Add --interface command line option

Passing --interface will force the packets through the specified
interface instead of the default one.

Signed-off-by: Andrea Barberio <[email protected]>

Author: insomniacslk

.gitignore

@@ -4,3 +4,6 @@
 *.dylib
 build
 go/dublintraceroute/cmd/dublin-traceroute/dublin-traceroute
+go/dublintraceroute/cmd/routest/routest
+.travis/trace.json
+integ/trace.json

include/dublintraceroute/dublin_traceroute.h

@@ -51,6 +51,7 @@ class  DublinTraceroute {
 	const bool		 broken_nat_,
 				 use_srcport_for_path_generation_,
 				 no_dns_;
+	std::string		 interface_;
 	std::mutex		 mutex_tracerouting,
 				 mutex_sniffed_packets;
 	IPv4Address		 my_address;
@@ -67,6 +68,7 @@ class  DublinTraceroute {
 	static const bool	 default_broken_nat = false;
 	static const bool	 default_use_srcport_for_path_generation = false;
 	static const bool	 default_no_dns = false;
+	static const std::string default_interface;
 	DublinTraceroute(
 			const std::string &dst,
 			const uint16_t srcport = default_srcport,
@@ -77,7 +79,8 @@ class  DublinTraceroute {
 			const uint16_t delay = default_delay,
 			const bool broken_nat = default_broken_nat,
 			const bool use_srcport_for_path_generation = default_use_srcport_for_path_generation,
-			const bool no_dns = default_no_dns
+			const bool no_dns = default_no_dns,
+			const std::string interface = default_interface
 			):
 				srcport_(srcport),
 				dstport_(dstport),
@@ -88,7 +91,8 @@ class  DublinTraceroute {
 				delay_(delay),
 				broken_nat_(broken_nat),
 				use_srcport_for_path_generation_(use_srcport_for_path_generation),
-				no_dns_(no_dns)
+				no_dns_(no_dns),
+				interface_(interface)
 	{ validate_arguments(); }
 	DublinTraceroute(
 			const char *dst,
@@ -100,7 +104,8 @@ class  DublinTraceroute {
 			const uint16_t delay = default_delay,
 			const bool broken_nat = default_broken_nat,
 			const bool use_srcport_for_path_generation = default_use_srcport_for_path_generation,
-			const bool no_dns = default_no_dns
+			const bool no_dns = default_no_dns,
+			const std::string interface = default_interface
 		       ):
 				srcport_(srcport),
 				dstport_(dstport),
@@ -111,7 +116,8 @@ class  DublinTraceroute {
 				delay_(delay),
 				broken_nat_(broken_nat),
 				use_srcport_for_path_generation_(use_srcport_for_path_generation),
-				no_dns_(no_dns)
+				no_dns_(no_dns),
+				interface_(interface)
 	{ validate_arguments(); }
 	~DublinTraceroute() { std::lock_guard<std::mutex> lock(mutex_tracerouting); };
 	DublinTraceroute(const DublinTraceroute& source):
@@ -124,7 +130,8 @@ class  DublinTraceroute {
 		delay_(source.delay_),
 		broken_nat_(source.broken_nat_),
 		use_srcport_for_path_generation_(source.use_srcport_for_path_generation_),
-		no_dns_(source.no_dns_)
+		no_dns_(source.no_dns_),
+		interface_(source.interface_)
 	{ validate_arguments(); }
 
 	inline const uint16_t srcport() const { return srcport_; }
@@ -135,6 +142,7 @@ class  DublinTraceroute {
 	inline const uint16_t delay() const { return delay_; }
 	inline const bool broken_nat() const { return broken_nat_; }
 	inline const bool no_dns() const { return no_dns_; }
+	inline const std::string interface() const { return interface_; }
 	inline const bool use_srcport_for_path_generation() const { return use_srcport_for_path_generation_; }
 	inline const std::string &dst() const { return dst_; }
 	inline const IPv4Address &target() const { return target_; }

include/dublintraceroute/udpv4probe.h

@@ -25,6 +25,7 @@ class UDPv4Probe {
 	uint16_t local_port_;
 	uint16_t remote_port_;
 	uint8_t ttl_;
+	std::string interface_;
 	IP *packet = nullptr;
 
 public:
@@ -33,17 +34,20 @@ class UDPv4Probe {
 	const uint16_t local_port() const { return local_port_; };
 	const uint16_t remote_port() const { return remote_port_; };
 	const uint8_t ttl() const { return ttl_; };
+	const std::string interface() const { return interface_; };
 
