New upcall API

17 files changed, 1728 insertions, 7 deletions

diff --git a/programs/CMakeLists.txt b/programs/CMakeLists.txt
index ab4c7fda..e84dcaf9 100644
--- a/programs/CMakeLists.txt
+++ b/programs/CMakeLists.txt
@@ -83,6 +83,12 @@ set(check_programs
 	test_libmgmt.c
 	test_timer.c
 	tsctp.c
+	http_client_upcall.c
+        client_upcall.c
+        discard_server_upcall.c
+        echo_server_upcall.c
+        chargen_server_upcall.c
+        daytime_server_upcall.c
 )
 
 foreach (source_file ${check_programs})
diff --git a/programs/chargen_server_upcall.c b/programs/chargen_server_upcall.c
new file mode 100644
index 00000000..bb654111
--- /dev/null
+++ b/programs/chargen_server_upcall.c
@@ -0,0 +1,239 @@
+/*
+ * Copyright (C) 2012-2013 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: daytime_server [local_encaps_port] [remote_encaps_port]
+ */
+
+#ifdef _WIN32
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#ifndef _WIN32
+#include <unistd.h>
+#include <time.h>
+#include <sys/socket.h>
+#include <sys/errno.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#endif
+#include <usrsctp.h>
+
+#define BUFFERSIZE 10240
+#define PORT 19
+
+char buffer[95];
+int done = 0;
+int send_done = 0;
+
+static void
+initBuffer() {
+	int i, j;
+	for (i = 32, j = 0; i < 126; i++, j++) {
+		buffer[j] = i;
+	}
+}
+
+unsigned int signCounter = 0;
+static void
+handle_upcall(struct socket *sock, void *data, int flgs);
+
+static void
+handle_accept(struct socket *sock, void *data, int flags)
+{
+	struct socket *conn_sock;
+
+	if (((conn_sock = usrsctp_accept(sock, NULL, NULL)) == NULL)
+	    && (errno != EINPROGRESS)) {
+		perror("usrsctp_accept");
+		return;
+	}
+	done = 0;
+	printf("connection accepted from socket %p\n", (void *)conn_sock);
+	usrsctp_set_upcall(conn_sock, handle_upcall, NULL);
+}
+
+static void
+handle_upcall(struct socket *sock, void *data, int flgs)
+{
+	int events = usrsctp_get_events(sock);
+
+	if (events & SCTP_EVENT_READ && !send_done) {
+		char *buf;
+		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");
+			done = 1;
+			usrsctp_close(sock);
+			printf("client socket %p closed\n", (void *)sock);
+			sock = NULL;
+			return;
+		}
+		if (n == 0) {
+			done = 1;
+			usrsctp_close(sock);
+			printf("client socket %p closed\n", (void *)sock);
+			sock = NULL;
+			return;
+		}
+		if (n > 0) {
+			if (flags & MSG_NOTIFICATION) {
+				printf("Notification of length %d received.\n", (int)n);
+			} else {
+				printf("data of size %zd received\n", n);
+			}
+		}
+		free(buf);
+	}
+
+	if ((events & SCTP_EVENT_WRITE) && !done) {
+		struct sctp_sndinfo snd_info;
+		snd_info.snd_sid = 0;
+		snd_info.snd_flags = 0;
+		snd_info.snd_ppid = 0;
+		snd_info.snd_context = 0;
+		snd_info.snd_assoc_id = 0;
+		if (usrsctp_sendv(sock, buffer, strlen(buffer), NULL, 0, &snd_info, (socklen_t)sizeof(struct sctp_sndinfo), SCTP_SENDV_SNDINFO, 0) < 0) {
+			if (errno != EAGAIN) {
+				send_done = 1;
+				usrsctp_close(sock);
+				printf("client socket %p closed\n", (void *)sock);
+				return;
+			}
+		}
+	}
+
+	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 *listening_socket;
+	struct sockaddr_in6 addr;
+	struct sctp_udpencaps encaps;
+	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 ((listening_socket = usrsctp_socket(AF_INET6, SOCK_STREAM, IPPROTO_SCTP, NULL, NULL, 0, NULL)) == NULL) {
+		perror("usrsctp_socket");
+	}
+	usrsctp_set_non_blocking(listening_socket, 1);
+	if (usrsctp_setsockopt(listening_socket, 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(listening_socket, IPPROTO_SCTP, SCTP_CONTEXT, (const void*)&av, (socklen_t)sizeof(struct sctp_assoc_value)) < 0) {
+		perror("usrsctp_setsockopt SCTP_CONTEXT");
+	}
+	if (usrsctp_setsockopt(listening_socket, 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(listening_socket, 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");
+		}
+	}
+
+	initBuffer();
+
+	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(listening_socket, (struct sockaddr *)&addr, sizeof(struct sockaddr_in6)) < 0) {
+		perror("usrsctp_bind");
+	}
+	if (usrsctp_listen(listening_socket, 1) < 0) {
+		perror("usrsctp_listen");
+	}
+	usrsctp_set_upcall(listening_socket, handle_accept, NULL);
+
+	while (1) {
+#ifdef _WIN32
+		Sleep(1*1000);
+#else
+		sleep(1);
+#endif
+	}
+	usrsctp_close(listening_socket);
+	while (usrsctp_finish() != 0) {
+#ifdef _WIN32
+		Sleep(1000);
+#else
+		sleep(1);
+#endif
+	}
+	return (0);
+}
diff --git a/programs/client_upcall.c b/programs/client_upcall.c
new file mode 100644
index 00000000..2785cd04
--- /dev/null
+++ b/programs/client_upcall.c
@@ -0,0 +1,333 @@
+/*
+ * 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: client remote_addr remote_port [local_port] [local_encaps_port] [remote_encaps_port]
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+#include <sys/types.h>
+#ifndef _WIN32
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#else
