5 files changed, 105 insertions, 12 deletions

diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt
index 1b5581a30d77..c7a81ace35d0 100644
--- a/Documentation/networking/ip-sysctl.txt
+++ b/Documentation/networking/ip-sysctl.txt
@@ -769,8 +769,21 @@ icmp_ratelimit - INTEGER
 	icmp_ratemask (see below) to specific targets.
 	0 to disable any limiting,
 	otherwise the minimal space between responses in milliseconds.
+	Note that another sysctl, icmp_msgs_per_sec limits the number
+	of ICMP packets	sent on all targets.
 	Default: 1000
 
+icmp_msgs_per_sec - INTEGER
+	Limit maximal number of ICMP packets sent per second from this host.
+	Only messages whose type matches icmp_ratemask (see below) are
+	controlled by this limit.
+	Default: 1000
+
+icmp_msgs_burst - INTEGER
+	icmp_msgs_per_sec controls number of ICMP packets sent per second,
+	while icmp_msgs_burst controls the burst size of these packets.
+	Default: 50
+
 icmp_ratemask - INTEGER
 	Mask made of ICMP types for which rates are being limited.
 	Significant bits: IHGFEDCBA9876543210
diff --git a/include/net/ip.h b/include/net/ip.h
index 14bfc8e1bcf9..fcd9068fb8c3 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -548,6 +548,10 @@ void ip_icmp_error(struct sock *sk, struct sk_buff *skb, int err, __be16 port,
 void ip_local_error(struct sock *sk, int err, __be32 daddr, __be16 dport,
 		    u32 info);
 
+bool icmp_global_allow(void);
+extern int sysctl_icmp_msgs_per_sec;
+extern int sysctl_icmp_msgs_burst;
+
 #ifdef CONFIG_PROC_FS
 int ip_misc_proc_init(void);
 #endif
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index ea7d4afe8205..5882f584910e 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -231,12 +231,62 @@ static inline void icmp_xmit_unlock(struct sock *sk)
 	spin_unlock_bh(&sk->sk_lock.slock);
 }
 
+int sysctl_icmp_msgs_per_sec __read_mostly = 1000;
+int sysctl_icmp_msgs_burst __read_mostly = 50;
+
+static struct {
+	spinlock_t	lock;
+	u32		credit;
+	u32		stamp;
+} icmp_global = {
+	.lock		= __SPIN_LOCK_UNLOCKED(icmp_global.lock),
+};
+
+/**
+ * icmp_global_allow - Are we allowed to send one more ICMP message ?
+ *
+ * Uses a token bucket to limit our ICMP messages to sysctl_icmp_msgs_per_sec.
+ * Returns false if we reached the limit and can not send another packet.
+ * Note: called with BH disabled
+ */
+bool icmp_global_allow(void)
+{
+	u32 credit, delta, incr = 0, now = (u32)jiffies;
+	bool rc = false;
+
+	/* Check if token bucket is empty and cannot be refilled
+	 * without taking the spinlock.
+	 */
+	if (!icmp_global.credit) {
+		delta = min_t(u32, now - icmp_global.stamp, HZ);
+		if (delta < HZ / 50)
+			return false;
+	}
+
+	spin_lock(&icmp_global.lock);
+	delta = min_t(u32, now - icmp_global.stamp, HZ);
+	if (delta >= HZ / 50) {
+		incr = sysctl_icmp_msgs_per_sec * delta / HZ ;
+		if (incr)
+			icmp_global.stamp = now;
+	}
+	credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst);
+	if (credit) {
+		credit--;
+		rc = true;
+	}
+	icmp_global.credit = credit;
+	spin_unlock(&icmp_global.lock);
+	return rc;
+}
+EXPORT_SYMBOL(icmp_global_allow);
+
 /*
  *	Send an ICMP frame.
  */
 
-static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
-				      struct flowi4 *fl4, int type, int code)
+static bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
+			       struct flowi4 *fl4, int type, int code)
 {
 	struct dst_entry *dst = &rt->dst;
 	bool rc = true;
@@ -253,8 +303,14 @@ static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
 		goto out;
 
 	/* Limit if icmp type is enabled in ratemask. */
-	if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) {
-		struct inet_peer *peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, 1);
+	if (!((1 << type) & net->ipv4.sysctl_icmp_ratemask))
+		goto out;
+
+	rc = false;
+	if (icmp_global_allow()) {
+		struct inet_peer *peer;
+
+		peer = inet_getpeer_v4(net->ipv4.peers, fl4->daddr, 1);
 		rc = inet_peer_xrlim_allow(peer,
 					   net->ipv4.sysctl_icmp_ratelimit);
 		if (peer)
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 1599966f4639..8a25509c35b3 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -731,6 +731,22 @@ static struct ctl_table ipv4_table[] = {
 		.extra2		= &one,
 	},
 	{
+		.procname	= "icmp_msgs_per_sec",
+		.data		= &sysctl_icmp_msgs_per_sec,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
+	},
+	{
+		.procname	= "icmp_msgs_burst",
+		.data		= &sysctl_icmp_msgs_burst,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= proc_dointvec_minmax,
+		.extra1		= &zero,
+	},
+	{
 		.procname	= "udp_mem",
 		.data		= &sysctl_udp_mem,
 		.maxlen		= sizeof(sysctl_udp_mem),
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 394bb824fe4b..141e1f3ab74e 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -170,11 +170,11 @@ static bool is_ineligible(const struct sk_buff *skb)
 /*
  * Check the ICMP output rate limit
  */
-static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
-				      struct flowi6 *fl6)
+static bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
+			       struct flowi6 *fl6)
 {
-	struct dst_entry *dst;
 	struct net *net = sock_net(sk);
+	struct dst_entry *dst;
 	bool res = false;
 
 	/* Informational messages are not limited. */
@@ -199,16 +199,20 @@ static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
 	} else {
 		struct rt6_info *rt = (struct rt6_info *)dst;
 		int tmo = net->ipv6.sysctl.icmpv6_time;
-		struct inet_peer *peer;
 
 		/* Give more bandwidth to wider prefixes. */
 		if (rt->rt6i_dst.plen < 128)
 			tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
 
-		peer = inet_getpeer_v6(net->ipv6.peers, &rt->rt6i_dst.addr, 1);
-		res = inet_peer_xrlim_allow(peer, tmo);
-		if (peer)
-			inet_putpeer(peer);
+		if (icmp_global_allow()) {
+			struct inet_peer *peer;
+
+			peer = inet_getpeer_v6(net->ipv6.peers,
+					       &rt->rt6i_dst.addr, 1);
+			res = inet_peer_xrlim_allow(peer, tmo);
+			if (peer)
+				inet_putpeer(peer);
+		}
 	}
 	dst_release(dst);
 	return res;