From a982a3c9d920f5d66fb5517b17ed3e22ccca7ddf Mon Sep 17 00:00:00 2001
From: folkert van heusden <mail@vanheusden.com>
Date: Tue, 30 Apr 2024 09:06:26 +0200
Subject: [PATCH] basic setup

---
 ESP32/dc11.cpp |   1 +
 ESP32/dc11.h   |   1 +
 dc11.cpp       | 106 ++++++++++++++++++++++++++++++++++++++++++++++++-
 dc11.h         |  21 ++++++++--
 main.cpp       |   2 +-
 5 files changed, 126 insertions(+), 5 deletions(-)
 create mode 120000 ESP32/dc11.cpp
 create mode 120000 ESP32/dc11.h

diff --git a/ESP32/dc11.cpp b/ESP32/dc11.cpp
new file mode 120000
index 0000000..0ccd621
--- /dev/null
+++ b/ESP32/dc11.cpp
@@ -0,0 +1 @@
+../dc11.cpp
\ No newline at end of file
diff --git a/ESP32/dc11.h b/ESP32/dc11.h
new file mode 120000
index 0000000..78e0baa
--- /dev/null
+++ b/ESP32/dc11.h
@@ -0,0 +1 @@
+../dc11.h
\ No newline at end of file
diff --git a/dc11.cpp b/dc11.cpp
index 1a7dab0..ff8eacb 100644
--- a/dc11.cpp
+++ b/dc11.cpp
@@ -1,17 +1,121 @@
 // (C) 2024 by Folkert van Heusden
 // Released under MIT license
 
+#include <cstring>
+#include <poll.h>
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+
 #include "bus.h"
+#include "cpu.h"
 #include "dc11.h"
+#include "log.h"
 
 
-dc11::dc11(bus *const b): b(b)
+dc11::dc11(const int base_port, bus *const b):
+	base_port(base_port),
+	b(b)
 {
+	th = new std::thread(std::ref(*this));
 }
 
 dc11::~dc11()
 {
 	stop_flag = true;
+
+	if (th) {
+		th->join();
+		delete th;
+	}
+}
+
+void dc11::operator()()
+{
+	int fds[dc11_n_lines] = { };
+
+	pollfd pfds[8] = { };
+
+	for(int i=0; i<dc11_n_lines; i++) {
+		// listen on port
+		pfds[i].fd = socket(AF_INET, SOCK_STREAM, 0);
+
+		int port = base_port + i + 1;
+
+	        sockaddr_in listen_addr;
+		memset(&listen_addr, 0, sizeof(listen_addr));
+		listen_addr.sin_family      = AF_INET;
+		listen_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+		listen_addr.sin_port        = htons(port);
+
+		if (bind(pfds[i].fd, reinterpret_cast<struct sockaddr *>(&listen_addr), sizeof(listen_addr)) == -1) {
+			close(pfds[i].fd);
+			fds[i] = -1;
+
+			DOLOG(warning, true, "Cannot bind to port %d (DC11)", port);
+		}
+
+		pfds[i].events = POLLIN;
+
+		// client session
+		pfds[dc11_n_lines + i].fd     = socket(AF_INET, SOCK_STREAM, 0);
+		pfds[dc11_n_lines + i].events = POLLIN;
+	}
+
+	while(!stop_flag) {
+		int rc = poll(pfds, dc11_n_lines * 2, 100);
+		if (rc == 0)
+			continue;
+
+		// accept any new session
+		for(int i=0; i<dc11_n_lines; i++) {
+			if (pfds[i].revents != POLLIN)
+				continue;
+
+			int client_i = dc11_n_lines + i;
+
+			// disconnect any existing client session
+			// yes, one can ddos with this
+			if (pfds[client_i].fd != -1) {
+				close(pfds[client_i].fd);
+				DOLOG(info, false, "Restarting session for port %d", base_port + i + 1);
+			}
+
+			pfds[client_i].fd = accept(pfds[i].fd, nullptr, nullptr);
+		}
+
+		// receive data
+		for(int i=dc11_n_lines; i<dc11_n_lines * 2; i++) {
+			if (pfds[i].revents != POLLIN)
+				continue;
+
+			char buffer[32] { };
+			int rc = read(pfds[i].fd, buffer, sizeof buffer);
+			if (rc <= 0) {  // closed or error?
+				DOLOG(info, false, "Failed reading on port %d", base_port + i + 1);
+				close(pfds[i].fd);
+				pfds[i].fd = -1;
+			}
+			else {
+				int line_nr = i - dc11_n_lines;
+
+				std::unique_lock<std::mutex> lck(input_lock[line_nr]);
+
+				for(int k=0; k<rc; k++)
+					recv_buffers[line_nr].push_back(buffer[k]);
+
+				have_data[line_nr].notify_all();
+
+				if (registers[line_nr * 4] & 64)  // interrupts enabled?
+					b->getCpu()->queue_interrupt(4, 0320 + line_nr * 4);
+			}
+		}
+	}
+
+	for(int i=0; i<dc11_n_lines * 2; i++) {
+		if (fds[i] != -1)
+			close(fds[i]);
+	}
 }
 
 void dc11::reset()
diff --git a/dc11.h b/dc11.h
index 43ce23b..2d0fb23 100644
--- a/dc11.h
+++ b/dc11.h
@@ -3,7 +3,11 @@
 
 #pragma once
 #include <atomic>
+#include <condition_variable>
 #include <cstdint>
+#include <mutex>
+#include <thread>
+#include <vector>
 
 #include "gen.h"
 #include "bus.h"
@@ -15,16 +19,25 @@
 
 class bus;
 
+// 4 interfaces
+constexpr const int dc11_n_lines = 4;
+
 class dc11
 {
 private:
+	int              base_port        { 1100    };
 	bus             *const b          { nullptr };
-	// 4 interfaces
-	uint16_t         registers[4 * 4] {         };
+	uint16_t         registers[4 * dc11_n_lines] { };
 	std::atomic_bool stop_flag        { false   };
+	std::thread     *th               { nullptr };
+
+	std::vector<char> recv_buffers[dc11_n_lines];
+        std::condition_variable have_data[dc11_n_lines];
+        std::mutex        input_lock[dc11_n_lines];
+
 
 public:
-	dc11(bus *const b);
+	dc11(const int base_port, bus *const b);
 	virtual ~dc11();
 
 #if IS_POSIX
@@ -39,4 +52,6 @@ public:
 
 	void write_byte(const uint16_t addr, const uint8_t v);
 	void write_word(const uint16_t addr, uint16_t v);
+
+	void operator()();
 };
diff --git a/main.cpp b/main.cpp
index f3fd5db..c085854 100644
--- a/main.cpp
+++ b/main.cpp
@@ -582,7 +582,7 @@ int main(int argc, char *argv[])
 	cnsl->begin();
 
 	// TODO
-	dc11 *dc11_ = new dc11(b);
+	dc11 *dc11_ = new dc11(1100, b);
 	b->add_DC11(dc11_);
 
 	running = cnsl->get_running_flag();