Merge pull request #16 from insomniacslk/min_ttl

Added support for --min-ttl

documentation/readme/README.md

@@ -227,6 +227,7 @@ Usage:
   dublin-traceroute <target> [--sport=SRC_PORT]
                              [--dport=dest_base_port]
                              [--npaths=num_paths]
+                             [--min-ttl=min_ttl]
                              [--max-ttl=max_ttl]
                              [--broken-nat]
                              [--help]
@@ -238,7 +239,8 @@ Options:
   -s SRC_PORT --sport=SRC_PORT  the source port to send packets from
   -d DST_PORT --dport=DST_PORT  the base destination port to send packets to
   -n NPATHS --npaths=NPATHS     the number of paths to probe
-  -t MAX_TTL --max-ttl=MAX_TTL  the maximum TTL to probe
+  -t MIN_TTL --min-ttl=MIN_TTL  the MINIMUM TTL to probe. Must be greater or equal than the minimum TTL
+  -T MAX_TTL --max-ttl=MAX_TTL  the maximum TTL to probe
   -b --broken-nat               the network has a broken NAT configuration (e.g. no payload fixup). Try this if you see less hops than expected
 
 

documentation/readme/TODO.md

@@ -15,7 +15,7 @@
 * break on destination unreachable
 * improve documentation
 * put everything under a namespace
-* implement command line parser in main.cc
+* ~~implement command line parser in main.cc~~ done in [commit 8a3ae75](https://github.com/insomniacslk/dublin-traceroute/commit/8a3ae7513645afdad5eabd8d6f368383dff98c8b)
 * Add an uninstall target in the Makefile for the python extension
 * Fix the memory leak where TracerouteResults is not freed
 * IP_ID_MATCHING must become a constructor parameter
@@ -30,3 +30,4 @@
 * Integrate the ASN graph with a world map (e.g. openstreetmap or google maps)
 * Add --webserver to the python CLI to expose a SimpleHTTPServer that serves a PNG with the traceroute diagram
 * heat map/flame graph of the network latencies over time (links history)
+* ~~improve the build system (there is just a static Makefile now)~~ done in [commit ffa9d3c](https://github.com/insomniacslk/dublin-traceroute/commit/ffa9d3c306fb772e2c95963a94cdc386b0126206), using CMake

include/dublintraceroute/dublin_traceroute.h

@@ -45,6 +45,7 @@ class  DublinTraceroute {
 	const std::string	 dst_;
 	IPv4Address		 target_;
 	const uint8_t		 npaths_,
+				 min_ttl_,
 				 max_ttl_;
 	const bool		 broken_nat_;
 	std::mutex		 mutex_tracerouting,
@@ -56,20 +57,23 @@ class  DublinTraceroute {
 	static const uint16_t	 default_srcport = 12345;
 	static const uint16_t	 default_dstport = 33434;
 	static const uint8_t	 default_npaths = 20;
+	static const uint8_t	 default_min_ttl = 1;
 	static const uint8_t	 default_max_ttl = 30;
 	static const bool	 default_broken_nat = false;
 	DublinTraceroute(
 			const std::string &dst,
 			const uint16_t srcport = default_srcport,
 			const uint16_t dstport = default_dstport,
 			const uint8_t npaths = default_npaths,
+			const uint8_t min_ttl = default_min_ttl,
 			const uint8_t max_ttl = default_max_ttl,
 			const bool broken_nat = default_broken_nat
 			):
 				srcport_(srcport),
 				dstport_(dstport),
 				dst_(dst),
 				npaths_(npaths),
+				min_ttl_(min_ttl),
 				max_ttl_(max_ttl),
 				broken_nat_(broken_nat)
 	{ }
@@ -78,13 +82,15 @@ class  DublinTraceroute {
 			const uint16_t srcport = default_srcport,
 			const uint16_t dstport = default_dstport,
 			const uint8_t npaths = default_npaths,
+			const uint8_t min_ttl = default_min_ttl,
 			const uint8_t max_ttl = default_max_ttl,
 			const bool broken_nat = default_broken_nat
 		       ):
 				srcport_(srcport),
 				dstport_(dstport),
 				dst_(std::string(dst)),
 				npaths_(npaths),
+				min_ttl_(min_ttl),
 				max_ttl_(max_ttl),
 				broken_nat_(broken_nat)
 	{ }
@@ -94,13 +100,15 @@ class  DublinTraceroute {
 		dstport_(source.dstport_),
 		dst_(source.dst_),
 		npaths_(source.npaths_),
+		min_ttl_(source.min_ttl_),
 		max_ttl_(source.max_ttl_),
 		broken_nat_(source.broken_nat_)
 	{ }
 
