From ec63d0d2850e4294430643d343ccc6049f201624 Mon Sep 17 00:00:00 2001
From: Nate Brown <nbrown.us@gmail.com>
Date: Fri, 22 Nov 2019 15:22:31 -0800
Subject: [PATCH] Remove magic numbers, support mips64le

---
 Makefile              |  8 ++++++-
 udp_linux.go          | 15 ++++---------
 udp_linux_mips64le.go | 50 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 61 insertions(+), 12 deletions(-)
 create mode 100644 udp_linux_mips64le.go

diff --git a/Makefile b/Makefile
index 91e6fce..aca5e54 100644
--- a/Makefile
+++ b/Makefile
@@ -3,7 +3,7 @@ BUILD_NUMBER ?= dev+$(shell date -u '+%Y%m%d%H%M%S')
 GO111MODULE = on
 export GO111MODULE
 
-all: bin-linux bin-arm bin-arm6 bin-arm64 bin-darwin bin-windows bin-mips64
+all: bin-linux bin-arm bin-arm6 bin-arm64 bin-darwin bin-windows bin-mips64 bin-mips64le
 
 bin:
 	go build -ldflags "-X main.Build=$(BUILD_NUMBER)" -o ./nebula ${NEBULA_CMD_PATH}
@@ -52,6 +52,11 @@ bin-mips64:
 	GOARCH=mips64 GOOS=linux go build -o build/mips64/nebula -ldflags "-X main.Build=$(BUILD_NUMBER)" ./cmd/nebula
 	GOARCH=mips64 GOOS=linux go build -o build/mips64/nebula-cert -ldflags "-X main.Build=$(BUILD_NUMBER)" ./cmd/nebula-cert
 
+bin-mips64le:
+	mkdir -p build/mips64le
+	GOARCH=mips64le GOOS=linux go build -o build/mips64le/nebula -ldflags "-X main.Build=$(BUILD_NUMBER)" ./cmd/nebula
+	GOARCH=mips64le GOOS=linux go build -o build/mips64le/nebula-cert -ldflags "-X main.Build=$(BUILD_NUMBER)" ./cmd/nebula-cert
+
 release: all
 	tar -zcv -C build/arm/ -f nebula-linux-arm.tar.gz nebula nebula-cert
 	tar -zcv -C build/arm6/ -f nebula-linux-arm6.tar.gz nebula nebula-cert
@@ -60,6 +65,7 @@ release: all
 	tar -zcv -C build/windows/ -f nebula-windows-amd64.tar.gz nebula.exe nebula-cert.exe
 	tar -zcv -C build/linux/ -f nebula-linux-amd64.tar.gz nebula nebula-cert
 	tar -zcv -C build/mips64/ -f nebula-linux-mips64.tar.gz nebula nebula-cert
+	tar -zcv -C build/mips64le/ -f nebula-linux-mips64le.tar.gz nebula nebula-cert
 
 vet:
 	go vet -v ./...
diff --git a/udp_linux.go b/udp_linux.go
index 593b896..2a1b0d0 100644
--- a/udp_linux.go
+++ b/udp_linux.go
@@ -63,25 +63,18 @@ func NewListener(ip string, port int, multi bool) (*udpConn, error) {
 
 	if err != nil {
 		syscall.Close(fd)
-		return nil, err
+		return nil, fmt.Errorf("unable to open socket: %s", err)
 	}
 
 	var lip [4]byte
 	copy(lip[:], net.ParseIP(ip).To4())
 
-	if err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, 0x0F, 1); err != nil {
-		return nil, err
+	if err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {
+		return nil, fmt.Errorf("unable to set SO_REUSEPORT: %s", err)
 	}
 
 	if err = syscall.Bind(fd, &syscall.SockaddrInet4{Port: port}); err != nil {
-		return nil, err
-	}
-
-	// SO_REUSEADDR does not load balance so we use PORT
-	if multi {
-		if err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, unix.SO_REUSEPORT, 1); err != nil {
-			return nil, err
-		}
+		return nil, fmt.Errorf("unable to bind to socket: %s", err)
 	}
 
 	//TODO: this may be useful for forcing threads into specific cores
diff --git a/udp_linux_mips64le.go b/udp_linux_mips64le.go
new file mode 100644
index 0000000..a61e0c8
--- /dev/null
+++ b/udp_linux_mips64le.go
@@ -0,0 +1,50 @@
+package nebula
+
+import "unsafe"
+
+type iovec struct {
+	Base *byte
+	Len  uint64
+}
+
+type msghdr struct {
+	Name       *byte
+	Namelen    uint32
+	Pad0       [4]byte
+	Iov        *iovec
+	Iovlen     uint64
+	Control    *byte
+	Controllen uint64
+	Flags      int32
+	Pad1       [4]byte
+}
+
+type rawMessage struct {
+	Hdr  msghdr
+	Len  uint32
+	Pad0 [4]byte
+}
+
+func (u *udpConn) PrepareRawMessages(n int) ([]rawMessage, [][]byte, [][]byte) {
+	msgs := make([]rawMessage, n)
+	buffers := make([][]byte, n)
+	names := make([][]byte, n)
+
+	for i := range msgs {
+		buffers[i] = make([]byte, mtu)
+		names[i] = make([]byte, 0x1c) //TODO = sizeofSockaddrInet6
+
+		//TODO: this is still silly, no need for an array
+		vs := []iovec{
+			{Base: (*byte)(unsafe.Pointer(&buffers[i][0])), Len: uint64(len(buffers[i]))},
+		}
+
+		msgs[i].Hdr.Iov = &vs[0]
+		msgs[i].Hdr.Iovlen = uint64(len(vs))
+
+		msgs[i].Hdr.Name = (*byte)(unsafe.Pointer(&names[i][0]))
+		msgs[i].Hdr.Namelen = uint32(len(names[i]))
+	}
+
+	return msgs, buffers, names
+}