Add sudo command, add effective UID and GID, and groups file

Makefile

@@ -29,9 +29,12 @@ clean:
 	cargo clean --manifest-path drivers/pcid/Cargo.toml
 	cargo clean --manifest-path drivers/vesad/Cargo.toml
 	cargo clean --manifest-path programs/getty/Cargo.toml
+	cargo clean --manifest-path programs/id/Cargo.toml
 	cargo clean --manifest-path programs/init/Cargo.toml
+	cargo clean --manifest-path programs/sudo/Cargo.toml
 	cargo clean --manifest-path programs/ion/Cargo.toml
 	cargo clean --manifest-path programs/login/Cargo.toml
+	cargo clean --manifest-path programs/sudo/Cargo.toml
 	cargo clean --manifest-path programs/coreutils/Cargo.toml
 	cargo clean --manifest-path programs/extrautils/Cargo.toml
 	cargo clean --manifest-path programs/smith/Cargo.toml
@@ -279,7 +282,8 @@ $(BUILD)/filesystem.bin: \
 		filesystem/bin/id \
 		filesystem/bin/ion \
 		filesystem/bin/login \
-		filesystem/bin/smith
+		filesystem/bin/smith \
+		filesystem/bin/sudo
 	rm -rf $@ $(BUILD)/filesystem/
 	echo exit | cargo run --manifest-path schemes/redoxfs/Cargo.toml --bin redoxfs-utility $@ 8
 	mkdir -p $(BUILD)/filesystem/
@@ -290,6 +294,7 @@ $(BUILD)/filesystem.bin: \
 	-chown -R 1000:1000 $(BUILD)/filesystem/home/user/
 	-chmod 700 $(BUILD)/filesystem/root/
 	-chmod 700 $(BUILD)/filesystem/home/user/
+	-chmod +s $(BUILD)/filesystem/bin/sudo
 	sync
 	-fusermount -u $(BUILD)/filesystem/
 	rm -rf $(BUILD)/filesystem/

filesystem/etc/group

@@ -0,0 +1 @@
+sudo;1;user

kernel/context/context.rs

@@ -22,10 +22,14 @@ pub struct Context {
     pub id: usize,
     /// The ID of the parent context
     pub ppid: usize,
-    /// The user id
-    pub uid: u32,
-    /// The group id
-    pub gid: u32,
+    /// The real user id
+    pub ruid: u32,
+    /// The real group id
+    pub rgid: u32,
+    /// The effective user id
+    pub euid: u32,
+    /// The effective group id
+    pub egid: u32,
     /// Status of context
     pub status: Status,
     /// Context running or not
@@ -62,8 +66,10 @@ impl Context {
         Context {
             id: id,
             ppid: 0,
-            uid: 0,
-            gid: 0,
+            ruid: 0,
+            rgid: 0,
+            euid: 0,
+            egid: 0,
             status: Status::Blocked,
             running: false,
             vfork: false,

kernel/scheme/user.rs

@@ -38,7 +38,7 @@ impl UserInner {
             let contexts = context::contexts();
             let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
             let context = context_lock.read();
-            (context.id, context.uid, context.gid)
+            (context.id, context.euid, context.egid)
         };
 
         let id = self.next_id.fetch_add(1, Ordering::SeqCst);

kernel/syscall/fs.rs

@@ -11,7 +11,7 @@ pub fn file_op(a: usize, fd: usize, c: usize, d: usize) -> Result<usize> {
         let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
         let context = context_lock.read();
         let file = context.get_file(fd).ok_or(Error::new(EBADF))?;
-        (file, context.id, context.uid, context.gid)
+        (file, context.id, context.euid, context.egid)
     };
 
     let scheme = {
@@ -74,7 +74,7 @@ pub fn open(path: &[u8], flags: usize) -> Result<usize> {
         let contexts = context::contexts();
         let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
         let context = context_lock.read();
-        (context.canonicalize(path), context.uid, context.gid)
+        (context.canonicalize(path), context.euid, context.egid)
     };
 
     let mut parts = path_canon.splitn(2, |&b| b == b':');
@@ -107,7 +107,7 @@ pub fn mkdir(path: &[u8], mode: u16) -> Result<usize> {
         let contexts = context::contexts();
         let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
         let context = context_lock.read();
-        (context.canonicalize(path), context.uid, context.gid)
+        (context.canonicalize(path), context.euid, context.egid)
     };
 
     let mut parts = path_canon.splitn(2, |&b| b == b':');
@@ -129,7 +129,7 @@ pub fn rmdir(path: &[u8]) -> Result<usize> {
         let contexts = context::contexts();
         let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
         let context = context_lock.read();
-        (context.canonicalize(path), context.uid, context.gid)
+        (context.canonicalize(path), context.euid, context.egid)
     };
 
     let mut parts = path_canon.splitn(2, |&b| b == b':');
@@ -151,7 +151,7 @@ pub fn unlink(path: &[u8]) -> Result<usize> {
         let contexts = context::contexts();
         let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
         let context = context_lock.read();
-        (context.canonicalize(path), context.uid, context.gid)
+        (context.canonicalize(path), context.euid, context.egid)
     };
 
