git.ozlabs.org Git - ccan/blob - ccan/failtest/failtest.c

   1 #include <stdarg.h>
   2 #include <string.h>
   3 #include <stdio.h>
   4 #include <stdarg.h>
   5 #include <ctype.h>
   6 #include <err.h>
   7 #include <unistd.h>
   8 #include <poll.h>
   9 #include <errno.h>
  10 #include <sys/types.h>
  11 #include <sys/wait.h>
  12 #include <sys/stat.h>
  13 #include <sys/time.h>
  14 #include <assert.h>
  15 #include <ccan/read_write_all/read_write_all.h>
  16 #include <ccan/failtest/failtest_proto.h>
  17 #include <ccan/failtest/failtest.h>
  18 #include <ccan/build_assert/build_assert.h>
  19
  20 bool (*failtest_hook)(struct failtest_call *history, unsigned num)
  21 = failtest_default_hook;
  22
  23 static int tracefd = -1;
  24
  25 unsigned int failtest_timeout_ms = 20000;
  26
  27 const char *failpath;
  28
  29 enum info_type {
  30         WRITE,
  31         RELEASE_LOCKS,
  32         FAILURE,
  33         SUCCESS,
  34         UNEXPECTED
  35 };
  36
  37 struct lock_info {
  38         int fd;
  39         /* end is inclusive: you can't have a 0-byte lock. */
  40         off_t start, end;
  41         int type;
  42 };
  43
  44 bool (*failtest_exit_check)(struct failtest_call *history, unsigned num);
  45
  46 static struct failtest_call *history = NULL;
  47 static unsigned int history_num = 0;
  48 static int control_fd = -1;
  49 static struct timeval start;
  50
  51 static struct write_call *child_writes = NULL;
  52 static unsigned int child_writes_num = 0;
  53
  54 static pid_t lock_owner;
  55 static struct lock_info *locks = NULL;
  56 static unsigned int lock_num = 0;
  57
  58 static const char info_to_arg[] = "mceoprwf";
  59
  60 /* Dummy call used for failtest_undo wrappers. */
  61 static struct failtest_call unrecorded_call;
  62
  63 static struct failtest_call *add_history_(enum failtest_call_type type,
  64                                           const char *file,
  65                                           unsigned int line,
  66                                           const void *elem,
  67                                           size_t elem_size)
  68 {
  69         /* NULL file is how we suppress failure. */
  70         if (!file)
  71                 return &unrecorded_call;
  72
  73         history = realloc(history, (history_num + 1) * sizeof(*history));
  74         history[history_num].type = type;
  75         history[history_num].file = file;
  76         history[history_num].line = line;
  77         history[history_num].cleanup = NULL;
  78         memcpy(&history[history_num].u, elem, elem_size);
  79         return &history[history_num++];
  80 }
  81
  82 #define add_history(type, file, line, elem) \
  83         add_history_((type), (file), (line), (elem), sizeof(*(elem)))
  84
  85 #define set_cleanup(call, clean, type)                  \
  86         (call)->cleanup = (void *)((void)sizeof(clean((type *)NULL)), (clean))
  87
  88 bool failtest_default_hook(struct failtest_call *history, unsigned num)
  89 {
  90         return true;
  91 }
  92
  93 static bool read_write_info(int fd)
  94 {
  95         struct write_call *w;
  96         char *buf;
  97
  98         /* We don't need all of this, but it's simple. */
  99         child_writes = realloc(child_writes,
 100                                (child_writes_num+1) * sizeof(child_writes[0]));
 101         w = &child_writes[child_writes_num];
 102         if (!read_all(fd, w, sizeof(*w)))
 103                 return false;
 104
 105         w->buf = buf = malloc(w->count);
 106         if (!read_all(fd, buf, w->count))
 107                 return false;
 108
 109         child_writes_num++;
 110         return true;
 111 }
 112
 113 static char *failpath_string(void)
 114 {
 115         unsigned int i;
 116         char *ret = malloc(history_num + 1);
 117
 118         for (i = 0; i < history_num; i++) {
 119                 ret[i] = info_to_arg[history[i].type];
 120                 if (history[i].fail)
 121                         ret[i] = toupper(ret[i]);
 122         }
 123         ret[i] = '\0';
 124         return ret;
 125 }
 126
 127 static void tell_parent(enum info_type type)
 128 {
 129         if (control_fd != -1)
 130                 write_all(control_fd, &type, sizeof(type));
 131 }
 132
 133 static void child_fail(const char *out, size_t outlen, const char *fmt, ...)
