853 lines
28 KiB
C
853 lines
28 KiB
C
/* SPDX-License-Identifier: LGPL-2.1+ */
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#include <errno.h>
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#include <linux/filter.h>
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#include <linux/netlink.h>
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#include <poll.h>
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#include <stddef.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <sys/socket.h>
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#include <unistd.h>
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#include "libudev.h"
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#include "alloc-util.h"
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#include "device-private.h"
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#include "device-util.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "format-util.h"
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#include "hashmap.h"
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#include "libudev-device-internal.h"
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#include "libudev-private.h"
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#include "missing.h"
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#include "mount-util.h"
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#include "set.h"
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#include "socket-util.h"
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#include "string-util.h"
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#include "strv.h"
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/**
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* SECTION:libudev-monitor
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* @short_description: device event source
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*
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* Connects to a device event source.
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*/
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/**
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* udev_monitor:
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*
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* Opaque object handling an event source.
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*/
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struct udev_monitor {
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struct udev *udev;
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unsigned n_ref;
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int sock;
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union sockaddr_union snl;
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union sockaddr_union snl_trusted_sender;
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union sockaddr_union snl_destination;
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socklen_t addrlen;
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Hashmap *subsystem_filter;
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Set *tag_filter;
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bool bound;
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};
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enum udev_monitor_netlink_group {
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UDEV_MONITOR_NONE,
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UDEV_MONITOR_KERNEL,
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UDEV_MONITOR_UDEV,
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};
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#define UDEV_MONITOR_MAGIC 0xfeedcafe
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struct udev_monitor_netlink_header {
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/* "libudev" prefix to distinguish libudev and kernel messages */
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char prefix[8];
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/*
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* magic to protect against daemon <-> library message format mismatch
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* used in the kernel from socket filter rules; needs to be stored in network order
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*/
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unsigned magic;
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/* total length of header structure known to the sender */
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unsigned header_size;
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/* properties string buffer */
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unsigned properties_off;
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unsigned properties_len;
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/*
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* hashes of primary device properties strings, to let libudev subscribers
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* use in-kernel socket filters; values need to be stored in network order
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*/
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unsigned filter_subsystem_hash;
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unsigned filter_devtype_hash;
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unsigned filter_tag_bloom_hi;
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unsigned filter_tag_bloom_lo;
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};
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static int udev_monitor_set_nl_address(struct udev_monitor *udev_monitor) {
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union sockaddr_union snl;
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socklen_t addrlen;
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assert(udev_monitor);
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/* Get the address the kernel has assigned us.
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* It is usually, but not necessarily the pid. */
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addrlen = sizeof(struct sockaddr_nl);
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if (getsockname(udev_monitor->sock, &snl.sa, &addrlen) < 0)
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return -errno;
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udev_monitor->snl.nl.nl_pid = snl.nl.nl_pid;
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return 0;
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}
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struct udev_monitor *udev_monitor_new_from_netlink_fd(struct udev *udev, const char *name, int fd) {
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_cleanup_(udev_monitor_unrefp) struct udev_monitor *udev_monitor = NULL;
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_cleanup_close_ int sock = -1;
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unsigned group;
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int r;
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assert_return_errno(!name || STR_IN_SET(name, "udev", "kernel"), NULL, EINVAL);
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if (!name)
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group = UDEV_MONITOR_NONE;
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else if (streq(name, "udev")) {
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/*
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* We do not support subscribing to uevents if no instance of
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* udev is running. Uevents would otherwise broadcast the
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* processing data of the host into containers, which is not
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* desired.
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*
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* Containers will currently not get any udev uevents, until
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* a supporting infrastructure is available.
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*
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* We do not set a netlink multicast group here, so the socket
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* will not receive any messages.
