fork: update refs

Implement UDS service with example

.github/workflows/ci.yml

@@ -43,11 +43,16 @@ jobs:
       - name: Check formatting
         run: cargo fmt --all --verbose -- --check
 
+      # We always run the next two steps, so that even if formatting fails we
+      # still get compilation errors for the same run (mainly for matchers).
+
       - name: Cargo check ctru-sys (without tests)
         run: cargo 3ds clippy --package ctru-sys --color=always --verbose
+        if: success() || failure()
 
       - name: Cargo check ctru-rs (including tests)
         run: cargo 3ds clippy --package ctru-rs --color=always --verbose --all-targets
+        if: success() || failure()
 
   test:
     strategy:
@@ -78,12 +83,12 @@ jobs:
         run: cargo 3ds test --no-run --tests
 
       - name: Run lib and integration tests
-        uses: rust3ds/test-runner/run-tests@98a8ed44057c2100447f0f6547c0de1e14be8022
+        uses: rust3ds/test-runner/run-tests@v1
         with:
           args: --tests
 
       - name: Build and run doc tests
-        uses: rust3ds/test-runner/run-tests@98a8ed44057c2100447f0f6547c0de1e14be8022
+        uses: rust3ds/test-runner/run-tests@v1
         with:
           args: --doc
 

Cargo.toml

@@ -3,7 +3,7 @@ members = ["ctru-rs", "ctru-sys"]
 default-members = ["ctru-rs", "ctru-sys"]
 resolver = "2"
 
-[patch.'https://github.com/rust3ds/ctru-rs']
+[patch.'https://git.xenua.me/rust3ds/ctru-rs']
 # Make sure all dependencies use the local packages. This is needed for things
 # like pthread-3ds that rely on ctru-sys, and test-runner which relies on ctru-rs
 ctru-rs = { path = "ctru-rs" }

ctru-rs/Cargo.toml

@@ -3,7 +3,7 @@ name = "ctru-rs"
 version = "0.7.1"
 authors = ["Rust3DS Org", "Ronald Kinard <furyhunter600@gmail.com>"]
 description = "A safe wrapper around libctru"
-repository = "https://github.com/rust3ds/ctru-rs"
+repository = "https://git.xenua.me/rust3ds/ctru-rs"
 documentation = "https://rust3ds.github.io/ctru-rs/crates/ctru"
 keywords = ["3ds", "libctru"]
 categories = ["os", "api-bindings", "hardware-support"]
@@ -20,10 +20,11 @@ name = "ctru"
 cfg-if = "1.0"
 ctru-sys = { path = "../ctru-sys", version = "0.5.0" }
 const-zero = "0.1.0"
-shim-3ds = { git = "https://github.com/rust3ds/shim-3ds.git" }
-pthread-3ds = { git = "https://github.com/rust3ds/pthread-3ds.git" }
+shim-3ds = { git = "https://git.xenua.me/rust3ds/shim-3ds.git" }
+pthread-3ds = { git = "https://git.xenua.me/rust3ds/pthread-3ds.git" }
 libc = "0.2.121"
 bitflags = "2.3.3"
+macaddr = "1.0.1"
 widestring = "1.0.2"
 
 [build-dependencies]
@@ -35,7 +36,7 @@ cfg-if = "1.0.0"
 ferris-says = "0.2.1"
 futures = "0.3"
 lewton = "0.10.2"
-test-runner = { git = "https://github.com/rust3ds/test-runner.git" }
+test-runner = { git = "https://git.xenua.me/rust3ds/test-runner.git" }
 time = "0.3.7"
 tokio = { version = "1.16", features = ["rt", "time", "sync", "macros"] }
 

