Re-work of thread model

src/Sockets.cpp

@@ -0,0 +1,817 @@
+/*
+ * ZeroTier SDK - Network Virtualization Everywhere
+ * Copyright (C) 2011-2019  ZeroTier, Inc.  https://www.zerotier.com/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * --
+ *
+ * You can be released from the requirements of the license by purchasing
+ * a commercial license. Buying such a license is mandatory as soon as you
+ * develop commercial closed-source software that incorporates or links
+ * directly against ZeroTier software without disclosing the source code
+ * of your own application.
+ */
+
+/**
+ * @file
+ *
+ * ZeroTier Socket API
+ */
+
+#include <string.h>
+
+#include "lwip/sockets.h"
+#include "lwip/def.h"
+
+#include "libzt.h"
+#include "Options.h"
+#include "Debug.hpp"
+#include "Controls.hpp"
+
+#ifdef SDK_JNI
+	#include <jni.h>
+#ifndef _MSC_VER
+	//#include <sys/socket.h>
+	//#include <sys/types.h>
+	//#include <sys/select.h>
+	//#include <sys/ioctl.h>
+#endif
+#endif
+
+namespace ZeroTier {
+
+//////////////////////////////////////////////////////////////////////////////
+// Socket API                                                               //
+//////////////////////////////////////////////////////////////////////////////
+
+extern bool _run_service;
+extern bool _run_lwip_tcpip;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef SDK_JNI
+void ss2zta(JNIEnv *env, struct sockaddr_storage *ss, jobject addr);
+void zta2ss(JNIEnv *env, struct sockaddr_storage *ss, jobject addr);
+void ztfdset2fdset(JNIEnv *env, int nfds, jobject src_ztfd_set, fd_set *dest_fd_set);
+void fdset2ztfdset(JNIEnv *env, int nfds, fd_set *src_fd_set, jobject dest_ztfd_set);
+#endif
+
+// Copied from lwip/src/include/sockets.h and renamed to prevent a name collision
+// with system definitions
+struct lwip_sockaddr {
+  u8_t        sa_len;
+  sa_family_t sa_family;
+  char        sa_data[14];
+};
+
+//////////////////////////////////////////////////////////////////////////////
+// ZeroTier Socket API                                                      //
+//////////////////////////////////////////////////////////////////////////////
+
+extern int zts_errno;
+
+int zts_socket(int socket_family, int socket_type, int protocol)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_socket(socket_family, socket_type, protocol);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_socket(
+	JNIEnv *env, jobject thisObj, jint family, jint type, jint protocol)
+{
+	zts_err_t retval = zts_socket(family, type, protocol);
+	return retval > -1 ? retval : -(zts_errno); // Encode lwip errno in return value for JNI functions only
+}
+#endif
+
+int zts_connect(int fd, const struct sockaddr *addr, socklen_t addrlen)
+{
+	if (!addr) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	if (addrlen > (int)sizeof(struct sockaddr_storage) || addrlen < (int)sizeof(struct sockaddr_in)) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_connect(fd, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_connect(
+	JNIEnv *env, jobject thisObj, jint fd, jobject addr)
+{
+	struct sockaddr_storage ss;
+	zta2ss(env, &ss, addr);
+	socklen_t addrlen = ss.ss_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
+	zts_err_t retval = zts_connect(fd, (struct sockaddr *)&ss, addrlen);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_bind(int fd, const struct sockaddr *addr, socklen_t addrlen)
+{
+	if (!addr) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	if (addrlen > (int)sizeof(struct sockaddr_storage) || addrlen < (int)sizeof(struct sockaddr_in)) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_bind(fd, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_bind(
+	JNIEnv *env, jobject thisObj, jint fd, jobject addr)
