Merge branch 'netdev-support-dumping-a-single-netdev-in-qstats'

Jakub Kicinski says:

====================
netdev: support dumping a single netdev in qstats

I was writing a test for page pool which depended on qstats,
and got tired of having to filter dumps in user space.
Add support for dumping stats for a single netdev.

To get there we first need to add full support for extack
in dumps (and fix a dump error handling bug in YNL, sent
separately to the net tree).
====================

Link: https://lore.kernel.org/r/20240420023543.3300306-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 59 insertions, 3 deletions

diff --git a/tools/testing/selftests/drivers/net/stats.py b/tools/testing/selftests/drivers/net/stats.py
index 947df3eb681f..7a7b16b180e2 100755
--- a/tools/testing/selftests/drivers/net/stats.py
+++ b/tools/testing/selftests/drivers/net/stats.py
@@ -1,8 +1,8 @@
 #!/usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0
 
-from lib.py import ksft_run, ksft_exit
-from lib.py import ksft_in, ksft_true, KsftSkipEx, KsftXfailEx
+from lib.py import ksft_run, ksft_exit, ksft_pr
+from lib.py import ksft_ge, ksft_eq, ksft_in, ksft_true, ksft_raises, KsftSkipEx, KsftXfailEx
 from lib.py import EthtoolFamily, NetdevFamily, RtnlFamily, NlError
 from lib.py import NetDrvEnv
 
@@ -77,9 +77,65 @@ def pkt_byte_sum(cfg) -> None:
             raise Exception("Qstats are lower, fetched later")
 
 
+def qstat_by_ifindex(cfg) -> None:
+    global netfam
+    global rtnl
+
+    # Construct a map ifindex -> [dump, by-index, dump]
+    ifindexes = {}
+    stats = netfam.qstats_get({}, dump=True)
+    for entry in stats:
+        ifindexes[entry['ifindex']] = [entry, None, None]
+
+    for ifindex in ifindexes.keys():
+        entry = netfam.qstats_get({"ifindex": ifindex}, dump=True)
+        ksft_eq(len(entry), 1)
+        ifindexes[entry[0]['ifindex']][1] = entry[0]
+
+    stats = netfam.qstats_get({}, dump=True)
+    for entry in stats:
+        ifindexes[entry['ifindex']][2] = entry
+
+    if len(ifindexes) == 0:
+        raise KsftSkipEx("No ifindex supports qstats")
+
+    # Now make sure the stats match/make sense
+    for ifindex, triple in ifindexes.items():
+        all_keys = triple[0].keys() | triple[1].keys() | triple[2].keys()
+
+        for key in all_keys:
+            ksft_ge(triple[1][key], triple[0][key], comment="bad key: " + key)
+            ksft_ge(triple[2][key], triple[1][key], comment="bad key: " + key)
+
+    # Test invalid dumps
+    # 0 is invalid
+    with ksft_raises(NlError) as cm:
+        netfam.qstats_get({"ifindex": 0}, dump=True)
+    ksft_eq(cm.exception.nl_msg.error, -34)
+    ksft_eq(cm.exception.nl_msg.extack['bad-attr'], '.ifindex')
+
+    # loopback has no stats
+    with ksft_raises(NlError) as cm:
+        netfam.qstats_get({"ifindex": 1}, dump=True)
+    ksft_eq(cm.exception.nl_msg.error, -95)
+    ksft_eq(cm.exception.nl_msg.extack['bad-attr'], '.ifindex')
+
+    # Try to get stats for lowest unused ifindex but not 0
+    devs = rtnl.getlink({}, dump=True)
+    all_ifindexes = set([dev["ifi-index"] for dev in devs])
+    lowest = 2
+    while lowest in all_ifindexes:
+        lowest += 1
+
+    with ksft_raises(NlError) as cm:
+        netfam.qstats_get({"ifindex": lowest}, dump=True)
+    ksft_eq(cm.exception.nl_msg.error, -19)
+    ksft_eq(cm.exception.nl_msg.extack['bad-attr'], '.ifindex')
+
+
 def main() -> None:
     with NetDrvEnv(__file__) as cfg:
-        ksft_run([check_pause, check_fec, pkt_byte_sum],
+        ksft_run([check_pause, check_fec, pkt_byte_sum, qstat_by_ifindex],
                  args=(cfg, ))
     ksft_exit()