src/basic/device-nodes.c

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 /***
   3   This file is part of systemd.
   4
   5   Copyright 2008-2011 Kay Sievers
   6 ***/
   7
   8 #include <errno.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11
  12 #include "device-nodes.h"
  13 #include "utf8.h"
  14
  15 int whitelisted_char_for_devnode(char c, const char *white) {
  16
  17         if ((c >= '0' && c <= '9') ||
  18             (c >= 'A' && c <= 'Z') ||
  19             (c >= 'a' && c <= 'z') ||
  20             strchr("#+-.:=@_", c) != NULL ||
  21             (white != NULL && strchr(white, c) != NULL))
  22                 return 1;
  23
  24         return 0;
  25 }
  26
  27 int encode_devnode_name(const char *str, char *str_enc, size_t len) {
  28         size_t i, j;
  29
  30         if (!str || !str_enc)
  31                 return -EINVAL;
  32
  33         for (i = 0, j = 0; str[i] != '\0'; i++) {
  34                 int seqlen;
  35
  36                 seqlen = utf8_encoded_valid_unichar(&str[i]);
  37                 if (seqlen > 1) {
  38
  39                         if (len-j < (size_t)seqlen)
  40                                 return -EINVAL;
  41
  42                         memcpy(&str_enc[j], &str[i], seqlen);
  43                         j += seqlen;
  44                         i += (seqlen-1);
  45
  46                 } else if (str[i] == '\\' || !whitelisted_char_for_devnode(str[i], NULL)) {
  47
  48                         if (len-j < 4)
  49                                 return -EINVAL;
  50
  51                         sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
  52                         j += 4;
  53
  54                 } else {
  55                         if (len-j < 1)
  56                                 return -EINVAL;
  57
  58                         str_enc[j] = str[i];
  59                         j++;
  60                 }
  61         }
  62
  63         if (len-j < 1)
  64                 return -EINVAL;
  65
  66         str_enc[j] = '\0';
  67         return 0;
  68 }