diff mbox

[ovs-dev,02/11] datapath: more accurate checksumming in queue_userspace_packet()

Message ID 20170721234614.2800-3-joe@ovn.org
State Accepted
Headers show

Commit Message

Joe Stringer July 21, 2017, 11:46 p.m. UTC 
Upstream commit:
    commit 7529390d08f07fbf9b0174c5a87600b5caa1a8e8
    Author: Davide Caratti <dcaratti@redhat.com>
    Date:   Thu May 18 15:44:42 2017 +0200

    openvswitch: more accurate checksumming in queue_userspace_packet()

    if skb carries an SCTP packet and ip_summed is CHECKSUM_PARTIAL, it needs
    CRC32c in place of Internet Checksum: use skb_csum_hwoffload_help to avoid
    corrupting such packets while queueing them towards userspace.

    Signed-off-by: Davide Caratti <dcaratti@redhat.com>
    Signed-off-by: David S. Miller <davem@davemloft.net>

Signed-off-by: Joe Stringer <joe@ovn.org>
---
 acinclude.m4                                    |  1 +
 datapath/datapath.c                             |  2 +-
 datapath/linux/compat/include/linux/netdevice.h | 15 +++++++++++++++
 3 files changed, 17 insertions(+), 1 deletion(-)
diff mbox

Patch

diff --git a/acinclude.m4 b/acinclude.m4
index 62a91e650a4a..91a5585e2512 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -538,6 +538,7 @@  AC_DEFUN([OVS_CHECK_LINUX_COMPAT], [
                   [OVS_DEFINE([HAVE_PCPU_SW_NETSTATS])])
   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [netif_needs_gso.*net_device],
                   [OVS_DEFINE([HAVE_NETIF_NEEDS_GSO_NETDEV])])
+  OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [skb_csum_hwoffload_help])
   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload])
   OVS_GREP_IFELSE([$KSRC/include/linux/netdevice.h], [udp_offload.*uoff],
                   [OVS_DEFINE([HAVE_UDP_OFFLOAD_ARG_UOFF])])
diff --git a/datapath/datapath.c b/datapath/datapath.c
index 82cad74b7972..6d252d7516d3 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -460,7 +460,7 @@  static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 
 	/* Complete checksum if needed */
 	if (skb->ip_summed == CHECKSUM_PARTIAL &&
-	    (err = skb_checksum_help(skb)))
+	    (err = skb_csum_hwoffload_help(skb, 0)))
 		goto out;
 
 	/* Older versions of OVS user space enforce alignment of the last
diff --git a/datapath/linux/compat/include/linux/netdevice.h b/datapath/linux/compat/include/linux/netdevice.h
index 75315dc16e02..878c30a6da4a 100644
--- a/datapath/linux/compat/include/linux/netdevice.h
+++ b/datapath/linux/compat/include/linux/netdevice.h
@@ -270,4 +270,19 @@  static inline void netdev_reset_rx_headroom(struct net_device *dev)
 #define IFF_NO_QUEUE 0
 #endif
 
+#ifndef HAVE_SKB_CSUM_HWOFFLOAD_HELP
+static inline int skb_csum_hwoffload_help(struct sk_buff *skb,
+					  const netdev_features_t features)
+{
+	/* It's less accurate to approximate to this for older kernels, but
+	 * it was sufficient for a long time. If you care about ensuring that
+	 * upstream commit 7529390d08f0 has the same effect on older kernels,
+	 * consider backporting the following commits:
+	 * b72b5bf6a8fc ("net: introduce skb_crc32c_csum_help")
+	 * 43c26a1a4593 ("net: more accurate checksumming in validate_xmit_skb()")
+	 */
+	return skb_checksum_help(skb);
+}
+#endif
+
 #endif /* __LINUX_NETDEVICE_WRAPPER_H */