PPP-Blinky - Small Internet Protocol Stack using a standard se…

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Nicolas Nackel / Mbed 2 deprecated PPP-Blinky

Small Internet Protocol Stack using a standard serial port.

PPP-Blinky - TCP/IP Networking Over a Serial Port

Note: The source code is at the bottom of this page.

/media/uploads/nixnax/blinky-connected.gif
A Windows desktop showing PPP-Blinky in the network connections list.

Describe PPP-Blinky in Three Sentences

PPP-Blinky is a tiny library that enables Internet protocols (IPv4) to any mbed target hardware by using only a serial port.

The code runs on processors with as little as 8k RAM, for example the Nucleo-L053R8 board.

PPP-Blinky uses the industry-standard PPP (Point-to-Point) Protocol and a tiny "stateless" TCP/IP stack.

No Ethernet Port Required

No ethernet port is required - PPP-Blinky uses a serial port to send IP packets to your PC.

PPP-Blinky emulates a standard dial-up modem and therefore connects to Windows, Linux or Adroid machines.

The code runs on most ARM mbed platforms such as the LPC11U24 shown in the picture below:

/media/uploads/nixnax/blinky-to-laptop1.jpg mbed LPC11u24 acting as a webserver to a Windows laptop.

Webserver

The Webserver and WebSocket functions are ideal for building browser-based GUIs on mbed-enabled hardware.

PPP-Blinky's HTTP webserver works with most web clients such as Internet Explorer, Mozilla Firefox, Google Chrome, Safari, Curl, wget and Lynx as well as Microsoft Powershell Invoke-Webrequest command.

In the image below Firefox web browser displays the main web page embedded into PPP-Blinky's code:

/media/uploads/nixnax/ppp-blinky-firefox.jpg Firefox web browser displays a web page embedded into PPP-Blinky's code

WebSocket Service

WebSocket is the most popular protocol standard for real-time bidirectional TCP/IP communication between clients and servers.
In the image below a small Internet Explorer script has connected to PPP-Blinky's WebSocket Service.
A websocket message was then sent by the browser and was echoed back by the WebSocket, triggering the onmessage event in the script.
The WebSocket service enables bidirectional real-time interaction between PPP-Blinky and any element in the browser DOM via JavaScript.
If you already have PPP-Blinky up and running you can test your WebSocket service using this: http://jsfiddle.net/d26cyuh2/112/embedded/result
Websockets are ideal for building browser-based GUIs for mbed hardware.

/media/uploads/nixnax/ppp-blinky-websocke-2.gif

Trying PPP-Blinky on your mbed board

You will need an mbed-enabled hardware board: https://developer.mbed.org/platforms/

Establish a serial port connection between your host PC and your mbed board. The easiest way is to use mbed hardware with a USB serial debug port. I've tried the ST-Micro Nucleo-L476RG, Nucleo-L152RE, Nucleo-F401RE, Nucleo-L432KC, Nucleo-L053R8, mbed-LPC11U24 and mbed-LPC1768 boards and they all work out of the box. Use the mbed online compiler to compile the software for your target board. Save the compiled binary to your hardware.

Before establishing a network connection, you can verify the operation of the code by opening a terminal program such as Tera Term, and setting the baud rate of the COM port on your mbed board to 115200 baud. LED1 should toggle for every two 0x7E (~) (i.e. tilde) characters you type, as 0x7E is the PPP frame start/end marker. Don't forget to close the port when your'e done testing, or else Windows Dial-up Networking will report that the COM port is in use by another program when you try to connect.

Once you are certain that the serial port and firmware is working, proceed to creating a new network connection on your PC -see below.

Creating a Dial-up Connection in Windows

/media/uploads/nixnax/modem.jpg

Setting up Dial-Up Networking (DUN) on your Windows 7 or 8 PC is essentially a two-step process: First, you create a new modem device, because PPP-blinky partially emulates a standard Windows serial port modem device. Second, you create a new Internet connection (in practice, a new network adapter) which is associated with your new "modem".

Step-by-step description of how to configure Windows for PPP-Blinky here:

/users/nixnax/code/PPP-Blinky/wiki/Configuring-Windows-Dial-Up-Networking

There is also a screen on how to set up Linux dial-up networking near the bottom of this page.

Connecting to PPP-Blinky from your PC

Once Windows networking is configured you can establish a dial-up connection to your mbed board over the USB virtual com port.

The IP address you manually assigned to the new dial-up network adapter (172.10.10.1) functions as a gateway to any valid IP address on that subnet. In the screen capture below, I'm sending pings from the Windows 8 command line to my ST-Micro Nucleo-L476RG board over the USB virtual serial Port. I'm also using a second serial port and Tera Term to capture the debug output from a second serial port on the hardware. The optional debug output from the board prints out the IP source and destination address and the first few bytes of the data payload. Note that the source is the adapter IP address, (172.10.10.1 in this case) and the destination is some other address on that subnet - all packets to the subnet are sent to our mbed hardware. For example, you could also ping 172.10.10.123 or, if your PPP-Blinky is running, simply click on this link: http://172.10.10.123

/media/uploads/nixnax/ping-cap-3.gif

One Million Pings!

In the image below the ICMP ("ping") echo reply service was tested by sending one million pings to ppp-Blinky. This took over two hours.
The ping tool used on the Windows 8 PC was psping.exe from PsTools by Mark Russinovich - http://bit.ly/PingFast
The average reply time for a short ping (1 byte of payload data) was 11 milliseconds at 115200 baud on the $10 Nucleo-L053R8 board - barely enough time for 130 bytes to be sent over the port!

/media/uploads/nixnax/ppp-blinky-ping-results.jpg

Monitoring PPP-Blinky Packets

The image below is from a Microsoft Network Monitor 3.4 capture session.

Responses from PPP-Blinky are shown in blue.

Frame 2 - Internet Explorer at IP 172.10.10.1 (the Dial-Up Adapter IP) requests a TCP connection by sending an S (SYN) flag.
Frame 3 - PPP-Blinky at IP 172.10.10.2 responds with an ACK in frame 3. One direction of the link is now established.
Frame 4 - The PC acknowledges the SYN sent by PPP-Blinky in frame 3. The TCP link is now fully established.
Frame 5 - The browser "pushes" (P flag is set) an HTTP GET request to PPP-Blinky.
Frame 6 - PPP-Blinky responds with a standard HTTP response "pushes" (P flag set) back a small web page. It also sets the A (ACK) flag to acknowledge the message sent in frame 6.
Frame 7 - The PC acknowledges reception of the HTTP payload.
Frame 8 - The PC starts to shut down the TCP connection by sending a FIN flag.
Frame 9 - PPP-Blinky acknowledges the FIN request - the connection is now closed in one direction. It also sets a FIN flag in the response to request closure of the opposite direction of the connection.
Frame 10 - The PC acknowledges the FIN request. The closing of the TCP connection is now confirmed in both directions.

/media/uploads/nixnax/ms-network-monitor-http-get-1.gif

Debug Output

PPP-Blinky can output handy debug information to an optional second serial port.
The image below shows the debug output (Ident, Source, Destination, TCP Flags) for a complete HTTP conversation.
The PC messages are displayed in black. PPP-Blinky messages are blue.
Notice how PPP-blinky automatically inserts a blank line after each full HTTP conversation.

/media/uploads/nixnax/tcp-data-3.gif

Creating a Dial-Up Connection in Linux

The screen below shows the required pppd command to connect to PPP-Blinky from a Linux machine. This was much simpler than Windows! The USB serial port of the mbed LPC1768 board registered as /dev/ttyACM0 on my Linux box. Do a websearch on pppd if you want to learn more about pppd, the Linux PPP handler. Near the bottom of the screen below, two webpages are fetched (/ and /y) by using the curl command on the command line. Gnome Webkit and Firefox work fine, too. Also try echo GET / HTTP/1.1 | nc 172.10.10.2 which uses netcat, the "Swiss army knife" of networking tools. PPP-Blinky was also tested with ApacheBench, the Apache server benchmark software. After 100000 fetches, the mean page fetch rate was reported as 6 page fetches per second for a small page.

/media/uploads/nixnax/pppd-screen.png

Caveats

PPP Blinky is an extremely sparse implementation (1.5k lines) of HTTP,WebSocket,TCP, UDP, ICMP, IPCP and LCP over PPP, requiring around 8kB of RAM. The minimum functionality required to establish connectivity is implemented. These are often acceptable tradeoffs for embedded projects as well as a handy tool to learn the practical details of everyday networking implementations.

PPP-Blinky/ppp-blinky.cpp@275:bb2d582c20d6, 2020-10-18 (annotated)

Committer:: nixnax
Date:: Sun Oct 18 17:30:29 2020 +0000
Revision:: 275:bb2d582c20d6
Parent:: 274:b1bc40deb637

Formatting

Who changed what in which revision?