     let mut parts = path_canon.splitn(2, |&b| b == b':');

kernel/syscall/mod.rs

@@ -55,6 +55,8 @@ pub extern fn syscall(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize
                 SYS_GETCWD => getcwd(validate_slice_mut(b as *mut u8, c)?),
                 SYS_GETUID => getuid(),
                 SYS_GETGID => getgid(),
+                SYS_GETEUID => geteuid(),
+                SYS_GETEGID => getegid(),
                 SYS_SETUID => setuid(b as u32),
                 SYS_SETGID => setgid(b as u32),
                 SYS_PHYSALLOC => physalloc(b),

kernel/syscall/process.rs

@@ -1,7 +1,7 @@
 ///! Process syscalls
 use alloc::arc::Arc;
 use alloc::boxed::Box;
-use collections::Vec;
+use collections::{BTreeMap, Vec};
 use core::mem;
 use core::str;
 use spin::Mutex;
@@ -58,8 +58,10 @@ pub fn clone(flags: usize, stack_base: usize) -> Result<usize> {
     let ppid;
     let pid;
     {
-        let uid;
-        let gid;
+        let ruid;
+        let rgid;
+        let euid;
+        let egid;
         let arch;
         let vfork;
         let mut kfx_option = None;
@@ -80,8 +82,10 @@ pub fn clone(flags: usize, stack_base: usize) -> Result<usize> {
             let context = context_lock.read();
 
             ppid = context.id;
-            uid = context.uid;
-            gid = context.gid;
+            ruid = context.ruid;
+            rgid = context.rgid;
+            euid = context.euid;
+            egid = context.egid;
 
             arch = context.arch.clone();
 
@@ -191,7 +195,11 @@ pub fn clone(flags: usize, stack_base: usize) -> Result<usize> {
             if flags & CLONE_VM == CLONE_VM {
                 env = context.env.clone();
             } else {
-                env = Arc::new(Mutex::new(context.env.lock().clone()));
+                let mut new_env = BTreeMap::new();
+                for item in context.env.lock().iter() {
+                    new_env.insert(item.0.clone(), Arc::new(Mutex::new(item.1.lock().clone())));
+                }
+                env = Arc::new(Mutex::new(new_env));
             }
 
             if flags & CLONE_FILES == CLONE_FILES {
@@ -253,8 +261,10 @@ pub fn clone(flags: usize, stack_base: usize) -> Result<usize> {
             pid = context.id;
 
             context.ppid = ppid;
-            context.uid = uid;
-            context.gid = gid;
+            context.ruid = ruid;
+            context.rgid = rgid;
+            context.euid = euid;
+            context.egid = egid;
 
             context.status = context::Status::Runnable;
 
@@ -436,7 +446,7 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
             let contexts = context::contexts();
             let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
             let context = context_lock.read();
-            (context.uid, context.gid)
+            (context.euid, context.egid)
         };
 
         let file = syscall::open(path, 0)?;
@@ -483,11 +493,11 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
                     context.grants = Arc::new(Mutex::new(Vec::new()));
 
                     if stat.st_mode & syscall::flag::MODE_SETUID == syscall::flag::MODE_SETUID {
-                        context.uid = stat.st_uid;
+                        context.euid = stat.st_uid;
                     }
 
                     if stat.st_mode & syscall::flag::MODE_SETGID == syscall::flag::MODE_SETGID {
-                        context.gid = stat.st_gid;
+                        context.egid = stat.st_gid;
                     }
 
                     // Map and copy new segments
@@ -612,11 +622,25 @@ pub fn exec(path: &[u8], arg_ptrs: &[[usize; 2]]) -> Result<usize> {
     unsafe { usermode(entry, sp); }
 }
 
+pub fn getegid() -> Result<usize> {
+    let contexts = context::contexts();
+    let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+    let context = context_lock.read();
+    Ok(context.egid as usize)
+}
+
+pub fn geteuid() -> Result<usize> {
+    let contexts = context::contexts();
+    let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
+    let context = context_lock.read();
+    Ok(context.euid as usize)
+}
+
 pub fn getgid() -> Result<usize> {
     let contexts = context::contexts();
     let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
     let context = context_lock.read();
-    Ok(context.gid as usize)
+    Ok(context.rgid as usize)
 }
 
 pub fn getpid() -> Result<usize> {
@@ -630,7 +654,7 @@ pub fn getuid() -> Result<usize> {
     let contexts = context::contexts();
     let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
     let context = context_lock.read();
-    Ok(context.uid as usize)
+    Ok(context.ruid as usize)
 }
 
