net: FIB tracepoints

A few useful tracepoints developing VRF driver.

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/trace/events/fib.h

@@ -0,0 +1,111 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fib
+
+#if !defined(_TRACE_FIB_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FIB_H
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <net/ip_fib.h>
+#include <linux/tracepoint.h>
+
+TRACE_EVENT(fib_table_lookup,
+
+	TP_PROTO(int tb_id, const struct flowi4 *flp),
+
+	TP_ARGS(tb_id, flp),
+
+	TP_STRUCT__entry(
+		__field(	int,	tb_id		)
+		__field(	int,	oif		)
+		__field(	int,	iif		)
+		__field(	__u8,	tos		)
+		__field(	__u8,	scope		)
+		__field(	__u8,	flags		)
+		__array(	__u8,	src,	4	)
+		__array(	__u8,	dst,	4	)
+	),
+
+	TP_fast_assign(
+		__be32 *p32;
+
+		__entry->tb_id = tb_id;
+		__entry->oif = flp->flowi4_oif;
+		__entry->iif = flp->flowi4_iif;
+		__entry->tos = flp->flowi4_tos;
+		__entry->scope = flp->flowi4_scope;
+		__entry->flags = flp->flowi4_flags;
+
+		p32 = (__be32 *) __entry->src;
+		*p32 = flp->saddr;
+
+		p32 = (__be32 *) __entry->dst;
+		*p32 = flp->daddr;
+	),
+
+	TP_printk("table %d oif %d iif %d src %pI4 dst %pI4 tos %d scope %d flags %x",
+		  __entry->tb_id, __entry->oif, __entry->iif,
+		  __entry->src, __entry->dst, __entry->tos, __entry->scope,
+		  __entry->flags)
+);
+
+TRACE_EVENT(fib_table_lookup_nh,
+
+	TP_PROTO(const struct fib_nh *nh),
+
+	TP_ARGS(nh),
+
+	TP_STRUCT__entry(
+		__string(	name,	nh->nh_dev->name)
+		__field(	int,	oif		)
+		__array(	__u8,	src,	4	)
+	),
+
+	TP_fast_assign(
+		__be32 *p32 = (__be32 *) __entry->src;
+
+		__assign_str(name, nh->nh_dev ? nh->nh_dev->name : "not set");
+		__entry->oif = nh->nh_oif;
+		*p32 = nh->nh_saddr;
+	),
+
+	TP_printk("nexthop dev %s oif %d src %pI4",
+		  __get_str(name), __entry->oif, __entry->src)
+);
+
+TRACE_EVENT(fib_validate_source,
+
+	TP_PROTO(const struct net_device *dev, const struct flowi4 *flp),
+
+	TP_ARGS(dev, flp),
+
+	TP_STRUCT__entry(
+		__string(	name,	dev->name	)
+		__field(	int,	oif		)
+		__field(	int,	iif		)
+		__array(	__u8,	src,	4	)
+		__array(	__u8,	dst,	4	)
+	),
+
+	TP_fast_assign(
+		__be32 *p32;
+
+		__assign_str(name, dev ? dev->name : "not set");
+		__entry->oif = flp->flowi4_oif;
+		__entry->iif = flp->flowi4_iif;
+
+		p32 = (__be32 *) __entry->src;
+		*p32 = flp->saddr;
+
+		p32 = (__be32 *) __entry->dst;
+		*p32 = flp->daddr;
+	),
+
+	TP_printk("dev %s oif %d iif %d src %pI4 dst %pI4",
+		  __get_str(name), __entry->oif, __entry->iif,
+		  __entry->src, __entry->dst)
+);
+#endif /* _TRACE_FIB_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>

net/core/net-traces.c

@@ -31,6 +31,7 @@
 #include <trace/events/napi.h>
 #include <trace/events/sock.h>
 #include <trace/events/udp.h>
+#include <trace/events/fib.h>
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(kfree_skb);
 

net/ipv4/fib_frontend.c

@@ -46,6 +46,7 @@
 #include <net/rtnetlink.h>
 #include <net/xfrm.h>
 #include <net/vrf.h>
+#include <trace/events/fib.h>
 
 #ifndef CONFIG_IP_MULTIPLE_TABLES
 
@@ -344,6 +345,8 @@ static int __fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst,
 
 	fl4.flowi4_mark = IN_DEV_SRC_VMARK(idev) ? skb->mark : 0;
 
+	trace_fib_validate_source(dev, &fl4);
+
 	net = dev_net(dev);
 	if (fib_lookup(net, &fl4, &res, 0))
 		goto last_resort;

net/ipv4/fib_trie.c

@@ -81,6 +81,7 @@
 #include <net/sock.h>
 #include <net/ip_fib.h>
 #include <net/switchdev.h>
+#include <trace/events/fib.h>
 #include "fib_lookup.h"
 
 #define MAX_STAT_DEPTH 32
@@ -1278,6 +1279,8 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 	unsigned long index;
 	t_key cindex;
 
+	trace_fib_table_lookup(tb->tb_id, flp);
+
 	pn = t->kv;
 	cindex = 0;
 
@@ -1442,6 +1445,8 @@ found:
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 			this_cpu_inc(stats->semantic_match_passed);
 #endif
+			trace_fib_table_lookup_nh(nh);
+
 			return err;
 		}
 	}