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-rw-r--r--src/udev/udev-ctrl.c427
1 files changed, 427 insertions, 0 deletions
diff --git a/src/udev/udev-ctrl.c b/src/udev/udev-ctrl.c
new file mode 100644
index 0000000..c217815
--- /dev/null
+++ b/src/udev/udev-ctrl.c
@@ -0,0 +1,427 @@
+/* SPDX-License-Identifier: LGPL-2.1+
+ *
+ * libudev - interface to udev device information
+ *
+ * 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 <poll.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "io-util.h"
+#include "socket-util.h"
+#include "strxcpyx.h"
+#include "udev-ctrl.h"
+#include "util.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 magic;
+ enum udev_ctrl_msg_type type;
+ union {
+ int intval;
+ char buf[256];
+ };
+};
+
+struct udev_ctrl_msg {
+ unsigned n_ref;
+ struct udev_ctrl_connection *conn;
+ struct udev_ctrl_msg_wire ctrl_msg_wire;
+};
+
+struct udev_ctrl {
+ unsigned n_ref;
+ int sock;
+ union sockaddr_union saddr;
+ socklen_t addrlen;
+ bool bound;
+ bool cleanup_socket;
+ bool connected;
+};
+
+struct udev_ctrl_connection {
+ unsigned n_ref;
+ struct udev_ctrl *uctrl;
+ int sock;
+};
+
+struct udev_ctrl *udev_ctrl_new_from_fd(int fd) {
+ struct udev_ctrl *uctrl;
+ int r;
+
+ uctrl = new0(struct udev_ctrl, 1);
+ if (!uctrl)
+ return NULL;
+ uctrl->n_ref = 1;
+
+ if (fd < 0) {
+ uctrl->sock = socket(AF_LOCAL, SOCK_SEQPACKET|SOCK_NONBLOCK|SOCK_CLOEXEC, 0);
+ if (uctrl->sock < 0) {
+ log_error_errno(errno, "Failed to create socket: %m");
+ udev_ctrl_unref(uctrl);
+ return NULL;
+ }
+ } else {
+ uctrl->bound = true;
+ uctrl->sock = fd;
+ }
+
+ /*
+ * FIXME: remove it as soon as we can depend on this:
+ * http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=90c6bd34f884cd9cee21f1d152baf6c18bcac949
+ */
+ r = setsockopt_int(uctrl->sock, SOL_SOCKET, SO_PASSCRED, true);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SO_PASSCRED: %m");
+
+ uctrl->saddr.un = (struct sockaddr_un) {
+ .sun_family = AF_UNIX,
+ .sun_path = "/run/udev/control",
+ };
+
+ uctrl->addrlen = SOCKADDR_UN_LEN(uctrl->saddr.un);
+ return uctrl;
+}
+
+struct udev_ctrl *udev_ctrl_new(void) {
+ return udev_ctrl_new_from_fd(-1);
+}
+
+int udev_ctrl_enable_receiving(struct udev_ctrl *uctrl) {
+ int err;
+
+ if (!uctrl->bound) {
+ err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen);
+ if (err < 0 && errno == EADDRINUSE) {
+ (void) sockaddr_un_unlink(&uctrl->saddr.un);
+ err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen);
+ }
+
+ if (err < 0)
+ return log_error_errno(errno, "Failed to bind socket: %m");
+
+ err = listen(uctrl->sock, 0);
+ if (err < 0)
+ return log_error_errno(errno, "Failed to listen: %m");
+
+ uctrl->bound = true;
+ uctrl->cleanup_socket = true;
+ }
+ return 0;
+}
+
+static struct udev_ctrl *udev_ctrl_free(struct udev_ctrl *uctrl) {
+ assert(uctrl);
+
+ safe_close(uctrl->sock);
+ return mfree(uctrl);
+}
+
+DEFINE_PRIVATE_TRIVIAL_REF_FUNC(struct udev_ctrl, udev_ctrl);
+DEFINE_TRIVIAL_UNREF_FUNC(struct udev_ctrl, udev_ctrl, udev_ctrl_free);
+
+int udev_ctrl_cleanup(struct udev_ctrl *uctrl) {
+ if (!uctrl)
+ return 0;
+ if (uctrl->cleanup_socket)
+ sockaddr_un_unlink(&uctrl->saddr.un);
+ return 0;
+}
+
+int udev_ctrl_get_fd(struct udev_ctrl *uctrl) {
+ if (!uctrl)
+ 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 = {};
+ int r;
+
+ conn = new(struct udev_ctrl_connection, 1);
+ if (!conn)
+ return NULL;
+ conn->n_ref = 1;
+ conn->uctrl = uctrl;
+
+ conn->sock = accept4(uctrl->sock, NULL, NULL, SOCK_CLOEXEC|SOCK_NONBLOCK);
+ if (conn->sock < 0) {
+ if (errno != EINTR)
+ log_error_errno(errno, "Failed to receive ctrl connection: %m");
+ goto err;
+ }
+
+ /* check peer credential of connection */
+ r = getpeercred(conn->sock, &ucred);
+ if (r < 0) {
+ log_error_errno(r, "Failed to receive credentials of ctrl connection: %m");
+ goto err;
+ }
+ if (ucred.uid > 0) {
+ log_error("Sender uid="UID_FMT", message ignored", ucred.uid);
+ goto err;
+ }
+
+ /* enable receiving of the sender credentials in the messages */
+ r = setsockopt_int(conn->sock, SOL_SOCKET, SO_PASSCRED, true);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set SO_PASSCRED: %m");
+
+ udev_ctrl_ref(uctrl);
+ return conn;
+err:
+ safe_close(conn->sock);
+ return mfree(conn);
+}
+
