MEDIUM: connections: Introduce a handshake pseudo-XPRT.

Add a new XPRT that is used when using non-SSL handshakes, such as proxy
protocol or Netscaler, instead of taking care of it in conn_fd_handler().
This XPRT is installed when any of those is used, and it removes itself once
the handshake is done.
This should allow us to remove the distinction between CO_FL_SOCK* and
CO_FL_XPRT*.
diff --git a/Makefile b/Makefile
index 6695974..5d83867 100644
--- a/Makefile
+++ b/Makefile
@@ -788,7 +788,8 @@
        src/xxhash.o src/hpack-enc.o src/h2.o src/freq_ctr.o src/lru.o         \
        src/protocol.o src/arg.o src/hpack-huff.o src/hdr_idx.o src/base64.o   \
        src/hash.o src/mailers.o src/activity.o src/http_msg.o src/version.o   \
-       src/mworker.o src/mworker-prog.o src/debug.o src/wdt.o src/dict.o
+       src/mworker.o src/mworker-prog.o src/debug.o src/wdt.o src/dict.o      \
+       src/xprt_handshake.o
 
 EBTREE_OBJS = $(EBTREE_DIR)/ebtree.o $(EBTREE_DIR)/eb32sctree.o \
               $(EBTREE_DIR)/eb32tree.o $(EBTREE_DIR)/eb64tree.o \
diff --git a/include/proto/connection.h b/include/proto/connection.h
index 3e4a1ef..ac4e5de 100644
--- a/include/proto/connection.h
+++ b/include/proto/connection.h
@@ -946,6 +946,41 @@
 	return registered_xprt[id];
 }
 
+/* Try to add a handshake pseudo-XPRT. If the connection's first XPRT is
+ * raw_sock, then just use the new XPRT as the connection XPRT, otherwise
+ * call the xprt's add_xprt() method.
+ * Returns 0 on success, or non-zero on failure.
+ */
+static inline int xprt_add_hs(struct connection *conn)
+{
+	void *xprt_ctx = NULL;
+	const struct xprt_ops *ops = xprt_get(XPRT_HANDSHAKE);
+	void *nextxprt_ctx = NULL;
+	const struct xprt_ops *nextxprt_ops = NULL;
+
+	if (conn->flags & CO_FL_ERROR)
+		return -1;
+	if (ops->init(conn, &xprt_ctx) < 0)
+		return -1;
+	if (conn->xprt == xprt_get(XPRT_RAW)) {
+		nextxprt_ctx = conn->xprt_ctx;
+		nextxprt_ops = conn->xprt;
+		conn->xprt_ctx = xprt_ctx;
+		conn->xprt = ops;
+	} else {
+		if (conn->xprt->add_xprt(conn, conn->xprt_ctx, xprt_ctx, ops,
+		                         &nextxprt_ctx, &nextxprt_ops) != 0) {
+			ops->close(conn, xprt_ctx);
+			return -1;
+		}
+	}
+	if (ops->add_xprt(conn, xprt_ctx, nextxprt_ctx, nextxprt_ops, NULL, NULL) != 0) {
+		ops->close(conn, xprt_ctx);
+		return -1;
+	}
+	return 0;
+}
+
 static inline int conn_get_alpn(const struct connection *conn, const char **str, int *len)
 {
 	if (!conn_xprt_ready(conn) || !conn->xprt->get_alpn)
diff --git a/include/types/connection.h b/include/types/connection.h
index 74060b0..e706b87 100644
--- a/include/types/connection.h
+++ b/include/types/connection.h
@@ -301,6 +301,7 @@
 enum {
 	XPRT_RAW = 0,
 	XPRT_SSL = 1,
+	XPRT_HANDSHAKE = 2,
 	XPRT_ENTRIES /* must be last one */
 };
 
diff --git a/src/backend.c b/src/backend.c
index cfd2462..36936a5 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1213,6 +1213,7 @@
 	int reuse_orphan = 0;
 	int init_mux = 0;
 	int alloced_cs = 0;
+	int flags_hs = 0;
 	int err;
 
