sudo apt update
sudo apt install -y isc-dhcp-client tcpdump tshark

#!/bin/bash
# v6_v4_probe.sh
# ONU 直結時の DHCPv6-PD と DHCPv4 を同時調査する
#
# Usage: sudo ./v6_v4_probe.sh <NIC>
# Example: sudo ./v6_v4_probe.sh eth0

set -u

# ============================================================
# 引数 / 事前チェック
# ============================================================
if [ $# -ne 1 ] || [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
    cat <<EOF
Usage: sudo $0 <NIC>

NIC 名は \`ip -br link\` で確認できます。
例:
    sudo $0 enx04ab18fe556e
    sudo $0 enp3s0

NetworkManager / systemd-networkd / dhcpcd を自動停止し、
DHCPv6-PD と DHCPv4 を順次取得して結果をまとめます。
ログは /tmp/v6v4-probe-<timestamp>/ に保存されます。
EOF
    exit 1
fi

IFACE="$1"

if [ "$EUID" -ne 0 ]; then
    echo "[ERROR] root 権限が必要です: sudo $0 $IFACE" >&2
    exit 1
fi

if ! ip link show "$IFACE" &>/dev/null; then
    echo "[ERROR] インターフェース $IFACE が見つかりません" >&2
    echo "" >&2
    echo "利用可能な NIC:" >&2
    ip -br link >&2
    exit 1
fi

for cmd in dhclient tcpdump ip; do
    if ! command -v "$cmd" &>/dev/null; then
        echo "[ERROR] $cmd が見つかりません" >&2
        echo "        sudo apt install -y isc-dhcp-client tcpdump" >&2
        echo "        (option 125 自動抽出に tshark もあると便利)" >&2
        exit 1
    fi
done

# tshark は任意(あれば SIP 抽出が自動化される)
if ! command -v tshark &>/dev/null; then
    echo "[INFO] tshark 未インストール。SIP 情報は pcap を Wireshark で見てください"
    echo "       (自動抽出したい場合: sudo apt install -y tshark)"
fi

# ============================================================
# ログディレクトリ
# ============================================================
TS=$(date +%Y%m%d-%H%M%S)
LOGDIR="/tmp/v6v4-probe-${TS}"
mkdir -p "$LOGDIR"

# ============================================================
# クリーンアップ(EXIT/INT/TERM 時)
# ============================================================
PIDS=()
STOPPED_SVCS=()

cleanup() {
    echo ""
    echo "[INFO] 後片付け中..."

    # バックグラウンドプロセス停止
    for pid in "${PIDS[@]}"; do
        kill "$pid" 2>/dev/null || true
    done

    # dhclient 停止
    pkill -f "dhclient.*${IFACE}" 2>/dev/null || true

    sleep 1

    echo ""
    echo "[INFO] ログ保存先: $LOGDIR"
    if [ ${#STOPPED_SVCS[@]} -gt 0 ]; then
        echo ""
        echo "[INFO] 停止したサービス(必要なら手動で復帰):"
        for svc in "${STOPPED_SVCS[@]}"; do
            echo "    sudo systemctl start $svc"
        done
    fi
}
trap cleanup EXIT INT TERM

# ============================================================
# 干渉サービス停止
# ============================================================
echo "[INFO] 干渉する可能性のあるサービスを停止..."
for svc in NetworkManager systemd-networkd wpa_supplicant dhcpcd; do
    if systemctl is-active --quiet "$svc" 2>/dev/null; then
        echo "    - $svc を停止"
        systemctl stop "$svc"
        STOPPED_SVCS+=("$svc")
    fi
done

# 既存 dhclient プロセス停止
pkill -f "dhclient.*${IFACE}" 2>/dev/null || true
sleep 1

# ============================================================
# インターフェース UP
# ============================================================
echo "[INFO] $IFACE を up..."
ip link set "$IFACE" up
sleep 2

if ip link show "$IFACE" | grep -q "NO-CARRIER"; then
    echo "[WARN] $IFACE がリンクダウンしています。ケーブル接続を確認してください"
    echo "       5秒待って再確認します..."
    sleep 5
    if ip link show "$IFACE" | grep -q "NO-CARRIER"; then
        echo "[ERROR] リンクアップしません。中断します"
        exit 1
    fi
fi
echo "[INFO] リンクアップ確認 OK"

# ============================================================
# tcpdump 起動(3 種類並列)
# ============================================================
echo "[INFO] パケットキャプチャ開始..."

# DHCPv4 pcap
tcpdump -i "$IFACE" -nev -s 0 -w "$LOGDIR/dhcpv4.pcap" \
    'port 67 or port 68' >/dev/null 2>"$LOGDIR/tcpdump-v4.err" &
PIDS+=($!)

# DHCPv6 pcap
tcpdump -i "$IFACE" -nev -s 0 -w "$LOGDIR/dhcpv6.pcap" \
    'ip6 and (port 546 or port 547)' >/dev/null 2>"$LOGDIR/tcpdump-v6.err" &
PIDS+=($!)

