static int ip_rt_min_pmtu __read_mostly = 512 + 20 + 20;
static int ip_rt_min_advmss __read_mostly = 256;
static int ip_rt_secret_interval __read_mostly = 10 * 60 * HZ;
+static int rt_chain_length_max __read_mostly = 20;
static void rt_worker_func(struct work_struct *work);
static DECLARE_DELAYED_WORK(expires_work, rt_worker_func);
static void ipv4_link_failure(struct sk_buff *skb);
static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu);
static int rt_garbage_collect(struct dst_ops *ops);
+static void rt_emergency_hash_rebuild(struct net *net);
static struct dst_ops ipv4_dst_ops = {
struct rt_hash_bucket {
struct rtable *chain;
};
+
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) || \
defined(CONFIG_PROVE_LOCKING)
/*
struct rtable *r = NULL;
for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
+ if (!rt_hash_table[st->bucket].chain)
+ continue;
rcu_read_lock_bh();
r = rcu_dereference(rt_hash_table[st->bucket].chain);
while (r) {
struct rtable *r)
{
struct rt_cache_iter_state *st = seq->private;
+
r = r->u.dst.rt_next;
while (!r) {
rcu_read_unlock_bh();
- if (--st->bucket < 0)
- break;
+ do {
+ if (--st->bucket < 0)
+ return NULL;
+ } while (!rt_hash_table[st->bucket].chain);
rcu_read_lock_bh();
r = rt_hash_table[st->bucket].chain;
}
return score;
}
+static inline bool rt_caching(const struct net *net)
+{
+ return net->ipv4.current_rt_cache_rebuild_count <=
+ net->ipv4.sysctl_rt_cache_rebuild_count;
+}
+
+static inline bool compare_hash_inputs(const struct flowi *fl1,
+ const struct flowi *fl2)
+{
+ return (__force u32)(((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
+ (fl1->nl_u.ip4_u.saddr ^ fl2->nl_u.ip4_u.saddr) |
+ (fl1->iif ^ fl2->iif)) == 0);
+}
+
static inline int compare_keys(struct flowi *fl1, struct flowi *fl2)
{
return ((__force u32)((fl1->nl_u.ip4_u.daddr ^ fl2->nl_u.ip4_u.daddr) |
}
}
+/*
+ * While freeing expired entries, we compute average chain length
+ * and standard deviation, using fixed-point arithmetic.
+ * This to have an estimation of rt_chain_length_max
+ * rt_chain_length_max = max(elasticity, AVG + 4*SD)
+ * We use 3 bits for frational part, and 29 (or 61) for magnitude.
+ */
+
+#define FRACT_BITS 3
+#define ONE (1UL << FRACT_BITS)
+
static void rt_check_expire(void)
{
static unsigned int rover;
unsigned int i = rover, goal;
struct rtable *rth, **rthp;
+ unsigned long length = 0, samples = 0;
+ unsigned long sum = 0, sum2 = 0;
u64 mult;
mult = ((u64)ip_rt_gc_interval) << rt_hash_log;
goal = (unsigned int)mult;
if (goal > rt_hash_mask)
goal = rt_hash_mask + 1;
+ length = 0;
for (; goal > 0; goal--) {
unsigned long tmo = ip_rt_gc_timeout;
if (need_resched())
cond_resched();
+ samples++;
+
if (*rthp == NULL)
continue;
spin_lock_bh(rt_hash_lock_addr(i));
if (time_before_eq(jiffies, rth->u.dst.expires)) {
tmo >>= 1;
rthp = &rth->u.dst.rt_next;
+ /*
+ * Only bump our length if the hash
+ * inputs on entries n and n+1 are not
+ * the same, we only count entries on
+ * a chain with equal hash inputs once
+ * so that entries for different QOS
+ * levels, and other non-hash input