 
@@ -1483,6 +1484,7 @@
 			return SF_ERR_INTERNAL;
 	}
 
+	flags_hs = srv_conn->flags & CO_FL_HANDSHAKE_NOSSL;
 	if (!conn_xprt_ready(srv_conn) && !srv_conn->mux) {
 		/* set the correct protocol on the output stream interface */
 		if (srv)
@@ -1590,6 +1592,15 @@
 		    srv_conn->mux->avail_streams(srv_conn) > 0)
 			LIST_ADD(&srv->idle_conns[tid], &srv_conn->list);
 	}
+	/* The CO_FL_SEND_PROXY flag may have been set by the connect method,
+	 * if so, add our handshake pseudo-XPRT now.
+	 */
+	if (!flags_hs && (srv_conn->flags & CO_FL_SEND_PROXY)) {
+		if (xprt_add_hs(srv_conn) < 0) {
+			conn_full_close(srv_conn);
+			return SF_ERR_INTERNAL;
+		}
+	}
 
 
 #if USE_OPENSSL && (defined(OPENSSL_IS_BORINGSSL) || (HA_OPENSSL_VERSION_NUMBER >= 0x10101000L))
diff --git a/src/checks.c b/src/checks.c
index c4d956e..308b4b7 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -1662,6 +1662,8 @@
 	if (s->check.send_proxy && !(check->state & CHK_ST_AGENT)) {
 		conn->send_proxy_ofs = 1;
 		conn->flags |= CO_FL_SEND_PROXY;
+		if (xprt_add_hs(conn) < 0)
+			ret = SF_ERR_RESOURCE;
 	}
 
 	return ret;
@@ -2885,6 +2887,8 @@
 			if (check->current_step->conn_opts & TCPCHK_OPT_SEND_PROXY) {
 				conn->send_proxy_ofs = 1;
 				conn->flags |= CO_FL_SEND_PROXY;
+				if (xprt_add_hs(conn) < 0)
+					ret = SF_ERR_RESOURCE;
 			}
 
 			/* It can return one of :
diff --git a/src/connection.c b/src/connection.c
index 1c81a0c..838d8fd 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -58,51 +58,12 @@
 
 	flags = conn->flags & ~CO_FL_ERROR; /* ensure to call the wake handler upon error */
 
- process_handshake:
-	/* The handshake callbacks are called in sequence. If either of them is
-	 * missing something, it must enable the required polling at the socket
-	 * layer of the connection. Polling state is not guaranteed when entering
-	 * these handlers, so any handshake handler which does not complete its
-	 * work must explicitly disable events it's not interested in. Error
-	 * handling is also performed here in order to reduce the number of tests
-	 * around.
-	 */
-	while (unlikely(conn->flags & (CO_FL_HANDSHAKE | CO_FL_ERROR))) {
-		if (unlikely(conn->flags & CO_FL_ERROR))
-			goto leave;
-
-		if (conn->flags & CO_FL_SOCKS4_SEND)
-			if (!conn_send_socks4_proxy_request(conn))
-				goto leave;
-
-		if (conn->flags & CO_FL_SOCKS4_RECV)
-			if (!conn_recv_socks4_proxy_response(conn))
-				goto leave;
-
-		if (conn->flags & CO_FL_ACCEPT_CIP)
-			if (!conn_recv_netscaler_cip(conn, CO_FL_ACCEPT_CIP))
-				goto leave;
-
-		if (conn->flags & CO_FL_ACCEPT_PROXY)
-			if (!conn_recv_proxy(conn, CO_FL_ACCEPT_PROXY))
-				goto leave;
-
-		if (conn->flags & CO_FL_SEND_PROXY)
-			if (!conn_si_send_proxy(conn, CO_FL_SEND_PROXY))
-				goto leave;
-		/* sock polling may have been activated by the connection,
-		 * so remove it if we don't want it.
-		 */
-		if (conn->flags & CO_FL_SSL_WAIT_HS) {
-			if (!conn->send_wait)
-				__conn_sock_stop_send(conn);
-			if (!conn->recv_wait)
-				__conn_sock_stop_recv(conn);
-			break;
-		}
+	if (conn->flags & CO_FL_HANDSHAKE) {
+		if (!conn->send_wait)
+			__conn_sock_stop_send(conn);
+		if (!conn->recv_wait)
+			__conn_sock_stop_recv(conn);
 	}
-
-	/* Once we're purely in the data phase, we disable handshake polling */
 	if (!(conn->flags & CO_FL_POLL_SOCK))
 		__conn_sock_stop_both(conn);
 