User	Revision	Line number	New contents of line
nixnax	182:f039ec218c9f	1	// PPP-Blinky - "The Most Basic Internet Thing"
nixnax	259:f694046fc06f	2	// A Tiny IPv4 Stack and HTTP Webserver Using Windows XP/7/8/10/Linux Dial-Up Networking Over A Serial Port.
nixnax	259:f694046fc06f	3	// Aka PPP over serial (PPPOS)
nixnax	142:54d1543e23e5	4	// Receives UDP packets and responds to ping (ICMP Echo requests)
nixnax	142:54d1543e23e5	5	// WebSocket Service - see https://en.wikipedia.org/wiki/WebSocket
nixnax	142:54d1543e23e5	6
nixnax	267:40ea40e040d2	7	// Copyright 2016/2017/2018/2019/2020 Nicolas Nackel aka Nixnax. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
nixnax	142:54d1543e23e5	8
nixnax	142:54d1543e23e5	9	// Notes and Instructions
nixnax	142:54d1543e23e5	10	// http://bit.ly/PPP-Blinky-Instructions
nixnax	142:54d1543e23e5	11	// http://bit.ly/win-rasdial-config
nixnax	142:54d1543e23e5	12
nixnax	201:9fcf92e9f427	13	// Important - ensure that you are using the latest mbed firmware for your specific mbed target board
nixnax	201:9fcf92e9f427	14
nixnax	142:54d1543e23e5	15	// Handy reading material
nixnax	142:54d1543e23e5	16	// https://technet.microsoft.com/en-us/library/cc957992.aspx
nixnax	142:54d1543e23e5	17	// https://en.wikibooks.org/wiki/Serial_Programming/IP_Over_Serial_Connections
nixnax	142:54d1543e23e5	18	// http://atari.kensclassics.org/wcomlog.htm
nixnax	249:9ff0e20325f7	19	// https://en.wikipedia.org/wiki/Favicon (see also html5 <link> tag)
nixnax	142:54d1543e23e5	20
nixnax	142:54d1543e23e5	21	// Handy tools
nixnax	142:54d1543e23e5	22	// https://ttssh2.osdn.jp/index.html.en - Tera Term, a good terminal program to monitor the debug output from the second serial port with!
nixnax	142:54d1543e23e5	23	// https://www.microsoft.com/en-us/download/details.aspx?id=4865 - Microsoft network monitor - real-time monitoring of PPP packets
nixnax	142:54d1543e23e5	24	// http://pingtester.net/ - nice tool for high rate ping testing
nixnax	142:54d1543e23e5	25	// http://www.sunshine2k.de/coding/javascript/crc/crc_js.html - Correctly calculates the 16-bit FCS (crc) on our frames (Choose CRC16_CCITT_FALSE), then custom relected-in=1, reflected-out=1
nixnax	142:54d1543e23e5	26	// https://technet.microsoft.com/en-us/sysinternals/pstools.aspx - psping for fast testing of ICMP ping function
nixnax	142:54d1543e23e5	27	// https://eternallybored.org/misc/netcat/ - use netcat -u 172.10.10.1 80 to send/receive UDP packets from PPP-Blinky
nixnax	142:54d1543e23e5	28	// Windows Powershell invoke-webrequest command - use it to stress test the webserver like this: while (1){ invoke-webrequest -uri 172.10.10.1/x }
nixnax	142:54d1543e23e5	29
nixnax	142:54d1543e23e5	30	// Connecting PPP-Blinky to Linux
nixnax	142:54d1543e23e5	31	// PPP-Blinky can be made to talk to Linux - tested on Fedora - the following command, which uses pppd, works:
nixnax	142:54d1543e23e5	32	// pppd /dev/ttyACM0 115200 debug dump local passive noccp novj nodetach nocrtscts 172.10.10.1:172.10.10.2
nixnax	142:54d1543e23e5	33	// in the above command 172.10.10.1 is the adapter IP, and 172.10.10.2 is the IP of PPP-Blinky.
nixnax	142:54d1543e23e5	34	// See also https://en.wikipedia.org/wiki/Point-to-Point_Protocol_daemon
nixnax	142:54d1543e23e5	35
nixnax	142:54d1543e23e5	36	// Special pages when PPP-Blinky is running
nixnax	142:54d1543e23e5	37	// 172.10.10.2 root page
nixnax	182:f039ec218c9f	38	// 172.10.10.2/x returns the number of ppp frames sent - this is handy for testing
nixnax	182:f039ec218c9f	39	// 172.10.10.2/xb also returns number of ppp frames sent, but issues a fast refresh meta command. This allows you to use your browser to benchmark page load speed
nixnax	142:54d1543e23e5	40	// 172.10.10.2/ws a simple WebSocket demo
nixnax	182:f039ec218c9f	41	// http://jsfiddle.net/d26cyuh2/ more complete WebSocket demo in JSFiddle, showing cross-domain access
nixnax	207:28cd834b785d	42
nixnax	142:54d1543e23e5	43	// Ok, enough talking, time to check out some code!!
nixnax	142:54d1543e23e5	44
nixnax	142:54d1543e23e5	45	#include "ppp-blinky.h"
nixnax	142:54d1543e23e5	46
nixnax	142:54d1543e23e5	47	// The #define below enables/disables a second (OPTIONAL) serial port that prints out interesting diagnostic messages.
nixnax	146:a45f49a2b29c	48	// Change to SERIAL_PORT_MONITOR_YES to enable diagnostics messages. You need to wire a second serial port to your mbed hardware to monitor the debug output.
nixnax	142:54d1543e23e5	49	// Using the second serial port will slow down packet response time
nixnax	142:54d1543e23e5	50	// Note - the LPC11U24 does NOT have a second serial port
nixnax	146:a45f49a2b29c	51
nixnax	183:6d3ba874b267	52	#define SERIAL_PORT_MONITOR_NO /* change to SERIAL_PORT_MONITOR_YES for debug messages */
nixnax	142:54d1543e23e5	53
nixnax	142:54d1543e23e5	54	// here we define the OPTIONAL, second debug serial port for various mbed target boards
nixnax	142:54d1543e23e5	55	#ifdef SERIAL_PORT_MONITOR_YES
nixnax	142:54d1543e23e5	56	#if defined(TARGET_LPC1768)
nixnax	179:ba2b2ddd0da5	57	RawSerial xx(p9, p10); // Second serial port on LPC1768 - not required to run, if you get compile error here, change #define SERIAL_PORT_MONITOR_YES to #define SERIAL_PORT_MONITOR_NO
nixnax	142:54d1543e23e5	58	#elif defined(TARGET_NUCLEO_F446RE) \|\| defined(TARGET_NUCLEO_L152RE) \|\| defined(TARGET_NUCLEO_L053R8) \|\| defined(TARGET_NUCLEO_L476RG) \|\| defined(TARGET_NUCLEO_F401RE)
nixnax	179:ba2b2ddd0da5	59	RawSerial xx(PC_10, PC_11); // Second serial port on NUCLEO boards - not required to run, if you get compile error here, change #define SERIAL_PORT_MONITOR_YES to #define SERIAL_PORT_MONITOR_NO
nixnax	196:8791e241be80	60	#elif defined(TARGET_NUCLEO_L432KC)
nixnax	196:8791e241be80	61	RawSerial xx(PA_9, PA_10); // Second serial port on NUCLEO-L432KC - not required to run, if you get compile error here, change #define SERIAL_PORT_MONITOR_YES to #define SERIAL_PORT_MONITOR_NO
nixnax	142:54d1543e23e5	62	#elif defined(TARGET_LPC11U24)
nixnax	142:54d1543e23e5	63	#error The LPC11U24 does not have a second serial port to use for debugging - change SERIAL_PORT_MONITOR_YES back to SERIAL_PORT_MONITOR_NO
nixnax	142:54d1543e23e5	64	#elif defined (TARGET_KL46Z) \|\| (TARGET_KL25Z)
nixnax	179:ba2b2ddd0da5	65	RawSerial xx(PTE0,PTE1); // Second serial port on FRDM-KL46Z board
nixnax	193:48072570f41d	66	#elif defined(TARGET_KW41Z)
nixnax	194:5b23ebfb3626	67	RawSerial xx(PTC3, PTC2); // Second serial port on FRDM-KW41Z board
nixnax	142:54d1543e23e5	68	#elif defined(YOUR_TARGET_BOARD_NAME_HERE)
nixnax	142:54d1543e23e5	69	// change the next line to YOUR target board's second serial port pin definition if it's not present - and if it works, please send it to me - thanks!!!
nixnax	226:4898247048c7	70	RawSerial xx(p9, p10); // change this to YOUR board's second serial port pin definition - and please send it to me if it works!!!
nixnax	142:54d1543e23e5	71	#else
nixnax	142:54d1543e23e5	72	#error Add your target board's second serial port here if you want to use debugging - or simply change SERIAL_PORT_MONITOR_YES to SERIAL_PORT_MONITOR_NO
nixnax	142:54d1543e23e5	73	#endif
nixnax	179:ba2b2ddd0da5	74	#define debugPrintf(x...) xx.printf (x) /* if we have a serial port we can print debug messages */
nixnax	142:54d1543e23e5	75	#define debugPutc(x...) xx.putc(x)
nixnax	221:1d7c32d8256b	76	#define debugPuts(x...) xx.puts(x)
nixnax	142:54d1543e23e5	77	#define debugBaudRate(x...) xx.baud(x)
nixnax	142:54d1543e23e5	78	#else
nixnax	142:54d1543e23e5	79	// if we don't have a debug port the debug print functions do nothing
nixnax	142:54d1543e23e5	80	#define debugPrintf(x...) {}
nixnax	142:54d1543e23e5	81	#define debugPutc(x...) {}
nixnax	221:1d7c32d8256b	82	#define debugPuts(x...) {}
nixnax	142:54d1543e23e5	83	#define debugBaudRate(x...) {}
nixnax	142:54d1543e23e5	84	#endif
nixnax	142:54d1543e23e5	85
nixnax	142:54d1543e23e5	86	// verbosity flags used in debug printouts - change to 1 to see increasingly more detailed debug info.
nixnax	182:f039ec218c9f	87	#define v0 1
nixnax	142:54d1543e23e5	88	#define v1 0
nixnax	142:54d1543e23e5	89	#define v2 0
nixnax	182:f039ec218c9f	90	#define IP_HEADER_DUMP_YES /* YES for ip header dump */
nixnax	182:f039ec218c9f	91	#define TCP_HEADER_DUMP_YES /* YES for tcp header dump */
nixnax	226:4898247048c7	92	#define DUMP_RECEIVED_PPP_FRAMES_NO /* YES to dump received PPP frames */
nixnax	142:54d1543e23e5	93
nixnax	226:4898247048c7	94	// below is the webpage we serve when we get an HTTP request to root (/)
nixnax	226:4898247048c7	95	// keep size under ~1400 bytes to fit into a single PPP packet
nixnax	249:9ff0e20325f7	96	// the <link rel="icon" ...> tag stops browsers from asking for file favicon.ico
nixnax	142:54d1543e23e5	97
nixnax	142:54d1543e23e5	98	const static char rootWebPage[] = "\
nixnax	142:54d1543e23e5	99	<!DOCTYPE html>\
nixnax	142:54d1543e23e5	100	<html>\
nixnax	248:5aca1c98fc24	101	<!--Comment-->\
nixnax	142:54d1543e23e5	102	<head>\
nixnax	146:a45f49a2b29c	103	<title>mbed PPP-Blinky</title>\r\n\
nixnax	248:5aca1c98fc24	104	<link rel=\"icon\" href=\"data:image/gif;base64,R0lGODlhAQABAIABAP8AAAAAACwAAAAAAQABAAACAkQBADs=\">\
nixnax	226:4898247048c7	105	<style>\
nixnax	241:dece92cb7296	106	body {font-family:sans-serif; font-size:140%; text-align:center; color:#807070;}\
nixnax	248:5aca1c98fc24	107	</style>\r\n\
nixnax	142:54d1543e23e5	108	</head>\
nixnax	226:4898247048c7	109	<body>\
nixnax	142:54d1543e23e5	110	<h1>mbed PPP-Blinky Up and Running</h1>\
nixnax	142:54d1543e23e5	111	<h1><a href=\"http://bit.ly/pppBlink2\">Source on mbed</a></h1>\
nixnax	210:a2a651249a9a	112	<h1><a href=\"/w\">WebSocket Test</a></h1>\
nixnax	245:544cea761769	113	<h1><a href=\"/x?Parameter1=Example\">Benchmark 1</a></h1>\
nixnax	142:54d1543e23e5	114	<h1><a href=\"/xb\">Benchmark 2</a></h1>\
nixnax	257:1990a41a1e31	115	<h1><a href=\"http://bit.ly/websocket-demo-jsfiddle\">JSFiddle Demo</a></h1>\
nixnax	270:98099fbc46fb	116	<h1><a href=\"/xt\">Toggle LED</a></h1>\
nixnax	252:b3c8c5699153	117	<h1>TCP, LCP & Ping Count: 0000000000</h1>\
nixnax	254:7345c9a6f4c2	118	<h1>System Core Clock: 0000000000</h1>\
nixnax	241:dece92cb7296	119	</body>\
nixnax	271:06c2c2a4e0bf	120	</html>\r\n"; // size = 718 bytes + 1 null byte = 719 bytes
nixnax	142:54d1543e23e5	121
nixnax	167:ff8a2d8beeb1	122	// this is a websocket demo html page we serve when GET /ws is requested
nixnax	226:4898247048c7	123	// it contains some javascript to handle the websocket activities
nixnax	249:9ff0e20325f7	124	// the <link rel="icon" ...> tag stops browsers from asking for file favicon.ico
nixnax	142:54d1543e23e5	125	const static char webSocketPage[] = "\
nixnax	142:54d1543e23e5	126	<!DOCTYPE html>\
nixnax	142:54d1543e23e5	127	<html>\
nixnax	142:54d1543e23e5	128	<head>\
nixnax	226:4898247048c7	129	<title>mbed PPP-Blinky WebSocket</title>\
nixnax	248:5aca1c98fc24	130	<link rel=\"icon\" href=\"data:image/gif;base64,R0lGODlhAQABAIABAP8AAAAAACwAAAAAAQABAAACAkQBADs=\">\
nixnax	142:54d1543e23e5	131	<script>\
nixnax	142:54d1543e23e5	132	window.onload=function(){\
nixnax	142:54d1543e23e5	133	var url=\"ws://172.10.10.2\";\
nixnax	142:54d1543e23e5	134	var sts=document.getElementById(\"sts\");\
nixnax	142:54d1543e23e5	135	var btn=document.getElementById(\"btn\");\
nixnax	142:54d1543e23e5	136	var ctr=0;\
nixnax	142:54d1543e23e5	137	function show(text){sts.textContent=text;}\
nixnax	142:54d1543e23e5	138	btn.onclick=function(){\
nixnax	142:54d1543e23e5	139	if(btn.textContent==\"Connect\"){\
nixnax	142:54d1543e23e5	140	x=new WebSocket(url);\
nixnax	142:54d1543e23e5	141	x.onopen=function(){\
nixnax	226:4898247048c7	142	show(\"Connected to PPP-Blinky WebSocket service at: \"+url);\
nixnax	142:54d1543e23e5	143	btn.textContent=\"Send \\\"\"+ctr+\"\\\"\";\
nixnax	142:54d1543e23e5	144	};\
nixnax	226:4898247048c7	145	x.onclose=function(){show(\"WebSocket closed\");};\
nixnax	226:4898247048c7	146	x.onmessage=function(msg){show(\"PPP-Blinky WebSocket service responded with: \\\"\"+msg.data+\"\\\"\");};\
nixnax	142:54d1543e23e5	147	} else {\
nixnax	142:54d1543e23e5	148	x.send(ctr);\
nixnax	142:54d1543e23e5	149	ctr=ctr+1;\
nixnax	142:54d1543e23e5	150	btn.textContent=\"Send \\\"\"+ctr+\"\\\"\";\
nixnax	142:54d1543e23e5	151	}\
nixnax	142:54d1543e23e5	152	};\
nixnax	142:54d1543e23e5	153	};\
nixnax	142:54d1543e23e5	154	</script>\
nixnax	226:4898247048c7	155	<style>\
nixnax	241:dece92cb7296	156	body {font-family:sans-serif; font-size:140%; text-align:center; color:#807070;}\
nixnax	241:dece92cb7296	157	button {font-size:140%; background-color:#7eeeee; border-radius:15px; border:none; margin-top:20px; }\
nixnax	226:4898247048c7	158	</style>\
nixnax	226:4898247048c7	159	<body>\
nixnax	226:4898247048c7	160	<h1>mbed PPP-Blinky WebSocket Test</h1>\
nixnax	226:4898247048c7	161	<h1><div id=\"sts\">Idle</div><h1>\
nixnax	226:4898247048c7	162	<button id=\"btn\">Connect</button>\
nixnax	142:54d1543e23e5	163	</body>\
nixnax	226:4898247048c7	164	</html>"; // size = 1037 bytes + 1 null byte = 1038 bytes
nixnax	142:54d1543e23e5	165
nixnax	142:54d1543e23e5	166	// The serial port on your mbed hardware. Your PC should be configured to view this port as a standard dial-up networking modem.
nixnax	142:54d1543e23e5	167	// On Windows the model type of the modem should be selected as "Communications cable between two computers"
nixnax	142:54d1543e23e5	168	// The modem baud rate should be set to 115200 baud
nixnax	142:54d1543e23e5	169	// See instructions at the top.
nixnax	142:54d1543e23e5	170	// On a typical mbed hardware platform this serial port is a USB virtual com port (VCP) and the USB serial driver is supplied by the board vendor.
nixnax	264:71c191a24d30	171	// Stream does not allow putc/getc in an interrupt routine, making serial interrupts useless. RawSerial allows use of putc/getc in interrupt.
nixnax	179:ba2b2ddd0da5	172	RawSerial pc (USBTX, USBRX); // usb virtual com port for mbed hardware
nixnax	142:54d1543e23e5	173
nixnax	142:54d1543e23e5	174	DigitalOut led1(LED1); // this led toggles when a packet is received
nixnax	142:54d1543e23e5	175
nixnax	142:54d1543e23e5	176	pppType ppp; // our global - definitely not thread safe
nixnax	142:54d1543e23e5	177
nixnax	142:54d1543e23e5	178	/// Initialize the ppp structure and clear the receive buffer
nixnax	142:54d1543e23e5	179	void pppInitStruct()
nixnax	142:54d1543e23e5	180	{
nixnax	223:917b554cb8a5	181	memset( (void *)ppp.rx.buf, 0, RXBUFLEN+1); // one extra byte at the end which always remains zero so strstr() cannot exceed the buffer
nixnax	142:54d1543e23e5	182	ppp.online=0;
nixnax	142:54d1543e23e5	183	ppp.rx.tail=0;
nixnax	142:54d1543e23e5	184	ppp.rx.rtail=0;
nixnax	142:54d1543e23e5	185	ppp.rx.head=0;
nixnax	142:54d1543e23e5	186	ppp.rx.buflevel=0;
nixnax	209:aa514cd631ee	187	ppp.rx.maxbuflevel=0;
nixnax	221:1d7c32d8256b	188	ppp.rx.bufferfull=0;
nixnax	142:54d1543e23e5	189	ppp.pkt.len=0;
