Add wifi tests

board/common/qemu/Config.in.in

@@ -253,3 +253,19 @@ config QEMU_NET_PORTS
 	int "Number of Rocker switch ports"
 	depends on QEMU_NET_ROCKER
 	default 10
+
+comment "Wireless"
+
+config QEMU_WIFI_RADIOS
+	int "Number of virtual WiFi radios (mac80211_hwsim)"
+	default 0
+	help
+	  Number of simulated 802.11 radios to create with mac80211_hwsim.
+	  The count is passed to the guest via the opt/wifi fw_cfg and loaded
+	  by the 00-hwsim boot script.
+
+	  0 (default) means no radios, so nothing wireless clutters the guest.
+	  Set a small number (e.g. 2) for local AP/station experiments.
+
+	  Note: 'make run' is a single guest with no inter-guest wireless
+	  medium, so these radios only reach each other within this one guest.

board/common/qemu/run.sh

@@ -310,6 +310,16 @@ EOF
     echo -n "-fw_cfg name=opt/vpd,file=$vpd_file"
 }
 
+wifi_args()
+{
+    # Number of mac80211_hwsim radios for the guest, read at boot by 00-hwsim
+    # (fw_cfg opt/wifi).  Default 0 -> no radios, no wifi clutter.
+    radios=${CONFIG_QEMU_WIFI_RADIOS:-0}
+    wifi="${qdir}/wifi"
+    echo "$radios" > "$wifi"
+    echo -n "-fw_cfg name=opt/wifi,file=$wifi "
+}
+
 wdt_args()
 {
     echo -n "-device i6300esb "
@@ -387,6 +397,7 @@ run_qemu()
 	  $(usb_args) \
 	  $(host_args) \
 	  $(net_args) \
+	  $(wifi_args) \
 	  $(wdt_args) \
 	  $(rtc_args) \
 	  $(vpd_args) \

board/common/rootfs/usr/libexec/infix/init.d/00-probe

@@ -654,10 +654,17 @@ def main():
         err = 1
 
     os.umask(0o337)
+    # Write atomically: confd reads system.json as soon as ixinit signals
+    # done, so a truncated in-place write could be read half-written.  Write
+    # to a temp file in the same dir, then rename (atomic on the same fs).
     # pylint: disable=invalid-name
-    with open(SYSTEM_JSON, "w", encoding="ascii") as f:
+    tmp = SYSTEM_JSON + ".tmp"
+    with open(tmp, "w", encoding="ascii") as f:
         json.dump(out, f)
-    shutil.chown(SYSTEM_JSON, user="root", group="wheel")
+        f.flush()
+        os.fsync(f.fileno())
+    shutil.chown(tmp, user="root", group="wheel")
+    os.replace(tmp, SYSTEM_JSON)
     return err
 
 

board/common/rootfs/usr/libexec/infix/init.d/20-nameif

@@ -43,5 +43,12 @@ for iface in $ports; do
 	ip link set "$iface" group port
 done
 
+# The mac80211_hwsim monitor tap (hwsim test images only) is a debug
+# observer, not a user-facing interface.  It cannot be deleted (no rtnl
+# link ops), so classify it as internal like the DSA CPU interfaces.
+if [ -d /sys/class/net/hwsim0 ]; then
+	ip link set dev hwsim0 group internal
+fi
+
 # At least loopback in iface group
 ip link set lo group iface

board/common/rootfs/usr/libexec/infix/iw.py

@@ -176,19 +176,25 @@ def parse_phy_info(phy_name):
     if current_band and current_band.get('frequencies'):
         result['bands'].append(current_band)
 
