ip: Support bridge VLAN stats in `ip stats'

ip stats displays bridge-related multicast and STP stats, but not VLAN stats. There is code for requesting, decoding and formatting these stats accessible through bridge -s vlan', but the ip stats' suite lacks it. In this patchset, extract the bridge vlan' code to a generally accessible place and extend ip stats' to use it.

This reuses the existing display and JSON format, and plugs it into the existing `ip stats' hierarchy:

 # ip stats show dev v2 group xstats_slave subgroup bridge suite vlan
 2: v2: group xstats_slave subgroup bridge suite vlan
                   10
                     RX: 3376 bytes 50 packets
                     TX: 2824 bytes 44 packets

20
RX: 684 bytes 7 packets
TX: 0 bytes 0 packets

 # ip -j -p stats show dev v2 group xstats_slave subgroup bridge suite vlan
 [ {
         "ifindex": 2,
         "ifname": "v2",
         "group": "xstats_slave",
         "subgroup": "bridge",
         "suite": "vlan",
         "vlans": [ {
                 "vid": 10,
                 "rx_bytes": 3376,
                 "rx_packets": 50,
                 "tx_bytes": 2824,
                 "tx_packets": 44
             },{
                 "vid": 20,
                 "rx_bytes": 684,
                 "rx_packets": 7,
                 "tx_bytes": 0,
                 "tx_packets": 0
             } ]
     } ]

Similarly for the master stats:

 # ip stats show dev br1 group xstats subgroup bridge suite vlan
 211: br1: group xstats subgroup bridge suite vlan
                   10
                     RX: 3376 bytes 50 packets
                     TX: 2824 bytes 44 packets

20
RX: 684 bytes 7 packets
TX: 0 bytes 0 packets

 # ip -j -p stats show dev br1 group xstats subgroup bridge suite vlan
 [ {
         "ifindex": 211,
         "ifname": "br1",
         "group": "xstats",
         "subgroup": "bridge",
         "suite": "vlan",
         "vlans": [ {
                 "vid": 10,
                 "flags": [ ],
                 "rx_bytes": 3376,
                 "rx_packets": 50,
                 "tx_bytes": 2824,
                 "tx_packets": 44
             },{
                 "vid": 20,
                 "flags": [ ],
                 "rx_bytes": 684,
                 "rx_packets": 7,
                 "tx_bytes": 0,
                 "tx_packets": 0
             } ]
     } ]

v2:
- Patch #1:
- Use rtattr_for_each_nested
- Drop #include <alloca.h>, it's not used anymore
- Patch #3:
- Add MAINTAINERS entry for the module
- Patch #4:
- Add the master stats as well.

Petr Machata (4):
ip: ipstats: Iterate all xstats attributes
ip: ip_common: Drop ipstats_stat_desc_xstats::inner_max
lib: bridge: Add a module for bridge-related helpers
ip: iplink_bridge: Support bridge VLAN stats in `ip stats'

 MAINTAINERS        |  2 ++
 bridge/vlan.c      | 50 +++++---------------------------------------
 include/bridge.h   | 11 ++++++++++
 ip/ip_common.h     |  1 -
 ip/iplink_bond.c   |  2 --
 ip/iplink_bridge.c | 52 ++++++++++++++++++++++++++++++++++++++++++----
 ip/ipstats.c       | 17 +++++++--------
 lib/Makefile       |  3 ++-
 lib/bridge.c       | 47 +++++++++++++++++++++++++++++++++++++++++
 9 files changed, 122 insertions(+), 63 deletions(-)
 create mode 100644 include/bridge.h
 create mode 100644 lib/bridge.c

2.49.0

ipstats_stat_desc_show_xstats() operates by first parsing the attribute stream into a type-indexed table, and then accessing the right attribute. But bridge VLAN stats are given as several BRIDGE_XSTATS_VLAN attributes, one per VLAN. With the above approach to parsing, only one of these attributes would be shown. Instead, iterate the stream of attributes and call the show_cb for each one with a matching type.