+#include <io.h>
+#endif
+#include <usrsctp.h>
+#include <fcntl.h>
+
+#define BUFFERSIZE                 (1<<16)
+
+int done = 0, input_done = 0, connected = 0;
+
+#ifdef _WIN32
+typedef char* caddr_t;
+#endif
+
+int inputAvailable()
+{
+  struct timeval tv;
+  fd_set fds;
+  tv.tv_sec = 0;
+  tv.tv_usec = 0;
+  FD_ZERO(&fds);
+  FD_SET(STDIN_FILENO, &fds);
+  select(STDIN_FILENO+1, &fds, NULL, NULL, &tv);
+  return (FD_ISSET(0, &fds));
+}
+
+static void
+handle_upcall(struct socket *sock, void *arg, int flgs)
+{
+	int events = usrsctp_get_events(sock);
+
+	if (events & SCTP_EVENT_WRITE && !done && !connected) {
+		connected = 1;
+		printf("socket connected\n");
+		return;
+	}
+
+	while (events & SCTP_EVENT_READ && !done && connected) {
+		struct sctp_recvv_rn rn;
+		ssize_t n;
+		struct sockaddr_in addr;
+		char *buf = calloc(1, BUFFERSIZE);
+		int flags = 0;
+		socklen_t len = (socklen_t)sizeof(struct sockaddr_in);
+		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) {
+#ifdef _WIN32
+			_write(_fileno(stdout), buf, (unsigned int)n);
+#else
+			if (write(fileno(stdout), buf, n) < 0) {
+				perror("write");
+			}
+#endif
+		} else if (n == 0) {
+			done = 1;
+			input_done = 1;
+			free(buf);
+			break;
+		} else {
+			perror("\nusrsctp_recvv");
+			free (buf);
+			break;
+		}
+		free(buf);
+		events = usrsctp_get_events(sock);
+	}
+	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 *addr, *addrs;
+	struct sockaddr_in addr4;
+	struct sockaddr_in6 addr6;
+	struct sctp_udpencaps encaps;
+	struct sctpstat stat;
+	char buffer[200];
+	int i, n;
+
+	if (argc > 4) {
+		usrsctp_init(atoi(argv[4]), 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_STREAM, IPPROTO_SCTP, NULL, NULL, 0, NULL)) == NULL) {
+		perror("usrsctp_socket");
+		exit(1);
+	}
+
+	usrsctp_set_non_blocking(sock, 1);
+
+	if (argc > 3) {
+		memset((void *)&addr6, 0, sizeof(struct sockaddr_in6));
+#ifdef HAVE_SIN6_LEN
+		addr6.sin6_len = sizeof(struct sockaddr_in6);
+#endif
+		addr6.sin6_family = AF_INET6;
+		addr6.sin6_port = htons(atoi(argv[3]));
+		addr6.sin6_addr = in6addr_any;
+		if (usrsctp_bind(sock, (struct sockaddr *)&addr6, sizeof(struct sockaddr_in6)) < 0) {
+			perror("bind");
+			usrsctp_close(sock);
+			exit(1);
+		}
+	}
+	if (argc > 5) {
+		memset(&encaps, 0, sizeof(struct sctp_udpencaps));
+		encaps.sue_address.ss_family = AF_INET6;
+		encaps.sue_port = htons(atoi(argv[5]));
+		if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_REMOTE_UDP_ENCAPS_PORT, (const void*)&encaps, (socklen_t)sizeof(struct sctp_udpencaps)) < 0) {
+			perror("setsockopt");
+			usrsctp_close(sock);
+			exit(1);
+		}
+	}
+
+	memset((void *)&addr4, 0, sizeof(struct sockaddr_in));
+	memset((void *)&addr6, 0, sizeof(struct sockaddr_in6));
+#ifdef HAVE_SIN_LEN
+	addr4.sin_len = sizeof(struct sockaddr_in);
+#endif
+#ifdef HAVE_SIN6_LEN
+	addr6.sin6_len = sizeof(struct sockaddr_in6);
+#endif
+	addr4.sin_family = AF_INET;
+	addr6.sin6_family = AF_INET6;
+	addr4.sin_port = htons(atoi(argv[2]));
+	addr6.sin6_port = htons(atoi(argv[2]));
+	if (inet_pton(AF_INET6, argv[1], &addr6.sin6_addr) == 1) {
+		if (usrsctp_connect(sock, (struct sockaddr *)&addr6, sizeof(struct sockaddr_in6)) < 0) {
+			perror("usrsctp_connect");
+		}
+	} else if (inet_pton(AF_INET, argv[1], &addr4.sin_addr) == 1) {
+		if (usrsctp_connect(sock, (struct sockaddr *)&addr4, sizeof(struct sockaddr_in)) < 0) {
+			perror("usrsctp_connect");
+		}
+	} else {
+		printf("Illegal destination address.\n");
+	}
+
+	usrsctp_set_upcall(sock, handle_upcall, NULL);
+	if ((n = usrsctp_getladdrs(sock, 0, &addrs)) < 0) {
+		perror("usrsctp_getladdrs");
+	} else {
+		addr = addrs;
+		printf("Local addresses: ");
+		for (i = 0; i < n; i++) {
+			if (i > 0) {
+				printf("%s", ", ");
+			}
+			switch (addr->sa_family) {
+			case AF_INET:
+			{
+				struct sockaddr_in *sin;
+				char buf[INET_ADDRSTRLEN];
+				const char *name;
+
+				sin = (struct sockaddr_in *)addr;
+				name = inet_ntop(AF_INET, &sin->sin_addr, buf, INET_ADDRSTRLEN);
+				printf("%s", name);
+#ifndef HAVE_SA_LEN
+				addr = (struct sockaddr *)((caddr_t)addr + sizeof(struct sockaddr_in));
+#endif
+				break;
+			}
+			case AF_INET6:
+			{
+				struct sockaddr_in6 *sin6;
+				char buf[INET6_ADDRSTRLEN];
+				const char *name;
+
+				sin6 = (struct sockaddr_in6 *)addr;
+				name = inet_ntop(AF_INET6, &sin6->sin6_addr, buf, INET6_ADDRSTRLEN);
+				printf("%s", name);
+#ifndef HAVE_SA_LEN
+				addr = (struct sockaddr *)((caddr_t)addr + sizeof(struct sockaddr_in6));
+#endif
+				break;
+			}
+			default:
+				break;
+			}
+#ifdef HAVE_SA_LEN
+			addr = (struct sockaddr *)((caddr_t)addr + addr->sa_len);
+#endif
+		}
+		printf(".\n");
+		usrsctp_freeladdrs(addrs);
+	}
+	if ((n = usrsctp_getpaddrs(sock, 0, &addrs)) < 0) {
+		perror("usrsctp_getpaddrs");
+	} else {
+		addr = addrs;
+		printf("Peer addresses: ");
+		for (i = 0; i < n; i++) {
+			if (i > 0) {
