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Date: Fri, 04 Feb 2011 16:24:02 -0800 (PST)
From: David Miller <davem@...emloft.net>
To: netdev@...r.kernel.org
Subject: inetpeer: Move ICMP rate limiting state into inet_peer entries.
Like metrics, the ICMP rate limiting bits are cached state about
a destination. So move it into the inet_peer entries.
If an inet_peer cannot be bound (the reason is memory allocation
failure or similar), the policy is to allow.
Signed-off-by: David S. Miller <davem@...emloft.net>
---
include/net/dst.h | 2 -
include/net/icmp.h | 3 --
include/net/inetpeer.h | 3 ++
net/ipv4/icmp.c | 49 ++++++-----------------------------------
net/ipv4/inetpeer.c | 43 ++++++++++++++++++++++++++++++++++++
net/ipv4/route.c | 56 ++++++++++++++++++++++++++++++++---------------
net/ipv6/icmp.c | 16 +++++++------
net/ipv6/ip6_output.c | 5 +++-
net/ipv6/ndisc.c | 4 ++-
9 files changed, 108 insertions(+), 73 deletions(-)
diff --git a/include/net/dst.h b/include/net/dst.h
index 484f80b..e550195 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -78,8 +78,6 @@ struct dst_entry {
atomic_t __refcnt; /* client references */
int __use;
unsigned long lastuse;
- unsigned long rate_last; /* rate limiting for ICMP */
- unsigned int rate_tokens;
int flags;
#define DST_HOST 0x0001
#define DST_NOXFRM 0x0002
diff --git a/include/net/icmp.h b/include/net/icmp.h
index 6e991e0..f0698b9 100644
--- a/include/net/icmp.h
+++ b/include/net/icmp.h
@@ -45,7 +45,4 @@ extern int icmp_ioctl(struct sock *sk, int cmd, unsigned long arg);
extern int icmp_init(void);
extern void icmp_out_count(struct net *net, unsigned char type);
-/* Move into dst.h ? */
-extern int xrlim_allow(struct dst_entry *dst, int timeout);
-
#endif /* _ICMP_H */
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h
index 61f2c66..ead2cb2 100644
--- a/include/net/inetpeer.h
+++ b/include/net/inetpeer.h
@@ -44,6 +44,8 @@ struct inet_peer {
__u32 tcp_ts;
__u32 tcp_ts_stamp;
u32 metrics[RTAX_MAX];
+ u32 rate_tokens; /* rate limiting for ICMP */
+ unsigned long rate_last;
};
struct rcu_head rcu;
};
@@ -81,6 +83,7 @@ static inline struct inet_peer *inet_getpeer_v6(struct in6_addr *v6daddr, int cr
/* can be called from BH context or outside */
extern void inet_putpeer(struct inet_peer *p);
+extern bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout);
/*
* temporary check to make sure we dont access rid, ip_id_count, tcp_ts,
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 4aa1b7f..ad2bcf1 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -233,48 +233,11 @@ static inline void icmp_xmit_unlock(struct sock *sk)
* Send an ICMP frame.
*/
-/*
- * Check transmit rate limitation for given message.
- * The rate information is held in the destination cache now.
- * This function is generic and could be used for other purposes
- * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov.
- *
- * Note that the same dst_entry fields are modified by functions in
- * route.c too, but these work for packet destinations while xrlim_allow
- * works for icmp destinations. This means the rate limiting information
- * for one "ip object" is shared - and these ICMPs are twice limited:
- * by source and by destination.
- *
- * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
- * SHOULD allow setting of rate limits
- *
- * Shared between ICMPv4 and ICMPv6.
- */
-#define XRLIM_BURST_FACTOR 6
-int xrlim_allow(struct dst_entry *dst, int timeout)
-{
- unsigned long now, token = dst->rate_tokens;
- int rc = 0;
-
- now = jiffies;
- token += now - dst->rate_last;
- dst->rate_last = now;
- if (token > XRLIM_BURST_FACTOR * timeout)
- token = XRLIM_BURST_FACTOR * timeout;
- if (token >= timeout) {
- token -= timeout;
- rc = 1;
- }
- dst->rate_tokens = token;
- return rc;
-}
-EXPORT_SYMBOL(xrlim_allow);
-
-static inline int icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
+static inline bool icmpv4_xrlim_allow(struct net *net, struct rtable *rt,
int type, int code)
{
struct dst_entry *dst = &rt->dst;
- int rc = 1;
+ bool rc = true;
if (type > NR_ICMP_TYPES)
goto out;
@@ -288,8 +251,12 @@ static inline int 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)
- rc = xrlim_allow(dst, net->ipv4.sysctl_icmp_ratelimit);
+ if ((1 << type) & net->ipv4.sysctl_icmp_ratemask) {
+ if (!rt->peer)
+ rt_bind_peer(rt, 1);
+ rc = inet_peer_xrlim_allow(rt->peer,
+ net->ipv4.sysctl_icmp_ratelimit);
+ }
out:
return rc;
}
diff --git a/net/ipv4/inetpeer.c b/net/ipv4/inetpeer.c
index b6513b1..709fbb4 100644
--- a/net/ipv4/inetpeer.c
+++ b/net/ipv4/inetpeer.c
@@ -513,6 +513,8 @@ struct inet_peer *inet_getpeer(struct inetpeer_addr *daddr, int create)
atomic_set(&p->ip_id_count, secure_ip_id(daddr->a4));
p->tcp_ts_stamp = 0;
p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
+ p->rate_tokens = 0;
+ p->rate_last = 0;
INIT_LIST_HEAD(&p->unused);
@@ -580,3 +582,44 @@ void inet_putpeer(struct inet_peer *p)
local_bh_enable();
}
EXPORT_SYMBOL_GPL(inet_putpeer);
+
+/*
+ * Check transmit rate limitation for given message.
