Add support for building on Windows

This makes it possible to compile cfws with Visual Studio. Since winsock
and POSIX use very similar APIs, porting is mostly just a matter of
placing ifdefs around #includes and functions with slightly different
names.

However, CGI scripts and command line arguments are not available in
this port yet, since they used the Unix-exclusive getopt.h and popen.

3 files changed, 56 insertions, 11 deletions

diff --git a/src/ClientConnection.cpp b/src/ClientConnection.cpp
index c434212..e8e6692 100644
--- a/src/ClientConnection.cpp
+++ b/src/ClientConnection.cpp
@@ -3,7 +3,13 @@
 #include <cstring>
 #include <iostream>
 #include <sstream>
-#include <unistd.h>
+
+#ifdef _WIN32
+	#include <winsock2.h>
+	#pragma comment(lib, "ws2_32.lib")
+#else
+	#include <unistd.h>
+#endif
 
 ClientConnection::ClientConnection(int socket)
 	: m_socket_fd(socket)
@@ -19,7 +25,12 @@ HttpRequest ClientConnection::read_request() const
 	int n = 0;
 
 	memset(buffer, 0, BUFFER_SIZE);
-	while ((n = read(m_socket_fd, buffer, BUFFER_SIZE - 1)) > 0) {
+#ifdef _WIN32
+	n = recv(m_socket_fd, buffer, BUFFER_SIZE - 1, 0);
+#else
+	n = read(m_socket_fd, buffer, BUFFER_SIZE - 1);
+#endif
+	while (n > 0) {
 		if (buffer[n - 1] == '\n')
 			break;
 
@@ -35,7 +46,11 @@ bool ClientConnection::send(const HttpResponse& response) const
 		return false;
 
 	std::string result = response.to_string();
+#ifdef _WIN32
+	::send(m_socket_fd, result.c_str(), result.length(), 0);
+#else
 	write(m_socket_fd, result.c_str(), result.length());
+#endif
 
 	return true;
 }
@@ -43,5 +58,9 @@ bool ClientConnection::send(const HttpResponse& response) const
 void ClientConnection::close_connection()
 {
 	m_is_open = false;
+#ifdef _WIN32
+	closesocket(m_socket_fd);
+#else
 	close(m_socket_fd);
+#endif
 }
diff --git a/src/ServerConnection.cpp b/src/ServerConnection.cpp
index 64692b6..0a47dc3 100644
--- a/src/ServerConnection.cpp
+++ b/src/ServerConnection.cpp
@@ -1,13 +1,17 @@
 #include "ServerConnection.h"
 
-#include <arpa/inet.h>
-#include <csignal>
-#include <netdb.h>
-#include <sys/ioctl.h>
-#include <sys/socket.h>
-#include <sys/time.h>
 #include <sys/types.h>
-#include <unistd.h>
+
+#ifdef _WIN32
+	#include <winsock2.h>
+	#pragma comment(lib, "ws2_32.lib")
+#else
+	#include <arpa/inet.h>
+	#include <sys/ioctl.h>
+	#include <sys/socket.h>
+	#include <sys/time.h>
+	#include <unistd.h>
+#endif
 
 #include "ClientConnection.h"
 
@@ -19,14 +23,22 @@ static void error_and_die(const char* message)
 
 ServerConnection::ServerConnection(int port)
 {
+#ifdef _WIN32
+	WSADATA wsaData;
+	if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
+		error_and_die("Failed to initialize Winsock");
+#endif
+
 	sockaddr_in address {};
 	int socket_options = 1;
 
 	if ((m_socket_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
 		error_and_die("Failed to create socket");
 
+#ifndef _WIN32
 	if (setsockopt(m_socket_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, &socket_options, sizeof(socket_options)) != 0)
 		error_and_die("setsockopt");
+#endif
 
 	address.sin_family = AF_INET;
 	address.sin_addr.s_addr = htonl(INADDR_ANY);
diff --git a/src/main.cpp b/src/main.cpp
index c0c9bb3..4937f0d 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,11 +1,15 @@
+#ifndef _WIN32
 #include <getopt.h>
+#endif
 
 #include <filesystem>
 #include <fstream>
 #include <iostream>
 #include <sstream>
 
+#ifndef _WIN32
 #include "CGIScript.h"
+#endif
 #include "ClientConnection.h"
 #include "HttpRequest.h"
 #include "HttpResponse.h"
@@ -66,6 +70,7 @@ static HttpResponse serve_from_filesystem(const HttpRequest& request)
 	return response;
 }
 
+#ifndef _WIN32
 static HttpResponse serve_from_cgi(const std::string& script_path, const HttpRequest& request)
 {
 	HttpResponse response;
@@ -99,11 +104,14 @@ static HttpResponse serve_from_cgi(const std::string& script_path, const HttpReq
 	response.add_headers_and_content(script.read_output());
 	return response;
 }
+#endif
 
+#ifndef _WIN32
 static option long_options[] = {
 	{ "cgi", required_argument, nullptr, 'c' },
 	{ "port", required_argument, nullptr, 'p' },
 };
+#endif
 
 int main(int argc, char** argv)
 {
@@ -111,6 +119,8 @@ int main(int argc, char** argv)
 	bool in_cgi_mode = false;
 	std::string cgi_program_name;
 
+	// TODO: getopt.h is not available on Windows, so this part needs to be rewritten.
+#ifndef _WIN32
 	int c = 0;
 	int option_index = 0;
 	while ((c = getopt_long(argc, argv, "c:p:", long_options, &option_index)) != -1) {
@@ -135,6 +145,7 @@ int main(int argc, char** argv)
 	// script before attempting to start the server.
 	if (in_cgi_mode)
 		CGIScript::validate_path(cgi_program_name);
+#endif
 
 	ServerConnection server(port);
 	std::cout << "Serving a " << (in_cgi_mode ? "CGI script" : "directory") << " on port " << port << std::endl;
@@ -144,11 +155,14 @@ int main(int argc, char** argv)
 		HttpRequest request = client.read_request();
 		HttpResponse response;
 
+		// TODO: Support running CGI executables on Windows
+#ifndef _WIN32
 		if (in_cgi_mode) {
 			response = serve_from_cgi(cgi_program_name, request);
-		} else {
+		} else
+#endif
 			response = serve_from_filesystem(request);
-		}
+
 
 		client.send(response);
 		client.close_connection();