src/udev/udevadm-trigger.c

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <getopt.h>
   6 #include <stddef.h>
   7 #include <stdio.h>
   8 #include <string.h>
   9 #include <unistd.h>
  10
  11 #include "fd-util.h"
  12 #include "set.h"
  13 #include "string-util.h"
  14 #include "udev.h"
  15 #include "udevadm.h"
  16 #include "udevadm-util.h"
  17 #include "util.h"
  18
  19 static int verbose;
  20 static int dry_run;
  21
  22 static int exec_list(struct udev_enumerate *udev_enumerate, const char *action, Set *settle_set) {
  23         struct udev_list_entry *entry;
  24         int r;
  25
  26         udev_list_entry_foreach(entry, udev_enumerate_get_list_entry(udev_enumerate)) {
  27                 char filename[UTIL_PATH_SIZE];
  28                 const char *syspath;
  29                 _cleanup_close_ int fd = -1;
  30
  31                 syspath = udev_list_entry_get_name(entry);
  32                 if (verbose)
  33                         printf("%s\n", syspath);
  34                 if (dry_run)
  35                         continue;
  36
  37                 strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
  38                 fd = open(filename, O_WRONLY|O_CLOEXEC);
  39                 if (fd < 0)
  40                         continue;
  41
  42                 if (settle_set) {
  43                         r = set_put_strdup(settle_set, syspath);
  44                         if (r < 0)
  45                                 return log_oom();
  46                 }
  47
  48                 if (write(fd, action, strlen(action)) < 0)
  49                         log_debug_errno(errno, "error writing '%s' to '%s': %m", action, filename);
  50         }
  51
  52         return 0;
  53 }
  54
  55 static const char *keyval(const char *str, const char **val, char *buf, size_t size) {
  56         char *pos;
  57
  58         strscpy(buf, size,str);
  59         pos = strchr(buf, '=');
  60         if (pos != NULL) {
  61                 pos[0] = 0;
  62                 pos++;
  63         }
  64         *val = pos;
  65         return buf;
  66 }
  67
  68 static int help(void) {
  69         printf("%s trigger [OPTIONS] DEVPATH\n\n"
  70                "Request events from the kernel.\n\n"
  71                "  -h --help                         Show this help\n"
  72                "  -V --version                      Show package version\n"
  73                "  -v --verbose                      Print the list of devices while running\n"
  74                "  -n --dry-run                      Do not actually trigger the events\n"
  75                "  -t --type=                        Type of events to trigger\n"
  76                "          devices                     sysfs devices (default)\n"
  77                "          subsystems                  sysfs subsystems and drivers\n"
  78                "  -c --action=ACTION                Event action value, default is \"change\"\n"
  79                "  -s --subsystem-match=SUBSYSTEM    Trigger devices from a matching subsystem\n"
  80                "  -S --subsystem-nomatch=SUBSYSTEM  Exclude devices from a matching subsystem\n"
  81                "  -a --attr-match=FILE[=VALUE]      Trigger devices with a matching attribute\n"
  82                "  -A --attr-nomatch=FILE[=VALUE]    Exclude devices with a matching attribute\n"
  83                "  -p --property-match=KEY=VALUE     Trigger devices with a matching property\n"
  84                "  -g --tag-match=KEY=VALUE          Trigger devices with a matching property\n"
  85                "  -y --sysname-match=NAME           Trigger devices with this /sys path\n"
  86                "     --name-match=NAME              Trigger devices with this /dev name\n"
  87                "  -b --parent-match=NAME            Trigger devices with that parent device\n"
  88                "  -w --settle                       Wait for the triggered events to complete\n"
  89                , program_invocation_short_name);
  90
  91         return 0;
  92 }
  93
  94 int trigger_main(int argc, char *argv[], void *userdata) {
  95         enum {
  96                 ARG_NAME = 0x100,
  97         };
  98
  99         static const struct option options[] = {
 100                 { "verbose",           no_argument,       NULL, 'v'      },
 101                 { "dry-run",           no_argument,       NULL, 'n'      },
 102                 { "type",              required_argument, NULL, 't'      },
 103                 { "action",            required_argument, NULL, 'c'      },
 104                 { "subsystem-match",   required_argument, NULL, 's'      },
 105                 { "subsystem-nomatch", required_argument, NULL, 'S'      },
 106                 { "attr-match",        required_argument, NULL, 'a'      },
 107                 { "attr-nomatch",      required_argument, NULL, 'A'      },
 108                 { "property-match",    required_argument, NULL, 'p'      },
 109                 { "tag-match",         required_argument, NULL, 'g'      },
 110                 { "sysname-match",     required_argument, NULL, 'y'      },
 111                 { "name-match",        required_argument, NULL, ARG_NAME },
