Lectures notes for 2010 - KTH

packetsize+=ip->ihlcheck=0; /* ignore UDP checksum */
packetsize+=sizeof(struct udphdr);
/* end of udp header */
/* add data to UDP payload if you want: */
for (datasize=0;datasizelen=htons(sizeof(struct udphdr)+datasize);
ip->tot_len=htons(packetsize);
if (sendto(s, (char *)outpack, packetsize, 0, &addrto, sizeof(struct sockaddr))==-1)
{perror("sendto"); exit(2);}
}
printf("packet sent !\n");
close(s);
exit(0);
Maguire Building a UDP packet from scratch 4: 26 of 74
maguire@kth.se 2010.03.21 Internetworking/Internetteknik