-    # Determine band names and assign band numbers
+    # Keep only the bands Infix supports (2.4/5/6 GHz), naming them by their
+    # first frequency.  Hardware may expose others (e.g. S1G on hwsim) that we
+    # neither configure nor report.
+    bands = []
     for band in result['bands']:
-        if band['frequencies']:
-            freq = band['frequencies'][0]
-            if 2400 <= freq <= 2500:
-                band['name'] = '2.4GHz'
-                band['band'] = 1
-            elif 5150 <= freq <= 5900:
-                band['name'] = '5GHz'
-                band['band'] = 2
-            elif 5955 <= freq <= 7115:
-                band['name'] = '6GHz'
-                band['band'] = 3
+        freq = band['frequencies'][0]
+        if 2400 <= freq <= 2500:
+            band['name'] = '2.4GHz'
+            band['band'] = 1
+        elif 5150 <= freq <= 5900:
+            band['name'] = '5GHz'
+            band['band'] = 2
+        elif 5955 <= freq <= 7115:
+            band['name'] = '6GHz'
+            band['band'] = 3
+        else:
+            continue
+        bands.append(band)
+    result['bands'] = bands
 
     # Set max TX power
     if max_power is not None:
@@ -207,7 +213,9 @@ def parse_phy_info(phy_name):
 
             # Map driver to manufacturer
             driver_lower = driver_name.lower()
-            if 'mt' in driver_lower or 'mediatek' in driver_lower:
+            if 'hwsim' in driver_lower:
+                result['manufacturer'] = 'Virtual (hwsim)'
+            elif 'mt' in driver_lower or 'mediatek' in driver_lower:
                 result['manufacturer'] = 'MediaTek Inc.'
             elif 'rtw' in driver_lower or 'realtek' in driver_lower:
                 result['manufacturer'] = 'Realtek Semiconductor Corp.'

configs/x86_64_defconfig

@@ -146,6 +146,7 @@ INFIX_DOC="https://www.kernelkit.org/infix/"
 INFIX_SUPPORT="mailto:kernelkit@googlegroups.com"
 BR2_PACKAGE_FEATURE_GPS=y
 BR2_PACKAGE_FEATURE_WIFI=y
+BR2_PACKAGE_FEATURE_WIFI_HWSIM=y
 BR2_PACKAGE_FEATURE_WIFI_MEDIATEK=y
 BR2_PACKAGE_FEATURE_WIFI_QUALCOMM=y
 BR2_PACKAGE_FEATURE_WIFI_REALTEK=y

doc/test-arch.md

@@ -297,6 +297,36 @@ image.  The device will boot into test mode on first power-on.
 > unless `startup_override()` is called first (or the marker is removed
 > and a normal startup config is saved).
 
+Simulated Wi-Fi
+---------------
+
+The virtual topology has no real radios, so Wi-Fi tests run against
+`mac80211_hwsim` devices and the "air" between guests is faked.  A small
+relay, `wifimedium` (`package/feature-wifi/wifimedium`), takes every frame
+a radio transmits, forwards it to the other guests, and injects what
+arrives back into the local radios.
+
+Each radio (`radio0`, `radio1`, ...) is paired with a carrier NIC of the
+same name, and that carrier joins the multicast group (a *cell*) the
+topology wires it to.  Two radios hear each other only when their carriers
+share a cell.  Radios on the same cell that tune to different channels are
+still kept apart, as on real hardware.
+
+By convention the two general cells carry `radio0` and `radio1` across all
+DUTs, so most tests put communicating radios on the same index: a station
+joins an AP on the same `radioN`.  The mesh-roaming test, for instance,
+uses `radio1` for both the gateway APs and the client.  That is only a
+convention, though.  A cell can carry any set of radios, including two of
+the *same* DUT.  The band-steering test relies on that: it wires one DUT's
+`radio2` (2.4GHz) and `radio3` (5GHz) onto a dedicated cell so a single
+client radio hears the same SSID on both bands.
+
+How many radios each DUT gets depends on the topology.  The number of
+`radioN` ports wired to a node is passed in via the `opt/wifi` fw_cfg and
+loaded at boot by the `00-hwsim` script, so a node with no wifi links has
+no radios at all.  The wiring for the standard suite lives in
+`test/virt/quad`.
+
 [9PM]:    https://github.com/rical/9pm
 [Qeneth]: https://github.com/wkz/qeneth
 [TAP]:    https://testanything.org/