+{
+	struct sockaddr_storage ss;
+	zta2ss(env, &ss, addr);
+	socklen_t addrlen = ss.ss_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
+	zts_err_t retval = zts_bind(fd, (struct sockaddr*)&ss, addrlen);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_listen(int fd, int backlog)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_listen(fd, backlog);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_listen(
+	JNIEnv *env, jobject thisObj, jint fd, int backlog)
+{
+	zts_err_t retval = zts_listen(fd, backlog);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_accept(int fd, struct sockaddr *addr, socklen_t *addrlen)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_accept(fd, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_accept(
+	JNIEnv *env, jobject thisObj, jint fd, jobject addr, jint port)
+{
+	struct sockaddr_storage ss;
+	socklen_t addrlen = sizeof(struct sockaddr_storage);
+	zts_err_t retval =zts_accept(fd, (struct sockaddr *)&ss, &addrlen);
+	ss2zta(env, &ss, addr);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+#if defined(__linux__)
+int zts_accept4(int fd, struct sockaddr *addr, socklen_t *addrlen, int flags)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_INVALID_OP : ZTS_ERR_INVALID_OP;
+}
+#endif
+#ifdef SDK_JNI
+#if defined(__linux__)
+ JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_accept4(
+	JNIEnv *env, jobject thisObj, jint fd, jobject addr, jint port, jint flags)
+ {
+	struct sockaddr_storage ss;
+	socklen_t addrlen = sizeof(struct sockaddr_storage);
+	zts_err_t retval = zts_accept4(fd, (struct sockaddr *)&ss, &addrlen, flags);
+	ss2zta(env, &ss, addr);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+#endif
+
+int zts_setsockopt(int fd, int level, int optname, const void *optval, socklen_t optlen)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_setsockopt(fd, level, optname, optval, optlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_setsockopt(
+	JNIEnv *env, jobject thisObj, jint fd, jint level, jint optname, jobject optval)
+{
+	jclass c = (*env).GetObjectClass(optval);
+	if (!c) {
+		return ZTS_ERR_INVALID_OP;
+	}
+	int optval_int = -1;
+
+	if (optname == ZTS_SO_BROADCAST
+		|| optname == ZTS_SO_KEEPALIVE
+		|| optname == ZTS_SO_REUSEADDR	
+		|| optname == ZTS_SO_REUSEPORT
+		|| optname == ZTS_TCP_NODELAY)
+	{
+		jfieldID fid = (*env).GetFieldID(c, "booleanValue", "Z");
+		optval_int = (int)(*env).GetBooleanField(optval, fid);
+	}
+	if (optname == ZTS_IP_TTL
+		|| optname == ZTS_SO_RCVTIMEO
+		|| optname == ZTS_IP_TOS
+		|| optname == ZTS_SO_LINGER
+		|| optname == ZTS_SO_RCVBUF
+		|| optname == ZTS_SO_SNDBUF)
+	{
+		jfieldID fid = (*env).GetFieldID(c, "integerValue", "I");
+		optval_int = (*env).GetIntField(optval, fid);
+	}
+
+	zts_err_t retval = ZTS_ERR_OK;
+
+	if (optname == ZTS_SO_RCVTIMEO) {
+		struct timeval tv;
+		// Convert milliseconds from setSoTimeout() call to seconds and microseconds
+		tv.tv_usec = optval_int * 1000;
+		tv.tv_sec = optval_int / 1000000;
+		retval = zts_setsockopt(fd, level, optname, &tv, sizeof(tv));
+	}
+	else {
+		retval = zts_setsockopt(fd, level, optname, &optval_int, sizeof(optval_int));
+	}
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_getsockopt(int fd, int level, int optname, void *optval, socklen_t *optlen)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_getsockopt(fd, level, optname, optval, optlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_getsockopt(
+	JNIEnv *env, jobject thisObj, jint fd, jint level, jint optname, jobject optval)
+{
+	jclass c = (*env).GetObjectClass(optval);
+	if (!c) {
+		return ZTS_ERR_INVALID_OP;
+	}
+	int optval_int = 0;
+	int optlen; // Intentionally not used
+
+	zts_err_t retval;
+
