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 <limits.h>
  10 #include <sys/types.h>
  11 #include <sys/stat.h>
  12 #include <sys/socket.h>
  13 #include <sys/wait.h>
  14 #include <sys/un.h>
  15 #include <fcntl.h>
  16 #include <errno.h>
  17 #include <string.h>
  18 #include <asm/byteorder.h>
  19 #include <linux/cdrom.h>
  20 #include <sys/ioctl.h>
  21
  22 #include "parser.h"
  23 #include "paths.h"
  24 #include "petitboot-paths.h"
  25
  26 /* Define below to operate without the frontend */
  27 #undef USE_FAKE_SOCKET
  28
  29 /* Delay in seconds between polling of removable devices */
  30 #define REMOVABLE_SLEEP_DELAY   2
  31
  32 static FILE *logf;
  33 static int sock;
  34
  35 void pb_log(const char *fmt, ...)
  36 {
  37         va_list ap;
  38
  39         va_start(ap, fmt);
  40         vfprintf(logf, fmt, ap);
  41         va_end(ap);
  42 }
  43
  44 static void print_boot_option(const struct boot_option *opt)
  45 {
  46         pb_log("\tname: %s\n", opt->name);
  47         pb_log("\tdescription: %s\n", opt->description);
  48         pb_log("\tboot_image: %s\n", opt->boot_image_file);
  49         pb_log("\tinitrd: %s\n", opt->initrd_file);
  50         pb_log("\tboot_args: %s\n", opt->boot_args);
  51
  52 }
  53
  54 static void print_device(const struct device *dev)
  55 {
  56         pb_log("\tid: %s\n", dev->id);
  57         pb_log("\tname: %s\n", dev->name);
  58         pb_log("\tdescription: %s\n", dev->description);
  59         pb_log("\tboot_image: %s\n", dev->icon_file);
  60 }
  61
  62 static int write_action(int fd, enum device_action action)
  63 {
  64         uint8_t action_buf = action;
  65         return write(fd, &action_buf, sizeof(action_buf)) != sizeof(action_buf);
  66 }
  67
  68 static int write_string(int fd, const char *str)
  69 {
  70         int len, pos = 0;
  71         uint32_t len_buf;
  72
  73         if (!str) {
  74                 len_buf = 0;
  75                 if (write(fd, &len_buf, sizeof(len_buf)) != sizeof(len_buf)) {
  76                         pb_log("write failed: %s\n", strerror(errno));
  77                         return -1;
  78                 }
  79                 return 0;
  80         }
  81
  82         len = strlen(str);
  83         if (len > (1ull << (sizeof(len_buf) * 8 - 1))) {
  84                 pb_log("string too large\n");
  85                 return -1;
  86         }
  87
  88         len_buf = __cpu_to_be32(len);
  89         if (write(fd, &len_buf, sizeof(len_buf)) != sizeof(len_buf)) {
  90                 pb_log("write failed: %s\n", strerror(errno));
  91                 return -1;
  92         }
  93
  94         while (pos < len) {
  95                 int rc = write(fd, str, len - pos);
  96                 if (rc <= 0) {
  97                         pb_log("write failed: %s\n", strerror(errno));
  98                         return -1;
  99                 }
 100                 pos += rc;
 101                 str += rc;
 102         }
 103
 104         return 0;
 105 }
 106
 107 int add_device(const struct device *dev)
 108 {
 109         int rc;
 110
 111         pb_log("device added:\n");
 112         print_device(dev);
 113         rc = write_action(sock, DEV_ACTION_ADD_DEVICE) ||
 114                 write_string(sock, dev->id) ||
 115                 write_string(sock, dev->name) ||
 116                 write_string(sock, dev->description) ||
 117                 write_string(sock, dev->icon_file);
 118
 119         if (rc)
 120                 pb_log("error writing device %s to socket\n", dev->name);
 121
 122         return rc;
 123 }
 124
 125 int add_boot_option(const struct boot_option *opt)
 126 {
 127         int rc;
 128
 129         pb_log("boot option added:\n");
 130         print_boot_option(opt);
 131
 132         rc = write_action(sock, DEV_ACTION_ADD_OPTION) ||
 133                 write_string(sock, opt->id) ||
 134                 write_string(sock, opt->name) ||
 135                 write_string(sock, opt->description) ||
 136                 write_string(sock, opt->icon_file) ||
 137                 write_string(sock, opt->boot_image_file) ||
