Merge pull request #28 from darrenw/initial

Tweak to the IPv6 address zero-compression function
node-pcap · Jan 15, 2012 · f0c04a5 · f0c04a5
2 parents 8221090 + 62eb9cd
commit f0c04a5
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Showing 2 changed files with 67 additions and 33 deletions.
diff --git a/pcap.js b/pcap.js
@@ -171,16 +171,37 @@ var unpack = {
         ].join('.');
     },
 	ipv6_addr: function (raw_packet, offset) {
-		var ret = '';
+	    var ret = '';
-		for (var i=offset; i<offset+16; i+=2) {
+	    var octets = [];
-			if (i > offset) {
+	    for (var i=offset; i<offset+16; i+=2) {
-				ret += ':';
+		octets.push(unpack.uint16(raw_packet,i).toString(16));
+	    }
+	    var curr_start, curr_len = undefined;
+	    var max_start, max_len = undefined;
+	    for(var i = 0; i < 8; i++){
+		if(octets[i] == "0"){
+		    if(curr_start === undefined){
+			curr_len = 1;
+			curr_start = i;
+		    }else{
+			curr_len++;
+			if(!max_start || curr_len > max_len){
+			    max_start = curr_start;
+			    max_len = curr_len;
 			}
-			ret += unpack.uint16(raw_packet, i).toString(16);
+		    }
+		}else{
+			curr_start = undefined;
 		}
-		// TODO: do a better job to compress out largest run of zeros.
+	    }
-		return ret.replace(/(0:)+/, ':');
+
-		return ret;
+	    if(max_start !== undefined){
+			var tosplice = max_start == 0 || (max_start + max_len > 7) ? ":" : "";
+			octets.splice(max_start, max_len,tosplice);
+			if(max_len == 8){octets.push("");}
+	    }
+		ret = octets.join(":");
+	    return ret;
 	}
 };
 exports.unpack = unpack;

diff --git a/pcap_binding.cc b/pcap_binding.cc
@@ -200,13 +200,15 @@ Open(bool live, const Arguments& args)
         return ThrowException(Exception::Error(String::New(errbuf)));
     }
 
-    // TODO - if filter is empty, don't bother with compile or set
+    if(filter.length() != 0){
-    if (pcap_compile(pcap_handle, &fp, (char *) *filter, 1, net) == -1) {
+      if (pcap_compile(pcap_handle, &fp, (char *) *filter, 1, net) == -1) {
         return ThrowException(Exception::Error(String::New(pcap_geterr(pcap_handle))));
-    }
+      }
-
+      
-    if (pcap_setfilter(pcap_handle, &fp) == -1) {
+      if (pcap_setfilter(pcap_handle, &fp) == -1) {
         return ThrowException(Exception::Error(String::New(pcap_geterr(pcap_handle))));
+      }
+      pcap_freecode(&fp);
     }
 
     // Work around buffering bug in BPF on OSX 10.6 as of May 19, 2010
@@ -256,6 +258,27 @@ OpenOffline(const Arguments& args)
     return Open(false, args);
 }
 
+// Helper method, convert a sockaddr* (AF_INET or AF_INET6) to a string, and set it as the property
+// named 'key' in the Address object you pass in.
+void SetAddrStringHelper(const char* key, sockaddr *addr, Local<Object> Address){
+  if(key && addr){
+    char dst_addr[INET6_ADDRSTRLEN + 1] = {0};
+    char* src = 0;
+    socklen_t size = 0;
+    if(addr->sa_family == AF_INET){
+      struct sockaddr_in* saddr = (struct sockaddr_in*) addr;
+      src = (char*) &(saddr->sin_addr);
+      size = INET_ADDRSTRLEN;
+    }else{
+      struct sockaddr_in6* saddr6 = (struct sockaddr_in6*) addr;
+      src = (char*) &(saddr6->sin6_addr);
+      size = INET6_ADDRSTRLEN;
+    }
+    const char* address = inet_ntop(addr->sa_family, src, dst_addr, size);
+    Address->Set(String::New(key), String::New(address));
+  }
+}
+
 Handle<Value>
 FindAllDevs(const Arguments& args)
 {
@@ -280,27 +303,17 @@ FindAllDevs(const Arguments& args)
         Local<Array> AddrArray = Array::New();
         int j = 0;
         for (pcap_addr_t *cur_addr = cur_dev->addresses ; cur_addr != NULL ; cur_addr = cur_addr->next, j++) {
-            if (cur_addr->addr && cur_addr->addr->sa_family == AF_INET) {
+	  if (cur_addr->addr){
-                Local<Object> Address = Object::New();
+		int af = cur_addr->addr->sa_family;
-
+		if(af == AF_INET || af == AF_INET6){
-                struct sockaddr_in *sin = (struct sockaddr_in *) cur_addr->addr;
+		  Local<Object> Address = Object::New();
-                Address->Set(String::New("addr"), String::New(inet_ntoa(sin->sin_addr)));
+		  SetAddrStringHelper("addr", cur_addr->addr, Address);
-
+		  SetAddrStringHelper("netmask", cur_addr->netmask, Address);
-                if (cur_addr->netmask != NULL) {
+		  SetAddrStringHelper("broadaddr", cur_addr->broadaddr, Address);
-                    sin = (struct sockaddr_in *) cur_addr->netmask;
+		  SetAddrStringHelper("dstaddr", cur_addr->dstaddr, Address);
-                    Address->Set(String::New("netmask"), String::New(inet_ntoa(sin->sin_addr)));
+		  AddrArray->Set(Integer::New(j), Address);
-                }
+		}
-                if (cur_addr->broadaddr != NULL) {
-                    sin = (struct sockaddr_in *) cur_addr->broadaddr;
-                    Address->Set(String::New("broadaddr"), String::New(inet_ntoa(sin->sin_addr)));
-                }
-                if (cur_addr->dstaddr != NULL) {
-                    sin = (struct sockaddr_in *) cur_addr->dstaddr;
-                    Address->Set(String::New("dstaddr"), String::New(inet_ntoa(sin->sin_addr)));
-                }
-                AddrArray->Set(Integer::New(j), Address);
             }
-            // TODO - support AF_INET6
         }
 
         Dev->Set(String::New("addresses"), AddrArray);