From: jan <jan@openbsd.org>
Date: Fri, 2 Sep 2022 14:08:09 +0000 (+0000)
Subject: Fix TSO large receive offloading in ix(4).
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=f09e68de7a2f31e9de90f7dfdb80212c85f7653f;p=openbsd

Fix TSO large receive offloading in ix(4).

Without this diff it might happen that content of different
TCP connection get mixed up, when reading coalesced buffers
from the receive ring.

Thanks, for a lot of testing effort to mbuhl.

OK mbuhl@
---

diff --git a/sys/dev/pci/if_ix.c b/sys/dev/pci/if_ix.c
index 550fdfd3025..b59ec28d9f1 100644
--- a/sys/dev/pci/if_ix.c
+++ b/sys/dev/pci/if_ix.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_ix.c,v 1.188 2022/08/30 19:52:58 benno Exp $	*/
+/*	$OpenBSD: if_ix.c,v 1.189 2022/09/02 14:08:09 jan Exp $	*/
 
 /******************************************************************************
 
@@ -3110,7 +3110,7 @@ ixgbe_rxeof(struct rx_ring *rxr)
 	struct ixgbe_rx_buf	*rxbuf, *nxbuf;
 	union ixgbe_adv_rx_desc	*rxdesc;
 	size_t			 dsize = sizeof(union ixgbe_adv_rx_desc);
-	int			 i, nextp;
+	int			 i, nextp, rsccnt;
 
 	if (!ISSET(ifp->if_flags, IFF_RUNNING))
 		return FALSE;
@@ -3149,6 +3149,9 @@ ixgbe_rxeof(struct rx_ring *rxr)
 		hashtype =
 		    lemtoh16(&rxdesc->wb.lower.lo_dword.hs_rss.pkt_info) &
 		    IXGBE_RXDADV_RSSTYPE_MASK;
+		rsccnt = lemtoh32(&rxdesc->wb.lower.lo_dword.data) &
+		    IXGBE_RXDADV_RSCCNT_MASK;
+		rsccnt >>= IXGBE_RXDADV_RSCCNT_SHIFT;
 
 		if (staterr & IXGBE_RXDADV_ERR_FRAME_ERR_MASK) {
 			if (rxbuf->fmp) {
@@ -3168,12 +3171,16 @@ ixgbe_rxeof(struct rx_ring *rxr)
 			    rxr->last_desc_filled);
 		}
 
-		/* Currently no HW RSC support of 82599 */
 		if (!eop) {
 			/*
 			 * Figure out the next descriptor of this frame.
 			 */
-			nextp = i + 1;
+			if (rsccnt) {
+				nextp = staterr & IXGBE_RXDADV_NEXTP_MASK;
+				nextp >>= IXGBE_RXDADV_NEXTP_SHIFT;
+			} else {
+				nextp = i + 1;
+			}
 			if (nextp == sc->num_rx_desc)
 				nextp = 0;
 			nxbuf = &rxr->rx_buffers[nextp];