git.ozlabs.org Git - petitboot/blob - devices/udev-helper.c

   1
   2 #define _GNU_SOURCE
   3
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <stdarg.h>
   7 #include <stdint.h>
   8 #include <unistd.h>
   9 #include <sys/types.h>
  10 #include <sys/stat.h>
  11 #include <sys/socket.h>
  12 #include <sys/wait.h>
  13 #include <sys/un.h>
  14 #include <fcntl.h>
  15 #include <errno.h>
  16 #include <string.h>
  17 #include <asm/byteorder.h>
  18 #include <linux/cdrom.h>
  19 #include <sys/ioctl.h>
  20
  21 #include "parser.h"
  22 #include "petitboot-paths.h"
  23
  24 /* Define below to operate without the frontend */
  25 #undef USE_FAKE_SOCKET
  26
  27 /* Delay in seconds between polling of removable devices */
  28 #define REMOVABLE_SLEEP_DELAY   2
  29
  30 static FILE *logf;
  31 static int sock;
  32
  33 void pb_log(const char *fmt, ...)
  34 {
  35         va_list ap;
  36
  37         va_start(ap, fmt);
  38         vfprintf(logf, fmt, ap);
  39         va_end(ap);
  40 }
  41
  42 static void print_boot_option(const struct boot_option *opt)
  43 {
  44         pb_log("\tname: %s\n", opt->name);
  45         pb_log("\tdescription: %s\n", opt->description);
  46         pb_log("\tboot_image: %s\n", opt->boot_image_file);
  47         pb_log("\tinitrd: %s\n", opt->initrd_file);
  48         pb_log("\tboot_args: %s\n", opt->boot_args);
  49
  50 }
  51
  52 static void print_device(const struct device *dev)
  53 {
  54         pb_log("\tid: %s\n", dev->id);
  55         pb_log("\tname: %s\n", dev->name);
  56         pb_log("\tdescription: %s\n", dev->description);
  57         pb_log("\tboot_image: %s\n", dev->icon_file);
  58 }
  59
  60 static int write_action(int fd, enum device_action action)
  61 {
  62         uint8_t action_buf = action;
  63         return write(fd, &action_buf, sizeof(action_buf)) != sizeof(action_buf);
  64 }
  65
  66 static int write_string(int fd, const char *str)
  67 {
  68         int len, pos = 0;
  69         uint32_t len_buf;
  70
  71         if (!str) {
  72                 len_buf = 0;
  73                 if (write(fd, &len_buf, sizeof(len_buf)) != sizeof(len_buf)) {
  74                         pb_log("write failed: %s\n", strerror(errno));
  75                         return -1;
  76                 }
  77                 return 0;
  78         }
  79
  80         len = strlen(str);
  81         if (len > (1ull << (sizeof(len_buf) * 8 - 1))) {
  82                 pb_log("string too large\n");
  83                 return -1;
  84         }
  85
  86         len_buf = __cpu_to_be32(len);
  87         if (write(fd, &len_buf, sizeof(len_buf)) != sizeof(len_buf)) {
  88                 pb_log("write failed: %s\n", strerror(errno));
  89                 return -1;
  90         }
  91
  92         while (pos < len) {
  93                 int rc = write(fd, str, len - pos);
  94                 if (rc <= 0) {
  95                         pb_log("write failed: %s\n", strerror(errno));
  96                         return -1;
  97                 }
  98                 pos += rc;
  99                 str += rc;
 100         }
 101
 102         return 0;
 103 }
 104
 105 int add_device(const struct device *dev)
 106 {
 107         int rc;
 108
 109         pb_log("device added:\n");
 110         print_device(dev);
 111         rc = write_action(sock, DEV_ACTION_ADD_DEVICE) ||
 112                 write_string(sock, dev->id) ||
 113                 write_string(sock, dev->name) ||
 114                 write_string(sock, dev->description) ||
