ppp-blinky.h

00001 /// ppp-blinky.h
00002 
00003 #include "mbed.h"
00004 #include "sha1.h"
00005 
00006 void initializePpp();
00007 int connectedPpp();
00008 void waitForPcConnectString();
00009 void waitForPppFrame();
00010 void determinePacketType();
00011 void sendUdpData();
00012 
00013 /// PPP header
00014 typedef struct { // [ff 03 00 21]
00015     unsigned int address : 8;  // always 0xff
00016     unsigned int control : 8;  // always 03
00017     unsigned int protocolR : 16; // byte reversed, 0x0021 for ip
00018 } pppHeaderType;
00019 
00020 /// LCP and IPCP header
00021 typedef struct {
00022     // ppp part
00023     unsigned int address : 8;  // always 0xff
00024     unsigned int control : 8;  // always 03
00025     unsigned int protocolR : 16; // byte reversed, 0x0021 for ip
00026 
00027     // ipcp and lcp part
00028     unsigned int code : 8; // IPCP and LCP contain a code field which identifies the requested action or response
00029     unsigned int identifier : 8 ;
00030     unsigned int lengthR : 16;
00031     char request [0];
00032 } ipcpHeaderType;
00033 
00034 /// IP header
00035 typedef struct {
00036     unsigned int headerLength   :  4;  // ip headerlength / 4
00037     unsigned int version        :  4;  // ip version number
00038     unsigned int ect            :  1;  // ecn capable transport
00039     unsigned int ce             :  1;  // ecn-ce
00040     unsigned int dscp           :  6;  // differentiated services
00041     unsigned int lengthR        : 16;  // ip packet length (byte-reversed)
00042 
00043     unsigned int identR         : 16;  // ident, byte reversed
00044     unsigned int fragmentOffsHi :  5;
00045     unsigned int lastFragment   :  1;
00046     unsigned int dontFragment   :  1;
00047     unsigned int reservedIP     :  1;
00048     unsigned int fragmentOffsLo :  8;
00049 
00050     unsigned int ttl            :  8;
00051     unsigned int protocol       :  8;  // next protocol
00052     unsigned int checksumR      : 16;  // ip checksum, byte reversed
00053     union {
00054         unsigned int srcAdrR; // source IP address
00055         char srcAdrPtr [0]; // so we also have a char * to srcAdrR
00056     };
00057     union {
00058         unsigned int dstAdrR; // destination IP address
00059         char dstAdrPtr [0];  // so we also have a char * to dstAdrR
00060     };
00061 } ipHeaderType;
00062 
00063 /// IP pseudoheader. Used in TCP/UDP checksum calculations.
00064 typedef struct {
00065     union {
00066         char start [0]; // a char * to avoid type conversions
00067         unsigned int srcAdrR; // source IP address
00068     };
00069     unsigned int dstAdrR; // destination IP address
00070     unsigned int zero     :  8;
00071     unsigned int protocol :  8;
00072     unsigned int lengthR  : 16; // byte reversed
00073 } pseudoIpHeaderType;
00074 
00075 /// TCP header
00076 typedef struct {
00077     unsigned int    srcPortR : 16; // byte reversed
00078     unsigned int    dstPortR : 16; // byte reversed
00079     unsigned int    seqTcpR;      // byte reversed
00080     unsigned int    ackTcpR;      // byte reversed
00081     unsigned int resvd1  : 4;  // reserved
00082     unsigned int offset  : 4; // tcp header length [5..15]
00083     union {
00084         unsigned char All;  // all 8 flag bits
00085         struct {            // individual flag bits
00086             unsigned char fin:  1, // fin
00087                      syn    :  1, // syn
00088                      rst    :  1, // rst
00089                      psh    :  1, // psh
00090                      ack    :  1, // ack
00091                      urg    :  1, // urg
00092                      ece    :  1, // ece
00093                      cwr    :  1; // cwr
00094         };
00095     } flag;
00096     unsigned int windowR : 16; // byte reversed
00097     unsigned int    checksumR : 16; // byte reversed
00098     unsigned int    urgentPointerR : 16; // byte reversed;
00099     unsigned int    tcpOptions[10]; // up to 10 words of options possible
00100 } tcpHeaderType;
00101 
00102 /// UDP header.
