src/basic/fileio.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2
   3 #include <errno.h>
   4 #include <fcntl.h>
   5 #include <limits.h>
   6 #include <stdarg.h>
   7 #include <stdint.h>
   8 #include <stdio_ext.h>
   9 #include <stdlib.h>
  10 #include <string.h>
  11 #include <sys/mman.h>
  12 #include <sys/stat.h>
  13 #include <sys/types.h>
  14 #include <unistd.h>
  15
  16 #include "alloc-util.h"
  17 #include "ctype.h"
  18 #include "env-util.h"
  19 #include "escape.h"
  20 #include "fd-util.h"
  21 #include "fileio.h"
  22 #include "fs-util.h"
  23 #include "hexdecoct.h"
  24 #include "log.h"
  25 #include "macro.h"
  26 #include "missing.h"
  27 #include "parse-util.h"
  28 #include "path-util.h"
  29 #include "process-util.h"
  30 #include "random-util.h"
  31 #include "stdio-util.h"
  32 #include "string-util.h"
  33 #include "strv.h"
  34 #include "time-util.h"
  35 #include "umask-util.h"
  36 #include "utf8.h"
  37
  38 #define READ_FULL_BYTES_MAX (4U*1024U*1024U)
  39
  40 int write_string_stream_ts(
  41                 FILE *f,
  42                 const char *line,
  43                 WriteStringFileFlags flags,
  44                 struct timespec *ts) {
  45
  46         bool needs_nl;
  47         int r;
  48
  49         assert(f);
  50         assert(line);
  51
  52         if (ferror(f))
  53                 return -EIO;
  54
  55         needs_nl = !(flags & WRITE_STRING_FILE_AVOID_NEWLINE) && !endswith(line, "\n");
  56
  57         if (needs_nl && (flags & WRITE_STRING_FILE_DISABLE_BUFFER)) {
  58                 /* If STDIO buffering was disabled, then let's append the newline character to the string itself, so
  59                  * that the write goes out in one go, instead of two */
  60
  61                 line = strjoina(line, "\n");
  62                 needs_nl = false;
  63         }
  64
  65         if (fputs(line, f) == EOF)
  66                 return -errno;
  67
  68         if (needs_nl)
  69                 if (fputc('\n', f) == EOF)
  70                         return -errno;
  71
  72         if (flags & WRITE_STRING_FILE_SYNC)
  73                 r = fflush_sync_and_check(f);
  74         else
  75                 r = fflush_and_check(f);
  76         if (r < 0)
  77                 return r;
  78
  79         if (ts) {
  80                 struct timespec twice[2] = {*ts, *ts};
  81
  82                 if (futimens(fileno(f), twice) < 0)
  83                         return -errno;
  84         }
  85
  86         return 0;
  87 }
  88
  89 static int write_string_file_atomic(
  90                 const char *fn,
  91                 const char *line,
  92                 WriteStringFileFlags flags,
  93                 struct timespec *ts) {
  94
  95         _cleanup_fclose_ FILE *f = NULL;
  96         _cleanup_free_ char *p = NULL;
  97         int r;
  98
  99         assert(fn);
 100         assert(line);
 101
 102         r = fopen_temporary(fn, &f, &p);
 103         if (r < 0)
 104                 return r;
 105
 106         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 107         (void) fchmod_umask(fileno(f), 0644);
 108
 109         r = write_string_stream_ts(f, line, flags, ts);
 110         if (r < 0)
 111                 goto fail;
 112
 113         if (rename(p, fn) < 0) {
 114                 r = -errno;
 115                 goto fail;
 116         }
 117
 118         return 0;
 119
 120 fail:
 121         (void) unlink(p);
 122         return r;
 123 }
 124
 125 int write_string_file_ts(
 126                 const char *fn,
 127                 const char *line,
 128                 WriteStringFileFlags flags,
 129                 struct timespec *ts) {
 130
 131         _cleanup_fclose_ FILE *f = NULL;
 132         int q, r;
 133
 134         assert(fn);
 135         assert(line);
 136
 137         /* We don't know how to verify whether the file contents was already on-disk. */
 138         assert(!((flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE) && (flags & WRITE_STRING_FILE_SYNC)));
 139
 140         if (flags & WRITE_STRING_FILE_ATOMIC) {
 141                 assert(flags & WRITE_STRING_FILE_CREATE);
 142
 143                 r = write_string_file_atomic(fn, line, flags, ts);
 144                 if (r < 0)
 145                         goto fail;
 146
 147                 return r;
 148         } else
 149                 assert(!ts);
 150
 151         if (flags & WRITE_STRING_FILE_CREATE) {
 152                 f = fopen(fn, "we");
 153                 if (!f) {
 154                         r = -errno;
 155                         goto fail;
 156                 }
 157         } else {
 158                 int fd;
 159
 160                 /* We manually build our own version of fopen(..., "we") that
 161                  * works without O_CREAT */
 162                 fd = open(fn, O_WRONLY|O_CLOEXEC|O_NOCTTY | ((flags & WRITE_STRING_FILE_NOFOLLOW) ? O_NOFOLLOW : 0));
 163                 if (fd < 0) {
 164                         r = -errno;
 165                         goto fail;
 166                 }
 167
 168                 f = fdopen(fd, "we");
 169                 if (!f) {
 170                         r = -errno;
 171                         safe_close(fd);
 172                         goto fail;
 173                 }
 174         }
 175
 176         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 177
 178         if (flags & WRITE_STRING_FILE_DISABLE_BUFFER)
 179                 setvbuf(f, NULL, _IONBF, 0);
 180
 181         r = write_string_stream_ts(f, line, flags, ts);
 182         if (r < 0)
 183                 goto fail;
 184
 185         return 0;
 186
 187 fail:
 188         if (!(flags & WRITE_STRING_FILE_VERIFY_ON_FAILURE))
 189                 return r;
 190
 191         f = safe_fclose(f);
 192
 193         /* OK, the operation failed, but let's see if the right
 194          * contents in place already. If so, eat up the error. */
 195
 196         q = verify_file(fn, line, !(flags & WRITE_STRING_FILE_AVOID_NEWLINE));
 197         if (q <= 0)
 198                 return r;
 199
 200         return 0;
 201 }
 202
 203 int write_string_filef(
 204                 const char *fn,
 205                 WriteStringFileFlags flags,
 206                 const char *format, ...) {
 207
 208         _cleanup_free_ char *p = NULL;
 209         va_list ap;
 210         int r;
 211
 212         va_start(ap, format);
 213         r = vasprintf(&p, format, ap);
 214         va_end(ap);
 215
 216         if (r < 0)
 217                 return -ENOMEM;
 218
 219         return write_string_file(fn, p, flags);
 220 }
 221
 222 int read_one_line_file(const char *fn, char **line) {
 223         _cleanup_fclose_ FILE *f = NULL;
 224         int r;
 225
 226         assert(fn);
 227         assert(line);
 228
 229         f = fopen(fn, "re");
 230         if (!f)
 231                 return -errno;
 232
 233         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 234
 235         r = read_line(f, LONG_LINE_MAX, line);
 236         return r < 0 ? r : 0;
 237 }
 238
 239 int verify_file(const char *fn, const char *blob, bool accept_extra_nl) {
 240         _cleanup_fclose_ FILE *f = NULL;
 241         _cleanup_free_ char *buf = NULL;