+				printf("%s", ", ");
+			}
+			switch (addr->sa_family) {
+			case AF_INET:
+			{
+				struct sockaddr_in *sin;
+				char buf[INET_ADDRSTRLEN];
+				const char *name;
+
+				sin = (struct sockaddr_in *)addr;
+				name = inet_ntop(AF_INET, &sin->sin_addr, buf, INET_ADDRSTRLEN);
+				printf("%s", name);
+#ifndef HAVE_SA_LEN
+				addr = (struct sockaddr *)((caddr_t)addr + sizeof(struct sockaddr_in));
+#endif
+				break;
+			}
+			case AF_INET6:
+			{
+				struct sockaddr_in6 *sin6;
+				char buf[INET6_ADDRSTRLEN];
+				const char *name;
+
+				sin6 = (struct sockaddr_in6 *)addr;
+				name = inet_ntop(AF_INET6, &sin6->sin6_addr, buf, INET6_ADDRSTRLEN);
+				printf("%s", name);
+#ifndef HAVE_SA_LEN
+				addr = (struct sockaddr *)((caddr_t)addr + sizeof(struct sockaddr_in6));
+#endif
+				break;
+			}
+			default:
+				break;
+			}
+#ifdef HAVE_SA_LEN
+			addr = (struct sockaddr *)((caddr_t)addr + addr->sa_len);
+#endif
+		}
+		printf(".\n");
+		usrsctp_freepaddrs(addrs);
+	}
+	while (!done && !input_done) {
+		if (inputAvailable()) {
+			if (fgets(buffer, sizeof(buffer), stdin) != NULL) {
+				buffer[strlen(buffer)] = '\0';
+				usrsctp_sendv(sock, buffer, strlen(buffer), NULL, 0, NULL, 0, SCTP_SENDV_NOINFO, 0);
+			} else {
+				if (usrsctp_shutdown(sock, SHUT_WR) < 0) {
+					perror("usrsctp_shutdown");
+				}
+				break;
+			}
+		}
+	}
+	sleep(1);
+	usrsctp_close(sock);
+
+	usrsctp_get_stat(&stat);
+	printf("Number of packets (sent/received): (%u/%u).\n",
+	       stat.sctps_outpackets, stat.sctps_inpackets);
+	while (usrsctp_finish() != 0) {
+#ifdef _WIN32
+		Sleep(1000);
+#else
+		sleep(1);
+#endif
+	}
+	printf("Client finished\n");
+	return(0);
+}
diff --git a/programs/daytime_server_upcall.c b/programs/daytime_server_upcall.c
new file mode 100644
index 00000000..f2d786b4
--- /dev/null
+++ b/programs/daytime_server_upcall.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2012-2013 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: daytime_server [local_encaps_port] [remote_encaps_port]
+ */
+
+#ifdef _WIN32
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <time.h>
+#ifndef _WIN32
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#endif
+#include <usrsctp.h>
+
+#define DAYTIME_PPID 40
+#define PORT 13
+
+static void
+handle_accept(struct socket *sock, void *data, int flags)
+{
+	struct socket *conn_sock;
+	char buffer[80];
+	time_t now;
+	socklen_t addr_len = 0;
+	struct sctp_sndinfo sndinfo;
+
+	if (((conn_sock = usrsctp_accept(sock, NULL, &addr_len)) == NULL)
+	    && (errno != EINPROGRESS)) {
+		perror("usrsctp_accept");
+		return;
+	}
+	time(&now);
+#ifdef _WIN32
+		_snprintf(buffer, sizeof(buffer), "%s", ctime(&now));
+#else
+		snprintf(buffer, sizeof(buffer), "%s", ctime(&now));
+#endif
+		sndinfo.snd_sid = 0;
+		sndinfo.snd_flags = 0;
+		sndinfo.snd_ppid = htonl(DAYTIME_PPID);
+		sndinfo.snd_context = 0;
+		sndinfo.snd_assoc_id = 0;
+		usrsctp_sendv(conn_sock, buffer, strlen(buffer), NULL, 0, (void *)&sndinfo,
+		              (socklen_t)sizeof(struct sctp_sndinfo), SCTP_SENDV_SNDINFO, 0);
+		usrsctp_close(conn_sock);
+}
+
+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_in addr;
+	struct sctp_udpencaps encaps;
+
+	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_INET, SOCK_STREAM, IPPROTO_SCTP, NULL, NULL, 0, NULL)) == NULL) {
+		perror("usrsctp_socket");
+	}
+	usrsctp_set_non_blocking(sock, 1);
+	if (argc > 2) {
+		memset(&encaps, 0, sizeof(struct sctp_udpencaps));
+		encaps.sue_address.ss_family = AF_INET;
+		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("setsockopt");
+		}
+	}
+	memset((void *)&addr, 0, sizeof(struct sockaddr_in));
+#ifdef HAVE_SIN_LEN
+	addr.sin_len = sizeof(struct sockaddr_in);
+#endif
+	addr.sin_family = AF_INET;
+	addr.sin_port = htons(PORT);
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	if (usrsctp_bind(sock, (struct sockaddr *)&addr, sizeof(struct sockaddr_in)) < 0) {
+		perror("usrsctp_bind");
+	}
+	if (usrsctp_listen(sock, 1) < 0) {
+		perror("usrsctp_listen");
+	}
+
+	usrsctp_set_upcall(sock, handle_accept, NULL);
+
+	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);
+}
diff --git a/programs/discard_server_upcall.c b/programs/discard_server_upcall.c
new file mode 100644
index 00000000..c0c5b8f7
--- /dev/null
+++ b/programs/discard_server_upcall.c
@@ -0,0 +1,242 @@
+/*
+ * 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 [local_encaps_port] [remote_encaps_port]
+ */
+
+#ifdef _WIN32
+#define _CRT_SECURE_NO_WARNINGS
+#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 9
+
+
+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) {
+			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);
+			}
+		}
+		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);
+}
diff --git a/programs/echo_server.c b/programs/echo_server.c
index 64f12c56..313eda63 100644
--- a/programs/echo_server.c
+++ b/programs/echo_server.c
@@ -30,7 +30,7 @@
 
