From 5cefe5e556a4d29eaa50d87b5157adb365b0cc8f Mon Sep 17 00:00:00 2001
From: Ted Lemon <source@isc.org>
Date: Fri, 1 Sep 2000 23:03:39 +0000
Subject: [PATCH] - Do what people expect when they don't declare the subnet to
 which an   interface is attached.

---
 common/bpf.c      |  8 +++++++-
 common/discover.c | 28 +++++++++++++++++++++++-----
 common/dlpi.c     |  8 +++++++-
 common/lpf.c      |  8 +++++++-
 common/nit.c      |  8 +++++++-
 common/socket.c   | 21 +++++++++++++++++----
 common/upf.c      |  8 +++++++-
 7 files changed, 75 insertions(+), 14 deletions(-)

diff --git a/common/bpf.c b/common/bpf.c
index f55d7754f..7f883019b 100644
--- a/common/bpf.c
+++ b/common/bpf.c
@@ -47,7 +47,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: bpf.c,v 1.41 2000/07/27 09:02:29 mellon Exp $ Copyright (c) 1995-2000 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: bpf.c,v 1.42 2000/09/01 23:03:31 mellon Exp $ Copyright (c) 1995-2000 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -517,6 +517,12 @@ int can_receive_unicast_unconfigured (ip)
 	return 1;
 }
 
+int supports_multiple_interfaces (ip)
+	struct interface_info *ip;
+{
+	return 1;
+}
+
 void maybe_setup_fallback ()
 {
 	isc_result_t status;
diff --git a/common/discover.c b/common/discover.c
index c0c9c5cea..3075cbca1 100644
--- a/common/discover.c
+++ b/common/discover.c
@@ -43,7 +43,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: discover.c,v 1.30 2000/07/06 22:37:39 mellon Exp $ Copyright (c) 1995-2000 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: discover.c,v 1.31 2000/09/01 23:03:33 mellon Exp $ Copyright (c) 1995-2000 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -489,10 +489,27 @@ void discover_interfaces (state)
 		if (!tmp -> shared_network && (state == DISCOVER_SERVER)) {
 			log_error ("No subnet declaration for %s (%s).",
 				   tmp -> name, inet_ntoa (foo.sin_addr));
-			log_error ("Please write a subnet declaration in %s",
-				   "your dhcpd.conf file for the");
-			log_fatal ("network segment to which interface %s %s",
-				   tmp -> name, "is attached.");
+			if (supports_multiple_interfaces (tmp)) {
+				log_error ("Ignoring requests on %s.",
+					   tmp -> name);
+				log_error ("If this is not what you want, %s",
+				   "please write");
+				log_error ("a subnet declaration in your %s",
+				   "dhcpd.conf file for");
+				log_error ("the network segment to %s %s %s",
+					   "which interface",
+					   tmp -> name, "is attached.");
+				goto next;
+			} else {
+				log_error ("You must write a subnet %s",
+					   " declaration for this");
+				log_error ("subnet.   You cannot prevent %s",
+					   "the DHCP server");
+				log_error ("from listening on this subnet %s",
+					   "because your");
+				log_fatal ("operating system does not %s.",
+					   "support this capability");
+			}
 		}
 
 		/* Find subnets that don't have valid interface
@@ -523,6 +540,7 @@ void discover_interfaces (state)
 					   tmp -> name);
 		}
 #endif
+	      next:
 		interface_dereference (&tmp, MDL);
 		if (next)
 			interface_reference (&tmp, next, MDL);
diff --git a/common/dlpi.c b/common/dlpi.c
index 90a62ebda..e8cd1cc0a 100644
--- a/common/dlpi.c
+++ b/common/dlpi.c
@@ -84,7 +84,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: dlpi.c,v 1.22 2000/07/27 09:02:31 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: dlpi.c,v 1.23 2000/09/01 23:03:34 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -1311,6 +1311,12 @@ int can_receive_unicast_unconfigured (ip)
 	return 1;
 }
 
