#!/bin/bash

# 检查是否以root权限运行
if [ "$(id -u)" -ne 0 ]; then
    echo "错误：请使用root权限运行（sudo ./pub_route.sh）"
    exit 1
fi

# 配置参数
TABLE_NAME="ipv4_pub"        # 路由表名称
TABLE_ID=102                 # 路由表编号（1-252之间）
SOURCE_CIDR="44.32.191.0/24" # 源网段（必须正确填写，否则规则无效）
FROM_PRIORITY=1000           # 来源策略优先级
TO_PRIORITY=800              # 目的策略优先级
RT_TABLES="/etc/iproute2/rt_tables"

# 网络出口设定
TARGET_IP="10.188.0.44"      # 新加坡Vultr

# 1. 验证源网段是否合法
if ! echo "$SOURCE_CIDR" | grep -qE '^([0-9]{1,3}\.){3}[0-9]{1,3}/[0-9]{1,2}$'; then
    echo "错误：源网段$SOURCE_CIDR格式无效，请检查配置"
    exit 1
fi

# 2.获取网关
echo "正在获取网关..."
GATEWAY=$(ip route get "$TARGET_IP" | grep -oP 'via \K\d+\.\d+\.\d+\.\d+')
if [ -z "$GATEWAY" ]; then
    echo "错误：无法获取网关，请检查网络"
    exit 1
fi
echo "成功获取网关：$GATEWAY"

# 3. 确保路由表存在
if ! grep -q "^${TABLE_ID}[[:space:]]\+${TABLE_NAME}" "$RT_TABLES"; then
    echo "添加路由表 $TABLE_NAME（编号$TABLE_ID）..."
    echo "${TABLE_ID}  ${TABLE_NAME}" >> "$RT_TABLES"
else
    echo "路由表 $TABLE_NAME 已存在，无需创建"
fi

# 4. 配置/更新默认路由
echo "配置$TABLE_NAME表的默认路由（via $GATEWAY）..."
ip route del default table "$TABLE_NAME" 2>/dev/null  # 删除旧路由
ip route add default via "$GATEWAY" table "$TABLE_NAME"  # 添加新路由
echo "默认路由已更新为：default via $GATEWAY table $TABLE_NAME"

# 5. 配置/更新策略规则（使用正确的源网段）
echo "配置策略规则：来源$SOURCE_CIDR使用$TABLE_NAME表..."
# 来源访问任何
ip rule del from "$SOURCE_CIDR" table "$TABLE_NAME" 2>/dev/null
ip rule add from "$SOURCE_CIDR" table "$TABLE_NAME" priority "$FROM_PRIORITY"
# 任何访问来源
ip rule del to "$SOURCE_CIDR" table main 2>/dev/null 
ip rule add to "$SOURCE_CIDR" table main priority "$TO_PRIORITY" 
echo "策略规则已更新为：from $SOURCE_CIDR table $TABLE_NAME priority $PRIORITY"

# 6. 验证配置
echo -e "\n===== 配置验证 ====="
echo "$TABLE_NAME表中的路由："
ip route show table "$TABLE_NAME"

echo -e "\n策略规则："
ip rule show

# 7. 持久化配置（Debian/Ubuntu）
echo -e "\n===== 持久化配置 ====="
INTERFACE_FILE="/etc/network/interfaces"
PERSIST_MARKER="# 策略路由持久化配置（$TABLE_NAME表）"
PERSIST_COMMANDS=$(cat <<EOF
$PERSIST_MARKER
up ip route add default via $GATEWAY table $TABLE_NAME
up ip rule add from $SOURCE_CIDR table $TABLE_NAME priority $PRIORITY
up ip rule add to "$SOURCE_CIDR" table main priority "$TO_PRIORITY" 
EOF
)

# 删除旧的持久化配置
if grep -q "$PERSIST_MARKER" "$INTERFACE_FILE"; then
    echo "删除旧的持久化配置..."
    sed -i "/$PERSIST_MARKER/,+2d" "$INTERFACE_FILE"
fi
# 添加新的持久化配置
echo "添加更新后的持久化配置到$INTERFACE_FILE..."
echo "$PERSIST_COMMANDS" >> "$INTERFACE_FILE"

echo -e "\n配置完成！所有配置已生效"