Added more debugging

2026-05-08 10:54:03 -04:00
parent 7c14cb4e80
commit 86eb122f98
5 changed files with 356 additions and 9 deletions
--- a/fips_debug.md
+++ b/fips_debug.md
@@ -132,3 +132,103 @@ A backup of the prior local file was created before modification.
 ## Final status

 The target `.fips` web page is reachable from this local node after lowering local UDP MTU to `1280` and restarting `fips.service`.
+
+---
+
+## Additional root cause discovered later (boot-time route collision)
+
+A subsequent incident showed another failure mode that can present as the same `curl: (7) Failed to connect` symptom:
+
+1. A stale kernel route existed: `fd00::/8 via fe80::... dev eth0`.
+2. During startup, `fips.service` attempted to install `fd00::/8 dev fips0`.
+3. Kernel returned `EEXIST`, so TUN initialization failed (`tun_state: failed`, no `fips0`).
+4. Without TUN, `.fips` reachability failed even if service looked partially alive.
+
+### Key diagnostic indicators
+
+- `sudo fipsctl show status` reports:
+  - `tun_state: failed`
+  - missing/empty `tun_name`
+- `ip -6 route show fd00::/8` points to non-`fips0` device (for example `eth0`)
+- `ip -o link show dev fips0` fails
+
+### Immediate runtime recovery
+
+```bash
+sudo ip -6 route del fd00::/8
+sudo systemctl restart fips.service
+```
+
+After recovery, verify:
+
+- `tun_state: active`
+- `fips0` exists and is UP
+- `ip -6 route show fd00::/8` -> `dev fips0`
+
+### Persistence/hardening
+
+To make this robust across reboots and service restarts:
+
+1. Keep config MTU safeguards:
+   - `tun.mtu: 1280`
+   - `transports.udp.mtu: 1280`
+2. Ensure `fips.service` is enabled:
+   - `sudo systemctl enable fips.service`
+3. Add a systemd drop-in `ExecStartPre` hook that removes stale non-`fips0` `fd00::/8` routes before daemon start.
+
+This repository now includes deployment-script updates to install that hook automatically.
+
+---
+
+## Latest incident addendum (Qubes inter-qube `.fips` debug)
+
+### New findings
+
+1. **Mesh + DNS can be healthy while app check still fails**
+   - We observed successful `.fips` DNS resolution and ICMP reachability to the remote FIPS IPv6.
+   - Yet HTTP checks still failed due to listener/bind mismatch.
+
+2. **Qubes resolver path must include local dnsmasq for `.fips`**
+   - `dig @127.0.0.1 -p 5354 <npub>.fips AAAA` worked while `getent ahosts <npub>.fips` initially failed.
+   - Root cause: `/etc/resolv.conf` lacked `nameserver 127.0.0.1` on the local qube.
+   - Adding `127.0.0.1` restored system resolver `.fips` lookups.
+
+3. **Persistence in Qubes requires `/rw/config/rc.local` hygiene**
+   - Runtime fixes to `/etc/resolv.conf` are not enough.
+   - Persisting the resolver injection in `/rw/config/rc.local` is required for reboot durability.
+   - We also discovered/remediated a stale legacy block (`# === AI FIPS ROUTE START ===`) that forced `fd00::/8` via `eth0`; this must be removed to avoid breaking TUN routing on boot.
+
+4. **Remote service bind must match transport family used by `.fips` path**
+   - Remote python server bound to `0.0.0.0:80` (IPv4) was not reachable via `.fips` IPv6 destination.
+   - Rebinding server to remote FIPS IPv6 (`fd56:...:982f`) fixed HTTP connectivity immediately.
+
+### Practical runbook update for inter-qube checks
+
+Add these checks before concluding “FIPS is broken”:
+
+1. **Resolver path sanity**
+   - `getent ahosts <npub>.fips`