nixnax	269:ad9e99728fdf	190	ppp.ipData.ident=11111; // easy to recognize in ip packet dumps
nixnax	142:54d1543e23e5	191	ppp.ledState=0;
nixnax	142:54d1543e23e5	192	ppp.hdlc.frameStartIndex=0;
nixnax	146:a45f49a2b29c	193	ppp.responseCounter=0;
nixnax	262:c044fed611aa	194	ppp.pppCount=0; // number of ICMP pings we have received
nixnax	142:54d1543e23e5	195	ppp.firstFrame=1;
nixnax	175:b4e6f8a6fe00	196	ppp.ppp = (pppHeaderType *)ppp.pkt.buf; // pointer to ppp header
nixnax	175:b4e6f8a6fe00	197	ppp.ip = (ipHeaderType *)(ppp.pkt.buf+4); // pointer to IP header
nixnax	142:54d1543e23e5	198	}
nixnax	142:54d1543e23e5	199
nixnax	275:bb2d582c20d6	200	/// Toggle the LED
nixnax	142:54d1543e23e5	201	void led1Toggle()
nixnax	142:54d1543e23e5	202	{
nixnax	263:83a6d767c349	203	led1 = (ppp.ledState >> 0) & 1; // use first bit, in other words toggle LED only every packet
nixnax	143:c5019f856a56	204	ppp.ledState++;
nixnax	142:54d1543e23e5	205	}
nixnax	142:54d1543e23e5	206
nixnax	179:ba2b2ddd0da5	207	/// Returns 1 after a connect message, 0 at startup or after a disconnect message
nixnax	150:3366bf3d294e	208	int connectedPpp()
nixnax	142:54d1543e23e5	209	{
nixnax	142:54d1543e23e5	210	return ppp.online;
nixnax	143:c5019f856a56	211	}
nixnax	142:54d1543e23e5	212
nixnax	179:ba2b2ddd0da5	213	/// PPP serial port receive interrupt handler.
nixnax	143:c5019f856a56	214	/// Check for available characters from the PC and read them into our own circular serial receive buffer at ppp.rx.buf.
nixnax	143:c5019f856a56	215	/// Also, if we are offline and a 0x7e frame start character is seen, we go online immediately
nixnax	179:ba2b2ddd0da5	216	void pppReceiveHandler()
nixnax	142:54d1543e23e5	217	{
nixnax	142:54d1543e23e5	218	char ch;
nixnax	179:ba2b2ddd0da5	219	while ( pc.readable() ) {
nixnax	223:917b554cb8a5	220	int localHead = (ppp.rx.head+1); // local head index
nixnax	223:917b554cb8a5	221	if (localHead > RXBUFLEN) localHead=0; // increment and wrap head index
nixnax	223:917b554cb8a5	222	if ( localHead == ppp.rx.rtail ) {
nixnax	221:1d7c32d8256b	223	ppp.rx.bufferfull = 1; // set flag if rx buffer is full
nixnax	252:b3c8c5699153	224	#define BUFFER_FULL_TRAP_YES
nixnax	258:1eb9abd66922	225	#ifdef BUFFER_FULL_TRAP_YES
nixnax	243:24f899297799	226	while(1) {
nixnax	270:98099fbc46fb	227	//led1Toggle(); // flash LED at a slow rate to indicate buffer overfloe
nixnax	258:1eb9abd66922	228	wait_ms(150);
nixnax	243:24f899297799	229	}
nixnax	258:1eb9abd66922	230	#else
nixnax	221:1d7c32d8256b	231	return; // don't read if rx buffer is full
nixnax	258:1eb9abd66922	232	#endif
nixnax	142:54d1543e23e5	233	}
nixnax	142:54d1543e23e5	234	ch = pc.getc(); // read new character
nixnax	142:54d1543e23e5	235	ppp.rx.buf[ppp.rx.head] = ch; // insert in our receive buffer
nixnax	209:aa514cd631ee	236	if (ch == 0x7E) { // check for ppp frame start character
nixnax	258:1eb9abd66922	237	ppp.online = 1; // if we see a frame sync character we immediately change status to online
nixnax	142:54d1543e23e5	238	}
nixnax	223:917b554cb8a5	239	ppp.rx.head = localHead; // update real head pointer
nixnax	221:1d7c32d8256b	240	ppp.rx.buflevel++; // update buffer level counter
nixnax	209:aa514cd631ee	241	if ( ppp.rx.buflevel > ppp.rx.maxbuflevel ) {
nixnax	221:1d7c32d8256b	242	ppp.rx.maxbuflevel = ppp.rx.buflevel; // remember the maximum usage of rx buffer
nixnax	209:aa514cd631ee	243	}
nixnax	142:54d1543e23e5	244	}
nixnax	142:54d1543e23e5	245	}
nixnax	142:54d1543e23e5	246
nixnax	145:098b6ed2f7f2	247	/// update the cumulative PPP FCS (frame check sequence)
nixnax	226:4898247048c7	248	void fcsDo(register int x)
nixnax	142:54d1543e23e5	249	{
nixnax	230:ee097c486e45	250	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	251	x>>=1;
nixnax	230:ee097c486e45	252	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	253	x>>=1;
nixnax	230:ee097c486e45	254	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	255	x>>=1;
nixnax	230:ee097c486e45	256	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	257	x>>=1;
nixnax	230:ee097c486e45	258	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	259	x>>=1;
nixnax	230:ee097c486e45	260	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	261	x>>=1;
nixnax	230:ee097c486e45	262	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	220:54f45f924707	263	x>>=1;
nixnax	230:ee097c486e45	264	ppp.fcs=((ppp.fcs^x)&1) ? (ppp.fcs>>1)^0x8408 : ppp.fcs>>1;
nixnax	142:54d1543e23e5	265	}
nixnax	142:54d1543e23e5	266
nixnax	145:098b6ed2f7f2	267	/// calculate the PPP FCS (frame check sequence) on an entire block of memory
nixnax	145:098b6ed2f7f2	268	int fcsBuf(char * buf, int size) // crc on an entire block of memory
nixnax	142:54d1543e23e5	269	{
nixnax	226:4898247048c7	270	ppp.fcs=0xffff; // fcs initial value
nixnax	145:098b6ed2f7f2	271	for(int i=0; i<size; i++)fcsDo(*buf++);
nixnax	145:098b6ed2f7f2	272	return ppp.fcs;
nixnax	142:54d1543e23e5	273	}
nixnax	142:54d1543e23e5	274
nixnax	142:54d1543e23e5	275	/// Get one character from our received PPP buffer
nixnax	142:54d1543e23e5	276	int pc_getBuf()
nixnax	142:54d1543e23e5	277	{
nixnax	142:54d1543e23e5	278	int x = ppp.rx.buf[ ppp.rx.tail ];
nixnax	230:ee097c486e45	279	int temptail = ppp.rx.tail+1;
nixnax	230:ee097c486e45	280	if (temptail > RXBUFLEN) temptail=0;
nixnax	142:54d1543e23e5	281	ppp.rx.buflevel--;
nixnax	230:ee097c486e45	282	ppp.rx.tail = temptail;
nixnax	142:54d1543e23e5	283	return x;
nixnax	142:54d1543e23e5	284	}
nixnax	142:54d1543e23e5	285
nixnax	142:54d1543e23e5	286	/// Dump a PPP frame to the debug serial port
nixnax	142:54d1543e23e5	287	/// Note - the hex output of dumpPPPFrame() can be imported into WireShark
nixnax	142:54d1543e23e5	288	/// Capture the frame's hex output in your terminal program and save as a text file
nixnax	164:c3de3d212c4b	289	/// In WireShark, use "Import Hex File". Import options are: Offset=None, Protocol=PPP.
nixnax	142:54d1543e23e5	290	void dumpPPPFrame()
nixnax	142:54d1543e23e5	291	{
nixnax	230:ee097c486e45	292	char pbuf[100];
nixnax	142:54d1543e23e5	293	for(int i=0; i<ppp.pkt.len; i++) {
nixnax	210:a2a651249a9a	294
nixnax	142:54d1543e23e5	295	sprintf(pbuf, "%02x ", ppp.pkt.buf[i]);
nixnax	210:a2a651249a9a	296
nixnax	221:1d7c32d8256b	297	debugPuts(pbuf);
nixnax	142:54d1543e23e5	298	}
nixnax	210:a2a651249a9a	299
nixnax	142:54d1543e23e5	300	sprintf(pbuf, " CRC=%04x Len=%d\n", ppp.pkt.crc, ppp.pkt.len);
nixnax	210:a2a651249a9a	301
nixnax	221:1d7c32d8256b	302	debugPuts(pbuf);
nixnax	142:54d1543e23e5	303	}
nixnax	142:54d1543e23e5	304
nixnax	142:54d1543e23e5	305	/// Process a received PPP frame
nixnax	142:54d1543e23e5	306	void processPPPFrame(int start, int end)
nixnax	142:54d1543e23e5	307	{
nixnax	262:c044fed611aa	308	if(start==end) return; // ignore empty frames
nixnax	268:a81648a9c7bf	309	// led1Toggle(); // change led1 state on received frames
nixnax	262:c044fed611aa	310	ppp.pppCount++; // count any non-empty frame
nixnax	226:4898247048c7	311	ppp.fcs=0xffff; // fcs initial value
nixnax	142:54d1543e23e5	312	char * dest = ppp.pkt.buf;
nixnax	142:54d1543e23e5	313	ppp.pkt.len=0;
nixnax	142:54d1543e23e5	314	int unstuff=0;
nixnax	142:54d1543e23e5	315	int idx = start;
nixnax	258:1eb9abd66922	316	char bufchar;
nixnax	142:54d1543e23e5	317	while(1) {
nixnax	258:1eb9abd66922	318	bufchar = ppp.rx.buf[idx];
nixnax	142:54d1543e23e5	319	if (unstuff==0) {
nixnax	258:1eb9abd66922	320	if (bufchar==0x7d) unstuff=1;
nixnax	142:54d1543e23e5	321	else {
nixnax	258:1eb9abd66922	322	*dest = bufchar;
nixnax	258:1eb9abd66922	323	fcsDo(*dest);
nixnax	258:1eb9abd66922	324	dest++;
nixnax	142:54d1543e23e5	325	ppp.pkt.len++;
nixnax	142:54d1543e23e5	326	}
nixnax	142:54d1543e23e5	327	} else { // unstuff characters prefixed with 0x7d
nixnax	258:1eb9abd66922	328	*dest = bufchar^0x20;
nixnax	258:1eb9abd66922	329	fcsDo(*dest);
nixnax	258:1eb9abd66922	330	dest++;
nixnax	142:54d1543e23e5	331	ppp.pkt.len++;
nixnax	142:54d1543e23e5	332	unstuff=0;
nixnax	142:54d1543e23e5	333	}
nixnax	216:e3c5a5b47295	334	idx = idx+1;
nixnax	216:e3c5a5b47295	335	if (idx > RXBUFLEN) idx=0;
nixnax	142:54d1543e23e5	336	if (idx == end) break;
nixnax	142:54d1543e23e5	337	}
nixnax	145:098b6ed2f7f2	338	ppp.pkt.crc = ppp.fcs & 0xffff;
nixnax	226:4898247048c7	339	#ifdef DUMP_RECEIVED_PPP_FRAMES_YES
nixnax	226:4898247048c7	340	dumpPPPFrame(); // hex dump ALL ppp frames to the debug port
nixnax	226:4898247048c7	341	#endif
nixnax	142:54d1543e23e5	342	if (ppp.pkt.crc == 0xf0b8) { // check for good CRC
nixnax	142:54d1543e23e5	343	determinePacketType();
nixnax	142:54d1543e23e5	344	} else {
nixnax	142:54d1543e23e5	345	#define REPORT_FCS_ERROR_YES
nixnax	142:54d1543e23e5	346	#ifdef REPORT_FCS_ERROR_YES
nixnax	230:ee097c486e45	347	char pbuf[100]; // local print buffer
nixnax	142:54d1543e23e5	348	sprintf(pbuf, "\nPPP FCS(crc) Error CRC=%x Length = %d\n",ppp.pkt.crc,ppp.pkt.len); // print a debug line
nixnax	221:1d7c32d8256b	349	debugPuts( pbuf );
nixnax	226:4898247048c7	350	#define DUMP_PPP_FRAME_ON_ERROR_NO
nixnax	226:4898247048c7	351	#ifdef DUMP_PPP_FRAME_ON_ERROR_YES
nixnax	226:4898247048c7	352	dumpPPPFrame(); // dump frames with errors in them
nixnax	226:4898247048c7	353	#endif
nixnax	142:54d1543e23e5	354	#endif
nixnax	142:54d1543e23e5	355	}
nixnax	142:54d1543e23e5	356	}
nixnax	142:54d1543e23e5	357
nixnax	142:54d1543e23e5	358	/// do PPP HDLC-like handling of special (flag) characters
nixnax	143:c5019f856a56	359	void hdlcPut(int ch)
nixnax	142:54d1543e23e5	360	{
nixnax	258:1eb9abd66922	361	if ( (ch<0x20) \|\| (ch==0x7d) \|\| (ch==0x7e) /* \|\| (ch>0x7f) */ ) {
nixnax	226:4898247048c7	362	pc.putc(0x7d);
nixnax	226:4898247048c7	363	pc.putc(ch^0x20); // these characters need special handling
nixnax	142:54d1543e23e5	364	} else {
nixnax	226:4898247048c7	365	pc.putc(ch);
nixnax	142:54d1543e23e5	366	}
nixnax	142:54d1543e23e5	367	}
nixnax	142:54d1543e23e5	368
nixnax	142:54d1543e23e5	369	/// send a PPP frame in HDLC format
nixnax	144:01d98cf7738e	370	void sendPppFrame()
nixnax	143:c5019f856a56	371	{
nixnax	172:449dd7a28955	372	ppp.responseCounter++; // count the number of ppp frames we send
nixnax	145:098b6ed2f7f2	373	int crc = fcsBuf(ppp.pkt.buf, ppp.pkt.len-2); // update crc
nixnax	142:54d1543e23e5	374	ppp.pkt.buf[ ppp.pkt.len-2 ] = (~crc>>0); // fcs lo (crc)
nixnax	142:54d1543e23e5	375	ppp.pkt.buf[ ppp.pkt.len-1 ] = (~crc>>8); // fcs hi (crc)
nixnax	226:4898247048c7	376	pc.putc(0x7e); // hdlc start-of-frame "flag"
nixnax	142:54d1543e23e5	377	for(int i=0; i<ppp.pkt.len; i++) {
nixnax	226:4898247048c7	378	// wait_us(86); // wait one character time
nixnax	210:a2a651249a9a	379
nixnax	142:54d1543e23e5	380	hdlcPut( ppp.pkt.buf[i] ); // send a character
nixnax	142:54d1543e23e5	381	}
nixnax	226:4898247048c7	382	pc.putc(0x7e); // hdlc end-of-frame "flag"
nixnax	142:54d1543e23e5	383	}
nixnax	142:54d1543e23e5	384
nixnax	143:c5019f856a56	385	/// convert a network ip address in the buffer to an integer (IP adresses are big-endian, i.e most significant byte first)
nixnax	143:c5019f856a56	386	int bufferToIP(char * buffer)
nixnax	143:c5019f856a56	387	{
nixnax	143:c5019f856a56	388	int result=0;
nixnax	143:c5019f856a56	389	for(int i=0; i<4; i++) result = (result<<8)\|(*buffer++ & 0xff);
nixnax	143:c5019f856a56	390	return result;
nixnax	143:c5019f856a56	391	}
nixnax	143:c5019f856a56	392
nixnax	177:dab9e685af53	393	/// convert 4-byte ip address to 32-bit
nixnax	228:7fb878500862	394	unsigned int integersToIp( int a, int b, int c, int d)
nixnax	179:ba2b2ddd0da5	395	{
nixnax	177:dab9e685af53	396	return a<<24 \| b<<16 \| c<<8 \| d;
nixnax	177:dab9e685af53	397	}
nixnax	177:dab9e685af53	398
nixnax	142:54d1543e23e5	399	/// handle IPCP configuration requests
nixnax	142:54d1543e23e5	400	void ipcpConfigRequestHandler()
nixnax	142:54d1543e23e5	401	{
nixnax	230:ee097c486e45	402	debugPuts("Their IPCP Config Req, Our Ack\n");
nixnax	173:6774a0c851c4	403	if(ppp.ipcp->request[0]==3) {
nixnax	143:c5019f856a56	404	ppp.hostIP = bufferToIP(ppp.pkt.buf+10);
nixnax	173:6774a0c851c4	405	debugPrintf("Host IP = %d.%d.%d.%d (%08x)\n", ppp.ipcp->request[2],ppp.ipcp->request[3],ppp.ipcp->request[4],ppp.ipcp->request[5],ppp.hostIP);
nixnax	143:c5019f856a56	406	}
nixnax	143:c5019f856a56	407
nixnax	167:ff8a2d8beeb1	408	ppp.ipcp->code=2; // change code to ack
nixnax	144:01d98cf7738e	409	sendPppFrame(); // acknowledge everything they ask for - assume it's IP addresses
nixnax	142:54d1543e23e5	410
nixnax	230:ee097c486e45	411	debugPuts("Our IPCP Ask (no options)\n");
nixnax	167:ff8a2d8beeb1	412	ppp.ipcp->code=1; // change code to request
nixnax	167:ff8a2d8beeb1	413	ppp.ipcp->lengthR = __REV16( 4 ); // 4 is minimum length - no options in this request
nixnax	167:ff8a2d8beeb1	414	ppp.pkt.len=4+4+2; // no options in this request shortest ipcp packet possible (4 ppp + 4 ipcp + 2 crc)
nixnax	144:01d98cf7738e	415	sendPppFrame(); // send our request
nixnax	142:54d1543e23e5	416	}
nixnax	142:54d1543e23e5	417
nixnax	142:54d1543e23e5	418	/// handle IPCP acknowledge (do nothing)
nixnax	142:54d1543e23e5	419	void ipcpAckHandler()
nixnax	142:54d1543e23e5	420	{
nixnax	230:ee097c486e45	421	debugPuts("Their IPCP Grant\n");
nixnax	142:54d1543e23e5	422	}
nixnax	142:54d1543e23e5	423
nixnax	143:c5019f856a56	424	/// Handle IPCP NACK by sending our suggested IP address if there is an IP involved.
nixnax	143:c5019f856a56	425	/// This is how Linux responds to an IPCP request with no options - Windows assumes any IP address on the submnet is OK.
nixnax	142:54d1543e23e5	426	void ipcpNackHandler()
nixnax	142:54d1543e23e5	427	{
nixnax	230:ee097c486e45	428	debugPuts("Their IPCP Nack\n");
nixnax	173:6774a0c851c4	429	if (ppp.ipcp->request[0]==3) { // check if the NACK contains an IP address parameter
nixnax	167:ff8a2d8beeb1	430	ppp.ipcp->code=1; // assume the NACK contains our "suggested" IP address
nixnax	144:01d98cf7738e	431	sendPppFrame(); // let's request this IP address as ours
nixnax	230:ee097c486e45	432	debugPuts("Our IPCP ACK (received an IP)\n");
nixnax	146:a45f49a2b29c	433	} else { // if it's not an IP nack we ignore it
nixnax	230:ee097c486e45	434	debugPuts("IPCP Nack Ignored\n");
nixnax	146:a45f49a2b29c	435	}
nixnax	142:54d1543e23e5	436	}
nixnax	142:54d1543e23e5	437
nixnax	142:54d1543e23e5	438	/// handle all other IPCP requests (by ignoring them)
nixnax	142:54d1543e23e5	439	void ipcpDefaultHandler()
nixnax	142:54d1543e23e5	440	{
nixnax	230:ee097c486e45	441	debugPuts("Their IPCP Other\n");
nixnax	142:54d1543e23e5	442	}
nixnax	142:54d1543e23e5	443
nixnax	142:54d1543e23e5	444	/// process an incoming IPCP packet
nixnax	142:54d1543e23e5	445	void IPCPframe()
nixnax	142:54d1543e23e5	446	{
nixnax	167:ff8a2d8beeb1	447	int action = ppp.ipcp->code; // packet type is here
nixnax	167:ff8a2d8beeb1	448	switch (action) {
nixnax	142:54d1543e23e5	449	case 1:
nixnax	142:54d1543e23e5	450	ipcpConfigRequestHandler();
nixnax	142:54d1543e23e5	451	break;
nixnax	142:54d1543e23e5	452	case 2:
nixnax	142:54d1543e23e5	453	ipcpAckHandler();
