wasmer/lib/emscripten/src/env.rs
2019-01-18 18:36:28 -06:00

222 lines
7.4 KiB
Rust

/// NOTE: These syscalls only support wasm_32 for now because they take u32 offset
use libc::{
c_int, c_long, getenv, getgrnam as libc_getgrnam, getpwnam as libc_getpwnam, putenv, setenv,
sysconf, unsetenv,
};
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 wasmer_runtime::{types::Value, Instance};
//use super::EmscriptenData;
//impl Instance {
// pub fn memory_offset_addr(&self, index: usize, offset: usize) -> *const usize {
// unimplemented!("TODO replace this stub")
// }
//
// pub fn emscripten_data(&self) -> &'static mut Option<EmscriptenData> {
// unimplemented!("TODO replace this stub")
// }
//}
// #[no_mangle]
/// emscripten: _getenv // (name: *const char) -> *const c_char;
pub extern "C" fn _getenv(name: c_int, instance: &mut Instance) -> u32 {
debug!("emscripten::_getenv");
let name_addr = instance.memory_offset_addr(0, name as usize) as *const c_char;
debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
let c_str = unsafe { getenv(name_addr) };
if c_str.is_null() {
return 0;
}
unsafe { copy_cstr_into_wasm(instance, c_str) }
}
/// emscripten: _setenv // (name: *const char, name: *const value, overwrite: int);
pub extern "C" fn _setenv(name: c_int, value: c_int, overwrite: c_int, instance: &mut Instance) {
debug!("emscripten::_setenv");
let name_addr = instance.memory_offset_addr(0, name as usize) as *const c_char;
let value_addr = instance.memory_offset_addr(0, value as usize) as *const c_char;
debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
debug!("=> value({:?})", unsafe { CStr::from_ptr(value_addr) });
unsafe { setenv(name_addr, value_addr, overwrite) };
}
/// emscripten: _putenv // (name: *const char);
pub extern "C" fn _putenv(name: c_int, instance: &mut Instance) {
debug!("emscripten::_putenv");
let name_addr = instance.memory_offset_addr(0, name as usize) as *const c_char;
debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
unsafe { putenv(name_addr as _) };
}
/// emscripten: _unsetenv // (name: *const char);
pub extern "C" fn _unsetenv(name: c_int, instance: &mut Instance) {
debug!("emscripten::_unsetenv");
let name_addr = instance.memory_offset_addr(0, name as usize) as *const c_char;
debug!("=> name({:?})", unsafe { CStr::from_ptr(name_addr) });
unsafe { unsetenv(name_addr) };
}
#[allow(clippy::cast_ptr_alignment)]
pub extern "C" fn _getpwnam(name_ptr: c_int, instance: &mut Instance) -> 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 = instance.memory_offset_addr(0, name_ptr as usize) 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 _, instance);
let passwd_struct_ptr =
instance.memory_offset_addr(0, passwd_struct_offset as _) as *mut GuestPasswd;
(*passwd_struct_ptr).pw_name = copy_cstr_into_wasm(instance, passwd.pw_name);
(*passwd_struct_ptr).pw_passwd = copy_cstr_into_wasm(instance, passwd.pw_passwd);
(*passwd_struct_ptr).pw_gecos = copy_cstr_into_wasm(instance, passwd.pw_gecos);
(*passwd_struct_ptr).pw_dir = copy_cstr_into_wasm(instance, passwd.pw_dir);
(*passwd_struct_ptr).pw_shell = copy_cstr_into_wasm(instance, 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 extern "C" fn _getgrnam(name_ptr: c_int, instance: &mut Instance) -> 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 = instance.memory_offset_addr(0, name_ptr as usize) 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 _, instance);
let group_struct_ptr =
instance.memory_offset_addr(0, group_struct_offset as _) as *mut GuestGroup;
(*group_struct_ptr).gr_name = copy_cstr_into_wasm(instance, group.gr_name);
(*group_struct_ptr).gr_passwd = copy_cstr_into_wasm(instance, group.gr_passwd);
(*group_struct_ptr).gr_gid = group.gr_gid;
(*group_struct_ptr).gr_mem = copy_terminated_array_of_cstrs(instance, group.gr_mem);
group_struct_offset as c_int
}
}
pub fn call_malloc(size: i32, instance: &mut Instance) -> u32 {
let ret = instance
.call("_malloc", &[Value::I32(size)])
.expect("_malloc call failed");
if let Some(Value::I32(ptr)) = ret {
ptr as u32
} else {
panic!("unexpected value from _malloc: {:?}", ret);
}
}
pub fn call_memalign(alignment: u32, size: u32, instance: &mut Instance) -> u32 {
let ret = instance
.call(
"_memalign",
&[Value::I32(alignment as i32), Value::I32(size as i32)],
)
.expect("_memalign call failed");
if let Some(Value::I32(res)) = ret {
res as u32
} else {
panic!("unexpected value from _memalign {:?}", ret);
}
}
pub fn call_memset(pointer: u32, value: i32, size: u32, instance: &mut Instance) -> u32 {
let ret = instance
.call(
"_memset",
&[
Value::I32(pointer as i32),
Value::I32(value),
Value::I32(size as i32),
],
)
.expect("_memset call failed");
if let Some(Value::I32(res)) = ret {
res as u32
} else {
panic!("unexpected value from _memset {:?}", ret);
}
}
pub extern "C" fn _getpagesize() -> u32 {
debug!("emscripten::_getpagesize");
16384
}
#[allow(clippy::cast_ptr_alignment)]
pub extern "C" fn ___build_environment(environ: c_int, instance: &mut Instance) {
debug!("emscripten::___build_environment {}", environ);
const MAX_ENV_VALUES: u32 = 64;
const TOTAL_ENV_SIZE: u32 = 1024;
let mut environment = instance.memory_offset_addr(0, environ as _) as *mut c_int;
unsafe {
let (pool_offset, _pool_slice): (u32, &mut [u8]) =
allocate_on_stack(TOTAL_ENV_SIZE as u32, instance);
let (env_offset, _env_slice): (u32, &mut [u8]) =
allocate_on_stack((MAX_ENV_VALUES * 4) as u32, instance);
let mut env_ptr = instance.memory_offset_addr(0, env_offset as _) as *mut c_int;
let mut _pool_ptr = instance.memory_offset_addr(0, pool_offset as _) as *mut c_int;
*env_ptr = pool_offset as i32;
*environment = env_offset as i32;
// *env_ptr = 0;
};
// unsafe {
// *env_ptr = 0;
// };
}
pub extern "C" fn _sysconf(name: c_int, _instance: &mut Instance) -> c_long {
debug!("emscripten::_sysconf {}", name);
// TODO: Implement like emscripten expects regarding memory/page size
unsafe { sysconf(name) }
}