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authorDavid S. Miller <davem@davemloft.net>2011-02-04 15:55:25 -0800
committerDavid S. Miller <davem@davemloft.net>2011-02-04 15:59:53 -0800
commit92d8682926342d2b6aa5b2ecc02221e00e1573a0 (patch)
tree7f70b9cc2975716ab60ddd632b9fecf0a51b828d /net/ipv4
parent0131ba451e20239c5dc701027c1a2edef95e1a6e (diff)
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@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/icmp.c49
-rw-r--r--net/ipv4/inetpeer.c43
-rw-r--r--net/ipv4/route.c56
3 files changed, 89 insertions, 59 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 4aa1b7f01ea..ad2bcf1b69a 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 b6513b13d72..709fbb4132d 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 0ba6a382b2b..2e225dafc4f 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;