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 int udevadm_monitor(struct udev *udev, int argc, char *argv[])
  45 {
  46         struct sigaction act;
  47         int option;
  48         int env = 0;
  49         int print_kernel = 0;
  50         int print_udev = 0;
  51         struct udev_monitor *udev_monitor = NULL;
  52         struct udev_monitor *kernel_monitor = NULL;
  53         fd_set readfds;
  54         int rc = 0;
  55
  56         static const struct option options[] = {
  57                 { "environment", 0, NULL, 'e' },
  58                 { "kernel", 0, NULL, 'k' },
  59                 { "udev", 0, NULL, 'u' },
  60                 { "help", 0, NULL, 'h' },
  61                 {}
  62         };
  63
  64         while (1) {
  65                 option = getopt_long(argc, argv, "ekuh", options, NULL);
  66                 if (option == -1)
  67                         break;
  68
  69                 switch (option) {
  70                 case 'e':
  71                         env = 1;
  72                         break;
  73                 case 'k':
  74                         print_kernel = 1;
  75                         break;
  76                 case 'u':
  77                         print_udev = 1;
  78                         break;
  79                 case 'h':
  80                         printf("Usage: udevadm monitor [--environment] [--kernel] [--udev] [--help]\n"
  81                                "  --env    print the whole event environment\n"
  82                                "  --kernel print kernel uevents\n"
  83                                "  --udev   print udev events\n"
  84                                "  --help   print this help text\n\n");
  85                 default:
  86                         goto out;
  87                 }
  88         }
  89
  90         if (!print_kernel && !print_udev) {
  91                 print_kernel = 1;
  92                 print_udev =1;
  93         }
  94
  95         if (getuid() != 0 && print_kernel) {
  96                 fprintf(stderr, "root privileges needed to subscribe to kernel events\n");
  97                 goto out;
  98         }
  99
 100         /* set signal handlers */
 101         memset(&act, 0x00, sizeof(struct sigaction));
 102         act.sa_handler = (void (*)(int)) sig_handler;
 103         sigemptyset(&act.sa_mask);
 104         act.sa_flags = SA_RESTART;
 105         sigaction(SIGINT, &act, NULL);
 106         sigaction(SIGTERM, &act, NULL);
 107
 108         printf("monitor will print the received events for:\n");
 109         if (print_udev) {
 110                 udev_monitor = udev_monitor_new_from_socket(udev, "@/org/kernel/udev/monitor");
 111                 if (udev_monitor == NULL) {
 112                         rc = 1;
 113                         goto out;
 114                 }
 115                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 116                         rc = 2;
 117                         goto out;
 118                 }
 119                 printf("UDEV the event which udev sends out after rule processing\n");
 120         }
 121         if (print_kernel) {
 122                 kernel_monitor = udev_monitor_new_from_netlink(udev);
 123                 if (kernel_monitor == NULL) {
 124                         rc = 3;
 125                         goto out;
 126                 }
 127                 if (udev_monitor_enable_receiving(kernel_monitor) < 0) {
 128                         rc = 4;
 129                         goto out;
 130                 }
 131                 printf("UEVENT the kernel uevent\n");
 132         }
 133         printf("\n");
 134
 135         while (!udev_exit) {
 136                 int fdcount;
 137                 struct timeval tv;
 138                 struct timezone tz;
 139                 char timestr[64];
 140
 141                 FD_ZERO(&readfds);
 142                 if (kernel_monitor != NULL)
 143                         FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 144                 if (udev_monitor != NULL)
 145                         FD_SET(udev_monitor_get_fd(udev_monitor), &readfds);
 146
 147                 fdcount = select(UDEV_MAX(udev_monitor_get_fd(kernel_monitor), udev_monitor_get_fd(udev_monitor))+1,
 148                                  &readfds, NULL, NULL, NULL);
 149                 if (fdcount < 0) {
 150                         if (errno != EINTR)
 151                                 fprintf(stderr, "error receiving uevent message: %s\n", strerror(errno));
 152                         continue;
 153                 }
 154
 155                 if (gettimeofday(&tv, &tz) == 0) {
 156                         snprintf(timestr, sizeof(timestr), "%llu.%06u",
 157                                  (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec);
 158                 } else
 159                         timestr[0] = '\0';
 160
 161                 if ((kernel_monitor != NULL) && FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 162                         struct udev_device *device = udev_monitor_receive_device(kernel_monitor);
 163                         if (device == NULL)
 164                                 continue;
 165                         printf("UEVENT[%s] %-8s %s (%s)\n", timestr,
 166                                udev_device_get_action(device),
 167                                udev_device_get_devpath(device),
 168                                udev_device_get_subsystem(device));
 169                         if (env) {
 170                                 struct udev_list *list;
 171
 172                                 list = udev_device_get_properties_list(device);
 173                                 while (list != NULL) {
 174                                         printf("%s=%s\n", udev_list_get_name(list), udev_list_get_value(list));
 175                                         list = udev_list_get_next(list);
 176                                 }
 177                                 printf("\n");
 178                         }
 179                         udev_device_unref(device);
 180                 }
 181
 182                 if ((udev_monitor != NULL) && FD_ISSET(udev_monitor_get_fd(udev_monitor), &readfds)) {
 183                         struct udev_device *device = udev_monitor_receive_device(udev_monitor);
 184                         if (device == NULL)
 185                                 continue;
 186                         printf("UDEV  [%s] %-8s %s (%s)\n", timestr,
 187                                udev_device_get_action(device),
 188                                udev_device_get_devpath(device),
 189                                udev_device_get_subsystem(device));
 190                         if (env) {
 191                                 struct udev_list *list;
 192
 193                                 list = udev_device_get_properties_list(device);
 194                                 while (list != NULL) {
 195                                         printf("%s=%s\n", udev_list_get_name(list), udev_list_get_value(list));
 196                                         list = udev_list_get_next(list);
 197                                 }
 198                                 printf("\n");
 199                         }
 200                         udev_device_unref(device);
 201                 }
 202         }
 203
 204 out:
 205         udev_monitor_unref(udev_monitor);
 206         udev_monitor_unref(kernel_monitor);
 207         return rc;
 208 }