aboutsummaryrefslogtreecommitdiffstats
path: root/net/ipv4/udp.c
diff options
context:
space:
mode:
authorJosh Hunt <johunt@akamai.com>2019-10-02 13:29:23 -0400
committerDavid S. Miller <davem@davemloft.net>2019-10-03 11:47:10 -0400
commit4094871db1d65810acab3d57f6089aa39ef7f648 (patch)
tree4e5ce254832ec5c61c808e325a520e65f11e0442 /net/ipv4/udp.c
parentudp: fix gso_segs calculations (diff)
downloadlinux-dev-4094871db1d65810acab3d57f6089aa39ef7f648.tar.xz
linux-dev-4094871db1d65810acab3d57f6089aa39ef7f648.zip
udp: only do GSO if # of segs > 1
Prior to this change an application sending <= 1MSS worth of data and enabling UDP GSO would fail if the system had SW GSO enabled, but the same send would succeed if HW GSO offload is enabled. In addition to this inconsistency the error in the SW GSO case does not get back to the application if sending out of a real device so the user is unaware of this failure. With this change we only perform GSO if the # of segments is > 1 even if the application has enabled segmentation. I've also updated the relevant udpgso selftests. Fixes: bec1f6f69736 ("udp: generate gso with UDP_SEGMENT") Signed-off-by: Josh Hunt <johunt@akamai.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
-rw-r--r--net/ipv4/udp.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 3e2b90181879..14bc654b6842 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -821,6 +821,7 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
int is_udplite = IS_UDPLITE(sk);
int offset = skb_transport_offset(skb);
int len = skb->len - offset;
+ int datalen = len - sizeof(*uh);
__wsum csum = 0;
/*
@@ -854,10 +855,12 @@ static int udp_send_skb(struct sk_buff *skb, struct flowi4 *fl4,
return -EIO;
}
- skb_shinfo(skb)->gso_size = cork->gso_size;
- skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
- skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(len - sizeof(*uh),
- cork->gso_size);
+ if (datalen > cork->gso_size) {
+ skb_shinfo(skb)->gso_size = cork->gso_size;
+ skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4;
+ skb_shinfo(skb)->gso_segs = DIV_ROUND_UP(datalen,
+ cork->gso_size);
+ }
goto csum_partial;
}