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_list_node subsystem_match_list;
  75         struct udev_monitor *udev_monitor = NULL;
  76         struct udev_monitor *kernel_monitor = NULL;
  77         fd_set readfds;
  78         int rc = 0;
  79
  80         static const struct option options[] = {
  81                 { "environment", no_argument, NULL, 'e' },
  82                 { "kernel", no_argument, NULL, 'k' },
  83                 { "udev", no_argument, NULL, 'u' },
  84                 { "subsystem-match", required_argument, NULL, 's' },
  85                 { "help", no_argument, NULL, 'h' },
  86                 {}
  87         };
  88
  89         udev_list_init(&subsystem_match_list);
  90         while (1) {
  91                 option = getopt_long(argc, argv, "ekus:h", options, NULL);
  92                 if (option == -1)
  93                         break;
  94
  95                 switch (option) {
  96                 case 'e':
  97                         env = 1;
  98                         break;
  99                 case 'k':
 100                         print_kernel = 1;
 101                         break;
 102                 case 'u':
 103                         print_udev = 1;
 104                         break;
 105                 case 's':
 106                         udev_list_entry_add(udev, &subsystem_match_list, optarg, NULL, 1, 0);
 107                         break;
 108                 case 'h':
 109                         printf("Usage: udevadm monitor [--environment] [--kernel] [--udev] [--help]\n"
 110                                "  --env    print the whole event environment\n"
 111                                "  --kernel print kernel uevents\n"
 112                                "  --udev   print udev events\n"
 113                                "  --help\n\n");
 114                 default:
 115                         goto out;
 116                 }
 117         }
 118
 119         if (!print_kernel && !print_udev) {
 120                 print_kernel = 1;
 121                 print_udev =1;
 122         }
 123
 124         /* set signal handlers */
 125         memset(&act, 0x00, sizeof(struct sigaction));
 126         act.sa_handler = (void (*)(int)) sig_handler;
 127         sigemptyset(&act.sa_mask);
 128         act.sa_flags = SA_RESTART;
 129         sigaction(SIGINT, &act, NULL);
 130         sigaction(SIGTERM, &act, NULL);
 131
 132         printf("monitor will print the received events for:\n");
 133         if (print_udev) {
 134                 struct udev_list_entry *entry;
 135
 136                 udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
 137                 if (udev_monitor == NULL) {
 138                         fprintf(stderr, "error: unable to create netlink socket\n");
 139                         rc = 1;
 140                         goto out;
 141                 }
 142
 143                 udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
 144                         const char *subsys = udev_list_entry_get_name(entry);
 145
 146                         if (udev_monitor_filter_add_match_subsystem(udev_monitor, subsys) < 0)
 147                                 fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
 148                 }
 149
 150                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 151                         fprintf(stderr, "error: unable to subscribe to udev events\n");
 152                         rc = 2;
 153                         goto out;
 154                 }
 155                 printf("UDEV - the event which udev sends out after rule processing\n");
 156         }
 157         if (print_kernel) {
 158                 kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
 159                 if (kernel_monitor == NULL) {
 160                         fprintf(stderr, "error: unable to create netlink socket\n");
 161                         rc = 3;
 162                         goto out;
 163                 }
 164                 if (udev_monitor_enable_receiving(kernel_monitor) < 0) {
 165                         fprintf(stderr, "error: unable to subscribe to kernel events\n");
 166                         rc = 4;
 167                         goto out;
 168                 }
 169                 printf("KERNEL - the kernel uevent\n");
 170         }
 171         printf("\n");
 172
 173         while (!udev_exit) {
 174                 int fdcount;
 175
 176                 FD_ZERO(&readfds);
 177                 if (kernel_monitor != NULL)
 178                         FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
 179                 if (udev_monitor != NULL)
 180                         FD_SET(udev_monitor_get_fd(udev_monitor), &readfds);
 181
 182                 fdcount = select(UDEV_MAX(udev_monitor_get_fd(kernel_monitor), udev_monitor_get_fd(udev_monitor))+1,
 183                                  &readfds, NULL, NULL, NULL);
 184                 if (fdcount < 0) {
 185                         if (errno != EINTR)
 186                                 fprintf(stderr, "error receiving uevent message: %m\n");
 187                         continue;
 188                 }
 189
 190                 if ((kernel_monitor != NULL) && FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
 191                         struct udev_device *device;
 192
 193                         device = udev_monitor_receive_device(kernel_monitor);
 194                         if (device == NULL)
 195                                 continue;
 196                         print_device(device, "KERNEL", env);
 197                         udev_device_unref(device);
 198                 }
 199
 200                 if ((udev_monitor != NULL) && FD_ISSET(udev_monitor_get_fd(udev_monitor), &readfds)) {
 201                         struct udev_device *device;
 202
 203                         device = udev_monitor_receive_device(udev_monitor);
 204                         if (device == NULL)
 205                                 continue;
 206                         print_device(device, "UDEV", env);
 207                         udev_device_unref(device);
 208                 }
 209         }
 210
 211 out:
 212         udev_monitor_unref(udev_monitor);
 213         udev_monitor_unref(kernel_monitor);
 214         udev_list_cleanup_entries(udev, &subsystem_match_list);
 215         return rc;
 216 }