On Thu, 26 Jan 2023 18:01:14 +0100
Petr Machata <pe...@nvidia.com> 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 192.0.2.1/:: grp 239.1.1.1/::/00:00:00:00:00:00 vid 0
> dev v2 af 10 src 0.0.0.0/2001:db8:1::1 grp
> 0.0.0.0/ff0e::1/00:00:00:00:00:00 vid 0
> dev v2 af 2 src 192.0.2.1/:: grp 239.1.1.1/::/00:00:00:00:00:00 vid 10
> dev v2 af 10 src 0.0.0.0/2001:db8:1::1 grp
> 0.0.0.0/ff0e::1/00:00:00:00:00:00 vid 10
>
> CC: Steven Rostedt <rost...@goodmis.org>
> CC: linux-trace-ker...@vger.kernel.org
> Signed-off-by: Petr Machata <pe...@nvidia.com>
> Reviewed-by: Ido Schimmel <ido...@nvidia.com>
> ---
> include/trace/events/bridge.h | 67 +++++++++++++++++++++++++++++++++++
> net/core/net-traces.c | 1 +
> 2 files changed, 68 insertions(+)
>
> diff --git a/include/trace/events/bridge.h b/include/trace/events/bridge.h
> index 6b200059c2c5..00d5e2dcb3ad 100644
> --- a/include/trace/events/bridge.h
> +++ b/include/trace/events/bridge.h
> @@ -122,6 +122,73 @@ 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, src4, 4)
> + __array(__u8, src6, 16)
> + __array(__u8, grp4, 4)
> + __array(__u8, grp6, 16)
> + __array(__u8, grpmac, ETH_ALEN) /* For af == 0. */
Instead of wasting ring buffer space, why not just have:
__array(__u8, src, 16)
__array(__u8, grp, 16)
> + ),
> +
> + TP_fast_assign(
> + __assign_str(dev, dev->name);
> + __entry->vid = group->vid;
> +
> + if (!group->proto) {
> + __entry->af = 0;
> +
> + memset(__entry->src4, 0, sizeof(__entry->src4));
> + memset(__entry->src6, 0, sizeof(__entry->src6));
> + memset(__entry->grp4, 0, sizeof(__entry->grp4));
> + memset(__entry->grp6, 0, sizeof(__entry->grp6));
> + memcpy(__entry->grpmac, group->dst.mac_addr, ETH_ALEN);
> + } else if (group->proto == htons(ETH_P_IP)) {
> + __be32 *p32;
> +
> + __entry->af = AF_INET;
> +
> + p32 = (__be32 *) __entry->src4;
> + *p32 = group->src.ip4;
> +
> + p32 = (__be32 *) __entry->grp4;
> + *p32 = group->dst.ip4;
struct in6_addr *in6;
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->grp.ip4, in6);
> +
> + memset(__entry->src6, 0, sizeof(__entry->src6));
> + memset(__entry->grp6, 0, sizeof(__entry->grp6));
> + memset(__entry->grpmac, 0, ETH_ALEN);
> +#if IS_ENABLED(CONFIG_IPV6)
> + } else {
> + struct in6_addr *in6;
> +
> + __entry->af = AF_INET6;
> +
> + in6 = (struct in6_addr *)__entry->src6;
> + *in6 = group->src.ip6;
> +
> + in6 = (struct in6_addr *)__entry->grp6;
> + *in6 = group->dst.ip6;
> +
> + memset(__entry->src4, 0, sizeof(__entry->src4));
> + memset(__entry->grp4, 0, sizeof(__entry->grp4));
> + memset(__entry->grpmac, 0, ETH_ALEN);
> +#endif
> + }
> + ),
> +
> + TP_printk("dev %s af %u src %pI4/%pI6c grp %pI4/%pI6c/%pM vid %u",
> + __get_str(dev), __entry->af, __entry->src4, __entry->src6,
> + __entry->grp4, __entry->grp6, __entry->grpmac, __entry->vid)
And just have:
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)
As the %pI6c should detect that it's a ipv4 address and show that.
-- Steve
> +);
>
> #endif /* _TRACE_BRIDGE_H */
>
> diff --git a/net/core/net-traces.c b/net/core/net-traces.c
> index ee7006bbe49b..805b7385dd8d 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)
