From 18dfa16d5522b5fdfbbeaa85b4a078b58d71977d Mon Sep 17 00:00:00 2001
From: caskd <caskd@420blaze.it>
Date: Mon, 10 Feb 2020 12:35:53 +0100
Subject: [PATCH] Add simple TCP server

---
 CMakeLists.txt  |  2 +-
 src/tcpserver.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 src/tcpserver.c

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a58241f..b51c668 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.0)
 
 project(programmingquest LANGUAGES C)
 
-SET(CHALLANGE format)
+SET(CHALLANGE tcpserver)
 
 add_executable(binary
 	src/${CHALLANGE}.c
diff --git a/src/tcpserver.c b/src/tcpserver.c
new file mode 100644
index 0000000..9add8f7
--- /dev/null
+++ b/src/tcpserver.c
@@ -0,0 +1,50 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <string.h>
+#include <errno.h>
+
+#define die(MSG) { fprintf(stderr, "%s %s. (%i)\n", MSG, strerror(errno), errno); return errno; }
+#define SVPORT 8081
+#define MAXCONN 2000000
+
+int main(int argc, char *argv[]) {
+	int			sock_fd;
+	struct sockaddr_in	serv_addr;
+	// Open socket and die if invalid file descriptor is returned
+	if ((sock_fd = socket(AF_INET,SOCK_STREAM, 0)) < 0)
+		die("Failed to open socket.");
+	// Set server address and port
+	memset(&serv_addr, 0, sizeof(serv_addr));
+	serv_addr.sin_family		= AF_INET;
+	serv_addr.sin_addr.s_addr	= htonl(INADDR_ANY);
+	serv_addr.sin_port		= htons(SVPORT);
+	// Bind to socket
+	if (bind(sock_fd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
+		die("Couldn't bind to socket.");
+	// Go in passive(LISTEN) mode
+	if ((listen(sock_fd, MAXCONN)) < 0)
+		die("Failed to listen on socket.");
+	printf("Now listening for connections.\n");
+	// Accept connections
+	char buffer[] = "Hello, fellow navigator!\n";
+	for (int conncount=0;; conncount++) {
+		int			conn_fd;
+		socklen_t		client_len;
+		struct sockaddr_in	client_addr;
+		client_len = sizeof(client_addr);
+		if ((conn_fd = accept(sock_fd, (struct sockaddr *) &client_addr, &client_len)) < 0)
+			die("Failed to accept connection.");
+		printf("Processed %i connections, last from %15s on port %5i.\r", conncount, inet_ntoa(client_addr.sin_addr), client_addr.sin_port);
+		setvbuf(stdout, NULL, _IONBF, 0);
+		if (send(conn_fd, buffer, strlen(buffer),0) < 0)
+			fprintf(stderr, "\nFailed to send data. %s.\n", strerror(errno));
+		if (close(conn_fd) < 0)
+			die("Failed to close connection.");
+	}
+	close(sock_fd);
+	return 1;
+}