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                 { "exit-if-exists", required_argument, NULL, 'E' },
  58                 { "quiet", no_argument, NULL, 'q' },
  59                 { "help", no_argument, NULL, 'h' },
  60                 {}
  61         };
  62         unsigned long long start = 0;
  63         unsigned long long end = 0;
  64         int quiet = 0;
  65         const char *exists = NULL;
  66         int timeout = DEFAULT_TIMEOUT;
  67         struct sigaction act;
  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         sigaction(SIGUSR1, &act, NULL);
  80
  81         while (1) {
  82                 int option;
  83                 int seconds;
  84
  85                 option = getopt_long(argc, argv, "s:e:t:E:qh", options, NULL);
  86                 if (option == -1)
  87                         break;
  88
  89                 switch (option) {
  90                 case 's':
  91                         start = strtoull(optarg, NULL, 0);
  92                         break;
  93                 case 'e':
  94                         end = strtoull(optarg, NULL, 0);
  95                         break;
  96                 case 't':
  97                         seconds = atoi(optarg);
  98                         if (seconds >= 0)
  99                                 timeout = seconds;
 100                         else
 101                                 fprintf(stderr, "invalid timeout value\n");
 102                         dbg(udev, "timeout=%i\n", timeout);
 103                         break;
 104                 case 'q':
 105                         quiet = 1;
 106                         break;
 107                 case 'E':
 108                         exists = optarg;
 109                         break;
 110                 case 'h':
 111                         printf("Usage: udevadm settle OPTIONS\n"
 112                                "  --timeout=<seconds>     maximum time to wait for events\n"
 113                                "  --seq-start=<seqnum>    first seqnum to wait for\n"
 114                                "  --seq-end=<seqnum>      last seqnum to wait for\n"
 115                                "  --exit-if-exists=<file> stop waiting if file exists\n"
 116                                "  --quiet                 do not print list after timeout\n"
 117                                "  --help\n\n");
 118                         exit(0);
 119                 }
 120         }
 121
 122         if (timeout > 0)
 123                 alarm(timeout);
 124         else
 125                 is_timeout = 1;
 126
 127         udev_queue = udev_queue_new(udev);
 128         if (udev_queue == NULL)
 129                 exit(2);
 130
 131         if (start > 0) {
 132                 unsigned long long kernel_seq;
 133
 134                 kernel_seq = udev_queue_get_kernel_seqnum(udev_queue);
 135
 136                 /* unless specified, the last event is the current kernel seqnum */
 137                 if (end == 0)
 138                         end = udev_queue_get_kernel_seqnum(udev_queue);
 139
 140                 if (start > end) {
 141                         err(udev, "seq-start larger than seq-end, ignoring\n");
 142                         fprintf(stderr, "seq-start larger than seq-end, ignoring\n");
 143                         start = 0;
 144                         end = 0;
 145                 }
 146
 147                 if (start > kernel_seq || end > kernel_seq) {
 148                         err(udev, "seq-start or seq-end larger than current kernel value, ignoring\n");
 149                         fprintf(stderr, "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                         fprintf(stderr, "seq-end needs seq-start parameter, ignoring\n");
 158                         end = 0;
 159                 }
 160         }
 161
 162         /* guarantee that the udev daemon isn't pre-processing */
 163         if (getuid() == 0) {
 164                 struct udev_ctrl *uctrl;
 165
 166                 uctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
 167                 if (uctrl != NULL) {
 168                         sigset_t mask, oldmask;
 169
 170                         sigemptyset(&mask);
 171                         sigaddset(&mask, SIGUSR1);
 172                         sigaddset(&mask, SIGALRM);
 173                         sigprocmask(SIG_BLOCK, &mask, &oldmask);
 174                         if (udev_ctrl_send_settle(uctrl) > 0)
 175                                 sigsuspend(&oldmask);
 176                         sigprocmask(SIG_SETMASK, &oldmask, NULL);
 177                         udev_ctrl_unref(uctrl);
 178                 }
 179         }
 180
 181         while (1) {
 182                 struct stat statbuf;
 183
 184                 if (exists != NULL && stat(exists, &statbuf) == 0) {
 185                         rc = 0;
 186                         break;
 187                 }
 188
 189                 if (start > 0) {
 190                         /* if asked for, wait for a specific sequence of events */
 191                         if (udev_queue_get_seqnum_sequence_is_finished(udev_queue, start, end) == 1) {
 192                                 rc = 0;
 193                                 break;
 194                         }
 195                 } else {
 196                         /* exit if queue is empty */
 197                         if (udev_queue_get_queue_is_empty(udev_queue)) {
 198                                 rc = 0;
 199                                 break;
 200                         }
 201                 }
 202
 203                 if (is_timeout)
 204                         break;
 205
 206                 usleep(1000 * 1000 / LOOP_PER_SECOND);
 207         }
 208
 209         /* if we reached the timeout, print the list of remaining events */
 210         if (is_timeout) {
 211                 struct udev_list_entry *list_entry;
 212
 213                 if (!quiet && udev_queue_get_queued_list_entry(udev_queue) != NULL) {
 214                         info(udev, "timeout waiting for udev queue\n");
 215                         printf("\nudevadm settle - timeout of %i seconds reached, the event queue contains:\n", timeout);
 216                         udev_list_entry_foreach(list_entry, udev_queue_get_queued_list_entry(udev_queue))
 217                                 printf("  %s (%s)\n",
 218                                        udev_list_entry_get_name(list_entry),
 219                                        udev_list_entry_get_value(list_entry));
 220                 }
 221         }
 222
 223         udev_queue_unref(udev_queue);
 224         return rc;
 225 }