src/shared/fileio.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <unistd.h>
  23 #include "fileio.h"
  24 #include "util.h"
  25 #include "strv.h"
  26
  27 int write_string_file(const char *fn, const char *line) {
  28         _cleanup_fclose_ FILE *f = NULL;
  29
  30         assert(fn);
  31         assert(line);
  32
  33         f = fopen(fn, "we");
  34         if (!f)
  35                 return -errno;
  36
  37         errno = 0;
  38         if (fputs(line, f) < 0)
  39                 return errno ? -errno : -EIO;
  40
  41         if (!endswith(line, "\n"))
  42                 fputc('\n', f);
  43
  44         fflush(f);
  45
  46         if (ferror(f))
  47                 return errno ? -errno : -EIO;
  48
  49         return 0;
  50 }
  51
  52 int write_string_file_atomic(const char *fn, const char *line) {
  53         _cleanup_fclose_ FILE *f = NULL;
  54         _cleanup_free_ char *p = NULL;
  55         int r;
  56
  57         assert(fn);
  58         assert(line);
  59
  60         r = fopen_temporary(fn, &f, &p);
  61         if (r < 0)
  62                 return r;
  63
  64         fchmod_umask(fileno(f), 0644);
  65
  66         errno = 0;
  67         if (fputs(line, f) < 0) {
  68                 r = -errno;
  69                 goto finish;
  70         }
  71
  72         if (!endswith(line, "\n"))
  73                 fputc('\n', f);
  74
  75         fflush(f);
  76
  77         if (ferror(f))
  78                 r = errno ? -errno : -EIO;
  79         else {
  80                 if (rename(p, fn) < 0)
  81                         r = -errno;
  82                 else
  83                         r = 0;
  84         }
  85
  86 finish:
  87         if (r < 0)
  88                 unlink(p);
  89
  90         return r;
  91 }
  92
  93 int read_one_line_file(const char *fn, char **line) {
  94         _cleanup_fclose_ FILE *f = NULL;
  95         char t[LINE_MAX], *c;
  96
  97         assert(fn);
  98         assert(line);
  99
 100         f = fopen(fn, "re");
 101         if (!f)
 102                 return -errno;
 103
 104         if (!fgets(t, sizeof(t), f)) {
 105
 106                 if (ferror(f))
 107                         return errno ? -errno : -EIO;
 108
 109                 t[0] = 0;
 110         }
 111
 112         c = strdup(t);
 113         if (!c)
 114                 return -ENOMEM;
 115         truncate_nl(c);
 116
 117         *line = c;
 118         return 0;
 119 }
 120
 121 int read_full_file(const char *fn, char **contents, size_t *size) {
 122         _cleanup_fclose_ FILE *f = NULL;
 123         size_t n, l;
 124         _cleanup_free_ char *buf = NULL;
 125         struct stat st;
 126
 127         assert(fn);
 128         assert(contents);
 129
 130         f = fopen(fn, "re");
 131         if (!f)
 132                 return -errno;
 133
 134         if (fstat(fileno(f), &st) < 0)
 135                 return -errno;
 136
 137         /* Safety check */
 138         if (st.st_size > 4*1024*1024)
 139                 return -E2BIG;
 140
 141         n = st.st_size > 0 ? st.st_size : LINE_MAX;
 142         l = 0;
 143
 144         for (;;) {
 145                 char *t;
 146                 size_t k;
 147
 148                 t = realloc(buf, n+1);
 149                 if (!t)
 150                         return -ENOMEM;
 151
 152                 buf = t;
 153                 k = fread(buf + l, 1, n - l, f);
 154
 155                 if (k <= 0) {
 156                         if (ferror(f))
 157                                 return -errno;
 158
 159                         break;
 160                 }
 161
 162                 l += k;
 163                 n *= 2;
 164
 165                 /* Safety check */
 166                 if (n > 4*1024*1024)
 167                         return -E2BIG;
 168         }
 169
 170         buf[l] = 0;
 171         *contents = buf;
 172         buf = NULL;
 173
 174         if (size)
 175                 *size = l;
 176
 177         return 0;
 178 }
 179
 180 static int parse_env_file_internal(
 181                 const char *fname,
 182                 const char *newline,
 183                 int (*push) (const char *key, char *value, void *userdata),
 184                 void *userdata) {
 185
 186         _cleanup_free_ char *contents = NULL, *key = NULL;
 187         size_t key_alloc = 0, n_key = 0, value_alloc = 0, n_value = 0, last_whitespace = (size_t) -1;
 188         char *p, *value = NULL;
 189         int r;
 190
 191         enum {
 192                 PRE_KEY,
 193                 KEY,
 194                 PRE_EQUAL,
 195                 PRE_VALUE,
 196                 VALUE,
 197                 VALUE_ESCAPE,
 198                 SINGLE_QUOTE_VALUE,
 199                 SINGLE_QUOTE_VALUE_ESCAPE,
 200                 DOUBLE_QUOTE_VALUE,
 201                 DOUBLE_QUOTE_VALUE_ESCAPE,
 202                 COMMENT,
 203                 COMMENT_ESCAPE
 204         } state = PRE_KEY;
 205
 206         assert(fname);
 207         assert(newline);
 208
 209         r = read_full_file(fname, &contents, NULL);
 210         if (r < 0)
 211                 return r;
 212
 213         for (p = contents; *p; p++) {
 214                 char c = *p;
 215
 216                 switch (state) {
 217
 218                 case PRE_KEY:
 219                         if (strchr(COMMENTS, c))
 220                                 state = COMMENT;
 221                         else if (!strchr(WHITESPACE, c)) {
 222                                 state = KEY;
 223                                 if (!greedy_realloc((void**) &key, &key_alloc, n_key+2)) {
 224                                         r = -ENOMEM;
 225                                         goto fail;
 226                                 }
 227
 228                                 key[n_key++] = c;
 229                         }
 230                         break;