 138                 write_string(sock, opt->initrd_file) ||
 139                 write_string(sock, opt->boot_args);
 140
 141         if (rc)
 142                 pb_log("error writing boot option %s to socket\n", opt->name);
 143
 144         return rc;
 145 }
 146
 147 int remove_device(const char *dev_path)
 148 {
 149         return write_action(sock, DEV_ACTION_REMOVE_DEVICE) ||
 150                 write_string(sock, dev_path);
 151 }
 152
 153 int connect_to_socket()
 154 {
 155 #ifndef USE_FAKE_SOCKET
 156         int fd;
 157         struct sockaddr_un addr;
 158
 159         fd = socket(PF_UNIX, SOCK_STREAM, 0);
 160         if (fd == -1) {
 161                 pb_log("can't create socket: %s\n", strerror(errno));
 162                 return -1;
 163         }
 164
 165         addr.sun_family = AF_UNIX;
 166         strcpy(addr.sun_path, PBOOT_DEVICE_SOCKET);
 167
 168         if (connect(fd, (struct sockaddr *)&addr, sizeof(addr))) {
 169                 pb_log("can't connect to %s: %s\n",
 170                                 addr.sun_path, strerror(errno));
 171                 return -1;
 172         }
 173         sock = fd;
 174
 175         return 0;
 176 #else
 177         int fd;
 178         fd = open("./debug_socket", O_WRONLY | O_CREAT, 0640);
 179         if (fd < 0) {
 180                 pb_log("can't create output file: %s\n", strerror(errno));
 181                 return -1;
 182         }
 183         sock = fd;
 184         return 0;
 185 #endif
 186 }
 187
 188 static int mkdir_recursive(const char *dir)
 189 {
 190         char *str, *sep;
 191         int mode = 0755;
 192         struct stat statbuf;
 193
 194         pb_log("mkdir_recursive(%s)\n", dir);
 195
 196         if (!*dir)
 197                 return 0;
 198
 199         if (!stat(dir, &statbuf)) {
 200                 if (!S_ISDIR(statbuf.st_mode)) {
 201                         pb_log("%s: %s exists, but isn't a directory\n",
 202                                         __func__, dir);
 203                         return -1;
 204                 }
 205                 return 0;
 206         }
 207
 208         str = strdup(dir);
 209         sep = strchr(*str == '/' ? str + 1 : str, '/');
 210
 211         while (1) {
 212
 213                 /* terminate the path at sep */
 214                 if (sep)
 215                         *sep = '\0';
 216                 pb_log("mkdir(%s)\n", str);
 217
 218                 if (mkdir(str, mode) && errno != EEXIST) {
 219                         pb_log("mkdir(%s): %s\n", str, strerror(errno));
 220                         return -1;
 221                 }
 222
 223                 if (!sep)
 224                         break;
 225
 226                 /* reset dir to the full path */
 227                 strcpy(str, dir);
 228                 sep = strchr(sep + 1, '/');
 229         }
 230
 231         free(str);
 232
 233         return 0;
 234 }
 235
 236 static void setup_device_links(const char *device)
 237 {
 238         struct link {
 239                 char *env, *dir;
 240         } *link, links[] = {
 241                 {
 242                         .env = "ID_FS_UUID",
 243                         .dir = "disk/by-uuid"
 244                 },
 245                 {
 246                         .env = "ID_FS_LABEL",
 247                         .dir = "disk/by-label"
 248                 },
 249                 {
 250                         .env = NULL
 251                 }
 252         };
 253
 254         for (link = links; link->env; link++) {
 255                 char *value, *dir, *path;
 256
 257                 value = getenv(link->env);
 258                 if (!value)
 259                         continue;
 260
 261                 value = encode_label(value);
 262                 dir = join_paths(TMP_DIR, link->dir);
 263                 path = join_paths(dir, value);
 264
 265                 if (!mkdir_recursive(dir)) {
 266                         unlink(path);
 267                         if (symlink(mountpoint_for_device(device), path)) {
