From 769132af531e3d6a80981b04475dce68c162a616 Mon Sep 17 00:00:00 2001
From: netjaileRS <groche@gmail.com>
Date: Mon, 23 Sep 2024 18:01:59 +0200
Subject: [PATCH] Start using function pointers

---
 src/main.rs                     |  2 +-
 src/namespace/bind_interface.rs | 27 ++++++++++++++++-----------
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/src/main.rs b/src/main.rs
index 3340774..ee61c8c 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -11,5 +11,5 @@ fn main() {
     //namespace::create_ns::create_ns();
     let ns_name = "test-newns".to_string();
     block_on(NetworkNamespace::add(ns_name.clone()));
-    namespace::bind_interface::run_in_namespace(&ns_name);
+    namespace::bind_interface::run_in_namespace(|| {namespace::bind_interface::set_lo_up().unwrap();},&ns_name);
 }
diff --git a/src/namespace/bind_interface.rs b/src/namespace/bind_interface.rs
index 0618ae0..4710224 100644
--- a/src/namespace/bind_interface.rs
+++ b/src/namespace/bind_interface.rs
@@ -21,7 +21,7 @@ use std::process::exit;
 use std::os::unix::io::RawFd;
 use std::os::fd::FromRawFd;
 
-pub fn run_in_namespace(ns_name: &String) -> Result<(), ()> {
+pub fn run_in_namespace<F>(f: F,ns_name: &String) -> Result<(), ()> where F:FnMut() + Copy {
     // Configure networking in the child namespace:
     // Fork a process that is set to the newly created namespace
     // Here set the veth ip addr, routing tables etc.
@@ -34,12 +34,12 @@ pub fn run_in_namespace(ns_name: &String) -> Result<(), ()> {
 
     unsafe {
         match clone(
-            Box::new(|| run_child(&ns_name.clone())),
+            Box::new(|| run_child(f,&ns_name.clone())),
             &mut tmp_stack,
             flags,
             Some(Signal::SIGCHLD as i32)) {
-                Ok(pid) => Ok(()),
-                Err(e) => {
+                Ok(_pid) => Ok(()),
+                Err(_e) => {
                     return Err(());
                 }
             }
@@ -47,8 +47,8 @@ pub fn run_in_namespace(ns_name: &String) -> Result<(), ()> {
 
 }
 
-fn run_child(ns_name: &String) -> isize {
-    let res = split_namespace(ns_name);
+fn run_child<F>(mut f: F, ns_name: &String) -> isize where F:FnMut() {
+    let res = prepare_namespace(ns_name);
 
     match res {
         Err(_) => {
@@ -57,12 +57,13 @@ fn run_child(ns_name: &String) -> isize {
         }
         Ok(()) => {
             log::debug!("Child exited normally");
+            f();
             return 0;
         }
     }
 }
 
-fn split_namespace(ns_name: &String) -> Result<(), ()> {
+fn prepare_namespace(ns_name: &String) -> Result<(), ()> {
     // First create the network namespace
     // NetworkNamespace::add(ns_name.to_string()).await.map_err(|e| {
     //     log::error!("Can not create namespace {}", e);
@@ -114,10 +115,16 @@ fn split_namespace(ns_name: &String) -> Result<(), ()> {
     // TODO do not exit for EINVAL error
     // unmount_path(&sys_path)?;
     // consider the case that a sysfs is not present
-    let stat_sys = statvfs(&sys_path)
+    let stat_sys = match statvfs(&sys_path)
         .map_err(|e| {
             log::error!("Can not stat sys: {}", e);
-    }).unwrap();
+    }){
+        Ok(stat) => stat,
+        Err(_e) => {
+            log::error!("Error in stat sys");
+            return Err(());
+        }
+    };
     if stat_sys.flags().contains(FsFlags::ST_RDONLY) {
         mount_flags.insert(MsFlags::MS_RDONLY);
     }
@@ -128,8 +135,6 @@ fn split_namespace(ns_name: &String) -> Result<(), ()> {
         ()
     }
 
-    set_lo_up().unwrap();
-
     Ok(())
 }