 115                 write_string(sock, dev->icon_file);
 116
 117         if (rc)
 118                 pb_log("error writing device %s to socket\n", dev->name);
 119
 120         return rc;
 121 }
 122
 123 int add_boot_option(const struct boot_option *opt)
 124 {
 125         int rc;
 126
 127         pb_log("boot option added:\n");
 128         print_boot_option(opt);
 129
 130         rc = write_action(sock, DEV_ACTION_ADD_OPTION) ||
 131                 write_string(sock, opt->id) ||
 132                 write_string(sock, opt->name) ||
 133                 write_string(sock, opt->description) ||
 134                 write_string(sock, opt->icon_file) ||
 135                 write_string(sock, opt->boot_image_file) ||
 136                 write_string(sock, opt->initrd_file) ||
 137                 write_string(sock, opt->boot_args);
 138
 139         if (rc)
 140                 pb_log("error writing boot option %s to socket\n", opt->name);
 141
 142         return rc;
 143 }
 144
 145 int remove_device(const char *dev_path)
 146 {
 147         return write_action(sock, DEV_ACTION_REMOVE_DEVICE) ||
 148                 write_string(sock, dev_path);
 149 }
 150
 151 int connect_to_socket()
 152 {
 153 #ifndef USE_FAKE_SOCKET
 154         int fd;
 155         struct sockaddr_un addr;
 156
 157         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 158         if (fd == -1) {
 159                 pb_log("can't create socket: %s\n", strerror(errno));
 160                 return -1;
 161         }
 162
 163         addr.sun_family = AF_UNIX;
 164         strcpy(addr.sun_path, PBOOT_DEVICE_SOCKET);
 165
 166         if (connect(fd, (struct sockaddr *)&addr, sizeof(addr))) {
 167                 pb_log("can't connect to %s: %s\n",
 168                                 addr.sun_path, strerror(errno));
 169                 return -1;
 170         }
 171         sock = fd;
 172
 173         return 0;
 174 #else
 175         int fd;
 176         fd = open("./debug_socket", O_WRONLY | O_CREAT, 0640);
 177         if (fd < 0) {
 178                 pb_log("can't create output file: %s\n", strerror(errno));
 179                 return -1;
 180         }
 181         sock = fd;
 182         return 0;
 183 #endif
 184 }
 185
 186 struct device_map {
 187         char *dev, *mnt;
 188 };
 189
 190 #define DEVICE_MAP_SIZE 32
 191 static struct device_map device_map[DEVICE_MAP_SIZE];
 192
 193 const char *mountpoint_for_device(const char *dev_path)
 194 {
 195         int i;
 196         const char *basename;
 197
 198         /* shorten '/dev/foo' to 'foo' */
 199         basename = strrchr(dev_path, '/');
 200         if (basename)
 201                 basename++;
 202         else
 203                 basename = dev_path;
 204
 205         /* check existing entries in the map */
 206         for (i = 0; (i < DEVICE_MAP_SIZE) && device_map[i].dev; i++)
 207                 if (!strcmp(device_map[i].dev, basename))
 208                         return device_map[i].mnt;
 209
 210         if (i == DEVICE_MAP_SIZE)
 211                 return NULL;
 212
 213         device_map[i].dev = strdup(dev_path);
 214         asprintf(&device_map[i].mnt, "%s/%s", TMP_DIR, basename);
 215         return device_map[i].mnt;
 216 }
 217
 218 /**
 219  * Resolve a path given in a config file, to a path in the local filesystem.
 220  * Paths may be of the form:
 221  *  device:path (eg /dev/sda:/boot/vmlinux)
 222  *
 223  * or just a path:
 224  *  /boot/vmlinux
 225  * - in this case, the default mountpoint is used.
