[PATCH 2/6] SNMP tapset

["David J. Wilder" <dwilder at us dot ibm dot com>]

This tapset provides probes used to count IP SNMP management events.
Operation of these probe points are similar to the tcpipmib.stp tapset
except that the callback function has a different format. Here is a
description of the user callback:

function ipmib_filter_key:long (skb:long, op:long, SourceIsLocal:long)

ipmib_filter_key() should compute and return a value used to index
the statistical counter. The skb is a pointer to the struct sk_buff
being processed at the time. The local ip-address and port number will
be located in either the source or destination fields of the network
packet. SourceIsLocal will be true if the local address is in the source
field. The probe handler will add the value of op to the counter index
by the returned value.

Signed-off-by: David Wilder <dwilder@us.ibm.com>

------------------------------------------------------
 tapset/ipmib.stp |  514 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 514 insertions(+), 0 deletions(-)

diff --git a/tapset/ipmib.stp b/tapset/ipmib.stp
new file mode 100644
index 0000000..3430a8a
--- /dev/null
+++ b/tapset/ipmib.stp
@@ -0,0 +1,514 @@
+/*
+ *      Copyright (C) 2009 IBM Corp.
+ *      This file is part of systemtap, and is free software.  You can
+ *      redistribute it and/or modify it under the terms of the GNU General
+ *      Public License (GPL); either version 2, or (at your option) any
+ *      later version.
+ *      
+ *      Version 1.0     wilder@us.ibm.com     2009-07-06
+ */
+
+%{ /* pure */
+#include <net/route.h>
+#include <linux/skbuff.h>
+#include <linux/icmp.h>
+#include <linux/rtnetlink.h>
+#include <linux/tcp.h>
+%}
+
+
+/* Commented globals represent statistics that are not supported in this
+ * version. 
+ */
+global InReceives
+// global InHdrErrors
+// global InTooBigErrors
+global InNoRoutes  
+global InAddrErrors
+global InUnknownProtos
+// global InTruncatedPkts
+global InDiscards // included counts of InHdrErrors InTruncatedPkts
+// global InDelivers
+global ForwDatagrams
+global OutRequests
+// global OutDiscards
+// global OutNoRoutes
+global ReasmTimeout
+global ReasmReqds
+//global ReasmOKs
+// global ReasmFails
+global FragOKs
+global FragFails
+// global FragCreates
+global InMcastPkts
+global OutMcastPkts
+global InBcastPkts
+global OutBcastPkts
+
+/**
+ * sfunction ipmib_remote_addr - Get the remote ip address.
+ *
+ * Returns the remote ip address from an sk_buff.
+ * @skb: Pointer to a struct sk_buff.
+ *
+ */
+function ipmib_remote_addr:long (skb:long, SourceIsLocal:long)
+{
+	iphdr = __get_skb_iphdr(skb);
+	if ( SourceIsLocal )
+		return ntohl(__ip_skb_daddr(iphdr));
+	return ntohl(__ip_skb_saddr(iphdr));
+}
+
+/**
+ * sfunction ipmib_local_addr - Get the local ip address.
+ *
+ * Returns the local ip address from an sk_buff.
+ * @skb: Pointer to a struct sk_buff.
+ *
+ */
+function ipmib_local_addr:long (skb:long, SourceIsLocal:long)
+{
+	iphdr = __get_skb_iphdr(skb);
+	if ( SourceIsLocal )
+		return ntohl(__ip_skb_saddr(iphdr));
+	return ntohl(__ip_skb_daddr(iphdr));
+}
+
+/**
+ * sfunction ipmib_tcp_remote_port - Get the remote tcp port.
+ *
+ * Returns the remote tcp port from an sk_buff.
+ * @skb: Pointer to a struct sk_buff.
+ *
+ */
+function ipmib_tcp_remote_port:long (skb:long, SourceIsLocal:long)
+{
+	th = _plunge_into_tcphdr(skb);
+	if ( SourceIsLocal )
+		return _tcphdr_get_dport(th);
+	return _tcphdr_get_sport(th);
+}
+
+/**
+ * sfunction ipmib_tcp_local_port - Get the local tcp port.
+ *
+ * Returns the local tcp port from an sk_buff.
+ * @skb: Pointer to a struct sk_buff.
+ *
+ */
+function ipmib_tcp_local_port:long (skb:long, SourceIsLocal:long)
+{
+	th = _plunge_into_tcphdr(skb);
+	if ( SourceIsLocal )
+		return _tcphdr_get_sport(th);
+	return _tcphdr_get_dport(th);
+}
+
+/**
+ * sfunction ipmib_get_proto - Get the protocol value
+ *
+ * Returns the protocol value from ip header.
+ * @skb: Pointer to a struct sk_buff.
+ *
+ */
+function ipmib_get_proto:long (skb:long)
+{
+	iphdr = __get_skb_iphdr(skb);
+	return __ip_skb_proto(iphdr);
+}
+
+/* Internal functions */
+
+/*
+ * We can't assume the pointer to the sk_buff->transport_header 
