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

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2
   3 #include <errno.h>
   4 #include <stdarg.h>
   5 #include <stdbool.h>
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8
   9 #include "sd-bus.h"
  10
  11 #include "alloc-util.h"
  12 #include "bus-error.h"
  13 #include "errno-list.h"
  14 #include "errno-util.h"
  15 #include "string-util.h"
  16 #include "strv.h"
  17 #include "util.h"
  18
  19 BUS_ERROR_MAP_ELF_REGISTER const sd_bus_error_map bus_standard_errors[] = {
  20         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.Failed",                           EACCES),
  21         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoMemory",                         ENOMEM),
  22         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.ServiceUnknown",                   EHOSTUNREACH),
  23         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NameHasNoOwner",                   ENXIO),
  24         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoReply",                          ETIMEDOUT),
  25         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.IOError",                          EIO),
  26         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.BadAddress",                       EADDRNOTAVAIL),
  27         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NotSupported",                     EOPNOTSUPP),
  28         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.LimitsExceeded",                   ENOBUFS),
  29         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.AccessDenied",                     EACCES),
  30         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.AuthFailed",                       EACCES),
  31         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InteractiveAuthorizationRequired", EACCES),
  32         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoServer",                         EHOSTDOWN),
  33         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.Timeout",                          ETIMEDOUT),
  34         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.NoNetwork",                        ENONET),
  35         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.AddressInUse",                     EADDRINUSE),
  36         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.Disconnected",                     ECONNRESET),
  37         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InvalidArgs",                      EINVAL),
  38         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.FileNotFound",                     ENOENT),
  39         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.FileExists",                       EEXIST),
  40         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownMethod",                    EBADR),
  41         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownObject",                    EBADR),
  42         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownInterface",                 EBADR),
  43         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnknownProperty",                  EBADR),
  44         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.PropertyReadOnly",                 EROFS),
  45         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.UnixProcessIdUnknown",             ESRCH),
  46         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InvalidSignature",                 EINVAL),
  47         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InconsistentMessage",              EBADMSG),
  48         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.TimedOut",                         ETIMEDOUT),
  49         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.MatchRuleInvalid",                 EINVAL),
  50         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.InvalidFileContent",               EINVAL),
  51         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.MatchRuleNotFound",                ENOENT),
  52         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.SELinuxSecurityContextUnknown",    ESRCH),
  53         SD_BUS_ERROR_MAP("org.freedesktop.DBus.Error.ObjectPathInUse",                  EBUSY),
  54         SD_BUS_ERROR_MAP_END
  55 };
  56
  57 /* GCC maps this magically to the beginning and end of the BUS_ERROR_MAP section */
  58 extern const sd_bus_error_map __start_SYSTEMD_BUS_ERROR_MAP[];
  59 extern const sd_bus_error_map __stop_SYSTEMD_BUS_ERROR_MAP[];
  60
