mirror of
https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git
synced 2025-10-14 14:11:23 -04:00
0790954020
The difficulty here is that the whole point of turbotunnel sessions is that they are not necessarily tied to a single WebSocket connection, nor even a single client IP address. We use a heuristic: whenever a WebSocket connection starts that has a new ClientID, we store a mapping from that ClientID to the IP address attached to the WebSocket connection in a lookup table. Later, when enough packets have arrived to establish a turbotunnel session, we recover the ClientID associated with the session (which kcp-go has stored in the RemoteAddr field), and look it up in the table to get an IP address. We introduce a new data type, clientIDMap, to store the clientID-to-IP mapping during the short time between when a WebSocket connection starts and handleSession receives a fully fledged KCP session.
119 lines
3.2 KiB
Go
119 lines
3.2 KiB
Go
package main
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import (
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"encoding/binary"
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"testing"
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"git.torproject.org/pluggable-transports/snowflake.git/common/turbotunnel"
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)
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func TestClientIDMap(t *testing.T) {
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// Convert a uint64 into a ClientID.
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id := func(n uint64) turbotunnel.ClientID {
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var clientID turbotunnel.ClientID
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binary.PutUvarint(clientID[:], n)
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return clientID
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}
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// Does m.Get(key) and checks that the output matches what is expected.
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expectGet := func(m *clientIDMap, clientID turbotunnel.ClientID, expectedAddr string, expectedOK bool) {
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t.Helper()
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addr, ok := m.Get(clientID)
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if addr != expectedAddr || ok != expectedOK {
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t.Errorf("expected (%+q, %v), got (%+q, %v)", expectedAddr, expectedOK, addr, ok)
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}
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}
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// Checks that the len of m.current is as expected.
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expectSize := func(m *clientIDMap, expectedLen int) {
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t.Helper()
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if len(m.current) != expectedLen {
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t.Errorf("expected map len %d, got %d %+v", expectedLen, len(m.current), m.current)
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}
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}
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// Zero-capacity map can't remember anything.
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{
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m := newClientIDMap(0)
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expectSize(m, 0)
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expectGet(m, id(0), "", false)
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expectGet(m, id(1234), "", false)
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m.Set(id(0), "A")
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expectSize(m, 0)
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expectGet(m, id(0), "", false)
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expectGet(m, id(1234), "", false)
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m.Set(id(1234), "A")
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expectSize(m, 0)
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expectGet(m, id(0), "", false)
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expectGet(m, id(1234), "", false)
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}
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{
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m := newClientIDMap(1)
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expectSize(m, 0)
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expectGet(m, id(0), "", false)
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expectGet(m, id(1), "", false)
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m.Set(id(0), "A")
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expectSize(m, 1)
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expectGet(m, id(0), "A", true)
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expectGet(m, id(1), "", false)
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m.Set(id(1), "B") // forgets the (0, "A") entry
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expectSize(m, 1)
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expectGet(m, id(0), "", false)
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expectGet(m, id(1), "B", true)
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m.Set(id(1), "C") // forgets the (1, "B") entry
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expectSize(m, 1)
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expectGet(m, id(0), "", false)
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expectGet(m, id(1), "C", true)
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}
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{
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m := newClientIDMap(5)
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m.Set(id(0), "A")
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m.Set(id(1), "B")
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m.Set(id(2), "C")
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m.Set(id(0), "D") // shadows the (0, "D") entry
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m.Set(id(3), "E")
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expectSize(m, 4)
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expectGet(m, id(0), "D", true)
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expectGet(m, id(1), "B", true)
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expectGet(m, id(2), "C", true)
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expectGet(m, id(3), "E", true)
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expectGet(m, id(4), "", false)
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m.Set(id(4), "F") // forgets the (0, "A") entry but should preserve (0, "D")
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expectSize(m, 5)
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expectGet(m, id(0), "D", true)
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expectGet(m, id(1), "B", true)
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expectGet(m, id(2), "C", true)
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expectGet(m, id(3), "E", true)
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expectGet(m, id(4), "F", true)
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m.Set(id(5), "G") // forgets the (1, "B") entry
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m.Set(id(0), "H") // forgets the (2, "C") entry and shadows (0, "D")
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expectSize(m, 4)
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expectGet(m, id(0), "H", true)
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expectGet(m, id(1), "", false)
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expectGet(m, id(2), "", false)
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expectGet(m, id(3), "E", true)
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expectGet(m, id(4), "F", true)
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expectGet(m, id(5), "G", true)
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m.Set(id(0), "I") // forgets the (0, "D") entry and shadows (0, "H")
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m.Set(id(0), "J") // forgets the (3, "E") entry and shadows (0, "I")
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m.Set(id(0), "K") // forgets the (4, "F") entry and shadows (0, "J")
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m.Set(id(0), "L") // forgets the (5, "G") entry and shadows (0, "K")
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expectSize(m, 1)
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expectGet(m, id(0), "L", true)
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expectGet(m, id(1), "", false)
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expectGet(m, id(2), "", false)
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expectGet(m, id(3), "", false)
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expectGet(m, id(4), "", false)
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expectGet(m, id(5), "", false)
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}
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}
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