Re: [PATCH net-next] net: IPv6 fib lookup tracepoint

[David Miller]

From: David Ahern 
Date: Thu, 19 Nov 2015 12:24:22 -0800

> Add tracepoint to show fib6 table lookups and result.
> 
> Signed-off-by: David Ahern 

Applied, thanks.
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[PATCH net-next] net: IPv6 fib lookup tracepoint

[David Ahern]

Add tracepoint to show fib6 table lookups and result.

Signed-off-by: David Ahern 
---
 include/trace/events/fib6.h | 76 +
 net/core/net-traces.c   |  4 +++
 net/ipv6/route.c| 10 ++
 3 files changed, 90 insertions(+)
 create mode 100644 include/trace/events/fib6.h

diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h
new file mode 100644
index ..4cf6bac4686d
--- /dev/null
+++ b/include/trace/events/fib6.h
@@ -0,0 +1,76 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fib6
+
+#if !defined(_TRACE_FIB6_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FIB6_H
+
+#include 
+#include 
+#include 
+#include 
+
+TRACE_EVENT(fib6_table_lookup,
+
+   TP_PROTO(const struct net *net, const struct rt6_info *rt,
+u32 tb_id, const struct flowi6 *flp),
+
+   TP_ARGS(net, rt, tb_id, flp),
+
+   TP_STRUCT__entry(
+   __field(u32,tb_id   )
+
+   __field(int,oif )
+   __field(int,iif )
+   __field(__u8,   tos )
+   __field(__u8,   scope   )
+   __field(__u8,   flags   )
+   __array(__u8,   src,16  )
+   __array(__u8,   dst,16  )
+
+   __dynamic_array(char,   name,   IFNAMSIZ )
+   __array(__u8,   gw, 16   )
+   ),
+
+   TP_fast_assign(
+   struct in6_addr *in6;
+
+   __entry->tb_id = tb_id;
+   __entry->oif = flp->flowi6_oif;
+   __entry->iif = flp->flowi6_iif;
+   __entry->tos = flp->flowi6_tos;
+   __entry->scope = flp->flowi6_scope;
+   __entry->flags = flp->flowi6_flags;
+
+   in6 = (struct in6_addr *)__entry->src;
+   *in6 = flp->saddr;
+
+   in6 = (struct in6_addr *)__entry->dst;
+   *in6 = flp->daddr;
+
+   if (rt->rt6i_idev) {
+   __assign_str(name, rt->rt6i_idev->dev->name);
+   } else {
+   __assign_str(name, "");
+   }
+   if (rt == net->ipv6.ip6_null_entry) {
+   struct in6_addr in6_zero = {};
+
+   in6 = (struct in6_addr *)__entry->gw;
+   *in6 = in6_zero;
+
+   } else if (rt) {
+   in6 = (struct in6_addr *)__entry->gw;
+   *in6 = rt->rt6i_gateway;
+   }
+   ),
+
+   TP_printk("table %3u oif %d iif %d src %pI6c dst %pI6c tos %d scope %d 
flags %x ==> dev %s gw %pI6c",
+ __entry->tb_id, __entry->oif, __entry->iif,
+ __entry->src, __entry->dst, __entry->tos, __entry->scope,
+ __entry->flags, __get_str(name), __entry->gw)
+);
+
+#endif /* _TRACE_FIB6_H */
+
+/* This part must be outside protection */
+#include 
diff --git a/net/core/net-traces.c b/net/core/net-traces.c
index adef015b2f41..92da5e4ceb4f 100644
--- a/net/core/net-traces.c
+++ b/net/core/net-traces.c
@@ -32,6 +32,10 @@
 #include 
 #include 
 #include 
+#if IS_ENABLED(CONFIG_IPV6)
+#include 
+EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
+#endif
 
 EXPORT_TRACEPOINT_SYMBOL_GPL(kfree_skb);
 
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 6f01fe122abd..89758be9c6a6 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -62,6 +62,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 
@@ -865,6 +866,9 @@ static struct rt6_info *ip6_pol_route_lookup(struct net 
*net,
}
dst_use(>dst, jiffies);
read_unlock_bh(>tb6_lock);
+
+   trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
+
return rt;
 
 }
@@ -1078,6 +1082,8 @@ static struct rt6_info *ip6_pol_route(struct net *net, 
struct fib6_table *table,
read_unlock_bh(>tb6_lock);
 
rt6_dst_from_metrics_check(rt);
+
+   trace_fib6_table_lookup(net, rt, table->tb6_id, fl6);
return rt;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
!(rt->rt6i_flags & RTF_GATEWAY))) {
@@ -1101,6 +1107,8 @@ static struct rt6_info *ip6_pol_route(struct net *net, 
struct fib6_table *table,
uncached_rt = net->ipv6.ip6_null_entry;
 
dst_hold(_rt->dst);
+
+   trace_fib6_table_lookup(net, uncached_rt, table->tb6_id, fl6);
return uncached_rt;
 
} else {
@@ -1125,6 +1133,7 @@ static struct rt6_info *ip6_pol_route(struct net *net, 
struct fib6_table *table,
dst_release(>dst);
}
 
+   trace_fib6_table_lookup(net, pcpu_rt, table->tb6_id, fl6);
return pcpu_rt;
 
}
@@ -1474,6 +1483,7 @@