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*/
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if (access("/run/udev/control", F_OK) < 0 && dev_is_devtmpfs() <= 0) {
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log_debug("The udev service seems not to be active, disabling the monitor");
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group = UDEV_MONITOR_NONE;
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} else
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group = UDEV_MONITOR_UDEV;
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} else {
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assert(streq(name, "kernel"));
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group = UDEV_MONITOR_KERNEL;
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}
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if (fd < 0) {
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sock = socket(PF_NETLINK, SOCK_RAW|SOCK_CLOEXEC|SOCK_NONBLOCK, NETLINK_KOBJECT_UEVENT);
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if (sock < 0) {
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log_debug_errno(errno, "Failed to create socket: %m");
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return NULL;
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}
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}
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udev_monitor = new(struct udev_monitor, 1);
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if (!udev_monitor) {
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errno = ENOMEM;
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return NULL;
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}
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*udev_monitor = (struct udev_monitor) {
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.udev = udev,
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.n_ref = 1,
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.sock = fd >= 0 ? fd : TAKE_FD(sock),
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.bound = fd >= 0,
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.snl.nl.nl_family = AF_NETLINK,
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.snl.nl.nl_groups = group,
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/* default destination for sending */
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.snl_destination.nl.nl_family = AF_NETLINK,
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.snl_destination.nl.nl_groups = UDEV_MONITOR_UDEV,
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};
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if (fd >= 0) {
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r = udev_monitor_set_nl_address(udev_monitor);
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if (r < 0) {
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log_debug_errno(r, "Failed to set netlink address: %m");
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return NULL;
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}
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}
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return TAKE_PTR(udev_monitor);
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}
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/**
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* udev_monitor_new_from_netlink:
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* @udev: udev library context
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* @name: name of event source
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*
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* Create new udev monitor and connect to a specified event
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* source. Valid sources identifiers are "udev" and "kernel".
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*
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* Applications should usually not connect directly to the
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* "kernel" events, because the devices might not be useable
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* at that time, before udev has configured them, and created
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* device nodes. Accessing devices at the same time as udev,
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* might result in unpredictable behavior. The "udev" events
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* are sent out after udev has finished its event processing,
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* all rules have been processed, and needed device nodes are
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* created.
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*
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* The initial refcount is 1, and needs to be decremented to
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* release the resources of the udev monitor.
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*
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* Returns: a new udev monitor, or #NULL, in case of an error
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**/
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_public_ struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char *name) {
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return udev_monitor_new_from_netlink_fd(udev, name, -1);
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}
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static void bpf_stmt(struct sock_filter *ins, unsigned *i,
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unsigned short code, unsigned data) {
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ins[(*i)++] = (struct sock_filter) {
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.code = code,
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.k = data,
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};
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}
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static void bpf_jmp(struct sock_filter *ins, unsigned *i,
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unsigned short code, unsigned data,
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unsigned short jt, unsigned short jf) {
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ins[(*i)++] = (struct sock_filter) {
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.code = code,
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.jt = jt,
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.jf = jf,
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.k = data,
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};
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}
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/**
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* udev_monitor_filter_update:
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* @udev_monitor: monitor
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*
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* Update the installed socket filter. This is only needed,
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* if the filter was removed or changed.
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*
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* Returns: 0 on success, otherwise a negative error value.
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*/
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_public_ int udev_monitor_filter_update(struct udev_monitor *udev_monitor) {
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struct sock_filter ins[512] = {};
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struct sock_fprog filter;
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const char *subsystem, *devtype, *tag;
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unsigned i = 0;
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Iterator it;
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assert_return(udev_monitor, -EINVAL);
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if (hashmap_isempty(udev_monitor->subsystem_filter) &&
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set_isempty(udev_monitor->tag_filter))
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return 0;
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/* load magic in A */
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bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, magic));
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/* jump if magic matches */
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bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, UDEV_MONITOR_MAGIC, 1, 0);
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/* wrong magic, pass packet */
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bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
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if (!set_isempty(udev_monitor->tag_filter)) {
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int tag_matches = set_size(udev_monitor->tag_filter);
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/* add all tags matches */
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SET_FOREACH(tag, udev_monitor->tag_filter, it) {
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uint64_t tag_bloom_bits = util_string_bloom64(tag);
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uint32_t tag_bloom_hi = tag_bloom_bits >> 32;
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uint32_t tag_bloom_lo = tag_bloom_bits & 0xffffffff;
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/* load device bloom bits in A */
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bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_tag_bloom_hi));
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/* clear bits (tag bits & bloom bits) */
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bpf_stmt(ins, &i, BPF_ALU|BPF_AND|BPF_K, tag_bloom_hi);
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/* jump to next tag if it does not match */
