migrate to golang.zx2c4.com/wireguard/wgctrl (#239)

* migrate to golang.zx2c4.com/wireguard/wgctrl

This commit introduces the usage of wgctrl.
It avoids the usage of exec calls of the wg command
and parsing the output of `wg show`.

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* vendor wgctrl

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* apply suggestions from code review

Remove wireguard.Enpoint struct and use net.UDPAddr for the resolved
endpoint and addr string (dnsanme:port) if a DN was supplied.

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* pkg/*: use wireguard.Enpoint

This commit introduces the wireguard.Enpoint struct.
It encapsulates a DN name with port and a net.UPDAddr.
The fields are private and only accessible over exported Methods
to avoid accidental modification.

Also iptables.GetProtocol is improved to avoid ipv4 rules being applied
by `ip6tables`.

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* pkg/wireguard/conf_test.go: add tests for Endpoint

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* cmd/kg/main.go: validate port range

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* add suggestions from review

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* pkg/mesh/mesh.go: use Equal func

Implement an Equal func for Enpoint and use it instead of comparing
strings.

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* cmd/kgctl/main.go: check port range

Signed-off-by: leonnicolas <leonloechner@gmx.de>

* vendor

Signed-off-by: leonnicolas <leonloechner@gmx.de>

vendor/golang.org/x/net/http2/hpack/huffman.go

@@ -140,25 +140,29 @@ func buildRootHuffmanNode() {
 		panic("unexpected size")
 	}
 	lazyRootHuffmanNode = newInternalNode()
-	for i, code := range huffmanCodes {
-		addDecoderNode(byte(i), code, huffmanCodeLen[i])
-	}
-}
+	// allocate a leaf node for each of the 256 symbols
+	leaves := new([256]node)
 
-func addDecoderNode(sym byte, code uint32, codeLen uint8) {
-	cur := lazyRootHuffmanNode
-	for codeLen > 8 {
-		codeLen -= 8
-		i := uint8(code >> codeLen)
-		if cur.children[i] == nil {
-			cur.children[i] = newInternalNode()
+	for sym, code := range huffmanCodes {
+		codeLen := huffmanCodeLen[sym]
+
+		cur := lazyRootHuffmanNode
+		for codeLen > 8 {
+			codeLen -= 8
+			i := uint8(code >> codeLen)
+			if cur.children[i] == nil {
+				cur.children[i] = newInternalNode()
+			}
+			cur = cur.children[i]
+		}
+		shift := 8 - codeLen
+		start, end := int(uint8(code<<shift)), int(1<<shift)
+
+		leaves[sym].sym = byte(sym)
+		leaves[sym].codeLen = codeLen
+		for i := start; i < start+end; i++ {
+			cur.children[i] = &leaves[sym]
 		}
-		cur = cur.children[i]
-	}
-	shift := 8 - codeLen
-	start, end := int(uint8(code<<shift)), int(1<<shift)
-	for i := start; i < start+end; i++ {
-		cur.children[i] = &node{sym: sym, codeLen: codeLen}
 	}
 }