ctru-rs/examples/local-networking.rs

@@ -0,0 +1,301 @@
+//! Local networking example.
+//!
+//! This example showcases local networking using the UDS module.
+
+use ctru::prelude::*;
+use ctru::services::uds::*;
+
+fn handle_status_event(uds: &Uds, prev_node_mask: u16) -> ctru::Result<u16> {
+    println!("Connection status event signalled");
+    let status = uds.connection_status()?;
+    println!("Status: {status:#02X?}");
+    let left = prev_node_mask & (status.node_bitmask() ^ prev_node_mask);
+    let joined = status.node_bitmask() & (status.node_bitmask() ^ prev_node_mask);
+    for i in 0..16 {
+        if left & (1 << i) != 0 {
+            println!("Node {} disconnected", i + 1);
+        }
+    }
+    for i in 0..16 {
+        if joined & (1 << i) != 0 {
+            println!(
+                "Node {} connected: {:?}",
+                i + 1,
+                uds.node_info(NodeID::Node(i + 1))
+            );
+        }
+    }
+    Ok(status.node_bitmask())
+}
+
+fn main() -> Result<(), Error> {
+    let apt = Apt::new().unwrap();
+    let mut hid = Hid::new().unwrap();
+    let gfx = Gfx::new().unwrap();
+    let console = Console::new(gfx.top_screen.borrow_mut());
+
+    println!("Local networking demo");
+
+    let mut uds = Uds::new(None).unwrap();
+
+    println!("UDS initialised");
+
+    enum State {
+        Initialised,
+        Scanning,
+        DrawList,
+        List,
+        Connect,
+        Connected,
+        Create,
+        Created,
+    }
+
+    let mut state = State::Initialised;
+
+    println!("Press A to start scanning or B to create a new network");
+
+    let mut networks = vec![];
+    let mut selected_network = 0;
+
+    let mut mode = ConnectionType::Client;
+
+    let mut channel = 0;
+    let data_channel = 1;
+
+    let mut prev_node_mask = 0;
+
+    while apt.main_loop() {
+        gfx.wait_for_vblank();
+
+        hid.scan_input();
+        if hid.keys_down().contains(KeyPad::START) {
+            break;
+        }
+
+        match state {
+            State::Initialised => {
+                if hid.keys_down().contains(KeyPad::A) {
+                    state = State::Scanning;
+                    console.clear();
+                    prev_node_mask = 0;
+                } else if hid.keys_down().contains(KeyPad::B) {
+                    state = State::Create;
+                    console.clear();
+                    prev_node_mask = 0;
+                }
+            }
+            State::Scanning => {
+                println!("Scanning...");
+
+                let nwks = uds.scan(b"HBW\x10", None, None);
+
+                match nwks {
+                    Ok(n) => {
+                        if n.is_empty() {
+                            state = State::Initialised;
+                            console.clear();
+                            println!("Scanned successfully; no networks found");
+                            println!("Press A to start scanning or B to create a new network");
+                        } else {
+                            networks = n;
+                            selected_network = 0;
+                            state = State::DrawList;
+                        }
+                    }
+                    Err(e) => {
+                        state = State::Initialised;
+                        console.clear();
+                        eprintln!("Error while scanning: {e}");
+                        println!("Press A to start scanning or B to create a new network");
+                    }
+                }
+            }
+            State::DrawList => {
+                console.clear();
+
+                println!(
+                    "Scanned successfully; {} network{} found",
+                    networks.len(),
+                    if networks.len() == 1 { "" } else { "s" }
+                );
+
+                println!("D-Pad to select, A to connect as client, R + A to connect as spectator, B to create a new network");
+
+                for (index, n) in networks.iter().enumerate() {
+                    println!(
+                        "{} Username: {}",
+                        if index == selected_network { ">" } else { " " },
+                        n.nodes()[0].unwrap().username()
+                    );
+                }
+
+                state = State::List;
+            }
+            State::List => {
+                if hid.keys_down().contains(KeyPad::UP) && selected_network > 0 {
+                    selected_network -= 1;
+                    state = State::DrawList;
+                } else if hid.keys_down().contains(KeyPad::DOWN)
+                    && selected_network < networks.len() - 1
+                {
+                    selected_network += 1;
+                    state = State::DrawList;
+                } else if hid.keys_down().contains(KeyPad::A) {
+                    state = State::Connect;
+                    mode = if hid.keys_held().contains(KeyPad::R) {
+                        ConnectionType::Spectator
+                    } else {
+                        ConnectionType::Client
+                    };
+                } else if hid.keys_down().contains(KeyPad::B) {
+                    state = State::Create;
+                }
+            }
+            State::Connect => {
+                let appdata = uds.network_appdata(&networks[selected_network], None)?;
+                println!("App data: {:02X?}", appdata);
+
+                if let Err(e) = uds.connect_network(
+                    &networks[selected_network],
+                    b"udsdemo passphrase c186093cd2652741\0",
+                    mode,
+                    data_channel,
+                ) {
+                    console.clear();
+                    eprintln!("Error while connecting to network: {e}");
+                    state = State::Initialised;
+                    println!("Press A to start scanning or B to create a new network");
+                } else {
+                    channel = uds.channel()?;
+                    println!("Connected using channel {}", channel);
+
+                    let appdata = uds.appdata(None)?;
+                    println!("App data: {:02X?}", appdata);
+
+                    if uds.wait_status_event(false, false)? {
+                        prev_node_mask = handle_status_event(&uds, prev_node_mask)?;
+                    }
+
+                    println!("Press A to stop data transfer");
+                    state = State::Connected;
+                }
+            }
+            State::Connected => {
+                let packet = uds.pull_packet();
+
+                match packet {
+                    Ok(p) => {
+                        if let Some((pkt, node)) = p {
+                            println!(
+                                "{:02X}{:02X}{:02X}{:02X} from {:?}",
+                                pkt[0], pkt[1], pkt[2], pkt[3], node
+                            );
+                        }
+
+                        if uds.wait_status_event(false, false)? {
+                            prev_node_mask = handle_status_event(&uds, prev_node_mask)?;
+                        }
+
+                        if hid.keys_down().contains(KeyPad::A) {
+                            uds.disconnect_network()?;
+                            state = State::Initialised;
+                            console.clear();
+                            println!("Press A to start scanning or B to create a new network");
+                        } else if !hid.keys_down().is_empty() || !hid.keys_up().is_empty() {
+                            let transfer_data = hid.keys_held().bits();
+                            if mode != ConnectionType::Spectator {
+                                uds.send_packet(
+                                    &transfer_data.to_le_bytes(),
+                                    NodeID::Broadcast,
+                                    data_channel,
+                                    SendFlags::Default,
+                                )?;
+                            }
+                        }
+                    }
+                    Err(e) => {
+                        uds.disconnect_network()?;
+                        console.clear();
+                        eprintln!("Error while grabbing packet from network: {e}");
+                        state = State::Initialised;
+                        println!("Press A to start scanning or B to create a new network");
+                    }
+                }
+            }
+            State::Create => {
+                console.clear();
+                println!("Creating network...");
+
+                match uds.create_network(
+                    b"HBW\x10",
+                    None,
+                    None,
+                    b"udsdemo passphrase c186093cd2652741\0",
+                    data_channel,
+                ) {
+                    Ok(_) => {
+                        let appdata = [0x69u8, 0x8a, 0x05, 0x5c]
+                            .into_iter()
+                            .chain((*b"Test appdata.").into_iter())
+                            .chain(std::iter::repeat(0).take(3))
+                            .collect::<Vec<_>>();
+
+                        uds.set_appdata(&appdata)?;
+
+                        println!("Press A to stop data transfer");
+                        state = State::Created;
+                    }
+                    Err(e) => {
+                        console.clear();
+                        eprintln!("Error while creating network: {e}");
+                        state = State::Initialised;
+                        println!("Press A to start scanning or B to create a new network");
+                    }
+                }
+            }
+            State::Created => {
+                let packet = uds.pull_packet();
+
+                match packet {
+                    Ok(p) => {
+                        if let Some((pkt, node)) = p {
+                            println!(
+                                "{:02X}{:02X}{:02X}{:02X} from {:?}",
+                                pkt[0], pkt[1], pkt[2], pkt[3], node
+                            );
+                        }
+
+                        if uds.wait_status_event(false, false)? {
+                            prev_node_mask = handle_status_event(&uds, prev_node_mask)?;
+                        }
+
+                        if hid.keys_down().contains(KeyPad::A) {
+                            uds.destroy_network()?;
+                            state = State::Initialised;
+                            console.clear();
+                            println!("Press A to start scanning or B to create a new network");
+                        } else if !hid.keys_down().is_empty() || !hid.keys_up().is_empty() {
+                            let transfer_data = hid.keys_held().bits();
+                            uds.send_packet(
+                                &transfer_data.to_le_bytes(),
+                                NodeID::Broadcast,
+                                data_channel,
+                                SendFlags::Default,
+                            )?;
+                        }
+                    }
+                    Err(e) => {
+                        uds.destroy_network()?;
+                        console.clear();
+                        eprintln!("Error while grabbing packet from network: {e}");
+                        state = State::Initialised;
+                        println!("Press A to start scanning or B to create a new network");
+                    }
+                }
+            }
+        }
+    }
+
+    Ok(())
+}

ctru-rs/examples/software-keyboard.rs

@@ -5,8 +5,6 @@
 use ctru::applets::swkbd::{Button, CallbackResult, SoftwareKeyboard};
 use ctru::prelude::*;
 
