Diff: main.cpp

Revision:

82:051f77f7dd72

Parent:

81:9ede60e9a2c8

Child:

83:cdcb81d1910f

--- a/main.cpp	Sat Jul 15 20:50:13 2017 +0000
+++ b/main.cpp	Sun Jul 16 13:54:08 2017 +0000
@@ -29,7 +29,7 @@
 
 // The #define below enables/disables a SECOND (optional) serial port that prints out interesting diagnostic messages.
 // Change to SERIAL_PORT_MONITOR_YES to enable diagnostics messages. You need to wire a second serial port to your mbed hardware to monitor this.
-#define SERIAL_PORT_MONITOR_YES /* or change to SERIAL_PORT_MONITOR_YES */
+#define SERIAL_PORT_MONITOR_NO /* or change to SERIAL_PORT_MONITOR_YES */
 
 #ifndef SERIAL_PORT_MONITOR_NO
 Serial xx(PC_10, PC_11); // Not required to run, if you get compile error here, change #define SERIAL_PORT_MONITOR_YES to #define SERIAL_PORT_MONITOR_NO
@@ -488,7 +488,7 @@
     snprintf(srcIP,16, "%d.%d.%d.%d", srcAdr[0],srcAdr[1],srcAdr[2],srcAdr[3]);
     char dstIP [16];
     snprintf(dstIP,16, "%d.%d.%d.%d", dstAdr[0],dstAdr[1],dstAdr[2],dstAdr[3]);
-    if (v0) debug("IP %s %s v%d h%d d%d e%d L%d ",srcIP,dstIP,versionIP,headerSizeIP,dscpIP,ecnIP,packetLength);
+    if (v0) debug("IP %s %s v%d h%d d%d e%d L%03d ",srcIP,dstIP,versionIP,headerSizeIP,dscpIP,ecnIP,packetLength);
     if (v0) debug("i%04x f%d t%d p%d C%04x\n",identIP,flagsIP,ttlIP,protocolIP,checksumIP);
 }
 
@@ -595,6 +595,7 @@
     char * acktcp        = s + 8;  // 4 bytes
     char * offset        = s + 12; // 4 bits
     char * flagbitstcp   = s + 12; // 9 bits
+    char * windowsizetcp = s + 14; // 2 bytes
     char * checksumtcp   = s + 16; // 2 bytes
 
     int tcpSize = packetLength - headerSizeIP;
@@ -629,6 +630,14 @@
             if ( tcpDataSize != 1 ) return;
             ack++;
         case TCP_FLAG_SYN:
+            // ignore all TCP options by shortening packet to 40 bytes
+            pktLen[1] = 40; // shorten packet to 40 bytes
+            packetLength = 40; // shorten packet to 40 bytes
+            headerSizeTCP = 20; // shorten packet to 40 bytes
+            tcpSize = 20; // shorten packet to 40 bytes
+            headerSizeTCP = 20; // shorten packet to 40 bytes
+            offset[0] =  (headerSizeTCP/4)<<4; // shorten packet to 40 bytes
+
             flagsOut = TCP_FLAG_SYN | TCP_FLAG_ACK; // something wants to connect - ack it
             ppp.seq = ppp.seq + 10000; // create a new sequence number (normally random)
             seq = ppp.seq; // create a new sequence number (normally random)
@@ -667,6 +676,9 @@
     memcpy(tempHold, srctcp,2);
     memcpy(srctcp, dsttcp,2);
     memcpy(dsttcp, tempHold,2); // swap ip port source/dest
+    
+    windowsizetcp[0]=16; // ignore window size negotiation
+    windowsizetcp[1]=0; // ignore winodw size negotiation
 
     acktcp[0]=ack>>24;
     acktcp[1]=ack>>16;
@@ -773,7 +785,7 @@
     char dstIP [16];
     snprintf(dstIP,16, "%d.%d.%d.%d", dstAdr[0],dstAdr[1],dstAdr[2],dstAdr[3]);
     if (v0) {
-        debug("IP %s %s v%d h%d d%d e%d L%d ",srcIP,dstIP,versionIP,headerSizeIP,dscpIP,ecnIP,packetLength);
+        debug("IP %s %s v%d h%d d%d e%d L%03d ",srcIP,dstIP,versionIP,headerSizeIP,dscpIP,ecnIP,packetLength);
     }
     if (v0) {
         debug("i%04x f%d t%d p%d C%04x\n",identIP,flagsIP,ttlIP,protocolIP,checksumIP);
@@ -933,9 +945,8 @@
         void * found2 = memchr( (char *)ppp.rx.buf, 0x7e, RXBUFLEN );
         if( (found1 != NULL) | (found2 != NULL) ) {
             if (found1 != NULL) {
-                //strcpy( found1, "FOUND!FOUND!" ); // overwrite so we don't find it again
+                memset(ppp.rx.buf, 0x20, RXBUFLEN); // clear the receive buffer
                 // respond with Windows Dialup networking expected "Direct Connection Between Two Computers" response string
-                memset(ppp.rx.buf, 0, RXBUFLEN); // clear the receive buffer
                 pc.puts("CLIENTSERVER");
                 if (v0) debug("Found connect string \"CLIENTCLIENT\"\n");
             }
@@ -960,9 +971,7 @@
 
     pc.attach(&rxHandler,Serial::RxIrq); // start the receive handler
     while(1) {
-        debug("scan\n");
         scanForConnectString(); // respond to connect command from windows dial up networking
-        debug("found\n");
         while(ppp.online) {
             wait_for_HDLC_frame();
         }