support configuration of fragmentation of the tunnel traffic

diff --git a/sys/net/if_gre.c b/sys/net/if_gre.c
index ecfb2cc..cf743c9 100644 (file)
--- a/sys/net/if_gre.c
+++ b/sys/net/if_gre.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: if_gre.c,v 1.104 2018/02/16 06:26:10 dlg Exp $ */
+/*      $OpenBSD: if_gre.c,v 1.105 2018/02/19 00:46:27 dlg Exp $ */
 /*     $NetBSD: if_gre.c,v 1.9 1999/10/25 19:18:11 drochner Exp $ */
 
 /*
@@ -157,6 +157,7 @@ struct gre_tunnel {
 #define t_dst4 t_dst.in4
 #define t_dst6 t_dst.in6
        int                     t_ttl;
+       uint16_t                t_df;
        sa_family_t             t_af;
 };
 
@@ -321,6 +322,7 @@ gre_clone_create(struct if_clone *ifc, int unit)
        ifp->if_rtrequest = p2p_rtrequest;
 
        sc->sc_tunnel.t_ttl = ip_defttl;
+       sc->sc_tunnel.t_df = htons(0);
 
        timeout_set(&sc->sc_ka_send, gre_keepalive_send, sc);
        timeout_set_proc(&sc->sc_ka_hold, gre_keepalive_hold, sc);
@@ -381,6 +383,7 @@ egre_clone_create(struct if_clone *ifc, int unit)
        ether_fakeaddr(ifp);
 
        sc->sc_tunnel.t_ttl = ip_defttl;
+       sc->sc_tunnel.t_df = htons(0);
 
        ifmedia_init(&sc->sc_media, 0, egre_media_change, egre_media_status);
        ifmedia_add(&sc->sc_media, IFM_ETHER | IFM_AUTO, 0, NULL);
@@ -999,7 +1002,7 @@ gre_encap(const struct gre_tunnel *tunnel, struct mbuf *m, uint16_t proto,
                        return (NULL);
 
                ip = mtod(m, struct ip *);
-               ip->ip_off = 0; /* DF ? */
+               ip->ip_off = tunnel->t_df;
                ip->ip_tos = tos;
                ip->ip_len = htons(m->m_pkthdr.len);
                ip->ip_ttl = ttl;
@@ -1026,6 +1029,10 @@ gre_encap(const struct gre_tunnel *tunnel, struct mbuf *m, uint16_t proto,
                ip6->ip6_hlim = ttl;
                ip6->ip6_src = tunnel->t_src6;
                ip6->ip6_dst = tunnel->t_dst6;
+
+               if (tunnel->t_df)
+                       SET(m->m_pkthdr.csum_flags, M_IPV6_DF_OUT);
+
                break;
        }
 #endif /* INET6 */
@@ -1117,6 +1124,14 @@ gre_tunnel_ioctl(struct ifnet *ifp, struct gre_tunnel *tunnel,
                ifr->ifr_rdomainid = tunnel->t_rtableid;
                break;
 
+       case SIOCSLIFPHYDF:
+               /* commit */
+               tunnel->t_df = ifr->ifr_df ? htons(IP_DF) : htons(0);
+               break;
+       case SIOCGLIFPHYDF:
+               ifr->ifr_df = tunnel->t_df ? 1 : 0;
+               break;
+
        default:
                error = ENOTTY;
                break;
@@ -1369,6 +1384,7 @@ gre_keepalive_send(void *arg)
        ttl = sc->sc_tunnel.t_ttl == -1 ? ip_defttl : sc->sc_tunnel.t_ttl;
 
        t.t_af = sc->sc_tunnel.t_af;
+       t.t_df = sc->sc_tunnel.t_df;
        t.t_src = sc->sc_tunnel.t_dst;
        t.t_dst = sc->sc_tunnel.t_src;
        t.t_key = sc->sc_tunnel.t_key;