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_BUS_ERROR_MAP[];
  58 extern const sd_bus_error_map __stop_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 = __start_BUS_ERROR_MAP;
  93 #ifndef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
  94         while (m < __stop_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 = ALIGN8_PTR(m+1);
 103                         continue;
 104                 }
 105
 106                 if (streq(m->name, name))
 107                         return m->code;
 108
 109                 m++;
 110         }
 111 #endif
 112
 113         return EIO;
 114 }
 115
 116 static sd_bus_error errno_to_bus_error_const(int error) {
 117
 118         if (error < 0)
 119                 error = -error;
 120
 121         switch (error) {
 122
 123         case ENOMEM:
 124                 return BUS_ERROR_OOM;
 125
 126         case EPERM:
 127         case EACCES:
 128                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_ACCESS_DENIED, "Access denied");
 129
 130         case EINVAL:
 131                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INVALID_ARGS, "Invalid argument");
 132
 133         case ESRCH:
 134                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_UNIX_PROCESS_ID_UNKNOWN, "No such process");
 135
 136         case ENOENT:
 137                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_FILE_NOT_FOUND, "File not found");
 138
 139         case EEXIST:
 140                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_FILE_EXISTS, "File exists");
 141
 142         case ETIMEDOUT:
 143         case ETIME:
 144                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_TIMEOUT, "Timed out");
 145
 146         case EIO:
 147                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_IO_ERROR, "Input/output error");
 148
 149         case ENETRESET:
 150         case ECONNABORTED:
 151         case ECONNRESET:
 152                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_DISCONNECTED, "Disconnected");
 153
 154         case EOPNOTSUPP:
 155                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_NOT_SUPPORTED, "Not supported");
 156
 157         case EADDRNOTAVAIL:
 158                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_BAD_ADDRESS, "Address not available");
 159
 160         case ENOBUFS:
 161                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_LIMITS_EXCEEDED, "Limits exceeded");
 162
 163         case EADDRINUSE:
 164                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_ADDRESS_IN_USE, "Address in use");
 165
 166         case EBADMSG:
 167                 return SD_BUS_ERROR_MAKE_CONST(SD_BUS_ERROR_INCONSISTENT_MESSAGE, "Inconsistent message");
 168         }
 169
 170         return SD_BUS_ERROR_NULL;
 171 }
 172
 173 static int errno_to_bus_error_name_new(int error, char **ret) {
 174         const char *name;
 175         char *n;
 176
 177         if (error < 0)
 178                 error = -error;
 179
 180         name = errno_to_name(error);
 181         if (!name)
 182                 return 0;
 183
 184         n = strappend("System.Error.", name);
 185         if (!n)
 186                 return -ENOMEM;
 187
 188         *ret = n;
 189         return 1;
 190 }
 191
 192 bool bus_error_is_dirty(sd_bus_error *e) {
 193         if (!e)
 194                 return false;
 195
 196         return e->name || e->message || e->_need_free != 0;
 197 }
 198
 199 _public_ void sd_bus_error_free(sd_bus_error *e) {
 200         if (!e)
 201                 return;
 202
 203         if (e->_need_free > 0) {
 204                 free((void*) e->name);
 205                 free((void*) e->message);
 206         }
 207
 208         *e = SD_BUS_ERROR_NULL;
 209 }
 210
 211 _public_ int sd_bus_error_set(sd_bus_error *e, const char *name, const char *message) {
 212
 213         if (!name)
 214                 return 0;
 215         if (!e)
 216                 goto finish;
 217
 218         assert_return(!bus_error_is_dirty(e), -EINVAL);
 219
 220         e->name = strdup(name);
 221         if (!e->name) {
 222                 *e = BUS_ERROR_OOM;
 223                 return -ENOMEM;
 224         }
 225
 226         if (message)
 227                 e->message = strdup(message);
 228
 229         e->_need_free = 1;
 230
 231 finish:
 232         return -bus_error_name_to_errno(name);
 233 }
 234
 235 int bus_error_setfv(sd_bus_error *e, const char *name, const char *format, va_list ap) {
 236
 237         if (!name)
 238                 return 0;
 239
 240         if (e) {
 241                 assert_return(!bus_error_is_dirty(e), -EINVAL);
 242
 243                 e->name = strdup(name);
 244                 if (!e->name) {
 245                         *e = BUS_ERROR_OOM;
 246                         return -ENOMEM;
 247                 }
 248
 249                 /* If we hit OOM on formatting the pretty message, we ignore
 250                  * this, since we at least managed to write the error name */
 251                 if (format)
 252                         (void) vasprintf((char**) &e->message, format, ap);
 253
 254                 e->_need_free = 1;
 255         }
 256
 257         return -bus_error_name_to_errno(name);
 258 }
 259
 260 _public_ int sd_bus_error_setf(sd_bus_error *e, const char *name, const char *format, ...) {
 261
 262         if (format) {
 263                 int r;
 264                 va_list ap;
 265
 266                 va_start(ap, format);
 267                 r = bus_error_setfv(e, name, format, ap);
 268                 va_end(ap);
 269
 270                 return r;
 271         }
 272
 273         return sd_bus_error_set(e, name, NULL);
 274 }
 275
 276 _public_ int sd_bus_error_copy(sd_bus_error *dest, const sd_bus_error *e) {
 277
 278         if (!sd_bus_error_is_set(e))
 279                 return 0;
 280         if (!dest)
 281                 goto finish;
 282
 283         assert_return(!bus_error_is_dirty(dest), -EINVAL);
 284
 285         /*
 286          * _need_free  < 0 indicates that the error is temporarily const, needs deep copying
 287          * _need_free == 0 indicates that the error is perpetually const, needs no deep copying
 288          * _need_free  > 0 indicates that the error is fully dynamic, needs deep copying
 289          */
 290
 291         if (e->_need_free == 0)
 292                 *dest = *e;
 293         else {
 294                 dest->name = strdup(e->name);
 295                 if (!dest->name) {
 296                         *dest = BUS_ERROR_OOM;
 297                         return -ENOMEM;
 298                 }
 299
 300                 if (e->message)
 301                         dest->message = strdup(e->message);
 302
 303                 dest->_need_free = 1;
 304         }
 305
 306 finish:
 307         return -bus_error_name_to_errno(e->name);
 308 }
 309
 310 _public_ int sd_bus_error_move(sd_bus_error *dest, sd_bus_error *e) {
 311         int r;
 312
 313         if (!sd_bus_error_is_set(e)) {
 314
 315                 if (dest)
 316                         *dest = SD_BUS_ERROR_NULL;
 317
 318                 return 0;
 319         }
 320
 321         r = -bus_error_name_to_errno(e->name);
 322
 323         if (dest) {
 324                 *dest = *e;
 325                 *e = SD_BUS_ERROR_NULL;
 326         } else
 327                 sd_bus_error_free(e);
 328
 329         return r;
 330 }
 331
 332 _public_ int sd_bus_error_set_const(sd_bus_error *e, const char *name, const char *message) {
 333         if (!name)
 334                 return 0;
 335         if (!e)
 336                 goto finish;
 337
 338         assert_return(!bus_error_is_dirty(e), -EINVAL);
 339
 340         *e = SD_BUS_ERROR_MAKE_CONST(name, message);
 341
 342 finish:
 343         return -bus_error_name_to_errno(name);
 344 }
 345
 346 _public_ int sd_bus_error_is_set(const sd_bus_error *e) {
 347         if (!e)
 348                 return 0;
 349
 350         return !!e->name;
 351 }
 352
 353 _public_ int sd_bus_error_has_name(const sd_bus_error *e, const char *name) {
 354         if (!e)
 355                 return 0;
 356
 357         return streq_ptr(e->name, name);
 358 }
 359
 360 _public_ int sd_bus_error_get_errno(const sd_bus_error* e) {
 361         if (!e)
 362                 return 0;
 363
 364         if (!e->name)
 365                 return 0;
 366
 367         return bus_error_name_to_errno(e->name);
 368 }
 369
 370 static void bus_error_strerror(sd_bus_error *e, int error) {
 371         size_t k = 64;
 372         char *m;
 373
 374         assert(e);
 375
 376         for (;;) {
 377                 char *x;
 378
 379                 m = new(char, k);
 380                 if (!m)
 381                         return;
 382
 383                 errno = 0;
 384                 x = strerror_r(error, m, k);
 385                 if (errno == ERANGE || strlen(x) >= k - 1) {
 386                         free(m);
 387                         k *= 2;
 388                         continue;
 389                 }
 390
 391                 if (errno) {
 392                         free(m);
 393                         return;
 394                 }
 395
 396                 if (x == m) {
 397                         if (e->_need_free > 0) {
 398                                 /* Error is already dynamic, let's just update the message */
 399                                 free((char*) e->message);
 400                                 e->message = x;
 401
 402                         } else {
 403                                 char *t;
 404                                 /* Error was const so far, let's make it dynamic, if we can */
 405
 406                                 t = strdup(e->name);
 407                                 if (!t) {
 408                                         free(m);
 409                                         return;
 410                                 }
 411
 412                                 e->_need_free = 1;
 413                                 e->name = t;
 414                                 e->message = x;
 415                         }
 416                 } else {
 417                         free(m);
 418
 419                         if (e->_need_free > 0) {
 420                                 char *t;
 421
 422                                 /* Error is dynamic, let's hence make the message also dynamic */
 423                                 t = strdup(x);
 424                                 if (!t)
 425                                         return;
 426
 427                                 free((char*) e->message);
 428                                 e->message = t;
 429                         } else {
 430                                 /* Error is const, hence we can just override */
 431                                 e->message = x;
 432                         }
 433                 }
 434
 435                 return;
 436         }
 437 }
 438
 439 _public_ int sd_bus_error_set_errno(sd_bus_error *e, int error) {
 440
 441         if (error < 0)
 442                 error = -error;
 443
 444         if (!e)
 445                 return -error;
