| From foo@baz Wed Aug 9 11:19:16 PDT 2017 |
| From: zheng li <james.z.li@ericsson.com> |
| Date: Mon, 12 Dec 2016 09:56:05 +0800 |
| Subject: ipv4: Should use consistent conditional judgement for ip fragment in __ip_append_data and ip_finish_output |
| |
| From: zheng li <james.z.li@ericsson.com> |
| |
| |
| [ Upstream commit 0a28cfd51e17f4f0a056bcf66bfbe492c3b99f38 ] |
| |
| There is an inconsistent conditional judgement in __ip_append_data and |
| ip_finish_output functions, the variable length in __ip_append_data just |
| include the length of application's payload and udp header, don't include |
| the length of ip header, but in ip_finish_output use |
| (skb->len > ip_skb_dst_mtu(skb)) as judgement, and skb->len include the |
| length of ip header. |
| |
| That causes some particular application's udp payload whose length is |
| between (MTU - IP Header) and MTU were fragmented by ip_fragment even |
| though the rst->dev support UFO feature. |
| |
| Add the length of ip header to length in __ip_append_data to keep |
| consistent conditional judgement as ip_finish_output for ip fragment. |
| |
| Signed-off-by: Zheng Li <james.z.li@ericsson.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Sasha Levin <alexander.levin@verizon.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| net/ipv4/ip_output.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/net/ipv4/ip_output.c |
| +++ b/net/ipv4/ip_output.c |
| @@ -922,7 +922,7 @@ static int __ip_append_data(struct sock |
| csummode = CHECKSUM_PARTIAL; |
| |
| cork->length += length; |
| - if (((length > mtu) || (skb && skb_is_gso(skb))) && |
| + if ((((length + fragheaderlen) > mtu) || (skb && skb_is_gso(skb))) && |
| (sk->sk_protocol == IPPROTO_UDP) && |
| (rt->dst.dev->features & NETIF_F_UFO) && !rt->dst.header_len && |
| (sk->sk_type == SOCK_DGRAM) && !sk->sk_no_check_tx) { |
