Lab2_web
/
webserverBlinky
Important changes to repositories hosted on mbed.com
Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.
To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.
It is also possible to export all your personal repositories from the account settings page.
Dependencies: mbed
Fork of
webserverBlinky
by 
RealTimeCompLab2
Diff: main.cpp
- Revision:
- 67:a63e3486bcda
- Parent:
- 66:f005b9fdf4d1
- Child:
- 68:0b74763ae67f
diff -r f005b9fdf4d1 -r a63e3486bcda main.cpp
--- a/main.cpp Mon Jun 05 15:34:53 2017 +0000
+++ b/main.cpp Mon Jun 05 16:45:03 2017 +0000
@@ -513,6 +513,55 @@
}
}
+int httpResponse( char * dataStart)
+{
+ int n=0; // number of bytes we have printed so far
+ if(strncmp(dataStart, "GET / HTTP/1.1", 14) == 0 ) {
+ n=n+sprintf(n+dataStart,"HTTP/1.1 200 OK\r\nServer: PPP-Blinky\r\n"); // http header
+ n=n+sprintf(n+dataStart,"Content-Length: "); // http header
+ int contentLengthStart = n; // remember where Content-Length is in buffer
+ n=n+sprintf(n+dataStart,"?????\r\n"); // leave five spaces for content length - will be updated later
+ n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n\r\n"); // http header must end with empty line (\r\n)
+ int nHeader=n; // byte size of the HTTP header. Note - seems like this must be 1+(multiple of four)
+
+ // this is where we insert our web page into the buffer
+ n=n+sprintf(n+dataStart,"%s\r\n", ourWebPage);
+
+ int contentLength = n-nHeader; // contentLength is the count of every character after the header
+#define CONTENTLENGTHSIZE 5
+ char contentLengthString[CONTENTLENGTHSIZE+1]; // temporary buffer to create Content-Length string
+ snprintf(contentLengthString,CONTENTLENGTHSIZE+1,"%*d",CONTENTLENGTHSIZE,contentLength); // print Content-Length with leading spaces and fixed width equal to csize
+ memcpy(dataStart+contentLengthStart, contentLengthString, CONTENTLENGTHSIZE); // copy Content-Length to it's place in the send buffer
+
+ if (v0) {
+ debug("HTTP GET BufferSize %d*32=%d Header %d Content-Length %d Total %d Available %d\n",dataLen/32,dataLen,nHeader,contentLength,n,dataLen-n);
+ }
+ } else { // all remaining requests get 404 Not Found response
+ n=n+sprintf(n+dataStart,"HTTP/1.1 404 Not Found\r\nServer: PPP-Blinky\r\n"); // http header
+ n=n+sprintf(n+dataStart,"Content-Length: "); // http header
+ int contentLengthStart = n; // remember where Content-Length is in buffer
+ n=n+sprintf(n+dataStart,"?????\r\n"); // leave five spaces for content length - will be updated later
+ n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n\r\n"); // http header must end with empty line (\r\n)
+ int nHeader=n; // byte total of all headers. Note - seems like this must be 1+(multiple of four)
+
+ n=n+sprintf(n+dataStart,"<!DOCTYPE html><html><head></head>"); // html start
+ n=n+sprintf(n+dataStart,"<body><h1>File Not Found</h1></body>");
+ n=n+sprintf(n+dataStart,"</html>\r\n"); // html end
+
+ int contentLength = n-nHeader; // Content-Length is the count of every character after the header
+ int cSize = 5; // maximum number of digits we allow for Content-Length
+ char contentLengthString[cSize+1]; // temporary buffer to create Content-Length string
+ snprintf(contentLengthString,cSize+1,"%*d",cSize,contentLength); // print Content-Length with leading spaces and fixed width = csize
+ memcpy(dataStart+contentLengthStart, contentLengthString, cSize); // copy Content-Length to the send buffer
