Commit cb75994e authored by Wang Chen's avatar Wang Chen Committed by David S. Miller
Browse files

[UDP]: Defer InDataGrams increment until recvmsg() does checksum 



Thanks dave, herbert, gerrit, andi and other people for your
discussion about this problem.

UdpInDatagrams can be confusing because it counts packets that
might be dropped later.
Move UdpInDatagrams into recvmsg() as allowed by the RFC.

Signed-off-by: default avatarWang Chen <wangchen@cn.fujitsu.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6859d494

Documentation/networking/udplite.txt

+1 −1
Original line number Original line Diff line number Diff line
@@ -236,7 +236,7 @@ 




  This displays UDP-Lite statistics variables, whose meaning is as follows.

  This displays UDP-Lite statistics variables, whose meaning is as follows.





   InDatagrams:     Total number of received datagrams.

   InDatagrams:     The total number of datagrams delivered to users.





   NoPorts:         Number of packets received to an unknown port.

   NoPorts:         Number of packets received to an unknown port.

                    These cases are counted separately (not as InErrors).

                    These cases are counted separately (not as InErrors).

net/ipv4/udp.c

+3 −4
Original line number Original line Diff line number Diff line
@@ -873,6 +873,8 @@ try_again: 
	if (err)

	if (err)

		goto out_free;

		goto out_free;





	UDP_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite);



	sock_recv_timestamp(msg, sk, skb);

	sock_recv_timestamp(msg, sk, skb);





	/* Copy the address. */

	/* Copy the address. */
@@ -966,11 +968,9 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) 
			int ret;

			int ret;





			ret = (*up->encap_rcv)(sk, skb);

			ret = (*up->encap_rcv)(sk, skb);

			if (ret <= 0) {

			if (ret <= 0)

				UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);

				return -ret;

				return -ret;

		}

		}

		}





		/* FALLTHROUGH -- it's a UDP Packet */

		/* FALLTHROUGH -- it's a UDP Packet */

	}

	}
@@ -1023,7 +1023,6 @@ int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) 
		goto drop;

		goto drop;

	}

	}





	UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);

	return 0;

	return 0;





drop:

drop:

net/ipv6/udp.c

+3 −1
Original line number Original line Diff line number Diff line
@@ -164,6 +164,8 @@ try_again: 
	if (err)

	if (err)

		goto out_free;

		goto out_free;





	UDP6_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite);



	sock_recv_timestamp(msg, sk, skb);

	sock_recv_timestamp(msg, sk, skb);





	/* Copy the address. */

	/* Copy the address. */
@@ -292,7 +294,7 @@ int udpv6_queue_rcv_skb(struct sock * sk, struct sk_buff *skb) 
			UDP6_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);

			UDP6_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);

		goto drop;

		goto drop;

	}

	}

	UDP6_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);



	return 0;

	return 0;

drop:

drop:

	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);

	UDP6_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);

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