 242         size_t l, k;
 243
 244         assert(fn);
 245         assert(blob);
 246
 247         l = strlen(blob);
 248
 249         if (accept_extra_nl && endswith(blob, "\n"))
 250                 accept_extra_nl = false;
 251
 252         buf = malloc(l + accept_extra_nl + 1);
 253         if (!buf)
 254                 return -ENOMEM;
 255
 256         f = fopen(fn, "re");
 257         if (!f)
 258                 return -errno;
 259
 260         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 261
 262         /* We try to read one byte more than we need, so that we know whether we hit eof */
 263         errno = 0;
 264         k = fread(buf, 1, l + accept_extra_nl + 1, f);
 265         if (ferror(f))
 266                 return errno > 0 ? -errno : -EIO;
 267
 268         if (k != l && k != l + accept_extra_nl)
 269                 return 0;
 270         if (memcmp(buf, blob, l) != 0)
 271                 return 0;
 272         if (k > l && buf[l] != '\n')
 273                 return 0;
 274
 275         return 1;
 276 }
 277
 278 int read_full_stream(FILE *f, char **contents, size_t *size) {
 279         _cleanup_free_ char *buf = NULL;
 280         struct stat st;
 281         size_t n, l;
 282         int fd;
 283
 284         assert(f);
 285         assert(contents);
 286
 287         n = LINE_MAX;
 288
 289         fd = fileno(f);
 290         if (fd >= 0) { /* If the FILE* object is backed by an fd (as opposed to memory or such, see fmemopen(), let's
 291                         * optimize our buffering) */
 292
 293                 if (fstat(fileno(f), &st) < 0)
 294                         return -errno;
 295
 296                 if (S_ISREG(st.st_mode)) {
 297
 298                         /* Safety check */
 299                         if (st.st_size > READ_FULL_BYTES_MAX)
 300                                 return -E2BIG;
 301
 302                         /* Start with the right file size, but be prepared for files from /proc which generally report a file
 303                          * size of 0. Note that we increase the size to read here by one, so that the first read attempt
 304                          * already makes us notice the EOF. */
 305                         if (st.st_size > 0)
 306                                 n = st.st_size + 1;
 307                 }
 308         }
 309
 310         l = 0;
 311         for (;;) {
 312                 char *t;
 313                 size_t k;
 314
 315                 t = realloc(buf, n + 1);
 316                 if (!t)
 317                         return -ENOMEM;
 318
 319                 buf = t;
 320                 errno = 0;
 321                 k = fread(buf + l, 1, n - l, f);
 322                 if (k > 0)
 323                         l += k;
 324
 325                 if (ferror(f))
 326                         return errno > 0 ? -errno : -EIO;
 327
 328                 if (feof(f))
 329                         break;
 330
 331                 /* We aren't expecting fread() to return a short read outside
 332                  * of (error && eof), assert buffer is full and enlarge buffer.
 333                  */
 334                 assert(l == n);
 335
 336                 /* Safety check */
 337                 if (n >= READ_FULL_BYTES_MAX)
 338                         return -E2BIG;
 339
 340                 n = MIN(n * 2, READ_FULL_BYTES_MAX);
 341         }
 342
 343         buf[l] = 0;
 344         *contents = TAKE_PTR(buf);
 345
 346         if (size)
 347                 *size = l;
 348
 349         return 0;
 350 }
 351
 352 int read_full_file(const char *fn, char **contents, size_t *size) {
 353         _cleanup_fclose_ FILE *f = NULL;
 354
 355         assert(fn);
 356         assert(contents);
 357
 358         f = fopen(fn, "re");
 359         if (!f)
 360                 return -errno;
 361
 362         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 363
 364         return read_full_stream(f, contents, size);
 365 }
 366
 367 static int parse_env_file_internal(
 368                 FILE *f,
 369                 const char *fname,
 370                 int (*push) (const char *filename, unsigned line,
 371                              const char *key, char *value, void *userdata, int *n_pushed),
 372                 void *userdata,
 373                 int *n_pushed) {
 374
 375         size_t key_alloc = 0, n_key = 0, value_alloc = 0, n_value = 0, last_value_whitespace = (size_t) -1, last_key_whitespace = (size_t) -1;
 376         _cleanup_free_ char *contents = NULL, *key = NULL, *value = NULL;
 377         unsigned line = 1;
 378         char *p;
 379         int r;
 380
 381         enum {
 382                 PRE_KEY,
 383                 KEY,
 384                 PRE_VALUE,
 385                 VALUE,
 386                 VALUE_ESCAPE,
 387                 SINGLE_QUOTE_VALUE,
 388                 SINGLE_QUOTE_VALUE_ESCAPE,
 389                 DOUBLE_QUOTE_VALUE,
 390                 DOUBLE_QUOTE_VALUE_ESCAPE,
 391                 COMMENT,
 392                 COMMENT_ESCAPE
 393         } state = PRE_KEY;
 394
 395         if (f)
 396                 r = read_full_stream(f, &contents, NULL);
 397         else
 398                 r = read_full_file(fname, &contents, NULL);
 399         if (r < 0)
 400                 return r;
 401
 402         for (p = contents; *p; p++) {
 403                 char c = *p;
 404
 405                 switch (state) {
 406
 407                 case PRE_KEY:
 408                         if (strchr(COMMENTS, c))
 409                                 state = COMMENT;
 410                         else if (!strchr(WHITESPACE, c)) {
 411                                 state = KEY;
 412                                 last_key_whitespace = (size_t) -1;
 413
 414                                 if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
 415                                         return -ENOMEM;
 416
 417                                 key[n_key++] = c;
 418                         }
 419                         break;
 420
 421                 case KEY:
 422                         if (strchr(NEWLINE, c)) {
 423                                 state = PRE_KEY;
 424                                 line++;
 425                                 n_key = 0;
 426                         } else if (c == '=') {
 427                                 state = PRE_VALUE;
 428                                 last_value_whitespace = (size_t) -1;
 429                         } else {
 430                                 if (!strchr(WHITESPACE, c))
 431                                         last_key_whitespace = (size_t) -1;
 432                                 else if (last_key_whitespace == (size_t) -1)
 433                                          last_key_whitespace = n_key;
 434
 435                                 if (!GREEDY_REALLOC(key, key_alloc, n_key+2))
 436                                         return -ENOMEM;
 437
 438                                 key[n_key++] = c;
 439                         }
 440
 441                         break;
 442
 443                 case PRE_VALUE:
 444                         if (strchr(NEWLINE, c)) {
 445                                 state = PRE_KEY;