+static struct udev_ctrl_connection *udev_ctrl_connection_free(struct udev_ctrl_connection *conn) {
+ assert(conn);
+
+ safe_close(conn->sock);
+ udev_ctrl_unref(conn->uctrl);
+ return mfree(conn);
+}
+
+DEFINE_TRIVIAL_REF_UNREF_FUNC(struct udev_ctrl_connection, udev_ctrl_connection, udev_ctrl_connection_free);
+
+static int ctrl_send(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, int intval, const char *buf, usec_t timeout) {
+ struct udev_ctrl_msg_wire ctrl_msg_wire = {
+ .version = "udev-" STRINGIFY(PROJECT_VERSION),
+ .magic = UDEV_CTRL_MAGIC,
+ .type = type,
+ };
+
+ if (buf)
+ strscpy(ctrl_msg_wire.buf, sizeof(ctrl_msg_wire.buf), buf);
+ else
+ ctrl_msg_wire.intval = intval;
+
+ if (!uctrl->connected) {
+ if (connect(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen) < 0)
+ return -errno;
+ uctrl->connected = true;
+ }
+ if (send(uctrl->sock, &ctrl_msg_wire, sizeof(ctrl_msg_wire), 0) < 0)
+ return -errno;
+
+ /* wait for peer message handling or disconnect */
+ for (;;) {
+ struct pollfd pfd = {
+ .fd = uctrl->sock,
+ .events = POLLIN,
+ };
+ int r;
+
+ r = poll(&pfd, 1, DIV_ROUND_UP(timeout, USEC_PER_MSEC));
+ if (r < 0) {
+ if (errno == EINTR)
+ continue;
+ return -errno;
+ }
+ if (r == 0)
+ return -ETIMEDOUT;
+ if (pfd.revents & POLLERR)
+ return -EIO;
+ return 0;
+ }
+}
+
+int udev_ctrl_send_set_log_level(struct udev_ctrl *uctrl, int priority, usec_t timeout) {
+ return ctrl_send(uctrl, UDEV_CTRL_SET_LOG_LEVEL, priority, NULL, timeout);
+}
+
+int udev_ctrl_send_stop_exec_queue(struct udev_ctrl *uctrl, usec_t timeout) {
+ return ctrl_send(uctrl, UDEV_CTRL_STOP_EXEC_QUEUE, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_start_exec_queue(struct udev_ctrl *uctrl, usec_t timeout) {
+ return ctrl_send(uctrl, UDEV_CTRL_START_EXEC_QUEUE, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_reload(struct udev_ctrl *uctrl, usec_t timeout) {
+ return ctrl_send(uctrl, UDEV_CTRL_RELOAD, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_set_env(struct udev_ctrl *uctrl, const char *key, usec_t 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, usec_t timeout) {
+ return ctrl_send(uctrl, UDEV_CTRL_SET_CHILDREN_MAX, count, NULL, timeout);
+}
+
+int udev_ctrl_send_ping(struct udev_ctrl *uctrl, usec_t timeout) {
+ return ctrl_send(uctrl, UDEV_CTRL_PING, 0, NULL, timeout);
+}
+
+int udev_ctrl_send_exit(struct udev_ctrl *uctrl, usec_t 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_ctrl_msg *uctrl_msg;
+ ssize_t size;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
+ struct msghdr smsg = {
+ .msg_iov = &iov,
+ .msg_iovlen = 1,
+ .msg_control = cred_msg,
+ .msg_controllen = sizeof(cred_msg),
+ };
+ struct ucred *cred;
+
+ uctrl_msg = new0(struct udev_ctrl_msg, 1);
+ if (!uctrl_msg)
+ return NULL;
+ uctrl_msg->n_ref = 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) {
+ log_error("Timeout waiting for ctrl message");
+ goto err;
+ } else {
+ if (!(pfd[0].revents & POLLIN)) {
+ log_error("Invalid ctrl connection: %m");
+ goto err;
+ }
+ }
+
+ break;
+ }
+
+ iov = IOVEC_MAKE(&uctrl_msg->ctrl_msg_wire, sizeof(struct udev_ctrl_msg_wire));
+
+ size = recvmsg(conn->sock, &smsg, 0);
+ if (size < 0) {
+ log_error_errno(errno, "Failed to receive ctrl message: %m");
+ goto err;
+ }
+
+ cmsg_close_all(&smsg);
+
+ cmsg = CMSG_FIRSTHDR(&smsg);
+
+ if (!cmsg || cmsg->cmsg_type != SCM_CREDENTIALS) {
+ log_error("No sender credentials received, ignoring message");
+ goto err;
+ }
+
+ cred = (struct ucred *) CMSG_DATA(cmsg);
+
+ if (cred->uid != 0) {
+ log_error("Sender uid="UID_FMT", ignoring message", cred->uid);
+ goto err;
+ }
+
+ if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) {
+ log_error("Message magic 0x%08x doesn't match, ignoring", uctrl_msg->ctrl_msg_wire.magic);
+ goto err;
+ }
+
+ return uctrl_msg;
+err:
+ udev_ctrl_msg_unref(uctrl_msg);
+ return NULL;
+}
+
+static struct udev_ctrl_msg *udev_ctrl_msg_free(struct udev_ctrl_msg *ctrl_msg) {
+ assert(ctrl_msg);
+
+ udev_ctrl_connection_unref(ctrl_msg->conn);
+ return mfree(ctrl_msg);
+}
+
+DEFINE_TRIVIAL_UNREF_FUNC(struct udev_ctrl_msg, udev_ctrl_msg, udev_ctrl_msg_free);
+
+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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-08-13 13:27:11 +0000