lib/util/util_file.c

   1 /*
   2  * Unix SMB/CIFS implementation.
   3  * SMB parameters and setup
   4  * Copyright (C) Andrew Tridgell 1992-1998 Modified by Jeremy Allison 1995.
   5  *
   6  * Added afdgets() Jelmer Vernooij 2005
   7  *
   8  * This program is free software; you can redistribute it and/or modify it under
   9  * the terms of the GNU General Public License as published by the Free
  10  * Software Foundation; either version 3 of the License, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but WITHOUT
  14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  16  * more details.
  17  *
  18  * You should have received a copy of the GNU General Public License along with
  19  * this program; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "replace.h"
  23 #include "system/shmem.h"
  24 #include "system/filesys.h"
  25 #include <talloc.h>
  26 #include "lib/util/samba_util.h"
  27 #include "lib/util/debug.h"
  28
  29 /**
  30  * @file
  31  * @brief File-related utility functions
  32  */
  33
  34 /**
  35 read a line from a file with possible \ continuation chars.
  36 Blanks at the start or end of a line are stripped.
  37 The string will be allocated if s2 is NULL
  38 **/
  39 _PUBLIC_ char *fgets_slash(char *s2,int maxlen,XFILE *f)
  40 {
  41   char *s=s2;
  42   int len = 0;
  43   int c;
  44   bool start_of_line = true;
  45
  46   if (x_feof(f))
  47     return(NULL);
  48
  49   if (maxlen <2) return(NULL);
  50
  51   if (!s2)
  52     {
  53       maxlen = MIN(maxlen,8);
  54       s = (char *)malloc(maxlen);
  55     }
  56
  57   if (!s) return(NULL);
  58
  59   *s = 0;
  60
  61   while (len < maxlen-1)
  62     {
  63       c = x_getc(f);
  64       switch (c)
  65         {
  66         case '\r':
  67           break;
  68         case '\n':
  69           while (len > 0 && s[len-1] == ' ')
  70             {
  71               s[--len] = 0;
  72             }
  73           if (len > 0 && s[len-1] == '\\')
  74             {
  75               s[--len] = 0;
  76               start_of_line = true;
  77               break;
  78             }
  79           return(s);
  80         case EOF:
  81           if (len <= 0 && !s2)
  82             SAFE_FREE(s);
  83           return(len>0?s:NULL);
  84         case ' ':
  85           if (start_of_line)
  86             break;
  87           /* fall through */
  88         default:
  89           start_of_line = false;
  90           s[len++] = c;
  91           s[len] = 0;
  92         }
  93       if (!s2 && len > maxlen-3)
  94         {
  95           char *t;
  96
  97           maxlen *= 2;
  98           t = realloc_p(s, char, maxlen);
  99           if (!t) {
 100             DEBUG(0,("fgets_slash: failed to expand buffer!\n"));
 101             SAFE_FREE(s);
 102             return(NULL);
 103           } else s = t;
 104         }
 105     }
 106   return(s);
 107 }
 108
 109 /**
 110  * Read one line (data until next newline or eof) and allocate it
 111  */
 112 _PUBLIC_ char *afdgets(int fd, TALLOC_CTX *mem_ctx, size_t hint)
 113 {
 114         char *data = NULL;
 115         ssize_t alloc_size = 0, offset = 0, ret;
 116         int p;
 117
 118         if (hint <= 0) hint = 0x100;
 119
 120         do {
 121                 alloc_size += hint;
 122
 123                 data = talloc_realloc(mem_ctx, data, char, alloc_size);
 124
 125                 if (!data)
 126                         return NULL;
 127
 128                 ret = read(fd, data + offset, hint);
 129
 130                 if (ret == 0) {
 131                         return NULL;
 132                 }
 133
 134                 if (ret == -1) {
 135                         talloc_free(data);
 136                         return NULL;
 137                 }
 138
 139                 /* Find newline */
 140                 for (p = 0; p < ret; p++) {
 141                         if (data[offset + p] == '\n')
 142                                 break;
 143                 }
 144
 145                 if (p < ret) {
 146                         data[offset + p] = '\0';
 147
 148                         /* Go back to position of newline */
 149                         lseek(fd, p - ret + 1, SEEK_CUR);
 150                         return data;
 151                 }
 152
 153                 offset += ret;
 154
 155         } while (ret == hint);
 156
 157         data[offset] = '\0';
 158
 159         return data;
 160 }
 161
 162
 163 /**
 164 load a file into memory from a fd.