00103 typedef struct {
00104     unsigned int srcPortR  : 16; // byte reversed
00105     unsigned int dstPortR  : 16; // byte reversed
00106     unsigned int lengthR   : 16; // byte reversed
00107     unsigned int checksumR : 16; // byte reversed
00108     char data [0]; // data area
00109 } udpHeaderType;
00110 
00111 /// ICMP header.
00112 typedef struct {
00113     unsigned int type : 8;
00114     unsigned int code : 8;
00115     unsigned int checkSumR : 16; // byte reversed
00116     unsigned int idR : 16; // byte reversed
00117     unsigned int sequenceR : 16; // byte reversed
00118     char data [0]; // data area
00119 } icmpHeaderType;
00120 
00121 /// Structure to manage all ppp variables.
00122 typedef struct pppType {
00123     union {
00124         pppHeaderType * ppp; // pointer to ppp structure
00125         ipcpHeaderType * ipcp; // pointer to ipcp structure
00126         ipcpHeaderType * lcp; // pointer to lcp structure (same as ipcp)
00127     };
00128     union {
00129         ipHeaderType * ip; // pointer to ip header struct
00130         char * ipStart; // char pointer to ip header struct (need a char pointer for byte offset calculations)
00131     };
00132     union { // a union for the packet type contained in the IP packet
00133         tcpHeaderType  * tcp;  // pointer to tcp header struct
00134         udpHeaderType  * udp;  // pointer to udp header struct
00135         icmpHeaderType * icmp; // pointer to udp header struct
00136         char * tcpStart;  // char pointer to tcp header struct  (need a char pointer for byte offset calculations)
00137         char * udpStart;  // char pointer to udp header struct  (need a char pointer for byte offset calculations)
00138         char * icmpStart; // char pointer to icmp header struct (need a char pointer for byte offset calculations)
00139     };
00140     char * tcpData; // char pointer to where tcp data starts
00141     int online; // we hunt for a PPP connection if this is zero
00142     int hostIP; // ip address of host
00143     int fcs; // PPP "frame check sequence" - a 16-bit HDLC-like checksum used in all PPP frames
00144     int ledState; // state of LED1
00145     int responseCounter;
00146     int firstFrame; // cleared after first frame
00147     unsigned int sum; // a checksum used in headers
00148     struct {
00149 #define RXBUFLEN (1<<11)
00150         // the serial port receive buffer and packet buffer, size is RXBUFLEN (currently 2048 bytes)
00151         char buf[RXBUFLEN]; // RXBUFLEN MUST be a power of two because we use & operator for fast wrap-around in ring buffer
00152         volatile int head; // declared volatile so user code knows this variable changes in the interrupt handler
00153         int tail;
00154         int rtail;
00155         int buflevel;
00156     } rx; // serial port objects
00157     struct {
00158         int len; // number of bytes in buffer
00159         int crc; // PPP CRC (frame check)
00160 #define PPP_max_size 1600
00161         // we are assuming 100 bytes more than MTU size of 1500
00162         char buf[PPP_max_size]; // send and receive buffer large enough for largest IP packet
00163     } pkt; // ppp buffer objects
00164     struct {
00165         int frameStartIndex; // frame start marker
00166         int frameEndIndex; // frame end marker
00167     } hdlc; // hdlc frame objects
00168     struct {
00169         unsigned int ident; // our IP ident value (outgoing frame count)
00170     } ipData; // ip related object
00171 } pppVariables;
00172 
00173 void t_print(int i, char* process);
00174 void l_off(void);void l_on(void);
00175 void led_flash(void);