 268                                 pb_log("symlink(%s): %s\n",
 269                                                 path, strerror(errno));
 270                         }
 271                 }
 272
 273                 free(path);
 274                 free(dir);
 275                 free(value);
 276         }
 277 }
 278
 279 int mount_device(const char *dev_path)
 280 {
 281         const char *dir;
 282         int pid, status, rc = -1;
 283         struct stat statbuf;
 284
 285         dir = mountpoint_for_device(dev_path);
 286
 287         if (stat(dir, &statbuf)) {
 288                 if (mkdir(dir, 0755)) {
 289                         pb_log("couldn't create directory %s: %s\n",
 290                                         dir, strerror(errno));
 291                         goto out;
 292                 }
 293         } else {
 294                 if (!S_ISDIR(statbuf.st_mode)) {
 295                         pb_log("mountpoint %s exists, "
 296                                         "but isn't a directory\n", dir);
 297                         goto out;
 298                 }
 299         }
 300
 301
 302         pid = fork();
 303         if (pid == -1) {
 304                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 305                 goto out;
 306         }
 307
 308         if (pid == 0) {
 309                 execl(MOUNT_BIN, MOUNT_BIN, dev_path, dir, "-o", "ro", NULL);
 310                 exit(EXIT_FAILURE);
 311         }
 312
 313         if (waitpid(pid, &status, 0) == -1) {
 314                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 315                                 strerror(errno));
 316                 goto out;
 317         }
 318
 319         if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
 320                 setup_device_links(dev_path);
 321                 rc = 0;
 322         }
 323
 324 out:
 325         return rc;
 326 }
 327
 328 static int unmount_device(const char *dev_path)
 329 {
 330         int pid, status, rc;
 331
 332         pid = fork();
 333
 334         if (pid == -1) {
 335                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 336                 return -1;
 337         }
 338
 339         if (pid == 0) {
 340                 execl(UMOUNT_BIN, UMOUNT_BIN, dev_path, NULL);
 341                 exit(EXIT_FAILURE);
 342         }
 343
 344         if (waitpid(pid, &status, 0) == -1) {
 345                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 346                                 strerror(errno));
 347                 return -1;
 348         }
 349
 350         rc = !WIFEXITED(status) || WEXITSTATUS(status) != 0;
 351
 352         return rc;
 353 }
 354
 355 static const struct device fake_boot_devices[] =
 356 {
 357         {
 358                 .id             = "fakeDisk0",
 359                 .name           = "Hard Disk",
 360                 .icon_file      = artwork_pathname("hdd.png"),
 361         },
 362         {
 363                 .id             = "fakeDisk1",
 364                 .name           = "PinkCat Linux CD",
 365                 .icon_file      = artwork_pathname("cdrom.png"),
 366         }
 367 };
 368
 369 static const struct boot_option fake_boot_options[] =
 370 {
 371         {
 372                 .id             = "fakeBoot0",
 373                 .name           = "Bloobuntu Linux",
 374                 .description    = "Boot Bloobuntu Linux",
 375                 .icon_file      = artwork_pathname("hdd.png"),
 376         },
 377         {
 378                 .id             = "fakeBoot1",
 379                 .name           = "Pendora Gore 6",
 380                 .description    = "Boot Pendora Gora 6",
 381                 .icon_file      = artwork_pathname("hdd.png"),
 382         },
 383         {
 384                 .id             = "fakeBoot2",
 385                 .name           = "Genfoo Minux",
 386                 .description    = "Boot Genfoo Minux",
 387                 .icon_file      = artwork_pathname("hdd.png"),
 388         },
 389         {
 390                 .id             = "fakeBoot3",