 112                 { "parent-match",      required_argument, NULL, 'b'      },
 113                 { "settle",            no_argument,       NULL, 'w'      },
 114                 { "version",           no_argument,       NULL, 'V'      },
 115                 { "help",              no_argument,       NULL, 'h'      },
 116                 {}
 117         };
 118         enum {
 119                 TYPE_DEVICES,
 120                 TYPE_SUBSYSTEMS,
 121         } device_type = TYPE_DEVICES;
 122         const char *action = "change";
 123         _cleanup_(udev_enumerate_unrefp) struct udev_enumerate *udev_enumerate = NULL;
 124         _cleanup_(udev_monitor_unrefp) struct udev_monitor *udev_monitor = NULL;
 125         _cleanup_close_ int fd_ep = -1;
 126         int fd_udev = -1;
 127         struct epoll_event ep_udev;
 128         bool settle = false;
 129         _cleanup_set_free_free_ Set *settle_set = NULL;
 130         int c, r;
 131
 132         udev_enumerate = udev_enumerate_new(NULL);
 133         if (!udev_enumerate)
 134                 return -errno;
 135
 136         while ((c = getopt_long(argc, argv, "vnt:c:s:S:a:A:p:g:y:b:wVh", options, NULL)) >= 0) {
 137                 const char *key;
 138                 const char *val;
 139                 char buf[UTIL_PATH_SIZE];
 140
 141                 switch (c) {
 142                 case 'v':
 143                         verbose = 1;
 144                         break;
 145                 case 'n':
 146                         dry_run = 1;
 147                         break;
 148                 case 't':
 149                         if (streq(optarg, "devices"))
 150                                 device_type = TYPE_DEVICES;
 151                         else if (streq(optarg, "subsystems"))
 152                                 device_type = TYPE_SUBSYSTEMS;
 153                         else {
 154                                 log_error("unknown type --type=%s", optarg);
 155                                 return -EINVAL;
 156                         }
 157                         break;
 158                 case 'c':
 159                         if (STR_IN_SET(optarg, "add", "remove", "change"))
 160                                 action = optarg;
 161                         else {
 162                                 log_error("unknown action '%s'", optarg);
 163                                 return -EINVAL;
 164                         }
 165
 166                         break;
 167                 case 's':
 168                         r = udev_enumerate_add_match_subsystem(udev_enumerate, optarg);
 169                         if (r < 0)
 170                                 return log_error_errno(r, "could not add subsystem match '%s': %m", optarg);
 171                         break;
 172                 case 'S':
 173                         r = udev_enumerate_add_nomatch_subsystem(udev_enumerate, optarg);
 174                         if (r < 0)
 175                                 return log_error_errno(r, "could not add negative subsystem match '%s': %m", optarg);
 176                         break;
 177                 case 'a':
 178                         key = keyval(optarg, &val, buf, sizeof(buf));
 179                         r = udev_enumerate_add_match_sysattr(udev_enumerate, key, val);
 180                         if (r < 0)
 181                                 return log_error_errno(r, "could not add sysattr match '%s=%s': %m", key, val);
 182                         break;
 183                 case 'A':
 184                         key = keyval(optarg, &val, buf, sizeof(buf));
 185                         r = udev_enumerate_add_nomatch_sysattr(udev_enumerate, key, val);
 186                         if (r < 0)
 187                                 return log_error_errno(r, "could not add negative sysattr match '%s=%s': %m", key, val);
 188                         break;
 189                 case 'p':
 190                         key = keyval(optarg, &val, buf, sizeof(buf));
 191                         r = udev_enumerate_add_match_property(udev_enumerate, key, val);
 192                         if (r < 0)
 193                                 return log_error_errno(r, "could not add property match '%s=%s': %m", key, val);
 194                         break;
 195                 case 'g':
 196                         r = udev_enumerate_add_match_tag(udev_enumerate, optarg);
 197                         if (r < 0)
 198                                 return log_error_errno(r, "could not add tag match '%s': %m", optarg);
 199                         break;
 200                 case 'y':
 201                         r = udev_enumerate_add_match_sysname(udev_enumerate, optarg);
 202                         if (r < 0)
 203                                 return log_error_errno(r, "could not add sysname match '%s': %m", optarg);
 204                         break;
 205                 case 'b': {
 206                         _cleanup_(udev_device_unrefp) struct udev_device *dev;
 207
 208                         dev = find_device(optarg, "/sys");
 209                         if (!dev)
 210                                 return log_error_errno(errno, "unable to open the device '%s'", optarg);