 226  *
 227  * Returns a newly-allocated string containing a full path to the file in path
 228  */
 229 char *resolve_path(const char *path, const char *default_mountpoint)
 230 {
 231         char *ret;
 232         const char *devpath, *sep;
 233
 234         sep = strchr(path, ':');
 235         if (!sep) {
 236                 devpath = default_mountpoint;
 237                 asprintf(&ret, "%s/%s", devpath, path);
 238         } else {
 239                 /* copy just the device name into tmp */
 240                 char *dev = strndup(path, sep - path);
 241                 devpath = mountpoint_for_device(dev);
 242                 asprintf(&ret, "%s/%s", devpath, sep + 1);
 243                 free(dev);
 244         }
 245
 246         return ret;
 247 }
 248
 249 int mount_device(const char *dev_path)
 250 {
 251         const char *dir;
 252         int pid, status, rc = -1;
 253         struct stat statbuf;
 254
 255         dir = mountpoint_for_device(dev_path);
 256
 257         if (stat(dir, &statbuf)) {
 258                 if (mkdir(dir, 0755)) {
 259                         pb_log("couldn't create directory %s: %s\n",
 260                                         dir, strerror(errno));
 261                         goto out;
 262                 }
 263         } else {
 264                 if (!S_ISDIR(statbuf.st_mode)) {
 265                         pb_log("mountpoint %s exists, "
 266                                         "but isn't a directory\n", dir);
 267                         goto out;
 268                 }
 269         }
 270
 271
 272         pid = fork();
 273         if (pid == -1) {
 274                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 275                 goto out;
 276         }
 277
 278         if (pid == 0) {
 279                 execl(MOUNT_BIN, MOUNT_BIN, dev_path, dir, "-o", "ro", NULL);
 280                 exit(EXIT_FAILURE);
 281         }
 282
 283         if (waitpid(pid, &status, 0) == -1) {
 284                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 285                                 strerror(errno));
 286                 goto out;
 287         }
 288
 289         if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
 290                 rc = 0;
 291
 292 out:
 293         return rc;
 294 }
 295
 296 static int unmount_device(const char *dev_path)
 297 {
 298         int pid, status, rc;
 299
 300         pid = fork();
 301
 302         if (pid == -1) {
 303                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 304                 return -1;
 305         }
 306
 307         if (pid == 0) {
 308                 execl(UMOUNT_BIN, UMOUNT_BIN, dev_path, NULL);
 309                 exit(EXIT_FAILURE);
 310         }
 311
 312         if (waitpid(pid, &status, 0) == -1) {
 313                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 314                                 strerror(errno));
 315                 return -1;
 316         }
 317
 318         rc = !WIFEXITED(status) || WEXITSTATUS(status) != 0;
 319
 320         return rc;
 321 }
 322
 323 static const struct device fake_boot_devices[] =
 324 {
 325         {
 326                 .id             = "fakeDisk0",
 327                 .name           = "Hard Disk",
 328                 .icon_file      = artwork_pathname("hdd.png"),
 329         },
 330         {
 331                 .id             = "fakeDisk1",
 332                 .name           = "PinkCat Linux CD",
 333                 .icon_file      = artwork_pathname("cdrom.png"),
 334         }
 335 };
 336
 337 static const struct boot_option fake_boot_options[] =
 338 {
 339         {
 340                 .id             = "fakeBoot0",
 341                 .name           = "Bloobuntu Linux",
 342                 .description    = "Boot Bloobuntu Linux",
 343                 .icon_file      = artwork_pathname("hdd.png"),
 344         },
 345         {
 346                 .id             = "fakeBoot1",
 347                 .name           = "Pendora Gore 6",
 348                 .description    = "Boot Pendora Gora 6",
 349                 .icon_file      = artwork_pathname("hdd.png"),
 350         },
 351         {
 352                 .id             = "fakeBoot2",
 353                 .name           = "Genfoo Minux",
 354                 .description    = "Boot Genfoo Minux",
 355                 .icon_file      = artwork_pathname("hdd.png"),
