cli: add support of route filtering in show commands

$ gobgp global rib
   Network     Next Hop AS_PATH Age        Attrs
*> 10.0.0.0/24 0.0.0.0  65000   00:10:17   [{Origin: IGP}]
*> 10.0.0.0/25 0.0.0.0  65000   00:10:16   [{Origin: IGP}]
*> 10.0.0.0/26 0.0.0.0  65000   00:10:15   [{Origin: IGP}]
*> 10.0.1.0/24 0.0.0.0  65000   00:10:21   [{Origin: IGP}]
*> 10.0.2.0/24 0.0.0.0  65000   00:10:20   [{Origin: IGP}]

$ gobgp global rib 10.0.0.0/24
   Network     Next Hop AS_PATH Age        Attrs
*> 10.0.0.0/24 0.0.0.0  65000   00:10:54   [{Origin: IGP}]

$ gobgp global rib 10.0.0.10
   Network     Next Hop AS_PATH Age        Attrs
*> 10.0.0.0/26 0.0.0.0  65000   00:11:16   [{Origin: IGP}]

Signed-off-by: ISHIDA Wataru <ishida.wataru@lab.ntt.co.jp>

3 files changed, 75 insertions, 59 deletions

diff --git a/docs/sources/cli-command-syntax.md b/docs/sources/cli-command-syntax.md
index f183d281..fa7747dd 100644
--- a/docs/sources/cli-command-syntax.md
+++ b/docs/sources/cli-command-syntax.md
@@ -26,6 +26,8 @@ Note: Currently gobgp supports only **global** and **neighbor** subcommand.
 % gobgp global rib del <prefix> [-a <address family>]
 # show all Route information
 % gobgp global rib [-a <address family>]
+# show a specific route information
+% gobgp global rib [<prefix>|<host>] [-a <address family>]
 ```
  - **Option**
   - \-a , \-\-address-family: specify the ipv4, ipv6, evpn, encap, or rtc
@@ -58,9 +60,10 @@ Note: Currently gobgp supports only **global** and **neighbor** subcommand.
 
 ### Show Rib - local-rib/adj-rib-in/adj-rib-out -
 ```shell
-% gobgp neighbor <neighbor address> local [-a <address family>]
-% gobgp neighbor <neighbor address> adj-in [-a <address family>]
-% gobgp neighbor <neighbor address> adj-out [-a <address family>]
+# show all routes in [local|adj-in|adj-out] table
+% gobgp neighbor <neighbor address> [local|adj-in|adj-out] [-a <address family>]
+# show a specific route in [local|adj-in|adj-out] table
+% gobgp neighbor <neighbor address> [local|adj-in|adj-out] [<prefix>|<host>] [-a <address family>]
 ```
  - **Option**
   - \-a , \-\-address-family: specify the ipv4 or ipv6
@@ -167,4 +170,4 @@ Note: Currently gobgp supports only **global** and **neighbor** subcommand.
 
   Specify the options of action when you use the routepolicy add subcommand.
   - \-\-a-route     : specify the action(accept, reject) of the route that match to the conditions
-  - \-\-a-community : specify the community operation of the route that match to the conditions
\ No newline at end of file
+  - \-\-a-community : specify the community operation of the route that match to the conditions
diff --git a/gobgp/global.go b/gobgp/global.go
index 93bd1fde..00b0da6c 100644
--- a/gobgp/global.go
+++ b/gobgp/global.go
@@ -16,62 +16,17 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
 	"github.com/osrg/gobgp/api"
 	"github.com/spf13/cobra"
 	"golang.org/x/net/context"
-	"io"
 	"net"
-	"sort"
 	"strconv"
 )
 
-func showGlobalRib() error {
-	rt, err := checkAddressFamily(net.IP{})
-	if err != nil {
-		return err
-	}
-	arg := &api.Arguments{
-		Resource: api.Resource_GLOBAL,
-		Af:       rt,
-	}
-
-	stream, e := client.GetRib(context.Background(), arg)
-	if e != nil {
-		return e
-	}
-	ds := []*api.Destination{}
-	for {
-		d, e := stream.Recv()
-		if e == io.EOF {
-			break
-		} else if e != nil {
-			return e
-		}
-		ds = append(ds, d)
-	}
-
-	if globalOpts.Json {
-		j, _ := json.Marshal(ds)
-		fmt.Println(string(j))
-		return nil
-	}
-
-	ps := paths{}
-	for _, d := range ds {
-		for idx, p := range d.Paths {
-			if idx == int(d.BestPathIdx) {
-				p.Best = true
-			}
-			ps = append(ps, p)
-		}
-	}
-
-	sort.Sort(ps)
-
-	showRoute(ps, true, true, false)
-	return nil
+func showGlobalRib(args []string) error {
+	bogusIp := net.IP{}
+	return showNeighborRib(CMD_GLOBAL, bogusIp, args)
 }
 
 func modPath(modtype string, eArgs []string) error {
@@ -208,7 +163,7 @@ func NewGlobalCmd() *cobra.Command {
 	ribCmd := &cobra.Command{
 		Use: CMD_RIB,
 		Run: func(cmd *cobra.Command, args []string) {
-			showGlobalRib()
