pc_wifi_drv: add RFKILL support

This commits hooks up a RFKILL management to the driver. The
'README' contains instructions on how to use it.

Fixes #4506.

repos/pc/lib/mk/wifi.inc

@@ -32,6 +32,11 @@ CC_C_OPT += -I$(LX_SRC_DIR)/include/linux
 
 CC_C_OPT += -Wno-address-of-packed-member
 
+# need net/rfkill/rfkill.h
+CC_OPT_lx_emul += -I$(LX_SRC_DIR)
+
+CC_C_OPT += -DCONFIG_RFKILL_INPUT
+
 #CC_OPT += -DCONFIG_IWLWIFI_DEBUG
 
 

repos/pc/run/wifi.run

@@ -155,7 +155,7 @@ append config {
 				<inline description="connect">
 } [wifi_config 30 5 no [list "[wifi_ssid] WPA2 [wifi_psk] yes"]] {
 				</inline>
-				<sleep milliseconds="6000000"/>
+				<sleep milliseconds="60000"/>
 				<inline description="rfkill block">
 } [wifi_config 30 5 yes [list "[wifi_ssid] WPA2 [wifi_psk] yes"]] {
 				</inline>

repos/pc/src/drivers/wifi/pc/main.cc

@@ -85,10 +85,9 @@ void wifi_notify_event(void)
 
 
 /* exported by wifi.lib.so */
-extern void wifi_init(Genode::Env&,
-                      Genode::Blockade&,
-                      bool,
-                      Genode::Signal_context_capability);
+extern void wifi_init(Genode::Env&, Genode::Blockade&, bool);
+extern void wifi_set_rfkill_sigh(Genode::Signal_context_capability);
+
 
 struct Main
 {
@@ -103,8 +102,7 @@ struct Main
 	{
 		_wpa.construct(env, _wpa_startup_blockade);
 
-		wifi_init(env, _wpa_startup_blockade, false,
-		          Genode::Signal_context_capability());
+		wifi_init(env, _wpa_startup_blockade, false);
 	}
 };
 
@@ -132,6 +130,7 @@ void *wifi_get_buffer(void)
 
 		_main->_frontend.construct(_main->env);
 		_wifi_frontend = &*_main->_frontend;
+		wifi_set_rfkill_sigh(_wifi_frontend->rfkill_sigh());
 	});
 
 	return &_wifi_frontend->msg_buffer();

repos/pc/src/include/lx_emul/initcall_order.h

@@ -1,7 +1,7 @@
 /*
  * \brief  Array defining order of Linux Kernel initcalls
  * \author Automatically generated file - do no edit
- * \date   2022-05-03
+ * \date   2022-05-13
  */
 
 #pragma once
@@ -103,6 +103,7 @@ static const char * lx_emul_initcall_order[] = {
 	"__initcall_fib_notifier_init4",
 	"__initcall_ethnl_init4",
 	"__initcall_ieee80211_init4",
+	"__initcall_rfkill_init4",
 	"__initcall_pci_subsys_init4",
 	"__initcall_nmi_warning_debugfs5",
 	"__initcall_hpet_late_init5",

repos/pc/src/lib/wifi/dep.list

@@ -154,6 +154,7 @@ include/linux/ip.h
 include/linux/ipv6_route.h
 include/linux/kcov.h
 include/linux/leds.h
+include/linux/miscdevice.h
 include/linux/mpls.h
 include/linux/netfilter.h
 include/linux/netfilter_ingress.h
@@ -309,6 +310,7 @@ net/mac80211/wme.h
 net/mac80211/wpa.h
 net/netlink/af_netlink.h
 net/packet/internal.h
+net/rfkill/rfkill.h
 net/wireless/core.h
 net/wireless/debugfs.h
 net/wireless/nl80211.h

repos/pc/src/lib/wifi/lx_emul.c

@@ -510,3 +510,77 @@ void page_frag_free(void * addr)
 
 	__free_pages(page, 0ul);
 }
+
+
+#include <linux/miscdevice.h>
+
+int misc_register(struct miscdevice *misc)
+{
+	return 0;
+}
+
+void misc_deregister(struct miscdevice *misc)
+{
+}
+
+
+/* rfkill support */
+
+#include <linux/rfkill.h>
+#include <net/rfkill/rfkill.h>
+
+int __init rfkill_handler_init(void)
+{
+	return 0;
+}
+
+static struct
+{
+	int rfkilled;
+	int blocked;
+} _rfkill_state;
+
+
+struct task_struct *rfkill_task_struct_ptr;
+
+
+int lx_emul_rfkill_get_any(void)
+{
+	return _rfkill_state.rfkilled;
+}
+
+
+void lx_emul_rfkill_switch_all(int blocked)
+{
+	_rfkill_state.blocked = blocked;
+}
+
+
+static int rfkill_task_function(void *arg)
+{
+	(void)arg;
+
+	for (;;) {
+
+		bool rfkilled = !!rfkill_get_global_sw_state(RFKILL_TYPE_WLAN);
+
+		if (rfkilled != _rfkill_state.blocked)
+			rfkill_switch_all(RFKILL_TYPE_WLAN, !!_rfkill_state.blocked);
+
+		_rfkill_state.rfkilled = rfkilled;
+
+		lx_emul_task_schedule(true);
+	}
+
+	return 0;
+}
+
+
+void rfkill_init(void)
+{
+	pid_t pid;
+
+	pid = kernel_thread(rfkill_task_function, NULL, CLONE_FS | CLONE_FILES);
+
+	rfkill_task_struct_ptr = find_task_by_pid_ns(pid, NULL);
+}

repos/pc/src/lib/wifi/lx_emul.h

@@ -31,6 +31,8 @@ void lx_emul_time_udelay(unsigned long usec);
 void         lx_emul_get_random_bytes(void *buf, unsigned long nbytes);
 unsigned int lx_emul_get_random_u32(void);
 
