[feat] Add method to get current access point info controller (#4401)

[DaneSlattery]

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• I have updated existing examples or added new ones (if applicable).
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Pull Request Details 📖

Description

Resolves this issue #4401 by exposing the c api esp_wifi_sta_get_ap_info from the esp-wifi-sys crate

Testing

I tested this on an esp32 dev kit, modifying the example for embassy_dhcp:
I can include this change in the PR if required

     match controller.connect_async().await {
            Ok(_) => {
                println!("Wifi connected!");
                let ap = controller.ap_info().unwrap();
                println!("AP Info={ap:?}")
            }
            Err(e) => {
                println!("Failed to connect to wifi: {e:?}");
                Timer::after(Duration::from_millis(5000)).await
            }
        }

[bugadani]

This is UB, you can't do this.

[DaneSlattery]

I see that now, assume_init_mut before is not the way to go.

TBH, I don’t know this FFI stuff to well so I just used the same idea as line 3047, should I fix that as well?

[bugadani]

No need, we'll do that, just don't introduce more code like it, please :)

[bugadani]

Please see #4408 - it's okay to pass a pointer like that to the C code, and assume C code has initialized the data if the call succeeds.

[DaneSlattery]

Done!

[bjoernQ]

this somehow fell off my radar - probably #4460 should get in first

[github-actions]

Binary Size Report

esp32

sleep-timer Diff (PR vs. Base)

FILE SIZE        VM SIZE    
--------------  -------------- 
+0.0%      +5  [ = ]       0    [Unmapped]
-0.0%    -180  [ = ]       0    TOTAL

embassy-dhcp Diff (PR vs. Base)

FILE SIZE        VM SIZE    
--------------  -------------- 
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+33% +2.25Ki  [ = ]       0    [Unmapped]
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[ = ]       0  -0.1%    -136    .stack
+0.8% +53.7Ki  +0.6% +4.85Ki    TOTAL

esp32c3

sleep-timer Diff (PR vs. Base)

FILE SIZE        VM SIZE    
--------------  -------------- 
+0.0%      +4  [ = ]       0    TOTAL

embassy-dhcp Diff (PR vs. Base)

FILE SIZE        VM SIZE    
--------------  -------------- 
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+2.7% +1.15Ki  +2.7% +1.15Ki    .rodata
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[ = ]       0  -0.0%     -80    .stack
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esp32c6

sleep-timer Diff (PR vs. Base)

FILE SIZE        VM SIZE    
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-0.0%      -3  [ = ]       0    [Unmapped]
[ = ]       0  [ = ]       0    TOTAL

embassy-dhcp Diff (PR vs. Base)

FILE SIZE        VM SIZE    
--------------  -------------- 
+0.8% +3.48Ki  +0.8% +3.48Ki    .text
+2.2% +1.20Ki  +2.2% +1.20Ki    .rodata
+1.0%    +220  [ = ]       0    .eh_frame
+1.3%     +96  +1.3%     +96    .data
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[ = ]       0  +0.0%      +8    .bss
[ = ]       0  -0.1%    -176    .stack
-6.9%    -867  [ = ]       0    [Unmapped]
+0.6% +49.7Ki  +0.4% +4.68Ki    TOTAL