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Code Issues Releases Wiki Activity

Fix traceroute example.

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This commit is contained in:
Matias Fontanini
2015-06-20 10:58:36 -07:00
parent b451a9eae0
commit 2c2c92325d
1 changed files with 49 additions and 19 deletions
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68
examples/traceroute.cpp
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@@ -31,8 +31,11 @@
#include <chrono>
#include <thread>
#include <cstdint>
#include <random>
#include <map>
#include <algorithm>
#include <atomic>
#include <limits>
#include <mutex>
#include <tins/tins.h>
@@ -43,7 +46,9 @@ public:
typedef std::map<uint16_t, IPv4Address> result_type;
Traceroute(NetworkInterface interface, IPv4Address address)
: iface(interface), addr(address) { }
: iface(interface), addr(address), lowest_dest_ttl(std::numeric_limits<int>::max()) {
sequence = std::random_device()();
}
result_type trace() {
SnifferConfiguration config;
@@ -70,6 +75,10 @@ public:
);
send_packets(sender);
sniff_thread.join();
// If the final hop responded, add its address at the appropriate ttl
if (lowest_dest_ttl != std::numeric_limits<int>::max()) {
results[lowest_dest_ttl] = addr;
}
// Clear our results and return what we've found
return std::move(results);
}
@@ -79,11 +88,13 @@ private:
void send_packets(PacketSender &sender) {
// ICMPs are icmp-requests by default
IP ip = IP(addr, iface.addresses().ip_addr) / ICMP();
// We'll find at most 10 hops.
ICMP& icmp = ip.rfind_pdu<ICMP>();
icmp.sequence(sequence);
// We'll find at most 20 hops.
for(auto i = 1; i <= 10; ++i) {
// Set this "unique" id
ip.id(i);
for(auto i = 1; i <= 20; ++i) {
// Set this ICMP id
icmp.id(i);
// Set the time-to-live option
ip.ttl(i);
@@ -102,20 +113,37 @@ private:
}
bool sniff_callback(PDU &pdu) {
// Find IP and ICMP PDUs
const IP &ip = pdu.rfind_pdu<IP>();
ttl_map::const_iterator iter;
// Fetch the IP PDU attached to the ICMP response
const IP inner_ip = pdu.rfind_pdu<RawPDU>().to<IP>();
// Critical section
{
std::lock_guard<std::mutex> _(lock);
iter = ttls.find(inner_ip.id());
}
const ICMP &icmp = pdu.rfind_pdu<ICMP>();
// Check if this is an ICMP TTL exceeded error response
if (icmp.type() == ICMP::TIME_EXCEEDED) {
// Fetch the IP PDU attached to the ICMP response
const IP inner_ip = pdu.rfind_pdu<RawPDU>().to<IP>();
// Now get the ICMP layer
const ICMP& inner_icmp = inner_ip.rfind_pdu<ICMP>();
// Make sure this is one of our packets.
if (inner_icmp.sequence() == sequence) {
ttl_map::const_iterator iter;
// It's an actual response
if(iter != ttls.end()) {
// Store it
results[inner_ip.id()] = ip.src_addr();
// Critical section
{
std::lock_guard<std::mutex> _(lock);
iter = ttls.find(inner_icmp.id());
}
// It's an actual response
if(iter != ttls.end()) {
// Store it
results[inner_icmp.id()] = ip.src_addr();
}
}
}
// Otherwise, this could be the final hop making an echo response
else if (icmp.type() == ICMP::ECHO_REPLY && icmp.sequence() == sequence &&
ip.src_addr() == addr) {
// Keep the lowest ttl seen for the destination.
lowest_dest_ttl = std::min(lowest_dest_ttl, static_cast<int>(icmp.id()));
}
return running;
}
@@ -126,10 +154,12 @@ private:
ttl_map ttls;
result_type results;
std::mutex lock;
uint16_t sequence;
int lowest_dest_ttl;
};
int main(int argc, char* argv[]) {
if(argc <= 1 && std::cout << "Usage: " << *argv << " <IP_ADDRESS>\n")
if(argc <= 1 && std::cout << "Usage: " << *argv << " <ip_address>\n")
return 1;
try {
IPv4Address addr((std::string(argv[1])));
@@ -140,7 +170,7 @@ int main(int argc, char* argv[]) {
else {
std::cout << "Results: " << std::endl;
for(const auto &entry : results) {
std::cout << entry.first << " - " << entry.second << std::endl;
std::cout << std::setw(2) << entry.first << " - " << entry.second << std::endl;
}
}
}