mirror of
https://github.com/slackhq/nebula.git
synced 2026-08-15 23:46:58 +02:00
JackDoan
aacb4e2334
Multi-disciplinary correctness review of the batched tun / GSO-GRO / sendmmsg rework. Each fix has a regression test; the merged tree builds on linux/darwin/openbsd/windows/freebsd/netbsd, vets clean, passes the unit and e2e suites, and is -race clean. Critical: - C1 zero-length inner UDP datagram no longer panics the process (remote DoS): the UDP coalescer routes payLen==0 to passthrough instead of seeding a GSO slot, and WriteGSO skips empty payload iovecs as defense in depth. - C2 segmenter no longer corrupts inner headers when gsoSize < headerLen: the L3+L4 header is snapshotted once and each segment stamped from the copy, replacing the destructive overlapping in-place slide (SegmentTCP + SegmentUDP). High: - H1 applyOuterECN updates the IPv4 header checksum (RFC 1624 incremental) when folding outer CE into the inner ToS, so passthrough packets are no longer dropped by the peer stack. - H2 the GRO reject path caps the borrowed RX segment ([:n:n]) so a reject can no longer overrun into the next coalesced segment's Nebula header. Note: oversized ICMPv6 rejects that need >16B beyond the segment are now refused rather than sent under GRO (safe; see TOFIX.md for the scratch-buffer follow-up). - H3 WriteBatch falls back to per-packet WriteTo for a chunk when writeSockaddr fails, so one bad-family destination costs only its own packet, not the batch. - H4 UserDevice.Readers returns N distinct queue wrappers with private buffers (sharing the pipes) so concurrent readers no longer race/overwrite borrowed packet bytes. - H5 Poll.Close / Offload.Close no longer null t.fd (matching master's tunFile.Close), removing the data race with a concurrent readOne load. Medium/Low: - M1 the UDP GSO 127-segment gate moved from kernel >=5.5 to >=6.9 (the real UDP_MAX_SEGMENTS 64->128 threshold), avoiding EINVAL + per-packet fallback on 5.5-6.8 kernels. - M2 NewMultiQueueReader replays the offload mask newTun actually negotiated instead of the TSO-only mask, so adding a queue no longer disables USO device-wide; the advertised USO capability derives from the same mask. - M3 the shutdown eventfd is closed in pollQueueSet.Close / offloadQueueSet.Close (double-close guarded), fixing the per-lifecycle fd leak. - M4 dual-stack ECN selects the cmsg by address family, not socket family: RX parseRecvCmsg reads both IP_TOS and IPV6_TCLASS; TX writeEntryCmsg stamps IP_TOS for v4/v4-mapped dests and IPV6_TCLASS for v6 (on-host verified). - L1 newPoll no longer closes the fd on failure (matching newOffload), removing the double-close on QueueSet.Add error.
523 lines
17 KiB
Go
523 lines
17 KiB
Go
package iputil
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import (
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"bytes"
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"encoding/binary"
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"net"
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"testing"
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"github.com/stretchr/testify/assert"
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"golang.org/x/net/ipv4"
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"golang.org/x/net/ipv6"
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)
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func Test_CreateRejectPacket(t *testing.T) {
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h := ipv4.Header{
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Len: 20,
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Src: net.IPv4(10, 0, 0, 1),
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Dst: net.IPv4(10, 0, 0, 2),
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Protocol: 1, // ICMP
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}
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b, err := h.Marshal()
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if err != nil {
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t.Fatalf("h.Marhshal: %v", err)
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}
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b = append(b, []byte{0, 3, 0, 4}...)
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expectedLen := ipv4.HeaderLen + 8 + h.Len + 4
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out := make([]byte, expectedLen)
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rejectPacket := CreateRejectPacket(b, out)
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assert.NotNil(t, rejectPacket)
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assert.Len(t, rejectPacket, expectedLen)
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// ICMP with max header len
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h = ipv4.Header{
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Len: 60,
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Src: net.IPv4(10, 0, 0, 1),
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Dst: net.IPv4(10, 0, 0, 2),
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Protocol: 1, // ICMP
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Options: make([]byte, 40),
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}
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b, err = h.Marshal()
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if err != nil {
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t.Fatalf("h.Marhshal: %v", err)
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}
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b = append(b, []byte{0, 3, 0, 4, 0, 0, 0, 0}...)
