/* UDS server */

#include <errno.h>
#include <poll.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>
#include <sys/timerfd.h>
#include <sys/un.h>


// use abstract address
#define SOCKET "\0udsbench.socket"

static int die(const char *msg)
{
	if (errno)
		fprintf(stderr, "%s: error %d %m\n", msg, errno);
	else
		fprintf(stderr, "%s\n", msg);
	if (errno != ECONNRESET)
		exit(EXIT_FAILURE);
	return 0;
}

int main(int argc, char *argv[])
{
	struct sockaddr_un addr = {
		.sun_family = AF_UNIX,
		.sun_path = SOCKET,
	};
	int sock, client1, client2 = -1, rc, len;
	struct pollfd pfd[2];
	char buf[65536];
	unsigned long cnt = 0;
	bool single = false;

	if (argc != 2)
		die("usage: server {single|dbus}");
	if (!strcmp(argv[1], "single"))
		single = true;
	printf("running in %s mode\n", single ? "single" : "dbus");

	sock = socket(AF_UNIX, SOCK_SEQPACKET, 0);
	if (sock < 0)
		die("can't create socket");
	if (bind(sock, (struct sockaddr *) &addr, sizeof(addr)) < 0)
		die("can't bind address");
	if (listen(sock, 5) < 0)
		die("can't listen");

	printf("waiting for client 1\n");
	client1 = accept(sock, NULL, NULL);
	if (client1 < 0)
		die("accept");

	if (!single) {
		printf("waiting for client 2\n");
		client2 = accept(sock, NULL, NULL);
		if (client2 < 0)
			die("accept");

		write(client2, "\01", 1);
	}
	write(client1, "\0", 1);

	printf("enter event loop\n");
	pfd[0].fd = client1;
	pfd[1].fd = client2;
	pfd[0].events = pfd[1].events = POLLIN;
	for (;;) {
		rc = poll(pfd, single ? 1 : 2, -1);
		if (rc < 0)
			die("poll");
		if (pfd[0].revents & POLLIN) {
			len = read(client1, buf, sizeof(buf));
			if (len < 0) {
				die("read from client 1");
				break;
			}
			if (len == 0) {
				printf("client 1 EOF\n");
				break;
			}
			rc = write(single ? client1 : client2, buf, len);
			if (len != rc) {
				die("write to client 2");
				break;
			}
			cnt++;
		}
		if (pfd[1].revents & POLLIN) {
			len = read(client2, buf, sizeof(buf));
			if (len < 0) {
				die("read from client 2");
				break;
			}
			if (len == 0) {
				printf("client 2 EOF\n");
				break;
			}
			rc = write(client1, buf, len);
			if (len != rc) {
				die("write to client 1");
				break;
			}
			cnt++;
		}
	}
	printf("passed %lu messages\n", cnt);
	return EXIT_SUCCESS;
}