udev/udevadm-monitor.c

   1 /*
   2  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #include <unistd.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <string.h>
  23 #include <fcntl.h>
  24 #include <errno.h>
  25 #include <signal.h>
  26 #include <getopt.h>
  27 #include <sys/time.h>
  28 #include <sys/socket.h>
  29 #include <sys/un.h>
  30 #include <sys/select.h>
  31 #include <linux/types.h>
  32 #include <linux/netlink.h>
  33
  34 #include "udev.h"
  35
  36 static int udev_exit;
  37
  38 static void asmlinkage sig_handler(int signum)
  39 {
  40         if (signum == SIGINT || signum == SIGTERM)
  41                 udev_exit = 1;
  42 }
  43
  44 static void print_device(struct udev_device *device, const char *source, int env)
  45 {
  46         struct timeval tv;
  47         struct timezone tz;
  48
  49         gettimeofday(&tv, &tz);
  50         printf("%-6s[%llu.%06u] %-8s %s (%s)\n",
  51                source,
  52                (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
  53                udev_device_get_action(device),
  54                udev_device_get_devpath(device),
  55                udev_device_get_subsystem(device));
  56         if (env) {
  57                 struct udev_list_entry *list_entry;
  58
  59                 udev_list_entry_foreach(list_entry, udev_device_get_properties_list_entry(device))
  60                         printf("%s=%s\n",
  61                                udev_list_entry_get_name(list_entry),
  62                                udev_list_entry_get_value(list_entry));
  63                 printf("\n");
  64         }
  65 }
  66
  67 int udevadm_monitor(struct udev *udev, int argc, char *argv[])
  68 {
  69         struct sigaction act;
  70         int option;
  71         int env = 0;
  72         int print_kernel = 0;
  73         int print_udev = 0;
  74         struct udev_monitor *udev_monitor = NULL;
  75         struct udev_monitor *kernel_monitor = NULL;
  76         fd_set readfds;
  77         int rc = 0;
  78
  79         static const struct option options[] = {
  80                 { "environment", 0, NULL, 'e' },
  81                 { "kernel", 0, NULL, 'k' },
  82                 { "udev", 0, NULL, 'u' },
  83                 { "help", 0, NULL, 'h' },
  84                 {}
  85         };
  86
  87         while (1) {
  88                 option = getopt_long(argc, argv, "ekuh", options, NULL);
  89                 if (option == -1)
  90                         break;
  91
  92                 switch (option) {
  93                 case 'e':
  94                         env = 1;
  95                         break;
  96                 case 'k':
  97                         print_kernel = 1;
  98                         break;
  99                 case 'u':
 100                         print_udev = 1;
 101                         break;
 102                 case 'h':
 103                         printf("Usage: udevadm monitor [--environment] [--kernel] [--udev] [--help]\n"
 104                                "  --env    print the whole event environment\n"
 105                                "  --kernel print kernel uevents\n"
 106                                "  --udev   print udev events\n"
 107                                "  --help   print this help text\n\n");
 108                 default:
 109                         goto out;
 110                 }
 111         }
 112
 113         if (!print_kernel && !print_udev) {
 114                 print_kernel = 1;
 115                 print_udev =1;
 116         }
 117
 118         if (getuid() != 0 && print_kernel) {
 119                 fprintf(stderr, "root privileges needed to subscribe to kernel events\n");
 120                 goto out;
 121         }
 122
 123         /* set signal handlers */
 124         memset(&act, 0x00, sizeof(struct sigaction));
 125         act.sa_handler = (void (*)(int)) sig_handler;
 126         sigemptyset(&act.sa_mask);
 127         act.sa_flags = SA_RESTART;
 128         sigaction(SIGINT, &act, NULL);
 129         sigaction(SIGTERM, &act, NULL);
 130
 131         printf("monitor will print the received events for:\n");
 132         if (print_udev) {
 133                 udev_monitor = udev_monitor_new_from_socket(udev, "@/org/kernel/udev/monitor");
 134                 if (udev_monitor == NULL) {
 135                         rc = 1;
 136                         goto out;
 137                 }
 138                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 139                         rc = 2;
 140                         goto out;
 141                 }
 142                 printf("UDEV the event which udev sends out after rule processing\n");
 143         }
 144         if (print_kernel) {
 145                 kernel_monitor = udev_monitor_new_from_netlink(udev);
 146                 if (kernel_monitor == NULL) {
 147                         rc = 3;
 148                         goto out;
 149                 }
 150                 if (udev_monitor_enable_receiving(kernel_monitor) < 0) {
 151                         rc = 4;
 152                         goto out;
 153                 }
 154                 printf("UEVENT the kernel uevent\n");
 155         }
 156         printf("\n");
 157
 158         while (!udev_exit) {
 159                 int fdcount;
 160
 161                 FD_ZERO(&readfds);
 162                 if (kernel_monitor != NULL)
 163                         FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 164                 if (udev_monitor != NULL)
 165                         FD_SET(udev_monitor_get_fd(udev_monitor), &readfds);
 166
 167                 fdcount = select(UDEV_MAX(udev_monitor_get_fd(kernel_monitor), udev_monitor_get_fd(udev_monitor))+1,
 168                                  &readfds, NULL, NULL, NULL);
 169                 if (fdcount < 0) {
 170                         if (errno != EINTR)
 171                                 fprintf(stderr, "error receiving uevent message: %m\n");
 172                         continue;
 173                 }
 174
 175                 if ((kernel_monitor != NULL) && FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 176                         struct udev_device *device;
 177
 178                         device = udev_monitor_receive_device(kernel_monitor);
 179                         if (device == NULL)
 180                                 continue;
 181                         print_device(device, "UEVENT", env);
 182                         udev_device_unref(device);
 183                 }
 184
 185                 if ((udev_monitor != NULL) && FD_ISSET(udev_monitor_get_fd(udev_monitor), &readfds)) {
 186                         struct udev_device *device;
 187
 188                         device = udev_monitor_receive_device(udev_monitor);
 189                         if (device == NULL)
 190                                 continue;
 191                         print_device(device, "UDEV", env);
 192                         udev_device_unref(device);
 193                 }
 194         }
 195
 196 out:
 197         udev_monitor_unref(udev_monitor);
 198         udev_monitor_unref(kernel_monitor);
 199         return rc;
 200 }