Nicolas Nackel / Mbed 2 deprecated PPP-Blinky

Small Internet Protocol Stack using a standard serial port.

Dependencies:   mbed

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.

main.cpp@35:e7068df4d971, 2017-01-05 (annotated)

Committer:
nixnax
Date:
Thu Jan 05 08:16:50 2017 +0000
Revision:
35:e7068df4d971
Parent:
34:8a6fbc73a7f1
Child:
36:2a9b457f8276
TCP State Handler Fiddle

Who changed what in which revision?

UserRevisionLine numberNew contents of line
nixnax 0:2cf4880c312a 1 #include "mbed.h"
nixnax 0:2cf4880c312a 2
nixnax 29:30de79d658f6 3 // Copyright 2016 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 12:db0dc91f0231 4
nixnax 0:2cf4880c312a 5 // Proof-of-concept for TCP/IP using Windows 7/8/10 Dial Up Networking over MBED USB Virtual COM Port
nixnax 0:2cf4880c312a 6
nixnax 4:a469050d5b80 7 // Toggles LED1 every time the PC sends an IP packet over the PPP link
nixnax 4:a469050d5b80 8
nixnax 29:30de79d658f6 9 // Note - turn off all Dial Up authentication, passwords, compression options - Simplest link possible.
nixnax 29:30de79d658f6 10 // Be sure to read the section on mbed on "Windows 7/8/10 PPP bug" if you keep on getting Dial Up Error 777.
nixnax 0:2cf4880c312a 11
nixnax 9:0992486d4a30 12 // Handy links
nixnax 29:30de79d658f6 13 // https://developer.mbed.org/users/nixnax/code/PPP-Blinky/ - Handy Notes, Instructions and introduction
nixnax 6:fba4c2e817b8 14 // http://atari.kensclassics.org/wcomlog.htm
nixnax 6:fba4c2e817b8 15 // https://technet.microsoft.com/en-us/library/cc957992.aspx
nixnax 9:0992486d4a30 16 // https://en.wikibooks.org/wiki/Serial_Programming/IP_Over_Serial_Connections
nixnax 6:fba4c2e817b8 17
nixnax 29:30de79d658f6 18 // Handy tools
nixnax 29:30de79d658f6 19 // https://ttssh2.osdn.jp/index.html.en - A good terminal program to monitor the debug output from the second serial port with!
nixnax 29:30de79d658f6 20 // Wireshark - can't monitor Dial-Up network packets on windows, but very hand - can import our dumpFrame routine's hex output
nixnax 29:30de79d658f6 21 // Microsoft network monitor - real-time monitoring of all our packets
nixnax 29:30de79d658f6 22 // http://pingtester.net/ - nice tool for high rate ping testing
nixnax 29:30de79d658f6 23 // http://www.sunshine2k.de/coding/javascript/crc/crc_js.html - Correctly calculates the 16-bit FCS (crc) on our frames (Choose CRC16_CCITT_FALSE)
nixnax 29:30de79d658f6 24 // The curl program in Windows Powershell - use like this to test the webserver: while (1) { curl 172.10.10.1 }
nixnax 29:30de79d658f6 25 // https://technet.microsoft.com/en-us/sysinternals/pstools.aspx - psping for fast testing of ICMP ping function
nixnax 29:30de79d658f6 26 // https://eternallybored.org/misc/netcat/ - use netcat -u 172.10.10.1 80 to send/receive UDP packets from our board
nixnax 0:2cf4880c312a 27
nixnax 29:30de79d658f6 28 Serial pc(USBTX, USBRX); // The USB com port - Set this up as a Dial-Up Modem on your pc
nixnax 29:30de79d658f6 29 Serial xx(PC_10, PC_11); // See debug messages here. Not necessary to work, but VERY interesting output!
nixnax 29:30de79d658f6 30
nixnax 29:30de79d658f6 31 int v0=1;
nixnax 29:30de79d658f6 32 int v1=1; // verbosity flags used in debug printouts - change to 1/0 to see more/less debug info
nixnax 29:30de79d658f6 33
nixnax 29:30de79d658f6 34 // the commented #define below gets rid of ALL the debug printfs
nixnax 20:5db9b77b38a6 35 #define debug(x) xx.printf x
nixnax 19:e53cdee9a33c 36 //#define debug(x) {}
nixnax 9:0992486d4a30 37
nixnax 29:30de79d658f6 38 DigitalOut led1(LED1); // this led toggles when a packet is received
nixnax 4:a469050d5b80 39
nixnax 29:30de79d658f6 40 // the standard hdlc frame start/end character
nixnax 4:a469050d5b80 41 #define FRAME_7E (0x7e)
nixnax 29:30de79d658f6 42
nixnax 29:30de79d658f6 43 // the serial port receive buffer and packet buffer
nixnax 29:30de79d658f6 44 #define BUFLEN (1<<12)
nixnax 20:5db9b77b38a6 45 char rxbuf[BUFLEN];
nixnax 29:30de79d658f6 46 char frbuf[3000]; // send/receive buffer for ppp frames
nixnax 0:2cf4880c312a 47
nixnax 29:30de79d658f6 48 // a structure to keep all our ppp globals in
nixnax 29:30de79d658f6 49 struct pppType {
nixnax 29:30de79d658f6 50 int online;
nixnax 26:11f4eb2663a7 51 int ident;
nixnax 28:1aa629be05e7 52 int sync;
nixnax 31:e000c1b9c565 53 unsigned int seq;
nixnax 29:30de79d658f6 54 int crc;
nixnax 29:30de79d658f6 55 int ledState;
nixnax 4:a469050d5b80 56 struct {
nixnax 20:5db9b77b38a6 57 char * buf;
nixnax 29:30de79d658f6 58 volatile int head;
nixnax 29:30de79d658f6 59 volatile int tail;
nixnax 9:0992486d4a30 60 int total;
nixnax 4:a469050d5b80 61 } rx; // serial port buffer
nixnax 4:a469050d5b80 62 struct {
nixnax 6:fba4c2e817b8 63 int id;
nixnax 4:a469050d5b80 64 int len;
nixnax 4:a469050d5b80 65 int crc;
nixnax 4:a469050d5b80 66 char * buf;
nixnax 4:a469050d5b80 67 } pkt; // ppp buffer
nixnax 29:30de79d658f6 68 };
nixnax 31:e000c1b9c565 69
nixnax 29:30de79d658f6 70 pppType ppp; // our global - definitely not thread safe
nixnax 0:2cf4880c312a 71
nixnax 29:30de79d658f6 72 // intitialize our globals
nixnax 29:30de79d658f6 73 void pppInitStruct()
nixnax 29:30de79d658f6 74 {
nixnax 29:30de79d658f6 75 ppp.online=0;
nixnax 29:30de79d658f6 76 ppp.rx.buf=rxbuf;
nixnax 29:30de79d658f6 77 ppp.rx.tail=0;
nixnax 29:30de79d658f6 78 ppp.rx.head=0;
nixnax 29:30de79d658f6 79 ppp.rx.total=0;
nixnax 29:30de79d658f6 80 ppp.pkt.buf=frbuf;
nixnax 29:30de79d658f6 81 ppp.pkt.len=0;
nixnax 29:30de79d658f6 82 ppp.ident=0;
nixnax 29:30de79d658f6 83 ppp.sync=0;
nixnax 35:e7068df4d971 84 ppp.seq=1000;
nixnax 29:30de79d658f6 85 ppp.ledState=0;
nixnax 29:30de79d658f6 86 }
nixnax 26:11f4eb2663a7 87
nixnax 29:30de79d658f6 88 void crcReset()
nixnax 29:30de79d658f6 89 {
nixnax 29:30de79d658f6 90 ppp.crc=0xffff; // crc restart
nixnax 29:30de79d658f6 91 }
nixnax 4:a469050d5b80 92
nixnax 29:30de79d658f6 93 void crcDo(int x) // cumulative crc
nixnax 29:30de79d658f6 94 {
nixnax 29:30de79d658f6 95 for (int i=0; i<8; i++) {
