git.ozlabs.org Git - petitboot/blob - devices/petitboot-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 "paths.h"
  23 #include "petitboot-paths.h"
  24
  25 /* Define below to operate without the frontend */
  26 #undef USE_FAKE_SOCKET
  27
  28 /* Delay in seconds between polling of removable devices */
  29 #define REMOVABLE_SLEEP_DELAY   2
  30
  31 static FILE *logf;
  32 static int sock;
  33
  34 void pb_log(const char *fmt, ...)
  35 {
  36         va_list ap;
  37
  38         va_start(ap, fmt);
  39         vfprintf(logf, fmt, ap);
  40         va_end(ap);
  41 }
  42
  43 static void print_boot_option(const struct boot_option *opt)
  44 {
  45         pb_log("\tname: %s\n", opt->name);
  46         pb_log("\tdescription: %s\n", opt->description);
  47         pb_log("\tboot_image: %s\n", opt->boot_image_file);
  48         pb_log("\tinitrd: %s\n", opt->initrd_file);
  49         pb_log("\tboot_args: %s\n", opt->boot_args);
  50
  51 }
  52
  53 static void print_device(const struct device *dev)
  54 {
  55         pb_log("\tid: %s\n", dev->id);
  56         pb_log("\tname: %s\n", dev->name);
  57         pb_log("\tdescription: %s\n", dev->description);
  58         pb_log("\tboot_image: %s\n", dev->icon_file);
  59 }
  60
  61 static int write_action(int fd, enum device_action action)
  62 {
  63         uint8_t action_buf = action;
  64         return write(fd, &action_buf, sizeof(action_buf)) != sizeof(action_buf);
  65 }
  66
  67 static int write_string(int fd, const char *str)
  68 {
  69         int len, pos = 0;
  70         uint32_t len_buf;
  71
  72         if (!str) {
  73                 len_buf = 0;
  74                 if (write(fd, &len_buf, sizeof(len_buf)) != sizeof(len_buf)) {
  75                         pb_log("write failed: %s\n", strerror(errno));
  76                         return -1;
  77                 }
  78                 return 0;
  79         }
  80
  81         len = strlen(str);
  82         if (len > (1ull << (sizeof(len_buf) * 8 - 1))) {
  83                 pb_log("string too large\n");
  84                 return -1;
  85         }
  86
  87         len_buf = __cpu_to_be32(len);
  88         if (write(fd, &len_buf, sizeof(len_buf)) != sizeof(len_buf)) {
  89                 pb_log("write failed: %s\n", strerror(errno));
  90                 return -1;
  91         }
  92
  93         while (pos < len) {
  94                 int rc = write(fd, str, len - pos);
  95                 if (rc <= 0) {
  96                         pb_log("write failed: %s\n", strerror(errno));
  97                         return -1;
  98                 }
  99                 pos += rc;
 100                 str += rc;
 101         }
 102
 103         return 0;
 104 }
 105
 106 int add_device(const struct device *dev)
 107 {
 108         int rc;
 109
 110         pb_log("device added:\n");
 111         print_device(dev);
 112         rc = write_action(sock, DEV_ACTION_ADD_DEVICE) ||
 113                 write_string(sock, dev->id) ||
 114                 write_string(sock, dev->name) ||
 115                 write_string(sock, dev->description) ||
 116                 write_string(sock, dev->icon_file);
 117
 118         if (rc)
 119                 pb_log("error writing device %s to socket\n", dev->name);
 120
 121         return rc;
 122 }
 123
 124 int add_boot_option(const struct boot_option *opt)
 125 {
 126         int rc;
 127
 128         pb_log("boot option added:\n");
 129         print_boot_option(opt);
 130
 131         rc = write_action(sock, DEV_ACTION_ADD_OPTION) ||
 132                 write_string(sock, opt->id) ||
 133                 write_string(sock, opt->name) ||
 134                 write_string(sock, opt->description) ||
 135                 write_string(sock, opt->icon_file) ||
 136                 write_string(sock, opt->boot_image_file) ||
 137                 write_string(sock, opt->initrd_file) ||
 138                 write_string(sock, opt->boot_args);
 139
 140         if (rc)
 141                 pb_log("error writing boot option %s to socket\n", opt->name);
 142
 143         return rc;
 144 }
 145
 146 int remove_device(const char *dev_path)
 147 {
 148         return write_action(sock, DEV_ACTION_REMOVE_DEVICE) ||
 149                 write_string(sock, dev_path);
 150 }
 151
 152 int connect_to_socket()
 153 {
 154 #ifndef USE_FAKE_SOCKET
 155         int fd;
 156         struct sockaddr_un addr;
 157
 158         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 159         if (fd == -1) {
 160                 pb_log("can't create socket: %s\n", strerror(errno));
 161                 return -1;
 162         }
 163
 164         addr.sun_family = AF_UNIX;
 165         strcpy(addr.sun_path, PBOOT_DEVICE_SOCKET);
 166
 167         if (connect(fd, (struct sockaddr *)&addr, sizeof(addr))) {
 168                 pb_log("can't connect to %s: %s\n",
 169                                 addr.sun_path, strerror(errno));
 170                 return -1;
 171         }
 172         sock = fd;
 173
