Skip to content

netlink: test debug output on big-endian systems #313

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
dlanov wants to merge 1 commit into
base: main
Choose a base branch
from
Open

netlink: test debug output on big-endian systems #313

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
30 changes: 30 additions & 0 deletions .github/workflows/linux-test.yml
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -32,3 +32,33 @@ jobs:

- name: Run tests
run: go test -v -race -tags gofuzz ./...

big-endian:
runs-on: ubuntu-latest

steps:
- name: Set up Go
uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7.0.0
with:
go-version: "1.26"

- name: Check out code
uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0

- name: Install s390x emulator
run: |
sudo apt-get update
sudo apt-get install -y --no-install-recommends qemu-user-static

- name: Run tests on s390x
env:
GOOS: linux
GOARCH: s390x
CGO_ENABLED: "0"
run: |
go test \
-exec qemu-s390x-static \
-tags gofuzz \
-count=1 \
-skip Integration \
./nlenc ./nltest .
2 changes: 1 addition & 1 deletion conn_linux_integration_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -560,7 +560,7 @@ func (s *blockingSocket) ReceiveIter() iter.Seq2[netlink.Message, error] {
}
}

func TestReceiveIter(t *testing.T) {
func TestIntegrationReceiveIter(t *testing.T) {
t.Parallel()
c, err := netlink.Dial(unix.NETLINK_GENERIC, nil)
if err != nil {
Expand Down
238 changes: 216 additions & 22 deletions debug_linux_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,32 +4,152 @@ package netlink

import (
"bytes"
"encoding/binary"
"testing"

"github.com/google/go-cmp/cmp"
"golang.org/x/sys/unix"
)

type debugTestAttribute func(*AttributeEncoder)

func debugStringAttribute(typ uint16, value string) debugTestAttribute {
return func(ae *AttributeEncoder) { ae.String(typ, value) }
}

func debugUint32Attribute(typ uint16, value uint32) debugTestAttribute {
return func(ae *AttributeEncoder) { ae.Uint32(typ, value) }
}

func debugBytesAttribute(typ uint16, value []byte) debugTestAttribute {
return func(ae *AttributeEncoder) { ae.Bytes(typ, value) }
}

func debugNestedAttribute(typ uint16, attrs ...debugTestAttribute) debugTestAttribute {
return func(ae *AttributeEncoder) {
ae.Nested(typ, func(nae *AttributeEncoder) error {
for _, attr := range attrs {
attr(nae)
}
return nil
})
}
}

func debugExpression(name string, attrs ...debugTestAttribute) debugTestAttribute {
return debugNestedAttribute(
unix.NFTA_LIST_ELEM,
debugStringAttribute(unix.NFTA_EXPR_NAME, name),
debugNestedAttribute(unix.NFTA_EXPR_DATA, attrs...),
)
}

func debugMetaExpression(key, dreg uint32) debugTestAttribute {
return debugExpression(
"meta",
debugUint32Attribute(unix.NFTA_META_KEY, key),
debugUint32Attribute(unix.NFTA_META_DREG, dreg),
)
}

func debugCmpExpression(sreg, op uint32, value []byte) debugTestAttribute {
return debugExpression(
"cmp",
debugUint32Attribute(unix.NFTA_CMP_SREG, sreg),
debugUint32Attribute(unix.NFTA_CMP_OP, op),
debugNestedAttribute(
unix.NFTA_CMP_DATA,
debugBytesAttribute(unix.NFTA_DATA_VALUE, value),
),
)
}

func debugPayloadExpression(dreg, base, offset, length uint32) debugTestAttribute {
return debugExpression(
"payload",
debugUint32Attribute(unix.NFTA_PAYLOAD_DREG, dreg),
debugUint32Attribute(unix.NFTA_PAYLOAD_BASE, base),
debugUint32Attribute(unix.NFTA_PAYLOAD_OFFSET, offset),
debugUint32Attribute(unix.NFTA_PAYLOAD_LEN, length),
)
}

func debugImmediateExpression(dreg uint32, value []byte) debugTestAttribute {
return debugExpression(
"immediate",
debugUint32Attribute(unix.NFTA_IMMEDIATE_DREG, dreg),
debugNestedAttribute(
unix.NFTA_IMMEDIATE_DATA,
debugBytesAttribute(unix.NFTA_DATA_VALUE, value),
),
)
}