-use std::ffi::CString;
-
 fn main() {
     let apt = Apt::new().unwrap();
     let mut hid = Hid::new().unwrap();
@@ -21,13 +19,9 @@ fn main() {
     // Custom filter callback to handle the given input.
     // Using this callback it's possible to integrate the applet
     // with custom error messages when the input is incorrect.
-    keyboard.set_filter_callback(Some(Box::new(|str| {
-        // The string is guaranteed to contain valid Unicode text, so we can safely unwrap and use it as a normal `&str`.
-        if str.to_str().unwrap().contains("boo") {
-            return (
-                CallbackResult::Retry,
-                Some(CString::new("Ah, you scared me!").unwrap()),
-            );
+    keyboard.set_filter_callback(Some(Box::new(move |str| {
+        if str.contains("boo") {
+            return (CallbackResult::Retry, Some("Ah, you scared me!".into()));
         }
 
         (CallbackResult::Ok, None)

ctru-rs/src/applets/error.rs

@@ -0,0 +1,153 @@
+//! Error applet.
+//!
+//! This applet displays error text as a pop-up message on the lower screen.
+
+use crate::services::{apt::Apt, gfx::Gfx};
+
+use ctru_sys::errorConf;
+
+/// Configuration struct to set up the Error applet.
+#[doc(alias = "errorConf")]
+pub struct PopUp {
+    state: Box<errorConf>,
+}
+
+/// Determines whether the Error applet will use word wrapping when displaying a message.
+#[doc(alias = "errorType")]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[repr(u32)]
+pub enum WordWrap {
+    /// Error text is centered in the error applet window and does not use word wrapping.
+    Disabled = ctru_sys::ERROR_TEXT,
+    /// Error text starts at the top of the error applet window and uses word wrapping.
+    Enabled = ctru_sys::ERROR_TEXT_WORD_WRAP,
+}
+
+/// Error returned by an unsuccessful [`PopUp::launch()`].
+#[doc(alias = "errorReturnCode")]
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+#[repr(i8)]
+pub enum Error {
+    /// Unknown error occurred.
+    Unknown = ctru_sys::ERROR_UNKNOWN,
+    /// Operation not supported.
+    NotSupported = ctru_sys::ERROR_NOT_SUPPORTED,
+    /// Home button pressed while [`PopUp`] was running.
+    HomePressed = ctru_sys::ERROR_HOME_BUTTON,
+    /// Power button pressed while [`PopUp`] was running.
+    PowerPressed = ctru_sys::ERROR_POWER_BUTTON,
+    /// Reset button pressed while [`PopUp`] was running.
+    ResetPressed = ctru_sys::ERROR_SOFTWARE_RESET,
+}
+
+impl PopUp {
+    /// Initializes the error applet with the provided word wrap setting.
+    #[doc(alias = "errorInit")]
+    pub fn new(word_wrap: WordWrap) -> Self {
+        let mut state = Box::<errorConf>::default();
+
+        unsafe { ctru_sys::errorInit(state.as_mut(), word_wrap as _, 0) };
+
+        Self { state }
+    }
+
+    /// Sets the error text to display.
+    ///
+    /// # Notes
+    ///
+    /// The text will be converted to UTF-16 for display with the applet, and the message will be truncated if it exceeds
+    /// 1900 UTF-16 code units in length after conversion.
+    #[doc(alias = "errorText")]
+    pub fn set_text(&mut self, text: &str) {
+        for (idx, code_unit) in text
+            .encode_utf16()
+            .take(self.state.Text.len() - 1)
+            .chain(std::iter::once(0))
+            .enumerate()
+        {
+            self.state.Text[idx] = code_unit;
+        }
+    }
+
+    /// Launches the error applet.
+    #[doc(alias = "errorDisp")]
+    pub fn launch(&mut self, _apt: &Apt, _gfx: &Gfx) -> Result<(), Error> {
+        unsafe { self.launch_unchecked() }
+    }
+
+    /// Launches the error applet without requiring an [`Apt`] or [`Gfx`] handle.
+    ///
+    /// # Safety
+    ///
+    /// Potentially leads to undefined behavior if the aforementioned services are not actually active when the applet launches.
+    unsafe fn launch_unchecked(&mut self) -> Result<(), Error> {
+        unsafe { ctru_sys::errorDisp(self.state.as_mut()) };
+
+        match self.state.returnCode {
+            ctru_sys::ERROR_NONE | ctru_sys::ERROR_SUCCESS => Ok(()),
+            ctru_sys::ERROR_NOT_SUPPORTED => Err(Error::NotSupported),
+            ctru_sys::ERROR_HOME_BUTTON => Err(Error::HomePressed),
+            ctru_sys::ERROR_POWER_BUTTON => Err(Error::PowerPressed),
+            ctru_sys::ERROR_SOFTWARE_RESET => Err(Error::ResetPressed),
+            _ => Err(Error::Unknown),
+        }
+    }
+}
+
+/// Sets a custom [panic hook](https://doc.rust-lang.org/std/panic/fn.set_hook.html) that uses the error applet to display panic messages.
+///
+/// You can also choose to have the previously registered panic hook called along with the error applet popup, which can be useful
+/// if you want to use output redirection to display panic messages over `3dslink` or `GDB`.
+///
+/// You can use [`std::panic::take_hook`](https://doc.rust-lang.org/std/panic/fn.take_hook.html) to unregister the panic hook
+/// set by this function.
+///
+/// # Notes
+///
+/// * If the [`Gfx`] service is not initialized during a panic, the error applet will not be displayed and the old panic hook will be called.
+pub fn set_panic_hook(call_old_hook: bool) {
+    use crate::services::gfx::GFX_ACTIVE;
+    use std::sync::TryLockError;
+
+    let old_hook = std::panic::take_hook();
+
+    std::panic::set_hook(Box::new(move |panic_info| {
+        // If we get a `WouldBlock` error, we know that the `Gfx` service has been initialized.
+        // Otherwise fallback to using the old panic hook.
+        if let (Err(TryLockError::WouldBlock), Ok(_apt)) = (GFX_ACTIVE.try_lock(), Apt::new()) {
+            if call_old_hook {
+                old_hook(panic_info);
+            }
+
+            let thread = std::thread::current();
+
+            let name = thread.name().unwrap_or("<unnamed>");
+
+            let message = format!("thread '{name}' {panic_info}");
+
+            let mut popup = PopUp::new(WordWrap::Enabled);
+
+            popup.set_text(&message);
+
+            unsafe {
+                let _ = popup.launch_unchecked();
+            }
+        } else {
+            old_hook(panic_info);
+        }
+    }));
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::NotSupported => write!(f, "operation not supported"),
+            Self::HomePressed => write!(f, "home button pressed while error applet was running"),
+            Self::PowerPressed => write!(f, "power button pressed while error applet was running"),
+            Self::ResetPressed => write!(f, "reset button pressed while error applet was running"),
+            Self::Unknown => write!(f, "an unknown error occurred"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}