 174         return 0;
 175 #else
 176         int fd;
 177         fd = open("./debug_socket", O_WRONLY | O_CREAT, 0640);
 178         if (fd < 0) {
 179                 pb_log("can't create output file: %s\n", strerror(errno));
 180                 return -1;
 181         }
 182         sock = fd;
 183         return 0;
 184 #endif
 185 }
 186
 187 static int mkdir_recursive(const char *dir)
 188 {
 189         char *str, *sep;
 190         int mode = 0755;
 191         struct stat statbuf;
 192
 193         pb_log("mkdir_recursive(%s)\n", dir);
 194
 195         if (!*dir)
 196                 return 0;
 197
 198         if (!stat(dir, &statbuf)) {
 199                 if (!S_ISDIR(statbuf.st_mode)) {
 200                         pb_log("%s: %s exists, but isn't a directory\n",
 201                                         __func__, dir);
 202                         return -1;
 203                 }
 204                 return 0;
 205         }
 206
 207         str = strdup(dir);
 208         sep = strchr(*str == '/' ? str + 1 : str, '/');
 209
 210         while (1) {
 211
 212                 /* terminate the path at sep */
 213                 if (sep)
 214                         *sep = '\0';
 215                 pb_log("mkdir(%s)\n", str);
 216
 217                 if (mkdir(str, mode) && errno != EEXIST) {
 218                         pb_log("mkdir(%s): %s\n", str, strerror(errno));
 219                         return -1;
 220                 }
 221
 222                 if (!sep)
 223                         break;
 224
 225                 /* reset dir to the full path */
 226                 strcpy(str, dir);
 227                 sep = strchr(sep + 1, '/');
 228         }
 229
 230         free(str);
 231
 232         return 0;
 233 }
 234
 235 static void setup_device_links(const char *device)
 236 {
 237         struct link {
 238                 char *env, *dir;
 239         } *link, links[] = {
 240                 {
 241                         .env = "ID_FS_UUID",
 242                         .dir = "disk/by-uuid"
 243                 },
 244                 {
 245                         .env = "ID_FS_LABEL",
 246                         .dir = "disk/by-label"
 247                 },
 248                 {
 249                         .env = NULL
 250                 }
 251         };
 252
 253         for (link = links; link->env; link++) {
 254                 char *value, *dir, *path;
 255
 256                 value = getenv(link->env);
 257                 if (!value)
 258                         continue;
 259
 260                 value = encode_label(value);
 261                 dir = join_paths(TMP_DIR, link->dir);
 262                 path = join_paths(dir, value);
 263
 264                 if (!mkdir_recursive(dir)) {
 265                         unlink(path);
 266                         if (symlink(mountpoint_for_device(device), path)) {
 267                                 pb_log("symlink(%s): %s\n",
 268                                                 path, strerror(errno));
 269                         }
 270                 }
 271
 272                 free(path);
 273                 free(dir);
 274                 free(value);
 275         }
 276 }
 277
 278 int mount_device(const char *dev_path)
 279 {
 280         const char *dir;
 281         int pid, status, rc = -1;
 282         struct stat statbuf;
 283
 284         dir = mountpoint_for_device(dev_path);
 285
 286         if (stat(dir, &statbuf)) {
 287                 if (mkdir(dir, 0755)) {
 288                         pb_log("couldn't create directory %s: %s\n",
 289                                         dir, strerror(errno));
 290                         goto out;
 291                 }
 292         } else {
 293                 if (!S_ISDIR(statbuf.st_mode)) {
 294                         pb_log("mountpoint %s exists, "
 295                                         "but isn't a directory\n", dir);
 296                         goto out;
 297                 }
 298         }
 299
 300
 301         pid = fork();
 302         if (pid == -1) {
 303                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 304                 goto out;
 305         }
 306
 307         if (pid == 0) {
 308                 execl(MOUNT_BIN, MOUNT_BIN, dev_path, dir, "-o", "ro", 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                 goto out;
 316         }
 317
 318         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
 319                 setup_device_links(dev_path);
 320                 rc = 0;
 321         }
 322
 323 out:
 324         return rc;
 325 }
 326
 327 static int unmount_device(const char *dev_path)
 328 {
 329         int pid, status, rc;
 330
 331         pid = fork();
 332
 333         if (pid == -1) {
 334                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 335                 return -1;
 336         }
 337
 338         if (pid == 0) {
 339                 execl(UMOUNT_BIN, UMOUNT_BIN, dev_path, NULL);