+ * attributes don't unfairly skew
+ * the length computation
+ */
+ if ((*rthp == NULL) ||
+ !compare_hash_inputs(&(*rthp)->fl,
+ &rth->fl))
+ length += ONE;
continue;
}
} else if (!rt_may_expire(rth, tmo, ip_rt_gc_timeout)) {
tmo >>= 1;
rthp = &rth->u.dst.rt_next;
+ if ((*rthp == NULL) ||
+ !compare_hash_inputs(&(*rthp)->fl,
+ &rth->fl))
+ length += ONE;
continue;
}
rt_free(rth);
}
spin_unlock_bh(rt_hash_lock_addr(i));
+ sum += length;
+ sum2 += length*length;
+ }
+ if (samples) {
+ unsigned long avg = sum / samples;
+ unsigned long sd = int_sqrt(sum2 / samples - avg*avg);
+ rt_chain_length_max = max_t(unsigned long,
+ ip_rt_gc_elasticity,
+ (avg + 4*sd) >> FRACT_BITS);
}
rover = i;
}
mod_timer(&net->ipv4.rt_secret_timer, jiffies + ip_rt_secret_interval);
}
+static void rt_secret_rebuild_oneshot(struct net *net)
+{
+ del_timer_sync(&net->ipv4.rt_secret_timer);
+ rt_cache_invalidate(net);
+ if (ip_rt_secret_interval) {
+ net->ipv4.rt_secret_timer.expires += ip_rt_secret_interval;
+ add_timer(&net->ipv4.rt_secret_timer);
+ }
+}
+
+static void rt_emergency_hash_rebuild(struct net *net)
+{
+ if (net_ratelimit()) {
+ printk(KERN_WARNING "Route hash chain too long!\n");
+ printk(KERN_WARNING "Adjust your secret_interval!\n");
+ }
+
+ rt_secret_rebuild_oneshot(net);
+}
+
/*
Short description of GC goals.
static int rt_intern_hash(unsigned hash, struct rtable *rt, struct rtable **rp)
{
struct rtable *rth, **rthp;
+ struct rtable *rthi;
unsigned long now;
struct rtable *cand, **candp;
u32 min_score;
candp = NULL;
now = jiffies;
+ if (!rt_caching(dev_net(rt->u.dst.dev))) {
+ rt_drop(rt);
+ return 0;
+ }
+
rthp = &rt_hash_table[hash].chain;
+ rthi = NULL;
spin_lock_bh(rt_hash_lock_addr(hash));
while ((rth = *rthp) != NULL) {
chain_length++;
rthp = &rth->u.dst.rt_next;
+
+ /*
+ * check to see if the next entry in the chain
+ * contains the same hash input values as rt. If it does
+ * This is where we will insert into the list, instead of
+ * at the head. This groups entries that differ by aspects not
+ * relvant to the hash function together, which we use to adjust
+ * our chain length
+ */
+ if (*rthp && compare_hash_inputs(&(*rthp)->fl, &rt->fl))
+ rthi = rth;
}
if (cand) {
*candp = cand->u.dst.rt_next;
rt_free(cand);
}
+ } else {
+ if (chain_length > rt_chain_length_max) {
+ struct net *net = dev_net(rt->u.dst.dev);
+ int num = ++net->ipv4.current_rt_cache_rebuild_count;
+ if (!rt_caching(dev_net(rt->u.dst.dev))) {
+ printk(KERN_WARNING "%s: %d rebuilds is over limit, route caching disabled\n",
+ rt->u.dst.dev->name, num);
+ }
+ rt_emergency_hash_rebuild(dev_net(rt->u.dst.dev));
+ }
}
/* Try to bind route to arp only if it is output
}
}
- rt->u.dst.rt_next = rt_hash_table[hash].chain;
+ if (rthi)
+ rt->u.dst.rt_next = rthi->u.dst.rt_next;
+ else
+ rt->u.dst.rt_next = rt_hash_table[hash].chain;
+
#if RT_CACHE_DEBUG >= 2
if (rt->u.dst.rt_next) {
struct rtable *trt;
printk("\n");
}
#endif
- rt_hash_table[hash].chain = rt;
+ /*
+ * Since lookup is lockfree, we must make sure
+ * previous writes to rt are comitted to memory
+ * before making rt visible to other CPUS.
