github.com/zhuohuang-hust/src-cbuild@v0.0.0-20230105071821-c7aab3e7c840/mergeCode/libnetwork/drivers/bridge/setup_ipv4.go (about)

     1  package bridge
     2  
     3  import (
     4  	"fmt"
     5  	"io/ioutil"
     6  	"path/filepath"
     7  
     8  	log "github.com/Sirupsen/logrus"
     9  	"github.com/docker/libnetwork/types"
    10  	"github.com/vishvananda/netlink"
    11  )
    12  
    13  func setupBridgeIPv4(config *networkConfiguration, i *bridgeInterface) error {
    14  	addrv4, _, err := i.addresses()
    15  	if err != nil {
    16  		return fmt.Errorf("failed to retrieve bridge interface addresses: %v", err)
    17  	}
    18  
    19  	if !types.CompareIPNet(addrv4.IPNet, config.AddressIPv4) {
    20  		if addrv4.IPNet != nil {
    21  			if err := i.nlh.AddrDel(i.Link, &addrv4); err != nil {
    22  				return fmt.Errorf("failed to remove current ip address from bridge: %v", err)
    23  			}
    24  		}
    25  		log.Debugf("Assigning address to bridge interface %s: %s", config.BridgeName, config.AddressIPv4)
    26  		if err := i.nlh.AddrAdd(i.Link, &netlink.Addr{IPNet: config.AddressIPv4}); err != nil {
    27  			return &IPv4AddrAddError{IP: config.AddressIPv4, Err: err}
    28  		}
    29  	}
    30  
    31  	// Store bridge network and default gateway
    32  	i.bridgeIPv4 = config.AddressIPv4
    33  	i.gatewayIPv4 = config.AddressIPv4.IP
    34  
    35  	return nil
    36  }
    37  
    38  func setupGatewayIPv4(config *networkConfiguration, i *bridgeInterface) error {
    39  	if !i.bridgeIPv4.Contains(config.DefaultGatewayIPv4) {
    40  		return &ErrInvalidGateway{}
    41  	}
    42  
    43  	// Store requested default gateway
    44  	i.gatewayIPv4 = config.DefaultGatewayIPv4
    45  
    46  	return nil
    47  }
    48  
    49  func setupLoopbackAdressesRouting(config *networkConfiguration, i *bridgeInterface) error {
    50  	sysPath := filepath.Join("/proc/sys/net/ipv4/conf", config.BridgeName, "route_localnet")
    51  	ipv4LoRoutingData, err := ioutil.ReadFile(sysPath)
    52  	if err != nil {
    53  		return fmt.Errorf("Cannot read IPv4 local routing setup: %v", err)
    54  	}
    55  	// Enable loopback adresses routing only if it isn't already enabled
    56  	if ipv4LoRoutingData[0] != '1' {
    57  		if err := ioutil.WriteFile(sysPath, []byte{'1', '\n'}, 0644); err != nil {
    58  			return fmt.Errorf("Unable to enable local routing for hairpin mode: %v", err)
    59  		}
    60  	}
    61  	return nil
    62  }