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udp: Fix the SNMP counter of UDP_MIB_INDATAGRAMS 

If UDP echo is sent to xinetd/echo-dgram, the UDP reply will be received
at the sender. But the SNMP counter of UDP_MIB_INDATAGRAMS will be not
increased, UDP6_MIB_INDATAGRAMS will be increased instead.

  Endpoint A                      Endpoint B
  UDP Echo request ----------->
  (IPv4, Dst port=7)
                   <----------    UDP Echo Reply
                                  (IPv4, Src port=7)

This bug is come from this patch cb75994ec3.

It do counter UDP[6]_MIB_INDATAGRAMS until udp[v6]_recvmsg. Because
xinetd used IPv6 socket to receive UDP messages, thus, when received
UDP packet, the UDP6_MIB_INDATAGRAMS will be increased in function
udpv6_recvmsg() even if the packet is a IPv4 UDP packet.

This patch fixed the problem.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Wei Yongjun 2008-11-02 16:11:01 +00:00 committed by David S. Miller
parent 70d9d15833
commit f26ba17511
1 changed files with 13 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

18
net/ipv6/udp.c
View File

@ -138,6 +138,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
int peeked;
int err;
int is_udplite = IS_UDPLITE(sk);
int is_udp4;
if (addr_len)
*addr_len=sizeof(struct sockaddr_in6);
@ -158,6 +159,8 @@ try_again:
else if (copied < ulen)
msg->msg_flags |= MSG_TRUNC;
is_udp4 = (skb->protocol == htons(ETH_P_IP));
/*
* If checksum is needed at all, try to do it while copying the
* data. If the data is truncated, or if we only want a partial
@ -180,9 +183,14 @@ try_again:
if (err)
goto out_free;
if (!peeked)
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_INDATAGRAMS, is_udplite);
if (!peeked) {
if (is_udp4)
UDP_INC_STATS_USER(sock_net(sk),
UDP_MIB_INDATAGRAMS, is_udplite);
else
UDP6_INC_STATS_USER(sock_net(sk),
UDP_MIB_INDATAGRAMS, is_udplite);
}
sock_recv_timestamp(msg, sk, skb);
@ -196,7 +204,7 @@ try_again:
sin6->sin6_flowinfo = 0;
sin6->sin6_scope_id = 0;
if (skb->protocol == htons(ETH_P_IP))
if (is_udp4)
ipv6_addr_set(&sin6->sin6_addr, 0, 0,
htonl(0xffff), ip_hdr(skb)->saddr);
else {
@ -207,7 +215,7 @@ try_again:
}
}
if (skb->protocol == htons(ETH_P_IP)) {
if (is_udp4) {
if (inet->cmsg_flags)
ip_cmsg_recv(msg, skb);
} else {