 340                 exit(EXIT_FAILURE);
 341         }
 342
 343         if (waitpid(pid, &status, 0) == -1) {
 344                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 345                                 strerror(errno));
 346                 return -1;
 347         }
 348
 349         rc = !WIFEXITED(status) || WEXITSTATUS(status) != 0;
 350
 351         return rc;
 352 }
 353
 354 static const struct device fake_boot_devices[] =
 355 {
 356         {
 357                 .id             = "fakeDisk0",
 358                 .name           = "Hard Disk",
 359                 .icon_file      = artwork_pathname("hdd.png"),
 360         },
 361         {
 362                 .id             = "fakeDisk1",
 363                 .name           = "PinkCat Linux CD",
 364                 .icon_file      = artwork_pathname("cdrom.png"),
 365         }
 366 };
 367
 368 static const struct boot_option fake_boot_options[] =
 369 {
 370         {
 371                 .id             = "fakeBoot0",
 372                 .name           = "Bloobuntu Linux",
 373                 .description    = "Boot Bloobuntu Linux",
 374                 .icon_file      = artwork_pathname("hdd.png"),
 375         },
 376         {
 377                 .id             = "fakeBoot1",
 378                 .name           = "Pendora Gore 6",
 379                 .description    = "Boot Pendora Gora 6",
 380                 .icon_file      = artwork_pathname("hdd.png"),
 381         },
 382         {
 383                 .id             = "fakeBoot2",
 384                 .name           = "Genfoo Minux",
 385                 .description    = "Boot Genfoo Minux",
 386                 .icon_file      = artwork_pathname("hdd.png"),
 387         },
 388         {
 389                 .id             = "fakeBoot3",
 390                 .name           = "PinkCat Linux",
 391                 .description    = "Install PinkCat Linux - Graphical install",
 392                 .icon_file      = artwork_pathname("cdrom.png"),
 393         },
 394 };
 395
 396 enum generic_icon_type guess_device_type(void)
 397 {
 398         const char *type = getenv("ID_TYPE");
 399         const char *bus = getenv("ID_BUS");
 400         if (type && streq(type, "cd"))
 401                 return ICON_TYPE_OPTICAL;
 402         if (!bus)
 403                 return ICON_TYPE_UNKNOWN;
 404         if (streq(bus, "usb"))
 405                 return ICON_TYPE_USB;
 406         if (streq(bus, "ata") || streq(bus, "scsi"))
 407                 return ICON_TYPE_DISK;
 408         return ICON_TYPE_UNKNOWN;
 409 }
 410
 411
 412 static int is_removable_device(const char *sysfs_path)
 413 {
 414         char full_path[PATH_MAX];
 415         char buf[80];
 416         int fd, buf_len;
 417
 418         sprintf(full_path, "/sys/%s/removable", sysfs_path);
 419         fd = open(full_path, O_RDONLY);
 420         pb_log(" -> removable check on %s, fd=%d\n", full_path, fd);
 421         if (fd < 0)
 422                 return 0;
 423         buf_len = read(fd, buf, 79);
 424         close(fd);
 425         if (buf_len < 0)
 426                 return 0;
 427         buf[buf_len] = 0;
 428         return strtol(buf, NULL, 10);
 429 }
 430
 431 static int is_ignored_device(const char *devname)
 432 {
 433         static const char *ignored_devices[] =
 434                 { "/dev/ram", "/dev/loop", NULL };
 435         const char **dev;
 436
 437         for (dev = ignored_devices; *dev; dev++)
 438                 if (!strncmp(devname, *dev, strlen(*dev)))
 439                         return 1;
 440
 441         return 0;
 442 }
 443
 444 static int found_new_device(const char *dev_path)
 445 {
 446         const char *mountpoint = mountpoint_for_device(dev_path);
 447
 448         if (mount_device(dev_path)) {
 449                 pb_log("failed to mount %s\n", dev_path);
 450                 return EXIT_FAILURE;
 451         }
 452
 453         pb_log("mounted %s at %s\n", dev_path, mountpoint);
 454
 455         iterate_parsers(dev_path, mountpoint);
 456
 457         return EXIT_SUCCESS;
 458 }
 459
 460 static void detach_and_sleep(int sec)
 461 {
 462         static int forked = 0;
 463         int rc = 0;
 464
 465         if (sec <= 0)
 466                 return;
 467
 468         if (!forked) {
 469                 pb_log("running in background...");
 470                 rc = fork();
 471                 forked = 1;
 472         }
 473
 474         if (rc == 0) {
 475                 sleep(sec);
 476
 477         } else if (rc == -1) {
 478                 perror("fork()");
 479                 exit(EXIT_FAILURE);
 480         } else {
 481                 exit(EXIT_SUCCESS);
 482         }
 483 }
 484
 485 static int poll_device_plug(const char *dev_path,
 486                             int *optical)
 487 {
 488         int rc, fd;
 489
 490         /* Polling loop for optical drive */
 491         for (; (*optical) != 0; ) {
 492                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 493                 if (fd < 0)
