udevadm-monitor.c revision 9ec6e95b046de71c0198cb9d17acc5462dc76c74
/*
* Copyright (C) 2004-2010 Kay Sievers <kay@vrfy.org>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <signal.h>
#include <getopt.h>
#include <time.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/epoll.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include "udev.h"
#include "udev-util.h"
static bool udev_exit;
static void sig_handler(int signum) {
if (signum == SIGINT || signum == SIGTERM)
udev_exit = true;
}
static void print_device(struct udev_device *device, const char *source, int prop) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
printf("%-6s[%"PRI_TIME".%06ld] %-8s %s (%s)\n",
source,
ts.tv_sec, ts.tv_nsec/1000,
udev_device_get_action(device),
udev_device_get_devpath(device),
udev_device_get_subsystem(device));
if (prop) {
struct udev_list_entry *list_entry;
udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(device))
printf("%s=%s\n",
udev_list_entry_get_name(list_entry),
udev_list_entry_get_value(list_entry));
printf("\n");
}
}
static void help(void) {
printf("Usage: udevadm monitor [--property] [--kernel] [--udev] [--help]\n"
" -p,--property print the event properties\n"
" -k,--kernel print kernel uevents\n"
" -u,--udev print udev events\n"
" -s,--subsystem-match=SUBSYSTEM[/DEVTYPE] filter events by subsystem\n"
" -t,--tag-match=TAG filter events by tag\n"
" -h,--help\n\n");
}
static int adm_monitor(struct udev *udev, int argc, char *argv[]) {
struct sigaction act = {};
sigset_t mask;
bool prop = false;
bool print_kernel = false;
bool print_udev = false;
_cleanup_udev_list_cleanup_ struct udev_list subsystem_match_list;
_cleanup_udev_list_cleanup_ struct udev_list tag_match_list;
_cleanup_udev_monitor_unref_ struct udev_monitor *udev_monitor = NULL;
_cleanup_udev_monitor_unref_ struct udev_monitor *kernel_monitor = NULL;
_cleanup_close_ int fd_ep = -1;
int fd_kernel = -1, fd_udev = -1;
struct epoll_event ep_kernel, ep_udev;
int c;
static const struct option options[] = {
{ "property", no_argument, NULL, 'p' },
{ "environment", no_argument, NULL, 'e' }, /* alias for -p */
{ "kernel", no_argument, NULL, 'k' },
{ "udev", no_argument, NULL, 'u' },
{ "subsystem-match", required_argument, NULL, 's' },
{ "tag-match", required_argument, NULL, 't' },
{ "help", no_argument, NULL, 'h' },
{}
};
udev_list_init(udev, &subsystem_match_list, true);
udev_list_init(udev, &tag_match_list, true);
while((c = getopt_long(argc, argv, "pekus:t:h", options, NULL)) >= 0)
switch (c) {
case 'p':
case 'e':
prop = true;
break;
case 'k':
print_kernel = true;
break;
case 'u':
print_udev = true;
break;
case 's':
{
char subsys[UTIL_NAME_SIZE];
char *devtype;
strscpy(subsys, sizeof(subsys), optarg);
devtype = strchr(subsys, '/');
if (devtype != NULL) {
devtype[0] = '\0';
devtype++;
}
udev_list_entry_add(&subsystem_match_list, subsys, devtype);
break;
}
case 't':
udev_list_entry_add(&tag_match_list, optarg, NULL);
break;
case 'h':
help();
return 0;
default:
return 1;
}
if (!print_kernel && !print_udev) {
print_kernel = true;
print_udev = true;
}
/* set signal handlers */
act.sa_handler = sig_handler;
act.sa_flags = SA_RESTART;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
sigemptyset(&mask);
sigaddset(&mask, SIGINT);
sigaddset(&mask, SIGTERM);
sigprocmask(SIG_UNBLOCK, &mask, NULL);
fd_ep = epoll_create1(EPOLL_CLOEXEC);
if (fd_ep < 0) {
log_error("error creating epoll fd: %m");
return 1;
}
printf("monitor will print the received events for:\n");
if (print_udev) {
struct udev_list_entry *entry;
udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
if (udev_monitor == NULL) {
fprintf(stderr, "error: unable to create netlink socket\n");
return 1;
}
udev_monitor_set_receive_buffer_size(udev_monitor, 128*1024*1024);
fd_udev = udev_monitor_get_fd(udev_monitor);
udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
const char *subsys = udev_list_entry_get_name(entry);
const char *devtype = udev_list_entry_get_value(entry);
if (udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, subsys, devtype) < 0)
fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
}
udev_list_entry_foreach(entry, udev_list_get_entry(&tag_match_list)) {
const char *tag = udev_list_entry_get_name(entry);
if (udev_monitor_filter_add_match_tag(udev_monitor, tag) < 0)
fprintf(stderr, "error: unable to apply tag filter '%s'\n", tag);
}
if (udev_monitor_enable_receiving(udev_monitor) < 0) {
fprintf(stderr, "error: unable to subscribe to udev events\n");
return 2;
}
memzero(&ep_udev, sizeof(struct epoll_event));
ep_udev.events = EPOLLIN;
ep_udev.data.fd = fd_udev;
if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0) {
log_error("fail to add fd to epoll: %m");
return 2;
}
printf("UDEV - the event which udev sends out after rule processing\n");
}
if (print_kernel) {
struct udev_list_entry *entry;
kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
if (kernel_monitor == NULL) {
fprintf(stderr, "error: unable to create netlink socket\n");
return 3;
}
udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
fd_kernel = udev_monitor_get_fd(kernel_monitor);
udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
const char *subsys = udev_list_entry_get_name(entry);
if (udev_monitor_filter_add_match_subsystem_devtype(kernel_monitor, subsys, NULL) < 0)
fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
}
if (udev_monitor_enable_receiving(kernel_monitor) < 0) {
fprintf(stderr, "error: unable to subscribe to kernel events\n");
return 4;
}
memzero(&ep_kernel, sizeof(struct epoll_event));
ep_kernel.events = EPOLLIN;
ep_kernel.data.fd = fd_kernel;
if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_kernel, &ep_kernel) < 0) {
log_error("fail to add fd to epoll: %m");
return 5;
}
printf("KERNEL - the kernel uevent\n");
}
printf("\n");
while (!udev_exit) {
int fdcount;
struct epoll_event ev[4];
int i;
fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
if (fdcount < 0) {
if (errno != EINTR)
fprintf(stderr, "error receiving uevent message: %m\n");
continue;
}
for (i = 0; i < fdcount; i++) {
if (ev[i].data.fd == fd_kernel && ev[i].events & EPOLLIN) {
struct udev_device *device;
device = udev_monitor_receive_device(kernel_monitor);
if (device == NULL)
continue;
print_device(device, "KERNEL", prop);
udev_device_unref(device);
} else if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) {
struct udev_device *device;
device = udev_monitor_receive_device(udev_monitor);
if (device == NULL)
continue;
print_device(device, "UDEV", prop);
udev_device_unref(device);
}
}
}
return 0;
}
const struct udevadm_cmd udevadm_monitor = {
.name = "monitor",
.cmd = adm_monitor,
.help = "listen to kernel and udev events",
};