+	if (optname == ZTS_SO_RCVTIMEO) {
+		struct timeval tv;
+		optlen = sizeof(tv);
+		retval = zts_getsockopt(fd, level, optname, &tv, &optlen);
+		// Convert seconds and microseconds back to milliseconds
+		optval_int = (tv.tv_sec * 1000) + (tv.tv_usec / 1000);
+	}
+	else {
+		retval = zts_getsockopt(fd, level, optname, &optval_int, &optlen);
+	}
+	
+	if (optname == ZTS_SO_BROADCAST
+		|| optname == ZTS_SO_KEEPALIVE
+		|| optname == ZTS_SO_REUSEADDR	
+		|| optname == ZTS_SO_REUSEPORT
+		|| optname == ZTS_TCP_NODELAY)
+	{
+		jfieldID fid = (*env).GetFieldID(c, "isBoolean", "Z");
+		(*env).SetBooleanField(optval, fid, true);
+		fid = (*env).GetFieldID(c, "booleanValue", "Z");
+		(*env).SetBooleanField(optval, fid, (bool)optval_int);
+	}
+	if (optname == ZTS_IP_TTL
+		|| optname == ZTS_SO_RCVTIMEO	
+		|| optname == ZTS_IP_TOS
+		|| optname == ZTS_SO_LINGER
+		|| optname == ZTS_SO_RCVBUF
+		|| optname == ZTS_SO_SNDBUF)
+	{
+		jfieldID fid = (*env).GetFieldID(c, "isInteger", "Z");
+		(*env).SetBooleanField(optval, fid, true);
+		fid = (*env).GetFieldID(c, "integerValue", "I");
+		(*env).SetIntField(optval, fid, optval_int);
+	}
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_getsockname(int fd, struct sockaddr *addr, socklen_t *addrlen)
+{
+	if (!addr) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	if (*addrlen > (int)sizeof(struct sockaddr_storage) || *addrlen < (int)sizeof(struct sockaddr_in)) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_getsockname(fd, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jboolean JNICALL Java_com_zerotier_libzt_ZeroTier_getsockname(JNIEnv *env, jobject thisObj,
+	jint fd, jobject addr)
+{
+	struct sockaddr_storage ss;
+	socklen_t addrlen = sizeof(struct sockaddr_storage);
+	zts_err_t retval =zts_getsockname(fd, (struct sockaddr *)&ss, &addrlen);
+	ss2zta(env, &ss, addr);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_getpeername(int fd, struct sockaddr *addr, socklen_t *addrlen)
+{
+	if (!addr) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	if (*addrlen > (int)sizeof(struct sockaddr_storage) || *addrlen < (int)sizeof(struct sockaddr_in)) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_getpeername(fd, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_getpeername(JNIEnv *env, jobject thisObj,
+	jint fd, jobject addr)
+{
+	struct sockaddr_storage ss;
+	zts_err_t retval = zts_getpeername(fd, (struct sockaddr *)&ss, (socklen_t *)sizeof(struct sockaddr_storage));
+	ss2zta(env, &ss, addr);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_gethostname(char *name, size_t len)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_INVALID_OP : ZTS_ERR_INVALID_OP; // TODO
+}
+#ifdef SDK_JNI
+#endif
+
+int zts_sethostname(const char *name, size_t len)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_INVALID_OP : ZTS_ERR_INVALID_OP; // TODO
+}
+#ifdef SDK_JNI
+#endif
+
+/*
+struct hostent *zts_gethostbyname(const char *name)
+{
+	return (struct hostent *)((!_run_service || !_run_lwip_tcpip) ? NULL : NULL);
+	// TODO: Test thread safety
+	char buf[256];
+	int buflen = 256;
+	int h_err = 0;
+	struct hostent hret;
+	struct hostent **result = NULL;
+	int err = 0;
+	if ((err = lwip_gethostbyname_r(name, &hret, buf, buflen, result, &h_err)) != 0) {
+		DEBUG_ERROR("err = %d", err);
+		DEBUG_ERROR("h_err = %d", h_err);
+		errno = h_err;
+		return NULL; // failure
+	}
+	return *result;
+	
+	return lwip_gethostbyname(name);
+}
+#ifdef SDK_JNI
+#endif
+*/
+
+int zts_close(int fd)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_close(fd);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_close(
+	JNIEnv *env, jobject thisObj, jint fd)
+{
+	return zts_close(fd);
+}
+#endif
+
+int zts_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