 /*
  * Usage: echo_server [local_encaps_port] [remote_encaps_port]
- * 
+ *
  * Example
  * Server: $ ./echo_server 11111 22222
  * Client: $ ./client 127.0.0.1 7 0 22222 11111
diff --git a/programs/echo_server_upcall.c b/programs/echo_server_upcall.c
new file mode 100644
index 00000000..1a39a019
--- /dev/null
+++ b/programs/echo_server_upcall.c
@@ -0,0 +1,258 @@
+/*
+ * 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 [local_encaps_port] [remote_encaps_port]
+ */
+
+#ifdef _WIN32
+#define _CRT_SECURE_NO_WARNINGS
+#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, 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);
+}
diff --git a/programs/http_client_upcall.c b/programs/http_client_upcall.c
new file mode 100644
index 00000000..c091ad62
--- /dev/null
+++ b/programs/http_client_upcall.c
@@ -0,0 +1,252 @@
+/*
+ * Copyright (C) 2016 Felix Weinrank
+ *
+ * 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: http_client_upcall remote_addr remote_port [local_port] [local_encaps_port] [remote_encaps_port] [uri]
+ */
+
+#ifdef _WIN32
+#define _CRT_SECURE_NO_WARNINGS
+#endif
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#ifndef _WIN32
+#include <unistd.h>
+#endif
+#include <sys/types.h>
+#ifndef _WIN32
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#else
+#include <io.h>
+#endif
+#include <usrsctp.h>
+
+int done = 0;
+int writePending = 1;
+
+static const char *request_prefix = "GET";
+static const char *request_postfix = "HTTP/1.0\r\nUser-agent: libusrsctp\r\nConnection: close\r\n\r\n";
+char request[512];
+
+#ifdef _WIN32
+typedef char* caddr_t;
+#endif
+
+#define BUFFERSIZE                 (1<<16)
+
+
+static void handle_upcall(struct socket *sock, void *arg, int flgs)
+{
+	int events = usrsctp_get_events(sock);
+	int bytesSent = 0;
+	char *buf;
+
+	if ((events & SCTP_EVENT_WRITE) && writePending) {
+		writePending = 0;
+		printf("\nHTTP request:\n%s\n", request);
+		printf("\nHTTP response:\n");
+
+		/* send GET request */
+		bytesSent = usrsctp_sendv(sock, request, strlen(request), NULL, 0, NULL, 0, SCTP_SENDV_NOINFO, 0);
+		if (bytesSent < 0) {
+			perror("usrsctp_sendv");
+			usrsctp_close(sock);
+		} else {
+			printf("%d bytes sent\n", bytesSent);
+		}
+	}
+
+	if ((events & SCTP_EVENT_READ) && !done) {
+		struct sctp_recvv_rn rn;
+		ssize_t n;
+		struct sockaddr_in addr;
+		buf = malloc(BUFFERSIZE);
+		int flags = 0;
+		socklen_t len = (socklen_t)sizeof(struct sockaddr_in);
+		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)
+			write(1, buf, n);
+		done = 1;
+		usrsctp_close(sock);
+		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_in addr4;
+	struct sockaddr_in6 addr6;
+	struct sctp_udpencaps encaps;
+	int result;
+
+    if (argc < 3) {
+        printf("Usage: http_client_upcall remote_addr remote_port [local_port] [local_encaps_port] [remote_encaps_port] [uri]\n");
+        return(EXIT_FAILURE);
+    }
+
+	result = 0;
+	if (argc > 4) {
+		usrsctp_init(atoi(argv[4]), NULL, debug_printf);
+	} else {
+		usrsctp_init(9899, NULL, debug_printf);
+	}
+
+#ifdef SCTP_DEBUG
+	usrsctp_sysctl_set_sctp_debug_on(SCTP_DEBUG_ALL);
+#endif
+
+	usrsctp_sysctl_set_sctp_blackhole(2);
+
+	if ((sock = usrsctp_socket(AF_INET6, SOCK_STREAM, IPPROTO_SCTP, NULL, NULL, 0, NULL)) == NULL) {
+		perror("usrsctp_socket");
+		result = 1;
+		goto out;
+	}
+
+	usrsctp_set_non_blocking(sock, 1);
+
+	if (argc > 3) {
+		memset((void *)&addr6, 0, sizeof(struct sockaddr_in6));
+#ifdef HAVE_SIN6_LEN
+		addr6.sin6_len = sizeof(struct sockaddr_in6);
+#endif
+		addr6.sin6_family = AF_INET6;
+		addr6.sin6_port = htons(atoi(argv[3]));
+		addr6.sin6_addr = in6addr_any;
+		if (usrsctp_bind(sock, (struct sockaddr *)&addr6, sizeof(struct sockaddr_in6)) < 0) {
+			perror("bind");
+			usrsctp_close(sock);
+			result = 2;
+			goto out;
+		}
+	}
+
+	if (argc > 5) {
+		memset(&encaps, 0, sizeof(struct sctp_udpencaps));
+		encaps.sue_address.ss_family = AF_INET6;
+		encaps.sue_port = htons(atoi(argv[5]));
+		if (usrsctp_setsockopt(sock, IPPROTO_SCTP, SCTP_REMOTE_UDP_ENCAPS_PORT, (const void *)&encaps, (socklen_t)sizeof(struct sctp_udpencaps)) < 0) {
+			perror("setsockopt");
+			usrsctp_close(sock);
+			result = 3;
+			goto out;
+		}
+	}
+
+	if (argc > 6) {
+#ifdef _WIN32
+		_snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix);
+#else
+		snprintf(request, sizeof(request), "%s %s %s", request_prefix, argv[6], request_postfix);
+#endif
+	} else {
+#ifdef _WIN32
+		_snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix);
+#else
+		snprintf(request, sizeof(request), "%s %s %s", request_prefix, "/", request_postfix);
+#endif
+	}
+
+	usrsctp_set_upcall(sock, handle_upcall, NULL);
+
+	memset((void *)&addr4, 0, sizeof(struct sockaddr_in));
+	memset((void *)&addr6, 0, sizeof(struct sockaddr_in6));
+#ifdef HAVE_SIN_LEN
+	addr4.sin_len = sizeof(struct sockaddr_in);
+#endif
+#ifdef HAVE_SIN6_LEN
+	addr6.sin6_len = sizeof(struct sockaddr_in6);
+#endif
+	addr4.sin_family = AF_INET;
+	addr6.sin6_family = AF_INET6;
+	addr4.sin_port = htons(atoi(argv[2]));
+	addr6.sin6_port = htons(atoi(argv[2]));
+	if (inet_pton(AF_INET6, argv[1], &addr6.sin6_addr) == 1) {
+		if (usrsctp_connect(sock, (struct sockaddr *)&addr6, sizeof(struct sockaddr_in6)) < 0) {
+			if (errno != EINPROGRESS) {
+				perror("usrsctp_connect");
+				usrsctp_close(sock);
+				result = 4;
+				goto out;
+			}
+		}
+	} else if (inet_pton(AF_INET, argv[1], &addr4.sin_addr) == 1) {
+		if (usrsctp_connect(sock, (struct sockaddr *)&addr4, sizeof(struct sockaddr_in)) < 0) {
+			if (errno != EINPROGRESS) {
+				perror("usrsctp_connect");
+				usrsctp_close(sock);
+				result = 5;
+				goto out;
+			}
+		}
+	} else {
+		printf("Illegal destination address\n");
+		usrsctp_close(sock);
+		result = 6;
+		goto out;
+	}
+	while (!done) {
+#ifdef _WIN32
+		Sleep(1*1000);
+#else
+		sleep(1);
+#endif
+	}
+out:
+	while (usrsctp_finish() != 0) {
+#ifdef _WIN32
+		Sleep(1000);
+#else
+		sleep(1);
+#endif
+	}
+	return (result);
+}
diff --git a/usrsctplib/netinet/sctp_callout.c b/usrsctplib/netinet/sctp_callout.c
index 30bfa0d5..2e8c630a 100755
--- a/usrsctplib/netinet/sctp_callout.c
+++ b/usrsctplib/netinet/sctp_callout.c
@@ -144,8 +144,8 @@ sctp_os_timer_stop(sctp_os_timer_t *c)
 	return (1);
 }
 
-static void
-sctp_handle_tick(int delta)
+void
+sctp_handle_tick(unsigned int delta)
 {
 	sctp_os_timer_t *c;
 	void (*c_func)(void *);
diff --git a/usrsctplib/netinet/sctp_callout.h b/usrsctplib/netinet/sctp_callout.h
index 765f966b..a4fe52f9 100755
--- a/usrsctplib/netinet/sctp_callout.h
+++ b/usrsctplib/netinet/sctp_callout.h
@@ -90,6 +90,7 @@ typedef struct sctp_callout sctp_os_timer_t;
 void sctp_os_timer_init(sctp_os_timer_t *tmr);
 void sctp_os_timer_start(sctp_os_timer_t *, int, void (*)(void *), void *);
 int sctp_os_timer_stop(sctp_os_timer_t *);
+void sctp_handle_tick(unsigned int);
 
 #define SCTP_OS_TIMER_INIT	sctp_os_timer_init
 #define SCTP_OS_TIMER_START	sctp_os_timer_start
diff --git a/usrsctplib/netinet/sctp_input.c b/usrsctplib/netinet/sctp_input.c
index 208da68f..29ca9dcb 100755
--- a/usrsctplib/netinet/sctp_input.c
+++ b/usrsctplib/netinet/sctp_input.c
@@ -5735,7 +5735,9 @@ sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int lengt
 	struct sctp_inpcb *inp = NULL, *inp_decr = NULL;
 	struct sctp_tcb *stcb = NULL;
 	struct sctp_nets *net = NULL;
-
+#if defined(__Userspace__)
+	struct socket *upcall_socket = NULL;
+#endif
 	SCTP_STAT_INCR(sctps_recvdatagrams);
 #ifdef SCTP_AUDITING_ENABLED
 	sctp_audit_log(0xE0, 1);
@@ -5884,6 +5886,20 @@ sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int lengt
 		}
 