 446                                 line++;
 447                                 key[n_key] = 0;
 448
 449                                 if (value)
 450                                         value[n_value] = 0;
 451
 452                                 /* strip trailing whitespace from key */
 453                                 if (last_key_whitespace != (size_t) -1)
 454                                         key[last_key_whitespace] = 0;
 455
 456                                 r = push(fname, line, key, value, userdata, n_pushed);
 457                                 if (r < 0)
 458                                         return r;
 459
 460                                 n_key = 0;
 461                                 value = NULL;
 462                                 value_alloc = n_value = 0;
 463
 464                         } else if (c == '\'')
 465                                 state = SINGLE_QUOTE_VALUE;
 466                         else if (c == '\"')
 467                                 state = DOUBLE_QUOTE_VALUE;
 468                         else if (c == '\\')
 469                                 state = VALUE_ESCAPE;
 470                         else if (!strchr(WHITESPACE, c)) {
 471                                 state = VALUE;
 472
 473                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 474                                         return  -ENOMEM;
 475
 476                                 value[n_value++] = c;
 477                         }
 478
 479                         break;
 480
 481                 case VALUE:
 482                         if (strchr(NEWLINE, c)) {
 483                                 state = PRE_KEY;
 484                                 line++;
 485
 486                                 key[n_key] = 0;
 487
 488                                 if (value)
 489                                         value[n_value] = 0;
 490
 491                                 /* Chomp off trailing whitespace from value */
 492                                 if (last_value_whitespace != (size_t) -1)
 493                                         value[last_value_whitespace] = 0;
 494
 495                                 /* strip trailing whitespace from key */
 496                                 if (last_key_whitespace != (size_t) -1)
 497                                         key[last_key_whitespace] = 0;
 498
 499                                 r = push(fname, line, key, value, userdata, n_pushed);
 500                                 if (r < 0)
 501                                         return r;
 502
 503                                 n_key = 0;
 504                                 value = NULL;
 505                                 value_alloc = n_value = 0;
 506
 507                         } else if (c == '\\') {
 508                                 state = VALUE_ESCAPE;
 509                                 last_value_whitespace = (size_t) -1;
 510                         } else {
 511                                 if (!strchr(WHITESPACE, c))
 512                                         last_value_whitespace = (size_t) -1;
 513                                 else if (last_value_whitespace == (size_t) -1)
 514                                         last_value_whitespace = n_value;
 515
 516                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 517                                         return -ENOMEM;
 518
 519                                 value[n_value++] = c;
 520                         }
 521
 522                         break;
 523
 524                 case VALUE_ESCAPE:
 525                         state = VALUE;
 526
 527                         if (!strchr(NEWLINE, c)) {
 528                                 /* Escaped newlines we eat up entirely */
 529                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 530                                         return -ENOMEM;
 531
 532                                 value[n_value++] = c;
 533                         }
 534                         break;
 535
 536                 case SINGLE_QUOTE_VALUE:
 537                         if (c == '\'')
 538                                 state = PRE_VALUE;
 539                         else if (c == '\\')
 540                                 state = SINGLE_QUOTE_VALUE_ESCAPE;
 541                         else {
 542                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 543                                         return -ENOMEM;
 544
 545                                 value[n_value++] = c;
 546                         }
 547
 548                         break;
 549
 550                 case SINGLE_QUOTE_VALUE_ESCAPE:
 551                         state = SINGLE_QUOTE_VALUE;
 552
 553                         if (!strchr(NEWLINE, c)) {
 554                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 555                                         return -ENOMEM;
 556
 557                                 value[n_value++] = c;
 558                         }
 559                         break;
 560
 561                 case DOUBLE_QUOTE_VALUE:
 562                         if (c == '\"')
 563                                 state = PRE_VALUE;
 564                         else if (c == '\\')
 565                                 state = DOUBLE_QUOTE_VALUE_ESCAPE;
 566                         else {
 567                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 568                                         return -ENOMEM;
 569
 570                                 value[n_value++] = c;
 571                         }
 572
 573                         break;
 574
 575                 case DOUBLE_QUOTE_VALUE_ESCAPE:
 576                         state = DOUBLE_QUOTE_VALUE;
 577
 578                         if (!strchr(NEWLINE, c)) {
 579                                 if (!GREEDY_REALLOC(value, value_alloc, n_value+2))
 580                                         return -ENOMEM;
 581
 582                                 value[n_value++] = c;
 583                         }
 584                         break;
 585
 586                 case COMMENT:
 587                         if (c == '\\')
 588                                 state = COMMENT_ESCAPE;
 589                         else if (strchr(NEWLINE, c)) {
 590                                 state = PRE_KEY;
 591                                 line++;
 592                         }
 593                         break;
 594
 595                 case COMMENT_ESCAPE:
 596                         state = COMMENT;
 597                         break;
 598                 }
 599         }
 600
 601         if (IN_SET(state,
 602                    PRE_VALUE,
 603                    VALUE,
 604                    VALUE_ESCAPE,
 605                    SINGLE_QUOTE_VALUE,
 606                    SINGLE_QUOTE_VALUE_ESCAPE,
 607                    DOUBLE_QUOTE_VALUE,
 608                    DOUBLE_QUOTE_VALUE_ESCAPE)) {
 609
 610                 key[n_key] = 0;
 611
 612                 if (value)
 613                         value[n_value] = 0;
 614
 615                 if (state == VALUE)
 616                         if (last_value_whitespace != (size_t) -1)
