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[UDP]: Only increment counter on first peek/recv

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The previous move of the the UDP inDatagrams counter caused each
peek of the same packet to be counted separately.  This may be
undesirable.

This patch fixes this by adding a bit to sk_buff to record whether
this packet has already been seen through skb_recv_datagram.  We
then only increment the counter when the packet is seen for the
first time.

The only dodgy part is the fact that skb_recv_datagram doesn't have
a good way of returning this new bit of information.  So I've added
a new function __skb_recv_datagram that does return this and made
skb_recv_datagram a wrapper around it.

The plan is to eventually replace all uses of skb_recv_datagram with
this new function at which time it can be renamed its proper name.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Herbert Xu
2007-12-05 01:53:40 -08:00
committed by David S. Miller
parent 1781f7f580
commit a59322be07
4 changed files with 39 additions and 19 deletions
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7
net/ipv4/udp.c
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@@ -827,6 +827,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
struct sk_buff *skb;
unsigned int ulen, copied;
int peeked;
int err;
int is_udplite = IS_UDPLITE(sk);
@@ -840,7 +841,8 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
return ip_recv_error(sk, msg, len);
try_again:
skb = skb_recv_datagram(sk, flags, noblock, &err);
skb = __skb_recv_datagram(sk, flags | (noblock ? MSG_DONTWAIT : 0),
&peeked, &err);
if (!skb)
goto out;
@@ -875,7 +877,8 @@ try_again:
if (err)
goto out_free;
UDP_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite);
if (!peeked)
UDP_INC_STATS_USER(UDP_MIB_INDATAGRAMS, is_udplite);
sock_recv_timestamp(msg, sk, skb);