Changeset 1691 for trunk/lib/protocols_transport.c

Timestamp:

02/22/11 10:01:08 (2 years ago)

Author:

salcock

Message:

• Fixed poor performance of the event API by greatly reducing the amount of packets created, copied and freed
• We now cache the transport header and payload length for each packet
• We now deal with Linux SLL Ethernet captures taken using tcpdump with -i any correctly.
• Changed parameters for internal function trace_get_payload_from_sll - it now sets both the arphrd type and the next protocol
• Moved ARPHRD definitions into a separate header file, as they come in handy anywhere we deal with SLL headers

File:

• trunk/lib/protocols_transport.c (modified) (4 diffs)

trunk/lib/protocols_transport.c

@@ -68 +68 @@
         size_t len = 0;
 
-        
-
+        /* Just use the cached length if we can */
+        if (packet->payload_length != -1)
+                return packet->payload_length;  
+
+        /* Set to zero so that we can return early without having to 
+         * worry about forgetting to update the cached value */
+        ((libtrace_packet_t *)packet)->payload_length = 0;
         layer = trace_get_layer3(packet, &ethertype, &rem);
-
         if (!layer)
                 return 0;
@@ -122 +126 @@
         }
 
+
+        ((libtrace_packet_t *)packet)->payload_length = len;
         return len;
 
@@ -139 +145 @@
 
         if (!remaining) remaining=&dummy_remaining;
+
+        if (packet->l4_header) {
+                void *link;
+                libtrace_linktype_t linktype;
+                link = trace_get_packet_buffer(packet, &linktype, remaining);
+                if (!link)
+                        return NULL;
+                *proto = packet->transport_proto;
+                *remaining -= (packet->l4_header - link);
+                return packet->l4_header;
+        }
 
         transport = trace_get_layer3(packet,&ethertype,remaining);
@@ -154 +171 @@
                                  (libtrace_ip6_t*)transport, proto,remaining);
                         }
-                        return transport;
+                        break;
                 case TRACE_ETHERTYPE_IPV6: /* IPv6 */
-                        return trace_get_payload_from_ip6(
+                        transport = trace_get_payload_from_ip6(
                                 (libtrace_ip6_t*)transport, proto, remaining);
+                        break;
+                default:
+                        *proto = 0;
+                        transport = NULL;
+                        break;
                         
         }
 
-        *proto=0;
-        return NULL;
+        ((libtrace_packet_t *)packet)->transport_proto = *proto;
+        ((libtrace_packet_t *)packet)->l4_header = transport;
+
+
+        return transport;
 }