// SPDX-License-Identifier: MPL-2.0

#include <stdio.h>
#include <stdlib.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <unistd.h>

int main()
{
	int sockfd;
	int option;

	// Create tcp socket
	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	if (sockfd < 0) {
		perror("Socket creation failed");
		exit(EXIT_FAILURE);
	}

	// Get send buffer size
	int sendbuf;
	socklen_t sendbuf_len = sizeof(sendbuf);
	if (getsockopt(sockfd, SOL_SOCKET, SO_SNDBUF, &sendbuf, &sendbuf_len) <
		    0 ||
	    sendbuf_len != sizeof(sendbuf)) {
		perror("Getting SO_SNDBUF option failed");
		exit(EXIT_FAILURE);
	}

	int error;
	socklen_t error_len = sizeof(error);
	if (getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &error, &error_len) < 0 ||
	    error_len != sizeof(error) || error != 0) {
		perror("Getting SO_SNDBUF option failed");
		exit(EXIT_FAILURE);
	}

	// Disable Nagle algorithm
	option = 1;
	if (setsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, &option,
		       sizeof(option)) < 0) {
		perror("Setting TCP_NODELAY option failed");
		exit(EXIT_FAILURE);
	}

	// Enable reuse addr
	option = 1;
	if (setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &option,
		       sizeof(option)) < 0) {
		perror("Setting SO_REUSEADDR option failed");
		exit(EXIT_FAILURE);
	}

	// Print new value
	int nagle;
	socklen_t nagle_len = sizeof(nagle);
	if (getsockopt(sockfd, IPPROTO_TCP, TCP_NODELAY, &nagle, &nagle_len) <
		    0 ||
	    nagle != 1) {
		perror("Getting TCP_NODELAY option failed.");
		exit(EXIT_FAILURE);
	}

	int reuseaddr;
	socklen_t reuseaddr_len = sizeof(reuseaddr);
	if (getsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR, &reuseaddr,
		       &reuseaddr_len) < 0 ||
	    reuseaddr != 1) {
		perror("Getting SO_REUSEADDR option failed.");
		exit(EXIT_FAILURE);
	}

	// Close socket
	close(sockfd);

	return 0;
}