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moby--moby/libnetwork/ipamutils/utils.go
allencloud 9f415d0cdb use grep to find a/an misuse
Signed-off-by: allencloud <allen.sun@daocloud.io>
2016-06-03 16:35:33 +08:00

50 lines
1.5 KiB
Go

// Package ipamutils provides utility functions for ipam management
package ipamutils
import (
"net"
"sync"
)
var (
// PredefinedBroadNetworks contains a list of 31 IPv4 private networks with host size 16 and 12
// (172.17-31.x.x/16, 192.168.x.x/20) which do not overlap with the networks in `PredefinedGranularNetworks`
PredefinedBroadNetworks []*net.IPNet
// PredefinedGranularNetworks contains a list of 64K IPv4 private networks with host size 8
// (10.x.x.x/24) which do not overlap with the networks in `PredefinedBroadNetworks`
PredefinedGranularNetworks []*net.IPNet
initNetworksOnce sync.Once
)
// InitNetworks initializes the pre-defined networks used by the built-in IP allocator
func InitNetworks() {
initNetworksOnce.Do(func() {
PredefinedBroadNetworks = initBroadPredefinedNetworks()
PredefinedGranularNetworks = initGranularPredefinedNetworks()
})
}
func initBroadPredefinedNetworks() []*net.IPNet {
pl := make([]*net.IPNet, 0, 31)
mask := []byte{255, 255, 0, 0}
for i := 17; i < 32; i++ {
pl = append(pl, &net.IPNet{IP: []byte{172, byte(i), 0, 0}, Mask: mask})
}
mask20 := []byte{255, 255, 240, 0}
for i := 0; i < 16; i++ {
pl = append(pl, &net.IPNet{IP: []byte{192, 168, byte(i << 4), 0}, Mask: mask20})
}
return pl
}
func initGranularPredefinedNetworks() []*net.IPNet {
pl := make([]*net.IPNet, 0, 256*256)
mask := []byte{255, 255, 255, 0}
for i := 0; i < 256; i++ {
for j := 0; j < 256; j++ {
pl = append(pl, &net.IPNet{IP: []byte{10, byte(i), byte(j), 0}, Mask: mask})
}
}
return pl
}