nixnax	142:54d1543e23e5	454	break;
nixnax	142:54d1543e23e5	455	case 3:
nixnax	142:54d1543e23e5	456	ipcpNackHandler();
nixnax	142:54d1543e23e5	457	break;
nixnax	142:54d1543e23e5	458	default:
nixnax	142:54d1543e23e5	459	ipcpDefaultHandler();
nixnax	142:54d1543e23e5	460	}
nixnax	142:54d1543e23e5	461	}
nixnax	142:54d1543e23e5	462
nixnax	142:54d1543e23e5	463	/// perform a 16-bit checksum. if the byte count is odd, stuff in an extra zero byte.
nixnax	161:d59f778bc8ab	464	unsigned int dataCheckSum(char * ptr, int len, int restart)
nixnax	142:54d1543e23e5	465	{
nixnax	159:4d1bf96a59cd	466	unsigned int i,hi,lo;
nixnax	142:54d1543e23e5	467	unsigned char placeHolder;
nixnax	161:d59f778bc8ab	468	if (restart) ppp.sum=0;
nixnax	142:54d1543e23e5	469	if (len&1) {
nixnax	142:54d1543e23e5	470	placeHolder = ptr[len];
nixnax	142:54d1543e23e5	471	ptr[len]=0; // if the byte count is odd, insert one extra zero byte is after the last real byte because we sum byte PAIRS
nixnax	142:54d1543e23e5	472	}
nixnax	142:54d1543e23e5	473	i=0;
nixnax	142:54d1543e23e5	474	while ( i<len ) {
nixnax	210:a2a651249a9a	475
nixnax	142:54d1543e23e5	476	hi = ptr[i++];
nixnax	142:54d1543e23e5	477	lo = ptr[i++];
nixnax	159:4d1bf96a59cd	478	ppp.sum = ppp.sum + ((hi<<8)\|lo);
nixnax	142:54d1543e23e5	479	}
nixnax	142:54d1543e23e5	480	if (len&1) {
nixnax	142:54d1543e23e5	481	ptr[len] = placeHolder; // restore the extra byte we made zero
nixnax	142:54d1543e23e5	482	}
nixnax	159:4d1bf96a59cd	483	ppp.sum = (ppp.sum & 0xffff) + (ppp.sum>>16);
nixnax	159:4d1bf96a59cd	484	ppp.sum = (ppp.sum & 0xffff) + (ppp.sum>>16); // sum one more time to catch any carry from the carry
nixnax	159:4d1bf96a59cd	485	return ~ppp.sum;
nixnax	142:54d1543e23e5	486	}
nixnax	142:54d1543e23e5	487
nixnax	142:54d1543e23e5	488	/// perform the checksum on an IP header
nixnax	146:a45f49a2b29c	489	void IpHeaderCheckSum()
nixnax	142:54d1543e23e5	490	{
nixnax	161:d59f778bc8ab	491	ppp.ip->checksumR=0; // zero the checsum in the IP header
nixnax	161:d59f778bc8ab	492	int len = 4 * ppp.ip->headerLength; // length of IP header in bytes
nixnax	161:d59f778bc8ab	493	unsigned int sum = dataCheckSum(ppp.ipStart,len,1);
nixnax	161:d59f778bc8ab	494	ppp.ip->checksumR = __REV16( sum ); // insert fresh checksum
nixnax	146:a45f49a2b29c	495	}
nixnax	146:a45f49a2b29c	496
nixnax	147:0f40005cbc5f	497	/// swap the IP source and destination addresses
nixnax	147:0f40005cbc5f	498	void swapIpAddresses()
nixnax	147:0f40005cbc5f	499	{
nixnax	162:594729c0e5c1	500	unsigned int tempHold;
nixnax	162:594729c0e5c1	501	tempHold = ppp.ip->srcAdrR; // tempHold <- source IP
nixnax	162:594729c0e5c1	502	ppp.ip->srcAdrR = ppp.ip->dstAdrR; // source <- dest
nixnax	162:594729c0e5c1	503	ppp.ip->dstAdrR = tempHold; // dest <- tempHold*/
nixnax	147:0f40005cbc5f	504	}
nixnax	147:0f40005cbc5f	505
nixnax	149:969d98f6fb88	506	/// swap the IP source and destination ports
nixnax	149:969d98f6fb88	507	void swapIpPorts()
nixnax	149:969d98f6fb88	508	{
nixnax	173:6774a0c851c4	509	int headerSizeIP = 4 * (ppp.ip->headerLength); // calculate size of IP header
nixnax	173:6774a0c851c4	510	char * ipSrcPort = ppp.ipStart + headerSizeIP + 0; // ip source port location
nixnax	173:6774a0c851c4	511	char * ipDstPort = ppp.ipStart + headerSizeIP + 2; // ip destin port location
nixnax	149:969d98f6fb88	512	char tempHold[2];
nixnax	149:969d98f6fb88	513	memcpy(tempHold, ipSrcPort,2); // tempHold <- source
nixnax	149:969d98f6fb88	514	memcpy(ipSrcPort,ipDstPort,2); // source <- dest
nixnax	149:969d98f6fb88	515	memcpy(ipDstPort,tempHold, 2); // dest <- tempHold
nixnax	149:969d98f6fb88	516	}
nixnax	149:969d98f6fb88	517
nixnax	170:3d3b2126181c	518	/// Build the "pseudo header" required for UDP and TCP, then calculate its checksum
nixnax	170:3d3b2126181c	519	void checkSumPseudoHeader( unsigned int packetLength )
nixnax	170:3d3b2126181c	520	{
nixnax	170:3d3b2126181c	521	// this header contains the most important parts of the IP header, i.e. source and destination address, protocol number and data length.
nixnax	170:3d3b2126181c	522	pseudoIpHeaderType pseudoHeader; // create pseudo header
nixnax	170:3d3b2126181c	523	pseudoHeader.srcAdrR = ppp.ip->srcAdrR; // copy in ip source address
nixnax	170:3d3b2126181c	524	pseudoHeader.dstAdrR = ppp.ip->dstAdrR; // copy in ip dest address
nixnax	170:3d3b2126181c	525	pseudoHeader.zero = 0; // zero byte
nixnax	170:3d3b2126181c	526	pseudoHeader.protocol = ppp.ip->protocol; // protocol number (udp or tcp)
nixnax	170:3d3b2126181c	527	pseudoHeader.lengthR = __REV16( packetLength ); // size of tcp or udp packet
nixnax	170:3d3b2126181c	528	dataCheckSum(pseudoHeader.start, 12, 1); // calculate this header's checksum
nixnax	170:3d3b2126181c	529	}
nixnax	170:3d3b2126181c	530
nixnax	171:46b36d4edd1d	531	/// initialize an IP packet to send
nixnax	171:46b36d4edd1d	532	void initIP (unsigned int srcIp, unsigned int dstIp, unsigned int srcPort, unsigned int dstPort, unsigned int protocol)
nixnax	171:46b36d4edd1d	533	{
nixnax	171:46b36d4edd1d	534	ppp.ppp->address = 0xff;
nixnax	171:46b36d4edd1d	535	ppp.ppp->control = 3;
nixnax	171:46b36d4edd1d	536	ppp.ppp->protocolR = __REV16( 0x0021 );
nixnax	171:46b36d4edd1d	537	ppp.ip->version = 4;
nixnax	171:46b36d4edd1d	538	ppp.ip->headerLength = 5; // 5 words = 20 bytes
nixnax	171:46b36d4edd1d	539	ppp.ip->identR = __REV16(ppp.ipData.ident++); // insert our ident
nixnax	171:46b36d4edd1d	540	ppp.ip->dontFragment=1;
nixnax	171:46b36d4edd1d	541	ppp.ip->ttl=128;
nixnax	171:46b36d4edd1d	542	ppp.ip->protocol = protocol; // udp
nixnax	171:46b36d4edd1d	543	ppp.ip->srcAdrR = __REV(srcIp);
nixnax	171:46b36d4edd1d	544	ppp.ip->dstAdrR = __REV(dstIp);
nixnax	171:46b36d4edd1d	545	ppp.udpStart = ppp.ipStart + 20; // calculate start of udp header
nixnax	171:46b36d4edd1d	546	ppp.udp->srcPortR = __REV16(srcPort); // source port
nixnax	171:46b36d4edd1d	547	ppp.udp->dstPortR = __REV16(dstPort); // dest port
nixnax	171:46b36d4edd1d	548	}
nixnax	171:46b36d4edd1d	549
nixnax	171:46b36d4edd1d	550
nixnax	171:46b36d4edd1d	551	/// Build a UDP packet from scratch
nixnax	171:46b36d4edd1d	552	void sendUdp(unsigned int srcIp, unsigned int dstIp, unsigned int srcPort, unsigned int dstPort, char * message,int msgLen)
nixnax	171:46b36d4edd1d	553	{
nixnax	171:46b36d4edd1d	554	struct {
nixnax	171:46b36d4edd1d	555	unsigned int ipAll; // length of entire ip packet
nixnax	171:46b36d4edd1d	556	unsigned int ipHeader; // length of ip header
nixnax	171:46b36d4edd1d	557	unsigned int udpAll; // length of entire udp packet
nixnax	171:46b36d4edd1d	558	unsigned int udpData; // length of udp data segment
nixnax	171:46b36d4edd1d	559	} len;
nixnax	171:46b36d4edd1d	560	len.ipHeader = 20; // ip header length
nixnax	171:46b36d4edd1d	561	len.udpData = msgLen; // udp data size
nixnax	171:46b36d4edd1d	562	len.udpAll = len.udpData+8; // update local udp packet length
nixnax	171:46b36d4edd1d	563	len.ipAll = len.ipHeader + len.udpAll; // update IP Length
nixnax	171:46b36d4edd1d	564	initIP(srcIp, dstIp, srcPort, dstPort, 17); // init a UDP packet
nixnax	171:46b36d4edd1d	565	ppp.ip->lengthR = __REV16(len.ipAll); // update IP length in buffer
nixnax	171:46b36d4edd1d	566	ppp.udpStart = ppp.ipStart + len.ipHeader; // calculate start of udp header
nixnax	171:46b36d4edd1d	567	memcpy( ppp.udp->data, message, len.udpData ); // copy the message to the buffer
nixnax	171:46b36d4edd1d	568	ppp.udp->lengthR = __REV16(len.udpAll); // update UDP length in buffer
nixnax	171:46b36d4edd1d	569	ppp.pkt.len = len.ipAll+2+4; // update ppp packet length
nixnax	171:46b36d4edd1d	570	IpHeaderCheckSum(); // refresh IP header checksum
nixnax	171:46b36d4edd1d	571	checkSumPseudoHeader( len.udpAll ); // get the UDP pseudo-header checksum
nixnax	171:46b36d4edd1d	572	ppp.udp->checksumR = 0; // before TCP checksum calculations the checksum bytes must be set cleared
nixnax	171:46b36d4edd1d	573	unsigned int pseudoHeaderSum=dataCheckSum(ppp.udpStart,len.udpAll, 0); // continue the TCP checksum on the whole TCP packet
nixnax	171:46b36d4edd1d	574	ppp.udp->checksumR = __REV16( pseudoHeaderSum); // tcp checksum done, store it in the TCP header
nixnax	171:46b36d4edd1d	575	sendPppFrame(); // send the UDP message back
nixnax	171:46b36d4edd1d	576	}
nixnax	171:46b36d4edd1d	577
nixnax	146:a45f49a2b29c	578	/// Process an incoming UDP packet.
nixnax	146:a45f49a2b29c	579	/// If the packet starts with the string "echo " or "test" we echo back a special packet
nixnax	146:a45f49a2b29c	580	void UDPpacket()
nixnax	146:a45f49a2b29c	581	{
nixnax	163:d1b4328e9f08	582	struct {
nixnax	163:d1b4328e9f08	583	unsigned int all; // length of entire ip packet
nixnax	163:d1b4328e9f08	584	unsigned int header; // length of ip header
nixnax	163:d1b4328e9f08	585	} ipLength;
nixnax	163:d1b4328e9f08	586
nixnax	163:d1b4328e9f08	587	struct {
nixnax	165:c47826d07e0d	588	unsigned int all; // length of entire udp packet
nixnax	163:d1b4328e9f08	589	unsigned int data; // length of udp data segment
nixnax	163:d1b4328e9f08	590	} udpLength;
nixnax	163:d1b4328e9f08	591
nixnax	163:d1b4328e9f08	592	ipLength.header = 4 * ppp.ip->headerLength; // length of ip header
nixnax	163:d1b4328e9f08	593	ppp.udpStart = ppp.ipStart + ipLength.header; // calculate start of udp header
nixnax	171:46b36d4edd1d	594	udpLength.all = __REV16( ppp.udp->lengthR ); // size of udp packet
nixnax	163:d1b4328e9f08	595	udpLength.data = udpLength.all - 8; // size of udp data
nixnax	147:0f40005cbc5f	596
nixnax	146:a45f49a2b29c	597	#ifdef SERIAL_PORT_MONITOR_YES
nixnax	171:46b36d4edd1d	598	char * srcIP = ppp.ip->srcAdrPtr; // IP source
nixnax	171:46b36d4edd1d	599	char * dstIP = ppp.ip->dstAdrPtr; //IP destination
nixnax	163:d1b4328e9f08	600
nixnax	171:46b36d4edd1d	601	unsigned int udpSrcPort = __REV16( ppp.udp->srcPortR ); // integer of UDP source port
nixnax	171:46b36d4edd1d	602	unsigned int udpDstPort = __REV16( ppp.udp->dstPortR ); // integer of UDP dest port
nixnax	163:d1b4328e9f08	603
nixnax	163:d1b4328e9f08	604	if(v0) {
nixnax	163:d1b4328e9f08	605	debugPrintf("UDP %d.%d.%d.%d:%d ", srcIP[0],srcIP[1],srcIP[2],srcIP[3],udpSrcPort);
nixnax	163:d1b4328e9f08	606	debugPrintf("%d.%d.%d.%d:%d ", dstIP[0],dstIP[1],dstIP[2],dstIP[3],udpDstPort);
nixnax	163:d1b4328e9f08	607	debugPrintf("Len %03d", udpLength);
nixnax	163:d1b4328e9f08	608	}
nixnax	146:a45f49a2b29c	609	if (v1) {
nixnax	163:d1b4328e9f08	610	int printSize = udpLength.data;
nixnax	146:a45f49a2b29c	611	if (printSize > 20) printSize = 20; // print only first 20 characters
nixnax	146:a45f49a2b29c	612	for (int i=0; i<printSize; i++) {
nixnax	163:d1b4328e9f08	613	char ch = ppp.udp->data[i];
nixnax	146:a45f49a2b29c	614	if (ch>31 && ch<127) {
nixnax	146:a45f49a2b29c	615	debugPrintf("%c", ch);
nixnax	146:a45f49a2b29c	616	} else {
nixnax	230:ee097c486e45	617	debugPuts("_");
nixnax	146:a45f49a2b29c	618	}
nixnax	146:a45f49a2b29c	619	}
nixnax	146:a45f49a2b29c	620	}
nixnax	230:ee097c486e45	621	if (v0) debugPuts("\n");
nixnax	146:a45f49a2b29c	622	#endif
nixnax	163:d1b4328e9f08	623	int echoFound = !strncmp(ppp.udp->data,"echo ",5); // true if UDP message starts with "echo "
nixnax	258:1eb9abd66922	624	int testFound = !strncmp(ppp.udp->data,"test",4); // true if UDP message starts with "test"
nixnax	146:a45f49a2b29c	625	if ( (echoFound) \|\| (testFound)) { // if the UDP message starts with "echo " or "test" we answer back
nixnax	146:a45f49a2b29c	626	if (echoFound) {
nixnax	171:46b36d4edd1d	627	swapIpAddresses(); // swap IP source and destination
nixnax	171:46b36d4edd1d	628	swapIpPorts(); // swap IP source and destination ports
nixnax	163:d1b4328e9f08	629	memcpy(ppp.udp->data,"Got{",4); // in the UDP data modify "echo" to "Got:"
nixnax	170:3d3b2126181c	630	int n=0;
nixnax	230:ee097c486e45	631	#define IDENTIFY_UDP_SERVER_NO
nixnax	258:1eb9abd66922	632	#ifdef IDENTIFY_UDP_SERVER_YES
nixnax	170:3d3b2126181c	633	n=n+sprintf(n+ppp.udp->data+udpLength.data, "} UDP Server: PPP-Blinky\n"); // an appendix
nixnax	230:ee097c486e45	634	#endif
nixnax	168:c77eb908042a	635	udpLength.data = udpLength.data + n; // update udp data size with the size of the appendix
nixnax	171:46b36d4edd1d	636	// we may have changed data length, update all the lengths
nixnax	171:46b36d4edd1d	637	udpLength.all = udpLength.data+8; // update local udp packet length
nixnax	171:46b36d4edd1d	638	ipLength.all = ipLength.header + udpLength.all; // update IP Length
nixnax	171:46b36d4edd1d	639	ppp.ip->lengthR = __REV16(ipLength.all); // update IP length in buffer
nixnax	171:46b36d4edd1d	640	ppp.udp->lengthR = __REV16(udpLength.all); // update UDP length in buffer
nixnax	171:46b36d4edd1d	641	ppp.pkt.len = ipLength.all+2+4; // update ppp packet length
nixnax	171:46b36d4edd1d	642	IpHeaderCheckSum(); // refresh IP header checksum
nixnax	171:46b36d4edd1d	643	checkSumPseudoHeader( udpLength.all ); // get the UDP pseudo-header checksum
nixnax	171:46b36d4edd1d	644	ppp.udp->checksumR = 0; // before TCP checksum calculations the checksum bytes must be set cleared
nixnax	171:46b36d4edd1d	645	unsigned int pseudoHeaderSum=dataCheckSum(ppp.udpStart,udpLength.all, 0); // continue the TCP checksum on the whole TCP packet
nixnax	171:46b36d4edd1d	646	ppp.udp->checksumR = __REV16( pseudoHeaderSum); // tcp checksum done, store it in the TCP header
nixnax	171:46b36d4edd1d	647	sendPppFrame(); // send the UDP message back
nixnax	171:46b36d4edd1d	648	} else if ( testFound ) {
nixnax	171:46b36d4edd1d	649	unsigned int sI = __REV( ppp.ip->srcAdrR );
nixnax	171:46b36d4edd1d	650	unsigned int dI = __REV( ppp.ip->dstAdrR );
nixnax	171:46b36d4edd1d	651	unsigned int sp = __REV16( ppp.udp->srcPortR );
nixnax	171:46b36d4edd1d	652	unsigned int dp = __REV16( ppp.udp->dstPortR );
nixnax	172:449dd7a28955	653	int n=sprintf(ppp.pkt.buf+200,"Response Count %d\n", ppp.responseCounter);
nixnax	171:46b36d4edd1d	654	sendUdp(dI,sI,dp,sp,ppp.pkt.buf+200,n); // build a udp packet from the ground up
nixnax	146:a45f49a2b29c	655	}
nixnax	146:a45f49a2b29c	656	}
nixnax	142:54d1543e23e5	657	}
nixnax	142:54d1543e23e5	658
nixnax	174:e5a3f16421a5	659	/// UDP demo that sends a udp packet containing a character received from the second debug serial port.
nixnax	174:e5a3f16421a5	660	/// Sends a 48 byte IP/UDP header for every 1 byte of data so line-mode would probably be better.
nixnax	178:3f17aa0ce5ce	661	/// If you want ip packets from ppp blinky to be routed to other networks, ensure you have ip routing enabled.
nixnax	178:3f17aa0ce5ce	662	/// See http://www.wikihow.com/Enable-IP-Routing.
nixnax	179:ba2b2ddd0da5	663	/// Also ensure that the firewall on the receiving machine has the receiving UDP port (12345 in this example) enabled.
nixnax	179:ba2b2ddd0da5	664	/// The netcat UDP receive command on the remote host would be: nc -ul 12345
nixnax	174:e5a3f16421a5	665	void sendUdpData()
nixnax	174:e5a3f16421a5	666	{
nixnax	174:e5a3f16421a5	667	#ifdef SERIAL_PORT_MONITOR_YES
nixnax	179:ba2b2ddd0da5	668	if (ppp.online) {