 	UDPv4Probe(
 		IPv4Address remote_addr,
 		uint16_t remote_port,
 		uint16_t local_port,
 		uint8_t ttl,
+		std::string interface = "",
 		IPv4Address local_addr = 0):
 			remote_addr_(remote_addr),
 			remote_port_(remote_port),
 			local_port_(local_port),
 			ttl_(ttl),
+			interface_(interface),
 			local_addr_(local_addr) { };
 	~UDPv4Probe();
 	IP* forge();

src/dublin_traceroute.cc

@@ -41,6 +41,8 @@ extern int errno;
 
 #define SNIFFER_TIMEOUT_MS	2000
 
+// this is not necessary in C++17 and can be assigned in the header file.
+const std::string DublinTraceroute::default_interface = "";
 
 Tins::Timestamp extract_timestamp_from_msg(struct msghdr &msg) {
 	int level, type;
@@ -218,10 +220,10 @@ std::shared_ptr<TracerouteResults> DublinTraceroute::traceroute() {
 
 			UDPv4Probe *probe = NULL;
 			if(use_srcport_for_path_generation()){
-				probe = new UDPv4Probe(target(), dstport(), iterated_port, ttl);
+				probe = new UDPv4Probe(target(), dstport(), iterated_port, ttl, interface());
 			}
 			else{
-				probe = new UDPv4Probe(target(), iterated_port, srcport(), ttl);
+				probe = new UDPv4Probe(target(), iterated_port, srcport(), ttl, interface());
 				//UDPv4Probe probe(target(), dport, srcport(), ttl);	
 			}
 			IP *packet;

src/main.cc

@@ -32,6 +32,7 @@ const struct option longopts[] = {
 	{"broken-nat", no_argument, NULL, 'b'},
 	{"use-srcport", no_argument, NULL, 'i'},
 	{"no-dns", no_argument, NULL, 'N'},
+	{"interface", required_argument, NULL, 'I'},
 	{"output-file", required_argument, NULL, 'o'},
 	{NULL, 0, NULL, 0},
 };
@@ -51,23 +52,25 @@ R"(Written by Andrea Barberio - https://insomniac.slackware.it
                              [--broken-nat]
                              [--use-srcport]
                              [--no-dns]
+                             [--interface=ifname]
                              [--output-file=file_name]
                              [--help]
                              [--version]
 
 Options:
-  -h --help                     this help
-  -v --version                  print the version of Dublin Traceroute
-  -s SRC_PORT --sport=SRC_PORT  the source port to send packets from (default: )" << DublinTraceroute::default_srcport << R"()
-  -d DST_PORT --dport=DST_PORT  the base destination port to send packets to (default: )" << DublinTraceroute::default_dstport << R"()
-  -n NPATHS --npaths=NPATHS     the number of paths to probe (default: )" << static_cast<int>(DublinTraceroute::default_npaths) << R"()
-  -t MIN_TTL --min-ttl=MIN_TTL  the minimum TTL to probe (default: )" << static_cast<int>(DublinTraceroute::default_min_ttl) << R"()
-  -T MAX_TTL --max-ttl=MAX_TTL  the maximum TTL to probe. Must be greater or equal than the minimum TTL (default: )" << static_cast<int>(DublinTraceroute::default_max_ttl) << R"()
-  -D DELAY --delay=DELAY        the inter-packet delay in milliseconds (default: )" << DublinTraceroute::default_delay << R"()
-  -b --broken-nat               the network has a broken NAT configuration (e.g. no payload fixup). Try this if you see fewer hops than expected
-  -i --use-srcport              generate paths using source port instead of destination port
-  -N --no-dns                   do not attempt to do reverse DNS lookup of the hops
-  -o --output-file              the output file name (default: )" << DEFAULT_OUTPUT_FILE << R"()
+  -h, --help                    this help
+  -v, --version                 print the version of Dublin Traceroute
+  -s, --sport=SRC_PORT          the source port to send packets from (default: )" << DublinTraceroute::default_srcport << R"()
+  -d, --dport=DST_PORT          the base destination port to send packets to (default: )" << DublinTraceroute::default_dstport << R"()
+  -n, --npaths=NPATHS           the number of paths to probe (default: )" << static_cast<int>(DublinTraceroute::default_npaths) << R"()
+  -t, --min-ttl=MIN_TTL         the minimum TTL to probe (default: )" << static_cast<int>(DublinTraceroute::default_min_ttl) << R"()
+  -T, --max-ttl=MAX_TTL         the maximum TTL to probe. Must be greater or equal than the minimum TTL (default: )" << static_cast<int>(DublinTraceroute::default_max_ttl) << R"()
+  -D, --delay=DELAY             the inter-packet delay in milliseconds (default: )" << DublinTraceroute::default_delay << R"()
+  -b, --broken-nat              the network has a broken NAT configuration (e.g. no payload fixup). Try this if you see fewer hops than expected
+  -i, --use-srcport             generate paths using source port instead of destination port
+  -N, --no-dns                  do not attempt to do reverse DNS lookup of the hops
+  -I, --interface=INTERFACE     force packets through the specified interface. If not specified, the default interface for the target will be used
+  -o, --output-file=OUTFILE     the output file name (default: )" << DEFAULT_OUTPUT_FILE << R"()
 
