Adding upstream version 3.2.1.upstream/3.2.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 848 insertions, 0 deletions

diff --git a/tests/pytests/rehandshake/tls-proxy.c b/tests/pytests/rehandshake/tls-proxy.c
new file mode 100644
index 0000000..bf6cc0d
--- /dev/null
+++ b/tests/pytests/rehandshake/tls-proxy.c
@@ -0,0 +1,848 @@
+#include <assert.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <gnutls/gnutls.h>
+#include <uv.h>
+#include "array.h"
+
+#define TLS_MAX_SEND_RETRIES 100
+#define CLIENT_ANSWER_CHUNK_SIZE 8
+struct buf {
+	char buf[16 * 1024];
+	size_t size;
+};
+
+enum peer_state {
+	STATE_NOT_CONNECTED,
+	STATE_LISTENING,
+	STATE_CONNECTED,
+	STATE_CONNECT_IN_PROGRESS,
+	STATE_CLOSING_IN_PROGRESS
+};
+
+enum handshake_state {
+	TLS_HS_NOT_STARTED = 0,
+	TLS_HS_EXPECTED,
+	TLS_HS_IN_PROGRESS,
+	TLS_HS_DONE,
+	TLS_HS_CLOSING,
+	TLS_HS_LAST
+};
+
+struct tls_ctx {
+	gnutls_session_t session;
+	int handshake_state;
+	gnutls_certificate_credentials_t credentials;
+        gnutls_priority_t priority_cache;
+	/* for reading from the network */
+	const uint8_t *buf;
+	ssize_t nread;
+	ssize_t consumed;
+	uint8_t recv_buf[4096];
+};
+
+struct tls_proxy_ctx {
+	uv_loop_t *loop;
+	uv_tcp_t server;
+	uv_tcp_t client;
+	uv_tcp_t upstream;
+	struct sockaddr_storage server_addr;
+	struct sockaddr_storage upstream_addr;
+	struct sockaddr_storage client_addr;
+	
+	int server_state;
+	int client_state;
+	int upstream_state;
+
+	array_t(struct buf *) buffer_pool;
+	array_t(struct buf *) upstream_pending;
+	array_t(struct buf *) client_pending;
+	
+	char io_buf[0xFFFF];
+	struct tls_ctx tls;
+};
+
+static void read_from_upstream_cb(uv_stream_t *upstream, ssize_t nread, const uv_buf_t *buf);
+static void read_from_client_cb(uv_stream_t *client, ssize_t nread, const uv_buf_t *buf);
+static ssize_t proxy_gnutls_pull(gnutls_transport_ptr_t h, void *buf, size_t len);
+static ssize_t proxy_gnutls_push(gnutls_transport_ptr_t h, const void *buf, size_t len);
+static int tls_process_from_upstream(struct tls_proxy_ctx *proxy, const uint8_t *buf, ssize_t nread);
+static int tls_process_from_client(struct tls_proxy_ctx *proxy, const uint8_t *buf, ssize_t nread);
+static int write_to_upstream_pending(struct tls_proxy_ctx *proxy);
+static int write_to_client_pending(struct tls_proxy_ctx *proxy);
+
+
+static int gnutls_references = 0;
+
+const void *ip_addr(const struct sockaddr *addr)
+{
+	if (!addr) {
+		return NULL;
+	}
+	switch (addr->sa_family) {
+	case AF_INET:  return (const void *)&(((const struct sockaddr_in *)addr)->sin_addr);
+	case AF_INET6: return (const void *)&(((const struct sockaddr_in6 *)addr)->sin6_addr);
+	default:       return NULL;
+	}
+}
+
+uint16_t ip_addr_port(const struct sockaddr *addr)
+{
+	if (!addr) {
+		return 0;
+	}
+	switch (addr->sa_family) {
+	case AF_INET:  return ntohs(((const struct sockaddr_in *)addr)->sin_port);
+	case AF_INET6: return ntohs(((const struct sockaddr_in6 *)addr)->sin6_port);
+	default:       return 0;
+	}
+}
+
+static int ip_addr_str(const struct sockaddr *addr, char *buf, size_t *buflen)
+{
+	int ret = 0;
+	if (!addr || !buf || !buflen) {