+int  lx_emul_rfkill_get_any(void);
+void lx_emul_rfkill_switch_all(int blocked);
 
 #ifdef __cplusplus
 }

repos/pc/src/lib/wifi/lx_user.c

@@ -21,6 +21,7 @@
 void lx_user_init(void)
 {
 	uplink_init();
+	rfkill_init();
 	socketcall_init();
 }
 

repos/pc/src/lib/wifi/lx_user.h

@@ -23,6 +23,9 @@ void uplink_init(void);
 extern struct task_struct *socketcall_task_struct_ptr;
 void socketcall_init(void);
 
+extern struct task_struct *rfkill_task_struct_ptr;
+void rfkill_init(void);
+
 #ifdef __cplusplus
 }
 #endif

repos/pc/src/lib/wifi/spec/x86_32/source.list

@@ -250,6 +250,7 @@ net/netlink/af_netlink.c
 net/netlink/genetlink.c
 net/netlink/policy.c
 net/packet/af_packet.c
+net/rfkill/core.c
 net/sched/sch_generic.c
 net/sched/sch_mq.c
 net/socket.c

repos/pc/src/lib/wifi/spec/x86_64/source.list

@@ -250,6 +250,7 @@ net/netlink/af_netlink.c
 net/netlink/genetlink.c
 net/netlink/policy.c
 net/packet/af_packet.c
+net/rfkill/core.c
 net/sched/sch_generic.c
 net/sched/sch_mq.c
 net/socket.c

repos/pc/src/lib/wifi/wlan.cc

@@ -28,19 +28,46 @@
 /* local includes */
 #include "lx_user.h"
 
-
 using namespace Genode;
 
 
+extern "C" int  lx_emul_rfkill_get_any(void);
+extern "C" void lx_emul_rfkill_switch_all(int blocked);
+
+static Genode::Signal_context_capability _rfkill_sigh_cap;
+
 bool wifi_get_rfkill(void)
 {
-	return false;
+	if (!rfkill_task_struct_ptr)
+		return false;
+
+	lx_emul_task_unblock(rfkill_task_struct_ptr);
+	Lx_kit::env().scheduler.schedule();
+
+	return lx_emul_rfkill_get_any();
 }
 
 
 void wifi_set_rfkill(bool blocked)
 {
-	(void)blocked;
+	if (!rfkill_task_struct_ptr)
+		return;
+
+	lx_emul_rfkill_switch_all(blocked);
+
+	lx_emul_task_unblock(rfkill_task_struct_ptr);
+	Lx_kit::env().scheduler.schedule();
+
+	/*
+	 * We have to open the device again after unblocking
+	 * as otherwise we will get ENETDOWN. So unblock the uplink
+	 * task _afterwards_ because there we call * 'dev_open()'
+	 * unconditionally and that will bring the netdevice UP again.
+	 */
+	lx_emul_task_unblock(uplink_task_struct_ptr);
+	Lx_kit::env().scheduler.schedule();
+
+	Genode::Signal_transmitter(_rfkill_sigh_cap).submit();
 }
 
 
@@ -57,9 +84,6 @@ extern "C" char const *wifi_ifname(void)
 	return "wlan0";
 }
 
-
-extern "C" struct task_struct *uplink_task_struct_ptr;
-
 struct Wlan
 {
 	Env                    &_env;
@@ -90,15 +114,19 @@ struct Wlan
 Genode::Blockade *wpa_blockade;
 
 
-void wifi_init(Genode::Env                       &env,
-               Genode::Blockade                  &blockade,
-               bool                               disable_11n,
-               Genode::Signal_context_capability  rfkill)
+void wifi_init(Genode::Env      &env,
+               Genode::Blockade &blockade,
+               bool              disable_11n)
 {
 	(void)disable_11n;
-	(void)rfkill;
 
 	wpa_blockade = &blockade;
 
 	static Wlan wlan(env);
 }
+
+
+void wifi_set_rfkill_sigh(Genode::Signal_context_capability cap)
+{
+	_rfkill_sigh_cap = cap;
+}

repos/pc/src/pc_linux/target.inc

@@ -20,6 +20,7 @@ LX_ENABLE += ACPI
 # general network and WLAN support
 LX_ENABLE += NET NETDEVICES PACKET
 LX_ENABLE += WLAN CFG80211 MAC80211
+LX_ENABLE += RFKILL
 
 # iwlwifi
 LX_ENABLE += WLAN_VENDOR_INTEL IWLWIFI IWLDVM IWLMVM