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 "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 int mount_device(const char *dev_path)
 188 {
 189         const char *dir;
 190         int pid, status, rc = -1;
 191         struct stat statbuf;
 192
 193         dir = mountpoint_for_device(dev_path);
 194
 195         if (stat(dir, &statbuf)) {
 196                 if (mkdir(dir, 0755)) {
 197                         pb_log("couldn't create directory %s: %s\n",
 198                                         dir, strerror(errno));
 199                         goto out;
 200                 }
 201         } else {
 202                 if (!S_ISDIR(statbuf.st_mode)) {
 203                         pb_log("mountpoint %s exists, "
 204                                         "but isn't a directory\n", dir);
 205                         goto out;
 206                 }
 207         }
 208
 209
 210         pid = fork();
 211         if (pid == -1) {
 212                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 213                 goto out;
 214         }
 215
 216         if (pid == 0) {
 217                 execl(MOUNT_BIN, MOUNT_BIN, dev_path, dir, "-o", "ro", NULL);
 218                 exit(EXIT_FAILURE);
 219         }
 220
 221         if (waitpid(pid, &status, 0) == -1) {
 222                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 223                                 strerror(errno));
 224                 goto out;
 225         }
 226
 227         if (WIFEXITED(status) && WEXITSTATUS(status) == 0)
 228                 rc = 0;
 229
 230 out:
 231         return rc;
 232 }
 233
 234 static int unmount_device(const char *dev_path)
 235 {
 236         int pid, status, rc;
 237
 238         pid = fork();
 239
 240         if (pid == -1) {
 241                 pb_log("%s: fork failed: %s\n", __FUNCTION__, strerror(errno));
 242                 return -1;
 243         }
 244
 245         if (pid == 0) {
 246                 execl(UMOUNT_BIN, UMOUNT_BIN, dev_path, NULL);
 247                 exit(EXIT_FAILURE);
 248         }
 249
 250         if (waitpid(pid, &status, 0) == -1) {
 251                 pb_log("%s: waitpid failed: %s\n", __FUNCTION__,
 252                                 strerror(errno));
 253                 return -1;
 254         }
 255
 256         rc = !WIFEXITED(status) || WEXITSTATUS(status) != 0;
 257
 258         return rc;
 259 }
 260
 261 static const struct device fake_boot_devices[] =
 262 {
 263         {
 264                 .id             = "fakeDisk0",
 265                 .name           = "Hard Disk",
 266                 .icon_file      = artwork_pathname("hdd.png"),
 267         },
 268         {
 269                 .id             = "fakeDisk1",
 270                 .name           = "PinkCat Linux CD",
 271                 .icon_file      = artwork_pathname("cdrom.png"),
 272         }
 273 };
 274
 275 static const struct boot_option fake_boot_options[] =
 276 {
 277         {
 278                 .id             = "fakeBoot0",
 279                 .name           = "Bloobuntu Linux",
 280                 .description    = "Boot Bloobuntu Linux",
 281                 .icon_file      = artwork_pathname("hdd.png"),
 282         },
 283         {
 284                 .id             = "fakeBoot1",
 285                 .name           = "Pendora Gore 6",
 286                 .description    = "Boot Pendora Gora 6",
 287                 .icon_file      = artwork_pathname("hdd.png"),
 288         },
 289         {
 290                 .id             = "fakeBoot2",
 291                 .name           = "Genfoo Minux",
 292                 .description    = "Boot Genfoo Minux",
 293                 .icon_file      = artwork_pathname("hdd.png"),
 294         },
 295         {
 296                 .id             = "fakeBoot3",
 297                 .name           = "PinkCat Linux",
 298                 .description    = "Install PinkCat Linux - Graphical install",
 299                 .icon_file      = artwork_pathname("cdrom.png"),
 300         },
 301 };
 302
 303 enum generic_icon_type guess_device_type(void)
 304 {
 305         const char *type = getenv("ID_TYPE");
