diff --git a/include/haproxy/stconn-t.h b/include/haproxy/stconn-t.h
index 39b479b0c..1aace1287 100644
--- a/include/haproxy/stconn-t.h
+++ b/include/haproxy/stconn-t.h
@@ -30,10 +30,16 @@
 
 enum iobuf_flags {
 	IOBUF_FL_NONE             = 0x00000000, /* For initialization purposes */
+	IOBUF_FL_NO_FF            = 0x00000001, /* Fast-forwarding is not supported */
+	IOBUF_FL_NO_SPLICING      = 0x00000002, /* Splicing is not supported or unusable for this stream */
+	IOBUF_FL_FF_BLOCKED       = 0x00000004, /* Fast-forwarding is blocked (buffer allocation/full) */
 };
 
 struct iobuf {
 	struct pipe *pipe;     /* non-NULL only when data present */
+	struct buffer *buf;
+	size_t offset;
+	size_t data;
 	unsigned int flags;
 };
 
diff --git a/include/haproxy/stconn.h b/include/haproxy/stconn.h
index d58fd791e..12ac81b21 100644
--- a/include/haproxy/stconn.h
+++ b/include/haproxy/stconn.h
@@ -124,12 +124,12 @@ static inline void se_expect_data(struct sedesc *se)
 
 static inline unsigned int se_have_ff_data(struct sedesc *se)
 {
-	return ((long)se->iobuf.pipe);
+	return (se->iobuf.data | (long)se->iobuf.pipe);
 }
 
 static inline size_t se_ff_data(struct sedesc *se)
 {
-	return ((se->iobuf.pipe ? se->iobuf.pipe->data : 0));
+	return (se->iobuf.data + (se->iobuf.pipe ? se->iobuf.pipe->data : 0));
 }
 
 
diff --git a/src/stconn.c b/src/stconn.c
index 63d4383e0..f208678da 100644
--- a/src/stconn.c
+++ b/src/stconn.c
@@ -99,6 +99,8 @@ void sedesc_init(struct sedesc *sedesc)
 	se_fl_setall(sedesc, SE_FL_NONE);
 
 	sedesc->iobuf.pipe = NULL;
+	sedesc->iobuf.buf = NULL;
+	sedesc->iobuf.offset = sedesc->iobuf.data = 0;
 	sedesc->iobuf.flags = IOBUF_FL_NONE;
 }
 
diff --git a/src/stream.c b/src/stream.c
index 06db5636f..6ccbe8623 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -3307,6 +3307,14 @@ void strm_dump_to_buffer(struct buffer *buf, const struct stream *strm, const ch
 	chunk_appendf(buf, " wex=%s\n",
 		      sc_ep_snd_ex(scf) ? human_time(TICKS_TO_MS(sc_ep_snd_ex(scf) - now_ms), TICKS_TO_MS(1000)) : "<NEVER>");
 
+	chunk_appendf(&trash, "%s    iobuf.flags=0x%08x .pipe=%d .buf=%u@%p+%u/%u\n", pfx,
+		      scf->sedesc->iobuf.flags,
+		      scf->sedesc->iobuf.pipe ? scf->sedesc->iobuf.pipe->data : 0,
+		      scf->sedesc->iobuf.buf ? (unsigned int)b_data(scf->sedesc->iobuf.buf): 0,
+		      scf->sedesc->iobuf.buf ? b_orig(scf->sedesc->iobuf.buf): NULL,
+		      scf->sedesc->iobuf.buf ? (unsigned int)b_head_ofs(scf->sedesc->iobuf.buf): 0,
+		      scf->sedesc->iobuf.buf ? (unsigned int)b_size(scf->sedesc->iobuf.buf): 0);
+
 	if ((conn = sc_conn(scf)) != NULL) {
 		if (conn->mux && conn->mux->show_sd) {
 			char muxpfx[100] = "";
@@ -3356,6 +3364,14 @@ void strm_dump_to_buffer(struct buffer *buf, const struct stream *strm, const ch
 	chunk_appendf(buf, " wex=%s\n",
 		      sc_ep_snd_ex(scb) ? human_time(TICKS_TO_MS(sc_ep_snd_ex(scb) - now_ms), TICKS_TO_MS(1000)) : "<NEVER>");
 
+	chunk_appendf(&trash, "%s    iobuf.flags=0x%08x .pipe=%d .buf=%u@%p+%u/%u\n", pfx,
+		      scb->sedesc->iobuf.flags,
+		      scb->sedesc->iobuf.pipe ? scb->sedesc->iobuf.pipe->data : 0,
+		      scb->sedesc->iobuf.buf ? (unsigned int)b_data(scb->sedesc->iobuf.buf): 0,
+		      scb->sedesc->iobuf.buf ? b_orig(scb->sedesc->iobuf.buf): NULL,
+		      scb->sedesc->iobuf.buf ? (unsigned int)b_head_ofs(scb->sedesc->iobuf.buf): 0,
+		      scb->sedesc->iobuf.buf ? (unsigned int)b_size(scb->sedesc->iobuf.buf): 0);
+
 	if ((conn = sc_conn(scb)) != NULL) {
 		if (conn->mux && conn->mux->show_sd) {
 			char muxpfx[100] = "";
@@ -3408,12 +3424,11 @@ void strm_dump_to_buffer(struct buffer *buf, const struct stream *strm, const ch
 	}
 
 	chunk_appendf(buf,
-		     "%s  req=%p (f=0x%06x an=0x%x pipe=%d tofwd=%d total=%lld)\n"
+		     "%s  req=%p (f=0x%06x an=0x%x tofwd=%d total=%lld)\n"
 		     "%s      an_exp=%s buf=%p data=%p o=%u p=%u i=%u size=%u\n",
 		     pfx,
 		     &strm->req,
 		     strm->req.flags, strm->req.analysers,
-		     strm->scb->sedesc->iobuf.pipe ? strm->scb->sedesc->iobuf.pipe->data : 0,
 		     strm->req.to_forward, strm->req.total,
 		     pfx,
 		     strm->req.analyse_exp ?
@@ -3441,12 +3456,11 @@ void strm_dump_to_buffer(struct buffer *buf, const struct stream *strm, const ch
 	}
 
 	chunk_appendf(buf,
-		     "%s  res=%p (f=0x%06x an=0x%x pipe=%d tofwd=%d total=%lld)\n"
+		     "%s  res=%p (f=0x%06x an=0x%x tofwd=%d total=%lld)\n"
 		     "%s      an_exp=%s buf=%p data=%p o=%u p=%u i=%u size=%u\n",
 		     pfx,
 		     &strm->res,
 		     strm->res.flags, strm->res.analysers,
-		     strm->scf->sedesc->iobuf.pipe ? strm->scf->sedesc->iobuf.pipe->data : 0,
 		     strm->res.to_forward, strm->res.total,
 		     pfx,
 		     strm->res.analyse_exp ?