src/udev/udevadm-control.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * This program is free software: you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation, either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <errno.h>
  15 #include <getopt.h>
  16 #include <stddef.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <string.h>
  20 #include <unistd.h>
  21
  22 #include "parse-util.h"
  23 #include "process-util.h"
  24 #include "syslog-util.h"
  25 #include "time-util.h"
  26 #include "udevadm.h"
  27 #include "udev-ctrl.h"
  28 #include "util.h"
  29 #include "virt.h"
  30
  31 static int help(void) {
  32         printf("%s control OPTION\n\n"
  33                "Control the udev daemon.\n\n"
  34                "  -h --help                Show this help\n"
  35                "  -V --version             Show package version\n"
  36                "  -e --exit                Instruct the daemon to cleanup and exit\n"
  37                "  -l --log-priority=LEVEL  Set the udev log level for the daemon\n"
  38                "  -s --stop-exec-queue     Do not execute events, queue only\n"
  39                "  -S --start-exec-queue    Execute events, flush queue\n"
  40                "  -R --reload              Reload rules and databases\n"
  41                "  -p --property=KEY=VALUE  Set a global property for all events\n"
  42                "  -m --children-max=N      Maximum number of children\n"
  43                "     --ping                Wait for udev to respond to a ping message\n"
  44                "  -t --timeout=SECONDS     Maximum time to block for a reply\n"
  45                , program_invocation_short_name);
  46
  47         return 0;
  48 }
  49
  50 int control_main(int argc, char *argv[], void *userdata) {
  51         _cleanup_(udev_ctrl_unrefp) struct udev_ctrl *uctrl = NULL;
  52         usec_t timeout = 60 * USEC_PER_SEC;
  53         int c, r;
  54
  55         enum {
  56                 ARG_PING = 0x100,
  57         };
  58
  59         static const struct option options[] = {
  60                 { "exit",             no_argument,       NULL, 'e'      },
  61                 { "log-priority",     required_argument, NULL, 'l'      },
  62                 { "stop-exec-queue",  no_argument,       NULL, 's'      },
  63                 { "start-exec-queue", no_argument,       NULL, 'S'      },
  64                 { "reload",           no_argument,       NULL, 'R'      },
  65                 { "reload-rules",     no_argument,       NULL, 'R'      }, /* alias for -R */
  66                 { "property",         required_argument, NULL, 'p'      },
  67                 { "env",              required_argument, NULL, 'p'      }, /* alias for -p */
  68                 { "children-max",     required_argument, NULL, 'm'      },
  69                 { "ping",             no_argument,       NULL, ARG_PING },
  70                 { "timeout",          required_argument, NULL, 't'      },
  71                 { "version",          no_argument,       NULL, 'V'      },
  72                 { "help",             no_argument,       NULL, 'h'      },
  73                 {}
  74         };
  75
  76         r = must_be_root();
  77         if (r < 0)
  78                 return r;
  79
  80         if (running_in_chroot() > 0) {
  81                 log_info("Running in chroot, ignoring request.");
  82                 return 0;
  83         }
  84
  85         if (argc <= 1)
  86                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
  87                                        "This command expects one or more options.");
  88
  89         r = udev_ctrl_new(&uctrl);
  90         if (r < 0)
  91                 return log_error_errno(r, "Failed to initialize udev control: %m");
  92
  93         while ((c = getopt_long(argc, argv, "el:sSRp:m:t:Vh", options, NULL)) >= 0)
  94                 switch (c) {
  95                 case 'e':
  96                         r = udev_ctrl_send_exit(uctrl);
  97                         if (r == -ENOANO)
  98                                 log_warning("Cannot specify --exit after --exit, ignoring.");
  99                         else if (r < 0)
 100                                 return log_error_errno(r, "Failed to send exit request: %m");
 101                         break;
 102                 case 'l':
 103                         r = log_level_from_string(optarg);
 104                         if (r < 0)
 105                                 return log_error_errno(r, "Failed to parse log priority '%s': %m", optarg);
 106
 107                         r = udev_ctrl_send_set_log_level(uctrl, r);
 108                         if (r == -ENOANO)
 109                                 log_warning("Cannot specify --log-priority after --exit, ignoring.");
 110                         else if (r < 0)
 111                                 return log_error_errno(r, "Failed to send request to set log level: %m");
 112                         break;
 113                 case 's':
 114                         r = udev_ctrl_send_stop_exec_queue(uctrl);
 115                         if (r == -ENOANO)
 116                                 log_warning("Cannot specify --stop-exec-queue after --exit, ignoring.");
 117                         else if (r < 0)
 118                                 return log_error_errno(r, "Failed to send request to stop exec queue: %m");
 119                         break;
 120                 case 'S':
 121                         r = udev_ctrl_send_start_exec_queue(uctrl);
 122                         if (r == -ENOANO)
 123                                 log_warning("Cannot specify --start-exec-queue after --exit, ignoring.");
 124                         else if (r < 0)
 125                                 return log_error_errno(r, "Failed to send request to start exec queue: %m");
 126                         break;
 127                 case 'R':
 128                         r = udev_ctrl_send_reload(uctrl);
 129                         if (r == -ENOANO)
 130                                 log_warning("Cannot specify --reload after --exit, ignoring.");
 131                         else if (r < 0)
 132                                 return log_error_errno(r, "Failed to send reload request: %m");
 133                         break;
 134                 case 'p':
 135                         if (!strchr(optarg, '='))
 136                                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "expect <KEY>=<value> instead of '%s'", optarg);
 137
 138                         r = udev_ctrl_send_set_env(uctrl, optarg);
 139                         if (r == -ENOANO)
 140                                 log_warning("Cannot specify --property after --exit, ignoring.");
 141                         else if (r < 0)
 142                                 return log_error_errno(r, "Failed to send request to update environment: %m");
 143                         break;
 144                 case 'm': {
 145                         unsigned i;
 146
 147                         r = safe_atou(optarg, &i);
 148                         if (r < 0)
 149                                 return log_error_errno(r, "Failed to parse maximum number of events '%s': %m", optarg);
 150
 151                         r = udev_ctrl_send_set_children_max(uctrl, i);
 152                         if (r == -ENOANO)
 153                                 log_warning("Cannot specify --children-max after --exit, ignoring.");
 154                         else if (r < 0)
 155                                 return log_error_errno(r, "Failed to send request to set number of children: %m");
 156                         break;
 157                 }
 158                 case ARG_PING:
 159                         r = udev_ctrl_send_ping(uctrl);
 160                         if (r == -ENOANO)
 161                                 log_error("Cannot specify --ping after --exit, ignoring.");
 162                         else if (r < 0)
 163                                 return log_error_errno(r, "Failed to send a ping message: %m");
 164                         break;
 165                 case 't':
 166                         r = parse_sec(optarg, &timeout);
 167                         if (r < 0)
 168                                 return log_error_errno(r, "Failed to parse timeout value '%s': %m", optarg);
 169                         break;
 170                 case 'V':
 171                         return print_version();
 172                 case 'h':
 173                         return help();
 174                 case '?':
 175                         return -EINVAL;
 176                 default:
 177                         assert_not_reached("Unknown option.");
 178                 }
 179
 180         if (optind < argc)
 181                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
 182                                        "Extraneous argument: %s", argv[optind]);
 183
 184         r = udev_ctrl_wait(uctrl, timeout);
 185         if (r < 0)
 186                 return log_error_errno(r, "Failed to wait for daemon to reply: %m");
 187
 188         return 0;
 189 }