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bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, tag_bloom_hi, 0, 3);
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/* load device bloom bits in A */
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bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_tag_bloom_lo));
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/* clear bits (tag bits & bloom bits) */
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bpf_stmt(ins, &i, BPF_ALU|BPF_AND|BPF_K, tag_bloom_lo);
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/* jump behind end of tag match block if tag matches */
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tag_matches--;
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bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, tag_bloom_lo, 1 + (tag_matches * 6), 0);
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}
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/* nothing matched, drop packet */
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bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
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}
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/* add all subsystem matches */
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if (!hashmap_isempty(udev_monitor->subsystem_filter)) {
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HASHMAP_FOREACH_KEY(devtype, subsystem, udev_monitor->subsystem_filter, it) {
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uint32_t hash = util_string_hash32(subsystem);
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/* load device subsystem value in A */
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bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_subsystem_hash));
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if (!devtype) {
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/* jump if subsystem does not match */
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bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
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} else {
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hash = util_string_hash32(devtype);
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/* jump if subsystem does not match */
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bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 3);
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/* load device devtype value in A */
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bpf_stmt(ins, &i, BPF_LD|BPF_W|BPF_ABS, offsetof(struct udev_monitor_netlink_header, filter_devtype_hash));
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/* jump if value does not match */
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bpf_jmp(ins, &i, BPF_JMP|BPF_JEQ|BPF_K, hash, 0, 1);
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}
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/* matched, pass packet */
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bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
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if (i+1 >= ELEMENTSOF(ins))
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return -E2BIG;
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}
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/* nothing matched, drop packet */
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bpf_stmt(ins, &i, BPF_RET|BPF_K, 0);
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}
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/* matched, pass packet */
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bpf_stmt(ins, &i, BPF_RET|BPF_K, 0xffffffff);
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/* install filter */
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filter = (struct sock_fprog) {
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.len = i,
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.filter = ins,
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};
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if (setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) < 0)
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return -errno;
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return 0;
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}
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int udev_monitor_allow_unicast_sender(struct udev_monitor *udev_monitor, struct udev_monitor *sender) {
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assert_return(udev_monitor, -EINVAL);
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assert_return(sender, -EINVAL);
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udev_monitor->snl_trusted_sender.nl.nl_pid = sender->snl.nl.nl_pid;
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return 0;
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}
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/**
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* udev_monitor_enable_receiving:
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* @udev_monitor: the monitor which should receive events
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*
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* Binds the @udev_monitor socket to the event source.
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*
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* Returns: 0 on success, otherwise a negative error value.
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*/
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_public_ int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor) {
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const int on = 1;
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int r;
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assert_return(udev_monitor, -EINVAL);
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r = udev_monitor_filter_update(udev_monitor);
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if (r < 0)
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return log_debug_errno(r, "Failed to update filter: %m");
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if (!udev_monitor->bound) {
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if (bind(udev_monitor->sock, &udev_monitor->snl.sa, sizeof(struct sockaddr_nl)) < 0)
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return log_debug_errno(errno, "Failed to bind udev monitor socket to event source: %m");
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udev_monitor->bound = true;
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}
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r = udev_monitor_set_nl_address(udev_monitor);
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if (r < 0)
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return log_debug_errno(r, "Failed to set address: %m");
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/* enable receiving of sender credentials */
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if (setsockopt(udev_monitor->sock, SOL_SOCKET, SO_PASSCRED, &on, sizeof(on)) < 0)
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return log_debug_errno(errno, "Failed to set socket option SO_PASSCRED: %m");
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return 0;
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}
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/**
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* udev_monitor_set_receive_buffer_size:
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* @udev_monitor: the monitor which should receive events
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* @size: the size in bytes
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*
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* Set the size of the kernel socket buffer. This call needs the
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* appropriate privileges to succeed.
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*
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* Returns: 0 on success, otherwise -1 on error.
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*/
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_public_ int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int size) {
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assert_return(udev_monitor, -EINVAL);
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if (setsockopt(udev_monitor->sock, SOL_SOCKET, SO_RCVBUFFORCE, &size, sizeof(size)) < 0)
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return -errno;
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return 0;
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}
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int udev_monitor_disconnect(struct udev_monitor *udev_monitor) {
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assert(udev_monitor);
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udev_monitor->sock = safe_close(udev_monitor->sock);
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return 0;
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}
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static struct udev_monitor *udev_monitor_free(struct udev_monitor *udev_monitor) {
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assert(udev_monitor);
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udev_monitor_disconnect(udev_monitor);
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hashmap_free_free_free(udev_monitor->subsystem_filter);
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set_free_free(udev_monitor->tag_filter);
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return mfree(udev_monitor);
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}
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/**
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* udev_monitor_ref:
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* @udev_monitor: udev monitor
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*
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* Take a reference of a udev monitor.
