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/socket.h>
21 #include "socket-util.h"
22 #include "formats-util.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 union sockaddr_union 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
.un
.sun_family
= AF_LOCAL
;
100 strscpy(uctrl
->saddr
.un
.sun_path
, sizeof(uctrl
->saddr
.un
.sun_path
), "/run/udev/control");
101 uctrl
->addrlen
= offsetof(struct sockaddr_un
, sun_path
) + strlen(uctrl
->saddr
.un
.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
, &uctrl
->saddr
.sa
, uctrl
->addrlen
);
114 if (err
< 0 && errno
== EADDRINUSE
) {
115 unlink(uctrl
->saddr
.un
.sun_path
);
116 err
= bind(uctrl
->sock
, &uctrl
->saddr
.sa
, 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
) {
150 if (uctrl
&& -- uctrl
->refcount
== 0) {
151 if (uctrl
->sock
>= 0)
159 int udev_ctrl_cleanup(struct udev_ctrl
*uctrl
) {
162 if (uctrl
->cleanup_socket
)
163 unlink(uctrl
->saddr
.un
.sun_path
);
167 int udev_ctrl_get_fd(struct udev_ctrl
*uctrl
) {
173 struct udev_ctrl_connection
*udev_ctrl_get_connection(struct udev_ctrl
*uctrl
) {
174 struct udev_ctrl_connection
*conn
;
175 struct ucred ucred
= {};
179 conn
= new(struct udev_ctrl_connection
, 1);
185 conn
->sock
= accept4(uctrl
->sock
, NULL
, NULL
, SOCK_CLOEXEC
|SOCK_NONBLOCK
);
186 if (conn
->sock
< 0) {
188 log_error_errno(errno
, "unable to receive ctrl connection: %m");
192 /* check peer credential of connection */
193 r
= getpeercred(conn
->sock
, &ucred
);
195 log_error_errno(r
, "unable to receive credentials of ctrl connection: %m");
199 log_error("sender uid="UID_FMT
", message ignored", ucred
.uid
);
203 /* enable receiving of the sender credentials in the messages */
204 r
= setsockopt(conn
->sock
, SOL_SOCKET
, SO_PASSCRED
, &on
, sizeof(on
));
206 log_warning_errno(errno
, "could not set SO_PASSCRED: %m");
208 udev_ctrl_ref(uctrl
);
217 struct udev_ctrl_connection
*udev_ctrl_connection_ref(struct udev_ctrl_connection
*conn
) {
224 struct udev_ctrl_connection
*udev_ctrl_connection_unref(struct udev_ctrl_connection
*conn
) {
225 if (conn
&& -- conn
->refcount
== 0) {
229 udev_ctrl_unref(conn
->uctrl
);
237 static int ctrl_send(struct udev_ctrl
*uctrl
, enum udev_ctrl_msg_type type
, int intval
, const char *buf
, int timeout
) {
238 struct udev_ctrl_msg_wire ctrl_msg_wire
;
241 memzero(&ctrl_msg_wire
, sizeof(struct udev_ctrl_msg_wire
));
242 strcpy(ctrl_msg_wire
.version
, "udev-" VERSION
);
243 ctrl_msg_wire
.magic
= UDEV_CTRL_MAGIC
;
244 ctrl_msg_wire
.type
= type
;
247 strscpy(ctrl_msg_wire
.buf
, sizeof(ctrl_msg_wire
.buf
), buf
);
249 ctrl_msg_wire
.intval
= intval
;
251 if (!uctrl
->connected
) {
252 if (connect(uctrl
->sock
, &uctrl
->saddr
.sa
, uctrl
->addrlen
) < 0) {
256 uctrl
->connected
= true;
258 if (send(uctrl
->sock
, &ctrl_msg_wire
, sizeof(ctrl_msg_wire
), 0) < 0) {
263 /* wait for peer message handling or disconnect */
265 struct pollfd pfd
[1];
268 pfd
[0].fd
= uctrl
->sock
;
269 pfd
[0].events
= POLLIN
;
270 r
= poll(pfd
, 1, timeout
* MSEC_PER_SEC
);
278 if (r
> 0 && pfd
[0].revents
& POLLERR
) {
291 int udev_ctrl_send_set_log_level(struct udev_ctrl
*uctrl
, int priority
, int timeout
) {
292 return ctrl_send(uctrl
, UDEV_CTRL_SET_LOG_LEVEL
, priority
, NULL
, timeout
);
295 int udev_ctrl_send_stop_exec_queue(struct udev_ctrl
*uctrl
, int timeout
) {
296 return ctrl_send(uctrl
, UDEV_CTRL_STOP_EXEC_QUEUE
, 0, NULL
, timeout
);
299 int udev_ctrl_send_start_exec_queue(struct udev_ctrl
*uctrl
, int timeout
) {
300 return ctrl_send(uctrl
, UDEV_CTRL_START_EXEC_QUEUE
, 0, NULL
, timeout
);
303 int udev_ctrl_send_reload(struct udev_ctrl
*uctrl
, int timeout
