diff options
Diffstat (limited to 'src/grp-udev/libudev-core/udev-ctrl.c')
| -rw-r--r-- | src/grp-udev/libudev-core/udev-ctrl.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/src/grp-udev/libudev-core/udev-ctrl.c b/src/grp-udev/libudev-core/udev-ctrl.c new file mode 100644 index 0000000000..616ba7d199 --- /dev/null +++ b/src/grp-udev/libudev-core/udev-ctrl.c @@ -0,0 +1,461 @@ +/* + * libudev - interface to udev device information + * + * Copyright (C) 2008 Kay Sievers <kay@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 <poll.h> +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <unistd.h> + +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/formats-util.h" +#include "systemd-basic/socket-util.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; + union sockaddr_union 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; + const int on = 1; + int r; + + uctrl = new0(struct udev_ctrl, 1); + 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) { + log_error_errno(errno, "error getting 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(uctrl->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + if (r < 0) + log_warning_errno(errno, "could not set SO_PASSCRED: %m"); + + uctrl->saddr.un.sun_family = AF_LOCAL; + strscpy(uctrl->saddr.un.sun_path, sizeof(uctrl->saddr.un.sun_path), "/run/udev/control"); + uctrl->addrlen = SOCKADDR_UN_LEN(uctrl->saddr.un); + 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, &uctrl->saddr.sa, uctrl->addrlen); + if (err < 0 && errno == EADDRINUSE) { + unlink(uctrl->saddr.un.sun_path); + err = bind(uctrl->sock, &uctrl->saddr.sa, uctrl->addrlen); + } + + if (err < 0) + return log_error_errno(errno, "bind failed: %m"); + + err = listen(uctrl->sock, 0); + if (err < 0) + return log_error_errno(errno, "listen failed: %m"); + + uctrl->bound = true; + uctrl->cleanup_socket = true; + } + return 0; +} + +struct udev *udev_ctrl_get_udev(struct udev_ctrl *uctrl) { + return uctrl->udev; +} + +static struct udev_ctrl *udev_ctrl_ref(struct udev_ctrl *uctrl) { + if (uctrl) + uctrl->refcount++; + + return uctrl; +} + +struct udev_ctrl *udev_ctrl_unref(struct udev_ctrl *uctrl) { + if (uctrl && -- uctrl->refcount == 0) { + 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.un.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 = {}; + const int on = 1; + int r; + + conn = new(struct udev_ctrl_connection, 1); + 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) + log_error_errno(errno, "unable to receive ctrl connection: %m"); + goto err; + } + + /* check peer credential of connection */ + r = getpeercred(conn->sock, &ucred); + if (r < 0) { + log_error_errno(r, "unable 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(conn->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)); + if (r < 0) + log_warning_errno(errno, "could not set SO_PASSCRED: %m"); + + udev_ctrl_ref(uctrl); + return conn; +err: + if (conn->sock >= 0) + close(conn->sock); + return mfree(conn); +} + +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 && -- conn->refcount == 0) { + 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; + + memzero(&ctrl_msg_wire, 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) + 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) { + 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 * MSEC_PER_SEC); + 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_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 == 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) { + log_error("timeout waiting for ctrl message"); + goto err; + } else { + if (!(pfd[0].revents & POLLIN)) { + log_error_errno(errno, "ctrl connection error: %m"); + goto err; + } + } + + break; + } + + iov.iov_base = &uctrl_msg->ctrl_msg_wire; + iov.iov_len = sizeof(struct udev_ctrl_msg_wire); + + size = recvmsg(conn->sock, &smsg, 0); + if (size < 0) { + log_error_errno(errno, "unable to receive ctrl message: %m"); + goto err; + } + + cmsg_close_all(&smsg); + + cmsg = CMSG_FIRSTHDR(&smsg); + + if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) { + log_error("no sender credentials received, message ignored"); + goto err; + } + + cred = (struct ucred *) CMSG_DATA(cmsg); + + if (cred->uid != 0) { + log_error("sender uid="UID_FMT", message ignored", cred->uid); + goto err; + } + + if (uctrl_msg->ctrl_msg_wire.magic != UDEV_CTRL_MAGIC) { + log_error("message magic 0x%08x doesn't match, ignore it", uctrl_msg->ctrl_msg_wire.magic); + goto err; + } + + return uctrl_msg; +err: + udev_ctrl_msg_unref(uctrl_msg); + return NULL; +} + +struct udev_ctrl_msg *udev_ctrl_msg_unref(struct udev_ctrl_msg *ctrl_msg) { + if (ctrl_msg && -- ctrl_msg->refcount == 0) { + 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; +} |