 356         },
 357         {
 358                 .id             = "fakeBoot3",
 359                 .name           = "PinkCat Linux",
 360                 .description    = "Install PinkCat Linux - Graphical install",
 361                 .icon_file      = artwork_pathname("cdrom.png"),
 362         },
 363 };
 364
 365 enum generic_icon_type guess_device_type(void)
 366 {
 367         const char *type = getenv("ID_TYPE");
 368         const char *bus = getenv("ID_BUS");
 369         if (type && streq(type, "cd"))
 370                 return ICON_TYPE_OPTICAL;
 371         if (!bus)
 372                 return ICON_TYPE_UNKNOWN;
 373         if (streq(bus, "usb"))
 374                 return ICON_TYPE_USB;
 375         if (streq(bus, "ata") || streq(bus, "scsi"))
 376                 return ICON_TYPE_DISK;
 377         return ICON_TYPE_UNKNOWN;
 378 }
 379
 380
 381 static int is_removable_device(const char *sysfs_path)
 382 {
 383         char full_path[PATH_MAX];
 384         char buf[80];
 385         int fd, buf_len;
 386
 387         sprintf(full_path, "/sys/%s/removable", sysfs_path);
 388         fd = open(full_path, O_RDONLY);
 389         pb_log(" -> removable check on %s, fd=%d\n", full_path, fd);
 390         if (fd < 0)
 391                 return 0;
 392         buf_len = read(fd, buf, 79);
 393         close(fd);
 394         if (buf_len < 0)
 395                 return 0;
 396         buf[buf_len] = 0;
 397         return strtol(buf, NULL, 10);
 398 }
 399
 400 static int is_ignored_device(const char *devname)
 401 {
 402         static const char *ignored_devices[] = { "/dev/ram", NULL };
 403         const char **dev;
 404
 405         for (dev = ignored_devices; *dev; dev++)
 406                 if (!strncmp(devname, *dev, strlen(*dev)))
 407                         return 1;
 408
 409         return 0;
 410 }
 411
 412 static int found_new_device(const char *dev_path)
 413 {
 414         const char *mountpoint = mountpoint_for_device(dev_path);
 415
 416         if (mount_device(dev_path)) {
 417                 pb_log("failed to mount %s\n", dev_path);
 418                 return EXIT_FAILURE;
 419         }
 420
 421         pb_log("mounted %s at %s\n", dev_path, mountpoint);
 422
 423         iterate_parsers(dev_path, mountpoint);
 424
 425         return EXIT_SUCCESS;
 426 }
 427
 428 static void detach_and_sleep(int sec)
 429 {
 430         static int forked = 0;
 431         int rc = 0;
 432
 433         if (sec <= 0)
 434                 return;
 435
 436         if (!forked) {
 437                 pb_log("running in background...");
 438                 rc = fork();
 439                 forked = 1;
 440         }
 441
 442         if (rc == 0) {
 443                 sleep(sec);
 444
 445         } else if (rc == -1) {
 446                 perror("fork()");
 447                 exit(EXIT_FAILURE);
 448         } else {
 449                 exit(EXIT_SUCCESS);
 450         }
 451 }
 452
 453 static int poll_device_plug(const char *dev_path,
 454                             int *optical)
 455 {
 456         int rc, fd;
 457
 458         /* Polling loop for optical drive */
 459         for (; (*optical) != 0; ) {
 460                 pb_log("poll for optical drive insertion ...\n");
 461                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 462                 if (fd < 0)
 463                         return EXIT_FAILURE;
 464                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 465                 close(fd);
 466                 if (rc == -1) {
 467                         pb_log("not an optical drive, fallback...\n");
 468                         break;
 469                 }
 470                 *optical = 1;
 471                 if (rc == CDS_DISC_OK)
 472                         return EXIT_SUCCESS;
 473
 474                 pb_log("no... waiting\n");
 475                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 476         }
 477
 478         /* Fall back to bare open() */
 479         *optical = 0;
 480         for (;;) {
 481                 pb_log("poll for non-optical drive insertion ...\n");
 482                 fd = open(dev_path, O_RDONLY);
 483                 if (fd < 0 && errno != ENOMEDIUM)
 484                         return EXIT_FAILURE;
 485                 close(fd);
 486                 if (fd >= 0)
 487                         return EXIT_SUCCESS;
