Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 221 insertions, 0 deletions

diff --git a/third_party/rust/android_system_properties/src/lib.rs b/third_party/rust/android_system_properties/src/lib.rs
new file mode 100644
index 0000000000..9cd9d49161
--- /dev/null
+++ b/third_party/rust/android_system_properties/src/lib.rs
@@ -0,0 +1,221 @@
+//! A thin rust wrapper for Android system properties.
+//!
+//! This crate is similar to the `android-properties` crate with the exception that
+//! the necessary Android libc symbols are loaded dynamically instead of linked
+//! statically. In practice this means that the same binary will work with old and
+//! new versions of Android, even though the API for reading system properties changed
+//! around Android L.
+//!
+//! ## Example
+//!
+//! ```rust
+//! use android_system_properties::AndroidSystemProperties;
+//!
+//! let properties = AndroidSystemProperties::new();
+//!
+//! if let Some(value) = properties.get("persist.sys.timezone") {
+//!    println!("{}", value);
+//! }
+//! ```
+//!
+//! ## Listing and setting properties
+//!
+//! For the sake of simplicity this crate currently only contains what's needed by wgpu.
+//! The implementations for listing and setting properties can be added back if anyone needs
+//! them (let me know by filing an issue).
+//!
+//! ## License
+//!
+//! Licensed under either of
+//!
+//!  * Apache License, Version 2.0 ([LICENSE-APACHE] or <http://www.apache.org/licenses/LICENSE-2.0>)
+//!  * MIT license ([LICENSE-MIT] or <http://opensource.org/licenses/MIT>)
+//!
+//! at your option.
+//!
+//! [LICENSE-APACHE]: https://github.com/nical/android_system_properties/blob/804681c5c1c93d4fab29c1a2f47b7d808dc70fd3/LICENSE-APACHE
+//! [LICENSE-MIT]: https://github.com/nical/android_system_properties/blob/804681c5c1c93d4fab29c1a2f47b7d808dc70fd3/LICENSE-MIT
+
+use std::{
+    ffi::{CStr, CString},
+    os::raw::{c_char, c_int, c_void},
+};
+
+#[cfg(target_os = "android")]
+use std::mem;
+
+unsafe fn property_callback(payload: *mut String, _name: *const c_char, value: *const c_char, _serial: u32) {
+    let cvalue = CStr::from_ptr(value);
+    (*payload) = cvalue.to_str().unwrap().to_string();
+}
+
+type Callback = unsafe fn(*mut String, *const c_char, *const c_char, u32);
+
+type SystemPropertyGetFn = unsafe extern "C" fn(*const c_char, *mut c_char) -> c_int;
+type SystemPropertyFindFn = unsafe extern "C" fn(*const c_char) -> *const c_void;
+type SystemPropertyReadCallbackFn = unsafe extern "C" fn(*const c_void, Callback, *mut String) -> *const c_void;
+
+#[derive(Debug)]
+/// An object that can retrieve android system properties.
+///
+/// ## Example
+///
+/// ```
+/// use android_system_properties::AndroidSystemProperties;
+///
+/// let properties = AndroidSystemProperties::new();
+///
+/// if let Some(value) = properties.get("persist.sys.timezone") {
+///    println!("{}", value);
+/// }
+/// ```
+pub struct AndroidSystemProperties {
+    libc_so: *mut c_void,
+    get_fn: Option<SystemPropertyGetFn>,
+    find_fn: Option<SystemPropertyFindFn>,
+    read_callback_fn: Option<SystemPropertyReadCallbackFn>,
+}
+
+unsafe impl Send for AndroidSystemProperties {}
+unsafe impl Sync for AndroidSystemProperties {}
+
+impl AndroidSystemProperties {
+    #[cfg(not(target_os = "android"))]
+    /// Create an entry point for accessing Android properties.
+    pub fn new() -> Self {
+        AndroidSystemProperties {
+            libc_so: std::ptr::null_mut(),
+            find_fn: None,
+            read_callback_fn: None,
+            get_fn: None,
+        }
+    }
+
+    #[cfg(target_os = "android")]
+    /// Create an entry point for accessing Android properties.