 306         const char *bus = getenv("ID_BUS");
 307         if (type && streq(type, "cd"))
 308                 return ICON_TYPE_OPTICAL;
 309         if (!bus)
 310                 return ICON_TYPE_UNKNOWN;
 311         if (streq(bus, "usb"))
 312                 return ICON_TYPE_USB;
 313         if (streq(bus, "ata") || streq(bus, "scsi"))
 314                 return ICON_TYPE_DISK;
 315         return ICON_TYPE_UNKNOWN;
 316 }
 317
 318
 319 static int is_removable_device(const char *sysfs_path)
 320 {
 321         char full_path[PATH_MAX];
 322         char buf[80];
 323         int fd, buf_len;
 324
 325         sprintf(full_path, "/sys/%s/removable", sysfs_path);
 326         fd = open(full_path, O_RDONLY);
 327         pb_log(" -> removable check on %s, fd=%d\n", full_path, fd);
 328         if (fd < 0)
 329                 return 0;
 330         buf_len = read(fd, buf, 79);
 331         close(fd);
 332         if (buf_len < 0)
 333                 return 0;
 334         buf[buf_len] = 0;
 335         return strtol(buf, NULL, 10);
 336 }
 337
 338 static int is_ignored_device(const char *devname)
 339 {
 340         static const char *ignored_devices[] = { "/dev/ram", NULL };
 341         const char **dev;
 342
 343         for (dev = ignored_devices; *dev; dev++)
 344                 if (!strncmp(devname, *dev, strlen(*dev)))
 345                         return 1;
 346
 347         return 0;
 348 }
 349
 350 static int found_new_device(const char *dev_path)
 351 {
 352         const char *mountpoint = mountpoint_for_device(dev_path);
 353
 354         if (mount_device(dev_path)) {
 355                 pb_log("failed to mount %s\n", dev_path);
 356                 return EXIT_FAILURE;
 357         }
 358
 359         pb_log("mounted %s at %s\n", dev_path, mountpoint);
 360
 361         iterate_parsers(dev_path, mountpoint);
 362
 363         return EXIT_SUCCESS;
 364 }
 365
 366 static void detach_and_sleep(int sec)
 367 {
 368         static int forked = 0;
 369         int rc = 0;
 370
 371         if (sec <= 0)
 372                 return;
 373
 374         if (!forked) {
 375                 pb_log("running in background...");
 376                 rc = fork();
 377                 forked = 1;
 378         }
 379
 380         if (rc == 0) {
 381                 sleep(sec);
 382
 383         } else if (rc == -1) {
 384                 perror("fork()");
 385                 exit(EXIT_FAILURE);
 386         } else {
 387                 exit(EXIT_SUCCESS);
 388         }
 389 }
 390
 391 static int poll_device_plug(const char *dev_path,
 392                             int *optical)
 393 {
 394         int rc, fd;
 395
 396         /* Polling loop for optical drive */
 397         for (; (*optical) != 0; ) {
 398                 pb_log("poll for optical drive insertion ...\n");
 399                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 400                 if (fd < 0)
 401                         return EXIT_FAILURE;
 402                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 403                 close(fd);
 404                 if (rc == -1) {
 405                         pb_log("not an optical drive, fallback...\n");
 406                         break;
 407                 }
 408                 *optical = 1;
 409                 if (rc == CDS_DISC_OK)
 410                         return EXIT_SUCCESS;
 411
 412                 pb_log("no... waiting\n");
 413                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 414         }
 415
 416         /* Fall back to bare open() */
 417         *optical = 0;
 418         for (;;) {
 419                 pb_log("poll for non-optical drive insertion ...\n");
 420                 fd = open(dev_path, O_RDONLY);
 421                 if (fd < 0 && errno != ENOMEDIUM)
 422                         return EXIT_FAILURE;
 423                 close(fd);
 424                 if (fd >= 0)
 425                         return EXIT_SUCCESS;
 426                 pb_log("no... waiting\n");
 427                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 428         }
 429 }
 430
 431 static int poll_device_unplug(const char *dev_path, int optical)
 432 {
