release/src/router/udev/udevsettle.c

   1 /*
   2  * Copyright (C) 2006 Kay Sievers <kay@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 <stdlib.h>
  20 #include <stddef.h>
  21 #include <string.h>
  22 #include <stdio.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <dirent.h>
  26 #include <fcntl.h>
  27 #include <syslog.h>
  28 #include <getopt.h>
  29 #include <sys/stat.h>
  30 #include <sys/types.h>
  31
  32 #include "udev.h"
  33 #include "udevd.h"
  34
  35 #define DEFAULT_TIMEOUT                 180
  36 #define LOOP_PER_SECOND                 20
  37
  38
  39 #ifdef USE_LOG
  40 void log_message(int priority, const char *format, ...)
  41 {
  42         va_list args;
  43
  44         if (priority > udev_log_priority)
  45                 return;
  46
  47         va_start(args, format);
  48         vsyslog(priority, format, args);
  49         va_end(args);
  50 }
  51 #endif
  52
  53 int main(int argc, char *argv[], char *envp[])
  54 {
  55         char queuename[PATH_SIZE];
  56         char filename[PATH_SIZE];
  57         unsigned long long seq_kernel;
  58         unsigned long long seq_udev;
  59         char seqnum[32];
  60         int fd;
  61         ssize_t len;
  62         int timeout = DEFAULT_TIMEOUT;
  63         int loop;
  64         static const struct option options[] = {
  65                 { "timeout", 1, NULL, 't' },
  66                 { "help", 0, NULL, 'h' },
  67                 {}
  68         };
  69         int option;
  70         int rc = 1;
  71         int seconds;
  72
  73         logging_init("udevsettle");
  74         udev_config_init();
  75         dbg("version %s", UDEV_VERSION);
  76         sysfs_init();
  77
  78         while (1) {
  79                 option = getopt_long(argc, argv, "t:h", options, NULL);
  80                 if (option == -1)
  81                         break;
  82
  83                 switch (option) {
  84                 case 't':
  85                         seconds = atoi(optarg);
  86                         if (seconds > 0)
  87                                 timeout = seconds;
  88                         else
  89                                 fprintf(stderr, "invalid timeout value\n");
  90                         dbg("timeout=%i", timeout);
  91                         break;
  92                 case 'h':
  93                         printf("Usage: udevsettle [--help] [--timeout=<seconds>]\n\n");
  94                         goto exit;
  95                 }
  96         }
  97
  98         strlcpy(queuename, udev_root, sizeof(queuename));
  99         strlcat(queuename, "/" EVENT_QUEUE_DIR, sizeof(queuename));
 100
 101         loop = timeout * LOOP_PER_SECOND;
 102         while (loop--) {
 103                 /* wait for events in queue to finish */
 104                 while (loop--) {
 105                         struct stat statbuf;
 106
 107                         if (stat(queuename, &statbuf) < 0) {
 108                                 info("queue is empty");
 109                                 break;
 110                         }
 111                         usleep(1000 * 1000 / LOOP_PER_SECOND);
 112                 }
 113                 if (loop <= 0) {
 114                         info("timeout waiting for queue");
 115                         goto exit;
 116                 }
 117
 118                 /* read current udev seqnum */
 119                 strlcpy(filename, udev_root, sizeof(filename));
 120                 strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename));
 121                 fd = open(filename, O_RDONLY);
 122                 if (fd < 0)
 123                         goto exit;
 124                 len = read(fd, seqnum, sizeof(seqnum)-1);
 125                 close(fd);
 126                 if (len <= 0)
 127                         goto exit;
 128                 seqnum[len] = '\0';
 129                 seq_udev = strtoull(seqnum, NULL, 10);
 130                 info("udev seqnum = %llu", seq_udev);
 131
 132                 /* read current kernel seqnum */
 133                 strlcpy(filename, sysfs_path, sizeof(filename));
 134                 strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
 135                 fd = open(filename, O_RDONLY);
 136                 if (fd < 0)
 137                         goto exit;
 138                 len = read(fd, seqnum, sizeof(seqnum)-1);
 139                 close(fd);
 140                 if (len <= 0)
 141                         goto exit;
 142                 seqnum[len] = '\0';
 143                 seq_kernel = strtoull(seqnum, NULL, 10);
 144                 info("kernel seqnum = %llu", seq_kernel);
 145
 146                 /* make sure all kernel events have arrived in the queue */
 147                 if (seq_udev >= seq_kernel) {
 148                         info("queue is empty and no pending events left");
 149                         rc = 0;
 150                         goto exit;
 151                 }
 152                 usleep(1000 * 1000 / LOOP_PER_SECOND);
 153                 info("queue is empty, but events still pending");
 154         }
 155
 156 exit:
 157         sysfs_cleanup();
 158         logging_close();
 159         return rc;
 160 }