/*
 * Copyright (C) 2011-2013 Michael Tuexen
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the project nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.	IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Usage: discard_server_upcall [local_encaps_port] [remote_encaps_port]
 */

#ifdef _WIN32
#define _CRT_SECURE_NO_WARNINGS
#include <io.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <sys/types.h>
#ifndef _WIN32
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#endif
#include <usrsctp.h>

#define BUFFERSIZE 10240
#define PORT 7

static void
handle_upcall(struct socket *sock, void *data, int flgs)
{
	char namebuf[INET6_ADDRSTRLEN];
	const char *name;
	uint16_t port;
	char *buf;
	int events;

	while ((events = usrsctp_get_events(sock)) && (events & SCTP_EVENT_READ)) {
		struct sctp_recvv_rn rn;
		ssize_t n;
		struct sockaddr_storage addr;
		buf = malloc(BUFFERSIZE);
		int flags = 0;
		socklen_t len = (socklen_t)sizeof(struct sockaddr_storage);
		unsigned int infotype = 0;
		socklen_t infolen = sizeof(struct sctp_recvv_rn);
		memset(&rn, 0, sizeof(struct sctp_recvv_rn));
		n = usrsctp_recvv(sock, buf, BUFFERSIZE, (struct sockaddr *) &addr, &len, (void *)&rn,
		             &infolen, &infotype, &flags);
		if (n < 0) {
			perror("usrsctp_recvv");
		}
		if (n == 0) {
			usrsctp_close(sock);
			return;
		}
		if (n > 0) {
			if (flags & MSG_NOTIFICATION) {
				printf("Notification of length %d received.\n", (int)n);
			} else {
#ifdef _WIN32
				_write(_fileno(stdout), buf, (unsigned int)n);
#else
				if (write(fileno(stdout), buf, n) < 0) {
					perror("write");
				}
#endif
				switch (addr.ss_family) {
#ifdef INET
					case AF_INET: {
						struct sockaddr_in addr4;
						memcpy(&addr4, (struct sockaddr_in *)&addr, sizeof(struct sockaddr_in));
						name = inet_ntop(AF_INET, &addr4.sin_addr, namebuf, INET_ADDRSTRLEN);
						port = ntohs(addr4.sin_port);
						break;
						}
#endif
#ifdef INET6
					case AF_INET6: {
						struct sockaddr_in6 addr6;
						memcpy(&addr6, (struct sockaddr_in6 *)&addr, sizeof(struct sockaddr_in6));
						name = inet_ntop(AF_INET6, &addr6.sin6_addr, namebuf, INET6_ADDRSTRLEN),
						port = ntohs(addr6.sin6_port);
						break;
						}
#endif
					default:
						name = NULL;
						port = 0;
						break;
					}

					if (name == NULL) {
						printf("inet_ntop failed\n");
						free(buf);
						return;
					}

				printf("Msg of length %d received from %s:%u on stream %d with SSN %u and TSN %u, PPID %u, context %u.\n",
				       (int)n,
				       namebuf,
				       port,
				       rn.recvv_rcvinfo.rcv_sid,
				       rn.recvv_rcvinfo.rcv_ssn,
				       rn.recvv_rcvinfo.rcv_tsn,
				       ntohl(rn.recvv_rcvinfo.rcv_ppid),
				       rn.recvv_rcvinfo.rcv_context);
				if (flags & MSG_EOR) {
					struct sctp_sndinfo snd_info;

					snd_info.snd_sid = rn.recvv_rcvinfo.rcv_sid;
					snd_info.snd_flags = 0;
					if (rn.recvv_rcvinfo.rcv_flags & SCTP_UNORDERED) {
						snd_info.snd_flags |= SCTP_UNORDERED;
					}
					snd_info.snd_ppid = rn.recvv_rcvinfo.rcv_ppid;
					snd_info.snd_context = 0;
					snd_info.snd_assoc_id = rn.recvv_rcvinfo.rcv_assoc_id;
					if (usrsctp_sendv(sock, buf, (size_t) n, NULL, 0, &snd_info, sizeof(struct sctp_sndinfo), SCTP_SENDV_SNDINFO, 0) < 0) {
						perror("sctp_sendv");
					}
				}
			}
		}
		free(buf);
	}
	return;
}

