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"
24 /* wire protocol magic must match */
25 #define UDEV_CTRL_MAGIC 0xdead1dea
27 enum udev_ctrl_msg_type {
29 UDEV_CTRL_SET_LOG_LEVEL,
30 UDEV_CTRL_STOP_EXEC_QUEUE,
31 UDEV_CTRL_START_EXEC_QUEUE,
34 UDEV_CTRL_SET_CHILDREN_MAX,
39 struct udev_ctrl_msg_wire {
42 enum udev_ctrl_msg_type type;
49 struct udev_ctrl_msg {
51 struct udev_ctrl_connection *conn;
52 struct udev_ctrl_msg_wire ctrl_msg_wire;
59 union sockaddr_union saddr;
66 struct udev_ctrl_connection {
68 struct udev_ctrl *uctrl;
72 struct udev_ctrl *udev_ctrl_new_from_fd(struct udev *udev, int fd) {
73 struct udev_ctrl *uctrl;
77 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);
94 r = setsockopt(uctrl->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
96 log_warning_errno(errno, "could not set SO_PASSCRED: %m");
98 uctrl->saddr.un.sun_family = AF_LOCAL;
99 strscpy(uctrl->saddr.un.sun_path, sizeof(uctrl->saddr.un.sun_path), "/run/udev/control");
100 uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.un.sun_path);
104 struct udev_ctrl *udev_ctrl_new(struct udev *udev) {
105 return udev_ctrl_new_from_fd(udev, -1);
108 int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl) {
112 err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen);
113 if (err < 0 && errno == EADDRINUSE) {
114 unlink(uctrl->saddr.un.sun_path);
115 err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen);
120 log_error_errno(errno, "bind failed: %m");
124 err = listen(uctrl->sock, 0);
127 log_error_errno(errno, "listen failed: %m");
132 uctrl->cleanup_socket = true;
137 struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl) {
141 static struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl) {
148 struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl) {
152 if (uctrl->refcount > 0)
154 if (uctrl->sock >= 0)
160 int udev_ctrl_cleanup(struct udev_ctrl *uctrl) {
163 if (uctrl->cleanup_socket)
164 unlink(uctrl->saddr.un.sun_path);
168 int udev_ctrl_get_fd(struct udev_ctrl *uctrl) {
174 struct udev_ctrl_connection *udev_ctrl_get_connection(struct udev_ctrl *uctrl) {
175 struct udev_ctrl_connection *conn;
176 struct ucred ucred = {};
180 conn = new(struct udev_ctrl_connection, 1);
186 conn->sock = accept4(uctrl->sock, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
187 if (conn->sock < 0) {
189 log_error_errno(errno, "unable to receive ctrl connection: %m");
193 /* check peer credential of connection */
194 r = getpeercred(conn->sock, &ucred);
196 log_error_errno(r, "unable to receive credentials of ctrl connection: %m");
200 log_error("sender uid="UID_FMT", message ignored", ucred.uid);
204 /* enable receiving of the sender credentials in the messages */
205 r = setsockopt(conn->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
207 log_warning_errno(errno, "could not set SO_PASSCRED: %m");
209 udev_ctrl_ref(uctrl);
218 struct udev_ctrl_connection *udev_ctrl_connection_ref(struct udev_ctrl_connection *conn) {
225 struct udev_ctrl_connection *udev_ctrl_connection_unref(struct udev_ctrl_connection *conn) {
229 if (conn->refcount > 0)
233 udev_ctrl_unref(conn->uctrl);
238 static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf, int timeout) {
239 struct udev_ctrl_msg_wire ctrl_msg_wire;
242 memzero(&ctrl_msg_wire, sizeof(struct udev_ctrl_msg_wire));
243 strcpy(ctrl_msg_wire.version, "udev-" VERSION);
244 ctrl_msg_wire.magic = UDEV_CTRL_MAGIC;
245 ctrl_msg_wire.type = type;
248 strscpy(ctrl_msg_wire.buf, sizeof(ctrl_msg_wire.buf), buf);
250 ctrl_msg_wire.intval = intval;
252 if (!uctrl->connected) {
253 if (connect(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0) {
257 uctrl->connected = true;
259 if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0) {
264 /* wait for peer message handling or disconnect */
266 struct pollfd pfd[1];
269 pfd[0].fd = uctrl->sock;
270 pfd[0].events = POLLIN;
271 r = poll(pfd, 1, timeout * MSEC_PER_SEC);
279 if (r > 0 && pfd[0].revents & POLLERR) {
292 int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority, int timeout) {
