Attempt to support NetBSD

This code actually consolidates a lot of the BSD code together, and even setting the interface MTU with SIOCSIFMTU seems to work fine.

What doesn't work though is setting the interface address using SIOCSIFADDR_IN6, which I attempted to plagiarise from the Darwin code.

As a fallback, ifconfig is used, which solves the problem enough to get it working.

src/yggdrasil/tun_bsd.go

@@ -1,15 +1,20 @@
-// +build openbsd freebsd
+// +build openbsd freebsd netbsd
 
 package yggdrasil
 
-import "os"
-import "os/exec"
 import "unsafe"
+import "syscall"
+import "strings"
+import "strconv"
+import "encoding/binary"
+import "os/exec"
 
 import "golang.org/x/sys/unix"
 
 import "github.com/yggdrasil-network/water"
 
+const SIOCSIFADDR_IN6 = (0x80000000) | ((288 & 0x1fff) << 16) | uint32(byte('i'))<<8 | 12
+
 type in6_addrlifetime struct {
 	ia6t_expire    float64
 	ia6t_preferred float64
@@ -26,13 +31,43 @@ type sockaddr_in6 struct {
 	sin6_scope_id uint32
 }
 
-type in6_aliasreq struct {
+/*
-	ifra_name       [16]byte
+from <netinet6/in6_var.h>
-	ifra_addr       sockaddr_in6
+struct  in6_ifreq {
-	ifra_dstaddr    sockaddr_in6
+ 277         char    ifr_name[IFNAMSIZ];
-	ifra_prefixmask sockaddr_in6
+ 278         union {
-	ifra_flags      uint32
+ 279                 struct  sockaddr_in6 ifru_addr;
-	ifra_lifetime   in6_addrlifetime
+ 280                 struct  sockaddr_in6 ifru_dstaddr;
+ 281                 int     ifru_flags;
+ 282                 int     ifru_flags6;
+ 283                 int     ifru_metric;
+ 284                 caddr_t ifru_data;
+ 285                 struct in6_addrlifetime ifru_lifetime;
+ 286                 struct in6_ifstat ifru_stat;
+ 287                 struct icmp6_ifstat ifru_icmp6stat;
+ 288                 u_int32_t ifru_scope_id[16];
+ 289         } ifr_ifru;
+ 290 };
+*/
+
+type in6_ifreq_mtu struct {
+	ifr_name [syscall.IFNAMSIZ]byte
+	ifru_mtu int
+}
+
+type in6_ifreq_addr struct {
+	ifr_name  [syscall.IFNAMSIZ]byte
+	ifru_addr sockaddr_in6
+}
+
+type in6_ifreq_flags struct {
+	ifr_name [syscall.IFNAMSIZ]byte
+	flags    int
+}
+
+type in6_ifreq_lifetime struct {
+	ifr_name          [syscall.IFNAMSIZ]byte
+	ifru_addrlifetime in6_addrlifetime
 }
 
 func (tun *tunDevice) setup(ifname string, iftapmode bool, addr string, mtu int) error {
@@ -62,38 +97,67 @@ func (tun *tunDevice) setup(ifname string, iftapmode bool, addr string, mtu int)
 }
 
 func (tun *tunDevice) setupAddress(addr string) error {
-	fd := tun.iface.ReadWriteCloser.(*os.File).Fd()
+	var sfd int
 	var err error
-	var ti tuninfo
 
+	// Create system socket
+	if sfd, err = unix.Socket(unix.AF_INET, unix.SOCK_DGRAM, 0); err != nil {
+		tun.core.log.Printf("Create AF_INET socket failed: %v.", err)
+		return err
+	}
+
+	// Friendly output
 	tun.core.log.Printf("Interface name: %s", tun.iface.Name())
 	tun.core.log.Printf("Interface IPv6: %s", addr)
 	tun.core.log.Printf("Interface MTU: %d", tun.mtu)
 
