diff --git a/include/haproxy/connection-t.h b/include/haproxy/connection-t.h
index 3bee5fd43..ce6bf1177 100644
--- a/include/haproxy/connection-t.h
+++ b/include/haproxy/connection-t.h
@@ -274,6 +274,7 @@ enum {
 	CO_RFL_READ_ONCE     = 0x0004,    /* don't loop even if the request/response is small */
 	CO_RFL_KEEP_RECV     = 0x0008,    /* Instruct the mux to still wait for read events  */
 	CO_RFL_BUF_NOT_STUCK = 0x0010,    /* Buffer is not stuck. Optims are possible during data copy */
+	CO_RFL_MAY_SPLICE    = 0x0020,    /* The producer can use the kernel splicing */
 };
 
 /* flags that can be passed to xprt->snd_buf() and mux->snd_buf() */
@@ -422,6 +423,10 @@ struct mux_ops {
 	int  (*wake)(struct connection *conn);        /* mux-layer callback to report activity, mandatory */
 	size_t (*rcv_buf)(struct stconn *sc, struct buffer *buf, size_t count, int flags); /* Called from the upper layer to get data */
 	size_t (*snd_buf)(struct stconn *sc, struct buffer *buf, size_t count, int flags); /* Called from the upper layer to send data */
+	size_t (*init_fastfwd)(struct stconn *sc, struct buffer *input, size_t count, unsigned int may_splice); /* Callback to fill the SD iobuf */
+	void (*done_fastfwd)(struct stconn *sc); /* Callback to terminate fast data forwarding */
+	int (*fastfwd)(struct stconn *sc, unsigned int count, unsigned int flags); /* Callback to init fast data forwarding */
+	int (*resume_fastfwd)(struct stconn *sc, unsigned int flags); /* Callback to resume fast data forwarding */
 	int  (*rcv_pipe)(struct stconn *sc, struct pipe *pipe, unsigned int count); /* recv-to-pipe callback */
 	int  (*snd_pipe)(struct stconn *sc, struct pipe *pipe); /* send-to-pipe callback */
 	void (*shutr)(struct stconn *sc, enum co_shr_mode);     /* shutr function */
diff --git a/include/haproxy/stconn.h b/include/haproxy/stconn.h
index 12ac81b21..71338ada1 100644
--- a/include/haproxy/stconn.h
+++ b/include/haproxy/stconn.h
@@ -132,6 +132,40 @@ static inline size_t se_ff_data(struct sedesc *se)
 	return (se->iobuf.data + (se->iobuf.pipe ? se->iobuf.pipe->data : 0));
 }
 
+static inline size_t se_init_ff(struct sedesc *se, struct buffer *input, size_t count, unsigned int may_splice)
+{
+	size_t ret = 0;
+
+	if (se_fl_test(se, SE_FL_T_MUX)) {
+		const struct mux_ops *mux = se->conn->mux;
+
+		se->iobuf.flags &= ~IOBUF_FL_FF_BLOCKED;
+		if (mux->init_fastfwd && mux->done_fastfwd) {
+			ret = mux->init_fastfwd(se->sc, input, count, may_splice);
+			if ((se->iobuf.flags & IOBUF_FL_FF_BLOCKED) && !(se->sc->wait_event.events & SUB_RETRY_SEND)) {
+				/* The SC must be subs for send to be notify when some
+				 * space is made
+				 */
+				mux->subscribe(se->sc, SUB_RETRY_SEND, &se->sc->wait_event);
+			}
+			goto end;
+		}
+	}
+	se->iobuf.flags |= IOBUF_FL_NO_FF;
+
+  end:
+	return ret;
+}
+
+static inline void se_done_ff(struct sedesc *se)
+{
+	if (se_fl_test(se, SE_FL_T_MUX)) {
+		const struct mux_ops *mux = se->conn->mux;
+
+		BUG_ON(!mux->done_fastfwd);
+		mux->done_fastfwd(se->sc);
+	}
+}
 
 /* stream connector version */
 static forceinline void sc_ep_zero(struct stconn *sc)