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>
23 /* wire protocol magic must match */
24 #define UDEV_CTRL_MAGIC 0xdead1dea
26 enum udev_ctrl_msg_type {
28 UDEV_CTRL_SET_LOG_LEVEL,
29 UDEV_CTRL_STOP_EXEC_QUEUE,
30 UDEV_CTRL_START_EXEC_QUEUE,
33 UDEV_CTRL_SET_CHILDREN_MAX,
38 struct udev_ctrl_msg_wire {
41 enum udev_ctrl_msg_type type;
48 struct udev_ctrl_msg {
50 struct udev_ctrl_connection *conn;
51 struct udev_ctrl_msg_wire ctrl_msg_wire;
58 struct sockaddr_un saddr;
65 struct udev_ctrl_connection {
67 struct udev_ctrl *uctrl;
71 struct udev_ctrl *udev_ctrl_new_from_fd(struct udev *udev, int fd) {
72 struct udev_ctrl *uctrl;
76 uctrl = new0(struct udev_ctrl, 1);
83 uctrl->sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
84 if (uctrl->sock < 0) {
85 log_error_errno(errno, "error getting socket: %m");
86 udev_ctrl_unref(uctrl);
93 r = setsockopt(uctrl->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
95 log_warning_errno(errno, "could not set SO_PASSCRED: %m");
97 uctrl->saddr.sun_family = AF_LOCAL;
98 strscpy(uctrl->saddr.sun_path, sizeof(uctrl->saddr.sun_path), "/run/udev/control");
99 uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.sun_path);
103 struct udev_ctrl *udev_ctrl_new(struct udev *udev) {
104 return udev_ctrl_new_from_fd(udev, -1);
107 int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl) {
111 err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
112 if (err < 0 && errno == EADDRINUSE) {
113 unlink(uctrl->saddr.sun_path);
114 err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
119 log_error_errno(errno, "bind failed: %m");
123 err = listen(uctrl->sock, 0);
126 log_error_errno(errno, "listen failed: %m");
131 uctrl->cleanup_socket = true;
136 struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl) {
140 static struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl) {
147 struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl) {
151 if (uctrl->refcount > 0)
153 if (uctrl->sock >= 0)
159 int udev_ctrl_cleanup(struct udev_ctrl *uctrl) {
162 if (uctrl->cleanup_socket)
163 unlink(uctrl->saddr.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) {
228 if (conn->refcount > 0)
232 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, (struct sockaddr *)&uctrl->saddr, 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 == NULL)
408 ctrl_msg->refcount--;
409 if (ctrl_msg->refcount > 0)
411 udev_ctrl_connection_unref(ctrl_msg->conn);
416 int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg) {
417 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_LOG_LEVEL)
418 return ctrl_msg->ctrl_msg_wire.intval;
422 int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg *ctrl_msg) {
423 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_STOP_EXEC_QUEUE)
428 int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg *ctrl_msg) {
429 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_START_EXEC_QUEUE)
434 int udev_ctrl_get_reload(struct udev_ctrl_msg *ctrl_msg) {
435 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_RELOAD)
440 const char *udev_ctrl_get_set_env(struct udev_ctrl_msg *ctrl_msg) {
441 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_ENV)
442 return ctrl_msg->ctrl_msg_wire.buf;
446 int udev_ctrl_get_set_children_max(struct udev_ctrl_msg *ctrl_msg) {
447 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_CHILDREN_MAX)
448 return ctrl_msg->ctrl_msg_wire.intval;
452 int udev_ctrl_get_ping(struct udev_ctrl_msg *ctrl_msg) {
453 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_PING)
458 int udev_ctrl_get_exit(struct udev_ctrl_msg *ctrl_msg) {
459 if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_EXIT)