+	struct timeval *timeout)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_select(nfds, readfds, writefds, exceptfds, timeout);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_select(JNIEnv *env, jobject thisObj,
+	jint nfds, jobject readfds, jobject writefds, jobject exceptfds, jint timeout_sec, jint timeout_usec)
+{
+	struct timeval _timeout;
+	_timeout.tv_sec  = timeout_sec;
+	_timeout.tv_usec = timeout_usec;
+	fd_set _readfds, _writefds, _exceptfds;   		
+	fd_set *r = NULL;
+	fd_set *w = NULL;
+	fd_set *e = NULL;
+	if (readfds) {
+		r = &_readfds;
+		ztfdset2fdset(env, nfds, readfds, &_readfds);
+	}
+	if (writefds) {
+		w = &_writefds;
+		ztfdset2fdset(env, nfds, writefds, &_writefds);
+	}
+	if (exceptfds) {
+		e = &_exceptfds;
+		ztfdset2fdset(env, nfds, exceptfds, &_exceptfds);
+	}
+	zts_err_t retval = zts_select(nfds, r, w, e, &_timeout);
+	if (readfds) {
+		fdset2ztfdset(env, nfds, &_readfds, readfds);
+	}
+	if (writefds) {
+		fdset2ztfdset(env, nfds, &_writefds, writefds);
+	}
+	if (exceptfds) {
+		fdset2ztfdset(env, nfds, &_exceptfds, exceptfds);
+	}	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_fcntl(int fd, int cmd, int flags)
+{
+	// translation from platform flag values to stack flag values
+	int translated_flags = 0;
+#if defined(__linux__)
+	if (flags == 2048) {
+		translated_flags = 1;
+	}
+#endif
+#if defined(__APPLE__)
+	if (flags == 4) {
+		translated_flags = 1;
+	}
+#endif
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_fcntl(fd, cmd, translated_flags);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_fcntl(
+	JNIEnv *env, jobject thisObj, jint fd, jint cmd, jint flags)
+{
+	zts_err_t retval = zts_fcntl(fd, cmd, flags);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_ioctl(int fd, unsigned long request, void *argp)
+{
+	if (!argp) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_ioctl(fd, request, argp);
+}
+#ifdef SDK_JNI
+JNIEXPORT int JNICALL Java_com_zerotier_libzt_ZeroTier_ioctl(
+	JNIEnv *env, jobject thisObj, jint fd, jlong request, jobject argp)
+{
+	zts_err_t retval = ZTS_ERR_OK;
+	if (request == FIONREAD) {
+		DEBUG_ERROR("FIONREAD");
+		int bytesRemaining = 0;
+		retval = zts_ioctl(fd, request, &bytesRemaining);	
+		// set value in general object
+		jclass c = (*env).GetObjectClass(argp);
+		if (!c) {
+			return ZTS_ERR_INVALID_ARG;
+		}
+		jfieldID fid = (*env).GetFieldID(c, "integer", "I");
+		(*env).SetIntField(argp, fid, bytesRemaining);
+	}
+	if (request == FIONBIO) {
+		// TODO: double check
+		int meaninglessVariable = 0;
+		DEBUG_ERROR("FIONBIO");
+		retval = zts_ioctl(fd, request, &meaninglessVariable);		
+	}
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+ssize_t zts_send(int fd, const void *buf, size_t len, int flags)
+{
+	if (!buf || len <= 0) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_send(fd, buf, len, flags);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_send(
+	JNIEnv *env, jobject thisObj, jint fd, jbyteArray buf, int flags)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_send(fd, data, env->GetArrayLength(buf), flags);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+ssize_t zts_sendto(int fd, const void *buf, size_t len, int flags, 
+	const struct sockaddr *addr, socklen_t addrlen)
+{
+	if (!addr || !buf || len <= 0) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	if (addrlen > (int)sizeof(struct sockaddr_storage) || addrlen < (int)sizeof(struct sockaddr_in)) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_sendto(fd, buf, len, flags, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_sendto(
+	JNIEnv *env, jobject thisObj, jint fd, jbyteArray buf, jint flags, jobject addr)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	struct sockaddr_storage ss;
