Reduce the interface MTU by 2 when MPPE has been successfully negotiated.

This is necessary because MPPE will combine the protocol id with the
payload received on the tun interface, encrypt it, then prepend its
own protocol id, effectively increasing the payload by two bytes.

8 files changed, 75 insertions, 15 deletions

diff --git a/usr.sbin/ppp/ppp/bundle.c b/usr.sbin/ppp/ppp/bundle.c
index c26d9cf0f0d..9af16bc4052 100644
--- a/usr.sbin/ppp/ppp/bundle.c
+++ b/usr.sbin/ppp/ppp/bundle.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: bundle.c,v 1.57 2001/06/19 10:24:49 brian Exp $
+ *	$OpenBSD: bundle.c,v 1.58 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/param.h>
@@ -276,7 +276,8 @@ bundle_LayerUp(void *v, struct fsm *fp)
     bundle_StartIdleTimer(bundle, 0);
     bundle_Notify(bundle, EX_NORMAL);
     mp_CheckAutoloadTimer(&fp->bundle->ncp.mp);
-  }
+  } else if (fp->proto == PROTO_CCP)
+    bundle_CalculateBandwidth(fp->bundle);	/* Against ccp_MTUOverhead */
 }
 
 static void
@@ -1816,11 +1817,16 @@ void
 bundle_CalculateBandwidth(struct bundle *bundle)
 {
   struct datalink *dl;
-  int sp;
+  int sp, overhead, maxoverhead;
 
   bundle->bandwidth = 0;
   bundle->iface->mtu = 0;
-  for (dl = bundle->links; dl; dl = dl->next)
+  maxoverhead = 0;
+
+  for (dl = bundle->links; dl; dl = dl->next) {
+    overhead = ccp_MTUOverhead(&dl->physical->link.ccp);
+    if (maxoverhead < overhead)
+      maxoverhead = overhead;
     if (dl->state == DATALINK_OPEN) {
       if ((sp = dl->mp.bandwidth) == 0 &&
           (sp = physical_GetSpeed(dl->physical)) == 0)
@@ -1833,13 +1839,17 @@ bundle_CalculateBandwidth(struct bundle *bundle)
         break;
       }
     }
+  }
 
   if(bundle->bandwidth == 0)
     bundle->bandwidth = 115200;		/* Shrug */
 
-  if (bundle->ncp.mp.active)
+  if (bundle->ncp.mp.active) {
     bundle->iface->mtu = bundle->ncp.mp.peer_mrru;
-  else if (!bundle->iface->mtu)
+    overhead = ccp_MTUOverhead(&bundle->ncp.mp.link.ccp);
+    if (maxoverhead < overhead)
+      maxoverhead = overhead;
+  } else if (!bundle->iface->mtu)
     bundle->iface->mtu = DEF_MRU;
 
 #ifndef NORADIUS
@@ -1851,6 +1861,12 @@ bundle_CalculateBandwidth(struct bundle *bundle)
   }
 #endif
 
+  if (maxoverhead) {
+    log_Printf(LogLCP, "Reducing MTU from %d to %d (CCP requirement)\n",
+               bundle->iface->mtu, bundle->iface->mtu - maxoverhead);
+    bundle->iface->mtu -= maxoverhead;
+  }
+
   tun_configure(bundle);
 
   route_UpdateMTU(bundle);
diff --git a/usr.sbin/ppp/ppp/ccp.c b/usr.sbin/ppp/ppp/ccp.c
index db3eceb3b58..08127c5a1d7 100644
--- a/usr.sbin/ppp/ppp/ccp.c
+++ b/usr.sbin/ppp/ppp/ccp.c
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: ccp.c,v 1.20 2001/06/19 10:24:50 brian Exp $
+ * $OpenBSD: ccp.c,v 1.21 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/param.h>
@@ -299,6 +299,19 @@ ccp_Required(struct ccp *ccp)
   return 0;
 }
 