@@ -113,7 +74,7 @@
 	 * leave instead. The caller must immediately unregister itself once
 	 * called.
 	 */
-	if (!(conn->flags & CO_FL_SSL_WAIT_HS) &&
+	if (!(conn->flags & CO_FL_HANDSHAKE) &&
 	    conn->xprt_done_cb && conn->xprt_done_cb(conn) < 0)
 		return;
 
@@ -151,12 +112,6 @@
 		__conn_xprt_stop_recv(conn);
 	}
 
-	/* It may happen during the data phase that a handshake is
-	 * enabled again (eg: SSL)
-	 */
-	if (unlikely(conn->flags & (CO_FL_HANDSHAKE_NOSSL | CO_FL_ERROR)))
-		goto process_handshake;
-
 	if (unlikely(conn->flags & CO_FL_WAIT_L4_CONN)) {
 		/* still waiting for a connection to establish and nothing was
 		 * attempted yet to probe the connection. Then let's retry the
@@ -198,7 +153,7 @@
 	if ((io_available || (((conn->flags ^ flags) & CO_FL_NOTIFY_DATA) ||
 	     ((flags & (CO_FL_CONNECTED|CO_FL_HANDSHAKE)) != CO_FL_CONNECTED &&
 	      (conn->flags & (CO_FL_CONNECTED|CO_FL_HANDSHAKE)) == CO_FL_CONNECTED))) &&
-	    conn->mux->wake && conn->mux->wake(conn) < 0)
+	    conn->mux && conn->mux->wake && conn->mux->wake(conn) < 0)
 		return;
 
 	/* commit polling changes */
diff --git a/src/session.c b/src/session.c
index 718b97f..0ce1c4e 100644
--- a/src/session.c
+++ b/src/session.c
@@ -165,21 +165,22 @@
 	conn_ctrl_init(cli_conn);
 
 	/* wait for a PROXY protocol header */
-	if (l->options & LI_O_ACC_PROXY) {
+	if (l->options & LI_O_ACC_PROXY)
 		cli_conn->flags |= CO_FL_ACCEPT_PROXY;
-		conn_sock_want_recv(cli_conn);
-	}
 
 	/* wait for a NetScaler client IP insertion protocol header */
-	if (l->options & LI_O_ACC_CIP) {
+	if (l->options & LI_O_ACC_CIP)
 		cli_conn->flags |= CO_FL_ACCEPT_CIP;
-		conn_sock_want_recv(cli_conn);
-	}
 
 	conn_xprt_want_recv(cli_conn);
 	if (conn_xprt_init(cli_conn) < 0)
 		goto out_free_conn;
 