 494                         return EXIT_FAILURE;
 495                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 496                 close(fd);
 497                 if (rc == -1)
 498                         break;
 499
 500                 *optical = 1;
 501                 if (rc == CDS_DISC_OK)
 502                         return EXIT_SUCCESS;
 503
 504                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 505         }
 506
 507         /* Fall back to bare open() */
 508         *optical = 0;
 509         for (;;) {
 510                 fd = open(dev_path, O_RDONLY);
 511                 if (fd < 0 && errno != ENOMEDIUM)
 512                         return EXIT_FAILURE;
 513                 close(fd);
 514                 if (fd >= 0)
 515                         return EXIT_SUCCESS;
 516                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 517         }
 518 }
 519
 520 static int poll_device_unplug(const char *dev_path, int optical)
 521 {
 522         int rc, fd;
 523
 524         for (;optical;) {
 525                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 526                 if (fd < 0)
 527                         return EXIT_FAILURE;
 528                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 529                 close(fd);
 530                 if (rc != CDS_DISC_OK)
 531                         return EXIT_SUCCESS;
 532                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 533         }
 534
 535         /* Fall back to bare open() */
 536         for (;;) {
 537                 fd = open(dev_path, O_RDONLY);
 538                 if (fd < 0 && errno != ENOMEDIUM)
 539                         return EXIT_FAILURE;
 540                 close(fd);
 541                 if (fd < 0)
 542                         return EXIT_SUCCESS;
 543                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 544         }
 545 }
 546
 547 static int poll_removable_device(const char *sysfs_path,
 548                                  const char *dev_path)
 549 {
 550         int rc, mounted, optical = -1;
 551
 552         for (;;) {
 553                 rc = poll_device_plug(dev_path, &optical);
 554                 if (rc == EXIT_FAILURE)
 555                         return rc;
 556                 rc = found_new_device(dev_path);
 557                 mounted = (rc == EXIT_SUCCESS);
 558
 559                 poll_device_unplug(dev_path, optical);
 560
 561                 remove_device(dev_path);
 562
 563                 /* Unmount it repeatedly, if needs be */
 564                 while (mounted && !unmount_device(dev_path))
 565                         ;
 566                 detach_and_sleep(1);
 567         }
 568 }
 569
 570 int main(int argc, char **argv)
 571 {
 572         char *dev_path, *action;
 573         int rc;
 574
 575         action = getenv("ACTION");
 576
 577         logf = fopen("/var/log/petitboot-udev-helpers.log", "a");
 578         if (!logf)
 579                 logf = stdout;
 580         pb_log("%d started\n", getpid());
 581         rc = EXIT_SUCCESS;
 582
 583         if (!action) {
 584                 pb_log("missing environment?\n");
 585                 return EXIT_FAILURE;
 586         }
 587
 588         set_mount_base(TMP_DIR);
 589
 590         if (connect_to_socket())
 591                 return EXIT_FAILURE;
 592
 593         if (streq(action, "fake")) {
 594                 pb_log("fake mode");
 595
 596                 add_device(&fake_boot_devices[0]);
 597                 add_boot_option(&fake_boot_options[0]);
 598                 add_boot_option(&fake_boot_options[1]);
 599                 add_boot_option(&fake_boot_options[2]);
 600                 add_device(&fake_boot_devices[1]);
 601                 add_boot_option(&fake_boot_options[3]);
 602
 603                 return EXIT_SUCCESS;
 604         }
 605
 606         dev_path = getenv("DEVNAME");
 607         if (!dev_path) {
 608                 pb_log("missing environment?\n");
 609                 return EXIT_FAILURE;
 610         }
 611
 612         if (is_ignored_device(dev_path))
 613                 return EXIT_SUCCESS;
 614
 615         if (streq(action, "add")) {
 616                 char *sysfs_path = getenv("DEVPATH");
 617                 if (sysfs_path && is_removable_device(sysfs_path))
 618                         rc = poll_removable_device(sysfs_path, dev_path);
 619                 else
 620                         rc = found_new_device(dev_path);
 621         } else if (streq(action, "remove")) {
 622                 pb_log("%s removed\n", dev_path);
 623
 624                 remove_device(dev_path);
 625
 626                 /* Unmount it repeatedly, if needs be */
 627                 while (!unmount_device(dev_path))
 628                         ;
 629
 630         } else {
 631                 pb_log("invalid action '%s'\n", action);
 632                 rc = EXIT_FAILURE;
 633         }
 634         return rc;
 635 }