 488                 pb_log("no... waiting\n");
 489                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 490         }
 491 }
 492
 493 static int poll_device_unplug(const char *dev_path, int optical)
 494 {
 495         int rc, fd;
 496
 497         for (;optical;) {
 498                 pb_log("poll for optical drive removal ...\n");
 499                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 500                 if (fd < 0)
 501                         return EXIT_FAILURE;
 502                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 503                 close(fd);
 504                 if (rc != CDS_DISC_OK)
 505                         return EXIT_SUCCESS;
 506                 pb_log("no... waiting\n");
 507                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 508         }
 509
 510         /* Fall back to bare open() */
 511         for (;;) {
 512                 pb_log("poll for non-optical drive removal ...\n");
 513                 fd = open(dev_path, O_RDONLY);
 514                 if (fd < 0 && errno != ENOMEDIUM)
 515                         return EXIT_FAILURE;
 516                 close(fd);
 517                 if (fd < 0)
 518                         return EXIT_SUCCESS;
 519                 pb_log("no... waiting\n");
 520                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 521         }
 522 }
 523
 524 static int poll_removable_device(const char *sysfs_path,
 525                                  const char *dev_path)
 526 {
 527         int rc, mounted, optical = -1;
 528
 529         for (;;) {
 530                 rc = poll_device_plug(dev_path, &optical);
 531                 if (rc == EXIT_FAILURE)
 532                         return rc;
 533                 rc = found_new_device(dev_path);
 534                 mounted = (rc == EXIT_SUCCESS);
 535
 536                 poll_device_unplug(dev_path, optical);
 537
 538                 remove_device(dev_path);
 539
 540                 /* Unmount it repeatedly, if needs be */
 541                 while (mounted && !unmount_device(dev_path))
 542                         ;
 543                 detach_and_sleep(1);
 544         }
 545 }
 546
 547 int main(int argc, char **argv)
 548 {
 549         char *dev_path, *action;
 550         int rc;
 551
 552         action = getenv("ACTION");
 553
 554         logf = fopen("/var/log/petitboot-udev-helpers.log", "a");
 555         if (!logf)
 556                 logf = stdout;
 557         pb_log("%d started\n", getpid());
 558         rc = EXIT_SUCCESS;
 559
 560         if (!action) {
 561                 pb_log("missing environment?\n");
 562                 return EXIT_FAILURE;
 563         }
 564
 565         if (connect_to_socket())
 566                 return EXIT_FAILURE;
 567
 568         if (streq(action, "fake")) {
 569                 pb_log("fake mode");
 570
 571                 add_device(&fake_boot_devices[0]);
 572                 add_boot_option(&fake_boot_options[0]);
 573                 add_boot_option(&fake_boot_options[1]);
 574                 add_boot_option(&fake_boot_options[2]);
 575                 add_device(&fake_boot_devices[1]);
 576                 add_boot_option(&fake_boot_options[3]);
 577
 578                 return EXIT_SUCCESS;
 579         }
 580
 581         dev_path = getenv("DEVNAME");
 582         if (!dev_path) {
 583                 pb_log("missing environment?\n");
 584                 return EXIT_FAILURE;
 585         }
 586
 587         if (is_ignored_device(dev_path))
 588                 return EXIT_SUCCESS;
 589
 590         if (streq(action, "add")) {
 591                 char *sysfs_path = getenv("DEVPATH");
 592                 if (sysfs_path && is_removable_device(sysfs_path))
 593                         rc = poll_removable_device(sysfs_path, dev_path);
 594                 else
 595                         rc = found_new_device(dev_path);
 596         } else if (streq(action, "remove")) {
 597                 pb_log("%s removed\n", dev_path);
 598
 599                 remove_device(dev_path);
 600
 601                 /* Unmount it repeatedly, if needs be */
 602                 while (!unmount_device(dev_path))
 603                         ;
 604
 605         } else {
 606                 pb_log("invalid action '%s'\n", action);
 607                 rc = EXIT_FAILURE;
 608         }
 609         return rc;
 610 }