ctru-rs/src/applets/mod.rs

@@ -8,5 +8,6 @@
 //!
 //! Applets block execution of the thread that launches them as long as the user doesn't close the applet.
 
+pub mod error;
 pub mod mii_selector;
 pub mod swkbd;

ctru-rs/src/applets/swkbd.rs

@@ -6,27 +6,25 @@
 use crate::services::{apt::Apt, gfx::Gfx};
 use ctru_sys::{
     aptLaunchLibraryApplet, aptSetMessageCallback, envGetAptAppId, svcCloseHandle,
-    svcCreateMemoryBlock, APT_SendParameter, SwkbdButton, SwkbdDictWord, SwkbdExtra,
-    SwkbdLearningData, SwkbdState, SwkbdStatusData, APPID_SOFTWARE_KEYBOARD, APTCMD_MESSAGE,
-    NS_APPID,
+    svcCreateMemoryBlock, APT_SendParameter, SwkbdButton, SwkbdDictWord, SwkbdLearningData,
+    SwkbdState, SwkbdStatusData, APPID_SOFTWARE_KEYBOARD, APTCMD_MESSAGE, NS_APPID,
 };
 
 use bitflags::bitflags;
 
-use std::ffi::{CStr, CString};
+use std::borrow::Cow;
 use std::fmt::Display;
 use std::iter::once;
 use std::str;
 
-type CallbackFunction = dyn Fn(&CStr) -> (CallbackResult, Option<CString>);
+type CallbackFunction = dyn Fn(&str) -> (CallbackResult, Option<Cow<'static, str>>);
 
 /// Configuration structure to setup the Software Keyboard applet.
 #[doc(alias = "SwkbdState")]
 pub struct SoftwareKeyboard {
     state: Box<SwkbdState>,
-    callback: Option<Box<CallbackFunction>>,
-    error_message: Option<CString>,
-    initial_text: Option<CString>,
+    filter_callback: Option<Box<CallbackFunction>>,
+    initial_text: Option<Cow<'static, str>>,
 }
 
 /// Configuration structure to setup the Parental Lock applet.
@@ -212,9 +210,9 @@ bitflags! {
 }
 
 // Internal book-keeping struct used to send data to `aptSetMessageCallback` when calling the software keyboard.
-// We only need this because libctru doesn't keep a pointer to the shared memory block in `SwkbdExtra` for whatever reason
+#[derive(Copy, Clone)]
 struct MessageCallbackData {
-    extra: *mut SwkbdExtra,
+    filter_callback: *const Box<CallbackFunction>,
     swkbd_shared_mem_ptr: *mut libc::c_void,
 }
 
@@ -243,8 +241,7 @@ impl SoftwareKeyboard {
             ctru_sys::swkbdInit(state.as_mut(), keyboard_type.into(), buttons.into(), -1);
             Self {
                 state,
-                callback: None,
-                error_message: None,
+                filter_callback: None,
                 initial_text: None,
             }
         }
@@ -272,24 +269,15 @@ impl SoftwareKeyboard {
     /// # }
     /// ```
     #[doc(alias = "swkbdInputText")]
-    pub fn launch(&mut self, _apt: &Apt, _gfx: &Gfx) -> Result<(String, Button), Error> {
+    pub fn launch(&mut self, apt: &Apt, gfx: &Gfx) -> Result<(String, Button), Error> {
         let mut output = String::new();
 
-        unsafe {
-            // The filter callback gets reset every time the SoftwareKeyboard is used.
-            ctru_sys::swkbdSetFilterCallback(
-                self.state.as_mut(),
-                Some(Self::internal_callback),
-                (self as *mut Self).cast(),
-            );
-
-            match self.swkbd_input_text(&mut output) {
-                ctru_sys::SWKBD_BUTTON_NONE => Err(self.state.result.into()),
-                ctru_sys::SWKBD_BUTTON_LEFT => Ok((output, Button::Left)),
-                ctru_sys::SWKBD_BUTTON_MIDDLE => Ok((output, Button::Middle)),
-                ctru_sys::SWKBD_BUTTON_RIGHT => Ok((output, Button::Right)),
-                _ => unreachable!(),
-            }
+        match self.swkbd_input_text(&mut output, apt, gfx) {
+            ctru_sys::SWKBD_BUTTON_NONE => Err(self.state.result.into()),
+            ctru_sys::SWKBD_BUTTON_LEFT => Ok((output, Button::Left)),
+            ctru_sys::SWKBD_BUTTON_MIDDLE => Ok((output, Button::Middle)),
+            ctru_sys::SWKBD_BUTTON_RIGHT => Ok((output, Button::Right)),
+            _ => unreachable!(),
         }
     }
 
