1 files changed, 494 insertions, 0 deletions
diff --git a/src/udev-ctrl.c b/src/udev-ctrl.c
new file mode 100644
index 0000000000..fab1108de0
--- /dev/null
+++ b/src/udev-ctrl.c
@@ -0,0 +1,494 @@
+/*
+ * libudev - interface to udev device information
+ *
+ * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ */
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/poll.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include "udev.h"
+
+/* wire protocol magic must match */
+#define UDEV_CTRL_MAGIC				0xdead1dea
+
+enum udev_ctrl_msg_type {
+	UDEV_CTRL_UNKNOWN,
+	UDEV_CTRL_SET_LOG_LEVEL,
+	UDEV_CTRL_STOP_EXEC_QUEUE,
+	UDEV_CTRL_START_EXEC_QUEUE,
+	UDEV_CTRL_RELOAD,
+	UDEV_CTRL_SET_ENV,
+	UDEV_CTRL_SET_CHILDREN_MAX,
+	UDEV_CTRL_PING,
+	UDEV_CTRL_EXIT,
+};
+
+struct udev_ctrl_msg_wire {
+	char version[16];
+	unsigned int magic;
+	enum udev_ctrl_msg_type type;
+	union {
+		int intval;
+		char buf[256];
+	};
+};
+
+struct udev_ctrl_msg {
+	int refcount;
+	struct udev_ctrl_connection *conn;
+	struct udev_ctrl_msg_wire ctrl_msg_wire;
+};
+
+struct udev_ctrl {
+	int refcount;
+	struct udev *udev;
+	int sock;
+	struct sockaddr_un saddr;
+	socklen_t addrlen;
+	bool bound;
+	bool cleanup_socket;
+	bool connected;
+};
+
+struct udev_ctrl_connection {
+	int refcount;
+	struct udev_ctrl *uctrl;
+	int sock;
+};
+
+struct udev_ctrl *udev_ctrl_new_from_fd(struct udev *udev, int fd)
+{
+	struct udev_ctrl *uctrl;
+
+	uctrl = calloc(1, sizeof(struct udev_ctrl));
+	if (uctrl == NULL)
+		return NULL;
+	uctrl->refcount = 1;
+	uctrl->udev = udev;
+
+	if (fd < 0) {
+		uctrl->sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
+		if (uctrl->sock < 0) {
+			err(udev, "error getting socket: %m\n");
+			udev_ctrl_unref(uctrl);
+			return NULL;
+		}
+	} else {
+		uctrl->bound = true;
+		uctrl->sock = fd;
+	}
+
+	uctrl->saddr.sun_family = AF_LOCAL;
+	util_strscpyl(uctrl->saddr.sun_path, sizeof(uctrl->saddr.sun_path),
+                      udev_get_run_path(udev), "/control", NULL);
+	uctrl->addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(uctrl->saddr.sun_path);
+	return uctrl;
+}
+
+struct udev_ctrl *udev_ctrl_new(struct udev *udev)
+{
+	return udev_ctrl_new_from_fd(udev, -1);
+}
+
+int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl)
+{
+	int err;
+
+	if (!uctrl->bound) {
+		err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
+		if (err < 0 && errno == EADDRINUSE) {
+			unlink(uctrl->saddr.sun_path);
+			err = bind(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen);
+		}
+
+		if (err < 0) {
+			err = -errno;
+			err(uctrl->udev, "bind failed: %m\n");
+			return err;
+		}
+
+		err = listen(uctrl->sock, 0);
+		if (err < 0) {
+			err = -errno;
+			err(uctrl->udev, "listen failed: %m\n");
+			return err;
+		}
+
+		uctrl->bound = true;
+		uctrl->cleanup_socket = true;
+	}
+	return 0;
+}
+
+struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl)
+{
+	return uctrl->udev;
+}
+
+struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl)
+{
+	if (uctrl == NULL)
+		return NULL;
+	uctrl->refcount++;
+	return uctrl;
+}
+
+struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl)
+{
+	if (uctrl == NULL)
+		return NULL;
+	uctrl->refcount--;
+	if (uctrl->refcount > 0)
+		return uctrl;
+	if (uctrl->sock >= 0)
+		close(uctrl->sock);
+	free(uctrl);
+	return NULL;
+}
+
+int udev_ctrl_cleanup(struct udev_ctrl *uctrl)
+{
+	if (uctrl == NULL)
+		return 0;
+	if (uctrl->cleanup_socket)
+		unlink(uctrl->saddr.sun_path);
+	return 0;
+}
+
+int udev_ctrl_get_fd(struct udev_ctrl *uctrl)
+{
+	if (uctrl == NULL)
+		return -EINVAL;
+	return uctrl->sock;
+}
+