+
+ if (v0) {
+ debug("HTTP GET BufSize %d*32=%d Header %d Content-Length %d Total %d Available %d\n",dataLen/32,dataLen,nHeader,contentLength,n,dataLen-n);
+ }
+ }
+ return n; // total byte size of our response
+}
+
+
void tcpHandler()
{
char * ipPkt = ppp.pkt.buf+4; // ip packet start
@@ -548,7 +597,7 @@
int flagsTCP = ((flagbitstcp[0]&1)<<8)|flagbitstcp[1];
char * dataStart = ppp.pkt.buf + 4 + headerSizeIP + headerSizeTCP; // start of data block after TCP header
- int incomingLen = tcpSize - headerSizeTCP; // size of data block after TCP header
+ int tcpDataSize = tcpSize - headerSizeTCP; // size of data block after TCP header
#define TCP_FLAG_ACK (1<<4)
#define TCP_FLAG_SYN (1<<1)
@@ -566,9 +615,8 @@
ppp.seq = ack; // always adopt their sequence number calculation in place of doing our own calculation
- // if ( ((flagsTCP & ~TCP_FLAG_ACK) == 0) && ((flagsTCP & TCP_FLAG_ACK) != 0) ) {
if ( flagsTCP == TCP_FLAG_ACK ) {
- if (incomingLen == 0) { // ignore - just an empty ack packet
+ if (tcpDataSize == 0) { // ignore - just an empty ack packet
return;
}
} else if ( (flagsTCP & TCP_FLAG_SYN) != 0 ) { // got SYN flag
@@ -580,66 +628,12 @@
flagsOut = TCP_FLAG_ACK | TCP_FLAG_FIN; // for every push we answer once AND close the link
fastResponse = 1; // we can respond fast to a push
// It's a push, so let's check the incoming data for an HTTP GET request
- if ( strncmp(dataStart, "GET / HTTP/1.1", 14) == 0) {
- dataLen = 1024; // this buffer has to hold the web page and the content below, so keep total size under 1024 or increase this
- memset(dataStart,'x', dataLen ); // initialize the data block
-
- int n=0; // number of bytes we have printed so far
- n=n+sprintf(n+dataStart,"HTTP/1.1 200 OK\r\nServer: PPP-Blinky\r\n"); // http header
- n=n+sprintf(n+dataStart,"Content-Length: "); // http header
- int contentLengthStart = n; // remember where Content-Length is in buffer
- n=n+sprintf(n+dataStart,"?????\r\n"); // leave five spaces for content length - will be updated later
- n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n\r\n"); // http header must end with empty line (\r\n)
- int nHeader=n; // byte size of the HTTP header. Note - seems like this must be 1+(multiple of four)
-
- // this is where we insert our web page into the buffer
- n=n+sprintf(n+dataStart,"%s\r\n", ourWebPage);
-
- int contentLength = n-nHeader; // contentLength is the count of every character after the header
- int cSize = 5; // maximum number of digits we allow for Content-Length
- char contentLengthString[cSize+1]; // temporary buffer to create Content-Length string
- snprintf(contentLengthString,cSize+1,"%*d",cSize,contentLength); // print Content-Length with leading spaces and fixed width equal to csize
- memcpy(dataStart+contentLengthStart, contentLengthString, cSize); // copy Content-Length to it's place in the send buffer
-
- if (v0) {
- debug("HTTP GET BufferSize %d*32=%d Header %d Content-Length %d Total %d Available %d\n",dataLen/32,dataLen,nHeader,contentLength,n,dataLen-n);
- }
- dataLen=n; // update the buffer size
- } else if ( strncmp(dataStart, "GET /", 4) == 0) { // all other HTTP GET requests get 404 Not Found response
- dataLen = 32*32; // maximum size for File not found webpage
- memset(dataStart,'x', dataLen ); // initialize the data block
-
- int n=0; // number of bytes we have printed so far
