src/libsystemd/sd-bus/bus-error.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <stdarg.h>
   5 #include <stdbool.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9
  10 #include "sd-bus.h"
  11
  12 #include "alloc-util.h"
  13 #include "bus-error.h"
  14 #include "errno-list.h"
  15 #include "string-util.h"
  16 #include "util.h"
  17
  18 BUS_ERROR_MAP_ELF_REGISTER const sd_bus_error_map bus_standard_errors[] = {
  19         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.Failed",                           EACCES),
  20         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoMemory",                         ENOMEM),
  21         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.ServiceUnknown",                   EHOSTUNREACH),
  22         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NameHasNoOwner",                   ENXIO),
  23         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoReply",                          ETIMEDOUT),
  24         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.IOError",                          EIO),
  25         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.BadAddress",                       EADDRNOTAVAIL),
  26         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NotSupported",                     EOPNOTSUPP),
  27         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.LimitsExceeded",                   ENOBUFS),
  28         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.AccessDenied",                     EACCES),
  29         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.AuthFailed",                       EACCES),
  30         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InteractiveAuthorizationRequired", EACCES),
  31         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoServer",                         EHOSTDOWN),
  32         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.Timeout",                          ETIMEDOUT),
  33         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoNetwork",                        ENONET),
  34         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.AddressInUse",                     EADDRINUSE),
  35         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.Disconnected",                     ECONNRESET),
  36         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InvalidArgs",                      EINVAL),
  37         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.FileNotFound",                     ENOENT),
  38         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.FileExists",                       EEXIST),
  39         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownMethod",                    EBADR),
  40         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownObject",                    EBADR),
  41         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownInterface",                 EBADR),
  42         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownProperty",                  EBADR),
  43         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.PropertyReadOnly",                 EROFS),
  44         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnixProcessIdUnknown",             ESRCH),
  45         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InvalidSignature",                 EINVAL),
  46         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InconsistentMessage",              EBADMSG),
  47         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.TimedOut",                         ETIMEDOUT),
  48         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.MatchRuleInvalid",                 EINVAL),
  49         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InvalidFileContent",               EINVAL),
  50         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.MatchRuleNotFound",                ENOENT),
  51         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.SELinuxSecurityContextUnknown",    ESRCH),
  52         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.ObjectPathInUse",                  EBUSY),
  53         SD_BUS_ERROR_MAP_END
  54 };
  55
  56 /* GCC maps this magically to the beginning and end of the BUS_ERROR_MAP section */
  57 extern const sd_bus_error_map __start_SYSTEMD_BUS_ERROR_MAP[];
  58 extern const sd_bus_error_map __stop_SYSTEMD_BUS_ERROR_MAP[];
  59
  60 /* Additional maps registered with sd_bus_error_add_map() are in this
  61  * NULL terminated array */
  62 static const sd_bus_error_map **additional_error_maps = NULL;
  63
  64 static int bus_error_name_to_errno(const char *name) {
  65         const sd_bus_error_map **map, *m;
  66         const char *p;
  67         int r;
  68
  69         if (!name)
  70                 return EINVAL;
  71
  72         p = startswith(name, "System.Error.");
  73         if (p) {
  74                 r = errno_from_name(p);
  75                 if (r < 0)
  76                         return EIO;
  77
  78                 return r;
  79         }
  80
  81         if (additional_error_maps)
  82                 for (map = additional_error_maps; *map; map++)
  83                         for (m = *map;; m++) {
  84                                 /* For additional error maps the end marker is actually the end marker */
  85                                 if (m->code == BUS_ERROR_MAP_END_MARKER)
  86                                         break;
  87
  88                                 if (streq(m->name, name))
  89                                         return m->code;
  90                         }
  91
  92         m = ALIGN_TO_PTR(__start_SYSTEMD_BUS_ERROR_MAP, sizeof(void*));
