udev/udevadm-settle.c

   1 /*
   2  * Copyright (C) 2006-2008 Kay Sievers <kay@vrfy.org>
   3  * Copyright (C) 2009 Canonical Ltd.
   4  * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdlib.h>
  21 #include <stddef.h>
  22 #include <string.h>
  23 #include <stdio.h>
  24 #include <unistd.h>
  25 #include <errno.h>
  26 #include <dirent.h>
  27 #include <fcntl.h>
  28 #include <syslog.h>
  29 #include <getopt.h>
  30 #include <signal.h>
  31 #include <sys/stat.h>
  32 #include <sys/types.h>
  33
  34 #include "udev.h"
  35
  36 #define DEFAULT_TIMEOUT                 180
  37 #define LOOP_PER_SECOND                 20
  38
  39 static volatile sig_atomic_t is_timeout;
  40
  41 static void sig_handler(int signum)
  42 {
  43         switch (signum) {
  44                 case SIGALRM:
  45                         is_timeout = 1;
  46                 case SIGUSR1:
  47                         ;
  48         }
  49 }
  50
  51 int udevadm_settle(struct udev *udev, int argc, char *argv[])
  52 {
  53         static const struct option options[] = {
  54                 { "seq-start", required_argument, NULL, 's' },
  55                 { "seq-end", required_argument, NULL, 'e' },
  56                 { "timeout", required_argument, NULL, 't' },
  57                 { "quiet", no_argument, NULL, 'q' },
  58                 { "help", no_argument, NULL, 'h' },
  59                 {}
  60         };
  61         unsigned long long start = 0;
  62         unsigned long long end = 0;
  63         int quiet = 0;
  64         int timeout = 0;
  65         struct sigaction act;
  66         struct udev_queue *udev_queue = NULL;
  67         int rc = 0;
  68
  69         dbg(udev, "version %s\n", VERSION);
  70
  71         /* set signal handlers */
  72         memset(&act, 0x00, sizeof(act));
  73         act.sa_handler = sig_handler;
  74         sigemptyset (&act.sa_mask);
  75         act.sa_flags = 0;
  76         sigaction(SIGALRM, &act, NULL);
  77         sigaction(SIGUSR1, &act, NULL);
  78
  79         while (1) {
  80                 int option;
  81                 int seconds;
  82
  83                 option = getopt_long(argc, argv, "s:e:t:qh", options, NULL);
  84                 if (option == -1)
  85                         break;
  86
  87                 switch (option) {
  88                 case 's':
  89                         start = strtoull(optarg, NULL, 0);
  90                         break;
  91                 case 'e':
  92                         end = strtoull(optarg, NULL, 0);
  93                         break;
  94                 case 't':
  95                         seconds = atoi(optarg);
  96                         if (seconds >= 0)
  97                                 timeout = seconds;
  98                         else
  99                                 fprintf(stderr, "invalid timeout value\n");
 100                         dbg(udev, "timeout=%i\n", timeout);
 101                         break;
 102                 case 'q':
 103                         quiet = 1;
 104                         break;
 105                 case 'h':
 106                         printf("Usage: udevadm settle OPTIONS\n"
 107                                "  --timeout=<seconds>   maximum time to wait for events\n"
 108                                "  --seq-start=<seqnum>  first seqnum to wait for\n"
 109                                "  --seq-end=<seqnum>    last seqnum to wait for\n"
 110                                "  --quiet               do not print list after timeout\n"
 111                                "  --help\n\n");
 112                         goto exit;
 113                 }
 114         }
 115
 116         if (timeout > 0)
 117                 alarm(timeout);
 118         else
 119                 alarm(DEFAULT_TIMEOUT);
 120
 121         udev_queue = udev_queue_new(udev);
 122         if (udev_queue == NULL)
 123                 goto exit;
 124
 125         if (start > 0) {
 126                 unsigned long long kernel_seq;
 127
 128                 kernel_seq = udev_queue_get_kernel_seqnum(udev_queue);
 129
 130                 /* unless specified, the last event is the current kernel seqnum */
 131                 if (end == 0)
 132                         end = udev_queue_get_kernel_seqnum(udev_queue);
 133
 134                 if (start > end) {
 135                         err(udev, "seq-start larger than seq-end, ignoring\n");
 136                         fprintf(stderr, "seq-start larger than seq-end, ignoring\n");
 137                         start = 0;
 138                         end = 0;
 139                 }
 140
 141                 if (start > kernel_seq || end > kernel_seq) {
 142                         err(udev, "seq-start or seq-end larger than current kernel value, ignoring\n");
 143                         fprintf(stderr, "seq-start or seq-end larger than current kernel value, ignoring\n");
 144                         start = 0;
 145                         end = 0;
 146                 }
 147                 info(udev, "start=%llu end=%llu current=%llu\n", start, end, kernel_seq);
 148         } else {
 149                 if (end > 0) {
 150                         err(udev, "seq-end needs seq-start parameter, ignoring\n");
 151                         fprintf(stderr, "seq-end needs seq-start parameter, ignoring\n");
 152                         end = 0;
 153                 }
 154         }
 155
 156         /* guarantee that the udev daemon isn't pre-processing */
 157         if (getuid() == 0) {
 158                 struct udev_ctrl *uctrl;
 159
 160                 uctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 161                 if (uctrl != NULL) {
 162                         sigset_t mask, oldmask;
 163
 164                         sigemptyset(&mask);
 165                         sigaddset(&mask, SIGUSR1);
 166                         sigaddset(&mask, SIGALRM);
 167                         sigprocmask(SIG_BLOCK, &mask, &oldmask);
 168                         if (udev_ctrl_send_settle(uctrl) > 0)
 169                                 sigsuspend(&oldmask);
 170                         sigprocmask(SIG_SETMASK, &oldmask, NULL);
 171                         udev_ctrl_unref(uctrl);
 172                 }
 173         }
 174
 175         while (!is_timeout) {
 176                 if (start > 0) {
 177                         /* if asked for, wait for a specific sequence of events */
 178                         if (udev_queue_get_seqnum_sequence_is_finished(udev_queue, start, end) == 1)
 179                                 break;
 180                 } else {
 181                         /* exit if queue is empty */
 182                         if (udev_queue_get_queue_is_empty(udev_queue))
 183                                 break;
 184                 }
 185
 186                 usleep(1000 * 1000 / LOOP_PER_SECOND);
 187         }
 188
 189         /* if we reached the timeout, print the list of remaining events */
 190         if (is_timeout) {
 191                 struct udev_list_entry *list_entry;
 192
 193                 if (!quiet) {
 194                         info(udev, "timeout waiting for udev queue\n");
 195                         printf("\nudevadm settle - timeout of %i seconds reached, the event queue contains:\n", timeout);
 196                         udev_list_entry_foreach(list_entry, udev_queue_get_queued_list_entry(udev_queue))
 197                                 printf("  %s (%s)\n",
 198                                        udev_list_entry_get_name(list_entry),
 199                                        udev_list_entry_get_value(list_entry));
 200                 }
 201                 rc = 1;
 202         }
 203 exit:
 204         udev_queue_unref(udev_queue);
 205         return rc;
 206 }