src/shared/device-nodes.c

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