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         }
  48 }
  49
  50 int udevadm_settle(struct udev *udev, int argc, char *argv[])
  51 {
  52         static const struct option options[] = {
  53                 { "seq-start", required_argument, NULL, 's' },
  54                 { "seq-end", required_argument, NULL, 'e' },
  55                 { "timeout", required_argument, NULL, 't' },
  56                 { "exit-if-exists", required_argument, NULL, 'E' },
  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         const char *exists = NULL;
  65         int timeout = DEFAULT_TIMEOUT;
  66         struct sigaction act;
  67         sigset_t mask;
  68         struct udev_queue *udev_queue = NULL;
  69         int rc = 1;
  70
  71         dbg(udev, "version %s\n", VERSION);
  72
  73         /* set signal handlers */
  74         memset(&act, 0x00, sizeof(act));
  75         act.sa_handler = sig_handler;
  76         sigemptyset (&act.sa_mask);
  77         act.sa_flags = 0;
  78         sigaction(SIGALRM, &act, NULL);
  79         sigemptyset(&mask);
  80         sigaddset(&mask, SIGALRM);
  81         sigprocmask(SIG_UNBLOCK, &mask, NULL);
  82
  83         for (;;) {
  84                 int option;
  85                 int seconds;
  86
  87                 option = getopt_long(argc, argv, "s:e:t:E:qh", options, NULL);
  88                 if (option == -1)
  89                         break;
  90
  91                 switch (option) {
  92                 case 's':
  93                         start = strtoull(optarg, NULL, 0);
  94                         break;
  95                 case 'e':
  96                         end = strtoull(optarg, NULL, 0);
  97                         break;
  98                 case 't':
  99                         seconds = atoi(optarg);
 100                         if (seconds >= 0)
 101                                 timeout = seconds;
 102                         else
 103                                 fprintf(stderr, "invalid timeout value\n");
 104                         dbg(udev, "timeout=%i\n", timeout);
 105                         break;
 106                 case 'q':
 107                         quiet = 1;
 108                         break;
 109                 case 'E':
 110                         exists = optarg;
 111                         break;
 112                 case 'h':
 113                         printf("Usage: udevadm settle OPTIONS\n"
 114                                "  --timeout=<seconds>     maximum time to wait for events\n"
 115                                "  --seq-start=<seqnum>    first seqnum to wait for\n"
 116                                "  --seq-end=<seqnum>      last seqnum to wait for\n"
 117                                "  --exit-if-exists=<file> stop waiting if file exists\n"
 118                                "  --quiet                 do not print list after timeout\n"
 119                                "  --help\n\n");
 120                         exit(0);
 121                 }
 122         }
 123
 124         if (timeout > 0)
 125                 alarm(timeout);
 126         else
 127                 is_timeout = 1;
 128
 129         udev_queue = udev_queue_new(udev);
 130         if (udev_queue == NULL)
 131                 exit(2);
 132
 133         if (start > 0) {
 134                 unsigned long long kernel_seq;
 135
 136                 kernel_seq = udev_queue_get_kernel_seqnum(udev_queue);
 137
 138                 /* unless specified, the last event is the current kernel seqnum */
 139                 if (end == 0)
 140                         end = udev_queue_get_kernel_seqnum(udev_queue);
 141
 142                 if (start > end) {
 143                         err(udev, "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                         start = 0;
 151                         end = 0;
 152                 }
 153                 info(udev, "start=%llu end=%llu current=%llu\n", start, end, kernel_seq);
 154         } else {
 155                 if (end > 0) {
 156                         err(udev, "seq-end needs seq-start parameter, ignoring\n");
 157                         end = 0;
 158                 }
 159         }
 160
 161         /* guarantee that the udev daemon isn't pre-processing */
 162         if (getuid() == 0) {
 163                 struct udev_ctrl *uctrl;
 164
 165                 uctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 166                 if (uctrl != NULL) {
 167                         if (udev_ctrl_send_ping(uctrl, timeout) < 0) {
 168                                 info(udev, "no connection to daemon\n");
 169                                 udev_ctrl_unref(uctrl);
 170                                 rc = 0;
 171                                 goto out;
 172                         }
 173                         udev_ctrl_unref(uctrl);
 174                 }
 175         }
 176
 177         for (;;) {
 178                 struct stat statbuf;
 179                 const struct timespec duration = { 0 , 1000 * 1000 * 1000 / LOOP_PER_SECOND };
 180
 181                 if (exists != NULL && stat(exists, &statbuf) == 0) {
 182                         rc = 0;
 183                         break;
 184                 }
 185
 186                 if (start > 0) {
 187                         /* if asked for, wait for a specific sequence of events */
 188                         if (udev_queue_get_seqnum_sequence_is_finished(udev_queue, start, end) == 1) {
 189                                 rc = 0;
 190                                 break;
 191                         }
 192                 } else {
 193                         /* exit if queue is empty */
 194                         if (udev_queue_get_queue_is_empty(udev_queue)) {
 195                                 rc = 0;
 196                                 break;
 197                         }
 198                 }
 199
 200                 if (is_timeout)
 201                         break;
 202
 203                 nanosleep(&duration, NULL);
 204         }
 205
 206         /* if we reached the timeout, print the list of remaining events */
 207         if (is_timeout) {
 208                 struct udev_list_entry *list_entry;
 209
 210                 if (!quiet && udev_queue_get_queued_list_entry(udev_queue) != NULL) {
 211                         info(udev, "timeout waiting for udev queue\n");
 212                         printf("\nudevadm settle - timeout of %i seconds reached, the event queue contains:\n", timeout);
 213                         udev_list_entry_foreach(list_entry, udev_queue_get_queued_list_entry(udev_queue))
 214                                 printf("  %s (%s)\n",
 215                                        udev_list_entry_get_name(list_entry),
 216                                        udev_list_entry_get_value(list_entry));
 217                 }
 218         }
 219 out:
 220         udev_queue_unref(udev_queue);
 221         return rc;
 222 }