src/udev/udevadm-monitor.c

   1 /*
   2  * Copyright (C) 2004-2010 Kay Sievers <kay@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 <time.h>
  28 #include <sys/time.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <sys/epoll.h>
  32 #include <linux/types.h>
  33 #include <linux/netlink.h>
  34
  35 #include "udev.h"
  36
  37 static bool udev_exit;
  38
  39 static void sig_handler(int signum)
  40 {
  41         if (signum == SIGINT || signum == SIGTERM)
  42                 udev_exit = true;
  43 }
  44
  45 static void print_device(struct udev_device *device, const char *source, int prop)
  46 {
  47         struct timespec ts;
  48
  49         clock_gettime(CLOCK_MONOTONIC, &ts);
  50         printf("%-6s[%llu.%06u] %-8s %s (%s)\n",
  51                source,
  52                (unsigned long long) ts.tv_sec, (unsigned int) ts.tv_nsec/1000,
  53                udev_device_get_action(device),
  54                udev_device_get_devpath(device),
  55                udev_device_get_subsystem(device));
  56         if (prop) {
  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 static int adm_monitor(struct udev *udev, int argc, char *argv[])
  68 {
  69         struct sigaction act;
  70         sigset_t mask;
  71         int option;
  72         bool prop = false;
  73         bool print_kernel = false;
  74         bool print_udev = false;
  75         struct udev_list subsystem_match_list;
  76         struct udev_list tag_match_list;
  77         struct udev_monitor *udev_monitor = NULL;
  78         struct udev_monitor *kernel_monitor = NULL;
  79         int fd_ep = -1;
  80         int fd_kernel = -1, fd_udev = -1;
  81         struct epoll_event ep_kernel, ep_udev;
  82         int rc = 0;
  83
  84         static const struct option options[] = {
  85                 { "property", no_argument, NULL, 'p' },
  86                 { "environment", no_argument, NULL, 'e' },
  87                 { "kernel", no_argument, NULL, 'k' },
  88                 { "udev", no_argument, NULL, 'u' },
  89                 { "subsystem-match", required_argument, NULL, 's' },
  90                 { "tag-match", required_argument, NULL, 't' },
  91                 { "help", no_argument, NULL, 'h' },
  92                 {}
  93         };
  94
  95         udev_list_init(udev, &subsystem_match_list, true);
  96         udev_list_init(udev, &tag_match_list, true);
  97
  98         for (;;) {
  99                 option = getopt_long(argc, argv, "pekus:t:h", options, NULL);
 100                 if (option == -1)
 101                         break;
 102
 103                 switch (option) {
 104                 case 'p':
 105                 case 'e':
 106                         prop = true;
 107                         break;
 108                 case 'k':
 109                         print_kernel = true;
 110                         break;
 111                 case 'u':
 112                         print_udev = true;
 113                         break;
 114                 case 's':
 115                         {
 116                                 char subsys[UTIL_NAME_SIZE];
 117                                 char *devtype;
 118
 119                                 util_strscpy(subsys, sizeof(subsys), optarg);
 120                                 devtype = strchr(subsys, '/');
 121                                 if (devtype != NULL) {
 122                                         devtype[0] = '\0';
 123                                         devtype++;
 124                                 }
 125                                 udev_list_entry_add(&subsystem_match_list, subsys, devtype);
 126                                 break;
 127                         }
 128                 case 't':
 129                         udev_list_entry_add(&tag_match_list, optarg, NULL);
 130                         break;
 131                 case 'h':
 132                         printf("Usage: udevadm monitor [--property] [--kernel] [--udev] [--help]\n"
 133                                "  --property                              print the event properties\n"
 134                                "  --kernel                                print kernel uevents\n"
 135                                "  --udev                                  print udev events\n"
 136                                "  --subsystem-match=<subsystem[/devtype]> filter events by subsystem\n"
 137                                "  --tag-match=<tag>                       filter events by tag\n"
 138                                "  --help\n\n");
 139                         goto out;
 140                 default:
 141                         rc = 1;
 142                         goto out;
 143                 }
 144         }
 145
 146         if (!print_kernel && !print_udev) {
 147                 print_kernel = true;
 148                 print_udev = true;
 149         }
 150
 151         /* set signal handlers */
 152         memset(&act, 0x00, sizeof(struct sigaction));
 153         act.sa_handler = sig_handler;
 154         sigemptyset(&act.sa_mask);
 155         act.sa_flags = SA_RESTART;
 156         sigaction(SIGINT, &act, NULL);
 157         sigaction(SIGTERM, &act, NULL);
 158         sigemptyset(&mask);
 159         sigaddset(&mask, SIGINT);
 160         sigaddset(&mask, SIGTERM);
 161         sigprocmask(SIG_UNBLOCK, &mask, NULL);
 162
 163         fd_ep = epoll_create1(EPOLL_CLOEXEC);
 164         if (fd_ep < 0) {
 165                 log_error("error creating epoll fd: %m\n");
 166                 goto out;
 167         }
 168
 169         printf("monitor will print the received events for:\n");
 170         if (print_udev) {
 171                 struct udev_list_entry *entry;
 172
 173                 udev_monitor = udev_monitor_new_from_netlink(udev, "udev");
 174                 if (udev_monitor == NULL) {