 pub fn iopl(_level: usize) -> Result<usize> {
@@ -734,10 +758,9 @@ pub fn setgid(gid: u32) -> Result<usize> {
     let contexts = context::contexts();
     let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
     let mut context = context_lock.write();
-    if context.gid == 0 {
-        context.gid = gid;
-        Ok(0)
-    } else if context.gid == gid {
+    if context.egid == 0 {
+        context.rgid = gid;
+        context.egid = gid;
         Ok(0)
     } else {
         Err(Error::new(EPERM))
@@ -748,10 +771,9 @@ pub fn setuid(uid: u32) -> Result<usize> {
     let contexts = context::contexts();
     let context_lock = contexts.current().ok_or(Error::new(ESRCH))?;
     let mut context = context_lock.write();
-    if context.uid == 0 {
-        context.uid = uid;
-        Ok(0)
-    } else if context.uid == uid {
+    if context.euid == 0 {
+        context.ruid = uid;
+        context.euid = uid;
         Ok(0)
     } else {
         Err(Error::new(EPERM))

libstd

@@ -1 +1 @@
-Subproject commit 0484051024316956c9e658ed7c3211f76a30a2f9
+Subproject commit 07d687dedcb9a8d76830fd54f6b992cbc3e49aa4

programs/id/src/main.rs

@@ -1,5 +1,3 @@
-#![feature(question_mark)]
-
 extern crate syscall;
 
 use std::env;

programs/login/src/main.rs

@@ -6,9 +6,10 @@ extern crate termion;
 use octavo::octavo_digest::Digest;
 use octavo::octavo_digest::sha3::Sha512;
 use std::fs::File;
-use std::io::{Read, Write};
-use std::process::{Command, CommandExt};
-use std::{io, str};
+use std::io::{self, Read, Write};
+use std::os::unix::process::CommandExt;
+use std::process::Command;
+use std::str;
 use termion::input::TermRead;
 
 pub struct Passwd<'a> {

programs/sudo/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "sudo"
+version = "0.1.0"
+
+[dependencies]
+syscall = { path = "../../syscall/" }

programs/sudo/src/main.rs

@@ -0,0 +1,123 @@
+#![feature(question_mark)]
+
+extern crate syscall;
+
+use std::env;
+use std::fs::File;
+use std::io::Read;
+use std::os::unix::process::CommandExt;
+use std::process::{self, Command};
+
+pub struct Passwd<'a> {
+    user: &'a str,
+    hash: &'a str,
+    uid: u32,
+    gid: u32,
+    name: &'a str,
+    home: &'a str,
+    shell: &'a str
+}
+
+impl<'a> Passwd<'a> {
+    pub fn parse(line: &'a str) -> Result<Passwd<'a>, ()> {
+        let mut parts = line.split(';');
+
+        let user = parts.next().ok_or(())?;
+        let hash = parts.next().ok_or(())?;
+        let uid = parts.next().ok_or(())?.parse::<u32>().or(Err(()))?;
+        let gid = parts.next().ok_or(())?.parse::<u32>().or(Err(()))?;
+        let name = parts.next().ok_or(())?;
+        let home = parts.next().ok_or(())?;
+        let shell = parts.next().ok_or(())?;
+
+        Ok(Passwd {
+            user: user,
+            hash: hash,
+            uid: uid,
+            gid: gid,
+            name: name,
+            home: home,
+            shell: shell
+        })
+    }
+}
+
+pub struct Group<'a> {
+    group: &'a str,
+    gid: u32,
+    users: &'a str,
+}
+
+impl<'a> Group<'a> {
+    pub fn parse(line: &'a str) -> Result<Group<'a>, ()> {
+        let mut parts = line.split(';');
+
+        let group = parts.next().ok_or(())?;
+        let gid = parts.next().ok_or(())?.parse::<u32>().or(Err(()))?;
+        let users = parts.next().ok_or(())?;
+
+        Ok(Group {
+            group: group,
+            gid: gid,
+            users: users
+        })
+    }
+}
+
+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("file: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("file: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");
+
+    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)
+        },
+        Err(err) => panic!("sudo: failed to execute {}: {}", cmd, err)
+    }
+}

syscall/src/lib.rs

@@ -88,6 +88,14 @@ pub fn getcwd(buf: &mut [u8]) -> Result<usize> {
     unsafe { syscall2(SYS_GETCWD, buf.as_mut_ptr() as usize, buf.len()) }
 }
 
+pub fn getegid() -> Result<usize> {
+    unsafe { syscall0(SYS_GETEGID) }
+}
+
+pub fn geteuid() -> Result<usize> {
+    unsafe { syscall0(SYS_GETEUID) }
+}
+
 pub fn getgid() -> Result<usize> {
     unsafe { syscall0(SYS_GETGID) }
 }

syscall/src/number.rs

@@ -35,6 +35,8 @@ pub const SYS_EXECVE: usize =   11;
 pub const SYS_EXIT: usize =     1;
 pub const SYS_FUTEX: usize =    240;
 pub const SYS_GETCWD: usize =   183;
+pub const SYS_GETEGID: usize =  202;
+pub const SYS_GETEUID: usize =  201;
 pub const SYS_GETGID: usize =   200;
 pub const SYS_GETPID: usize =   20;
 pub const SYS_GETUID: usize =   199;