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-rw-r--r--sys/netinet/in_rmx.c10
-rw-r--r--sys/netinet/ip_icmp.c82
-rw-r--r--sys/netinet/ip_var.h5
-rw-r--r--sys/netinet/tcp_subr.c30
-rw-r--r--sys/netinet/tcp_timewait.c30
5 files changed, 152 insertions, 5 deletions
diff --git a/sys/netinet/in_rmx.c b/sys/netinet/in_rmx.c
index 4768362..42cf46d 100644
--- a/sys/netinet/in_rmx.c
+++ b/sys/netinet/in_rmx.c
@@ -26,7 +26,7 @@
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
- * $Id: in_rmx.c,v 1.14 1995/06/21 19:48:53 wollman Exp $
+ * $Id: in_rmx.c,v 1.15 1995/07/10 15:39:10 wollman Exp $
*/
/*
@@ -64,7 +64,9 @@
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
+#ifndef MTUDISC
#include <netinet/tcpip.h>
+#endif /* not MTUDISC */
#define RTPRF_OURS RTF_PROTO3 /* set on routes we manage */
@@ -104,16 +106,22 @@ in_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
if (!rt->rt_rmx.rmx_recvpipe && !(rt->rt_rmx.rmx_locks & RTV_RPIPE))
rt->rt_rmx.rmx_recvpipe = tcp_recvspace;
+#ifndef MTUDISC
/*
* Finally, set an MTU, again duplicating logic in TCP.
* The in_localaddr() business will go away when we have
* proper PMTU discovery.
*/
+#endif /* not MTUDISC */
if (!rt->rt_rmx.rmx_mtu && !(rt->rt_rmx.rmx_locks & RTV_MTU)
&& rt->rt_ifp)
+#ifndef MTUDISC
rt->rt_rmx.rmx_mtu = (in_localaddr(sin->sin_addr)
? rt->rt_ifp->if_mtu
: tcp_mssdflt + sizeof(struct tcpiphdr));
+#else /* MTUDISC */
+ rt->rt_rmx.rmx_mtu = rt->rt_ifp->if_mtu;
+#endif /* MTUDISC */
return rn_addroute(v_arg, n_arg, head, treenodes);
}
diff --git a/sys/netinet/ip_icmp.c b/sys/netinet/ip_icmp.c
index 14b763e..507d770 100644
--- a/sys/netinet/ip_icmp.c
+++ b/sys/netinet/ip_icmp.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)ip_icmp.c 8.2 (Berkeley) 1/4/94
- * $Id: ip_icmp.c,v 1.8 1995/07/10 16:16:00 wollman Exp $
+ * $Id: ip_icmp.c,v 1.9 1995/08/29 17:49:04 wollman Exp $
*/
#include <sys/param.h>
@@ -302,6 +302,46 @@ icmp_input(m, hlen)
printf("deliver to protocol %d\n", icp->icmp_ip.ip_p);
#endif
icmpsrc.sin_addr = icp->icmp_ip.ip_dst;
+#ifdef MTUDISC
+ /*
+ * MTU discovery:
+ * If we got a needfrag and there is a host route to the
+ * original destination, and the MTU is not locked, then
+ * set the MTU in the route to the suggested new value
+ * (if given) and then notify as usual. The ULPs will
+ * notice that the MTU has changed and adapt accordingly.
+ * If no new MTU was suggested, then we guess a new one
+ * less than the current value. If the new MTU is
+ * unreasonably small (arbitrarily set at 296), then
+ * we reset the MTU to the interface value and enable the
+ * lock bit, indicating that we are no longer doing MTU
+ * discovery.
+ */
+ if (code == PRC_MSGSIZE) {
+ struct rtentry *rt;
+ int mtu;
+
+ rt = rtalloc1((struct sockaddr *)&icmpsrc, 0,
+ RTF_CLONING | RTF_PRCLONING);
+ if (rt && (rt->rt_flags & RTF_HOST)
+ && !(rt->rt_rmx.rmx_locks & RTV_MTU)) {
+ mtu = ntohs(icp->icmp_nextmtu);
+ if (!mtu)
+ mtu = ip_next_mtu(rt->rt_rmx.rmx_mtu,
+ 1);
+ if (!mtu || mtu < 296) {
+ rt->rt_rmx.rmx_mtu =
+ rt->rt_ifp->if_mtu;
+ rt->rt_rmx.rmx_locks |= RTV_MTU;
+ } else if (rt->rt_rmx.rmx_mtu > mtu) {
+ rt->rt_rmx.rmx_mtu = mtu;
+ }
+ }
+ if (rt)
+ RTFREE(rt);
+ }
+
+#endif /* MTUDISC */
ctlfunc = inetsw[ip_protox[icp->icmp_ip.ip_p]].pr_ctlinput;
if (ctlfunc)
(*ctlfunc)(code, (struct sockaddr *)&icmpsrc,
@@ -612,3 +652,43 @@ icmp_sysctl(name, namelen, oldp, oldlenp, newp, newlen)
}
/* NOTREACHED */
}
+
+#ifdef MTUDISC
+/*
+ * Return the next larger or smaller MTU plateau (table from RFC 1191)
+ * given current value MTU. If DIR is less than zero, a larger plateau
+ * is returned; otherwise, a smaller value is returned.
