Changeset ef90843 for lib

Timestamp:

10/21/05 10:43:29 (17 years ago)

Author:

Shane Alcock <salcock@…>

Branches:

4.0.1-hotfixes, cachetimestamps, develop, dpdk-ndag, etsilive, getfragoff, help, libtrace4, master, ndag_format, pfring, rc-4.0.1, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance, ringtimestampfixes

Children:

0675ea1

Parents:

194d49b

Message:

Updated documentation for trace_get_capture_length
Corrected error where erfhdr.rlen was being set to trace_get_capture_length
in erf_write_packet
Corrected erf_get_capture_length to not include capture format headers

Location:

lib

Files:

• format_erf.c (modified) (2 diffs)
• trace.c (modified) (1 diff)

lib/format_erf.c

@@ -647 +647 @@
                 // Flags. Can't do this
                 memset(&erfhdr.flags,1,1);
-                // Packet length
-                erfhdr.rlen = trace_get_capture_length(packet);
+                // Packet length (rlen includes format overhead)
+                erfhdr.rlen = trace_get_capture_length(packet) + sizeof(dag_record_t);
                 // loss counter. Can't do this
                 erfhdr.lctr = 0;
@@ -747 +747 @@
         dag_record_t *erfptr = 0;
         erfptr = (dag_record_t *)packet->buffer;
-        return ntohs(erfptr->rlen);
+        return (ntohs(erfptr->rlen) - sizeof(dag_record_t));
 }
 

lib/trace.c

@@ -952 +952 @@
 
 /* Get the size of the packet in the trace
- * @param packet the packet opaque pointer
+ * @param packet        the packet opaque pointer
  * @returns the size of the packet in the trace
  * @author Perry Lorier
+ * @note The return size refers to the network-level payload of the packet and
+ * does not include any capture headers. For example, an Ethernet packet with
+ * an empty TCP packet will return sizeof(ethernet_header) + sizeof(ip_header)
+ * + sizeof(tcp_header).
  * @note Due to this being a header capture, or anonymisation, this may not
  * be the same size as the original packet.  See trace_get_wire_length() for the 
  * original size of the packet.
  * @note This can (and often is) different for different packets in a trace!
- * @par 
- *  This is sometimes called the "snaplen".
+ * @note This is sometimes called the "snaplen".
  */ 
 int trace_get_capture_length(const struct libtrace_packet_t *packet) {