Subject: [PATCH net-next 1/3] net/ipv4: Udate fib_table_lookup tracepoint

From: [email-masked]
Date: Mon, 21 May 2018 14:24:41 -0700

From: David Ahern <[email-masked]>

Commit 4a2d73a4fb36 ("ipv4: fib_rules: support match on sport, dport
and ip proto") added support for protocol and ports to FIB rules.
Update the FIB lookup tracepoint to dump the parameters.

In addition, make the IPv4 tracepoint similar to the IPv6 one where
the lookup parameters and result are dumped in 1 event. It is much
easier to use and understand the outcome of the lookup.

Signed-off-by: David Ahern <[email-masked]>
---
 include/trace/events/fib.h | 72 +++++++++++++++++++++++++++-------------------
 net/ipv4/fib_trie.c        | 14 +++++----
 2 files changed, 52 insertions(+), 34 deletions(-)

diff --git a/include/trace/events/fib.h b/include/trace/events/fib.h
index 81b7e985bb45..f5a1d4c518d8 100644
--- a/include/trace/events/fib.h
+++ b/include/trace/events/fib.h
@@ -12,12 +12,14 @@
 
 TRACE_EVENT(fib_table_lookup,
 
-	TP_PROTO(u32 tb_id, const struct flowi4 *flp),
+	TP_PROTO(u32 tb_id, const struct flowi4 *flp,
+		 const struct fib_nh *nh, int err),
 
-	TP_ARGS(tb_id, flp),
+	TP_ARGS(tb_id, flp, nh, err),
 
 	TP_STRUCT__entry(
 		__field(	u32,	tb_id		)
+		__field(	int,	err		)
 		__field(	int,	oif		)
 		__field(	int,	iif		)
 		__field(	__u8,	tos		)
@@ -25,12 +27,19 @@ TRACE_EVENT(fib_table_lookup,
 		__field(	__u8,	flags		)
 		__array(	__u8,	src,	4	)
 		__array(	__u8,	dst,	4	)
+		__array(	__u8,	gw,	4	)
+		__array(	__u8,	saddr,	4	)
+		__field(	u16,	sport		)
+		__field(	u16,	dport		)
+		__field(	u8,	proto		)
+		__dynamic_array(char,  name,   IFNAMSIZ )
 	),
 
 	TP_fast_assign(
 		__be32 *p32;
 
 		__entry->tb_id = tb_id;
+		__entry->err = err;
 		__entry->oif = flp->flowi4_oif;
 		__entry->iif = flp->flowi4_iif;
 		__entry->tos = flp->flowi4_tos;
@@ -42,36 +51,41 @@ TRACE_EVENT(fib_table_lookup,
 
 		p32 = (__be32 *) __entry->dst;
 		*p32 = flp->daddr;
-	),
-
-	TP_printk("table %u 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;
+		__entry->proto = flp->flowi4_proto;
+		if (__entry->proto == IPPROTO_TCP ||
+		    __entry->proto == IPPROTO_UDP) {
+			__entry->sport = ntohs(flp->fl4_sport);
+			__entry->dport = ntohs(flp->fl4_dport);
+		} else {
+			__entry->sport = 0;
+			__entry->dport = 0;
+		}
+
+		if (nh) {
+			p32 = (__be32 *) __entry->saddr;
+			*p32 = nh->nh_saddr;
+
+			p32 = (__be32 *) __entry->gw;
+			*p32 = nh->nh_gw;
+
+			__assign_str(name, nh->nh_dev ? nh->nh_dev->name : "-");
+		} else {
+			p32 = (__be32 *) __entry->saddr;
+			*p32 = 0;
+
+			p32 = (__be32 *) __entry->gw;
+			*p32 = 0;
+
+			__assign_str(name, "-");
+		}
 	),
 
-	TP_printk("nexthop dev %s oif %d src %pI4",
-		  __get_str(name), __entry->oif, __entry->src)
+	TP_printk("table %u oif %d iif %d proto %u %pI4/%u -> %pI4/%u tos %d scope %d flags %x ==> dev %s gw %pI4 src %pI4 err %d",
+		  __entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
+		  __entry->src, __entry->sport, __entry->dst, __entry->dport,
+		  __entry->tos, __entry->scope, __entry->flags,
+		  __get_str(name), __entry->gw, __entry->saddr, __entry->err)
 );
 
 TRACE_EVENT(fib_validate_source,
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 3dcffd3ce98c..65c340f230ae 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1326,14 +1326,14 @@ 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;
 
 	n = get_child_rcu(pn, cindex);
-	if (!n)
+	if (!n) {
+		trace_fib_table_lookup(tb->tb_id, flp, NULL, -EAGAIN);
 		return -EAGAIN;
+	}
 
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 	this_cpu_inc(stats->gets);
@@ -1416,8 +1416,11 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 				 * nothing for us to do as we do not have any
 				 * further nodes to parse.
 				 */
-				if (IS_TRIE(pn))
+				if (IS_TRIE(pn)) {
+					trace_fib_table_lookup(tb->tb_id, flp,
+							       NULL, -EAGAIN);
 					return -EAGAIN;
+				}
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 				this_cpu_inc(stats->backtrack);
 #endif
@@ -1459,6 +1462,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 			this_cpu_inc(stats->semantic_match_passed);
 #endif
+			trace_fib_table_lookup(tb->tb_id, flp, NULL, err);
 			return err;
 		}
 		if (fi->fib_flags & RTNH_F_DEAD)
@@ -1494,7 +1498,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 			this_cpu_inc(stats->semantic_match_passed);
 #endif
-			trace_fib_table_lookup_nh(nh);
+			trace_fib_table_lookup(tb->tb_id, flp, nh, err);
 
 			return err;
 		}
-- 
2.11.0