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#include <u.h>
#include <libc.h>
typedef struct IPNet IPNet;
struct IPNet
{
u32int addr;
u32int mask;
u32int minaddr;
u32int maxaddr;
u32int bcast;
uint nhosts;
int cidr;
};
void
printip(u32int addr)
{
uchar ip4[4];
ip4[0] = (addr>>24)&0xff;
ip4[1] = (addr>>16)&0xff;
ip4[2] = (addr>>8)&0xff;
ip4[3] = addr&0xff;
print("%d.%d.%d.%d\n", ip4[0], ip4[1], ip4[2], ip4[3]);
}
void
printipnet(IPNet net)
{
print("network "); printip(net.addr);
print("netmask "); printip(net.mask);
print("minaddr "); printip(net.minaddr);
print("maxaddr "); printip(net.maxaddr);
print("bcast "); printip(net.bcast);
print("hosts %d\n", net.nhosts);
print("cidr %d\n", net.cidr);
}
int
countones(u32int addr)
{
int cnt, shift;
for(cnt = 0, shift = 31; cnt < 32 && (addr&(1<<shift)) != 0; cnt++, shift--)
;
return cnt;
}
void
usage(void)
{
fprint(2, "usage: %s addr mask\n", argv0);
exits("usage");
}
void
main(int argc, char *argv[])
{
IPNet net;
u32int addr, mask;
char *a, *m;
ARGBEGIN{
default: usage();
}ARGEND;
if(argc != 2)
usage();
a = argv[0];
addr = strtoul(a, &a, 10) << 24;
addr |= strtoul(++a, &a, 10) << 16;
addr |= strtoul(++a, &a, 10) << 8;
addr |= strtoul(++a, &a, 10);
m = argv[1];
mask = strtoul(m, &m, 10) << 24;
mask |= strtoul(++m, &m, 10) << 16;
mask |= strtoul(++m, &m, 10) << 8;
mask |= strtoul(++m, &m, 10);
net.addr = addr&mask;
net.mask = mask;
net.bcast = addr|~mask;
net.minaddr = net.addr+1;
net.maxaddr = net.bcast-1;
net.nhosts = net.maxaddr-net.minaddr;
net.cidr = countones(net.mask);
printipnet(net);
exits(nil);
}
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