nixnax 29:30de79d658f6 96 ppp.crc=((ppp.crc&1)^(x&1))?(ppp.crc>>1)^0x8408:ppp.crc>>1; // crc calculator
nixnax 29:30de79d658f6 97 x>>=1;
nixnax 29:30de79d658f6 98 }
nixnax 29:30de79d658f6 99 }
nixnax 29:30de79d658f6 100
nixnax 29:30de79d658f6 101 int crcBuf(char * buf, int size) // crc on an entire block of memory
nixnax 29:30de79d658f6 102 {
nixnax 31:e000c1b9c565 103 crcReset();
nixnax 31:e000c1b9c565 104 for(int i=0; i<size; i++)crcDo(*buf++);
nixnax 29:30de79d658f6 105 return ppp.crc;
nixnax 29:30de79d658f6 106 }
nixnax 0:2cf4880c312a 107
nixnax 0:2cf4880c312a 108 void rxHandler() // serial port receive interrupt handler
nixnax 0:2cf4880c312a 109 {
nixnax 17:4918c893d802 110 while ( pc.readable() ) {
nixnax 20:5db9b77b38a6 111 int hd = (ppp.rx.head+1)&(BUFLEN-1); // increment/wrap
nixnax 20:5db9b77b38a6 112 if ( hd == ppp.rx.tail ) break; // watch for buffer full
nixnax 17:4918c893d802 113 ppp.rx.buf[ppp.rx.head]=pc.getc(); // insert in rx buffer
nixnax 20:5db9b77b38a6 114 ppp.rx.head = hd; // update head pointer
nixnax 15:b0154c910143 115 }
nixnax 0:2cf4880c312a 116 }
nixnax 0:2cf4880c312a 117
nixnax 29:30de79d658f6 118 void led1Toggle()
nixnax 29:30de79d658f6 119 {
nixnax 29:30de79d658f6 120 ppp.ledState = ppp.ledState? 0 : 1;
nixnax 29:30de79d658f6 121 led1 = ppp.ledState;
nixnax 14:c65831c25aaa 122 }
nixnax 14:c65831c25aaa 123
nixnax 22:00df34cd4d7e 124 int rxbufNotEmpty() // check if rx buffer has data
nixnax 0:2cf4880c312a 125 {
nixnax 22:00df34cd4d7e 126 __disable_irq(); // critical section start
nixnax 29:30de79d658f6 127 int notEmpty = (ppp.rx.head==ppp.rx.tail) ? 0 : 1 ;
nixnax 22:00df34cd4d7e 128 __enable_irq(); // critical section end
nixnax 22:00df34cd4d7e 129 return notEmpty;
nixnax 0:2cf4880c312a 130 }
nixnax 0:2cf4880c312a 131
nixnax 0:2cf4880c312a 132 int pc_getBuf() // get one character from the buffer
nixnax 0:2cf4880c312a 133 {
nixnax 22:00df34cd4d7e 134 if ( rxbufNotEmpty() ) {
nixnax 4:a469050d5b80 135 int x = ppp.rx.buf[ ppp.rx.tail ];
nixnax 20:5db9b77b38a6 136 __disable_irq(); // critical section start
nixnax 29:30de79d658f6 137 ppp.rx.tail=(ppp.rx.tail+1)&(BUFLEN-1);
nixnax 20:5db9b77b38a6 138 __enable_irq(); // critical section end
nixnax 0:2cf4880c312a 139 return x;
nixnax 20:5db9b77b38a6 140 } else return -1;
nixnax 0:2cf4880c312a 141 }
nixnax 0:2cf4880c312a 142
nixnax 4:a469050d5b80 143 void scanForConnectString(); // scan for connect attempts from pc
nixnax 1:9e03798d4367 144
nixnax 29:30de79d658f6 145 void processFrame(int start, int end) // process received frame
nixnax 29:30de79d658f6 146 {
nixnax 14:c65831c25aaa 147 led1Toggle(); // change led1 state when frames are received
nixnax 29:30de79d658f6 148 if(start==end) {
nixnax 29:30de79d658f6 149 pc.putc(0x7e);
nixnax 29:30de79d658f6 150 return;
nixnax 29:30de79d658f6 151 }
nixnax 9:0992486d4a30 152 crcReset();
nixnax 9:0992486d4a30 153 char * dest = ppp.pkt.buf;
nixnax 9:0992486d4a30 154 ppp.pkt.len=0;
nixnax 9:0992486d4a30 155 int unstuff=0;
nixnax 17:4918c893d802 156 int idx = start;
nixnax 17:4918c893d802 157 while(1) {
nixnax 9:0992486d4a30 158 if (unstuff==0) {
nixnax 29:30de79d658f6 159 if (rxbuf[idx]==0x7d) unstuff=1;
nixnax 29:30de79d658f6 160 else {
nixnax 29:30de79d658f6 161 *dest = rxbuf[idx];
nixnax 29:30de79d658f6 162 ppp.pkt.len++;
nixnax 29:30de79d658f6 163 dest++;
nixnax 29:30de79d658f6 164 crcDo(rxbuf[idx]);
nixnax 29:30de79d658f6 165 }
nixnax 12:db0dc91f0231 166 } else { // unstuff
nixnax 29:30de79d658f6 167 *dest = rxbuf[idx]^0x20;
nixnax 29:30de79d658f6 168 ppp.pkt.len++;
nixnax 29:30de79d658f6 169 dest++;
nixnax 29:30de79d658f6 170 crcDo(rxbuf[idx]^0x20);
nixnax 9:0992486d4a30 171 unstuff=0;
nixnax 9:0992486d4a30 172 }
nixnax 17:4918c893d802 173 idx = (idx+1) & (BUFLEN-1);
nixnax 17:4918c893d802 174 if (idx == end) break;
nixnax 9:0992486d4a30 175 }
nixnax 29:30de79d658f6 176 ppp.pkt.crc = ppp.crc & 0xffff;
nixnax 9:0992486d4a30 177 if (ppp.pkt.crc == 0xf0b8) { // check for good CRC
nixnax 16:cb0b80c24ba2 178 void determinePacketType(); // declaration only
nixnax 9:0992486d4a30 179 determinePacketType();
nixnax 29:30de79d658f6 180 } else if (v0) {
nixnax 29:30de79d658f6 181 debug(("PPP FCS(crc) Error CRC=%x Length = %d\n",ppp.pkt.crc,ppp.pkt.len));
nixnax 9:0992486d4a30 182 }
nixnax 9:0992486d4a30 183 }
nixnax 9:0992486d4a30 184
nixnax 29:30de79d658f6 185 // Note - the hex output of dumpframe can be imported into WireShark
nixnax 29:30de79d658f6 186 // Copy the frame's hex output from your terminal program and save as a text file
nixnax 29:30de79d658f6 187 // In WireShark, use "Import Hex File". Options are No Offset, protocol=PPP.
nixnax 29:30de79d658f6 188 void dumpFrame()
nixnax 29:30de79d658f6 189 {
nixnax 29:30de79d658f6 190 for(int i=0; i<ppp.pkt.len; i++) debug(("%02x ", ppp.pkt.buf[i]));
nixnax 16:cb0b80c24ba2 191 debug((" C=%02x %02x L=%d\n", ppp.pkt.crc&0xff, (ppp.pkt.crc>>8)&0xff, ppp.pkt.len));
nixnax 16:cb0b80c24ba2 192 }
nixnax 16:cb0b80c24ba2 193
nixnax 29:30de79d658f6 194 void hdlcPut(int ch) // do hdlc handling of special (flag) characters
nixnax 29:30de79d658f6 195 {
nixnax 29:30de79d658f6 196 if ( (ch<0x20) || (ch==0x7d) || (ch==0x7e) ) {
nixnax 29:30de79d658f6 197 pc.putc(0x7d);
nixnax 29:30de79d658f6 198 pc.putc(ch^0x20);
nixnax 29:30de79d658f6 199 } else {
nixnax 29:30de79d658f6 200 pc.putc(ch);
nixnax 29:30de79d658f6 201 }
nixnax 11:f58998c24f0b 202 }
nixnax 9:0992486d4a30 203
nixnax 29:30de79d658f6 204 void sendFrame()
nixnax 29:30de79d658f6 205 {
nixnax 17:4918c893d802 206 int crc = crcBuf(ppp.pkt.buf, ppp.pkt.len-2); // update crc
nixnax 12:db0dc91f0231 207 ppp.pkt.buf[ ppp.pkt.len-2 ] = (~crc>>0); // fcs lo (crc)
nixnax 12:db0dc91f0231 208 ppp.pkt.buf[ ppp.pkt.len-1 ] = (~crc>>8); // fcs hi (crc)
nixnax 16:cb0b80c24ba2 209 pc.putc(0x7e); // hdlc start-of-frame "flag"
nixnax 29:30de79d658f6 210 for(int i=0; i<ppp.pkt.len; i++) hdlcPut( ppp.pkt.buf[i] );
nixnax 16:cb0b80c24ba2 211 pc.putc(0x7e); // hdlc end-of-frame "flag"
