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>

diff --git a/include/net/dst.h b/include/net/dst.h
index 484f80b..e550195 100644 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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 (file)
--- 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) {