From a1da95c9067565f64c0f948b2456cd8a7958b756 Mon Sep 17 00:00:00 2001
From: winlin <winlin@vip.126.com>
Date: Fri, 7 Aug 2020 17:04:34 +0800
Subject: [PATCH] RTC: Support server hijacker

---
 trunk/src/app/srs_app_rtc_server.cpp | 26 ++++++++++++++++++++++++++
 trunk/src/app/srs_app_rtc_server.hpp | 13 +++++++++++++
 2 files changed, 39 insertions(+)

diff --git a/trunk/src/app/srs_app_rtc_server.cpp b/trunk/src/app/srs_app_rtc_server.cpp
index 1c8c6d747..de8bdcc9e 100644
--- a/trunk/src/app/srs_app_rtc_server.cpp
+++ b/trunk/src/app/srs_app_rtc_server.cpp
@@ -204,9 +204,18 @@ ISrsRtcServerHandler::~ISrsRtcServerHandler()
 {
 }
 
+ISrsRtcServerHijacker::ISrsRtcServerHijacker()
+{
+}
+
+ISrsRtcServerHijacker::~ISrsRtcServerHijacker()
+{
+}
+
 SrsRtcServer::SrsRtcServer()
 {
     handler = NULL;
+    hijacker = NULL;
     timer = new SrsHourGlass(this, 1 * SRS_UTIME_SECONDS);
 }
 
@@ -257,6 +266,11 @@ void SrsRtcServer::set_handler(ISrsRtcServerHandler* h)
     handler = h;
 }
 
+void SrsRtcServer::set_hijacker(ISrsRtcServerHijacker* h)
+{
+    hijacker = h;
+}
+
 srs_error_t SrsRtcServer::listen_udp()
 {
     srs_error_t err = srs_success;
@@ -309,6 +323,18 @@ srs_error_t SrsRtcServer::on_udp_packet(SrsUdpMuxSocket* skt)
         }
     }
 
+    // Notify hijack to handle the UDP packet.
+    if (hijacker) {
+        bool consumed = false;
+        if ((err = hijacker->on_udp_packet(&consumed)) != srs_success) {
+            return srs_error_wrap(err, "hijack consumed=%u", consumed);
+        }
+
+        if (consumed) {
+            return err;
+        }
+    }
+
     // For STUN, the peer address may change.
     if (srs_is_stun((uint8_t*)data, size)) {
         SrsStunPacket ping;
diff --git a/trunk/src/app/srs_app_rtc_server.hpp b/trunk/src/app/srs_app_rtc_server.hpp
index aa02b7425..51276a7e4 100644
--- a/trunk/src/app/srs_app_rtc_server.hpp
+++ b/trunk/src/app/srs_app_rtc_server.hpp
@@ -72,6 +72,17 @@ public:
     virtual void on_timeout(SrsRtcConnection* session) = 0;
 };
 
+// The hijacker to hook server.
+class ISrsRtcServerHijacker
+{
+public:
+    ISrsRtcServerHijacker();
+    virtual ~ISrsRtcServerHijacker();
+public:
+    // If consumed set to true, server will ignore the packet.
+    virtual srs_error_t on_udp_packet(bool* pconsumed) = 0;
+};
+
 // The RTC server instance, listen UDP port, handle UDP packet, manage RTC connections.
 class SrsRtcServer : virtual public ISrsUdpMuxHandler, virtual public ISrsHourGlass
 {
@@ -79,6 +90,7 @@ private:
     SrsHourGlass* timer;
     std::vector<SrsUdpMuxListener*> listeners;
     ISrsRtcServerHandler* handler;
+    ISrsRtcServerHijacker* hijacker;
 private:
     // TODO: FIXME: Rename it.
     std::map<std::string, SrsRtcConnection*> map_username_session; // key: username(local_ufrag + ":" + remote_ufrag)
@@ -93,6 +105,7 @@ public:
     virtual srs_error_t initialize();
     // Set the handler for server events.
     void set_handler(ISrsRtcServerHandler* h);
+    void set_hijacker(ISrsRtcServerHijacker* h);
 public:
     // TODO: FIXME: Support gracefully quit.
     // TODO: FIXME: Support reload.