Add new TCP and IP functions

This patch adds some basic functions to the IP and TCP tapsets.
Mainly, it's possible to get the iphdr and tcphdr from a sk_buff structure.

As a consequence, a TCP probe called tcp.receive() was created and
is probed every time a TCP packet is received, and a lot of
useful fields is available, as the TCP flags.

Also a small example that works like tcpdump for received TCP packets was
created.

This patch was tested on x86 and ppc machines, on 2.6.18 kernel and also on
mainline one.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: Andre Detsch <adetsch@br.ibm.com>
Signed-off-by: Josh Stone <jistone@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/testsuite/systemtap.examples/network/tcpdumplike.stp b/testsuite/systemtap.examples/network/tcpdumplike.stp
new file mode 100644
index 00000000..4026e7a7
--- /dev/null
+++ b/testsuite/systemtap.examples/network/tcpdumplike.stp
@@ -0,0 +1,12 @@
+// A TCP dump like example
+
+probe begin, timer.s(1) {
+	printf("-----------------------------------------------------------------\n");
+	printf("       Source IP         Dest IP  SPort  DPort  U  A  P  R  S  F \n");
+	printf("-----------------------------------------------------------------\n");
+}
+
+probe tcp.receive {
+	printf(" %15s %15s  %5d  %5d  %d  %d  %d  %d  %d  %d\n",
+		saddr, daddr, sport, dport, urg, ack, psh, rst, syn, fin)
+}