From 8d4ceb9cc49dded04f320ed36c92350355755077 Mon Sep 17 00:00:00 2001 From: Stephen Hurd Date: Wed, 14 Nov 2018 15:23:39 +0000 Subject: [PATCH] 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 MFC after: 1 week Sponsored by: Limelight Networks Differential Revision: https://reviews.freebsd.org/D17801 --- sys/net/iflib.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/sys/net/iflib.c b/sys/net/iflib.c index e13d2a9d9d27..1925a6d0f7c5 100644 --- a/sys/net/iflib.c +++ b/sys/net/iflib.c @@ -2973,9 +2973,6 @@ iflib_parse_header(iflib_txq_t txq, if_pkt_info_t pi, struct mbuf **mp) 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, struct mbuf **mp) 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, struct mbuf **mp) } } } + 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, struct mbuf **mp) 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);