 617                                 value[last_value_whitespace] = 0;
 618
 619                 /* strip trailing whitespace from key */
 620                 if (last_key_whitespace != (size_t) -1)
 621                         key[last_key_whitespace] = 0;
 622
 623                 r = push(fname, line, key, value, userdata, n_pushed);
 624                 if (r < 0)
 625                         return r;
 626
 627                 value = NULL;
 628         }
 629
 630         return 0;
 631 }
 632
 633 static int check_utf8ness_and_warn(
 634                 const char *filename, unsigned line,
 635                 const char *key, char *value) {
 636
 637         if (!utf8_is_valid(key)) {
 638                 _cleanup_free_ char *p = NULL;
 639
 640                 p = utf8_escape_invalid(key);
 641                 log_error("%s:%u: invalid UTF-8 in key '%s', ignoring.", strna(filename), line, p);
 642                 return -EINVAL;
 643         }
 644
 645         if (value && !utf8_is_valid(value)) {
 646                 _cleanup_free_ char *p = NULL;
 647
 648                 p = utf8_escape_invalid(value);
 649                 log_error("%s:%u: invalid UTF-8 value for key %s: '%s', ignoring.", strna(filename), line, key, p);
 650                 return -EINVAL;
 651         }
 652
 653         return 0;
 654 }
 655
 656 static int parse_env_file_push(
 657                 const char *filename, unsigned line,
 658                 const char *key, char *value,
 659                 void *userdata,
 660                 int *n_pushed) {
 661
 662         const char *k;
 663         va_list aq, *ap = userdata;
 664         int r;
 665
 666         r = check_utf8ness_and_warn(filename, line, key, value);
 667         if (r < 0)
 668                 return r;
 669
 670         va_copy(aq, *ap);
 671
 672         while ((k = va_arg(aq, const char *))) {
 673                 char **v;
 674
 675                 v = va_arg(aq, char **);
 676
 677                 if (streq(key, k)) {
 678                         va_end(aq);
 679                         free(*v);
 680                         *v = value;
 681
 682                         if (n_pushed)
 683                                 (*n_pushed)++;
 684
 685                         return 1;
 686                 }
 687         }
 688
 689         va_end(aq);
 690         free(value);
 691
 692         return 0;
 693 }
 694
 695 int parse_env_filev(
 696                 FILE *f,
 697                 const char *fname,
 698                 va_list ap) {
 699
 700         int r, n_pushed = 0;
 701         va_list aq;
 702
 703         va_copy(aq, ap);
 704         r = parse_env_file_internal(f, fname, parse_env_file_push, &aq, &n_pushed);
 705         va_end(aq);
 706         if (r < 0)
 707                 return r;
 708
 709         return n_pushed;
 710 }
 711
 712 int parse_env_file_sentinel(
 713                 FILE *f,
 714                 const char *fname,
 715                 ...) {
 716
 717         va_list ap;
 718         int r;
 719
 720         va_start(ap, fname);
 721         r = parse_env_filev(f, fname, ap);
 722         va_end(ap);
 723
 724         return r;
 725 }
 726
 727 static int load_env_file_push(
 728                 const char *filename, unsigned line,
 729                 const char *key, char *value,
 730                 void *userdata,
 731                 int *n_pushed) {
 732         char ***m = userdata;
 733         char *p;
 734         int r;
 735
 736         r = check_utf8ness_and_warn(filename, line, key, value);
 737         if (r < 0)
 738                 return r;
 739
 740         p = strjoin(key, "=", value);
 741         if (!p)
 742                 return -ENOMEM;
 743
 744         r = strv_env_replace(m, p);
 745         if (r < 0) {
 746                 free(p);
 747                 return r;
 748         }
 749
 750         if (n_pushed)
 751                 (*n_pushed)++;
 752
 753         free(value);
 754         return 0;
 755 }
 756
 757 int load_env_file(FILE *f, const char *fname, char ***rl) {
 758         char **m = NULL;
 759         int r;
 760
 761         r = parse_env_file_internal(f, fname, load_env_file_push, &m, NULL);
 762         if (r < 0) {
 763                 strv_free(m);
 764                 return r;
 765         }
 766
 767         *rl = m;
 768         return 0;
 769 }
 770
 771 static int load_env_file_push_pairs(
 772                 const char *filename, unsigned line,
 773                 const char *key, char *value,
 774                 void *userdata,
 775                 int *n_pushed) {
 776         char ***m = userdata;
 777         int r;
 778
 779         r = check_utf8ness_and_warn(filename, line, key, value);
 780         if (r < 0)
 781                 return r;
 782
 783         r = strv_extend(m, key);
 784         if (r < 0)
 785                 return -ENOMEM;
 786
 787         if (!value) {
 788                 r = strv_extend(m, "");
 789                 if (r < 0)
 790                         return -ENOMEM;
 791         } else {
 792                 r = strv_push(m, value);
 793                 if (r < 0)
 794                         return r;
 795         }
 796
 797         if (n_pushed)
 798                 (*n_pushed)++;
 799
 800         return 0;
 801 }
 802
 803 int load_env_file_pairs(FILE *f, const char *fname, char ***rl) {
 804         char **m = NULL;
 805         int r;
 806
 807         r = parse_env_file_internal(f, fname, load_env_file_push_pairs, &m, NULL);
 808         if (r < 0) {
 809                 strv_free(m);
 810                 return r;
 811         }
 812
 813         *rl = m;
 814         return 0;
 815 }
 816
 817 static int merge_env_file_push(
 818                 const char *filename, unsigned line,
 819                 const char *key, char *value,
 820                 void *userdata,
 821                 int *n_pushed) {
 822
 823         char ***env = userdata;
 824         char *expanded_value;
 825
 826         assert(env);
 827
 828         if (!value) {
 829                 log_error("%s:%u: invalid syntax (around \"%s\"), ignoring.", strna(filename), line, key);
 830                 return 0;
 831         }
 832
 833         if (!env_name_is_valid(key)) {
 834                 log_error("%s:%u: invalid variable name \"%s\", ignoring.", strna(filename), line, key);
 835                 free(value);
 836                 return 0;
 837         }
 838
 839         expanded_value = replace_env(value, *env,
 840                                      REPLACE_ENV_USE_ENVIRONMENT|
 841                                      REPLACE_ENV_ALLOW_BRACELESS|
 842                                      REPLACE_ENV_ALLOW_EXTENDED);
 843         if (!expanded_value)
 844                 return -ENOMEM;
 845
 846         free_and_replace(value, expanded_value);
 847
 848         return load_env_file_push(filename, line, key, value, env, n_pushed);
 849 }
 850
 851 int merge_env_file(
 852                 char ***env,
 853                 FILE *f,
 854                 const char *fname) {
 855
 856         /* NOTE: this function supports braceful and braceless variable expansions,
 857          * plus "extended" substitutions, unlike other exported parsing functions.