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expectedLen = maxIPv4RejectPacketSize
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out = make([]byte, MaxRejectPacketSize)
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rejectPacket = CreateRejectPacket(b, out)
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assert.NotNil(t, rejectPacket)
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assert.Len(t, rejectPacket, expectedLen)
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// TCP with max header len
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h = ipv4.Header{
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Len: 60,
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Src: net.IPv4(10, 0, 0, 1),
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Dst: net.IPv4(10, 0, 0, 2),
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Protocol: 6, // TCP
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Options: make([]byte, 40),
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}
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b, err = h.Marshal()
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if err != nil {
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t.Fatalf("h.Marhshal: %v", err)
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}
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b = append(b, []byte{0, 3, 0, 4}...)
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b = append(b, make([]byte, 16)...)
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expectedLen = ipv4.HeaderLen + 20
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out = make([]byte, expectedLen)
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rejectPacket = CreateRejectPacket(b, out)
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assert.NotNil(t, rejectPacket)
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assert.Len(t, rejectPacket, expectedLen)
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}
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func Test_CreateRejectPacket_NoFragment(t *testing.T) {
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out := make([]byte, MaxRejectPacketSize)
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// IPv4: non-zero fragment offset should not generate reject packet
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h := ipv4.Header{
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Len: 20,
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Src: net.IPv4(10, 0, 0, 1),
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Dst: net.IPv4(10, 0, 0, 2),
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Protocol: 17, // UDP
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}
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b, err := h.Marshal()
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if err != nil {
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t.Fatalf("h.Marshal: %v", err)
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}
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b = append(b, make([]byte, 8)...)
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// Set fragment offset to non-zero (byte 6-7, offset in 8-byte units)
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b[6] = 0x00
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b[7] = 0x01
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assert.Nil(t, CreateRejectPacket(b, out))
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// MF flag with zero offset (first fragment) should still generate reject
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b[6] = 0x20 // MF flag set
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b[7] = 0x00
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assert.NotNil(t, CreateRejectPacket(b, out))
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// Non-fragment should still generate reject packet
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b[6] = 0x00
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b[7] = 0x00
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assert.NotNil(t, CreateRejectPacket(b, out))
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// DF flag only (not a fragment) should still generate reject packet
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b[6] = 0x40
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b[7] = 0x00
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assert.NotNil(t, CreateRejectPacket(b, out))
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}
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func Test_CreateRejectPacketIPv6_NoFragment(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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out := make([]byte, MaxRejectPacketSize)
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// IPv6 with Fragment header and non-zero offset should not generate reject
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fragHeader := []byte{
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17, // next header: UDP
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0, // reserved
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0, 9, // fragment offset=1 (shifted left 3), M=1
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0, 0, 0, 1, // identification
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}
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udpPayload := make([]byte, 8)
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payload := append(fragHeader, udpPayload...)
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packet := makeIPv6Packet(src, dst, 44, payload) // next header 44 = Fragment
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assert.Nil(t, CreateRejectPacket(packet, out))
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// Fragment header with zero offset (first fragment) should still generate reject
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fragHeader[2] = 0
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fragHeader[3] = 1 // offset=0, M=1
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payload = append(fragHeader, udpPayload...)
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packet = makeIPv6Packet(src, dst, 44, payload)
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assert.NotNil(t, CreateRejectPacket(packet, out))
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}
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func Test_CreateRejectPacket_NoICMPError(t *testing.T) {
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out := make([]byte, MaxRejectPacketSize)
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// ICMP error types should not generate reject packets
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icmpErrorTypes := []byte{3, 4, 5, 11, 12}
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for _, icmpType := range icmpErrorTypes {
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h := ipv4.Header{
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Len: 20,
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Src: net.IPv4(10, 0, 0, 1),
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Dst: net.IPv4(10, 0, 0, 2),
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Protocol: 1, // ICMP
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}
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b, err := h.Marshal()
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if err != nil {
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t.Fatalf("h.Marshal: %v", err)
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}
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b = append(b, icmpType, 0, 0, 0, 0, 0, 0, 0)
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rejectPacket := CreateRejectPacket(b, out)
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assert.Nil(t, rejectPacket, "ICMP type %d should not generate a reject packet", icmpType)
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}
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// ICMP non-error types should still generate reject packets
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icmpNonErrorTypes := []byte{0, 8, 13, 14}
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for _, icmpType := range icmpNonErrorTypes {
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h := ipv4.Header{
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Len: 20,
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Src: net.IPv4(10, 0, 0, 1),
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Dst: net.IPv4(10, 0, 0, 2),
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Protocol: 1, // ICMP
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}
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b, err := h.Marshal()
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if err != nil {
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t.Fatalf("h.Marshal: %v", err)
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}
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b = append(b, icmpType, 0, 0, 0, 0, 0, 0, 0)
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rejectPacket := CreateRejectPacket(b, out)
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assert.NotNil(t, rejectPacket, "ICMP type %d should generate a reject packet", icmpType)
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}
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}
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// Test_CreateRejectPacket_RespectsCap guards against H2: with UDP GRO the
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// scratch buffer reused to build a reject is a single coalesced segment inside
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// a shared recvmmsg row. Its length covers just that segment, but an uncapped
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// slice's capacity runs on into the next, not-yet-processed segment. Because
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// CreateRejectPacket honors cap, capping the borrowed segment to its own length
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// (cap==len) makes it physically impossible for an oversized ICMPv6 reject to
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// overwrite the neighbor segment's bytes.