+ */
+ if (rthi)
+ rcu_assign_pointer(rthi->u.dst.rt_next, rt);
+ else
+ rcu_assign_pointer(rt_hash_table[hash].chain, rt);
+
spin_unlock_bh(rt_hash_lock_addr(hash));
*rp = rt;
return 0;
|| ipv4_is_zeronet(new_gw))
goto reject_redirect;
+ if (!rt_caching(net))
+ goto reject_redirect;
+
if (!IN_DEV_SHARED_MEDIA(in_dev)) {
if (!inet_addr_onlink(in_dev, new_gw, old_gw))
goto reject_redirect;
rt->u.dst.path = &rt->u.dst;
rt->u.dst.neighbour = NULL;
rt->u.dst.hh = NULL;
+#ifdef CONFIG_XFRM
rt->u.dst.xfrm = NULL;
+#endif
rt->rt_genid = rt_genid(net);
rt->rt_flags |= RTCF_REDIRECTED;
break;
case ENETUNREACH:
code = ICMP_NET_UNREACH;
- IP_INC_STATS_BH(IPSTATS_MIB_INNOROUTES);
+ IP_INC_STATS_BH(dev_net(rt->u.dst.dev),
+ IPSTATS_MIB_INNOROUTES);
break;
case EACCES:
code = ICMP_PKT_FILTERED;
rth->fl.iif != 0 ||
dst_metric_locked(&rth->u.dst, RTAX_MTU) ||
!net_eq(dev_net(rth->u.dst.dev), net) ||
- !rt_is_expired(rth))
+ rt_is_expired(rth))
continue;
if (new_mtu < 68 || new_mtu >= old_mtu) {
/* BSD 4.2 compatibility hack :-( */
if (mtu == 0 &&
- old_mtu >= dst_metric(&rth->u.dst, RTAX_MTU) &&
+ old_mtu >= dst_mtu(&rth->u.dst) &&
old_mtu >= 68 + (iph->ihl << 2))
old_mtu -= iph->ihl << 2;
mtu = guess_mtu(old_mtu);
}
- if (mtu <= dst_metric(&rth->u.dst, RTAX_MTU)) {
- if (mtu < dst_metric(&rth->u.dst, RTAX_MTU)) {
+ if (mtu <= dst_mtu(&rth->u.dst)) {
+ if (mtu < dst_mtu(&rth->u.dst)) {
dst_confirm(&rth->u.dst);
if (mtu < ip_rt_min_pmtu) {
mtu = ip_rt_min_pmtu;
static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
{
- if (dst_metric(dst, RTAX_MTU) > mtu && mtu >= 68 &&
+ if (dst_mtu(dst) > mtu && mtu >= 68 &&
!(dst_metric_locked(dst, RTAX_MTU))) {
if (mtu < ip_rt_min_pmtu) {
mtu = ip_rt_min_pmtu;
if (dst_metric(&rt->u.dst, RTAX_HOPLIMIT) == 0)
rt->u.dst.metrics[RTAX_HOPLIMIT-1] = sysctl_ip_default_ttl;
- if (dst_metric(&rt->u.dst, RTAX_MTU) > IP_MAX_MTU)
+ if (dst_mtu(&rt->u.dst) > IP_MAX_MTU)
rt->u.dst.metrics[RTAX_MTU-1] = IP_MAX_MTU;
if (dst_metric(&rt->u.dst, RTAX_ADVMSS) == 0)
rt->u.dst.metrics[RTAX_ADVMSS-1] = max_t(unsigned int, rt->u.dst.dev->mtu - 40,
struct net *net;
net = dev_net(dev);
+
+ if (!rt_caching(net))
+ goto skip_cache;
+
tos &= IPTOS_RT_MASK;
hash = rt_hash(daddr, saddr, iif, rt_genid(net));
}
rcu_read_unlock();
+skip_cache:
/* Multicast recognition logic is moved from route cache to here.
