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ICMPSerializer Class Reference

#include <ICMPSerializer.h>

List of all members.

Detailed Description

Converts between ICMPMessage and binary (network byte order) ICMP header.


Public Member Functions

 ICMPSerializer ()
int serialize (ICMPMessage *pkt, unsigned char *buf, unsigned int bufsize)
void parse (unsigned char *buf, unsigned int bufsize, ICMPMessage *pkt)

Static Public Member Functions

static unsigned short checksum (unsigned char *addr, unsigned int count)

Constructor & Destructor Documentation

ICMPSerializer::ICMPSerializer (   )  [inline]
  

00032 {}

Member Function Documentation

unsigned short ICMPSerializer::checksum (  unsigned char *  addr,
unsigned int  count
)  [static]
 

Helper: calculate checksum 

00136 {
00137     long sum = 0;
00138 
00139     while (count > 1)  {
00140         sum += *((unsigned short *&)addr)++;
00141         if (sum & 0x80000000)
00142             sum = (sum & 0xFFFF) + (sum >> 16);
00143         count -= 2;
00144     }
00145 
00146     if (count)
00147         sum += *(unsigned char *)addr;
00148 
00149     while (sum >> 16)
00150         sum = (sum & 0xffff) + (sum >> 16);
00151 
00152     return ~sum;
00153 }

void ICMPSerializer::parse (  unsigned char *  buf,
unsigned int  bufsize,
ICMPMessage *  pkt
) 
 

Puts a packet sniffed from the wire into an ICMPMessage. 

00085 {
00086     struct icmp *icmp = (struct icmp*) buf;
00087 
00088     switch(icmp->icmp_type)
00089     {
00090         case ICMP_ECHO:
00091         {
00092             PingPayload *pp;
00093             char name[32];
00094 
00095             pkt->setType(ICMP_ECHO_REQUEST);
00096             pkt->setCode(0);
00097             pkt->setByteLength(4);
00098             sprintf(name,"ping%ld", ntohs(icmp->icmp_seq));
00099             pp = new PingPayload(name);
00100             pp->setOriginatorId(ntohs(icmp->icmp_id));
00101             pp->setSeqNo(ntohs(icmp->icmp_seq));
00102             pp->setByteLength(bufsize - 4);
00103             pp->setDataArraySize(bufsize - ICMP_MINLEN);
00104             for(unsigned int i=0; i<bufsize - ICMP_MINLEN; i++)
00105                 pp->setData(i, icmp->icmp_data[i]);
00106             pkt->encapsulate(pp);
00107             pkt->setName(pp->name());
00108             break;
00109         }
00110         case ICMP_ECHOREPLY:
00111         {
00112             PingPayload *pp;
00113             char name[32];
00114 
00115             pkt->setType(ICMP_ECHO_REPLY);
00116             pkt->setCode(0);
00117             pkt->setByteLength(4);
00118             sprintf(name,"ping%ld-reply", ntohs(icmp->icmp_seq));
00119             pp = new PingPayload(name);
00120             pp->setOriginatorId(ntohs(icmp->icmp_id));
00121             pp->setSeqNo(ntohs(icmp->icmp_seq));
00122             pp->setByteLength(bufsize - 4);
00123             pkt->encapsulate(pp);
00124             pkt->setName(pp->name());
00125             break;
00126         }
00127         default:
00128         {
00129             EV << "Can not create ICMP packet: type " << icmp->icmp_type << " not supported.";
00130             break;
00131         }
00132     }
00133 }

int ICMPSerializer::serialize (  ICMPMessage *  pkt,
unsigned char *  buf,
unsigned int  bufsize
) 
 

Serializes an ICMPMessage for transmission on the wire. Returns the length of data written into buffer. 

00041 {
00042     struct icmp *icmp = (struct icmp *) (buf);
00043     int packetLength;
00044 
00045     switch(pkt->getType())
00046     {
00047         case ICMP_ECHO_REQUEST:
00048         {
00049             PingPayload *pp = check_and_cast<PingPayload* >(pkt->encapsulatedMsg());
00050             icmp->icmp_type = ICMP_ECHO;
00051             icmp->icmp_code = 0;
00052             icmp->icmp_id   = htons(pp->originatorId());
00053             icmp->icmp_seq  = htons(pp->seqNo());
00054             unsigned int datalen = (pp->byteLength() - 4);
00055             for(unsigned int i=0; i < datalen; i++)
00056                 icmp->icmp_data[i] = 'a';
00057             packetLength = ICMP_MINLEN + datalen;
00058             break;
00059         }
00060         case ICMP_ECHO_REPLY:
00061         {
00062             PingPayload *pp = check_and_cast<PingPayload* >(pkt->encapsulatedMsg());
00063             icmp->icmp_type = ICMP_ECHOREPLY;
00064             icmp->icmp_code = 0;
00065             icmp->icmp_id   = htons(pp->originatorId());
00066             icmp->icmp_seq  = htons(pp->seqNo());
00067             unsigned int datalen = pp->dataArraySize();
00068             for(unsigned int i=0; i < datalen; i++)
00069                 icmp->icmp_data[i] = pp->data(i);
00070             packetLength = ICMP_MINLEN + datalen;
00071             break;
00072         }
00073         default:
00074         {
00075             packetLength = 0;
00076             EV << "Can not serialize ICMP packet: type " << icmp->icmp_type << " not supported.";
00077             break;
00078         }
00079     }
00080     icmp->icmp_cksum = checksum(buf, packetLength);
00081     return packetLength;
00082 }

The documentation for this class was generated from the following files:
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