udev/udevadm-settle.c

   1 /*
   2  * Copyright (C) 2006-2009 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 <time.h>
  32 #include <sys/stat.h>
  33 #include <sys/types.h>
  34
  35 #include "udev.h"
  36
  37 #define DEFAULT_TIMEOUT                 180
  38 #define LOOP_PER_SECOND                 20
  39
  40 static volatile sig_atomic_t is_timeout;
  41
  42 static void sig_handler(int signum)
  43 {
  44         switch (signum) {
  45                 case SIGALRM:
  46                         is_timeout = 1;
  47                 case SIGUSR1:
  48                         ;
  49         }
  50 }
  51
  52 int udevadm_settle(struct udev *udev, int argc, char *argv[])
  53 {
  54         static const struct option options[] = {
  55                 { "seq-start", required_argument, NULL, 's' },
  56                 { "seq-end", required_argument, NULL, 'e' },
  57                 { "timeout", required_argument, NULL, 't' },
  58                 { "exit-if-exists", required_argument, NULL, 'E' },
  59                 { "quiet", no_argument, NULL, 'q' },
  60                 { "help", no_argument, NULL, 'h' },
  61                 {}
  62         };
  63         unsigned long long start = 0;
  64         unsigned long long end = 0;
  65         int quiet = 0;
  66         const char *exists = NULL;
  67         int timeout = DEFAULT_TIMEOUT;
  68         struct sigaction act;
  69         struct udev_queue *udev_queue = NULL;
  70         int rc = 1;
  71
  72         dbg(udev, "version %s\n", VERSION);
  73
  74         /* set signal handlers */
  75         memset(&act, 0x00, sizeof(act));
  76         act.sa_handler = sig_handler;
  77         sigemptyset (&act.sa_mask);
  78         act.sa_flags = 0;
  79         sigaction(SIGALRM, &act, NULL);
  80         sigaction(SIGUSR1, &act, NULL);
  81
  82         while (1) {
  83                 int option;
  84                 int seconds;
  85
  86                 option = getopt_long(argc, argv, "s:e:t:E:qh", options, NULL);
  87                 if (option == -1)
  88                         break;
  89
  90                 switch (option) {
  91                 case 's':
  92                         start = strtoull(optarg, NULL, 0);
  93                         break;
  94                 case 'e':
  95                         end = strtoull(optarg, NULL, 0);
  96                         break;
  97                 case 't':
  98                         seconds = atoi(optarg);
  99                         if (seconds >= 0)
 100                                 timeout = seconds;
 101                         else
 102                                 fprintf(stderr, "invalid timeout value\n");
 103                         dbg(udev, "timeout=%i\n", timeout);
 104                         break;
 105                 case 'q':
 106                         quiet = 1;
 107                         break;
 108                 case 'E':
 109                         exists = optarg;
 110                         break;
 111                 case 'h':
 112                         printf("Usage: udevadm settle OPTIONS\n"
 113                                "  --timeout=<seconds>     maximum time to wait for events\n"
 114                                "  --seq-start=<seqnum>    first seqnum to wait for\n"
 115                                "  --seq-end=<seqnum>      last seqnum to wait for\n"
 116                                "  --exit-if-exists=<file> stop waiting if file exists\n"
 117                                "  --quiet                 do not print list after timeout\n"
 118                                "  --help\n\n");
 119                         exit(0);
 120                 }
 121         }
 122
 123         if (timeout > 0)
 124                 alarm(timeout);
 125         else
 126                 is_timeout = 1;
 127
 128         udev_queue = udev_queue_new(udev);
 129         if (udev_queue == NULL)
 130                 exit(2);
 131
 132         if (start > 0) {
 133                 unsigned long long kernel_seq;
 134
 135                 kernel_seq = udev_queue_get_kernel_seqnum(udev_queue);
 136
 137                 /* unless specified, the last event is the current kernel seqnum */
 138                 if (end == 0)
 139                         end = udev_queue_get_kernel_seqnum(udev_queue);
 140
 141                 if (start > end) {
 142                         err(udev, "seq-start larger than seq-end, ignoring\n");
 143                         fprintf(stderr, "seq-start larger than seq-end, ignoring\n");
 144                         start = 0;
 145                         end = 0;
 146                 }
 147
 148                 if (start > kernel_seq || end > kernel_seq) {
 149                         err(udev, "seq-start or seq-end larger than current kernel value, ignoring\n");
 150                         fprintf(stderr, "seq-start or seq-end larger than current kernel value, ignoring\n");
 151                         start = 0;
 152                         end = 0;
 153                 }
 154                 info(udev, "start=%llu end=%llu current=%llu\n", start, end, kernel_seq);
 155         } else {
 156                 if (end > 0) {
 157                         err(udev, "seq-end needs seq-start parameter, ignoring\n");
 158                         fprintf(stderr, "seq-end needs seq-start parameter, ignoring\n");
 159                         end = 0;
 160                 }
 161         }
 162
 163         /* guarantee that the udev daemon isn't pre-processing */
 164         if (getuid() == 0) {
 165                 struct udev_ctrl *uctrl;
 166
 167                 uctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 168                 if (uctrl != NULL) {
 169                         sigset_t mask, oldmask;
 170
 171                         sigemptyset(&mask);
 172                         sigaddset(&mask, SIGUSR1);
 173                         sigaddset(&mask, SIGALRM);
 174                         sigprocmask(SIG_BLOCK, &mask, &oldmask);
 175                         if (udev_ctrl_send_settle(uctrl) > 0)
 176                                 sigsuspend(&oldmask);
 177                         sigprocmask(SIG_SETMASK, &oldmask, NULL);
 178                         udev_ctrl_unref(uctrl);
 179                 }
 180         }
 181
 182         while (1) {
 183                 struct stat statbuf;
 184                 const struct timespec duration = { 0 , 1000 * 1000 * 1000 / LOOP_PER_SECOND };
 185
 186                 if (exists != NULL && stat(exists, &statbuf) == 0) {
 187                         rc = 0;
 188                         break;
 189                 }
 190
 191                 if (start > 0) {
 192                         /* if asked for, wait for a specific sequence of events */
 193                         if (udev_queue_get_seqnum_sequence_is_finished(udev_queue, start, end) == 1) {
 194                                 rc = 0;
 195                                 break;
 196                         }
 197                 } else {
 198                         /* exit if queue is empty */
 199                         if (udev_queue_get_queue_is_empty(udev_queue)) {
 200                                 rc = 0;
 201                                 break;
 202                         }
 203                 }
 204
 205                 if (is_timeout)
 206                         break;
 207
 208                 nanosleep(&duration, NULL);
 209         }
 210
 211         /* if we reached the timeout, print the list of remaining events */
 212         if (is_timeout) {
 213                 struct udev_list_entry *list_entry;
 214
 215                 if (!quiet && udev_queue_get_queued_list_entry(udev_queue) != NULL) {
 216                         info(udev, "timeout waiting for udev queue\n");
 217                         printf("\nudevadm settle - timeout of %i seconds reached, the event queue contains:\n", timeout);
 218                         udev_list_entry_foreach(list_entry, udev_queue_get_queued_list_entry(udev_queue))
 219                                 printf("  %s (%s)\n",
 220                                        udev_list_entry_get_name(list_entry),
 221                                        udev_list_entry_get_value(list_entry));
 222                 }
 223         }
 224
 225         udev_queue_unref(udev_queue);
 226         return rc;
 227 }