---

Notes:
v2:
- Use rtattr_for_each_nested
- Drop #include <alloca.h>, it's not used anymore

 ip/ipstats.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

index cb9d9cbb..f0f8dcdc 100644
@@ -1,5 +1,4 @@
 // SPDX-License-Identifier: GPL-2.0+
-#include <alloca.h>
 #include <assert.h>
 #include <errno.h>
 #include <stdio.h>

@@ -590,7 +589,7 @@ int ipstats_stat_desc_show_xstats(struct ipstats_stat_show_attrs *attrs,
 {
 	struct ipstats_stat_desc_xstats *xdesc;
 	const struct rtattr *at;
-	struct rtattr **tb;
+	const struct rtattr *i;
 	int err;
 
 	xdesc = container_of(desc, struct ipstats_stat_desc_xstats, desc);

@@ -600,15 +599,13 @@ int ipstats_stat_desc_show_xstats(struct ipstats_stat_show_attrs *attrs,
 	if (at == NULL)
 		return err;
 
-	tb = alloca(sizeof(*tb) * (xdesc->inner_max + 1));
-	err = parse_rtattr_nested(tb, xdesc->inner_max, at);
-	if (err != 0)
-		return err;
-
-	if (tb[xdesc->inner_at] != NULL) {
-		print_nl();
-		xdesc->show_cb(tb[xdesc->inner_at]);
+	rtattr_for_each_nested(i, at) {
+		if (i->rta_type == xdesc->inner_at) {
+			print_nl();
+			xdesc->show_cb(i);
+		}
 	}
+
 	return 0;
 }
 

2.49.0

After the previous patch, this field is not read anymore. Drop it.

---
 ip/ip_common.h     | 1 -
 ip/iplink_bond.c   | 2 --
 ip/iplink_bridge.c | 4 ----
 3 files changed, 7 deletions(-)

index 37de09d4..3f55ea33 100644
@@ -195,7 +195,6 @@ struct ipstats_stat_desc_xstats {
 	const struct ipstats_stat_desc desc;
 	int xstats_at;
 	int link_type_at;
-	int inner_max;
 	int inner_at;
 	void (*show_cb)(const struct rtattr *at);
 };

index 19af67d0..a964f547 100644
@@ -940,7 +940,6 @@ ipstats_stat_desc_xstats_bond_lacp = {
 	.desc = IPSTATS_STAT_DESC_XSTATS_LEAF("802.3ad"),
 	.xstats_at = IFLA_STATS_LINK_XSTATS,
 	.link_type_at = LINK_XSTATS_TYPE_BOND,
-	.inner_max = BOND_XSTATS_MAX,
 	.inner_at = BOND_XSTATS_3AD,
 	.show_cb = &bond_print_3ad_stats,
 };

@@ -962,7 +961,6 @@ ipstats_stat_desc_xstats_slave_bond_lacp = {
 	.desc = IPSTATS_STAT_DESC_XSTATS_LEAF("802.3ad"),
 	.xstats_at = IFLA_STATS_LINK_XSTATS_SLAVE,
 	.link_type_at = LINK_XSTATS_TYPE_BOND,
-	.inner_max = BOND_XSTATS_MAX,
 	.inner_at = BOND_XSTATS_3AD,
 	.show_cb = &bond_print_3ad_stats,
 };

index d98bfa5a..3d54e203 100644
@@ -1075,7 +1075,6 @@ ipstats_stat_desc_xstats_bridge_stp = {
 	.desc = IPSTATS_STAT_DESC_XSTATS_LEAF("stp"),
 	.xstats_at = IFLA_STATS_LINK_XSTATS,
 	.link_type_at = LINK_XSTATS_TYPE_BRIDGE,
-	.inner_max = BRIDGE_XSTATS_MAX,
 	.inner_at = BRIDGE_XSTATS_STP,
 	.show_cb = &bridge_print_stats_stp,
 };

@@ -1085,7 +1084,6 @@ ipstats_stat_desc_xstats_bridge_mcast = {
 	.desc = IPSTATS_STAT_DESC_XSTATS_LEAF("mcast"),
 	.xstats_at = IFLA_STATS_LINK_XSTATS,
 	.link_type_at = LINK_XSTATS_TYPE_BRIDGE,
-	.inner_max = BRIDGE_XSTATS_MAX,
 	.inner_at = BRIDGE_XSTATS_MCAST,
 	.show_cb = &bridge_print_stats_mcast,
 };

@@ -1108,7 +1106,6 @@ ipstats_stat_desc_xstats_slave_bridge_stp = {
 	.desc = IPSTATS_STAT_DESC_XSTATS_LEAF("stp"),
 	.xstats_at = IFLA_STATS_LINK_XSTATS_SLAVE,
 	.link_type_at = LINK_XSTATS_TYPE_BRIDGE,
-	.inner_max = BRIDGE_XSTATS_MAX,
 	.inner_at = BRIDGE_XSTATS_STP,
 	.show_cb = &bridge_print_stats_stp,
 };

