Commit a3ce2b10 authored by Menglong Dong's avatar Menglong Dong Committed by Jakub Kicinski
Browse files

net: udp: introduce UDP_MIB_MEMERRORS for udp_mem 



When udp_memory_allocated is at the limit, __udp_enqueue_schedule_skb
will return a -ENOBUFS, and skb will be dropped in __udp_queue_rcv_skb
without any counters being done. It's hard to find out what happened
once this happen.

So we introduce a UDP_MIB_MEMERRORS to do this job. Well, this change
looks friendly to the existing users, such as netstat:

$ netstat -u -s
Udp:
    0 packets received
    639 packets to unknown port received.
    158689 packet receive errors
    180022 packets sent
    RcvbufErrors: 20930
    MemErrors: 137759
UdpLite:
IpExt:
    InOctets: 257426235
    OutOctets: 257460598
    InNoECTPkts: 181177

v2:
- Fix some alignment problems

Signed-off-by: default avatarMenglong Dong <dong.menglong@zte.com.cn>
Link: https://lore.kernel.org/r/1604627354-43207-1-git-send-email-dong.menglong@zte.com.cn


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent bff6f1db

include/uapi/linux/snmp.h

+1 −0
Original line number Diff line number Diff line
@@ -159,6 +159,7 @@ enum 
	UDP_MIB_SNDBUFERRORS,			/* SndbufErrors */

	UDP_MIB_CSUMERRORS,			/* InCsumErrors */

	UDP_MIB_IGNOREDMULTI,			/* IgnoredMulti */

	UDP_MIB_MEMERRORS,			/* MemErrors */

	__UDP_MIB_MAX

};

net/ipv4/proc.c

+1 −0
Original line number Diff line number Diff line
@@ -167,6 +167,7 @@ static const struct snmp_mib snmp4_udp_list[] = { 
	SNMP_MIB_ITEM("SndbufErrors", UDP_MIB_SNDBUFERRORS),

	SNMP_MIB_ITEM("InCsumErrors", UDP_MIB_CSUMERRORS),

	SNMP_MIB_ITEM("IgnoredMulti", UDP_MIB_IGNOREDMULTI),

	SNMP_MIB_ITEM("MemErrors", UDP_MIB_MEMERRORS),

	SNMP_MIB_SENTINEL

};

net/ipv4/udp.c

+3 −0
Original line number Diff line number Diff line
@@ -2038,6 +2038,9 @@ static int __udp_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
		if (rc == -ENOMEM)

			UDP_INC_STATS(sock_net(sk), UDP_MIB_RCVBUFERRORS,

					is_udplite);

		else

			UDP_INC_STATS(sock_net(sk), UDP_MIB_MEMERRORS,

				      is_udplite);

		UDP_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);

		kfree_skb(skb);

		trace_udp_fail_queue_rcv_skb(rc, sk);

net/ipv6/proc.c

+2 −0
Original line number Diff line number Diff line
@@ -126,6 +126,7 @@ static const struct snmp_mib snmp6_udp6_list[] = { 
	SNMP_MIB_ITEM("Udp6SndbufErrors", UDP_MIB_SNDBUFERRORS),

	SNMP_MIB_ITEM("Udp6InCsumErrors", UDP_MIB_CSUMERRORS),

	SNMP_MIB_ITEM("Udp6IgnoredMulti", UDP_MIB_IGNOREDMULTI),

	SNMP_MIB_ITEM("Udp6MemErrors", UDP_MIB_MEMERRORS),

	SNMP_MIB_SENTINEL

};
@@ -137,6 +138,7 @@ static const struct snmp_mib snmp6_udplite6_list[] = { 
	SNMP_MIB_ITEM("UdpLite6RcvbufErrors", UDP_MIB_RCVBUFERRORS),

	SNMP_MIB_ITEM("UdpLite6SndbufErrors", UDP_MIB_SNDBUFERRORS),

	SNMP_MIB_ITEM("UdpLite6InCsumErrors", UDP_MIB_CSUMERRORS),

	SNMP_MIB_ITEM("UdpLite6MemErrors", UDP_MIB_MEMERRORS),

	SNMP_MIB_SENTINEL

};

net/ipv6/udp.c

+3 −0
Original line number Diff line number Diff line
@@ -637,6 +637,9 @@ static int __udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb) 
		if (rc == -ENOMEM)

			UDP6_INC_STATS(sock_net(sk),

					 UDP_MIB_RCVBUFERRORS, is_udplite);

		else

			UDP6_INC_STATS(sock_net(sk),

				       UDP_MIB_MEMERRORS, is_udplite);

		UDP6_INC_STATS(sock_net(sk), UDP_MIB_INERRORS, is_udplite);

		kfree_skb(skb);

		return -1;

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