wireguard-go: Use multi-af mode for NetBSD tun(4)

[snow flurry <snow%datagirl.xyz@localhost>]

Module Name:	pkgsrc-wip
Committed By:	snow flurry <snow%datagirl.xyz@localhost>
Pushed By:	flurry
Date:		Mon Jul 3 19:39:28 2023 +0000
Changeset:	d314da09a8ef045da91fd0d66246fbd6d7c2c511

Modified Files:
	wireguard-go/Makefile
	wireguard-go/distinfo
Added Files:
	wireguard-go/patches/patch-tun_tun__netbsd.go

Log Message:
wireguard-go: Use multi-af mode for NetBSD tun(4)

OpenBSD only provides "multi-af" mode in tun(4). To make porting to
NetBSD easier, we can enable "multi-af" mode after creating the tun
device.

To see a diff of this commit:
https://wip.pkgsrc.org/cgi-bin/gitweb.cgi?p=pkgsrc-wip.git;a=commitdiff;h=d314da09a8ef045da91fd0d66246fbd6d7c2c511

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.

diffstat:
 wireguard-go/Makefile                         |  4 +--
 wireguard-go/distinfo                         |  1 +
 wireguard-go/patches/patch-tun_tun__netbsd.go | 38 +++++++++++++++++++++++++++
 3 files changed, 41 insertions(+), 2 deletions(-)

diffs:
diff --git a/wireguard-go/Makefile b/wireguard-go/Makefile
index 85212de1d2..31387107f7 100644
--- a/wireguard-go/Makefile
+++ b/wireguard-go/Makefile
@@ -18,8 +18,8 @@ do-install:
 
 GO_BUILD_PATTERN=	.
 
-post-patch:
-	cd ${WRKSRC}/tun && ${LN} -sf tun_openbsd.go tun_netbsd.go
+pre-patch:
+	cd ${WRKSRC}/tun && ${CP} tun_openbsd.go tun_netbsd.go
 
 .include "go-modules.mk"
 
diff --git a/wireguard-go/distinfo b/wireguard-go/distinfo
index 22cec0bb32..5777c63470 100644
--- a/wireguard-go/distinfo
+++ b/wireguard-go/distinfo
@@ -29,3 +29,4 @@ SHA512 (wireguard-go-0.0.20220316.tar.xz) = 82b53210502e01d454a62a1a7694f57b2f72
 Size (wireguard-go-0.0.20220316.tar.xz) = 110444 bytes
 SHA1 (patch-ipc_uapi__bsd.go) = 028dd8415c52abb844ee1e8b234cc13872e697e3
 SHA1 (patch-ipc_uapi__unix.go) = 8b0c917db05bfb94f446cf6b68b5c4ac655ebd9f
+SHA1 (patch-tun_tun__netbsd.go) = 0a9b925b520f7b6169e37dd8afa42c04ab2b0b6e
diff --git a/wireguard-go/patches/patch-tun_tun__netbsd.go b/wireguard-go/patches/patch-tun_tun__netbsd.go
new file mode 100644
index 0000000000..3266c14a35
--- /dev/null
+++ b/wireguard-go/patches/patch-tun_tun__netbsd.go
@@ -0,0 +1,38 @@
+$NetBSD$
+
+Enables multi-af mode for NetBSD tun(4).
+
+--- tun/tun_netbsd.go.orig	2023-07-03 19:33:35.358738005 +0000
++++ tun/tun_netbsd.go
+@@ -25,7 +25,7 @@ type ifreq_mtu struct {
+ 	Pad0 [12]byte
+ }
+ 
+-const _TUNSIFMODE = 0x8004745d
++const _TUNSIFHEAD = 0x80047442
+ 
+ type NativeTun struct {
+ 	name        string
+@@ -130,6 +130,22 @@ func CreateTUN(name string, mtu int) (De
+ 
+ 	tun, err := CreateTUNFromFile(tunfile, mtu)
+ 
++	// set multi-af mode
++	ifheadmode := 1
++	var errno syscall.Errno
++	_, _, errno = unix.Syscall(
++		unix.SYS_IOCTL,
++		tunfile.Fd(),
++		uintptr(_TUNSIFHEAD),
++		uintptr(unsafe.Pointer(&ifheadmode)),
++	)
++
++	if errno != 0 {
++		tunfile.Close()
++		return nil, fmt.Errorf("Unable to put into multi-af mode: %v", errno)
++	}
++
++
+ 	if err == nil && name == "tun" {
+ 		fname := os.Getenv("WG_TUN_NAME_FILE")
+ 		if fname != "" {