src/basic/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 "utf8.h"
   9
  10 int allow_listed_char_for_devnode(char c, const char *white) {
  11
  12         if ((c >= '0' && c <= '9') ||
  13             (c >= 'A' && c <= 'Z') ||
  14             (c >= 'a' && c <= 'z') ||
  15             strchr("#+-.:=@_", c) != NULL ||
  16             (white != NULL && strchr(white, c) != NULL))
  17                 return 1;
  18
  19         return 0;
  20 }
  21
  22 int encode_devnode_name(const char *str, char *str_enc, size_t len) {
  23         size_t i, j;
  24
  25         if (!str || !str_enc)
  26                 return -EINVAL;
  27
  28         for (i = 0, j = 0; str[i] != '\0'; i++) {
  29                 int seqlen;
  30
  31                 seqlen = utf8_encoded_valid_unichar(str + i, SIZE_MAX);
  32                 if (seqlen > 1) {
  33
  34                         if (len-j < (size_t)seqlen)
  35                                 return -EINVAL;
  36
  37                         memcpy(&str_enc[j], &str[i], seqlen);
  38                         j += seqlen;
  39                         i += (seqlen-1);
  40
  41                 } else if (str[i] == '\\' || !allow_listed_char_for_devnode(str[i], NULL)) {
  42
  43                         if (len-j < 4)
  44                                 return -EINVAL;
  45
  46                         sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
  47                         j += 4;
  48
  49                 } else {
  50                         if (len-j < 1)
  51                                 return -EINVAL;
  52
  53                         str_enc[j] = str[i];
  54                         j++;
  55                 }
  56         }
  57
  58         if (len-j < 1)
  59                 return -EINVAL;
  60
  61         str_enc[j] = '\0';
  62         return 0;
  63 }