src/udev-builtin-path_id.c

   1 /*
   2  * compose persistent device path
   3  *
   4  * Copyright (C) 2009-2011 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * Logic based on Hannes Reinecke's shell script.
   7  *
   8  * This program is free software: you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation, either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <stdarg.h>
  25 #include <unistd.h>
  26 #include <string.h>
  27 #include <ctype.h>
  28 #include <fcntl.h>
  29 #include <errno.h>
  30 #include <dirent.h>
  31 #include <getopt.h>
  32
  33 #include "udev.h"
  34
  35 static int path_prepend(char **path, const char *fmt, ...)
  36 {
  37         va_list va;
  38         char *pre;
  39         int err = 0;
  40
  41         va_start(va, fmt);
  42         err = vasprintf(&pre, fmt, va);
  43         va_end(va);
  44         if (err < 0)
  45                 goto out;
  46
  47         if (*path != NULL) {
  48                 char *new;
  49
  50                 err = asprintf(&new, "%s-%s", pre, *path);
  51                 free(pre);
  52                 if (err < 0)
  53                         goto out;
  54                 free(*path);
  55                 *path = new;
  56         } else {
  57                 *path = pre;
  58         }
  59 out:
  60         return err;
  61 }
  62
  63 /*
  64 ** Linux only supports 32 bit luns.
  65 ** See drivers/scsi/scsi_scan.c::scsilun_to_int() for more details.
  66 */
  67 static int format_lun_number(struct udev_device *dev, char **path)
  68 {
  69         unsigned long lun = strtoul(udev_device_get_sysnum(dev), NULL, 10);
  70
  71         /* address method 0, peripheral device addressing with bus id of zero */
  72         if (lun < 256)
  73                 return path_prepend(path, "lun-%d", lun);
  74         /* handle all other lun addressing methods by using a variant of the original lun format */
  75         return path_prepend(path, "lun-0x%04x%04x00000000", (lun & 0xffff), (lun >> 16) & 0xffff);
  76 }
  77
  78 static struct udev_device *skip_subsystem(struct udev_device *dev, const char *subsys)
  79 {
  80         struct udev_device *parent = dev;
  81
  82         while (parent != NULL) {
  83                 const char *subsystem;
  84
  85                 subsystem = udev_device_get_subsystem(parent);
  86                 if (subsystem == NULL || strcmp(subsystem, subsys) != 0)
  87                         break;
  88                 dev = parent;
  89                 parent = udev_device_get_parent(parent);
  90         }
  91         return dev;
  92 }
  93
  94 static struct udev_device *handle_scsi_fibre_channel(struct udev_device *parent, char **path)
  95 {
  96         struct udev *udev  = udev_device_get_udev(parent);
  97         struct udev_device *targetdev;
  98         struct udev_device *fcdev = NULL;
  99         const char *port;
 100         char *lun = NULL;;
 101
 102         targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
 103         if (targetdev == NULL)
 104                 return NULL;
 105
 106         fcdev = udev_device_new_from_subsystem_sysname(udev, "fc_transport", udev_device_get_sysname(targetdev));
 107         if (fcdev == NULL)
 108                 return NULL;
 109         port = udev_device_get_sysattr_value(fcdev, "port_name");
 110         if (port == NULL) {
 111                 parent = NULL;
 112                 goto out;
 113         }
 114
 115         format_lun_number(parent, &lun);
 116         path_prepend(path, "fc-%s-%s", port, lun);
 117         if (lun)
 118                 free(lun);
 119 out:
 120         udev_device_unref(fcdev);
 121         return parent;
 122 }
 123
 124 static struct udev_device *handle_scsi_sas(struct udev_device *parent, char **path)
 125 {
 126         struct udev *udev  = udev_device_get_udev(parent);
 127         struct udev_device *targetdev;
 128         struct udev_device *target_parent;
 129         struct udev_device *sasdev;
 130         const char *sas_address;
 131         char *lun = NULL;
 132
 133         targetdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_target");
 134         if (targetdev == NULL)
 135                 return NULL;
 136
 137         target_parent = udev_device_get_parent(targetdev);
 138         if (target_parent == NULL)
 139                 return NULL;
 140
 141         sasdev = udev_device_new_from_subsystem_sysname(udev, "sas_device",
