config: Enable to configure VRF via config file

This patch enables to configure VRF tables by using config file. This
feature is useful when using VRF-Neighbor feature.

Example of Usage:

```toml
[[vrfs]]
  [vrfs.config]
    name = "vrf1"
    id = 1
    rd = "65000:100"
    both-rt-list = ["65000:100"]
```

Signed-off-by: IWASE Yusuke <iwase.yusuke0@gmail.com>

3 files changed, 203 insertions, 3 deletions

diff --git a/config/bgp_configs.go b/config/bgp_configs.go
index 402bff40..062ef8f7 100644
--- a/config/bgp_configs.go
+++ b/config/bgp_configs.go
@@ -1250,6 +1250,112 @@ func (lhs *Mrt) Equal(rhs *Mrt) bool {
 }
 
 // struct for container gobgp:state.
+// Configured states of VRF.
+type VrfState struct {
+	// original -> gobgp:name
+	// Unique name among all VRF instances.
+	Name string `mapstructure:"name" json:"name,omitempty"`
+	// original -> gobgp:id
+	// Unique identifier among all VRF instances.
+	Id uint32 `mapstructure:"id" json:"id,omitempty"`
+	// original -> gobgp:rd
+	// Route Distinguisher for this VRF.
+	Rd string `mapstructure:"rd" json:"rd,omitempty"`
+	// original -> gobgp:import-rt
+	// List of import Route Targets for this VRF.
+	ImportRtList []string `mapstructure:"import-rt-list" json:"import-rt-list,omitempty"`
+	// original -> gobgp:export-rt
+	// List of export Route Targets for this VRF.
+	ExportRtList []string `mapstructure:"export-rt-list" json:"export-rt-list,omitempty"`
+}
+
+// struct for container gobgp:config.
+// Configuration parameters for VRF.
+type VrfConfig struct {
+	// original -> gobgp:name
+	// Unique name among all VRF instances.
+	Name string `mapstructure:"name" json:"name,omitempty"`
+	// original -> gobgp:id
+	// Unique identifier among all VRF instances.
+	Id uint32 `mapstructure:"id" json:"id,omitempty"`
+	// original -> gobgp:rd
+	// Route Distinguisher for this VRF.
+	Rd string `mapstructure:"rd" json:"rd,omitempty"`
+	// original -> gobgp:import-rt
+	// List of import Route Targets for this VRF.
+	ImportRtList []string `mapstructure:"import-rt-list" json:"import-rt-list,omitempty"`
+	// original -> gobgp:export-rt
+	// List of export Route Targets for this VRF.
+	ExportRtList []string `mapstructure:"export-rt-list" json:"export-rt-list,omitempty"`
+	// original -> gobgp:both-rt
+	// List of both import and export Route Targets for this VRF. Each
+	// configuration for import and export Route Targets will be preferred.
+	BothRtList []string `mapstructure:"both-rt-list" json:"both-rt-list,omitempty"`
+}
+
+func (lhs *VrfConfig) Equal(rhs *VrfConfig) bool {
+	if lhs == nil || rhs == nil {
+		return false
+	}
+	if lhs.Name != rhs.Name {
+		return false
+	}
+	if lhs.Id != rhs.Id {
+		return false
+	}
+	if lhs.Rd != rhs.Rd {
+		return false
+	}
+	if len(lhs.ImportRtList) != len(rhs.ImportRtList) {
+		return false
+	}
+	for idx, l := range lhs.ImportRtList {
+		if l != rhs.ImportRtList[idx] {
+			return false
+		}
+	}
+	if len(lhs.ExportRtList) != len(rhs.ExportRtList) {
+		return false
+	}
+	for idx, l := range lhs.ExportRtList {
+		if l != rhs.ExportRtList[idx] {
+			return false
+		}
+	}
+	if len(lhs.BothRtList) != len(rhs.BothRtList) {
+		return false
+	}
+	for idx, l := range lhs.BothRtList {
+		if l != rhs.BothRtList[idx] {
+			return false
+		}
+	}
+	return true
+}
+
+// struct for container gobgp:vrf.
+// VRF instance configurations on the local system.
+type Vrf struct {
+	// original -> gobgp:name
+	// original -> gobgp:vrf-config
+	// Configuration parameters for VRF.
+	Config VrfConfig `mapstructure:"config" json:"config,omitempty"`
+	// original -> gobgp:vrf-state
+	// Configured states of VRF.
+	State VrfState `mapstructure:"state" json:"state,omitempty"`
+}
+
+func (lhs *Vrf) Equal(rhs *Vrf) bool {
+	if lhs == nil || rhs == nil {
+		return false
+	}
+	if !lhs.Config.Equal(&(rhs.Config)) {
+		return false
+	}
+	return true
+}
+
+// struct for container gobgp:state.
 // Configuration parameters relating to BMP server.
 type BmpServerState struct {
 	// original -> gobgp:address
@@ -4785,6 +4891,8 @@ type Bgp struct {
 	RpkiServers []RpkiServer `mapstructure:"rpki-servers" json:"rpki-servers,omitempty"`
 	// original -> gobgp:bmp-servers
 	BmpServers []BmpServer `mapstructure:"bmp-servers" json:"bmp-servers,omitempty"`
+	// original -> gobgp:vrfs
+	Vrfs []Vrf `mapstructure:"vrfs" json:"vrfs,omitempty"`
 	// original -> gobgp:mrt-dump
 	MrtDump []Mrt `mapstructure:"mrt-dump" json:"mrt-dump,omitempty"`
 	// original -> gobgp:zebra
@@ -4866,6 +4974,22 @@ func (lhs *Bgp) Equal(rhs *Bgp) bool {
 			}
 		}
 	}
+	if len(lhs.Vrfs) != len(rhs.Vrfs) {
+		return false
+	}
+	{
+		lmap := make(map[string]*Vrf)
+		for i, l := range lhs.Vrfs {
+			lmap[mapkey(i, string(l.Config.Name))] = &lhs.Vrfs[i]
+		}
+		for i, r := range rhs.Vrfs {
+			if l, y := lmap[mapkey(i, string(r.Config.Name))]; !y {
+				return false
+			} else if !r.Equal(l) {
+				return false
+			}
+		}
+	}
 	if len(lhs.MrtDump) != len(rhs.MrtDump) {
 		return false
 	}
diff --git a/config/default.go b/config/default.go
index 5c472909..f5bf809e 100644
--- a/config/default.go
+++ b/config/default.go
@@ -2,13 +2,15 @@ package config
 
