From: Frank Kardel <kardel@ntp.org>
Date: Sat, 23 Sep 2006 17:23:36 +0000 (+0000)
Subject: ntpd.h, ntpd.c, ntp_timer.c, ntp_io.c, cmd_args.c:
X-Git-Tag: NTP_4_2_3P50~2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=12d5306b38e6f974e400489f42748a3050ff7c1d;p=thirdparty%2Fntp.git

ntpd.h, ntpd.c, ntp_timer.c, ntp_io.c, cmd_args.c:
  disable dynamic update when giving up the root privilege

bk: 45156d98_LKtm_adWalp1HX2GnFPOA
---

diff --git a/include/ntpd.h b/include/ntpd.h
index d51ddf74f..3495cc85d 100644
--- a/include/ntpd.h
+++ b/include/ntpd.h
@@ -70,6 +70,8 @@ typedef struct interface_info {
 
 typedef void (*interface_receiver_t)(void *, interface_info_t *);
 
+extern  volatile int disable_dynamic_updates;
+
 extern  void    interface_enumerate P((interface_receiver_t, void *));
 extern	struct interface *findinterface P((struct sockaddr_storage *));
 extern  struct interface *findbcastinter P((struct sockaddr_storage *));
@@ -220,6 +222,7 @@ extern	void	reinit_timer	P((void));
 extern	void	timer		P((void));
 extern	void	timer_clr_stats P((void));
 extern  void    timer_interfacetimeout P((u_long));
+extern  volatile int interface_interval;
 
 #ifdef OPENSSL
 extern	char	*sys_hostname;
diff --git a/ntpd/cmd_args.c b/ntpd/cmd_args.c
index f89e37be0..c71167ec1 100644
--- a/ntpd/cmd_args.c
+++ b/ntpd/cmd_args.c
@@ -184,7 +184,6 @@ getCmdOpts(
 
 	if (HAVE_OPT( UPDATEINTERVAL )) {
 		long val = OPT_VALUE_UPDATEINTERVAL;
-		extern int interface_interval;
 			  
 		if ((val >= 60) || (val == 0))
 			interface_interval = val;
diff --git a/ntpd/ntp_io.c b/ntpd/ntp_io.c
index 8027dd9b9..b3b70ae3f 100644
--- a/ntpd/ntp_io.c
+++ b/ntpd/ntp_io.c
@@ -132,6 +132,8 @@ struct interface *loopback_interface;	/* loopback ipv4 interface */
 
 int ninterfaces;			/* Total number of interfaces */
 
+volatile int disable_dynamic_updates;   /* when set to != 0 dynamic updates won't happen */
+
 #ifdef REFCLOCK
 /*
  * Refclock stuff.	We keep a chain of structures with data concerning
@@ -1034,9 +1036,11 @@ refresh_interface(struct interface * interface)
 void
 interface_update(interface_receiver_t receiver, void *data)
 {
-  	BLOCKIO();
-	update_interfaces(htons(NTP_PORT), receiver, data);
-  	UNBLOCKIO();
+	if (!disable_dynamic_updates) {
+		BLOCKIO();
+		update_interfaces(htons(NTP_PORT), receiver, data);
+		UNBLOCKIO();
+	}
 }
 
 /*
@@ -1060,6 +1064,7 @@ is_wildcard_addr(struct sockaddr_storage *sas)
 	return 0;
 }
 
+#ifdef OS_NEEDS_REUSEADDR_FOR_IFADDRBIND
 /*
  * enable/disable re-use of wildcard address socket
  */
@@ -1100,6 +1105,7 @@ set_wildcard_reuse(int family, int on)
 				  &any_interface->sin : &any6_interface->sin)));
 	}
 }
+#endif /* OS_NEEDS_REUSEADDR_FOR_IFADDRBIND */
 
 /*
  * update_interface strategy
@@ -1115,7 +1121,7 @@ set_wildcard_reuse(int family, int on)
  *     attempt to create a new interface entry
  *
  * Phase 2:
- * forall currently known interfaces
+ * forall currently known non MCAST and WILDCARD interfaces
  *   if interface does not match configuration phase (not seen in phase 1):
  *     remove interface from known interface list
  *     forall peers associated with this interface
@@ -1996,6 +2002,7 @@ io_multicast_add(
 						htonl(~(u_int32)0);
 		DPRINT_INTERFACE(2, (interface, "multicast add ", "\n"));
 		add_interface(interface);
+		list_if_listening(interface, NTP_PORT);
 	}
 	else
 	{
@@ -3686,6 +3693,16 @@ process_routing_msgs(struct asyncio_reader *reader)
 
 	int cnt;
 	
+	if (disable_dynamic_updates) {
+		/*
+		 * discard ourselves if we are not need any more
+		 * usually happens when running unprivileged
+		 */
+		remove_asyncio_reader(reader);
+		delete_asyncio_reader(reader);
+		return;
+	}
+
 	cnt = read(reader->fd, buffer, sizeof(buffer));
 	
 	if (cnt < 0) {
@@ -3776,7 +3793,7 @@ init_async_notifications()
 		reader->fd = fd;
 		reader->receiver = process_routing_msgs;
 		
-		add_asyncio_reader(reader, FD_TYPE_FILE);
+		add_asyncio_reader(reader, FD_TYPE_SOCKET);
 		msyslog(LOG_INFO, "Listening on routing socket on fd #%d for interface updates", fd);
 	} else {
 		msyslog(LOG_ERR, "unable to open routing socket (%m) - using polled interface update");
diff --git a/ntpd/ntp_timer.c b/ntpd/ntp_timer.c
index bd01745b0..fb6de702a 100644
--- a/ntpd/ntp_timer.c
+++ b/ntpd/ntp_timer.c
@@ -34,7 +34,7 @@
  * procedure to do cleanup and print a message.
  */
 
-volatile u_long interface_interval = 300;     /* update interface every 5 minutes as default */
+volatile int interface_interval = 300;     /* update interface every 5 minutes as default */
 	  
 /*
  * Alarm flag.	The mainline code imports this.
diff --git a/ntpd/ntpd.c b/ntpd/ntpd.c
index 29feb2f43..6b01881c0 100644
--- a/ntpd/ntpd.c
+++ b/ntpd/ntpd.c
@@ -930,6 +930,18 @@ getgroup:
 			exit (-1);
 		}
 	
+		/*
+		 * for now assume that the privilege to bind to privileged ports
+		 * is associated with running with uid 0 - should be refined on
+		 * ports that allow binding to NTP_PORT with uid != 0
+		 */
+		disable_dynamic_updates |= (sw_uid != 0);  /* also notifies routing message listener */
+
+		if (disable_dynamic_updates && interface_interval) {
+			interface_interval = 0;
+			msyslog(LOG_INFO, "running in unprivileged mode disables dynamic interface tracking");
+		}
+
 #ifdef HAVE_LINUX_CAPABILITIES
 		do {
 			/*  We may be running under non-root uid now, but we still hold full root privileges!