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From:   Yafang Shao <laoar.shao@gmail.com>
To:     edumazet@google.com, davem@davemloft.net
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v2 net-next 2/2] tcp: fix the error count of tcpInSegs
Date:   Sun,  9 Sep 2018 11:14:22 +0800
Message-Id: <1536462862-11767-2-git-send-email-laoar.shao@gmail.com>
In-Reply-To: <1536462862-11767-1-git-send-email-laoar.shao@gmail.com>
References: <1536462862-11767-1-git-send-email-laoar.shao@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In RFC1213, the tcpInSegs is the total number of segments received.
While currently it is the total number of SKBs received.
The number of SKBs may be not equal with the numer of segments because of
GRO.
So fix this error count.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 include/net/tcp.h   | 2 ++
 net/ipv4/tcp_ipv4.c | 3 ++-
 net/ipv6/tcp_ipv6.c | 3 ++-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 770917d..66578f4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -310,6 +310,8 @@ static inline bool tcp_too_many_orphans(struct sock *sk, int shift)
 #define __TCP_INC_STATS(net, field)	__SNMP_INC_STATS((net)->mib.tcp_statistics, field)
 #define TCP_DEC_STATS(net, field)	SNMP_DEC_STATS((net)->mib.tcp_statistics, field)
 #define TCP_ADD_STATS(net, field, val)	SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val)
+#define __TCP_ADD_STATS(net, field, val)	\
+	__SNMP_ADD_STATS((net)->mib.tcp_statistics, field, val)
 
 void tcp_tasklet_init(void);
 
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 23d7cb5..2b98242 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1703,7 +1703,8 @@ int tcp_v4_rcv(struct sk_buff *skb)
 		goto discard_it;
 
 	/* Count it even if it's bad */
-	__TCP_INC_STATS(net, TCP_MIB_INSEGS);
+	__TCP_ADD_STATS(net, TCP_MIB_INSEGS,
+			max_t(u16, 1, skb_shinfo(skb)->gso_segs));
 
 	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
 		goto discard_it;
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index bbf7667..8d4ef46 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1441,7 +1441,8 @@ static int tcp_v6_rcv(struct sk_buff *skb)
 	/*
 	 *	Count it even if it's bad.
 	 */
-	__TCP_INC_STATS(net, TCP_MIB_INSEGS);
+	__TCP_ADD_STATS(net, TCP_MIB_INSEGS,
+			max_t(u16, 1, skb_shinfo(skb)->gso_segs));
 
 	if (!pskb_may_pull(skb, sizeof(struct tcphdr)))
 		goto discard_it;
-- 
1.8.3.1