Do not issue "network" or "broadcast" addresses (0 or 255)

This commit is contained in:
Kristoffer Dalby 2021-08-03 10:06:42 +01:00
parent d3349aa4d1
commit ea615e3a26
No known key found for this signature in database
GPG key ID: 09F62DC067465735
2 changed files with 20 additions and 24 deletions

View file

@ -79,21 +79,6 @@ func (h *Headscale) getAvailableIP() (*netaddr.IP, error) {
return nil, err
}
// for _, ip := range usedIps {
// nextIP := ip.Next()
// if !containsIPs(usedIps, nextIP) && ipPrefix.Contains(nextIP) {
// return &nextIP, nil
// }
// }
// // If there are no IPs in use, we are starting fresh and
// // can issue IPs from the beginning of the prefix.
// ip := ipPrefix.IP()
// return &ip, nil
// return nil, fmt.Errorf("failed to find any available IP in %s", ipPrefix)
// Get the first IP in our prefix
ip := ipPrefix.IP()
@ -102,8 +87,19 @@ func (h *Headscale) getAvailableIP() (*netaddr.IP, error) {
return nil, fmt.Errorf("could not find any suitable IP in %s", ipPrefix)
}
// Some OS (including Linux) does not like when IPs ends with 0 or 255, which
// is typically called network or broadcast. Lets avoid them and continue
// to look when we get one of those traditionally reserved IPs.
ipRaw := ip.As4()
if ipRaw[3] == 0 || ipRaw[3] == 255 {
ip = ip.Next()
continue
}
if ip.IsZero() &&
ip.IsLoopback() {
ip = ip.Next()
continue
}

View file

@ -10,7 +10,7 @@ func (s *Suite) TestGetAvailableIp(c *check.C) {
c.Assert(err, check.IsNil)
expected := netaddr.MustParseIP("10.27.0.0")
expected := netaddr.MustParseIP("10.27.0.1")
c.Assert(ip.String(), check.Equals, expected.String())
}
@ -46,7 +46,7 @@ func (s *Suite) TestGetUsedIps(c *check.C) {
c.Assert(err, check.IsNil)
expected := netaddr.MustParseIP("10.27.0.0")
expected := netaddr.MustParseIP("10.27.0.1")
c.Assert(ips[0], check.Equals, expected)
@ -91,20 +91,20 @@ func (s *Suite) TestGetMultiIp(c *check.C) {
c.Assert(len(ips), check.Equals, 350)
c.Assert(ips[0], check.Equals, netaddr.MustParseIP("10.27.0.0"))
c.Assert(ips[9], check.Equals, netaddr.MustParseIP("10.27.0.9"))
c.Assert(ips[300], check.Equals, netaddr.MustParseIP("10.27.1.44"))
c.Assert(ips[0], check.Equals, netaddr.MustParseIP("10.27.0.1"))
c.Assert(ips[9], check.Equals, netaddr.MustParseIP("10.27.0.10"))
c.Assert(ips[300], check.Equals, netaddr.MustParseIP("10.27.1.47"))
// Check that we can read back the IPs
m1, err := h.GetMachineByID(1)
c.Assert(err, check.IsNil)
c.Assert(m1.IPAddress, check.Equals, netaddr.MustParseIP("10.27.0.0").String())
c.Assert(m1.IPAddress, check.Equals, netaddr.MustParseIP("10.27.0.1").String())
m50, err := h.GetMachineByID(50)
c.Assert(err, check.IsNil)
c.Assert(m50.IPAddress, check.Equals, netaddr.MustParseIP("10.27.0.49").String())
c.Assert(m50.IPAddress, check.Equals, netaddr.MustParseIP("10.27.0.50").String())
expectedNextIP := netaddr.MustParseIP("10.27.1.94")
expectedNextIP := netaddr.MustParseIP("10.27.1.97")
nextIP, err := h.getAvailableIP()
c.Assert(err, check.IsNil)
@ -122,7 +122,7 @@ func (s *Suite) TestGetAvailableIpMachineWithoutIP(c *check.C) {
ip, err := h.getAvailableIP()
c.Assert(err, check.IsNil)
expected := netaddr.MustParseIP("10.27.0.0")
expected := netaddr.MustParseIP("10.27.0.1")
c.Assert(ip.String(), check.Equals, expected.String())