1 files changed, 30 insertions, 0 deletions
diff --git a/src/libs6dns/s6dns_domain_decode.c b/src/libs6dns/s6dns_domain_decode.c
new file mode 100644
index 0000000..db4ccf5
--- /dev/null
+++ b/src/libs6dns/s6dns_domain_decode.c
@@ -0,0 +1,30 @@
+/* ISC license. */
+
+#include <errno.h>
+#include <skalibs/error.h>
+#include <skalibs/bytestr.h>
+#include <s6-dns/s6dns-domain.h>
+
+static inline unsigned int s6dns_domain_label_decode (char *s, unsigned int max)
+{
+  unsigned int len = *(unsigned char *)s ;
+  if ((len > 63) || (len >= max)) return (errno = EPROTO, 0) ;
+  *s = '.' ;
+  case_lowerb(s+1, len) ;
+  return len + 1 ;
+}
+
+int s6dns_domain_decode (s6dns_domain_t *d)
+{
+  unsigned int max = 255 ;
+  unsigned int pos = 0 ;
+  for (;;)
+  {
+    register unsigned int r = s6dns_domain_label_decode(d->s + pos, max - pos) ;
+    if (!r) return 0 ;
+    pos += r ;
+    if (r == 1) break ;
+  }
+  d->len = pos ;
+  return 1 ;
+}