fix putenv and setenv for windows (wasmerio#140)

lib/emscripten/src/env/mod.rs

@@ -0,0 +1,11 @@
+#[cfg(unix)]
+mod unix;
+
+#[cfg(windows)]
+mod windows;
+
+#[cfg(unix)]
+pub use self::unix::*;
+
+#[cfg(windows)]
+pub use self::windows::*;

lib/emscripten/src/env.rs → lib/emscripten/src/env/unix/mod.rs

@@ -7,8 +7,8 @@ use std::ffi::CStr;
 use std::mem;
 use std::os::raw::c_char;
 
-use super::utils::{allocate_on_stack, copy_cstr_into_wasm, copy_terminated_array_of_cstrs};
-use super::EmscriptenData;
+use crate::utils::{allocate_on_stack, copy_cstr_into_wasm, copy_terminated_array_of_cstrs};
+use crate::EmscriptenData;
 use wasmer_runtime_core::vm::Ctx;
 
 pub fn _getaddrinfo(_one: i32, _two: i32, _three: i32, _four: i32, _ctx: &mut Ctx) -> i32 {

lib/emscripten/src/env/windows/mod.rs

@@ -0,0 +1,218 @@
+/// NOTE: These syscalls only support wasm_32 for now because they take u32 offset
+use libc::{
+    c_int,
+    c_long,
+    getenv,
+    //sysconf, unsetenv,
+};
+
+use core::slice;
+use std::ffi::{CStr, CString};
+use std::mem;
+use std::os::raw::c_char;
+
+use crate::utils::{
+    allocate_on_stack, copy_cstr_into_wasm, copy_terminated_array_of_cstrs, read_string_from_wasm,
+};
+use crate::EmscriptenData;
+use wasmer_runtime_core::memory::Memory;
+use wasmer_runtime_core::vm::Ctx;
+
+#[link(name = "c")]
+extern "C" {
+    #[link_name = "_putenv"]
+    pub fn putenv(s: *const c_char) -> c_int;
+}
+
+pub fn _getaddrinfo(_one: i32, _two: i32, _three: i32, _four: i32, _ctx: &mut Ctx) -> i32 {
+    debug!("emscripten::_getaddrinfo");
+    -1
+}
+
+// #[no_mangle]
+/// emscripten: _getenv // (name: *const char) -> *const c_char;
+pub fn _getenv(name: i32, ctx: &mut Ctx) -> u32 {
+    debug!("emscripten::_getenv");
+
+    let memory = ctx.memory(0);
+
+    let name_addr = emscripten_memory_pointer!(ctx.memory(0), name) as _;
+
+    debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
+
+    let c_str: *mut c_char = unsafe { getenv(name_addr as _) } as _;
+    if c_str.is_null() {
+        return 0;
+    }
+
+    unsafe { copy_cstr_into_wasm(ctx, c_str) }
+}
+
+/// emscripten: _setenv // (name: *const char, name: *const value, overwrite: int);
+pub fn _setenv(name: u32, value: u32, overwrite: u32, ctx: &mut Ctx) -> c_int {
+    debug!("emscripten::_setenv");
+    let name_addr = emscripten_memory_pointer!(ctx.memory(0), name);
+    let value_addr = emscripten_memory_pointer!(ctx.memory(0), value);
+    // setenv does not exist on windows, so we hack it with _putenv
+    let name = read_string_from_wasm(ctx.memory(0), name);
+    let value = read_string_from_wasm(ctx.memory(0), value);
+    let putenv_string = format!("{}={}", name, value);
+    let putenv_cstring = CString::new(putenv_string).unwrap();
+    let putenv_raw_ptr = putenv_cstring.as_ptr();
+    debug!("=> name({:?})", name);
+    debug!("=> value({:?})", value);
+    unsafe { putenv(putenv_raw_ptr) }
+}
+
+/// emscripten: _putenv // (name: *const char);
+pub fn _putenv(name: c_int, ctx: &mut Ctx) -> c_int {
+    debug!("emscripten::_putenv");
+
+    let name_addr = emscripten_memory_pointer!(ctx.memory(0), name) as *const c_char;
+
+    debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
+    unsafe { putenv(name_addr) }
+}
+
+/// emscripten: _unsetenv // (name: *const char);
+pub fn _unsetenv(name: c_int, ctx: &mut Ctx) -> c_int {
+    debug!("emscripten::_unsetenv");
+
+    let name_addr = emscripten_memory_pointer!(ctx.memory(0), name);
+
+    debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
+
+    unsafe { unsetenv(name_addr) }
+}
+
+#[allow(clippy::cast_ptr_alignment)]
+pub fn _getpwnam(name_ptr: c_int, ctx: &mut Ctx) -> c_int {
+    debug!("emscripten::_getpwnam {}", name_ptr);
+
+    #[repr(C)]
+    struct GuestPasswd {
+        pw_name: u32,
+        pw_passwd: u32,
+        pw_uid: u32,
+        pw_gid: u32,
+        pw_gecos: u32,
+        pw_dir: u32,
+        pw_shell: u32,
+    }
+
+    let name = unsafe {
+        let memory_name_ptr = emscripten_memory_pointer!(ctx.memory(0), name_ptr) as *const c_char;
+        CStr::from_ptr(memory_name_ptr)
+    };
+
