From e561507a1fc5c579aec8860ede9c22a614ff439e Mon Sep 17 00:00:00 2001
From: tron <tron@NetBSD.org>
Date: Fri, 11 Mar 2005 13:28:25 +0000
Subject: [PATCH] Add support for changing the MTU to stf(4).

---
 sys/net/if_stf.c | 36 ++++++++++++++++++++++++++----------
 sys/net/if_stf.h |  6 +++++-
 2 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/sys/net/if_stf.c b/sys/net/if_stf.c
index 9b34be19b730..3dfada8af89d 100644
--- a/sys/net/if_stf.c
+++ b/sys/net/if_stf.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: if_stf.c,v 1.45 2005/02/26 22:45:09 perry Exp $	*/
+/*	$NetBSD: if_stf.c,v 1.46 2005/03/11 13:28:25 tron Exp $	*/
 /*	$KAME: if_stf.c,v 1.62 2001/06/07 22:32:16 itojun Exp $	*/
 
 /*
@@ -75,7 +75,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_stf.c,v 1.45 2005/02/26 22:45:09 perry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_stf.c,v 1.46 2005/03/11 13:28:25 tron Exp $");
 
 #include "opt_inet.h"
 
@@ -86,6 +86,7 @@ __KERNEL_RCSID(0, "$NetBSD: if_stf.c,v 1.45 2005/02/26 22:45:09 perry Exp $");
 #include <sys/mbuf.h>
 #include <sys/errno.h>
 #include <sys/ioctl.h>
+#include <sys/proc.h>
 #include <sys/protosw.h>
 #include <sys/queue.h>
 #include <sys/syslog.h>
@@ -212,7 +213,7 @@ stf_clone_create(ifc, unit)
 		return (EIO);	/* XXX */
 	}
 
-	sc->sc_if.if_mtu    = IPV6_MMTU;
+	sc->sc_if.if_mtu    = STF_MTU;
 	sc->sc_if.if_flags  = 0;
 	sc->sc_if.if_ioctl  = stf_ioctl;
 	sc->sc_if.if_output = stf_output;
@@ -689,9 +690,12 @@ stf_rtrequest(cmd, rt, info)
 	struct rtentry *rt;
 	struct rt_addrinfo *info;
 {
+	if (rt != NULL) {
+		struct stf_softc *sc;
 
-	if (rt)
-		rt->rt_rmx.rmx_mtu = IPV6_MMTU;
+		sc = LIST_FIRST(&stf_softc_list);
+		rt->rt_rmx.rmx_mtu = (sc != NULL) ? sc->sc_if.if_mtu : STF_MTU;
+	}
 }
 
 static int
@@ -700,10 +704,12 @@ stf_ioctl(ifp, cmd, data)
 	u_long cmd;
 	caddr_t data;
 {
-	struct ifaddr *ifa;
-	struct ifreq *ifr;
-	struct sockaddr_in6 *sin6;
-	int error;
+	struct proc 		*p = curproc;	/* XXX */
+	struct ifaddr		*ifa;
+	struct ifreq		*ifr;
+	struct sockaddr_in6	*sin6;
+	int			error;
+	u_long			mtu;
 
 	error = 0;
 	switch (cmd) {
@@ -725,12 +731,22 @@ stf_ioctl(ifp, cmd, data)
 	case SIOCADDMULTI:
 	case SIOCDELMULTI:
 		ifr = (struct ifreq *)data;
-		if (ifr && ifr->ifr_addr.sa_family == AF_INET6)
+		if (ifr != NULL && ifr->ifr_addr.sa_family == AF_INET6)
 			;
 		else
 			error = EAFNOSUPPORT;
 		break;
 
+	case SIOCSIFMTU:
+		if ((error = suser(p->p_ucred, &p->p_acflag)) != 0)
+			break;
+		ifr = (struct ifreq *)data;
+		mtu = ifr->ifr_mtu;
+		if (mtu < STF_MTU_MIN || mtu > STF_MTU_MAX)
+			return EINVAL;
+		ifp->if_mtu = mtu;
+		break;
+
 	default:
 		error = EINVAL;
 		break;
diff --git a/sys/net/if_stf.h b/sys/net/if_stf.h
index 8c0d6a2a7ebe..0175d4709663 100644
--- a/sys/net/if_stf.h
+++ b/sys/net/if_stf.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: if_stf.h,v 1.1 2000/04/19 06:30:53 itojun Exp $	*/
+/*	$NetBSD: if_stf.h,v 1.2 2005/03/11 13:28:25 tron Exp $	*/
 /*	$KAME: if_stf.h,v 1.3 2000/03/25 07:23:33 sumikawa Exp $	*/
 
 /*
@@ -33,6 +33,10 @@
 #ifndef _NET_IF_STF_H_
 #define _NET_IF_STF_H_
 
+#define STF_MTU		(1280)	/* Default MTU */
+#define	STF_MTU_MIN	(1280)	/* Minimum MTU */
+#define	STF_MTU_MAX	(8192)	/* Maximum MTU */
+
 void in_stf_input __P((struct mbuf *, ...));
 
 #endif /* _NET_IF_STF_H_ */