Add misc safe rules (#264)

Author: lucic71

libcc2rs/src/libc_shims/dirent.rs

@@ -25,6 +25,21 @@ impl Default for Dirent {
     }
 }
 
+impl Dirent {
+    pub fn from_entry(ino: u64, name: &[u8], d_type: u8) -> Self {
+        let de = Dirent::default();
+        *de.d_ino.borrow_mut() = ino;
+        *de.d_type.borrow_mut() = d_type;
+        {
+            let mut nm = de.d_name.borrow_mut();
+            let n = name.len().min(nm.len() - 1);
+            nm[..n].copy_from_slice(&name[..n]);
+            nm[n] = 0;
+        }
+        de
+    }
+}
+
 impl Clone for Dirent {
     fn clone(&self) -> Self {
         Self {
@@ -44,6 +59,29 @@ pub struct CDir {
     pub pos: Cell<usize>,
 }
 
+impl CDir {
+    pub fn from_dir(dir: nix::dir::Dir) -> Self {
+        let mut entries: Vec<(u64, Vec<u8>, u8)> = Vec::new();
+        for ent in dir.into_iter().flatten() {
+            let ty = match ent.file_type() {
+                Some(nix::dir::Type::Fifo) => ::libc::DT_FIFO,
+                Some(nix::dir::Type::CharacterDevice) => ::libc::DT_CHR,
+                Some(nix::dir::Type::Directory) => ::libc::DT_DIR,
+                Some(nix::dir::Type::BlockDevice) => ::libc::DT_BLK,
+                Some(nix::dir::Type::File) => ::libc::DT_REG,
+                Some(nix::dir::Type::Symlink) => ::libc::DT_LNK,
+                Some(nix::dir::Type::Socket) => ::libc::DT_SOCK,
+                None => ::libc::DT_UNKNOWN,
+            };
+            entries.push((ent.ino(), ent.file_name().to_bytes().to_vec(), ty));
+        }
+        Self {
+            entries,
+            pos: Cell::new(0),
+        }
+    }
+}
+
 impl ByteRepr for CDir {}
 
 impl ByteRepr for ::libc::dirent {}

libcc2rs/src/libc_shims/pwd.rs

@@ -16,6 +16,25 @@ pub struct Passwd {
     pub pw_shell: Value<Ptr<u8>>,
 }
 
+impl Passwd {
+    pub fn from_user(u: &nix::unistd::User) -> Self {
+        let mk = |s: &[u8]| -> Value<Ptr<u8>> {
+            let mut v = s.to_vec();
+            v.push(0);
+            Rc::new(RefCell::new(Ptr::alloc_array(v.into_boxed_slice())))
+        };
+        Self {
+            pw_name: mk(u.name.as_bytes()),
+            pw_passwd: mk(u.passwd.as_bytes()),
+            pw_uid: Rc::new(RefCell::new(u.uid.as_raw())),
+            pw_gid: Rc::new(RefCell::new(u.gid.as_raw())),
+            pw_gecos: mk(u.gecos.as_bytes()),
+            pw_dir: mk(u.dir.as_os_str().as_encoded_bytes()),
+            pw_shell: mk(u.shell.as_os_str().as_encoded_bytes()),
+        }
+    }
+}
+
 impl Clone for Passwd {
     fn clone(&self) -> Self {
         Self {

libcc2rs/src/libc_shims/stat.rs

@@ -22,6 +22,27 @@ pub struct Stat {
     pub st_ctime: Value<i64>,
 }
 
+impl Stat {
+    #[allow(clippy::unnecessary_cast)]
+    pub fn from_libc(s: &::libc::stat) -> Self {
+        Self {
+            st_dev: Rc::new(RefCell::new(s.st_dev as u64)),
+            st_ino: Rc::new(RefCell::new(s.st_ino as u64)),
+            st_nlink: Rc::new(RefCell::new(s.st_nlink as u64)),
+            st_mode: Rc::new(RefCell::new(s.st_mode as u32)),
+            st_uid: Rc::new(RefCell::new(s.st_uid)),
+            st_gid: Rc::new(RefCell::new(s.st_gid)),
+            st_rdev: Rc::new(RefCell::new(s.st_rdev as u64)),
+            st_size: Rc::new(RefCell::new(s.st_size as i64)),
+            st_blksize: Rc::new(RefCell::new(s.st_blksize as i64)),
+            st_blocks: Rc::new(RefCell::new(s.st_blocks as i64)),
+            st_atime: Rc::new(RefCell::new(s.st_atime as i64)),
+            st_mtime: Rc::new(RefCell::new(s.st_mtime as i64)),
+            st_ctime: Rc::new(RefCell::new(s.st_ctime as i64)),
+        }
+    }
+}
+
 impl Clone for Stat {
     fn clone(&self) -> Self {
         Self {

rules/cstdlib/tgt_refcount.rs

@@ -19,6 +19,17 @@ fn f5(a0: usize, a1: usize) -> AnyPtr {
     libcc2rs::calloc_refcount(a0, a1)
 }
 