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func Test_CreateRejectPacket_RespectsCap(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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// Inner IPv6 UDP packet. An ICMPv6 reject copies the whole inner packet
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// plus a 48-byte header (40 IPv6 + 8 ICMPv6), so it needs 48 more bytes
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// than the inner packet length.
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inner := makeIPv6Packet(src, dst, 17, make([]byte, 20))
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// The ciphertext scratch reused as the reject buffer is the received
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// datagram: 16-byte Nebula header + inner + 16-byte AEAD tag. That is only
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// 32 bytes of slack, so a full ICMPv6 reject overruns it by 16 bytes.
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const nebulaOverhead = 32
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segLen := len(inner) + nebulaOverhead
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// Shared backing row laid out as [segment][neighbor's 16-byte Nebula header].
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const neighborHdr = 16
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sentinel := bytes.Repeat([]byte{0xAB}, neighborHdr)
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// Uncapped: the slice's capacity reaches into the neighbor, reproducing
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// the overrun that silently drops the neighbor packet.
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backing := make([]byte, segLen+neighborHdr)
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copy(backing[segLen:], sentinel)
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reject := CreateRejectPacket(inner, backing[:segLen])
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assert.NotNil(t, reject, "uncapped buffer reaches into the neighbor, so the reject is built")
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assert.NotEqual(t, sentinel, backing[segLen:segLen+neighborHdr],
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"without the cap the oversized reject overruns into the neighbor segment")
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// Capped (the fix): cap==len, so the builder cannot exceed the segment. The
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// reject does not fit, so it is refused rather than corrupting the neighbor.
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backing = make([]byte, segLen+neighborHdr)
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copy(backing[segLen:], sentinel)
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reject = CreateRejectPacket(inner, backing[:segLen:segLen])
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assert.Nil(t, reject, "capped segment is 16 bytes too small for a full ICMPv6 reject, so it is refused")
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assert.Equal(t, sentinel, backing[segLen:segLen+neighborHdr],
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"capped segment must leave the neighbor untouched")
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}
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func makeIPv6Packet(src, dst net.IP, nextHeader uint8, payload []byte) []byte {
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b := make([]byte, ipv6.HeaderLen+len(payload))
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b[0] = ipv6.Version << 4
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binary.BigEndian.PutUint16(b[4:], uint16(len(payload)))
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b[6] = nextHeader
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b[7] = 64
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copy(b[8:24], src.To16())
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copy(b[24:40], dst.To16())
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copy(b[ipv6.HeaderLen:], payload)
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return b
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}
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func Test_CreateRejectPacketIPv6_ICMP(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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// Small UDP packet: entire original included in body
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udpPayload := make([]byte, 20)
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udpPayload[0] = 0x00 // src port high
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udpPayload[1] = 0x50 // src port low (80)
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udpPayload[2] = 0x01 // dst port high
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udpPayload[3] = 0xBB // dst port low (443)
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packet := makeIPv6Packet(src, dst, 17, udpPayload)
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out := make([]byte, MaxRejectPacketSize)
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rejectPacket := CreateRejectPacket(packet, out)