+struct udev_ctrl_connection *udev_ctrl_get_connection(struct udev_ctrl *uctrl)
+{
+	struct udev_ctrl_connection *conn;
+	struct ucred ucred;
+	socklen_t slen;
+	const int on = 1;
+
+	conn = calloc(1, sizeof(struct udev_ctrl_connection));
+	if (conn == NULL)
+		return NULL;
+	conn->refcount = 1;
+	conn->uctrl = uctrl;
+
+	conn->sock = accept4(uctrl->sock, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
+	if (conn->sock < 0) {
+		if (errno != EINTR)
+			err(uctrl->udev, "unable to receive ctrl connection: %m\n");
+		goto err;
+	}
+
+	/* check peer credential of connection */
+	slen = sizeof(ucred);
+	if (getsockopt(conn->sock, SOL_SOCKET, SO_PEERCRED, &ucred, &slen) < 0) {
+		err(uctrl->udev, "unable to receive credentials of ctrl connection: %m\n");
+		goto err;
+	}
+	if (ucred.uid > 0) {
+		err(uctrl->udev, "sender uid=%i, message ignored\n", ucred.uid);
+		goto err;
+	}
+
+	/* enable receiving of the sender credentials in the messages */
+	setsockopt(conn->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on));
+	udev_ctrl_ref(uctrl);
+	return conn;
+err:
+	if (conn->sock >= 0)
+		close(conn->sock);
+	free(conn);
+	return NULL;
+}
+
+struct udev_ctrl_connection *udev_ctrl_connection_ref(struct udev_ctrl_connection *conn)
+{
+	if (conn == NULL)
+		return NULL;
+	conn->refcount++;
+	return conn;
+}
+
+struct udev_ctrl_connection *udev_ctrl_connection_unref(struct udev_ctrl_connection *conn)
+{
+	if (conn == NULL)
+		return NULL;
+	conn->refcount--;
+	if (conn->refcount > 0)
+		return conn;
+	if (conn->sock >= 0)
+		close(conn->sock);
+	udev_ctrl_unref(conn->uctrl);
+	free(conn);
+	return NULL;
+}
+
+static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf, int timeout)
+{
+	struct udev_ctrl_msg_wire ctrl_msg_wire;
+	int err = 0;
+
+	memset(&ctrl_msg_wire, 0x00, sizeof(struct udev_ctrl_msg_wire));
+	strcpy(ctrl_msg_wire.version, "udev-" VERSION);
+	ctrl_msg_wire.magic = UDEV_CTRL_MAGIC;
+	ctrl_msg_wire.type = type;
+
+	if (buf != NULL)
+		util_strscpy(ctrl_msg_wire.buf, sizeof(ctrl_msg_wire.buf), buf);
+	else
+		ctrl_msg_wire.intval = intval;
+
+	if (!uctrl->connected) {
+		if (connect(uctrl->sock, (struct sockaddr *)&uctrl->saddr, uctrl->addrlen) < 0) {
+			err = -errno;
+			goto out;
+		}
+		uctrl->connected = true;
+	}
+	if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0) {
+		err = -errno;
+		goto out;
+	}
+
+	/* wait for peer message handling or disconnect */
+	for (;;) {
+		struct pollfd pfd[1];
+		int r;
+
+		pfd[0].fd = uctrl->sock;
+		pfd[0].events = POLLIN;
+		r = poll(pfd, 1, timeout * 1000);
+		if (r  < 0) {
+			if (errno == EINTR)
+				continue;
+			err = -errno;
+			break;
+		}
+
+		if (r > 0 && pfd[0].revents & POLLERR) {
+			err = -EIO;
+			break;
+		}
+
+		if (r == 0)
+			err = -ETIMEDOUT;
+		break;
+	}
+out:
+	return err;
+}
+
+int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL, timeout);
+}
+
+int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_reload(struct udev_ctrl *uctrl, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_RELOAD, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_SET_ENV, 0, key, timeout);
+}
+
+int udev_ctrl_send_set_children_max(struct udev_ctrl *uctrl, int count, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL, timeout);
+}
+
+int udev_ctrl_send_ping(struct udev_ctrl *uctrl, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_PING, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_exit(struct udev_ctrl *uctrl, int timeout)
+{
+	return ctrl_send(uctrl, UDEV_CTRL_EXIT, 0, NULL, timeout);
+}
+
+struct udev_ctrl_msg *udev_ctrl_receive_msg(struct udev_ctrl_connection *conn)
+{
+	struct udev *udev = conn->uctrl->udev;
+	struct udev_ctrl_msg *uctrl_msg;
+	ssize_t size;
+	struct msghdr smsg;
+	struct cmsghdr *cmsg;
+	struct iovec iov;
+	struct ucred *cred;
+	char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+
+	uctrl_msg = calloc(1, sizeof(struct udev_ctrl_msg));
+	if (uctrl_msg == NULL)
+		return NULL;
+	uctrl_msg->refcount = 1;
+	uctrl_msg->conn = conn;
+	udev_ctrl_connection_ref(conn);
+
+	/* wait for the incoming message */
+	for(;;) {
+		struct pollfd pfd[1];
+		int r;
+
+		pfd[0].fd = conn->sock;
+		pfd[0].events = POLLIN;
+
+		r = poll(pfd, 1, 10000);
+		if (r  < 0) {
+			if (errno == EINTR)
+				continue;
+			goto err;
+		} else if (r == 0) {
+			err(udev, "timeout waiting for ctrl message\n");
+			goto err;
+		} else {
+			if (!(pfd[0].revents & POLLIN)) {
+				err(udev, "ctrl connection error: %m\n");
+				goto err;
+			}
+		}
+
+		break;
+	}
+
+	iov.iov_base = &uctrl_msg->ctrl_msg_wire;
+	iov.iov_len = sizeof(struct udev_ctrl_msg_wire);
+	memset(&smsg, 0x00, sizeof(struct msghdr));
+	smsg.msg_iov = &iov;
+	smsg.msg_iovlen = 1;
+	smsg.msg_control = cred_msg;
+	smsg.msg_controllen = sizeof(cred_msg);
+	size = recvmsg(conn->sock, &smsg, 0);
+	if (size <  0) {
+		err(udev, "unable to receive ctrl message: %m\n");
+		goto err;
+	}
+	cmsg = CMSG_FIRSTHDR(&smsg);
+	cred = (struct ucred *) CMSG_DATA(cmsg);
+
+	if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) {
+		err(udev, "no sender credentials received, message ignored\n");
+		goto err;
+	}
+
+	if (cred->uid != 0) {
+		err(udev, "sender uid=%i, message ignored\n", cred->uid);
+		goto err;
+	}
+
+	if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
+		err(udev, "message magic 0x%08x doesn't match, ignore it\n", uctrl_msg->ctrl_msg_wire.magic);
+		goto err;
+	}
+
+	dbg(udev, "created ctrl_msg %p (%i)\n", uctrl_msg, uctrl_msg->ctrl_msg_wire.type);
+	return uctrl_msg;
+err:
+	udev_ctrl_msg_unref(uctrl_msg);
+	return NULL;
+}
+
+struct udev_ctrl_msg *udev_ctrl_msg_ref(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg == NULL)
+		return NULL;
+	ctrl_msg->refcount++;
+	return ctrl_msg;
+}
+
+struct udev_ctrl_msg *udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg == NULL)
+		return NULL;
+	ctrl_msg->refcount--;
+	if (ctrl_msg->refcount > 0)
+		return ctrl_msg;
+	dbg(ctrl_msg->conn->uctrl->udev, "release ctrl_msg %p\n", ctrl_msg);
+	udev_ctrl_connection_unref(ctrl_msg->conn);
+	free(ctrl_msg);
+	return NULL;
+}
+
+int udev_ctrl_get_set_log_level(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_LOG_LEVEL)
+		return ctrl_msg->ctrl_msg_wire.intval;
+	return -1;
+}
+
+int udev_ctrl_get_stop_exec_queue(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_STOP_EXEC_QUEUE)
+		return 1;
+	return -1;
+}
+
+int udev_ctrl_get_start_exec_queue(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_START_EXEC_QUEUE)
+		return 1;
+	return -1;
+}
+
+int udev_ctrl_get_reload(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_RELOAD)
+		return 1;
+	return -1;
+}
+
+const char *udev_ctrl_get_set_env(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_ENV)
+		return ctrl_msg->ctrl_msg_wire.buf;
+	return NULL;
+}
+
+int udev_ctrl_get_set_children_max(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_SET_CHILDREN_MAX)
+		return ctrl_msg->ctrl_msg_wire.intval;
+	return -1;
+}
+
+int udev_ctrl_get_ping(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_PING)
+		return 1;
+	return -1;
+}
+
+int udev_ctrl_get_exit(struct udev_ctrl_msg *ctrl_msg)
+{
+	if (ctrl_msg->ctrl_msg_wire.type == UDEV_CTRL_EXIT)
+		return 1;
+	return -1;
+}