 175                         fprintf(stderr, "error: unable to create netlink socket\n");
 176                         rc = 1;
 177                         goto out;
 178                 }
 179                 udev_monitor_set_receive_buffer_size(udev_monitor, 128*1024*1024);
 180                 fd_udev = udev_monitor_get_fd(udev_monitor);
 181
 182                 udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
 183                         const char *subsys = udev_list_entry_get_name(entry);
 184                         const char *devtype = udev_list_entry_get_value(entry);
 185
 186                         if (udev_monitor_filter_add_match_subsystem_devtype(udev_monitor, subsys, devtype) < 0)
 187                                 fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
 188                 }
 189
 190                 udev_list_entry_foreach(entry, udev_list_get_entry(&tag_match_list)) {
 191                         const char *tag = udev_list_entry_get_name(entry);
 192
 193                         if (udev_monitor_filter_add_match_tag(udev_monitor, tag) < 0)
 194                                 fprintf(stderr, "error: unable to apply tag filter '%s'\n", tag);
 195                 }
 196
 197                 if (udev_monitor_enable_receiving(udev_monitor) < 0) {
 198                         fprintf(stderr, "error: unable to subscribe to udev events\n");
 199                         rc = 2;
 200                         goto out;
 201                 }
 202
 203                 memset(&ep_udev, 0, sizeof(struct epoll_event));
 204                 ep_udev.events = EPOLLIN;
 205                 ep_udev.data.fd = fd_udev;
 206                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0) {
 207                         log_error("fail to add fd to epoll: %m\n");
 208                         goto out;
 209                 }
 210
 211                 printf("UDEV - the event which udev sends out after rule processing\n");
 212         }
 213
 214         if (print_kernel) {
 215                 struct udev_list_entry *entry;
 216
 217                 kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
 218                 if (kernel_monitor == NULL) {
 219                         fprintf(stderr, "error: unable to create netlink socket\n");
 220                         rc = 3;
 221                         goto out;
 222                 }
 223                 udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 224                 fd_kernel = udev_monitor_get_fd(kernel_monitor);
 225
 226                 udev_list_entry_foreach(entry, udev_list_get_entry(&subsystem_match_list)) {
 227                         const char *subsys = udev_list_entry_get_name(entry);
 228
 229                         if (udev_monitor_filter_add_match_subsystem_devtype(kernel_monitor, subsys, NULL) < 0)
 230                                 fprintf(stderr, "error: unable to apply subsystem filter '%s'\n", subsys);
 231                 }
 232
 233                 if (udev_monitor_enable_receiving(kernel_monitor) < 0) {
 234                         fprintf(stderr, "error: unable to subscribe to kernel events\n");
 235                         rc = 4;
 236                         goto out;
 237                 }
 238
 239                 memset(&ep_kernel, 0, sizeof(struct epoll_event));
 240                 ep_kernel.events = EPOLLIN;
 241                 ep_kernel.data.fd = fd_kernel;
 242                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_kernel, &ep_kernel) < 0) {
 243                         log_error("fail to add fd to epoll: %m\n");
 244                         goto out;
 245                 }
 246
 247                 printf("KERNEL - the kernel uevent\n");
 248         }
 249         printf("\n");
 250
 251         while (!udev_exit) {
 252                 int fdcount;
 253                 struct epoll_event ev[4];
 254                 int i;
 255
 256                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 257                 if (fdcount < 0) {
 258                         if (errno != EINTR)
 259                                 fprintf(stderr, "error receiving uevent message: %m\n");
 260                         continue;
 261                 }
 262
 263                 for (i = 0; i < fdcount; i++) {
 264                         if (ev[i].data.fd == fd_kernel && ev[i].events & EPOLLIN) {
 265                                 struct udev_device *device;
 266
 267                                 device = udev_monitor_receive_device(kernel_monitor);
 268                                 if (device == NULL)
 269                                         continue;
 270                                 print_device(device, "KERNEL", prop);
 271                                 udev_device_unref(device);
 272                         } else if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) {
 273                                 struct udev_device *device;
 274
 275                                 device = udev_monitor_receive_device(udev_monitor);
 276                                 if (device == NULL)
 277                                         continue;
 278                                 print_device(device, "UDEV", prop);
 279                                 udev_device_unref(device);
 280                         }
 281                 }
 282         }
 283 out:
 284         if (fd_ep >= 0)
 285                 close(fd_ep);
 286         udev_monitor_unref(udev_monitor);
 287         udev_monitor_unref(kernel_monitor);
 288         udev_list_cleanup(&subsystem_match_list);
 289         udev_list_cleanup(&tag_match_list);
 290         return rc;
 291 }
 292
 293 const struct udevadm_cmd udevadm_monitor = {
 294         .name = "monitor",
 295         .cmd = adm_monitor,
 296         .help = "listen to kernel and udev events",
 297 };