+   - If fail, check `/etc/resolv.conf` includes `nameserver 127.0.0.1`
+   - Confirm dnsmasq forwards `/fips/` to local FIPS DNS (`127.0.0.1#5354` or `::1#5354`)
+
+2. **Control/data plane split checks**
+   - DNS AAAA success + `ping6 <npub>.fips` success proves overlay path exists
+   - If HTTP fails, test TCP port explicitly (`/dev/tcp` or `curl -v -6`)
+
+3. **Listener-family verification on remote**
+   - `ss -lntp | grep ':80 '`
+   - Ensure remote listener is IPv6-capable for `.fips` access
+
+### Script updates from this incident
+
+- `test_qube_pair.sh`
+  - Added resolver hints when `.fips` name does not resolve
+  - Added IPv6 curl (`curl -6`) and configurable HTTP port via `REMOTE_HTTP_PORT`
+  - Added port probe diagnostics on HTTP failure
+- `test_fips.sh`
+  - Added `/etc/resolv.conf` sanity reporting for `nameserver 127.0.0.1`
+- `update_and_deploy_fips.sh`
+  - Persisted rc.local network overrides
+  - Added cleanup of legacy `# === AI FIPS ROUTE START/END ===` block when rewriting rc.local
+- `start_py_http80.sh`
+  - Binds to detected local FIPS IPv6 by default (instead of IPv4-only bind)
--- a/start_py_http80.sh
+++ b/start_py_http80.sh
@@ -0,0 +1,74 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Start a simple Python HTTP server on port 80 for FIPS reachability tests.
+# Run this script on the OTHER qube.
+#
+# Usage:
+#   ./start_py_http80.sh [serve_dir]
+#
+# Behavior:
+# - Detects local FIPS IPv6 from fipsctl (if available)
+# - Binds http.server to that FIPS IPv6 address (critical for .fips inbound tests)
+# - Falls back to :: if detection fails
+# - Prints listener info so you can confirm IPv6 bind
+#
+# Cross-reference:
+# - test_qube_pair.sh expects HTTP over .fips on port 80 by default
+# - If server binds only to 0.0.0.0 (IPv4), .fips curl from another qube may fail
+
+if ! command -v python3 >/dev/null 2>&1; then
+  echo "Error: python3 is required" >&2
+  exit 1
+fi
+
+SERVE_DIR="${1:-$HOME/fips_http_root}"
+mkdir -p "${SERVE_DIR}"
+
+if [[ ! -f "${SERVE_DIR}/index.html" ]]; then
+  cat > "${SERVE_DIR}/index.html" <<'HTML'
+<!doctype html>
+<html>
+  <head><meta charset="utf-8"><title>FIPS test server</title></head>
+  <body>
+    <h1>FIPS test server is running on port 80</h1>
+    <p>If you can read this over .fips, HTTP over FIPS is working.</p>
+  </body>
+</html>
+HTML
+fi
+
+BIND_ADDR="::"
+if command -v fipsctl >/dev/null 2>&1; then
+  FIPS_IPV6="$(sudo fipsctl show status 2>/dev/null | python3 -c 'import json,sys
+try:
+    d=json.loads(sys.stdin.read())
+    print(d.get("ipv6_addr") or "")
+except Exception:
+    print("")' || true)"
+  if [[ -n "${FIPS_IPV6}" ]]; then
+    BIND_ADDR="${FIPS_IPV6}"
+  fi
+fi
+
+echo "Serving directory: ${SERVE_DIR}"
+echo "Binding python HTTP server to [${BIND_ADDR}]:80 (sudo required)"
+
+echo "Stopping any existing python http.server processes..."
+sudo pkill -f "python3 -m http.server" >/dev/null 2>&1 || true
+
+cd "${SERVE_DIR}"
+
+echo "Starting server..."
+# Start in background briefly so we can validate listener, then wait on it.
+sudo python3 -m http.server 80 --bind "${BIND_ADDR}" &
+SERVER_PID=$!
+sleep 1
+
+echo "Listener check:"
+sudo ss -lntp | grep ':80 ' || true
+
+echo "Server PID: ${SERVER_PID}"
+echo "Press Ctrl+C to stop."
+wait "${SERVER_PID}"
+
--- a/test_fips.sh
+++ b/test_fips.sh
@@ -10,6 +10,11 @@ if ! command -v curl >/dev/null 2>&1; then
  exit 1
 fi

