add option to specify network interface (#2384)

* add option to specify network interface

* add source-ip flag

* fix typo

* fix err return

* readme update

Co-authored-by: Sandeep Singh <sandeep@projectdiscovery.io>

README.md

@@ -142,6 +142,7 @@ OUTPUT:
 
 CONFIGURATIONS:
    -config string              path to the nuclei configuration file
+   -config-directory string    override the default config path ($home/.config)
    -fr, -follow-redirects      enable following redirects for http templates
    -mr, -max-redirects int     max number of redirects to follow for http templates (default 10)
    -dr, -disable-redirects     disable redirects for http templates
@@ -158,6 +159,8 @@ CONFIGURATIONS:
    -sml, -show-match-line      show match lines for file templates, works with extractors only
    -ztls                       use ztls library with autofallback to standard one for tls13
    -sni string                 tls sni hostname to use (default: input domain name)
+   -i, -interface string       network interface to use for network scan
+   -sip, -source-ip string     source ip address to use for network scan
 
 INTERACTSH:
    -iserver, -interactsh-server string  interactsh server url for self-hosted instance (default: oast.pro,oast.live,oast.site,oast.online,oast.fun,oast.me)

v2/cmd/nuclei/main.go

@@ -183,6 +183,8 @@ on extensive configurability, massive extensibility and ease of use.`)
 		flagSet.BoolVarP(&options.ShowMatchLine, "show-match-line", "sml", false, "show match lines for file templates, works with extractors only"),
 		flagSet.BoolVar(&options.ZTLS, "ztls", false, "use ztls library with autofallback to standard one for tls13"),
 		flagSet.StringVar(&options.SNI, "sni", "", "tls sni hostname to use (default: input domain name)"),
+		flagSet.StringVarP(&options.Interface, "interface", "i", "", "network interface to use for network scan"),
+		flagSet.StringVarP(&options.SourceIP, "source-ip", "sip", "", "source ip address to use for network scan"),
 		flagSet.StringVar(&options.CustomConfigDir, "config-directory", "", "Override the default config path ($home/.config)"),
 	)
 

v2/pkg/protocols/common/protocolstate/state.go

@@ -1,6 +1,9 @@
 package protocolstate
 
 import (
+	"fmt"
+	"net"
+
 	"github.com/pkg/errors"
 
 	"github.com/projectdiscovery/fastdialer/fastdialer"
@@ -16,6 +19,48 @@ func Init(options *types.Options) error {
 		return nil
 	}
 	opts := fastdialer.DefaultOptions
+
+	switch {
+	case options.SourceIP != "" && options.Interface != "":
+		isAssociated, err := isIpAssociatedWithInterface(options.SourceIP, options.Interface)
+		if err != nil {
+			return err
+		}
+		if isAssociated {
+			opts.Dialer = &net.Dialer{
+				LocalAddr: &net.TCPAddr{
+					IP: net.ParseIP(options.SourceIP),
+				},
+			}
+		} else {
+			return fmt.Errorf("source ip (%s) is not associated with the interface (%s)", options.SourceIP, options.Interface)
+		}
+	case options.SourceIP != "":
+		isAssociated, err := isIpAssociatedWithInterface(options.SourceIP, "any")
+		if err != nil {
+			return err
+		}
+		if isAssociated {
+			opts.Dialer = &net.Dialer{
+				LocalAddr: &net.TCPAddr{
+					IP: net.ParseIP(options.SourceIP),
+				},
+			}
+		} else {
+			return fmt.Errorf("source ip (%s) is not associated with any network interface", options.SourceIP)
+		}
+	case options.Interface != "":
+		ifadrr, err := interfaceAddress(options.Interface)
+		if err != nil {
+			return err
+		}
+		opts.Dialer = &net.Dialer{
+			LocalAddr: &net.TCPAddr{
+				IP: ifadrr,
+			},
+		}
+	}
+
 	if options.SystemResolvers {
 		opts.EnableFallback = true
 	}
@@ -33,6 +78,58 @@ func Init(options *types.Options) error {
 	return nil
 }
 
+// isIpAssociatedWithInterface checks if the given IP is associated with the given interface.
+func isIpAssociatedWithInterface(souceIP, interfaceName string) (bool, error) {
+	addrs, err := interfaceAddresses(interfaceName)
+	if err != nil {
+		return false, err
+	}
+	for _, addr := range addrs {
+		if ipnet, ok := addr.(*net.IPNet); ok {
+			if ipnet.IP.String() == souceIP {
+				return true, nil
+			}
+		}
+	}
+	return false, nil
+}
+
+// interfaceAddress returns the first IPv4 address of the given interface.
+func interfaceAddress(interfaceName string) (net.IP, error) {
+	addrs, err := interfaceAddresses(interfaceName)
+	if err != nil {
+		return nil, err
+	}
+	var address net.IP
+	for _, addr := range addrs {
+		if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
+			if ipnet.IP.To4() != nil {
+				address = ipnet.IP
+			}
+		}
+	}
+	if address == nil {
+		return nil, fmt.Errorf("no suitable address found for interface: `%s`", interfaceName)
+	}
+	return address, nil
+}
+
+// interfaceAddresses returns all interface addresses.
+func interfaceAddresses(interfaceName string) ([]net.Addr, error) {
+	if interfaceName == "any" {
+		return net.InterfaceAddrs()
+	}
+	ief, err := net.InterfaceByName(interfaceName)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to get interface: `%s`", interfaceName)
+	}
+	addrs, err := ief.Addrs()
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to get interface addresses for: `%s`", interfaceName)
+	}
+	return addrs, nil
+}
+
 // Close closes the global shared fastdialer
 func Close() {
 	if Dialer != nil {

v2/pkg/types/types.go

@@ -230,6 +230,10 @@ type Options struct {
 	DisableRedirects bool
 	// SNI custom hostname
 	SNI string
+	// Interface to use for network scan
+	Interface string
+	// SourceIP sets custom source IP address for network requests
+	SourceIP string
 	// Health Check
 	HealthCheck bool
 	// Time to wait between each input read operation before closing the stream