@@ -1118,7 +1115,6 @@ ipstats_stat_desc_xstats_slave_bridge_mcast = {
 	.desc = IPSTATS_STAT_DESC_XSTATS_LEAF("mcast"),
 	.xstats_at = IFLA_STATS_LINK_XSTATS_SLAVE,
 	.link_type_at = LINK_XSTATS_TYPE_BRIDGE,
-	.inner_max = BRIDGE_XSTATS_MAX,
 	.inner_at = BRIDGE_XSTATS_MCAST,
 	.show_cb = &bridge_print_stats_mcast,
 };

2.49.0

ip stats' displays a range of bridge_slave-related statistics, but not the VLAN stats. bridge vlan' actually has code to show these. Extract the code to libutil so that it can be reused between the bridge and ip stats tools.

Rename them reasonably so as not to litter the global namespace.

---

Notes:
v2:
- Add MAINTAINERS entry for the module

 MAINTAINERS      |  2 ++
 bridge/vlan.c    | 50 +++++-------------------------------------------
 include/bridge.h | 11 +++++++++++
 lib/Makefile     |  3 ++-
 lib/bridge.c     | 47 +++++++++++++++++++++++++++++++++++++++++++++
 5 files changed, 67 insertions(+), 46 deletions(-)
 create mode 100644 include/bridge.h
 create mode 100644 lib/bridge.c

index c9ea3ea5..82043c1b 100644
@@ -31,6 +31,8 @@ M: Nikolay Aleksandrov <[email protected]>
 L: [email protected] (moderated for non-subscribers)
 F: bridge/*
 F: ip/iplink_bridge*
+F: lib/bridge*
+F: include/bridge*
 
 Data Center Bridging - dcb
 M: Petr Machata <[email protected]>

new file mode 100644
index 00000000..8bcd1e38
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __BRIDGE_H__
+#define __BRIDGE_H__ 1
+
+#include <linux/if_bridge.h>
+
+void bridge_print_vlan_flags(__u16 flags);
+void bridge_print_vlan_stats_only(const struct bridge_vlan_xstats *vstats);
+void bridge_print_vlan_stats(const struct bridge_vlan_xstats *vstats);
+
+#endif /* __BRIDGE_H__ */

index aa7bbd2e..0ba62942 100644
@@ -5,7 +5,8 @@ CFLAGS += -fPIC
 
 UTILOBJ = utils.o utils_math.o rt_names.o ll_map.o ll_types.o ll_proto.o ll_addr.o \
 	inet_proto.o namespace.o json_writer.o json_print.o json_print_math.o \
-	names.o color.o bpf_legacy.o bpf_glue.o exec.o fs.o cg_map.o ppp_proto.o
+	names.o color.o bpf_legacy.o bpf_glue.o exec.o fs.o cg_map.o \
+	ppp_proto.o bridge.o
 
 ifeq ($(HAVE_ELF),y)
 ifeq ($(HAVE_LIBBPF),y)

2.49.0

Add support for displaying bridge VLAN statistics in ip stats'. Reuse the existing bridge vlan' display and JSON format:

 # ip stats show dev v2 group xstats_slave subgroup bridge suite vlan
 2: v2: group xstats_slave subgroup bridge suite vlan
                   10
                     RX: 3376 bytes 50 packets
                     TX: 2824 bytes 44 packets

20
RX: 684 bytes 7 packets
TX: 0 bytes 0 packets

 # ip -j -p stats show dev v2 group xstats_slave subgroup bridge suite vlan
 [ {
         "ifindex": 2,
         "ifname": "v2",
         "group": "xstats_slave",
         "subgroup": "bridge",
         "suite": "vlan",
         "vlans": [ {
                 "vid": 10,
                 "rx_bytes": 3376,
                 "rx_packets": 50,
                 "tx_bytes": 2824,
                 "tx_packets": 44
             },{
                 "vid": 20,
                 "rx_bytes": 684,
                 "rx_packets": 7,
                 "tx_bytes": 0,
                 "tx_packets": 0
             } ]
     } ]

Similarly for the master stats:

 # ip stats show dev br1 group xstats subgroup bridge suite vlan
 211: br1: group xstats subgroup bridge suite vlan
                   10
                     RX: 3376 bytes 50 packets
                     TX: 2824 bytes 44 packets