# 全関連トラフィックのテキストログ
tcpdump -i "$IFACE" -nev -s 0 \
    '(port 67 or port 68) or (ip6 and (port 546 or port 547)) or icmp6' \
    >"$LOGDIR/all-traffic.log" 2>&1 &
PIDS+=($!)

sleep 2

# ============================================================
# DHCPv6-PD 取得
# ============================================================
echo ""
echo "============================================================"
echo " DHCPv6-PD (IPv6 Prefix Delegation)"
echo "============================================================"
timeout 30 dhclient -6 -P -v "$IFACE" 2>&1 | tee "$LOGDIR/dhclient-v6.log" || true
echo ""

sleep 3

# ============================================================
# DHCPv4 取得
# ============================================================
echo "============================================================"
echo " DHCPv4"
echo "============================================================"
dhclient -r "$IFACE" 2>/dev/null || true
sleep 1
timeout 30 dhclient -v "$IFACE" 2>&1 | tee "$LOGDIR/dhclient-v4.log" || true
echo ""

# RA を追加で待つ
echo "[INFO] 追加の RA を 5 秒待機..."
sleep 5

# ============================================================
# 最終状態スナップショット
# ============================================================
{
    echo "===== ip -6 addr show dev $IFACE ====="
    ip -6 addr show dev "$IFACE"
    echo ""
    echo "===== ip -4 addr show dev $IFACE ====="
    ip -4 addr show dev "$IFACE"
    echo ""
    echo "===== ip -6 route ====="
    ip -6 route
    echo ""
    echo "===== ip -4 route ====="
    ip -4 route
} > "$LOGDIR/final-state.txt"

# tcpdump 停止
for pid in "${PIDS[@]}"; do
    kill "$pid" 2>/dev/null || true
done
wait 2>/dev/null || true
PIDS=()

# ============================================================
# サマリ表示
# ============================================================
echo ""
echo "============================================================"
echo " 結果サマリ"
echo "============================================================"

# --- IPv6 ---
echo ""
echo "IPv6"
echo "----"
PD_LINE=$(grep -E "IAPREFIX|IA_PD-prefix" "$LOGDIR/dhclient-v6.log" 2>/dev/null | head -1)
if [ -n "$PD_LINE" ]; then
    PD=$(echo "$PD_LINE" | grep -oE '[0-9a-f:]+/[0-9]+')
    echo "  受領 PD     : $PD"
    PD_SIZE=$(echo "$PD" | grep -oE '/[0-9]+')
    echo "  サイズ      : $PD_SIZE"
else
    echo "  受領 PD     : (取得失敗)"
fi
V6_ADDRS=$(ip -6 addr show dev "$IFACE" | awk '/inet6/ && !/fe80/ {print $2}')
if [ -n "$V6_ADDRS" ]; then
    echo "  IF アドレス :"
    echo "$V6_ADDRS" | sed 's/^/    /'
fi

# --- IPv4 ---
echo ""
echo "IPv4"
echo "----"
V4_ADDR=$(ip -4 addr show dev "$IFACE" | awk '/inet / {print $2}' | head -1)
if [ -n "$V4_ADDR" ]; then
    echo "  IF アドレス : $V4_ADDR"
    V4_MASK=$(echo "$V4_ADDR" | grep -oE '/[0-9]+')
    if [ "$V4_MASK" = "/30" ]; then
        echo "  /30 リース  : YES(ひかり電話セグメントの可能性大)"
    else
        echo "  /30 リース  : NO($V4_MASK)"
    fi
else
    echo "  IF アドレス : (取得失敗)"
fi

# --- DHCP オプション ---
echo ""
echo "DHCPv4 SIP情報"
echo "----"
SIP_HIT=0
if command -v tshark &>/dev/null && [ -s "$LOGDIR/dhcpv4.pcap" ]; then
    OPT125=$(tshark -r "$LOGDIR/dhcpv4.pcap" -V 2>/dev/null | \
        awk '/Option: \(125\)/,/Option: \([0-9]+\)/' | head -40)
    if [ -n "$OPT125" ]; then
        echo "$OPT125" | sed 's/^/    /'
        SIP_HIT=1
    fi
    # ntt-east / ntt-west / sip 文字列が pcap 内に存在するか
    if tshark -r "$LOGDIR/dhcpv4.pcap" -V 2>/dev/null | grep -qiE "ntt-east|ntt-west|\.sip\."; then
        echo ""
        echo "  SIP ドメイン文字列を検出"
        SIP_HIT=1
    fi
fi
if [ "$SIP_HIT" -eq 0 ]; then
    echo "  (tshark での自動抽出失敗 or オプション無し)"
    echo "  → Wireshark で $LOGDIR/dhcpv4.pcap を開いて手動確認"
    echo "    フィルタ: bootp.option.type == 125"
fi

# ============================================================
# 保存ファイル一覧
# ============================================================
echo ""
echo "============================================================"
echo " 保存ファイル"
echo "============================================================"
echo "  $LOGDIR/"
echo "    ├ dhclient-v6.log   : DHCPv6-PD 詳細ログ"
echo "    ├ dhclient-v4.log   : DHCPv4 詳細ログ"
echo "    ├ dhcpv6.pcap       : DHCPv6 パケットキャプチャ"
echo "    ├ dhcpv4.pcap       : DHCPv4 パケットキャプチャ"
echo "    ├ all-traffic.log   : 全 DHCP + ICMPv6 テキストログ"
echo "    └ final-state.txt   : 最終的な ip addr / route スナップショット"
echo ""
echo "詳細解析:"
echo "    wireshark $LOGDIR/dhcpv4.pcap"
echo "    wireshark $LOGDIR/dhcpv6.pcap"
echo ""