 import (
 	"fmt"
+	"math"
 	"net"
 	"reflect"
 
+	"github.com/spf13/viper"
+
 	"github.com/osrg/gobgp/packet/bgp"
 	"github.com/osrg/gobgp/packet/bmp"
 	"github.com/osrg/gobgp/packet/rtr"
-	"github.com/spf13/viper"
 )
 
 const (
@@ -265,6 +267,43 @@ func SetDefaultGlobalConfigValues(g *Global) error {
 	return nil
 }
 
+func setDefaultVrfConfigValues(v *Vrf) error {
+	if v == nil {
+		return fmt.Errorf("cannot set default values for nil vrf config")
+	}
+
+	if v.Config.Name == "" {
+		return fmt.Errorf("specify vrf name")
+	}
+
+	_, err := bgp.ParseRouteDistinguisher(v.Config.Rd)
+	if err != nil {
+		return fmt.Errorf("invalid rd for vrf %s: %s", v.Config.Name, v.Config.Rd)
+	}
+
+	if len(v.Config.ImportRtList) == 0 {
+		v.Config.ImportRtList = v.Config.BothRtList
+	}
+	for _, rtString := range v.Config.ImportRtList {
+		_, err := bgp.ParseRouteTarget(rtString)
+		if err != nil {
+			return fmt.Errorf("invalid import rt for vrf %s: %s", v.Config.Name, rtString)
+		}
+	}
+
+	if len(v.Config.ExportRtList) == 0 {
+		v.Config.ExportRtList = v.Config.BothRtList
+	}
+	for _, rtString := range v.Config.ExportRtList {
+		_, err := bgp.ParseRouteTarget(rtString)
+		if err != nil {
+			return fmt.Errorf("invalid export rt for vrf %s: %s", v.Config.Name, rtString)
+		}
+	}
+
+	return nil
+}
+
 func SetDefaultConfigValues(b *BgpConfigSet) error {
 	return setDefaultConfigValuesWithViper(nil, b)
 }
@@ -309,6 +348,41 @@ func setDefaultConfigValuesWithViper(v *viper.Viper, b *BgpConfigSet) error {
 		b.BmpServers[idx] = server
 	}
 
+	vrfNames := make(map[string]struct{})
+	vrfIDs := make(map[uint32]struct{})
+	for idx, vrf := range b.Vrfs {
+		if err := setDefaultVrfConfigValues(&vrf); err != nil {
+			return err
+		}
+
+		if _, ok := vrfNames[vrf.Config.Name]; ok {
+			return fmt.Errorf("duplicated vrf name: %s", vrf.Config.Name)
+		}
+		vrfNames[vrf.Config.Name] = struct{}{}
+
+		if vrf.Config.Id != 0 {
+			if _, ok := vrfIDs[vrf.Config.Id]; ok {
+				return fmt.Errorf("duplicated vrf id: %d", vrf.Config.Id)
+			}
+			vrfIDs[vrf.Config.Id] = struct{}{}
+		}
+
+		b.Vrfs[idx] = vrf
+	}
+	// Auto assign VRF identifier
+	for idx, vrf := range b.Vrfs {
+		if vrf.Config.Id == 0 {
+			for id := uint32(1); id < math.MaxUint32; id++ {
+				if _, ok := vrfIDs[id]; !ok {
+					vrf.Config.Id = id
+					vrfIDs[id] = struct{}{}
+					break
+				}
+			}
+		}
+		b.Vrfs[idx] = vrf
+	}
+
 	if b.Zebra.Config.Url == "" {
 		b.Zebra.Config.Url = "unix:/var/run/quagga/zserv.api"
 	}
diff --git a/config/serve.go b/config/serve.go
index 45c70ea9..7705b1f8 100644
--- a/config/serve.go
+++ b/config/serve.go
@@ -1,11 +1,12 @@
 package config
 
 import (
-	log "github.com/sirupsen/logrus"
-	"github.com/spf13/viper"
 	"os"
 	"os/signal"
 	"syscall"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/spf13/viper"
 )
 
 type BgpConfigSet struct {
@@ -14,6 +15,7 @@ type BgpConfigSet struct {
 	PeerGroups        []PeerGroup        `mapstructure:"peer-groups"`
 	RpkiServers       []RpkiServer       `mapstructure:"rpki-servers"`
 	BmpServers        []BmpServer        `mapstructure:"bmp-servers"`
+	Vrfs              []Vrf              `mapstructure:"vrfs"`
 	MrtDump           []Mrt              `mapstructure:"mrt-dump"`
 	Zebra             Zebra              `mapstructure:"zebra"`
 	Collector         Collector          `mapstructure:"collector"`