ntp: add interface index to NTP_Local_Address

This will allow us to get the interface index when sending responses to
clients.

addressing.h

@@ -50,8 +50,11 @@ typedef struct {
   unsigned short port;
 } NTP_Remote_Address;
 
+#define INVALID_IF_INDEX -1
+
 typedef struct {
   IPAddr ip_addr;
+  int if_index;
   int sock_fd;
 } NTP_Local_Address;
 

ntp_core.c

@@ -482,6 +482,7 @@ NCR_GetInstance(NTP_Remote_Address *remote_addr, NTP_Source_Type type, SourcePar
 
   result->remote_addr = *remote_addr;
   result->local_addr.ip_addr.family = IPADDR_UNSPEC;
+  result->local_addr.if_index = INVALID_IF_INDEX;
 
   switch (type) {
     case NTP_SERVER:
@@ -665,6 +666,7 @@ NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remote_addr)
   else {
     NIO_CloseServerSocket(inst->local_addr.sock_fd);
     inst->local_addr.ip_addr.family = IPADDR_UNSPEC;
+    inst->local_addr.if_index = INVALID_IF_INDEX;
     inst->local_addr.sock_fd = NIO_OpenServerSocket(remote_addr);
   }
 
@@ -1094,6 +1096,7 @@ transmit_timeout(void *arg)
 
   /* Don't require the packet to be sent from the same address as before */
   local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
   local_addr.sock_fd = inst->local_addr.sock_fd;
 
   /* Check whether we need to 'warm up' the link to the other end by
@@ -1627,8 +1630,9 @@ receive_packet(NCR_Instance inst, NTP_Local_Address *local_addr,
        server and the socket can be closed */
     close_client_socket(inst);
 
-    /* Update the local address */
+    /* Update the local address and interface */
     inst->local_addr.ip_addr = local_addr->ip_addr;
+    inst->local_addr.if_index = local_addr->if_index;
 
     /* And now, requeue the timer */
     if (inst->opmode != MD_OFFLINE) {
@@ -2392,6 +2396,7 @@ NCR_AddBroadcastDestination(IPAddr *addr, unsigned short port, int interval)
   destination->addr.ip_addr = *addr;
   destination->addr.port = port;
   destination->local_addr.ip_addr.family = IPADDR_UNSPEC;
+  destination->local_addr.if_index = INVALID_IF_INDEX;
   destination->local_addr.sock_fd = NIO_OpenServerSocket(&destination->addr);
   destination->interval = CLAMP(1, interval, 1 << MAX_POLL);
 

ntp_io.c

@@ -578,7 +578,6 @@ process_message(struct msghdr *hdr, int length, int sock_fd)
   NTP_Local_Timestamp local_ts;
   struct timespec sched_ts;
   struct cmsghdr *cmsg;
-  int if_index;
 
   SCH_GetLastEventTime(&local_ts.ts, &local_ts.err, NULL);
   local_ts.source = NTP_TS_DAEMON;
@@ -598,8 +597,8 @@ process_message(struct msghdr *hdr, int length, int sock_fd)
   }
 
   local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
   local_addr.sock_fd = sock_fd;
-  if_index = -1;
 
   if (hdr->msg_flags & MSG_TRUNC) {
     DEBUG_LOG(LOGF_NtpIO, "Received truncated message from %s:%d",
@@ -620,7 +619,7 @@ process_message(struct msghdr *hdr, int length, int sock_fd)
       memcpy(&ipi, CMSG_DATA(cmsg), sizeof(ipi));
       local_addr.ip_addr.addr.in4 = ntohl(ipi.ipi_addr.s_addr);
       local_addr.ip_addr.family = IPADDR_INET4;
-      if_index = ipi.ipi_ifindex;
+      local_addr.if_index = ipi.ipi_ifindex;
     }
 #endif
 
@@ -632,7 +631,7 @@ process_message(struct msghdr *hdr, int length, int sock_fd)
       memcpy(&local_addr.ip_addr.addr.in6, &ipi.ipi6_addr.s6_addr,
              sizeof (local_addr.ip_addr.addr.in6));
       local_addr.ip_addr.family = IPADDR_INET6;
-      if_index = ipi.ipi6_ifindex;
+      local_addr.if_index = ipi.ipi6_ifindex;
     }
 #endif
 
