Commit 01deb691 authored by Willem de Bruijn's avatar Willem de Bruijn Committed by Sasha Levin

net: avoid skb_warn_bad_offload false positives on UFO

[ Upstream commit 8d63bee6 ]

skb_warn_bad_offload triggers a warning when an skb enters the GSO
stack at __skb_gso_segment that does not have CHECKSUM_PARTIAL
checksum offload set.

Commit b2504a5d ("net: reduce skb_warn_bad_offload() noise")
observed that SKB_GSO_DODGY producers can trigger the check and
that passing those packets through the GSO handlers will fix it
up. But, the software UFO handler will set ip_summed to
CHECKSUM_NONE.

When __skb_gso_segment is called from the receive path, this
triggers the warning again.

Make UFO set CHECKSUM_UNNECESSARY instead of CHECKSUM_NONE. On
Tx these two are equivalent. On Rx, this better matches the
skb state (checksum computed), as CHECKSUM_NONE here means no
checksum computed.

See also this thread for context:
http://patchwork.ozlabs.org/patch/799015/

Fixes: b2504a5d ("net: reduce skb_warn_bad_offload() noise")
Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
parent 731160f5
...@@ -2466,7 +2466,7 @@ static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path) ...@@ -2466,7 +2466,7 @@ static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
{ {
if (tx_path) if (tx_path)
return skb->ip_summed != CHECKSUM_PARTIAL && return skb->ip_summed != CHECKSUM_PARTIAL &&
skb->ip_summed != CHECKSUM_NONE; skb->ip_summed != CHECKSUM_UNNECESSARY;
return skb->ip_summed == CHECKSUM_NONE; return skb->ip_summed == CHECKSUM_NONE;
} }
......
...@@ -231,7 +231,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb, ...@@ -231,7 +231,7 @@ static struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
if (uh->check == 0) if (uh->check == 0)
uh->check = CSUM_MANGLED_0; uh->check = CSUM_MANGLED_0;
skb->ip_summed = CHECKSUM_NONE; skb->ip_summed = CHECKSUM_UNNECESSARY;
/* Fragment the skb. IP headers of the fragments are updated in /* Fragment the skb. IP headers of the fragments are updated in
* inet_gso_segment() * inet_gso_segment()
......
...@@ -86,7 +86,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb, ...@@ -86,7 +86,7 @@ static struct sk_buff *udp6_ufo_fragment(struct sk_buff *skb,
if (uh->check == 0) if (uh->check == 0)
uh->check = CSUM_MANGLED_0; uh->check = CSUM_MANGLED_0;
skb->ip_summed = CHECKSUM_NONE; skb->ip_summed = CHECKSUM_UNNECESSARY;
/* Check if there is enough headroom to insert fragment header. */ /* Check if there is enough headroom to insert fragment header. */
tnl_hlen = skb_tnl_header_len(skb); tnl_hlen = skb_tnl_header_len(skb);
......
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