 858          */
 859
 860         return parse_env_file_internal(f, fname, merge_env_file_push, env, NULL);
 861 }
 862
 863 static void write_env_var(FILE *f, const char *v) {
 864         const char *p;
 865
 866         p = strchr(v, '=');
 867         if (!p) {
 868                 /* Fallback */
 869                 fputs_unlocked(v, f);
 870                 fputc_unlocked('\n', f);
 871                 return;
 872         }
 873
 874         p++;
 875         fwrite_unlocked(v, 1, p-v, f);
 876
 877         if (string_has_cc(p, NULL) || chars_intersect(p, WHITESPACE SHELL_NEED_QUOTES)) {
 878                 fputc_unlocked('\"', f);
 879
 880                 for (; *p; p++) {
 881                         if (strchr(SHELL_NEED_ESCAPE, *p))
 882                                 fputc_unlocked('\\', f);
 883
 884                         fputc_unlocked(*p, f);
 885                 }
 886
 887                 fputc_unlocked('\"', f);
 888         } else
 889                 fputs_unlocked(p, f);
 890
 891         fputc_unlocked('\n', f);
 892 }
 893
 894 int write_env_file(const char *fname, char **l) {
 895         _cleanup_fclose_ FILE *f = NULL;
 896         _cleanup_free_ char *p = NULL;
 897         char **i;
 898         int r;
 899
 900         assert(fname);
 901
 902         r = fopen_temporary(fname, &f, &p);
 903         if (r < 0)
 904                 return r;
 905
 906         (void) __fsetlocking(f, FSETLOCKING_BYCALLER);
 907         (void) fchmod_umask(fileno(f), 0644);
 908
 909         STRV_FOREACH(i, l)
 910                 write_env_var(f, *i);
 911
 912         r = fflush_and_check(f);
 913         if (r >= 0) {
 914                 if (rename(p, fname) >= 0)
 915                         return 0;
 916
 917                 r = -errno;
 918         }
 919
 920         unlink(p);
 921         return r;
 922 }
 923
 924 int executable_is_script(const char *path, char **interpreter) {
 925         _cleanup_free_ char *line = NULL;
 926         size_t len;
 927         char *ans;
 928         int r;
 929
 930         assert(path);
 931
 932         r = read_one_line_file(path, &line);
 933         if (r == -ENOBUFS) /* First line overly long? if so, then it's not a script */
 934                 return 0;
 935         if (r < 0)
 936                 return r;
 937
 938         if (!startswith(line, "#!"))
 939                 return 0;
 940
 941         ans = strstrip(line + 2);
 942         len = strcspn(ans, " \t");
 943
 944         if (len == 0)
 945                 return 0;
 946
 947         ans = strndup(ans, len);
 948         if (!ans)
 949                 return -ENOMEM;
 950
 951         *interpreter = ans;
 952         return 1;
 953 }
 954
 955 /**
 956  * Retrieve one field from a file like /proc/self/status.  pattern
 957  * should not include whitespace or the delimiter (':'). pattern matches only
 958  * the beginning of a line. Whitespace before ':' is skipped. Whitespace and
 959  * zeros after the ':' will be skipped. field must be freed afterwards.
 960  * terminator specifies the terminating characters of the field value (not
 961  * included in the value).
 962  */
 963 int get_proc_field(const char *filename, const char *pattern, const char *terminator, char **field) {
 964         _cleanup_free_ char *status = NULL;
 965         char *t, *f;
 966         size_t len;
 967         int r;
 968
 969         assert(terminator);
 970         assert(filename);
 971         assert(pattern);
 972         assert(field);
 973
 974         r = read_full_file(filename, &status, NULL);
 975         if (r < 0)
 976                 return r;
 977
 978         t = status;
 979
 980         do {
 981                 bool pattern_ok;
 982
 983                 do {
 984                         t = strstr(t, pattern);
 985                         if (!t)
 986                                 return -ENOENT;
 987
 988                         /* Check that pattern occurs in beginning of line. */
 989                         pattern_ok = (t == status || t[-1] == '\n');
 990
 991                         t += strlen(pattern);
 992
 993                 } while (!pattern_ok);
 994
 995                 t += strspn(t, " \t");
 996                 if (!*t)
 997                         return -ENOENT;
 998
 999         } while (*t != ':');
1000
1001         t++;
1002
1003         if (*t) {
1004                 t += strspn(t, " \t");
1005
1006                 /* Also skip zeros, because when this is used for
1007                  * capabilities, we don't want the zeros. This way the
1008                  * same capability set always maps to the same string,
1009                  * irrespective of the total capability set size. For
1010                  * other numbers it shouldn't matter. */
1011                 t += strspn(t, "0");
1012                 /* Back off one char if there's nothing but whitespace
1013                    and zeros */
1014                 if (!*t || isspace(*t))
1015                         t--;
1016         }
1017
1018         len = strcspn(t, terminator);
1019
1020         f = strndup(t, len);
1021         if (!f)
1022                 return -ENOMEM;
1023
1024         *field = f;
1025         return 0;
1026 }
1027
1028 DIR *xopendirat(int fd, const char *name, int flags) {
1029         int nfd;
1030         DIR *d;
1031
1032         assert(!(flags & O_CREAT));
1033
1034         nfd = openat(fd, name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC|flags, 0);
1035         if (nfd < 0)
1036                 return NULL;
1037
1038         d = fdopendir(nfd);
1039         if (!d) {
1040                 safe_close(nfd);
1041                 return NULL;
1042         }
1043
1044         return d;
1045 }
1046
1047 static int search_and_fopen_internal(const char *path, const char *mode, const char *root, char **search, FILE **_f) {
1048         char **i;
1049
1050         assert(path);
1051         assert(mode);
1052         assert(_f);
1053
1054         if (!path_strv_resolve_uniq(search, root))
1055                 return -ENOMEM;
1056
1057         STRV_FOREACH(i, search) {
1058                 _cleanup_free_ char *p = NULL;
1059                 FILE *f;
1060
1061                 if (root)
1062                         p = strjoin(root, *i, "/", path);
1063                 else
1064                         p = strjoin(*i, "/", path);
1065                 if (!p)
1066                         return -ENOMEM;
