From f26ba1751145edbf52b2c89a40e389f2fbdfc1af Mon Sep 17 00:00:00 2001 From: Wei Yongjun Date: Sun, 2 Nov 2008 16:11:01 +0000 Subject: [PATCH] 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 cb75994ec311b2cd50e5205efdcc0696abd6675d. 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 Signed-off-by: David S. Miller --- net/ipv6/udp.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 71e259e866a1..18696af106d6 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -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 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, 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 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, 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 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, 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 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, } } - if (skb->protocol == htons(ETH_P_IP)) { + if (is_udp4) { if (inet->cmsg_flags) ip_cmsg_recv(msg, skb); } else {