+		return EINVAL;
+	}
+
+	char str[INET6_ADDRSTRLEN + 6];
+	if (!inet_ntop(addr->sa_family, ip_addr(addr), str, sizeof(str))) {
+		return errno;
+	}
+	int len = strlen(str);
+	str[len] = '#';
+	snprintf(&str[len + 1], 6, "%uh", ip_addr_port(addr));
+	len += 6;
+	str[len] = 0;
+	if (len >= *buflen) {
+		ret = ENOSPC;
+	} else {
+		memcpy(buf, str, len + 1);
+	}
+	*buflen = len;
+	return ret;
+}
+
+static inline char *ip_straddr(const struct sockaddr *addr)
+{
+	assert(addr != NULL);
+	/* We are the sinle-threaded application */
+	static char str[INET6_ADDRSTRLEN + 6];
+	size_t len = sizeof(str);
+	int ret = ip_addr_str(addr, str, &len);
+	return ret != 0 || len == 0 ? NULL : str;
+}
+
+static struct buf *borrow_io_buffer(struct tls_proxy_ctx *proxy)
+{
+	struct buf *buf = NULL;
+	if (proxy->buffer_pool.len > 0) {
+		buf = array_tail(proxy->buffer_pool);
+		array_pop(proxy->buffer_pool);
+	} else {
+		buf = calloc(1, sizeof (struct buf));
+	}
+	return buf;
+}
+
+static void release_io_buffer(struct tls_proxy_ctx *proxy, struct buf *buf)
+{
+	if (!buf) {
+		return;
+	}
+
+	if (proxy->buffer_pool.len < 1000) {
+		buf->size = 0;
+		array_push(proxy->buffer_pool, buf);
+	} else {
+		free(buf);
+	}
+}
+
+static struct buf *get_first_upstream_pending(struct tls_proxy_ctx *proxy)
+{
+	struct buf *buf = NULL;
+	if (proxy->upstream_pending.len > 0) {
+		buf = proxy->upstream_pending.at[0];
+	}
+	return buf;
+}
+
+static struct buf *get_first_client_pending(struct tls_proxy_ctx *proxy)
+{
+	struct buf *buf = NULL;
+	if (proxy->client_pending.len > 0) {
+		buf = proxy->client_pending.at[0];
+	}
+	return buf;
+}
+
+static void remove_first_upstream_pending(struct tls_proxy_ctx *proxy)
+{
+	for (int i = 1; i < proxy->upstream_pending.len; ++i) {
+		proxy->upstream_pending.at[i - 1] = proxy->upstream_pending.at[i];
+	}
+	if (proxy->upstream_pending.len > 0) {
+		proxy->upstream_pending.len -= 1;
+	}
+}
+
+static void remove_first_client_pending(struct tls_proxy_ctx *proxy)
+{
+	for (int i = 1; i < proxy->client_pending.len; ++i) {
+		proxy->client_pending.at[i - 1] = proxy->client_pending.at[i];
+	}
+	if (proxy->client_pending.len > 0) {
+		proxy->client_pending.len -= 1;
+	}
+}
+
+static void clear_upstream_pending(struct tls_proxy_ctx *proxy)
+{
+	for (int i = 0; i < proxy->upstream_pending.len; ++i) {
+		struct buf *b = proxy->upstream_pending.at[i];
+		release_io_buffer(proxy, b);
+	}
+	proxy->upstream_pending.len = 0;
+}
+
+static void clear_client_pending(struct tls_proxy_ctx *proxy)
+{
+	for (int i = 0; i < proxy->client_pending.len; ++i) {
+		struct buf *b = proxy->client_pending.at[i];
+		release_io_buffer(proxy, b);
+	}
+	proxy->client_pending.len = 0;
+}
+
+static void clear_buffer_pool(struct tls_proxy_ctx *proxy)
+{
+	for (int i = 0; i < proxy->buffer_pool.len; ++i) {
+		struct buf *b = proxy->buffer_pool.at[i];
+		free(b);
+	}
+	proxy->buffer_pool.len = 0;
+}
+
+static void alloc_uv_buffer(uv_handle_t *handle, size_t suggested_size, uv_buf_t *buf)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)handle->loop->data;
+	buf->base = proxy->io_buf;
+	buf->len = sizeof(proxy->io_buf);
+}
