release/src/router/udev/udevmonitor.c

   1 /*
   2  * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  *      This program is free software; you can redistribute it and/or modify it
   5  *      under the terms of the GNU General Public License as published by the
   6  *      Free Software Foundation version 2 of the License.
   7  *
   8  *      This program is distributed in the hope that it will be useful, but
   9  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  *      General Public License for more details.
  12  *
  13  *      You should have received a copy of the GNU General Public License along
  14  *      with this program; if not, write to the Free Software Foundation, Inc.,
  15  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16  *
  17  */
  18
  19 #include <unistd.h>
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stddef.h>
  23 #include <string.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <signal.h>
  27 #include <getopt.h>
  28 #include <sys/time.h>
  29 #include <sys/socket.h>
  30 #include <sys/un.h>
  31 #include <sys/select.h>
  32 #include <linux/types.h>
  33 #include <linux/netlink.h>
  34
  35 #include "udev.h"
  36 #include "udevd.h"
  37
  38 static int uevent_netlink_sock = -1;
  39 static int udev_monitor_sock = -1;
  40 static volatile int udev_exit;
  41
  42 static int init_udev_monitor_socket(void)
  43 {
  44         struct sockaddr_un saddr;
  45         socklen_t addrlen;
  46         const int feature_on = 1;
  47         int retval;
  48
  49         memset(&saddr, 0x00, sizeof(saddr));
  50         saddr.sun_family = AF_LOCAL;
  51         /* use abstract namespace for socket path */
  52         strcpy(&saddr.sun_path[1], "/org/kernel/udev/monitor");
  53         addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1;
  54
  55         udev_monitor_sock = socket(AF_LOCAL, SOCK_DGRAM, 0);
  56         if (udev_monitor_sock == -1) {
  57                 fprintf(stderr, "error getting socket: %s\n", strerror(errno));
  58                 return -1;
  59         }
  60
  61         /* the bind takes care of ensuring only one copy running */
  62         retval = bind(udev_monitor_sock, (struct sockaddr *) &saddr, addrlen);
  63         if (retval < 0) {
  64                 fprintf(stderr, "bind failed: %s\n", strerror(errno));
  65                 close(udev_monitor_sock);
  66                 udev_monitor_sock = -1;
  67                 return -1;
  68         }
  69
  70         /* enable receiving of the sender credentials */
  71         setsockopt(udev_monitor_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on));
  72
  73         return 0;
  74 }
  75
  76 static int init_uevent_netlink_sock(void)
  77 {
  78         struct sockaddr_nl snl;
  79         int retval;
  80
  81         memset(&snl, 0x00, sizeof(struct sockaddr_nl));
  82         snl.nl_family = AF_NETLINK;
  83         snl.nl_pid = getpid();
  84         snl.nl_groups = 1;
  85
  86         uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
  87         if (uevent_netlink_sock == -1) {
  88                 fprintf(stderr, "error getting socket: %s\n", strerror(errno));
  89                 return -1;
  90         }
  91
  92         retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl,
  93                       sizeof(struct sockaddr_nl));
  94         if (retval < 0) {
  95                 fprintf(stderr, "bind failed: %s\n", strerror(errno));
  96                 close(uevent_netlink_sock);
  97                 uevent_netlink_sock = -1;
  98                 return -1;
  99         }
 100
 101         return 0;
 102 }
 103
 104 static void asmlinkage sig_handler(int signum)
 105 {
 106         if (signum == SIGINT || signum == SIGTERM)
 107                 udev_exit = 1;
 108 }
 109
 110 static const char *search_key(const char *searchkey, const char *buf, size_t buflen)
 111 {
 112         size_t bufpos = 0;
 113         size_t searchkeylen = strlen(searchkey);
 114
 115         while (bufpos < buflen) {
 116                 const char *key;
 117                 int keylen;
 118
 119                 key = &buf[bufpos];
 120                 keylen = strlen(key);
 121                 if (keylen == 0)
 122                         break;
 123                  if ((strncmp(searchkey, key, searchkeylen) == 0) && key[searchkeylen] == '=')
 124                         return &key[searchkeylen + 1];
 125                 bufpos += keylen + 1;
 126         }
 127         return NULL;
 128 }
 129
 130 int main(int argc, char *argv[])
 131 {
 132         struct sigaction act;
 133         int option;
 134         int env = 0;
 135         int kernel = 0;
 136         int udev = 0;
 137         fd_set readfds;
 138         int retval = 0;
 139
 140         static const struct option options[] = {
 141                 { "environment", 0, NULL, 'e' },
 142                 { "kernel", 0, NULL, 'k' },
 143                 { "udev", 0, NULL, 'u' },
 144                 { "help", 0, NULL, 'h' },
 145                 {}
 146         };
 147
 148         while (1) {
 149                 option = getopt_long(argc, argv, "ekuh", options, NULL);
 150                 if (option == -1)
 151                         break;
 152
 153                 switch (option) {
 154                 case 'e':
 155                         env = 1;
 156                         break;
 157                 case 'k':
 158                         kernel = 1;
 159                         break;
 160                 case 'u':
 161                         udev = 1;
 162                         break;
 163                 case 'h':
