all: convert more code to use net/netip directly

perl -i -npe 's,netaddr.IPPrefixFrom,netip.PrefixFrom,' $(git grep -l -F netaddr.)
    perl -i -npe 's,netaddr.IPPortFrom,netip.AddrPortFrom,' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPrefix,netip.Prefix,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPPort,netip.AddrPort,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IP\b,netip.Addr,g' $(git grep -l -F netaddr. )
    perl -i -npe 's,netaddr.IPv6Raw\b,netip.AddrFrom16,g' $(git grep -l -F netaddr. )
    goimports -w .

Then delete some stuff from the net/netaddr shim package which is no
longer neeed.

Updates #5162

Change-Id: Ia7a86893fe21c7e3ee1ec823e8aba288d4566cd8
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

net/packet/ip4.go

@@ -7,8 +7,8 @@ package packet
 import (
 	"encoding/binary"
 	"errors"
+	"net/netip"
 
-	"tailscale.com/net/netaddr"
 	"tailscale.com/types/ipproto"
 )
 
@@ -19,8 +19,8 @@ const ip4HeaderLength = 20
 type IP4Header struct {
 	IPProto ipproto.Proto
 	IPID    uint16
-	Src     netaddr.IP
-	Dst     netaddr.IP
+	Src     netip.Addr
+	Dst     netip.Addr
 }
 
 // Len implements Header.

net/packet/ip6.go

@@ -6,8 +6,8 @@ package packet
 
 import (
 	"encoding/binary"
+	"net/netip"
 
-	"tailscale.com/net/netaddr"
 	"tailscale.com/types/ipproto"
 )
 
@@ -18,8 +18,8 @@ const ip6HeaderLength = 40
 type IP6Header struct {
 	IPProto ipproto.Proto
 	IPID    uint32 // only lower 20 bits used
-	Src     netaddr.IP
-	Dst     netaddr.IP
+	Src     netip.Addr
+	Dst     netip.Addr
 }
 
 // Len implements Header.

net/packet/packet.go

@@ -54,9 +54,9 @@ type Parsed struct {
 	IPProto ipproto.Proto
 	// SrcIP4 is the source address. Family matches IPVersion. Port is
 	// valid iff IPProto == TCP || IPProto == UDP.
-	Src netaddr.IPPort
+	Src netip.AddrPort
 	// DstIP4 is the destination address. Family matches IPVersion.
-	Dst netaddr.IPPort
+	Dst netip.AddrPort
 	// TCPFlags is the packet's TCP flag bits. Valid iff IPProto == TCP.
 	TCPFlags TCPFlag
 }

net/packet/packet_test.go

@@ -10,7 +10,6 @@ import (
 	"reflect"
 	"testing"
 
-	"tailscale.com/net/netaddr"
 	"tailscale.com/tstest"
 	"tailscale.com/types/ipproto"
 )
@@ -27,7 +26,7 @@ const (
 	Fragment = ipproto.Fragment
 )
 
-func mustIPPort(s string) netaddr.IPPort {
+func mustIPPort(s string) netip.AddrPort {
 	ipp, err := netip.ParseAddrPort(s)
 	if err != nil {
 		panic(err)

net/packet/tsmp.go

@@ -14,9 +14,9 @@ import (
 	"encoding/binary"
 	"errors"
 	"fmt"
+	"net/netip"
 
 	"tailscale.com/net/flowtrack"
-	"tailscale.com/net/netaddr"
 	"tailscale.com/types/ipproto"
 )
 
@@ -36,10 +36,10 @@ import (
 // In the future it might also accept 16 byte IP flow src/dst IPs
 // after the header, if they're different than the IP-level ones.
 type TailscaleRejectedHeader struct {
-	IPSrc  netaddr.IP            // IPv4 or IPv6 header's src IP
-	IPDst  netaddr.IP            // IPv4 or IPv6 header's dst IP
-	Src    netaddr.IPPort        // rejected flow's src
-	Dst    netaddr.IPPort        // rejected flow's dst
+	IPSrc  netip.Addr            // IPv4 or IPv6 header's src IP
+	IPDst  netip.Addr            // IPv4 or IPv6 header's dst IP
+	Src    netip.AddrPort        // rejected flow's src
+	Dst    netip.AddrPort        // rejected flow's dst
 	Proto  ipproto.Proto         // proto that was rejected (TCP or UDP)
 	Reason TailscaleRejectReason // why the connection was rejected
 
@@ -192,8 +192,8 @@ func (pp *Parsed) AsTailscaleRejectedHeader() (h TailscaleRejectedHeader, ok boo
 		Reason: TailscaleRejectReason(p[2]),
 		IPSrc:  pp.Src.Addr(),
 		IPDst:  pp.Dst.Addr(),
-		Src:    netaddr.IPPortFrom(pp.Dst.Addr(), binary.BigEndian.Uint16(p[3:5])),
-		Dst:    netaddr.IPPortFrom(pp.Src.Addr(), binary.BigEndian.Uint16(p[5:7])),
+		Src:    netip.AddrPortFrom(pp.Dst.Addr(), binary.BigEndian.Uint16(p[3:5])),
+		Dst:    netip.AddrPortFrom(pp.Src.Addr(), binary.BigEndian.Uint16(p[5:7])),
 	}
 	if len(p) > 7 {
 		flags := p[7]