+if ! command -v ip >/dev/null 2>&1; then
+  echo "Error: iproute2 (ip command) is required." >&2
+  exit 1
+fi
+
 if ! command -v python3 >/dev/null 2>&1; then
  echo "Error: python3 is required." >&2
  exit 1
@@ -110,6 +115,43 @@ FIPSCTL_VERSION="$(fipsctl --version | head -n1)"
 STATUS_JSON="$(get_cmd_output fipsctl show status)"
 PEERS_JSON="$(get_cmd_output fipsctl show peers)"

+TUN_STATE="$(json_get "${STATUS_JSON}" tun_state)"
+TUN_NAME="$(json_get "${STATUS_JSON}" tun_name)"
+if [[ "${TUN_NAME}" == "n/a" || -z "${TUN_NAME}" ]]; then
+  TUN_NAME="fips0"
+fi
+
+if grep -Eq '^[[:space:]]*nameserver[[:space:]]+127\.0\.0\.1([[:space:]]|$)' /etc/resolv.conf 2>/dev/null; then
+  RESOLV_127_STATUS="present"
+else
+  RESOLV_127_STATUS="missing"
+fi
+
+if [[ "${TUN_STATE}" != "active" ]]; then
+  echo "Error: expected tun_state=active, got ${TUN_STATE}." >&2
+  exit 1
+fi
+
+if ! ip -o link show dev "${TUN_NAME}" >/dev/null 2>&1; then
+  echo "Error: expected TUN interface ${TUN_NAME} to exist." >&2
+  exit 1
+fi
+
+FD00_ROUTE_LINE="$(ip -6 route show fd00::/8 2>/dev/null | head -n1 || true)"
+if [[ -z "${FD00_ROUTE_LINE}" ]]; then
+  echo "Error: missing fd00::/8 route." >&2
+  exit 1
+fi
+
+if [[ "${FD00_ROUTE_LINE}" != *"dev ${TUN_NAME}"* ]]; then
+  echo "Error: fd00::/8 route is not installed via ${TUN_NAME}: ${FD00_ROUTE_LINE}" >&2
+  exit 1
+fi
+
+if [[ "${RESOLV_127_STATUS}" == "missing" ]]; then
+  echo "Warning: /etc/resolv.conf does not contain nameserver 127.0.0.1; .fips DNS may fail in some environments." >&2
+fi
+
 echo "==> Testing .fips URL reachability"
 TMP_BODY="$(mktemp)"
 trap 'rm -f "${TMP_BODY}"' EXIT
@@ -139,6 +181,10 @@ echo "7) peer_count: $(json_get "${STATUS_JSON}" peer_count)"
 echo "8) link_count: $(json_get "${STATUS_JSON}" link_count)"
 echo "9) session_count: $(json_get "${STATUS_JSON}" session_count)"
 echo "10) connected_peer_example: $(first_connected_peer "${PEERS_JSON}")"
+echo "11) tun_state: ${TUN_STATE}"
+echo "12) tun_name: ${TUN_NAME}"
+echo "13) fd00_route: ${FD00_ROUTE_LINE}"
+echo "14) resolv_conf_nameserver_127.0.0.1: ${RESOLV_127_STATUS}"

 echo ""
 echo "URL test: HTTP=${HTTP_CODE}, bytes=${BYTES}"
--- a/test_qube_pair.sh
+++ b/test_qube_pair.sh
@@ -6,6 +6,11 @@ set -euo pipefail
 #   ./test_qube_pair.sh <remote_npub> [remote_underlay_addr:port]
 # Example:
 #   ./test_qube_pair.sh npub1... 10.137.0.22:2121
+#
+# Optional env vars:
+#   REMOTE_HTTP_PORT=80   # target port for HTTP validation over .fips
+#   CURL_TIMEOUT=10
+#   MIN_BYTES=200

 if [[ $# -lt 1 ]]; then
  echo "Usage: $0 <remote_npub> [remote_underlay_addr:port]" >&2
@@ -17,6 +22,13 @@ REMOTE_ADDR="${2:-}"
 REMOTE_FQDN="${REMOTE_NPUB}.fips"
 CURL_TIMEOUT="${CURL_TIMEOUT:-10}"
 MIN_BYTES="${MIN_BYTES:-200}"
+REMOTE_HTTP_PORT="${REMOTE_HTTP_PORT:-80}"
+REMOTE_URL="http://${REMOTE_FQDN}"
+if [[ "${REMOTE_HTTP_PORT}" != "80" ]]; then
+  REMOTE_URL="http://${REMOTE_FQDN}:${REMOTE_HTTP_PORT}/"
+else
+  REMOTE_URL="http://${REMOTE_FQDN}/"
+fi

 need_cmd() {
  if ! command -v "$1" >/dev/null 2>&1; then
@@ -29,6 +41,7 @@ need_cmd curl
 need_cmd python3
 need_cmd getent
 need_cmd fipsctl
+need_cmd ip

 echo "==> Local node"
 STATUS_JSON="$(sudo fipsctl show status)"
@@ -44,6 +57,46 @@ print(f"peer_count={s.get('peer_count')}")
 print(f"session_count={s.get('session_count')}")
 PY

