capture list of ports (#935)

Co-authored-by: Leonid Bugaev <leonsbox@gmail.com>

Added a way to capture multiple ports at the same time, with a single listener. 
Ports should be separated by comma like this: --input-raw :80,8080,3000

capture/capture.go

@@ -48,7 +48,7 @@ type Listener struct {
 	Reading    chan bool // this channel is closed when the listener has started reading packets
 	PcapOptions
 	Engine        EngineType
-	port          uint16 // src or/and dst port
+	ports         []uint16 // src or/and dst ports
 	trackResponse bool
 
 	host string // pcap file name or interface (name, hardware addr, index or ip address)
@@ -99,15 +99,15 @@ func (eng *EngineType) String() (e string) {
 // NewListener creates and initialize a new Listener. if transport or/and engine are invalid/unsupported
 // is "tcp" and "pcap", are assumed. l.Engine and l.Transport can help to get the values used.
 // if there is an error it will be associated with getting network interfaces
-func NewListener(host string, port uint16, transport string, engine EngineType, trackResponse bool) (l *Listener, err error) {
+func NewListener(host string, ports []uint16, transport string, engine EngineType, trackResponse bool) (l *Listener, err error) {
 	l = &Listener{}
 
 	l.host = host
 	if l.host == "localhost" {
 		l.host = "127.0.0.1"
 	}
-
 	l.port = port
+
 	l.Transport = "tcp"
 	if transport != "" {
 		l.Transport = transport
@@ -181,7 +181,7 @@ func (l *Listener) Filter(ifi pcap.Interface) (filter string) {
 		hosts = interfaceAddresses(ifi)
 	}
 
-	filter = portsFilter(l.Transport, "dst", l.port)
+	filter = portsFilter(l.Transport, "dst", l.ports)
 
 	if len(hosts) != 0 {
 		filter = fmt.Sprintf("((%s) and (%s))", filter, hostsFilter("dst", hosts))
@@ -190,7 +190,7 @@ func (l *Listener) Filter(ifi pcap.Interface) (filter string) {
 	}
 
 	if l.trackResponse {
-		responseFilter := portsFilter(l.Transport, "src", l.port)
+		responseFilter := portsFilter(l.Transport, "src", l.ports)
 
 		if len(hosts) != 0 {
 			responseFilter = fmt.Sprintf("((%s) and (%s))", responseFilter, hostsFilter("src", hosts))
@@ -501,12 +501,16 @@ func listenAll(addr string) bool {
 	return false
 }
 
-func portsFilter(transport string, direction string, port uint16) string {
-	if port == 0 {
+func portsFilter(transport string, direction string, ports []uint16) string {
+	if len(ports) == 0 || ports[0] == 0 {
 		return fmt.Sprintf("%s %s portrange 0-%d", transport, direction, 1<<16-1)
 	}
 
-	return fmt.Sprintf("%s %s port %d", transport, direction, port)
+	var filters []string
+	for _, port := range ports {
+		filters = append(filters, fmt.Sprintf("%s %s port %d", transport, direction, port))
+	}
+	return strings.Join(filters, " or ")
 }
 
 func hostsFilter(direction string, hosts []string) string {

input_raw.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"net"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -61,7 +62,7 @@ type RAWInputConfig struct {
 	Stats          bool               `json:"input-raw-stats"`
 	quit           chan bool          // Channel used only to indicate goroutine should shutdown
 	host           string
-	port           uint16
+	ports          []uint16
 }
 
 // RAWInput used for intercepting traffic for given address
@@ -81,22 +82,28 @@ func NewRAWInput(address string, config RAWInputConfig) (i *RAWInput) {
 	i.RAWInputConfig = config
 	i.message = make(chan *tcp.Message, 10000)
 	i.quit = make(chan bool)
-	var host, _port string
-	var err error
-	var port int
-	host, _port, err = net.SplitHostPort(address)
+
+	host, _ports, err := net.SplitHostPort(address)
 	if err != nil {
 		log.Fatalf("input-raw: error while parsing address: %s", err)
 	}
-	if _port != "" {
-		port, err = strconv.Atoi(_port)
-	}
 
-	if err != nil {
-		log.Fatalf("parsing port error: %v", err)
+	var ports []uint16
+	if _ports != "" {
+		portsStr := strings.Split(_ports, ",")
+
+		for _, portStr := range portsStr {
+			port, err := strconv.Atoi(strings.TrimSpace(portStr))
+			if err != nil {
+				log.Fatalf("parsing port error: %v", err)
+			}
+			ports = append(ports, uint16(port))
+
+		}
 	}
+
 	i.host = host
-	i.port = uint16(port)
+	i.ports = ports
 
 	i.listen(address)
 
@@ -141,7 +148,7 @@ func (i *RAWInput) PluginRead() (*Message, error) {
 
 func (i *RAWInput) listen(address string) {
 	var err error
-	i.listener, err = capture.NewListener(i.host, i.port, "", i.Engine, i.TrackResponse)
+	i.listener, err = capture.NewListener(i.host, i.ports, "", i.Engine, i.TrackResponse)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -172,7 +179,7 @@ func (i *RAWInput) messageEmitter(m *tcp.Message) {
 }
 
 func (i *RAWInput) String() string {
-	return fmt.Sprintf("Intercepting traffic from: %s:%d", i.host, i.port)
+	return fmt.Sprintf("Intercepting traffic from: %s:%s", i.host, strings.Join(strings.Fields(fmt.Sprint(i.ports)), ","))
 }
 
 // GetStats returns the stats so far and reset the stats