nixnax	179:ba2b2ddd0da5	669	if (xx.readable()) {
nixnax	179:ba2b2ddd0da5	670	char inchar = xx.getc();
nixnax	179:ba2b2ddd0da5	671	xx.putc( inchar ); // echo the received character on the debug serial port
nixnax	228:7fb878500862	672	sendUdp(integersToIp(172,10,10,2), integersToIp(192,168,0,109), 1, 12345, &inchar, 1); // send a 1 byte UDP message to a remote machine at IP 192.168.0.109:12345
nixnax	179:ba2b2ddd0da5	673	}
nixnax	174:e5a3f16421a5	674	}
nixnax	174:e5a3f16421a5	675	#endif
nixnax	174:e5a3f16421a5	676	}
nixnax	174:e5a3f16421a5	677
nixnax	142:54d1543e23e5	678	/// handle a PING ICMP (internet control message protocol) packet
nixnax	142:54d1543e23e5	679	void ICMPpacket() // internet control message protocol
nixnax	142:54d1543e23e5	680	{
nixnax	165:c47826d07e0d	681	struct {
nixnax	165:c47826d07e0d	682	unsigned int all; // length of entire ip packet
nixnax	165:c47826d07e0d	683	unsigned int header; // length of ip header
nixnax	165:c47826d07e0d	684	} ipLength;
nixnax	165:c47826d07e0d	685	struct {
nixnax	165:c47826d07e0d	686	unsigned int all; // length of entire udp packet
nixnax	165:c47826d07e0d	687	unsigned int data; // length of udp data segment
nixnax	165:c47826d07e0d	688	} icmpLength;
nixnax	165:c47826d07e0d	689	ipLength.all = __REV16( ppp.ip->lengthR ); // length of ip packet
nixnax	165:c47826d07e0d	690	ipLength.header = 4 * ppp.ip->headerLength; // length of ip header
nixnax	165:c47826d07e0d	691	ppp.icmpStart = ppp.ipStart + ipLength.header; // calculate start of udp header
nixnax	165:c47826d07e0d	692	icmpLength.all = ipLength.all - ipLength.header; // length of icmp packet
nixnax	165:c47826d07e0d	693	icmpLength.data = icmpLength.all - 8; // length of icmp data
nixnax	142:54d1543e23e5	694	#define ICMP_TYPE_PING_REQUEST 8
nixnax	165:c47826d07e0d	695	if ( ppp.icmp->type == ICMP_TYPE_PING_REQUEST ) {
nixnax	165:c47826d07e0d	696	ppp.ip->ttl--; // decrement time to live (so we have to update header checksum)
nixnax	147:0f40005cbc5f	697	#ifdef SERIAL_PORT_MONITOR_YES
nixnax	167:ff8a2d8beeb1	698	char * srcAdr = ppp.ip->srcAdrPtr;
nixnax	167:ff8a2d8beeb1	699	char * dstAdr = ppp.ip->dstAdrPtr;
nixnax	165:c47826d07e0d	700	int icmpIdent = __REV16( ppp.ip->identR ); // byte reversed - big endian
nixnax	165:c47826d07e0d	701	int icmpSequence = __REV16( ppp.icmp->sequenceR ); // byte reversed - big endian
nixnax	142:54d1543e23e5	702	if(1) {
nixnax	230:ee097c486e45	703	char pbuf[100];
nixnax	210:a2a651249a9a	704
nixnax	142:54d1543e23e5	705	sprintf(pbuf, "ICMP PING %d.%d.%d.%d %d.%d.%d.%d ", srcAdr[0],srcAdr[1],srcAdr[2],srcAdr[3],dstAdr[0],dstAdr[1],dstAdr[2],dstAdr[3]);
nixnax	221:1d7c32d8256b	706	debugPuts( pbuf );
nixnax	210:a2a651249a9a	707
nixnax	142:54d1543e23e5	708	sprintf(pbuf, "Ident %04x Sequence %04d \n",icmpIdent,icmpSequence);
nixnax	210:a2a651249a9a	709
nixnax	221:1d7c32d8256b	710	debugPuts( pbuf );
nixnax	142:54d1543e23e5	711	}
nixnax	142:54d1543e23e5	712	#endif
nixnax	147:0f40005cbc5f	713	swapIpAddresses(); // swap the IP source and destination addresses
nixnax	147:0f40005cbc5f	714	IpHeaderCheckSum(); // new ip header checksum (required because we changed TTL)
nixnax	142:54d1543e23e5	715	#define ICMP_TYPE_ECHO_REPLY 0
nixnax	165:c47826d07e0d	716	ppp.icmp->type = ICMP_TYPE_ECHO_REPLY; // icmp echo reply
nixnax	165:c47826d07e0d	717	ppp.icmp->checkSumR = 0; // zero the checksum for recalculation
nixnax	165:c47826d07e0d	718	unsigned int sum = dataCheckSum(ppp.icmpStart, icmpLength.all, 1); // icmp checksum
nixnax	165:c47826d07e0d	719	ppp.icmp->checkSumR = __REV16( sum ); // save big-endian icmp checksum
nixnax	226:4898247048c7	720	#define DUMP_ICMP_PACKETS_NO
nixnax	226:4898247048c7	721	#ifdef DUMP_ICMP_PACKETS_YES
nixnax	165:c47826d07e0d	722	int printSize = icmpLength.data; // exclude size of icmp header
nixnax	142:54d1543e23e5	723	if (printSize > 10) printSize = 10; // print up to 20 characters
nixnax	226:4898247048c7	724	for (int i=0; i<printSize; i++) {
nixnax	226:4898247048c7	725	char ch = ppp.icmp->data[i];
nixnax	226:4898247048c7	726	if (ch>31 && ch<127) {
nixnax	226:4898247048c7	727	debugPutc(ch);
nixnax	226:4898247048c7	728	} else {
nixnax	226:4898247048c7	729	debugPutc('_'); // for non-printable characters
nixnax	142:54d1543e23e5	730	}
nixnax	142:54d1543e23e5	731	}
nixnax	226:4898247048c7	732	debugPutc('\n');
nixnax	226:4898247048c7	733	#endif
nixnax	144:01d98cf7738e	734	sendPppFrame(); // reply to the ping
nixnax	142:54d1543e23e5	735	} else {
nixnax	142:54d1543e23e5	736	if (v0) {
nixnax	165:c47826d07e0d	737	debugPrintf("ICMP type=%x \n", ppp.icmp->type);
nixnax	142:54d1543e23e5	738	}
nixnax	142:54d1543e23e5	739	}
nixnax	142:54d1543e23e5	740	}
nixnax	142:54d1543e23e5	741
nixnax	142:54d1543e23e5	742	/// handle an IGMP (internet group managment protocol) packet (by ignoring it)
nixnax	142:54d1543e23e5	743	void IGMPpacket()
nixnax	142:54d1543e23e5	744	{
nixnax	142:54d1543e23e5	745	if (v0) debugPrintf("IGMP type=%d \n", ppp.pkt.buf[28]);
nixnax	142:54d1543e23e5	746	}
nixnax	142:54d1543e23e5	747
nixnax	142:54d1543e23e5	748	/// dump the header of an IP pakcet on the (optional) debug serial port
nixnax	142:54d1543e23e5	749	void dumpHeaderIP (int outGoing)
nixnax	142:54d1543e23e5	750	{
nixnax	142:54d1543e23e5	751	#if defined(IP_HEADER_DUMP_YES) && defined(SERIAL_PORT_MONITOR_YES)
nixnax	210:a2a651249a9a	752
nixnax	155:9c6a1d249e26	753	int IPv4Id = __REV16(ppp.ip->identR);
nixnax	230:ee097c486e45	754	char pbuf[100]; // local print buffer
nixnax	142:54d1543e23e5	755	int n=0;
nixnax	142:54d1543e23e5	756	n=n+sprintf(pbuf+n, outGoing ? "\x1b[34m" : "\x1b[30m" ); // VT100 color code, print black for incoming, blue for outgoing headers
nixnax	142:54d1543e23e5	757	n=n+sprintf(pbuf+n, "%05d ",IPv4Id); // IPv4Id is a good way to correlate our dumps with net monitor or wireshark traces
nixnax	142:54d1543e23e5	758	#define DUMP_FULL_IP_ADDRESS_YES
nixnax	142:54d1543e23e5	759	#ifdef DUMP_FULL_IP_ADDRESS_YES
nixnax	167:ff8a2d8beeb1	760	char * srcAdr = ppp.ip->srcAdrPtr;
nixnax	167:ff8a2d8beeb1	761	char * dstAdr = ppp.ip->dstAdrPtr;
nixnax	142:54d1543e23e5	762	n=n+sprintf(pbuf+n, " %d.%d.%d.%d %d.%d.%d.%d ",srcAdr[0],srcAdr[1],srcAdr[2],srcAdr[3], dstAdr[0],dstAdr[1],dstAdr[2],dstAdr[3]); // full ip addresses
nixnax	142:54d1543e23e5	763	#endif
nixnax	221:1d7c32d8256b	764	debugPuts( pbuf );
nixnax	142:54d1543e23e5	765	#ifndef TCP_HEADER_DUMP_YES
nixnax	221:1d7c32d8256b	766	debugPuts('\x1b[30m\n'); // if there's no TCP header dump we terminate the line with \n and VT100 code for black
nixnax	142:54d1543e23e5	767	#endif
nixnax	142:54d1543e23e5	768	#endif
nixnax	142:54d1543e23e5	769	}
nixnax	142:54d1543e23e5	770
nixnax	142:54d1543e23e5	771	/// dump a TCP header on the optional debug serial port
nixnax	142:54d1543e23e5	772	void dumpHeaderTCP(int outGoing)
nixnax	142:54d1543e23e5	773	{
nixnax	142:54d1543e23e5	774	#if defined(TCP_HEADER_DUMP_YES) && defined(SERIAL_PORT_MONITOR_YES)
nixnax	155:9c6a1d249e26	775	char flagString[9]; // text string presenting the 8 most important TCP flags
nixnax	142:54d1543e23e5	776	#define PRINT_ALL_TCP_FLAGS_YES
nixnax	142:54d1543e23e5	777	#ifdef PRINT_ALL_TCP_FLAGS_YES
nixnax	155:9c6a1d249e26	778	memset(flagString,'.', 8); // fill string with "........"
nixnax	156:163c23249731	779	if (ppp.tcp->flag.fin) flagString[7]='F';
nixnax	156:163c23249731	780	if (ppp.tcp->flag.syn) flagString[6]='S';
nixnax	156:163c23249731	781	if (ppp.tcp->flag.rst) flagString[5]='R';
nixnax	156:163c23249731	782	if (ppp.tcp->flag.psh) flagString[4]='P';
nixnax	156:163c23249731	783	if (ppp.tcp->flag.ack) flagString[3]='A';
nixnax	156:163c23249731	784	if (ppp.tcp->flag.urg) flagString[2]='U';
nixnax	156:163c23249731	785	if (ppp.tcp->flag.ece) flagString[1]='E';
nixnax	156:163c23249731	786	if (ppp.tcp->flag.cwr) flagString[0]='C';
nixnax	155:9c6a1d249e26	787	flagString[8]=0; // null terminate string
nixnax	142:54d1543e23e5	788	#else
nixnax	156:163c23249731	789	if (ppp.tcp->flag.ack) flagString[0]='A'; // choose only the most important flag to print
nixnax	156:163c23249731	790	if (ppp.tcp->flag.syn) flagString[0]='S';
nixnax	156:163c23249731	791	if (ppp.tcp->flag.fin) flagString[0]='F';
nixnax	156:163c23249731	792	if (ppp.tcp->flag.psh) flagString[0]='P';
nixnax	156:163c23249731	793	if (ppp.tcp->flag.rst) flagString[0]='R';
nixnax	155:9c6a1d249e26	794	flagString[1]=0; // null terminate string
nixnax	142:54d1543e23e5	795	#endif
nixnax	221:1d7c32d8256b	796	debugPuts( flagString );
nixnax	142:54d1543e23e5	797	#define EVERY_PACKET_ON_A_NEW_LINE_YES
nixnax	142:54d1543e23e5	798	#ifdef EVERY_PACKET_ON_A_NEW_LINE_YES
nixnax	221:1d7c32d8256b	799	debugPuts("\x1b[30m\n"); // write a black color and newline after every packet
nixnax	160:bd701ad564cb	800	#else
nixnax	221:1d7c32d8256b	801	debugPuts("\x1b[30m"); // write a black color after every packet
nixnax	142:54d1543e23e5	802	#endif
nixnax	156:163c23249731	803	if( outGoing && ppp.tcp->flag.fin ) { // ACK/FIN - if this is an outgoing FIN it's the end of a tcp conversation
nixnax	221:1d7c32d8256b	804	debugPutc('\n'); // insert an extra new line to mark the end (except for final ack) of an HTTP conversation
nixnax	142:54d1543e23e5	805	}
nixnax	142:54d1543e23e5	806	#endif
nixnax	142:54d1543e23e5	807	}
nixnax	142:54d1543e23e5	808
nixnax	143:c5019f856a56	809	/// Encode a buffer in base-64
nixnax	184:4133f557d4d4	810	const static char lut [] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
nixnax	142:54d1543e23e5	811	void enc64(char * in, char * out, int len)
nixnax	142:54d1543e23e5	812	{
nixnax	142:54d1543e23e5	813	int i,j,a,b,c;
nixnax	142:54d1543e23e5	814	i=0;
nixnax	142:54d1543e23e5	815	j=0;
nixnax	142:54d1543e23e5	816	while(1) {
nixnax	142:54d1543e23e5	817	if (i<len) {
nixnax	142:54d1543e23e5	818	a = in[i++];
nixnax	142:54d1543e23e5	819	out[j++] = lut[ ( (a >> 2) & 0x3f) ];
nixnax	142:54d1543e23e5	820	} else break;
nixnax	142:54d1543e23e5	821	if (i<len) {
nixnax	142:54d1543e23e5	822	b = in[i++];
nixnax	142:54d1543e23e5	823	out[j++] = lut[ ( (a << 4) & 0x30) \| ( (b >> 4) & 0x0f) ];
nixnax	142:54d1543e23e5	824	out[j++] = lut[ ( (b << 2) & 0x3c) ];
nixnax	142:54d1543e23e5	825	} else out[j++] = '=';
nixnax	142:54d1543e23e5	826	if (i<len) {
nixnax	142:54d1543e23e5	827	c = in[i++];
nixnax	142:54d1543e23e5	828	j--;
nixnax	142:54d1543e23e5	829	out[j++] = lut[ ( (b << 2) & 0x3c) \| ( (c >> 6) & 0x03) ];
nixnax	142:54d1543e23e5	830	out[j++] = lut[ ( (c >> 0) & 0x3f) ];
nixnax	142:54d1543e23e5	831	} else out[j++] = '=';
nixnax	142:54d1543e23e5	832	}
nixnax	142:54d1543e23e5	833	out[j]=0;
nixnax	142:54d1543e23e5	834	}
nixnax	142:54d1543e23e5	835
nixnax	160:bd701ad564cb	836	/// Handle a request for an http websocket.
nixnax	160:bd701ad564cb	837	/// We end up here if we enter the following javascript in a web browser console: x = new WebSocket("ws://172.10.10.2");
nixnax	142:54d1543e23e5	838	int webSocketHandler(char * dataStart)
nixnax	142:54d1543e23e5	839	{
nixnax	142:54d1543e23e5	840	int n=0; // byte counter
nixnax	184:4133f557d4d4	841	char * key = strstr(dataStart, "Sec-WebSocket-Key:"); // search for the key in the payload
nixnax	142:54d1543e23e5	842	if (key != NULL) {
nixnax	184:4133f557d4d4	843	key = key + 18; // skip over the key ident string "Sec-WebSocket-Key:"
nixnax	221:1d7c32d8256b	844	if (v0) debugPuts("WebSocket Request\n");
nixnax	184:4133f557d4d4	845	while ( strchr(lut, *key) == NULL) key++; // skip non-valid base-64 characters (whitespace)
nixnax	184:4133f557d4d4	846	char challenge [80];
nixnax	184:4133f557d4d4	847	int i=0;
nixnax	184:4133f557d4d4	848	char * copyTo = challenge;
nixnax	184:4133f557d4d4	849	while (strchr(lut, *key) != NULL) { // copy while we see valid base-64 characters
nixnax	184:4133f557d4d4	850	if (i++ >40) break; // prevent buffer overflow
nixnax	184:4133f557d4d4	851	copyTo++ = key++; // copy next valid base-64 character
nixnax	184:4133f557d4d4	852	}
nixnax	184:4133f557d4d4	853	strcpy(copyTo,"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"); // append websocket gui code
nixnax	226:4898247048c7	854	#define DUMP_WEBSOCKET_CHALLENGE_NO
nixnax	226:4898247048c7	855	#ifdef DUMP_WEBSOCKET_CHALLENGE_YES
nixnax	226:4898247048c7	856	debugPrintf("Challenge is %s\n", challenge); // the string we hash for the challenge
nixnax	227:f87156f9ef11	857	#endif
nixnax	142:54d1543e23e5	858	char shaOutput [20]; // sha1 output
nixnax	184:4133f557d4d4	859	sha1( shaOutput, challenge, strlen(challenge)); // hash the challenge
nixnax	142:54d1543e23e5	860	char encOut[50];
nixnax	184:4133f557d4d4	861	enc64( shaOutput, encOut, 20); // base-64 encode
nixnax	142:54d1543e23e5	862	char * versionstring = strstr(dataStart, "Sec-WebSocket-Version:");
nixnax	142:54d1543e23e5	863	char * version = challenge;
nixnax	184:4133f557d4d4	864	strncpy(version, versionstring,70); // copy their version string
nixnax	142:54d1543e23e5	865	*strchr(version,'\r')=0; // null terminate so we can sprintf it
nixnax	240:d7a01533397d	866	memset(dataStart,0,500); // blank out old data before sending the websocket response header
nixnax	142:54d1543e23e5	867	n=n+sprintf(dataStart+n, "HTTP/1.1 101 Switching Protocols\r\n");
nixnax	142:54d1543e23e5	868	n=n+sprintf(dataStart+n, "Upgrade: websocket\r\n");
nixnax	142:54d1543e23e5	869	n=n+sprintf(dataStart+n, "Connection: Upgrade\r\n");
nixnax	142:54d1543e23e5	870	n=n+sprintf(dataStart+n, "Sec-WebSocket-Accept: %s\r\n",encOut);
nixnax	142:54d1543e23e5	871	n=n+sprintf(dataStart+n, "%s\r\n",version);
nixnax	261:272ec8e2a7d4	872	#define SHOW_MBED_IN_RESPONSE_YES // change to SHOW_MBED_IN_RESPONSE_NO to exclude
nixnax	261:272ec8e2a7d4	873	#ifdef SHOW_MBED_IN_RESPONSE_YES
nixnax	142:54d1543e23e5	874	n=n+sprintf(dataStart+n, "mbed-Code: PPP-Blinky\r\n");
nixnax	262:c044fed611aa	875	#endif
nixnax	142:54d1543e23e5	876	n=n+sprintf(dataStart+n, "\r\n"); // websocket response header ending
nixnax	142:54d1543e23e5	877	}
nixnax	142:54d1543e23e5	878	return n; // this response should satisfy a web browser's websocket protocol request
nixnax	142:54d1543e23e5	879	}
nixnax	142:54d1543e23e5	880
nixnax	142:54d1543e23e5	881	#define TCP_FLAG_ACK (1<<4)
nixnax	142:54d1543e23e5	882	#define TCP_FLAG_SYN (1<<1)
nixnax	142:54d1543e23e5	883	#define TCP_FLAG_PSH (1<<3)
nixnax	142:54d1543e23e5	884	#define TCP_FLAG_RST (1<<2)
nixnax	142:54d1543e23e5	885	#define TCP_FLAG_FIN (1<<0)
nixnax	142:54d1543e23e5	886
nixnax	142:54d1543e23e5	887	/// respond to an HTTP request
nixnax	185:4cd8f91e9d49	888	int httpResponse(char * dataStart, int * flags)
nixnax	142:54d1543e23e5	889	{
nixnax	142:54d1543e23e5	890	int n=0; // number of bytes we have printed so far
nixnax	142:54d1543e23e5	891	n = webSocketHandler( dataStart ); // test for and handle WebSocket upgrade requests
nixnax	160:bd701ad564cb	892	if (n>0) return n; // if n>0 we already have a response, so return
nixnax	142:54d1543e23e5	893
nixnax	142:54d1543e23e5	894	int nHeader; // byte size of HTTP header
