0002-batman-adv-add-fixes-for-packet-checksum-handling.patch

From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Mon, 22 Jan 2018 20:41:41 +0100
Subject: batman-adv: add fixes for packet checksum handling

diff --git a/batman-adv/patches/0001-batman-adv-fix-packet-checksum-in-receive-path.patch b/batman-adv/patches/0001-batman-adv-fix-packet-checksum-in-receive-path.patch
new file mode 100644
index 0000000000000000000000000000000000000000..ce1a5345be1405ccf034ab948b2061be46cda090
--- /dev/null
+++ b/batman-adv/patches/0001-batman-adv-fix-packet-checksum-in-receive-path.patch
@@ -0,0 +1,44 @@
+From 05cee97344804ffb2a8df87603663a098fd0cb36 Mon Sep 17 00:00:00 2001
+Message-Id: <05cee97344804ffb2a8df87603663a098fd0cb36.1516705934.git.mschiffer@universe-factory.net>
+From: Matthias Schiffer <mschiffer@universe-factory.net>
+Date: Mon, 22 Jan 2018 20:06:51 +0100
+Subject: [PATCH 1/2] batman-adv: fix packet checksum in receive path
+
+eth_type_trans() internally calls skb_pull(), which does not adjust the
+skb checksum; skb_postpull_rcsum() is necessary to avoid log spam of the
+form "bat0: hw csum failure" when packets with CHECKSUM_COMPLETE are
+received.
+
+Note that in usual setups, packets don't reach batman-adv with
+CHECKSUM_COMPLETE (I assume NICs bail out of checksumming when they see
+batadv's ethtype?), which is why the log messages do nor occur on every
+system using batman-adv. I could reproduce this issue by stacking
+batman-adv on top of a VXLAN interface.
+
+Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
+---
+ net/batman-adv/soft-interface.c | 8 +-------
+ 1 file changed, 1 insertion(+), 7 deletions(-)
+
+diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
+index 9f673cdf..6f7ce7a6 100644
+--- a/net/batman-adv/soft-interface.c
++++ b/net/batman-adv/soft-interface.c
+@@ -451,13 +451,7 @@ void batadv_interface_rx(struct net_device *soft_iface,
+ 
+ 	/* skb->dev & skb->pkt_type are set here */
+ 	skb->protocol = eth_type_trans(skb, soft_iface);
+-
+-	/* should not be necessary anymore as we use skb_pull_rcsum()
+-	 * TODO: please verify this and remove this TODO
+-	 * -- Dec 21st 2009, Simon Wunderlich
+-	 */
+-
+-	/* skb->ip_summed = CHECKSUM_UNNECESSARY; */
++	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+ 
+ 	batadv_inc_counter(bat_priv, BATADV_CNT_RX);
+ 	batadv_add_counter(bat_priv, BATADV_CNT_RX_BYTES,
+-- 
+2.16.1
+
diff --git a/batman-adv/patches/0002-batman-adv-invalidate-checksum-on-fragment-reassembl.patch b/batman-adv/patches/0002-batman-adv-invalidate-checksum-on-fragment-reassembl.patch
new file mode 100644
index 0000000000000000000000000000000000000000..957fc345846acde05345963bcd66eed47b167358
--- /dev/null
+++ b/batman-adv/patches/0002-batman-adv-invalidate-checksum-on-fragment-reassembl.patch
@@ -0,0 +1,42 @@
+From 3f5713999a5f61ed7221944276393b4ff40a9416 Mon Sep 17 00:00:00 2001
+Message-Id: <3f5713999a5f61ed7221944276393b4ff40a9416.1516705934.git.mschiffer@universe-factory.net>
+In-Reply-To: <05cee97344804ffb2a8df87603663a098fd0cb36.1516705934.git.mschiffer@universe-factory.net>
+References: <05cee97344804ffb2a8df87603663a098fd0cb36.1516705934.git.mschiffer@universe-factory.net>
+From: Matthias Schiffer <mschiffer@universe-factory.net>
+Date: Tue, 23 Jan 2018 10:24:45 +0100
+Subject: [PATCH 2/2] batman-adv: invalidate checksum on fragment reassembly
+
+A more sophisticated implementation could try to combine fragment checksums
+when all fragments have CHECKSUM_COMPLETE and are split at even offsets.