+    unsafe {
+        let passwd = &*libc_getpwnam(name.as_ptr());
+        let passwd_struct_offset = call_malloc(mem::size_of::<GuestPasswd>() as _, ctx);
+
+        let passwd_struct_ptr =
+            emscripten_memory_pointer!(ctx.memory(0), passwd_struct_offset) as *mut GuestPasswd;
+        (*passwd_struct_ptr).pw_name = copy_cstr_into_wasm(ctx, passwd.pw_name);
+        (*passwd_struct_ptr).pw_passwd = copy_cstr_into_wasm(ctx, passwd.pw_passwd);
+        (*passwd_struct_ptr).pw_gecos = copy_cstr_into_wasm(ctx, passwd.pw_gecos);
+        (*passwd_struct_ptr).pw_dir = copy_cstr_into_wasm(ctx, passwd.pw_dir);
+        (*passwd_struct_ptr).pw_shell = copy_cstr_into_wasm(ctx, passwd.pw_shell);
+        (*passwd_struct_ptr).pw_uid = passwd.pw_uid;
+        (*passwd_struct_ptr).pw_gid = passwd.pw_gid;
+
+        passwd_struct_offset as c_int
+    }
+}
+
+#[allow(clippy::cast_ptr_alignment)]
+pub fn _getgrnam(name_ptr: c_int, ctx: &mut Ctx) -> c_int {
+    debug!("emscripten::_getgrnam {}", name_ptr);
+
+    #[repr(C)]
+    struct GuestGroup {
+        gr_name: u32,
+        gr_passwd: u32,
+        gr_gid: u32,
+        gr_mem: u32,
+    }
+
+    let name = unsafe {
+        let memory_name_ptr = emscripten_memory_pointer!(ctx.memory(0), name_ptr) as *const c_char;
+        CStr::from_ptr(memory_name_ptr)
+    };
+
+    unsafe {
+        let group = &*libc_getgrnam(name.as_ptr());
+        let group_struct_offset = call_malloc(mem::size_of::<GuestGroup>() as _, ctx);
+
+        let group_struct_ptr =
+            emscripten_memory_pointer!(ctx.memory(0), group_struct_offset) as *mut GuestGroup;
+        (*group_struct_ptr).gr_name = copy_cstr_into_wasm(ctx, group.gr_name);
+        (*group_struct_ptr).gr_passwd = copy_cstr_into_wasm(ctx, group.gr_passwd);
+        (*group_struct_ptr).gr_gid = group.gr_gid;
+        (*group_struct_ptr).gr_mem = copy_terminated_array_of_cstrs(ctx, group.gr_mem);
+
+        group_struct_offset as c_int
+    }
+}
+
+pub fn call_malloc(size: u32, ctx: &mut Ctx) -> u32 {
+    get_emscripten_data(ctx).malloc.call(size).unwrap()
+}
+
+pub fn call_memalign(alignment: u32, size: u32, ctx: &mut Ctx) -> u32 {
+    get_emscripten_data(ctx)
+        .memalign
+        .call(alignment, size)
+        .unwrap()
+}
+
+pub fn call_memset(pointer: u32, value: u32, size: u32, ctx: &mut Ctx) -> u32 {
+    get_emscripten_data(ctx)
+        .memset
+        .call(pointer, value, size)
+        .unwrap()
+}
+
+pub(crate) fn get_emscripten_data(ctx: &mut Ctx) -> &mut EmscriptenData {
+    unsafe { &mut *(ctx.data as *mut EmscriptenData) }
+}
+
+pub fn _getpagesize(_ctx: &mut Ctx) -> u32 {
+    debug!("emscripten::_getpagesize");
+    16384
+}
+
+#[allow(clippy::cast_ptr_alignment)]
+pub fn ___build_environment(environ: c_int, ctx: &mut Ctx) {
+    debug!("emscripten::___build_environment {}", environ);
+    const MAX_ENV_VALUES: u32 = 64;
+    const TOTAL_ENV_SIZE: u32 = 1024;
+    let environment = emscripten_memory_pointer!(ctx.memory(0), environ) as *mut c_int;
+    unsafe {
+        let (pool_offset, _pool_slice): (u32, &mut [u8]) =
+            allocate_on_stack(TOTAL_ENV_SIZE as u32, ctx);
+        let (env_offset, _env_slice): (u32, &mut [u8]) =
+            allocate_on_stack((MAX_ENV_VALUES * 4) as u32, ctx);
+        let env_ptr = emscripten_memory_pointer!(ctx.memory(0), env_offset) as *mut c_int;
+        let mut _pool_ptr = emscripten_memory_pointer!(ctx.memory(0), pool_offset) as *mut c_int;
+        *env_ptr = pool_offset as i32;
+        *environment = env_offset as i32;
+
+        // *env_ptr = 0;
+    };
+    // unsafe {
+    //     *env_ptr = 0;
+    // };
+}
+
+pub fn _sysconf(name: c_int, _ctx: &mut Ctx) -> c_long {
+    debug!("emscripten::_sysconf {}", name);
+    // TODO: Implement like emscripten expects regarding memory/page size
+    unsafe { sysconf(name) }
+}
+
+pub fn ___assert_fail(a: c_int, b: c_int, c: c_int, d: c_int, _ctx: &mut Ctx) {
+    debug!("emscripten::___assert_fail {} {} {} {}", a, b, c, d);
+    // TODO: Implement like emscripten expects regarding memory/page size
+    // TODO raise an error
+}

