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

     1  // Copyright (c) 2019 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  //go:generate descriptor-adapter --descriptor-name RuleChain --value-type *linux_iptables.RuleChain --import "go.ligato.io/vpp-agent/v3/proto/ligato/linux/iptables" --output-dir "descriptor"
    16  
    17  package iptablesplugin
    18  
    19  import (
    20  	"math"
    21  
    22  	"go.ligato.io/cn-infra/v2/infra"
    23  	kvs "go.ligato.io/vpp-agent/v3/plugins/kvscheduler/api"
    24  	"go.ligato.io/vpp-agent/v3/plugins/linux/iptablesplugin/descriptor"
    25  	"go.ligato.io/vpp-agent/v3/plugins/linux/iptablesplugin/linuxcalls"
    26  	"go.ligato.io/vpp-agent/v3/plugins/linux/nsplugin"
    27  )
    28  
    29  const (
    30  	// by default, at most 10 go routines will split the configured rule chains
    31  	// to execute the Retrieve operation in parallel.
    32  	defaultGoRoutinesCnt = 10
    33  
    34  	// by default, no rules will be added by alternative performance strategy using
    35  	// iptables-save/modify data/iptables-store technique
    36  	// If this performance technique is needed, then the minimum rule limit should be lowered
    37  	// by configuration to some lower value (0 means that the permance strategy is
    38  	// always used)
    39  	defaultMinRuleCountForPerfRuleAddition = math.MaxInt32
    40  )
    41  
    42  // IPTablesPlugin configures Linux iptables rules.
    43  type IPTablesPlugin struct {
    44  	Deps
    45  
    46  	// From configuration file
    47  	disabled    bool
    48  	configFound bool
    49  
    50  	// system handlers
    51  	iptHandler linuxcalls.IPTablesAPI
    52  }
    53  
    54  // Deps lists dependencies of the plugin.
    55  type Deps struct {
    56  	infra.PluginDeps
    57  	KVScheduler kvs.KVScheduler
    58  	NsPlugin    nsplugin.API
    59  }
    60  
    61  // Config holds the plugin configuration.
    62  type Config struct {
    63  	linuxcalls.HandlerConfig `json:"handler"`
    64  
    65  	Disabled      bool `json:"disabled"`
    66  	GoRoutinesCnt int  `json:"go-routines-count"`
    67  }
    68  
    69  // Init initializes and registers descriptors and handlers for Linux iptables rules.
    70  func (p *IPTablesPlugin) Init() error {
    71  	// parse configuration file
    72  	config, err := p.retrieveConfig()
    73  	if err != nil {
    74  		return err
    75  	}
    76  	p.Log.Debugf("Linux iptables config: %+v", config)
    77  	if config.Disabled {
    78  		p.disabled = true
    79  		p.Log.Infof("Disabling iptables plugin")
    80  		return nil
    81  	}
    82  
    83  	// init iptables handler
    84  	p.iptHandler = linuxcalls.NewIPTablesHandler()
    85  	err = p.iptHandler.Init(&config.HandlerConfig)
    86  	if err != nil && p.configFound {
    87  		// just warn here, iptables / ip6tables just may not be installed - will return
    88  		// an error by attempt to configure it
    89  		p.Log.Warnf("Error by initializing iptables handler: %v", err)
    90  	}
    91  
    92  	// init & register the descriptor
    93  	ruleChainDescriptor := descriptor.NewRuleChainDescriptor(
    94  		p.KVScheduler, p.iptHandler, p.NsPlugin, p.Log, config.GoRoutinesCnt, config.MinRuleCountForPerfRuleAddition)
    95  
    96  	err = p.Deps.KVScheduler.RegisterKVDescriptor(ruleChainDescriptor)
    97  	if err != nil {
    98  		return err
    99  	}
   100  
   101  	return nil
   102  }
   103  
   104  // Close does nothing here.
   105  func (p *IPTablesPlugin) Close() error {
   106  	return nil
   107  }
   108  
   109  // retrieveConfig loads plugin configuration file.
   110  func (p *IPTablesPlugin) retrieveConfig() (*Config, error) {
   111  	config := &Config{
   112  		// default configuration
   113  		GoRoutinesCnt: defaultGoRoutinesCnt,
   114  		HandlerConfig: linuxcalls.HandlerConfig{
   115  			MinRuleCountForPerfRuleAddition: defaultMinRuleCountForPerfRuleAddition,
   116  		},
   117  	}
   118  	found, err := p.Cfg.LoadValue(config)
   119  	if !found {
   120  		p.Log.Debug("Linux IPTablesPlugin config not found")
   121  		return config, nil
   122  	}
   123  	if err != nil {
   124  		return nil, err
   125  	}
   126  	p.configFound = true
   127  	return config, err
   128  }