X-Git-Url: http://git.ozlabs.org/?p=ppp.git;a=blobdiff_plain;f=pppd%2Fccp.c;h=bade39a8403c026d60d4a6fa7cf31ae728dfdb82;hp=5e90ce6ecf42dc25400d8021058a9fd163429b92;hb=1b9f7635dd45d643b2fb7cf496f67789892897c5;hpb=045d19436a083f9c180993ff35a68597af65bc12

diff --git a/pppd/ccp.c b/pppd/ccp.c
index 5e90ce6..bade39a 100644
--- a/pppd/ccp.c
+++ b/pppd/ccp.c
@@ -1,9 +1,32 @@
 /*
  * ccp.c - PPP Compression Control Protocol.
+ *
+ * Copyright (c) 1994 The Australian National University.
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and distribute this software and its
+ * documentation is hereby granted, provided that the above copyright
+ * notice appears in all copies.  This software is provided without any
+ * warranty, express or implied. The Australian National University
+ * makes no representations about the suitability of this software for
+ * any purpose.
+ *
+ * IN NO EVENT SHALL THE AUSTRALIAN NATIONAL UNIVERSITY BE LIABLE TO ANY
+ * PARTY FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
+ * THE AUSTRALIAN NATIONAL UNIVERSITY HAVE BEEN ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * THE AUSTRALIAN NATIONAL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE AUSTRALIAN NATIONAL UNIVERSITY HAS NO
+ * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
+ * OR MODIFICATIONS.
  */
 
 #ifndef lint
-static char rcsid[] = "$Id: ccp.c,v 1.1 1994/08/11 01:44:32 paulus Exp $";
+static char rcsid[] = "$Id: ccp.c,v 1.4 1994/09/16 02:14:31 paulus Exp $";
 #endif
 
 #include <syslog.h>
@@ -64,6 +87,19 @@ static fsm_callbacks ccp_callbacks = {
  */
 #define CI_BSD_COMPRESS	0x21
 
+/*
+ * Information relating to BSD Compress configuration options.
+ */
+#define BSD_NBITS(x)		((x) & 0x1F)
+#define BSD_VERSION(x)		((x) >> 5)
+#define BSD_CURRENT_VERSION	1
+#define BSD_MAKE_OPT(v, n)	(((v) << 5) | (n))
+
+/*
+ * Do we want / did we get any compression?
+ */
+#define ANY_COMPRESS(opt)	((opt).bsd_compress)
+
 /*
  * Local state (mainly for handling reset-reqs and reset-acks
  */
@@ -109,6 +145,8 @@ ccp_open(unit)
 
     if (f->state != OPENED)
 	ccp_flags_set(unit, 1, 0);
+    if (!ANY_COMPRESS(ccp_wantoptions[unit]))
+	f->flags |= OPT_SILENT;
     fsm_open(f);
 }
 
@@ -152,7 +190,16 @@ ccp_input(unit, p, len)
     u_char *p;
     int len;
 {
-    fsm_input(&ccp_fsm[unit], p, len);
+    fsm *f = &ccp_fsm[unit];
+    int oldstate;
+
+    /*
+     * Check for a terminate-request so we can print a message.
+     */
+    oldstate = f->state;
+    fsm_input(f, p, len);
+    if (oldstate == OPENED && p[0] == TERMREQ && f->state != OPENED)
+	syslog(LOG_NOTICE, "Compression disabled by peer.");
 }
 
 /*
@@ -206,7 +253,17 @@ static void
 ccp_resetci(f)
     fsm *f;
 {
-    ccp_gotoptions[f->unit] = ccp_wantoptions[f->unit];
+    ccp_options *go = &ccp_gotoptions[f->unit];
+    u_char opt_buf[16];
+
+    *go = ccp_wantoptions[f->unit];
+    if (go->bsd_compress) {
+	opt_buf[0] = CI_BSD_COMPRESS;
+	opt_buf[1] = CILEN_BSD;
+	opt_buf[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
+	if (!ccp_test(f->unit, opt_buf, CILEN_BSD, 0))
+	    go->bsd_compress = 0;
+    }
 }
 