 165 **/
 166 _PUBLIC_ char *fd_load(int fd, size_t *psize, size_t maxsize, TALLOC_CTX *mem_ctx)
 167 {
 168         struct stat sbuf;
 169         char *p;
 170         size_t size;
 171
 172         if (fstat(fd, &sbuf) != 0) return NULL;
 173
 174         size = sbuf.st_size;
 175
 176         if (maxsize) {
 177                 size = MIN(size, maxsize);
 178         }
 179
 180         p = (char *)talloc_size(mem_ctx, size+1);
 181         if (!p) return NULL;
 182
 183         if (read(fd, p, size) != size) {
 184                 talloc_free(p);
 185                 return NULL;
 186         }
 187         p[size] = 0;
 188
 189         if (psize) *psize = size;
 190
 191         return p;
 192 }
 193
 194 /**
 195 load a file into memory
 196 **/
 197 _PUBLIC_ char *file_load(const char *fname, size_t *size, size_t maxsize, TALLOC_CTX *mem_ctx)
 198 {
 199         int fd;
 200         char *p;
 201
 202         if (!fname || !*fname) return NULL;
 203
 204         fd = open(fname,O_RDONLY);
 205         if (fd == -1) return NULL;
 206
 207         p = fd_load(fd, size, maxsize, mem_ctx);
 208
 209         close(fd);
 210
 211         return p;
 212 }
 213
 214
 215 /**
 216 mmap (if possible) or read a file
 217 **/
 218 _PUBLIC_ void *map_file(const char *fname, size_t size)
 219 {
 220         size_t s2 = 0;
 221         void *p = NULL;
 222 #ifdef HAVE_MMAP
 223         int fd;
 224         fd = open(fname, O_RDONLY, 0);
 225         if (fd == -1) {
 226                 DEBUG(2,("Failed to load %s - %s\n", fname, strerror(errno)));
 227                 return NULL;
 228         }
 229         p = mmap(NULL, size, PROT_READ, MAP_SHARED|MAP_FILE, fd, 0);
 230         close(fd);
 231         if (p == MAP_FAILED) {
 232                 DEBUG(1,("Failed to mmap %s - %s\n", fname, strerror(errno)));
 233                 return NULL;
 234         }
 235 #endif
 236         if (!p) {
 237                 p = file_load(fname, &s2, 0, NULL);
 238                 if (!p) return NULL;
 239                 if (s2 != size) {
 240                         DEBUG(1,("incorrect size for %s - got %d expected %d\n",
 241                                  fname, (int)s2, (int)size));
 242                         talloc_free(p);
 243                         return NULL;
 244                 }
 245         }
 246
 247         return p;
 248 }
 249
 250 /**
 251  unmap or free memory
 252 **/
 253
 254 bool unmap_file(void *start, size_t size)
 255 {
 256 #ifdef HAVE_MMAP
 257         if (munmap( start, size ) != 0) {
 258                 DEBUG( 1, ("map_file: Failed to unmap address %p "
 259                         "of size %u - %s\n",
 260                         start, (unsigned int)size, strerror(errno) ));
 261                 return false;
 262         }
 263         return true;
 264 #else
 265         talloc_free(start);
 266         return true;
 267 #endif
 268 }
 269
 270 /**
 271 parse a buffer into lines
 272 'p' will be freed on error, and otherwise will be made a child of the returned array
 273 **/
 274 char **file_lines_parse(char *p, size_t size, int *numlines, TALLOC_CTX *mem_ctx)
 275 {
 276         int i;
 277         char *s, **ret;
 278
 279         if (!p) return NULL;
 280
 281         for (s = p, i=0; s < p+size; s++) {
 282                 if (s[0] == '\n') i++;
 283         }
 284
 285         ret = talloc_array(mem_ctx, char *, i+2);
 286         if (!ret) {
 287                 talloc_free(p);
 288                 return NULL;
 289         }
 290
 291         talloc_steal(ret, p);
 292
 293         memset(ret, 0, sizeof(ret[0])*(i+2));
 294
 295         ret[0] = p;
 296         for (s = p, i=0; s < p+size; s++) {
 297                 if (s[0] == '\n') {
 298                         s[0] = 0;
 299                         i++;
 300                         ret[i] = s+1;
 301                 }
 302                 if (s[0] == '\r') s[0] = 0;
 303         }
 304
 305         /* remove any blank lines at the end */
 306         while (i > 0 && ret[i-1][0] == 0) {
 307                 i--;
 308         }
 309
 310         if (numlines) *numlines = i;
 311
 312         return ret;
 313 }
 314
 315
 316 /**
 317 load a file into memory and return an array of pointers to lines in the file
 318 must be freed with talloc_free().