+/*
+ * Report whether it's possible to increase a packet's size after
+ * compression (and by how much).
+ */
+int
+ccp_MTUOverhead(struct ccp *ccp)
+{
+  if (ccp->fsm.state == ST_OPENED)
+    return algorithm[ccp->out.algorithm]->o.MTUOverhead;
+
+  return 0;
+}
+
 static void
 CcpInitRestartCounter(struct fsm *fp, int what)
 {
@@ -474,7 +487,24 @@ CcpLayerUp(struct fsm *fp)
   /* We're now up */
   struct ccp *ccp = fsm2ccp(fp);
   struct ccp_opt **o;
-  int f;
+  int f, fail;
+
+  for (f = fail = 0; f < NALGORITHMS; f++)
+    if (IsEnabled(ccp->cfg.neg[algorithm[f]->Neg]) &&
+        (*algorithm[f]->Required)(&ccp->fsm) &&
+        (ccp->in.algorithm != f || ccp->out.algorithm != f)) {
+      /* Blow it all away - we haven't negotiated a required algorithm */
+      log_Printf(LogWARN, "%s: Failed to negotiate (required) %s\n",
+                 fp->link->name, protoname(algorithm[f]->id));
+      fail = 1;
+    }
+
+  if (fail) {
+    ccp->his_proto = ccp->my_proto = -1;
+    fsm_Close(fp);
+    fsm_Close(&fp->link->lcp.fsm);
+    return 0;
+  }
 
   log_Printf(LogCCP, "%s: LayerUp.\n", fp->link->name);
 
diff --git a/usr.sbin/ppp/ppp/ccp.h b/usr.sbin/ppp/ppp/ccp.h
index 49918eb703d..9de531fa4a6 100644
--- a/usr.sbin/ppp/ppp/ccp.h
+++ b/usr.sbin/ppp/ppp/ccp.h
@@ -25,7 +25,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: ccp.h,v 1.10 2001/06/19 10:24:50 brian Exp $
+ * $OpenBSD: ccp.h,v 1.11 2001/07/03 22:23:56 brian Exp $
  */
 
 #define	CCP_MAXCODE	CODE_RESETACK
@@ -135,6 +135,7 @@ struct ccp_algorithm {
     void (*DictSetup)(void *, struct ccp *, u_short, struct mbuf *);
   } i;
   struct {
+    int MTUOverhead;
     void (*OptInit)(struct lcp_opt *, const struct ccp_config *);
     int (*Set)(struct lcp_opt *, const struct ccp_config *);
     void *(*Init)(struct lcp_opt *);
@@ -149,6 +150,7 @@ extern void ccp_Init(struct ccp *, struct bundle *, struct link *,
                      const struct fsm_parent *);
 extern void ccp_Setup(struct ccp *);
 extern int ccp_Required(struct ccp *);
+extern int ccp_MTUOverhead(struct ccp *);
 
 extern void ccp_SendResetReq(struct fsm *);
 extern struct mbuf *ccp_Input(struct bundle *, struct link *, struct mbuf *);
diff --git a/usr.sbin/ppp/ppp/datalink.c b/usr.sbin/ppp/ppp/datalink.c
index fcc8a07e081..02d749366f3 100644
--- a/usr.sbin/ppp/ppp/datalink.c
+++ b/usr.sbin/ppp/ppp/datalink.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: datalink.c,v 1.35 2001/06/04 16:09:28 brian Exp $
+ *	$OpenBSD: datalink.c,v 1.36 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/param.h>
@@ -570,7 +570,8 @@ datalink_LayerUp(void *v, struct fsm *fp)
         auth_StartReq(&dl->chap.auth);
     } else
       datalink_AuthOk(dl);
-  }
+  } else if (fp->proto == PROTO_CCP)
+    (*dl->parent->LayerUp)(dl->parent->object, &dl->physical->link.ccp.fsm);
 }
 
