ksud: support set-manager (#114)

* ksud: support set-manager

* ksud: rework apk sign

Co-authored-by: Ylarod <me@ylarod.cn>

userspace/ksud/src/debug.rs

@@ -0,0 +1,61 @@
+use anyhow::{ensure, Context, Ok, Result};
+use std::{
+    path::{Path, PathBuf},
+    process::Command,
+};
+
+use crate::apk_sign::get_apk_signature;
+
+const KERNEL_PARAM_PATH: &str = "/sys/module/kernelsu";
+
+fn read_u32(path: &PathBuf) -> Result<u32> {
+    let content = std::fs::read_to_string(path)?;
+    let content = content.trim();
+    let content = content.parse::<u32>()?;
+    Ok(content)
+}
+
+fn set_kernel_param(size: u32, hash: u32) -> Result<()> {
+    let kernel_param_path = Path::new(KERNEL_PARAM_PATH).join("parameters");
+    let expeced_size_path = kernel_param_path.join("ksu_expected_size");
+    let expeced_hash_path = kernel_param_path.join("ksu_expected_hash");
+
+    println!(
+        "before size: {:#x} hash: {:#x}",
+        read_u32(&expeced_size_path)?,
+        read_u32(&expeced_hash_path)?
+    );
+
+    std::fs::write(&expeced_size_path, size.to_string())?;
+    std::fs::write(&expeced_hash_path, hash.to_string())?;
+
+    println!(
+        "after size: {:#x} hash: {:#x}",
+        read_u32(&expeced_size_path)?,
+        read_u32(&expeced_hash_path)?
+    );
+
+    Ok(())
+}
+
+fn get_apk_path(package_name: &str) -> Result<String> {
+    let cmd = format!("pm path {}", package_name);
+    let output = Command::new("sh").arg("-c").arg(cmd).output()?;
+
+    // package:/data/app/<xxxx>/base.apk
+    let output = String::from_utf8_lossy(&output.stdout);
+    let path = output.trim().replace("package:", "");
+    Ok(path)
+}
+
+pub fn set_manager(pkg: &str) -> Result<()> {
+    ensure!(
+        Path::new(KERNEL_PARAM_PATH).exists(),
+        "CONFIG_KSU_DEBUG is not enabled"
+    );
+
+    let path = get_apk_path(pkg).with_context(|| format!("{} not exist!", pkg))?;
+    let sign = get_apk_signature(path.as_str())?;
+    set_kernel_param(sign.0, sign.1)?;
+    Ok(())
+}