nixnax 9:0992486d4a30 212 }
nixnax 9:0992486d4a30 213
nixnax 29:30de79d658f6 214 void ipRequestHandler()
nixnax 29:30de79d658f6 215 {
nixnax 15:b0154c910143 216 debug(("IPCP Conf "));
nixnax 9:0992486d4a30 217 if ( ppp.pkt.buf[7] != 4 ) {
nixnax 15:b0154c910143 218 debug(("Rej\n")); // reject if any options are requested
nixnax 9:0992486d4a30 219 ppp.pkt.buf[4]=4;
nixnax 9:0992486d4a30 220 sendFrame();
nixnax 9:0992486d4a30 221 } else {
nixnax 15:b0154c910143 222 debug(("Ack\n"));
nixnax 9:0992486d4a30 223 ppp.pkt.buf[4]=2; // ack the minimum
nixnax 9:0992486d4a30 224 sendFrame(); // acknowledge
nixnax 29:30de79d658f6 225 debug(("IPCP Ask\n"));
nixnax 9:0992486d4a30 226 // send our own request now
nixnax 12:db0dc91f0231 227 ppp.pkt.buf[4]=1; // request no options
nixnax 9:0992486d4a30 228 ppp.pkt.buf[5]++; // next sequence
nixnax 9:0992486d4a30 229 sendFrame(); // this is our request
nixnax 9:0992486d4a30 230 }
nixnax 9:0992486d4a30 231 }
nixnax 9:0992486d4a30 232
nixnax 29:30de79d658f6 233 void ipAckHandler()
nixnax 29:30de79d658f6 234 {
nixnax 29:30de79d658f6 235 debug(("IPCP Grant\n"));
nixnax 29:30de79d658f6 236 }
nixnax 9:0992486d4a30 237
nixnax 29:30de79d658f6 238 void ipNackHandler()
nixnax 29:30de79d658f6 239 {
nixnax 29:30de79d658f6 240 debug(("IPCP Nack\n"));
nixnax 29:30de79d658f6 241 }
nixnax 9:0992486d4a30 242
nixnax 29:30de79d658f6 243 void ipDefaultHandler()
nixnax 29:30de79d658f6 244 {
nixnax 29:30de79d658f6 245 debug(("IPCP Other\n"));
nixnax 29:30de79d658f6 246 }
nixnax 29:30de79d658f6 247
nixnax 29:30de79d658f6 248 void IPCPframe()
nixnax 29:30de79d658f6 249 {
nixnax 9:0992486d4a30 250 int code = ppp.pkt.buf[4]; // packet type is here
nixnax 9:0992486d4a30 251 switch (code) {
nixnax 29:30de79d658f6 252 case 1:
nixnax 29:30de79d658f6 253 ipRequestHandler();
nixnax 29:30de79d658f6 254 break;
nixnax 29:30de79d658f6 255 case 2:
nixnax 29:30de79d658f6 256 ipAckHandler();
nixnax 29:30de79d658f6 257 break;
nixnax 29:30de79d658f6 258 case 3:
nixnax 29:30de79d658f6 259 ipNackHandler();
nixnax 29:30de79d658f6 260 break;
nixnax 29:30de79d658f6 261 default:
nixnax 29:30de79d658f6 262 ipDefaultHandler();
nixnax 9:0992486d4a30 263 }
nixnax 29:30de79d658f6 264 }
nixnax 9:0992486d4a30 265
nixnax 29:30de79d658f6 266 void UDPpacket()
nixnax 29:30de79d658f6 267 {
nixnax 12:db0dc91f0231 268 char * udpPkt = ppp.pkt.buf+4; // udp packet start
nixnax 16:cb0b80c24ba2 269 int headerSizeIP = (( udpPkt[0]&0xf)*4);
nixnax 29:30de79d658f6 270 char * udpBlock = udpPkt + headerSizeIP; // udp info start
nixnax 12:db0dc91f0231 271 char * udpSrc = udpBlock; // source port
nixnax 12:db0dc91f0231 272 char * udpDst = udpBlock+2; // destination port
nixnax 12:db0dc91f0231 273 char * udpLen = udpBlock+4; // udp data length
nixnax 12:db0dc91f0231 274 char * udpInf = udpBlock+8; // actual start of info
nixnax 12:db0dc91f0231 275 int srcPort = (udpSrc[0]<<8) | udpSrc[1];
nixnax 12:db0dc91f0231 276 int dstPort = (udpDst[0]<<8) | udpDst[1];
nixnax 12:db0dc91f0231 277 char * srcIP = udpPkt+12; // udp src addr
nixnax 12:db0dc91f0231 278 char * dstIP = udpPkt+16; // udp dst addr
nixnax 29:30de79d658f6 279 #define UDP_HEADER_SIZE 8
nixnax 12:db0dc91f0231 280 int udpLength = ((udpLen[0]<<8) | udpLen[1]) - UDP_HEADER_SIZE; // size of the actual udp data
nixnax 29:30de79d658f6 281 if(v1) debug(("UDP %d.%d.%d.%d:%d ", srcIP[0],srcIP[1],srcIP[2],srcIP[3],srcPort));
nixnax 29:30de79d658f6 282 if(v1) debug(("%d.%d.%d.%d:%d ", dstIP[1],dstIP[1],dstIP[1],dstIP[1],dstPort));
nixnax 15:b0154c910143 283 debug(("Len %d ", udpLength));
nixnax 29:30de79d658f6 284 int printSize = udpLength;
nixnax 29:30de79d658f6 285 if (printSize > 20) printSize = 20; // print only first 20 characters
nixnax 29:30de79d658f6 286 if (v0) {
nixnax 29:30de79d658f6 287 for (int i=0; i<printSize; i++) {
nixnax 29:30de79d658f6 288 char ch = udpInf[i];
nixnax 29:30de79d658f6 289 if (ch>31 && ch<127) {
nixnax 29:30de79d658f6 290 debug(("%c", ch));
nixnax 29:30de79d658f6 291 } else {
nixnax 29:30de79d658f6 292 debug(("_"));
nixnax 29:30de79d658f6 293 }
nixnax 29:30de79d658f6 294 }
nixnax 29:30de79d658f6 295 debug(("\n"));
nixnax 29:30de79d658f6 296 }
nixnax 12:db0dc91f0231 297 }
nixnax 11:f58998c24f0b 298
nixnax 29:30de79d658f6 299 int dataCheckSum(char * ptr, int len)
nixnax 29:30de79d658f6 300 {
nixnax 29:30de79d658f6 301 int sum=0;
nixnax 29:30de79d658f6 302 int placeHolder;
nixnax 29:30de79d658f6 303 if (len&1) {
nixnax 29:30de79d658f6 304 placeHolder = ptr[len-1]; // when length is odd zero stuff
nixnax 29:30de79d658f6 305 ptr[len-1]=0;
nixnax 29:30de79d658f6 306 }
nixnax 29:30de79d658f6 307 for (int i=0; i<len/2; i++) {
nixnax 29:30de79d658f6 308 int hi = *ptr;
nixnax 29:30de79d658f6 309 ptr++;
nixnax 29:30de79d658f6 310 int lo = *ptr;
nixnax 29:30de79d658f6 311 ptr++;
nixnax 11:f58998c24f0b 312 int val = ( lo & 0xff ) | ( (hi<<8) & 0xff00 );
nixnax 11:f58998c24f0b 313 sum = sum + val;
nixnax 11:f58998c24f0b 314 }
nixnax 11:f58998c24f0b 315 sum = sum + (sum>>16);
nixnax 29:30de79d658f6 316 if (len&1) {
nixnax 29:30de79d658f6 317 ptr[len-1] = placeHolder; // restore the last byte for odd lengths
nixnax 29:30de79d658f6 318 }
nixnax 12:db0dc91f0231 319 return ~sum;
nixnax 29:30de79d658f6 320 }
nixnax 11:f58998c24f0b 321
nixnax 29:30de79d658f6 322 void headerCheckSum()
nixnax 29:30de79d658f6 323 {
nixnax 11:f58998c24f0b 324 int len =(ppp.pkt.buf[4]&0xf)*4; // length of header in bytes
nixnax 11:f58998c24f0b 325 char * ptr = ppp.pkt.buf+4; // start of ip packet
nixnax 11:f58998c24f0b 326 int sum=0;
nixnax 11:f58998c24f0b 327
nixnax 29:30de79d658f6 328 for (int i=0; i<len/2; i++) {
nixnax 29:30de79d658f6 329 int hi = *ptr;
nixnax 29:30de79d658f6 330 ptr++;
nixnax 29:30de79d658f6 331 int lo = *ptr;
nixnax 29:30de79d658f6 332 ptr++;
nixnax 11:f58998c24f0b 333 int val = ( lo & 0xff ) | ( (hi<<8) & 0xff00 );
nixnax 11:f58998c24f0b 334 sum = sum + val;
nixnax 11:f58998c24f0b 335 }
nixnax 11:f58998c24f0b 336 sum = sum + (sum>>16);
