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         sigset_t mask;
  70         struct udev_queue *udev_queue = NULL;
  71         int rc = 1;
  72
  73         dbg(udev, "version %s\n", VERSION);
  74
  75         /* set signal handlers */
  76         memset(&act, 0x00, sizeof(act));
  77         act.sa_handler = sig_handler;
  78         sigemptyset (&act.sa_mask);
  79         act.sa_flags = 0;
  80         sigaction(SIGALRM, &act, NULL);
  81         sigaction(SIGUSR1, &act, NULL);
  82         sigemptyset(&mask);
  83         sigaddset(&mask, SIGUSR1);
  84         sigaddset(&mask, SIGALRM);
  85         sigprocmask(SIG_UNBLOCK, &mask, NULL);
  86
  87         for (;;) {
  88                 int option;
  89                 int seconds;
  90
  91                 option = getopt_long(argc, argv, "s:e:t:E:qh", options, NULL);
  92                 if (option == -1)
  93                         break;
  94
  95                 switch (option) {
  96                 case 's':
  97                         start = strtoull(optarg, NULL, 0);
  98                         break;
  99                 case 'e':
 100                         end = strtoull(optarg, NULL, 0);
 101                         break;
 102                 case 't':
 103                         seconds = atoi(optarg);
 104                         if (seconds >= 0)
 105                                 timeout = seconds;
 106                         else
 107                                 fprintf(stderr, "invalid timeout value\n");
 108                         dbg(udev, "timeout=%i\n", timeout);
 109                         break;
 110                 case 'q':
 111                         quiet = 1;
 112                         break;
 113                 case 'E':
 114                         exists = optarg;
 115                         break;
 116                 case 'h':
 117                         printf("Usage: udevadm settle OPTIONS\n"
 118                                "  --timeout=<seconds>     maximum time to wait for events\n"
 119                                "  --seq-start=<seqnum>    first seqnum to wait for\n"
 120                                "  --seq-end=<seqnum>      last seqnum to wait for\n"
 121                                "  --exit-if-exists=<file> stop waiting if file exists\n"
 122                                "  --quiet                 do not print list after timeout\n"
 123                                "  --help\n\n");
 124                         exit(0);
 125                 }
 126         }
 127
 128         if (timeout > 0)
 129                 alarm(timeout);
 130         else
 131                 is_timeout = 1;
 132
 133         udev_queue = udev_queue_new(udev);
 134         if (udev_queue == NULL)
 135                 exit(2);
 136
 137         if (start > 0) {
 138                 unsigned long long kernel_seq;
 139
 140                 kernel_seq = udev_queue_get_kernel_seqnum(udev_queue);
 141
 142                 /* unless specified, the last event is the current kernel seqnum */
 143                 if (end == 0)
 144                         end = udev_queue_get_kernel_seqnum(udev_queue);
 145
 146                 if (start > end) {
 147                         err(udev, "seq-start larger than seq-end, ignoring\n");
 148                         start = 0;
 149                         end = 0;
 150                 }
 151
 152                 if (start > kernel_seq || end > kernel_seq) {
 153                         err(udev, "seq-start or seq-end larger than current kernel value, ignoring\n");
 154                         start = 0;
 155                         end = 0;
 156                 }
 157                 info(udev, "start=%llu end=%llu current=%llu\n", start, end, kernel_seq);
 158         } else {
 159                 if (end > 0) {
 160                         err(udev, "seq-end needs seq-start parameter, ignoring\n");
 161                         end = 0;
 162                 }
 163         }
 164
 165         /* guarantee that the udev daemon isn't pre-processing */
 166         if (getuid() == 0) {
 167                 struct udev_ctrl *uctrl;
 168
 169                 uctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 170                 if (uctrl != NULL) {
 171                         sigset_t oldmask;
 172
 173                         sigemptyset(&mask);
 174                         sigaddset(&mask, SIGUSR1);
 175                         sigaddset(&mask, SIGALRM);
 176                         sigprocmask(SIG_BLOCK, &mask, &oldmask);
 177                         if (udev_ctrl_send_settle(uctrl) > 0)
 178                                 sigsuspend(&oldmask);
 179                         sigprocmask(SIG_SETMASK, &oldmask, NULL);
 180                         udev_ctrl_unref(uctrl);
 181                 }
 182         }
 183
 184         for (;;) {
 185                 struct stat statbuf;
 186                 const struct timespec duration = { 0 , 1000 * 1000 * 1000 / LOOP_PER_SECOND };
 187
 188                 if (exists != NULL && stat(exists, &statbuf) == 0) {
 189                         rc = 0;
 190                         break;
 191                 }
 192
 193                 if (start > 0) {
 194                         /* if asked for, wait for a specific sequence of events */
 195                         if (udev_queue_get_seqnum_sequence_is_finished(udev_queue, start, end) == 1) {
 196                                 rc = 0;
 197                                 break;
 198                         }
 199                 } else {
 200                         /* exit if queue is empty */
 201                         if (udev_queue_get_queue_is_empty(udev_queue)) {
 202                                 rc = 0;
 203                                 break;
 204                         }
 205                 }
 206
 207                 if (is_timeout)
 208                         break;
 209
 210                 nanosleep(&duration, NULL);
 211         }
 212
 213         /* if we reached the timeout, print the list of remaining events */
 214         if (is_timeout) {
 215                 struct udev_list_entry *list_entry;
 216
 217                 if (!quiet && udev_queue_get_queued_list_entry(udev_queue) != NULL) {
 218                         info(udev, "timeout waiting for udev queue\n");
 219                         printf("\nudevadm settle - timeout of %i seconds reached, the event queue contains:\n", timeout);
 220                         udev_list_entry_foreach(list_entry, udev_queue_get_queued_list_entry(udev_queue))
 221                                 printf("  %s (%s)\n",
 222                                        udev_list_entry_get_name(list_entry),
 223                                        udev_list_entry_get_value(list_entry));
 224                 }
 225         }
 226
 227         udev_queue_unref(udev_queue);
 228         return rc;
 229 }