 134 {
 135         va_list ap;
 136         char *path = failpath_string();
 137
 138         va_start(ap, fmt);
 139         vfprintf(stderr, fmt, ap);
 140         va_end(ap);
 141
 142         fprintf(stderr, "%.*s", (int)outlen, out);
 143         printf("To reproduce: --failpath=%s\n", path);
 144         free(path);
 145         tell_parent(FAILURE);
 146         exit(1);
 147 }
 148
 149 static pid_t child;
 150
 151 static void hand_down(int signal)
 152 {
 153         kill(child, signal);
 154 }
 155
 156 static void release_locks(void)
 157 {
 158         /* Locks were never acquired/reacquired? */
 159         if (lock_owner == 0)
 160                 return;
 161
 162         /* We own them?  Release them all. */
 163         if (lock_owner == getpid()) {
 164                 unsigned int i;
 165                 struct flock fl;
 166                 fl.l_type = F_UNLCK;
 167                 fl.l_whence = SEEK_SET;
 168                 fl.l_start = 0;
 169                 fl.l_len = 0;
 170
 171                 for (i = 0; i < lock_num; i++)
 172                         fcntl(locks[i].fd, F_SETLK, &fl);
 173         } else {
 174                 /* Our parent must have them; pass request up. */
 175                 enum info_type type = RELEASE_LOCKS;
 176                 assert(control_fd != -1);
 177                 write_all(control_fd, &type, sizeof(type));
 178         }
 179         lock_owner = 0;
 180 }
 181
 182 /* off_t is a signed type.  Getting its max is non-trivial. */
 183 static off_t off_max(void)
 184 {
 185         BUILD_ASSERT(sizeof(off_t) == 4 || sizeof(off_t) == 8);
 186         if (sizeof(off_t) == 4)
 187                 return (off_t)0x7FFFFFF;
 188         else
 189                 return (off_t)0x7FFFFFFFFFFFFFFULL;
 190 }
 191
 192 static void get_locks(void)
 193 {
 194         unsigned int i;
 195         struct flock fl;
 196
 197         if (lock_owner == getpid())
 198                 return;
 199
 200         if (lock_owner != 0) {
 201                 enum info_type type = RELEASE_LOCKS;
 202                 assert(control_fd != -1);
 203                 write_all(control_fd, &type, sizeof(type));
 204         }
 205
 206         fl.l_whence = SEEK_SET;
 207
 208         for (i = 0; i < lock_num; i++) {
 209                 fl.l_type = locks[i].type;
 210                 fl.l_start = locks[i].start;
 211                 if (locks[i].end == off_max())
 212                         fl.l_len = 0;
 213                 else
 214                         fl.l_len = locks[i].end - locks[i].start + 1;
 215
 216                 if (fcntl(locks[i].fd, F_SETLKW, &fl) != 0)
 217                         abort();
 218         }
 219         lock_owner = getpid();
 220 }
 221
 222 static void trace_str(const char *str)
 223 {
 224         ssize_t ret;
 225
 226         while ((ret = write(tracefd, str, strlen(str))) <= 0) {
 227                 str += ret;
 228                 if (!*str)
 229                         return;
 230         }
 231         err(1, "Writing trace.");
 232 }
 233
 234 static bool should_fail(struct failtest_call *call)
 235 {
 236         int status;
 237         int control[2], output[2];
 238         enum info_type type = UNEXPECTED;
 239         char *out = NULL;
 240         size_t outlen = 0;
 241
 242         if (call == &unrecorded_call)
 243                 return false;
 244
 245         if (failpath) {
 246                 /* + means continue after end, like normal. */
 247                 if (*failpath == '+')
 248                         failpath = NULL;
 249                 else {
 250                         if (tolower(*failpath) != info_to_arg[call->type])
 251                                 errx(1, "Failpath expected '%c' got '%c'\n",
 252                                      info_to_arg[call->type], *failpath);
 253                         call->fail = isupper(*(failpath++));
 254                         return call->fail;
 255                 }
 256         }
 257
 258         if (!failtest_hook(history, history_num)) {
 259                 call->fail = false;
 260                 return false;
 261         }
 262
 263         /* We're going to fail in the child. */
 264         call->fail = true;
 265         if (pipe(control) != 0 || pipe(output) != 0)
 266                 err(1, "opening pipe");
 267
 268         /* Prevent double-printing (in child and parent) */