nixnax	142:54d1543e23e5	895	int contentLengthStart; // index where HTML starts
nixnax	142:54d1543e23e5	896	int httpGet5,httpGet6,httpGetx, httpGetRoot; // temporary storage of strncmp results
nixnax	185:4cd8f91e9d49	897	*flags = TCP_FLAG_ACK \| TCP_FLAG_FIN; // the default case is that we close the connection
nixnax	142:54d1543e23e5	898
nixnax	142:54d1543e23e5	899	httpGetRoot = strncmp(dataStart, "GET / HTTP/1.", 13); // found a GET to the root directory
nixnax	142:54d1543e23e5	900	httpGetx = strncmp(dataStart, "GET /x", 6); // found a GET to /x which we will treat special (anything starting with /x, e.g. /x, /xyz, /xABC?pqr=123
nixnax	142:54d1543e23e5	901	httpGet5 = dataStart[5]; // the first character in the path name, we use it for special functions later on
nixnax	142:54d1543e23e5	902	httpGet6 = dataStart[6]; // the second character in the path name, we use it for special functions later on
nixnax	142:54d1543e23e5	903	// for example, you could try this using netcat (nc): echo "GET /x" \| nc 172.10.10.2
nixnax	271:06c2c2a4e0bf	904	n=n+sprintf(n+dataStart,"HTTP/1.1 "); // start of response header
nixnax	270:98099fbc46fb	905	if( (httpGetRoot==0) \|\| (httpGetx==0) \|\| (httpGet5 == 'w' ) ) {
nixnax	271:06c2c2a4e0bf	906	n=n+sprintf(n+dataStart,"200 OK\r\n"); // 200 OK header
nixnax	142:54d1543e23e5	907	} else {
nixnax	271:06c2c2a4e0bf	908	n=n+sprintf(n+dataStart,"404 Not Found\r\n"); // 404 header
nixnax	142:54d1543e23e5	909	}
nixnax	271:06c2c2a4e0bf	910	#define SHOWSERVERNAME_NO
nixnax	271:06c2c2a4e0bf	911	#ifdef SHOWSERVERNAME_YES
nixnax	271:06c2c2a4e0bf	912	n=n+sprintf(n+dataStart,"Server: mbed PPP-Blinky\r\n"); // Server in response header
nixnax	275:bb2d582c20d6	913	#endif
nixnax	271:06c2c2a4e0bf	914	#define SHOWMAXBUFLEVEL_NO
nixnax	209:aa514cd631ee	915	#ifdef SHOWMAXBUFLEVEL_YES
nixnax	209:aa514cd631ee	916	// if this is enabled then the maximum value of the serial port receive buffer will show up in the http headers of your browser - nice for debugging
nixnax	210:a2a651249a9a	917	n=n+sprintf(n+dataStart,"Maxbuflevel: %d\r\n", ppp.rx.maxbuflevel);
nixnax	210:a2a651249a9a	918	#endif
nixnax	262:c044fed611aa	919	#define SHOWPPPCOUNT_NO
nixnax	262:c044fed611aa	920	#ifdef SHOWPPPCOUNT_YES
nixnax	262:c044fed611aa	921	// if this is enabled then the received PPP packet count will show up in the http headers of your browser - disabled for now because it's also displayed in the root page
nixnax	262:c044fed611aa	922	n=n+sprintf(n+dataStart,"PPP-RX-Packets: %d\r\n", ppp.pppCount);
nixnax	240:d7a01533397d	923	#endif
nixnax	271:06c2c2a4e0bf	924	n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n"); // http header must end with empty line (\r\n)
nixnax	271:06c2c2a4e0bf	925	n=n+sprintf(n+dataStart,"Content-Length: ?????\r\n\r\n"); // leave five spaces for content length - will be updated later
nixnax	271:06c2c2a4e0bf	926	contentLengthStart = n-9; // remember where Content-Length starts in the buffer
nixnax	271:06c2c2a4e0bf	927	nHeader=n; // size of HTTP header and start of payload
nixnax	142:54d1543e23e5	928	if( httpGetRoot == 0 ) {
nixnax	142:54d1543e23e5	929	// this is where we insert our web page into the buffer
nixnax	142:54d1543e23e5	930	memcpy(n+dataStart,rootWebPage,sizeof(rootWebPage));
nixnax	142:54d1543e23e5	931	n = n + sizeof(rootWebPage)-1; // one less than sizeof because we don't count the null byte at the end
nixnax	262:c044fed611aa	932	// naximum length of pppCount (maximum number of digits of an unsigned 32-bit int)
nixnax	262:c044fed611aa	933	#define PPPCOUNTMAXLEN (10)
nixnax	262:c044fed611aa	934	char pppCountString[PPPCOUNTMAXLEN+1]; // space for the ten digits and a string terminator 0
nixnax	262:c044fed611aa	935	snprintf(pppCountString,PPPCOUNTMAXLEN+1,"%*d",PPPCOUNTMAXLEN,ppp.pppCount); // print number of received PPP packets right justified in 10 spaces
nixnax	258:1eb9abd66922	936	char * tenNulls = "0000000000";
nixnax	262:c044fed611aa	937	char * pppCountStart = strstr(dataStart,tenNulls); // find the ten zeros in the page - this is where we must paste in the PPP Rx packet count
nixnax	262:c044fed611aa	938	if ( pppCountStart != NULL )
nixnax	262:c044fed611aa	939	memcpy(pppCountStart, pppCountString, PPPCOUNTMAXLEN); // copy ping count over the ten zeros in the page
nixnax	262:c044fed611aa	940	snprintf(pppCountString,PPPCOUNTMAXLEN+1,"%*d",PPPCOUNTMAXLEN,SystemCoreClock); // print System Core Clock speed
nixnax	258:1eb9abd66922	941	char * coreClockStart = strstr(dataStart,tenNulls); // find the ten zeros in the page - this is where we must paste in the core clock speed
nixnax	258:1eb9abd66922	942	if ( coreClockStart != NULL )
nixnax	262:c044fed611aa	943	memcpy(coreClockStart, pppCountString, PPPCOUNTMAXLEN); // copy core clock speed over the ten zeros in the page
nixnax	210:a2a651249a9a	944	} else if ( httpGet5 == 'w' ) { // "w" is a special page for websocket demo
nixnax	142:54d1543e23e5	945	memcpy(n+dataStart,webSocketPage,sizeof(webSocketPage));
nixnax	142:54d1543e23e5	946	n = n + sizeof(webSocketPage)-1; // one less than size
nixnax	185:4cd8f91e9d49	947	*flags = TCP_FLAG_ACK \| TCP_FLAG_PSH; // for a websocket page we do NOT close the connection
nixnax	142:54d1543e23e5	948	} else {
nixnax	142:54d1543e23e5	949	if (httpGetx == 0) { // the page request started with "GET /x" - here we treat anything starting with /x special:
nixnax	142:54d1543e23e5	950	#define W3C_COMPLIANT_RESPONSE_NO
nixnax	142:54d1543e23e5	951	// change the above to W3C_COMPLIANT_RESPONSE_YES if you want a W3C.org compliant HTTP response
nixnax	142:54d1543e23e5	952	#ifdef W3C_COMPLIANT_RESPONSE_YES
nixnax	142:54d1543e23e5	953	n=n+sprintf(n+dataStart,"<!DOCTYPE html><title>mbed PPP-Blinky</title>"); // html title (W3C.org required elements)
nixnax	258:1eb9abd66922	954	#endif
nixnax	272:9ea94556c6f6	955	if( (ppp.ledState & 1) == 0) // check lowest bit of LED state and respond with red or green favicon - this stops browsers from asking for favicon.ico file
nixnax	258:1eb9abd66922	956	n=n+sprintf(n+dataStart,"<link rel=\"icon\" id=\"red-pixel\" href=\"data:image/gif;base64,R0lGODlhAQABAIABAP8AAAAAACwAAAAAAQABAAACAkQBADs\">"); // data url containing 1 red pixel gif
nixnax	248:5aca1c98fc24	957	else
nixnax	258:1eb9abd66922	958	n=n+sprintf(n+dataStart,"<link rel=\"icon\" id=\"grn-pixel\" href=\"data:image/gif;base64,R0lGODlhAQABAIABAAD/AAAAACwAAAAAAQABAAACAkQBADs=\">"); // data url containing 1 green pixel gif
nixnax	248:5aca1c98fc24	959	if( httpGet6 == 'b' ) // if the fetched page is "xb" send a meta command to let the browser continuously reload
nixnax	248:5aca1c98fc24	960	n=n+sprintf(n+dataStart, "<meta http-equiv=\"refresh\" content=\"0\">"); // reload loop - handy for benchmarking
nixnax	248:5aca1c98fc24	961	// /x is a very short page, in fact, it is only a decimal number showing the http Page count
nixnax	270:98099fbc46fb	962	if (httpGet6 == 't' ) // if the fetched pages is "xt" toggle the LEd
nixnax	275:bb2d582c20d6	963	led1Toggle();
nixnax	248:5aca1c98fc24	964	#ifdef W3C_COMPLIANT_RESPONSE_YES
nixnax	146:a45f49a2b29c	965	n=n+sprintf(n+dataStart,"<body>%d</body>",ppp.responseCounter); // body = the http frame count
nixnax	258:1eb9abd66922	966	#else
nixnax	272:9ea94556c6f6	967	n=n+sprintf(n+dataStart,"%d",ppp.responseCounter); // not really valid html but most browsers and curl are ok with it
nixnax	142:54d1543e23e5	968	#endif
nixnax	258:1eb9abd66922	969	} else {
nixnax	273:3b3de186ea2f	970	// all other requests get a Not Found response
nixnax	257:1990a41a1e31	971	n=n+sprintf(n+dataStart,"<!DOCTYPE html><title>mbed PPP-Blinky</title>"); // html title (W3C.org required elements)
nixnax	274:b1bc40deb637	972	n=n+sprintf(n+dataStart,"<body>404 Not Found</body>"); // not found message
nixnax	142:54d1543e23e5	973	}
nixnax	142:54d1543e23e5	974	}
nixnax	142:54d1543e23e5	975	#define CONTENTLENGTHSIZE 5
nixnax	142:54d1543e23e5	976	char contentLengthString[CONTENTLENGTHSIZE+1];
nixnax	142:54d1543e23e5	977	snprintf(contentLengthString,CONTENTLENGTHSIZE+1,"%*d",CONTENTLENGTHSIZE,n-nHeader); // print Content-Length with leading spaces and fixed width equal to csize
nixnax	142:54d1543e23e5	978	memcpy(dataStart+contentLengthStart, contentLengthString, CONTENTLENGTHSIZE); // copy Content-Length to it's place in the send buffer
nixnax	142:54d1543e23e5	979	return n; // total byte size of our response
nixnax	142:54d1543e23e5	980	}
nixnax	142:54d1543e23e5	981
nixnax	160:bd701ad564cb	982	/// Handle TCP data that is not an HTTP GET.
nixnax	160:bd701ad564cb	983	/// This is handy when for example you want to use netcat (nc.exe) to talk to PPP-Blinky.
nixnax	160:bd701ad564cb	984	/// This could also be a websocket receive event - especially if the first byte is 0x81 (websocket data push)
nixnax	142:54d1543e23e5	985	int tcpResponse(char * dataStart, int len, int * outFlags)
nixnax	142:54d1543e23e5	986	{
nixnax	142:54d1543e23e5	987	int n=0; // number of bytes we have printed so far
nixnax	142:54d1543e23e5	988	if (dataStart[0] == 0x81) { // check if this is a websocket push message
nixnax	160:bd701ad564cb	989	char mask [4];
nixnax	160:bd701ad564cb	990	memcpy ( mask, dataStart+2, 4); // websocket messages are "masked", so first we obtain the 4-byte mask
nixnax	160:bd701ad564cb	991	int websocketMessageSize = len - 6; // 1 byte prefix (0x81), 1 byte, 4 bytes mask = 6 bytes
nixnax	160:bd701ad564cb	992	if((dataStart[1]&0x80)==0x80) // test if the mask bit is set, which means all data is xor'ed with the mask
nixnax	160:bd701ad564cb	993	for (int i=0; i<websocketMessageSize; i++) dataStart[i+6]^= mask[i%4]; // unmask each byte with one of the mask bytes
nixnax	160:bd701ad564cb	994	dataStart[1] = len-2; // add four extra bytes to the message length because we don't use mask bytes for the send
nixnax	160:bd701ad564cb	995	memcpy(dataStart+2, "Got:",4); // insert our own text into the four mask bytes
nixnax	160:bd701ad564cb	996	n = len; // our response size remains exactly the same length as what we received
nixnax	142:54d1543e23e5	997	} else if ( (dataStart[0]==0x88) && (dataStart[1]==0x80) && (len == 6) ) { // test for a websocket close request
nixnax	142:54d1543e23e5	998	n=2; // our close command is only two bytes long because we don't use the four mask bytes
nixnax	142:54d1543e23e5	999	dataStart[1]=0; // we don't have mask bytes on
nixnax	160:bd701ad564cb	1000	} else {
nixnax	184:4133f557d4d4	1001	if ( len > 1 ) { // we assume a length of 1 is a keep-alive or push packet
nixnax	221:1d7c32d8256b	1002	if (v1) debugPuts("TCP data received\n"); // all other tcp push packets
nixnax	184:4133f557d4d4	1003	}
nixnax	163:d1b4328e9f08	1004	}
nixnax	142:54d1543e23e5	1005	return n; // total byte size of our response
nixnax	142:54d1543e23e5	1006	}
nixnax	142:54d1543e23e5	1007
nixnax	173:6774a0c851c4	1008	/// dump the TCP data to the debug serial port
nixnax	173:6774a0c851c4	1009	void dumpDataTCP(int outGoing)
nixnax	173:6774a0c851c4	1010	{
nixnax	173:6774a0c851c4	1011	#ifdef SERIAL_PORT_MONITOR_YES
nixnax	173:6774a0c851c4	1012	if (v2) {
nixnax	173:6774a0c851c4	1013	int packetLengthIp = __REV16(ppp.ip->lengthR ); // size of ip packet
nixnax	173:6774a0c851c4	1014	int headerSizeIp = 4 * ppp.ip->headerLength; // size of ip header
nixnax	173:6774a0c851c4	1015	ppp.tcpStart = ppp.ipStart + headerSizeIp; // calculate where the TCP header starts
nixnax	173:6774a0c851c4	1016	int headerSizeTcp = 4 * (ppp.tcp->offset); // tcp "offset" for start of data is also the header size
nixnax	173:6774a0c851c4	1017	ppp.tcpData = ppp.tcpStart + headerSizeTcp; // start of tcp data
nixnax	173:6774a0c851c4	1018	int tcpSize = packetLengthIp - headerSizeIp; // tcp size = size of ip payload
nixnax	173:6774a0c851c4	1019	int tcpDataSize = tcpSize - headerSizeTcp; // size of data block after TCP header
nixnax	230:ee097c486e45	1020	char pbuf[100]; // local print buffer
nixnax	173:6774a0c851c4	1021	int n=0;
nixnax	210:a2a651249a9a	1022
nixnax	173:6774a0c851c4	1023	n=n+sprintf(pbuf+n, outGoing ? "\x1b[34m" : "\x1b[30m" ); // VT100 color code, print black for incoming, blue for outgoing headers
nixnax	210:a2a651249a9a	1024
nixnax	173:6774a0c851c4	1025	n=n+sprintf(pbuf+n, "IP:%d ipHeader:%d tcpHeader:%d tcpData:%d\n", packetLengthIp, headerSizeIp, headerSizeTcp, tcpDataSize); // 1 for more verbose
nixnax	230:ee097c486e45	1026	if (n>95) debugPuts("n>pbuf overflow in dumpDataTCP()\n");
nixnax	210:a2a651249a9a	1027
nixnax	221:1d7c32d8256b	1028	debugPuts( pbuf );
nixnax	173:6774a0c851c4	1029	if (tcpDataSize > 0) {
nixnax	173:6774a0c851c4	1030	ppp.tcpData[tcpDataSize]=0; // insert a null after the data so debug printf stops printing after the data
nixnax	221:1d7c32d8256b	1031	debugPuts( ppp.tcpData ); // print the tcp payload data
nixnax	221:1d7c32d8256b	1032	debugPuts("\n");
nixnax	173:6774a0c851c4	1033	}
nixnax	221:1d7c32d8256b	1034	debugPuts( "\x1b[30m" ); // VT100 color code, print black
nixnax	173:6774a0c851c4	1035	}
nixnax	173:6774a0c851c4	1036	#endif
nixnax	173:6774a0c851c4	1037	}
nixnax	173:6774a0c851c4	1038
nixnax	142:54d1543e23e5	1039	/// handle an incoming TCP packet
nixnax	142:54d1543e23e5	1040	/// use the first few bytes to figure out if it's a websocket, an http request or just pure incoming TCP data
nixnax	142:54d1543e23e5	1041	void tcpHandler()
nixnax	142:54d1543e23e5	1042	{
nixnax	154:18b2bd92f557	1043	int packetLengthIp = __REV16(ppp.ip->lengthR ); // size of ip packet
nixnax	154:18b2bd92f557	1044	int headerSizeIp = 4 * ppp.ip->headerLength; // size of ip header
nixnax	173:6774a0c851c4	1045	ppp.tcpStart = ppp.ipStart + headerSizeIp; // calculate TCP header start
nixnax	154:18b2bd92f557	1046	int tcpSize = packetLengthIp - headerSizeIp; // tcp size = size of ip payload
nixnax	154:18b2bd92f557	1047	int headerSizeTcp = 4 * (ppp.tcp->offset); // tcp "offset" for start of data is also the header size
nixnax	227:f87156f9ef11	1048	char * tcpDataIn = ppp.tcpStart + headerSizeTcp; // start of TCP data after TCP header
nixnax	154:18b2bd92f557	1049	int tcpDataSize = tcpSize - headerSizeTcp; // size of data block after TCP header
nixnax	154:18b2bd92f557	1050
nixnax	227:f87156f9ef11	1051	unsigned int seq_in = __REV(ppp.tcp->seqTcpR); // incoming sequence number
nixnax	227:f87156f9ef11	1052	unsigned int ack_in = __REV(ppp.tcp->ackTcpR); // incoming acknowledge number
nixnax	227:f87156f9ef11	1053	unsigned int ack_out = seq_in + tcpDataSize; // calculate the acknowledge based on size of received packet
nixnax	227:f87156f9ef11	1054	unsigned int seq_out = ack_in; // adopt their version of our sequence number as our sequence number
nixnax	142:54d1543e23e5	1055
nixnax	142:54d1543e23e5	1056	// first we shorten the TCP response header to only 20 bytes. This means we ignore all TCP option requests
nixnax	173:6774a0c851c4	1057	headerSizeIp=20;
nixnax	173:6774a0c851c4	1058	ppp.ip->headerLength = headerSizeIp/4; // ip header is 20 bytes long
nixnax	173:6774a0c851c4	1059	ppp.ip->lengthR = __REV(40); // 20 ip header + 20 tcp header
