Changeset 9c87732 for lib/trace.c

Timestamp:

12/15/05 15:37:19 (16 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:

5baec88

Parents:

d56089a

Message:

Added trace_get_transport and trace_get_transport_from_ip functions to
do generic transport layer header grabbing.
Changed all the various get_tcp, get_udp and get_icmp functions to
act as wrappers around trace_get_transport_from_ip.

File:

• lib/trace.c (modified) (7 diffs)

lib/trace.c

@@ -720 +720 @@
 #define SW_IP_OFFMASK 0xff1f
 
+/* Gets a pointer to the transport layer header (if any)
+ * @param packet        a pointer to a libtrace_packet structure
+ *
+ * @returns a pointer to the transport layer header, or NULL if there is no header
+ */
+void *trace_get_transport(const struct libtrace_packet_t *packet) {
+        void *trans_ptr = 0;
+        struct libtrace_ip *ipptr = 0;
+
+        if (!(ipptr = trace_get_ip(packet))) {
+                return 0;
+        }
+
+        if ((ipptr->ip_off & SW_IP_OFFMASK) == 0) {
+                trans_ptr = (void *)((ptrdiff_t)ipptr + (ipptr->ip_hl * 4));
+        }
+        return trans_ptr;
+}
+
+/* Gets a pointer to the transport layer header (if any) given a pointer to the
+ * IP header
+ * @param ip            The IP Header
+ * @param[out] skipped  An output variable of the number of bytes skipped
+ *
+ * @returns a pointer to the transport layer header, or NULL if there is no header
+ *
+ * Skipped can be NULL, in which case it will be ignored
+ */
+void *trace_get_transport_from_ip(const struct libtrace_ip *ip, int *skipped) {
+        void *trans_ptr = 0;    
+
+        if ((ip->ip_off & SW_IP_OFFMASK) == 0) {
+                trans_ptr = (void *)((ptrdiff_t)ip + (ip->ip_hl * 4));
+        }
+
+        if (skipped)
+                *skipped = (ip->ip_hl*4);
+
+        return trans_ptr;
+}
+
 /* get a pointer to the TCP header (if any)
  * @param packet        a pointer to a libtrace_packet structure
@@ -732 +773 @@
                 return 0;
         }
-        if ((ipptr->ip_p == 6) && ((ipptr->ip_off & SW_IP_OFFMASK) == 0))  {
-                tcpptr = (struct libtrace_tcp *)((ptrdiff_t)ipptr + (ipptr->ip_hl * 4));
+        if (ipptr->ip_p == 6) {
+                tcpptr = (struct libtrace_tcp *)trace_get_transport_from_ip(ipptr, 0);
         }
         return tcpptr;
@@ -751 +792 @@
         struct libtrace_tcp *tcpptr = 0;
 
-        if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0))  {
-                tcpptr = (struct libtrace_tcp *)((ptrdiff_t)ip+ (ip->ip_hl * 4));
-        }
-
-        if (skipped)
-                *skipped=(ip->ip_hl*4);
+        if (ip->ip_p == 6)  {
+                tcpptr = (struct libtrace_tcp *)trace_get_transport_from_ip(ip, skipped);
+        }
 
         return tcpptr;
@@ -773 +811 @@
                 return 0;
         }
-        if ((ipptr->ip_p == 17) && ((ipptr->ip_off & SW_IP_OFFMASK) == 0)) {
-                udpptr = (struct libtrace_udp *)((ptrdiff_t)ipptr + (ipptr->ip_hl * 4));
+        if (ipptr->ip_p == 17)  {
+                udpptr = (struct libtrace_udp *)trace_get_transport_from_ip(ipptr, 0);
         }
 
@@ -792 +830 @@
         struct libtrace_udp *udpptr = 0;
 
-        if ((ip->ip_p == 17) && ((ip->ip_off & SW_IP_OFFMASK) == 0))  {
-                udpptr = (struct libtrace_udp *)((ptrdiff_t)ip+ (ip->ip_hl * 4));
-        }
-
-        if (skipped)
-                *skipped=(ip->ip_hl*4);
+        if (ip->ip_p == 17) {
+                udpptr = (struct libtrace_udp *)trace_get_transport_from_ip(ip, skipped);
+        }
 
         return udpptr;
@@ -815 +850 @@
                 return 0;
         }
-        if ((ipptr->ip_p == 1)&& ((ipptr->ip_off & SW_IP_OFFMASK) == 0 )){
-                icmpptr = (struct libtrace_icmp *)((ptrdiff_t)ipptr + (ipptr->ip_hl * 4));
+        if (ipptr->ip_p == 1){
+                icmpptr = (struct libtrace_icmp *)trace_get_transport_from_ip(ipptr, 0);
         }
         return icmpptr;
@@ -833 +868 @@
         struct libtrace_icmp *icmpptr = 0;
 
-        if ((ip->ip_p == 6) && ((ip->ip_off & SW_IP_OFFMASK) == 0))  {
-                icmpptr = (struct libtrace_icmp *)((ptrdiff_t)ip+ (ip->ip_hl * 4));
-        }
-
-        if (skipped)
-                *skipped=(ip->ip_hl*4);
+        if (ip->ip_p == 1)  {
+                icmpptr = (struct libtrace_icmp *)trace_get_transport_from_ip(ip, skipped);
+        }
 
         return icmpptr;