 269         fflush(stdout);
 270         child = fork();
 271         if (child == -1)
 272                 err(1, "forking failed");
 273
 274         if (child == 0) {
 275                 if (tracefd != -1) {
 276                         struct timeval now;
 277                         char str[50], *p;
 278                         gettimeofday(&now, NULL);
 279                         if (now.tv_usec < start.tv_usec) {
 280                                 now.tv_sec--;
 281                                 now.tv_usec += 1000000;
 282                         }
 283                         now.tv_usec -= start.tv_usec;
 284                         now.tv_sec -= start.tv_sec;
 285                         sprintf(str, "%u (%u.%02u): ", getpid(),
 286                                 (int)now.tv_sec, (int)now.tv_usec / 10000);
 287                         trace_str(str);
 288                         p = failpath_string();
 289                         trace_str(p);
 290                         free(p);
 291                         trace_str("(");
 292                         p = strchr(history[history_num-1].file, '/');
 293                         if (p)
 294                                 trace_str(p+1);
 295                         else
 296                                 trace_str(history[history_num-1].file);
 297                         sprintf(str, ":%u)\n", history[history_num-1].line);
 298                         trace_str(str);
 299                 }
 300                 close(control[0]);
 301                 close(output[0]);
 302                 dup2(output[1], STDOUT_FILENO);
 303                 dup2(output[1], STDERR_FILENO);
 304                 if (output[1] != STDOUT_FILENO && output[1] != STDERR_FILENO)
 305                         close(output[1]);
 306                 control_fd = control[1];
 307                 return true;
 308         }
 309
 310         signal(SIGUSR1, hand_down);
 311
 312         close(control[1]);
 313         close(output[1]);
 314
 315         /* We grab output so we can display it; we grab writes so we
 316          * can compare. */
 317         do {
 318                 struct pollfd pfd[2];
 319                 int ret;
 320
 321                 pfd[0].fd = output[0];
 322                 pfd[0].events = POLLIN|POLLHUP;
 323                 pfd[1].fd = control[0];
 324                 pfd[1].events = POLLIN|POLLHUP;
 325
 326                 if (type == SUCCESS)
 327                         ret = poll(pfd, 1, failtest_timeout_ms);
 328                 else
 329                         ret = poll(pfd, 2, failtest_timeout_ms);
 330
 331                 if (ret <= 0)
 332                         hand_down(SIGUSR1);
 333
 334                 if (pfd[0].revents & POLLIN) {
 335                         ssize_t len;
 336
 337                         out = realloc(out, outlen + 8192);
 338                         len = read(output[0], out + outlen, 8192);
 339                         outlen += len;
 340                 } else if (type != SUCCESS && (pfd[1].revents & POLLIN)) {
 341                         if (read_all(control[0], &type, sizeof(type))) {
 342                                 if (type == WRITE) {
 343                                         if (!read_write_info(control[0]))
 344                                                 break;
 345                                 } else if (type == RELEASE_LOCKS) {
 346                                         release_locks();
 347                                         /* FIXME: Tell them we're done... */
 348                                 }
 349                         }
 350                 } else if (pfd[0].revents & POLLHUP) {
 351                         break;
 352                 }
 353         } while (type != FAILURE);
 354
 355         close(output[0]);
 356         close(control[0]);
 357         waitpid(child, &status, 0);
 358         if (!WIFEXITED(status))
 359                 child_fail(out, outlen, "Killed by signal %u: ",
 360                            WTERMSIG(status));
 361         /* Child printed failure already, just pass up exit code. */
 362         if (type == FAILURE) {
 363                 fprintf(stderr, "%.*s", (int)outlen, out);
 364                 tell_parent(type);
 365                 exit(WEXITSTATUS(status) ? WEXITSTATUS(status) : 1);
 366         }
