init: Maintain default service env vars separate from init env vars

With this only the env vars set using export or explicitly specify for a
service are passed to services (in addition to RUST_BACKTRACE, PATH and
LD_LIBRARY_PATH). As such we no longer need to manually unset bootloader
env vars to keep the environment clean. And finally this means that env
var substitutions in shell scripts always use the bootloader provided
env vars rather than locally specified ones.

This does regress multi monitor support when there is no proper graphics
driver.

init.d/20_graphics

@@ -1,7 +1,5 @@
 scheme input inputd
 notify FRAMEBUFFER_ADDR=$ FRAMEBUFFER_VIRT=$ FRAMEBUFFER_WIDTH=$ FRAMEBUFFER_HEIGHT=$ FRAMEBUFFER_STRIDE=$ vesad
-unset FRAMEBUFFER_ADDR FRAMEBUFFER_VIRT FRAMEBUFFER_WIDTH FRAMEBUFFER_HEIGHT FRAMEBUFFER_STRIDE
-#TODO: unset FRAMEBUFFER1 and beyond?
 scheme fbbootlog fbbootlogd
 # Activate framebuffer log VT, which disables kernel graphical debug
 inputd -A 1

init.d/40_drivers

@@ -1,4 +1,3 @@
 notify ps2d
 notify RSDP_ADDR=$ RSDP_SIZE=$ hwd
-unset RSDP_ADDR RSDP_SIZE
 pcid-spawner --initfs

init.d/50_rootfs

@@ -1,2 +1 @@
 REDOXFS_PASSWORD_ADDR=$ REDOXFS_PASSWORD_SIZE=$ redoxfs --uuid $REDOXFS_UUID file $REDOXFS_BLOCK
-unset REDOXFS_UUID REDOXFS_BLOCK REDOXFS_PASSWORD_ADDR REDOXFS_PASSWORD_SIZE

init/src/main.rs

@@ -1,4 +1,6 @@
+use std::collections::BTreeMap;
 use std::env;
+use std::ffi::OsString;
 use std::io::Result;
 use std::path::Path;
 
@@ -23,6 +25,7 @@ fn switch_stdio(stdio: &str) -> Result<()> {
 struct InitConfig {
     log_debug: bool,
     skip_cmd: Vec<String>,
+    envs: BTreeMap<String, OsString>,
 }
 
 impl InitConfig {
@@ -37,15 +40,20 @@ impl InitConfig {
         Self {
             log_debug,
             skip_cmd,
+            envs: BTreeMap::from([("RUST_BACKTRACE".to_owned(), "1".into())]),
         }
     }
 }
 
-fn switch_root(prefix: &Path, etcdir: &Path, config: &InitConfig) {
-    unsafe {
-        env::set_var("PATH", prefix.join("bin"));
-        env::set_var("LD_LIBRARY_PATH", prefix.join("lib"));
-    }
+fn switch_root(prefix: &Path, etcdir: &Path, config: &mut InitConfig) {
+    config
+        .envs
+        .insert("PATH".to_owned(), prefix.join("bin").into_os_string());
+    config.envs.insert(
+        "LD_LIBRARY_PATH".to_owned(),
+        prefix.join("lib").into_os_string(),
+    );
+
     let entries = match config::config_for_dirs(&[
         prefix.join("lib").join("init.d"),
         etcdir.join("init.d"),
@@ -64,7 +72,7 @@ fn switch_root(prefix: &Path, etcdir: &Path, config: &InitConfig) {
     }
 }
 
-fn run(file: &Path, config: &InitConfig) -> Result<()> {
+fn run(file: &Path, config: &mut InitConfig) -> Result<()> {
     let (script, errors) = script::Script::from_file(file)?;
 
     for error in errors {
@@ -81,7 +89,7 @@ fn run(file: &Path, config: &InitConfig) -> Result<()> {
     Ok(())
 }
 
-fn run_command(cmd: Command, config: &InitConfig) {
+fn run_command(cmd: Command, config: &mut InitConfig) {
     match cmd {
         Command::Nothing => {}
         Command::Echo(text) => println!("{text}"),
@@ -105,7 +113,7 @@ fn run_command(cmd: Command, config: &InitConfig) {
                 return;
             }
 
-            let mut command = cmd.into_command();
+            let mut command = cmd.into_command(&config.envs);
 
             match command.spawn() {
                 Ok(_child) => {}
@@ -118,7 +126,7 @@ fn run_command(cmd: Command, config: &InitConfig) {
                 return;
             }
 
-            let command = cmd.into_command();
+            let command = cmd.into_command(&config.envs);
 
             daemon::Daemon::spawn(command);
         }
@@ -128,7 +136,7 @@ fn run_command(cmd: Command, config: &InitConfig) {
                 return;
             }
 
-            let command = cmd.into_command();
+            let command = cmd.into_command(&config.envs);
 
             daemon::SchemeDaemon::spawn(command, &scheme);
         }
@@ -138,7 +146,7 @@ fn run_command(cmd: Command, config: &InitConfig) {
                 return;
             }
 
-            let mut command = cmd.into_command();
+            let mut command = cmd.into_command(&config.envs);
 
             let mut child = match command.spawn() {
                 Ok(child) => child,
@@ -162,11 +170,11 @@ fn run_command(cmd: Command, config: &InitConfig) {
 }
 
 fn main() {
-    let init_config = InitConfig::new();
+    let mut init_config = InitConfig::new();
     switch_root(
         Path::new("/scheme/initfs"),
         Path::new("/scheme/initfs/etc"),
-        &init_config,
+        &mut init_config,
     );
 
     libredox::call::setrens(0, 0).expect("init: failed to enter null namespace");

init/src/script.rs

@@ -1,3 +1,5 @@
+use std::collections::BTreeMap;
+use std::ffi::OsString;
 use std::path::{Path, PathBuf};
 use std::{env, fs, io, iter, process};
 
@@ -149,9 +151,10 @@ impl Process {
         }
     }
 
-    pub fn into_command(self) -> process::Command {
+    pub fn into_command(self, base_envs: &BTreeMap<String, OsString>) -> process::Command {
         let mut command = process::Command::new(self.cmd);
-        command.args(self.args).envs(self.envs);
+        command.args(self.args);
+        command.env_clear().envs(base_envs).envs(self.envs);
         command
     }
 }