  93         while (m < __stop_SYSTEMD_BUS_ERROR_MAP) {
  94                 /* For magic ELF error maps, the end marker might
  95                  * appear in the middle of things, since multiple maps
  96                  * might appear in the same section. Hence, let's skip
  97                  * over it, but realign the pointer to the next 8 byte
  98                  * boundary, which is the selected alignment for the
  99                  * arrays. */
 100                 if (m->code == BUS_ERROR_MAP_END_MARKER) {
 101                         m = ALIGN_TO_PTR(m + 1, sizeof(void*));
 102                         continue;
 103                 }
 104
 105                 if (streq(m->name, name))
 106                         return m->code;
 107
 108                 m++;
 109         }
 110
 111         return EIO;
 112 }
 113
 114 static sd_bus_error errno_to_bus_error_const(int error) {
 115
 116         if (error < 0)
 117                 error = -error;
 118
 119         switch (error) {
 120
 121         case ENOMEM:
 122                 return BUS_ERROR_OOM;
 123
 124         case EPERM:
 125         case EACCES:
 126                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_ACCESS_DENIED, "Access denied");
 127
 128         case EINVAL:
 129                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid argument");
 130
 131         case ESRCH:
 132                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_UNIX_PROCESS_ID_UNKNOWN, "No such process");
 133
 134         case ENOENT:
 135                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_FILE_NOT_FOUND, "File not found");
 136
 137         case EEXIST:
 138                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_FILE_EXISTS, "File exists");
 139
 140         case ETIMEDOUT:
 141         case ETIME:
 142                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_TIMEOUT, "Timed out");
 143
 144         case EIO:
 145                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_IO_ERROR, "Input/output error");
 146
 147         case ENETRESET:
 148         case ECONNABORTED:
 149         case ECONNRESET:
 150                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_DISCONNECTED, "Disconnected");
 151
 152         case EOPNOTSUPP:
 153                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NOT_SUPPORTED, "Not supported");
 154
 155         case EADDRNOTAVAIL:
 156                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_BAD_ADDRESS, "Address not available");
 157
 158         case ENOBUFS:
 159                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_LIMITS_EXCEEDED, "Limits exceeded");
 160
 161         case EADDRINUSE:
 162                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_ADDRESS_IN_USE, "Address in use");
 163
 164         case EBADMSG:
 165                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INCONSISTENT_MESSAGE, "Inconsistent message");
 166         }
 167
 168         return SD_BUS_ERROR_NULL;
 169 }
 170
 171 static int errno_to_bus_error_name_new(int error, char **ret) {
 172         const char *name;
 173         char *n;
 174
 175         if (error < 0)
 176                 error = -error;
 177
 178         name = errno_to_name(error);
 179         if (!name)
 180                 return 0;
 181
 182         n = strappend("System.Error.", name);
 183         if (!n)
 184                 return -ENOMEM;
 185
 186         *ret = n;
 187         return 1;
 188 }
 189
 190 bool bus_error_is_dirty(sd_bus_error *e) {
 191         if (!e)
 192                 return false;
 193
 194         return e->name || e->message || e->_need_free != 0;
 195 }
 196
 197 _public_ void sd_bus_error_free(sd_bus_error *e) {
 198         if (!e)
 199                 return;
 200
 201         if (e->_need_free > 0) {
 202                 free((void*) e->name);
 203                 free((void*) e->message);
 204         }
 205
 206         *e = SD_BUS_ERROR_NULL;
 207 }
 208
 209 _public_ int sd_bus_error_set(sd_bus_error *e, const char *name, const char *message) {
 210
 211         if (!name)
 212                 return 0;
 213         if (!e)
 214                 goto finish;
 215
 216         assert_return(!bus_error_is_dirty(e), -EINVAL);
 217
 218         e->name = strdup(name);
 219         if (!e->name) {
 220                 *e = BUS_ERROR_OOM;
 221                 return -ENOMEM;
 222         }
 223
 224         if (message)
 225                 e->message = strdup(message);
 226
 227         e->_need_free = 1;
 228
 229 finish:
 230         return -bus_error_name_to_errno(name);
 231 }
 232
 233 int bus_error_setfv(sd_bus_error *e, const char *name, const char *format, va_list ap) {
 234
 235         if (!name)
 236                 return 0;
 237
 238         if (e) {
 239                 assert_return(!bus_error_is_dirty(e), -EINVAL);
 240
 241                 e->name = strdup(name);
 242                 if (!e->name) {
 243                         *e = BUS_ERROR_OOM;
 244                         return -ENOMEM;
 245                 }
 246
 247                 /* If we hit OOM on formatting the pretty message, we ignore
 248                  * this, since we at least managed to write the error name */
 249                 if (format)
 250                         (void) vasprintf((char**) &e->message, format, ap);
 251
 252                 e->_need_free = 1;
 253         }
 254
 255         return -bus_error_name_to_errno(name);
 256 }
 257
 258 _public_ int sd_bus_error_setf(sd_bus_error *e, const char *name, const char *format, ...) {
 259
 260         if (format) {
 261                 int r;