 367         if (WEXITSTATUS(status) != 0)
 368                 child_fail(out, outlen, "Exited with status %i: ",
 369                            WEXITSTATUS(status));
 370
 371         free(out);
 372         signal(SIGUSR1, SIG_DFL);
 373
 374         /* We continue onwards without failing. */
 375         call->fail = false;
 376         return false;
 377 }
 378
 379 static void cleanup_calloc(struct calloc_call *call)
 380 {
 381         free(call->ret);
 382 }
 383
 384 void *failtest_calloc(size_t nmemb, size_t size,
 385                       const char *file, unsigned line)
 386 {
 387         struct failtest_call *p;
 388         struct calloc_call call;
 389         call.nmemb = nmemb;
 390         call.size = size;
 391         p = add_history(FAILTEST_CALLOC, file, line, &call);
 392
 393         if (should_fail(p)) {
 394                 p->u.calloc.ret = NULL;
 395                 p->error = ENOMEM;
 396         } else {
 397                 p->u.calloc.ret = calloc(nmemb, size);
 398                 set_cleanup(p, cleanup_calloc, struct calloc_call);
 399         }
 400         errno = p->error;
 401         return p->u.calloc.ret;
 402 }
 403
 404 static void cleanup_malloc(struct malloc_call *call)
 405 {
 406         free(call->ret);
 407 }
 408
 409 void *failtest_malloc(size_t size, const char *file, unsigned line)
 410 {
 411         struct failtest_call *p;
 412         struct malloc_call call;
 413         call.size = size;
 414
 415         p = add_history(FAILTEST_MALLOC, file, line, &call);
 416         if (should_fail(p)) {
 417                 p->u.calloc.ret = NULL;
 418                 p->error = ENOMEM;
 419         } else {
 420                 p->u.calloc.ret = malloc(size);
 421                 set_cleanup(p, cleanup_malloc, struct malloc_call);
 422         }
 423         errno = p->error;
 424         return p->u.calloc.ret;
 425 }
 426
 427 static void cleanup_realloc(struct realloc_call *call)
 428 {
 429         free(call->ret);
 430 }
 431
 432 /* Walk back and find out if we got this ptr from a previous routine. */
 433 static void fixup_ptr_history(void *ptr, unsigned int last)
 434 {
 435         int i;
 436
 437         /* Start at end of history, work back. */
 438         for (i = last - 1; i >= 0; i--) {
 439                 switch (history[i].type) {
 440                 case FAILTEST_REALLOC:
 441                         if (history[i].u.realloc.ret == ptr) {
 442                                 history[i].cleanup = NULL;
 443                                 return;
 444                         }
 445                         break;
 446                 case FAILTEST_MALLOC:
 447                         if (history[i].u.malloc.ret == ptr) {
 448                                 history[i].cleanup = NULL;
 449                                 return;
 450                         }
 451                         break;
 452                 case FAILTEST_CALLOC:
 453                         if (history[i].u.calloc.ret == ptr) {
 454                                 history[i].cleanup = NULL;
 455                                 return;
 456                         }
 457                         break;
 458                 default:
 459                         break;
 460                 }
 461         }
 462 }
 463
 464 void *failtest_realloc(void *ptr, size_t size, const char *file, unsigned line)
 465 {
 466         struct failtest_call *p;
 467         struct realloc_call call;
 468         call.size = size;
 469         p = add_history(FAILTEST_REALLOC, file, line, &call);
 470
 471         /* FIXME: Try one child moving allocation, one not. */
 472         if (should_fail(p)) {
 473                 p->u.realloc.ret = NULL;
 474                 p->error = ENOMEM;
 475         } else {
 476                 fixup_ptr_history(ptr, history_num-1);
 477                 p->u.realloc.ret = realloc(ptr, size);
 478                 set_cleanup(p, cleanup_realloc, struct realloc_call);
 479         }
 480         errno = p->error;
 481         return p->u.realloc.ret;
 482 }
 483
 484 void failtest_free(void *ptr)
 485 {
 486         fixup_ptr_history(ptr, history_num);
 487         free(ptr);
 488 }
 489
 490 static void cleanup_open(struct open_call *call)
 491 {
 492         close(call->ret);
 493 }
 494
 495 int failtest_open(const char *pathname,
 496                   const char *file, unsigned line, ...)