+	zta2ss(env, &ss, addr);
+	socklen_t addrlen = ss.ss_family == AF_INET ? sizeof(struct sockaddr_in) : sizeof(struct sockaddr_in6);
+	zts_err_t retval = zts_sendto(fd, data, env->GetArrayLength(buf), flags, (struct sockaddr *)&ss, addrlen);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+ssize_t zts_sendmsg(int fd, const struct msghdr *msg, int flags)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_sendmsg(fd, msg, flags);
+}
+#ifdef SDK_JNI
+#endif
+
+ssize_t zts_recv(int fd, void *buf, size_t len, int flags)
+{
+	if (!buf) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_recv(fd, buf, len, flags);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_recv(JNIEnv *env, jobject thisObj,
+	jint fd, jbyteArray buf, jint flags)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_recv(fd, data, env->GetArrayLength(buf), flags);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+ssize_t zts_recvfrom(int fd, void *buf, size_t len, int flags, 
+	struct sockaddr *addr, socklen_t *addrlen)
+{
+	if (!buf) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_recvfrom(fd, buf, len, flags, addr, addrlen);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_recvfrom(
+	JNIEnv *env, jobject thisObj, jint fd, jbyteArray buf, jint flags, jobject addr)
+{
+	socklen_t addrlen = sizeof(struct sockaddr_storage);
+	struct sockaddr_storage ss;
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_recvfrom(fd, data, env->GetArrayLength(buf), flags, (struct sockaddr *)&ss, &addrlen);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);
+	ss2zta(env, &ss, addr);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+ssize_t zts_recvmsg(int fd, struct msghdr *msg, int flags)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : -1; // Not currently implemented by stack
+}
+#ifdef SDK_JNI
+#endif
+
+int zts_read(int fd, void *buf, size_t len)
+{
+	if (!buf) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_read(fd, buf, len);
+}
+int zts_read_offset(int fd, void *buf, size_t offset, size_t len)
+{
+	if (!buf) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	char *cbuf = (char*)buf;
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_read(fd, &(cbuf[offset]), len);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_read(JNIEnv *env, jobject thisObj,
+	jint fd, jbyteArray buf)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_read(fd, data, env->GetArrayLength(buf));
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_read_1offset(JNIEnv *env, jobject thisObj,
+	jint fd, jbyteArray buf, jint offset, jint len)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_read_offset(fd, data, offset, len);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_read_1length(JNIEnv *env, jobject thisObj,
+	jint fd, jbyteArray buf, jint len)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_read(fd, data, len);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_write(int fd, const void *buf, size_t len)
+{
+	if (!buf || len <= 0) {
+		return ZTS_ERR_INVALID_ARG;
+	}
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_write(fd, buf, len);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_write__IB(JNIEnv *env, jobject thisObj,
+	jint fd, jbyteArray buf)
+{
+	void *data = env->GetPrimitiveArrayCritical(buf, NULL);
+	zts_err_t retval = zts_write(fd, data, env->GetArrayLength(buf));
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	 
+	return retval > -1 ? retval : -(zts_errno);
+}
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_write_1offset(JNIEnv *env, jobject thisObj,
+	jint fd, jbyteArray buf, jint offset, jint len)
+{
+	void *data = env->GetPrimitiveArrayCritical(&(buf[offset]), NULL); // PENDING: check?