  61 /* Additional maps registered with sd_bus_error_add_map() are in this
  62  * NULL terminated array */
  63 static const sd_bus_error_map **additional_error_maps = NULL;
  64
  65 static int bus_error_name_to_errno(const char *name) {
  66         const sd_bus_error_map **map, *m;
  67         const char *p;
  68         int r;
  69
  70         if (!name)
  71                 return EINVAL;
  72
  73         p = startswith(name, "System.Error.");
  74         if (p) {
  75                 r = errno_from_name(p);
  76                 if (r < 0)
  77                         return EIO;
  78
  79                 return r;
  80         }
  81
  82         if (additional_error_maps)
  83                 for (map = additional_error_maps; *map; map++)
  84                         for (m = *map;; m++) {
  85                                 /* For additional error maps the end marker is actually the end marker */
  86                                 if (m->code == BUS_ERROR_MAP_END_MARKER)
  87                                         break;
  88
  89                                 if (streq(m->name, name))
  90                                         return m->code;
  91                         }
  92
  93         m = ALIGN_TO_PTR(__start_SYSTEMD_BUS_ERROR_MAP, sizeof(void*));
  94         while (m < __stop_SYSTEMD_BUS_ERROR_MAP) {
  95                 /* For magic ELF error maps, the end marker might
  96                  * appear in the middle of things, since multiple maps
  97                  * might appear in the same section. Hence, let's skip
  98                  * over it, but realign the pointer to the next 8 byte
  99                  * boundary, which is the selected alignment for the
 100                  * arrays. */
 101                 if (m->code == BUS_ERROR_MAP_END_MARKER) {
 102                         m = ALIGN_TO_PTR(m + 1, sizeof(void*));
 103                         continue;
 104                 }
 105
 106                 if (streq(m->name, name))
 107                         return m->code;
 108
 109                 m++;
 110         }
 111
 112         return EIO;
 113 }
 114
 115 static sd_bus_error errno_to_bus_error_const(int error) {
 116
 117         if (error < 0)
 118                 error = -error;
 119
 120         switch (error) {
 121
 122         case ENOMEM:
 123                 return BUS_ERROR_OOM;
 124
 125         case EPERM:
 126         case EACCES:
 127                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_ACCESS_DENIED, "Access denied");
 128
 129         case EINVAL:
 130                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid argument");
 131
 132         case ESRCH:
 133                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_UNIX_PROCESS_ID_UNKNOWN, "No such process");
 134
 135         case ENOENT:
 136                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_FILE_NOT_FOUND, "File not found");
 137
 138         case EEXIST:
 139                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_FILE_EXISTS, "File exists");
 140
 141         case ETIMEDOUT:
 142         case ETIME:
 143                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_TIMEOUT, "Timed out");
 144
 145         case EIO:
 146                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_IO_ERROR, "Input/output error");
 147
 148         case ENETRESET:
 149         case ECONNABORTED:
 150         case ECONNRESET:
 151                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_DISCONNECTED, "Disconnected");
 152
 153         case EOPNOTSUPP:
 154                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NOT_SUPPORTED, "Not supported");
 155
 156         case EADDRNOTAVAIL:
 157                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_BAD_ADDRESS, "Address not available");
 158
 159         case ENOBUFS:
 160                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_LIMITS_EXCEEDED, "Limits exceeded");
 161
 162         case EADDRINUSE:
 163                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_ADDRESS_IN_USE, "Address in use");
 164
 165         case EBADMSG:
 166                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INCONSISTENT_MESSAGE, "Inconsistent message");
 167         }
 168
 169         return SD_BUS_ERROR_NULL;
 170 }
 171
 172 static int errno_to_bus_error_name_new(int error, char **ret) {
 173         const char *name;
 174         char *n;
 175
 176         if (error < 0)
 177                 error = -error;
 178
 179         name = errno_to_name(error);