 	inline const uint16_t srcport() const { return srcport_; }
 	inline const uint16_t dstport() const { return dstport_; }
 	inline const uint8_t npaths() const { return npaths_; }
+	inline const uint8_t min_ttl() const { return min_ttl_; }
 	inline const uint8_t max_ttl() const { return max_ttl_; }
 	inline const bool broken_nat() const { return broken_nat_; }
 	inline const std::string &dst() const { return dst_; }

include/dublintraceroute/traceroute_results.h

@@ -23,11 +23,12 @@
 class TracerouteResults {
 private:
 	std::shared_ptr<flow_map_t> flows_;
+	uint8_t min_ttl = 1;
 	bool compressed_;
 	bool broken_nat_;
 
 public:
-	TracerouteResults(std::shared_ptr<flow_map_t> flows, const bool broken_nat /* = false */);
+	TracerouteResults(std::shared_ptr<flow_map_t> flows, const uint8_t min_ttl /* = 1 */, const bool broken_nat /* = false */);
 	~TracerouteResults() { };
 	inline flow_map_t &flows() { return *flows_; }
 	std::shared_ptr<IP> match_packet(const Packet &packet);

src/dublin_traceroute.cc

@@ -69,6 +69,11 @@ std::shared_ptr<flow_map_t> DublinTraceroute::generate_per_flow_packets() {
 		target(IPv4Address(dst()));
 	}
 
+	// check for valid min and max TTL
+	if (min_ttl_ > max_ttl_) {
+		throw std::invalid_argument("max_ttl must be greater or equal than min_ttl");
+	}
+
 	// forge the packets to send
 	for (uint16_t dport = dstport(); dport < dstport() + npaths(); dport++) {
 		hops_t hops(new std::vector<Hop>());
@@ -86,7 +91,7 @@ std::shared_ptr<flow_map_t> DublinTraceroute::generate_per_flow_packets() {
 		 *   UDP.sport
 		 *   UDP.dport
 		 */
-		for (uint8_t ttl = 1; ttl <= max_ttl_; ttl++) {
+		for (uint8_t ttl = min_ttl_; ttl <= max_ttl_; ttl++) {
 			/*
 		 	 * Adjust the payload for each flow to obtain the same UDP
 		 	 * checksum. The UDP checksum is used to identify the flow.
@@ -170,7 +175,7 @@ TracerouteResults &DublinTraceroute::traceroute() {
 	}
 	std::shared_ptr<Sniffer> sniffer(_sniffer);
 
-	TracerouteResults *results = new TracerouteResults(flows, broken_nat());
+	TracerouteResults *results = new TracerouteResults(flows, min_ttl_, broken_nat());
 
 	// configure the sniffing handler
 	auto handler = std::bind(

src/main.cc

@@ -15,14 +15,15 @@
 
 #include <dublintraceroute/dublin_traceroute.h>
 
-const char *shortopts = "hvs:d:n:t:b";
+const char *shortopts = "hvs:d:n:t:T:b";
 const struct option longopts[] = {
 	{"help", no_argument, NULL, 'h'},
 	{"version", no_argument, NULL, 'v'},
 	{"sport", required_argument, NULL, 's'},
 	{"dport", required_argument, NULL, 'd'},
 	{"npaths", required_argument, NULL, 'n'},
-	{"max-ttl", required_argument, NULL, 't'},
+	{"min-ttl", required_argument, NULL, 't'},
+	{"max-ttl", required_argument, NULL, 'T'},
 	{"broken-nat", no_argument, NULL, 'b'},
 	{NULL, 0, NULL, 0},
 };
@@ -36,6 +37,7 @@ Written by Andrea Barberio - https://insomniac.slackware.it
   dublin-traceroute <target> [--sport=SRC_PORT]
                              [--dport=dest_base_port]
                              [--npaths=num_paths]
+                             [--min-ttl=min_ttl]
                              [--max-ttl=max_ttl]
                              [--broken-nat]
                              [--help]
@@ -47,7 +49,8 @@ Written by Andrea Barberio - https://insomniac.slackware.it
   -s SRC_PORT --sport=SRC_PORT  the source port to send packets from
   -d DST_PORT --dport=DST_PORT  the base destination port to send packets to
   -n NPATHS --npaths=NPATHS     the number of paths to probe
-  -t MAX_TTL --max-ttl=MAX_TTL  the maximum TTL to probe
+  -t MIN_TTL --min-ttl=MIN_TTL  the minimum TTL to probe
+  -T MAX_TTL --max-ttl=MAX_TTL  the maximum TTL to probe. Must be greater or equal than the minimum TTL
   -b --broken-nat               the network has a broken NAT configuration (e.g. no payload fixup). Try this if you see less hops than expected
 