+	/* Add the handshake pseudo-XPRT */
+	if (cli_conn->flags & (CO_FL_ACCEPT_PROXY | CO_FL_ACCEPT_CIP)) {
+		if (xprt_add_hs(cli_conn) != 0)
+			goto out_free_conn;
+	}
 	sess = session_new(p, l, &cli_conn->obj_type);
 	if (!sess)
 		goto out_free_conn;
diff --git a/src/tcp_rules.c b/src/tcp_rules.c
index 13057ce..a70c4c0 100644
--- a/src/tcp_rules.c
+++ b/src/tcp_rules.c
@@ -455,12 +455,22 @@
 					stream_track_stkctr(&sess->stkctr[trk_idx(rule->action)], t, ts);
 			}
 			else if (rule->action == ACT_TCP_EXPECT_PX) {
+				if (!(conn->flags & (CO_FL_HANDSHAKE_NOSSL))) {
+					if (xprt_add_hs(conn) < 0) {
+						result = 0;
+						break;
+					}
+				}
 				conn->flags |= CO_FL_ACCEPT_PROXY;
-				conn_sock_want_recv(conn);
 			}
 			else if (rule->action == ACT_TCP_EXPECT_CIP) {
+				if (!(conn->flags & (CO_FL_HANDSHAKE_NOSSL))) {
+					if (xprt_add_hs(conn) < 0) {
+						result = 0;
+						break;
+					}
+				}
 				conn->flags |= CO_FL_ACCEPT_CIP;
-				conn_sock_want_recv(conn);
 			}
 			else {
 				/* Custom keywords. */
diff --git a/src/xprt_handshake.c b/src/xprt_handshake.c
new file mode 100644
index 0000000..2770385
--- /dev/null
+++ b/src/xprt_handshake.c
@@ -0,0 +1,306 @@
+/*
+ * Pseudo-xprt to handle any handshake except the SSL handshake
+ *
+ * Copyright 2019 HAProxy Technologies, Olivier Houchard <ohouchard@haproxy.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
+ * 2 of the License, or (at your option) any later version.
+ *
+ */
+
+#include <proto/connection.h>
+#include <proto/stream_interface.h>
+
+struct xprt_handshake_ctx {
+	struct connection *conn;
+	struct wait_event *send_wait;
+	struct wait_event *recv_wait;
+	struct wait_event wait_event;
+	const struct xprt_ops *xprt;
+	void *xprt_ctx;
+};
+
+DECLARE_STATIC_POOL(xprt_handshake_ctx_pool, "xprt_handshake_ctx_pool", sizeof(struct xprt_handshake_ctx));
+
+/* This XPRT doesn't take care of sending or receiving data, once its handshake
+ * is done, it just removes itself
+ */
+static size_t xprt_handshake_from_buf(struct connection *conn, void *xprt_ctx, const struct buffer *buf, size_t count, int flags)
+{
+	return 0;
+}
+
+static size_t xprt_handshake_to_buf(struct connection *conn, void *xprt_ctx, struct buffer *buf, size_t count, int flags)
+{
+	return 0;
+}
+
+static struct task *xprt_handshake_io_cb(struct task *t, void *bctx, unsigned short state)
+{
+	struct xprt_handshake_ctx *ctx = bctx;
+	struct connection *conn = ctx->conn;
+
+	if (conn->flags & CO_FL_SOCKS4_SEND)
+		if (!conn_send_socks4_proxy_request(conn)) {
+			ctx->xprt->subscribe(conn, ctx->xprt_ctx, SUB_RETRY_SEND,
+			                     &ctx->wait_event);
+
+			goto out;
+		}
+
+	if (conn->flags & CO_FL_SOCKS4_RECV)
+		if (!conn_recv_socks4_proxy_response(conn)) {
+			ctx->xprt->subscribe(conn, ctx->xprt_ctx, SUB_RETRY_RECV,
+			                     &ctx->wait_event);
+			goto out;
+		}
+
+	if (conn->flags & CO_FL_ACCEPT_CIP)
+		if (!conn_recv_netscaler_cip(conn, CO_FL_ACCEPT_CIP)) {
+			ctx->xprt->subscribe(conn, ctx->xprt_ctx, SUB_RETRY_RECV,
+			    &ctx->wait_event);
+			goto out;
+		}
+
+	if (conn->flags & CO_FL_ACCEPT_PROXY)
+		if (!conn_recv_proxy(conn, CO_FL_ACCEPT_PROXY)) {
+			ctx->xprt->subscribe(conn, ctx->xprt_ctx, SUB_RETRY_RECV,
+			    &ctx->wait_event);
+			goto out;
+		}
+
+	if (conn->flags & CO_FL_SEND_PROXY)
+		if (!conn_si_send_proxy(conn, CO_FL_SEND_PROXY)) {
+			ctx->xprt->subscribe(conn, ctx->xprt_ctx, SUB_RETRY_SEND,