20
RX: 684 bytes 7 packets
TX: 0 bytes 0 packets

 # ip -j -p stats show dev br1 group xstats subgroup bridge suite vlan
 [ {
         "ifindex": 211,
         "ifname": "br1",
         "group": "xstats",
         "subgroup": "bridge",
         "suite": "vlan",
         "vlans": [ {
                 "vid": 10,
                 "flags": [ ],
                 "rx_bytes": 3376,
                 "rx_packets": 50,
                 "tx_bytes": 2824,
                 "tx_packets": 44
             },{
                 "vid": 20,
                 "flags": [ ],
                 "rx_bytes": 684,
                 "rx_packets": 7,
                 "tx_bytes": 0,
                 "tx_packets": 0
             } ]
     } ]

---

Notes:
v2:
- Add the master stats as well.

 ip/iplink_bridge.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 48 insertions(+)

index 3d54e203..4a74ef3f 100644
@@ -14,6 +14,7 @@
 #include <linux/if_bridge.h>
 #include <net/if.h>
 
+#include "bridge.h"
 #include "rt_names.h"
 #include "utils.h"
 #include "ip_common.h"

@@ -978,6 +979,26 @@ static void bridge_print_stats_stp(const struct rtattr *attr)
 	close_json_object();
 }
 
+static void bridge_print_stats_vlan(const struct rtattr *attr)
+{
+	const struct bridge_vlan_xstats *vstats = RTA_DATA(attr);
+
+	print_string(PRINT_FP, NULL, "%-" textify(IFNAMSIZ) "s  ", "");
+	bridge_print_vlan_stats(vstats);
+}
+
+static int bridge_stat_desc_show_xstats(struct ipstats_stat_show_attrs *attrs,
+					const struct ipstats_stat_desc *desc)
+{
+	int ret;
+
+	open_json_array(PRINT_JSON, "vlans");
+	ret = ipstats_stat_desc_show_xstats(attrs, desc);
+	close_json_array(PRINT_JSON, "vlans");
+
+	return ret;
+}
+
 static void bridge_print_stats_attr(struct rtattr *attr, int ifindex)
 {
 	struct rtattr *brtb[LINK_XSTATS_TYPE_MAX+1];

@@ -1088,8 +1109,25 @@ ipstats_stat_desc_xstats_bridge_mcast = {
 	.show_cb = &bridge_print_stats_mcast,
 };
 
+#define IPSTATS_STAT_DESC_BRIDGE_VLAN {			\
+		.name = "vlan",				\
+		.kind = IPSTATS_STAT_DESC_KIND_LEAF,	\
+		.show = &bridge_stat_desc_show_xstats,	\
+		.pack = &ipstats_stat_desc_pack_xstats,	\
+	}
+
+static const struct ipstats_stat_desc_xstats
+ipstats_stat_desc_xstats_bridge_vlan = {
+	.desc = IPSTATS_STAT_DESC_BRIDGE_VLAN,
+	.xstats_at = IFLA_STATS_LINK_XSTATS,
+	.link_type_at = LINK_XSTATS_TYPE_BRIDGE,
+	.inner_at = BRIDGE_XSTATS_VLAN,
+	.show_cb = &bridge_print_stats_vlan,
+};
+
 static const struct ipstats_stat_desc *
 ipstats_stat_desc_xstats_bridge_subs[] = {
+	&ipstats_stat_desc_xstats_bridge_vlan.desc,
 	&ipstats_stat_desc_xstats_bridge_stp.desc,
 	&ipstats_stat_desc_xstats_bridge_mcast.desc,
 };

@@ -1119,10 +1157,20 @@ ipstats_stat_desc_xstats_slave_bridge_mcast = {
 	.show_cb = &bridge_print_stats_mcast,
 };
 
+static const struct ipstats_stat_desc_xstats
+ipstats_stat_desc_xstats_slave_bridge_vlan = {
+	.desc = IPSTATS_STAT_DESC_BRIDGE_VLAN,
+	.xstats_at = IFLA_STATS_LINK_XSTATS_SLAVE,
+	.link_type_at = LINK_XSTATS_TYPE_BRIDGE,
+	.inner_at = BRIDGE_XSTATS_VLAN,
+	.show_cb = &bridge_print_stats_vlan,
+};
+
 static const struct ipstats_stat_desc *
 ipstats_stat_desc_xstats_slave_bridge_subs[] = {
 	&ipstats_stat_desc_xstats_slave_bridge_stp.desc,
 	&ipstats_stat_desc_xstats_slave_bridge_mcast.desc,
+	&ipstats_stat_desc_xstats_slave_bridge_vlan.desc,
 };
 
 const struct ipstats_stat_desc ipstats_stat_desc_xstats_slave_bridge_group = {

2.49.0

Code LGTM, but I just realized that the new vlan suite needs to be added to the ip-stats man page

D'oh! v3 here we go.