1 files changed, 31 insertions, 0 deletions

diff --git a/src/ot_ip.h b/src/ot_ip.h
new file mode 100644
index 0000000..533403e
--- /dev/null
+++ b/src/ot_ip.h
@@ -0,0 +1,31 @@
+/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
+   It is considered beerware. Prost. Skol. Cheers or whatever. */
+
+#ifndef OT_IP_H__
+#define OT_IP_H__
+
+#include <stddef.h>
+#include <string.h>
+
+#include "trackerlogic.h"
+
+/* opentracker holds every address as sixteen bytes, writing IPv4 as the v4
+   mapped form of RFC 4291 section 2.5.5.2. */
+extern const char ip_v4mapped_prefix[12];
+
+static inline int ip_is_v4mapped(const void *ip) { return !memcmp(ip, ip_v4mapped_prefix, sizeof(ip_v4mapped_prefix)); }
+
+/* Read an address and return how many characters it took, or zero if src
+   does not start with one. A plain IPv4 address is accepted and stored in
+   its v4 mapped form.
+
+   The count lets the caller carry on where the address ended, which is how
+   "address:port" and "address/bits" are read. */
+size_t ip_parse(const char *src, ot_ip6 ip);
+
+/* Write an address and return how many characters it took. Nothing is
+   terminated, so a caller may keep appending. A v4 mapped address is written
+   as the plain dotted quad rather than "::ffff:1.2.3.4".  */
+size_t ip_format(char *dest, const ot_ip6 ip);
+
+#endif