@@ -660,14 +659,13 @@ process_message(struct msghdr *hdr, int length, int sock_fd)
   }
 
 #ifdef HAVE_LINUX_TIMESTAMPING
-  if (NIO_Linux_ProcessMessage(&remote_addr, &local_addr, &local_ts,
+  if (NIO_Linux_ProcessMessage(&remote_addr, &local_addr, &local_ts, hdr, length))
-                               hdr, length, sock_fd, if_index))
     return;
 #endif
 
   DEBUG_LOG(LOGF_NtpIO, "Received %d bytes from %s:%d to %s fd=%d if=%d tss=%d delay=%.9f",
             length, UTI_IPToString(&remote_addr.ip_addr), remote_addr.port,
-            UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd, if_index,
+            UTI_IPToString(&local_addr.ip_addr), local_addr.sock_fd, local_addr.if_index,
             local_ts.source, UTI_DiffTimespecsToDouble(&sched_ts, &local_ts.ts));
 
   /* Just ignore the packet if it's not of a recognized length */

ntp_io_linux.c

@@ -480,8 +480,7 @@ extract_udp_data(unsigned char *msg, NTP_Remote_Address *remote_addr, int len)
 
 int
 NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
-                         NTP_Local_Timestamp *local_ts, struct msghdr *hdr,
+                         NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length)
-                         int length, int sock_fd, int if_index)
 {
   struct Interface *iface;
   struct cmsghdr *cmsg;
@@ -500,12 +499,13 @@ NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *loc
         LCL_CookTime(&ts3.ts[0], &local_ts->ts, &local_ts->err);
         local_ts->source = NTP_TS_KERNEL;
       } else if (!UTI_IsZeroTimespec(&ts3.ts[2])) {
-        iface = get_interface(if_index);
+        iface = get_interface(local_addr->if_index);
         if (iface) {
           process_hw_timestamp(iface, &ts3.ts[2], local_ts, !is_tx ? length : 0,
                                remote_addr->ip_addr.family);
         } else {
-          DEBUG_LOG(LOGF_NtpIOLinux, "HW clock not found for interface %d", if_index);
+          DEBUG_LOG(LOGF_NtpIOLinux, "HW clock not found for interface %d",
+                    local_addr->if_index);
         }
       }
     }
@@ -537,7 +537,7 @@ NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *loc
 
   DEBUG_LOG(LOGF_NtpIOLinux, "Received %d (%d) bytes from error queue for %s:%d fd=%d if=%d tss=%d",
             l2_length, length, UTI_IPToString(&remote_addr->ip_addr), remote_addr->port,
-            sock_fd, if_index, local_ts->source);
+            local_addr->sock_fd, local_addr->if_index, local_ts->source);
 
   /* Update assumed position of UDP data at layer 2 for next received packet */
   if (iface && length) {

ntp_io_linux.h

@@ -31,7 +31,6 @@ extern void NIO_Linux_Finalise(void);
 extern int NIO_Linux_SetTimestampSocketOptions(int sock_fd, int client_only, int *events);
 
 extern int NIO_Linux_ProcessMessage(NTP_Remote_Address *remote_addr, NTP_Local_Address *local_addr,
-                                    NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length,
+                                    NTP_Local_Timestamp *local_ts, struct msghdr *hdr, int length);
-                                    int sock_fd, int if_index);
 
 extern int NIO_Linux_RequestTxTimestamp(struct msghdr *msg, int cmsglen, int sock_fd);

test/unit/ntp_core.c

@@ -80,6 +80,7 @@ send_request(void)
   advance_time(1e-4);
 
   local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
   local_addr.sock_fd = 101;
   local_ts.ts = current_time;
   local_ts.err = 0.0;
@@ -176,6 +177,7 @@ process_response(int valid, int updated)
   res = &res_buffer.ntp_pkt;
 
   local_addr.ip_addr.family = IPADDR_UNSPEC;
+  local_addr.if_index = INVALID_IF_INDEX;
   local_addr.sock_fd = NTP_LVM_TO_MODE(res->lvm) == MODE_ACTIVE ? 100 : 101;
   local_ts.ts = current_time;
   local_ts.err = 0.0;