 497 {
 498         struct failtest_call *p;
 499         struct open_call call;
 500         va_list ap;
 501
 502         call.pathname = strdup(pathname);
 503         va_start(ap, line);
 504         call.flags = va_arg(ap, int);
 505         if (call.flags & O_CREAT) {
 506                 call.mode = va_arg(ap, mode_t);
 507                 va_end(ap);
 508         }
 509         p = add_history(FAILTEST_OPEN, file, line, &call);
 510         /* Avoid memory leak! */
 511         if (p == &unrecorded_call)
 512                 free((char *)call.pathname);
 513         if (should_fail(p)) {
 514                 p->u.open.ret = -1;
 515                 /* FIXME: Play with error codes? */
 516                 p->error = EACCES;
 517         } else {
 518                 p->u.open.ret = open(pathname, call.flags, call.mode);
 519                 set_cleanup(p, cleanup_open, struct open_call);
 520                 p->u.open.dup_fd = p->u.open.ret;
 521         }
 522         errno = p->error;
 523         return p->u.open.ret;
 524 }
 525
 526 static void cleanup_pipe(struct pipe_call *call)
 527 {
 528         if (!call->closed[0])
 529                 close(call->fds[0]);
 530         if (!call->closed[1])
 531                 close(call->fds[1]);
 532 }
 533
 534 int failtest_pipe(int pipefd[2], const char *file, unsigned line)
 535 {
 536         struct failtest_call *p;
 537         struct pipe_call call;
 538
 539         p = add_history(FAILTEST_PIPE, file, line, &call);
 540         if (should_fail(p)) {
 541                 p->u.open.ret = -1;
 542                 /* FIXME: Play with error codes? */
 543                 p->error = EMFILE;
 544         } else {
 545                 p->u.pipe.ret = pipe(p->u.pipe.fds);
 546                 p->u.pipe.closed[0] = p->u.pipe.closed[1] = false;
 547                 set_cleanup(p, cleanup_pipe, struct pipe_call);
 548         }
 549         /* This causes valgrind to notice if they use pipefd[] after failure */
 550         memcpy(pipefd, p->u.pipe.fds, sizeof(p->u.pipe.fds));
 551         errno = p->error;
 552         return p->u.pipe.ret;
 553 }
 554
 555 static void cleanup_read(struct read_call *call)
 556 {
 557         lseek(call->fd, call->off, SEEK_SET);
 558 }
 559
 560 ssize_t failtest_pread(int fd, void *buf, size_t count, off_t off,
 561                        const char *file, unsigned line)
 562 {
 563         struct failtest_call *p;
 564         struct read_call call;
 565         call.fd = fd;
 566         call.buf = buf;
 567         call.count = count;
 568         call.off = off;
 569         p = add_history(FAILTEST_READ, file, line, &call);
 570
 571         /* FIXME: Try partial read returns. */
 572         if (should_fail(p)) {
 573                 p->u.read.ret = -1;
 574                 p->error = EIO;
 575         } else {
 576                 p->u.read.ret = pread(fd, buf, count, off);
 577                 set_cleanup(p, cleanup_read, struct read_call);
 578         }
 579         errno = p->error;
 580         return p->u.read.ret;
 581 }
 582
 583 static void cleanup_write(struct write_call *call)
 584 {
 585         lseek(call->dup_fd, call->off, SEEK_SET);
 586         write(call->dup_fd, call->saved_contents, call->saved_len);
 587         lseek(call->dup_fd, call->off, SEEK_SET);
 588         ftruncate(call->dup_fd, call->old_filelen);
 589         free(call->saved_contents);
 590 }
 591
 592 ssize_t failtest_pwrite(int fd, const void *buf, size_t count, off_t off,
 593                         const char *file, unsigned line)
 594 {
 595         struct failtest_call *p;
 596         struct write_call call;
 597
 598         call.fd = call.dup_fd = fd;
 599         call.buf = buf;
 600         call.count = count;
 601         call.off = off;
 602         p = add_history(FAILTEST_WRITE, file, line, &call);
 603
 604         /* Save old contents if we can */
 605         if (p->u.write.off != -1) {
 606                 ssize_t ret;
 607                 p->u.write.old_filelen = lseek(fd, 0, SEEK_END);
 608
 609                 /* Write past end of file?  Nothing to save.*/
 610                 if (p->u.write.old_filelen <= p->u.write.off)
 611                         p->u.write.saved_len = 0;
 612                 /* Write which goes over end of file?  Partial save. */
 613                 else if (p->u.write.off + count > p->u.write.old_filelen)
 614                         p->u.write.saved_len = p->u.write.old_filelen
 615                                 - p->u.write.off;
 616                 /* Full save. */
 617                 else