func debugNatExpression(
typ, family, addressRegister, portMinRegister, portMaxRegister uint32,
) debugTestAttribute {
return debugExpression(
"nat",
debugUint32Attribute(unix.NFTA_NAT_TYPE, typ),
debugUint32Attribute(unix.NFTA_NAT_FAMILY, family),
debugUint32Attribute(unix.NFTA_NAT_REG_ADDR_MIN, addressRegister),
debugUint32Attribute(unix.NFTA_NAT_REG_PROTO_MIN, portMinRegister),
debugUint32Attribute(unix.NFTA_NAT_REG_PROTO_MAX, portMaxRegister),
)
}

func debugBigEndianUint16(value uint16) []byte {
b := make([]byte, 2)
binary.BigEndian.PutUint16(b, value)
return b
}

func debugNftablesMessageData(t *testing.T, attrs ...debugTestAttribute) []byte {
t.Helper()

ae := NewAttributeEncoder()

// nftables integer attribute payloads use network byte order. Attribute
// headers are written in native byte order by MarshalAttributes.
ae.ByteOrder = binary.BigEndian

for _, attr := range attrs {
attr(ae)
}

b, err := ae.Encode()
if err != nil {
t.Fatalf("failed to encode nftables attributes: %v", err)
}

return append([]byte{unix.NFPROTO_IPV4, 0, 0, 0}, b...)
}

func TestNlmsgFprintf(t *testing.T) {
skipBigEndian(t)
// netlink messages obtained from https://github.com/google/nftables/blob/e99829fb4f26d75fdd0cfce8ba4632744e72c2bc/nftables_test.go#L245C1-L246C94
// nftables messages modeled after https://github.com/google/nftables/blob/e99829fb4f26d75fdd0cfce8ba4632744e72c2bc/nftables_test.go#L245C1-L246C94
tests := []struct {
name string
m Message
m func(t *testing.T) Message
colorize bool
want string
}{
{
name: "nft add table ip nat",
m: Message{
Header: Header{
Length: 40,
Type: HeaderType(uint16(unix.NFNL_SUBSYS_NFTABLES)<<8 | uint16(unix.NFT_MSG_NEWTABLE)),
Flags: Request,
Sequence: 1,
PID: 1234,
},
Data: []byte("\x02\x00\x00\x00\x08\x00\x01\x00\x6e\x61\x74\x00\x08\x00\x02\x00\x00\x00\x00\x00"),
m: func(t *testing.T) Message {
return Message{
Header: Header{
Length: 40,
Type: HeaderType(uint16(unix.NFNL_SUBSYS_NFTABLES)<<8 | uint16(unix.NFT_MSG_NEWTABLE)),
Flags: Request,
Sequence: 1,
PID: 1234,
},
Data: debugNftablesMessageData(
t,
debugStringAttribute(unix.NFTA_TABLE_NAME, "nat"),
debugUint32Attribute(unix.NFTA_TABLE_FLAGS, 0),
),
}
},
colorize: false,
want: `---------------- ------------------
Expand All @@ -48,15 +168,88 @@ func TestNlmsgFprintf(t *testing.T) {
},
{
name: "nft add rule nat prerouting iifname uplink0 udp dport 4070-4090 dnat 192.168.23.2:4070-4090",
m: Message{
Header: Header{
Length: 40,
Type: HeaderType(uint16(unix.NFNL_SUBSYS_NFTABLES)<<8 | uint16(unix.NFT_MSG_NEWRULE)),
Flags: Request,
Sequence: 1,
PID: 1234,
},
Data: []byte("\x02\x00\x00\x00\x08\x00\x01\x00\x6e\x61\x74\x00\x0f\x00\x02\x00\x70\x72\x65\x72\x6f\x75\x74\x69\x6e\x67\x00\x00\xf8\x01\x04\x80\x24\x00\x01\x80\x09\x00\x01\x00\x6d\x65\x74\x61\x00\x00\x00\x00\x14\x00\x02\x80\x08\x00\x02\x00\x00\x00\x00\x06\x08\x00\x01\x00\x00\x00\x00\x01\x38\x00\x01\x80\x08\x00\x01\x00\x63\x6d\x70\x00\x2c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x00\x18\x00\x03\x80\x14\x00\x01\x00\x75\x70\x6c\x69\x6e\x6b\x30\x00\x00\x00\x00\x00\x00\x00\x00\x00\x24\x00\x01\x80\x09\x00\x01\x00\x6d\x65\x74\x61\x00\x00\x00\x00\x14\x00\x02\x80\x08\x00\x02\x00\x00\x00\x00\x10\x08\x00\x01\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\x11\x00\x00\x00\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\x02\x08\x00\x03\x00\x00\x00\x00\x02\x08\x00\x04\x00\x00\x00\x00\x02\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\x05\x0c\x00\x03\x80\x06\x00\x01\x00\x0f\xe6\x00\x00\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\x03\x0c\x00\x03\x80\x06\x00\x01\x00\x0f\xfa\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\xc0\xa8\x17\x02\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\x0f\xe6\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\x03\x0c\x00\x02\x80\x06\x00\x01\x00\x0f\xfa\x00\x00\x38\x00\x01\x80\x08\x00\x01\x00\x6e\x61\x74\x00\x2c\x00\x02\x80\x08\x00\x01\x00\x00\x00\x00\x01\x08\x00\x02\x00\x00\x00\x00\x02\x08\x00\x03\x00\x00\x00\x00\x01\x08\x00\x05\x00\x00\x00\x00\x02\x08\x00\x06\x00\x00\x00\x00\x03"),
m: func(t *testing.T) Message {
return Message{
Header: Header{
Length: 40,
Type: HeaderType(uint16(unix.NFNL_SUBSYS_NFTABLES)<<8 | uint16(unix.NFT_MSG_NEWRULE)),
Flags: Request,
Sequence: 1,
PID: 1234,
},
Data: debugNftablesMessageData(
t,
debugStringAttribute(unix.NFTA_RULE_TABLE, "nat"),
debugStringAttribute(unix.NFTA_RULE_CHAIN, "prerouting"),
debugNestedAttribute(
unix.NFTA_RULE_EXPRESSIONS,

