add support for setting and displaying whether a tunnel allows fragmentation

ifconfig will output "nodf" or "df" on tunnel interfaces that support
the ioctl., and accepts "tunneldf" and "-tunneldf" as options to
try and configure it.

diff --git a/sbin/ifconfig/ifconfig.8 b/sbin/ifconfig/ifconfig.8
index 68f2491..42990ad 100644 (file)
--- a/sbin/ifconfig/ifconfig.8
+++ b/sbin/ifconfig/ifconfig.8
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: ifconfig.8,v 1.299 2018/02/15 04:21:46 dlg Exp $
+.\"    $OpenBSD: ifconfig.8,v 1.300 2018/02/19 00:23:57 dlg Exp $
 .\"    $NetBSD: ifconfig.8,v 1.11 1996/01/04 21:27:29 pk Exp $
 .\"     $FreeBSD: ifconfig.8,v 1.16 1998/02/01 07:03:29 steve Exp $
 .\"
@@ -31,7 +31,7 @@
 .\"
 .\"     @(#)ifconfig.8 8.4 (Berkeley) 6/1/94
 .\"
-.Dd $Mdocdate: February 15 2018 $
+.Dd $Mdocdate: February 19 2018 $
 .Dt IFCONFIG 8
 .Os
 .Sh NAME
@@ -1603,6 +1603,7 @@ for a complete list of the available protocols.
 .Op Oo Fl Oc Ns Cm keepalive Ar period count
 .Op Oo Fl Oc Ns Cm tunnel Ar src_address dest_address
 .Op Cm tunneldomain Ar tableid
+.Op Oo Fl Oc Ns Cm tunneldf
 .Op Cm tunnelttl Ar ttl
 .Op Oo Fl Oc Ns Cm vnetid Ar network-id
 .Ek
@@ -1654,6 +1655,10 @@ interface itself.
 .Ar tableid
 can be set to any valid routing table ID;
 the corresponding routing domain is derived from this table.
+.It Cm tunneldf
+Do not allow fragmentation of encapsulated packets.
+.It Cm -tunneldf
+Allow fragmentation of the encapsulated packets. 
 .It Cm tunnelttl Ar ttl
 Set the IP or multicast TTL of the tunnel packets.
 If supported by the tunnel protocol,

diff --git a/sbin/ifconfig/ifconfig.c b/sbin/ifconfig/ifconfig.c
index ac5705b..88956f0 100644 (file)
--- a/sbin/ifconfig/ifconfig.c
+++ b/sbin/ifconfig/ifconfig.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ifconfig.c,v 1.357 2018/02/10 05:55:26 florian Exp $  */
+/*     $OpenBSD: ifconfig.c,v 1.358 2018/02/19 00:23:57 dlg Exp $      */
 /*     $NetBSD: ifconfig.c,v 1.40 1997/10/01 02:19:43 enami Exp $      */
 
 /*
@@ -252,6 +252,8 @@ void        setpfsync_syncpeer(const char *, int);
 void   unsetpfsync_syncpeer(const char *, int);
 void   setpfsync_defer(const char *, int);
 void   pfsync_status(void);
+void   settunneldf(const char *, int);
+void   settunnelnodf(const char *, int);
 void   setpppoe_dev(const char *,int);
 void   setpppoe_svc(const char *,int);
 void   setpppoe_ac(const char *,int);
@@ -434,6 +436,8 @@ const struct        cmd {
        { "deletetunnel",  0,           0,              deletetunnel },
        { "tunneldomain", NEXTARG,      0,              settunnelinst },
        { "tunnelttl",  NEXTARG,        0,              settunnelttl },
+       { "tunneldf",   0,              0,              settunneldf },
+       { "-tunneldf",  0,              0,              settunnelnodf },
        { "pppoedev",   NEXTARG,        0,              setpppoe_dev },
        { "pppoesvc",   NEXTARG,        0,              setpppoe_svc },
        { "-pppoesvc",  1,              0,              setpppoe_svc },
@@ -2750,6 +2754,10 @@ phys_status(int force)
                else if (ifr.ifr_ttl > 0)
                        printf(" ttl %d", ifr.ifr_ttl);
        }
+
+       if (ioctl(s, SIOCGLIFPHYDF, (caddr_t)&ifr) == 0)
+               printf(" %s", ifr.ifr_df ? "df" : "nodf");
+
 #ifndef SMALL
        if (ioctl(s, SIOCGLIFPHYRTABLE, (caddr_t)&ifr) == 0 &&
            (rdomainid != 0 || ifr.ifr_rdomainid != 0))
@@ -3285,6 +3293,24 @@ settunnelttl(const char *id, int param)
                warn("SIOCSLIFPHYTTL");
 }
 
+void
+settunneldf(const char *ignored, int alsoignored)
+{
+       strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
+       ifr.ifr_df = 1;
+       if (ioctl(s, SIOCSLIFPHYDF, (caddr_t)&ifr) < 0)
+               warn("SIOCSLIFPHYDF");
+}
+
+void
+settunnelnodf(const char *ignored, int alsoignored)
+{
+       strlcpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
+       ifr.ifr_df = 0;
+       if (ioctl(s, SIOCSLIFPHYDF, (caddr_t)&ifr) < 0)
+               warn("SIOCSLIFPHYDF");
+}
+
 void
 mpe_status(void)
 {