// uses both friend functions above ...
friend StrInt operator + (const StrInt& a, const StrInt& b)
{
int len1 = a.snum.size();
int len2 = b.snum.size();
int ml = (len1 > len2 ? len1 : len2);
StrInt s;
s.snum.resize(ml);
int carry = 0;
while (len1 && len2)
s.snum[--ml] = sumof(a, --len1, b, --len2, carry);
if (len1)
while (len1)
s.snum[--ml] = sumof(a, --len1, carry);
else if (len2)
while (len2)
s.snum[--ml] = sumof(b, --len2, carry);
if (carry)
s.snum = "1" + s.snum;
return s;
}
//function for updating cost by Bellmann ford equation
int updaterouting(struct dv *dv1,struct message *sendmsg,struct message *revddata,struct details *neigh)
{
struct updating newcost[5];
char st[INET6_ADDRSTRLEN];
int i=0;
int mincost;
int32_t dest;
int16_t cofxv;
int16_t cofxy[5];
int32_t senderid;
cofxy[0]=neigh[0].cost;
cofxy[1]=neigh[1].cost;
cofxy[2]=neigh[2].cost;
cofxy[3]=neigh[3].cost;
cofxy[4]=neigh[4].cost;
struct sockaddr_in g;
memcpy(&g.sin_addr,&revddata[0].senderip,sizeof(revddata[0].senderip));
inet_ntop(AF_INET,&g.sin_addr,st,INET_ADDRSTRLEN);
for(i=0;i<dv1[0].n;i++)
{
if(revddata[0].senderip==neigh[i].nip)
{
cofxv=neigh[i].cost;
senderid=neigh[i].id;
//printf("\n sender id %d",senderid);
}
}
if(revddata[0].senderip==neigh[0].nip)
{
newcost[0].to1=revddata[0].cost;
newcost[0].to2=revddata[1].cost;
newcost[0].to3=revddata[2].cost;
newcost[0].to4=revddata[3].cost;
newcost[0].to5=revddata[4].cost;
}
if(revddata[0].senderip==neigh[1].nip)
{
newcost[0].to1=revddata[0].cost;
newcost[0].to2=revddata[1].cost;
newcost[0].to3=revddata[2].cost;
newcost[0].to4=revddata[3].cost;
newcost[0].to5=revddata[4].cost;
}
if(revddata[0].senderip==neigh[2].nip)
{
newcost[0].to1=revddata[0].cost;
newcost[0].to2=revddata[1].cost;
newcost[0].to3=revddata[2].cost;
newcost[0].to4=revddata[3].cost;
newcost[0].to5=revddata[4].cost;
}
if(revddata[0].senderip==neigh[3].nip)
{
newcost[0].to1=revddata[0].cost;
newcost[0].to2=revddata[1].cost;
newcost[0].to3=revddata[2].cost;
newcost[0].to4=revddata[3].cost;
newcost[0].to5=revddata[4].cost;
}
if(revddata[0].senderip==neigh[4].nip)
{
newcost[0].to1=revddata[0].cost;
newcost[0].to2=revddata[1].cost;
newcost[0].to3=revddata[2].cost;
newcost[0].to4=revddata[3].cost;
newcost[0].to5=revddata[4].cost;
}
for(i=0;i<dv1[0].n;i++)
{
dest=neigh[i].id;
if(dv1[0].presentnode==dest)
{
mincost=0;
if(neigh[i].id == dv1[0].presentnode)
{
neigh[i].cost=mincost;
}
}
else if(dest==neigh[0].id)
{
mincost=min(neigh[0].cost,sumof(cofxv,newcost[0].to1));
if(mincost != neigh[0].cost)
dv1[0].hopto=senderid;
neigh[0].cost=mincost;
}
else if(dest==neigh[1].id)
{
mincost=min(neigh[1].cost,sumof(cofxv,newcost[0].to2));
if(mincost != neigh[1].cost)
dv1[1].hopto=senderid;
neigh[1].cost=mincost;
}
else if(dest==neigh[2].id)
{
mincost=min(neigh[2].cost,sumof(cofxv,newcost[0].to3));
if(mincost != neigh[2].cost)
dv1[2].hopto=senderid;
neigh[2].cost=mincost;
}
else if(dest==neigh[3].id)
{
mincost=min(neigh[3].cost,sumof(cofxv,newcost[0].to4));
if(mincost != neigh[3].cost)
dv1[3].hopto=senderid;
neigh[3].cost=mincost;
}
else if(dest==neigh[4].id)
{
mincost=min(neigh[4].cost,sumof(cofxv,newcost[0].to5));
if(mincost != neigh[4].cost)
dv1[4].hopto=senderid;
neigh[4].cost=mincost;
}
}
//for copying the data from the neighbour structure to the routing table
for(i=0;i<dv1[0].n;i++)
{
dv1[i].sid=neigh[i].id;
dv1[i].cost=neigh[i].cost;
dv1[i].ip=neigh[i].nip;
dv1[i].port=neigh[i].nport;
}//for
return 0;
}