 433         int rc, fd;
 434
 435         for (;optical;) {
 436                 pb_log("poll for optical drive removal ...\n");
 437                 fd = open(dev_path, O_RDONLY|O_NONBLOCK);
 438                 if (fd < 0)
 439                         return EXIT_FAILURE;
 440                 rc = ioctl(fd, CDROM_DRIVE_STATUS, CDSL_CURRENT);
 441                 close(fd);
 442                 if (rc != CDS_DISC_OK)
 443                         return EXIT_SUCCESS;
 444                 pb_log("no... waiting\n");
 445                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 446         }
 447
 448         /* Fall back to bare open() */
 449         for (;;) {
 450                 pb_log("poll for non-optical drive removal ...\n");
 451                 fd = open(dev_path, O_RDONLY);
 452                 if (fd < 0 && errno != ENOMEDIUM)
 453                         return EXIT_FAILURE;
 454                 close(fd);
 455                 if (fd < 0)
 456                         return EXIT_SUCCESS;
 457                 pb_log("no... waiting\n");
 458                 detach_and_sleep(REMOVABLE_SLEEP_DELAY);
 459         }
 460 }
 461
 462 static int poll_removable_device(const char *sysfs_path,
 463                                  const char *dev_path)
 464 {
 465         int rc, mounted, optical = -1;
 466
 467         for (;;) {
 468                 rc = poll_device_plug(dev_path, &optical);
 469                 if (rc == EXIT_FAILURE)
 470                         return rc;
 471                 rc = found_new_device(dev_path);
 472                 mounted = (rc == EXIT_SUCCESS);
 473
 474                 poll_device_unplug(dev_path, optical);
 475
 476                 remove_device(dev_path);
 477
 478                 /* Unmount it repeatedly, if needs be */
 479                 while (mounted && !unmount_device(dev_path))
 480                         ;
 481                 detach_and_sleep(1);
 482         }
 483 }
 484
 485 int main(int argc, char **argv)
 486 {
 487         char *dev_path, *action;
 488         int rc;
 489
 490         action = getenv("ACTION");
 491
 492         logf = fopen("/var/log/petitboot-udev-helpers.log", "a");
 493         if (!logf)
 494                 logf = stdout;
 495         pb_log("%d started\n", getpid());
 496         rc = EXIT_SUCCESS;
 497
 498         if (!action) {
 499                 pb_log("missing environment?\n");
 500                 return EXIT_FAILURE;
 501         }
 502
 503         set_mount_base(TMP_DIR);
 504
 505         if (connect_to_socket())
 506                 return EXIT_FAILURE;
 507
 508         if (streq(action, "fake")) {
 509                 pb_log("fake mode");
 510
 511                 add_device(&fake_boot_devices[0]);
 512                 add_boot_option(&fake_boot_options[0]);
 513                 add_boot_option(&fake_boot_options[1]);
 514                 add_boot_option(&fake_boot_options[2]);
 515                 add_device(&fake_boot_devices[1]);
 516                 add_boot_option(&fake_boot_options[3]);
 517
 518                 return EXIT_SUCCESS;
 519         }
 520
 521         dev_path = getenv("DEVNAME");
 522         if (!dev_path) {
 523                 pb_log("missing environment?\n");
 524                 return EXIT_FAILURE;
 525         }
 526
 527         if (is_ignored_device(dev_path))
 528                 return EXIT_SUCCESS;
 529
 530         if (streq(action, "add")) {
 531                 char *sysfs_path = getenv("DEVPATH");
 532                 if (sysfs_path && is_removable_device(sysfs_path))
 533                         rc = poll_removable_device(sysfs_path, dev_path);
 534                 else
 535                         rc = found_new_device(dev_path);
 536         } else if (streq(action, "remove")) {
 537                 pb_log("%s removed\n", dev_path);
 538
 539                 remove_device(dev_path);
 540
 541                 /* Unmount it repeatedly, if needs be */
 542                 while (!unmount_device(dev_path))
 543                         ;
 544
 545         } else {
 546                 pb_log("invalid action '%s'\n", action);
 547                 rc = EXIT_FAILURE;
 548         }
 549         return rc;
 550 }