 180         if (!name)
 181                 return 0;
 182
 183         n = strjoin("System.Error.", name);
 184         if (!n)
 185                 return -ENOMEM;
 186
 187         *ret = n;
 188         return 1;
 189 }
 190
 191 bool bus_error_is_dirty(sd_bus_error *e) {
 192         if (!e)
 193                 return false;
 194
 195         return e->name || e->message || e->_need_free != 0;
 196 }
 197
 198 _public_ void sd_bus_error_free(sd_bus_error *e) {
 199         if (!e)
 200                 return;
 201
 202         if (e->_need_free > 0) {
 203                 free((void*) e->name);
 204                 free((void*) e->message);
 205         }
 206
 207         *e = SD_BUS_ERROR_NULL;
 208 }
 209
 210 _public_ int sd_bus_error_set(sd_bus_error *e, const char *name, const char *message) {
 211
 212         if (!name)
 213                 return 0;
 214         if (!e)
 215                 goto finish;
 216
 217         assert_return(!bus_error_is_dirty(e), -EINVAL);
 218
 219         e->name = strdup(name);
 220         if (!e->name) {
 221                 *e = BUS_ERROR_OOM;
 222                 return -ENOMEM;
 223         }
 224
 225         if (message)
 226                 e->message = strdup(message);
 227
 228         e->_need_free = 1;
 229
 230 finish:
 231         return -bus_error_name_to_errno(name);
 232 }
 233
 234 int bus_error_setfv(sd_bus_error *e, const char *name, const char *format, va_list ap) {
 235
 236         if (!name)
 237                 return 0;
 238
 239         if (e) {
 240                 assert_return(!bus_error_is_dirty(e), -EINVAL);
 241
 242                 e->name = strdup(name);
 243                 if (!e->name) {
 244                         *e = BUS_ERROR_OOM;
 245                         return -ENOMEM;
 246                 }
 247
 248                 /* If we hit OOM on formatting the pretty message, we ignore
 249                  * this, since we at least managed to write the error name */
 250                 if (format)
 251                         (void) vasprintf((char**) &e->message, format, ap);
 252
 253                 e->_need_free = 1;
 254         }
 255
 256         return -bus_error_name_to_errno(name);
 257 }
 258
 259 _public_ int sd_bus_error_setf(sd_bus_error *e, const char *name, const char *format, ...) {
 260
 261         if (format) {
 262                 int r;
 263                 va_list ap;
 264
 265                 va_start(ap, format);
 266                 r = bus_error_setfv(e, name, format, ap);
 267                 va_end(ap);
 268
 269                 return r;
 270         }
 271
 272         return sd_bus_error_set(e, name, NULL);
 273 }
 274
 275 _public_ int sd_bus_error_copy(sd_bus_error *dest, const sd_bus_error *e) {
 276
 277         if (!sd_bus_error_is_set(e))
 278                 return 0;
 279         if (!dest)
 280                 goto finish;
 281
 282         assert_return(!bus_error_is_dirty(dest), -EINVAL);
 283
 284         /*
 285          * _need_free  < 0 indicates that the error is temporarily const, needs deep copying
 286          * _need_free == 0 indicates that the error is perpetually const, needs no deep copying
 287          * _need_free  > 0 indicates that the error is fully dynamic, needs deep copying
 288          */
 289
 290         if (e->_need_free == 0)
 291                 *dest = *e;
 292         else {
 293                 dest->name = strdup(e->name);
 294                 if (!dest->name) {
 295                         *dest = BUS_ERROR_OOM;
 296                         return -ENOMEM;
 297                 }
 298
 299                 if (e->message)
 300                         dest->message = strdup(e->message);
 301
 302                 dest->_need_free = 1;
 303         }
 304
 305 finish:
 306         return -bus_error_name_to_errno(e->name);
 307 }
 308
 309 _public_ int sd_bus_error_move(sd_bus_error *dest, sd_bus_error *e) {
 310         int r;
 311
 312         if (!sd_bus_error_is_set(e)) {
 313
 314                 if (dest)
 315                         *dest = SD_BUS_ERROR_NULL;
 316
 317                 return 0;
 318         }
 319
 320         r = -bus_error_name_to_errno(e->name);
 321
 322         if (dest) {
 323                 *dest = *e;
 324                 *e = SD_BUS_ERROR_NULL;
 325         } else
 326                 sd_bus_error_free(e);
 327
 328         return r;
 329 }
 330
 331 _public_ int sd_bus_error_set_const(sd_bus_error *e, const char *name, const char *message) {
 332         if (!name)
 333                 return 0;
 334         if (!e)
 335                 goto finish;
