Commit d98d58a0 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by David S. Miller
Browse files

net: Set skb->mono_delivery_time and clear it after sch_handle_ingress() 



The previous patches handled the delivery_time before sch_handle_ingress().

This patch can now set the skb->mono_delivery_time to flag the skb->tstamp
is used as the mono delivery_time (EDT) instead of the (rcv) timestamp
and also clear it with skb_clear_delivery_time() after
sch_handle_ingress().  This will make the bpf_redirect_*()
to keep the mono delivery_time and used by a qdisc (fq) of
the egress-ing interface.

A latter patch will postpone the skb_clear_delivery_time() until the
stack learns that the skb is being delivered locally and that will
make other kernel forwarding paths (ip[6]_forward) able to keep
the delivery_time also.  Thus, like the previous patches on using
the skb->mono_delivery_time bit, calling skb_clear_delivery_time()
is not limited within the CONFIG_NET_INGRESS to avoid too many code
churns among this set.

Signed-off-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent d93376f5

include/linux/skbuff.h

+1 −2
Original line number Diff line number Diff line
@@ -3993,8 +3993,7 @@ static inline void skb_set_delivery_time(struct sk_buff *skb, ktime_t kt, 
					 bool mono)

{

	skb->tstamp = kt;

	/* Setting mono_delivery_time will be enabled later */

	skb->mono_delivery_time = 0;

	skb->mono_delivery_time = kt && mono;

}



DECLARE_STATIC_KEY_FALSE(netstamp_needed_key);

net/core/dev.c

+6 −2
Original line number Diff line number Diff line
@@ -5220,8 +5220,10 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc, 
			goto out;

	}



	if (skb_skip_tc_classify(skb))

	if (skb_skip_tc_classify(skb)) {

		skb_clear_delivery_time(skb);

		goto skip_classify;

	}



	if (pfmemalloc)

		goto skip_taps;
@@ -5250,12 +5252,14 @@ static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc, 
			goto another_round;

		if (!skb)

			goto out;

		skb_clear_delivery_time(skb);



		nf_skip_egress(skb, false);

		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)

			goto out;

	}

	} else

#endif

		skb_clear_delivery_time(skb);

	skb_reset_redirect(skb);

skip_classify:

	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))

net/ipv4/ip_output.c

+1 −2
Original line number Diff line number Diff line
@@ -1728,8 +1728,7 @@ void ip_send_unicast_reply(struct sock *sk, struct sk_buff *skb, 
			  arg->csumoffset) = csum_fold(csum_add(nskb->csum,

								arg->csum));

		nskb->ip_summed = CHECKSUM_NONE;

		/* Setting mono_delivery_time will be enabled later */

		nskb->mono_delivery_time = 0;

		nskb->mono_delivery_time = !!transmit_time;

		ip_push_pending_frames(sk, &fl4);

	}

out: