ntp: count references to NTP server sockets

Server sockets are now explicitly opened and closed for normal NTP
server, NTP broadcast and NTP peering. This will allow closing the
NTP port when not needed.

diff --git a/ntp_core.c b/ntp_core.c
index f179dbf95744ea4c32d14499ac9a8bf80adeb58b..e936a094e45808b03f5e3e6b82046225c072f777 100644 (file)
--- a/ntp_core.c
+++ b/ntp_core.c
@@ -229,6 +229,10 @@ static ARR_Instance broadcasts;
 
 /* ================================================== */
 
+/* Server IPv4/IPv6 sockets */
+static int server_sock_fd4;
+static int server_sock_fd6;
+
 static ADF_AuthTable access_auth_table;
 
 /* ================================================== */
@@ -305,6 +309,8 @@ do_time_checks(void)
 void
 NCR_Initialise(void)
 {
+  NTP_Remote_Address addr;
+
   do_size_checks();
   do_time_checks();
 
@@ -314,6 +320,11 @@ NCR_Initialise(void)
 
   access_auth_table = ADF_CreateTable();
   broadcasts = ARR_CreateInstance(sizeof (BroadcastDestination));
+
+  addr.ip_addr.family = IPADDR_INET4;
+  server_sock_fd4 = NIO_OpenServerSocket(&addr);
+  addr.ip_addr.family = IPADDR_INET6;
+  server_sock_fd6 = NIO_OpenServerSocket(&addr);
 }
 
 /* ================================================== */
@@ -321,6 +332,16 @@ NCR_Initialise(void)
 void
 NCR_Finalise(void)
 {
+  unsigned int i;
+
+  if (server_sock_fd4 != INVALID_SOCK_FD)
+    NIO_CloseServerSocket(server_sock_fd4);
+  if (server_sock_fd6 != INVALID_SOCK_FD)
+    NIO_CloseServerSocket(server_sock_fd6);
+
+  for (i = 0; i < ARR_GetSize(broadcasts); i++)
+    NIO_CloseServerSocket(((BroadcastDestination *)ARR_GetElement(broadcasts, i))->local_addr.sock_fd);
+
   ARR_DestroyInstance(broadcasts);
   ADF_DestroyTable(access_auth_table);
 }
@@ -490,6 +511,9 @@ NCR_DestroyInstance(NCR_Instance instance)
   if (instance->opmode != MD_OFFLINE)
     take_offline(instance);
 
+  if (instance->mode == MODE_ACTIVE)
+    NIO_CloseServerSocket(instance->local_addr.sock_fd);
+
   /* This will destroy the source instance inside the
      structure, which will cause reselection if this was the
      synchronising source etc. */
@@ -550,8 +574,10 @@ NCR_ChangeRemoteAddress(NCR_Instance inst, NTP_Remote_Address *remote_addr)
 
   if (inst->mode == MODE_CLIENT)
     close_client_socket(inst);
-  else
+  else {
+    NIO_CloseServerSocket(inst->local_addr.sock_fd);
     inst->local_addr.sock_fd = NIO_OpenServerSocket(remote_addr);
+  }
 
   /* Update the reference ID and reset the source/sourcestats instances */
   SRC_SetRefid(inst->source, UTI_IPToRefid(&remote_addr->ip_addr),

diff --git a/ntp_io.c b/ntp_io.c
index d45dba69c6b4d3dce784697d9cc542cbf797db68..fdf4bb6d9139ce6793ff9faa632fab1d5865dee1 100644 (file)
--- a/ntp_io.c
+++ b/ntp_io.c
@@ -57,10 +57,22 @@ static int server_sock_fd6;
 static int client_sock_fd6;
 #endif
 
+/* Reference counters for server sockets to keep them open only when needed */
+static int server_sock_ref4;
+#ifdef FEAT_IPV6
+static int server_sock_ref6;
+#endif
+
 /* Flag indicating we create a new connected client socket for each
    server instead of sharing client_sock_fd4 and client_sock_fd6 */
 static int separate_client_sockets;
 
+/* Flag indicating the server sockets are not created dynamically when needed,
+   either to have a socket for client requests when separate client sockets
+   are disabled and client port is equal to server port, or the server port is
+   disabled */
+static int permanent_server_sockets;
+
 /* Flag indicating that we have been initialised */
 static int initialised=0;
 
@@ -283,15 +295,20 @@ NIO_Initialise(int family)
   if (client_port < 0)
     client_port = 0;
 
+  permanent_server_sockets = !server_port || (!separate_client_sockets &&
+                                              client_port == server_port);
+
   server_sock_fd4 = INVALID_SOCK_FD;
   client_sock_fd4 = INVALID_SOCK_FD;
+  server_sock_ref4 = 0;
 #ifdef FEAT_IPV6
   server_sock_fd6 = INVALID_SOCK_FD;
   client_sock_fd6 = INVALID_SOCK_FD;
+  server_sock_ref6 = 0;
 #endif
 
   if (family == IPADDR_UNSPEC || family == IPADDR_INET4) {
-    if (server_port)
+    if (permanent_server_sockets && server_port)
       server_sock_fd4 = prepare_socket(AF_INET, server_port, 0);
     if (!separate_client_sockets) {
       if (client_port != server_port || !server_port)
@@ -302,7 +319,7 @@ NIO_Initialise(int family)
   }
 #ifdef FEAT_IPV6
   if (family == IPADDR_UNSPEC || family == IPADDR_INET6) {
-    if (server_port)
+    if (permanent_server_sockets && server_port)
       server_sock_fd6 = prepare_socket(AF_INET6, server_port, 0);
     if (!separate_client_sockets) {
       if (client_port != server_port || !server_port)
@@ -313,7 +330,8 @@ NIO_Initialise(int family)
   }
 #endif
 
-  if ((server_port && server_sock_fd4 == INVALID_SOCK_FD
+  if ((server_port && server_sock_fd4 == INVALID_SOCK_FD &&
+       permanent_server_sockets 
 #ifdef FEAT_IPV6
        && server_sock_fd6 == INVALID_SOCK_FD
 #endif
@@ -382,9 +400,21 @@ NIO_OpenServerSocket(NTP_Remote_Address *remote_addr)
 {
   switch (remote_addr->ip_addr.family) {
     case IPADDR_INET4:
+      if (permanent_server_sockets)
+        return server_sock_fd4;
+      if (server_sock_fd4 == INVALID_SOCK_FD)
+        server_sock_fd4 = prepare_socket(AF_INET, CNF_GetNTPPort(), 0);
+      if (server_sock_fd4 != INVALID_SOCK_FD)
+        server_sock_ref4++;
       return server_sock_fd4;
 #ifdef FEAT_IPV6
     case IPADDR_INET6:
+      if (permanent_server_sockets)
+        return server_sock_fd6;
+      if (server_sock_fd6 == INVALID_SOCK_FD)
+        server_sock_fd6 = prepare_socket(AF_INET6, CNF_GetNTPPort(), 0);
+      if (server_sock_fd6 != INVALID_SOCK_FD)
+        server_sock_ref6++;
       return server_sock_fd6;
 #endif
     default:
@@ -403,6 +433,33 @@ NIO_CloseClientSocket(int sock_fd)
 
 /* ================================================== */
 
+void
+NIO_CloseServerSocket(int sock_fd)
+{
+  if (permanent_server_sockets || sock_fd == INVALID_SOCK_FD)
+    return;
+
+  if (sock_fd == server_sock_fd4) {
+    if (--server_sock_ref4 <= 0) {
+      close_socket(server_sock_fd4);
+      server_sock_fd4 = INVALID_SOCK_FD;
+    }
+  }
+#ifdef FEAT_IPV6
+  else if (sock_fd == server_sock_fd6) {
+    if (--server_sock_ref6 <= 0) {
+      close_socket(server_sock_fd6);
+      server_sock_fd6 = INVALID_SOCK_FD;
+    }
+  }
+#endif
+  else {
+    assert(0);
+  }
+}
+
+/* ================================================== */
+
 int
 NIO_IsServerSocket(int sock_fd)
 {

diff --git a/ntp_io.h b/ntp_io.h
index 6714bfee8dd998373f5b2f2e86abfdcaeb7fe9c1..cbdee56737c65da22ea15be7d3b41353ec23c7f1 100644 (file)
--- a/ntp_io.h
+++ b/ntp_io.h
@@ -47,6 +47,9 @@ extern int NIO_OpenServerSocket(NTP_Remote_Address *remote_addr);
 /* Function to close a socket returned by NIO_OpenClientSocket() */
 extern void NIO_CloseClientSocket(int sock_fd);
 
+/* Function to close a socket returned by NIO_OpenServerSocket() */
+extern void NIO_CloseServerSocket(int sock_fd);
+
 /* Function to check if socket is a server socket */
 extern int NIO_IsServerSocket(int sock_fd);