Implement Reset{Req,Ack} properly, as per rfc 1962.

(I completely mis-read the rfc last time 'round!)

This means:
  o Better CCP/WARN Reset diagnostics.
  o After we've sent a REQ and before we've received an ACK, we drop
    incoming compressed data and send another REQ.
  o Before sending an ACK, re-sequence all pending PRI_NORMAL data in
    the modem queue so that pending packets won't get to the peer
    *after* the ResetAck.
  o Send ACKs with the `identifier' from the REQ frame.
  o After we've received a correct ACK, duplicate ACKs are ok (and will
    reset our history).
  o Incorrect ACKs (not matching the last REQ) are moaned about and dropped.

Also,

  o Calculate the correct FCS after compressing a packet.  DEFLATE
    *may* produce an mbuf with more than a single link in the chain,
    but HdlcOutput didn't know how to calculate the FCS :-(
  o Make `struct fsm'::reqid a u_char, not an int.
    This fix will prevent us from sending id `255' 2,000,000,000 times
    before wrapping to `0' for another 2,000,000,000 sends :-/
  o Bump the version number a little.

The end result:  DEFLATE now works over an unreliable link layer.
                 I can txfr a 1.5Mb kernel over a (rather bad) null-modem
                 cable at an average of 21679 bytes per second using rcp.
Repeat after me: Don't test compression using a loopback ppp/tcp setup as
                 we never lose packets and therefore never have to reset!

1 files changed, 5 insertions, 2 deletions

diff --git a/usr.sbin/ppp/ccp.h b/usr.sbin/ppp/ccp.h
index 840e2da..1be021c 100644
--- a/usr.sbin/ppp/ccp.h
+++ b/usr.sbin/ppp/ccp.h
@@ -15,7 +15,7 @@
  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * $Id: ccp.h,v 1.11 1997/12/03 23:27:55 brian Exp $
+ * $Id: ccp.h,v 1.12 1998/01/04 20:25:41 brian Exp $
  *
  *	TODO:
  */
@@ -39,6 +39,9 @@ struct ccpstate {
   u_long his_proto;		/* peer's compression protocol */
   u_long my_proto;		/* our compression protocol */
 
+  int reset_sent;		/* If != -1, ignore compressed 'till ack */
+  int last_reset;		/* We can receive more (dups) w/ this id */
+
   u_long his_reject;		/* Request codes rejected by peer */
   u_long my_reject;		/* Request codes I have rejected */
 
@@ -83,7 +86,7 @@ extern void CcpUp(void);
 extern void CcpOpen(void);
 extern void CcpInit(void);
 extern int ReportCcpStatus(struct cmdargs const *);
-extern void CcpResetInput(void);
+extern void CcpResetInput(u_char);
 extern int CcpOutput(int, u_short, struct mbuf *);
 extern struct mbuf *CompdInput(u_short *, struct mbuf *);
 extern void CcpDictSetup(u_short, struct mbuf *);