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*
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* Returns: the passed udev monitor
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**/
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/**
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* udev_monitor_unref:
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* @udev_monitor: udev monitor
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*
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* Drop a reference of a udev monitor. If the refcount reaches zero,
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* the bound socket will be closed, and the resources of the monitor
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* will be released.
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*
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* Returns: #NULL
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**/
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DEFINE_PUBLIC_TRIVIAL_REF_UNREF_FUNC(struct udev_monitor, udev_monitor, udev_monitor_free);
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/**
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* udev_monitor_get_udev:
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* @udev_monitor: udev monitor
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*
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* Retrieve the udev library context the monitor was created with.
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*
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* Returns: the udev library context
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**/
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_public_ struct udev *udev_monitor_get_udev(struct udev_monitor *udev_monitor) {
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assert_return(udev_monitor, NULL);
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return udev_monitor->udev;
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}
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/**
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* udev_monitor_get_fd:
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* @udev_monitor: udev monitor
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*
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* Retrieve the socket file descriptor associated with the monitor.
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*
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* Returns: the socket file descriptor
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**/
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_public_ int udev_monitor_get_fd(struct udev_monitor *udev_monitor) {
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assert_return(udev_monitor, -EINVAL);
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return udev_monitor->sock;
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}
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static int passes_filter(struct udev_monitor *udev_monitor, sd_device *device) {
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const char *tag, *subsystem, *devtype, *s, *d = NULL;
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Iterator i;
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int r;
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assert_return(udev_monitor, -EINVAL);
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assert_return(device, -EINVAL);
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if (hashmap_isempty(udev_monitor->subsystem_filter))
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goto tag;
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r = sd_device_get_subsystem(device, &s);
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if (r < 0)
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return r;
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r = sd_device_get_devtype(device, &d);
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if (r < 0 && r != -ENOENT)
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return r;
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HASHMAP_FOREACH_KEY(devtype, subsystem, udev_monitor->subsystem_filter, i) {
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if (!streq(s, subsystem))
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continue;
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if (!devtype)
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goto tag;
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if (!d)
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continue;
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if (streq(d, devtype))
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goto tag;
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}