+
+static void on_client_close(uv_handle_t *handle)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)handle->loop->data;
+	gnutls_deinit(proxy->tls.session);
+	proxy->tls.handshake_state = TLS_HS_NOT_STARTED;
+	proxy->client_state = STATE_NOT_CONNECTED;
+}
+
+static void on_dummmy_client_close(uv_handle_t *handle)
+{
+	free(handle);
+}
+
+static void on_upstream_close(uv_handle_t *handle)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)handle->loop->data;
+	proxy->upstream_state = STATE_NOT_CONNECTED;
+}
+
+static void write_to_client_cb(uv_write_t *req, int status)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)req->handle->loop->data;
+	free(req);
+	if (status) {
+		fprintf(stderr, "error writing to client: %s\n", uv_strerror(status));
+		clear_client_pending(proxy);
+		clear_upstream_pending(proxy);
+		if (proxy->client_state == STATE_CONNECTED) {
+			proxy->client_state = STATE_CLOSING_IN_PROGRESS;
+			uv_close((uv_handle_t*)&proxy->client, on_client_close);
+			return;
+		}
+	}
+	fprintf(stdout, "successfully wrote to client, pending len is %zd\n",
+		proxy->client_pending.len);
+	if (proxy->client_state == STATE_CONNECTED &&
+	    proxy->tls.handshake_state == TLS_HS_DONE) {
+		write_to_client_pending(proxy);
+	}
+}
+
+static void write_to_upstream_cb(uv_write_t *req, int status)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)req->handle->loop->data;
+	if (status) {
+		free(req);
+		fprintf(stderr, "error writing to upstream: %s\n", uv_strerror(status));
+		clear_upstream_pending(proxy);
+		proxy->upstream_state = STATE_CLOSING_IN_PROGRESS;
+		uv_close((uv_handle_t*)&proxy->upstream, on_upstream_close);
+		return;
+	}
+	if (req->data != NULL) {
+		assert(proxy->upstream_pending.len > 0);
+		struct buf *buf = get_first_upstream_pending(proxy);
+		assert(req->data == (void *)buf->buf);
+		fprintf(stdout, "successfully wrote %zi bytes to upstream, pending len is %zd\n",
+			buf->size, proxy->upstream_pending.len);
+		remove_first_upstream_pending(proxy);
+		release_io_buffer(proxy, buf);
+	} else {
+		fprintf(stdout, "successfully wrote bytes to upstream, pending len is %zd\n",
+			proxy->upstream_pending.len);
+	}
+	if (proxy->upstream_state == STATE_CONNECTED &&
+	    proxy->upstream_pending.len > 0) {
+		write_to_upstream_pending(proxy);
+	}
+	free(req);
+}
+
+static void on_client_connection(uv_stream_t *server, int status)
+{
+	if (status < 0) {
+		fprintf(stderr, "incoming connection error: %s\n", uv_strerror(status));
+		return;
+	}
+
+	int err = 0;
+	int ret = 0;
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)server->loop->data;
+	if (proxy->client_state != STATE_NOT_CONNECTED) {
+		fprintf(stderr, "incoming connection");
+		uv_tcp_t *dummy_client = malloc(sizeof(uv_tcp_t));
+		uv_tcp_init(proxy->loop, dummy_client);
+		err = uv_accept(server, (uv_stream_t*)dummy_client);
+		if (err == 0) {
+			struct sockaddr dummy_addr;
+			int dummy_addr_len = sizeof(dummy_addr);
+			ret = uv_tcp_getpeername(dummy_client,
+						 &dummy_addr,
+						 &dummy_addr_len);
+			if (ret == 0) {
+				fprintf(stderr, " from %s", ip_straddr(&dummy_addr));
+			}
