Add initgroups

src/header/grp/mod.rs

@@ -20,7 +20,7 @@ use alloc::{
 use crate::{
     c_str::CStr,
     fs::File,
-    header::{errno, fcntl, string::strlen},
+    header::{errno, fcntl, limits, string::strlen, unistd},
     io,
     io::{prelude::*, BufReader, Lines},
     platform,
@@ -443,3 +443,15 @@ pub unsafe extern "C" fn getgrouplist(
         grps.len() as c_int
     }
 }
+
+// MT-Safe locale
+// Not POSIX
+#[no_mangle]
+pub unsafe extern "C" fn initgroups(user: *const c_char, gid: gid_t) -> c_int {
+    let mut groups = [0; limits::NGROUPS_MAX];
+    let mut count = groups.len() as c_int;
+    if getgrouplist(user, gid, groups.as_mut_ptr(), &mut count) < 0 {
+        return -1;
+    }
+    unistd::setgroups(count as size_t, groups.as_ptr())
+}

src/header/limits/mod.rs

@@ -1,3 +1,4 @@
 //! limits.h implementation for relibc
 
 pub const PATH_MAX: usize = 4096;
+pub const NGROUPS_MAX: usize = 65536;

src/header/unistd/sysconf.rs

@@ -1,7 +1,7 @@
 use core::convert::TryInto;
 
 use crate::{
-    header::errno,
+    header::{errno, limits},
     platform::{self, types::*, Pal, Sys},
 };
 
@@ -37,7 +37,7 @@ pub extern "C" fn sysconf(name: c_int) -> c_long {
         _SC_ARG_MAX => 4096,
         _SC_CHILD_MAX => 65536,
         _SC_CLK_TCK => 100,
-        _SC_NGROUPS_MAX => 65536,
+        _SC_NGROUPS_MAX => limits::NGROUPS_MAX as c_long,
         _SC_OPEN_MAX => 1024,
         _SC_STREAM_MAX => 16,
         _SC_TZNAME_MAX => -1,