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assert.NotNil(t, rejectPacket)
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// Small packet fits entirely: 40 (ipv6 hdr) + 8 (icmpv6 hdr) + 60 (original)
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expectedLen := ipv6.HeaderLen + 8 + len(packet)
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assert.Len(t, rejectPacket, expectedLen)
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// Verify version
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assert.Equal(t, byte(ipv6.Version<<4), rejectPacket[0]&0xf0)
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// Verify next header is ICMPv6 (58)
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assert.Equal(t, byte(58), rejectPacket[6])
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// Verify src/dst are swapped
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assert.Equal(t, dst.To16(), net.IP(rejectPacket[8:24]))
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assert.Equal(t, src.To16(), net.IP(rejectPacket[24:40]))
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// Verify ICMPv6 type=1 (Dest Unreachable), code=1 (Administratively prohibited)
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assert.Equal(t, byte(1), rejectPacket[ipv6.HeaderLen])
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assert.Equal(t, byte(1), rejectPacket[ipv6.HeaderLen+1])
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// Verify entire original packet is included in body
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assert.Equal(t, packet, rejectPacket[ipv6.HeaderLen+8:])
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// Large packet: body is truncated to 1000 bytes
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largePkt := makeIPv6Packet(src, dst, 17, make([]byte, 1200))
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rejectPacket = CreateRejectPacket(largePkt, out)
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assert.NotNil(t, rejectPacket)
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assert.Len(t, rejectPacket, ipv6.HeaderLen+8+1000)
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assert.Equal(t, largePkt[:1000], rejectPacket[ipv6.HeaderLen+8:])
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}
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func Test_CreateRejectPacketIPv6_TCP(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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// TCP SYN packet (next header 6)
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tcpPayload := make([]byte, 20)
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tcpPayload[0] = 0x00 // src port high
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tcpPayload[1] = 0x50 // src port low (80)
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tcpPayload[2] = 0x01 // dst port high
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tcpPayload[3] = 0xBB // dst port low (443)
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binary.BigEndian.PutUint32(tcpPayload[4:], 1000) // seq
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binary.BigEndian.PutUint32(tcpPayload[8:], 0) // ack seq
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tcpPayload[12] = (20 >> 2) << 4 // data offset
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tcpPayload[13] = 0b00000010 // SYN flag
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packet := makeIPv6Packet(src, dst, 6, tcpPayload)
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out := make([]byte, MaxRejectPacketSize)
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rejectPacket := CreateRejectPacket(packet, out)
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assert.NotNil(t, rejectPacket)
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// Expected: 40 (ipv6 hdr) + 20 (tcp RST)
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expectedLen := ipv6.HeaderLen + 20
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assert.Len(t, rejectPacket, expectedLen)
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// Verify version
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assert.Equal(t, byte(ipv6.Version<<4), rejectPacket[0]&0xf0)
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// Verify next header is TCP (6)
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assert.Equal(t, byte(6), rejectPacket[6])
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// Verify src/dst are swapped
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assert.Equal(t, dst.To16(), net.IP(rejectPacket[8:24]))
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assert.Equal(t, src.To16(), net.IP(rejectPacket[24:40]))
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// Verify ports are swapped
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tcpOut := rejectPacket[ipv6.HeaderLen:]
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assert.Equal(t, uint16(443), binary.BigEndian.Uint16(tcpOut[0:2]))
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assert.Equal(t, uint16(80), binary.BigEndian.Uint16(tcpOut[2:4]))
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// RST+ACK flags (since input was SYN without ACK)