+			uv_close((uv_handle_t *)dummy_client, on_dummmy_client_close);
+		} else {
+			on_dummmy_client_close((uv_handle_t *)dummy_client);
+		}
+		fprintf(stderr, " - client already connected, rejecting\n");
+		return;
+	}
+
+	uv_tcp_init(proxy->loop, &proxy->client);
+	uv_tcp_nodelay((uv_tcp_t *)&proxy->client, 1);
+	proxy->client_state = STATE_CONNECTED;
+	err = uv_accept(server, (uv_stream_t*)&proxy->client);
+	if (err != 0) {
+		fprintf(stderr, "incoming connection - uv_accept() failed: (%d) %s\n",
+			     err, uv_strerror(err));
+		return;
+	}
+
+	struct sockaddr *addr = (struct sockaddr *)&(proxy->client_addr);
+	int addr_len = sizeof(proxy->client_addr);
+	ret = uv_tcp_getpeername(&proxy->client, addr, &addr_len);
+	if (ret || addr->sa_family == AF_UNSPEC) {
+		proxy->client_state = STATE_CLOSING_IN_PROGRESS;
+		uv_close((uv_handle_t*)&proxy->client, on_client_close);
+		fprintf(stderr, "incoming connection - uv_tcp_getpeername() failed: (%d) %s\n",
+			     err, uv_strerror(err));
+		return;
+	}
+	
+	fprintf(stdout, "incoming connection from %s\n", ip_straddr(addr));
+	
+	uv_read_start((uv_stream_t*)&proxy->client, alloc_uv_buffer, read_from_client_cb);
+
+	const char *errpos = NULL;
+	struct tls_ctx *tls = &proxy->tls;
+	assert (tls->handshake_state == TLS_HS_NOT_STARTED);
+	err = gnutls_init(&tls->session, GNUTLS_SERVER | GNUTLS_NONBLOCK);
+	if (err != GNUTLS_E_SUCCESS) {
+		fprintf(stderr, "gnutls_init() failed: (%d) %s\n",
+			     err, gnutls_strerror_name(err));
+	}
+        err = gnutls_priority_set(tls->session, tls->priority_cache);
+	if (err != GNUTLS_E_SUCCESS) {
+		fprintf(stderr, "gnutls_priority_set() failed: (%d) %s\n",
+			     err, gnutls_strerror_name(err));
+	}
+	err = gnutls_credentials_set(tls->session, GNUTLS_CRD_CERTIFICATE, tls->credentials);
+	if (err != GNUTLS_E_SUCCESS) {
+		fprintf(stderr, "gnutls_credentials_set() failed: (%d) %s\n",
+			     err, gnutls_strerror_name(err));
+	}
+	gnutls_certificate_server_set_request(tls->session, GNUTLS_CERT_IGNORE);
+	gnutls_handshake_set_timeout(tls->session, GNUTLS_DEFAULT_HANDSHAKE_TIMEOUT);
+
+	gnutls_transport_set_pull_function(tls->session, proxy_gnutls_pull);
+	gnutls_transport_set_push_function(tls->session, proxy_gnutls_push);
+	gnutls_transport_set_ptr(tls->session, proxy);
+
+	tls->handshake_state = TLS_HS_IN_PROGRESS;
+}
+
+static void on_connect_to_upstream(uv_connect_t *req, int status)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)req->handle->loop->data;
+	free(req);
+	if (status < 0) {
+		fprintf(stderr, "error connecting to upstream (%s): %s\n",
+			ip_straddr((struct sockaddr *)&proxy->upstream_addr),
+			uv_strerror(status));
+		clear_upstream_pending(proxy);
+		proxy->upstream_state = STATE_CLOSING_IN_PROGRESS;
+		uv_close((uv_handle_t*)&proxy->upstream, on_upstream_close);
+		return;
+	}
+	fprintf(stdout, "connected to %s\n", ip_straddr((struct sockaddr *)&proxy->upstream_addr));
+
+	proxy->upstream_state = STATE_CONNECTED;
+	uv_read_start((uv_stream_t*)&proxy->upstream, alloc_uv_buffer, read_from_upstream_cb);
+	if (proxy->upstream_pending.len > 0) {
+		write_to_upstream_pending(proxy);
+	}
