github.com/stackdocker/rkt@v0.10.1-0.20151109095037-1aa827478248/stage1/init/kvm/network.go (about)

     1  // Copyright 2015 The rkt Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package kvm
    16  
    17  import (
    18  	"fmt"
    19  	"net"
    20  
    21  	"github.com/coreos/rkt/networking"
    22  )
    23  
    24  // GetNetworkDescriptions explicitly convert slice of activeNets to slice of netDescribers
    25  // which is slice required by GetKVMNetArgs
    26  func GetNetworkDescriptions(n *networking.Networking) []netDescriber {
    27  	var nds []netDescriber
    28  	for _, an := range n.GetActiveNetworks() {
    29  		nds = append(nds, an)
    30  	}
    31  	return nds
    32  }
    33  
    34  // netDescriber is something that describes network configuration
    35  type netDescriber interface {
    36  	HostIP() net.IP
    37  	GuestIP() net.IP
    38  	Mask() net.IP
    39  	IfName() string
    40  	IPMasq() bool
    41  }
    42  
    43  // GetKVMNetArgs returns additional arguments that need to be passed to kernel
    44  // and lkvm tool to configure networks properly.
    45  // Logic is based on Network configuration extracted from Networking struct
    46  // and essentially from activeNets that expose netDescriber behavior
    47  func GetKVMNetArgs(nds []netDescriber) ([]string, []string, error) {
    48  
    49  	var lkvmArgs []string
    50  	var kernelParams []string
    51  
    52  	for i, nd := range nds {
    53  		// https://www.kernel.org/doc/Documentation/filesystems/nfs/nfsroot.txt
    54  		// ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>:<dns0-ip>:<dns1-ip>
    55  		var gw string
    56  		if nd.IPMasq() {
    57  			gw = nd.HostIP().String()
    58  		}
    59  		kernelParam := fmt.Sprintf("ip=%s::%s:%s::%s:::", nd.GuestIP(), gw, nd.Mask(), fmt.Sprintf(networking.IfNamePattern, i))
    60  		kernelParams = append(kernelParams, kernelParam)
    61  
    62  		lkvmArgs = append(lkvmArgs, "--network")
    63  		lkvmArg := fmt.Sprintf("mode=tap,tapif=%s,host_ip=%s,guest_ip=%s", nd.IfName(), nd.HostIP(), nd.GuestIP())
    64  		lkvmArgs = append(lkvmArgs, lkvmArg)
    65  	}
    66  
    67  	return lkvmArgs, kernelParams, nil
    68  }