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return 0;
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tag:
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if (set_isempty(udev_monitor->tag_filter))
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return 1;
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SET_FOREACH(tag, udev_monitor->tag_filter, i)
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if (sd_device_has_tag(device, tag) > 0)
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return 1;
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return 0;
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}
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static int udev_monitor_receive_device_one(struct udev_monitor *udev_monitor, sd_device **ret) {
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_cleanup_(sd_device_unrefp) sd_device *device = NULL;
|
|
union {
|
|
struct udev_monitor_netlink_header nlh;
|
|
char raw[8192];
|
|
} buf;
|
|
struct iovec iov = {
|
|
.iov_base = &buf,
|
|
.iov_len = sizeof(buf)
|
|
};
|
|
char cred_msg[CMSG_SPACE(sizeof(struct ucred))];
|
|
union sockaddr_union snl;
|
|
struct msghdr smsg = {
|
|
.msg_iov = &iov,
|
|
.msg_iovlen = 1,
|
|
.msg_control = cred_msg,
|
|
.msg_controllen = sizeof(cred_msg),
|
|
.msg_name = &snl,
|
|
.msg_namelen = sizeof(snl),
|
|
};
|
|
struct cmsghdr *cmsg;
|
|
struct ucred *cred;
|
|
ssize_t buflen, bufpos;
|
|
bool is_initialized = false;
|
|
int r;
|
|
|
|
assert(ret);
|
|
|
|
buflen = recvmsg(udev_monitor->sock, &smsg, 0);
|
|
if (buflen < 0) {
|
|
if (errno != EINTR)
|
|
log_debug_errno(errno, "Failed to receive message: %m");
|
|
return -errno;
|
|
}
|
|
|
|
if (buflen < 32 || (smsg.msg_flags & MSG_TRUNC))
|
|
return log_debug_errno(EINVAL, "Invalid message length.");
|
|
|
|
if (snl.nl.nl_groups == UDEV_MONITOR_NONE) {
|
|
/* unicast message, check if we trust the sender */
|
|
if (udev_monitor->snl_trusted_sender.nl.nl_pid == 0 ||
|
|
snl.nl.nl_pid != udev_monitor->snl_trusted_sender.nl.nl_pid)
|
|
return log_debug_errno(EAGAIN, "Unicast netlink message ignored.");
|
|
|
|
} else if (snl.nl.nl_groups == UDEV_MONITOR_KERNEL) {
|
|
if (snl.nl.nl_pid > 0)
|
|
return log_debug_errno(EAGAIN, "Multicast kernel netlink message from PID %"PRIu32" ignored.", snl.nl.nl_pid);
|
|
}
|
|
|
|
cmsg = CMSG_FIRSTHDR(&smsg);
|
|
if (!cmsg || cmsg->cmsg_type != SCM_CREDENTIALS)
|
|
return log_debug_errno(EAGAIN, "No sender credentials received, message ignored.");
|
|
|
|
cred = (struct ucred*) CMSG_DATA(cmsg);
|
|
if (cred->uid != 0)
|
|
return log_debug_errno(EAGAIN, "Sender uid="UID_FMT", message ignored.", cred->uid);
|
|
|
|
if (streq(buf.raw, "libudev")) {
|
|
/* udev message needs proper version magic */
|
|
if (buf.nlh.magic != htobe32(UDEV_MONITOR_MAGIC))
|
|
return log_debug_errno(EAGAIN, "Invalid message signature (%x != %x)",
|
|
buf.nlh.magic, htobe32(UDEV_MONITOR_MAGIC));
|
|
|
|
if (buf.nlh.properties_off+32 > (size_t) buflen)
|
|
return log_debug_errno(EAGAIN, "Invalid message length (%u > %zd)",
|
|
buf.nlh.properties_off+32, buflen);
|
|
|
|
bufpos = buf.nlh.properties_off;
|
|
|
|
/* devices received from udev are always initialized */
|
|
is_initialized = true;
|
|
|
|
} else {
|
|
/* kernel message with header */
|
|
bufpos = strlen(buf.raw) + 1;
|
|
if ((size_t) bufpos < sizeof("a@/d") || bufpos >= buflen)
|
|
return log_debug_errno(EAGAIN, "Invalid message length");
|
|
|
|
/* check message header */
|
|
if (!strstr(buf.raw, "@/"))
|
|
return log_debug_errno(EAGAIN, "Invalid message header");
|
|
}
|
|
|
|
r = device_new_from_nulstr(&device, (uint8_t*) &buf.raw[bufpos], buflen - bufpos);
|
|
if (r < 0)
|
|
return log_debug_errno(r, "Failed to create device: %m");
|
|
|
|
if (is_initialized)
|
|
device_set_is_initialized(device);
|
|
|
|
/* skip device, if it does not pass the current filter */
|
|
if (passes_filter(udev_monitor, device) <= 0)
|
|
return 0;
|
|
|
|
*ret = TAKE_PTR(device);
|
|
return 1;
|
|
}
|
|
|
|
int udev_monitor_receive_sd_device(struct udev_monitor *udev_monitor, sd_device **ret) {
|
|
struct pollfd pfd = {
|
|
.fd = udev_monitor->sock,
|
|
.events = POLLIN,
|
|
};
|
|
int r;
|
|
|
|
assert(udev_monitor);
|
|
assert(ret);
|
|
|
|
for (;;) {
|
|
/* r == 0 means a device is received but it does not pass the current filter. */
|
|
r = udev_monitor_receive_device_one(udev_monitor, ret);
|
|
if (r != 0)
|
|
return r;
|
|
|
|
for (;;) {
|
|
/* wait next message */
|
|
r = poll(&pfd, 1, 0);
|
|
if (r < 0) {
|
|
if (IN_SET(errno, EINTR, EAGAIN))
|
|
continue;
|
|
|
|
return -errno;
|
|
} else if (r == 0)
|
|
return -EAGAIN;
|
|
|
|
/* receive next message */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* udev_monitor_receive_device:
|
|
* @udev_monitor: udev monitor
|
|
*
|
|
* Receive data from the udev monitor socket, allocate a new udev
|
|
* device, fill in the received data, and return the device.
