src/basic/device-nodes.c

   1 /***
   2   This file is part of systemd.
   3
   4   Copyright 2008-2011 Kay Sievers
   5
   6   systemd is free software; you can redistribute it and/or modify it
   7   under the terms of the GNU Lesser General Public License as published by
   8   the Free Software Foundation; either version 2.1 of the License, or
   9   (at your option) any later version.
  10
  11   systemd is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   Lesser General Public License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public License
  17   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  18 ***/
  19
  20 #include <errno.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23
  24 #include "device-nodes.h"
  25 #include "utf8.h"
  26
  27 int whitelisted_char_for_devnode(char c, const char *white) {
  28
  29         if ((c >= '0' && c <= '9') ||
  30             (c >= 'A' && c <= 'Z') ||
  31             (c >= 'a' && c <= 'z') ||
  32             strchr("#+-.:=@_", c) != NULL ||
  33             (white != NULL && strchr(white, c) != NULL))
  34                 return 1;
  35
  36         return 0;
  37 }
  38
  39 int encode_devnode_name(const char *str, char *str_enc, size_t len) {
  40         size_t i, j;
  41
  42         if (str == NULL || str_enc == NULL)
  43                 return -EINVAL;
  44
  45         for (i = 0, j = 0; str[i] != '\0'; i++) {
  46                 int seqlen;
  47
  48                 seqlen = utf8_encoded_valid_unichar(&str[i]);
  49                 if (seqlen > 1) {
  50
  51                         if (len-j < (size_t)seqlen)
  52                                 return -EINVAL;
  53
  54                         memcpy(&str_enc[j], &str[i], seqlen);
  55                         j += seqlen;
  56                         i += (seqlen-1);
  57
  58                 } else if (str[i] == '\\' || !whitelisted_char_for_devnode(str[i], NULL)) {
  59
  60                         if (len-j < 4)
  61                                 return -EINVAL;
  62
  63                         sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
  64                         j += 4;
  65
  66                 } else {
  67                         if (len-j < 1)
  68                                 return -EINVAL;
  69
  70                         str_enc[j] = str[i];
  71                         j++;
  72                 }
  73         }
  74
  75         if (len-j < 1)
  76                 return -EINVAL;
  77
  78         str_enc[j] = '\0';
  79         return 0;
  80 }