[PATCH] hostapd: fix opclass during CSA with DFS channels

[marek at mazekey.pl]

We can easy reproduce it when switch to non DFS channel, then to DFS 
channel with different opclass, country code US.

Examples:
a)
- CSA to channel 36
- DFS CSA to channel 100
Could not convert op_class 115 channel 100 to operating frequency
b)
- CSA to channel 157
- DFS CSA to channel 56
Could not convert op_class 124 channel 56 to operating frequency

You can reproduce it with hwsim with small modification:

 From 5edc4a0a21ca677fc142857a349ba2a94b57ca2a Mon Sep 17 00:00:00 2001
 From: Marek Kwaczynski <marek at mazekey.pl>
Date: Sat, 27 Apr 2024 00:01:06 +0200
Subject: [PATCH] tests: hwsim: check CSA between non DFS and DFS chan

Add test to validate CSA between non DFS channel
and DFS channel with different operating class.

Signed-off-by: Marek Kwaczynski <marek at mazekey.pl>
---
  tests/hwsim/test_dfs.py | 35 ++++++++++++++++++++++++++++++++++-
  1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/tests/hwsim/test_dfs.py b/tests/hwsim/test_dfs.py
index d0bae5a66..3be64b147 100644
--- a/tests/hwsim/test_dfs.py
+++ b/tests/hwsim/test_dfs.py
@@ -640,7 +640,7 @@ def test_dfs_chan_switch(dev, apdev):
          if freq != "5260":
              raise Exception("Unexpected frequency")

-        dev[0].connect("dfs", key_mgmt="NONE", scan_freq="5260 5280")
+        dev[0].connect("dfs", key_mgmt="NONE", scan_freq="5260 5280 
5180 5500")
          dev[0].wait_regdom(country_ie=True)
          hwsim_utils.test_connectivity(dev[0], hapd)

@@ -666,6 +666,39 @@ def test_dfs_chan_switch(dev, apdev):

          dev[0].wait_connected(timeout=30)
          hwsim_utils.test_connectivity(dev[0], hapd)
+
+        # Move to non DFS channel: 36, opclass 115
+        if "OK" not in hapd.request("CHAN_SWITCH 5 5180"):
+                raise Exception("CHAN_SWITCH failed")
+        ev = wait_dfs_event(hapd, "AP-CSA-FINISHED", 5)
+
+        if "freq=5180" not in ev:
+            raise Exception("Unexpected channel: " + ev)
+        hwsim_utils.test_connectivity(dev[0], hapd)
+
+        # Move to channel 100, opclass 121
+        if "OK" not in hapd.request("CHAN_SWITCH 5 5500 ht"):
+            raise Exception("CHAN_SWITCH failed")
+        # This results in BSS going down before restart, so the STA is 
expected
+        # to report disconnection.
+        dev[0].wait_disconnected()
+        ev = wait_dfs_event(hapd, "DFS-CAC-START", 5)
+        if "freq=5500" not in ev:
+            raise Exception("Unexpected channel: " + ev)
+        ev = wait_dfs_event(hapd, "DFS-CAC-COMPLETED", 70)
+        if "success=1" not in ev:
+            raise Exception("CAC failed")
+        if "freq=5500" not in ev:
+            raise Exception("Unexpected DFS freq result")
+        ev = hapd.wait_event(["AP-ENABLED"], timeout=5)
+        if not ev:
+            raise Exception("AP setup timed out")
+        freq = hapd.get_status_field("freq")
+        if freq != "5500":
+            raise Exception("Unexpected frequency")
+
+        dev[0].wait_connected(timeout=30)
+        hwsim_utils.test_connectivity(dev[0], hapd)
      finally:
          clear_regdom(hapd, dev)

-- 
2.34.1