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.
This commit is contained in:
Neil Alexander 2018-03-04 23:47:01 +00:00
parent b30b6022a8
commit 166d25619d
5 changed files with 106 additions and 111 deletions

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@ -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
ifra_addr sockaddr_in6
ifra_dstaddr sockaddr_in6
ifra_prefixmask sockaddr_in6
ifra_flags uint32
ifra_lifetime in6_addrlifetime
/*
from <netinet6/in6_var.h>
struct in6_ifreq {
277 char ifr_name[IFNAMSIZ];
278 union {
279 struct sockaddr_in6 ifru_addr;
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 {
@ -62,39 +97,68 @@ 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
if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(TUNGIFINFO), uintptr(unsafe.Pointer(&ti))); errno != 0 {
// Create the MTU request
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)
return err
}
tun.core.log.Printf("Error in SIOCSIFMTU: %v", errno)
// Update with any OS-specific flags, MTU, etc.
ti.setInfo(tun)
// Set the new interface flags
if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(fd), uintptr(TUNSIFINFO), uintptr(unsafe.Pointer(&ti))); errno != 0 {
err = errno
tun.core.log.Printf("Error in TUNSIFINFO: %v", errno)
return err
}
// Set address
cmd := exec.Command("ifconfig", tun.iface.Name(), "inet6", addr)
//tun.core.log.Printf("ifconfig command: %v", strings.Join(cmd.Args, " "))
// 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("ifconfig failed: %v.", err)
tun.core.log.Printf("SIOCSIFMTU fallback failed: %v.", err)
tun.core.log.Println(string(output))
}
}
// Create the address request
// FIXME: I don't work!
var ar in6_ifreq_addr
copy(ar.ifr_name[:], tun.iface.Name())
ar.ifru_addr.sin6_len = uint8(unsafe.Sizeof(ar.ifru_addr))
ar.ifru_addr.sin6_family = unix.AF_INET6
parts := strings.Split(strings.TrimRight(addr, "/8"), ":")
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 the interface address
if _, _, errno := unix.Syscall(unix.SYS_IOCTL, uintptr(sfd), uintptr(SIOCSIFADDR_IN6), uintptr(unsafe.Pointer(&ar))); errno != 0 {
err = errno
tun.core.log.Printf("Error in SIOCSIFADDR_IN6: %v", errno)
// Fall back to ifconfig to set the address
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
}

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@ -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

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

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@ -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

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