+ * The rate information is held in the inet_peer entries now.
+ * This function is generic and could be used for other purposes
+ * too. It uses a Token bucket filter as suggested by Alexey Kuznetsov.
+ *
+ * Note that the same inet_peer fields are modified by functions in
+ * route.c too, but these work for packet destinations while xrlim_allow
+ * works for icmp destinations. This means the rate limiting information
+ * for one "ip object" is shared - and these ICMPs are twice limited:
+ * by source and by destination.
+ *
+ * RFC 1812: 4.3.2.8 SHOULD be able to limit error message rate
+ * SHOULD allow setting of rate limits
+ *
+ * Shared between ICMPv4 and ICMPv6.
+ */
+#define XRLIM_BURST_FACTOR 6
+bool inet_peer_xrlim_allow(struct inet_peer *peer, int timeout)
+{
+ unsigned long now, token;
+ bool rc = false;
+
+ if (!peer)
+ return true;
+
+ token = peer->rate_tokens;
+ now = jiffies;
+ token += now - peer->rate_last;
+ peer->rate_last = now;
+ if (token > XRLIM_BURST_FACTOR * timeout)
+ token = XRLIM_BURST_FACTOR * timeout;
+ if (token >= timeout) {
+ token -= timeout;
+ rc = true;
+ }
+ peer->rate_tokens = token;
+ return rc;
+}
+EXPORT_SYMBOL(inet_peer_xrlim_allow);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 0ba6a38..2e225da 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1563,6 +1563,7 @@ void ip_rt_send_redirect(struct sk_buff *skb)
{
struct rtable *rt = skb_rtable(skb);
struct in_device *in_dev;
+ struct inet_peer *peer;
int log_martians;
rcu_read_lock();
@@ -1574,33 +1575,41 @@ void ip_rt_send_redirect(struct sk_buff *skb)
log_martians = IN_DEV_LOG_MARTIANS(in_dev);
rcu_read_unlock();
+ if (!rt->peer)
+ rt_bind_peer(rt, 1);
+ peer = rt->peer;
+ if (!peer) {
+ icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
+ return;
+ }
+
/* No redirected packets during ip_rt_redirect_silence;
* reset the algorithm.
*/
- if (time_after(jiffies, rt->dst.rate_last + ip_rt_redirect_silence))
- rt->dst.rate_tokens = 0;
+ if (time_after(jiffies, peer->rate_last + ip_rt_redirect_silence))
+ peer->rate_tokens = 0;
/* Too many ignored redirects; do not send anything
* set dst.rate_last to the last seen redirected packet.
*/
- if (rt->dst.rate_tokens >= ip_rt_redirect_number) {
- rt->dst.rate_last = jiffies;
+ if (peer->rate_tokens >= ip_rt_redirect_number) {
+ peer->rate_last = jiffies;
return;
}
/* Check for load limit; set rate_last to the latest sent
* redirect.