+fn f6(a0: Ptr<u8>) -> Ptr<u8> {
+    match ::std::env::var(a0.to_rust_string()) {
+        Ok(__val) => {
+            let mut __bytes = __val.into_bytes();
+            __bytes.push(0);
+            Ptr::alloc_array(__bytes.into_boxed_slice())
+        }
+        Err(_) => Ptr::null(),
+    }
+}
+
 fn f8(a0: AnyPtr, a1: AnyPtr, a2: usize, a3: usize, a4: fn(AnyPtr, AnyPtr) -> i32) -> AnyPtr {
     let __base = a1.reinterpret_cast::<u8>();
     let mut __lo: isize = 0;

rules/dirent/tgt_refcount.rs

@@ -10,3 +10,35 @@ fn t1() -> Ptr<libcc2rs::CDir> {
 fn t2() -> libcc2rs::Dirent {
     Default::default()
 }
+
+fn f1(a0: Ptr<u8>) -> Ptr<CDir> {
+    match nix::dir::Dir::open(
+        a0.to_rust_string().as_str(),
+        nix::fcntl::OFlag::O_RDONLY,
+        nix::sys::stat::Mode::empty(),
+    ) {
+        Ok(__dir) => Ptr::alloc(CDir::from_dir(__dir)),
+        Err(__e) => {
+            libcc2rs::cpp2rust_errno().write(__e as i32);
+            Ptr::null()
+        }
+    }
+}
+
+fn f2(a0: Ptr<CDir>) -> Ptr<Dirent> {
+    a0.with(|__d| {
+        let __i = __d.pos.get();
+        if __i >= __d.entries.len() {
+            Ptr::null()
+        } else {
+            __d.pos.set(__i + 1);
+            let __e = &__d.entries[__i];
+            Ptr::alloc(Dirent::from_entry(__e.0, &__e.1, __e.2))
+        }
+    })
+}
+
+fn f3(a0: Ptr<CDir>) -> i32 {
+    a0.delete();
+    0
+}

rules/locale/tgt_refcount.rs

@@ -0,0 +1,12 @@
+// Copyright (c) 2022-present INESC-ID.
+// Distributed under the MIT license that can be found in the LICENSE file.
+
+use libcc2rs::*;
+
+// Rust does not have support for localization.
+//
+// TODO: we need to track ourselves the locale settings and change the behavior of the relevant
+// functions based on the set locale.
+fn f1(a0: i32, a1: Ptr<u8>) -> Ptr<u8> {
+    Ptr::from_string_literal(b"C")
+}

rules/pwd/tgt_refcount.rs

@@ -6,3 +6,14 @@ use libcc2rs::*;
 fn t1() -> libcc2rs::Passwd {
     Default::default()
 }
+
+fn f1(a0: u32) -> Ptr<Passwd> {
+    match nix::unistd::User::from_uid(nix::unistd::Uid::from_raw(a0)) {
+        Ok(Some(__u)) => Ptr::alloc(Passwd::from_user(&__u)),
+        Ok(None) => Ptr::null(),
+        Err(__e) => {
+            libcc2rs::cpp2rust_errno().write(__e as i32);
+            Ptr::null()
+        }
+    }
+}

rules/src/modules.rs

@@ -84,6 +84,8 @@ pub mod ip_tgt_refcount;
 pub mod ip_tgt_unsafe;
 #[path = r#"../limits/tgt_unsafe.rs"#]
 pub mod limits_tgt_unsafe;
+#[path = r#"../locale/tgt_refcount.rs"#]
+pub mod locale_tgt_refcount;
 #[path = r#"../locale/tgt_unsafe.rs"#]
 pub mod locale_tgt_unsafe;
 #[path = r#"../map/tgt_refcount.rs"#]

rules/stat/tgt_refcount.rs

@@ -6,3 +6,29 @@ use libcc2rs::*;
 fn t1() -> libcc2rs::Stat {
     Default::default()
 }
+
+fn f1(a0: Ptr<u8>, a1: Ptr<Stat>) -> i32 {
+    match nix::sys::stat::stat(a0.to_rust_string().as_str()) {
+        Ok(__s) => {
+            a1.with_mut(|__st| *__st = Stat::from_libc(&__s));
+            0
+        }
+        Err(__e) => {
+            libcc2rs::cpp2rust_errno().write(__e as i32);
+            -1
+        }
+    }
+}
+
+fn f3(a0: Ptr<u8>, a1: ::libc::mode_t) -> i32 {
+    match nix::unistd::mkdir(
+        a0.to_rust_string().as_str(),
+        nix::sys::stat::Mode::from_bits_truncate(a1),
+    ) {
+        Ok(()) => 0,
+        Err(__e) => {
+            libcc2rs::cpp2rust_errno().write(__e as i32);
+            -1
+        }
+    }
+}

tests/unit/libc_char_ptr_field.c

@@ -1,4 +1,3 @@
-// no-compile: refcount
 #include <dirent.h>
 #include <pwd.h>
 #include <unistd.h>