nixnax 11:f58998c24f0b 337 sum = ~sum;
nixnax 11:f58998c24f0b 338 ppp.pkt.buf[14]= (sum>>8);
nixnax 11:f58998c24f0b 339 ppp.pkt.buf[15]= (sum );
nixnax 29:30de79d658f6 340 }
nixnax 9:0992486d4a30 341
nixnax 29:30de79d658f6 342 void ICMPpacket() // internet control message protocol
nixnax 29:30de79d658f6 343 {
nixnax 12:db0dc91f0231 344 char * ipPkt = ppp.pkt.buf+4; // ip packet start
nixnax 12:db0dc91f0231 345 char * pktLen = ipPkt+2;
nixnax 12:db0dc91f0231 346 int packetLength = (pktLen[0]<<8) | pktLen[1]; // icmp packet length
nixnax 16:cb0b80c24ba2 347 int headerSizeIP = (( ipPkt[0]&0xf)*4);
nixnax 16:cb0b80c24ba2 348 char * icmpType = ipPkt + headerSizeIP; // icmp data start
nixnax 13:d882b8a042b4 349 char * icmpSum = icmpType+2; // icmp checksum
nixnax 29:30de79d658f6 350 #define ICMP_TYPE_PING_REQUEST 8
nixnax 29:30de79d658f6 351 if ( icmpType[0] == ICMP_TYPE_PING_REQUEST ) {
nixnax 12:db0dc91f0231 352 char * ipTTL = ipPkt+8; // time to live
nixnax 12:db0dc91f0231 353 ipTTL[0]--; // decrement time to live
nixnax 12:db0dc91f0231 354 char * srcAdr = ipPkt+12;
nixnax 12:db0dc91f0231 355 char * dstAdr = ipPkt+16;
nixnax 18:3e35de1bc877 356 int icmpIdent = (icmpType[4]<<8)|icmpType[5];
nixnax 29:30de79d658f6 357 int icmpSequence = (icmpType[6]<<8)|icmpType[7];
nixnax 25:0b0450e1b08b 358 debug(("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 25:0b0450e1b08b 359 debug(("Ident %04x Sequence %04d ",icmpIdent,icmpSequence));
nixnax 29:30de79d658f6 360 char src[4];
nixnax 29:30de79d658f6 361 char dst[4];
nixnax 12:db0dc91f0231 362 memcpy(src, srcAdr,4);
nixnax 12:db0dc91f0231 363 memcpy(dst, dstAdr,4);
nixnax 12:db0dc91f0231 364 memcpy(srcAdr, dst,4);
nixnax 12:db0dc91f0231 365 memcpy(dstAdr, src,4); // swap src & dest ip
nixnax 12:db0dc91f0231 366 char * chkSum = ipPkt+10;
nixnax 29:30de79d658f6 367 chkSum[0]=0;
nixnax 29:30de79d658f6 368 chkSum[1]=0;
nixnax 12:db0dc91f0231 369 headerCheckSum(); // new ip header checksum
nixnax 29:30de79d658f6 370 #define ICMP_TYPE_ECHO_REPLY 0
nixnax 16:cb0b80c24ba2 371 icmpType[0]=ICMP_TYPE_ECHO_REPLY; // icmp echo reply
nixnax 29:30de79d658f6 372 icmpSum[0]=0;
nixnax 29:30de79d658f6 373 icmpSum[1]=0; // zero the checksum for recalculation
nixnax 16:cb0b80c24ba2 374 int icmpLength = packetLength - headerSizeIP; // length of ICMP data portion
nixnax 16:cb0b80c24ba2 375 int sum = dataCheckSum( icmpType, icmpLength); // this checksum on icmp data portion
nixnax 29:30de79d658f6 376 icmpSum[0]=sum>>8;
nixnax 29:30de79d658f6 377 icmpSum[1]=sum; // new checksum for ICMP data portion
nixnax 16:cb0b80c24ba2 378
nixnax 16:cb0b80c24ba2 379 int printSize = icmpLength-8; // exclude size of icmp header
nixnax 25:0b0450e1b08b 380 char * icmpData = icmpType+8; // the actual payload data is after the header
nixnax 25:0b0450e1b08b 381 if (printSize > 10) printSize = 10; // print up to 20 characters
nixnax 29:30de79d658f6 382 if (v0) {
nixnax 29:30de79d658f6 383 for (int i=0; i<printSize; i++) {
nixnax 29:30de79d658f6 384 char ch = icmpData[i];
nixnax 29:30de79d658f6 385 if (ch>31 && ch<127) {
nixnax 29:30de79d658f6 386 debug(("%c",ch));
nixnax 29:30de79d658f6 387 } else {
nixnax 29:30de79d658f6 388 debug(("_"));
nixnax 29:30de79d658f6 389 }
nixnax 29:30de79d658f6 390 }
nixnax 29:30de79d658f6 391 debug(("\n"));
nixnax 29:30de79d658f6 392 }
nixnax 15:b0154c910143 393 sendFrame(); // reply to the ping
nixnax 29:30de79d658f6 394
nixnax 12:db0dc91f0231 395 } else {
nixnax 29:30de79d658f6 396 if (v0) {
nixnax 29:30de79d658f6 397 debug(("ICMP type=%d \n", icmpType[0]));
nixnax 29:30de79d658f6 398 }
nixnax 11:f58998c24f0b 399 }
nixnax 11:f58998c24f0b 400 }
nixnax 11:f58998c24f0b 401
nixnax 29:30de79d658f6 402 void IGMPpacket() // internet group management protocol
nixnax 29:30de79d658f6 403 {
nixnax 29:30de79d658f6 404 if (v0) {
nixnax 29:30de79d658f6 405 debug(("IGMP type=%d \n", ppp.pkt.buf[28]));
nixnax 29:30de79d658f6 406 }
nixnax 29:30de79d658f6 407 }
nixnax 11:f58998c24f0b 408
nixnax 29:30de79d658f6 409 void dumpHeaderIP ()
nixnax 29:30de79d658f6 410 {
nixnax 26:11f4eb2663a7 411 char * ipPkt = ppp.pkt.buf+4; // ip packet start
nixnax 26:11f4eb2663a7 412 char * version = ipPkt; // top 4 bits
nixnax 26:11f4eb2663a7 413 char * ihl = ipPkt; // bottom 4 bits
nixnax 26:11f4eb2663a7 414 char * dscp = ipPkt+1; // top 6 bits
nixnax 26:11f4eb2663a7 415 char * ecn = ipPkt+1; // lower 2 bits
nixnax 26:11f4eb2663a7 416 char * pktLen = ipPkt+2; // 2 bytes
nixnax 26:11f4eb2663a7 417 char * ident = ipPkt+4; // 2 bytes
nixnax 26:11f4eb2663a7 418 char * flags = ipPkt+6; // 2 bits
nixnax 26:11f4eb2663a7 419 char * ttl = ipPkt+8; // 1 byte
nixnax 26:11f4eb2663a7 420 char * protocol = ipPkt+9; // 1 byte
nixnax 29:30de79d658f6 421 char * headercheck= ipPkt+10; // 2 bytes
nixnax 26:11f4eb2663a7 422 char * srcAdr = ipPkt+12; // 4 bytes
nixnax 26:11f4eb2663a7 423 char * dstAdr = ipPkt+16; // 4 bytes = total of 20 bytes
nixnax 29:30de79d658f6 424
nixnax 29:30de79d658f6 425 int versionIP = (version[0]>>4)&0xf;
nixnax 26:11f4eb2663a7 426 int headerSizeIP = (ihl[0]&0xf)*4;
nixnax 26:11f4eb2663a7 427 int dscpIP = (dscp[0]>>2)&0x3f;
nixnax 26:11f4eb2663a7 428 int ecnIP = ecn[0]&3;
nixnax 26:11f4eb2663a7 429 int packetLength = (pktLen[0]<<8)|pktLen[1]; // ip total packet length
nixnax 26:11f4eb2663a7 430 int identIP = (ident[0]<<8)|ident[1];
nixnax 26:11f4eb2663a7 431 int flagsIP = flags[0]>>14&3;
nixnax 26:11f4eb2663a7 432 int ttlIP = ttl[0];
nixnax 26:11f4eb2663a7 433 int protocolIP = protocol[0];
nixnax 26:11f4eb2663a7 434 int checksumIP = (headercheck[0]<<8)|headercheck[1];
nixnax 29:30de79d658f6 435 char srcIP [16];
nixnax 29:30de79d658f6 436 snprintf(srcIP,16, "%d.%d.%d.%d", srcAdr[0],srcAdr[1],srcAdr[2],srcAdr[3]);
nixnax 29:30de79d658f6 437 char dstIP [16];
nixnax 29:30de79d658f6 438 snprintf(dstIP,16, "%d.%d.%d.%d", dstAdr[0],dstAdr[1],dstAdr[2],dstAdr[3]);
nixnax 26:11f4eb2663a7 439 debug(("IP %s %s v%d h%d d%d e%d L%d ",srcIP,dstIP,versionIP,headerSizeIP,dscpIP,ecnIP,packetLength));