+			    &ctx->wait_event);
+			goto out;
+		}
+
+out:
+	/* Wake the stream if we're done with the handshake, or we have a
+	 * connection error
+	 * */
+	if ((conn->flags & CO_FL_ERROR) ||
+	    !(conn->flags & CO_FL_HANDSHAKE_NOSSL)) {
+		int ret = 0;
+		int woke = 0;
+		int was_conn_ctx = 0;
+		/* On error, wake any waiter */
+		if (ctx->recv_wait) {
+			ctx->recv_wait->events &= ~SUB_RETRY_RECV;
+			tasklet_wakeup(ctx->recv_wait->task);
+			woke = 1;
+			ctx->recv_wait = NULL;
+		}
+		if (ctx->send_wait) {
+			ctx->send_wait->events &= ~SUB_RETRY_SEND;
+			tasklet_wakeup(ctx->send_wait->task);
+			woke = 1;
+			ctx->send_wait = NULL;
+		}
+		if (!(conn->flags & CO_FL_ERROR))
+			conn->flags |= CO_FL_CONNECTED;
+		/* Remove ourself from the xprt chain */
+		if (ctx->wait_event.events != 0)
+			ctx->xprt->unsubscribe(ctx->conn,
+			    ctx->xprt_ctx,
+			    ctx->wait_event.events,
+			    &ctx->wait_event);
+		if (conn->xprt_ctx == ctx) {
+			conn->xprt_ctx = ctx->xprt_ctx;
+			conn->xprt = ctx->xprt;
+			was_conn_ctx = 1;
+		} else
+			conn->xprt->remove_xprt(conn, conn->xprt_ctx, ctx,
+			    ctx->xprt, ctx->xprt_ctx);
+		/* If we're the first xprt for the connection, let the
+		 * upper layers know. If xprt_done_cb() is set, call it,
+		 * and if we have a mux, and it has a wake method, call it
+		 * too.
+		 */
+		if (was_conn_ctx) {
+			if (ctx->conn->xprt_done_cb)
+				ret = ctx->conn->xprt_done_cb(ctx->conn);
+			if (ret >= 0 && !woke && ctx->conn->mux && ctx->conn->mux->wake)
+				ret = ctx->conn->mux->wake(ctx->conn);
+		}
+		tasklet_free(ctx->wait_event.task);
+		pool_free(xprt_handshake_ctx_pool, ctx);
+	}
+	return NULL;
+}
+
+static int xprt_handshake_init(struct connection *conn, void **xprt_ctx)
+{
+	struct xprt_handshake_ctx *ctx;
+	/* already initialized */
+	if (*xprt_ctx)
+		return 0;
+	if (!conn_ctrl_ready(conn))
+		return 0;
+
+	ctx = pool_alloc(xprt_handshake_ctx_pool);
+	if (!ctx) {
+		conn->err_code = CO_ER_SSL_NO_MEM;
+		return -1;
+	}
+	ctx->conn = conn;
+	ctx->wait_event.task = tasklet_new();
+	if (!ctx->wait_event.task) {
+		conn->err_code = CO_ER_SSL_NO_MEM;
+		pool_free(xprt_handshake_ctx_pool, ctx);
+		return -1;
+	}
+	ctx->wait_event.task->process = xprt_handshake_io_cb;
+	ctx->wait_event.task->context = ctx;
+	ctx->wait_event.events = 0;
+	/* This XPRT expects the underlying XPRT to be provided later,
+	 * with an add_xprt() call, so we start trying to do the handshake
+	 * there, when we'll be provided an XPRT.
+	 */
+	ctx->xprt = NULL;
+	ctx->xprt_ctx = NULL;
+	ctx->send_wait = ctx->recv_wait = NULL;
+	*xprt_ctx = ctx;
+
+	return 0;
+}
+
+static void xprt_handshake_close(struct connection *conn, void *xprt_ctx)
+{
+	struct xprt_handshake_ctx *ctx = xprt_ctx;
+
+	if (ctx) {
+		if (ctx->wait_event.events != 0)
+			ctx->xprt->unsubscribe(ctx->conn, ctx->xprt_ctx,
+			                       ctx->wait_event.events,
+					       &ctx->wait_event);
+		if (ctx->send_wait) {
+			ctx->send_wait->events &= ~SUB_RETRY_SEND;
+			tasklet_wakeup(ctx->send_wait->task);
+		}
+		if (ctx->recv_wait) {
+			ctx->recv_wait->events &= ~SUB_RETRY_RECV;
+			tasklet_wakeup(ctx->recv_wait->task);
+		}
+
+		if (ctx->xprt && ctx->xprt->close)
+			ctx->xprt->close(conn, ctx->xprt_ctx);
+		/* Remove any handshake flag, and if we were the connection
+		 * xprt, get back to XPRT_RAW. If we're here because we
+		 * failed an outoging connection, it will be retried using