 142                                 udev_device_get_sysname(target_parent));
 143         if (sasdev == NULL)
 144                 return NULL;
 145
 146         sas_address = udev_device_get_sysattr_value(sasdev, "sas_address");
 147         if (sas_address == NULL) {
 148                 parent = NULL;
 149                 goto out;
 150         }
 151
 152         format_lun_number(parent, &lun);
 153         path_prepend(path, "sas-%s-%s", sas_address, lun);
 154         if (lun)
 155                 free(lun);
 156 out:
 157         udev_device_unref(sasdev);
 158         return parent;
 159 }
 160
 161 static struct udev_device *handle_scsi_iscsi(struct udev_device *parent, char **path)
 162 {
 163         struct udev *udev  = udev_device_get_udev(parent);
 164         struct udev_device *transportdev;
 165         struct udev_device *sessiondev = NULL;
 166         const char *target;
 167         char *connname;
 168         struct udev_device *conndev = NULL;
 169         const char *addr;
 170         const char *port;
 171         char *lun = NULL;
 172
 173         /* find iscsi session */
 174         transportdev = parent;
 175         for (;;) {
 176                 transportdev = udev_device_get_parent(transportdev);
 177                 if (transportdev == NULL)
 178                         return NULL;
 179                 if (strncmp(udev_device_get_sysname(transportdev), "session", 7) == 0)
 180                         break;
 181         }
 182
 183         /* find iscsi session device */
 184         sessiondev = udev_device_new_from_subsystem_sysname(udev, "iscsi_session", udev_device_get_sysname(transportdev));
 185         if (sessiondev == NULL)
 186                 return NULL;
 187         target = udev_device_get_sysattr_value(sessiondev, "targetname");
 188         if (target == NULL) {
 189                 parent = NULL;
 190                 goto out;
 191         }
 192
 193         if (asprintf(&connname, "connection%s:0", udev_device_get_sysnum(transportdev)) < 0) {
 194                 parent = NULL;
 195                 goto out;
 196         }
 197         conndev = udev_device_new_from_subsystem_sysname(udev, "iscsi_connection", connname);
 198         free(connname);
 199         if (conndev == NULL) {
 200                 parent = NULL;
 201                 goto out;
 202         }
 203         addr = udev_device_get_sysattr_value(conndev, "persistent_address");
 204         port = udev_device_get_sysattr_value(conndev, "persistent_port");
 205         if (addr == NULL || port == NULL) {
 206                 parent = NULL;
 207                 goto out;
 208         }
 209
 210         format_lun_number(parent, &lun);
 211         path_prepend(path, "ip-%s:%s-iscsi-%s-%s", addr, port, target, lun);
 212         if (lun)
 213                 free(lun);
 214 out:
 215         udev_device_unref(sessiondev);
 216         udev_device_unref(conndev);
 217         return parent;
 218 }
 219
 220 static struct udev_device *handle_scsi_default(struct udev_device *parent, char **path)
 221 {
 222         struct udev_device *hostdev;
 223         int host, bus, target, lun;
 224         const char *name;
 225         char *base;
 226         char *pos;
 227         DIR *dir;
 228         struct dirent *dent;
 229         int basenum;
 230
 231         hostdev = udev_device_get_parent_with_subsystem_devtype(parent, "scsi", "scsi_host");
 232         if (hostdev == NULL)
 233                 return NULL;
 234
 235         name = udev_device_get_sysname(parent);
 236         if (sscanf(name, "%d:%d:%d:%d", &host, &bus, &target, &lun) != 4)
 237                 return NULL;
 238
 239         /* rebase host offset to get the local relative number */
 240         basenum = -1;
 241         base = strdup(udev_device_get_syspath(hostdev));
 242         if (base == NULL)
 243                 return NULL;
 244         pos = strrchr(base, '/');
 245         if (pos == NULL) {
 246                 parent = NULL;
 247                 goto out;
 248         }
 249         pos[0] = '\0';
 250         dir = opendir(base);
 251         if (dir == NULL) {
 252                 parent = NULL;
 253                 goto out;
 254         }
 255         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 256                 char *rest;
 257                 int i;
 258
 259                 if (dent->d_name[0] == '.')
