From ed224cf912104853bf94ac723512ef189654b745 Mon Sep 17 00:00:00 2001
From: xushiwei <x@goplus.org>
Date: Thu, 18 Jul 2024 19:31:25 +0800
Subject: [PATCH] os.Sysctl

---
 c/os/os.go                          | 32 +++++++++++++++++++++++++++++
 internal/lib/syscall/syscall_bsd.go | 12 +++++++++--
 2 files changed, 42 insertions(+), 2 deletions(-)

diff --git a/c/os/os.go b/c/os/os.go
index e3efb039..d250ae84 100644
--- a/c/os/os.go
+++ b/c/os/os.go
@@ -328,3 +328,35 @@ func Getrlimit(resource c.Int, rlp *syscall.Rlimit) c.Int
 func Setrlimit(resource c.Int, rlp *syscall.Rlimit) c.Int
 
 // -----------------------------------------------------------------------------
+
+// Upon successful completion, the value 0 is returned; otherwise the value -1
+// is returned and the global variable errno is set to indicate the error.
+//
+//go:linkname Sysctl C.sysctl
+func Sysctl(
+	name *c.Int, namelen c.Uint,
+	oldp c.Pointer, oldlenp *uintptr,
+	newp c.Pointer, newlen uintptr) c.Int
+
+//go:linkname Sysctlbyname C.sysctlbyname
+func Sysctlbyname(
+	name *c.Char, oldp c.Pointer, oldlenp *uintptr,
+	newp c.Pointer, newlen uintptr) c.Int
+
+// The sysctlnametomib() function accepts an ASCII representation  of  the
+// name,  looks up the integer name	vector,	and returns the	numeric	repre-
+// sentation in the	mib array pointed to by	mibp.  The number of  elements
+// in the mib array	is given by the	location specified by sizep before the
+// call, and that location gives the number	of entries copied after	a suc-
+// cessful	call.	The  resulting	mib and	size may be used in subsequent
+// sysctl()	calls to get the data  associated  with	 the  requested	 ASCII
+// name.   This interface is intended for use by applications that want to
+// repeatedly request the same variable (the  sysctl()  function  runs  in
+// about  a	third the time as the same request made	via the	sysctlbyname()
+// function).  The sysctlnametomib() function is also useful for  fetching
+// mib  prefixes and then adding a final component.
+//
+//go:linkname Sysctlnametomib C.sysctlnametomib
+func Sysctlnametomib(name *c.Char, mibp *c.Int, sizep *uintptr) c.Int
+
+// -----------------------------------------------------------------------------
diff --git a/internal/lib/syscall/syscall_bsd.go b/internal/lib/syscall/syscall_bsd.go
index 715b463d..86c34364 100644
--- a/internal/lib/syscall/syscall_bsd.go
+++ b/internal/lib/syscall/syscall_bsd.go
@@ -13,7 +13,10 @@
 package syscall
 
 import (
+	"unsafe"
+
 	"github.com/goplus/llgo/c"
+	"github.com/goplus/llgo/c/os"
 	"github.com/goplus/llgo/c/syscall"
 )
 
@@ -456,11 +459,16 @@ func SysctlUint32(name string) (value uint32, err error) {
 		return 0, err
 	}
 	if n != 4 {
-		return 0, EIO
+		return 0, Errno(syscall.EIO)
 	}
 	return *(*uint32)(unsafe.Pointer(&buf[0])), nil
 	*/
-	panic("todo: syscall.SysctlUint32")
+	n := uintptr(4)
+	ret := os.Sysctlbyname(c.AllocaCStr(name), unsafe.Pointer(&value), &n, nil, 0)
+	if ret != 0 {
+		err = Errno(os.Errno)
+	}
+	return
 }
 
 /*