diff mbox series

[net-next,v3,06/16] net: bridge: Add a tracepoint for MDB overflows

Message ID a01c188bcbbb0f5f53e333ed9175f938eb2736be.1675359453.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit d47230a3480a5f6df98c5870ba26843850a600d5
Delegated to: Netdev Maintainers
Headers show
Series bridge: Limit number of MDB entries per port, port-vlan | expand

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Context Check Description
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count fail Series longer than 15 patches (and no cover letter)
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 2 this patch: 2
netdev/cc_maintainers warning 2 maintainers not CCed: peilin.ye@bytedance.com mhiramat@kernel.org
netdev/build_clang success Errors and warnings before: 1 this patch: 1
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 2 this patch: 2
netdev/checkpatch warning CHECK: Alignment should match open parenthesis CHECK: Lines should not end with a '('
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Petr Machata Feb. 2, 2023, 5:59 p.m. UTC
The following patch will add two more maximum MDB allowances to the global
one, mcast_hash_max, that exists today. In all these cases, attempts to add
MDB entries above the configured maximums through netlink, fail noisily and
obviously. Such visibility is missing when adding entries through the
control plane traffic, by IGMP or MLD packets.

To improve visibility in those cases, add a trace point that reports the
violation, including the relevant netdevice (be it a slave or the bridge
itself), and the MDB entry parameters:

	# perf record -e bridge:br_mdb_full &
	# [...]
	# perf script | cut -d: -f4-
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 0
	 dev v2 af 10 src :: grp ff0e::112/00:00:00:00:00:00 vid 0
	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 10
	 dev v2 af 10 src 2001:db8:1::1 grp ff0e::1/00:00:00:00:00:00 vid 10
	 dev v2 af 2 src ::ffff:192.0.2.1 grp ::ffff:239.1.1.1/00:00:00:00:00:00 vid 10

CC: Steven Rostedt <rostedt@goodmis.org>
CC: linux-trace-kernel@vger.kernel.org
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
---

Notes:
    v2:
    - Report IPv4 as an IPv6-mapped address through the IPv6 buffer
      as well, to save ring buffer space.

 include/trace/events/bridge.h | 58 +++++++++++++++++++++++++++++++++++
 net/core/net-traces.c         |  1 +
 2 files changed, 59 insertions(+)

Comments

Nikolay Aleksandrov Feb. 3, 2023, 8:58 a.m. UTC | #1
On 02/02/2023 19:59, Petr Machata wrote:
> The following patch will add two more maximum MDB allowances to the global
> one, mcast_hash_max, that exists today. In all these cases, attempts to add
> MDB entries above the configured maximums through netlink, fail noisily and
> obviously. Such visibility is missing when adding entries through the
> control plane traffic, by IGMP or MLD packets.
> 
> To improve visibility in those cases, add a trace point that reports the
> violation, including the relevant netdevice (be it a slave or the bridge
> itself), and the MDB entry parameters:
> 
> 	# perf record -e bridge:br_mdb_full &
> 	# [...]
> 	# perf script | cut -d: -f4-
> 	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 0
> 	 dev v2 af 10 src :: grp ff0e::112/00:00:00:00:00:00 vid 0
> 	 dev v2 af 2 src ::ffff:0.0.0.0 grp ::ffff:239.1.1.112/00:00:00:00:00:00 vid 10
> 	 dev v2 af 10 src 2001:db8:1::1 grp ff0e::1/00:00:00:00:00:00 vid 10
> 	 dev v2 af 2 src ::ffff:192.0.2.1 grp ::ffff:239.1.1.1/00:00:00:00:00:00 vid 10
> 
> CC: Steven Rostedt <rostedt@goodmis.org>
> CC: linux-trace-kernel@vger.kernel.org
> Signed-off-by: Petr Machata <petrm@nvidia.com>
> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
> ---
> 
> Notes:
>     v2:
>     - Report IPv4 as an IPv6-mapped address through the IPv6 buffer
>       as well, to save ring buffer space.
> 
>  include/trace/events/bridge.h | 58 +++++++++++++++++++++++++++++++++++
>  net/core/net-traces.c         |  1 +
>  2 files changed, 59 insertions(+)
> 

Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
diff mbox series

Patch

diff --git a/include/trace/events/bridge.h b/include/trace/events/bridge.h
index 6b200059c2c5..a6b3a4e409f0 100644
--- a/include/trace/events/bridge.h
+++ b/include/trace/events/bridge.h
@@ -122,6 +122,64 @@  TRACE_EVENT(br_fdb_update,
 		  __entry->flags)
 );
 
+TRACE_EVENT(br_mdb_full,
+
+	TP_PROTO(const struct net_device *dev,
+		 const struct br_ip *group),
+
+	TP_ARGS(dev, group),
+
+	TP_STRUCT__entry(
+		__string(dev, dev->name)
+		__field(int, af)
+		__field(u16, vid)
+		__array(__u8, src, 16)
+		__array(__u8, grp, 16)
+		__array(__u8, grpmac, ETH_ALEN) /* For af == 0. */
+	),
+
+	TP_fast_assign(
+		struct in6_addr *in6;
+
+		__assign_str(dev, dev->name);
+		__entry->vid = group->vid;
+
+		if (!group->proto) {
+			__entry->af = 0;
+
+			memset(__entry->src, 0, sizeof(__entry->src));
+			memset(__entry->grp, 0, sizeof(__entry->grp));
+			memcpy(__entry->grpmac, group->dst.mac_addr, ETH_ALEN);
+		} else if (group->proto == htons(ETH_P_IP)) {
+			__entry->af = AF_INET;
+
+			in6 = (struct in6_addr *)__entry->src;
+			ipv6_addr_set_v4mapped(group->src.ip4, in6);
+
+			in6 = (struct in6_addr *)__entry->grp;
+			ipv6_addr_set_v4mapped(group->dst.ip4, in6);
+
+			memset(__entry->grpmac, 0, ETH_ALEN);
+
+#if IS_ENABLED(CONFIG_IPV6)
+		} else {
+			__entry->af = AF_INET6;
+
+			in6 = (struct in6_addr *)__entry->src;
+			*in6 = group->src.ip6;
+
+			in6 = (struct in6_addr *)__entry->grp;
+			*in6 = group->dst.ip6;
+
+			memset(__entry->grpmac, 0, ETH_ALEN);
+#endif
+		}
+	),
+
+	TP_printk("dev %s af %u src %pI6c grp %pI6c/%pM vid %u",
+		  __get_str(dev), __entry->af, __entry->src, __entry->grp,
+		  __entry->grpmac, __entry->vid)
+);
 
 #endif /* _TRACE_BRIDGE_H */
 
diff --git a/net/core/net-traces.c b/net/core/net-traces.c
index c40cd8dd75c7..c6820ad2183f 100644
--- a/net/core/net-traces.c
+++ b/net/core/net-traces.c
@@ -41,6 +41,7 @@  EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_add);
 EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_external_learn_add);
 EXPORT_TRACEPOINT_SYMBOL_GPL(fdb_delete);
 EXPORT_TRACEPOINT_SYMBOL_GPL(br_fdb_update);
+EXPORT_TRACEPOINT_SYMBOL_GPL(br_mdb_full);
 #endif
 
 #if IS_ENABLED(CONFIG_PAGE_POOL)