doc/wifi.md

@@ -304,6 +304,7 @@ in-octets          : 148388
 out-octets         : 24555
 mode               : station
 ssid               : MyNetwork
+bssid              : b4:fb:e4:17:b6:a7
 signal             : -45 dBm (good)
 rx bitrate         : 72.2 Mbps
 tx bitrate         : 86.6 Mbps
@@ -319,6 +320,11 @@ In the CLI, signal strength is reported as: excellent, good, fair or bad.
 For precise signal strength values in dBm, use NETCONF or RESTCONF to access
 the `signal-strength` leaf in the operational datastore.
 
+When connected, `bssid` shows the MAC address of the access point the
+station is associated to.  It appears only while connected.  When several
+access points share one SSID (a roaming network), the `bssid` is what
+tells them apart, and it changes as the station roams between them.
+
 ## Passphrase Requirements
 
 To ensure your connection is secure and compatible with all network
@@ -378,6 +384,7 @@ operational status : up
 physical address   : f0:09:0d:36:5f:86
 mode               : station
 ssid               : MyHomeNetwork
+bssid              : b4:fb:e4:17:b6:a7
 signal             : -52 dBm (good)
 </code></pre>
 

package/feature-wifi/00-hwsim

@@ -0,0 +1,47 @@
+#!/bin/sh
+# Load mac80211_hwsim virtual radios sized to this DUT's topology, then wait
+# for udev to rename the phys (phyN -> radioN) before returning.
+#
+# The radio count comes from a dedicated fw_cfg file (opt/wifi) that qeneth
+# writes per node from the number of radioN carrier ports the topology wired
+# to it.  A node with no wifi links gets 0 (or no file), so hwsim is not loaded
+# at all -- no phys, nothing clutters its interface view.
+#
+# Runs early in ixinit, before 00-probe, so the system probe records the radios
+# by their final radioN names.  ixinit is past the <pid/syslogd> / udev-settle
+# barrier, so 60-rename-wifi-phy.rules (phyN -> radioN) and
+# 70-remove-virtual-wifi-interfaces.rules (drop the stray wlanN) are loaded and
+# fire on the phy add events.  On success it sets the <usr/hwsim> condition so
+# wifimedium starts only where radios exist.  Installed only with
+# BR2_PACKAGE_FEATURE_WIFI_HWSIM.
+
+wifi=/sys/firmware/qemu_fw_cfg/by_name/opt/wifi/raw
+ieee=/sys/class/ieee80211
+
+# Number of radios to create, from the topology (via fw_cfg).
+radios=0
+[ -r "$wifi" ] && radios=$(cat "$wifi" 2>/dev/null)
+
+# No radios wanted -> don't load hwsim, keep the view wifi-free.
+[ "$radios" -gt 0 ] 2>/dev/null || exit 0
+
+modprobe mac80211_hwsim radios="$radios" || exit 0
+
+# Wait (bounded ~10s) for the phyN -> radioN rename to finish: the class has
+# entries and none are still named phyN.  The rename is a udev RUN, so it lags
+# modprobe's return.  On timeout the radios never settled -- fail (and log) so
+# it is visible why 00-probe may record stale phyN names.
+TIMEOUT=100
+i=0
+while [ "$i" -lt "$TIMEOUT" ]; do
+	names=$(ls "$ieee" 2>/dev/null)
+	if [ -n "$names" ] && ! echo "$names" | grep -q '^phy'; then
+		initctl -bq cond set hwsim
+		exit 0
+	fi
+	i=$((i + 1))
+	sleep 0.1
+done
+
+logger -p user.err -t 00-hwsim "timed out waiting for hwsim phys to be renamed radioN"
+exit 1

package/feature-wifi/Config.in

@@ -18,6 +18,18 @@ config BR2_PACKAGE_FEATURE_WIFI
 	help
 	  Enables WiFi in Infix. Enables all requried applications.
 
