From 9a6607a7cb6a863e2fe4a4513555a059905a0c92 Mon Sep 17 00:00:00 2001
From: hades <hades>
Date: Tue, 28 Aug 2001 12:04:56 +0000
Subject: [PATCH] Major Bugfix in segment and reassembly works with broken and
 proper CES ATM driver now

---
 hadaq/nettrans.c | 73 ++++++++++++++++++++++++++----------------------
 1 file changed, 39 insertions(+), 34 deletions(-)

diff --git a/hadaq/nettrans.c b/hadaq/nettrans.c
index 8081230..d4eb893 100644
--- a/hadaq/nettrans.c
+++ b/hadaq/nettrans.c
@@ -1,4 +1,4 @@
-static char *rcsId = "$Header: /misc/hadesprojects/daq/cvsroot/eventbuilder/hadaq/nettrans.c,v 6.21 2001-03-07 16:02:44 hades Exp $";
+static char *rcsId = "$Header: /misc/hadesprojects/daq/cvsroot/eventbuilder/hadaq/nettrans.c,v 6.22 2001-08-28 12:04:56 hades Exp $";
 
 
 #define _GNU_SOURCE
@@ -108,7 +108,7 @@ static int openAtm(NetTrans *my, int vpi, int vci, size_t bw, int fl) {
 		if (0 > retVal) {
 			deleteLAtm(my->lAtm);
 		} else {
-			my->mtuSize = LAtm_mtu(my->lAtm);
+			my->mtuSize = 60 * 0x400;
 			my->fd = LAtm_fd(my->lAtm);
 		}
 	}
@@ -235,16 +235,6 @@ int recvGeneric(NetTrans *my) {
 		break;
 	}
 
-#if 0
-/*
-* due to a bug in the CES Lynx ATM driver, the packet size
-* does not match the transportet size right now, check disabled
-*/
-	if (retVal != Pkt_size(my->pkt)) {
-		retVal = -1;
-	}
-#endif
-
 	if (0 > retVal) {
 		msglog(LOG_DEBUG, "recvGeneric: %s\n", strerror(errno));
 	} else {
@@ -332,36 +322,47 @@ void NetTrans_remove(NetTrans *my)
 	freeMem(my);
 }
 
+static size_t adjustedSize(NetTrans *my, void *hadTu) {
+	size_t size;
+
+	size = HadTu_paddedSize(hadTu) + 32;
+	/* round to the next 1K boundary to circumvent bug in CES ATM driver */
+	size = (size & 0x3ff) == 0 ? size : (size & ~0x3ff) + 0x400;
+	if (size % my->mtuSize == 0) {
+		size += 0x400;
+	}
+	return size;
+}
+
 int NetTrans_send(NetTrans *my, void *hadTu)
 {
-	size_t pktSize;
+	char saveIt[32];
+	size_t size;
 
-	for (my->offset = 0; my->offset < HadTu_size(hadTu); my->offset += pktSize) {
-		my->pkt = (char *)hadTu + my->offset;
-		pktSize = min(my->mtuSize, HadTu_size(hadTu) - my->offset);
+	/* copy message header to end for check at receiver */
+	memcpy(saveIt, HadTu_end(hadTu), 32);
+	memcpy(HadTu_end(hadTu), hadTu, 32);
 
-		/* we reserve pkts < 32 Byte for control messages */
-		if (pktSize < (2 * 1024)) {
-			my->pktSize = (2 * 1024);
-		} else {
-			my->pktSize = pktSize;
-		}
+	size = adjustedSize(my, hadTu);
+
+	my->offset = 0;
+	do {
+		my->pkt = (char *)hadTu + my->offset;
+		my->pktSize = min(my->mtuSize, size - my->offset);
 
 		if (0 > sendGeneric(my)) {
 			return -1;
 		}
+
+		my->offset += my->pktSize;
 		(*my->pktsSent)++;
-	}
+	} while (my->pktSize == my->mtuSize);
 
-	/* mark the end of message */
-	my->pkt = hadTu;
-	my->pktSize = 1024;
+	memcpy(HadTu_end(hadTu), saveIt, 32);
 
-	if (0 > sendGeneric(my)) {
-		return -1;
-	}
 	(*my->msgsSent)++;
-	(*my->bytesSent) += my->offset;
+	(*my->bytesSent) += size;
+
 	return 0;
 }
 
@@ -387,13 +388,17 @@ static int assembleMsg(NetTrans *my, void *hadTu, size_t size)
 	if (0 > recvGeneric(my)) {
 		abort();
 	}
+	my->offset += my->pktSize;
+	(*my->pktsReceived)++;
 
-	if (my->pktSize != 1024) {
-		my->offset += my->pktSize;
-		(*my->pktsReceived)++;
+	if (my->pktSize == my->mtuSize) {
 		retVal = 0;
 	} else {
-		if (my->offset < HadTu_size(my->pkt) || memcmp(my->pkt, hadTu, 24)) {
+		size_t size;
+
+		size = adjustedSize(my, hadTu);
+
+		if (my->offset != size || memcmp(HadTu_end(hadTu), hadTu, 32)) {
 			(*my->msgsDiscarded)++;
 			retVal = 0;
 		} else {
-- 
2.43.0