implemented a fix to support ipv6 interface

.gitignore

@@ -26,3 +26,9 @@ tags
 /test/unit/Makefile
 /test/unit/*.test
 /test/unit/*.o
+
+# Build
+/cmake-build-*/
+
+# IDE
+/.idea/

CMakeLists.txt

@@ -0,0 +1,46 @@
+cmake_minimum_required(VERSION 3.10)
+project(chrony)
+
+# Directories configuration
+set(SYSCONFDIR "/etc")
+set(BINDIR "/usr/local/bin")
+set(SBINDIR "/usr/local/sbin")
+set(LOCALSTATEDIR "/var")
+set(CHRONYVARDIR "/var/lib/chrony")
+set(DESTDIR "")
+
+# Compiler and flags
+set(CMAKE_C_FLAGS "-O2 -g -D_FORTIFY_SOURCE=2 -fPIE -fstack-protector-strong --param=ssp-buffer-size=4 -Wmissing-prototypes -Wall -pthread")
+set(CMAKE_EXE_LINKER_FLAGS "-pie -Wl,-z,relro,-z,now")
+
+# Targets
+add_executable(chronyd
+        sys_generic.c sys_linux.c sys_timex.c sys_posix.c cmdmon.c manual.c pktlength.c ntp_auth.c ntp_core.c ntp_ext.c ntp_io.c
+        ntp_sources.c addrfilt.c clientlog.c keys.c nameserv.c refclock.c refclock_phc.c refclock_pps.c refclock_shm.c
+        refclock_sock.c nameserv_async.c hwclock.c ntp_io_linux.c rtc_linux.c hash_intmd5.c cmac_gnutls.c
+        nts_ntp_client.c
+        array.c cmdparse.c conf.c leapdb.c local.c logging.c main.c memory.c quantiles.c reference.c regress.c rtc.c samplefilt.c
+        sched.c socket.c sources.c sourcestats.c stubs.c smooth.c sys.c sys_null.c tempcomp.c util.c
+        nts_ntp_auth.c siv_gnutls.c nts_ke_client.c nts_ke_session.c nts_ntp_server.c nts_ke_server.c
+)
+add_executable(chronyc
+        array.c client.c cmdparse.c getdate.c memory.c nameserv.c pktlength.c socket.c util.c hash_intmd5.c cmac_gnutls.c)
+
+# Libraries
+target_link_libraries(chronyd m gnutls)
+target_link_libraries(chronyc m edit gnutls)
+
+# Install commands
+install(TARGETS chronyd DESTINATION ${DESTDIR}${SBINDIR})
+install(TARGETS chronyc DESTINATION ${DESTDIR}${BINDIR})
+
+# Docs
+add_custom_target(docs
+        COMMAND ${CMAKE_MAKE_PROGRAM} -C doc docs
+        COMMENT "Building documentation"
+)
+
+add_custom_target(install-docs
+        COMMAND ${CMAKE_MAKE_PROGRAM} -C doc install-docs
+        COMMENT "Installing documentation"
+)

addressing.h

@@ -45,7 +45,7 @@ typedef struct {
     uint32_t id;
   } addr;
   uint16_t family;
-  uint16_t _pad;
+  uint16_t interface;
 } IPAddr;
 
 typedef struct {

util.c

@@ -32,6 +32,9 @@
 #include "logging.h"
 #include "memory.h"
 #include "util.h"
+
+#include <net/if.h>
+
 #include "hash.h"
 
 #define NSEC_PER_SEC 1000000000
@@ -302,13 +305,21 @@ UTI_IPToString(const IPAddr *addr)
       break;
     case IPADDR_INET6:
       ip6 = addr->addr.in6;
+      uint32_t interface = addr->interface;
 #ifdef FEAT_IPV6
+      // compose the IPv6
       inet_ntop(AF_INET6, ip6, result, BUFFER_LENGTH);
+      // if used, append the interface name
+      if (interface != 0) {
+        char* result_if_delimiter = result + strlen(result);
+        *result_if_delimiter = '%';
+        if_indextoname(interface, result_if_delimiter + 1);
+      }
 #else
       assert(BUFFER_LENGTH >= 40);
       for (a = 0; a < 8; a++)
         snprintf(result + a * 5, 40 - a * 5, "%04x:",
-                 (unsigned int)(ip6[2 * a] << 8 | ip6[2 * a + 1]));
+                 (unsigned int)(ip6[2 * a] << 8 | ip6[2 * a + 1]));_pad
 #endif
       break;
     case IPADDR_ID:
@@ -332,15 +343,35 @@ UTI_StringToIP(const char *addr, IPAddr *ip)
 
   if (inet_pton(AF_INET, addr, &in4) > 0) {
     ip->family = IPADDR_INET4;
-    ip->_pad = 0;
+    ip->interface = 0;
     ip->addr.in4 = ntohl(in4.s_addr);
     return 1;
   }
 
 #ifdef FEAT_IPV6
-  if (inet_pton(AF_INET6, addr, &in6) > 0) {
+  // split the address into an IP and an interface.
+  char addr_ip[INET6_ADDRSTRLEN];
+  strncpy(addr_ip, addr, sizeof(addr_ip));
+  char *addr_if = strchr(addr_ip, '%');
+
+  // prepare the interface index
+  unsigned int addr_if_index = 0;
+  // check if an interface is specified
+  if (addr_if != NULL) {
+    // split the string into two string, by replacing the "%" into an end-of-string
+    *addr_if = '\0';
+    // the interface will now start on the next character
+    addr_if++;
+
+    // get the index of the interface
+    addr_if_index = if_nametoindex(addr_if);
+    if (addr_if_index == 0)
+      return 0;
+  }
+
+  if (inet_pton(AF_INET6, addr_ip, &in6) > 0) {
     ip->family = IPADDR_INET6;
-    ip->_pad = 0;
+    ip->interface = addr_if_index;
     memcpy(ip->addr.in6, in6.s6_addr, sizeof (ip->addr.in6));
     return 1;
   }
@@ -366,7 +397,7 @@ UTI_StringToIdIP(const char *addr, IPAddr *ip)
 {
   if (sscanf(addr, "ID#%"SCNu32, &ip->addr.id) == 1) {
     ip->family = IPADDR_ID;
-    ip->_pad = 0;
+    ip->interface = 0;
     return 1;
   }
 
@@ -481,7 +512,7 @@ void
 UTI_IPNetworkToHost(const IPAddr *src, IPAddr *dest)
 {
   dest->family = ntohs(src->family);
-  dest->_pad = 0;
+  dest->interface = 0;
 
   switch (dest->family) {
     case IPADDR_INET4: