#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[%llu.%06u] %-8s %s (%s)\n",

source,

(unsigned long long) ts.tv_sec, (unsigned int) 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;

}

memset(&ep_udev, 0, 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;

}

memset(&ep_kernel, 0, 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",

};