added support to dump the traffic to a file

node-pcap · Nov 17, 2011 · cb331da · cb331da
1 parent ba1b20e
commit cb331da
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Showing 2 changed files with 28 additions and 5 deletions.
diff --git a/pcap.js b/pcap.js
@@ -30,7 +30,7 @@ Pcap.prototype.findalldevs = function () {
     return binding.findalldevs();
 };
 
-Pcap.prototype.open = function (live, device, filter, buffer_size) {
+Pcap.prototype.open = function (live, device, filter, buffer_size, pcap_output_filename) {
     var me = this;
 
     if (typeof buffer_size === 'number' && !isNaN(buffer_size)) {
@@ -41,10 +41,10 @@ Pcap.prototype.open = function (live, device, filter, buffer_size) {
 
     if (live) {
         this.device_name = device || binding.default_device();
-        this.link_type = binding.open_live(this.device_name, filter || "", this.buffer_size);
+        this.link_type = binding.open_live(this.device_name, filter || "", this.buffer_size, pcap_output_filename || "");
     } else {
         this.device_name = device;
-        this.link_type = binding.open_offline(this.device_name, filter || "", this.buffer_size);
+        this.link_type = binding.open_offline(this.device_name, filter || "", this.buffer_size, pcap_output_filename || "");
     }
 
     this.fd = binding.fileno();

diff --git a/pcap_binding.cc b/pcap_binding.cc
@@ -22,6 +22,7 @@ struct bpf_program fp;
 bpf_u_int32 mask;
 bpf_u_int32 net;
 pcap_t *pcap_handle;
+pcap_dumper_t *pcap_dump_handle;
 
 // buffer data and length are global. To support more than one pcap session, we'll need a class container.
 char *buffer_data;
@@ -42,6 +43,10 @@ size_t buffer_length;
 void PacketReady(u_char *callback_p, const struct pcap_pkthdr* pkthdr, const u_char* packet) {
     HandleScope scope;
 
+    if (pcap_dump_handle != NULL) {
+        pcap_dump((u_char *) pcap_dump_handle, pkthdr, packet);
+    }
+
     Local<Function> * callback = (Local<Function>*)callback_p;
 
     size_t copy_len = pkthdr->caplen;
@@ -112,7 +117,7 @@ Open(bool live, const Arguments& args)
     HandleScope scope;
     char errbuf[PCAP_ERRBUF_SIZE];
 
-    if (args.Length() == 3) { 
+    if (args.Length() == 4) { 
         if (!args[0]->IsString()) {
             return ThrowException(Exception::TypeError(String::New("pcap Open: args[0] must be a String")));
         }
@@ -122,12 +127,16 @@ Open(bool live, const Arguments& args)
         if (!args[2]->IsInt32()) {
             return ThrowException(Exception::TypeError(String::New("pcap Open: args[2] must be a Number")));
         }
+        if (!args[3]->IsString()) {
+            return ThrowException(Exception::TypeError(String::New("pcap Open: args[3] must be a String")));
+        }
     } else {
-        return ThrowException(Exception::TypeError(String::New("pcap Open: expecting 3 arguments")));
+        return ThrowException(Exception::TypeError(String::New("pcap Open: expecting 4 arguments")));
     }
     String::Utf8Value device(args[0]->ToString());
     String::Utf8Value filter(args[1]->ToString());
     int buffer_size = args[2]->Int32Value();
+    String::Utf8Value pcap_output_filename(args[3]->ToString());
 
     if (live) {
         if (pcap_lookupnet((char *) *device, &net, &mask, errbuf) == -1) {
@@ -170,6 +179,15 @@ Open(bool live, const Arguments& args)
         if (pcap_activate(pcap_handle) != 0) {
             return ThrowException(Exception::Error(String::New(pcap_geterr(pcap_handle))));
         }
+
+        pcap_dump_handle = NULL;
+        if (strlen((char *) *pcap_output_filename) > 0) {
+            pcap_dump_handle = pcap_dump_open(pcap_handle, (char *) *pcap_output_filename);
+            if (pcap_dump_handle == NULL) {
+                return ThrowException(Exception::Error(String::New("error opening dump")));    
+            }
+        }
+
     } else {
         // Device is the path to the savefile
         pcap_handle = pcap_open_offline((char *) *device, errbuf);
@@ -303,6 +321,11 @@ Close(const Arguments& args)
 {
     HandleScope scope;
 
+    if (pcap_dump_handle != NULL) {
+        pcap_dump_close(pcap_dump_handle);
+        pcap_dump_handle = NULL;
+    }
+
     pcap_close(pcap_handle);
 
     return Undefined();