release/src/router/hotplug2/filemap_utils.c

   1 /*****************************************************************************\
   2 *  _  _       _          _              ___                                   *
   3 * | || | ___ | |_  _ __ | | _  _  __ _ |_  )                                  *
   4 * | __ |/ _ \|  _|| '_ \| || || |/ _` | / /                                   *
   5 * |_||_|\___/ \__|| .__/|_| \_,_|\__, |/___|                                  *
   6 *                 |_|            |___/                                        *
   7 \*****************************************************************************/
   8
   9 #include <string.h>
  10 #include <stdlib.h>
  11 #include <fcntl.h>
  12 #include <unistd.h>
  13 #include <sys/types.h>
  14 #include <sys/stat.h>
  15 #include <sys/mman.h>
  16
  17 #include "filemap_utils.h"
  18
  19 /**
  20  * Basic open/mmap wrapper to make things simpler.
  21  *
  22  * @1 Filename of the mmaped file
  23  * @2 Pointer to filemap structure
  24  *
  25  * Returns: 0 if success, 1 otherwise
  26  */
  27 int map_file(const char *filename, struct filemap_t *filemap) {
  28         struct stat statbuf;
  29
  30         filemap->fd = open(filename, O_RDONLY);
  31         if (filemap->fd == -1) {
  32                 return 1;
  33         }
  34
  35         if (fstat(filemap->fd, &statbuf)) {
  36                 close(filemap->fd);
  37                 return 1;
  38         }
  39
  40         filemap->size = statbuf.st_size;
  41
  42         filemap->map = mmap(0, filemap->size, PROT_READ, MAP_SHARED, filemap->fd, 0);
  43         if (filemap->map == MAP_FAILED) {
  44                 close(filemap->fd);
  45                 return 1;
  46         }
  47
  48         return 0;
  49 }
  50
  51 /**
  52  * Basic close/munmap wrapper.
  53  *
  54  * @1 Pointer to filemap structure
  55  *
  56  * Returns: always 0
  57  */
  58 int unmap_file(struct filemap_t *filemap) {
  59         munmap(filemap->map, filemap->size);
  60         close(filemap->fd);
  61
  62         return 0;
  63 }