nixnax 29:30de79d658f6 440 if (v1) debug(("i%04x f%d t%d p%d C%04x\n",identIP,flagsIP,ttlIP,protocolIP,checksumIP));
nixnax 29:30de79d658f6 441 }
nixnax 26:11f4eb2663a7 442
nixnax 29:30de79d658f6 443 void dumpHeaderTCP()
nixnax 29:30de79d658f6 444 {
nixnax 29:30de79d658f6 445 int headerSizeIP = (ppp.pkt.buf[4]&0xf)*4; // header size of ip portion
nixnax 29:30de79d658f6 446 char * tcpStart = ppp.pkt.buf+4+headerSizeIP; // start of tcp packet
nixnax 29:30de79d658f6 447 char * seqtcp = tcpStart + 4; // 4 bytes
nixnax 29:30de79d658f6 448 char * acktcp = tcpStart + 8; // 4 bytes
nixnax 29:30de79d658f6 449 char * flagbitstcp = tcpStart + 12; // 9 bits
nixnax 31:e000c1b9c565 450 unsigned int seq = (seqtcp[0]<<24)|(seqtcp[1]<<16)|(seqtcp[2]<<8)|(seqtcp[3]);
nixnax 31:e000c1b9c565 451 unsigned int ack = (acktcp[0]<<24)|(acktcp[1]<<16)|(acktcp[2]<<8)|(acktcp[3]);
nixnax 26:11f4eb2663a7 452 int flags = ((flagbitstcp[0]&1)<<8)|flagbitstcp[1];
nixnax 10:74f8233f72c0 453
nixnax 29:30de79d658f6 454 char flagInfo[10];
nixnax 29:30de79d658f6 455 memset(flagInfo,'.',10); // text presentation of TCP flags
nixnax 29:30de79d658f6 456 if (flags & (1<<0)) flagInfo[0]='F';
nixnax 29:30de79d658f6 457 if (flags & (1<<1)) flagInfo[1]='S';
nixnax 29:30de79d658f6 458 if (flags & (1<<2)) flagInfo[2]='R';
nixnax 29:30de79d658f6 459 if (flags & (1<<3)) flagInfo[3]='P';
nixnax 29:30de79d658f6 460 if (flags & (1<<4)) flagInfo[4]='A';
nixnax 29:30de79d658f6 461 if (flags & (1<<5)) flagInfo[5]='U';
nixnax 29:30de79d658f6 462 if (flags & (1<<6)) flagInfo[6]='E';
nixnax 29:30de79d658f6 463 if (flags & (1<<7)) flagInfo[7]='C';
nixnax 29:30de79d658f6 464 if (flags & (1<<8)) flagInfo[8]='N';
nixnax 29:30de79d658f6 465 flagInfo[9]=0; // null terminate string
nixnax 29:30de79d658f6 466 if (v0) {
nixnax 34:8a6fbc73a7f1 467 debug(("Flags %s Seq %u Ack %u", flagInfo, seq, ack));
nixnax 29:30de79d658f6 468 }
nixnax 29:30de79d658f6 469 }
nixnax 29:30de79d658f6 470
nixnax 29:30de79d658f6 471 void tcpHandler()
nixnax 29:30de79d658f6 472 {
nixnax 26:11f4eb2663a7 473 char * ipPkt = ppp.pkt.buf+4; // ip packet start
nixnax 29:30de79d658f6 474 char * headercheck= ipPkt+10; // 2 bytes
nixnax 26:11f4eb2663a7 475 char * ihl = ipPkt; // bottom 4 bits
nixnax 26:11f4eb2663a7 476 char * ident = ipPkt+4; // 2 bytes
nixnax 26:11f4eb2663a7 477 char * pktLen = ipPkt+2; // 2 bytes
nixnax 28:1aa629be05e7 478 char * protocol = ipPkt+9; // 1 byte
nixnax 26:11f4eb2663a7 479 char * srcAdr = ipPkt+12; // 4 bytes
nixnax 26:11f4eb2663a7 480 char * dstAdr = ipPkt+16; // 4 bytes = total of 20 bytes
nixnax 26:11f4eb2663a7 481 int headerSizeIP = (ihl[0]&0xf)*4;
nixnax 26:11f4eb2663a7 482 int packetLength = (pktLen[0]<<8)|pktLen[1]; // ip total packet length
nixnax 26:11f4eb2663a7 483
nixnax 29:30de79d658f6 484 ident[0] = ppp.ident>>8;
nixnax 29:30de79d658f6 485 ident[1] = ppp.ident>>0; // insert OUR ident
nixnax 29:30de79d658f6 486
nixnax 29:30de79d658f6 487 char * s = ppp.pkt.buf+4+headerSizeIP; // start of tcp packet
nixnax 26:11f4eb2663a7 488 char * srctcp = s + 0; // 2 bytes
nixnax 26:11f4eb2663a7 489 char * dsttcp = s + 2; // 2 bytes
nixnax 28:1aa629be05e7 490 char * seqtcp = s + 4; // 4 bytes
nixnax 28:1aa629be05e7 491 char * acktcp = s + 8; // 4 bytes
nixnax 28:1aa629be05e7 492 char * offset = s + 12; // 4 bits
nixnax 26:11f4eb2663a7 493 char * flagbitstcp = s + 12; // 9 bits
nixnax 26:11f4eb2663a7 494 char * checksumtcp = s + 16; // 2 bytes
nixnax 26:11f4eb2663a7 495
nixnax 26:11f4eb2663a7 496 int tcpSize = packetLength - headerSizeIP;
nixnax 35:e7068df4d971 497 int headerSizeTCP = ((offset[0]>>4)&0x0f)*4; // size of tcp header only
nixnax 29:30de79d658f6 498
nixnax 31:e000c1b9c565 499 unsigned int seq = (seqtcp[0]<<24)|(seqtcp[1]<<16)|(seqtcp[2]<<8)|(seqtcp[3]);
nixnax 31:e000c1b9c565 500 unsigned int ack = (acktcp[0]<<24)|(acktcp[1]<<16)|(acktcp[2]<<8)|(acktcp[3]);
nixnax 29:30de79d658f6 501
nixnax 35:e7068df4d971 502 int flagsTCP = ((flagbitstcp[0]&1)<<8)|flagbitstcp[1];
nixnax 29:30de79d658f6 503
nixnax 35:e7068df4d971 504 char * dataStart = ppp.pkt.buf + 4 + headerSizeIP + headerSizeTCP; // start of data block after TCP header
nixnax 35:e7068df4d971 505 int incomingLen = tcpSize - headerSizeTCP; // size of data block after TCP header
nixnax 28:1aa629be05e7 506
nixnax 29:30de79d658f6 507 #define TCP_FLAG_ACK (1<<4)
nixnax 29:30de79d658f6 508 #define TCP_FLAG_SYN (1<<1)
nixnax 29:30de79d658f6 509 #define TCP_FLAG_PSH (1<<3)
nixnax 29:30de79d658f6 510 #define TCP_FLAG_RST (1<<2)
nixnax 29:30de79d658f6 511 #define TCP_FLAG_FIN (1<<0)
nixnax 28:1aa629be05e7 512
nixnax 29:30de79d658f6 513 // A sparse TCP flag interpreter that implements basic TCP connections from a single source
nixnax 29:30de79d658f6 514
nixnax 35:e7068df4d971 515 int dataLen = 0; // most of our responses will have zero TCP data, only a header
nixnax 35:e7068df4d971 516 int teardown = 0; // see if we must tear down the link
nixnax 35:e7068df4d971 517
nixnax 35:e7068df4d971 518 if ( ((flagsTCP & ~TCP_FLAG_ACK) == 0) && ((flagsTCP & TCP_FLAG_ACK) != 0) ) {
nixnax 35:e7068df4d971 519 if (incomingLen == 0) return; // no new data
nixnax 29:30de79d658f6 520 } else if ( (flagsTCP & TCP_FLAG_FIN) != 0 ) { // got FIN
nixnax 35:e7068df4d971 521 flagbitstcp[1] = TCP_FLAG_ACK; // do an ack
nixnax 35:e7068df4d971 522 teardown=1;
nixnax 29:30de79d658f6 523 } else if ( (flagsTCP & TCP_FLAG_SYN) != 0 ) { // got SYN
nixnax 28:1aa629be05e7 524 flagbitstcp[1] |= TCP_FLAG_ACK; // do a syn-ack
nixnax 35:e7068df4d971 525 seq++;
nixnax 29:30de79d658f6 526 } else if ( (flagsTCP & TCP_FLAG_PSH) != 0 ) { // they are pushing data
nixnax 35:e7068df4d971 527 // It's a push - let's check the data for an HTTP home page GET request
nixnax 31:e000c1b9c565 528 if ( strncmp(dataStart, "GET / HTTP/1.1", 14) == 0) {
nixnax 35:e7068df4d971 529 flagbitstcp[1] = TCP_FLAG_ACK; // | TCP_FLAG_FIN; // close connection after delivering page
nixnax 31:e000c1b9c565 530 dataLen = 15*32; // this block has to hold the web page below, but keep it under 1k
