From a3ce2b109a59ee9670706ae8126dcc04cfe261cd Mon Sep 17 00:00:00 2001
From: Menglong Dong <dong.menglong@zte.com.cn>
Date: Thu, 5 Nov 2020 20:49:14 -0500
Subject: [PATCH] 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: Menglong 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: Jakub Kicinski <kuba@kernel.org>
---
include/uapi/linux/snmp.h | 1 +
net/ipv4/proc.c | 1 +
net/ipv4/udp.c | 3 +++
net/ipv6/proc.c | 2 ++
net/ipv6/udp.c | 3 +++
5 files changed, 10 insertions(+)
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index f84e7bcad6deb..26fc60ce92986 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -159,6 +159,7 @@ enum
UDP_MIB_SNDBUFERRORS, /* SndbufErrors */
UDP_MIB_CSUMERRORS, /* InCsumErrors */
UDP_MIB_IGNOREDMULTI, /* IgnoredMulti */
+ UDP_MIB_MEMERRORS, /* MemErrors */
__UDP_MIB_MAX
};
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index 8d5e1695b9aa8..63cd370ea29db 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -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
};
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ca04a8a35e52d..1e2e73accd11f 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -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);
diff --git a/net/ipv6/proc.c b/net/ipv6/proc.c
index bbff3e02e302b..d6306aa46bb1e 100644
--- a/net/ipv6/proc.c
+++ b/net/ipv6/proc.c
@@ -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
};
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index cde9b8874d4bc..559611bef0e6a 100644
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -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;
--
2.30.2