[PATCH iproute2-next v3 1/4] ip: ipstats: Iterate all xstats attributes

[Petr Machata <petrm@nvidia.com>]

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.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
---

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(-)

diff --git a/ip/ipstats.c b/ip/ipstats.c
index cb9d9cbb..f0f8dcdc 100644
--- a/ip/ipstats.c
+++ b/ip/ipstats.c
@@ -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