+ * has been updated, so we must calculate the value from the network_header.
+ * The caller must verify the skb is for a tcpip packet.
+ */
+function _plunge_into_tcphdr:long (skb:long)
+%{
+	struct sk_buff *skb = (struct sk_buff *)(long)THIS->skb;
+	/* as done by skb_network_header() */
+	#ifdef NET_SKBUFF_DATA_USES_OFFSET
+		THIS->__retvalue=(long)kread(&(skb->network_header)) +
+		(long)(kread(&(skb->head))) +
+		(long)sizeof(struct tcphdr);
+	#else
+		THIS->__retvalue=(long)kread(&(skb->network_header)) +
+		(long)sizeof(struct tcphdr);
+	#endif
+	CATCH_DEREF_FAULT();
+%}
+
+function _tcphdr_get_sport:long (th:long)
+%{ /* pure */
+	struct tcphdr *th = (struct tcphdr *) (long) THIS->th;
+	THIS->__retvalue = ntohs(kread(&(th->source)));
+	CATCH_DEREF_FAULT();
+%}
+
+function _tcphdr_get_dport:long (th:long)
+%{ /* pure */
+	struct tcphdr *th = (struct tcphdr *) (long) THIS->th;
+	THIS->__retvalue = ntohs(kread(&(th->dest)));
+	CATCH_DEREF_FAULT();
+%}
+
+function _ehostunreach:long ()
+%{
+	THIS->__retvalue = EHOSTUNREACH;
+%}
+
+function _enetunreach:long ()
+%{
+	THIS->__retvalue = ENETUNREACH;
+%}
+
+function _icmp_dest_unreach:long ()
+%{
+	THIS->__retvalue = ICMP_DEST_UNREACH;
+%}
+
+function _icmp_prot_unreach:long ()
+%{
+	THIS->__retvalue = ICMP_PROT_UNREACH;
+%}
+
+function _net_rx_drop:long ()
+%{
+	THIS->__retvalue = NET_RX_DROP;
+%}
+
+function _icmp_time_exceeded:long ()
+%{
+	THIS->__retvalue = ICMP_TIME_EXCEEDED;
+%}
+
+function _icmp_exc_fragtime:long ()
+%{
+	THIS->__retvalue = ICMP_EXC_FRAGTIME;
+%}
+
+function _rtn_multicast:long ()
+%{
+	THIS->__retvalue = RTN_MULTICAST;
+%}
+
+function _rtn_broadcast:long ()
+%{
+	THIS->__retvalue = RTN_BROADCAST;
+%}
+
+/**
+ * probe tcpmib.InReceives - Count an arriving packet.
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InReceives
+ * MIB: IPSTATS_MIB_INRECEIVES
+ *
+ */
+probe ipmib.InReceives=kernel.function("ip_rcv")
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) InReceives[key] += op;
+}
+
+/**
+ * probe tcpmib.InNoRoutes - Count an arriving packet with no matching socket.
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InNoRoutes
+ * MIB: IPSTATS_MIB_INNOROUTES
+ *
+ */
+probe ipmib.InNoRoutes=kernel.function("ip_route_input").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	if ( $return != -_enetunreach()) next;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) InNoRoutes[key] += op;
+}
+
+/**
+ * probe tcpmib.InAddrErrors - Count arriving packets with an incorrect address.
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InAddrErrors
+ * MIB: IPSTATS_MIB_INADDRERRORS
+ *
+ */
+probe ipmib.InAddrErrors=kernel.function("ip_route_input").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	if ( $return != -_ehostunreach()) next;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) InAddrErrors[key] += op;
+}
+
+/**
+ * probe tcpmib.InUnknownProtos - Count arriving packets with an unbound proto. 
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InUnknownProtos
+ * MIB: IPSTATS_MIB_INUNKNOWNPROTOS
+ *
+ */
+
+/* icmp_send() is called by ip_local_deliver_finish() */
+probe ipmib.InUnknownProtos=kernel.function("icmp_send")
+{
+	skb = $skb_in;
+	op = 1;
+	SourceIsLocal = 0;
+	if (($type==_icmp_dest_unreach())&&($code==_icmp_prot_unreach())){ 
+		key = ipmib_filter_key(skb,op,SourceIsLocal);
+		if ( key ) InUnknownProtos[key] += op;
+	}
+}
+
+/**
+ * probe tcpmib.InDiscards - Count discarded inbound packets.
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InDiscards
+ * MIB: STATS_MIB_INDISCARDS
+ *
+ */
+
+/*
+   This stat combines all instances of IPSTATS_MIB_INHDRERRORS,
+   IPSTATS_MIB_INTRUNCATEDPKTS, and STATS_MIB_INDISCARDS.
+*/
+probe ipmib.InDiscards=kernel.function("ip_rcv").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	if ( $return != _net_rx_drop() ) next;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) InDiscards[key] += op;
+}
+
+/**
+ * probe tcpmib.ForwDatagrams
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: ForwDatagrams
+ * MIB: IPSTATS_MIB_OUTFORWDATAGRAMS
+ *
+ */
+probe ipmib.ForwDatagrams=kernel.function("ip_forward_finish"),
+			 kernel.function("ipmr_forward_finish")
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) ForwDatagrams[key] += op;
