From 8a10f689006bf728a5cff35787713047f68e308a Mon Sep 17 00:00:00 2001 From: black-desk Date: Mon, 10 Jul 2023 14:38:01 +0800 Subject: [PATCH] Add address field for expr tproxy (#231) * Add address field for expr tproxy Signed-off-by: black-desk Co-authored-by: MrRedhat --- expr/tproxy.go | 26 +++++++++++++----- nftables_test.go | 68 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 88 insertions(+), 6 deletions(-) diff --git a/expr/tproxy.go b/expr/tproxy.go index ea936f3..2846aab 100644 --- a/expr/tproxy.go +++ b/expr/tproxy.go @@ -25,22 +25,34 @@ import ( const ( // NFTA_TPROXY_FAMILY defines attribute for a table family NFTA_TPROXY_FAMILY = 0x01 - // NFTA_TPROXY_REG defines attribute for a register carrying redirection port value - NFTA_TPROXY_REG = 0x03 + // NFTA_TPROXY_REG_ADDR defines attribute for a register carrying redirection address value + NFTA_TPROXY_REG_ADDR = 0x02 + // NFTA_TPROXY_REG_PORT defines attribute for a register carrying redirection port value + NFTA_TPROXY_REG_PORT = 0x03 ) // TProxy defines struct with parameters for the transparent proxy type TProxy struct { Family byte TableFamily byte + RegAddr uint32 RegPort uint32 } func (e *TProxy) marshal(fam byte) ([]byte, error) { - data, err := netlink.MarshalAttributes([]netlink.Attribute{ + attrs := []netlink.Attribute{ {Type: NFTA_TPROXY_FAMILY, Data: binaryutil.BigEndian.PutUint32(uint32(e.Family))}, - {Type: NFTA_TPROXY_REG, Data: binaryutil.BigEndian.PutUint32(e.RegPort)}, - }) + {Type: NFTA_TPROXY_REG_PORT, Data: binaryutil.BigEndian.PutUint32(e.RegPort)}, + } + + if e.RegAddr != 0 { + attrs = append(attrs, netlink.Attribute{ + Type: NFTA_TPROXY_REG_ADDR, + Data: binaryutil.BigEndian.PutUint32(e.RegAddr), + }) + } + + data, err := netlink.MarshalAttributes(attrs) if err != nil { return nil, err } @@ -60,8 +72,10 @@ func (e *TProxy) unmarshal(fam byte, data []byte) error { switch ad.Type() { case NFTA_TPROXY_FAMILY: e.Family = ad.Uint8() - case NFTA_TPROXY_REG: + case NFTA_TPROXY_REG_PORT: e.RegPort = ad.Uint32() + case NFTA_TPROXY_REG_ADDR: + e.RegAddr = ad.Uint32() } } return ad.Err() diff --git a/nftables_test.go b/nftables_test.go index 53a86f0..3158be3 100644 --- a/nftables_test.go +++ b/nftables_test.go @@ -1206,6 +1206,74 @@ func TestTProxy(t *testing.T) { } } +func TestTProxyWithAddrField(t *testing.T) { + want := [][]byte{ + // batch begin + []byte("\x00\x00\x00\x0a"), + // nft add rule filter divert ip protocol tcp tproxy to 10.10.72.1:50080 + []byte("\x02\x00\x00\x00\x0b\x00\x01\x00\x66\x69\x6c\x74\x65\x72\x00\x00\x0b\x00\x02\x00\x64\x69\x76\x65\x72\x74\x00\x00\xe8\x00\x04\x80\x34\x00\x01\x80\x0c\x00\x01\x00\x70\x61\x79\x6c\x6f\x61\x64\x00\x24\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x01\x08\x00\x03\x00\x00\x00\x00\x09\x08\x00\x04\x00\x00\x00\x00\x01\x2c\x00\x01\x80\x08\x00\x01\x00\x63\x6d\x70\x00\x20\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x00\x0c\x00\x03\x80\x05\x00\x01\x00\x06\x00\x00\x00\x2c\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x18\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x0c\x00\x02\x80\x08\x00\x01\x00\x0a\x0a\x48\x01\x2c\x00\x01\x80\x0e\x00\x01\x00\x69\x6d\x6d\x65\x64\x69\x61\x74\x65\x00\x00\x00\x18\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x02\x0c\x00\x02\x80\x06\x00\x01\x00\xc3\xa0\x00\x00\x2c\x00\x01\x80\x0b\x00\x01\x00\x74\x70\x72\x6f\x78\x79\x00\x00\x1c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x02\x08\x00\x03\x00\x00\x00\x00\x02\x08\x00\x02\x00\x00\x00\x00\x01"), + // batch end + []byte("\x00\x00\x00\x0a"), + } + + c, err := nftables.New(nftables.WithTestDial( + func(req []netlink.Message) ([]netlink.Message, error) { + for idx, msg := range req { + b, err := msg.MarshalBinary() + if err != nil { + t.Fatal(err) + } + if len(b) < 16 { + continue + } + b = b[16:] + if len(want) == 0 { + t.Errorf("no want entry for message %d: %x", idx, b) + continue + } + if got, want := b, want[0]; !bytes.Equal(got, want) { + t.Errorf("message %d: %s", idx, linediff(nfdump(got), nfdump(want))) + } + want = want[1:] + } + return req, nil + })) + if err != nil { + t.Fatal(err) + } + + c.AddRule(&nftables.Rule{ + Table: &nftables.Table{Name: "filter", Family: nftables.TableFamilyIPv4}, + Chain: &nftables.Chain{ + Name: "divert", + Type: nftables.ChainTypeFilter, + Hooknum: nftables.ChainHookPrerouting, + Priority: nftables.ChainPriorityRef(-150), + }, + Exprs: []expr.Any{ + // [ payload load 1b @ network header + 9 => reg 1 ] + &expr.Payload{DestRegister: 1, Base: expr.PayloadBaseNetworkHeader, Offset: 9, Len: 1}, + // [ cmp eq reg 1 0x00000006 ] + &expr.Cmp{Op: expr.CmpOpEq, Register: 1, Data: []byte{unix.IPPROTO_TCP}}, + // [ immediate reg 1 0x01480a0a ] + &expr.Immediate{Register: 1, Data: []byte("\x0a\x0a\x48\x01")}, + // [ immediate reg 2 0x0000a0c3 ] + &expr.Immediate{Register: 2, Data: binaryutil.BigEndian.PutUint16(50080)}, + // [ tproxy ip addr reg 1 port reg 2 ] + &expr.TProxy{ + Family: byte(nftables.TableFamilyIPv4), + TableFamily: byte(nftables.TableFamilyIPv4), + RegAddr: 1, + RegPort: 2, + }, + }, + }) + + if err := c.Flush(); err != nil { + t.Fatal(err) + } +} + func TestCt(t *testing.T) { want := [][]byte{ // batch begin