 	}
+#if defined(__Userspace__)
+	if (stcb && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+		if (stcb->sctp_socket != NULL) {
+			if (stcb->sctp_socket->so_head != NULL) {
+				upcall_socket = stcb->sctp_socket->so_head;
+			} else {
+				upcall_socket = stcb->sctp_socket;
+			}
+			SOCK_LOCK(upcall_socket);
+			soref(upcall_socket);
+			SOCK_UNLOCK(upcall_socket);
+		}
+	}
+#endif
 	if (IS_SCTP_CONTROL(ch)) {
 		/* process the control portion of the SCTP packet */
 		/* sa_ignore NO_NULL_CHK */
@@ -5962,7 +5978,20 @@ sctp_common_input_processing(struct mbuf **mm, int iphlen, int offset, int lengt
 		 */
 		goto out;
 	}
-
+#if defined(__Userspace__)
+	if (stcb && upcall_socket == NULL && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+		if (stcb->sctp_socket != NULL) {
+			if (stcb->sctp_socket->so_head != NULL) {
+				upcall_socket = stcb->sctp_socket->so_head;
+			} else {
+				upcall_socket = stcb->sctp_socket;
+			}
+			SOCK_LOCK(upcall_socket);
+			soref(upcall_socket);
+			SOCK_UNLOCK(upcall_socket);
+		}
+	}
+#endif
 	/*
 	 * DATA chunk processing
 	 */
@@ -6101,6 +6130,18 @@ trigger_send:
 	if (stcb != NULL) {
 		SCTP_TCB_UNLOCK(stcb);
 	}
+#if defined(__Userspace__)
+	if (upcall_socket != NULL) {
+		if (upcall_socket->so_upcall != NULL) {
+		    if (soreadable(upcall_socket) || sowriteable(upcall_socket) || upcall_socket->so_error) {
+			    (*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
+			}
+		}
+		ACCEPT_LOCK();
+		SOCK_LOCK(upcall_socket);
+		sorele(upcall_socket);
+	}
+#endif
 	if (inp_decr != NULL) {
 		/* reduce ref-count */
 		SCTP_INP_WLOCK(inp_decr);
diff --git a/usrsctplib/netinet/sctp_usrreq.c b/usrsctplib/netinet/sctp_usrreq.c
index 03255714..6a4d7b50 100755
--- a/usrsctplib/netinet/sctp_usrreq.c
+++ b/usrsctplib/netinet/sctp_usrreq.c
@@ -420,6 +420,11 @@ sctp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 #if defined(__FreeBSD__)
 	struct ip *outer_ip;
 #endif
+
+#if defined(__Userspace__)
+	struct socket *upcall_socket = NULL;
+#endif
+
 	struct ip *inner_ip;
 	struct sctphdr *sh;
 	struct icmp *icmp;
@@ -528,7 +533,29 @@ sctp_ctlinput(int cmd, struct sockaddr *sa, void *vip)
 #else
 			            inner_ip->ip_len,
 #endif
-			            (uint32_t)ntohs(icmp->icmp_nextmtu));
+			            ntohs(icmp->icmp_nextmtu));
+
+#if defined(__Userspace__)
+			if (stcb && upcall_socket == NULL && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+				if (stcb->sctp_socket != NULL) {
+					upcall_socket = stcb->sctp_socket;
+					SOCK_LOCK(upcall_socket);
+					soref(upcall_socket);
+					SOCK_UNLOCK(upcall_socket);
+				}
+			}
+			if (upcall_socket != NULL) {
+				if (upcall_socket->so_upcall != NULL) {
+					if (upcall_socket->so_error) {
+						(*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
+					}
+				}
+				ACCEPT_LOCK();
+				SOCK_LOCK(upcall_socket);
+				sorele(upcall_socket);
+			}
+#endif
+
 		} else {
 #if defined(__FreeBSD__) && __FreeBSD_version < 500000
 			/*
diff --git a/usrsctplib/netinet/sctputil.c b/usrsctplib/netinet/sctputil.c
index 2e404eb7..9665f12f 100755
--- a/usrsctplib/netinet/sctputil.c
+++ b/usrsctplib/netinet/sctputil.c
@@ -1609,6 +1609,9 @@ sctp_timeout_handler(void *t)
 	int did_output;
 	int type;
 