 336
 337         assert_return(!bus_error_is_dirty(e), -EINVAL);
 338
 339         *e = SD_BUS_ERROR_MAKE_CONST(name, message);
 340
 341 finish:
 342         return -bus_error_name_to_errno(name);
 343 }
 344
 345 _public_ int sd_bus_error_is_set(const sd_bus_error *e) {
 346         if (!e)
 347                 return 0;
 348
 349         return !!e->name;
 350 }
 351
 352 _public_ int sd_bus_error_has_name(const sd_bus_error *e, const char *name) {
 353         if (!e)
 354                 return 0;
 355
 356         return streq_ptr(e->name, name);
 357 }
 358
 359 _public_ int sd_bus_error_has_names_sentinel(const sd_bus_error *e, ...) {
 360         if (!e || !e->name)
 361                 return 0;
 362
 363         va_list ap;
 364         const char *p;
 365
 366         va_start(ap, e);
 367         while ((p = va_arg(ap, const char *)))
 368                 if (streq(p, e->name))
 369                         break;
 370         va_end(ap);
 371         return !!p;
 372 }
 373
 374 _public_ int sd_bus_error_get_errno(const sd_bus_error* e) {
 375         if (!e || !e->name)
 376                 return 0;
 377
 378         return bus_error_name_to_errno(e->name);
 379 }
 380
 381 static void bus_error_strerror(sd_bus_error *e, int error) {
 382         size_t k = 64;
 383         char *m;
 384
 385         assert(e);
 386
 387         for (;;) {
 388                 char *x;
 389
 390                 m = new(char, k);
 391                 if (!m)
 392                         return;
 393
 394                 errno = 0;
 395                 x = strerror_r(error, m, k);
 396                 if (errno == ERANGE || strlen(x) >= k - 1) {
 397                         free(m);
 398                         k *= 2;
 399                         continue;
 400                 }
 401
 402                 if (errno) {
 403                         free(m);
 404                         return;
 405                 }
 406
 407                 if (x == m) {
 408                         if (e->_need_free > 0) {
 409                                 /* Error is already dynamic, let's just update the message */
 410                                 free((char*) e->message);
 411                                 e->message = x;
 412
 413                         } else {
 414                                 char *t;
 415                                 /* Error was const so far, let's make it dynamic, if we can */
 416
 417                                 t = strdup(e->name);
 418                                 if (!t) {
 419                                         free(m);
 420                                         return;
 421                                 }
 422
 423                                 e->_need_free = 1;
 424                                 e->name = t;
 425                                 e->message = x;
 426                         }
 427                 } else {
 428                         free(m);
 429
 430                         if (e->_need_free > 0) {
 431                                 char *t;
 432
 433                                 /* Error is dynamic, let's hence make the message also dynamic */
 434                                 t = strdup(x);
 435                                 if (!t)
 436                                         return;
 437
 438                                 free((char*) e->message);
 439                                 e->message = t;
 440                         } else {
 441                                 /* Error is const, hence we can just override */
 442                                 e->message = x;
 443                         }
 444                 }
 445
 446                 return;
 447         }
 448 }
 449
 450 _public_ int sd_bus_error_set_errno(sd_bus_error *e, int error) {
 451
 452         if (error < 0)
 453                 error = -error;
 454
 455         if (!e)
 456                 return -error;
 457         if (error == 0)
 458                 return -error;
 459
 460         assert_return(!bus_error_is_dirty(e), -EINVAL);
 461
 462         /* First, try a const translation */
 463         *e = errno_to_bus_error_const(error);
 464
 465         if (!sd_bus_error_is_set(e)) {
 466                 int k;
 467
 468                 /* If that didn't work, try a dynamic one. */
 469
 470                 k = errno_to_bus_error_name_new(error, (char**) &e->name);
 471                 if (k > 0)
 472                         e->_need_free = 1;
 473                 else if (k < 0) {
 474                         *e = BUS_ERROR_OOM;