nixnax 31:e000c1b9c565 531 memset(dataStart,'x', dataLen ); // initialize the block
nixnax 35:e7068df4d971 532 int n=1; // number of bytes we have printed so far
nixnax 31:e000c1b9c565 533 n=n+sprintf(n+dataStart,"HTTP/1.1 200 OK\r\nServer: PPP-Blinky\r\n"); // http header
nixnax 35:e7068df4d971 534 n=n+sprintf(n+dataStart,"Content-Length: 376\r\n"); // http header
nixnax 32:512228c29209 535 n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n\r\n"); // http header
nixnax 31:e000c1b9c565 536 int nHeader=n; // byte total of all headers
nixnax 31:e000c1b9c565 537 n=n+sprintf(n+dataStart,"<html><head><title>mbed-PPP-Blinky</title><script>window.onload=function()"); // html
nixnax 31:e000c1b9c565 538 n=n+sprintf(n+dataStart,"{setInterval(function(){function x(){return document.getElementById('w');};"); // html
nixnax 31:e000c1b9c565 539 n=n+sprintf(n+dataStart,"x().innerText = parseInt(x().innerText)+1;},100);};</script></head><body>"); // html
nixnax 31:e000c1b9c565 540 n=n+sprintf(n+dataStart,"<h1>mbed-PPP-Blinky Up and Running</h1><h1 id=\"w\" style=\"text-align:"); // html
nixnax 31:e000c1b9c565 541 n=n+sprintf(n+dataStart," center\";>0</h1><h1><a href=\"http://bit.ly/pppBlinky\">Source on mbed</h1></body></html>"); // html
nixnax 31:e000c1b9c565 542 int contentLength = dataLen-nHeader; // this is how to calculate Content-Length, but using curl -v is easier
nixnax 31:e000c1b9c565 543 contentLength = contentLength+0; // get around unreferenced variable warning
nixnax 31:e000c1b9c565 544 if (v0) {
nixnax 35:e7068df4d971 545 debug(("HTTP GET dataLen %d*32=%d Header %d Content-Length %d Total %d Margin %d\n",dataLen/32,dataLen,nHeader,contentLength,n,dataLen-n));
nixnax 31:e000c1b9c565 546 }
nixnax 34:8a6fbc73a7f1 547 } else if ( strncmp(dataStart, "GET /", 4) == 0) { // all other files get 404 not found
nixnax 35:e7068df4d971 548 flagbitstcp[1] = TCP_FLAG_ACK;// | TCP_FLAG_FIN; // close connection after delivering page
nixnax 32:512228c29209 549 dataLen = 5*32; // this block has to hold the web page below, but keep it under 1k
nixnax 31:e000c1b9c565 550 memset(dataStart,'x', dataLen ); // initialize the block
nixnax 32:512228c29209 551 int n=0;
nixnax 32:512228c29209 552 n=n+sprintf(n+dataStart,"HTTP/1.1 200 OK\r\nServer: PPP-Blinky\r\n"); // http header
nixnax 32:512228c29209 553 n=n+sprintf(n+dataStart,"Content-Length: 58\r\n"); // http header
nixnax 32:512228c29209 554 n=n+sprintf(n+dataStart,"Content-Type: text/html; charset=us-ascii\r\n\r\n"); // http header
nixnax 32:512228c29209 555 int nHeader=n; // byte total of all headers
nixnax 32:512228c29209 556 n=n+sprintf(n+dataStart,"<html><head>"); // html
nixnax 32:512228c29209 557 n=n+sprintf(n+dataStart,"<body><h1>File Not Found</h1></body>\r\n</html>"); // html
nixnax 32:512228c29209 558 int contentLength = dataLen-nHeader; // this is how to calculate Content-Length, but using curl -v is easier
nixnax 32:512228c29209 559 contentLength = contentLength+0; // get around unreferenced variable warning
nixnax 31:e000c1b9c565 560 if (v0) {
nixnax 35:e7068df4d971 561 debug(("HTTP GET dataLen %d*32=%d Header %d Content-Length %d Total %d Margin %d\n",dataLen/32,dataLen,nHeader,contentLength,n,dataLen-n));
nixnax 31:e000c1b9c565 562 }
nixnax 35:e7068df4d971 563 } else {
nixnax 35:e7068df4d971 564 flagbitstcp[1] = TCP_FLAG_ACK; // we have nothing to say, just ack
nixnax 35:e7068df4d971 565 dataLen=0;
nixnax 29:30de79d658f6 566 }
nixnax 28:1aa629be05e7 567 }
nixnax 29:30de79d658f6 568
nixnax 35:e7068df4d971 569 // All the flag checking is now donw
nixnax 35:e7068df4d971 570
nixnax 35:e7068df4d971 571 // Now we have to recalculate all the header sizes
nixnax 29:30de79d658f6 572
nixnax 35:e7068df4d971 573 ack = seq + incomingLen; // acknowledge the number of bytes they sent by adding it to seq
nixnax 35:e7068df4d971 574 seq = ppp.seq;
nixnax 35:e7068df4d971 575
nixnax 35:e7068df4d971 576 teardownEntry:
nixnax 35:e7068df4d971 577
nixnax 35:e7068df4d971 578 int newPacketSize = headerSizeIP + headerSizeTCP + dataLen;
nixnax 29:30de79d658f6 579 pktLen[0] = (newPacketSize>>8);
nixnax 29:30de79d658f6 580 pktLen[1]=newPacketSize; // ip total packet size
nixnax 28:1aa629be05e7 581 ppp.pkt.len = newPacketSize+6; // ppp packet length
nixnax 35:e7068df4d971 582 tcpSize = headerSizeTCP + dataLen; // tcp packet size
nixnax 29:30de79d658f6 583
nixnax 28:1aa629be05e7 584 // redo all the header stuff
nixnax 29:30de79d658f6 585
nixnax 29:30de79d658f6 586 acktcp[0]=ack>>24;
nixnax 29:30de79d658f6 587 acktcp[1]=ack>>16;
nixnax 29:30de79d658f6 588 acktcp[2]=ack>>8;
nixnax 29:30de79d658f6 589 acktcp[3]=ack>>0; // save ack
nixnax 29:30de79d658f6 590 seqtcp[0]=seq>>24;
nixnax 29:30de79d658f6 591 seqtcp[1]=seq>>16;
nixnax 29:30de79d658f6 592 seqtcp[2]=seq>>8;
nixnax 29:30de79d658f6 593 seqtcp[3]=seq>>0; // save seq
nixnax 26:11f4eb2663a7 594
nixnax 29:30de79d658f6 595 char src[4];
nixnax 29:30de79d658f6 596 char dst[4];
nixnax 29:30de79d658f6 597 memcpy(src, srcAdr,4);
nixnax 29:30de79d658f6 598 memcpy(dst, dstAdr,4);
nixnax 29:30de79d658f6 599 memcpy(srcAdr, dst,4);
nixnax 29:30de79d658f6 600 memcpy(dstAdr, src,4); // swap ip address source/dest
nixnax 29:30de79d658f6 601 char psrc[2];
nixnax 29:30de79d658f6 602 char pdst[2];
nixnax 29:30de79d658f6 603 memcpy(psrc, srctcp,2);
nixnax 29:30de79d658f6 604 memcpy(pdst, dsttcp,2);
nixnax 29:30de79d658f6 605 memcpy(srctcp, pdst,2);
nixnax 29:30de79d658f6 606 memcpy(dsttcp, psrc,2); // swap ip port source/dest
nixnax 29:30de79d658f6 607
nixnax 29:30de79d658f6 608 headercheck[0]=0;
nixnax 29:30de79d658f6 609 headercheck[1]=0;
nixnax 29:30de79d658f6 610 headerCheckSum(); // redo the ip header checksum
nixnax 29:30de79d658f6 611 char pseudoHeader[12];
nixnax 29:30de79d658f6 612 int sum;
nixnax 29:30de79d658f6 613 char temp[12]; // for the terrible pseudoheader checksum
nixnax 26:11f4eb2663a7 614 memcpy( pseudoHeader+0, srcAdr, 8); // source and destination addresses.