nixnax	227:f87156f9ef11	1060	headerSizeTcp = 20; // shorten outgoing TCP header size to 20 bytes (no data)
nixnax	173:6774a0c851c4	1061	ppp.tcpStart = ppp.ipStart + headerSizeIp; // recalc TCP header start
nixnax	154:18b2bd92f557	1062	ppp.tcp->offset = (headerSizeTcp/4);
nixnax	173:6774a0c851c4	1063	char * tcpDataOut = ppp.tcpStart + headerSizeTcp; // start of outgoing data
nixnax	142:54d1543e23e5	1064
nixnax	142:54d1543e23e5	1065	int dataLen = 0; // most of our responses will have zero TCP data, only a header
nixnax	142:54d1543e23e5	1066	int flagsOut = TCP_FLAG_ACK; // the default case is an ACK packet
nixnax	160:bd701ad564cb	1067
nixnax	185:4cd8f91e9d49	1068	ppp.tcp->windowR = __REV16( 1200 ); // set tcp window size to 1200 bytes
nixnax	142:54d1543e23e5	1069
nixnax	142:54d1543e23e5	1070	// A sparse TCP flag interpreter that implements stateless TCP connections
nixnax	142:54d1543e23e5	1071
nixnax	156:163c23249731	1072	switch ( ppp.tcp->flag.All ) {
nixnax	142:54d1543e23e5	1073	case TCP_FLAG_SYN:
nixnax	142:54d1543e23e5	1074	flagsOut = TCP_FLAG_SYN \| TCP_FLAG_ACK; // something wants to connect - acknowledge it
nixnax	142:54d1543e23e5	1075	seq_out = seq_in+0x10000000U; // create a new sequence number using their sequence as a starting point, increase the highest digit
nixnax	142:54d1543e23e5	1076	ack_out++; // for SYN flag we have to increase the sequence by 1
nixnax	142:54d1543e23e5	1077	break;
nixnax	184:4133f557d4d4	1078	case TCP_FLAG_ACK:
nixnax	142:54d1543e23e5	1079	case TCP_FLAG_ACK \| TCP_FLAG_PSH:
nixnax	259:f694046fc06f	1080	if (tcpDataSize == 0) return; // handle zero-size ack messages by ignoring them
nixnax	259:f694046fc06f	1081	// if ( (ppp.tcp->flag.All == TCP_FLAG_ACK) && (tcpDataSize == 0)) return; // handle zero-size ack messages by ignoring them
nixnax	142:54d1543e23e5	1082	if ( (strncmp(tcpDataIn, "GET /", 5) == 0) ) { // check for an http GET command
nixnax	179:ba2b2ddd0da5	1083	flagsOut = TCP_FLAG_ACK \| TCP_FLAG_PSH; // we have data, set the PSH flag
nixnax	185:4cd8f91e9d49	1084	dataLen = httpResponse(tcpDataOut, &flagsOut); // send an http response
nixnax	142:54d1543e23e5	1085	} else {
nixnax	158:841592aed956	1086	dataLen = tcpResponse(tcpDataOut,tcpDataSize, &flagsOut); // not an http GET, handle as a tcp connection
nixnax	179:ba2b2ddd0da5	1087	if (dataLen > 0) flagsOut = TCP_FLAG_ACK \| TCP_FLAG_PSH; // if we have any data set the PSH flag
nixnax	142:54d1543e23e5	1088	}
nixnax	142:54d1543e23e5	1089	break;
nixnax	142:54d1543e23e5	1090	case TCP_FLAG_FIN:
nixnax	142:54d1543e23e5	1091	case TCP_FLAG_FIN \| TCP_FLAG_ACK:
nixnax	142:54d1543e23e5	1092	case TCP_FLAG_FIN \| TCP_FLAG_PSH \| TCP_FLAG_ACK:
nixnax	142:54d1543e23e5	1093	flagsOut = TCP_FLAG_ACK \| TCP_FLAG_FIN; // set outgoing FIN flag to ask them to close from their side
nixnax	142:54d1543e23e5	1094	ack_out++; // for FIN flag we have to increase the sequence by 1
nixnax	142:54d1543e23e5	1095	break;
nixnax	142:54d1543e23e5	1096	default:
nixnax	179:ba2b2ddd0da5	1097	return; // ignore all other packets
nixnax	142:54d1543e23e5	1098	} // switch
nixnax	142:54d1543e23e5	1099
nixnax	142:54d1543e23e5	1100	// The TCP flag handling is now done
nixnax	142:54d1543e23e5	1101	// first we swap source and destination TCP addresses and insert the new ack and seq numbers
nixnax	147:0f40005cbc5f	1102	swapIpAddresses(); // swap IP source and destination addresses
nixnax	149:969d98f6fb88	1103	swapIpPorts(); // swap IP source and destination ports
nixnax	142:54d1543e23e5	1104
nixnax	158:841592aed956	1105	ppp.tcp->ackTcpR = __REV( ack_out ); // byte reversed - tcp/ip messages are big-endian (high byte first)
nixnax	158:841592aed956	1106	ppp.tcp->seqTcpR = __REV( seq_out ); // byte reversed - tcp/ip messages are big-endian (high byte first)
nixnax	160:bd701ad564cb	1107
nixnax	156:163c23249731	1108	ppp.tcp->flag.All = flagsOut; // update the TCP flags
nixnax	142:54d1543e23e5	1109
nixnax	159:4d1bf96a59cd	1110	// recalculate all the header sizes
nixnax	154:18b2bd92f557	1111	tcpSize = headerSizeTcp + dataLen; // tcp packet size
nixnax	154:18b2bd92f557	1112	int newPacketSize = headerSizeIp + tcpSize; // calculate size of the outgoing packet
nixnax	159:4d1bf96a59cd	1113	ppp.ip->lengthR = __REV16 ( newPacketSize );
nixnax	142:54d1543e23e5	1114	ppp.pkt.len = newPacketSize+4+2; // ip packet length + 4-byte ppp prefix (ff 03 00 21) + 2 fcs (crc) bytes bytes at the end of the packet
nixnax	142:54d1543e23e5	1115
nixnax	142:54d1543e23e5	1116	// the header is all set up, now do the IP and TCP checksums
nixnax	146:a45f49a2b29c	1117	IpHeaderCheckSum(); // calculate new IP header checksum
nixnax	170:3d3b2126181c	1118	checkSumPseudoHeader( tcpSize ); // get the TCP pseudo-header checksum
nixnax	159:4d1bf96a59cd	1119	ppp.tcp->checksumR = 0; // before TCP checksum calculations the checksum bytes must be set cleared
nixnax	161:d59f778bc8ab	1120	unsigned int pseudoHeaderSum=dataCheckSum(ppp.tcpStart,tcpSize, 0); // continue the TCP checksum on the whole TCP packet
nixnax	159:4d1bf96a59cd	1121	ppp.tcp->checksumR = __REV16( pseudoHeaderSum); // tcp checksum done, store it in the TCP header
nixnax	160:bd701ad564cb	1122
nixnax	170:3d3b2126181c	1123	dumpHeaderIP(1); // dump outgoing IP header before sending the frame
nixnax	170:3d3b2126181c	1124	dumpHeaderTCP(1); // dump outgoing TCP header before sending the frame
nixnax	173:6774a0c851c4	1125	dumpDataTCP(1); // dump outgoing TCP data before sending the frame
nixnax	226:4898247048c7	1126	#define WAIT_BEFORE_IP_SEND_NO
nixnax	226:4898247048c7	1127	#ifdef WAIT_BEFORE_IP_SEND_YES
nixnax	226:4898247048c7	1128	wait_ms(45); // 45 ms delay before sending frame
nixnax	226:4898247048c7	1129	#endif
nixnax	144:01d98cf7738e	1130	sendPppFrame(); // All preparation complete - send the TCP response
nixnax	226:4898247048c7	1131	#define DUMP_TRANSMITTED_PPP_NO
nixnax	226:4898247048c7	1132	#ifdef DUMP_TRANSMITTED_PPP_YES
nixnax	226:4898247048c7	1133	dumpPPPFrame(); // dump every transmitted ppp frame to debug port
nixnax	226:4898247048c7	1134	#endif
nixnax	142:54d1543e23e5	1135	memset(ppp.pkt.buf+44,0,500); // flush out traces of previous data that we may scan for
nixnax	142:54d1543e23e5	1136	}
nixnax	142:54d1543e23e5	1137
nixnax	142:54d1543e23e5	1138	/// handle an incoming TCP packet
nixnax	142:54d1543e23e5	1139	void TCPpacket()
nixnax	142:54d1543e23e5	1140	{
nixnax	173:6774a0c851c4	1141	dumpHeaderIP(0); // dump incoming packet IP header
nixnax	173:6774a0c851c4	1142	dumpHeaderTCP(0); // dump incoming packet TCP header
nixnax	173:6774a0c851c4	1143	dumpDataTCP(0); // dump incoming packet data
nixnax	142:54d1543e23e5	1144	tcpHandler();
nixnax	142:54d1543e23e5	1145	}
nixnax	142:54d1543e23e5	1146
nixnax	142:54d1543e23e5	1147	/// handle the remaining IP protocols by ignoring them
nixnax	142:54d1543e23e5	1148	void otherProtocol()
nixnax	142:54d1543e23e5	1149	{
nixnax	230:ee097c486e45	1150	debugPuts("Other IP protocol");
nixnax	142:54d1543e23e5	1151	}
nixnax	142:54d1543e23e5	1152
nixnax	142:54d1543e23e5	1153	/// process an incoming IP packet
nixnax	142:54d1543e23e5	1154	void IPframe()
nixnax	142:54d1543e23e5	1155	{
nixnax	167:ff8a2d8beeb1	1156	int protocol = ppp.ip->protocol;
nixnax	142:54d1543e23e5	1157	switch (protocol) {
nixnax	142:54d1543e23e5	1158	case 1:
nixnax	142:54d1543e23e5	1159	ICMPpacket();
nixnax	142:54d1543e23e5	1160	break;
nixnax	142:54d1543e23e5	1161	case 2:
nixnax	142:54d1543e23e5	1162	IGMPpacket();
nixnax	142:54d1543e23e5	1163	break;
nixnax	142:54d1543e23e5	1164	case 17:
nixnax	142:54d1543e23e5	1165	UDPpacket();
nixnax	142:54d1543e23e5	1166	break;
nixnax	142:54d1543e23e5	1167	case 6:
nixnax	142:54d1543e23e5	1168	TCPpacket();
nixnax	142:54d1543e23e5	1169	break;
nixnax	142:54d1543e23e5	1170	default:
nixnax	142:54d1543e23e5	1171	otherProtocol();
nixnax	142:54d1543e23e5	1172	}
nixnax	142:54d1543e23e5	1173	}
nixnax	142:54d1543e23e5	1174
nixnax	227:f87156f9ef11	1175	/// process LCP packets
nixnax	142:54d1543e23e5	1176	void LCPframe()
nixnax	142:54d1543e23e5	1177	{
nixnax	175:b4e6f8a6fe00	1178	int code = ppp.lcp->code;
nixnax	142:54d1543e23e5	1179	switch (code) {
nixnax	227:f87156f9ef11	1180	case 1: // LCP configuration request
nixnax	231:6bd4523833a2	1181	debugPuts("LCP Config");
nixnax	227:f87156f9ef11	1182	if ( __REV16( ppp.lcp->lengthR ) == 4 ) {
nixnax	230:ee097c486e45	1183	debugPuts("LCP Ack\n");
nixnax	227:f87156f9ef11	1184	ppp.lcp->code=2; // acknowledge zero configuration request
nixnax	227:f87156f9ef11	1185	sendPppFrame();
nixnax	227:f87156f9ef11	1186	ppp.lcp->code=1; // request no options
nixnax	227:f87156f9ef11	1187	sendPppFrame();
nixnax	227:f87156f9ef11	1188	} else {
nixnax	230:ee097c486e45	1189	debugPuts("LCP request reject\n");
nixnax	227:f87156f9ef11	1190	ppp.lcp->code=4; // allow only "no options" which means Maximum Receive Unit (MRU) is default 1500 bytes
nixnax	227:f87156f9ef11	1191	sendPppFrame();
nixnax	227:f87156f9ef11	1192	}
nixnax	227:f87156f9ef11	1193	break;
nixnax	227:f87156f9ef11	1194	case 2: // LCP configuration acknowledge
nixnax	230:ee097c486e45	1195	debugPuts("LCP Ack\n"); // don't do anything, i.e. ignore
nixnax	227:f87156f9ef11	1196	break;
nixnax	227:f87156f9ef11	1197	case 5: // LCP end
nixnax	227:f87156f9ef11	1198	ppp.lcp->code=6; // acknowledge
nixnax	227:f87156f9ef11	1199	sendPppFrame(); // acknowledge
nixnax	227:f87156f9ef11	1200	ppp.online=0; // start hunting for connect string again
nixnax	227:f87156f9ef11	1201	pppInitStruct(); // flush the receive buffer
nixnax	230:ee097c486e45	1202	debugPuts("LCP End (Disconnect from host)\n");
nixnax	142:54d1543e23e5	1203	break; // end connection
nixnax	142:54d1543e23e5	1204	default:
nixnax	231:6bd4523833a2	1205	debugPuts("LCP Other\n");
nixnax	142:54d1543e23e5	1206	}
nixnax	142:54d1543e23e5	1207	}
nixnax	142:54d1543e23e5	1208
nixnax	142:54d1543e23e5	1209	/// discard packets that are not IP, IPCP, or LCP
nixnax	142:54d1543e23e5	1210	void discardedFrame()
nixnax	142:54d1543e23e5	1211	{
nixnax	142:54d1543e23e5	1212	if (v0) debugPrintf("Frame is not IP, IPCP or LCP: %02x %02x %02x %02x\n", ppp.pkt.buf[0],ppp.pkt.buf[1],ppp.pkt.buf[2],ppp.pkt.buf[3]);
nixnax	142:54d1543e23e5	1213	}
nixnax	142:54d1543e23e5	1214
nixnax	142:54d1543e23e5	1215	/// determine the packet type (IP, IPCP or LCP) of incoming packets
nixnax	142:54d1543e23e5	1216	void determinePacketType()
nixnax	142:54d1543e23e5	1217	{
nixnax	167:ff8a2d8beeb1	1218	if ( ppp.ppp->address != 0xff ) {
nixnax	231:6bd4523833a2	1219	debugPuts("Unexpected: PPP address != ff\n");
nixnax	142:54d1543e23e5	1220	return;
nixnax	142:54d1543e23e5	1221	}
nixnax	167:ff8a2d8beeb1	1222	if ( ppp.ppp->control != 3 ) {
nixnax	231:6bd4523833a2	1223	debugPuts("Unexpected: PPP control != 3\n");
nixnax	142:54d1543e23e5	1224	return;
nixnax	142:54d1543e23e5	1225	}
nixnax	167:ff8a2d8beeb1	1226	unsigned int protocol = __REV16( ppp.ppp->protocolR );
nixnax	167:ff8a2d8beeb1	1227	switch ( protocol ) {
nixnax	167:ff8a2d8beeb1	1228	case 0xc021:
nixnax	142:54d1543e23e5	1229	LCPframe();
nixnax	142:54d1543e23e5	1230	break; // link control
nixnax	167:ff8a2d8beeb1	1231	case 0x8021:
nixnax	142:54d1543e23e5	1232	IPCPframe();
nixnax	142:54d1543e23e5	1233	break; // IP control
nixnax	167:ff8a2d8beeb1	1234	case 0x0021:
nixnax	142:54d1543e23e5	1235	IPframe();
nixnax	142:54d1543e23e5	1236	break; // IP itself
nixnax	142:54d1543e23e5	1237	default:
nixnax	142:54d1543e23e5	1238	discardedFrame();
nixnax	142:54d1543e23e5	1239	}
nixnax	142:54d1543e23e5	1240	}
nixnax	142:54d1543e23e5	1241
nixnax	265:b05d78e226a9	1242
nixnax	265:b05d78e226a9	1243	/// SHA1 library
nixnax	265:b05d78e226a9	1244	/*
nixnax	265:b05d78e226a9	1245	SHA-1 in C
nixnax	265:b05d78e226a9	1246	By Steve Reid <steve@edmweb.com>
nixnax	265:b05d78e226a9	1247	100% Public Domain
nixnax	265:b05d78e226a9	1248	*/
nixnax	265:b05d78e226a9	1249
nixnax	265:b05d78e226a9	1250	#define SHA1HANDSOFF
nixnax	265:b05d78e226a9	1251
nixnax	265:b05d78e226a9	1252	#define rol(value, bits) (((value) << (bits)) \| ((value) >> (32 - (bits))))
nixnax	265:b05d78e226a9	1253
nixnax	265:b05d78e226a9	1254	/* blk0() and blk() perform the initial expand. */
nixnax	265:b05d78e226a9	1255	/* I got the idea of expanding during the round function from SSLeay */
nixnax	265:b05d78e226a9	1256	#if BYTE_ORDER == LITTLE_ENDIAN
nixnax	265:b05d78e226a9	1257	#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \
nixnax	265:b05d78e226a9	1258	\|(rol(block->l[i],8)&0x00FF00FF))
nixnax	265:b05d78e226a9	1259	#elif BYTE_ORDER == BIG_ENDIAN
nixnax	265:b05d78e226a9	1260	#define blk0(i) block->l[i]
nixnax	265:b05d78e226a9	1261	#else
nixnax	265:b05d78e226a9	1262	#error "Endianness not defined!"
nixnax	265:b05d78e226a9	1263	#endif
nixnax	265:b05d78e226a9	1264	#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \
nixnax	265:b05d78e226a9	1265	^block->l[(i+2)&15]^block->l[i&15],1))
nixnax	265:b05d78e226a9	1266
nixnax	265:b05d78e226a9	1267	/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
nixnax	265:b05d78e226a9	1268	#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
nixnax	265:b05d78e226a9	1269	#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30);
nixnax	265:b05d78e226a9	1270	#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
nixnax	265:b05d78e226a9	1271	#define R3(v,w,x,y,z,i) z+=(((w\|x)&y)\|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
nixnax	265:b05d78e226a9	1272	#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
nixnax	265:b05d78e226a9	1273
nixnax	265:b05d78e226a9	1274
nixnax	265:b05d78e226a9	1275	/* Hash a single 512-bit block. This is the core of the algorithm. */
nixnax	265:b05d78e226a9	1276
nixnax	265:b05d78e226a9	1277	void SHA1Transform(
nixnax	265:b05d78e226a9	1278	uint32_t state[5],
nixnax	265:b05d78e226a9	1279	const unsigned char buffer[64]
nixnax	265:b05d78e226a9	1280	)
nixnax	265:b05d78e226a9	1281	{
nixnax	265:b05d78e226a9	1282	uint32_t a, b, c, d, e;
nixnax	265:b05d78e226a9	1283
nixnax	275:bb2d582c20d6	1284	typedef union {
nixnax	265:b05d78e226a9	1285	unsigned char c[64];
nixnax	265:b05d78e226a9	1286	uint32_t l[16];
nixnax	265:b05d78e226a9	1287	} CHAR64LONG16;
nixnax	265:b05d78e226a9	1288
nixnax	265:b05d78e226a9	1289	#ifdef SHA1HANDSOFF
nixnax	265:b05d78e226a9	1290	CHAR64LONG16 block[1]; /* use array to appear as a pointer */
nixnax	265:b05d78e226a9	1291
nixnax	265:b05d78e226a9	1292	memcpy(block, buffer, 64);
nixnax	265:b05d78e226a9	1293	#else
nixnax	265:b05d78e226a9	1294	/* The following had better never be used because it causes the
nixnax	265:b05d78e226a9	1295	* pointer-to-const buffer to be cast into a pointer to non-const.
nixnax	265:b05d78e226a9	1296	* And the result is written through. I threw a "const" in, hoping
nixnax	265:b05d78e226a9	1297	* this will cause a diagnostic.
nixnax	265:b05d78e226a9	1298	*/
nixnax	265:b05d78e226a9	1299	CHAR64LONG16 block = (const CHAR64LONG16 ) buffer;
nixnax	265:b05d78e226a9	1300	#endif
