From 63e354026fcd8c745fbc5b92f16e73d8d7970b18 Mon Sep 17 00:00:00 2001
From: MichaelLee <lj1748503358@163.com>
Date: Thu, 2 Jan 2020 15:57:35 +0800
Subject: [PATCH] Add: force passive server ip

Add: force an IP address in PASS replies. -- for NAT
---
 config.yaml         | 7 ++++++-
 src/configure.cpp   | 8 ++++++++
 src/configure.h     | 1 +
 src/data_handle.cpp | 5 +++++
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/config.yaml b/config.yaml
index 29fa52b..d1bf74f 100644
--- a/config.yaml
+++ b/config.yaml
@@ -1,4 +1,5 @@
 server:
+  #  监听端口，0.0.0.0 允许任意主机连接
   listen_host: "0.0.0.0"  # server 端监听的主机地址
   listen_port: 2222 # 命令连接的监听的端口
 
@@ -7,4 +8,8 @@ PORT:
 
 PASV:  # PASV 模式，指定该模式下可以使用的端口范围
   port_low: 22222 # 数据连接所用的端口下限
-  port_high: 55555  # 数据连接所用的端口上限
\ No newline at end of file
+  port_high: 55555  # 数据连接所用的端口上限
+  # PASV 模式中强制使用的 IP 地址，在 NAT 网关后的主机可能不能自动解析到公网 IP
+  #   或者在网关采用动态 IP 的情况下有用
+  force_passive_ip: "" # 若使用程序自动解析的 ip 地址，则填为空字符串 ""
+
diff --git a/src/configure.cpp b/src/configure.cpp
index d868489..e545d0a 100644
--- a/src/configure.cpp
+++ b/src/configure.cpp
@@ -11,6 +11,7 @@ namespace configure {
     const char *config_file = "config.yaml";    /* 配置文件 */
 
     std::string SERVER_LISTEN_HOST;
+    std::string FORCE_PASSIVE_SERVER_IP;
     int SERVER_LISTEN_PORT;
 
     int PORT_CONN_PORT;
@@ -60,6 +61,13 @@ namespace configure {
             exit(EXIT_FAILURE);
         }
 
+        if (pasv_config["force_passive_ip"].IsDefined()) {
+            FORCE_PASSIVE_SERVER_IP = pasv_config["force_passive_ip"].as<std::string>();
+            utility::debug_info(std::string("Force Server IP Address: ") + FORCE_PASSIVE_SERVER_IP);
+        } else {
+            FORCE_PASSIVE_SERVER_IP = "";
+        }
+
         utility::debug_info(std::string("PASV port low: ") + std::to_string(PASV_PORT_LOW));
         utility::debug_info(std::string("PASV port high: ") + std::to_string(PASV_PORT_HIGH));
         assert(PASV_PORT_LOW > 0 && PASV_PORT_LOW < 65536);
diff --git a/src/configure.h b/src/configure.h
index 98c526c..0952a37 100644
--- a/src/configure.h
+++ b/src/configure.h
@@ -11,6 +11,7 @@
 namespace configure {
     /* 配置信息 */
     extern std::string SERVER_LISTEN_HOST;
+    extern std::string FORCE_PASSIVE_SERVER_IP;
     extern  int SERVER_LISTEN_PORT;
 
     extern int PORT_CONN_PORT;
diff --git a/src/data_handle.cpp b/src/data_handle.cpp
index d0b6688..888d5b3 100644
--- a/src/data_handle.cpp
+++ b/src/data_handle.cpp
@@ -175,6 +175,11 @@ void CLDataHandle::do_get_fd() {
 }
 
 const char *CLDataHandle::get_local_ip() {
+    if (!configure::FORCE_PASSIVE_SERVER_IP.empty()) {
+        m_ip_addr = configure::FORCE_PASSIVE_SERVER_IP;
+        return m_ip_addr.c_str();
+    }
+
     if (!m_ip_addr.empty() && m_b_pasv_mode) return m_ip_addr.c_str();
 
     char ip[48] = {0};