+ */
+int
+ip_next_mtu(mtu, dir)
+ int mtu;
+ int dir;
+{
+ static int mtutab[] = {
+ 65535, 32000, 17914, 8166, 4352, 2002, 1492, 1006, 508, 296,
+ 68, 0
+ };
+ int i;
+
+ for (i = 0; i < (sizeof mtutab) / (sizeof mtutab[0]); i++) {
+ if (mtu >= mtutab[i])
+ break;
+ }
+
+ if (dir < 0) {
+ if (i == 0) {
+ return 0;
+ } else {
+ return mtutab[i - 1];
+ }
+ } else {
+ if (mtutab[i] == 0) {
+ return 0;
+ } else if(mtu > mtutab[i]) {
+ return mtutab[i];
+ } else {
+ return mtutab[i + 1];
+ }
+ }
+}
+#endif /* MTUDISC */
diff --git a/sys/netinet/ip_var.h b/sys/netinet/ip_var.h
index 028939a..6863f9e 100644
--- a/sys/netinet/ip_var.h
+++ b/sys/netinet/ip_var.h
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)ip_var.h 8.1 (Berkeley) 6/10/93
- * $Id: ip_var.h,v 1.12 1995/06/28 05:13:02 davidg Exp $
+ * $Id: ip_var.h,v 1.13 1995/07/26 18:05:16 wollman Exp $
*/
#ifndef _NETINET_IP_VAR_H_
@@ -175,6 +175,9 @@ int ip_getmoptions __P((int, struct ip_moptions *, struct mbuf **));
void ip_init __P((void));
extern int (*ip_mforward) __P((struct ip *, struct ifnet *, struct mbuf *,
struct ip_moptions *));
+#ifdef MTUDISC
+int ip_next_mtu __P((int, int));
+#endif /* MTUDISC */
int ip_optcopy __P((struct ip *, struct ip *));
int ip_output __P((struct mbuf *,
struct mbuf *, struct route *, int, struct ip_moptions *));
diff --git a/sys/netinet/tcp_subr.c b/sys/netinet/tcp_subr.c
index cf0fc40..be84884 100644
--- a/sys/netinet/tcp_subr.c
+++ b/sys/netinet/tcp_subr.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)tcp_subr.c 8.1 (Berkeley) 6/10/93
- * $Id: tcp_subr.c,v 1.12 1995/06/19 16:45:33 wollman Exp $
+ * $Id: tcp_subr.c,v 1.13 1995/06/29 18:11:23 wollman Exp $
*/
#include <sys/param.h>
@@ -429,6 +429,10 @@ tcp_notify(inp, error)
sowwakeup(so);
}
+#ifdef MTUDISC
+static void tcp_mtudisc __P((struct inpcb *, int));
+#endif /* MTUDISC */
+
void
tcp_ctlinput(cmd, sa, ip)
int cmd;
@@ -440,6 +444,10 @@ tcp_ctlinput(cmd, sa, ip)
if (cmd == PRC_QUENCH)
notify = tcp_quench;
+#ifdef MTUDISC
+ else if (cmd == PRC_MSGSIZE)
+ notify = tcp_mtudisc;
+#endif /* MTUDISC */
else if (!PRC_IS_REDIRECT(cmd) &&
((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0))
return;
@@ -466,6 +474,26 @@ tcp_quench(inp, errno)
tp->snd_cwnd = tp->t_maxseg;
}
+#ifdef MTUDISC
+/*
+ * When `need fragmentation' ICMP is received, update our idea of the MSS
+ * based on the new value in the route. Also nudge TCP to send something,
+ * since we know the packet we just sent was dropped.
+ */
+static void
+tcp_mtudisc(inp, errno)
+ struct inpcb *inp;
+ int errno;
+{
+ struct tcpcb *tp = intotcpcb(inp);
+
+#if 0
+ if (tp)
+ ; /* XXX implement */
+#endif
+}
+#endif /* MTUDISC */
+
/*
* Look-up the routing entry to the peer of this inpcb. If no route
* is found and it cannot be allocated the return NULL. This routine
diff --git a/sys/netinet/tcp_timewait.c b/sys/netinet/tcp_timewait.c
index cf0fc40..be84884 100644
--- a/sys/netinet/tcp_timewait.c
+++ b/sys/netinet/tcp_timewait.c
@@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)tcp_subr.c 8.1 (Berkeley) 6/10/93
- * $Id: tcp_subr.c,v 1.12 1995/06/19 16:45:33 wollman Exp $
+ * $Id: tcp_subr.c,v 1.13 1995/06/29 18:11:23 wollman Exp $
*/
#include <sys/param.h>
@@ -429,6 +429,10 @@ tcp_notify(inp, error)
sowwakeup(so);
}
+#ifdef MTUDISC
+static void tcp_mtudisc __P((struct inpcb *, int));
+#endif /* MTUDISC */
+
void
tcp_ctlinput(cmd, sa, ip)
int cmd;
@@ -440,6 +444,10 @@ tcp_ctlinput(cmd, sa, ip)
if (cmd == PRC_QUENCH)
notify = tcp_quench;
+#ifdef MTUDISC
+ else if (cmd == PRC_MSGSIZE)
+ notify = tcp_mtudisc;
+#endif /* MTUDISC */
else if (!PRC_IS_REDIRECT(cmd) &&
((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0))
return;
@@ -466,6 +474,26 @@ tcp_quench(inp, errno)
tp->snd_cwnd = tp->t_maxseg;
}
+#ifdef MTUDISC
+/*
+ * When `need fragmentation' ICMP is received, update our idea of the MSS
+ * based on the new value in the route. Also nudge TCP to send something,
+ * since we know the packet we just sent was dropped.
+ */
+static void
+tcp_mtudisc(inp, errno)
+ struct inpcb *inp;
+ int errno;
+{
+ struct tcpcb *tp = intotcpcb(inp);
+
+#if 0
+ if (tp)
+ ; /* XXX implement */
+#endif
+}
+#endif /* MTUDISC */
+
/*
* Look-up the routing entry to the peer of this inpcb. If no route
* is found and it cannot be allocated the return NULL. This routine
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