Fixed bug in Utils::pseudoheader_checksum.

examples/Makefile.in

@@ -0,0 +1,26 @@
+CXX=@CXX@
+CFLAGS=-c -Wall @CFLAGS@
+LDFLAGS=-lpcap -ltins -lpthread
+SOURCES=arpspoofing.cpp portscan.cpp
+
+OBJECTS=$(SOURCES:.cpp=.o)
+INCLUDE=
+EXECUTABLES=arpspoof portscan
+
+all: $(SOURCES) $(EXECUTABLES)
+
+compile: $(OBJECTS)
+
+recompile: clean all
+
+arpspoof: arpspoofing.o
+	$(CXX) arpspoofing.o $(LDFLAGS) -o arpspoof
+
+portscan: portscan.o
+	$(CXX) portscan.o $(LDFLAGS) -o portscan
+
+.cpp.o:
+	$(CXX) $(CFLAGS) $(INCLUDE) $< -o $@
+
+clean:
+	rm $(OBJECTS) $(EXECUTABLE)

examples/arpspoofing.cpp

@@ -24,9 +24,9 @@
 #include <string>
 #include <stdint.h>
 #include <cstdlib>
-#include "arp.h"
-#include "utils.h"
-#include "ethernetII.h"
+#include <tins/arp.h>
+#include <tins/utils.h>
+#include <tins/ethernetII.h>
 
 using namespace std;
 using namespace Tins;

examples/configure.ac

@@ -0,0 +1,16 @@
+AC_INIT(myconfig, 0.1)
+
+AC_PROG_CXX()
+AC_LANG(C++)
+
+if test -n "$debug"
+then
+    CFLAGS="-DDEBUG -g"
+else
+    CFLAGS="-O3"
+fi
+
+AC_CHECK_HEADERS([pcap.h])
+AC_CHECK_LIB(pcap, pcap_loop, [], [AC_MSG_ERROR([pcap library is needed!])])
+AC_SUBST(CFLAGS)
+AC_OUTPUT(Makefile)

examples/portscan.cpp

@@ -23,12 +23,12 @@
 #include <string>
 #include <cstdlib>
 #include <pthread.h>
-#include "ip.h"
-#include "tcp.h"
-#include "ethernetII.h"
-#include "sniffer.h"
-#include "utils.h"
-#include "packetsender.h"
+#include <tins/ip.h>
+#include <tins/tcp.h>
+#include <tins/ethernetII.h>
+#include <tins/sniffer.h>
+#include <tins/utils.h>
+#include <tins/packetsender.h>
 
 
 using namespace std;
@@ -40,19 +40,14 @@ using namespace Tins;
  */
 struct ScanHandler {
     bool operator() (PDU *pdu) {
-        // Down-cast the inner PDU to IP.
-        IP *ip = dynamic_cast<IP*>(pdu->inner_pdu());
-        if(ip) {
-            // Down-cast IP's inner PDU to TCP.
-            TCP *tcp = dynamic_cast<TCP*>(ip->inner_pdu());
-            if(tcp) {
-                // Ok, it's a TCP PDU. Is RST flag on? Then port is closed.
-                if(tcp->get_flag(TCP::RST))
-                    cout << "Port: " << tcp->sport() << " closed\n";
-                // Is SYN flag on? Then port is open!
-                else if(tcp->get_flag(TCP::SYN))
-                    cout << "Port: " << tcp->sport() << " open\n";
-            }
+        TCP *tcp = (pdu->find_inner_pdu<TCP>(PDU::TCP));
+        if(tcp) {
+            // Ok, it's a TCP PDU. Is RST flag on? Then port is closed.
+            if(tcp->get_flag(TCP::RST))
+                cout << "Port: " << tcp->sport() << " closed\n";
+            // Is SYN flag on? Then port is open!
+            else if(tcp->get_flag(TCP::SYN))
+                cout << "Port: " << tcp->sport() << " open\n";
         }
         return true;
     }
@@ -91,8 +86,9 @@ void *thread_proc(void *param) {
     // The required subclass of AbstractSnifferHandler which will serve as
     // a proxy to our handler.
     AbstractSnifferHandler *my_handler = new SnifferHandler<ScanHandler>(&handler);
+    sniffer->set_filter("tcp and ip src " + *data + " and tcp[tcpflags] & (tcp-rst|tcp-syn) != 0");
     // Sniff loop. Only sniff TCP PDUs comming from the given IP and have either RST or SYN flag on.
-    sniffer->sniff_loop(my_handler, "tcp and ip src " + *data + " and tcp[tcpflags] & (tcp-rst|tcp-syn) != 0");
+    sniffer->sniff_loop(my_handler);
     delete my_handler;
     return 0;
 }

src/utils.cpp

@@ -269,8 +269,6 @@ uint32_t Tins::Utils::do_checksum(const uint8_t *start, const uint8_t *end) {
 
 uint32_t Tins::Utils::pseudoheader_checksum(uint32_t source_ip, uint32_t dest_ip, uint32_t len, uint32_t flag) {
     uint32_t checksum(0);
-    source_ip = Utils::net_to_host_l(source_ip);
-    dest_ip = Utils::net_to_host_l(dest_ip);
     uint16_t *ptr = (uint16_t*)&source_ip;
 
     checksum += (uint32_t)(*ptr) + (uint32_t)(*(ptr+1));