debugMetaExpression(
unix.NFT_META_IIFNAME,
unix.NFT_REG_1,
),

debugCmpExpression(
unix.NFT_REG_1,
unix.NFT_CMP_EQ,
append([]byte("uplink0"), make([]byte, 9)...),
),

debugMetaExpression(
unix.NFT_META_L4PROTO,
unix.NFT_REG_1,
),

debugCmpExpression(
unix.NFT_REG_1,
unix.NFT_CMP_EQ,
[]byte{unix.IPPROTO_UDP},
),

debugPayloadExpression(
unix.NFT_REG_1,
unix.NFT_PAYLOAD_TRANSPORT_HEADER,
2,
2,
),

debugCmpExpression(
unix.NFT_REG_1,
unix.NFT_CMP_GTE,
debugBigEndianUint16(4070),
),

debugCmpExpression(
unix.NFT_REG_1,
unix.NFT_CMP_LTE,
debugBigEndianUint16(4090),
),

debugImmediateExpression(
unix.NFT_REG_1,
[]byte{192, 168, 23, 2},
),

debugImmediateExpression(
unix.NFT_REG_2,
debugBigEndianUint16(4070),
),

debugImmediateExpression(
unix.NFT_REG_3,
debugBigEndianUint16(4090),
),

debugNatExpression(
unix.NFT_NAT_DNAT,
unix.NFPROTO_IPV4,
unix.NFT_REG_1,
unix.NFT_REG_2,
unix.NFT_REG_3,
),
),
),
}
},
colorize: false,
want: `---------------- ------------------
Expand Down Expand Up @@ -205,7 +398,8 @@ func TestNlmsgFprintf(t *testing.T) {
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
w := &bytes.Buffer{}
nlmsgFprintf(w, tt.m, tt.colorize)
m := tt.m(t)
nlmsgFprintf(w, m, tt.colorize)
got := w.String()
if got != tt.want {
t.Errorf("nlmsgFprintf() =\n%s,\nwant\n%s\ndiff:\n%s", got, tt.want, cmp.Diff(got, tt.want))
Expand Down