+		 * the same struct connection, and as xprt_handshake is a bit
+		 * magic, because it requires a call to add_xprt(), it's better
+		 * to fallback to the original XPRT to re-initiate the
+		 * connection.
+		 */
+		conn->flags &= ~CO_FL_HANDSHAKE_NOSSL;
+		if (conn->xprt == xprt_get(XPRT_HANDSHAKE))
+			conn->xprt = xprt_get(XPRT_RAW);
+		tasklet_free(ctx->wait_event.task);
+		pool_free(xprt_handshake_ctx_pool, ctx);
+	}
+}
+
+static int xprt_handshake_subscribe(struct connection *conn, void *xprt_ctx, int event_type, void *param)
+{
+	struct wait_event *sw;
+	struct xprt_handshake_ctx *ctx = xprt_ctx;
+
+	if (event_type & SUB_RETRY_RECV) {
+		sw = param;
+		BUG_ON(ctx->recv_wait !=  NULL || (sw->events & SUB_RETRY_RECV));
+		sw->events |= SUB_RETRY_RECV;
+		ctx->recv_wait = sw;
+		event_type &= ~SUB_RETRY_RECV;
+	}
+	if (event_type & SUB_RETRY_SEND) {
+		sw = param;
+		BUG_ON(ctx->send_wait !=  NULL || (sw->events & SUB_RETRY_SEND));
+		sw->events |= SUB_RETRY_SEND;
+		ctx->send_wait = sw;
+		event_type &= ~SUB_RETRY_SEND;
+        }
+	if (event_type != 0)
+                return -1;
+        return 0;
+
+}
+
+static int xprt_handshake_unsubscribe(struct connection *conn, void *xprt_ctx, int event_type, void *param)
+{
+	struct wait_event *sw;
+	struct xprt_handshake_ctx *ctx = xprt_ctx;
+
+	if (event_type & SUB_RETRY_RECV) {
+		sw = param;
+                BUG_ON(ctx->recv_wait != sw);
+                ctx->recv_wait = NULL;
+                sw->events &= ~SUB_RETRY_RECV;
+	}
+	if (event_type & SUB_RETRY_SEND) {
+		sw = param;
+		BUG_ON(ctx->send_wait != sw);
+		ctx->send_wait = NULL;
+		sw->events &= ~SUB_RETRY_SEND;
+	}
+	return 0;
+}
+
+/* Use the provided XPRT as an underlying XPRT, and provide the old one.
+ * Returns 0 on success, and non-zero on failure.
+ */
+static int xprt_handshake_add_xprt(struct connection *conn, void *xprt_ctx, void *toadd_ctx, const struct xprt_ops *toadd_ops, void **oldxprt_ctx, const struct xprt_ops **oldxprt_ops)
+{
+	struct xprt_handshake_ctx *ctx = xprt_ctx;
+
+	if (oldxprt_ops)
+		*oldxprt_ops = ctx->xprt;
+	if (oldxprt_ctx)
+		*oldxprt_ctx = ctx->xprt_ctx;
+	ctx->xprt = toadd_ops;
+	ctx->xprt_ctx = toadd_ctx;
+	/* Ok we know have an xprt, so let's try to do the handshake */
+	tasklet_wakeup(ctx->wait_event.task);
+	return 0;
+}
+
+/* Remove the specified xprt. If if it our underlying XPRT, remove it and
+ * return 0, otherwise just call the remove_xprt method from the underlying
+ * XPRT.
+ */
+static int xprt_handshake_remove_xprt(struct connection *conn, void *xprt_ctx, void *toremove_ctx, const struct xprt_ops *newops, void *newctx)
+{
+	struct xprt_handshake_ctx *ctx = xprt_ctx;
+
+	if (ctx->xprt_ctx == toremove_ctx) {
+		ctx->xprt_ctx = newctx;
+		ctx->xprt = newops;
+		return 0;
+	}
+	return (ctx->xprt->remove_xprt(conn, ctx->xprt_ctx, toremove_ctx, newops, newctx));
+}
+
+struct xprt_ops xprt_handshake = {
+	.snd_buf  = xprt_handshake_from_buf,
+	.rcv_buf  = xprt_handshake_to_buf,
+	.subscribe = xprt_handshake_subscribe,
+	.unsubscribe = xprt_handshake_unsubscribe,
+	.remove_xprt = xprt_handshake_remove_xprt,
+	.add_xprt = xprt_handshake_add_xprt,
+	.init = xprt_handshake_init,
+	.close= xprt_handshake_close,
+	.rcv_pipe = NULL,
+	.snd_pipe = NULL,
+	.shutr    = NULL,
+	.shutw    = NULL,
+	.name     = "HS",
+};
+
+__attribute__((constructor))
+static void __xprt_handshake_init(void)
+{
+	xprt_register(XPRT_HANDSHAKE, &xprt_handshake);
+}