From 1035b91a3dfae936144631d846652a7914acaeb5 Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Thu, 11 May 2023 20:11:09 +0200
Subject: [PATCH] su: Do not change directory/set variables by default, instead
 add a --login option

---
 apps/login.cpp           |  2 +-
 apps/su.cpp              | 12 ++++++++++--
 initrd/etc/init/99-login |  1 -
 3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/apps/login.cpp b/apps/login.cpp
index 9b8e14fd..055e6532 100644
--- a/apps/login.cpp
+++ b/apps/login.cpp
@@ -38,7 +38,7 @@ Result<int> luna_main(int argc, char** argv)
         username = name.view();
     }
 
-    execl("/bin/su", "login", "-p", "--", username.chars(), nullptr);
+    execl("/bin/su", "login", "-lp", "--", username.chars(), nullptr);
 
     perror("su");
     return 1;
diff --git a/apps/su.cpp b/apps/su.cpp
index 0f6d8486..0696311b 100644
--- a/apps/su.cpp
+++ b/apps/su.cpp
@@ -55,6 +55,7 @@ Result<int> luna_main(int argc, char** argv)
 {
     StringView name;
     bool prompt_password;
+    bool login;
 
     if (geteuid() != 0)
     {
@@ -67,6 +68,7 @@ Result<int> luna_main(int argc, char** argv)
     parser.add_system_program_info("su"_sv);
     parser.add_positional_argument(name, "name"_sv, "root"_sv);
     parser.add_switch_argument(prompt_password, 'p', "prompt", "prompt for a password even if running as root");
+    parser.add_switch_argument(login, 'l', "login"_sv, "change directory to the user's home and start a login shell");
     parser.parse(argc, argv);
 
     struct passwd* entry = getpwnam(name.chars());
@@ -93,10 +95,16 @@ Result<int> luna_main(int argc, char** argv)
     setgid(entry->pw_gid);
     setuid(entry->pw_uid);
 
-    chdir(entry->pw_dir);
+    if (login)
+    {
+        chdir(entry->pw_dir);
+        clearenv();
+        setenv("PATH", "/bin:/sbin", 1);
+    }
+
+    if (login || entry->pw_uid != 0) setenv("USER", entry->pw_name, 1);
 
     setenv("HOME", entry->pw_dir, 1);
-    setenv("USER", entry->pw_name, 1);
     setenv("SHELL", entry->pw_shell, 1);
 
     execl(entry->pw_shell, entry->pw_shell, NULL);
diff --git a/initrd/etc/init/99-login b/initrd/etc/init/99-login
index 631fd293..60edcd26 100644
--- a/initrd/etc/init/99-login
+++ b/initrd/etc/init/99-login
@@ -1,4 +1,3 @@
 Name=login
 Command=/bin/login
 Restart=true
-Environment=PATH=/bin:/sbin