udp: Fix the SNMP counter of UDP_MIB_INDATAGRAMS (f26ba175) · Commits · 戴 / test

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 . 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>

net/ipv6/udp.c

+13 −5

Original line number	Diff line number	Diff line
		@@ -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)
		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 {

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