+echo ""
+echo "==> Local TUN/route preflight"
+TUN_STATE="$(python3 - "${STATUS_JSON}" <<'PY'
+import json
+import sys
+s = json.loads(sys.argv[1])
+print(s.get("tun_state", "n/a"))
+PY
+)"
+TUN_NAME="$(python3 - "${STATUS_JSON}" <<'PY'
+import json
+import sys
+s = json.loads(sys.argv[1])
+print(s.get("tun_name") or "fips0")
+PY
+)"
+
+if [[ "${TUN_STATE}" != "active" ]]; then
+  echo "Error: local tun_state is ${TUN_STATE} (expected active)." >&2
+  exit 1
+fi
+
+if ! ip -o link show dev "${TUN_NAME}" >/dev/null 2>&1; then
+  echo "Error: local TUN interface ${TUN_NAME} is missing." >&2
+  exit 1
+fi
+
+FD00_ROUTE_LINE="$(ip -6 route show fd00::/8 2>/dev/null | head -n1 || true)"
+if [[ -z "${FD00_ROUTE_LINE}" ]]; then
+  echo "Error: missing local fd00::/8 route." >&2
+  exit 1
+fi
+if [[ "${FD00_ROUTE_LINE}" != *"dev ${TUN_NAME}"* ]]; then
+  echo "Error: local fd00::/8 route is not via ${TUN_NAME}: ${FD00_ROUTE_LINE}" >&2
+  exit 1
+fi
+
+echo "tun_state=${TUN_STATE} tun_name=${TUN_NAME}"
+echo "fd00_route=${FD00_ROUTE_LINE}"
+
 echo ""
 echo "==> Attempting to resolve ${REMOTE_FQDN}"
 REMOTE_IPV6=""
@@ -52,6 +105,11 @@ if RESOLVED="$(getent ahosts "${REMOTE_FQDN}" | awk '{print $1}' | head -n1)" &&
  echo "resolved_ipv6=${REMOTE_IPV6}"
 else
  echo "not_resolved"
+  if grep -Eq '^[[:space:]]*nameserver[[:space:]]+127\.0\.0\.1([[:space:]]|$)' /etc/resolv.conf 2>/dev/null; then
+    echo "resolver_hint=127.0.0.1_present"
+  else
+    echo "resolver_hint=127.0.0.1_missing_in_/etc/resolv.conf"
+  fi
 fi

 if [[ -n "${REMOTE_ADDR}" ]]; then
@@ -83,12 +141,21 @@ PY

 echo ""
 echo "==> HTTP check over .fips"
+echo "remote_url=${REMOTE_URL}"
 TMP_BODY="$(mktemp)"
 trap 'rm -f "${TMP_BODY}"' EXIT
-HTTP_CODE="$(curl -sS --max-time "${CURL_TIMEOUT}" -o "${TMP_BODY}" -w '%{http_code}' "http://${REMOTE_FQDN}/" || true)"
+HTTP_CODE="$(curl -6 -sS --max-time "${CURL_TIMEOUT}" -o "${TMP_BODY}" -w '%{http_code}' "${REMOTE_URL}" || true)"
 BYTES="$(wc -c < "${TMP_BODY}" | tr -d '[:space:]')"
 echo "http_code=${HTTP_CODE:-000} bytes=${BYTES}"

+if [[ "${HTTP_CODE:-000}" == "000" ]]; then
+  if timeout 2 bash -lc "cat </dev/null >/dev/tcp/${REMOTE_FQDN}/${REMOTE_HTTP_PORT}" >/dev/null 2>&1; then
+    echo "port_probe=tcp_open_but_http_failed"
+  else
+    echo "port_probe=tcp_closed_or_filtered"
+  fi
+fi
+
 if [[ "${HTTP_CODE:-000}" == "200" ]] && (( BYTES >= MIN_BYTES )); then
  echo ""
  echo "RESULT=PASS (inter-qube communication confirmed via .fips HTTP)"
@@ -99,8 +166,10 @@ echo ""
 echo "RESULT=FAIL (communication not yet proven)"
 echo ""
 echo "Next actions:"
-echo "1) In EACH qube, get underlay IP: ip -4 -o addr show dev eth0"
-echo "2) From this qube, connect to remote: sudo fipsctl connect ${REMOTE_NPUB} <REMOTE_ETH0_IP>:2121 udp"
-echo "3) From remote qube, connect back to this qube: sudo fipsctl connect <THIS_QUBE_NPUB> <THIS_QUBE_ETH0_IP>:2121 udp"
-echo "4) Re-run this script in both qubes."
+echo "1) If name did not resolve, ensure /etc/resolv.conf has nameserver 127.0.0.1 and dnsmasq forwards /fips/ to 127.0.0.1#5354"
+echo "2) In EACH qube, get underlay IP: ip -4 -o addr show dev eth0"
+echo "3) From this qube, connect to remote: sudo fipsctl connect ${REMOTE_NPUB} <REMOTE_ETH0_IP>:2121 udp"
+echo "4) From remote qube, connect back to this qube: sudo fipsctl connect <THIS_QUBE_NPUB> <THIS_QUBE_ETH0_IP>:2121 udp"
+echo "5) If app is up but script still fails, verify remote listener is IPv6-bound and set REMOTE_HTTP_PORT if non-80"
+echo "6) Re-run this script in both qubes."
 exit 1
--- a/update_and_deploy_fips.sh
+++ b/update_and_deploy_fips.sh
@@ -383,10 +383,12 @@ persist_qubes_rc_local_network_overrides() {
  fi