+    pub fn new() -> Self {
+        let libc_so = unsafe { libc::dlopen(b"libc.so\0".as_ptr().cast(), libc::RTLD_NOLOAD) };
+
+        let mut properties = AndroidSystemProperties {
+            libc_so,
+            find_fn: None,
+            read_callback_fn: None,
+            get_fn: None,
+        };
+
+        if libc_so.is_null() {
+            return properties;
+        }
+
+
+        unsafe fn load_fn(libc_so: *mut c_void, name: &[u8]) -> Option<*const c_void> {
+            let fn_ptr = libc::dlsym(libc_so, name.as_ptr().cast());
+
+            if fn_ptr.is_null() {
+                return None;
+            }
+
+            Some(fn_ptr)
+        }
+
+        unsafe {
+            properties.read_callback_fn = load_fn(libc_so, b"__system_property_read_callback\0")
+                .map(|raw| mem::transmute::<*const c_void, SystemPropertyReadCallbackFn>(raw));
+
+            properties.find_fn = load_fn(libc_so, b"__system_property_find\0")
+                .map(|raw| mem::transmute::<*const c_void, SystemPropertyFindFn>(raw));
+
+            // Fallback for old versions of Android.
+            if properties.read_callback_fn.is_none() || properties.find_fn.is_none() {
+                properties.get_fn = load_fn(libc_so, b"__system_property_get\0")
+                    .map(|raw| mem::transmute::<*const c_void, SystemPropertyGetFn>(raw));
+            }
+        }
+
+        properties
+    }
+
+    /// Retrieve a system property.
+    ///
+    /// Returns None if the operation fails.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use android_system_properties::AndroidSystemProperties;
+    /// let properties = AndroidSystemProperties::new();
+    ///
+    /// if let Some(value) = properties.get("persist.sys.timezone") {
+    ///     println!("{}", value);
+    /// }
+    /// ```
+    pub fn get(&self, name: &str) -> Option<String> {
+        let cname = CString::new(name).ok()?;
+        self.get_from_cstr(&cname)
+    }
+
+    /// Retrieve a system property using a [`CStr`] key.
+    ///
+    /// Returns None if the operation fails.
+    ///
+    /// # Example
+    ///
+    /// ```
+    /// # use android_system_properties::AndroidSystemProperties;
+    /// # use std::ffi::CStr;
+    /// let properties = AndroidSystemProperties::new();
+    ///
+    /// let key = unsafe { CStr::from_bytes_with_nul_unchecked(b"persist.sys.timezone\0") };
+    /// if let Some(value) = properties.get_from_cstr(key) {
+    ///     println!("{}", value);
+    /// }
+    /// ```
+    pub fn get_from_cstr(&self, cname: &std::ffi::CStr) -> Option<String> {
+        // If available, use the recommended approach to accessing properties (Android L and onward).
+        if let (Some(find_fn), Some(read_callback_fn)) = (self.find_fn, self.read_callback_fn) {
+            let info = unsafe { (find_fn)(cname.as_ptr()) };
+
+            if info.is_null() {
+                return None;
+            }
+
+            let mut result = String::new();
+
+            unsafe {
+                (read_callback_fn)(info, property_callback, &mut result);
+            }
+
+            return Some(result);
+        }
+
+        // Fall back to the older approach.
+        if let Some(get_fn) = self.get_fn {
+            // The constant is PROP_VALUE_MAX in Android's libc/include/sys/system_properties.h
+            const PROPERTY_VALUE_MAX: usize = 92;
+            let mut buffer: Vec<u8> = Vec::with_capacity(PROPERTY_VALUE_MAX);
+            let raw = buffer.as_mut_ptr() as *mut c_char;
+
+            let len = unsafe { (get_fn)(cname.as_ptr(), raw) };
+
+            if len > 0 {
+                assert!(len as usize <= buffer.capacity());
+                unsafe { buffer.set_len(len as usize); }
+                String::from_utf8(buffer).ok()
+            } else {
+                None
+            }
+        } else {
+            None
+        }
+    }
+}
+
+impl Drop for AndroidSystemProperties {
+    fn drop(&mut self) {
+        if !self.libc_so.is_null() {
+            unsafe {
+                libc::dlclose(self.libc_so);
+            }
+        }
+    }
+}