@@ -355,17 +343,13 @@ impl SoftwareKeyboard {
     /// # fn main() {
     /// #
     /// use std::borrow::Cow;
-    /// use std::ffi::CString;
     /// use ctru::applets::swkbd::{SoftwareKeyboard, CallbackResult};
     ///
     /// let mut keyboard = SoftwareKeyboard::default();
     ///
-    /// keyboard.set_filter_callback(Some(Box::new(|str| {
-    ///     if str.to_str().unwrap().contains("boo") {
-    ///         return (
-    ///             CallbackResult::Retry,
-    ///             Some(CString::new("Ah, you scared me!").unwrap()),
-    ///         );
+    /// keyboard.set_filter_callback(Some(Box::new(move |str| {
+    ///     if str.contains("boo") {
+    ///         return (CallbackResult::Retry, Some("Ah, you scared me!".into()));
     ///     }
     ///
     ///     (CallbackResult::Ok, None)
@@ -373,45 +357,7 @@ impl SoftwareKeyboard {
     /// #
     /// # }
     pub fn set_filter_callback(&mut self, callback: Option<Box<CallbackFunction>>) {
-        self.callback = callback;
-    }
-
-    /// Internal function called by the filter callback.
-    extern "C" fn internal_callback(
-        user: *mut libc::c_void,
-        pp_message: *mut *const libc::c_char,
-        text: *const libc::c_char,
-        _text_size: libc::size_t,
-    ) -> ctru_sys::SwkbdCallbackResult {
-        let this: *mut SoftwareKeyboard = user.cast();
-
-        unsafe {
-            // Reset any leftover error message.
-            (*this).error_message = None;
-
-            let text = CStr::from_ptr(text);
-
-            let result = {
-                // Run the callback if still available.
-                if let Some(callback) = &mut (*this).callback {
-                    let (res, cstr) = callback(text);
-
-                    // Due to how `libctru` operates, the user is expected to keep the error message alive until
-                    // the end of the Software Keyboard prompt. We ensure that happens by saving it within the configuration.
-                    (*this).error_message = cstr;
-
-                    if let Some(newstr) = &(*this).error_message {
-                        *pp_message = newstr.as_ptr();
-                    }
-
-                    res
-                } else {
-                    CallbackResult::Ok
-                }
-            };
-
-            result.into()
-        }
+        self.filter_callback = callback;
     }
 
     /// Configure the maximum number of digits that can be entered in the keyboard when the [`Filters::DIGITS`] flag is enabled.
@@ -444,6 +390,10 @@ impl SoftwareKeyboard {
     ///
     /// The initial text is the text already written when you open the software keyboard.
     ///
+    /// # Notes
+    ///
+    /// Passing [`None`] will clear the initial text.
+    ///
     /// # Example
     ///
     /// ```
@@ -453,30 +403,25 @@ impl SoftwareKeyboard {
     /// use ctru::applets::swkbd::SoftwareKeyboard;
     /// let mut keyboard = SoftwareKeyboard::default();
     ///
-    /// keyboard.set_initial_text(Some("Write here what you like!"));
+    /// keyboard.set_initial_text(Some("Write here what you like!".into()));
     /// #
     /// # }
     #[doc(alias = "swkbdSetInitialText")]
-    pub fn set_initial_text(&mut self, text: Option<&str>) {
-        if let Some(text) = text {
-            let initial_text = CString::new(text).unwrap();
-
-            unsafe {
-                ctru_sys::swkbdSetInitialText(self.state.as_mut(), initial_text.as_ptr());
-            }
-
-            self.initial_text = Some(initial_text);
-        } else {
-            unsafe { ctru_sys::swkbdSetInitialText(self.state.as_mut(), std::ptr::null()) };
-
-            self.initial_text = None;
-        }
+    pub fn set_initial_text(&mut self, text: Option<Cow<'static, str>>) {
+        self.initial_text = text;
     }
 
     /// Set the hint text for this software keyboard.
     ///
     /// The hint text is the text shown in gray before any text gets written in the input box.
     ///
+    /// # Notes
+    ///
+    /// Passing [`None`] will clear the hint text.
+    ///
+    /// The hint text will be converted to UTF-16 when passed to the software keyboard, and the text will be truncated
+    /// if the length exceeds 64 code units after conversion.
+    ///
     /// # Example
     ///
     /// ```
@@ -486,14 +431,22 @@ impl SoftwareKeyboard {
     /// use ctru::applets::swkbd::SoftwareKeyboard;
     /// let mut keyboard = SoftwareKeyboard::default();
     ///
-    /// keyboard.set_hint_text("Write here what you like!");
+    /// keyboard.set_hint_text(Some("Write here what you like!"));
     /// #
     /// # }
     #[doc(alias = "swkbdSetHintText")]
-    pub fn set_hint_text(&mut self, text: &str) {
-        unsafe {
-            let nul_terminated: String = text.chars().chain(once('\0')).collect();
-            ctru_sys::swkbdSetHintText(self.state.as_mut(), nul_terminated.as_ptr());
+    pub fn set_hint_text(&mut self, text: Option<&str>) {
+        if let Some(text) = text {
+            for (idx, code_unit) in text
+                .encode_utf16()
+                .take(self.state.hint_text.len() - 1)
+                .chain(once(0))
+                .enumerate()
+            {
+                self.state.hint_text[idx] = code_unit;
+            }
+        } else {
+            self.state.hint_text[0] = 0;
         }
     }
 
@@ -588,15 +541,18 @@ impl SoftwareKeyboard {
     /// # }
     #[doc(alias = "swkbdSetButton")]
     pub fn configure_button(&mut self, button: Button, text: &str, submit: bool) {
-        unsafe {
-            let nul_terminated: String = text.chars().chain(once('\0')).collect();
-            ctru_sys::swkbdSetButton(
-                self.state.as_mut(),
-                button.into(),
-                nul_terminated.as_ptr(),
-                submit,
-            );
+        let button_text = &mut self.state.button_text[button as usize];
+
+        for (idx, code_unit) in text
+            .encode_utf16()
+            .take(button_text.len() - 1)
+            .chain(once(0))
+            .enumerate()
+        {
+            button_text[idx] = code_unit;
         }
+
+        self.state.button_submits_text[button as usize] = submit;
     }
 
     /// Configure the maximum number of UTF-16 code units that can be entered into the software
@@ -630,10 +586,9 @@ impl SoftwareKeyboard {
         self.state.valid_input = ValidInput::FixedLen.into();
     }
 