 260                         continue;
 261                 if (dent->d_type != DT_DIR && dent->d_type != DT_LNK)
 262                         continue;
 263                 if (strncmp(dent->d_name, "host", 4) != 0)
 264                         continue;
 265                 i = strtoul(&dent->d_name[4], &rest, 10);
 266                 if (rest[0] != '\0')
 267                         continue;
 268                 if (basenum == -1 || i < basenum)
 269                         basenum = i;
 270         }
 271         closedir(dir);
 272         if (basenum == -1) {
 273                 parent = NULL;
 274                 goto out;
 275         }
 276         host -= basenum;
 277
 278         path_prepend(path, "scsi-%u:%u:%u:%u", host, bus, target, lun);
 279 out:
 280         free(base);
 281         return hostdev;
 282 }
 283
 284 static struct udev_device *handle_scsi(struct udev_device *parent, char **path)
 285 {
 286         const char *devtype;
 287         const char *name;
 288         const char *id;
 289
 290         devtype = udev_device_get_devtype(parent);
 291         if (devtype == NULL || strcmp(devtype, "scsi_device") != 0)
 292                 return parent;
 293
 294         /* firewire */
 295         id = udev_device_get_sysattr_value(parent, "ieee1394_id");
 296         if (id != NULL) {
 297                 parent = skip_subsystem(parent, "scsi");
 298                 path_prepend(path, "ieee1394-0x%s", id);
 299                 goto out;
 300         }
 301
 302         /* lousy scsi sysfs does not have a "subsystem" for the transport */
 303         name = udev_device_get_syspath(parent);
 304
 305         if (strstr(name, "/rport-") != NULL) {
 306                 parent = handle_scsi_fibre_channel(parent, path);
 307                 goto out;
 308         }
 309
 310         if (strstr(name, "/end_device-") != NULL) {
 311                 parent = handle_scsi_sas(parent, path);
 312                 goto out;
 313         }
 314
 315         if (strstr(name, "/session") != NULL) {
 316                 parent = handle_scsi_iscsi(parent, path);
 317                 goto out;
 318         }
 319
 320         parent = handle_scsi_default(parent, path);
 321 out:
 322         return parent;
 323 }
 324
 325 static void handle_scsi_tape(struct udev_device *dev, char **path)
 326 {
 327         const char *name;
 328
 329         /* must be the last device in the syspath */
 330         if (*path != NULL)
 331                 return;
 332
 333         name = udev_device_get_sysname(dev);
 334         if (strncmp(name, "nst", 3) == 0 && strchr("lma", name[3]) != NULL)
 335                 path_prepend(path, "nst%c", name[3]);
 336         else if (strncmp(name, "st", 2) == 0 && strchr("lma", name[2]) != NULL)
 337                 path_prepend(path, "st%c", name[2]);
 338 }
 339
 340 static struct udev_device *handle_usb(struct udev_device *parent, char **path)
 341 {
 342         const char *devtype;
 343         const char *str;
 344         const char *port;
 345
 346         devtype = udev_device_get_devtype(parent);
 347         if (devtype == NULL)
 348                 return parent;
 349         if (strcmp(devtype, "usb_interface") != 0 && strcmp(devtype, "usb_device") != 0)
 350                 return parent;
 351
 352         str = udev_device_get_sysname(parent);
 353         port = strchr(str, '-');
 354         if (port == NULL)
 355                 return parent;
 356         port++;
 357
 358         parent = skip_subsystem(parent, "usb");
 359         path_prepend(path, "usb-0:%s", port);
 360         return parent;
 361 }
 362
 363 static struct udev_device *handle_cciss(struct udev_device *parent, char **path)
 364 {
 365         return NULL;
 366 }
 367
 368 static struct udev_device *handle_ccw(struct udev_device *parent, struct udev_device *dev, char **path)
 369 {
 370         struct udev_device *scsi_dev;
 371
 372         scsi_dev = udev_device_get_parent_with_subsystem_devtype(dev, "scsi", "scsi_device");
 373         if (scsi_dev != NULL) {
 374                 const char *wwpn;
 375                 const char *lun;
 376                 const char *hba_id;
 377
 378                 hba_id = udev_device_get_sysattr_value(scsi_dev, "hba_id");
 379                 wwpn = udev_device_get_sysattr_value(scsi_dev, "wwpn");
 380                 lun = udev_device_get_sysattr_value(scsi_dev, "fcp_lun");
 381                 if (hba_id != NULL && lun != NULL && wwpn != NULL) {
 382                         path_prepend(path, "ccw-%s-zfcp-%s:%s", hba_id, wwpn, lun);
 383                         goto out;
 384                 }