|
|
*
|
|
* Only socket connections with uid=0 are accepted.
|
|
*
|
|
* The monitor socket is by default set to NONBLOCK. A variant of poll() on
|
|
* the file descriptor returned by udev_monitor_get_fd() should to be used to
|
|
* wake up when new devices arrive, or alternatively the file descriptor
|
|
* switched into blocking mode.
|
|
*
|
|
* The initial refcount is 1, and needs to be decremented to
|
|
* release the resources of the udev device.
|
|
*
|
|
* Returns: a new udev device, or #NULL, in case of an error
|
|
**/
|
|
_public_ struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monitor) {
|
|
_cleanup_(sd_device_unrefp) sd_device *device = NULL;
|
|
int r;
|
|
|
|
assert_return(udev_monitor, NULL);
|
|
|
|
r = udev_monitor_receive_sd_device(udev_monitor, &device);
|
|
if (r < 0) {
|
|
errno = -r;
|
|
return NULL;
|
|
}
|
|
|
|
return udev_device_new(udev_monitor->udev, device);
|
|
}
|
|
|
|
static int udev_monitor_send_sd_device(
|
|
struct udev_monitor *udev_monitor,
|
|
struct udev_monitor *destination,
|
|
sd_device *device) {
|
|
|
|
struct udev_monitor_netlink_header nlh = {
|
|
.prefix = "libudev",
|
|
.magic = htobe32(UDEV_MONITOR_MAGIC),
|
|
.header_size = sizeof nlh,
|
|
};
|
|
struct iovec iov[2] = {
|
|
{ .iov_base = &nlh, .iov_len = sizeof nlh },
|
|
};
|
|
struct msghdr smsg = {
|
|
.msg_iov = iov,
|
|
.msg_iovlen = 2,
|
|
};
|
|
uint64_t tag_bloom_bits;
|
|
const char *buf, *val;
|
|
ssize_t count;
|
|
size_t blen;
|
|
int r;
|
|
|
|
assert(udev_monitor);
|
|
assert(device);
|
|
|
|
r = device_get_properties_nulstr(device, (const uint8_t **) &buf, &blen);
|
|
if (r < 0)
|
|
return log_debug_errno(r, "Failed to get device properties: %m");
|
|
if (blen < 32) {
|
|
log_debug("Device buffer is too small to contain a valid device");
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* fill in versioned header */
|
|
r = sd_device_get_subsystem(device, &val);
|
|
if (r < 0)
|
|
return log_debug_errno(r, "Failed to get device subsystem: %m");
|
|
nlh.filter_subsystem_hash = htobe32(util_string_hash32(val));
|
|
|
|
if (sd_device_get_devtype(device, &val) >= 0 && val)
|
|
nlh.filter_devtype_hash = htobe32(util_string_hash32(val));
|
|
|
|
/* add tag bloom filter */
|
|
tag_bloom_bits = 0;
|
|
FOREACH_DEVICE_TAG(device, val)
|
|
tag_bloom_bits |= util_string_bloom64(val);
|
|
|
|
if (tag_bloom_bits > 0) {
|
|
nlh.filter_tag_bloom_hi = htobe32(tag_bloom_bits >> 32);
|
|
nlh.filter_tag_bloom_lo = htobe32(tag_bloom_bits & 0xffffffff);
|
|
}
|
|
|
|
/* add properties list */
|
|
nlh.properties_off = iov[0].iov_len;
|
|
nlh.properties_len = blen;
|
|
iov[1] = (struct iovec) {
|
|
.iov_base = (char*) buf,
|
|
.iov_len = blen,
|
|
};
|
|
|
|
/*
|
|
* Use custom address for target, or the default one.
|
|
*
|
|
* If we send to a multicast group, we will get
|
|
* ECONNREFUSED, which is expected.