 
@@ -64,6 +67,7 @@ main(int argc, char **argv) {
 	long	sport = DublinTraceroute::default_srcport;
 	long	dport = DublinTraceroute::default_dstport;
 	long	npaths = DublinTraceroute::default_npaths;
+	long	min_ttl = DublinTraceroute::default_min_ttl;
 	long	max_ttl = DublinTraceroute::default_max_ttl;
 	bool	broken_nat = DublinTraceroute::default_broken_nat;
 
@@ -102,6 +106,9 @@ main(int argc, char **argv) {
 				TO_LONG(npaths, optarg);
 				break;
 			case 't':
+				TO_LONG(min_ttl, optarg);
+				break;
+			case 'T':
 				TO_LONG(max_ttl, optarg);
 				break;
 			case 'b':
@@ -136,10 +143,18 @@ main(int argc, char **argv) {
 		std::cerr << "Number of paths must be between 1 and 65535" << std::endl;
 		std::exit(EXIT_FAILURE);
 	}
+	if (min_ttl < 1 || min_ttl > 255) {
+		std::cerr << "Min TTL must be between 1 and 255" << std::endl;
+		std::exit(EXIT_FAILURE);
+	}
 	if (max_ttl < 1 || max_ttl > 255) {
 		std::cerr << "Max TTL must be between 1 and 255" << std::endl;
 		std::exit(EXIT_FAILURE);
 	}
+	if (min_ttl > max_ttl) {
+		std::cerr << "Min TTL must be smaller or equal than max TTL" << std::endl;
+		std::exit(EXIT_FAILURE);
+	}
 	if (dport + npaths - 1 > 65535) {
 		std::cerr << "Destination port + number of paths must not exceed 65535" << std::endl;
 		std::exit(EXIT_FAILURE);
@@ -152,6 +167,7 @@ main(int argc, char **argv) {
 			sport,
 			dport,
 			npaths,
+			min_ttl,
 			max_ttl,
 			broken_nat
 	);
@@ -160,6 +176,7 @@ main(int argc, char **argv) {
 		<< " to " << Dublin.dst()
 		<< ":" << Dublin.dstport() << "~" << (Dublin.dstport() + npaths - 1)
 		<< " (probing " << npaths << " path" << (npaths == 1 ? "" : "s")
+		<< ", min TTL is " << min_ttl
 		<< ", max TTL is " << max_ttl << ")"
 		<< std::endl;
 

src/traceroute_results.cc

@@ -21,8 +21,8 @@
 #include "dublintraceroute/icmp_messages.h"
 
 
-TracerouteResults::TracerouteResults(std::shared_ptr<flow_map_t> flows, const bool broken_nat = true):
-		flows_(flows), compressed_(false), broken_nat_(broken_nat) {
+TracerouteResults::TracerouteResults(std::shared_ptr<flow_map_t> flows, const uint8_t min_ttl = 1, const bool broken_nat = true):
+		flows_(flows), min_ttl(min_ttl), compressed_(false), broken_nat_(broken_nat) {
 }
 
 
@@ -107,7 +107,7 @@ void TracerouteResults::show(std::ostream &stream) {
 	icmpmessages icmpm;
 
 	for (auto &iter: flows()) {
-		unsigned int hopnum = 1;
+		unsigned int hopnum = min_ttl;
 		unsigned int index = 0;
 		uint16_t prev_nat_id = 0;
 		stream << "== Flow ID " << iter.first << " ==" << std::endl;
@@ -117,7 +117,7 @@ void TracerouteResults::show(std::ostream &stream) {
 				stream << "*" << std::endl;
 			} else {
 				// print the IP address of the hop
-				stream << hop.received()->src_addr() << " (" << *hop.name() << ")"; 
+				stream << hop.received()->src_addr() << " (" << *hop.name() << ")";
 
 				// print the response IP ID, useful to detect
 				// loops due to NATs, fake hops, etc