mirror of https://github.com/k3s-io/k3s
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
119 lines
3.8 KiB
119 lines
3.8 KiB
// Copyright 2015 flannel authors
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package subnet
|
|
|
|
import (
|
|
"encoding/json"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"github.com/flannel-io/flannel/pkg/ip"
|
|
)
|
|
|
|
type Config struct {
|
|
Network ip.IP4Net
|
|
SubnetMin ip.IP4
|
|
SubnetMax ip.IP4
|
|
SubnetLen uint
|
|
BackendType string `json:"-"`
|
|
Backend json.RawMessage `json:",omitempty"`
|
|
}
|
|
|
|
func parseBackendType(be json.RawMessage) (string, error) {
|
|
var bt struct {
|
|
Type string
|
|
}
|
|
|
|
if len(be) == 0 {
|
|
return "udp", nil
|
|
} else if err := json.Unmarshal(be, &bt); err != nil {
|
|
return "", fmt.Errorf("error decoding Backend property of config: %v", err)
|
|
}
|
|
|
|
return bt.Type, nil
|
|
}
|
|
|
|
func ParseConfig(s string) (*Config, error) {
|
|
cfg := new(Config)
|
|
err := json.Unmarshal([]byte(s), cfg)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
if cfg.SubnetLen > 0 {
|
|
// SubnetLen needs to allow for a tunnel and bridge device on each host.
|
|
if cfg.SubnetLen > 30 {
|
|
return nil, errors.New("SubnetLen must be less than /31")
|
|
}
|
|
|
|
// SubnetLen needs to fit _more_ than twice into the Network.
|
|
// the first subnet isn't used, so splitting into two one only provide one usable host.
|
|
if cfg.SubnetLen < cfg.Network.PrefixLen+2 {
|
|
return nil, errors.New("Network must be able to accommodate at least four subnets")
|
|
}
|
|
} else {
|
|
// If the network is smaller than a /28 then the network isn't big enough for flannel so return an error.
|
|
// Default to giving each host at least a /24 (as long as the network is big enough to support at least four hosts)
|
|
// Otherwise, if the network is too small to give each host a /24 just split the network into four.
|
|
if cfg.Network.PrefixLen > 28 {
|
|
// Each subnet needs at least four addresses (/30) and the network needs to accommodate at least four
|
|
// since the first subnet isn't used, so splitting into two would only provide one usable host.
|
|
// So the min useful PrefixLen is /28
|
|
return nil, errors.New("Network is too small. Minimum useful network prefix is /28")
|
|
} else if cfg.Network.PrefixLen <= 22 {
|
|
// Network is big enough to give each host a /24
|
|
cfg.SubnetLen = 24
|
|
} else {
|
|
// Use +2 to provide four hosts per subnet.
|
|
cfg.SubnetLen = cfg.Network.PrefixLen + 2
|
|
}
|
|
}
|
|
|
|
subnetSize := ip.IP4(1 << (32 - cfg.SubnetLen))
|
|
|
|
if cfg.SubnetMin == ip.IP4(0) {
|
|
// skip over the first subnet otherwise it causes problems. e.g.
|
|
// if Network is 10.100.0.0/16, having an interface with 10.0.0.0
|
|
// conflicts with the broadcast address.
|
|
cfg.SubnetMin = cfg.Network.IP + subnetSize
|
|
} else if !cfg.Network.Contains(cfg.SubnetMin) {
|
|
return nil, errors.New("SubnetMin is not in the range of the Network")
|
|
}
|
|
|
|
if cfg.SubnetMax == ip.IP4(0) {
|
|
cfg.SubnetMax = cfg.Network.Next().IP - subnetSize
|
|
} else if !cfg.Network.Contains(cfg.SubnetMax) {
|
|
return nil, errors.New("SubnetMax is not in the range of the Network")
|
|
}
|
|
|
|
// The SubnetMin and SubnetMax need to be aligned to a SubnetLen boundary
|
|
mask := ip.IP4(0xFFFFFFFF << (32 - cfg.SubnetLen))
|
|
if cfg.SubnetMin != cfg.SubnetMin&mask {
|
|
return nil, fmt.Errorf("SubnetMin is not on a SubnetLen boundary: %v", cfg.SubnetMin)
|
|
}
|
|
|
|
if cfg.SubnetMax != cfg.SubnetMax&mask {
|
|
return nil, fmt.Errorf("SubnetMax is not on a SubnetLen boundary: %v", cfg.SubnetMax)
|
|
}
|
|
|
|
bt, err := parseBackendType(cfg.Backend)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
cfg.BackendType = bt
|
|
|
|
return cfg, nil
|
|
}
|