;
243 memzero(&ctrl_msg_wire
, sizeof(struct udev_ctrl_msg_wire
));
244 strcpy(ctrl_msg_wire
.version
, "udev-" VERSION
);
245 ctrl_msg_wire
.magic
= UDEV_CTRL_MAGIC
;
246 ctrl_msg_wire
.type
= type
;
249 strscpy(ctrl_msg_wire
.buf
, sizeof(ctrl_msg_wire
.buf
), buf
);
251 ctrl_msg_wire
.intval
= intval
;
253 if (!uctrl
->connected
) {
254 if (connect(uctrl
->sock
, (struct sockaddr
*)&uctrl
->saddr
, uctrl
->addrlen
) < 0) {
258 uctrl
->connected
= true;
260 if (send(uctrl
->sock
, &ctrl_msg_wire
, sizeof(ctrl_msg_wire
), 0) < 0) {
265 /* wait for peer message handling or disconnect */
267 struct pollfd pfd
[1];
270 pfd
[0].fd
= uctrl
->sock
;
271 pfd
[0].events
= POLLIN
;
272 r
= poll(pfd
, 1, timeout
* MSEC_PER_SEC
);
280 if (r
> 0 && pfd
[0].revents
& POLLERR
) {
293 int udev_ctrl_send_set_log_level(struct udev_ctrl
*uctrl
, int priority
, int timeout
) {
294 return ctrl_send(uctrl
, UDEV_CTRL_SET_LOG_LEVEL
, priority
, NULL
, timeout
);
297 int udev_ctrl_send_stop_exec_queue(struct udev_ctrl
*uctrl
, int timeout
) {
298 return ctrl_send(uctrl
, UDEV_CTRL_STOP_EXEC_QUEUE
, 0, NULL
, timeout
);
301 int udev_ctrl_send_start_exec_queue(struct udev_ctrl
*uctrl
, int timeout
) {
302 return ctrl_send(uctrl
, UDEV_CTRL_START_EXEC_QUEUE
, 0, NULL
, timeout
);
305 int udev_ctrl_send_reload(struct udev_ctrl
*uctrl
, int timeout
) {
306 return ctrl_send(uctrl
, UDEV_CTRL_RELOAD
, 0, NULL
, timeout
);
309 int udev_ctrl_send_set_env(struct udev_ctrl
*uctrl
, const char *key
, int timeout
) {
310 return ctrl_send(uctrl
, UDEV_CTRL_SET_ENV
, 0, key
, timeout
);
313 int udev_ctrl_send_set_children_max(struct udev_ctrl
*uctrl
, int count
, int timeout
) {
314 return ctrl_send(uctrl
, UDEV_CTRL_SET_CHILDREN_MAX
, count
, NULL
, timeout
);
317 int udev_ctrl_send_ping(struct udev_ctrl
*uctrl
, int timeout
) {
318 return ctrl_send(uctrl
, UDEV_CTRL_PING
, 0, NULL
, timeout
);
321 int udev_ctrl_send_exit(struct udev_ctrl
*uctrl
, int timeout
) {
322 return ctrl_send(uctrl
, UDEV_CTRL_EXIT
, 0, NULL
, timeout
);
325 struct udev_ctrl_msg
*udev_ctrl_receive_msg(struct udev_ctrl_connection
*conn
) {
326 struct udev_ctrl_msg
*uctrl_msg
;
328 struct cmsghdr
*cmsg
;
330 char cred_msg
[CMSG_SPACE(sizeof(struct ucred
))];
331 struct msghdr smsg
= {
334 .msg_control
= cred_msg
,
335 .msg_controllen
= sizeof(cred_msg
),
339 uctrl_msg
= new0(struct udev_ctrl_msg
, 1);
340 if (uctrl_msg
== NULL
)
342 uctrl_msg
->refcount
= 1;
343 uctrl_msg
->conn
= conn
;
344 udev_ctrl_connection_ref(conn
);
346 /* wait for the incoming message */
348 struct pollfd pfd
[1];
351 pfd
[0].fd
= conn
->sock
;
352 pfd
[0].events
= POLLIN
;
354 r
= poll(pfd
, 1, 10000);
360 log_error("timeout waiting for ctrl message");
363 if (!(pfd
[0].revents
& POLLIN
)) {
364 log_error_errno(errno
, "ctrl connection error: %m");
372 iov
.iov_base
= &uctrl_msg
->ctrl_msg_wire
;
373 iov
.iov_len
= sizeof(struct udev_ctrl_msg_wire
);
375 size
= recvmsg(conn
->sock
, &smsg
, 0);
377 log_error_errno(errno
, "unable to receive ctrl message: %m");
380 cmsg
= CMSG_FIRSTHDR(&smsg
);
381 cred
= (struct ucred
*) CMSG_DATA(cmsg
);
383 if (cmsg
== NULL
|| cmsg
->cmsg_type
!= SCM_CREDENTIALS
) {
384 log_error("no sender credentials received, message ignored");
388 if (cred
->uid
!= 0) {
389 log_error("sender uid="UID_FMT
", message ignored", cred
->uid
);
393 if (uctrl_msg
->ctrl_msg_wire
.magic
!= UDEV_CTRL_MAGIC
) {
394 log_error("message magic 0x%08x doesn't match, ignore it", uctrl_msg
->ctrl_msg_wire
.magic
);
400 udev_ctrl_msg_unref(uctrl_msg
);
404 struct udev_ctrl_msg
*udev_ctrl_msg_unref(struct udev_ctrl_msg
*ctrl_msg
) {
405 if (ctrl_msg
== NULL
)
407 ctrl_msg
->refcount
--;
408 if (ctrl_msg
->refcount
> 0)
410 udev_ctrl_connection_unref(ctrl_msg
->conn
);
415 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg
*ctrl_msg
) {
416 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_LOG_LEVEL
)
417 return ctrl_msg
->ctrl_msg_wire
.intval
;
421 int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg
*ctrl_msg
) {
422 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_STOP_EXEC_QUEUE
)
427 int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg
*ctrl_msg
) {
428 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_START_EXEC_QUEUE
)
433 int udev_ctrl_get_reload(struct udev_ctrl_msg
*ctrl_msg
) {
434 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_RELOAD
)
439 const char *udev_ctrl_get_set_env(struct udev_ctrl_msg
*ctrl_msg
) {
440 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_ENV
)
441 return ctrl_msg
->ctrl_msg_wire
.buf
;
445 int udev_ctrl_get_set_children_max(struct udev_ctrl_msg
*ctrl_msg
) {
446 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_CHILDREN_MAX
)
447 return ctrl_msg
->ctrl_msg_wire
.intval
;
451 int udev_ctrl_get_ping(struct udev_ctrl_msg
*ctrl_msg
) {
452 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_PING
)
457 int udev_ctrl_get_exit(struct udev_ctrl_msg
*ctrl_msg
) {
458 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_EXIT
)