+#if defined(__Userspace__)
+	struct socket *upcall_socket = NULL;
+#endif
 	tmr = (struct sctp_timer *)t;
 	inp = (struct sctp_inpcb *)tmr->ep;
 	stcb = (struct sctp_tcb *)tmr->tcb;
@@ -1744,6 +1747,16 @@ sctp_timeout_handler(void *t)
 	}
 	SCTP_OS_TIMER_DEACTIVATE(&tmr->timer);
 
+#if defined(__Userspace__)
+	if (stcb && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+		if (stcb->sctp_socket != NULL) {
+			upcall_socket = stcb->sctp_socket;
+			SOCK_LOCK(upcall_socket);
+			soref(upcall_socket);
+			SOCK_UNLOCK(upcall_socket);
+		}
+	}
+#endif
 	/* call the handler for the appropriate timer type */
 	switch (type) {
 	case SCTP_TIMER_TYPE_ADDR_WQ:
@@ -2045,6 +2058,18 @@ get_out:
 	}
 
 out_decr:
+#if defined(__Userspace__)
+	if (upcall_socket != NULL) {
+		if (upcall_socket->so_upcall != NULL) {
+		    if (upcall_socket->so_error) {
+			    (*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
+			}
+		}
+		ACCEPT_LOCK();
+		SOCK_LOCK(upcall_socket);
+		sorele(upcall_socket);
+	}
+#endif
 	if (inp) {
 		SCTP_INP_DECR_REF(inp);
 	}
@@ -7753,6 +7778,9 @@ sctp_recv_icmp_tunneled_packet(int cmd, struct sockaddr *sa, void *vip, void *ct
 	struct sockaddr_in src, dst;
 	uint8_t type, code;
 
+#if defined(__Userspace__)
+	struct socket *upcall_socket = NULL;
+#endif
 	inner_ip = (struct ip *)vip;
 	icmp = (struct icmp *)((caddr_t)inner_ip -
 	    (sizeof(struct icmp) - sizeof(struct ip)));
@@ -7837,7 +7865,27 @@ sctp_recv_icmp_tunneled_packet(int cmd, struct sockaddr *sa, void *vip, void *ct
 		}
 		sctp_notify(inp, stcb, net, type, code,
 		            ntohs(inner_ip->ip_len),
-		            (uint32_t)ntohs(icmp->icmp_nextmtu));
+		            ntohs(icmp->icmp_nextmtu));
+#if defined(__Userspace__)
+			if (stcb && upcall_socket == NULL && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+				if (stcb->sctp_socket != NULL) {
+					upcall_socket = stcb->sctp_socket;
+					SOCK_LOCK(upcall_socket);
+					soref(upcall_socket);
+					SOCK_UNLOCK(upcall_socket);
+				}
+			}
+			if (upcall_socket != NULL) {
+				if (upcall_socket->so_upcall != NULL) {
+					if (upcall_socket->so_error) {
+						(*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
+					}
+				}
+				ACCEPT_LOCK();
+				SOCK_LOCK(upcall_socket);
+				sorele(upcall_socket);
+			}
+#endif
 	} else {
 #if defined(__FreeBSD__) && __FreeBSD_version < 500000
 		/*
@@ -7875,6 +7923,9 @@ sctp_recv_icmp6_tunneled_packet(int cmd, struct sockaddr *sa, void *d, void *ctx
 	struct udphdr udp;
 	struct sockaddr_in6 src, dst;
 	uint8_t type, code;
+#if defined(__Userspace__)
+	struct socket *upcall_socket = NULL;
+#endif
 
 	ip6cp = (struct ip6ctlparam *)d;
 	/*
@@ -8003,6 +8054,26 @@ sctp_recv_icmp6_tunneled_packet(int cmd, struct sockaddr *sa, void *d, void *ctx
 		}
 		sctp6_notify(inp, stcb, net, type, code,
 			     ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
+#if defined(__Userspace__)
+			if (stcb && upcall_socket == NULL && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+				if (stcb->sctp_socket != NULL) {
+					upcall_socket = stcb->sctp_socket;
+					SOCK_LOCK(upcall_socket);
+					soref(upcall_socket);
+					SOCK_UNLOCK(upcall_socket);
+				}
+			}
+			if (upcall_socket != NULL) {
+				if (upcall_socket->so_upcall != NULL) {
+					if (upcall_socket->so_error) {
+						(*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
+					}
+				}
+				ACCEPT_LOCK();
+				SOCK_LOCK(upcall_socket);
+				sorele(upcall_socket);
+			}
+#endif
 	} else {
 #if defined(__FreeBSD__) && __FreeBSD_version < 500000
 		if (PRC_IS_REDIRECT(cmd) && (inp != NULL)) {
diff --git a/usrsctplib/netinet6/sctp6_usrreq.c b/usrsctplib/netinet6/sctp6_usrreq.c
index 897b4da5..0ae9bdf5 100644
--- a/usrsctplib/netinet6/sctp6_usrreq.c
+++ b/usrsctplib/netinet6/sctp6_usrreq.c
@@ -434,6 +434,9 @@ sctp6_ctlinput(int cmd, struct sockaddr *pktdst, void *d)
 	struct sctphdr sh;
 	struct sockaddr_in6 src, dst;
 