+}
+
+static void read_from_client_cb(uv_stream_t *client, ssize_t nread, const uv_buf_t *buf)
+{
+	fprintf(stdout, "reading %zd bytes from client\n", nread);
+	if (nread == 0) {
+		return;
+	}
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)client->loop->data;
+	if (nread < 0) {
+		if (nread != UV_EOF) {
+			fprintf(stderr, "error reading from client: %s\n", uv_err_name(nread));
+		} else {
+			fprintf(stdout, "client has closed the connection\n");
+		}
+		if (proxy->client_state == STATE_CONNECTED) {
+			proxy->client_state = STATE_CLOSING_IN_PROGRESS;
+			uv_close((uv_handle_t*) client, on_client_close);
+		}
+		return;
+	}
+
+	int res = tls_process_from_client(proxy, buf->base, nread);
+	if (res < 0) {
+		if (proxy->client_state == STATE_CONNECTED) {
+			proxy->client_state = STATE_CLOSING_IN_PROGRESS;
+			uv_close((uv_handle_t*) client, on_client_close);
+		}
+	}
+}
+
+static void read_from_upstream_cb(uv_stream_t *upstream, ssize_t nread, const uv_buf_t *buf)
+{
+	fprintf(stdout, "reading %zd bytes from upstream\n", nread);
+	if (nread == 0) {
+		return;
+	}
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)upstream->loop->data;
+	if (nread < 0) {
+		if (nread != UV_EOF) {
+			fprintf(stderr, "error reading from upstream: %s\n", uv_err_name(nread));
+		} else {
+			fprintf(stdout, "upstream has closed the connection\n");
+		}
+		clear_upstream_pending(proxy);
+		if (proxy->upstream_state == STATE_CONNECTED) {
+			proxy->upstream_state = STATE_CLOSING_IN_PROGRESS;
+			uv_close((uv_handle_t*)&proxy->upstream, on_upstream_close);
+		}
+		return;
+	}
+	int res = tls_process_from_upstream(proxy, buf->base, nread);
+	if (res < 0) {
+		fprintf(stderr, "error sending tls data to client\n");
+		if (proxy->client_state == STATE_CONNECTED) {
+			proxy->client_state = STATE_CLOSING_IN_PROGRESS;
+			uv_close((uv_handle_t*)&proxy->client, on_client_close);
+		}
+	}
+}
+
+static void push_to_upstream_pending(struct tls_proxy_ctx *proxy, const char *buf, size_t size)
+{
+	while (size > 0) {
+		struct buf *b = borrow_io_buffer(proxy);
+		b->size = size <= sizeof(b->buf) ? size : sizeof(b->buf);
+		memcpy(b->buf, buf, b->size);
+		array_push(proxy->upstream_pending, b);
+		size -= b->size;
+		buf += b->size;
+	}
+}
+
+static void push_to_client_pending(struct tls_proxy_ctx *proxy, const char *buf, size_t size)
+{
+	while (size > 0) {
+		struct buf *b = borrow_io_buffer(proxy);
+		b->size = size <= sizeof(b->buf) ? size : sizeof(b->buf);
+		if (b->size > CLIENT_ANSWER_CHUNK_SIZE) {
+			b->size = CLIENT_ANSWER_CHUNK_SIZE;
+		}
+		memcpy(b->buf, buf, b->size);
+		array_push(proxy->client_pending, b);
+		size -= b->size;
+		buf += b->size;
+	}
+}
+
+static int write_to_upstream_pending(struct tls_proxy_ctx *proxy)
+{
+	struct buf *buf = get_first_upstream_pending(proxy);
+	/* TODO avoid allocation */
+	uv_write_t *req = (uv_write_t *) malloc(sizeof(uv_write_t));
+	uv_buf_t wrbuf = uv_buf_init(buf->buf, buf->size);
+	req->data = buf->buf;
+	fprintf(stdout, "writing %zd bytes to upstream\n", buf->size);
+	return uv_write(req, (uv_stream_t *)&proxy->upstream, &wrbuf, 1, write_to_upstream_cb);