293 return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL, timeout);
296 int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl, int timeout) {
297 return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL, timeout);
300 int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl, int timeout) {
301 return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL, timeout);
304 int udev_ctrl_send_reload(struct udev_ctrl *uctrl, int timeout) {
305 return ctrl_send(uctrl, UDEV_CTRL_RELOAD, 0, NULL, timeout);
308 int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key, int timeout) {
309 return ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key, timeout);
312 int udev_ctrl_send_set_children_max(struct udev_ctrl *uctrl, int count, int timeout) {
313 return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL, timeout);
316 int udev_ctrl_send_ping(struct udev_ctrl *uctrl, int timeout) {
317 return ctrl_send(uctrl, UDEV_CTRL_PING, 0, NULL, timeout);
320 int udev_ctrl_send_exit(struct udev_ctrl *uctrl, int timeout) {
321 return ctrl_send(uctrl, UDEV_CTRL_EXIT, 0, NULL, timeout);
324 struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl_connection *conn) {
325 struct udev_ctrl_msg *uctrl_msg;
327 struct cmsghdr *cmsg;
329 char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
330 struct msghdr smsg = {
333 .msg_control = cred_msg,
334 .msg_controllen = sizeof(cred_msg),
338 uctrl_msg = new0(struct udev_ctrl_msg, 1);
339 if (uctrl_msg == NULL)
341 uctrl_msg->refcount = 1;
342 uctrl_msg->conn = conn;
343 udev_ctrl_connection_ref(conn);
345 /* wait for the incoming message */
347 struct pollfd pfd[1];
350 pfd[0].fd = conn->sock;
351 pfd[0].events = POLLIN;
353 r = poll(pfd, 1, 10000);
359 log_error("timeout waiting for ctrl message");
362 if (!(pfd[0].revents & POLLIN)) {
363 log_error_errno(errno, "ctrl connection error: %m");
371 iov.iov_base = &uctrl_msg->ctrl_msg_wire;
372 iov.iov_len = sizeof(struct udev_ctrl_msg_wire);
374 size = recvmsg(conn->sock, &smsg, 0);
376 log_error_errno(errno, "unable to receive ctrl message: %m");
380 cmsg_close_all(&smsg);
382 cmsg = CMSG_FIRSTHDR(&smsg);
383 cred = (struct ucred *) CMSG_DATA(cmsg);
385 if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
386 log_error("no sender credentials received, message ignored");
390 if (cred->uid != 0) {
391 log_error("sender uid="UID_FMT", message ignored", cred->uid);
395 if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
396 log_error("message magic 0x%08x doesn't match, ignore it", uctrl_msg->ctrl_msg_wire.magic);
402 udev_ctrl_msg_unref(uctrl_msg);
406 struct udev_ctrl_msg *udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg) {
407 if (ctrl_msg == NULL)
409 ctrl_msg->refcount--;
410 if (ctrl_msg->refcount > 0)
412 udev_ctrl_connection_unref(ctrl_msg->conn);
417 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg) {
418 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_LOG_LEVEL)
419 return ctrl_msg->ctrl_msg_wire.intval;
423 int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg *ctrl_msg) {
424 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_STOP_EXEC_QUEUE)
429 int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg *ctrl_msg) {
430 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_START_EXEC_QUEUE)
435 int udev_ctrl_get_reload(struct udev_ctrl_msg *ctrl_msg) {
436 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_RELOAD)
441 const char *udev_ctrl_get_set_env(struct udev_ctrl_msg *ctrl_msg) {
442 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_ENV)
443 return ctrl_msg->ctrl_msg_wire.buf;
447 int udev_ctrl_get_set_children_max(struct udev_ctrl_msg *ctrl_msg) {
448 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_CHILDREN_MAX)
449 return ctrl_msg->ctrl_msg_wire.intval;
453 int udev_ctrl_get_ping(struct udev_ctrl_msg *ctrl_msg) {
454 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_PING)
459 int udev_ctrl_get_exit(struct udev_ctrl_msg *ctrl_msg) {
460 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_EXIT)