 262                 va_list ap;
 263
 264                 va_start(ap, format);
 265                 r = bus_error_setfv(e, name, format, ap);
 266                 va_end(ap);
 267
 268                 return r;
 269         }
 270
 271         return sd_bus_error_set(e, name, NULL);
 272 }
 273
 274 _public_ int sd_bus_error_copy(sd_bus_error *dest, const sd_bus_error *e) {
 275
 276         if (!sd_bus_error_is_set(e))
 277                 return 0;
 278         if (!dest)
 279                 goto finish;
 280
 281         assert_return(!bus_error_is_dirty(dest), -EINVAL);
 282
 283         /*
 284          * _need_free  < 0 indicates that the error is temporarily const, needs deep copying
 285          * _need_free == 0 indicates that the error is perpetually const, needs no deep copying
 286          * _need_free  > 0 indicates that the error is fully dynamic, needs deep copying
 287          */
 288
 289         if (e->_need_free == 0)
 290                 *dest = *e;
 291         else {
 292                 dest->name = strdup(e->name);
 293                 if (!dest->name) {
 294                         *dest = BUS_ERROR_OOM;
 295                         return -ENOMEM;
 296                 }
 297
 298                 if (e->message)
 299                         dest->message = strdup(e->message);
 300
 301                 dest->_need_free = 1;
 302         }
 303
 304 finish:
 305         return -bus_error_name_to_errno(e->name);
 306 }
 307
 308 _public_ int sd_bus_error_move(sd_bus_error *dest, sd_bus_error *e) {
 309         int r;
 310
 311         if (!sd_bus_error_is_set(e)) {
 312
 313                 if (dest)
 314                         *dest = SD_BUS_ERROR_NULL;
 315
 316                 return 0;
 317         }
 318
 319         r = -bus_error_name_to_errno(e->name);
 320
 321         if (dest) {
 322                 *dest = *e;
 323                 *e = SD_BUS_ERROR_NULL;
 324         } else
 325                 sd_bus_error_free(e);
 326
 327         return r;
 328 }
 329
 330 _public_ int sd_bus_error_set_const(sd_bus_error *e, const char *name, const char *message) {
 331         if (!name)
 332                 return 0;
 333         if (!e)
 334                 goto finish;
 335
 336         assert_return(!bus_error_is_dirty(e), -EINVAL);
 337
 338         *e = SD_BUS_ERROR_MAKE_CONST(name, message);
 339
 340 finish:
 341         return -bus_error_name_to_errno(name);
 342 }
 343
 344 _public_ int sd_bus_error_is_set(const sd_bus_error *e) {
 345         if (!e)
 346                 return 0;
 347
 348         return !!e->name;
 349 }
 350
 351 _public_ int sd_bus_error_has_name(const sd_bus_error *e, const char *name) {
 352         if (!e)
 353                 return 0;
 354
 355         return streq_ptr(e->name, name);
 356 }
 357
 358 _public_ int sd_bus_error_get_errno(const sd_bus_error* e) {
 359         if (!e)
 360                 return 0;
 361
 362         if (!e->name)
 363                 return 0;
 364
 365         return bus_error_name_to_errno(e->name);
 366 }
 367
 368 static void bus_error_strerror(sd_bus_error *e, int error) {
 369         size_t k = 64;
 370         char *m;
 371
 372         assert(e);
 373
 374         for (;;) {
 375                 char *x;
 376
 377                 m = new(char, k);
 378                 if (!m)
 379                         return;
 380
 381                 errno = 0;
 382                 x = strerror_r(error, m, k);
 383                 if (errno == ERANGE || strlen(x) >= k - 1) {
 384                         free(m);
 385                         k *= 2;
 386                         continue;
 387                 }
 388
 389                 if (errno) {
 390                         free(m);
 391                         return;
 392                 }
 393
 394                 if (x == m) {
 395                         if (e->_need_free > 0) {
 396                                 /* Error is already dynamic, let's just update the message */
 397                                 free((char*) e->message);
 398                                 e->message = x;
 399
 400                         } else {
 401                                 char *t;
 402                                 /* Error was const so far, let's make it dynamic, if we can */
 403
 404                                 t = strdup(e->name);
 405                                 if (!t) {
 406                                         free(m);
 407                                         return;
 408                                 }
 409
 410                                 e->_need_free = 1;
 411                                 e->name = t;
 412                                 e->message = x;
 413                         }
 414                 } else {
 415                         free(m);
 416
 417                         if (e->_need_free > 0) {
 418                                 char *t;
 419
 420                                 /* Error is dynamic, let's hence make the message also dynamic */
 421                                 t = strdup(x);
 422                                 if (!t)
 423                                         return;
 424
 425                                 free((char*) e->message);
 426                                 e->message = t;
 427                         } else {
 428                                 /* Error is const, hence we can just override */
 429                                 e->message = x;
 430                         }
 431                 }
 432
 433                 return;
 434         }
 435 }
 436
 437 _public_ int sd_bus_error_set_errno(sd_bus_error *e, int error) {
 438
 439         if (error < 0)
 440                 error = -error;
