From 441b06bc38676163fff3b6f6e97a59906759b662 Mon Sep 17 00:00:00 2001
From: "roy@uberlaptop.marples.name" <roy@uberlaptop.marples.name>
Date: Sat, 4 Feb 2012 15:15:25 +0000
Subject: [PATCH] If the kernel is not configured to accept IPv6 or RA's then
 don't needless attempt to solicit an IPv6 RA.

---
 dhcpcd.c         |  3 +++
 ipv6rs.c         |  2 +-
 platform-bsd.c   | 37 ++++++++++++++++++++++++++++++++++++-
 platform-linux.c | 10 +++++++++-
 platform.h       |  3 ++-
 5 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/dhcpcd.c b/dhcpcd.c
index 621b83ac..bc2b4854 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -69,6 +69,7 @@ const char copyright[] = "Copyright (c) 2006-2012 Roy Marples";
 #include "ipv4ll.h"
 #include "ipv6rs.h"
 #include "net.h"
+#include "platform.h"
 #include "signals.h"
 
 /* We should define a maximum for the NAK exponential backoff */ 
@@ -1991,6 +1992,8 @@ main(int argc, char **argv)
 	}
 #endif
 
+	if (options & DHCPCD_IPV6RS && !check_ipv6())
+		options &= ~DHCPCD_IPV6RS;
 	if (options & DHCPCD_IPV6RS) {
 		ipv6rsfd = ipv6rs_open();
 		if (ipv6rsfd == -1) {
diff --git a/ipv6rs.c b/ipv6rs.c
index b9e7c9d6..69838e9d 100644
--- a/ipv6rs.c
+++ b/ipv6rs.c
@@ -1,6 +1,6 @@
 /* 
  * dhcpcd - DHCP client daemon
- * Copyright (c) 2006-2011 Roy Marples <roy@marples.name>
+ * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
  * All rights reserved
 
  * Redistribution and use in source and binary forms, with or without
diff --git a/platform-bsd.c b/platform-bsd.c
index dd5791ca..ff7379a2 100644
--- a/platform-bsd.c
+++ b/platform-bsd.c
@@ -1,6 +1,6 @@
 /* 
  * dhcpcd - DHCP client daemon
- * Copyright (c) 2006-2010 Roy Marples <roy@marples.name>
+ * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
  * All rights reserved
 
  * Redistribution and use in source and binary forms, with or without
@@ -26,8 +26,12 @@
  */
 
 #include <sys/param.h>
+#include <sys/socket.h>
 #include <sys/sysctl.h>
 #include <sys/utsname.h>
+#include <netinet/in.h>
+
+#include <syslog.h>
 
 #include "platform.h"
 
@@ -48,3 +52,34 @@ hardware_platform(void)
 		return NULL;
 	return march;
 }
+
+static int
+inet6_sysctl(int code)
+{
+	int mib[] = { CTL_NET, PF_INET6, IPPROTO_IPV6, 0 };
+	int val;
+	size_t size;
+
+	mib[3] = code;
+	size = sizeof(val);
+	if (sysctl(mib, sizeof(mib)/sizeof(mib[0]), &val, &size, NULL, 0) == -1)
+		return -1;
+	return val;
+}
+
+int
+check_ipv6(void)
+{
+
+	if (!inet6_sysctl(IPV6CTL_ACCEPT_RTADV)) {
+		syslog(LOG_WARNING,
+		    "Kernel is not configured to accept IPv6 RAs");
+		return 0;
+	}
+	if (inet6_sysctl(IPV6CTL_FORWARDING)) {
+		syslog(LOG_WARNING,
+		    "Kernel is configured as a router, not a host");
+		return 0;
+	}
+	return 1;
+}
diff --git a/platform-linux.c b/platform-linux.c
index 79562c84..923c9746 100644
--- a/platform-linux.c
+++ b/platform-linux.c
@@ -1,6 +1,6 @@
 /* 
  * dhcpcd - DHCP client daemon
- * Copyright (c) 2006-2010 Roy Marples <roy@marples.name>
+ * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
  * All rights reserved
 
  * Redistribution and use in source and binary forms, with or without
@@ -102,3 +102,11 @@ hardware_platform(void)
 		errno = ESRCH;
 	return p;
 }
+
+int
+check_ipv6(void)
+{
+    
+    // FIXME: Add IPv6 detection here
+    return 1;
+}
diff --git a/platform.h b/platform.h
index 24731ace..1286fe62 100644
--- a/platform.h
+++ b/platform.h
@@ -1,6 +1,6 @@
 /* 
  * dhcpcd - DHCP client daemon
- * Copyright (c) 2006-2010 Roy Marples <roy@marples.name>
+ * Copyright (c) 2006-2012 Roy Marples <roy@marples.name>
  * All rights reserved
 
  * Redistribution and use in source and binary forms, with or without
@@ -29,5 +29,6 @@
 #define PLATFORM_H
 
 char * hardware_platform(void);
+int check_ipv6(void);
 
 #endif
-- 
2.47.2