nixnax 29:30de79d658f6 615 pseudoHeader[8]=0;
nixnax 29:30de79d658f6 616 pseudoHeader[9]=protocol[0];
nixnax 29:30de79d658f6 617 pseudoHeader[10]=tcpSize>>8;
nixnax 29:30de79d658f6 618 pseudoHeader[11]=tcpSize;
nixnax 26:11f4eb2663a7 619 memcpy(temp, s-12, 12); // keep a copy
nixnax 26:11f4eb2663a7 620 memcpy( s-12, pseudoHeader, 12); // put the header on the tcp packet
nixnax 29:30de79d658f6 621 checksumtcp[0]=0;
nixnax 29:30de79d658f6 622 checksumtcp[1]=0;
nixnax 29:30de79d658f6 623 sum=dataCheckSum(s-12,tcpSize+12); // update TCP checksum
nixnax 29:30de79d658f6 624 checksumtcp[0]=sum>>8;
nixnax 29:30de79d658f6 625 checksumtcp[1]=sum;
nixnax 26:11f4eb2663a7 626 memcpy( s-12, temp, 12); // overwrite the pseudoheader
nixnax 26:11f4eb2663a7 627 sendFrame(); // return the TCP packet
nixnax 35:e7068df4d971 628 ppp.seq = ppp.seq + dataLen; // increase OUR sequence by outgoing data length - for the next round
nixnax 35:e7068df4d971 629 if (teardown) {
nixnax 35:e7068df4d971 630 teardown=0; // clear the teardown flag
nixnax 35:e7068df4d971 631 flagbitstcp[1] = TCP_FLAG_FIN; // we want to end the link
nixnax 35:e7068df4d971 632 dataLen=0; // no data needed
nixnax 35:e7068df4d971 633 goto teardownEntry;
nixnax 35:e7068df4d971 634 }
nixnax 29:30de79d658f6 635 }
nixnax 26:11f4eb2663a7 636
nixnax 29:30de79d658f6 637 void dumpDataTCP()
nixnax 29:30de79d658f6 638 {
nixnax 26:11f4eb2663a7 639 int ipPktLen = (ppp.pkt.buf[6]<<8)|ppp.pkt.buf[7]; // overall length of ip packet
nixnax 26:11f4eb2663a7 640 int ipHeaderLen = (ppp.pkt.buf[4]&0xf)*4; // length of ip header
nixnax 35:e7068df4d971 641 int headerSizeTCP = ((ppp.pkt.buf[4+ipHeaderLen+12]>>4)&0xf)*4;; // length of tcp header
nixnax 35:e7068df4d971 642 int dataLen = ipPktLen - ipHeaderLen - headerSizeTCP; // data is what's left after the two headers
nixnax 29:30de79d658f6 643 if (v1) {
nixnax 35:e7068df4d971 644 debug(("TCP %d ipHeader %d tcpHeader %d Data %d\n", ipPktLen, ipHeaderLen, headerSizeTCP, dataLen)); // 1 for more verbose
nixnax 29:30de79d658f6 645 }
nixnax 29:30de79d658f6 646 if (dataLen > 0) {
nixnax 35:e7068df4d971 647 debug(("%s\n",ppp.pkt.buf+4+ipHeaderLen+headerSizeTCP)); // show the data
nixnax 29:30de79d658f6 648 }
nixnax 29:30de79d658f6 649 }
nixnax 26:11f4eb2663a7 650
nixnax 29:30de79d658f6 651 void TCPpacket()
nixnax 29:30de79d658f6 652 {
nixnax 26:11f4eb2663a7 653 char * ipPkt = ppp.pkt.buf+4; // ip packet start
nixnax 26:11f4eb2663a7 654 char * version = ipPkt; // top 4 bits
nixnax 26:11f4eb2663a7 655 char * ihl = ipPkt; // bottom 4 bits
nixnax 26:11f4eb2663a7 656 char * dscp = ipPkt+1; // top 6 bits
nixnax 26:11f4eb2663a7 657 char * ecn = ipPkt+1; // lower 2 bits
nixnax 26:11f4eb2663a7 658 char * pktLen = ipPkt+2; // 2 bytes
nixnax 26:11f4eb2663a7 659 char * ident = ipPkt+4; // 2 bytes
nixnax 26:11f4eb2663a7 660 char * flags = ipPkt+6; // 2 bits
nixnax 26:11f4eb2663a7 661 char * ttl = ipPkt+8; // 1 byte
nixnax 26:11f4eb2663a7 662 char * protocol = ipPkt+9; // 1 byte
nixnax 29:30de79d658f6 663 char * headercheck= ipPkt+10; // 2 bytes
nixnax 26:11f4eb2663a7 664 char * srcAdr = ipPkt+12; // 4 bytes
nixnax 26:11f4eb2663a7 665 char * dstAdr = ipPkt+16; // 4 bytes = total of 20 bytes
nixnax 29:30de79d658f6 666
nixnax 29:30de79d658f6 667 int versionIP = (version[0]>>4)&0xf;
nixnax 26:11f4eb2663a7 668 int headerSizeIP = (ihl[0]&0xf)*4;
nixnax 26:11f4eb2663a7 669 int dscpIP = (dscp[0]>>2)&0x3f;
nixnax 26:11f4eb2663a7 670 int ecnIP = ecn[0]&3;
nixnax 26:11f4eb2663a7 671 int packetLength = (pktLen[0]<<8)|pktLen[1]; // ip total packet length
nixnax 26:11f4eb2663a7 672 int identIP = (ident[0]<<8)|ident[1];
nixnax 26:11f4eb2663a7 673 int flagsIP = flags[0]>>14&3;
nixnax 26:11f4eb2663a7 674 int ttlIP = ttl[0];
nixnax 26:11f4eb2663a7 675 int protocolIP = protocol[0];
nixnax 26:11f4eb2663a7 676 int checksumIP = (headercheck[0]<<8)|headercheck[1];
nixnax 29:30de79d658f6 677 char srcIP [16];
nixnax 29:30de79d658f6 678 snprintf(srcIP,16, "%d.%d.%d.%d", srcAdr[0],srcAdr[1],srcAdr[2],srcAdr[3]);
nixnax 29:30de79d658f6 679 char dstIP [16];
nixnax 29:30de79d658f6 680 snprintf(dstIP,16, "%d.%d.%d.%d", dstAdr[0],dstAdr[1],dstAdr[2],dstAdr[3]);
nixnax 29:30de79d658f6 681 if (v0) {
nixnax 29:30de79d658f6 682 debug(("IP %s %s v%d h%d d%d e%d L%d ",srcIP,dstIP,versionIP,headerSizeIP,dscpIP,ecnIP,packetLength));
nixnax 29:30de79d658f6 683 }
nixnax 29:30de79d658f6 684 if (v0) {
nixnax 29:30de79d658f6 685 debug(("i%04x f%d t%d p%d C%04x\n",identIP,flagsIP,ttlIP,protocolIP,checksumIP));
nixnax 29:30de79d658f6 686 }
nixnax 28:1aa629be05e7 687 dumpHeaderTCP();
nixnax 26:11f4eb2663a7 688 dumpDataTCP();
nixnax 26:11f4eb2663a7 689 tcpHandler();
nixnax 11:f58998c24f0b 690 }
nixnax 11:f58998c24f0b 691
nixnax 29:30de79d658f6 692 void otherProtocol()
nixnax 29:30de79d658f6 693 {
nixnax 29:30de79d658f6 694 debug(("Other IP protocol"));
nixnax 29:30de79d658f6 695 }
nixnax 26:11f4eb2663a7 696
nixnax 29:30de79d658f6 697 void IPframe()
nixnax 29:30de79d658f6 698 {
nixnax 10:74f8233f72c0 699 int protocol = ppp.pkt.buf[13];
nixnax 10:74f8233f72c0 700 switch (protocol) {
nixnax 29:30de79d658f6 701 case 1:
nixnax 29:30de79d658f6 702 ICMPpacket();
nixnax 29:30de79d658f6 703 break;
nixnax 29:30de79d658f6 704 case 2:
nixnax 29:30de79d658f6 705 IGMPpacket();
nixnax 29:30de79d658f6 706 break;
nixnax 29:30de79d658f6 707 case 17:
nixnax 29:30de79d658f6 708 UDPpacket();
nixnax 29:30de79d658f6 709 break;
nixnax 29:30de79d658f6 710 case 6:
nixnax 29:30de79d658f6 711 TCPpacket();
nixnax 29:30de79d658f6 712 break;
nixnax 29:30de79d658f6 713 default:
nixnax 29:30de79d658f6 714 otherProtocol();
nixnax 29:30de79d658f6 715 }
nixnax 29:30de79d658f6 716 }
nixnax 9:0992486d4a30 717
nixnax 29:30de79d658f6 718 void LCPconfReq()
nixnax 29:30de79d658f6 719 {
nixnax 15:b0154c910143 720 debug(("LCP Config "));
nixnax 9:0992486d4a30 721 if (ppp.pkt.buf[7] != 4) {
nixnax 11:f58998c24f0b 722 ppp.pkt.buf[4]=4; // allow only no options