1067
1068                 f = fopen(p, mode);
1069                 if (f) {
1070                         *_f = f;
1071                         return 0;
1072                 }
1073
1074                 if (errno != ENOENT)
1075                         return -errno;
1076         }
1077
1078         return -ENOENT;
1079 }
1080
1081 int search_and_fopen(const char *path, const char *mode, const char *root, const char **search, FILE **_f) {
1082         _cleanup_strv_free_ char **copy = NULL;
1083
1084         assert(path);
1085         assert(mode);
1086         assert(_f);
1087
1088         if (path_is_absolute(path)) {
1089                 FILE *f;
1090
1091                 f = fopen(path, mode);
1092                 if (f) {
1093                         *_f = f;
1094                         return 0;
1095                 }
1096
1097                 return -errno;
1098         }
1099
1100         copy = strv_copy((char**) search);
1101         if (!copy)
1102                 return -ENOMEM;
1103
1104         return search_and_fopen_internal(path, mode, root, copy, _f);
1105 }
1106
1107 int search_and_fopen_nulstr(const char *path, const char *mode, const char *root, const char *search, FILE **_f) {
1108         _cleanup_strv_free_ char **s = NULL;
1109
1110         if (path_is_absolute(path)) {
1111                 FILE *f;
1112
1113                 f = fopen(path, mode);
1114                 if (f) {
1115                         *_f = f;
1116                         return 0;
1117                 }
1118
1119                 return -errno;
1120         }
1121
1122         s = strv_split_nulstr(search);
1123         if (!s)
1124                 return -ENOMEM;
1125
1126         return search_and_fopen_internal(path, mode, root, s, _f);
1127 }
1128
1129 int fopen_temporary(const char *path, FILE **_f, char **_temp_path) {
1130         FILE *f;
1131         char *t;
1132         int r, fd;
1133
1134         assert(path);
1135         assert(_f);
1136         assert(_temp_path);
1137
1138         r = tempfn_xxxxxx(path, NULL, &t);
1139         if (r < 0)
1140                 return r;
1141
1142         fd = mkostemp_safe(t);
1143         if (fd < 0) {
1144                 free(t);
1145                 return -errno;
1146         }
1147
1148         f = fdopen(fd, "we");
1149         if (!f) {
1150                 unlink_noerrno(t);
1151                 free(t);
1152                 safe_close(fd);
1153                 return -errno;
1154         }
1155
1156         *_f = f;
1157         *_temp_path = t;
1158
1159         return 0;
1160 }
1161
1162 int fflush_and_check(FILE *f) {
1163         assert(f);
1164
1165         errno = 0;
1166         fflush(f);
1167
1168         if (ferror(f))
1169                 return errno > 0 ? -errno : -EIO;
1170
1171         return 0;
1172 }
1173
1174 int fflush_sync_and_check(FILE *f) {
1175         int r;
1176
1177         assert(f);
1178
1179         r = fflush_and_check(f);
1180         if (r < 0)
1181                 return r;
1182
1183         if (fsync(fileno(f)) < 0)
1184                 return -errno;
1185
1186         r = fsync_directory_of_file(fileno(f));
1187         if (r < 0)
1188                 return r;
1189
1190         return 0;
1191 }
1192
1193 /* This is much like mkostemp() but is subject to umask(). */
1194 int mkostemp_safe(char *pattern) {
1195         _cleanup_umask_ mode_t u = 0;
1196         int fd;
1197
1198         assert(pattern);
1199
1200         u = umask(077);
1201
1202         fd = mkostemp(pattern, O_CLOEXEC);
1203         if (fd < 0)
1204                 return -errno;
1205
1206         return fd;
1207 }
1208
1209 int fmkostemp_safe(char *pattern, const char *mode, FILE **ret_f) {
1210         int fd;
1211         FILE *f;
1212
1213         fd = mkostemp_safe(pattern);
1214         if (fd < 0)
1215                 return fd;
1216
1217         f = fdopen(fd, mode);
1218         if (!f) {
1219                 safe_close(fd);
1220                 return -errno;
1221         }
1222
1223         *ret_f = f;
1224         return 0;
1225 }
1226
1227 int tempfn_xxxxxx(const char *p, const char *extra, char **ret) {
1228         const char *fn;
1229         char *t;
1230
1231         assert(ret);
1232
1233         if (isempty(p))
1234                 return -EINVAL;
1235         if (path_equal(p, "/"))
1236                 return -EINVAL;
1237
1238         /*
1239          * Turns this:
1240          *         /foo/bar/waldo
1241          *
1242          * Into this:
1243          *         /foo/bar/.#<extra>waldoXXXXXX
1244          */
1245
1246         fn = basename(p);
1247         if (!filename_is_valid(fn))
1248                 return -EINVAL;
1249
1250         extra = strempty(extra);
1251
1252         t = new(char, strlen(p) + 2 + strlen(extra) + 6 + 1);
1253         if (!t)
1254                 return -ENOMEM;
1255
1256         strcpy(stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn), "XXXXXX");
1257
1258         *ret = path_simplify(t, false);
1259         return 0;
1260 }
1261
1262 int tempfn_random(const char *p, const char *extra, char **ret) {
1263         const char *fn;
1264         char *t, *x;
1265         uint64_t u;
1266         unsigned i;
1267
1268         assert(ret);
1269
1270         if (isempty(p))
1271                 return -EINVAL;
1272         if (path_equal(p, "/"))
1273                 return -EINVAL;
1274
1275         /*
1276          * Turns this:
1277          *         /foo/bar/waldo
1278          *
1279          * Into this:
1280          *         /foo/bar/.#<extra>waldobaa2a261115984a9
1281          */
1282
1283         fn = basename(p);
1284         if (!filename_is_valid(fn))
1285                 return -EINVAL;
1286
1287         extra = strempty(extra);
1288
1289         t = new(char, strlen(p) + 2 + strlen(extra) + 16 + 1);
1290         if (!t)
1291                 return -ENOMEM;
1292
1293         x = stpcpy(stpcpy(stpcpy(mempcpy(t, p, fn - p), ".#"), extra), fn);
1294
1295         u = random_u64();
1296         for (i = 0; i < 16; i++) {
1297                 *(x++) = hexchar(u & 0xF);
1298                 u >>= 4;
1299         }
1300
1301         *x = 0;
1302
1303         *ret = path_simplify(t, false);
1304         return 0;
1305 }
1306
1307 int tempfn_random_child(const char *p, const char *extra, char **ret) {
1308         char *t, *x;
1309         uint64_t u;
1310         unsigned i;
1311         int r;
1312
