release/src/router/udev/udev_utils_file.c

   1 /*
   2  * Copyright (C) 2004-2005 Kay Sievers <kay.sievers@vrfy.org>
   3  *
   4  *      This program is free software; you can redistribute it and/or modify it
   5  *      under the terms of the GNU General Public License as published by the
   6  *      Free Software Foundation version 2 of the License.
   7  *
   8  *      This program is distributed in the hope that it will be useful, but
   9  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  10  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11  *      General Public License for more details.
  12  *
  13  *      You should have received a copy of the GNU General Public License along
  14  *      with this program; if not, write to the Free Software Foundation, Inc.,
  15  *      51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16  *
  17  */
  18
  19
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <ctype.h>
  27 #include <dirent.h>
  28 #include <sys/stat.h>
  29 #include <sys/mman.h>
  30
  31 #include "udev.h"
  32
  33 int create_path(const char *path)
  34 {
  35         char p[PATH_SIZE];
  36         char *pos;
  37         struct stat stats;
  38
  39         strlcpy(p, path, sizeof(p));
  40         pos = strrchr(p, '/');
  41         if (pos == p || pos == NULL)
  42                 return 0;
  43
  44         while (pos[-1] == '/')
  45                 pos--;
  46         pos[0] = '\0';
  47
  48         dbg("stat '%s'", p);
  49         if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
  50                 return 0;
  51
  52         if (create_path (p) != 0)
  53                 return -1;
  54
  55         dbg("mkdir '%s'", p);
  56         if (mkdir(p, 0755) == 0)
  57                 return 0;
  58         if (errno == EEXIST)
  59                 if (stat(p, &stats) == 0 && (stats.st_mode & S_IFMT) == S_IFDIR)
  60                         return 0;
  61         return -1;
  62 }
  63
  64 int delete_path(const char *path)
  65 {
  66         char p[PATH_SIZE];
  67         char *pos;
  68         int retval;
  69
  70         strcpy (p, path);
  71         pos = strrchr(p, '/');
  72         if (pos == p || pos == NULL)
  73                 return 0;
  74
  75         while (1) {
  76                 *pos = '\0';
  77                 pos = strrchr(p, '/');
  78
  79                 /* don't remove the last one */
  80                 if ((pos == p) || (pos == NULL))
  81                         break;
  82
  83                 /* remove if empty */
  84                 retval = rmdir(p);
  85                 if (errno == ENOENT)
  86                         retval = 0;
  87                 if (retval) {
  88                         if (errno == ENOTEMPTY)
  89                                 return 0;
  90                         err("rmdir(%s) failed: %s", p, strerror(errno));
  91                         break;
  92                 }
  93                 dbg("removed '%s'", p);
  94         }
  95         return 0;
  96 }
  97
  98 /* Reset permissions on the device node, before unlinking it to make sure,
  99  * that permisions of possible hard links will be removed too.
 100  */
 101 int unlink_secure(const char *filename)
 102 {
 103         int retval;
 104
 105         retval = chown(filename, 0, 0);
 106         if (retval)
 107                 err("chown(%s, 0, 0) failed: %s", filename, strerror(errno));
 108
 109         retval = chmod(filename, 0000);
 110         if (retval)
 111                 err("chmod(%s, 0000) failed: %s", filename, strerror(errno));
 112
 113         retval = unlink(filename);
 114         if (errno == ENOENT)
 115                 retval = 0;
 116
 117         if (retval)
 118                 err("unlink(%s) failed: %s", filename, strerror(errno));
 119
 120         return retval;
 121 }
 122
 123 int file_map(const char *filename, char **buf, size_t *bufsize)
 124 {
 125         struct stat stats;
 126         int fd;
 127
 128         fd = open(filename, O_RDONLY);
 129         if (fd < 0) {
 130                 return -1;
 131         }
 132
 133         if (fstat(fd, &stats) < 0) {
 134                 close(fd);
 135                 return -1;
 136         }
 137
 138         *buf = mmap(NULL, stats.st_size, PROT_READ, MAP_SHARED, fd, 0);
 139         if (*buf == MAP_FAILED) {
 140                 close(fd);
 141                 return -1;
 142         }
 143         *bufsize = stats.st_size;
 144
 145         close(fd);
 146
 147         return 0;
 148 }
 149
 150 void file_unmap(void *buf, size_t bufsize)
 151 {
 152         munmap(buf, bufsize);
 153 }
 154
 155 /* return number of chars until the next newline, skip escaped newline */
 156 size_t buf_get_line(const char *buf, size_t buflen, size_t cur)
 157 {
 158         int escape = 0;
 159         size_t count;
 160
 161         for (count = cur; count < buflen; count++) {
 162                 if (!escape && buf[count] == '\n')
 163                         break;
 164
 165                 if (buf[count] == '\\')
 166                         escape = 1;
 167                 else
 168                         escape = 0;
 169         }
 170
 171         return count - cur;
 172 }