 164                         printf("Usage: udevmonitor [--environment] [--kernel] [--udev] [--help]\n"
 165                                "  --env    print the whole event environment\n"
 166                                "  --kernel print kernel uevents\n"
 167                                "  --udev   print udev events\n"
 168                                "  --help   print this help text\n\n");
 169                 default:
 170                         goto out;
 171                 }
 172         }
 173
 174         if (!kernel && !udev) {
 175                 kernel = 1;
 176                 udev =1;
 177         }
 178
 179         if (getuid() != 0 && kernel) {
 180                 fprintf(stderr, "root privileges needed to subscribe to kernel events\n");
 181                 goto out;
 182         }
 183
 184         /* set signal handlers */
 185         memset(&act, 0x00, sizeof(struct sigaction));
 186         act.sa_handler = (void (*)(int)) sig_handler;
 187         sigemptyset(&act.sa_mask);
 188         act.sa_flags = SA_RESTART;
 189         sigaction(SIGINT, &act, NULL);
 190         sigaction(SIGTERM, &act, NULL);
 191
 192         printf("udevmonitor will print the received events for:\n");
 193         if (udev) {
 194                 retval = init_udev_monitor_socket();
 195                 if (retval)
 196                         goto out;
 197                 printf("UDEV the event which udev sends out after rule processing\n");
 198         }
 199         if (kernel) {
 200                 retval = init_uevent_netlink_sock();
 201                 if (retval)
 202                         goto out;
 203                 printf("UEVENT the kernel uevent\n");
 204         }
 205         printf("\n");
 206
 207         while (!udev_exit) {
 208                 char buf[UEVENT_BUFFER_SIZE*2];
 209                 ssize_t buflen;
 210                 ssize_t bufpos;
 211                 ssize_t keys;
 212                 int fdcount;
 213                 struct timeval tv;
 214                 struct timezone tz;
 215                 char timestr[64];
 216                 const char *source = NULL;
 217                 const char *devpath, *action, *subsys;
 218
 219                 buflen = 0;
 220                 FD_ZERO(&readfds);
 221                 if (uevent_netlink_sock >= 0)
 222                         FD_SET(uevent_netlink_sock, &readfds);
 223                 if (udev_monitor_sock >= 0)
 224                         FD_SET(udev_monitor_sock, &readfds);
 225
 226                 fdcount = select(UDEV_MAX(uevent_netlink_sock, udev_monitor_sock)+1, &readfds, NULL, NULL, NULL);
 227                 if (fdcount < 0) {
 228                         if (errno != EINTR)
 229                                 fprintf(stderr, "error receiving uevent message: %s\n", strerror(errno));
 230                         continue;
 231                 }
 232
 233                 if (gettimeofday(&tv, &tz) == 0) {
 234                         snprintf(timestr, sizeof(timestr), "%llu.%06u",
 235                                  (unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec);
 236                 } else
 237                         timestr[0] = '\0';
 238
 239                 if ((uevent_netlink_sock >= 0) && FD_ISSET(uevent_netlink_sock, &readfds)) {
 240                         buflen = recv(uevent_netlink_sock, &buf, sizeof(buf), 0);
 241                         if (buflen <= 0) {
 242                                 fprintf(stderr, "error receiving uevent message: %s\n", strerror(errno));
 243                                 continue;
 244                         }
 245                         source = "UEVENT";
 246                 }
 247
 248                 if ((udev_monitor_sock >= 0) && FD_ISSET(udev_monitor_sock, &readfds)) {
 249                         buflen = recv(udev_monitor_sock, &buf, sizeof(buf), 0);
 250                         if (buflen <= 0) {
 251                                 fprintf(stderr, "error receiving udev message: %s\n", strerror(errno));
 252                                 continue;
 253                         }
 254                         source = "UDEV  ";
 255                 }
 256
 257                 if (buflen == 0)
 258                         continue;
 259
 260                 keys = strlen(buf) + 1; /* start of payload */
 261                 devpath = search_key("DEVPATH", &buf[keys], buflen);
 262                 action = search_key("ACTION", &buf[keys], buflen);
 263                 subsys = search_key("SUBSYSTEM", &buf[keys], buflen);
 264                 printf("%s[%s] %-8s %s (%s)\n", source, timestr, action, devpath, subsys);
 265
 266                 /* print environment */
 267                 bufpos = keys;
 268                 if (env) {
 269                         while (bufpos < buflen) {
 270                                 int keylen;
 271                                 char *key;
 272
 273                                 key = &buf[bufpos];
 274                                 keylen = strlen(key);
 275                                 if (keylen == 0)
 276                                         break;
 277                                 printf("%s\n", key);
 278                                 bufpos += keylen + 1;
 279                         }
 280                         printf("\n");
 281                 }
 282         }
 283
 284 out:
 285         if (uevent_netlink_sock >= 0)
 286                 close(uevent_netlink_sock);
 287         if (udev_monitor_sock >= 0)
 288                 close(udev_monitor_sock);
 289
 290         if (retval)
 291                 return 1;
 292         return 0;
 293 }