nixnax 15:b0154c910143 723 debug(("Reject\n"));
nixnax 29:30de79d658f6 724 sendFrame();
nixnax 9:0992486d4a30 725 } else {
nixnax 9:0992486d4a30 726 ppp.pkt.buf[4]=2; // ack zero conf
nixnax 15:b0154c910143 727 debug(("Ack\n"));
nixnax 9:0992486d4a30 728 sendFrame();
nixnax 15:b0154c910143 729 debug(("LCP Ask\n"));
nixnax 11:f58998c24f0b 730 ppp.pkt.buf[4]=1; // request no options
nixnax 9:0992486d4a30 731 sendFrame();
nixnax 9:0992486d4a30 732 }
nixnax 9:0992486d4a30 733 }
nixnax 9:0992486d4a30 734
nixnax 29:30de79d658f6 735 void LCPconfAck()
nixnax 29:30de79d658f6 736 {
nixnax 15:b0154c910143 737 debug(("LCP Ack\n"));
nixnax 29:30de79d658f6 738 }
nixnax 9:0992486d4a30 739
nixnax 29:30de79d658f6 740 void LCPend()
nixnax 29:30de79d658f6 741 {
nixnax 29:30de79d658f6 742 debug(("LCP End\n"));
nixnax 29:30de79d658f6 743 ppp.online=0; // start hunting for connect string again
nixnax 29:30de79d658f6 744 ppp.pkt.buf[4]=6;
nixnax 29:30de79d658f6 745 sendFrame(); // acknowledge
nixnax 9:0992486d4a30 746 }
nixnax 9:0992486d4a30 747
nixnax 29:30de79d658f6 748 void LCPother()
nixnax 29:30de79d658f6 749 {
nixnax 29:30de79d658f6 750 debug(("LCP Other\n"));
nixnax 29:30de79d658f6 751 dumpFrame();
nixnax 29:30de79d658f6 752 }
nixnax 29:30de79d658f6 753
nixnax 29:30de79d658f6 754 void LCPframe()
nixnax 29:30de79d658f6 755 {
nixnax 29:30de79d658f6 756 int code = ppp.pkt.buf[4];
nixnax 29:30de79d658f6 757 switch (code) {
nixnax 29:30de79d658f6 758 case 1:
nixnax 29:30de79d658f6 759 LCPconfReq();
nixnax 29:30de79d658f6 760 break; // config request
nixnax 29:30de79d658f6 761 case 2:
nixnax 29:30de79d658f6 762 LCPconfAck();
nixnax 29:30de79d658f6 763 break; // config ack
nixnax 29:30de79d658f6 764 case 5:
nixnax 29:30de79d658f6 765 LCPend();
nixnax 29:30de79d658f6 766 break; // end connection
nixnax 29:30de79d658f6 767 default:
nixnax 29:30de79d658f6 768 LCPother();
nixnax 29:30de79d658f6 769 }
nixnax 9:0992486d4a30 770 }
nixnax 9:0992486d4a30 771
nixnax 29:30de79d658f6 772 void discardedFrame()
nixnax 29:30de79d658f6 773 {
nixnax 29:30de79d658f6 774 if (v0) {
nixnax 29:30de79d658f6 775 debug(("Dropping frame %02x %02x %02x %02x\n", ppp.pkt.buf[0],ppp.pkt.buf[1],ppp.pkt.buf[2],ppp.pkt.buf[3]));
nixnax 29:30de79d658f6 776 }
nixnax 9:0992486d4a30 777 }
nixnax 9:0992486d4a30 778
nixnax 29:30de79d658f6 779 void determinePacketType()
nixnax 29:30de79d658f6 780 {
nixnax 29:30de79d658f6 781 if ( ppp.pkt.buf[0] != 0xff ) {
nixnax 29:30de79d658f6 782 debug(("byte0 != ff\n"));
nixnax 29:30de79d658f6 783 return;
nixnax 29:30de79d658f6 784 }
nixnax 29:30de79d658f6 785 if ( ppp.pkt.buf[1] != 3 ) {
nixnax 29:30de79d658f6 786 debug(("byte1 != 3\n"));
nixnax 29:30de79d658f6 787 return;
nixnax 29:30de79d658f6 788 }
nixnax 29:30de79d658f6 789 if ( ppp.pkt.buf[3] != 0x21 ) {
nixnax 29:30de79d658f6 790 debug(("byte2 != 21\n"));
nixnax 29:30de79d658f6 791 return;
nixnax 29:30de79d658f6 792 }
nixnax 9:0992486d4a30 793 int packetType = ppp.pkt.buf[2];
nixnax 9:0992486d4a30 794 switch (packetType) {
nixnax 29:30de79d658f6 795 case 0xc0:
nixnax 29:30de79d658f6 796 LCPframe();
nixnax 29:30de79d658f6 797 break; // link control
nixnax 29:30de79d658f6 798 case 0x80:
nixnax 29:30de79d658f6 799 IPCPframe();
nixnax 29:30de79d658f6 800 break; // IP control
nixnax 29:30de79d658f6 801 case 0x00:
nixnax 29:30de79d658f6 802 IPframe();
nixnax 29:30de79d658f6 803 break; // IP itself
nixnax 29:30de79d658f6 804 default:
nixnax 29:30de79d658f6 805 discardedFrame();
nixnax 9:0992486d4a30 806 }
nixnax 29:30de79d658f6 807 }
nixnax 9:0992486d4a30 808
nixnax 29:30de79d658f6 809 void scanForConnectString()
nixnax 29:30de79d658f6 810 {
nixnax 9:0992486d4a30 811 if ( ppp.online==0 ) {
nixnax 15:b0154c910143 812 char * clientFound = strstr( (char *)rxbuf, "CLIENTCLIENT" ); // look for PC string
nixnax 29:30de79d658f6 813 if( clientFound ) {
nixnax 9:0992486d4a30 814 strcpy( clientFound, "FOUND!FOUND!" ); // overwrite so we don't get fixated
nixnax 9:0992486d4a30 815 pc.printf("CLIENTSERVER"); // respond to PC
nixnax 9:0992486d4a30 816 ppp.online=1; // we can stop looking for the string
nixnax 15:b0154c910143 817 debug(("Connect string found\n"));
nixnax 9:0992486d4a30 818 }
nixnax 9:0992486d4a30 819 }
nixnax 9:0992486d4a30 820 }
nixnax 9:0992486d4a30 821
nixnax 0:2cf4880c312a 822 int main()
nixnax 0:2cf4880c312a 823 {
nixnax 14:c65831c25aaa 824 pc.baud(115200); // USB virtual serial port
nixnax 15:b0154c910143 825 xx.baud(115200); // second serial port for debug(((((((( messages
nixnax 9:0992486d4a30 826 xx.puts("\x1b[2J\x1b[HReady\n"); // VT100 code for clear screen & home
nixnax 29:30de79d658f6 827
nixnax 9:0992486d4a30 828 pppInitStruct(); // initialize all the PPP properties
nixnax 4:a469050d5b80 829
nixnax 9:0992486d4a30 830 pc.attach(&rxHandler,Serial::RxIrq); // start the receive handler
nixnax 4:a469050d5b80 831
nixnax 29:30de79d658f6 832 int frameStartIndex, frameEndIndex;
nixnax 29:30de79d658f6 833 int frameBusy=0;
nixnax 4:a469050d5b80 834
nixnax 0:2cf4880c312a 835 while(1) {
nixnax 9:0992486d4a30 836 if ( ppp.online==0 ) scanForConnectString(); // try to connect
nixnax 22:00df34cd4d7e 837 while ( rxbufNotEmpty() ) {
nixnax 1:9e03798d4367 838 int rx = pc_getBuf();
nixnax 29:30de79d658f6 839 if (frameBusy) {
nixnax 4:a469050d5b80 840 if (rx==FRAME_7E) {
nixnax 4:a469050d5b80 841 frameBusy=0; // done gathering frame
nixnax 4:a469050d5b80 842 frameEndIndex=ppp.rx.tail-1; // remember where frame ends
nixnax 4:a469050d5b80 843 processFrame(frameStartIndex, frameEndIndex);
nixnax 4:a469050d5b80 844 }
nixnax 29:30de79d658f6 845 } else {
nixnax 4:a469050d5b80 846 if (rx==FRAME_7E) {
nixnax 4:a469050d5b80 847 frameBusy=1; // start gathering frame
nixnax 9:0992486d4a30 848 frameStartIndex=ppp.rx.tail; // remember where frame started
nixnax 4:a469050d5b80 849 }
nixnax 0:2cf4880c312a 850 }
nixnax 4:a469050d5b80 851 }
nixnax 7:ab147f5e97ac 852 }
nixnax 7:ab147f5e97ac 853 }