 475                         return -error;
 476                 } else
 477                         *e = BUS_ERROR_FAILED;
 478         }
 479
 480         /* Now, fill in the message from strerror() if we can */
 481         bus_error_strerror(e, error);
 482         return -error;
 483 }
 484
 485 _public_ int sd_bus_error_set_errnofv(sd_bus_error *e, int error, const char *format, va_list ap) {
 486         PROTECT_ERRNO;
 487
 488         if (error < 0)
 489                 error = -error;
 490
 491         if (!e)
 492                 return -error;
 493         if (error == 0)
 494                 return 0;
 495
 496         assert_return(!bus_error_is_dirty(e), -EINVAL);
 497
 498         /* First, try a const translation */
 499         *e = errno_to_bus_error_const(error);
 500
 501         if (!sd_bus_error_is_set(e)) {
 502                 int k;
 503
 504                 /* If that didn't work, try a dynamic one */
 505
 506                 k = errno_to_bus_error_name_new(error, (char**) &e->name);
 507                 if (k > 0)
 508                         e->_need_free = 1;
 509                 else if (k < 0) {
 510                         *e = BUS_ERROR_OOM;
 511                         return -ENOMEM;
 512                 } else
 513                         *e = BUS_ERROR_FAILED;
 514         }
 515
 516         if (format) {
 517                 _cleanup_free_ char *m = NULL;
 518
 519                 /* Then, let's try to fill in the supplied message */
 520
 521                 errno = error; /* Make sure that %m resolves to the specified error */
 522                 if (vasprintf(&m, format, ap) < 0)
 523                         goto fail;
 524
 525                 if (e->_need_free <= 0) {
 526                         char *t;
 527
 528                         t = strdup(e->name);
 529                         if (!t)
 530                                 goto fail;
 531
 532                         e->_need_free = 1;
 533                         e->name = t;
 534                 }
 535
 536                 e->message = TAKE_PTR(m);
 537                 return -error;
 538         }
 539
 540 fail:
 541         /* If that didn't work, use strerror() for the message */
 542         bus_error_strerror(e, error);
 543         return -error;
 544 }
 545
 546 _public_ int sd_bus_error_set_errnof(sd_bus_error *e, int error, const char *format, ...) {
 547         int r;
 548
 549         if (error < 0)
 550                 error = -error;
 551
 552         if (!e)
 553                 return -error;
 554         if (error == 0)
 555                 return 0;
 556
 557         assert_return(!bus_error_is_dirty(e), -EINVAL);
 558
 559         if (format) {
 560                 va_list ap;
 561
 562                 va_start(ap, format);
 563                 r = sd_bus_error_set_errnofv(e, error, format, ap);
 564                 va_end(ap);
 565
 566                 return r;
 567         }
 568
 569         return sd_bus_error_set_errno(e, error);
 570 }
 571
 572 const char *bus_error_message(const sd_bus_error *e, int error) {
 573
 574         if (e) {
 575                 /* Sometimes, the D-Bus server is a little bit too verbose with
 576                  * its error messages, so let's override them here */
 577                 if (sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED))
 578                         return "Access denied";
 579
 580                 if (e->message)
 581                         return e->message;
 582         }
 583
 584         return strerror_safe(abs(error));
 585 }
 586
 587 static bool map_ok(const sd_bus_error_map *map) {
 588         for (; map->code != BUS_ERROR_MAP_END_MARKER; map++)
 589                 if (!map->name || map->code <=0)
 590                         return false;
 591         return true;
 592 }
 593
 594 _public_ int sd_bus_error_add_map(const sd_bus_error_map *map) {
 595         const sd_bus_error_map **maps = NULL;
 596         unsigned n = 0;
 597
 598         assert_return(map, -EINVAL);
 599         assert_return(map_ok(map), -EINVAL);
 600
 601         if (additional_error_maps)
 602                 for (; additional_error_maps[n] != NULL; n++)
 603                         if (additional_error_maps[n] == map)
 604                                 return 0;
 605
 606         maps = reallocarray(additional_error_maps, n + 2, sizeof(struct sd_bus_error_map*));
 607         if (!maps)
 608                 return -ENOMEM;
 609
 610         maps[n] = map;
 611         maps[n+1] = NULL;
 612
 613         additional_error_maps = maps;
 614         return 1;
 615 }