Re: [PATCH 8/9] rfkill: Userspace control for airplane mode
From: Dan Williams <hidden>
Date: 2016-02-08 16:11:32
Also in:
linux-api, lkml, netdev, platform-driver-x86
On Mon, 2016-02-08 at 10:41 -0500, João Paulo Rechi Vita wrote:
Provide an interface for the airplane-mode indicator be controlled from userspace. User has to first acquire the control through RFKILL_OP_AIRPLANE_MODE_ACQUIRE and keep the fd open for the whole time it wants to be in control of the indicator. Closing the fd or using RFKILL_OP_AIRPLANE_MODE_RELEASE restores the default policy. To change state of the indicator, the RFKILL_OP_AIRPLANE_MODE_CHANGE operation is used, passing the value on "struct rfkill_event.soft". If the caller has not acquired the airplane-mode control beforehand, the operation fails.
I'd like to clarify a bit, so tell me if I'm correct or not. Using RFKILL_OP_AIRPLANE_MODE_CHANGE does not actually change any device state. It's just an indicator with no relationship to any of the registered rfkill switches, right? I wonder if setting RFKILL_OP_AIRPLANE_MODE_CHANGE(true) shouldn't also softblock all switches, otherwise you can set airplane mode all day long with RFKILL_OP_AIRPLANE_MODE_CHANGE and it doesn't actually enable airplane mode at all? Dan
quoted hunk ↗ jump to hunk
Signed-off-by: João Paulo Rechi Vita <redacted> --- Documentation/rfkill.txt | 10 ++++++++++ include/uapi/linux/rfkill.h | 3 +++ net/rfkill/core.c | 47 ++++++++++++++++++++++++++++++++++++++++++--- 3 files changed, 57 insertions(+), 3 deletions(-)diff --git a/Documentation/rfkill.txt b/Documentation/rfkill.txt index b13025a..aa6e014 100644 --- a/Documentation/rfkill.txt +++ b/Documentation/rfkill.txt@@ -87,6 +87,7 @@ RFKill provides per-switch LED triggers, which canbe used to drive LEDs according to the switch state (LED_FULL when blocked, LED_OFF otherwise). An airplane-mode indicator LED trigger is also available, which triggers LED_FULL when all radios known by RFKill are blocked, and LED_OFF otherwise. +The airplane-mode indicator LED trigger policy can be overridden by userspace. 5. Userspace support@@ -123,5 +124,14 @@ RFKILL_TYPE The contents of these variables corresponds to the "name", "state"and "type" sysfs files explained above. +Userspace can also override the default airplane-mode indicator policy through +/dev/rfkill. Control of the airplane mode indicator has to be acquired first, +using RFKILL_OP_AIRPLANE_MODE_ACQUIRE, and is only available for one userspace +application at a time. Closing the fd or using RFKILL_OP_AIRPLANE_MODE_RELEASE +reverts the airplane-mode indicator back to the default kernel policy and makes +it available for other applications to take control. Changes to the +airplane-mode indicator state can be made using RFKILL_OP_AIRPLANE_MODE_CHANGE, +passing the new value in the 'soft' field of 'struct rfkill_event'. + For further details consult Documentation/ABI/stable/sysfs-class -rfkill.diff --git a/include/uapi/linux/rfkill.hb/include/uapi/linux/rfkill.h index 2e00dce..9cb999b 100644--- a/include/uapi/linux/rfkill.h +++ b/include/uapi/linux/rfkill.h@@ -67,6 +67,9 @@ enum rfkill_operation { RFKILL_OP_DEL, RFKILL_OP_CHANGE, RFKILL_OP_CHANGE_ALL, + RFKILL_OP_AIRPLANE_MODE_ACQUIRE, + RFKILL_OP_AIRPLANE_MODE_RELEASE, + RFKILL_OP_AIRPLANE_MODE_CHANGE, }; /**diff --git a/net/rfkill/core.c b/net/rfkill/core.c index fb11547..8067701 100644 --- a/net/rfkill/core.c +++ b/net/rfkill/core.c@@ -89,6 +89,7 @@ struct rfkill_data { struct mutex mtx; wait_queue_head_t read_wait; bool input_handler; + bool is_apm_owner; };@@ -123,7 +124,7 @@ static struct { } rfkill_global_states[NUM_RFKILL_TYPES]; static bool rfkill_epo_lock_active; - +static bool rfkill_apm_owned; #ifdef CONFIG_RFKILL_LEDS static struct led_trigger rfkill_apm_led_trigger;@@ -350,7 +351,8 @@ static void rfkill_update_global_state(enumrfkill_type type, bool blocked) for (i = 0; i < NUM_RFKILL_TYPES; i++) rfkill_global_states[i].cur = blocked; - rfkill_apm_led_trigger_event(blocked); + if (!rfkill_apm_owned) + rfkill_apm_led_trigger_event(blocked); } #ifdef CONFIG_RFKILL_INPUT@@ -1183,6 +1185,7 @@ static ssize_t rfkill_fop_read(struct file*file, char __user *buf, static ssize_t rfkill_fop_write(struct file *file, const char __user *buf, size_t count, loff_t *pos) { + struct rfkill_data *data = file->private_data; struct rfkill *rfkill; struct rfkill_event ev;@@ -1199,7 +1202,7 @@ static ssize_t rfkill_fop_write(struct file*file, const char __user *buf, if (copy_from_user(&ev, buf, count)) return -EFAULT; - if (ev.op != RFKILL_OP_CHANGE && ev.op != RFKILL_OP_CHANGE_ALL) + if (ev.op < RFKILL_OP_CHANGE) return -EINVAL; if (ev.type >= NUM_RFKILL_TYPES)@@ -1207,6 +1210,34 @@ static ssize_t rfkill_fop_write(struct file*file, const char __user *buf, mutex_lock(&rfkill_global_mutex); + if (ev.op == RFKILL_OP_AIRPLANE_MODE_ACQUIRE) { + if (rfkill_apm_owned && !data->is_apm_owner) { + count = -EACCES; + } else { + rfkill_apm_owned = true; + data->is_apm_owner = true; + } + } + + if (ev.op == RFKILL_OP_AIRPLANE_MODE_RELEASE) { + if (rfkill_apm_owned && !data->is_apm_owner) { + count = -EACCES; + } else { + bool state = rfkill_global_states[RFKILL_TYPE_ALL].cur; + + rfkill_apm_owned = false; + data->is_apm_owner = false; + rfkill_apm_led_trigger_event(state); + } + } + + if (ev.op == RFKILL_OP_AIRPLANE_MODE_CHANGE) { + if (rfkill_apm_owned && data->is_apm_owner) + rfkill_apm_led_trigger_event(ev.soft); + else + count = -EACCES; + } + if (ev.op == RFKILL_OP_CHANGE_ALL) rfkill_update_global_state(ev.type, ev.soft);@@ -1230,7 +1261,17 @@ static int rfkill_fop_release(struct inode*inode, struct file *file) struct rfkill_int_event *ev, *tmp; mutex_lock(&rfkill_global_mutex); + + if (data->is_apm_owner) { + bool state = rfkill_global_states[RFKILL_TYPE_ALL].cur; + + rfkill_apm_owned = false; + data->is_apm_owner = false; + rfkill_apm_led_trigger_event(state); + } + list_del(&data->list); + mutex_unlock(&rfkill_global_mutex); mutex_destroy(&data->mtx);