+}
+
+static ssize_t proxy_gnutls_pull(gnutls_transport_ptr_t h, void *buf, size_t len)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)h;
+	struct tls_ctx *t = &proxy->tls;
+
+	fprintf(stdout, "\t gnutls: pulling %zd bytes from client\n", len);
+
+	if (t->nread <= t->consumed) {
+		errno = EAGAIN;
+		fprintf(stdout, "\t gnutls: return EAGAIN\n");
+		return -1;
+	}
+
+	ssize_t	avail = t->nread - t->consumed;
+	ssize_t	transfer = (avail <= len ? avail : len);
+	memcpy(buf, t->buf + t->consumed, transfer);
+	t->consumed += transfer;
+	return transfer;
+}
+
+ssize_t proxy_gnutls_push(gnutls_transport_ptr_t h, const void *buf, size_t len)
+{
+	struct tls_proxy_ctx *proxy = (struct tls_proxy_ctx *)h;
+	struct tls_ctx *t = &proxy->tls;
+	fprintf(stdout, "\t gnutls: writing %zd bytes to client\n", len);
+
+	ssize_t ret = -1;
+	const size_t req_size_aligned = ((sizeof(uv_write_t) / 16) + 1) * 16;
+	char *common_buf = malloc(req_size_aligned + len);
+	uv_write_t *req = (uv_write_t *) common_buf;
+	char *data = common_buf + req_size_aligned;
+	const uv_buf_t uv_buf[1] = {
+		{ data, len }
+	};
+	memcpy(data, buf, len);
+	req->data = data;
+	int res = uv_write(req, (uv_stream_t *)&proxy->client, uv_buf, 1, write_to_client_cb);
+	if (res == 0) {
+		ret = len;
+	} else {
+		free(common_buf);
+		errno = EIO;
+	}
+	return ret;
+}
+
+static int write_to_client_pending(struct tls_proxy_ctx *proxy)
+{
+	if (proxy->client_pending.len == 0) {
+		return 0;
+	}
+
+	struct buf *buf = get_first_client_pending(proxy);
+	uv_buf_t wrbuf = uv_buf_init(buf->buf, buf->size);
+	fprintf(stdout, "writing %zd bytes to client\n", buf->size);
+
+	gnutls_session_t tls_session = proxy->tls.session;
+	assert(proxy->tls.handshake_state != TLS_HS_IN_PROGRESS);
+	assert(gnutls_record_check_corked(tls_session) == 0);
+
+	char *data = buf->buf;
+	size_t len = buf->size;
+
+	ssize_t count = 0;
+	ssize_t submitted = len;
+	ssize_t retries = 0;
+	do {
+		count = gnutls_record_send(tls_session, data, len);
+		if (count < 0) {
+			if (gnutls_error_is_fatal(count)) {
+				fprintf(stderr, "gnutls_record_send failed: %s (%zd)\n",
+					gnutls_strerror_name(count), count);
+				return -1;
+			}
+			if (++retries > TLS_MAX_SEND_RETRIES) {
+				fprintf(stderr, "gnutls_record_send: too many sequential non-fatal errors (%zd), last error is: %s (%zd)\n",
+					retries, gnutls_strerror_name(count), count);
+				return -1;
+			}
+		} else if (count != 0) {
+			data += count;
+			len -= count;
+			retries = 0;
+		} else {
+			if (++retries < TLS_MAX_SEND_RETRIES) {
+				continue;
+			}
+			fprintf(stderr, "gnutls_record_send: too many retries (%zd)\n",
+				retries);
+			fprintf(stderr, "tls_push_to_client didn't send all data(%zd of %zd)\n",
+				len, submitted);
+			return -1;
+		}
+	} while (len > 0);
+
+	remove_first_client_pending(proxy);
+	release_io_buffer(proxy, buf);
+
+	fprintf(stdout, "submitted %zd bytes to client\n", submitted);
+	assert (gnutls_safe_renegotiation_status(tls_session) != 0);
+	assert (gnutls_rehandshake(tls_session) == GNUTLS_E_SUCCESS);
+	/* Prevent write-to-client callback from sending next pending chunk.
