Add ham64 conversion utility

impl/CMakeLists.txt

@@ -79,3 +79,4 @@ target_link_libraries(
 )
 
 add_subdirectory(test)
+add_subdirectory(utils/ham64)

impl/utils/ham64/CMakeLists.txt

@@ -0,0 +1,13 @@
+add_executable(
+	call2ham64
+	../../src/layer2/ham64.c
+	../../src/layer2/ham64.h
+	../../src/logger.c
+	../../src/logger.h
+	call2ham64.c
+)
+
+target_link_libraries(
+	call2ham64
+	m
+)

impl/utils/ham64/call2ham64.c

@@ -0,0 +1,59 @@
+#include <layer2/ham64.h>
+#include <logger.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <arpa/inet.h>
+
+int main(int argc, char **argv)
+{
+	logger_init();
+
+	if(argc < 2) {
+		LOG(LVL_FATAL, "Not enough arguments!");
+		LOG(LVL_FATAL, "");
+		LOG(LVL_FATAL, "usage: %s <callsign>", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+	const char *callsign = argv[1];
+
+	size_t len = strlen(callsign);
+	if(len > 12) {
+		LOG(LVL_ERR, "Call sign too long: %zu chars (allowed: 12)", len);
+		return EXIT_FAILURE;
+	}
+
+	ham64_t ham64;
+	size_t encoded_len = ham64_encode(callsign, &ham64);
+
+	if(encoded_len == 0) {
+		LOG(LVL_ERR, "Encoding the call sign failed.");
+		return EXIT_FAILURE;
+	}
+
+	LOG(LVL_INFO, "Call sign encoded successfully: %zu words.", encoded_len);
+
+	char formatted[HAM64_FMT_MAX_LEN];
+	ham64_format(&ham64, formatted);
+
+	printf("ham64: %s\n", formatted);
+
+	// calculate IPv6 address
+	struct in6_addr ipv6_addr;
+	memset(&ipv6_addr, 0, sizeof(struct in6_addr));
+
+	// fill the host part from the ham64 address. The bytes are filled in
+	// reverse order to make the „readable“ IPv6 address as short as possible.
+	for(uint8_t i = 0; i < ham64.length; i++) {
+		ipv6_addr.s6_addr[15 - 2*i] = (ham64.addr[i] >> 8) & 0xFF;
+		ipv6_addr.s6_addr[14 - 2*i] = (ham64.addr[i] >> 0) & 0xFF;
+	}
+
+	// print the address
+	char ipv6_str[INET6_ADDRSTRLEN];
+	inet_ntop(AF_INET6, &ipv6_addr, ipv6_str, sizeof(ipv6_str));
+	printf("ipv6:  %s\n", ipv6_str);
+}