 446         if (error == 0)
 447                 return -error;
 448
 449         assert_return(!bus_error_is_dirty(e), -EINVAL);
 450
 451         /* First, try a const translation */
 452         *e = errno_to_bus_error_const(error);
 453
 454         if (!sd_bus_error_is_set(e)) {
 455                 int k;
 456
 457                 /* If that didn't work, try a dynamic one. */
 458
 459                 k = errno_to_bus_error_name_new(error, (char**) &e->name);
 460                 if (k > 0)
 461                         e->_need_free = 1;
 462                 else if (k < 0) {
 463                         *e = BUS_ERROR_OOM;
 464                         return -error;
 465                 } else
 466                         *e = BUS_ERROR_FAILED;
 467         }
 468
 469         /* Now, fill in the message from strerror() if we can */
 470         bus_error_strerror(e, error);
 471         return -error;
 472 }
 473
 474 _public_ int sd_bus_error_set_errnofv(sd_bus_error *e, int error, const char *format, va_list ap) {
 475         PROTECT_ERRNO;
 476         int r;
 477
 478         if (error < 0)
 479                 error = -error;
 480
 481         if (!e)
 482                 return -error;
 483         if (error == 0)
 484                 return 0;
 485
 486         assert_return(!bus_error_is_dirty(e), -EINVAL);
 487
 488         /* First, try a const translation */
 489         *e = errno_to_bus_error_const(error);
 490
 491         if (!sd_bus_error_is_set(e)) {
 492                 int k;
 493
 494                 /* If that didn't work, try a dynamic one */
 495
 496                 k = errno_to_bus_error_name_new(error, (char**) &e->name);
 497                 if (k > 0)
 498                         e->_need_free = 1;
 499                 else if (k < 0) {
 500                         *e = BUS_ERROR_OOM;
 501                         return -ENOMEM;
 502                 } else
 503                         *e = BUS_ERROR_FAILED;
 504         }
 505
 506         if (format) {
 507                 char *m;
 508
 509                 /* Then, let's try to fill in the supplied message */
 510
 511                 errno = error; /* Make sure that %m resolves to the specified error */
 512                 r = vasprintf(&m, format, ap);
 513                 if (r >= 0) {
 514
 515                         if (e->_need_free <= 0) {
 516                                 char *t;
 517
 518                                 t = strdup(e->name);
 519                                 if (t) {
 520                                         e->_need_free = 1;
 521                                         e->name = t;
 522                                         e->message = m;
 523                                         return -error;
 524                                 }
 525
 526                                 free(m);
 527                         } else {
 528                                 free((char*) e->message);
 529                                 e->message = m;
 530                                 return -error;
 531                         }
 532                 }
 533         }
 534
 535         /* If that didn't work, use strerror() for the message */
 536         bus_error_strerror(e, error);
 537         return -error;
 538 }
 539
 540 _public_ int sd_bus_error_set_errnof(sd_bus_error *e, int error, const char *format, ...) {
 541         int r;
 542
 543         if (error < 0)
 544                 error = -error;
 545
 546         if (!e)
 547                 return -error;
 548         if (error == 0)
 549                 return 0;
 550
 551         assert_return(!bus_error_is_dirty(e), -EINVAL);
 552
 553         if (format) {
 554                 va_list ap;
 555
 556                 va_start(ap, format);
 557                 r = sd_bus_error_set_errnofv(e, error, format, ap);
 558                 va_end(ap);
 559
 560                 return r;
 561         }
 562
 563         return sd_bus_error_set_errno(e, error);
 564 }
 565
 566 const char *bus_error_message(const sd_bus_error *e, int error) {
 567
 568         if (e) {
 569                 /* Sometimes, the D-Bus server is a little bit too verbose with
 570                  * its error messages, so let's override them here */
 571                 if (sd_bus_error_has_name(e, SD_BUS_ERROR_ACCESS_DENIED))
 572                         return "Access denied";
 573
 574                 if (e->message)
 575                         return e->message;
 576         }
 577
 578         if (error < 0)
 579                 error = -error;
 580
 581         return strerror(error);
 582 }
 583
 584 static bool map_ok(const sd_bus_error_map *map) {
 585         for (; map->code != BUS_ERROR_MAP_END_MARKER; map++)
 586                 if (!map->name || map->code <=0)
 587                         return false;
 588         return true;
 589 }
 590
 591 _public_ int sd_bus_error_add_map(const sd_bus_error_map *map) {
 592         const sd_bus_error_map **maps = NULL;
 593         unsigned n = 0;
 594
 595         assert_return(map, -EINVAL);
 596         assert_return(map_ok(map), -EINVAL);
 597
 598         if (additional_error_maps)
 599                 for (; additional_error_maps[n] != NULL; n++)
 600                         if (additional_error_maps[n] == map)
 601                                 return 0;
 602
 603         maps = reallocarray(additional_error_maps, n + 2, sizeof(struct sd_bus_error_map*));
 604         if (!maps)
 605                 return -ENOMEM;
 606
 607         maps[n] = map;
 608         maps[n+1] = NULL;
 609
 610         additional_error_maps = maps;
 611         return 1;
 612 }