+	 * At the same time tls_process_from_client() must not call gnutls_handshake()
+	 * as there can be application data in this direction.  */
+	proxy->tls.handshake_state = TLS_HS_EXPECTED;
+	fprintf(stdout, "rehandshake started\n");
+	return submitted;
+}
+
+static int tls_process_from_upstream(struct tls_proxy_ctx *proxy, const uint8_t *buf, ssize_t len)
+{
+	gnutls_session_t tls_session = proxy->tls.session;
+
+	fprintf(stdout, "pushing %zd bytes to client\n", len);
+
+	assert(gnutls_record_check_corked(tls_session) == 0);
+	ssize_t submitted = 0;
+	if (proxy->client_state != STATE_CONNECTED) {
+		return submitted;
+	}
+
+	bool list_was_empty = (proxy->client_pending.len == 0);
+	push_to_client_pending(proxy, buf, len);
+	submitted = len;
+	if (proxy->tls.handshake_state == TLS_HS_DONE) {
+		if (list_was_empty && proxy->client_pending.len > 0) {
+			int ret = write_to_client_pending(proxy);
+			if (ret < 0) {
+				submitted = -1;
+			}
+		}
+	}
+
+	return submitted;
+}
+
+int tls_process_handshake(struct tls_proxy_ctx *proxy)
+{
+	struct tls_ctx *tls = &proxy->tls;
+	int ret = 1;
+	while (tls->handshake_state == TLS_HS_IN_PROGRESS) {
+		fprintf(stdout, "TLS handshake in progress...\n");
+		int err = gnutls_handshake(tls->session);
+		if (err == GNUTLS_E_SUCCESS) {
+			tls->handshake_state = TLS_HS_DONE;
+			fprintf(stdout, "TLS handshake has completed\n");
+			ret = 1;
+			if (proxy->client_pending.len != 0) {
+				write_to_client_pending(proxy);
+			}
+		} else if (gnutls_error_is_fatal(err)) {
+			fprintf(stderr, "gnutls_handshake failed: %s (%d)\n",
+				gnutls_strerror_name(err), err);
+			ret = -1;
+			break;
+		} else {
+			fprintf(stderr, "gnutls_handshake nonfatal error: %s (%d)\n",
+				gnutls_strerror_name(err), err);
+			ret = 0;
+			break;
+		}
+	}
+	return ret;
+}
+
+int tls_process_from_client(struct tls_proxy_ctx *proxy, const uint8_t *buf, ssize_t nread)
+{
+	struct tls_ctx *tls = &proxy->tls;
+
+	tls->buf = buf;
+	tls->nread = nread >= 0 ? nread : 0;
+	tls->consumed = 0;
+
+	fprintf(stdout, "tls_process: reading %zd bytes from client\n", nread);
+
+	int ret = tls_process_handshake(proxy);
+	if (ret <= 0) {
+		return ret;
+	}
+
+	int submitted = 0;
+	while (true) {
+		ssize_t count = 0;
+		count = gnutls_record_recv(tls->session, tls->recv_buf, sizeof(tls->recv_buf));
+		if (count == GNUTLS_E_AGAIN) {
+			break;    /* No data available */
+		} else if (count == GNUTLS_E_INTERRUPTED) {
+			continue; /* Try reading again */
+		} else if (count == GNUTLS_E_REHANDSHAKE) {
+			tls->handshake_state = TLS_HS_IN_PROGRESS;
+			ret = tls_process_handshake(proxy);
+			if (ret <= 0) {
+				return ret;
+			}
+			continue;
+		} else if (count < 0) {
+			fprintf(stderr, "gnutls_record_recv failed: %s (%zd)\n",
+				gnutls_strerror_name(count), count);
+			return -1;
+		} else if (count == 0) {
+			break;
+		}
+		if (proxy->upstream_state == STATE_CONNECTED) {
+			bool upstream_pending_is_empty = (proxy->upstream_pending.len == 0);
+			push_to_upstream_pending(proxy, tls->recv_buf, count);
+			if (upstream_pending_is_empty) {
+				write_to_upstream_pending(proxy);
+			}
+		} else if (proxy->upstream_state == STATE_NOT_CONNECTED) {
+			/* TODO avoid allocation */
+			uv_tcp_init(proxy->loop, &proxy->upstream);	
+			uv_connect_t *conn = (uv_connect_t *) malloc(sizeof(uv_connect_t));
+			proxy->upstream_state = STATE_CONNECT_IN_PROGRESS;
+			fprintf(stdout, "connecting to %s\n",
+				ip_straddr((struct sockaddr *)&proxy->upstream_addr));
+			uv_tcp_connect(conn, &proxy->upstream, (struct sockaddr *)&proxy->upstream_addr,