-	// Get the existing interface flags
+	// Create the MTU request
-	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(TUNGIFINFO), uintptr(unsafe.Pointer(&ti))); errno != 0 {
+	var ir in6_ifreq_mtu
+	copy(ir.ifr_name[:], tun.iface.Name())
+	ir.ifru_mtu = int(tun.mtu)
+
+	// Set the MTU
+	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(sfd), uintptr(syscall.SIOCSIFMTU), uintptr(unsafe.Pointer(&ir))); errno != 0 {
 		err = errno
-		tun.core.log.Printf("Error in TUNGIFINFO: %v", errno)
+		tun.core.log.Printf("Error in SIOCSIFMTU: %v", errno)
-		return err
+
+		// Fall back to ifconfig to set the MTU
+		cmd := exec.Command("ifconfig", tun.iface.Name(), "mtu", string(tun.mtu))
+		tun.core.log.Printf("Using ifconfig as fallback: %v", strings.Join(cmd.Args, " "))
+		output, err := cmd.CombinedOutput()
+		if err != nil {
+			tun.core.log.Printf("SIOCSIFMTU fallback failed: %v.", err)
+			tun.core.log.Println(string(output))
+		}
 	}
 
-	// Update with any OS-specific flags, MTU, etc.
+	// Create the address request
-	ti.setInfo(tun)
+	// FIXME: I don't work!
-
+	var ar in6_ifreq_addr
-	// Set the new interface flags
+	copy(ar.ifr_name[:], tun.iface.Name())
-	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(TUNSIFINFO), uintptr(unsafe.Pointer(&ti))); errno != 0 {
+	ar.ifru_addr.sin6_len = uint8(unsafe.Sizeof(ar.ifru_addr))
-		err = errno
+	ar.ifru_addr.sin6_family = unix.AF_INET6
-		tun.core.log.Printf("Error in TUNSIFINFO: %v", errno)
+	parts := strings.Split(strings.TrimRight(addr, "/8"), ":")
-		return err
+	for i := 0; i < 8; i++ {
+		addr, _ := strconv.ParseUint(parts[i], 16, 16)
+		b := make([]byte, 16)
+		binary.LittleEndian.PutUint16(b, uint16(addr))
+		ar.ifru_addr.sin6_addr[i] = uint16(binary.BigEndian.Uint16(b))
 	}
 
-	// Set address
+	// Set the interface address
-	cmd := exec.Command("ifconfig", tun.iface.Name(), "inet6", addr)
+	if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(sfd), uintptr(SIOCSIFADDR_IN6), uintptr(unsafe.Pointer(&ar))); errno != 0 {
-	//tun.core.log.Printf("ifconfig command: %v", strings.Join(cmd.Args, " "))
+		err = errno
-	output, err := cmd.CombinedOutput()
+		tun.core.log.Printf("Error in SIOCSIFADDR_IN6: %v", errno)
-	if err != nil {
+
-		tun.core.log.Printf("ifconfig failed: %v.", err)
+		// Fall back to ifconfig to set the address
-		tun.core.log.Println(string(output))
+		cmd := exec.Command("ifconfig", tun.iface.Name(), "inet6", addr)
+		tun.core.log.Printf("Using ifconfig as fallback: %v", strings.Join(cmd.Args, " "))
+		output, err := cmd.CombinedOutput()
+		if err != nil {
+			tun.core.log.Printf("SIOCSIFADDR_IN6 fallback failed: %v.", err)
+			tun.core.log.Println(string(output))
+		}
 	}
 
