Snap for 8582999 from ddc1fbaba83105acae20ec87e52ab08046bdfb39 to mainline-extservices-release
Change-Id: Ie6a84e3bcced6c1f381f0feaf69352c6cc8aa022
diff --git a/Android.bp b/Android.bp
index dc7beaa..dfe020b 100644
--- a/Android.bp
+++ b/Android.bp
@@ -47,6 +47,7 @@
bindgen_flags: [
"--size_t-is-usize",
"--allowlist-function=__system_property_find",
+ "--allowlist-function=__system_property_foreach",
"--allowlist-function=__system_property_read_callback",
"--allowlist-function=__system_property_set",
"--allowlist-function=__system_property_wait",
diff --git a/system_properties.rs b/system_properties.rs
index d8ab2c8..eb46ec1 100644
--- a/system_properties.rs
+++ b/system_properties.rs
@@ -34,6 +34,9 @@
/// We can only watch for properties that exist when the watcher is created.
#[error("System property is absent")]
SystemPropertyAbsent,
+ /// System properties are not initialized
+ #[error("System properties are not initialized.")]
+ Uninitialized,
/// __system_property_wait timed out despite being given no timeout.
#[error("Wait failed")]
WaitFailed,
@@ -262,6 +265,59 @@
}
}
+/// Iterates through the properties (that the current process is allowed to access).
+pub fn foreach<F>(mut f: F) -> Result<()>
+where
+ F: FnMut(&str, &str),
+{
+ extern "C" fn read_callback<F: FnMut(&str, &str)>(
+ res_p: *mut c_void,
+ name: *const c_char,
+ value: *const c_char,
+ _: system_properties_bindgen::__uint32_t,
+ ) {
+ // SAFETY: system properties are null-terminated C string in UTF-8. See IsLegalPropertyName
+ // and IsLegalPropertyValue in system/core/init/util.cpp.
+ let name = unsafe { CStr::from_ptr(name) }.to_str().unwrap();
+ let value = unsafe { CStr::from_ptr(value) }.to_str().unwrap();
+
+ let ptr = res_p as *mut F;
+ // SAFETY: ptr points to the API user's callback, which was cast to `*mut c_void` below.
+ // Here we're casting it back.
+ let f = unsafe { ptr.as_mut() }.unwrap();
+ f(name, value);
+ }
+
+ extern "C" fn foreach_callback<F: FnMut(&str, &str)>(
+ prop_info: *const PropInfo,
+ res_p: *mut c_void,
+ ) {
+ // SAFETY: FFI call with an internal callback function in Rust, with other parameters
+ // passed through.
+ unsafe {
+ system_properties_bindgen::__system_property_read_callback(
+ prop_info,
+ Some(read_callback::<F>),
+ res_p,
+ )
+ }
+ }
+
+ // SAFETY: FFI call with an internal callback function in Rust, and another client's callback
+ // that's cast only for our own use right above.
+ let retval = unsafe {
+ system_properties_bindgen::__system_property_foreach(
+ Some(foreach_callback::<F>),
+ &mut f as *mut _ as *mut c_void,
+ )
+ };
+ if retval < 0 {
+ Err(PropertyWatcherError::Uninitialized)
+ } else {
+ Ok(())
+ }
+}
+
#[cfg(test)]
mod test {
use super::*;
@@ -286,4 +342,15 @@
assert!(read_bool(prop, true).unwrap_or(false));
assert!(!read_bool(prop, false).unwrap_or(true));
}
+
+ #[test]
+ fn foreach_test() {
+ let mut properties = Vec::new();
+ assert!(foreach(|name, value| {
+ properties.push((name.to_owned(), value.to_owned()));
+ })
+ .is_ok());
+ // Assuming the test runs on Android, any process can at least see some system properties.
+ assert!(!properties.is_empty());
+ }
}