 441
 442         if (!e)
 443                 return -error;
 444         if (error == 0)
 445                 return -error;
 446
 447         assert_return(!bus_error_is_dirty(e), -EINVAL);
 448
 449         /* First, try a const translation */
 450         *e = errno_to_bus_error_const(error);
 451
 452         if (!sd_bus_error_is_set(e)) {
 453                 int k;
 454
 455                 /* If that didn't work, try a dynamic one. */
 456
 457                 k = errno_to_bus_error_name_new(error, (char**) &e->name);
 458                 if (k > 0)
 459                         e->_need_free = 1;
 460                 else if (k < 0) {
 461                         *e = BUS_ERROR_OOM;
 462                         return -error;
 463                 } else
 464                         *e = BUS_ERROR_FAILED;
 465         }
 466
 467         /* Now, fill in the message from strerror() if we can */
 468         bus_error_strerror(e, error);
 469         return -error;
 470 }
 471
 472 _public_ int sd_bus_error_set_errnofv(sd_bus_error *e, int error, const char *format, va_list ap) {
 473         PROTECT_ERRNO;
 474         int r;
 475
 476         if (error < 0)
 477                 error = -error;
 478
 479         if (!e)
 480                 return -error;
 481         if (error == 0)
 482                 return 0;
 483
 484         assert_return(!bus_error_is_dirty(e), -EINVAL);
 485
 486         /* First, try a const translation */
 487         *e = errno_to_bus_error_const(error);
 488
 489         if (!sd_bus_error_is_set(e)) {
 490                 int k;
 491
 492                 /* If that didn't work, try a dynamic one */
 493
 494                 k = errno_to_bus_error_name_new(error, (char**) &e->name);
 495                 if (k > 0)
 496                         e->_need_free = 1;
 497                 else if (k < 0) {
 498                         *e = BUS_ERROR_OOM;
 499                         return -ENOMEM;
 500                 } else
 501                         *e = BUS_ERROR_FAILED;
 502         }
 503
 504         if (format) {
 505                 char *m;
 506
 507                 /* Then, let's try to fill in the supplied message */
 508
 509                 errno = error; /* Make sure that %m resolves to the specified error */
 510                 r = vasprintf(&m, format, ap);
 511                 if (r >= 0) {
 512
 513                         if (e->_need_free <= 0) {
 514                                 char *t;
 515
 516                                 t = strdup(e->name);
 517                                 if (t) {
 518                                         e->_need_free = 1;
 519                                         e->name = t;
 520                                         e->message = m;
 521                                         return -error;
 522                                 }
 523
 524                                 free(m);
 525                         } else {
 526                                 free((char*) e->message);
 527                                 e->message = m;
 528                                 return -error;
 529                         }
 530                 }
 531         }
 532
 533         /* If that didn't work, use strerror() for the message */
 534         bus_error_strerror(e, error);
 535         return -error;
 536 }
 537
 538 _public_ int sd_bus_error_set_errnof(sd_bus_error *e, int error, const char *format, ...) {
 539         int r;
 540
 541         if (error < 0)
 542                 error = -error;
 543
 544         if (!e)
 545                 return -error;
 546         if (error == 0)
 547                 return 0;
 548
 549         assert_return(!bus_error_is_dirty(e), -EINVAL);
 550
 551         if (format) {
 552                 va_list ap;
 553
 554                 va_start(ap, format);
 555                 r = sd_bus_error_set_errnofv(e, error, format, ap);
 556                 va_end(ap);
 557
 558                 return r;
 559         }
 560
 561         return sd_bus_error_set_errno(e, error);
 562 }
 563
 564 const char *bus_error_message(const sd_bus_error *e, int error) {
 565
 566         if (e) {
 567                 /* Sometimes, the D-Bus server is a little bit too verbose with
 568                  * its error messages, so let's override them here */
 569                 if (sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED))
 570                         return "Access denied";
 571
 572                 if (e->message)
 573                         return e->message;
 574         }
 575
 576         if (error < 0)
 577                 error = -error;
 578
 579         return strerror(error);
 580 }
 581
 582 static bool map_ok(const sd_bus_error_map *map) {
 583         for (; map->code != BUS_ERROR_MAP_END_MARKER; map++)
 584                 if (!map->name || map->code <=0)
 585                         return false;
 586         return true;
 587 }
 588
 589 _public_ int sd_bus_error_add_map(const sd_bus_error_map *map) {
 590         const sd_bus_error_map **maps = NULL;
 591         unsigned n = 0;
 592
 593         assert_return(map, -EINVAL);
 594         assert_return(map_ok(map), -EINVAL);
 595
 596         if (additional_error_maps)
 597                 for (; additional_error_maps[n] != NULL; n++)
 598                         if (additional_error_maps[n] == map)
 599                                 return 0;
 600
 601         maps = reallocarray(additional_error_maps, n + 2, sizeof(struct sd_bus_error_map*));
 602         if (!maps)
 603                 return -ENOMEM;
 604
 605         maps[n] = map;
 606         maps[n+1] = NULL;
 607
 608         additional_error_maps = maps;
 609         return 1;
 610 }