From 50341c6846dbde4d0eadd9a9d4ed3ae1863c12b8 Mon Sep 17 00:00:00 2001
From: azw <vcl_delphi@126.com>
Date: Sat, 15 Apr 2023 01:13:39 +0000
Subject: [PATCH] 1

---
 a8/udplistener.cc | 152 ++++++++++++++++++++++++++++++++++++++++++++++
 a8/udplistener.h  |  27 ++++++++
 2 files changed, 179 insertions(+)
 create mode 100644 a8/udplistener.cc
 create mode 100644 a8/udplistener.h

diff --git a/a8/udplistener.cc b/a8/udplistener.cc
new file mode 100644
index 0000000..5e8df4a
--- /dev/null
+++ b/a8/udplistener.cc
@@ -0,0 +1,152 @@
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <memory.h>
+
+#include <arpa/inet.h>
+#include <fcntl.h>
+#include <sys/epoll.h>
+#include <netinet/tcp.h>
+
+#include <string>
+#include <functional>
+#include <thread>
+
+#include <a8/udplistener.h>
+
+namespace a8
+{
+    struct UdpListenerImpl
+    {
+        a8::UdpListener* master = nullptr;
+
+        int listen_socket = -1;
+        std::thread* worker_thread = nullptr;
+
+        volatile bool shutdown = false;
+
+        bool IsActive()
+        {
+            return listen_socket != -1;
+        }
+
+        void SetActive(bool active)
+        {
+            if (active) {
+                if (IsActive()) {
+                    return;
+                }
+                if (!worker_thread) {
+                    shutdown = false;
+                    worker_thread = new std::thread(&a8::UdpListenerImpl::WorkerThreadProc, this);
+                }
+            } else {
+                if (IsActive()) {
+                    ActiveStop();
+                }
+            }
+        }
+
+        bool ActiveStart()
+        {
+            listen_socket = ::socket(AF_INET, SOCK_DGRAM, 0);
+            if (listen_socket == -1){
+                if (master->on_error) {
+                    master->on_error(master, errno);
+                }
+                return false;
+            }
+            // TIME_WAIT - argh
+            int on = 1;
+            if (::setsockopt(listen_socket, SOL_SOCKET, SO_REUSEADDR, (const char*)&on, sizeof(on)) == -1 ){
+                //return false;
+            }
+            sockaddr_in sa;
+            memset(&sa, 0, sizeof(sa));
+            sa.sin_family = AF_INET;
+            sa.sin_addr.s_addr = inet_addr(master->bind_address.c_str());
+            sa.sin_port = htons(master->bind_port);
+            if (::bind(listen_socket, (sockaddr*)&sa, sizeof(sa)) < 0) {
+                if (master->on_error) {
+                    master->on_error(master, errno);
+                }
+                ::close(listen_socket);
+                listen_socket = -1;
+                return false;
+            }
+            return true;
+        }
+
+        void ActiveStop()
+        {
+            if(listen_socket != -1){
+                ::close(listen_socket);
+                listen_socket = -1;
+            }
+            if (worker_thread) {
+                shutdown = true;
+                worker_thread->join();
+                delete worker_thread;
+                worker_thread = NULL;
+            }
+        }
+
+        void WorkerThreadProc()
+        {
+            if(!ActiveStart())
+                return;
+            struct sockaddr_in destAddr;
+            socklen_t addrLen = sizeof(sockaddr_in);
+            char recv_buf[1024 * 64];
+            int buflen = sizeof(recv_buf);
+            while (!shutdown) {
+                int ret = ::recvfrom(listen_socket,
+                                     recv_buf,
+                                     buflen,
+                                     0,
+                                     (struct sockaddr*)&destAddr,
+                                     (socklen_t*)&addrLen);
+                if(ret > 0){
+                    master->OnSocketRead(recv_buf, ret);
+                }
+            }
+        }
+
+    };
+
+    UdpListener::UdpListener()
+    {
+        impl_ = new a8::UdpListenerImpl();
+        impl_->master = this;
+    }
+
+    UdpListener::~UdpListener()
+    {
+        delete impl_;
+        impl_ = nullptr;
+    }
+
+    void UdpListener::OnSocketRead(char*, unsigned int)
+    {
+    }
+
+    void UdpListener::Open()
+    {
+        if (!IsActive()) {
+            impl_->SetActive(true);
+        }
+    }
+
+    void UdpListener::Close()
+    {
+        if (IsActive()) {
+            impl_->SetActive(false);
+        }
+    }
+
+    bool UdpListener::IsActive()
+    {
+        return impl_->IsActive();
+    }
+
+}
diff --git a/a8/udplistener.h b/a8/udplistener.h
new file mode 100644
index 0000000..509d25e
--- /dev/null
+++ b/a8/udplistener.h
@@ -0,0 +1,27 @@
+#pragma once
+
+namespace a8
+{
+
+    struct UdpListenerImpl;
+    class UdpListener
+    {
+    public:
+        std::function<void (a8::UdpListener*, int error_id)> on_error;
+        std::string bind_address;
+        unsigned short bind_port = 0;
+
+    public:
+        UdpListener();
+        ~UdpListener();
+
+        virtual void OnSocketRead(char*, unsigned int);
+        void Open();
+        void Close();
+        bool IsActive();
+
+    private:
+        a8::UdpListenerImpl* impl_ = nullptr;
+    };
+
+}