c-robinson / iplib Goto Github PK

See this example:

package main

import (
	"fmt"

	"github.com/c-robinson/iplib"
)

func GetNextSubnet(lastCIDR string, nextSize int) {
	lastNet := iplib.Net4FromStr(lastCIDR)

	if nextSize == 0 {
		nextSize, _ = lastNet.Mask().Size()
	}
	nextNet := lastNet.NextNet(nextSize)
	fmt.Printf("Next net: %s\n", nextNet)
}

func main() {
	GetNextSubnet("10.80.6.0/24", 18)
}

Outputs:

Next net: 10.80.0.0/18

Am I doing something wrong?

If I use the same subnet size, I get an expected result

GetNextSubnet("10.80.6.0/24", 0) // 0 default to the same size

output:

Next net: 10.80.7.0/24

and with:

GetNextSubnet("10.80.6.0/24", 22)

it goes backwards?

Next net: 10.80.4.0/22

This line causes an integer overflow when compiling for arm.

The solution would be to use uint32 instead of int for the datatype.

The error message is:
vendor/github.com/c-robinson/iplib/net6.go:337:21: constant 4294967295 overflows int

Hi,

I found incorrect dos in readme file related to using iplib.Net4. In this line:

n := NewNet4(net.ParseIP("192.168.0.0"), 16)

it should be:

n := iplib.NewNet4(net.ParseIP("192.168.0.0"), 16)

and in this one:

fmt.Println(n.Network()) // 192.168.0.0

it should be:

fmt.Println(n.IP()) // 192.168.0.0

Hi,

I'm packaging your software for Debian (as a build-dependency for https://www.crowdsec.net/) and I'm seeing the following test failure on 32-bit archs (e.g. armel, armhf, i386 as seen on https://ci.debian.net/packages/g/golang-github-c-robinson-iplib/):

   dh_auto_test -O--builddirectory=_build -O--buildsystem=golang
	cd _build && go test -vet=off -v -p 32 github.com/c-robinson/iplib github.com/c-robinson/iplib/iana github.com/c-robinson/iplib/iid
# github.com/c-robinson/iplib [github.com/c-robinson/iplib.test]
src/github.com/c-robinson/iplib/iplib_test.go:362:30: cannot use MaxIPv4 (untyped int constant 4294967295) as int value in argument to t.Errorf (overflows)
FAIL	github.com/c-robinson/iplib [build failed]

It can be trivially reproduced in an i386 chroot on an amd64 machine.

Casting the constant explicitly to uint in that error message does the trick, but maybe it should or could have been declared a uint32 in the first place? That being said, I don't know anything about Go, so I'll just mention the patch I'm considering applying to iplib_test.go in the Debian package until I've gotten some feedback here:

-               t.Errorf("want %d got %d", MaxIPv4, i)
+               t.Errorf("want %d got %d", uint(MaxIPv4), i)