main: Add a simple visualizer for stats

Signed-off-by: Simarpreet Singh <simar@linux.com>

go.mod

@@ -3,6 +3,7 @@ module github.com/simar7/ebpfwall
 go 1.13
 
 require (
+	github.com/buger/goterm v0.0.0-20181115115552-c206103e1f37
 	github.com/dropbox/goebpf v0.0.0-20191101224440-b4a5d6260e8c
 	github.com/stretchr/testify v1.4.0
 	github.com/vishvananda/netlink v1.0.0 // indirect

go.sum

@@ -1,5 +1,7 @@
 github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
+github.com/buger/goterm v0.0.0-20181115115552-c206103e1f37 h1:uxxtrnACqI9zK4ENDMf0WpXfUsHP5V8liuq5QdgDISU=
+github.com/buger/goterm v0.0.0-20181115115552-c206103e1f37/go.mod h1:u9UyCz2eTrSGy6fbupqJ54eY5c4IC8gREQ1053dK12U=
 github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=

main.go

@@ -5,8 +5,12 @@ import (
 	"fmt"
 	"log"
 	"net"
+	"os"
+	"os/signal"
 	"strings"
+	"time"
 
+	tm "github.com/buger/goterm"
 	"github.com/dropbox/goebpf"
 	"go.uber.org/zap"
 )
@@ -93,4 +97,33 @@ func main() {
 	}
 	defer w.xdp.Detach()
 
+	interrupt := make(chan os.Signal, 1)
+	signal.Notify(interrupt, os.Interrupt)
+
+	ticker := time.NewTicker(time.Second * 1)
+
+	for {
+		select {
+		case <-ticker.C:
+			tm.Clear()
+			tm.MoveCursor(1, 1)
+			_, _ = tm.Println("Current Time:", time.Now().Format(time.RFC1123))
+			table := tm.NewTable(0, 10, 5, ' ', 0)
+			_, _ = fmt.Fprintf(table, "IP\tDROPs\n")
+
+			for i := 0; i < len(w.IPAddrs); i++ {
+				value, err := w.Matches.Lookup(i)
+				if err != nil {
+					continue
+				}
+				_, _ = fmt.Fprintf(table, "%s\t%d\n", w.IPAddrs[i], value)
+			}
+			_, _ = tm.Println(table)
+			tm.Flush()
+		case <-interrupt:
+			w.lg.Info("Detaching and exiting..")
+			return
+		}
+	}
+
 }