+config BR2_PACKAGE_FEATURE_WIFI_HWSIM
+	bool "Virtual Wi-Fi radios (mac80211_hwsim)"
+	depends on BR2_PACKAGE_FEATURE_WIFI
+	help
+	  Build the mac80211_hwsim virtual radio driver (as a module) for the
+	  QEMU test target, to exercise AP, station, and mesh modes without
+	  physical WiFi adapters. The module is autoloaded at boot (see the
+	  x86_64 /etc/modules-load.d) and frames are bridged between guests by
+	  the wifimedium relay.
+
+	  Leave disabled on real hardware; it only provides simulated radios.
+
 config BR2_PACKAGE_FEATURE_WIFI_MEDIATEK
        bool "Mediatek WiFi Devices"
        depends on BR2_PACKAGE_FEATURE_WIFI

package/feature-wifi/feature-wifi.mk

@@ -14,6 +14,15 @@ define FEATURE_WIFI_LINUX_CONFIG_FIXUPS
 	$(call KCONFIG_SET_OPT,CONFIG_CFG80211,m)
 	$(call KCONFIG_ENABLE_OPT,CONFIG_MAC80211_MESH)
 
+	# Virtual radio for automated testing (mac80211_hwsim), built as a
+	# module and gated behind BR2_PACKAGE_FEATURE_WIFI_HWSIM so it is not
+	# built on real boards.  When selected, the module is loaded early in
+	# ixinit by 00-hwsim -- sized to the DUT's topology, so radio-less nodes
+	# load nothing -- and bridged between QEMU guests by the wifimedium relay
+	# (both installed by FEATURE_WIFI_INSTALL_HWSIM below).
+	$(if $(BR2_PACKAGE_FEATURE_WIFI_HWSIM),
+		$(call KCONFIG_SET_OPT,CONFIG_MAC80211_HWSIM,m))
+
 	$(if $(filter y,$(BR2_PACKAGE_FEATURE_WIFI_MEDIATEK)),
 		$(call KCONFIG_ENABLE_OPT,CONFIG_MT7601U)
 		$(call KCONFIG_ENABLE_OPT,CONFIG_MT76x0U)
@@ -76,5 +85,20 @@ define FEATURE_WIFI_INSTALL_IN_ROMFS
 endef
 FEATURE_WIFI_POST_INSTALL_TARGET_HOOKS += FEATURE_WIFI_INSTALL_IN_ROMFS
 
+# Virtual-radio (mac80211_hwsim) runtime, installed only when the option is
+# selected: the 00-hwsim ixinit script loads the module sized to the opt/wifi
+# fw_cfg qeneth writes per node (no radios -> not loaded), and the wifimedium
+# relay + its Finit service bridge hwsim frames between QEMU guests so they can
+# associate "wirelessly".
+ifeq ($(BR2_PACKAGE_FEATURE_WIFI_HWSIM),y)
+define FEATURE_WIFI_INSTALL_HWSIM
+	$(INSTALL) -D -m 0755 $(FEATURE_WIFI_PKGDIR)/00-hwsim $(TARGET_DIR)/usr/libexec/infix/init.d/00-hwsim
+	$(INSTALL) -D -m 0755 $(FEATURE_WIFI_PKGDIR)/wifimedium $(TARGET_DIR)/usr/libexec/infix/wifimedium
+	$(INSTALL) -D -m 0644 $(FEATURE_WIFI_PKGDIR)/wifimedium.conf $(TARGET_DIR)/etc/finit.d/available/wifimedium.conf
+	ln -sf ../available/wifimedium.conf $(TARGET_DIR)/etc/finit.d/enabled/wifimedium.conf
+endef
+FEATURE_WIFI_POST_INSTALL_TARGET_HOOKS += FEATURE_WIFI_INSTALL_HWSIM
+endif
+
 
 $(eval $(generic-package))