 	return nil

src/yggdrasil/tun_freebsd.go

@@ -1,7 +1,5 @@
 package yggdrasil
 
-// This is to catch FreeBSD and NetBSD
-
 func getDefaults() tunDefaultParameters {
 	return tunDefaultParameters{
 		maximumIfMTU:     32767,
@@ -10,34 +8,3 @@ func getDefaults() tunDefaultParameters {
 		defaultIfTAPMode: true,
 	}
 }
-
-// Warning! When porting this to other BSDs, the tuninfo struct can appear with
-// the fields in a different order, and the consts below might also have
-// different values
-
-/*
-FreeBSD/NetBSD, net/if_tun.h:
-
-struct tuninfo {
-	int	baudrate;
-	short	mtu;
-	u_char	type;
-	u_char	dummy;
-};
-*/
-
-type tuninfo struct {
-	tun_baudrate int32
-	tun_mtu      int16
-	tun_type     uint8
-	tun_dummy    uint8
-}
-
-func (ti *tuninfo) setInfo(tun *tunDevice) {
-	ti.tun_mtu = int16(tun.mtu)
-}
-
-const TUNSIFINFO = (0x80000000) | ((8 & 0x1fff) << 16) | uint32(byte('t'))<<8 | 91
-const TUNGIFINFO = (0x40000000) | ((8 & 0x1fff) << 16) | uint32(byte('t'))<<8 | 92
-const TUNSIFHEAD = (0x80000000) | ((4 & 0x1fff) << 16) | uint32(byte('t'))<<8 | 96
-const SIOCAIFADDR_IN6 = (0x80000000) | ((4 & 0x1fff) << 16) | uint32(byte('i'))<<8 | 27

src/yggdrasil/tun_netbsd.go

@@ -0,0 +1,10 @@
+package yggdrasil
+
+func getDefaults() tunDefaultParameters {
+	return tunDefaultParameters{
+		maximumIfMTU:     9000,
+		defaultIfMTU:     9000,
+		defaultIfName:    "/dev/tap0",
+		defaultIfTAPMode: true,
+	}
+}

src/yggdrasil/tun_openbsd.go

@@ -1,13 +1,5 @@
 package yggdrasil
 
-import "syscall"
-
-// This is to catch OpenBSD
-
-// TODO: Fix TUN mode for OpenBSD. It turns out that OpenBSD doesn't have a way
-// to disable the PI header when in TUN mode, so we need to modify the read/
-// writes to handle those first four bytes
-
 func getDefaults() tunDefaultParameters {
 	return tunDefaultParameters{
 		maximumIfMTU:     16384,
@@ -16,41 +8,3 @@ func getDefaults() tunDefaultParameters {
 		defaultIfTAPMode: true,
 	}
 }
-
-// Warning! When porting this to other BSDs, the tuninfo struct can appear with
-// the fields in a different order, and the consts below might also have
-// different values
-
-/*
-OpenBSD, net/if_tun.h:
-
-struct tuninfo {
-        u_int   mtu;
-        u_short type;
-        u_short flags;
-        u_int   baudrate;
-};
-*/
-
-type tuninfo struct {
-	tun_mtu      uint32
-	tun_type     uint16
-	tun_flags    uint16
-	tun_baudrate uint32
-}
-
-func (ti *tuninfo) setInfo(tun *tunDevice) {
-	ti.tun_flags |= syscall.IFF_UP
-	switch {
-	case tun.iface.IsTAP():
-		ti.tun_flags |= syscall.IFF_MULTICAST
-		ti.tun_flags |= syscall.IFF_BROADCAST
-	case tun.iface.IsTUN():
-		ti.tun_flags |= syscall.IFF_POINTOPOINT
-	}
-	ti.tun_mtu = uint32(tun.mtu)
-}
-
-const TUNSIFINFO = (0x80000000) | ((12 & 0x1fff) << 16) | uint32(byte('t'))<<8 | 91
-const TUNGIFINFO = (0x40000000) | ((12 & 0x1fff) << 16) | uint32(byte('t'))<<8 | 92
-const SIOCAIFADDR_IN6 = (0x80000000) | ((4 & 0x1fff) << 16) | uint32(byte('i'))<<8 | 27

src/yggdrasil/tun_other.go

@@ -1,4 +1,4 @@
-// +build !linux,!darwin,!windows,!openbsd,!freebsd
+// +build !linux,!darwin,!windows,!openbsd,!freebsd,!netbsd
 
 package yggdrasil