 211
 212                         r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 213                         if (r < 0)
 214                                 return log_error_errno(r, "could not add parent match '%s': %m", optarg);
 215                         break;
 216                 }
 217                 case 'w':
 218                         settle = true;
 219                         break;
 220
 221                 case ARG_NAME: {
 222                         _cleanup_(udev_device_unrefp) struct udev_device *dev;
 223
 224                         dev = find_device(optarg, "/dev/");
 225                         if (!dev)
 226                                 return log_error_errno(errno, "unable to open the device '%s'", optarg);
 227
 228                         r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 229                         if (r < 0)
 230                                 return log_error_errno(r, "could not add parent match '%s': %m", optarg);
 231                         break;
 232                 }
 233
 234                 case 'V':
 235                         return version();
 236                 case 'h':
 237                         return help();
 238                 case '?':
 239                         return -EINVAL;
 240                 default:
 241                         assert_not_reached("Unknown option");
 242                 }
 243         }
 244
 245         for (; optind < argc; optind++) {
 246                 _cleanup_(udev_device_unrefp) struct udev_device *dev;
 247
 248                 dev = find_device(argv[optind], NULL);
 249                 if (!dev) {
 250                         log_error("unable to open the device '%s'", argv[optind]);
 251                         return -EINVAL;
 252                 }
 253
 254                 r = udev_enumerate_add_match_parent(udev_enumerate, dev);
 255                 if (r < 0)
 256                         return log_error_errno(r, "could not add tag match '%s': %m", optarg);
 257         }
 258
 259         if (settle) {
 260                 fd_ep = epoll_create1(EPOLL_CLOEXEC);
 261                 if (fd_ep < 0)
 262                         return log_error_errno(errno, "error creating epoll fd: %m");
 263
 264                 udev_monitor = udev_monitor_new_from_netlink(NULL, "udev");
 265                 if (!udev_monitor)
 266                         return log_error_errno(errno, "error: unable to create netlink socket: %m");
 267
 268                 fd_udev = udev_monitor_get_fd(udev_monitor);
 269
 270                 r = udev_monitor_enable_receiving(udev_monitor);
 271                 if (r < 0)
 272                         return log_error_errno(r, "error: unable to subscribe to udev events: %m");
 273
 274                 ep_udev = (struct epoll_event) { .events = EPOLLIN, .data.fd = fd_udev };
 275                 if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_udev, &ep_udev) < 0)
 276                         return log_error_errno(errno, "fail to add fd to epoll: %m");
 277
 278                 settle_set = set_new(&string_hash_ops);
 279                 if (!settle_set)
 280                         return log_oom();
 281         }
 282
 283         switch (device_type) {
 284         case TYPE_SUBSYSTEMS:
 285                 udev_enumerate_scan_subsystems(udev_enumerate);
 286                 break;
 287         case TYPE_DEVICES:
 288                 udev_enumerate_scan_devices(udev_enumerate);
 289                 break;
 290         default:
 291                 assert_not_reached("device_type");
 292         }
 293         r = exec_list(udev_enumerate, action, settle_set);
 294         if (r < 0)
 295                 return r;
 296
 297         while (!set_isempty(settle_set)) {
 298                 int fdcount;
 299                 struct epoll_event ev[4];
 300                 int i;
 301
 302                 fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1);
 303                 if (fdcount < 0) {
 304                         if (errno != EINTR)
 305                                 log_error_errno(errno, "error receiving uevent message: %m");
 306                         continue;
 307                 }
 308
 309                 for (i = 0; i < fdcount; i++) {
 310                         if (ev[i].data.fd == fd_udev && ev[i].events & EPOLLIN) {
 311                                 _cleanup_(udev_device_unrefp) struct udev_device *device;
 312                                 const char *syspath = NULL;
 313
 314                                 device = udev_monitor_receive_device(udev_monitor);
 315                                 if (!device)
 316                                         continue;
 317
 318                                 syspath = udev_device_get_syspath(device);
 319                                 if (verbose)
 320                                         printf("settle %s\n", syspath);
 321                                 if (!set_remove(settle_set, syspath))
 322                                         log_debug("Got epoll event on syspath %s not present in syspath set", syspath);
 323                         }
 324                 }
 325         }
 326
 327         return 0;
 328 }