diff --git a/changelog.d/fixes/1809-mitm-stop-dns-before-kill.md b/changelog.d/fixes/1809-mitm-stop-dns-before-kill.md new file mode 100644 index 0000000000..06e42e461c --- /dev/null +++ b/changelog.d/fixes/1809-mitm-stop-dns-before-kill.md @@ -0,0 +1 @@ +- **fix(cli):** `stopMitm()` now removes /etc/hosts DNS-spoof entries before killing the MITM server process, closing the window where a client's DNS still resolved a target host to `127.0.0.1` while nothing was listening there — the cause of `connect ECONNREFUSED 127.0.0.1:443` right after stopping the MITM proxy (thanks @dionisius95). diff --git a/src/mitm/manager.ts b/src/mitm/manager.ts index 47765bf515..94fcf33b69 100644 --- a/src/mitm/manager.ts +++ b/src/mitm/manager.ts @@ -5,15 +5,22 @@ import { resolveMitmDataDir } from "./dataDir.ts"; import { removeDNSEntry, removeDNSEntries } from "./dns/dnsConfig.ts"; import { provisionDnsEntries } from "./dns/provision.ts"; import { generateCert } from "./cert/generate.ts"; -import { installCertResult, uninstallCert } from "./cert/install.ts"; +import { installCertResult } from "./cert/install.ts"; import { ALL_TARGETS } from "./targets/index.ts"; import { detectAgent } from "./detection/index.ts"; import type { AgentId, DetectionResult, MitmTarget } from "./types.ts"; import { getAllAgentBridgeStates } from "@/lib/db/agentBridgeState.ts"; -import { listCustomHosts } from "@/lib/db/inspectorCustomHosts.ts"; import { getUserBypassPatterns } from "@/lib/db/agentBridgeBypass.ts"; import { configureUpstreamCa } from "./upstreamTrust.ts"; import { createLogger } from "@/shared/utils/logger.ts"; +import { + buildRepairPlan, + collectManagedHosts, + performRepairSteps, + type RepairPlan, +} from "./repair.ts"; + +export { buildRepairPlan, collectManagedHosts, type RepairPlan }; const log = createLogger("mitm-manager"); @@ -57,6 +64,17 @@ export function interpretMitmStartupError(stderr: string, port: number): string let serverProcess: ChildProcess | null = null; let serverPid: number | null = null; +/** + * Test-only seam: install a fake server process (and pid) so stopMitm() can be + * exercised without spawning a real MITM child. Not part of the public API — + * only intended for unit tests that need to assert stopMitm()'s DNS/kill + * ordering (#1809). No-op in production code paths. + */ +export function __setServerProcessForTest(proc: ChildProcess | null, pid: number | null): void { + serverProcess = proc; + serverPid = pid; +} + // Set while startMitm() is in flight, from the guard check through spawn. // Guards a TOCTOU race: the "already running" check above only trips once // `serverProcess` is assigned by spawn() — ~130 lines and several awaits @@ -219,108 +237,20 @@ function isProcessAlive(pid: number): boolean { } } -/** - * Enumerate every hostname OmniRoute may have written to /etc/hosts during - * startMitm(): the full agent-target registry plus all custom hosts. Removal - * via removeDNSEntries() is idempotent (absent entries are skipped), so this - * set is intentionally over-inclusive — a host that was never spoofed costs - * nothing to "remove", but a host we forget to list leaks machine-wide. - * (Gap 8 — clean-stop DNS leak.) - */ -export function collectManagedHosts(): string[] { - const hosts = new Set(); - for (const target of ALL_TARGETS) { - for (const h of target.hosts) hosts.add(h); - } - try { - for (const ch of listCustomHosts()) hosts.add(ch.host); - } catch (err) { - log.error({ err }, "collectManagedHosts: failed to read custom hosts (continuing)"); - } - return [...hosts]; -} - -export interface RepairPlan { - dnsHostsToRemove: string[]; - removeCert: boolean; - revertSystemProxy: boolean; -} - -/** - * Pure description of what a repair must undo. Separated from repairMitm() so - * the enumeration is unit-testable without touching the OS or requiring sudo. - * (Gap 7.) - */ -export function buildRepairPlan(): RepairPlan { - return { - dnsHostsToRemove: collectManagedHosts(), - removeCert: true, - revertSystemProxy: true, - }; -} - -/** - * Best-effort revert of an applied system proxy. The applied state lives - * in-memory (captureState), so this only succeeds within the same process that - * applied it; after a crash the previousState is gone and this is a no-op. DNS - * + cert teardown are always reversible because they read on-disk state. - */ -async function revertSystemProxyIfApplied(): Promise { - try { - const { getSystemProxyState, clearSystemProxy } = await import("@/lib/inspector/captureState"); - const state = getSystemProxyState(); - if (!state.applied || !state.previousState) return false; - const { revert } = await import("./inspector/systemProxyConfig.ts"); - await revert(state.previousState); - clearSystemProxy(); - return true; - } catch (err) { - log.error({ err }, "revertSystemProxyIfApplied failed (continuing)"); - return false; - } -} - /** * Undo every system mutation startMitm() may have made, WITHOUT requiring the * MITM server to be running. Safe to call when state is already clean (every * step is idempotent). Used by: the /repair route, the CLI cleanup subcommand, * and the stale-PID auto-repair on app startup. (Gap 7 — the application-layer - * analogue of ProxyBridge's destructor + `--cleanup`.) + * analogue of ProxyBridge's destructor + `--cleanup`.) Steps 1-3 (DNS, cert, + * system-proxy) are delegated to `./repair.ts::performRepairSteps()`; the PID + * file + in-memory session cleanup below stays here since it touches this + * module's private state. */ export async function repairMitm(sudoPassword: string): Promise<{ repaired: string[] }> { - const plan = buildRepairPlan(); - const repaired: string[] = []; + const repaired = await performRepairSteps(sudoPassword); - // 1. DNS — remove every host we may have spoofed (idempotent, reads /etc/hosts). - try { - await removeDNSEntry(sudoPassword); - if (plan.dnsHostsToRemove.length > 0) { - await removeDNSEntries(plan.dnsHostsToRemove, sudoPassword); - } - repaired.push("dns"); - } catch (err) { - log.error({ err }, "repairMitm: DNS cleanup failed (continuing)"); - } - - // 2. Certificate — uninstall the MITM root CA from the trust store. - if (plan.removeCert) { - try { - const certPath = path.join(resolveMitmDataDir(), "mitm", "server.crt"); - if (fs.existsSync(certPath)) { - await uninstallCert(sudoPassword, certPath); - repaired.push("cert"); - } - } catch (err) { - log.error({ err }, "repairMitm: cert removal failed (continuing)"); - } - } - - // 3. System proxy — best-effort revert if applied in this process. - if (plan.revertSystemProxy) { - if (await revertSystemProxyIfApplied()) repaired.push("system-proxy"); - } - - // 4. Stale PID file. + // Stale PID file. try { if (fs.existsSync(PID_FILE)) fs.unlinkSync(PID_FILE); } catch { @@ -709,11 +639,38 @@ async function startMitmInternal( } /** - * Stop MITM proxy - * @param {string} sudoPassword - Sudo password for DNS cleanup + * DNS teardown step of stopMitm() (#1809) — split out purely to keep + * stopMitm()'s own cyclomatic complexity under the repo's ratchet; behavior + * is unchanged from the original inline implementation. */ -export async function stopMitm(sudoPassword: string): Promise<{ running: false; pid: null }> { - // 1. Kill server process (in-memory or from PID file) +async function removeStopDnsEntries( + deps: { + removeDNSEntry: (sudoPassword: string) => Promise; + removeDNSEntries: (hosts: string[], sudoPassword: string) => Promise; + collectManagedHosts: () => string[]; + }, + sudoPassword: string +): Promise { + log.info("Removing DNS entries..."); + await deps.removeDNSEntry(sudoPassword); + try { + const managed = deps.collectManagedHosts(); + if (managed.length > 0) { + await deps.removeDNSEntries(managed, sudoPassword); + } + } catch (err) { + log.error({ err }, "Failed to remove managed DNS entries during stop (continuing)"); + } +} + +/** + * Kill the MITM server process during stop — either the in-memory + * `serverProcess` handle or, if that's gone, the PID recorded in `PID_FILE`. + * Split out of stopMitm() purely to keep that function's complexity under + * the repo's ratchet; behavior is unchanged from the original inline + * implementation. + */ +async function killMitmServerProcessOnStop(): Promise { const proc = serverProcess; if (proc && !proc.killed) { log.info("Stopping MITM server..."); @@ -724,41 +681,64 @@ export async function stopMitm(sudoPassword: string): Promise<{ running: false; } serverProcess = null; serverPid = null; - } else { - // Fallback: kill by PID file - try { - if (fs.existsSync(PID_FILE)) { - const savedPid = parseInt(fs.readFileSync(PID_FILE, "utf-8").trim(), 10); - if (savedPid && isProcessAlive(savedPid)) { - log.info({ pid: savedPid }, "Killing MITM server by PID..."); - process.kill(savedPid, "SIGTERM"); - await new Promise((resolve) => setTimeout(resolve, 1000)); - if (isProcessAlive(savedPid)) { - process.kill(savedPid, "SIGKILL"); - } - } - } - } catch { - // Ignore - } - serverProcess = null; - serverPid = null; + return; } - // 2. Remove DNS entries — Antigravity defaults PLUS every agent + custom host - // that startMitm() may have spoofed. removeDNSEntries is idempotent, so - // over-inclusion is safe; under-inclusion leaks /etc/hosts lines that - // hijack resolution machine-wide after stop (Gap 8). - log.info("Removing DNS entries..."); - await removeDNSEntry(sudoPassword); + // Fallback: kill by PID file try { - const managed = collectManagedHosts(); - if (managed.length > 0) { - await removeDNSEntries(managed, sudoPassword); + if (fs.existsSync(PID_FILE)) { + const savedPid = parseInt(fs.readFileSync(PID_FILE, "utf-8").trim(), 10); + if (savedPid && isProcessAlive(savedPid)) { + log.info({ pid: savedPid }, "Killing MITM server by PID..."); + process.kill(savedPid, "SIGTERM"); + await new Promise((resolve) => setTimeout(resolve, 1000)); + if (isProcessAlive(savedPid)) { + process.kill(savedPid, "SIGKILL"); + } + } } - } catch (err) { - log.error({ err }, "Failed to remove managed DNS entries during stop (continuing)"); + } catch { + // Ignore } + serverProcess = null; + serverPid = null; +} + +/** + * Stop MITM proxy + * + * Ordering is deliberate and load-bearing (#1809 — "connect ECONNREFUSED + * 127.0.0.1:443" after stop). DNS entries MUST be removed BEFORE the server + * process is killed: if the process dies first, any client whose DNS still + * resolves the target host to 127.0.0.1 (from startMitm()'s spoof) but whose + * MITM listener is already dead gets ECONNREFUSED against a dead port for the + * whole window between the two steps. Removing DNS first closes that window — + * once /etc/hosts no longer points at 127.0.0.1, clients fall back to real + * resolution regardless of when the listener actually goes away. This mirrors + * the DNS-first ordering already used by repairMitm() and handleExitCleanup(). + * @param {string} sudoPassword - Sudo password for DNS cleanup + * @param _depsOverride - optional dependency override, used in tests for DI. + */ +export async function stopMitm( + sudoPassword: string, + _depsOverride?: { + removeDNSEntry?: (sudoPassword: string) => Promise; + removeDNSEntries?: (hosts: string[], sudoPassword: string) => Promise; + collectManagedHosts?: () => string[]; + } +): Promise<{ running: false; pid: null }> { + const deps = { + removeDNSEntry: _depsOverride?.removeDNSEntry ?? removeDNSEntry, + removeDNSEntries: _depsOverride?.removeDNSEntries ?? removeDNSEntries, + collectManagedHosts: _depsOverride?.collectManagedHosts ?? collectManagedHosts, + }; + + // 1. Remove DNS entries FIRST — see function doc + module doc above for why + // this must happen before the process kill (#1809, Gap 8). + await removeStopDnsEntries(deps, sudoPassword); + + // 2. Kill server process (in-memory or from PID file) + await killMitmServerProcessOnStop(); // 3. Clean up clearCachedPassword(); // Clear password from memory when proxy stops diff --git a/src/mitm/repair.ts b/src/mitm/repair.ts new file mode 100644 index 0000000000..4ee2f160f2 --- /dev/null +++ b/src/mitm/repair.ts @@ -0,0 +1,115 @@ +import path from "path"; +import fs from "fs"; +import { resolveMitmDataDir } from "./dataDir.ts"; +import { removeDNSEntry, removeDNSEntries } from "./dns/dnsConfig.ts"; +import { uninstallCert } from "./cert/install.ts"; +import { ALL_TARGETS } from "./targets/index.ts"; +import { listCustomHosts } from "@/lib/db/inspectorCustomHosts.ts"; +import { createLogger } from "@/shared/utils/logger.ts"; + +const log = createLogger("mitm-repair"); + +/** + * Enumerate every hostname OmniRoute may have written to /etc/hosts during + * startMitm(): the full agent-target registry plus all custom hosts. Removal + * via removeDNSEntries() is idempotent (absent entries are skipped), so this + * set is intentionally over-inclusive — a host that was never spoofed costs + * nothing to "remove", but a host we forget to list leaks machine-wide. + * (Gap 8 — clean-stop DNS leak.) + */ +export function collectManagedHosts(): string[] { + const hosts = new Set(); + for (const target of ALL_TARGETS) { + for (const h of target.hosts) hosts.add(h); + } + try { + for (const ch of listCustomHosts()) hosts.add(ch.host); + } catch (err) { + log.error({ err }, "collectManagedHosts: failed to read custom hosts (continuing)"); + } + return [...hosts]; +} + +export interface RepairPlan { + dnsHostsToRemove: string[]; + removeCert: boolean; + revertSystemProxy: boolean; +} + +/** + * Pure description of what a repair must undo. Separated from repairMitm() so + * the enumeration is unit-testable without touching the OS or requiring sudo. + * (Gap 7.) + */ +export function buildRepairPlan(): RepairPlan { + return { + dnsHostsToRemove: collectManagedHosts(), + removeCert: true, + revertSystemProxy: true, + }; +} + +/** + * Best-effort revert of an applied system proxy. The applied state lives + * in-memory (captureState), so this only succeeds within the same process that + * applied it; after a crash the previousState is gone and this is a no-op. DNS + * + cert teardown are always reversible because they read on-disk state. + */ +async function revertSystemProxyIfApplied(): Promise { + try { + const { getSystemProxyState, clearSystemProxy } = await import("@/lib/inspector/captureState"); + const state = getSystemProxyState(); + if (!state.applied || !state.previousState) return false; + const { revert } = await import("./inspector/systemProxyConfig.ts"); + await revert(state.previousState); + clearSystemProxy(); + return true; + } catch (err) { + log.error({ err }, "revertSystemProxyIfApplied failed (continuing)"); + return false; + } +} + +/** + * Run the DNS/cert/system-proxy teardown steps of a repair, WITHOUT touching + * any of `manager.ts`'s in-memory session state (cached password, orphaned + * flag, PID file) — that bookkeeping stays in `manager.ts::repairMitm()`, + * which calls this as its first step. Split out purely to keep + * `src/mitm/manager.ts` under the repo's file-size cap; behavior is + * unchanged from the original inline implementation. (Gap 7.) + */ +export async function performRepairSteps(sudoPassword: string): Promise { + const plan = buildRepairPlan(); + const repaired: string[] = []; + + // 1. DNS — remove every host we may have spoofed (idempotent, reads /etc/hosts). + try { + await removeDNSEntry(sudoPassword); + if (plan.dnsHostsToRemove.length > 0) { + await removeDNSEntries(plan.dnsHostsToRemove, sudoPassword); + } + repaired.push("dns"); + } catch (err) { + log.error({ err }, "repairMitm: DNS cleanup failed (continuing)"); + } + + // 2. Certificate — uninstall the MITM root CA from the trust store. + if (plan.removeCert) { + try { + const certPath = path.join(resolveMitmDataDir(), "mitm", "server.crt"); + if (fs.existsSync(certPath)) { + await uninstallCert(sudoPassword, certPath); + repaired.push("cert"); + } + } catch (err) { + log.error({ err }, "repairMitm: cert removal failed (continuing)"); + } + } + + // 3. System proxy — best-effort revert if applied in this process. + if (plan.revertSystemProxy) { + if (await revertSystemProxyIfApplied()) repaired.push("system-proxy"); + } + + return repaired; +} diff --git a/tests/unit/mitm-stop-dns-before-kill-1809.test.ts b/tests/unit/mitm-stop-dns-before-kill-1809.test.ts new file mode 100644 index 0000000000..3dd92dcaad --- /dev/null +++ b/tests/unit/mitm-stop-dns-before-kill-1809.test.ts @@ -0,0 +1,82 @@ +/** + * Regression test for upstream issue #1809: "connect ECONNREFUSED 127.0.0.1:443" + * after stopping the MITM proxy. + * + * Root cause: stopMitm() killed the spawned MITM server process FIRST, and only + * removed the /etc/hosts DNS-spoof entries AFTER. During that window any client + * whose DNS still resolved the target host to 127.0.0.1 (from startMitm's spoof) + * but whose MITM listener was already dead got ECONNREFUSED — exactly the + * community-confirmed workaround ("stop DNS before stopping the server") proves. + * + * This test drives stopMitm() with real DI: a fake serverProcess standing in for + * the spawned MITM child, and dependency-injected DNS-removal functions that + * record the order in which they are invoked relative to the process kill. The + * fix must remove DNS entries before killing the server process so no window + * exists where DNS points at 127.0.0.1 with nothing listening there. + * + * Uses the project's DATA_DIR-tmp + resetDbInstance pattern so the Node native + * test runner does not hang on open SQLite handles (CLAUDE.md PII learning #3). + */ +import test from "node:test"; +import assert from "node:assert/strict"; +import fs from "node:fs"; +import os from "node:os"; +import path from "node:path"; +import { EventEmitter } from "node:events"; + +const TEST_DATA_DIR = fs.mkdtempSync(path.join(os.tmpdir(), "omniroute-mitm-stop-order-")); +process.env.DATA_DIR = TEST_DATA_DIR; + +const core = await import("../../src/lib/db/core.ts"); +const manager = await import("../../src/mitm/manager.ts"); + +test.after(() => { + core.resetDbInstance(); + fs.rmSync(TEST_DATA_DIR, { recursive: true, force: true }); +}); + +test("stopMitm removes DNS entries before killing the MITM server process (#1809)", async () => { + const events: string[] = []; + + // Fake child process standing in for the spawned MITM server. + const fakeProc = new EventEmitter() as EventEmitter & { + killed: boolean; + kill: (signal?: string) => boolean; + }; + fakeProc.killed = false; + fakeProc.kill = (signal?: string) => { + events.push(`kill:${signal}`); + fakeProc.killed = true; + return true; + }; + + manager.__setServerProcessForTest(fakeProc as unknown as import("child_process").ChildProcess, 4242); + + const removeDNSEntry = async () => { + events.push("removeDNSEntry"); + }; + const removeDNSEntries = async () => { + events.push("removeDNSEntries"); + }; + const collectManagedHosts = () => ["fake.example.test"]; + + await manager.stopMitm("fake-sudo-password", { + removeDNSEntry, + removeDNSEntries, + collectManagedHosts, + }); + + const firstKillIndex = events.findIndex((e) => e.startsWith("kill:")); + const firstDnsIndex = events.findIndex( + (e) => e === "removeDNSEntry" || e === "removeDNSEntries" + ); + + assert.ok(firstKillIndex !== -1, "server process kill was never invoked"); + assert.ok(firstDnsIndex !== -1, "DNS removal was never invoked"); + assert.ok( + firstDnsIndex < firstKillIndex, + `DNS entries must be removed BEFORE the MITM server process is killed ` + + `(got order: ${JSON.stringify(events)}) — otherwise a client whose DNS still ` + + `points at 127.0.0.1 hits a dead listener and gets ECONNREFUSED (#1809)` + ); +});