From b21c9c86c1804600a626c6071e474c998b4f7046 Mon Sep 17 00:00:00 2001
From: ian <ian@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 20 Apr 2012 20:11:28 +0000
Subject: net, syscall: Use native endianness for GNU/Linux netlink code.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@186640 138bc75d-0d04-0410-961f-82ee72b054a4
---
 libgo/go/net/interface_linux.go   | 17 ++++++----------
 libgo/go/syscall/netlink_linux.go | 43 ++++++---------------------------------
 2 files changed, 12 insertions(+), 48 deletions(-)

(limited to 'libgo/go')

diff --git a/libgo/go/net/interface_linux.go b/libgo/go/net/interface_linux.go
index 0d7017f301e..ce2e921e865 100644
--- a/libgo/go/net/interface_linux.go
+++ b/libgo/go/net/interface_linux.go
@@ -64,11 +64,7 @@ func newLink(ifim *syscall.IfInfomsg, attrs []syscall.NetlinkRouteAttr) Interfac
 		case syscall.IFLA_IFNAME:
 			ifi.Name = string(a.Value[:len(a.Value)-1])
 		case syscall.IFLA_MTU:
-			if syscall.BigEndian {
-				ifi.MTU = int(uint32(a.Value[0])<<24 | uint32(a.Value[1])<<16 | uint32(a.Value[2])<<8 | uint32(a.Value[3]))
-			} else {
-				ifi.MTU = int(uint32(a.Value[3])<<24 | uint32(a.Value[2])<<16 | uint32(a.Value[1])<<8 | uint32(a.Value[0]))
-			}
+			ifi.MTU = int(*(*uint32)(unsafe.Pointer(&a.Value[:4][0])))
 		}
 	}
 	return ifi
@@ -197,15 +193,14 @@ func parseProcNetIGMP(path string, ifi *Interface) []Addr {
 			name = f[1]
 		case len(f[0]) == 8:
 			if ifi == nil || name == ifi.Name {
+				// The Linux kernel puts the IP
+				// address in /proc/net/igmp in native
+				// endianness.
 				for i := 0; i+1 < len(f[0]); i += 2 {
 					b[i/2], _ = xtoi2(f[0][i:i+2], 0)
 				}
-				var ifma IPAddr
-				if syscall.BigEndian {
-					ifma = IPAddr{IP: IPv4(b[0], b[1], b[2], b[3])}
-				} else {
-					ifma = IPAddr{IP: IPv4(b[3], b[2], b[1], b[0])}
-				}
+				i := *(*uint32)(unsafe.Pointer(&b[:4][0]))
+				ifma := IPAddr{IP: IPv4(byte(i>>24), byte(i>>16), byte(i>>8), byte(i))}
 				ifmat = append(ifmat, ifma.toAddr())
 			}
 		}
diff --git a/libgo/go/syscall/netlink_linux.go b/libgo/go/syscall/netlink_linux.go
index 1c99a81785f..d535713069b 100644
--- a/libgo/go/syscall/netlink_linux.go
+++ b/libgo/go/syscall/netlink_linux.go
@@ -30,43 +30,12 @@ type NetlinkRouteRequest struct {
 
 func (rr *NetlinkRouteRequest) toWireFormat() []byte {
 	b := make([]byte, rr.Header.Len)
-	if BigEndian {
-		b[0] = byte(rr.Header.Len >> 24)
-		b[1] = byte(rr.Header.Len >> 16)
-		b[2] = byte(rr.Header.Len >> 8)
-		b[3] = byte(rr.Header.Len)
-		b[4] = byte(rr.Header.Type >> 8)
-		b[5] = byte(rr.Header.Type)
-		b[6] = byte(rr.Header.Flags >> 8)
-		b[7] = byte(rr.Header.Flags)
-		b[8] = byte(rr.Header.Seq >> 24)
-		b[9] = byte(rr.Header.Seq >> 16)
-		b[10] = byte(rr.Header.Seq >> 8)
-		b[11] = byte(rr.Header.Seq)
-		b[12] = byte(rr.Header.Pid >> 24)
-		b[13] = byte(rr.Header.Pid >> 16)
-		b[14] = byte(rr.Header.Pid >> 8)
-		b[15] = byte(rr.Header.Pid)
-		b[16] = byte(rr.Data.Family)
-	} else {
-		b[0] = byte(rr.Header.Len)
-		b[1] = byte(rr.Header.Len >> 8)
-		b[2] = byte(rr.Header.Len >> 16)
-		b[3] = byte(rr.Header.Len >> 24)
-		b[4] = byte(rr.Header.Type)
-		b[5] = byte(rr.Header.Type >> 8)
-		b[6] = byte(rr.Header.Flags)
-		b[7] = byte(rr.Header.Flags >> 8)
-		b[8] = byte(rr.Header.Seq)
-		b[9] = byte(rr.Header.Seq >> 8)
-		b[10] = byte(rr.Header.Seq >> 16)
-		b[11] = byte(rr.Header.Seq >> 24)
-		b[12] = byte(rr.Header.Pid)
-		b[13] = byte(rr.Header.Pid >> 8)
-		b[14] = byte(rr.Header.Pid >> 16)
-		b[15] = byte(rr.Header.Pid >> 24)
-		b[16] = byte(rr.Data.Family)
-	}
+	*(*uint32)(unsafe.Pointer(&b[0:4][0])) = rr.Header.Len
+	*(*uint16)(unsafe.Pointer(&b[4:6][0])) = rr.Header.Type
+	*(*uint16)(unsafe.Pointer(&b[6:8][0])) = rr.Header.Flags
+	*(*uint32)(unsafe.Pointer(&b[8:12][0])) = rr.Header.Seq
+	*(*uint32)(unsafe.Pointer(&b[12:16][0])) = rr.Header.Pid
+	b[16] = byte(rr.Data.Family)
 	return b
 }
 
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