+			showGlobalRib(args)
 		},
 	}
 
diff --git a/gobgp/neighbor.go b/gobgp/neighbor.go
index c478f7a1..a3d8c27b 100644
--- a/gobgp/neighbor.go
+++ b/gobgp/neighbor.go
@@ -381,9 +381,11 @@ func showRoute(pathList []*api.Path, showAge bool, showBest bool, isMonitor bool
 	}
 }
 
-func showNeighborRib(r string, remoteIP net.IP) error {
+func showNeighborRib(r string, remoteIP net.IP, args []string) error {
 	var resource api.Resource
 	switch r {
+	case CMD_GLOBAL:
+		resource = api.Resource_GLOBAL
 	case CMD_LOCAL:
 		resource = api.Resource_LOCAL
 	case CMD_ADJ_IN:
@@ -395,6 +397,24 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 	if err != nil {
 		return err
 	}
+
+	var prefix string
+	var host net.IP
+	if len(args) > 0 {
+		if rt != api.AF_IPV4_UC && rt != api.AF_IPV6_UC {
+			return fmt.Errorf("route filtering is only supported for IPv4/IPv6 unicast routes")
+		}
+		_, p, err := net.ParseCIDR(args[0])
+		if err != nil {
+			host = net.ParseIP(args[0])
+			if host == nil {
+				return err
+			}
+		} else {
+			prefix = p.String()
+		}
+	}
+
 	arg := &api.Arguments{
 		Resource: resource,
 		Af:       rt,
@@ -405,7 +425,7 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 	showBest := false
 	showAge := true
 	switch resource {
-	case api.Resource_LOCAL:
+	case api.Resource_LOCAL, api.Resource_GLOBAL:
 		showBest = true
 		stream, e := client.GetRib(context.Background(), arg)
 		if e != nil {
@@ -413,6 +433,7 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 		}
 
 		ds := []*api.Destination{}
+		maxOnes := 0
 		for {
 			d, e := stream.Recv()
 			if e == io.EOF {
@@ -420,6 +441,19 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 			} else if e != nil {
 				return e
 			}
+			if prefix != "" && prefix != d.Prefix {
+				continue
+			}
+			if host != nil {
+				_, prefix, _ := net.ParseCIDR(d.Prefix)
+				ones, _ := prefix.Mask.Size()
+				if maxOnes < ones && prefix.Contains(host) {
+					ds = []*api.Destination{}
+					maxOnes = ones
+				} else {
+					continue
+				}
+			}
 			ds = append(ds, d)
 		}
 
@@ -445,6 +479,7 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 		if e != nil {
 			return e
 		}
+		maxOnes := 0
 		for {
 			p, e := stream.Recv()
 			if e == io.EOF {
@@ -452,6 +487,24 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 			} else if e != nil {
 				return e
 			}
+			if prefix != "" && prefix != p.Nlri.Prefix {
+				continue
+			}
+			if host != nil {
+				_, prefix, _ := net.ParseCIDR(p.Nlri.Prefix)
+				ones, _ := prefix.Mask.Size()
+				if prefix.Contains(host) {
+					if maxOnes < ones {
+						ps = paths{}
+						maxOnes = ones
+					} else if maxOnes > ones {
+						continue
+					}
+				} else {
+					continue
+				}
+			}
+
 			ps = append(ps, p)
 		}
 		if globalOpts.Json {
@@ -461,12 +514,17 @@ func showNeighborRib(r string, remoteIP net.IP) error {
 		}
 	}
 
+	if len(ps) == 0 {
+		fmt.Println("Network not in table")
+		return nil
+	}
+
 	sort.Sort(ps)
 	showRoute(ps, showAge, showBest, false)
 	return nil
 }
 
-func resetNeighbor(cmd string, remoteIP net.IP) error {
+func resetNeighbor(cmd string, remoteIP net.IP, args []string) error {
 	rt, err := checkAddressFamily(remoteIP)
 	if err != nil {
 		return err
@@ -488,7 +546,7 @@ func resetNeighbor(cmd string, remoteIP net.IP) error {
 	return nil
 }
 
-func stateChangeNeighbor(cmd string, remoteIP net.IP) error {
+func stateChangeNeighbor(cmd string, remoteIP net.IP, args []string) error {
 	arg := &api.Arguments{
 		Af:       api.AF_IPV4_UC,
 		RouterId: remoteIP.String(),
@@ -615,7 +673,7 @@ func NewNeighborCmd() *cobra.Command {
 
 	type cmds struct {
 		names []string
-		f     func(string, net.IP) error
+		f     func(string, net.IP, []string) error
 	}
 
 	c := make([]cmds, 0, 3)
@@ -634,7 +692,7 @@ func NewNeighborCmd() *cobra.Command {
 						fmt.Println("invalid ip address:", args[len(args)-1])
 						os.Exit(1)
 					}
-					err := f(cmd.Use, remoteIP)
+					err := f(cmd.Use, remoteIP, args[:len(args)-1])
 					if err != nil {
 						fmt.Println(err)
 						os.Exit(1)