 385         }
 386
 387         path_prepend(path, "ccw-%s", udev_device_get_sysname(parent));
 388 out:
 389         parent = skip_subsystem(parent, "ccw");
 390         return parent;
 391 }
 392
 393 static int builtin_path_id(struct udev_device *dev, int argc, char *argv[], bool test)
 394 {
 395         struct udev_device *parent;
 396         char *path = NULL;
 397
 398         /* S390 ccw bus */
 399         parent = udev_device_get_parent_with_subsystem_devtype(dev, "ccw", NULL);
 400         if (parent != NULL) {
 401                 handle_ccw(parent, dev, &path);
 402                 goto out;
 403         }
 404
 405         /* walk up the chain of devices and compose path */
 406         parent = dev;
 407         while (parent != NULL) {
 408                 const char *subsys;
 409
 410                 subsys = udev_device_get_subsystem(parent);
 411                 if (subsys == NULL) {
 412                         ;
 413                 } else if (strcmp(subsys, "scsi_tape") == 0) {
 414                         handle_scsi_tape(parent, &path);
 415                 } else if (strcmp(subsys, "scsi") == 0) {
 416                         parent = handle_scsi(parent, &path);
 417                 } else if (strcmp(subsys, "cciss") == 0) {
 418                         handle_cciss(parent, &path);
 419                 } else if (strcmp(subsys, "usb") == 0) {
 420                         parent = handle_usb(parent, &path);
 421                 } else if (strcmp(subsys, "serio") == 0) {
 422                         path_prepend(&path, "serio-%s", udev_device_get_sysnum(parent));
 423                         parent = skip_subsystem(parent, "serio");
 424                 } else if (strcmp(subsys, "pci") == 0) {
 425                         path_prepend(&path, "pci-%s", udev_device_get_sysname(parent));
 426                         parent = skip_subsystem(parent, "pci");
 427                 } else if (strcmp(subsys, "platform") == 0) {
 428                         path_prepend(&path, "platform-%s", udev_device_get_sysname(parent));
 429                         parent = skip_subsystem(parent, "platform");
 430                 } else if (strcmp(subsys, "acpi") == 0) {
 431                         path_prepend(&path, "acpi-%s", udev_device_get_sysname(parent));
 432                         parent = skip_subsystem(parent, "acpi");
 433                 } else if (strcmp(subsys, "xen") == 0) {
 434                         path_prepend(&path, "xen-%s", udev_device_get_sysname(parent));
 435                         parent = skip_subsystem(parent, "xen");
 436                 } else if (strcmp(subsys, "virtio") == 0) {
 437                         path_prepend(&path, "virtio-pci-%s", udev_device_get_sysname(parent));
 438                         parent = skip_subsystem(parent, "virtio");
 439                 }
 440
 441                 parent = udev_device_get_parent(parent);
 442         }
 443 out:
 444         if (path != NULL) {
 445                 char tag[UTIL_NAME_SIZE];
 446                 size_t i;
 447                 const char *p;
 448
 449                 /* compose valid udev tag name */
 450                 for (p = path, i = 0; *p; p++) {
 451                         if ((*p >= '0' && *p <= '9') ||
 452                             (*p >= 'A' && *p <= 'Z') ||
 453                             (*p >= 'a' && *p <= 'z') ||
 454                             *p == '-') {
 455                                 tag[i++] = *p;
 456                                 continue;
 457                         }
 458
 459                         /* skip all leading '_' */
 460                         if (i == 0)
 461                                 continue;
 462
 463                         /* avoid second '_' */
 464                         if (tag[i-1] == '_')
 465                                 continue;
 466
 467                         tag[i++] = '_';
 468                 }
 469                 /* strip trailing '_' */
 470                 while (i > 0 && tag[i-1] == '_')
 471                         i--;
 472                 tag[i] = '\0';
 473
 474                 udev_builtin_add_property(dev, test, "ID_PATH", path);
 475                 udev_builtin_add_property(dev, test, "ID_PATH_TAG", tag);
 476                 free(path);
 477                 return EXIT_SUCCESS;
 478         }
 479         return EXIT_FAILURE;
 480 }
 481
 482 const struct udev_builtin udev_builtin_path_id = {
 483         .name = "path_id",
 484         .cmd = builtin_path_id,
 485         .help = "compose persistent device path",
 486         .run_once = true,
 487 };