+int supports_multiple_interfaces (ip)
+	struct interface_info *ip;
+{
+	return 1;
+}
+
 void maybe_setup_fallback ()
 {
 	isc_result_t status;
diff --git a/common/lpf.c b/common/lpf.c
index 21a2fa93d..ebafb5920 100644
--- a/common/lpf.c
+++ b/common/lpf.c
@@ -37,7 +37,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: lpf.c,v 1.26 2000/07/27 09:02:33 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: lpf.c,v 1.27 2000/09/01 23:03:35 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -388,6 +388,12 @@ int can_receive_unicast_unconfigured (ip)
 	return 1;
 }
 
+int supports_multiple_interfaces (ip)
+	struct interface_info *ip;
+{
+	return 1;
+}
+
 void maybe_setup_fallback ()
 {
 	isc_result_t status;
diff --git a/common/nit.c b/common/nit.c
index c42be38bd..c21ac7926 100644
--- a/common/nit.c
+++ b/common/nit.c
@@ -44,7 +44,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: nit.c,v 1.31 2000/07/27 09:02:34 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: nit.c,v 1.32 2000/09/01 23:03:37 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -404,6 +404,12 @@ int can_receive_unicast_unconfigured (ip)
 	return 1;
 }
 
+int supports_multiple_interfaces (ip)
+	struct interface_info *ip;
+{
+	return 1;
+}
+
 void maybe_setup_fallback ()
 {
 	isc_result_t status;
diff --git a/common/socket.c b/common/socket.c
index d85af0da7..216bf2c7d 100644
--- a/common/socket.c
+++ b/common/socket.c
@@ -51,7 +51,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: socket.c,v 1.51 2000/07/20 03:15:00 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: socket.c,v 1.52 2000/09/01 23:03:38 mellon Exp $ Copyright (c) 1995, 1996, 1997, 1998, 1999 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -131,9 +131,12 @@ int if_register_socket (info)
 			(char *)&flag, sizeof flag) < 0)
 		log_fatal ("Can't set SO_REUSEADDR option on dhcp socket: %m");
 
-	/* Set the BROADCAST option so that we can broadcast DHCP responses. */
-	if (setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
-			(char *)&flag, sizeof flag) < 0)
+	/* Set the BROADCAST option so that we can broadcast DHCP responses.
+	   We shouldn't do this for fallback devices, and we can detect that
+	   a device is a fallback because it has no ifp structure. */
+	if (info -> ifp &&
+	    (setsockopt (sock, SOL_SOCKET, SO_BROADCAST,
+			 (char *)&flag, sizeof flag) < 0))
 		log_fatal ("Can't set SO_BROADCAST option on dhcp socket: %m");
 
 	/* Bind the socket to this interface's IP address. */
@@ -334,6 +337,16 @@ int can_receive_unicast_unconfigured (ip)
 #endif
 }
 
+int supports_multiple_interfaces (ip)
+	struct interface_info *ip;
+{
+#if defined (SO_BINDTODEVICE)
+	return 1;
+#else
+	return 0;
+#endif
+}
+
 /* If we have SO_BINDTODEVICE, set up a fallback interface; otherwise,
    do not. */
 
diff --git a/common/upf.c b/common/upf.c
index 78ac5b3cc..a737d57ab 100644
--- a/common/upf.c
+++ b/common/upf.c
@@ -43,7 +43,7 @@
 
 #ifndef lint
 static char copyright[] =
-"$Id: upf.c,v 1.20 2000/07/27 09:02:38 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
+"$Id: upf.c,v 1.21 2000/09/01 23:03:39 mellon Exp $ Copyright (c) 1996-2000 The Internet Software Consortium.  All rights reserved.\n";
 #endif /* not lint */
 
 #include "dhcpd.h"
@@ -358,6 +358,12 @@ int can_receive_unicast_unconfigured (ip)
 	return 1;
 }
 
+int supports_multiple_interfaces (ip)
+	struct interface_info *ip;
+{
+	return 1;
+}
+
 void maybe_setup_fallback ()
 {
 	isc_result_t status;
-- 
2.39.5