 618                         p->u.write.saved_len = count;
 619
 620                 p->u.write.saved_contents = malloc(p->u.write.saved_len);
 621                 lseek(fd, p->u.write.off, SEEK_SET);
 622                 ret = read(fd, p->u.write.saved_contents, p->u.write.saved_len);
 623                 if (ret != p->u.write.saved_len)
 624                         err(1, "Expected %i bytes, got %i",
 625                             (int)p->u.write.saved_len, (int)ret);
 626                 lseek(fd, p->u.write.off, SEEK_SET);
 627                 set_cleanup(p, cleanup_write, struct write_call);
 628         }
 629
 630         /* If we're a child, tell parent about write. */
 631         if (control_fd != -1) {
 632                 enum info_type type = WRITE;
 633
 634                 write_all(control_fd, &type, sizeof(type));
 635                 write_all(control_fd, &p->u.write, sizeof(p->u.write));
 636                 write_all(control_fd, buf, count);
 637         }
 638
 639         /* FIXME: Try partial write returns. */
 640         if (should_fail(p)) {
 641                 p->u.write.ret = -1;
 642                 p->error = EIO;
 643         } else {
 644                 /* FIXME: We assume same write order in parent and child */
 645                 if (child_writes_num != 0) {
 646                         if (child_writes[0].fd != fd)
 647                                 errx(1, "Child wrote to fd %u, not %u?",
 648                                      child_writes[0].fd, fd);
 649                         if (child_writes[0].off != p->u.write.off)
 650                                 errx(1, "Child wrote to offset %zu, not %zu?",
 651                                      (size_t)child_writes[0].off,
 652                                      (size_t)p->u.write.off);
 653                         if (child_writes[0].count != count)
 654                                 errx(1, "Child wrote length %zu, not %zu?",
 655                                      child_writes[0].count, count);
 656                         if (memcmp(child_writes[0].buf, buf, count)) {
 657                                 child_fail(NULL, 0,
 658                                            "Child wrote differently to"
 659                                            " fd %u than we did!\n", fd);
 660                         }
 661                         free((char *)child_writes[0].buf);
 662                         child_writes_num--;
 663                         memmove(&child_writes[0], &child_writes[1],
 664                                 sizeof(child_writes[0]) * child_writes_num);
 665
 666                         /* Is this is a socket or pipe, child wrote it
 667                            already. */
 668                         if (p->u.write.off == (off_t)-1) {
 669                                 p->u.write.ret = count;
 670                                 errno = p->error;
 671                                 return p->u.write.ret;
 672                         }
 673                 }
 674                 p->u.write.ret = pwrite(fd, buf, count, off);
 675         }
 676         errno = p->error;
 677         return p->u.write.ret;
 678 }
 679
 680 ssize_t failtest_read(int fd, void *buf, size_t count,
 681                       const char *file, unsigned line)
 682 {
 683         return failtest_pread(fd, buf, count, lseek(fd, 0, SEEK_CUR),
 684                               file, line);
 685 }
 686
 687 ssize_t failtest_write(int fd, const void *buf, size_t count,
 688                        const char *file, unsigned line)
 689 {
 690         return failtest_pwrite(fd, buf, count, lseek(fd, 0, SEEK_CUR),
 691                                file, line);
 692 }
 693
 694 static struct lock_info *WARN_UNUSED_RESULT
 695 add_lock(struct lock_info *locks, int fd, off_t start, off_t end, int type)
 696 {
 697         unsigned int i;
 698         struct lock_info *l;
 699
 700         for (i = 0; i < lock_num; i++) {
 701                 l = &locks[i];
 702
 703                 if (l->fd != fd)
 704                         continue;
 705                 /* Four cases we care about:
 706                  * Start overlap:
 707                  *      l =    |      |
 708                  *      new = |   |
 709                  * Mid overlap:
 710                  *      l =    |      |
 711                  *      new =    |  |
 712                  * End overlap:
 713                  *      l =    |      |
 714                  *      new =      |    |
 715                  * Total overlap:
 716                  *      l =    |      |