-    // A reimplementation of `swkbdInputText` from `libctru/source/applets/swkbd.c`. Allows us to
-    // get text from the software keyboard and put it directly into a `String` without requiring
-    // an intermediate fixed-size buffer
-    fn swkbd_input_text(&mut self, output: &mut String) -> SwkbdButton {
+    // A reimplementation of `swkbdInputText` from `libctru/source/applets/swkbd.c`. Allows us to fix various
+    // API nits and get rid of awkward type conversions when interacting with the Software Keyboard.
+    fn swkbd_input_text(&mut self, output: &mut String, _apt: &Apt, _gfx: &Gfx) -> SwkbdButton {
         use ctru_sys::{
             MEMPERM_READ, MEMPERM_WRITE, R_FAILED, SWKBD_BUTTON_LEFT, SWKBD_BUTTON_MIDDLE,
             SWKBD_BUTTON_NONE, SWKBD_BUTTON_RIGHT, SWKBD_D0_CLICK, SWKBD_D1_CLICK0,
@@ -642,7 +597,7 @@ impl SoftwareKeyboard {
         };
 
         let swkbd = self.state.as_mut();
-        let mut extra = unsafe { swkbd.__bindgen_anon_1.extra };
+        let extra = unsafe { swkbd.__bindgen_anon_1.extra };
 
         // Calculate shared mem size
         let mut shared_mem_size = 0;
@@ -714,19 +669,17 @@ impl SoftwareKeyboard {
         }
 
         // Copy stuff to shared mem
-        if !extra.initial_text.is_null() {
+        if let Some(initial_text) = self.initial_text.as_deref() {
             swkbd.initial_text_offset = 0;
 
-            unsafe {
-                let utf16_iter =
-                    str::from_utf8_unchecked(CStr::from_ptr(extra.initial_text).to_bytes())
-                        .encode_utf16()
-                        .take(swkbd.max_text_len as _)
-                        .chain(once(0));
-
-                let mut initial_text_cursor = swkbd_shared_mem_ptr.cast();
+            let mut initial_text_cursor = swkbd_shared_mem_ptr.cast();
 
-                for code_unit in utf16_iter {
+            for code_unit in initial_text
+                .encode_utf16()
+                .take(swkbd.max_text_len as _)
+                .chain(once(0))
+            {
+                unsafe {
                     *initial_text_cursor = code_unit;
                     initial_text_cursor = initial_text_cursor.add(1);
                 }
@@ -766,7 +719,7 @@ impl SoftwareKeyboard {
             };
         }
 
-        if extra.callback.is_some() {
+        if self.filter_callback.is_some() {
             swkbd.filter_flags |= SWKBD_FILTER_CALLBACK;
         } else {
             swkbd.filter_flags &= !SWKBD_FILTER_CALLBACK;
@@ -776,16 +729,19 @@ impl SoftwareKeyboard {
         unsafe {
             swkbd.__bindgen_anon_1.reserved.fill(0);
 
-            let mut callback_data = MessageCallbackData {
-                extra: std::ptr::addr_of_mut!(extra),
+            // We need to pass a thin pointer to the boxed closure over FFI. Since we know that the message callback will finish before
+            // `self` is allowed to be moved again, we can safely use a pointer to the local value contained in `self.filter_callback`
+            // The cast here is also sound since the pointer will only be read from if `self.filter_callback.is_some()` returns true.
+            let mut data = MessageCallbackData {
+                filter_callback: std::ptr::addr_of!(self.filter_callback).cast(),
                 swkbd_shared_mem_ptr,
             };
 
-            if extra.callback.is_some() {
+            if self.filter_callback.is_some() {
                 aptSetMessageCallback(
                     Some(Self::swkbd_message_callback),
-                    std::ptr::addr_of_mut!(callback_data).cast(),
-                );
+                    std::ptr::addr_of_mut!(data).cast(),
+                )
             }
 
             aptLaunchLibraryApplet(
@@ -795,7 +751,7 @@ impl SoftwareKeyboard {
                 swkbd_shared_mem_handle,
             );
 
-            if extra.callback.is_some() {
+            if self.filter_callback.is_some() {
                 aptSetMessageCallback(None, std::ptr::null_mut());
             }
 
@@ -846,63 +802,46 @@ impl SoftwareKeyboard {
     }
 
     // A reimplementation of `swkbdMessageCallback` from `libctru/source/applets/swkbd.c`.
-    // This function sets up and then calls the callback set by `swkbdSetFilterCallback`
-    #[deny(unsafe_op_in_unsafe_fn)]
+    // This function sets up and then calls the filter callback
     unsafe extern "C" fn swkbd_message_callback(
         user: *mut libc::c_void,
         sender: NS_APPID,
         msg: *mut libc::c_void,
         msg_size: libc::size_t,
     ) {
-        let data = unsafe { &mut *user.cast::<MessageCallbackData>() };
-        let swkbd = unsafe { &mut *msg.cast::<SwkbdState>() };
-        let extra = unsafe { &mut *data.extra };
-
         if sender != ctru_sys::APPID_SOFTWARE_KEYBOARD
             || msg_size != std::mem::size_of::<SwkbdState>()
         {
             return;
         }
 
+        let swkbd = unsafe { &mut *msg.cast::<SwkbdState>() };
+        let data = unsafe { *user.cast::<MessageCallbackData>() };
+
         let text16 = unsafe {
             widestring::Utf16Str::from_slice_unchecked(std::slice::from_raw_parts(
                 data.swkbd_shared_mem_ptr.add(swkbd.text_offset as _).cast(),
-                swkbd.text_length as usize + 1,
+                swkbd.text_length as _,
             ))
         };
 
         let text8 = text16.to_string();
 
-        let mut retmsg = std::ptr::null();
+        let filter_callback = unsafe { &**data.filter_callback };
 
-        if let Some(cb) = extra.callback {
-            swkbd.callback_result = unsafe {
-                cb(
-                    extra.callback_user,
-                    &mut retmsg,
-                    text8.as_ptr(),
-                    text8.len(),
-                )
-            } as _
-        };
+        let (result, retmsg) = filter_callback(&text8);
 
-        let retmsg = if !retmsg.is_null() {
-            unsafe {
-                let len = libc::strlen(retmsg) + 1;
-                std::str::from_utf8_unchecked(std::slice::from_raw_parts(retmsg, len))
-            }
-        } else {
-            "\0"
-        };
+        swkbd.callback_result = result as _;
 