+	zts_err_t retval = zts_write(fd, data, len);
+	env->ReleasePrimitiveArrayCritical(buf, data, 0);	
+	return retval > -1 ? retval : -(zts_errno);
+}
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_write_1byte(JNIEnv *env, jobject thisObj,
+	jint fd, jbyte buf)
+{
+	zts_err_t retval = zts_write(fd, &buf, 1);
+	return retval > -1 ? retval : -(zts_errno);
+}
+#endif
+
+int zts_shutdown(int fd, int how)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : lwip_shutdown(fd, how);
+}
+#ifdef SDK_JNI
+JNIEXPORT jint JNICALL Java_com_zerotier_libzt_ZeroTier_shutdown(
+	JNIEnv *env, jobject thisObj, int fd, int how)
+{
+	return zts_shutdown(fd, how);
+}
+#endif
+
+int zts_add_dns_nameserver(struct sockaddr *addr)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : -1; // TODO
+}
+#ifdef SDK_JNI
+#endif
+
+int zts_del_dns_nameserver(struct sockaddr *addr)
+{
+	return (!_run_service || !_run_lwip_tcpip) ? ZTS_ERR_SERVICE : -1; // TODO
+}
+#ifdef SDK_JNI
+#endif
+
+#ifdef SDK_JNI
+void ztfdset2fdset(JNIEnv *env, int nfds, jobject src_ztfd_set, fd_set *dest_fd_set)
+{
+	jclass c = (*env).GetObjectClass(src_ztfd_set);
+	if (!c) {
+		return;
+	}
+	FD_ZERO(dest_fd_set);
+	jfieldID fid = env->GetFieldID(c, "fds_bits", "[B");
+	jobject fdData = (*env).GetObjectField (src_ztfd_set, fid);
+	jbyteArray * arr = reinterpret_cast<jbyteArray*>(&fdData);
+	char *data = (char*)(*env).GetByteArrayElements(*arr, NULL);	
+	for (int i=0; i<nfds; i++) {
+		if (data[i] == 0x01)  {
+			FD_SET(i, dest_fd_set);
+		}
+	}
+	(*env).ReleaseByteArrayElements(*arr, (jbyte*)data, 0);
+	return;
+}
+
+void fdset2ztfdset(JNIEnv *env, int nfds, fd_set *src_fd_set, jobject dest_ztfd_set)
+{
+	jclass c = (*env).GetObjectClass(dest_ztfd_set);
+	if (!c) {
+		return;
+	}
+	jfieldID fid = env->GetFieldID(c, "fds_bits", "[B");
+	jobject fdData = (*env).GetObjectField (dest_ztfd_set, fid);
+	jbyteArray * arr = reinterpret_cast<jbyteArray*>(&fdData);
+	char *data = (char*)(*env).GetByteArrayElements(*arr, NULL);
+	for (int i=0; i<nfds; i++) {
+		if (FD_ISSET(i, src_fd_set)) {
+			data[i] = 0x01;
+		}
+	}
+	(*env).ReleaseByteArrayElements(*arr, (jbyte*)data, 0);
+	return;
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// Helpers (for moving data across the JNI barrier)                         //
+//////////////////////////////////////////////////////////////////////////////
+
+void ss2zta(JNIEnv *env, struct sockaddr_storage *ss, jobject addr)
+{
+	jclass c = (*env).GetObjectClass(addr);
+	if (!c) {
+		return;
+	}
+	if(ss->ss_family == AF_INET)
+	{
+		struct sockaddr_in *in4 = (struct sockaddr_in*)ss;
+		jfieldID fid = (*env).GetFieldID(c, "_port", "I");