+#if defined(__Userspace__)
+	struct socket *upcall_socket = NULL;
+#endif
 #ifdef HAVE_SA_LEN
 	if (pktdst->sa_family != AF_INET6 ||
 	    pktdst->sa_len != sizeof(struct sockaddr_in6)) {
@@ -567,6 +570,26 @@ sctp6_ctlinput(int cmd, struct sockaddr *pktdst, void *d)
 			             ip6cp->ip6c_icmp6->icmp6_type,
 			             ip6cp->ip6c_icmp6->icmp6_code,
 			             ntohl(ip6cp->ip6c_icmp6->icmp6_mtu));
+#if defined(__Userspace__)
+			if (stcb && upcall_socket == NULL && !(stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE)) {
+				if (stcb->sctp_socket != NULL) {
+					upcall_socket = stcb->sctp_socket;
+					SOCK_LOCK(upcall_socket);
+					soref(upcall_socket);
+					SOCK_UNLOCK(upcall_socket);
+				}
+			}
+			if (upcall_socket != NULL) {
+				if (upcall_socket->so_upcall != NULL) {
+					if (upcall_socket->so_error) {
+						(*upcall_socket->so_upcall)(upcall_socket, upcall_socket->so_upcallarg, M_NOWAIT);
+					}
+				}
+				ACCEPT_LOCK();
+				SOCK_LOCK(upcall_socket);
+				sorele(upcall_socket);
+			}
+#endif
 		} else {
 #if defined(__FreeBSD__) && __FreeBSD_version < 500000
 			if (PRC_IS_REDIRECT(cmd) && (inp != NULL)) {
diff --git a/usrsctplib/user_socket.c b/usrsctplib/user_socket.c
index 7261c9a9..4cd6e5eb 100755
--- a/usrsctplib/user_socket.c
+++ b/usrsctplib/user_socket.c
@@ -3500,6 +3500,57 @@ usrsctp_conninput(void *addr, const void *buffer, size_t length, uint8_t ecn_bit
 	return;
 }
 
+void usrsctp_handle_timers(unsigned int delta)
+{
+	sctp_handle_tick(MSEC_TO_TICKS(delta));
+}
+
+int
+usrsctp_get_events(struct socket *so)
+{
+	int events = 0;
+
+	if (so == NULL) {
+		errno = EBADF;
+		return -1;
+	}
+
+	if (soreadable(so)) {
+		events |= SCTP_EVENT_READ;
+	}
+	if (sowriteable(so)) {
+		events |= SCTP_EVENT_WRITE;
+	}
+	if (so->so_error) {
+		events |= SCTP_EVENT_ERROR;
+	}
+	return events;
+}
+
+int usrsctp_get_error(struct socket *so)
+{
+    if (so->so_error)
+        return so->so_error;
+    return -1;
+}
+
+int
+usrsctp_set_upcall(struct socket *so, void (*upcall)(struct socket *, void *, int), void *arg)
+{
+	if (so == NULL) {
+		errno = EBADF;
+		return (-1);
+	}
+
+	SOCK_LOCK(so);
+	so->so_upcall = upcall;
+	so->so_upcallarg = arg;
+	so->so_snd.sb_flags |= SB_UPCALL;
+	so->so_rcv.sb_flags |= SB_UPCALL;
+	SOCK_UNLOCK(so);
+
+	return (0);
+}
 
 #define USRSCTP_SYSCTL_SET_DEF(__field) \
 void usrsctp_sysctl_set_ ## __field(uint32_t value) { \
diff --git a/usrsctplib/user_socketvar.h b/usrsctplib/user_socketvar.h
index ffc8270e..e00c4c7a 100755
--- a/usrsctplib/user_socketvar.h
+++ b/usrsctplib/user_socketvar.h
@@ -365,6 +365,13 @@ extern userland_cond_t accept_cond;
 #define	SQ_COMP			0x1000	/* unaccepted, complete connection */
 
 /*
+ * Socket event flags
+ */
+#define SCTP_EVENT_READ		0x0001	/* socket is readable */
+#define SCTP_EVENT_WRITE	0x0002	/* socket is writeable */
+#define SCTP_EVENT_ERROR	0x0004	/* socket has an error state */
+
+/*
  * Externalized form of struct socket used by the sysctl(3) interface.
  */
 struct xsocket {
@@ -719,6 +726,7 @@ void	soisconnected(struct socket *so);
 struct socket * sonewconn(struct socket *head, int connstatus);
 void	socantrcvmore(struct socket *so);
 void	socantsendmore(struct socket *so);
+void	sofree(struct socket *so);
 
 
 
diff --git a/usrsctplib/usrsctp.h b/usrsctplib/usrsctp.h
index 16159f69..20e8c006 100644
--- a/usrsctplib/usrsctp.h
+++ b/usrsctplib/usrsctp.h
@@ -141,6 +141,10 @@ union sctp_sockstore {
 #define SCTP_CURRENT_ASSOC 1
 #define SCTP_ALL_ASSOC     2
 
+#define SCTP_EVENT_READ    0x0001
+#define SCTP_EVENT_WRITE   0x0002
+#define SCTP_EVENT_ERROR   0x0004
+
 /***  Structures and definitions to use the socket API  ***/
 
 #define SCTP_ALIGN_RESV_PAD 92
@@ -1008,6 +1012,15 @@ usrsctp_deregister_address(void *);
 int
 usrsctp_set_ulpinfo(struct socket *, void *);
 
+int
+usrsctp_set_upcall(struct socket *so,
+                   void (*upcall)(struct socket *, void *, int),
+                   void *arg);
+
+int
+usrsctp_get_events(struct socket *so);
+
+
 #define SCTP_DUMP_OUTBOUND 1
 #define SCTP_DUMP_INBOUND  0