svn commit: r340435 - head/sys/net

[Stephen Hurd]

Author: shurd
Date: Wed Nov 14 15:23:39 2018
New Revision: 340435
URL: https://svnweb.freebsd.org/changeset/base/340435

Log:
  Prevent POLA violation with TSO/CSUM offload
  
  Ensure that any time CSUM_IP_TSO or CSUM_IP6_TSO is set that the corresponding
  CSUM_IP6?_TCP / CSUM_IP flags are also set.
  
  Rather than requireing drivers to bake-in an understanding that TSO implies
  checksum offloads, make it explicit.
  
  This change requires us to move the IFLIB_NEED_ZERO_CSUM implementation to
  ensure it's zeroed for TSO.
  
  Reported by:	Jacob Keller <jacob.e.keller at intel.com>
  MFC after:	1 week
  Sponsored by:	Limelight Networks
  Differential Revision:	https://reviews.freebsd.org/D17801

Modified:
  head/sys/net/iflib.c

Modified: head/sys/net/iflib.c
==============================================================================
--- head/sys/net/iflib.c	Wed Nov 14 15:16:45 2018	(r340434)
+++ head/sys/net/iflib.c	Wed Nov 14 15:23:39 2018	(r340435)
@@ -2973,9 +2973,6 @@ iflib_parse_header(iflib_txq_t txq, if_pkt_info_t pi, 
 		pi->ipi_ipproto = ip->ip_p;
 		pi->ipi_flags |= IPI_TX_IPV4;
 
-		if ((sctx->isc_flags & IFLIB_NEED_ZERO_CSUM) && (pi->ipi_csum_flags & CSUM_IP))
-                       ip->ip_sum = 0;
-
 		/* TCP checksum offload may require TCP header length */
 		if (IS_TX_OFFLOAD4(pi)) {
 			if (__predict_true(pi->ipi_ipproto == IPPROTO_TCP)) {
@@ -2992,6 +2989,10 @@ iflib_parse_header(iflib_txq_t txq, if_pkt_info_t pi, 
 			if (IS_TSO4(pi)) {
 				if (__predict_false(ip->ip_p != IPPROTO_TCP))
 					return (ENXIO);
+				/*
+				 * TSO always requires hardware checksum offload.
+				 */
+				pi->ipi_csum_flags |= (CSUM_IP_TCP | CSUM_IP);
 				th->th_sum = in_pseudo(ip->ip_src.s_addr,
 						       ip->ip_dst.s_addr, htons(IPPROTO_TCP));
 				pi->ipi_tso_segsz = m->m_pkthdr.tso_segsz;
@@ -3001,6 +3002,9 @@ iflib_parse_header(iflib_txq_t txq, if_pkt_info_t pi, 
 				}
 			}
 		}
+		if ((sctx->isc_flags & IFLIB_NEED_ZERO_CSUM) && (pi->ipi_csum_flags & CSUM_IP))
+                       ip->ip_sum = 0;
+
 		break;
 	}
 #endif
@@ -3038,9 +3042,7 @@ iflib_parse_header(iflib_txq_t txq, if_pkt_info_t pi, 
 				if (__predict_false(ip6->ip6_nxt != IPPROTO_TCP))
 					return (ENXIO);
 				/*
-				 * The corresponding flag is set by the stack in the IPv4
-				 * TSO case, but not in IPv6 (at least in FreeBSD 10.2).
-				 * So, set it here because the rest of the flow requires it.
+				 * TSO always requires hardware checksum offload.
 				 */
 				pi->ipi_csum_flags |= CSUM_IP6_TCP;
 				th->th_sum = in6_cksum_pseudo(ip6, 0, IPPROTO_TCP, 0);