 319 **/
 320 _PUBLIC_ char **file_lines_load(const char *fname, int *numlines, size_t maxsize, TALLOC_CTX *mem_ctx)
 321 {
 322         char *p;
 323         size_t size;
 324
 325         p = file_load(fname, &size, maxsize, mem_ctx);
 326         if (!p) return NULL;
 327
 328         return file_lines_parse(p, size, numlines, mem_ctx);
 329 }
 330
 331 /**
 332 load a fd into memory and return an array of pointers to lines in the file
 333 must be freed with talloc_free(). If convert is true calls unix_to_dos on
 334 the list.
 335 **/
 336 _PUBLIC_ char **fd_lines_load(int fd, int *numlines, size_t maxsize, TALLOC_CTX *mem_ctx)
 337 {
 338         char *p;
 339         size_t size;
 340
 341         p = fd_load(fd, &size, maxsize, mem_ctx);
 342         if (!p) return NULL;
 343
 344         return file_lines_parse(p, size, numlines, mem_ctx);
 345 }
 346
 347
 348 /**
 349 take a list of lines and modify them to produce a list where \ continues
 350 a line
 351 **/
 352 _PUBLIC_ void file_lines_slashcont(char **lines)
 353 {
 354         int i, j;
 355
 356         for (i=0; lines[i];) {
 357                 int len = strlen(lines[i]);
 358                 if (lines[i][len-1] == '\\') {
 359                         lines[i][len-1] = ' ';
 360                         if (lines[i+1]) {
 361                                 char *p = &lines[i][len];
 362                                 while (p < lines[i+1]) *p++ = ' ';
 363                                 for (j = i+1; lines[j]; j++) lines[j] = lines[j+1];
 364                         }
 365                 } else {
 366                         i++;
 367                 }
 368         }
 369 }
 370
 371 /**
 372   save a lump of data into a file. Mostly used for debugging
 373 */
 374 _PUBLIC_ bool file_save(const char *fname, const void *packet, size_t length)
 375 {
 376         int fd;
 377         fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, 0644);
 378         if (fd == -1) {
 379                 return false;
 380         }
 381         if (write(fd, packet, length) != (size_t)length) {
 382                 close(fd);
 383                 return false;
 384         }
 385         close(fd);
 386         return true;
 387 }
 388
 389 _PUBLIC_ int vfdprintf(int fd, const char *format, va_list ap)
 390 {
 391         char *p;
 392         int len, ret;
 393         va_list ap2;
 394
 395         va_copy(ap2, ap);
 396         len = vasprintf(&p, format, ap2);
 397         va_end(ap2);
 398         if (len <= 0) return len;
 399         ret = write(fd, p, len);
 400         SAFE_FREE(p);
 401         return ret;
 402 }
 403
 404 _PUBLIC_ int fdprintf(int fd, const char *format, ...)
 405 {
 406         va_list ap;
 407         int ret;
 408
 409         va_start(ap, format);
 410         ret = vfdprintf(fd, format, ap);
 411         va_end(ap);
 412         return ret;
 413 }
 414
 415
 416 /*
 417   try to determine if the filesystem supports large files
 418 */
 419 _PUBLIC_ bool large_file_support(const char *path)
 420 {
 421         int fd;
 422         ssize_t ret;
 423         char c;
 424
 425         fd = open(path, O_RDWR|O_CREAT, 0600);
 426         unlink(path);
 427         if (fd == -1) {
 428                 /* have to assume large files are OK */
 429                 return true;
 430         }
 431         ret = pread(fd, &c, 1, ((uint64_t)1)<<32);
 432         close(fd);
 433         return ret == 0;
 434 }
 435
 436
 437 /*
 438   compare two files, return true if the two files have the same content
 439  */
 440 bool file_compare(const char *path1, const char *path2)
 441 {
 442         size_t size1, size2;
 443         char *p1, *p2;
 444         TALLOC_CTX *mem_ctx = talloc_new(NULL);
 445
 446         p1 = file_load(path1, &size1, 0, mem_ctx);
 447         p2 = file_load(path2, &size2, 0, mem_ctx);
 448         if (!p1 || !p2 || size1 != size2) {
 449                 talloc_free(mem_ctx);
 450                 return false;
 451         }
 452         if (memcmp(p1, p2, size1) != 0) {
 453                 talloc_free(mem_ctx);
 454                 return false;
 455         }
 456         talloc_free(mem_ctx);
 457         return true;
 458 }