netdev: support dumping a single netdev in qstats

Having to filter the right ifindex in the tests is a bit tedious.
Add support for dumping qstats for a single ifindex.

Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240420023543.3300306-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index 76352dbd2be4eb71ea192cb162dd00803005907b..679c4130707cd7bac5ef64084060a66aa594324b 100644 (file)
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -486,6 +486,7 @@ operations:
       dump:
         request:
           attributes:
+            - ifindex
             - scope
         reply:
           attributes:

diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index 8d8ace9ef87f6a0192d4daddad2f099cbb0d455e..8350a0afa9ec7bbf7ec88444cf48e8ff07165629 100644 (file)
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -70,6 +70,7 @@ static const struct nla_policy netdev_napi_get_dump_nl_policy[NETDEV_A_NAPI_IFIN
 
 /* NETDEV_CMD_QSTATS_GET - dump */
 static const struct nla_policy netdev_qstats_get_nl_policy[NETDEV_A_QSTATS_SCOPE + 1] = {
+       [NETDEV_A_QSTATS_IFINDEX] = NLA_POLICY_MIN(NLA_U32, 1),
        [NETDEV_A_QSTATS_SCOPE] = NLA_POLICY_MASK(NLA_UINT, 0x1),
 };
 

diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 7004b3399c2b0e045ace5222c6b1628c0cf81d87..dd6510f2c65259a9289d08cc7193ee4511fd84f9 100644 (file)
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -639,6 +639,24 @@ nla_put_failure:
        return -EMSGSIZE;
 }
 
+static int
+netdev_nl_qstats_get_dump_one(struct net_device *netdev, unsigned int scope,
+                             struct sk_buff *skb, const struct genl_info *info,
+                             struct netdev_nl_dump_ctx *ctx)
+{
+       if (!netdev->stat_ops)
+               return 0;
+
+       switch (scope) {
+       case 0:
+               return netdev_nl_stats_by_netdev(netdev, skb, info);
+       case NETDEV_QSTATS_SCOPE_QUEUE:
+               return netdev_nl_stats_by_queue(netdev, skb, info, ctx);
+       }
+
+       return -EINVAL; /* Should not happen, per netlink policy */
+}
+
 int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
                                struct netlink_callback *cb)
 {
@@ -646,6 +664,7 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
        const struct genl_info *info = genl_info_dump(cb);
        struct net *net = sock_net(skb->sk);
        struct net_device *netdev;
+       unsigned int ifindex;
        unsigned int scope;
        int err = 0;
 
@@ -653,21 +672,28 @@ int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
        if (info->attrs[NETDEV_A_QSTATS_SCOPE])
                scope = nla_get_uint(info->attrs[NETDEV_A_QSTATS_SCOPE]);
 
-       rtnl_lock();
-       for_each_netdev_dump(net, netdev, ctx->ifindex) {
-               if (!netdev->stat_ops)
-                       continue;
+       ifindex = 0;
+       if (info->attrs[NETDEV_A_QSTATS_IFINDEX])
+               ifindex = nla_get_u32(info->attrs[NETDEV_A_QSTATS_IFINDEX]);
 
-               switch (scope) {
-               case 0:
-                       err = netdev_nl_stats_by_netdev(netdev, skb, info);
-                       break;
-               case NETDEV_QSTATS_SCOPE_QUEUE:
-                       err = netdev_nl_stats_by_queue(netdev, skb, info, ctx);
-                       break;
+       rtnl_lock();
+       if (ifindex) {
+               netdev = __dev_get_by_index(net, ifindex);
+               if (netdev && netdev->stat_ops) {
+                       err = netdev_nl_qstats_get_dump_one(netdev, scope, skb,
+                                                           info, ctx);
+               } else {
+                       NL_SET_BAD_ATTR(info->extack,
+                                       info->attrs[NETDEV_A_QSTATS_IFINDEX]);
+                       err = netdev ? -EOPNOTSUPP : -ENODEV;
+               }
+       } else {
+               for_each_netdev_dump(net, netdev, ctx->ifindex) {
+                       err = netdev_nl_qstats_get_dump_one(netdev, scope, skb,
+                                                           info, ctx);
+                       if (err < 0)
+                               break;
                }
-               if (err < 0)
-                       break;
        }
        rtnl_unlock();