+		(*env).SetIntField(addr, fid, lwip_ntohs(in4->sin_port));
+		fid = (*env).GetFieldID(c,"_family", "I");
+		(*env).SetIntField(addr, fid, (in4->sin_family));
+		fid = env->GetFieldID(c, "_ip4", "[B");
+		jobject ipData = (*env).GetObjectField (addr, fid);
+		jbyteArray * arr = reinterpret_cast<jbyteArray*>(&ipData);
+		char *data = (char*)(*env).GetByteArrayElements(*arr, NULL);
+		memcpy(data, &(in4->sin_addr.s_addr), 4);
+		(*env).ReleaseByteArrayElements(*arr, (jbyte*)data, 0);
+
+		return;
+	}
+	if(ss->ss_family == AF_INET6)
+	{
+		struct sockaddr_in6 *in6 = (struct sockaddr_in6*)ss;
+		jfieldID fid = (*env).GetFieldID(c, "_port", "I");
+		(*env).SetIntField(addr, fid, lwip_ntohs(in6->sin6_port));
+		fid = (*env).GetFieldID(c,"_family", "I");
+		(*env).SetIntField(addr, fid, (in6->sin6_family));
+		fid = env->GetFieldID(c, "_ip6", "[B");
+		jobject ipData = (*env).GetObjectField (addr, fid);
+		jbyteArray * arr = reinterpret_cast<jbyteArray*>(&ipData);
+		char *data = (char*)(*env).GetByteArrayElements(*arr, NULL);
+		memcpy(data, &(in6->sin6_addr.s6_addr), 16);
+		(*env).ReleaseByteArrayElements(*arr, (jbyte*)data, 0);
+		return;
+	}
+}
+
+void zta2ss(JNIEnv *env, struct sockaddr_storage *ss, jobject addr)
+{
+	jclass c = (*env).GetObjectClass(addr);
+	if (!c) {
+		return;
+	}
+	jfieldID fid = (*env).GetFieldID(c, "_family", "I");
+	int family = (*env).GetIntField(addr, fid);
+	if (family == AF_INET)
+	{
+		struct sockaddr_in *in4 = (struct sockaddr_in*)ss;
+		fid = (*env).GetFieldID(c, "_port", "I");
+		in4->sin_port = lwip_htons((*env).GetIntField(addr, fid));
+		in4->sin_family = AF_INET;
+		fid = env->GetFieldID(c, "_ip4", "[B");
+		jobject ipData = (*env).GetObjectField (addr, fid);
+		jbyteArray * arr = reinterpret_cast<jbyteArray*>(&ipData);
+		char *data = (char*)(*env).GetByteArrayElements(*arr, NULL);
+		memcpy(&(in4->sin_addr.s_addr), data, 4);
+		(*env).ReleaseByteArrayElements(*arr, (jbyte*)data, 0);
+		return;
+	}
+	if (family == AF_INET6)
+	{
+		struct sockaddr_in6 *in6 = (struct sockaddr_in6*)ss;
+		jfieldID fid = (*env).GetFieldID(c, "_port", "I");
+		in6->sin6_port = lwip_htons((*env).GetIntField(addr, fid));
+		fid = (*env).GetFieldID(c,"_family", "I");
+		in6->sin6_family = AF_INET6;
+		fid = env->GetFieldID(c, "_ip6", "[B");
+		jobject ipData = (*env).GetObjectField (addr, fid);
+		jbyteArray * arr = reinterpret_cast<jbyteArray*>(&ipData);
+		char *data = (char*)(*env).GetByteArrayElements(*arr, NULL);
+		memcpy(&(in6->sin6_addr.s6_addr), data, 16);
+		(*env).ReleaseByteArrayElements(*arr, (jbyte*)data, 0);
+		return;
+	}
+}
+#endif // JNI
+
+#ifdef __cplusplus
+}
+#endif
+
+} // namespace ZeroTier