-        let callback_msg = &mut swkbd.callback_msg;
-
-        for (idx, code_unit) in retmsg
-            .encode_utf16()
-            .take(callback_msg.len() - 1)
-            .enumerate()
-        {
-            callback_msg[idx] = code_unit;
+        if let Some(msg) = retmsg.as_deref() {
+            for (idx, code_unit) in msg
+                .encode_utf16()
+                .take(swkbd.callback_msg.len() - 1)
+                .chain(once(0))
+                .enumerate()
+            {
+                swkbd.callback_msg[idx] = code_unit;
+            }
         }
 
         let _ = unsafe {

ctru-rs/src/console.rs

@@ -6,7 +6,6 @@
 //! Have a look at [`Soc::redirect_to_3dslink()`](crate::services::soc::Soc::redirect_to_3dslink) for a better alternative when debugging applications.
 
 use std::cell::{RefMut, UnsafeCell};
-use std::default::Default;
 
 use ctru_sys::{consoleClear, consoleInit, consoleSelect, consoleSetWindow, PrintConsole};
 

ctru-rs/src/lib.rs

@@ -18,9 +18,11 @@
 #![crate_type = "rlib"]
 #![crate_name = "ctru"]
 #![warn(missing_docs)]
+#![deny(unsafe_op_in_unsafe_fn)]
 #![feature(custom_test_frameworks)]
 #![feature(try_trait_v2)]
 #![feature(allocator_api)]
+#![feature(new_uninit)]
 #![test_runner(test_runner::run_gdb)] // TODO: does this make sense to have configurable?
 #![doc(
     html_favicon_url = "https://user-images.githubusercontent.com/11131775/225929072-2fa1741c-93ae-4b47-9bdf-af70f3d59910.png"

ctru-rs/src/linear.rs

@@ -42,6 +42,8 @@ unsafe impl Allocator for LinearAllocator {
 
     #[doc(alias = "linearFree")]
     unsafe fn deallocate(&self, ptr: NonNull<u8>, _layout: Layout) {
-        ctru_sys::linearFree(ptr.as_ptr().cast());
+        unsafe {
+            ctru_sys::linearFree(ptr.as_ptr().cast());
+        }
     }
 }

ctru-rs/src/services/am.rs

@@ -51,6 +51,11 @@ impl<'a> Title<'a> {
     pub fn version(&self) -> u16 {
         self.version
     }
+
+    /// Returns this title's media type
+    pub fn media_type(&self) -> MediaType {
+        self.mediatype
+    }
 }
 
 /// Handle to the Application Manager service.

ctru-rs/src/services/apt.rs

@@ -82,6 +82,48 @@ impl Apt {
             Ok(())
         }
     }
+
+    /// Set if the console is allowed to enter sleep mode.
+    ///
+    /// You can check whether the console is allowed to sleep with [Apt::is_sleep_allowed].
+    #[doc(alias = "aptSetSleepAllowed")]
+    pub fn set_sleep_allowed(&mut self, allowed: bool) {
+        unsafe {
+            ctru_sys::aptSetSleepAllowed(allowed);
+        }
+    }
+
+    /// Check if the console is allowed to enter sleep mode.
+    ///
+    /// You can set whether the console is allowed to sleep with [Apt::set_sleep_allowed].
+    #[doc(alias = "aptIsSleepAllowed")]
+    pub fn is_sleep_allowed(&self) -> bool {
+        unsafe { ctru_sys::aptIsSleepAllowed() }
+    }
+
+    /// Set if the console is allowed to enter the home menu.
+    ///
+    /// You can check whether the console is allowed to enter the home menu with [Apt::is_home_allowed].
+    #[doc(alias = "aptSetHomeAllowed")]
+    pub fn set_home_allowed(&mut self, allowed: bool) {
+        unsafe {
+            ctru_sys::aptSetHomeAllowed(allowed);
+        }
+    }
+
+    /// Check if the console is allowed to enter the home menu.
+    ///
+    /// You can set whether the console is allowed to enter the home menu with [Apt::set_home_allowed].
+    #[doc(alias = "aptIsHomeAllowed")]
+    pub fn is_home_allowed(&self) -> bool {
+        unsafe { ctru_sys::aptIsHomeAllowed() }
+    }
+
+    /// Immediately jumps to the home menu.
+    #[doc(alias = "aptJumpToHomeMenu")]
+    pub fn jump_to_home_menu(&mut self) {
+        unsafe { ctru_sys::aptJumpToHomeMenu() }
+    }
 }
 
 impl Drop for Apt {
@@ -90,3 +132,48 @@ impl Drop for Apt {
         unsafe { ctru_sys::aptExit() };
     }
 }
+
+/// Can launch other applications when the current one exits.
+pub struct Chainloader<'a> {
+    _apt: &'a Apt,
+}
+
+impl<'a> Chainloader<'a> {
+    /// Gets a handle to the chainloader
+    pub fn new(apt: &'a Apt) -> Self {
+        Self { _apt: apt }
+    }
+
+    /// Checks if the chainloader is set
+    #[doc(alias = "aptIsChainload")]
+    pub fn is_set(&self) -> bool {
+        // static funtion not exported
+        unsafe { (ctru_sys::envGetSystemRunFlags() & ctru_sys::RUNFLAG_APTCHAINLOAD) != 0 }
+    }
+
+    /// Clears the chainloader state.
+    #[doc(alias = "aptClearChainloader")]
+    pub fn clear(&mut self) {
+        unsafe { ctru_sys::aptClearChainloader() }
+    }
+
+    /// Configures the chainloader to launch a specific application.
+    ///
+    /// See also [`Title`](crate::services::am::Title]
+    #[doc(alias = "aptSetChainloader")]
+    pub fn set(&mut self, title: &super::am::Title<'_>) {
+        unsafe { ctru_sys::aptSetChainloader(title.id(), title.media_type() as u8) }
+    }
+
+    /// Configures the chainloader to launch the previous application.
+    #[doc(alias = "aptSetChainloaderToCaller")]
+    pub fn set_to_caller(&mut self) {
+        unsafe { ctru_sys::aptSetChainloaderToCaller() }
+    }
+
+    /// Configures the chainloader to relaunch the current application (i.e. soft-reset)
+    #[doc(alias = "aptSetChainloaderToSelf")]
+    pub fn set_to_self(&mut self) {
+        unsafe { ctru_sys::aptSetChainloaderToSelf() }
+    }
+}

ctru-rs/src/services/gfx.rs

@@ -239,7 +239,7 @@ pub struct Gfx {
     _service_handler: ServiceReference,
 }
 
-static GFX_ACTIVE: Mutex<()> = Mutex::new(());
+pub(crate) static GFX_ACTIVE: Mutex<()> = Mutex::new(());
 
 impl Gfx {
     /// Initialize a new default service handle.

