[src/trunk]: src/sys/net Make it possible to set MTU via "ifconfig" at run ti...

[tron <tron%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/6cf07bd81920
branches:  trunk
changeset: 467450:6cf07bd81920
user:      tron <tron%NetBSD.org@localhost>
date:      Thu Mar 25 00:52:14 1999 +0000

description:
Make it possible to set MTU via "ifconfig" at run time. "SLMTU" is now
used to set the initial value.

diffstat:

 sys/net/if_sl.c |  51 +++++++++++++++++++++++++++++++++++++--------------
 1 files changed, 37 insertions(+), 14 deletions(-)

diffs (145 lines):

diff -r 9d6215b8b8a0 -r 6cf07bd81920 sys/net/if_sl.c
--- a/sys/net/if_sl.c   Thu Mar 25 00:51:53 1999 +0000
+++ b/sys/net/if_sl.c   Thu Mar 25 00:52:14 1999 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_sl.c,v 1.53 1998/10/06 18:38:08 kleink Exp $        */
+/*     $NetBSD: if_sl.c,v 1.54 1999/03/25 00:52:14 tron Exp $  */
 
 /*
  * Copyright (c) 1987, 1989, 1992, 1993
@@ -283,17 +283,17 @@
                         * make sure tty output queue is large enough
                         * to hold a full-sized packet (including frame
                         * end, and a possible extra frame end).  full-sized
-                        * packet occupies a max of 2*SLMTU bytes (because
+                        * packet occupies a max of 2*SLMAX bytes (because
                         * of possible escapes), and add two on for frame
                         * ends.
                         */
                        s = spltty();
-                       if (tp->t_outq.c_cn < 2*SLMTU+2) {
+                       if (tp->t_outq.c_cn < 2*SLMAX+2) {
                                sc->sc_oldbufsize = tp->t_outq.c_cn;
                                sc->sc_oldbufquot = tp->t_outq.c_cq != 0;
 
                                clfree(&tp->t_outq);
-                               error = clalloc(&tp->t_outq, 3*SLMTU, 0);
+                               error = clalloc(&tp->t_outq, 2*SLMAX+2, 0);
                                if (error) {
                                        splx(s);
                                        return(error);
@@ -457,12 +457,15 @@
        int s;
        struct mbuf *m2;
 #if NBPFILTER > 0
-       u_char bpfbuf[SLMTU + SLIP_HDRLEN];
+       u_char *bpfbuf;
        register int len = 0;
 #endif
 #ifndef __NetBSD__                                     /* XXX - cgd */
        extern int cfreecount;
 #endif
+#if NBPFILTER > 0
+       MALLOC(bpfbuf, u_char *, SLMAX + SLIP_HDRLEN, M_DEVBUF, M_NOWAIT);
+#endif
 
        for (;;) {
                /*
@@ -472,24 +475,30 @@
                 */
                if (tp->t_outq.c_cc != 0) {
                        (*tp->t_oproc)(tp);
-                       if (tp->t_outq.c_cc > SLIP_HIWAT)
+                       if (tp->t_outq.c_cc > SLIP_HIWAT) {
+                               if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF);
                                return;
+                       }
                }
                /*
                 * This happens briefly when the line shuts down.
                 */
-               if (sc == NULL)
+               if (sc == NULL) {
+                       if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF);
                        return;
+               }
 
 #ifdef __NetBSD__                                      /* XXX - cgd */
                /*
                 * Do not remove the packet from the IP queue if it
                 * doesn't look like the packet will fit into the
                 * current serial output queue, with a packet full of
-                * escapes this could be as bad as SLMTU*2+2.
+                * escapes this could be as bad as MTU*2+2.
                 */
-               if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*SLMTU+2)
+               if (tp->t_outq.c_cn - tp->t_outq.c_cc < 2*sc->sc_if.if_mtu+2) {
+                       if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF);
                        return;
+               }
 #endif /* __NetBSD__ */
 
                /*
@@ -502,8 +511,10 @@
                else
                        IF_DEQUEUE(&sc->sc_if.if_snd, m);
                splx(s);
-               if (m == NULL)
+               if (m == NULL) {
+                       if (bpfbuf != NULL) FREE(bpfbuf, M_DEVBUF);
                        return;
+               }
 
                /*
                 * We do the header compression here rather than in sloutput
@@ -512,7 +523,7 @@
                 * munged when this happens.
                 */
 #if NBPFILTER > 0
-               if (sc->sc_bpf) {
+               if (sc->sc_bpf && bpfbuf != NULL) {
                        /*
                         * We need to save the TCP/IP header before it's
                         * compressed.  To avoid complicated code, we just
@@ -540,7 +551,7 @@
                                    &sc->sc_comp, 1);
                }
 #if NBPFILTER > 0
-               if (sc->sc_bpf) {
+               if (sc->sc_bpf && bpfbuf != NULL) {
                        /*
                         * Put the SLIP pseudo-"link header" in place.  The
                         * compressed header is now at the beginning of the
@@ -879,8 +890,9 @@
        caddr_t data;
 {
        register struct ifaddr *ifa = (struct ifaddr *)data;
-       register struct ifreq *ifr;
+       register struct ifreq *ifr = (struct ifreq *)data;
        register int s = splimp(), error = 0;
+       register struct sl_softc *sc = ifp->if_softc;
 
        switch (cmd) {
 
@@ -896,9 +908,20 @@
                        error = EAFNOSUPPORT;
                break;
 
+       case SIOCSIFMTU:
+               if ((ifr->ifr_mtu < 3) || (ifr->ifr_mtu > SLMAX)) {
+                   error = EINVAL;
+                   break;
+               }
+               sc->sc_if.if_mtu = ifr->ifr_mtu;
+               break;
+
+       case SIOCGIFMTU:
+               ifr->ifr_mtu = sc->sc_if.if_mtu;
+               break;
+
        case SIOCADDMULTI:
        case SIOCDELMULTI:
-               ifr = (struct ifreq *)data;
                if (ifr == 0) {
                        error = EAFNOSUPPORT;           /* XXX */
                        break;