volume_id: escape % character

[elogind.git] / extras / volume_id / lib / volume_id.c

diff --git a/extras/volume_id/lib/volume_id.c b/extras/volume_id/lib/volume_id.c
index 15e9cda4da57952f74af0bba6ab2ce36ee50221f..59303d5bffce2f2e8228f33980bf7a385151d3ee 100644 (file)
--- a/extras/volume_id/lib/volume_id.c
+++ b/extras/volume_id/lib/volume_id.c
@@ -276,6 +276,60 @@ int volume_id_get_type_version(struct volume_id *id, const char **type_version)
        return 1;
 }
 
+static int needs_encoding(const char c)
+{
+       if ((c >= '0' && c <= '9') ||
+           (c >= 'A' && c <= 'Z') ||
+           (c >= 'a' && c <= 'z') ||
+           strchr(ALLOWED_CHARS, c))
+               return 0;
+       return 1;
+}
+
+/**
+ * volume_id_encode_string:
+ * @str: Input string to be encoded.
+ * @str_enc: Target string to store the encoded input.
+ * @len: Location to store the encoded string. The target string,
+ * which may be four times as long as the input string.
+ *
+ * Encode all potentially unsafe characters of a string to the
+ * corresponding hex value prefixed by '\x'.
+ *
+ * Returns: 1 if the entire string was copied, 0 otherwise.
+ **/
+int volume_id_encode_string(const char *str, char *str_enc, size_t len)
+{
+       size_t i, j;
+
+       if (str == NULL || str_enc == NULL || len == 0)
+               return 0;
+
+       str_enc[0] = '\0';
+       for (i = 0, j = 0; str[i] != '\0'; i++) {
+               int seqlen;
+
+               seqlen = volume_id_utf8_encoded_valid_unichar(&str[i]);
+               if (seqlen > 1) {
+                       memcpy(&str_enc[j], &str[i], seqlen);
+                       j += seqlen;
+                       i += (seqlen-1);
+               } else if (str[i] == '\\' || needs_encoding(str[i])) {
+                       sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
+                       j += 4;
+               } else {
+                       str_enc[j] = str[i];
+                       j++;
+               }
+               if (j+3 >= len)
+                       goto err;
+       }
+       str_enc[j] = '\0';
+       return 1;
+err:
+       return 0;
+}
+
 /**
  * volume_id_probe_raid:
  * @id: Probing context.