lib/emscripten/src/utils.rs

@@ -4,7 +4,9 @@ use libc::stat;
 use std::ffi::CStr;
 use std::mem::size_of;
 use std::os::raw::c_char;
+use std::os::raw::c_int;
 use std::slice;
+use wasmer_runtime_core::memory::Memory;
 use wasmer_runtime_core::{
     module::Module,
     structures::TypedIndex,
@@ -54,11 +56,11 @@ pub unsafe fn copy_cstr_into_wasm(ctx: &mut Ctx, cstr: *const c_char) -> u32 {
     let s = CStr::from_ptr(cstr).to_str().unwrap();
     let cstr_len = s.len();
     let space_offset = env::call_malloc((cstr_len as u32) + 1, ctx);
-    let raw_memory = emscripten_memory_pointer!(ctx.memory(0), space_offset) as *mut u8;
+    let raw_memory = emscripten_memory_pointer!(ctx.memory(0), space_offset) as *mut c_char;
     let slice = slice::from_raw_parts_mut(raw_memory, cstr_len);
 
     for (byte, loc) in s.bytes().zip(slice.iter_mut()) {
-        *loc = byte;
+        *loc = byte as _;
     }
 
     // TODO: Appending null byte won't work, because there is CStr::from_ptr(cstr)
@@ -155,6 +157,14 @@ pub unsafe fn copy_stat_into_wasm(ctx: &mut Ctx, buf: u32, stat: &stat) {
     (*stat_ptr).st_ino = stat.st_ino as _;
 }
 
+pub fn read_string_from_wasm(memory: &Memory, offset: u32) -> String {
+    memory.view::<u8>()[(offset as usize)..]
+        .iter()
+        .take_while(|cell| cell.get() != 0)
+        .map(|cell| cell.get() as char)
+        .collect()
+}
+
 #[cfg(test)]
 mod tests {
     use super::is_emscripten_module;