 231
 232                 case KEY:
 233                         if (strchr(newline, c)) {
 234                                 state = PRE_KEY;
 235                                 n_key = 0;
 236                         } else if (strchr(WHITESPACE, c))
 237                                 state = PRE_EQUAL;
 238                         else if (c == '=')
 239                                 state = PRE_VALUE;
 240                         else {
 241                                 if (!greedy_realloc((void**) &key, &key_alloc, n_key+2)) {
 242                                         r = -ENOMEM;
 243                                         goto fail;
 244                                 }
 245
 246                                 key[n_key++] = c;
 247                         }
 248
 249                         break;
 250
 251                 case PRE_EQUAL:
 252                         if (strchr(newline, c)) {
 253                                 state = PRE_KEY;
 254                                 n_key = 0;
 255                         } else if (c == '=')
 256                                 state = PRE_VALUE;
 257                         else if (!strchr(WHITESPACE, c)) {
 258                                 n_key = 0;
 259                                 state = COMMENT;
 260                         }
 261
 262                         break;
 263
 264                 case PRE_VALUE:
 265                         if (strchr(newline, c)) {
 266                                 state = PRE_KEY;
 267                                 key[n_key] = 0;
 268
 269                                 if (value)
 270                                         value[n_value] = 0;
 271
 272                                 r = push(key, value, userdata);
 273                                 if (r < 0)
 274                                         goto fail;
 275
 276                                 n_key = 0;
 277                                 value = NULL;
 278                                 value_alloc = n_value = 0;
 279                         } else if (c == '\'')
 280                                 state = SINGLE_QUOTE_VALUE;
 281                         else if (c == '\"')
 282                                 state = DOUBLE_QUOTE_VALUE;
 283                         else if (c == '\\')
 284                                 state = VALUE_ESCAPE;
 285                         else if (!strchr(WHITESPACE, c)) {
 286                                 state = VALUE;
 287
 288                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 289                                         r = -ENOMEM;
 290                                         goto fail;
 291                                 }
 292
 293                                 value[n_value++] = c;
 294                         }
 295
 296                         break;
 297
 298                 case VALUE:
 299                         if (strchr(newline, c)) {
 300                                 state = PRE_KEY;
 301                                 key[n_key] = 0;
 302
 303                                 if (value)
 304                                         value[n_value] = 0;
 305
 306                                 /* Chomp off trailing whitespace */
 307                                 if (last_whitespace != (size_t) -1)
 308                                         value[last_whitespace] = 0;
 309
 310                                 r = push(key, value, userdata);
 311                                 if (r < 0)
 312                                         goto fail;
 313
 314                                 n_key = 0;
 315                                 value = NULL;
 316                                 value_alloc = n_value = 0;
 317                         } else if (c == '\\') {
 318                                 state = VALUE_ESCAPE;
 319                                 last_whitespace = (size_t) -1;
 320                         } else {
 321                                 if (!strchr(WHITESPACE, c))
 322                                         last_whitespace = (size_t) -1;
 323                                 else if (last_whitespace == (size_t) -1)
 324                                         last_whitespace = n_value;
 325
 326                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 327                                         r = -ENOMEM;
 328                                         goto fail;
 329                                 }
 330
 331                                 value[n_value++] = c;
 332                         }
 333
 334                         break;
 335
 336                 case VALUE_ESCAPE:
 337                         state = VALUE;
 338
 339                         if (!strchr(newline, c)) {
 340                                 /* Escaped newlines we eat up entirely */
 341                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 342                                         r = -ENOMEM;
 343                                         goto fail;
 344                                 }
 345
 346                                 value[n_value++] = c;
 347                         }
 348                         break;
 349
 350                 case SINGLE_QUOTE_VALUE:
 351                         if (c == '\'')
 352                                 state = PRE_VALUE;
 353                         else if (c == '\\')
 354                                 state = SINGLE_QUOTE_VALUE_ESCAPE;
 355                         else {
 356                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 357                                         r = -ENOMEM;
 358                                         goto fail;
 359                                 }
 360
 361                                 value[n_value++] = c;
 362                         }
 363
 364                         break;
 365
 366                 case SINGLE_QUOTE_VALUE_ESCAPE:
 367                         state = SINGLE_QUOTE_VALUE;
 368
 369                         if (!strchr(newline, c)) {
 370                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 371                                         r = -ENOMEM;
 372                                         goto fail;
 373                                 }
 374
 375                                 value[n_value++] = c;
 376                         }
 377                         break;
 378
 379                 case DOUBLE_QUOTE_VALUE:
 380                         if (c == '\"')
 381                                 state = PRE_VALUE;
 382                         else if (c == '\\')
 383                                 state = DOUBLE_QUOTE_VALUE_ESCAPE;
 384                         else {
 385                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 386                                         r = -ENOMEM;
 387                                         goto fail;
 388                                 }
 389
 390                                 value[n_value++] = c;
 391                         }
 392
 393                         break;
 394
 395                 case DOUBLE_QUOTE_VALUE_ESCAPE:
 396                         state = DOUBLE_QUOTE_VALUE;
 397
 398                         if (!strchr(newline, c)) {
 399                                 if (!greedy_realloc((void**) &value, &value_alloc, n_value+2)) {
 400                                         r = -ENOMEM;
 401                                         goto fail;
 402                                 }
 403
 404                                 value[n_value++] = c;
 405                         }
 406                         break;
 407
 408                 case COMMENT:
 409                         if (c == '\\')
 410                                 state = COMMENT_ESCAPE;
 411                         else if (strchr(newline, c))
 412                                 state = PRE_KEY;
 413                         break;
 414
 415                 case COMMENT_ESCAPE:
 416                         state = COMMENT;
 417                         break;
 418                 }
 419         }
 420
 421         if (state == PRE_VALUE ||
 422             state == VALUE ||
 423             state == VALUE_ESCAPE ||
 424             state == SINGLE_QUOTE_VALUE ||
 425             state == SINGLE_QUOTE_VALUE_ESCAPE ||
 426             state == DOUBLE_QUOTE_VALUE ||
 427             state == DOUBLE_QUOTE_VALUE_ESCAPE) {
 428
 429                 key[n_key] = 0;
 430
 431                 if (value)
 432                         value[n_value] = 0;
 433
 434                 r = push(key, value, userdata);
 435                 if (r < 0)
 436                         goto fail;
 437         }
 438
 439         return 0;
 440
 441 fail:
 442         free(value);
 443         return r;
 444 }
 445
 446 static int parse_env_file_push(const char *key, char *value, void *userdata) {
 447         const char *k;
 448         va_list* ap = (va_list*) userdata;
 449         va_list aq;
 450
 451         va_copy(aq, *ap);
 452
 453         while ((k = va_arg(aq, const char *))) {
 454                 char **v;
 455
 456                 v = va_arg(aq, char **);
 457
 458                 if (streq(key, k)) {
 459                         va_end(aq);
 460                         free(*v);
 461                         *v = value;
 462                         return 1;
 463                 }
 464         }
 465
 466         va_end(aq);
 467
 468         free(value);
 469         return 0;
 470 }
 471
 472 int parse_env_file(
 473                 const char *fname,
 474                 const char *newline, ...) {
 475
 476         va_list ap;
 477         int r;
 478
 479         if (!newline)
 480                 newline = NEWLINE;
 481
 482         va_start(ap, newline);
 483         r = parse_env_file_internal(fname, newline, parse_env_file_push, &ap);
 484         va_end(ap);
 485
 486         return r;
 487 }
 488
 489 static int load_env_file_push(const char *key, char *value, void *userdata) {
 490         char ***m = userdata;
 491         char *p;
 492         int r;
 493
 494         p = strjoin(key, "=", strempty(value), NULL);
 495         if (!p)
 496                 return -ENOMEM;
 497
 498         r = strv_push(m, p);
 499         if (r < 0) {
 500                 free(p);
 501                 return r;
 502         }
 503
 504         free(value);
 505         return 0;
 506 }
 507
 508 int load_env_file(const char *fname, const char *newline, char ***rl) {
 509         char **m = NULL;
 510         int r;
 511
 512         if (!newline)
 513                 newline = NEWLINE;
 514
 515         r = parse_env_file_internal(fname, newline, load_env_file_push, &m);
 516         if (r < 0) {
 517                 strv_free(m);
 518                 return r;
 519         }
 520
 521         *rl = m;
 522         return 0;
 523 }
 524
 525 int write_env_file(const char *fname, char **l) {
 526         char **i;
 527         char _cleanup_free_ *p = NULL;
 528         FILE _cleanup_fclose_ *f = NULL;
 529         int r;
 530
 531         r = fopen_temporary(fname, &f, &p);
 532         if (r < 0)
 533                 return r;
 534
 535         fchmod_umask(fileno(f), 0644);
 536
 537         errno = 0;
 538         STRV_FOREACH(i, l) {
 539                 fputs(*i, f);
 540                 fputc('\n', f);
 541         }
 542
 543         fflush(f);
 544
 545         if (ferror(f)) {
 546                 if (errno > 0)
 547                         r = -errno;
 548                 else
 549                         r = -EIO;
 550         } else {
 551                 if (rename(p, fname) < 0)
 552                         r = -errno;
 553                 else
 554                         r = 0;
 555         }
 556
 557         if (r < 0)
 558                 unlink(p);
 559
 560         return r;
 561 }