feat(traffic): добавить приём Traffic Flow с jump-host

Чтобы видеть «кто с кем», а не только объём порта: IPFIX внутри WG на хосте Docker MM, REST-счётчики не трогаем.

Co-authored-by: Cursor <[email protected]>

backend/src/services/traffic-flow-parse.test.ts

@@ -0,0 +1,34 @@
+import assert from "node:assert/strict"
+import { parseFlowPacket, protoName, resetFlowTemplatesForTests } from "./traffic-flow-parse.js"
+import { allocateOverlayAddress } from "./traffic-flow-overlay.js"
+
+function netflowV5One(): Buffer {
+  const buf = Buffer.alloc(24 + 48)
+  buf.writeUInt16BE(5, 0)
+  buf.writeUInt16BE(1, 2)
+  buf[24] = 10; buf[25] = 1; buf[26] = 1; buf[27] = 8
+  buf[28] = 8; buf[29] = 8; buf[30] = 8; buf[31] = 8
+  buf.writeUInt16BE(1, 24 + 12)
+  buf.writeUInt32BE(10, 24 + 16)
+  buf.writeUInt32BE(1500, 24 + 20)
+  buf.writeUInt16BE(443, 24 + 32)
+  buf.writeUInt16BE(443, 24 + 34)
+  buf.writeUInt8(6, 24 + 38)
+  return buf
+}
+
+resetFlowTemplatesForTests()
+const flows = parseFlowPacket(netflowV5One(), "10.255.254.5")
+assert.equal(flows.length, 1)
+assert.equal(flows[0]?.src, "10.1.1.8")
+assert.equal(flows[0]?.dst, "8.8.8.8")
+assert.equal(flows[0]?.proto, 6)
+assert.equal(flows[0]?.bytes, 1500)
+assert.equal(protoName(6), "TCP")
+assert.equal(parseFlowPacket(Buffer.from([0, 1]), "1.1.1.1").length, 0)
+
+const taken = new Set(["10.255.254.2"])
+assert.equal(allocateOverlayAddress("10.255.254.0/24", "10.255.254.1", 1, taken), "10.255.254.3")
+assert.equal(allocateOverlayAddress("10.255.254.0/24", "10.255.254.1", 2, new Set()), "10.255.254.3")
+
+console.log("traffic-flow-parse.test.ts: ok")