+}
+
+/**
+ * probe tcpmib.OutRequests - Count a request to send a packet.
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: OutRequests
+ * MIB: IPSTATS_MIB_OUTREQUESTS
+ *
+ */
+probe ipmib.OutRequests=kernel.function("ip_output"),
+			kernel.function("ip_mc_output")
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 1;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) OutRequests[key] += op;
+}
+
+/**
+ * probe tcpmib.ReasmTimeout
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: ReasmTimeout
+ * MIB: IPSTATS_MIB_REASMTIMEOUT
+ *
+ */
+probe ipmib.ReasmTimeout=kernel.function("icmp_send")
+{
+	skb = $skb_in;
+	op = 0;
+	SourceIsLocal = 1;
+	if(($type==_icmp_time_exceeded())&&($code==_icmp_exc_fragtime())){
+		key = ipmib_filter_key(skb,op,SourceIsLocal);
+		if ( key ) ReasmTimeout[key] += op;
+	}
+}
+
+/**
+ * probe tcpmib.ReasmReqds
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: ReasmReqds
+ * MIB: IPSTATS_MIB_REASMREQDS
+ *
+ */
+probe ipmib.ReasmReqds=kernel.function("ip_defrag")
+{
+	skb = $skb;
+	op = 0;
+	SourceIsLocal = 1;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) ReasmReqds[key] += op;
+}
+
+/**
+ * probe tcpmib.FragOKs
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: FragOKs
+ * MIB: IPSTATS_MIB_FRAGOKS
+ *
+ */
+probe ipmib.FragOKs=kernel.function("ip_fragment").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 1;
+	if ( $return ) next
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) FragOKs [key] += op;
+}
+
+/**
+ * probe tcpmib.FragFails
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: FragFails
+ * MIB: IPSTATS_MIB_FRAGFAILS
+ *
+ */
+probe ipmib.FragFails=kernel.function("ip_fragment").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 1;
+	if (!$return ) next
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) FragFails [key] += op;
+}
+
+function _input_route_type:long (skb:long)
+%{ /* pure */
+	struct rtable *rt;
+	struct sk_buff *skb = (struct sk_buff *)(long)THIS->skb;
+	rt = (struct rtable *)kread(&(skb->rtable)); 
+	THIS->__retvalue = kread(&(rt->rt_type));
+	CATCH_DEREF_FAULT();
+%}
+
+function _output_route_type:long (skb:long)
+%{ /* pure */
+	struct rtable *rt;
+	struct dst_entry *dst;
+	struct sk_buff *skb = (struct sk_buff *)(long)THIS->skb;
+	dst = (struct dst_entry *)kread(&(skb->dst));
+	rt = (struct rtable *)dst;
+	THIS->__retvalue = kread(&(rt->rt_type));
+	CATCH_DEREF_FAULT();
+%}
+
+/**
+ * probe tcpmib.InMcastPkts
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InMcastPkts
+ * MIB: IPSTATS_MIB_INMCASTPKTS
+ *
+ */
+probe ipmib.InMcastPkts=kernel.function("ip_rcv_finish").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	if ($return == _net_rx_drop()) next;
+	if (_input_route_type(skb) != _rtn_multicast()) next;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) InMcastPkts[key] += op;
+}
+
+/**
+ * probe tcpmib.OutMcastPkts
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: OutMcastPkts
+ * MIB: IPSTATS_MIB_OUTMCASTPKTS
+ *
+ */
+probe ipmib.OutMcastPkts=kernel.function("ip_finish_output2")
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 1;
+	if (_output_route_type(skb) != _rtn_multicast()) next
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) OutMcastPkts[key] += op;
+}
+
+/**
+ * probe tcpmib.InBcastPkts
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: InBcastPkts
+ * MIB: IPSTATS_MIB_INBCASTPKTS
+ *
+ */
+probe ipmib.InBcastPkts=kernel.function("ip_rcv_finish").return
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 0;
+	if ($return == _net_rx_drop()) next;
+	if (_input_route_type(skb) != _rtn_broadcast()) next;
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) InBcastPkts[key] += op;
+}
+
+/**
+ * probe tcpmib.OutBcastPkts
+ * @skb: Pointer to the struct sk_buff being acted on.
+ * @op: Value to be added to the counter (Operation). 
+ *
+ * Counter Name: OutBcastPkts
+ * MIB: IPSTATS_MIB_OUTBCASTPKTS
+ *
+ */
+probe ipmib.OutBcastPkts=kernel.function("ip_finish_output2")
+{
+	skb = $skb;
+	op = 1;
+	SourceIsLocal = 1;
+	if (_output_route_type(skb) != _rtn_broadcast()) next
+	key = ipmib_filter_key(skb,op,SourceIsLocal);
+	if ( key ) OutBcastPkts[key] += op;
+}