 /*
@@ -236,8 +293,11 @@ ccp_addci(f, p, lenp)
     if (go->bsd_compress) {
 	p[0] = CI_BSD_COMPRESS;
 	p[1] = CILEN_BSD;
-	p[2] = go->bsd_bits;
-	p += 3;
+	p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits);
+	if (ccp_test(f->unit, p, CILEN_BSD, 0))
+	    p += CILEN_BSD;
+	else
+	    go->bsd_compress = 0;
     }
     *lenp = p - p0;
 }
@@ -255,11 +315,11 @@ ccp_ackci(f, p, len)
     ccp_options *go = &ccp_gotoptions[f->unit];
 
     if (go->bsd_compress) {
-	if (len != 3 || p[0] != CI_BSD_COMPRESS
-	    || p[1] != CILEN_BSD || p[2] != go->bsd_bits)
+	if (len < CILEN_BSD || p[0] != CI_BSD_COMPRESS || p[1] != CILEN_BSD
+	    || p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
 	    return 0;
-	p += 3;
-	len -= 3;
+	p += CILEN_BSD;
+	len -= CILEN_BSD;
     }
     if (len != 0)
 	return 0;
@@ -283,14 +343,17 @@ ccp_nakci(f, p, len)
     memset(&no, 0, sizeof(no));
     try = *go;
 
-    if (go->bsd_compress && len >= CILEN_BSD && p[0] == CI_BSD_COMPRESS
-	&& p[1] == CILEN_BSD) {
+    if (go->bsd_compress && !no.bsd_compress && len >= CILEN_BSD
+	&& p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD) {
 	no.bsd_compress = 1;
 	/*
-	 * Peer wants us to use a different number of bits.
+	 * Peer wants us to use a different number of bits
+	 * or a different version.
 	 */
-	if (p[2] < go->bsd_bits)
-	    try.bsd_bits = p[2];
+	if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION)
+	    try.bsd_compress = 0;
+	else if (BSD_NBITS(p[2]) < go->bsd_bits)
+	    try.bsd_bits = BSD_NBITS(p[2]);
 	p += CILEN_BSD;
 	len -= CILEN_BSD;
     }
@@ -321,9 +384,9 @@ ccp_rejci(f, p, len)
 
     try = *go;
 
-    if (go->bsd_compress && len >= CILEN_BSD && p[0] == CI_BSD_COMPRESS
-	&& p[1] == CILEN_BSD) {
-	if (p[2] != go->bsd_bits)
+    if (go->bsd_compress && len >= CILEN_BSD
+	&& p[0] == CI_BSD_COMPRESS && p[1] == CILEN_BSD) {
+	if (p[2] != BSD_MAKE_OPT(BSD_CURRENT_VERSION, go->bsd_bits))
 	    return 0;
 	try.bsd_compress = 0;
 	p += CILEN_BSD;
@@ -353,12 +416,12 @@ ccp_reqci(f, p, lenp, dont_nak)
 {
     int ret, newret;
     u_char *p0, *retp;
-    int len, clen, type;
+    int len, clen, type, nb;
     ccp_options *ho = &ccp_hisoptions[f->unit];
     ccp_options *ao = &ccp_allowoptions[f->unit];
 
     ret = CONFACK;
-    p0 = p;
+    retp = p0 = p;
     len = *lenp;
 
     memset(ho, 0, sizeof(ccp_options));
@@ -382,13 +445,22 @@ ccp_reqci(f, p, lenp, dont_nak)
 		}
 
 		ho->bsd_compress = 1;
-		ho->bsd_bits = p[2];
-		if (ho->bsd_bits < MIN_BSD_BITS
-		    || ho->bsd_bits > ao->bsd_bits) {
+		ho->bsd_bits = nb = BSD_NBITS(p[2]);
+		if (BSD_VERSION(p[2]) != BSD_CURRENT_VERSION
+		    || nb > ao->bsd_bits) {
 		    newret = CONFNAK;
-		    if (!dont_nak)
-			p[2] = (ho->bsd_bits < MIN_BSD_BITS? MIN_BSD_BITS:
-				ao->bsd_bits);
+		    nb = ao->bsd_bits;
+		} else if (nb < MIN_BSD_BITS) {
+		    newret = CONFREJ;
+		} else if (!ccp_test(f->unit, p, CILEN_BSD, 1)) {
+		    if (nb > MIN_BSD_BITS) {
+			--nb;
+			newret = CONFNAK;
+		    } else
+			newret = CONFREJ;
+		}
+		if (newret == CONFNAK && !dont_nak) {
+		    p[2] = BSD_MAKE_OPT(BSD_CURRENT_VERSION, nb);
 		}
 