- n=n+sprintf(n+dataStart,"HTTP/1.1 404 Not Found\r\nServer: PPP-Blinky\r\n"); // http header
- n=n+sprintf(n+dataStart,"Content-Length: "); // http header
- int contentLengthStart = n; // remember where Content-Length is in buffer
- n=n+sprintf(n+dataStart,"?????\r\n"); // leave five spaces for content length - will be updated later
- n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n\r\n"); // http header must end with empty line (\r\n)
- int nHeader=n; // byte total of all headers. Note - seems like this must be 1+(multiple of four)
-
- n=n+sprintf(n+dataStart,"<!DOCTYPE html><html><head></head>"); // html start
- n=n+sprintf(n+dataStart,"<body><h1>File Not Found</h1></body>");
- n=n+sprintf(n+dataStart,"</html>\r\n"); // html end
-
- int contentLength = n-nHeader; // Content-Length is the count of every character after the header
- int cSize = 5; // maximum number of digits we allow for Content-Length
- char contentLengthString[cSize+1]; // temporary buffer to create Content-Length string
- snprintf(contentLengthString,cSize+1,"%*d",cSize,contentLength); // print Content-Length with leading spaces and fixed width = csize
- memcpy(dataStart+contentLengthStart, contentLengthString, cSize); // copy Content-Length to the send buffer
-
- if (v0) {
- debug("HTTP GET BufSize %d*32=%d Header %d Content-Length %d Total %d Available %d\n",dataLen/32,dataLen,nHeader,contentLength,n,dataLen-n);
- }
- dataLen=n; // update the buffer size
- } else {
- dataLen=0; // we did not find a valid HTTP request, so just ACK with zero data
+ if ( strncmp(dataStart, "GET ", 4) == 0) { // do we see an http GET command
+ dataLen = httpResponse(dataStart); // send an http response
}
- } else {
- dataLen=0; // it's not any TCP Flag Combo that needs special handling
}
// All the TCP flag handling is now done
-
// Now we have to recalculate all the header sizes, swap IP address/port source and destination, and do the IP and TCP checksums
char tempHold[12]; // it's 12 long because we later reuse it when building the TCP pseudo-header
@@ -651,18 +645,18 @@
memcpy(srctcp, dsttcp,2);
memcpy(dsttcp, tempHold,2); // swap ip port source/dest
- ack = seq + incomingLen; // acknowledge the number of bytes that they sent by adding it to "our" sequence number
+ ack = seq + tcpDataSize; // acknowledge the number of data bytes that they sent by adding it to "our" sequence number
seq = ppp.seq; // set up the sequence number we have to respond with
acktcp[0]=ack>>24;
acktcp[1]=ack>>16;
acktcp[2]=ack>>8;
- acktcp[3]=ack>>0; // save ack
+ acktcp[3]=ack>>0; // save ack 32-bit integer
seqtcp[0]=seq>>24;
seqtcp[1]=seq>>16;
seqtcp[2]=seq>>8;
- seqtcp[3]=seq>>0; // save seq
+ seqtcp[3]=seq>>0; // save seq 32-bit integer
flagbitstcp[1] = flagsOut; // set up the new flags
@@ -682,7 +676,7 @@
// this header contains the most important parts of the IP header, i.e. source and destination address, protocol number and data length.
char * pseudoHeader = s-12; // mark the start of the TCP pseudo-header
- memcpy(tempHold, pseudoHeader, 12); // preserve the 12 bytes in the IP header where the TCP pseudo-Header must be built
+ memcpy(tempHold, pseudoHeader, 12); // preserve the 12 bytes of the IP header where the TCP pseudo-Header will be built
memcpy( pseudoHeader+0, srcAdr, 8); // IP source and destination addresses from IP header
memset( pseudoHeader+8, 0, 1); // reserved, set to zero
memset( pseudoHeader+9, protocolIP, 1); // protocol from IP header