Better error messages for sudo

2017-02-27 15:34:35 -07:00
parent b1e0ae8722
commit 1ee223f926
1 changed files with 78 additions and 55 deletions
@@ -3,7 +3,7 @@ extern crate userutils;

 use std::env;
 use std::fs::File;
-use std::io::Read;
+use std::io::{stderr, Read, Write};
 use std::os::unix::process::CommandExt;
 use std::process::{self, Command};

@@ -11,60 +11,83 @@ use userutils::{Passwd, Group};

 pub fn main() {
    let mut args = env::args().skip(1);
-    let cmd = args.next().expect("sudo: no command provided");
-
-    let uid = syscall::getuid().unwrap() as u32;
-
-    if uid != 0 {
-        let mut passwd_string = String::new();
-        File::open("/etc/passwd").unwrap().read_to_string(&mut passwd_string).unwrap();
-
-        let mut passwd_option = None;
-        for line in passwd_string.lines() {
-            if let Ok(passwd) = Passwd::parse(line) {
-                if uid == passwd.uid {
-                    passwd_option = Some(passwd);
-                    break;
-                }
-            }
-        }
-
-        let passwd = passwd_option.expect("sudo: user not found in passwd");
-
-        let mut group_string = String::new();
-        File::open("/etc/group").unwrap().read_to_string(&mut group_string).unwrap();
-
-        let mut group_option = None;
-        for line in group_string.lines() {
-            if let Ok(group) = Group::parse(line) {
-                if group.group == "sudo" && group.users.split(',').any(|name| name == passwd.user) {
-                    group_option = Some(group);
-                    break;
-                }
-            }
-        }
-
-        if group_option.is_none() {
-            panic!("sudo: '{}' not in sudo group", passwd.user);
-        }
-    }
-
-    let mut command = Command::new(&cmd);
-    for arg in args {
-        command.arg(&arg);
-    }
-
-    command.uid(0);
-    command.gid(0);
-    command.env("USER", "root");
-    command.env("UID", "0");
-    command.env("GROUPS", "0");
-
-    match command.spawn() {
-        Ok(mut child) => match child.wait() {
-            Ok(status) => process::exit(status.code().unwrap_or(0)),
-            Err(err) => panic!("sudo: failed to wait for {}: {}", cmd, err)
+    match args.next() {
+        None => {
+            writeln!(stderr(), "sudo: no command provided").unwrap();
+            process::exit(1);
        },
-        Err(err) => panic!("sudo: failed to execute {}: {}", cmd, err)
+        Some(cmd) => {
+            let uid = syscall::getuid().unwrap() as u32;
+
+            if uid != 0 {
+                let mut passwd_string = String::new();
+                if let Ok(mut file) = File::open("/etc/passwd") {
+                    let _ = file.read_to_string(&mut passwd_string);
+                }
+
+                let mut passwd_option = None;
+                for line in passwd_string.lines() {
+                    if let Ok(passwd) = Passwd::parse(line) {
+                        if uid == passwd.uid {
+                            passwd_option = Some(passwd);
+                            break;
+                        }
+                    }
+                }
+
+                match passwd_option {
+                    None => {
+                        writeln!(stderr(), "sudo: user not found in passwd").unwrap();
+                        process::exit(1);
+                    },
+                    Some(passwd) => {
+                        let mut group_string = String::new();
+                        if let Ok(mut file) = File::open("/etc/group") {
+                            let _ = file.read_to_string(&mut group_string);
+                        }
+
+                        let mut group_option = None;
+                        for line in group_string.lines() {
+                            if let Ok(group) = Group::parse(line) {
+                                if group.group == "sudo" && group.users.split(',').any(|name| name == passwd.user) {
+                                    group_option = Some(group);
+                                    break;
+                                }
+                            }
+                        }
+
+                        if group_option.is_none() {
+                            writeln!(stderr(), "sudo: '{}' not in sudo group", passwd.user).unwrap();
+                            process::exit(1);
+                        }
+                    }
+                }
+            }
+
+            let mut command = Command::new(&cmd);
+            for arg in args {
+                command.arg(&arg);
+            }
+
+            command.uid(0);
+            command.gid(0);
+            command.env("USER", "root");
+            command.env("UID", "0");
+            command.env("GROUPS", "0");
+
+            match command.spawn() {
+                Ok(mut child) => match child.wait() {
+                    Ok(status) => process::exit(status.code().unwrap_or(0)),
+                    Err(err) => {
+                        writeln!(stderr(), "sudo: failed to wait for {}: {}", cmd, err).unwrap();
+                        process::exit(1);
+                    }
+                },
+                Err(err) => {
+                    writeln!(stderr(), "sudo: failed to execute {}: {}", cmd, err).unwrap();
+                    process::exit(1);
+                }
+            }
+        }
    }
 }