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From:   cgel.zte@gmail.com
To:     davem@davemloft.net, kuba@kernel.org, yoshfuji@linux-ipv6.org,
        dsahern@kernel.org
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        xu.xin16@zte.com.cn, Yunkai Zhang <zhang.yunkai@zte.com.cn>
Subject: [PATCH v3 2/3] ipv4: Namespaceify route/error_burst knob
Date:   Tue, 30 Aug 2022 09:16:57 +0000
Message-Id: <20220830091657.286396-1-xu.xin16@zte.com.cn>
In-Reply-To: <20220830091453.286285-1-xu.xin16@zte.com.cn>
References: <20220830091453.286285-1-xu.xin16@zte.com.cn>
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From: xu xin <xu.xin16@zte.com.cn>

Different netns has different requirement on the setting of error_burst
sysctl which is used to limit the frequency of sending ICMP_DEST_UNREACH
packet together with error_cost. To put it simply, if the rate of
error_burst over error_cost is larger, then allowd burstly-sent
ICMP_DEST_UNREACH packets after a long calm time (no dest-unreachable
icmp packets) is more.

Enable error_burst to be configured per network namespace.

Signed-off-by: xu xin (CGEL ZTE) <xu.xin16@zte.com.cn>
Reviewed-by: Yunkai Zhang (CGEL ZTE) <zhang.yunkai@zte.com.cn>
---
 include/net/netns/ipv4.h |  1 +
 net/ipv4/route.c         | 18 ++++++++++--------
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h
index 319395bbad3c..03d16cf32508 100644
--- a/include/net/netns/ipv4.h
+++ b/include/net/netns/ipv4.h
@@ -86,6 +86,7 @@ struct netns_ipv4 {
 	int ip_rt_mtu_expires;
 	int ip_rt_min_advmss;
 	int ip_rt_error_cost;
+	int ip_rt_error_burst;
 
 	struct local_ports ip_local_ports;
 
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 209539c201c2..4745a4085de5 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -114,11 +114,11 @@
 #define DEFAULT_MIN_PMTU (512 + 20 + 20)
 #define DEFAULT_MTU_EXPIRES (10 * 60 * HZ)
 #define DEFAULT_MIN_ADVMSS 256
+#define DEFAULT_ERROR_BURST	(5 * HZ)
 static int ip_rt_max_size;
 static int ip_rt_redirect_number __read_mostly	= 9;
 static int ip_rt_redirect_load __read_mostly	= HZ / 50;
 static int ip_rt_redirect_silence __read_mostly	= ((HZ / 50) << (9 + 1));
-static int ip_rt_error_burst __read_mostly	= 5 * HZ;
 
 static int ip_rt_gc_timeout __read_mostly	= RT_GC_TIMEOUT;
 
@@ -1000,6 +1000,7 @@ static int ip_error(struct sk_buff *skb)
 	send = true;
 	if (peer) {
 		int ip_rt_error_cost = READ_ONCE(net->ipv4.ip_rt_error_cost);
+		int ip_rt_error_burst = READ_ONCE(net->ipv4.ip_rt_error_burst);
 
 		now = jiffies;
 		peer->rate_tokens += now - peer->rate_last;
@@ -3536,13 +3537,6 @@ static struct ctl_table ipv4_route_table[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec,
 	},
-	{
-		.procname	= "error_burst",
-		.data		= &ip_rt_error_burst,
-		.maxlen		= sizeof(int),
-		.mode		= 0644,
-		.proc_handler	= proc_dointvec,
-	},
 	{
 		.procname	= "gc_elasticity",
 		.data		= &ip_rt_gc_elasticity,
@@ -3591,6 +3585,13 @@ static struct ctl_table ipv4_route_netns_table[] = {
 		.mode       = 0644,
 		.proc_handler   = proc_dointvec,
 	},
+	{
+		.procname       = "error_burst",
+		.data           = &init_net.ipv4.ip_rt_error_burst,
+		.maxlen     = sizeof(int),
+		.mode       = 0644,
+		.proc_handler   = proc_dointvec,
+	},
 	{ },
 };
 
@@ -3655,6 +3656,7 @@ static __net_init int netns_ip_rt_init(struct net *net)
 	net->ipv4.ip_rt_mtu_expires = DEFAULT_MTU_EXPIRES;
 	net->ipv4.ip_rt_min_advmss = DEFAULT_MIN_ADVMSS;
 	net->ipv4.ip_rt_error_cost = HZ;
+	net->ipv4.ip_rt_error_burst = DEFAULT_ERROR_BURST;
 	return 0;
 }
 
-- 
2.25.1