*/
- if (rt->dst.rate_tokens == 0 ||
+ if (peer->rate_tokens == 0 ||
time_after(jiffies,
- (rt->dst.rate_last +
- (ip_rt_redirect_load << rt->dst.rate_tokens)))) {
+ (peer->rate_last +
+ (ip_rt_redirect_load << peer->rate_tokens)))) {
icmp_send(skb, ICMP_REDIRECT, ICMP_REDIR_HOST, rt->rt_gateway);
- rt->dst.rate_last = jiffies;
- ++rt->dst.rate_tokens;
+ peer->rate_last = jiffies;
+ ++peer->rate_tokens;
#ifdef CONFIG_IP_ROUTE_VERBOSE
if (log_martians &&
- rt->dst.rate_tokens == ip_rt_redirect_number &&
+ peer->rate_tokens == ip_rt_redirect_number &&
net_ratelimit())
printk(KERN_WARNING "host %pI4/if%d ignores redirects for %pI4 to %pI4.\n",
&rt->rt_src, rt->rt_iif,
@@ -1612,7 +1621,9 @@ void ip_rt_send_redirect(struct sk_buff *skb)
static int ip_error(struct sk_buff *skb)
{
struct rtable *rt = skb_rtable(skb);
+ struct inet_peer *peer;
unsigned long now;
+ bool send;
int code;
switch (rt->dst.error) {
@@ -1632,15 +1643,24 @@ static int ip_error(struct sk_buff *skb)
break;
}
- now = jiffies;
- rt->dst.rate_tokens += now - rt->dst.rate_last;
- if (rt->dst.rate_tokens > ip_rt_error_burst)
- rt->dst.rate_tokens = ip_rt_error_burst;
- rt->dst.rate_last = now;
- if (rt->dst.rate_tokens >= ip_rt_error_cost) {
- rt->dst.rate_tokens -= ip_rt_error_cost;
- icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
+ if (!rt->peer)
+ rt_bind_peer(rt, 1);
+ peer = rt->peer;
+
+ send = true;
+ if (peer) {
+ now = jiffies;
+ peer->rate_tokens += now - peer->rate_last;
+ if (peer->rate_tokens > ip_rt_error_burst)
+ peer->rate_tokens = ip_rt_error_burst;
+ peer->rate_last = now;
+ if (peer->rate_tokens >= ip_rt_error_cost)
+ peer->rate_tokens -= ip_rt_error_cost;
+ else
+ send = false;
}
+ if (send)
+ icmp_send(skb, ICMP_DEST_UNREACH, code, 0);
out: kfree_skb(skb);
return 0;
diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 03e62f9..a31d91b 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -157,20 +157,20 @@ static int is_ineligible(struct sk_buff *skb)
/*
* Check the ICMP output rate limit
*/
-static inline int icmpv6_xrlim_allow(struct sock *sk, u8 type,
- struct flowi *fl)
+static inline bool icmpv6_xrlim_allow(struct sock *sk, u8 type,
+ struct flowi *fl)
{
struct dst_entry *dst;
struct net *net = sock_net(sk);
- int res = 0;
+ bool res = false;
/* Informational messages are not limited. */
if (type & ICMPV6_INFOMSG_MASK)
- return 1;
+ return true;
/* Do not limit pmtu discovery, it would break it. */
if (type == ICMPV6_PKT_TOOBIG)
- return 1;
+ return true;
/*
* Look up the output route.
@@ -182,7 +182,7 @@ static inline int icmpv6_xrlim_allow(struct sock *sk, u8 type,
IP6_INC_STATS(net, ip6_dst_idev(dst),
IPSTATS_MIB_OUTNOROUTES);
} else if (dst->dev && (dst->dev->flags&IFF_LOOPBACK)) {
- res = 1;
+ res = true;
} else {
struct rt6_info *rt = (struct rt6_info *)dst;
int tmo = net->ipv6.sysctl.icmpv6_time;
@@ -191,7 +191,9 @@ static inline int icmpv6_xrlim_allow(struct sock *sk, u8 type,
if (rt->rt6i_dst.plen < 128)
tmo >>= ((128 - rt->rt6i_dst.plen)>>5);
- res = xrlim_allow(dst, tmo);
+ if (!rt->rt6i_peer)
+ rt6_bind_peer(rt, 1);
+ res = inet_peer_xrlim_allow(rt->rt6i_peer, tmo);
}
dst_release(dst);
return res;
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 5f8d242..2600e22 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -479,10 +479,13 @@ int ip6_forward(struct sk_buff *skb)
else
target = &hdr->daddr;
+ if (!rt->rt6i_peer)
+ rt6_bind_peer(rt, 1);
+
/* Limit redirects both by destination (here)
and by source (inside ndisc_send_redirect)
*/
- if (xrlim_allow(dst, 1*HZ))
+ if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
ndisc_send_redirect(skb, n, target);
} else {
int addrtype = ipv6_addr_type(&hdr->saddr);
diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
index 2342545..7254ce3 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1553,7 +1553,9 @@ void ndisc_send_redirect(struct sk_buff *skb, struct neighbour *neigh,
"ICMPv6 Redirect: destination is not a neighbour.\n");
goto release;
}
- if (!xrlim_allow(dst, 1*HZ))
+ if (!rt->rt6i_peer)
+ rt6_bind_peer(rt, 1);
+ if (inet_peer_xrlim_allow(rt->rt6i_peer, 1*HZ))
goto release;
if (dev->addr_len) {
--
1.7.4
--
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