 static void
diff --git a/usr.sbin/ppp/ppp/deflate.c b/usr.sbin/ppp/ppp/deflate.c
index 0e9281db0f9..84edd30531c 100644
--- a/usr.sbin/ppp/ppp/deflate.c
+++ b/usr.sbin/ppp/ppp/deflate.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: deflate.c,v 1.12 2001/06/19 10:24:51 brian Exp $
+ *	$OpenBSD: deflate.c,v 1.13 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/types.h>
@@ -567,6 +567,7 @@ const struct ccp_algorithm PppdDeflateAlgorithm = {
     DeflateDictSetup
   },
   {
+    0,
     DeflateInitOptsOutput,
     DeflateSetOptsOutput,
     DeflateInitOutput,
@@ -591,6 +592,7 @@ const struct ccp_algorithm DeflateAlgorithm = {
     DeflateDictSetup
   },
   {
+    0,
     DeflateInitOptsOutput,
     DeflateSetOptsOutput,
     DeflateInitOutput,
diff --git a/usr.sbin/ppp/ppp/mp.c b/usr.sbin/ppp/ppp/mp.c
index bec0c0b399a..73c69cec417 100644
--- a/usr.sbin/ppp/ppp/mp.c
+++ b/usr.sbin/ppp/ppp/mp.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: mp.c,v 1.21 2000/11/02 00:54:34 brian Exp $
+ *	$OpenBSD: mp.c,v 1.22 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/param.h>
@@ -167,6 +167,8 @@ static void
 mp_LayerUp(void *v, struct fsm *fp)
 {
   /* The given fsm (ccp) is now up */
+
+  bundle_CalculateBandwidth(fp->bundle);	/* Against ccp_MTUOverhead */
 }
 
 static void
@@ -646,6 +648,11 @@ mp_Output(struct mp *mp, struct bundle *bundle, struct link *l,
                mp->out.seq, m_length(m), l->name);
   mp->out.seq = inc_seq(mp->peer_is12bit, mp->out.seq);
 
+  if (l->ccp.fsm.state != ST_OPENED && ccp_Required(&l->ccp)) {
+    log_Printf(LogPHASE, "%s: Not transmitting... waiting for CCP\n", l->name);
+    return;
+  }
+
   link_PushPacket(l, m, bundle, LINK_QUEUES(l) - 1, PROTO_MP);
 }
 
diff --git a/usr.sbin/ppp/ppp/mppe.c b/usr.sbin/ppp/ppp/mppe.c
index b2e4392fbd2..a1b0a246058 100644
--- a/usr.sbin/ppp/ppp/mppe.c
+++ b/usr.sbin/ppp/ppp/mppe.c
@@ -23,7 +23,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $OpenBSD: mppe.c,v 1.6 2001/06/19 10:24:56 brian Exp $
+ * $OpenBSD: mppe.c,v 1.7 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/types.h>
@@ -721,6 +721,7 @@ const struct ccp_algorithm MPPEAlgorithm = {
     MPPEDictSetup
   },
   {
+    2,
     MPPEInitOptsOutput,
     MPPESetOptsOutput,
     MPPEInitOutput,
diff --git a/usr.sbin/ppp/ppp/pred.c b/usr.sbin/ppp/ppp/pred.c
index c6b6150ce8f..c3e52be8006 100644
--- a/usr.sbin/ppp/ppp/pred.c
+++ b/usr.sbin/ppp/ppp/pred.c
@@ -26,7 +26,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$OpenBSD: pred.c,v 1.11 2001/06/19 10:24:57 brian Exp $
+ *	$OpenBSD: pred.c,v 1.12 2001/07/03 22:23:56 brian Exp $
  */
 
 #include <sys/types.h>
@@ -340,6 +340,7 @@ const struct ccp_algorithm Pred1Algorithm = {
     Pred1DictSetup
   },
   {
+    0,
     Pred1InitOptsOutput,
     Pred1SetOptsOutput,
     Pred1InitOutput,