  awk '
-    BEGIN { skip = 0 }
-    /^# BEGIN FIPS_DEPLOY_NETWORK_OVERRIDES$/ { skip = 1; next }
-    /^# END FIPS_DEPLOY_NETWORK_OVERRIDES$/ { skip = 0; next }
-    skip == 0 { print }
+    BEGIN { skip_fips = 0; skip_legacy_ai_route = 0 }
+    /^# BEGIN FIPS_DEPLOY_NETWORK_OVERRIDES$/ { skip_fips = 1; next }
+    /^# END FIPS_DEPLOY_NETWORK_OVERRIDES$/ { skip_fips = 0; next }
+    /^# === AI FIPS ROUTE START ===$/ { skip_legacy_ai_route = 1; next }
+    /^# === AI FIPS ROUTE END ===$/ { skip_legacy_ai_route = 0; next }
+    skip_fips == 0 && skip_legacy_ai_route == 0 { print }
  ' "${tmp_file}" > "${tmp_file}.clean"
  mv "${tmp_file}.clean" "${tmp_file}"

@@ -454,6 +456,60 @@ ensure_fips_ingress_allowed() {
  fi
 }

+install_fips_route_cleanup_hook() {
+  local helper_path="/usr/local/libexec/fips-route-sanitize.sh"
+  local dropin_dir="/etc/systemd/system/fips.service.d"
+  local dropin_file="${dropin_dir}/10-route-sanitize.conf"
+  local tmp_file
+
+  require_sudo
+
+  echo "==> Installing boot-time route cleanup hook for fips.service"
+  sudo mkdir -p "$(dirname "${helper_path}")" "${dropin_dir}"
+
+  tmp_file="$(mktemp)"
+  cat > "${tmp_file}" <<'SH'
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Remove stale fd00::/8 routes that are not owned by fips0.
+routes="$(ip -6 route show fd00::/8 2>/dev/null || true)"
+[[ -n "${routes}" ]] || exit 0
+
+while IFS= read -r line; do
+  [[ -n "${line}" ]] || continue
+  if [[ "${line}" == *" dev fips0"* ]]; then
+    continue
+  fi
+
+  if [[ "${line}" =~ ^fd00::/8[[:space:]]+via[[:space:]]+([^[:space:]]+)[[:space:]]+dev[[:space:]]+([^[:space:]]+) ]]; then
+    gw="${BASH_REMATCH[1]}"
+    dev="${BASH_REMATCH[2]}"
+    ip -6 route del fd00::/8 via "${gw}" dev "${dev}" >/dev/null 2>&1 || true
+  elif [[ "${line}" =~ ^fd00::/8[[:space:]]+dev[[:space:]]+([^[:space:]]+) ]]; then
+    dev="${BASH_REMATCH[1]}"
+    if [[ "${dev}" != "fips0" ]]; then
+      ip -6 route del fd00::/8 dev "${dev}" >/dev/null 2>&1 || true
+    fi
+  else
+    ip -6 route del fd00::/8 >/dev/null 2>&1 || true
+  fi
+done <<< "${routes}"
+SH
+  sudo install -m 0755 "${tmp_file}" "${helper_path}"
+  rm -f "${tmp_file}"
+
+  tmp_file="$(mktemp)"
+  cat > "${tmp_file}" <<EOF
+[Service]
+ExecStartPre=${helper_path}
+EOF
+  sudo install -m 0644 "${tmp_file}" "${dropin_file}"
+  rm -f "${tmp_file}"
+
+  sudo systemctl daemon-reload
+}
+
 ensure_build_toolchain
 ensure_tun_ready

@@ -667,6 +723,8 @@ if [[ "${ADD_CURRENT_USER_TO_FIPS_GROUP}" == "yes" ]]; then
  fi
 fi

+install_fips_route_cleanup_hook
+
 echo "==> Cleaning potentially stale fd00::/8 route state"
 require_sudo
 sudo ip -6 route del fd00::/8 >/dev/null 2>&1 || true