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assert.Equal(t, byte(0b00010100), tcpOut[13])
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// ack_seq = original seq (1000) + SYN (1) + FIN (0) + segment data (0)
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assert.Equal(t, uint32(1001), binary.BigEndian.Uint32(tcpOut[8:]))
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}
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func Test_CreateRejectPacketIPv6_TCPWithACK(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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// TCP packet with ACK set
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tcpPayload := make([]byte, 20)
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tcpPayload[0] = 0x00
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tcpPayload[1] = 0x50
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tcpPayload[2] = 0x01
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tcpPayload[3] = 0xBB
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binary.BigEndian.PutUint32(tcpPayload[4:], 1000) // seq
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binary.BigEndian.PutUint32(tcpPayload[8:], 2000) // ack seq
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tcpPayload[12] = (20 >> 2) << 4 // data offset
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tcpPayload[13] = 0b00010000 // ACK flag
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packet := makeIPv6Packet(src, dst, 6, tcpPayload)
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out := make([]byte, MaxRejectPacketSize)
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rejectPacket := CreateRejectPacket(packet, out)
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assert.NotNil(t, rejectPacket)
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tcpOut := rejectPacket[ipv6.HeaderLen:]
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// RST only (no ACK) since input had ACK
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assert.Equal(t, byte(0b00000100), tcpOut[13])
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// seq = original ack_seq
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assert.Equal(t, uint32(2000), binary.BigEndian.Uint32(tcpOut[4:]))
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}
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func Test_CreateRejectPacketIPv6_NoICMPError(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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out := make([]byte, MaxRejectPacketSize)
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// ICMPv6 error types (1-4) should not generate reject packets
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for icmpType := byte(1); icmpType <= 4; icmpType++ {
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payload := make([]byte, 8)
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payload[0] = icmpType
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packet := makeIPv6Packet(src, dst, 58, payload)
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rejectPacket := CreateRejectPacket(packet, out)
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assert.Nil(t, rejectPacket, "ICMPv6 type %d should not generate a reject packet", icmpType)
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}
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// ICMPv6 non-error types should still generate reject packets
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nonErrorTypes := []byte{128, 129, 133, 134}
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for _, icmpType := range nonErrorTypes {
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payload := make([]byte, 8)
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payload[0] = icmpType
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packet := makeIPv6Packet(src, dst, 58, payload)
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rejectPacket := CreateRejectPacket(packet, out)
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assert.NotNil(t, rejectPacket, "ICMPv6 type %d should generate a reject packet", icmpType)
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}
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}
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func Test_CreateRejectPacketIPv6_TooShort(t *testing.T) {
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// Packet too short to be valid IPv6
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out := make([]byte, MaxRejectPacketSize)
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assert.Nil(t, CreateRejectPacket([]byte{0x60}, out))
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assert.Nil(t, CreateRejectPacket(make([]byte, 39), out))
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}
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func Test_CreateRejectPacketIPv6_ExtensionHeaders(t *testing.T) {
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src := net.ParseIP("fd00::1")
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dst := net.ParseIP("fd00::2")
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// IPv6 + Hop-by-Hop extension header + TCP
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hopByHop := []byte{