 
 See documentation at https://dublin-traceroute.net
@@ -89,6 +92,7 @@ main(int argc, char **argv) {
 	bool	broken_nat = DublinTraceroute::default_broken_nat;
 	bool	use_srcport_for_path_generation = DublinTraceroute::default_use_srcport_for_path_generation;
 	bool	no_dns = DublinTraceroute::default_no_dns;
+	std::string interface = DublinTraceroute::default_interface;
 	std::string	output_file = DEFAULT_OUTPUT_FILE;
 
 	if (geteuid() == 0) {
@@ -143,6 +147,9 @@ main(int argc, char **argv) {
 			case 'N':
 				no_dns = true;
 				break;
+			case 'I':
+				interface = optarg;
+				break;
 			case 'o':
 				output_file.assign(optarg);
 				break;
@@ -215,18 +222,24 @@ main(int argc, char **argv) {
 			delay,
 			broken_nat,
 			use_srcport_for_path_generation,
-			no_dns
+			no_dns,
+			interface
 	);
 
 	std::cout << "Traceroute from 0.0.0.0:" << Dublin.srcport();
-	if(use_srcport_for_path_generation == 1){
+	if (use_srcport_for_path_generation == 1){
 		std::cout << "~" << (Dublin.srcport() + npaths - 1);
 	}
 
 	std::cout << " to " << Dublin.dst() << ":" << Dublin.dstport();
-	if(use_srcport_for_path_generation == 0){
+	if (use_srcport_for_path_generation == 0){
 		std::cout << "~" << (Dublin.dstport() + npaths - 1);
 	}
+	if (interface != "") {
+		std::cout << " through interface " << interface;
+	} else {
+		std::cout << " through default interface";
+	}
 
 	std::cout << " (probing " << npaths << " path" << (npaths == 1 ? "" : "s")
 		<< ", min TTL is " << min_ttl

src/udpv4probe.cc

@@ -55,12 +55,15 @@ IP* UDPv4Probe::forge() {
 }
 
 IP &UDPv4Probe::send() {
-	NetworkInterface iface = NetworkInterface::default_interface();
+	std::string ifname = NetworkInterface::default_interface().name();
+	if (interface_ != "") {
+		ifname = interface_;
+	}
 	PacketSender sender;
 	if (packet == nullptr) {
 		packet = forge();
 	}
-	sender.send(*packet, iface.name());
+	sender.send(*packet, ifname);
 	return *packet;
 }
 

tests/src/udpv4.cxx

@@ -12,7 +12,7 @@ class UDPv4Test: public ::testing::Test {
 };
 
 TEST_F(UDPv4Test, TestUDPv4Constructor) {
-	UDPv4Probe p = UDPv4Probe(IPv4Address("8.8.8.8"), 33434, 12345, 64, IPv4Address("127.0.0.2"));
+	UDPv4Probe p = UDPv4Probe(IPv4Address("8.8.8.8"), 33434, 12345, 64, "", IPv4Address("127.0.0.2"));
 	ASSERT_EQ(p.local_port(), 12345);
 	ASSERT_EQ(p.remote_port(), 33434);
 	ASSERT_EQ(p.ttl(), 64);
@@ -30,7 +30,7 @@ TEST_F(UDPv4Test, TestUDPv4ConstructorDefaultLocalAddr) {
 }
 
 TEST_F(UDPv4Test, TestUDPv4PacketForging) {
-	UDPv4Probe p = UDPv4Probe(IPv4Address("127.0.0.3"), 33434, 12345, 64, IPv4Address("127.0.0.2"));
+	UDPv4Probe p = UDPv4Probe(IPv4Address("127.0.0.3"), 33434, 12345, 64, "", IPv4Address("127.0.0.2"));
 	IP* ip = p.forge();
 	ASSERT_EQ(ip->tos(), 0);
 	ASSERT_EQ(ip->id(), 60794);