 717                  *      new = |         |
 718                  */
 719                 if (start > l->start && end < l->end) {
 720                         /* Mid overlap: trim entry, add new one. */
 721                         off_t new_start, new_end;
 722                         new_start = end + 1;
 723                         new_end = l->end;
 724                         l->end = start - 1;
 725                         locks = add_lock(locks,
 726                                          fd, new_start, new_end, l->type);
 727                         l = &locks[i];
 728                 } else if (start <= l->start && end >= l->end) {
 729                         /* Total overlap: eliminate entry. */
 730                         l->end = 0;
 731                         l->start = 1;
 732                 } else if (end >= l->start && end < l->end) {
 733                         /* Start overlap: trim entry. */
 734                         l->start = end + 1;
 735                 } else if (start > l->start && start <= l->end) {
 736                         /* End overlap: trim entry. */
 737                         l->end = start-1;
 738                 }
 739                 /* Nothing left?  Remove it. */
 740                 if (l->end < l->start) {
 741                         memmove(l, l + 1, (--lock_num - i) * sizeof(l[0]));
 742                         i--;
 743                 }
 744         }
 745
 746         if (type != F_UNLCK) {
 747                 locks = realloc(locks, (lock_num + 1) * sizeof(*locks));
 748                 l = &locks[lock_num++];
 749                 l->fd = fd;
 750                 l->start = start;
 751                 l->end = end;
 752                 l->type = type;
 753         }
 754         return locks;
 755 }
 756
 757 /* We only trap this so we can dup fds in case we need to restore. */
 758 int failtest_close(int fd)
 759 {
 760         int new_fd = -1, i;
 761
 762         if (fd < 0)
 763                 return close(fd);
 764
 765         /* Trace history to find source of fd, and if we need to cleanup writes. */
 766         for (i = history_num-1; i >= 0; i--) {
 767                 switch (history[i].type) {
 768                 case FAILTEST_WRITE:
 769                         if (history[i].u.write.fd != fd)
 770                                 break;
 771                         if (!history[i].cleanup)
 772                                 break;
 773                         /* We need to save fd so we can restore file. */
 774                         if (new_fd == -1)
 775                                 new_fd = dup(fd);
 776                         history[i].u.write.dup_fd = new_fd;
 777                         break;
 778                 case FAILTEST_READ:
 779                         /* We don't need to cleanup reads on closed fds. */
 780                         if (history[i].u.read.fd != fd)
 781                                 break;
 782                         history[i].cleanup = NULL;
 783                         break;
 784                 case FAILTEST_PIPE:
 785                         /* From a pipe?  We don't ever restore pipes... */
 786                         if (history[i].u.pipe.fds[0] == fd) {
 787                                 assert(new_fd == -1);
 788                                 history[i].u.pipe.closed[0] = true;
 789                                 goto out;
 790                         }
 791                         if (history[i].u.pipe.fds[1] == fd) {
 792                                 assert(new_fd == -1);
 793                                 history[i].u.pipe.closed[1] = true;
 794                                 goto out;
 795                         }
 796                         break;
 797                 case FAILTEST_OPEN:
 798                         if (history[i].u.open.ret == fd) {
 799                                 history[i].u.open.dup_fd = new_fd;
 800                                 goto out;
 801                         }
 802                         break;
 803                 default:
 804                         break;
 805                 }
 806         }
 807
 808 out:
 809         locks = add_lock(locks, fd, 0, off_max(), F_UNLCK);
 810         return close(fd);
 811 }
 812
 813 /* Zero length means "to end of file" */
 814 static off_t end_of(off_t start, off_t len)
 815 {
 816         if (len == 0)
 817                 return off_max();
 818         return start + len - 1;
 819 }
 820
 821 /* FIXME: This only handles locks, really. */
 822 int failtest_fcntl(int fd, const char *file, unsigned line, int cmd, ...)