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6, // next header: TCP
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0, // length (8 bytes total)
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0, 0, // padding
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0, 0, 0, 0,
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}
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tcpPayload := make([]byte, 20)
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tcpPayload[0] = 0x00
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tcpPayload[1] = 0x50
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tcpPayload[2] = 0x01
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tcpPayload[3] = 0xBB
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binary.BigEndian.PutUint32(tcpPayload[4:], 1000)
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binary.BigEndian.PutUint32(tcpPayload[8:], 2000)
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tcpPayload[12] = (20 >> 2) << 4
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tcpPayload[13] = 0b00010000 // ACK
|
|
|
|
payload := append(hopByHop, tcpPayload...)
|
|
packet := makeIPv6Packet(src, dst, 0, payload) // next header 0 = Hop-by-Hop
|
|
|
|
out := make([]byte, MaxRejectPacketSize)
|
|
rejectPacket := CreateRejectPacket(packet, out)
|
|
assert.NotNil(t, rejectPacket)
|
|
|
|
// Should produce TCP RST
|
|
expectedLen := ipv6.HeaderLen + 20
|
|
assert.Len(t, rejectPacket, expectedLen)
|
|
assert.Equal(t, byte(6), rejectPacket[6]) // next header is TCP
|
|
tcpOut := rejectPacket[ipv6.HeaderLen:]
|
|
assert.Equal(t, byte(0b00000100), tcpOut[13]) // RST only
|
|
}
|
|
|
|
func TestCreateICMPEchoResponse_IPv4(t *testing.T) {
|
|
// Build a simple IPv4 ICMP Echo Request
|
|
packet := make([]byte, 28)
|
|
packet[0] = 0x45 // version 4, IHL 5
|
|
binary.BigEndian.PutUint16(packet[2:], uint16(28)) // total length
|
|
packet[8] = 64 // TTL
|
|
packet[9] = 1 // protocol ICMP
|
|
copy(packet[12:16], net.IPv4(10, 0, 0, 1).To4()) // src
|
|
copy(packet[16:20], net.IPv4(10, 0, 0, 2).To4()) // dst
|
|
packet[20] = 8 // ICMP Echo Request
|
|
|
|
out := make([]byte, len(packet))
|
|
result := CreateICMPEchoResponse(packet, out)
|
|
assert.NotNil(t, result)
|
|
assert.Equal(t, byte(0x45), result[0])
|
|
// src/dst swapped
|
|
assert.Equal(t, net.IPv4(10, 0, 0, 2).To4(), net.IP(result[12:16]))
|
|
assert.Equal(t, net.IPv4(10, 0, 0, 1).To4(), net.IP(result[16:20]))
|
|
// ICMP Echo Reply
|
|
assert.Equal(t, byte(0), result[20])
|
|
}
|
|
|
|
func TestCreateICMPEchoResponse_IPv6(t *testing.T) {
|
|
src := net.ParseIP("fd00::1").To16()
|
|
dst := net.ParseIP("fd00::2").To16()
|
|
|
|
// Build an IPv6 ICMPv6 Echo Request packet
|
|
// IPv6 header (40 bytes) + ICMPv6 (8 bytes)
|
|
packet := make([]byte, 48)
|
|
packet[0] = 0x60 // version 6
|
|
payloadLen := uint16(8) // ICMPv6 header only
|
|
binary.BigEndian.PutUint16(packet[4:], payloadLen)
|
|
packet[6] = 58 // Next Header: ICMPv6
|
|
packet[7] = 64 // Hop Limit
|
|
copy(packet[8:24], src) // src address
|
|
copy(packet[24:40], dst) // dst address
|
|
|
|
// ICMPv6 Echo Request
|
|
icmp := packet[40:]
|
|
icmp[0] = 128 // type: Echo Request
|
|
icmp[1] = 0 // code
|
|
binary.BigEndian.PutUint16(icmp[4:], 1) // identifier
|
|
binary.BigEndian.PutUint16(icmp[6:], 1) // sequence number
|
|
|
|
// Compute correct checksum for the request
|
|
csum := ipv6PseudoheaderChecksum(src, dst, 58, uint32(payloadLen))
|
|
binary.BigEndian.PutUint16(icmp[2:], tcpipChecksum(icmp, csum))
|
|
|
|
out := make([]byte, len(packet))
|
|
result := CreateICMPEchoResponse(packet, out)
|
|
assert.NotNil(t, result)
|
|
|
|
// Version should still be 6
|
|
assert.Equal(t, byte(6), result[0]>>4)
|
|
// src/dst swapped
|
|
assert.Equal(t, dst, net.IP(result[8:24]))
|
|
assert.Equal(t, src, net.IP(result[24:40]))
|
|
// ICMPv6 Echo Reply type
|
|
assert.Equal(t, byte(129), result[40])
|
|
|
|
// Verify checksum is valid (tcpipChecksum returns 0 when data+checksum is correct)
|
|
respIcmp := result[40:]
|
|
verifyCsum := ipv6PseudoheaderChecksum(result[8:24], result[24:40], 58, uint32(payloadLen))
|
|
assert.Equal(t, uint16(0), tcpipChecksum(respIcmp, verifyCsum))
|
|
}
|
|
|
|
func TestCreateICMPEchoResponse_IPv6_NotEchoRequest(t *testing.T) {
|
|
src := net.ParseIP("fd00::1").To16()
|
|
dst := net.ParseIP("fd00::2").To16()
|
|
|
|
packet := make([]byte, 48)
|
|
packet[0] = 0x60
|
|
binary.BigEndian.PutUint16(packet[4:], 8)
|
|
packet[6] = 58
|
|
packet[7] = 64
|
|
copy(packet[8:24], src)
|
|
copy(packet[24:40], dst)
|
|
|
|
// ICMPv6 type 1 (Destination Unreachable) - not Echo Request
|
|
packet[40] = 1
|
|
|
|
out := make([]byte, len(packet))
|
|
result := CreateICMPEchoResponse(packet, out)
|
|
assert.Nil(t, result)
|
|
}
|
|
|
|
func TestCreateICMPEchoResponse_IPv6_NotICMPv6(t *testing.T) {
|
|
src := net.ParseIP("fd00::1").To16()
|
|
dst := net.ParseIP("fd00::2").To16()
|
|
|
|
packet := make([]byte, 48)
|
|
packet[0] = 0x60
|
|
binary.BigEndian.PutUint16(packet[4:], 8)
|
|
packet[6] = 6 // TCP, not ICMPv6
|
|
packet[7] = 64
|
|
copy(packet[8:24], src)
|
|
copy(packet[24:40], dst)
|
|
|
|
out := make([]byte, len(packet))
|
|
result := CreateICMPEchoResponse(packet, out)
|
|
assert.Nil(t, result)
|
|
}
|