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/* -*- Mode: rust; rust-indent-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#![allow(non_snake_case)]
use std::ffi::{CStr, OsString};
use std::os::raw::c_char;
#[macro_use]
extern crate serde_derive;
#[macro_use]
extern crate log;
use winapi::shared::ntdef::HRESULT;
use winapi::shared::winerror::{HRESULT_FROM_WIN32, S_OK};
use wio::wide::FromWide;
mod viaduct_wininet;
use viaduct_wininet::WinInetBackend;
// HRESULT with 0x80000000 is an error, 0x20000000 set is a customer error code.
#[allow(overflowing_literals)]
const HR_NETWORK_ERROR: HRESULT = 0x80000000 | 0x20000000 | 0x1;
#[allow(overflowing_literals)]
const HR_SETTINGS_ERROR: HRESULT = 0x80000000 | 0x20000000 | 0x2;
#[derive(Debug, Deserialize)]
pub struct EnabledRecord {
// Unknown fields are ignored by serde: see the docs for `#[serde(deny_unknown_fields)]`.
pub(crate) enabled: bool,
}
pub enum Error {
/// A backend error with an attached Windows error code from `GetLastError()`.
WindowsError(u32),
/// A network or otherwise transient error.
NetworkError,
/// A configuration or settings data error that probably requires code, configuration, or
/// server-side changes to address.
SettingsError,
}
impl From<viaduct::UnexpectedStatus> for Error {
fn from(_err: viaduct::UnexpectedStatus) -> Self {
Error::NetworkError
}
}
impl From<viaduct::Error> for Error {
fn from(err: viaduct::Error) -> Self {
match err {
viaduct::Error::NetworkError(_) => Error::NetworkError,
viaduct::Error::BackendError(raw) => {
// If we have a string that's a hex error code like
// "0xabcde", that's a Windows error.
if raw.starts_with("0x") {
let without_prefix = raw.trim_start_matches("0x");
let parse_result = u32::from_str_radix(without_prefix, 16);
if let Ok(parsed) = parse_result {
return Error::WindowsError(parsed);
}
}
Error::SettingsError
}
_ => Error::SettingsError,
}
}
}
impl From<serde_json::Error> for Error {
fn from(_err: serde_json::Error) -> Self {
Error::SettingsError
}
}
impl From<url::ParseError> for Error {
fn from(_err: url::ParseError) -> Self {
Error::SettingsError
}
}
fn is_agent_remote_disabled<S: AsRef<str>>(url: S) -> Result<bool, Error> {
// Be careful setting the viaduct backend twice. If the backend
// has been set already, assume that it's our backend: we may as
// well at least try to continue.
match viaduct::set_backend(&WinInetBackend) {
Ok(_) => {}
Err(viaduct::Error::SetBackendError) => {}
e => e?,
}
let url = url::Url::parse(url.as_ref())?;
let req = viaduct::Request::new(viaduct::Method::Get, url);
let resp = req.send()?;
let resp = resp.require_success()?;
let body: serde_json::Value = resp.json()?;
let data = body.get("data").ok_or(Error::SettingsError)?;
let record: EnabledRecord = serde_json::from_value(data.clone())?;
let disabled = !record.enabled;
Ok(disabled)
}
// This is an easy way to consume `MOZ_APP_DISPLAYNAME` from Rust code.
extern "C" {
static gWinEventLogSourceName: *const u16;
}
#[allow(dead_code)]
#[no_mangle]
extern "C" fn IsAgentRemoteDisabledRust(szUrl: *const c_char, lpdwDisabled: *mut u32) -> HRESULT {
let wineventlog_name = unsafe { OsString::from_wide_ptr_null(gWinEventLogSourceName) };
let logger = wineventlog::EventLogger::new(&wineventlog_name);
// It's fine to initialize logging twice.
let _ = log::set_boxed_logger(Box::new(logger));
log::set_max_level(log::LevelFilter::Info);
// Use an IIFE for `?`.
let disabled_result = (|| {
if lpdwDisabled.is_null() {
return Err(Error::SettingsError);
}
let url = unsafe { CStr::from_ptr(szUrl).to_str().map(|x| x.to_string()) }
.map_err(|_| Error::SettingsError)?;
info!("Using remote settings URL: {}", url);
is_agent_remote_disabled(url)
})();
match disabled_result {
Err(e) => {
return match e {
Error::WindowsError(errno) => {
let hr = HRESULT_FROM_WIN32(errno);
error!("Error::WindowsError({}) (HRESULT: 0x{:x})", errno, hr);
hr
}
Error::NetworkError => {
let hr = HR_NETWORK_ERROR;
error!("Error::NetworkError (HRESULT: 0x{:x})", hr);
hr
}
Error::SettingsError => {
let hr = HR_SETTINGS_ERROR;
error!("Error::SettingsError (HRESULT: 0x{:x})", hr);
hr
}
};
}
Ok(remote_disabled) => {
// We null-checked `lpdwDisabled` earlier, but just to be safe.
if !lpdwDisabled.is_null() {
unsafe { *lpdwDisabled = if remote_disabled { 1 } else { 0 } };
}
return S_OK;
}
}
}
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