 823 {
 824         struct failtest_call *p;
 825         struct fcntl_call call;
 826         va_list ap;
 827
 828         call.fd = fd;
 829         call.cmd = cmd;
 830
 831         /* Argument extraction. */
 832         switch (cmd) {
 833         case F_SETFL:
 834         case F_SETFD:
 835                 va_start(ap, cmd);
 836                 call.arg.l = va_arg(ap, long);
 837                 va_end(ap);
 838                 return fcntl(fd, cmd, call.arg.l);
 839         case F_GETFD:
 840         case F_GETFL:
 841                 return fcntl(fd, cmd);
 842         case F_GETLK:
 843                 get_locks();
 844                 va_start(ap, cmd);
 845                 call.arg.fl = *va_arg(ap, struct flock *);
 846                 va_end(ap);
 847                 return fcntl(fd, cmd, &call.arg.fl);
 848         case F_SETLK:
 849         case F_SETLKW:
 850                 va_start(ap, cmd);
 851                 call.arg.fl = *va_arg(ap, struct flock *);
 852                 va_end(ap);
 853                 break;
 854         default:
 855                 /* This means you need to implement it here. */
 856                 err(1, "failtest: unknown fcntl %u", cmd);
 857         }
 858
 859         p = add_history(FAILTEST_FCNTL, file, line, &call);
 860         get_locks();
 861
 862         if (should_fail(p)) {
 863                 p->u.fcntl.ret = -1;
 864                 if (p->u.fcntl.cmd == F_SETLK)
 865                         p->error = EAGAIN;
 866                 else
 867                         p->error = EDEADLK;
 868         } else {
 869                 p->u.fcntl.ret = fcntl(p->u.fcntl.fd, p->u.fcntl.cmd,
 870                                        &p->u.fcntl.arg.fl);
 871                 if (p->u.fcntl.ret == -1)
 872                         p->error = errno;
 873                 else {
 874                         /* We don't handle anything else yet. */
 875                         assert(p->u.fcntl.arg.fl.l_whence == SEEK_SET);
 876                         locks = add_lock(locks,
 877                                          p->u.fcntl.fd,
 878                                          p->u.fcntl.arg.fl.l_start,
 879                                          end_of(p->u.fcntl.arg.fl.l_start,
 880                                                 p->u.fcntl.arg.fl.l_len),
 881                                          p->u.fcntl.arg.fl.l_type);
 882                 }
 883         }
 884         errno = p->error;
 885         return p->u.fcntl.ret;
 886 }
 887
 888 void failtest_init(int argc, char *argv[])
 889 {
 890         unsigned int i;
 891
 892         for (i = 1; i < argc; i++) {
 893                 if (!strncmp(argv[i], "--failpath=", strlen("--failpath="))) {
 894                         failpath = argv[i] + strlen("--failpath=");
 895                 } else if (strcmp(argv[i], "--tracepath") == 0) {
 896                         tracefd = dup(STDERR_FILENO);
 897                         failtest_timeout_ms = -1;
 898                 }
 899         }
 900         gettimeofday(&start, NULL);
 901 }
 902
 903 /* Free up memory, so valgrind doesn't report leaks. */
 904 static void free_everything(void)
 905 {
 906         unsigned int i;
 907
 908         /* We don't do this in cleanup: needed even for failed opens. */
 909         for (i = 0; i < history_num; i++) {
 910                 if (history[i].type == FAILTEST_OPEN)
 911                         free((char *)history[i].u.open.pathname);
 912         }
 913         free(history);
 914 }
 915
 916 void failtest_exit(int status)
 917 {
 918         int i;
 919
 920         if (control_fd == -1) {
 921                 free_everything();
 922                 exit(status);
 923         }
 924
 925         if (failtest_exit_check) {
 926                 if (!failtest_exit_check(history, history_num))
 927                         child_fail(NULL, 0, "failtest_exit_check failed\n");
 928         }
 929
 930         /* Cleanup everything, in reverse order. */
 931         for (i = history_num - 1; i >= 0; i--)
 932                 if (history[i].cleanup)
 933                         history[i].cleanup(&history[i].u);
 934
 935         free_everything();
 936         tell_parent(SUCCESS);
 937         exit(0);
 938 }