 391                 .name           = "PinkCat Linux",
 392                 .description    = "Install PinkCat Linux - Graphical install",
 393                 .icon_file      = artwork_pathname("cdrom.png"),
 394         },
 395 };
 396
 397 enum generic_icon_type guess_device_type(void)
 398 {
 399         const char *type = getenv("ID_TYPE");
 400         const char *bus = getenv("ID_BUS");
 401         if (type && streq(type, "cd"))
 402                 return ICON_TYPE_OPTICAL;
 403         if (!bus)
 404                 return ICON_TYPE_UNKNOWN;
 405         if (streq(bus, "usb"))
 406                 return ICON_TYPE_USB;
 407         if (streq(bus, "ata") || streq(bus, "scsi"))
 408                 return ICON_TYPE_DISK;
 409         return ICON_TYPE_UNKNOWN;
 410 }
 411
 412
 413 static int is_removable_device(const char *sysfs_path)
 414 {
 415         char full_path[PATH_MAX];
 416         char buf[80];
 417         int fd, buf_len;
 418
 419         sprintf(full_path, "/sys/%s/removable", sysfs_path);
 420         fd = open(full_path, O_RDONLY);
 421         pb_log(" -> removable check on %s, fd=%d\n", full_path, fd);
 422         if (fd < 0)
 423                 return 0;
 424         buf_len = read(fd, buf, 79);
 425         close(fd);
 426         if (buf_len < 0)
 427                 return 0;
 428         buf[buf_len] = 0;
 429         return strtol(buf, NULL, 10);
 430 }
 431
 432 static int is_ignored_device(const char *devname)
 433 {
 434         static const char *ignored_devices[] =
 435                 { "/dev/ram", "/dev/loop", NULL };
 436         const char **dev;
 437
 438         for (dev = ignored_devices; *dev; dev++)
 439                 if (!strncmp(devname, *dev, strlen(*dev)))
 440                         return 1;
 441
 442         return 0;
 443 }
 444
 445 static int found_new_device(const char *dev_path)
 446 {
 447         const char *mountpoint = mountpoint_for_device(dev_path);
 448
 449         if (mount_device(dev_path)) {
 450                 pb_log("failed to mount %s\n", dev_path);
 451                 return EXIT_FAILURE;
 452         }
 453
 454         pb_log("mounted %s at %s\n", dev_path, mountpoint);
 455
 456         iterate_parsers(dev_path, mountpoint);
 457
 458         return EXIT_SUCCESS;
 459 }
 460
 461 static void detach_and_sleep(int sec)
 462 {
 463         static int forked = 0;
 464         int rc = 0;
 465
 466         if (sec <= 0)
 467                 return;
 468
 469         if (!forked) {
 470                 pb_log("running in background...");
 471                 rc = fork();
 472                 forked = 1;
 473         }
 474
 475         if (rc == 0) {
 476                 sleep(sec);
 477
 478         } else if (rc == -1) {
 479                 perror("fork()");
 480                 exit(EXIT_FAILURE);
 481         } else {
 482                 exit(EXIT_SUCCESS);
 483         }
 484 }
 485
 486 static int poll_device_plug(const char *dev_path,
 487                             int *optical)
 488 {
 489         int rc, fd;
 490
 491         /* Polling loop for optical drive */
 492         for (; (*optical) != 0; ) {
 493                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 494                 if (fd < 0)
 495                         return EXIT_FAILURE;
 496                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 497                 close(fd);
 498                 if (rc == -1)
 499                         break;
 500
 501                 *optical = 1;
 502                 if (rc == CDS_DISC_OK)
 503                         return EXIT_SUCCESS;
 504
 505                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 506         }
 507
 508         /* Fall back to bare open() */
 509         *optical = 0;
 510         for (;;) {
 511                 fd = open(dev_path, O_RDONLY);
 512                 if (fd < 0 && errno != ENOMEDIUM)
 513                         return EXIT_FAILURE;
 514                 close(fd);
 515                 if (fd >= 0)
 516                         return EXIT_SUCCESS;
 517                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 518         }
