X-Git-Url: http://git.ozlabs.org/?a=blobdiff_plain;ds=sidebyside;f=svr4%2Fppp_ahdlc.c;h=ffbe12078fa435a1b7b38af1a98adcd3b2cae75f;hb=db2e55aa1e6ae43e2846039325c22dbb671d2154;hp=dc35dda51c9688feb97a53d8eccc0c66259d1f69;hpb=c2b27e2f4f0a44fb3931383daf61d9e5b6aea053;p=ppp.git

diff --git a/svr4/ppp_ahdlc.c b/svr4/ppp_ahdlc.c
index dc35dda..ffbe120 100644
--- a/svr4/ppp_ahdlc.c
+++ b/svr4/ppp_ahdlc.c
@@ -24,7 +24,7 @@
  * OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS,
  * OR MODIFICATIONS.
  *
- * $Id: ppp_ahdlc.c,v 1.3 1995/05/29 06:45:49 paulus Exp $
+ * $Id: ppp_ahdlc.c,v 1.5 1995/10/27 03:57:10 paulus Exp $
  */
 
 /*
@@ -566,6 +566,17 @@ static unsigned paritytab[8] = {
     0x69969669, 0x96696996, 0x96696996, 0x69969669
 };
 
+#define UPDATE_FLAGS(c)	{				\
+    if ((c) & 0x80)					\
+	state->flags |= RCV_B7_1;			\
+    else						\
+	state->flags |= RCV_B7_0;			\
+    if (paritytab[(c) >> 5] & (1 << ((c) & 0x1F)))	\
+	state->flags |= RCV_ODDP;			\
+    else						\
+	state->flags |= RCV_EVNP;			\
+}
+
 /*
  * Process received characters.
  */
@@ -596,8 +607,7 @@ unstuff_chars(q, mp)
 	}
 
 	if ((state->flags & (IFLUSH|ESCAPED)) == 0
-	    && state->inlen >= PPP_HDRLEN
-	    && (om = state->cur_blk) != 0) {
+	    && state->inlen > 0 && (om = state->cur_blk) != 0) {
 	    /*
 	     * Process bulk chars as quickly as possible.
 	     */
@@ -616,26 +626,18 @@ unstuff_chars(q, mp)
 		if (c == PPP_FLAG)
 		    break;
 		++cp;
-		if (c & 0x80)
-		    state->flags |= RCV_B7_1;
-		else
-		    state->flags |= RCV_B7_0;
-		if (paritytab[c >> 5] & (1 << (c & 0x1F)))
-		    state->flags |= RCV_ODDP;
-		else
-		    state->flags |= RCV_EVNP;
+		UPDATE_FLAGS(c);
 		if (c == PPP_ESCAPE) {
 		    if (extra > 0) {
 			--extra;
 			++cpend;
-		    } else if (cp >= cpend) {
+		    }
+		    if (cp >= cpend || (c = *cp) == PPP_FLAG) {
 			state->flags |= ESCAPED;
 			break;
 		    }
-		    c = *cp;
-		    if (c == PPP_FLAG)
-			break;
 		    ++cp;
+		    UPDATE_FLAGS(c);
 		    c ^= PPP_TRANS;
 		}
 		*dp++ = c;
@@ -644,19 +646,12 @@ unstuff_chars(q, mp)
 	    state->inlen += dp - dp0;
 	    state->infcs = fcs;
 	    om->b_wptr = dp;
-	    if (cp >= cpend)
-		continue;	/* go back and check cp again */
+	    if (cp >= mp->b_wptr)
+		continue;	/* advance to the next mblk */
 	}
 
 	c = *cp++;
-	if (c & 0x80)
-	    state->flags |= RCV_B7_1;
-	else
-	    state->flags |= RCV_B7_0;
-	if (paritytab[c >> 5] & (1 << (c & 0x1F)))
-	    state->flags |= RCV_ODDP;
-	else
-	    state->flags |= RCV_EVNP;
+	UPDATE_FLAGS(c);
 	if (c == PPP_FLAG) {
 	    /*
 	     * End of a frame.
@@ -733,34 +728,26 @@ unstuff_chars(q, mp)
 		state->cur_blk = om;
 	    }
 	}
-	*om->b_wptr++ = c;
-	++state->inlen;
-	state->infcs = PPP_FCS(state->infcs, c);
 
-	if (state->inlen == PPP_HDRLEN) {
+	if (state->inlen == 0) {
 	    /*
 	     * We don't do address/control & protocol decompression here,
-	     * but we do leave space for the decompressed fields and
-	     * arrange for the info field to start on a word boundary.
+	     * but we try to put the first byte at an offset such that
+	     * the info field starts on a word boundary.  The code here
+	     * will do this except for packets with protocol compression
+	     * but not address/control compression.
 	     */
-	    dp = om->b_rptr;
-	    if (PPP_ADDRESS(dp) == PPP_ALLSTATIONS
-		&& PPP_CONTROL(dp) == PPP_UI)
-		dp += 2;
-	    if ((*dp & 1) == 0)
-		++dp;
-	    /* dp is now pointing at the last byte of the ppp protocol field */
-	    offset = 3 - ((unsigned)dp & 3);
-	    if (offset > 0) {
-		dp = om->b_wptr;
-		do {
-		    --dp;
-		    dp[offset] = dp[0];
-		} while (dp > om->b_rptr);
-		om->b_rptr += offset;
-		om->b_wptr += offset;
+	    if (c != PPP_ALLSTATIONS) {
+		om->b_wptr += 2;
+		if (c & 1)
+		    ++om->b_wptr;
+		om->b_rptr = om->b_wptr;
 	    }
 	}
+
+	*om->b_wptr++ = c;
+	++state->inlen;
+	state->infcs = PPP_FCS(state->infcs, c);
     }
 }