+				       on_connect_to_upstream);
+			push_to_upstream_pending(proxy, tls->recv_buf, count);
+		} else if (proxy->upstream_state == STATE_CONNECT_IN_PROGRESS) {
+			push_to_upstream_pending(proxy, tls->recv_buf, count);
+		}
+		submitted += count;
+	}
+	return submitted;
+}
+
+struct tls_proxy_ctx *tls_proxy_allocate()
+{
+	return malloc(sizeof(struct tls_proxy_ctx));
+}
+
+int tls_proxy_init(struct tls_proxy_ctx *proxy,
+		   const char *server_addr, int server_port,
+		   const char *upstream_addr, int upstream_port,
+		   const char *cert_file, const char *key_file)
+{	
+	proxy->loop = uv_default_loop();
+	uv_tcp_init(proxy->loop, &proxy->server);
+	int res = uv_ip4_addr(server_addr, server_port, (struct sockaddr_in *)&proxy->server_addr);
+	if (res != 0) {
+		fprintf(stderr, "uv_ip4_addr failed with string '%s'\n", server_addr);
+		return -1;
+	}
+	res = uv_ip4_addr(upstream_addr, upstream_port, (struct sockaddr_in *)&proxy->upstream_addr);
+	if (res != 0) {
+		fprintf(stderr, "uv_ip4_addr failed with string '%s'\n", upstream_addr);
+		return -1;
+	}
+	array_init(proxy->buffer_pool);
+	array_init(proxy->upstream_pending);
+	array_init(proxy->client_pending);
+	proxy->server_state = STATE_NOT_CONNECTED;
+	proxy->client_state = STATE_NOT_CONNECTED;
+	proxy->upstream_state = STATE_NOT_CONNECTED;
+
+	proxy->loop->data = proxy;
+	
+	int err = 0;
+	if (gnutls_references == 0) {
+		err = gnutls_global_init();
+		if (err != GNUTLS_E_SUCCESS) {
+			fprintf(stderr, "gnutls_global_init() failed: (%d) %s\n",
+				     err, gnutls_strerror_name(err));
+			return -1;
+		}
+	}
+	gnutls_references += 1;
+	
+	err = gnutls_certificate_allocate_credentials(&proxy->tls.credentials);
+	if (err != GNUTLS_E_SUCCESS) {
+		fprintf(stderr, "gnutls_certificate_allocate_credentials() failed: (%d) %s\n",
+			     err, gnutls_strerror_name(err));
+		return -1;
+	}
+
+	err = gnutls_certificate_set_x509_system_trust(proxy->tls.credentials);
+	if (err <= 0) {
+		fprintf(stderr, "gnutls_certificate_set_x509_system_trust() failed: (%d) %s\n",
+			     err, gnutls_strerror_name(err));
+		return -1;
+	}
+
+	if (cert_file && key_file) {
+		err = gnutls_certificate_set_x509_key_file(proxy->tls.credentials,
+						     cert_file, key_file, GNUTLS_X509_FMT_PEM);
+		if (err != GNUTLS_E_SUCCESS) {
+			fprintf(stderr, "gnutls_certificate_set_x509_key_file() failed: (%d) %s\n",
+				     err, gnutls_strerror_name(err));
+			return -1;
+		}
+	}
+
+	err = gnutls_priority_init(&proxy->tls.priority_cache, NULL, NULL);
+	if (err != GNUTLS_E_SUCCESS) {
+		fprintf(stderr, "gnutls_priority_init() failed: (%d) %s\n",
+			     err, gnutls_strerror_name(err));
+		return -1;
+	}
+
+	
+	proxy->tls.handshake_state = TLS_HS_NOT_STARTED;
+	return 0;
+}
+
+void tls_proxy_free(struct tls_proxy_ctx *proxy)
+{
+	if (!proxy) {
+		return;
+	}
+	clear_upstream_pending(proxy);
+	clear_client_pending(proxy);
+	clear_buffer_pool(proxy);
+	gnutls_certificate_free_credentials(proxy->tls.credentials);
+        gnutls_priority_deinit(proxy->tls.priority_cache);
+	/* TODO correctly close all the uv_tcp_t */
+	free(proxy);
+	
+	gnutls_references -= 1;
+	if (gnutls_references == 0) {
+		gnutls_global_deinit();
+	}
+}
+
+int tls_proxy_start_listen(struct tls_proxy_ctx *proxy)
+{	
+	uv_tcp_bind(&proxy->server, (const struct sockaddr*)&proxy->server_addr, 0);
+	int ret = uv_listen((uv_stream_t*)&proxy->server, 128, on_client_connection);
+	if (ret == 0) {
+		proxy->server_state = STATE_LISTENING;
+	}
+	return ret;
+}
+
+int tls_proxy_run(struct tls_proxy_ctx *proxy)
+{
+	return uv_run(proxy->loop, UV_RUN_DEFAULT);
+}