void
debug_printf(const char *format, ...)
{
	va_list ap;

	va_start(ap, format);
	vprintf(format, ap);
	va_end(ap);
}

int
main(int argc, char *argv[])
{
	struct socket *sock;
	struct sockaddr_in6 addr;
	struct sctp_udpencaps encaps;
	struct sctp_event event;
	uint16_t event_types[] = {SCTP_ASSOC_CHANGE,
	                          SCTP_PEER_ADDR_CHANGE,
	                          SCTP_REMOTE_ERROR,
	                          SCTP_SHUTDOWN_EVENT,
	                          SCTP_ADAPTATION_INDICATION,
	                          SCTP_PARTIAL_DELIVERY_EVENT};
	unsigned int i;
	struct sctp_assoc_value av;
	const int on = 1;

	if (argc > 1) {
		usrsctp_init(atoi(argv[1]), NULL, debug_printf);
	} else {
		usrsctp_init(9899, NULL, debug_printf);
	}
#ifdef SCTP_DEBUG
	usrsctp_sysctl_set_sctp_debug_on(SCTP_DEBUG_NONE);
#endif
	usrsctp_sysctl_set_sctp_blackhole(2);

	if ((sock = usrsctp_socket(AF_INET6, SOCK_SEQPACKET, IPPROTO_SCTP, NULL, NULL, 0, NULL)) == NULL) {
		perror("usrsctp_socket");
	}
	usrsctp_set_non_blocking(sock, 1);
	if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_I_WANT_MAPPED_V4_ADDR, (const void*)&on, (socklen_t)sizeof(int)) < 0) {
		perror("usrsctp_setsockopt SCTP_I_WANT_MAPPED_V4_ADDR");
	}
	memset(&av, 0, sizeof(struct sctp_assoc_value));
	av.assoc_id = SCTP_ALL_ASSOC;
	av.assoc_value = 47;

	if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_CONTEXT, (const void*)&av, (socklen_t)sizeof(struct sctp_assoc_value)) < 0) {
		perror("usrsctp_setsockopt SCTP_CONTEXT");
	}
	if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_RECVRCVINFO, &on, sizeof(int)) < 0) {
		perror("usrsctp_setsockopt SCTP_RECVRCVINFO");
	}
	if (argc > 2) {
		memset(&encaps, 0, sizeof(struct sctp_udpencaps));
		encaps.sue_address.ss_family = AF_INET6;
		encaps.sue_port = htons(atoi(argv[2]));
		if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_REMOTE_UDP_ENCAPS_PORT, (const void*)&encaps, (socklen_t)sizeof(struct sctp_udpencaps)) < 0) {
			perror("usrsctp_setsockopt SCTP_REMOTE_UDP_ENCAPS_PORT");
		}
	}
	memset(&event, 0, sizeof(event));
	event.se_assoc_id = SCTP_FUTURE_ASSOC;
	event.se_on = 1;
	for (i = 0; i < (unsigned int)(sizeof(event_types)/sizeof(uint16_t)); i++) {
		event.se_type = event_types[i];
		if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_EVENT, &event, sizeof(struct sctp_event)) < 0) {
			perror("usrsctp_setsockopt SCTP_EVENT");
		}
	}

	usrsctp_set_upcall(sock, handle_upcall, NULL);

	memset((void *)&addr, 0, sizeof(struct sockaddr_in6));
#ifdef HAVE_SIN6_LEN
	addr.sin6_len = sizeof(struct sockaddr_in6);
#endif
	addr.sin6_family = AF_INET6;
	addr.sin6_port = htons(PORT);
	addr.sin6_addr = in6addr_any;
	if (usrsctp_bind(sock, (struct sockaddr *)&addr, sizeof(struct sockaddr_in6)) < 0) {
		perror("usrsctp_bind");
	}
	if (usrsctp_listen(sock, 1) < 0) {
		perror("usrsctp_listen");
	}
	while (1) {
#ifdef _WIN32
		Sleep(1*1000);
#else
		sleep(1);
#endif
	}
	usrsctp_close(sock);
	while (usrsctp_finish() != 0) {
#ifdef _WIN32
		Sleep(1000);
#else
		sleep(1);
#endif
	}
	return (0);
}