1313         assert(ret);
1314
1315         /* Turns this:
1316          *         /foo/bar/waldo
1317          * Into this:
1318          *         /foo/bar/waldo/.#<extra>3c2b6219aa75d7d0
1319          */
1320
1321         if (!p) {
1322                 r = tmp_dir(&p);
1323                 if (r < 0)
1324                         return r;
1325         }
1326
1327         extra = strempty(extra);
1328
1329         t = new(char, strlen(p) + 3 + strlen(extra) + 16 + 1);
1330         if (!t)
1331                 return -ENOMEM;
1332
1333         if (isempty(p))
1334                 x = stpcpy(stpcpy(t, ".#"), extra);
1335         else
1336                 x = stpcpy(stpcpy(stpcpy(t, p), "/.#"), extra);
1337
1338         u = random_u64();
1339         for (i = 0; i < 16; i++) {
1340                 *(x++) = hexchar(u & 0xF);
1341                 u >>= 4;
1342         }
1343
1344         *x = 0;
1345
1346         *ret = path_simplify(t, false);
1347         return 0;
1348 }
1349
1350 int write_timestamp_file_atomic(const char *fn, usec_t n) {
1351         char ln[DECIMAL_STR_MAX(n)+2];
1352
1353         /* Creates a "timestamp" file, that contains nothing but a
1354          * usec_t timestamp, formatted in ASCII. */
1355
1356         if (n <= 0 || n >= USEC_INFINITY)
1357                 return -ERANGE;
1358
1359         xsprintf(ln, USEC_FMT "\n", n);
1360
1361         return write_string_file(fn, ln, WRITE_STRING_FILE_CREATE|WRITE_STRING_FILE_ATOMIC);
1362 }
1363
1364 int read_timestamp_file(const char *fn, usec_t *ret) {
1365         _cleanup_free_ char *ln = NULL;
1366         uint64_t t;
1367         int r;
1368
1369         r = read_one_line_file(fn, &ln);
1370         if (r < 0)
1371                 return r;
1372
1373         r = safe_atou64(ln, &t);
1374         if (r < 0)
1375                 return r;
1376
1377         if (t <= 0 || t >= (uint64_t) USEC_INFINITY)
1378                 return -ERANGE;
1379
1380         *ret = (usec_t) t;
1381         return 0;
1382 }
1383
1384 int fputs_with_space(FILE *f, const char *s, const char *separator, bool *space) {
1385         int r;
1386
1387         assert(s);
1388
1389         /* Outputs the specified string with fputs(), but optionally prefixes it with a separator. The *space parameter
1390          * when specified shall initially point to a boolean variable initialized to false. It is set to true after the
1391          * first invocation. This call is supposed to be use in loops, where a separator shall be inserted between each
1392          * element, but not before the first one. */
1393
1394         if (!f)
1395                 f = stdout;
1396
1397         if (space) {
1398                 if (!separator)
1399                         separator = " ";
1400
1401                 if (*space) {
1402                         r = fputs(separator, f);
1403                         if (r < 0)
1404                                 return r;
1405                 }
1406
1407                 *space = true;
1408         }
1409
1410         return fputs(s, f);
1411 }
1412
1413 int open_tmpfile_unlinkable(const char *directory, int flags) {
1414         char *p;
1415         int fd, r;
1416
1417         if (!directory) {
1418                 r = tmp_dir(&directory);
1419                 if (r < 0)
1420                         return r;
1421         } else if (isempty(directory))
1422                 return -EINVAL;
1423
1424         /* Returns an unlinked temporary file that cannot be linked into the file system anymore */
1425
1426         /* Try O_TMPFILE first, if it is supported */
1427         fd = open(directory, flags|O_TMPFILE|O_EXCL, S_IRUSR|S_IWUSR);
1428         if (fd >= 0)
1429                 return fd;
1430
1431         /* Fall back to unguessable name + unlinking */
1432         p = strjoina(directory, "/systemd-tmp-XXXXXX");
1433
1434         fd = mkostemp_safe(p);
1435         if (fd < 0)
1436                 return fd;
1437
1438         (void) unlink(p);
1439
1440         return fd;
1441 }
1442
1443 int open_tmpfile_linkable(const char *target, int flags, char **ret_path) {
1444         _cleanup_free_ char *tmp = NULL;
1445         int r, fd;
1446
1447         assert(target);
1448         assert(ret_path);
1449
1450         /* Don't allow O_EXCL, as that has a special meaning for O_TMPFILE */
1451         assert((flags & O_EXCL) == 0);
1452
1453         /* Creates a temporary file, that shall be renamed to "target" later. If possible, this uses O_TMPFILE – in
1454          * which case "ret_path" will be returned as NULL. If not possible a the tempoary path name used is returned in
1455          * "ret_path". Use link_tmpfile() below to rename the result after writing the file in full. */
1456
1457         fd = open_parent(target, O_TMPFILE|flags, 0640);
1458         if (fd >= 0) {
1459                 *ret_path = NULL;
1460                 return fd;
1461         }
1462
1463         log_debug_errno(fd, "Failed to use O_TMPFILE for %s: %m", target);
1464
1465         r = tempfn_random(target, NULL, &tmp);
1466         if (r < 0)
1467                 return r;
1468
1469         fd = open(tmp, O_CREAT|O_EXCL|O_NOFOLLOW|O_NOCTTY|flags, 0640);
1470         if (fd < 0)
1471                 return -errno;
1472
1473         *ret_path = TAKE_PTR(tmp);
1474
1475         return fd;
1476 }
1477
1478 int open_serialization_fd(const char *ident) {
1479         int fd = -1;
1480
1481         fd = memfd_create(ident, MFD_CLOEXEC);
1482         if (fd < 0) {
1483                 const char *path;
1484
1485                 path = getpid_cached() == 1 ? "/run/systemd" : "/tmp";
1486                 fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC);
1487                 if (fd < 0)
1488                         return fd;
1489
1490                 log_debug("Serializing %s to %s.", ident, path);
1491         } else
1492                 log_debug("Serializing %s to memfd.", ident);
1493
1494         return fd;
1495 }
1496
1497 int link_tmpfile(int fd, const char *path, const char *target) {
1498         int r;
1499
1500         assert(fd >= 0);
1501         assert(target);
1502
1503         /* Moves a temporary file created with open_tmpfile() above into its final place. if "path" is NULL an fd
1504          * created with O_TMPFILE is assumed, and linkat() is used. Otherwise it is assumed O_TMPFILE is not supported
1505          * on the directory, and renameat2() is used instead.