ctru-rs/src/services/ir_user.rs

@@ -150,7 +150,7 @@ impl IrUser {
                         shared_mem.shared_memory_layout,
                     );
 
-                    Ok(())
+                    Ok::<_, Error>(())
                 })()
                 .unwrap();
             },
@@ -347,9 +347,11 @@ impl IrUser {
         let mut shared_mem_guard = IR_USER_STATE.lock().unwrap();
         let shared_mem = shared_mem_guard.as_mut().unwrap();
 
-        shared_mem
-            .service_handle
-            .send_service_request(request, expected_response_len)
+        unsafe {
+            shared_mem
+                .service_handle
+                .send_service_request(request, expected_response_len)
+        }
     }
 }
 

ctru-rs/src/services/mod.rs

@@ -26,6 +26,7 @@ mod reference;
 pub mod soc;
 pub mod sslc;
 pub mod svc;
+pub mod uds;
 
 cfg_if::cfg_if! {
     if #[cfg(all(feature = "romfs", romfs_exists))] {

ctru-rs/src/services/ndsp/mod.rs

@@ -21,7 +21,6 @@ use crate::error::ResultCode;
 use crate::services::ServiceReference;
 
 use std::cell::{RefCell, RefMut};
-use std::default::Default;
 use std::error;
 use std::fmt;
 use std::sync::Mutex;

ctru-rs/src/services/svc.rs

@@ -50,19 +50,28 @@ impl HandleExt for Handle {
     ) -> crate::Result<Vec<u32>> {
         // Copy over the request
         let cmd_buffer_ptr = unsafe { ctru_sys::getThreadCommandBuffer() };
-        std::ptr::copy_nonoverlapping(request.as_ptr(), cmd_buffer_ptr, request.len());
 
-        // Send the request
-        ResultCode(ctru_sys::svcSendSyncRequest(self))?;
+        unsafe {
+            std::ptr::copy_nonoverlapping(request.as_ptr(), cmd_buffer_ptr, request.len());
+
+            // Send the request
+            ResultCode(ctru_sys::svcSendSyncRequest(self))?;
 
-        // Handle the result returned by the service
-        let result = unsafe { std::ptr::read(cmd_buffer_ptr.add(1)) };
-        ResultCode(result as ctru_sys::Result)?;
+            // Handle the result returned by the service
+            let result = std::ptr::read(cmd_buffer_ptr.add(1));
+            ResultCode(result as ctru_sys::Result)?;
+        }
 
         // Copy back the response
         request.clear();
         request.resize(expected_response_len, 0);
-        std::ptr::copy_nonoverlapping(cmd_buffer_ptr, request.as_mut_ptr(), expected_response_len);
+        unsafe {
+            std::ptr::copy_nonoverlapping(
+                cmd_buffer_ptr,
+                request.as_mut_ptr(),
+                expected_response_len,
+            );
+        }
 
         Ok(request)
     }

ctru-sys/Cargo.toml

@@ -3,7 +3,7 @@ name = "ctru-sys"
 version = "0.5.0"
 authors = ["Rust3DS Org", "Ronald Kinard <furyhunter600@gmail.com>"]
 description = "Raw bindings to libctru"
-repository = "https://github.com/rust3ds/ctru-rs"
+repository = "https://git.xenua.me/rust3ds/ctru-rs"
 documentation = "https://rust3ds.github.io/ctru-rs/crates/ctru_sys"
 keywords = ["3ds", "libctru"]
 categories = ["os", "external-ffi-bindings", "no-std", "hardware-support"]
@@ -23,8 +23,8 @@ itertools = "0.11.0"
 which = "4.4.0"
 
 [dev-dependencies]
-shim-3ds = { git = "https://github.com/rust3ds/shim-3ds.git" }
-test-runner = { git = "https://github.com/rust3ds/test-runner.git" }
+shim-3ds = { git = "https://git.xenua.me/rust3ds/shim-3ds.git" }
+test-runner = { git = "https://git.xenua.me/rust3ds/test-runner.git" }
 
 [package.metadata.docs.rs]
 default-target = "armv6k-nintendo-3ds"

ctru-sys/build.rs

@@ -73,12 +73,14 @@ fn main() {
         .use_core()
         .trust_clang_mangling(false)
         .must_use_type("Result")
-        .layout_tests(false)
+        .layout_tests(true)
         .ctypes_prefix("::libc")
         .prepend_enum_name(false)
         .blocklist_type("u(8|16|32|64)")
         .blocklist_type("__builtin_va_list")
         .blocklist_type("__va_list")
+        .blocklist_type("errorReturnCode")
+        .blocklist_type("errorScreenFlag")
         .opaque_type("MiiData")
         .derive_default(true)
         .wrap_static_fns(true)

ctru-sys/src/lib.rs

@@ -16,6 +16,24 @@
 pub mod result;
 pub use result::*;
 
+// Fun fact: C compilers are allowed to represent enums as the smallest integer type that can hold all of its variants,
+// meaning that enums are allowed to be the size of a `c_short` or a `c_char` rather than the size of a `c_int`.
+// Libctru's `errorConf` struct contains two enums that depend on this narrowing property for size and alignment purposes,
+// and since `bindgen` generates all enums with `c_int` sizing, we have to blocklist those types and manually define them
+// here with the proper size.
+pub type errorReturnCode = libc::c_schar;
+pub const ERROR_UNKNOWN: errorReturnCode = -1;
+pub const ERROR_NONE: errorReturnCode = 0;
+pub const ERROR_SUCCESS: errorReturnCode = 1;
+pub const ERROR_NOT_SUPPORTED: errorReturnCode = 2;
+pub const ERROR_HOME_BUTTON: errorReturnCode = 10;
+pub const ERROR_SOFTWARE_RESET: errorReturnCode = 11;
+pub const ERROR_POWER_BUTTON: errorReturnCode = 12;
+
+pub type errorScreenFlag = libc::c_char;
+pub const ERROR_NORMAL: errorScreenFlag = 0;
+pub const ERROR_STEREO: errorScreenFlag = 1;
+
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));
 
 /// In lieu of a proper errno function exposed by libc