From 92dd5452c1be873a1193561f4f691763103d22ac Mon Sep 17 00:00:00 2001 From: Edward Cree Date: Tue, 19 Sep 2017 18:45:56 +0100 Subject: net: change skb->mac_header when Generic XDP calls adjust_head Since XDP's view of the packet includes the MAC header, moving the start- of-packet with bpf_xdp_adjust_head needs to also update the offset of the MAC header (which is relative to skb->head, not to the skb->data that was changed). Without this, tcpdump sees packets starting from the old MAC header rather than the new one, at least in my tests on the loopback device. Fixes: b5cdae3291f7 ("net: Generic XDP") Signed-off-by: Edward Cree Signed-off-by: David S. Miller --- net/core/dev.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index fb766d9..9a2254f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3892,6 +3892,7 @@ static u32 netif_receive_generic_xdp(struct sk_buff *skb, __skb_pull(skb, off); else if (off < 0) __skb_push(skb, -off); + skb->mac_header += off; switch (act) { case XDP_REDIRECT: -- cgit v1.1 From 581fe0ea61584d88072527ae9fb9dcb9d1f2783e Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Fri, 22 Sep 2017 19:42:37 -0400 Subject: net: orphan frags on stand-alone ptype in dev_queue_xmit_nit Zerocopy skbs frags are copied when the skb is looped to a local sock. Commit 1080e512d44d ("net: orphan frags on receive") introduced calls to skb_orphan_frags to deliver_skb and __netif_receive_skb for this. With msg_zerocopy, these skbs can also exist in the tx path and thus loop from dev_queue_xmit_nit. This already calls deliver_skb in its loop. But it does not orphan before a separate pt_prev->func(). Add the missing skb_orphan_frags_rx. Changes v1->v2: handle skb_orphan_frags_rx failure Fixes: 1f8b977ab32d ("sock: enable MSG_ZEROCOPY") Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 9a2254f..588b473 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1948,8 +1948,12 @@ again: goto again; } out_unlock: - if (pt_prev) - pt_prev->func(skb2, skb->dev, pt_prev, skb->dev); + if (pt_prev) { + if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC)) + pt_prev->func(skb2, skb->dev, pt_prev, skb->dev); + else + kfree_skb(skb2); + } rcu_read_unlock(); } EXPORT_SYMBOL_GPL(dev_queue_xmit_nit); -- cgit v1.1