|
|
*/
|
|
smsg.msg_name = destination ? &destination->snl : &udev_monitor->snl_destination;
|
|
smsg.msg_namelen = sizeof(struct sockaddr_nl);
|
|
count = sendmsg(udev_monitor->sock, &smsg, 0);
|
|
if (count < 0) {
|
|
if (!destination && errno == ECONNREFUSED) {
|
|
log_debug("Passed device to netlink monitor %p", udev_monitor);
|
|
return 0;
|
|
} else
|
|
return log_debug_errno(errno, "Failed to send device to netlink monitor %p", udev_monitor);
|
|
}
|
|
|
|
log_debug("Passed %zi byte device to netlink monitor %p", count, udev_monitor);
|
|
return count;
|
|
}
|
|
|
|
int udev_monitor_send_device(
|
|
struct udev_monitor *udev_monitor,
|
|
struct udev_monitor *destination,
|
|
struct udev_device *udev_device) {
|
|
assert(udev_device);
|
|
|
|
return udev_monitor_send_sd_device(udev_monitor, destination, udev_device->device);
|
|
}
|
|
|
|
/**
|
|
* udev_monitor_filter_add_match_subsystem_devtype:
|
|
* @udev_monitor: the monitor
|
|
* @subsystem: the subsystem value to match the incoming devices against
|
|
* @devtype: the devtype value to match the incoming devices against
|
|
*
|
|
* This filter is efficiently executed inside the kernel, and libudev subscribers
|
|
* will usually not be woken up for devices which do not match.
|
|
*
|
|
* The filter must be installed before the monitor is switched to listening mode.
|
|
*
|
|
* Returns: 0 on success, otherwise a negative error value.
|
|
*/
|
|
_public_ int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype) {
|
|
_cleanup_free_ char *s = NULL, *d = NULL;
|
|
int r;
|
|
|
|
assert_return(udev_monitor, -EINVAL);
|
|
assert_return(subsystem, -EINVAL);
|
|
|
|
s = strdup(subsystem);
|
|
if (!s)
|
|
return -ENOMEM;
|
|
|
|
if (devtype) {
|
|
d = strdup(devtype);
|
|
if (!d)
|
|
return -ENOMEM;
|
|
}
|
|
|
|
r = hashmap_ensure_allocated(&udev_monitor->subsystem_filter, NULL);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = hashmap_put(udev_monitor->subsystem_filter, s, d);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
s = d = NULL;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* udev_monitor_filter_add_match_tag:
|
|
* @udev_monitor: the monitor
|
|
* @tag: the name of a tag
|
|
*
|
|
* This filter is efficiently executed inside the kernel, and libudev subscribers
|
|
* will usually not be woken up for devices which do not match.
|
|
*
|
|
* The filter must be installed before the monitor is switched to listening mode.
|
|
*
|
|
* Returns: 0 on success, otherwise a negative error value.
|
|
*/
|
|
_public_ int udev_monitor_filter_add_match_tag(struct udev_monitor *udev_monitor, const char *tag) {
|
|
_cleanup_free_ char *t = NULL;
|
|
int r;
|
|
|
|
assert_return(udev_monitor, -EINVAL);
|
|
assert_return(tag, -EINVAL);
|
|
|
|
t = strdup(tag);
|
|
if (!t)
|
|
return -ENOMEM;
|
|
|
|
r = set_ensure_allocated(&udev_monitor->tag_filter, &string_hash_ops);
|
|
if (r < 0)
|
|
return r;
|
|
|
|
r = set_put(udev_monitor->tag_filter, t);
|
|
if (r == -EEXIST)
|
|
return 0;
|
|
if (r < 0)
|
|
return r;
|
|
|
|
TAKE_PTR(t);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* udev_monitor_filter_remove:
|
|
* @udev_monitor: monitor
|
|
*
|
|
* Remove all filters from monitor.
|
|
*
|
|
* Returns: 0 on success, otherwise a negative error value.
|
|
*/
|
|
_public_ int udev_monitor_filter_remove(struct udev_monitor *udev_monitor) {
|
|
static const struct sock_fprog filter = { 0, NULL };
|
|
|
|
assert_return(udev_monitor, -EINVAL);
|
|
|
|
udev_monitor->subsystem_filter = hashmap_free_free_free(udev_monitor->subsystem_filter);
|
|
udev_monitor->tag_filter = set_free_free(udev_monitor->tag_filter);
|
|
|
|
if (setsockopt(udev_monitor->sock, SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)) < 0)
|
|
return -errno;
|
|
|
|
return 0;
|
|
}
|