1506          *
1507          * Note that in both cases we will not replace existing files. This is because linkat() does not support this
1508          * operation currently (renameat2() does), and there is no nice way to emulate this. */
1509
1510         if (path) {
1511                 r = rename_noreplace(AT_FDCWD, path, AT_FDCWD, target);
1512                 if (r < 0)
1513                         return r;
1514         } else {
1515                 char proc_fd_path[STRLEN("/proc/self/fd/") + DECIMAL_STR_MAX(fd) + 1];
1516
1517                 xsprintf(proc_fd_path, "/proc/self/fd/%i", fd);
1518
1519                 if (linkat(AT_FDCWD, proc_fd_path, AT_FDCWD, target, AT_SYMLINK_FOLLOW) < 0)
1520                         return -errno;
1521         }
1522
1523         return 0;
1524 }
1525
1526 int read_nul_string(FILE *f, char **ret) {
1527         _cleanup_free_ char *x = NULL;
1528         size_t allocated = 0, n = 0;
1529
1530         assert(f);
1531         assert(ret);
1532
1533         /* Reads a NUL-terminated string from the specified file. */
1534
1535         for (;;) {
1536                 int c;
1537
1538                 if (!GREEDY_REALLOC(x, allocated, n+2))
1539                         return -ENOMEM;
1540
1541                 c = fgetc(f);
1542                 if (c == 0) /* Terminate at NUL byte */
1543                         break;
1544                 if (c == EOF) {
1545                         if (ferror(f))
1546                                 return -errno;
1547                         break; /* Terminate at EOF */
1548                 }
1549
1550                 x[n++] = (char) c;
1551         }
1552
1553         if (x)
1554                 x[n] = 0;
1555         else {
1556                 x = new0(char, 1);
1557                 if (!x)
1558                         return -ENOMEM;
1559         }
1560
1561         *ret = TAKE_PTR(x);
1562
1563         return 0;
1564 }
1565
1566 int mkdtemp_malloc(const char *template, char **ret) {
1567         _cleanup_free_ char *p = NULL;
1568         int r;
1569
1570         assert(ret);
1571
1572         if (template)
1573                 p = strdup(template);
1574         else {
1575                 const char *tmp;
1576
1577                 r = tmp_dir(&tmp);
1578                 if (r < 0)
1579                         return r;
1580
1581                 p = strjoin(tmp, "/XXXXXX");
1582         }
1583         if (!p)
1584                 return -ENOMEM;
1585
1586         if (!mkdtemp(p))
1587                 return -errno;
1588
1589         *ret = TAKE_PTR(p);
1590         return 0;
1591 }
1592
1593 DEFINE_TRIVIAL_CLEANUP_FUNC(FILE*, funlockfile);
1594
1595 int read_line(FILE *f, size_t limit, char **ret) {
1596         _cleanup_free_ char *buffer = NULL;
1597         size_t n = 0, allocated = 0, count = 0;
1598
1599         assert(f);
1600
1601         /* Something like a bounded version of getline().
1602          *
1603          * Considers EOF, \n and \0 end of line delimiters, and does not include these delimiters in the string
1604          * returned.
1605          *
1606          * Returns the number of bytes read from the files (i.e. including delimiters — this hence usually differs from
1607          * the number of characters in the returned string). When EOF is hit, 0 is returned.
1608          *
1609          * The input parameter limit is the maximum numbers of characters in the returned string, i.e. excluding
1610          * delimiters. If the limit is hit we fail and return -ENOBUFS.
1611          *
1612          * If a line shall be skipped ret may be initialized as NULL. */
1613
1614         if (ret) {
1615                 if (!GREEDY_REALLOC(buffer, allocated, 1))
1616                         return -ENOMEM;
1617         }
1618
1619         {
1620                 _unused_ _cleanup_(funlockfilep) FILE *flocked = f;
1621                 flockfile(f);
1622
1623                 for (;;) {
1624                         int c;
1625
1626                         if (n >= limit)
1627                                 return -ENOBUFS;
1628
1629                         errno = 0;
1630                         c = fgetc_unlocked(f);
1631                         if (c == EOF) {
1632                                 /* if we read an error, and have no data to return, then propagate the error */
1633                                 if (ferror_unlocked(f) && n == 0)
1634                                         return errno > 0 ? -errno : -EIO;
1635
1636                                 break;
1637                         }
1638
1639                         count++;
1640
1641                         if (IN_SET(c, '\n', 0)) /* Reached a delimiter */
1642                                 break;
1643
1644                         if (ret) {
1645                                 if (!GREEDY_REALLOC(buffer, allocated, n + 2))
1646                                         return -ENOMEM;
1647
1648                                 buffer[n] = (char) c;
1649                         }
1650
1651                         n++;
1652                 }
1653         }
1654
1655         if (ret) {
1656                 buffer[n] = 0;
1657
1658                 *ret = TAKE_PTR(buffer);
1659         }
1660
1661         return (int) count;
1662 }