 		break;
@@ -400,10 +472,7 @@ ccp_reqci(f, p, lenp, dont_nak)
 
 	if (!(newret == CONFACK || newret == CONFNAK && ret == CONFREJ)) {
 	    /* we're returning this option */
-	    if (newret != ret) {
-		retp = p0;
-		ret = newret;
-	    }
+	    ret = newret;
 	    if (p != retp)
 		BCOPY(p, retp, clen);
 	    retp += clen;
@@ -425,7 +494,14 @@ static void
 ccp_up(f)
     fsm *f;
 {
+    ccp_options *go = &ccp_gotoptions[f->unit];
+    ccp_options *ho = &ccp_hisoptions[f->unit];
+
     ccp_flags_set(f->unit, 1, 1);
+    if (go->bsd_compress || ho->bsd_compress)
+	syslog(LOG_NOTICE, "%s enabled",
+	       go->bsd_compress? ho->bsd_compress? "Compression":
+	       "Receive compression": "Transmit compression");
 }
 
 /*
@@ -497,7 +573,8 @@ ccp_printpkt(p, plen, printer, arg)
 	    switch (code) {
 	    case CI_BSD_COMPRESS:
 		if (optlen >= CILEN_BSD) {
-		    printer(arg, "bsd %d", p[2]);
+		    printer(arg, "bsd v%d %d", BSD_VERSION(p[2]),
+			    BSD_NBITS(p[2]));
 		    p += CILEN_BSD;
 		}
 		break;
@@ -517,8 +594,16 @@ ccp_printpkt(p, plen, printer, arg)
 }
 
 /*
- * We have received a packet that the decompressor failed to decompress.
- * Issue a reset-req (if we haven't issued one recently).
+ * We have received a packet that the decompressor failed to
+ * decompress.  Here we would expect to issue a reset-request, but
+ * Motorola has a patent on resetting the compressor as a result of
+ * detecting an error in the decompressed data after decompression.
+ * (See US patent 5,130,993; international patent publication number
+ * WO 91/10289; Australian patent 73296/91.)
+ *
+ * So we ask the kernel whether the error was detected after
+ * decompression; if it was, we take CCP down, thus disabling
+ * compression :-(, otherwise we issue the reset-request.
  */
 void
 ccp_datainput(unit, pkt, len)
@@ -530,12 +615,25 @@ ccp_datainput(unit, pkt, len)
 
     f = &ccp_fsm[unit];
     if (f->state == OPENED) {
-	if (!(ccp_localstate[unit] & RACK_PENDING)) {
-	    fsm_sdata(f, RESETREQ, f->reqid = ++f->id, NULL, 0);
-	    TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
-	    ccp_localstate[unit] |= RACK_PENDING;
-	} else
-	    ccp_localstate[unit] |= RREQ_REPEAT;
+	if (ccp_fatal_error(unit)) {
+	    /*
+	     * Disable compression by taking CCP down.
+	     */
+	    syslog(LOG_ERR, "Lost compression sync: disabling compression");
+	    ccp_close(unit);
+	} else {
+	    /*
+	     * Send a reset-request to reset the peer's compressor.
+	     * We don't do that if we are still waiting for an
+	     * acknowledgement to a previous reset-request.
+	     */
+	    if (!(ccp_localstate[f->unit] & RACK_PENDING)) {
+		fsm_sdata(f, RESETREQ, f->reqid = ++f->id, NULL, 0);
+		TIMEOUT(ccp_rack_timeout, (caddr_t) f, RACKTIMEOUT);
+		ccp_localstate[f->unit] |= RACK_PENDING;
+	    } else
+		ccp_localstate[f->unit] |= RREQ_REPEAT;
+	}
     }
 }