nixnax	265:b05d78e226a9	1301	/* Copy context->state[] to working vars */
nixnax	265:b05d78e226a9	1302	a = state[0];
nixnax	265:b05d78e226a9	1303	b = state[1];
nixnax	265:b05d78e226a9	1304	c = state[2];
nixnax	265:b05d78e226a9	1305	d = state[3];
nixnax	265:b05d78e226a9	1306	e = state[4];
nixnax	265:b05d78e226a9	1307	/* 4 rounds of 20 operations each. Loop unrolled. */
nixnax	265:b05d78e226a9	1308	R0(a, b, c, d, e, 0);
nixnax	265:b05d78e226a9	1309	R0(e, a, b, c, d, 1);
nixnax	265:b05d78e226a9	1310	R0(d, e, a, b, c, 2);
nixnax	265:b05d78e226a9	1311	R0(c, d, e, a, b, 3);
nixnax	265:b05d78e226a9	1312	R0(b, c, d, e, a, 4);
nixnax	265:b05d78e226a9	1313	R0(a, b, c, d, e, 5);
nixnax	265:b05d78e226a9	1314	R0(e, a, b, c, d, 6);
nixnax	265:b05d78e226a9	1315	R0(d, e, a, b, c, 7);
nixnax	265:b05d78e226a9	1316	R0(c, d, e, a, b, 8);
nixnax	265:b05d78e226a9	1317	R0(b, c, d, e, a, 9);
nixnax	265:b05d78e226a9	1318	R0(a, b, c, d, e, 10);
nixnax	265:b05d78e226a9	1319	R0(e, a, b, c, d, 11);
nixnax	265:b05d78e226a9	1320	R0(d, e, a, b, c, 12);
nixnax	265:b05d78e226a9	1321	R0(c, d, e, a, b, 13);
nixnax	265:b05d78e226a9	1322	R0(b, c, d, e, a, 14);
nixnax	265:b05d78e226a9	1323	R0(a, b, c, d, e, 15);
nixnax	265:b05d78e226a9	1324	R1(e, a, b, c, d, 16);
nixnax	265:b05d78e226a9	1325	R1(d, e, a, b, c, 17);
nixnax	265:b05d78e226a9	1326	R1(c, d, e, a, b, 18);
nixnax	265:b05d78e226a9	1327	R1(b, c, d, e, a, 19);
nixnax	265:b05d78e226a9	1328	R2(a, b, c, d, e, 20);
nixnax	265:b05d78e226a9	1329	R2(e, a, b, c, d, 21);
nixnax	265:b05d78e226a9	1330	R2(d, e, a, b, c, 22);
nixnax	265:b05d78e226a9	1331	R2(c, d, e, a, b, 23);
nixnax	265:b05d78e226a9	1332	R2(b, c, d, e, a, 24);
nixnax	265:b05d78e226a9	1333	R2(a, b, c, d, e, 25);
nixnax	265:b05d78e226a9	1334	R2(e, a, b, c, d, 26);
nixnax	265:b05d78e226a9	1335	R2(d, e, a, b, c, 27);
nixnax	265:b05d78e226a9	1336	R2(c, d, e, a, b, 28);
nixnax	265:b05d78e226a9	1337	R2(b, c, d, e, a, 29);
nixnax	265:b05d78e226a9	1338	R2(a, b, c, d, e, 30);
nixnax	265:b05d78e226a9	1339	R2(e, a, b, c, d, 31);
nixnax	265:b05d78e226a9	1340	R2(d, e, a, b, c, 32);
nixnax	265:b05d78e226a9	1341	R2(c, d, e, a, b, 33);
nixnax	265:b05d78e226a9	1342	R2(b, c, d, e, a, 34);
nixnax	265:b05d78e226a9	1343	R2(a, b, c, d, e, 35);
nixnax	265:b05d78e226a9	1344	R2(e, a, b, c, d, 36);
nixnax	265:b05d78e226a9	1345	R2(d, e, a, b, c, 37);
nixnax	265:b05d78e226a9	1346	R2(c, d, e, a, b, 38);
nixnax	265:b05d78e226a9	1347	R2(b, c, d, e, a, 39);
nixnax	265:b05d78e226a9	1348	R3(a, b, c, d, e, 40);
nixnax	265:b05d78e226a9	1349	R3(e, a, b, c, d, 41);
nixnax	265:b05d78e226a9	1350	R3(d, e, a, b, c, 42);
nixnax	265:b05d78e226a9	1351	R3(c, d, e, a, b, 43);
nixnax	265:b05d78e226a9	1352	R3(b, c, d, e, a, 44);
nixnax	265:b05d78e226a9	1353	R3(a, b, c, d, e, 45);
nixnax	265:b05d78e226a9	1354	R3(e, a, b, c, d, 46);
nixnax	265:b05d78e226a9	1355	R3(d, e, a, b, c, 47);
nixnax	265:b05d78e226a9	1356	R3(c, d, e, a, b, 48);
nixnax	265:b05d78e226a9	1357	R3(b, c, d, e, a, 49);
nixnax	265:b05d78e226a9	1358	R3(a, b, c, d, e, 50);
nixnax	265:b05d78e226a9	1359	R3(e, a, b, c, d, 51);
nixnax	265:b05d78e226a9	1360	R3(d, e, a, b, c, 52);
nixnax	265:b05d78e226a9	1361	R3(c, d, e, a, b, 53);
nixnax	265:b05d78e226a9	1362	R3(b, c, d, e, a, 54);
nixnax	265:b05d78e226a9	1363	R3(a, b, c, d, e, 55);
nixnax	265:b05d78e226a9	1364	R3(e, a, b, c, d, 56);
nixnax	265:b05d78e226a9	1365	R3(d, e, a, b, c, 57);
nixnax	265:b05d78e226a9	1366	R3(c, d, e, a, b, 58);
nixnax	265:b05d78e226a9	1367	R3(b, c, d, e, a, 59);
nixnax	265:b05d78e226a9	1368	R4(a, b, c, d, e, 60);
nixnax	265:b05d78e226a9	1369	R4(e, a, b, c, d, 61);
nixnax	265:b05d78e226a9	1370	R4(d, e, a, b, c, 62);
nixnax	265:b05d78e226a9	1371	R4(c, d, e, a, b, 63);
nixnax	265:b05d78e226a9	1372	R4(b, c, d, e, a, 64);
nixnax	265:b05d78e226a9	1373	R4(a, b, c, d, e, 65);
nixnax	265:b05d78e226a9	1374	R4(e, a, b, c, d, 66);
nixnax	265:b05d78e226a9	1375	R4(d, e, a, b, c, 67);
nixnax	265:b05d78e226a9	1376	R4(c, d, e, a, b, 68);
nixnax	265:b05d78e226a9	1377	R4(b, c, d, e, a, 69);
nixnax	265:b05d78e226a9	1378	R4(a, b, c, d, e, 70);
nixnax	265:b05d78e226a9	1379	R4(e, a, b, c, d, 71);
nixnax	265:b05d78e226a9	1380	R4(d, e, a, b, c, 72);
nixnax	265:b05d78e226a9	1381	R4(c, d, e, a, b, 73);
nixnax	265:b05d78e226a9	1382	R4(b, c, d, e, a, 74);
nixnax	265:b05d78e226a9	1383	R4(a, b, c, d, e, 75);
nixnax	265:b05d78e226a9	1384	R4(e, a, b, c, d, 76);
nixnax	265:b05d78e226a9	1385	R4(d, e, a, b, c, 77);
nixnax	265:b05d78e226a9	1386	R4(c, d, e, a, b, 78);
nixnax	265:b05d78e226a9	1387	R4(b, c, d, e, a, 79);
nixnax	265:b05d78e226a9	1388	/* Add the working vars back into context.state[] */
nixnax	265:b05d78e226a9	1389	state[0] += a;
nixnax	265:b05d78e226a9	1390	state[1] += b;
nixnax	265:b05d78e226a9	1391	state[2] += c;
nixnax	265:b05d78e226a9	1392	state[3] += d;
nixnax	265:b05d78e226a9	1393	state[4] += e;
nixnax	265:b05d78e226a9	1394	/* Wipe variables */
nixnax	265:b05d78e226a9	1395	a = b = c = d = e = 0;
nixnax	265:b05d78e226a9	1396	#ifdef SHA1HANDSOFF
nixnax	265:b05d78e226a9	1397	memset(block, '\0', sizeof(block));
nixnax	265:b05d78e226a9	1398	#endif
nixnax	265:b05d78e226a9	1399	}
nixnax	265:b05d78e226a9	1400
nixnax	265:b05d78e226a9	1401
nixnax	265:b05d78e226a9	1402	/* SHA1Init - Initialize new context */
nixnax	265:b05d78e226a9	1403
nixnax	265:b05d78e226a9	1404	void SHA1Init(
nixnax	265:b05d78e226a9	1405	SHA1_CTX * context
nixnax	265:b05d78e226a9	1406	)
nixnax	265:b05d78e226a9	1407	{
nixnax	265:b05d78e226a9	1408	/* SHA1 initialization constants */
nixnax	265:b05d78e226a9	1409	context->state[0] = 0x67452301;
nixnax	265:b05d78e226a9	1410	context->state[1] = 0xEFCDAB89;
nixnax	265:b05d78e226a9	1411	context->state[2] = 0x98BADCFE;
nixnax	265:b05d78e226a9	1412	context->state[3] = 0x10325476;
nixnax	265:b05d78e226a9	1413	context->state[4] = 0xC3D2E1F0;
nixnax	265:b05d78e226a9	1414	context->count[0] = context->count[1] = 0;
nixnax	265:b05d78e226a9	1415	}
nixnax	265:b05d78e226a9	1416
nixnax	265:b05d78e226a9	1417
nixnax	265:b05d78e226a9	1418	/* Run your data through this. */
nixnax	265:b05d78e226a9	1419
nixnax	265:b05d78e226a9	1420	void SHA1Update(
nixnax	265:b05d78e226a9	1421	SHA1_CTX * context,
nixnax	265:b05d78e226a9	1422	const unsigned char *data,
nixnax	265:b05d78e226a9	1423	uint32_t len
nixnax	265:b05d78e226a9	1424	)
nixnax	265:b05d78e226a9	1425	{
nixnax	265:b05d78e226a9	1426	uint32_t i;
nixnax	265:b05d78e226a9	1427
nixnax	265:b05d78e226a9	1428	uint32_t j;
nixnax	265:b05d78e226a9	1429
nixnax	265:b05d78e226a9	1430	j = context->count[0];
nixnax	265:b05d78e226a9	1431	if ((context->count[0] += len << 3) < j)
nixnax	265:b05d78e226a9	1432	context->count[1]++;
nixnax	265:b05d78e226a9	1433	context->count[1] += (len >> 29);
nixnax	265:b05d78e226a9	1434	j = (j >> 3) & 63;
nixnax	275:bb2d582c20d6	1435	if ((j + len) > 63) {
nixnax	265:b05d78e226a9	1436	memcpy(&context->buffer[j], data, (i = 64 - j));
nixnax	265:b05d78e226a9	1437	SHA1Transform(context->state, context->buffer);
nixnax	275:bb2d582c20d6	1438	for (; i + 63 < len; i += 64) {
nixnax	265:b05d78e226a9	1439	SHA1Transform(context->state, &data[i]);
nixnax	265:b05d78e226a9	1440	}
nixnax	265:b05d78e226a9	1441	j = 0;
nixnax	275:bb2d582c20d6	1442	} else
nixnax	265:b05d78e226a9	1443	i = 0;
nixnax	265:b05d78e226a9	1444	memcpy(&context->buffer[j], &data[i], len - i);
nixnax	265:b05d78e226a9	1445	}
nixnax	265:b05d78e226a9	1446
nixnax	265:b05d78e226a9	1447
nixnax	265:b05d78e226a9	1448	/* Add padding and return the message digest. */
nixnax	265:b05d78e226a9	1449
nixnax	265:b05d78e226a9	1450	void SHA1Final(
nixnax	265:b05d78e226a9	1451	unsigned char digest[20],
nixnax	265:b05d78e226a9	1452	SHA1_CTX * context
nixnax	265:b05d78e226a9	1453	)
nixnax	265:b05d78e226a9	1454	{
nixnax	265:b05d78e226a9	1455	unsigned i;
nixnax	265:b05d78e226a9	1456
nixnax	265:b05d78e226a9	1457	unsigned char finalcount[8];
nixnax	265:b05d78e226a9	1458
nixnax	265:b05d78e226a9	1459	unsigned char c;
nixnax	265:b05d78e226a9	1460
nixnax	275:bb2d582c20d6	1461	for (i = 0; i < 8; i++) {
nixnax	265:b05d78e226a9	1462	finalcount[i] = (unsigned char) ((context->count[(i >= 4 ? 0 : 1)] >> ((3 - (i & 3)) * 8)) & 255); /* Endian independent */
nixnax	265:b05d78e226a9	1463	}
nixnax	265:b05d78e226a9	1464
nixnax	265:b05d78e226a9	1465	c = 0200;
nixnax	265:b05d78e226a9	1466	SHA1Update(context, &c, 1);
nixnax	275:bb2d582c20d6	1467	while ((context->count[0] & 504) != 448) {
nixnax	265:b05d78e226a9	1468	c = 0000;
nixnax	265:b05d78e226a9	1469	SHA1Update(context, &c, 1);
nixnax	265:b05d78e226a9	1470	}
nixnax	265:b05d78e226a9	1471	SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform() */
nixnax	275:bb2d582c20d6	1472	for (i = 0; i < 20; i++) {
nixnax	265:b05d78e226a9	1473	digest[i] = (unsigned char)
nixnax	275:bb2d582c20d6	1474	((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255);
nixnax	265:b05d78e226a9	1475	}
nixnax	265:b05d78e226a9	1476	/* Wipe variables */
nixnax	265:b05d78e226a9	1477	memset(context, '\0', sizeof(*context));
nixnax	265:b05d78e226a9	1478	memset(&finalcount, '\0', sizeof(finalcount));
nixnax	265:b05d78e226a9	1479	}
nixnax	265:b05d78e226a9	1480
nixnax	265:b05d78e226a9	1481	void sha1(
nixnax	265:b05d78e226a9	1482	char *hash_out,
nixnax	265:b05d78e226a9	1483	const char *str,
nixnax	265:b05d78e226a9	1484	int len)
nixnax	265:b05d78e226a9	1485	{
nixnax	265:b05d78e226a9	1486	SHA1_CTX ctx;
nixnax	265:b05d78e226a9	1487	unsigned int ii;
nixnax	265:b05d78e226a9	1488
nixnax	265:b05d78e226a9	1489	SHA1Init(&ctx);
nixnax	265:b05d78e226a9	1490	for (ii=0; ii<len; ii+=1)
nixnax	265:b05d78e226a9	1491	SHA1Update(&ctx, (const unsigned char*)str + ii, 1);
nixnax	265:b05d78e226a9	1492	SHA1Final((unsigned char *)hash_out, &ctx);
nixnax	265:b05d78e226a9	1493	// hash_out[20] = '\0';
nixnax	265:b05d78e226a9	1494	}
nixnax	265:b05d78e226a9	1495
nixnax	265:b05d78e226a9	1496
nixnax	146:a45f49a2b29c	1497	/// a sniffer tool to assist in figuring out where in the code we are having characters in the input buffer
nixnax	146:a45f49a2b29c	1498	void sniff()
nixnax	146:a45f49a2b29c	1499	{
nixnax	221:1d7c32d8256b	1500	if ( pc.readable() ) debugPuts( "Sniff - Char available!\n" ); // if this prints anything it means there is a character in the serial receive buffer
nixnax	146:a45f49a2b29c	1501	}
nixnax	146:a45f49a2b29c	1502
nixnax	142:54d1543e23e5	1503	/// scan the PPP serial input stream for frame start markers
nixnax	143:c5019f856a56	1504	void waitForPppFrame()
nixnax	142:54d1543e23e5	1505	{
nixnax	142:54d1543e23e5	1506	while(1) {
nixnax	266:47eea4b910ad	1507	if ( ppp.rx.head != ppp.rx.tail ) { // check for something in the receive buffer
nixnax	142:54d1543e23e5	1508	int oldTail = ppp.rx.tail; // remember where the character is located in the buffer
nixnax	142:54d1543e23e5	1509	int rx = pc_getBuf(); // get the character
nixnax	238:f39289ed5a2e	1510	if (rx==0x7e) { // check for frame start/end character 0x7e
nixnax	260:2c9a01c9d03e	1511	if (ppp.firstFrame) { // is this the start of the first frame
nixnax	142:54d1543e23e5	1512	ppp.rx.rtail = ppp.rx.tail; // update real-time tail with the virtual tail
nixnax	142:54d1543e23e5	1513	ppp.hdlc.frameStartIndex = ppp.rx.tail; // remember where first frame started
nixnax	181:bcfe7fe2142d	1514	ppp.firstFrame=0; // clear first frame flag
nixnax	142:54d1543e23e5	1515	} else {
nixnax	142:54d1543e23e5	1516	ppp.hdlc.frameEndIndex=oldTail; // mark the frame end character
nixnax	142:54d1543e23e5	1517	processPPPFrame(ppp.hdlc.frameStartIndex, ppp.hdlc.frameEndIndex); // process the frame
nixnax	142:54d1543e23e5	1518	ppp.rx.rtail = ppp.rx.tail; // update real-time tail with the virtual tail
nixnax	142:54d1543e23e5	1519	ppp.hdlc.frameStartIndex = ppp.rx.tail; // remember where next frame started
nixnax	142:54d1543e23e5	1520	break;
nixnax	142:54d1543e23e5	1521	}
nixnax	142:54d1543e23e5	1522	}
nixnax	142:54d1543e23e5	1523	}
nixnax	210:a2a651249a9a	1524	// change below to YES to enable the serial to UDP demo
nixnax	210:a2a651249a9a	1525	#define SERIAL_TO_UDP_NO
nixnax	210:a2a651249a9a	1526	#ifdef SERIAL_TO_UDP_YES
nixnax	210:a2a651249a9a	1527	sendUdpData(); // demo that sends characters received on the DEBUG serial port via UDP to another host
nixnax	210:a2a651249a9a	1528	#endif
nixnax	142:54d1543e23e5	1529	}
nixnax	142:54d1543e23e5	1530	}
nixnax	142:54d1543e23e5	1531
nixnax	265:b05d78e226a9	1532
nixnax	209:aa514cd631ee	1533	/// Wait for a dial-up modem connect command ("CLIENT") from the host PC, if found, we set ppp.online to true, which starts the IP packet scanner.
nixnax	209:aa514cd631ee	1534	// Note: a 0x7E in the input stream (ppp start of frame character) will also set ppp.online to true - see the code in pppReceiveHandler()
nixnax	153:7993def8663f	1535	void waitForPcConnectString()
nixnax	142:54d1543e23e5	1536	{
nixnax	142:54d1543e23e5	1537	while(ppp.online == 0) {
nixnax	142:54d1543e23e5	1538	// search for Windows Dialup Networking "Direct Connection Between Two Computers" expected connect string
nixnax	142:54d1543e23e5	1539	char * found1 = strstr( (char *)ppp.rx.buf, "CLIENT" );
nixnax	142:54d1543e23e5	1540	if (found1 != NULL) {
nixnax	230:ee097c486e45	1541	if (v0) debugPuts("Connected: Found connect string \"CLIENT\", sent \"CLIENTSERVER\"\n");
nixnax	208:73086736610a	1542	// respond with Windows Dialup networking expected "Direct Connection Between Two Computers" response string
nixnax	142:54d1543e23e5	1543	pc.puts("CLIENTSERVER");
nixnax	142:54d1543e23e5	1544	ppp.online=1; // we are connected - set flag so we stop looking for the connect string
nixnax	142:54d1543e23e5	1545	}
nixnax	142:54d1543e23e5	1546	}
nixnax	142:54d1543e23e5	1547	}
nixnax	142:54d1543e23e5	1548
nixnax	144:01d98cf7738e	1549	/// Initialize PPP data structure and set serial port(s) baud rate(s)
nixnax	144:01d98cf7738e	1550	void initializePpp()
nixnax	142:54d1543e23e5	1551	{
nixnax	210:a2a651249a9a	1552	#ifdef SERIAL_PORT_MONITOR_YES
nixnax	144:01d98cf7738e	1553	debugBaudRate(115200); // baud rate for (optional) debug serial port
nixnax	230:ee097c486e45	1554	debugPuts("\x1b[2J\x1b[H\x1b[30m"); // VT100 codes for clear_screen, home, black_text - Tera Term is a handy VT100 terminal
nixnax	184:4133f557d4d4	1555	wait_ms(200); // a brief wait so a human can see the reset event
nixnax	258:1eb9abd66922	1556	debugPuts("mbed PPP-Blinky HTTP & WebSocket server ready :)\n");
nixnax	210:a2a651249a9a	1557	#endif
nixnax	179:ba2b2ddd0da5	1558	pppInitStruct(); // initialize all the variables/properties/buffers
nixnax	179:ba2b2ddd0da5	1559	pc.baud(115200); // pc serial port acting as a dial-up modem - for PPP traffic
nixnax	179:ba2b2ddd0da5	1560	pc.attach(&pppReceiveHandler, RawSerial::RxIrq); // set up serial port receive interrupt handler
nixnax	143:c5019f856a56	1561	}
nixnax	265:b05d78e226a9	1562

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	27 Dec 2016
Imports:	426
Forks:	1
Commits:	276
Dependents:	0
Dependencies:	1
Followers:	22

The code in this repository is MIT licensed.