 519 }
 520
 521 static int poll_device_unplug(const char *dev_path, int optical)
 522 {
 523         int rc, fd;
 524
 525         for (;optical;) {
 526                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 527                 if (fd < 0)
 528                         return EXIT_FAILURE;
 529                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 530                 close(fd);
 531                 if (rc != CDS_DISC_OK)
 532                         return EXIT_SUCCESS;
 533                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 534         }
 535
 536         /* Fall back to bare open() */
 537         for (;;) {
 538                 fd = open(dev_path, O_RDONLY);
 539                 if (fd < 0 && errno != ENOMEDIUM)
 540                         return EXIT_FAILURE;
 541                 close(fd);
 542                 if (fd < 0)
 543                         return EXIT_SUCCESS;
 544                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 545         }
 546 }
 547
 548 static int poll_removable_device(const char *sysfs_path,
 549                                  const char *dev_path)
 550 {
 551         int rc, mounted, optical = -1;
 552
 553         for (;;) {
 554                 rc = poll_device_plug(dev_path, &optical);
 555                 if (rc == EXIT_FAILURE)
 556                         return rc;
 557                 rc = found_new_device(dev_path);
 558                 mounted = (rc == EXIT_SUCCESS);
 559
 560                 poll_device_unplug(dev_path, optical);
 561
 562                 remove_device(dev_path);
 563
 564                 /* Unmount it repeatedly, if needs be */
 565                 while (mounted && !unmount_device(dev_path))
 566                         ;
 567                 detach_and_sleep(1);
 568         }
 569 }
 570
 571 int main(int argc, char **argv)
 572 {
 573         char *dev_path, *action;
 574         int rc;
 575
 576         action = getenv("ACTION");
 577
 578         logf = fopen("/var/log/petitboot-udev-helpers.log", "a");
 579         if (!logf)
 580                 logf = stdout;
 581         pb_log("%d started\n", getpid());
 582         rc = EXIT_SUCCESS;
 583
 584         if (!action) {
 585                 pb_log("missing environment?\n");
 586                 return EXIT_FAILURE;
 587         }
 588
 589         set_mount_base(TMP_DIR);
 590
 591         if (connect_to_socket())
 592                 return EXIT_FAILURE;
 593
 594         if (streq(action, "fake")) {
 595                 pb_log("fake mode");
 596
 597                 add_device(&fake_boot_devices[0]);
 598                 add_boot_option(&fake_boot_options[0]);
 599                 add_boot_option(&fake_boot_options[1]);
 600                 add_boot_option(&fake_boot_options[2]);
 601                 add_device(&fake_boot_devices[1]);
 602                 add_boot_option(&fake_boot_options[3]);
 603
 604                 return EXIT_SUCCESS;
 605         }
 606
 607         dev_path = getenv("DEVNAME");
 608         if (!dev_path) {
 609                 pb_log("missing environment?\n");
 610                 return EXIT_FAILURE;
 611         }
 612
 613         if (is_ignored_device(dev_path))
 614                 return EXIT_SUCCESS;
 615
 616         if (streq(action, "add")) {
 617                 char *sysfs_path = getenv("DEVPATH");
 618                 if (sysfs_path && is_removable_device(sysfs_path))
 619                         rc = poll_removable_device(sysfs_path, dev_path);
 620                 else
 621                         rc = found_new_device(dev_path);
 622         } else if (streq(action, "remove")) {
 623                 pb_log("%s removed\n", dev_path);
 624
 625                 remove_device(dev_path);
 626
 627                 /* Unmount it repeatedly, if needs be */
 628                 while (!unmount_device(dev_path))
 629                         ;
 630
 631         } else {
 632                 pb_log("invalid action '%s'\n", action);
 633                 rc = EXIT_FAILURE;
 634         }
 635         return rc;
 636 }