) {
304 return ctrl_send(uctrl
, UDEV_CTRL_RELOAD
, 0, NULL
, timeout
);
307 int udev_ctrl_send_set_env(struct udev_ctrl
*uctrl
, const char *key
, int timeout
) {
308 return ctrl_send(uctrl
, UDEV_CTRL_SET_ENV
, 0, key
, timeout
);
311 int udev_ctrl_send_set_children_max(struct udev_ctrl
*uctrl
, int count
, int timeout
) {
312 return ctrl_send(uctrl
, UDEV_CTRL_SET_CHILDREN_MAX
, count
, NULL
, timeout
);
315 int udev_ctrl_send_ping(struct udev_ctrl
*uctrl
, int timeout
) {
316 return ctrl_send(uctrl
, UDEV_CTRL_PING
, 0, NULL
, timeout
);
319 int udev_ctrl_send_exit(struct udev_ctrl
*uctrl
, int timeout
) {
320 return ctrl_send(uctrl
, UDEV_CTRL_EXIT
, 0, NULL
, timeout
);
323 struct udev_ctrl_msg
*udev_ctrl_receive_msg(struct udev_ctrl_connection
*conn
) {
324 struct udev_ctrl_msg
*uctrl_msg
;
326 struct cmsghdr
*cmsg
;
328 char cred_msg
[CMSG_SPACE(sizeof(struct ucred
))];
329 struct msghdr smsg
= {
332 .msg_control
= cred_msg
,
333 .msg_controllen
= sizeof(cred_msg
),
337 uctrl_msg
= new0(struct udev_ctrl_msg
, 1);
338 if (uctrl_msg
== NULL
)
340 uctrl_msg
->refcount
= 1;
341 uctrl_msg
->conn
= conn
;
342 udev_ctrl_connection_ref(conn
);
344 /* wait for the incoming message */
346 struct pollfd pfd
[1];
349 pfd
[0].fd
= conn
->sock
;
350 pfd
[0].events
= POLLIN
;
352 r
= poll(pfd
, 1, 10000);
358 log_error("timeout waiting for ctrl message");
361 if (!(pfd
[0].revents
& POLLIN
)) {
362 log_error_errno(errno
, "ctrl connection error: %m");
370 iov
.iov_base
= &uctrl_msg
->ctrl_msg_wire
;
371 iov
.iov_len
= sizeof(struct udev_ctrl_msg_wire
);
373 size
= recvmsg(conn
->sock
, &smsg
, 0);
375 log_error_errno(errno
, "unable to receive ctrl message: %m");
379 cmsg_close_all(&smsg
);
381 cmsg
= CMSG_FIRSTHDR(&smsg
);
382 cred
= (struct ucred
*) CMSG_DATA(cmsg
);
384 if (cmsg
== NULL
|| cmsg
->cmsg_type
!= SCM_CREDENTIALS
) {
385 log_error("no sender credentials received, message ignored");
389 if (cred
->uid
!= 0) {
390 log_error("sender uid="UID_FMT
", message ignored", cred
->uid
);
394 if (uctrl_msg
->ctrl_msg_wire
.magic
!= UDEV_CTRL_MAGIC
) {
395 log_error("message magic 0x%08x doesn't match, ignore it", uctrl_msg
->ctrl_msg_wire
.magic
);
401 udev_ctrl_msg_unref(uctrl_msg
);
405 struct udev_ctrl_msg
*udev_ctrl_msg_unref(struct udev_ctrl_msg
*ctrl_msg
) {
406 if (ctrl_msg
&& -- ctrl_msg
->refcount
== 0) {
407 udev_ctrl_connection_unref(ctrl_msg
->conn
);
414 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg
*ctrl_msg
) {
415 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_LOG_LEVEL
)
416 return ctrl_msg
->ctrl_msg_wire
.intval
;
420 int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg
*ctrl_msg
) {
421 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_STOP_EXEC_QUEUE
)
426 int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg
*ctrl_msg
) {
427 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_START_EXEC_QUEUE
)
432 int udev_ctrl_get_reload(struct udev_ctrl_msg
*ctrl_msg
) {
433 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_RELOAD
)
438 const char *udev_ctrl_get_set_env(struct udev_ctrl_msg
*ctrl_msg
) {
439 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_ENV
)
440 return ctrl_msg
->ctrl_msg_wire
.buf
;
444 int udev_ctrl_get_set_children_max(struct udev_ctrl_msg
*ctrl_msg
) {
445 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_SET_CHILDREN_MAX
)
446 return ctrl_msg
->ctrl_msg_wire
.intval
;
450 int udev_ctrl_get_ping(struct udev_ctrl_msg
*ctrl_msg
) {
451 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_PING
)
456 int udev_ctrl_get_exit(struct udev_ctrl_msg
*ctrl_msg
) {
457 if (ctrl_msg
->ctrl_msg_wire
.type
== UDEV_CTRL_EXIT
)