go.ligato.io/vpp-agent/v3@v3.5.0/plugins/linux/ifplugin/descriptor/interface_tap.go (about)

     1  // Copyright (c) 2018 Cisco and/or its affiliates.
     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 descriptor
    16  
    17  import (
    18  	"strings"
    19  
    20  	"go.ligato.io/vpp-agent/v3/plugins/linux/ifplugin/linuxcalls"
    21  
    22  	"github.com/pkg/errors"
    23  
    24  	"go.ligato.io/vpp-agent/v3/plugins/linux/ifplugin/ifaceidx"
    25  	interfaces "go.ligato.io/vpp-agent/v3/proto/ligato/linux/interfaces"
    26  
    27  	nslinuxcalls "go.ligato.io/vpp-agent/v3/plugins/linux/nsplugin/linuxcalls"
    28  )
    29  
    30  // createTAPToVPP moves Linux-side of the VPP-TAP interface to the destination namespace
    31  // and sets the requested host name, IP addresses, etc.
    32  func (d *InterfaceDescriptor) createTAPToVPP(
    33  	nsCtx nslinuxcalls.NamespaceMgmtCtx, key string, linuxIf *interfaces.Interface,
    34  ) (
    35  	md *ifaceidx.LinuxIfMetadata, err error) {
    36  
    37  	// determine TAP interface name as set by VPP ifplugin
    38  	vppTapName := linuxIf.GetTap().GetVppTapIfName()
    39  	vppTapMeta, found := d.vppIfPlugin.GetInterfaceIndex().LookupByName(vppTapName)
    40  	if !found {
    41  		err = errors.Errorf("failed to find VPP-side for the TAP-To-VPP interface %s", linuxIf.Name)
    42  		d.log.Error(err)
    43  		return nil, err
    44  	}
    45  	vppTapHostName := vppTapMeta.TAPHostIfName
    46  	hostName := getHostIfName(linuxIf)
    47  
    48  	// context
    49  	agentPrefix := d.serviceLabel.GetAgentPrefix()
    50  
    51  	// add alias to associate TAP with the logical name and VPP-TAP reference
    52  	alias := agentPrefix + linuxcalls.GetTapAlias(linuxIf, vppTapHostName)
    53  	err = d.ifHandler.SetInterfaceAlias(vppTapHostName, alias)
    54  	if err != nil {
    55  		d.log.Error(err)
    56  		return nil, err
    57  	}
    58  
    59  	// move the TAP to the right namespace
    60  	err = d.setInterfaceNamespace(nsCtx, vppTapHostName, linuxIf.Namespace)
    61  	if err != nil {
    62  		d.log.Error(err)
    63  		return nil, err
    64  	}
    65  
    66  	// move to the namespace with the interface
    67  	revert, err := d.nsPlugin.SwitchToNamespace(nsCtx, linuxIf.Namespace)
    68  	if err != nil {
    69  		d.log.Error(err)
    70  		return nil, err
    71  	}
    72  	defer revert()
    73  
    74  	// rename from temporary host name to the request host name
    75  	if err := d.ifHandler.RenameInterface(vppTapHostName, hostName); err != nil {
    76  		d.log.Error(err)
    77  		return nil, err
    78  	}
    79  
    80  	// build metadata
    81  	link, err := d.ifHandler.GetLinkByName(hostName)
    82  	if err != nil {
    83  		d.log.Error(err)
    84  		return nil, err
    85  	}
    86  
    87  	return &ifaceidx.LinuxIfMetadata{
    88  		VPPTapName:   vppTapName,
    89  		Namespace:    linuxIf.Namespace,
    90  		LinuxIfIndex: link.Attrs().Index,
    91  	}, nil
    92  }
    93  
    94  // deleteAutoTAP returns TAP interface back to the default namespace and renames
    95  // the interface back to original name.
    96  func (d *InterfaceDescriptor) deleteAutoTAP(nsCtx nslinuxcalls.NamespaceMgmtCtx, key string, linuxIf *interfaces.Interface, metadata *ifaceidx.LinuxIfMetadata) error {
    97  	hostName := getHostIfName(linuxIf)
    98  	agentPrefix := d.serviceLabel.GetAgentPrefix()
    99  
   100  	// get original TAP name
   101  	link, err := d.ifHandler.GetLinkByName(hostName)
   102  	if err != nil {
   103  		d.log.Error(err)
   104  		return err
   105  	}
   106  	alias := strings.TrimPrefix(link.Attrs().Alias, agentPrefix)
   107  	_, _, origVppTapHostName := linuxcalls.ParseTapAlias(alias)
   108  	if origVppTapHostName == "" {
   109  		err = errors.New("failed to obtain the original TAP host name")
   110  		d.log.Error(err)
   111  		return err
   112  	}
   113  
   114  	// rename back to the temporary name
   115  	err = d.ifHandler.RenameInterface(hostName, origVppTapHostName)
   116  	if err != nil {
   117  		d.log.Error(err)
   118  		return err
   119  	}
   120  
   121  	// move TAP back to the default namespace
   122  	err = d.setInterfaceNamespace(nsCtx, origVppTapHostName, nil)
   123  	if err != nil {
   124  		d.log.Error(err)
   125  		return err
   126  	}
   127  
   128  	// move to the default namespace
   129  	revert, err := d.nsPlugin.SwitchToNamespace(nsCtx, nil)
   130  	if err != nil {
   131  		d.log.Error(err)
   132  		return err
   133  	}
   134  	defer revert()
   135  
   136  	// remove interface alias at last(!)
   137  	// - actually vishvananda/netlink does not support alias removal, so we just change
   138  	//   it to a string which is not prefixed with agent label
   139  	err = d.ifHandler.SetInterfaceAlias(origVppTapHostName, "unconfigured")
   140  	if err != nil {
   141  		d.log.Error(err)
   142  		return err
   143  	}
   144  
   145  	return nil
   146  }