The problem was that too many Ethernet cards have broken/missing
hardware multicast filters :-( As result the host on multicasting
ipv4_is_zeronet(oldflp->fl4_src))
goto out;
- /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
- dev_out = ip_dev_find(net, oldflp->fl4_src);
- if (dev_out == NULL)
- goto out;
-
/* I removed check for oif == dev_out->oif here.
It was wrong for two reasons:
1. ip_dev_find(net, saddr) can return wrong iface, if saddr
if (oldflp->oif == 0
&& (ipv4_is_multicast(oldflp->fl4_dst) ||
oldflp->fl4_dst == htonl(0xFFFFFFFF))) {
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(net, oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
+
/* Special hack: user can direct multicasts
and limited broadcast via necessary interface
without fiddling with IP_MULTICAST_IF or IP_PKTINFO.
fl.oif = dev_out->ifindex;
goto make_route;
}
- if (dev_out)
+
+ if (!(oldflp->flags & FLOWI_FLAG_ANYSRC)) {
+ /* It is equivalent to inet_addr_type(saddr) == RTN_LOCAL */
+ dev_out = ip_dev_find(net, oldflp->fl4_src);
+ if (dev_out == NULL)
+ goto out;
dev_put(dev_out);
- dev_out = NULL;
+ dev_out = NULL;
+ }
}
unsigned hash;
struct rtable *rth;
+ if (!rt_caching(net))
+ goto slow_output;
+
hash = rt_hash(flp->fl4_dst, flp->fl4_src, flp->oif, rt_genid(net));
rcu_read_lock_bh();
}
rcu_read_unlock_bh();
+slow_output:
return ip_route_output_slow(net, rp, flp);
}
if (s_h < 0)
s_h = 0;
s_idx = idx = cb->args[1];
- for (h = s_h; h <= rt_hash_mask; h++) {
+ for (h = s_h; h <= rt_hash_mask; h++, s_idx = 0) {
+ if (!rt_hash_table[h].chain)
+ continue;
rcu_read_lock_bh();
for (rt = rcu_dereference(rt_hash_table[h].chain), idx = 0; rt;
rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
dst_release(xchg(&skb->dst, NULL));
}
rcu_read_unlock_bh();
- s_idx = 0;
}
done:
}
static int ipv4_sysctl_rtcache_flush_strategy(ctl_table *table,
- int __user *name,
- int nlen,
void __user *oldval,
size_t __user *oldlenp,
void __user *newval,
return 0;
}
-ctl_table ipv4_route_table[] = {
+static void rt_secret_reschedule(int old)
+{
+ struct net *net;
+ int new = ip_rt_secret_interval;
+ int diff = new - old;
+
+ if (!diff)
+ return;
+
+ rtnl_lock();
+ for_each_net(net) {
+ int deleted = del_timer_sync(&net->ipv4.rt_secret_timer);
+
+ if (!new)
+ continue;
+
+ if (deleted) {
+ long time = net->ipv4.rt_secret_timer.expires - jiffies;
+
+ if (time <= 0 || (time += diff) <= 0)
+ time = 0;
+
+ net->ipv4.rt_secret_timer.expires = time;
+ } else
+ net->ipv4.rt_secret_timer.expires = new;
+
+ net->ipv4.rt_secret_timer.expires += jiffies;
+ add_timer(&net->ipv4.rt_secret_timer);
+ }
+ rtnl_unlock();
+}
+
+static int ipv4_sysctl_rt_secret_interval(ctl_table *ctl, int write,
+ struct file *filp,
+ void __user *buffer, size_t *lenp,
+ loff_t *ppos)
+{
+ int old = ip_rt_secret_interval;
+ int ret = proc_dointvec_jiffies(ctl, write, filp, buffer, lenp, ppos);
+
+ rt_secret_reschedule(old);
+
+ return ret;
+}
+
+static int ipv4_sysctl_rt_secret_interval_strategy(ctl_table *table,
+ void __user *oldval,
+ size_t __user *oldlenp,
+ void __user *newval,
+ size_t newlen)
+{
+ int old = ip_rt_secret_interval;
+ int ret = sysctl_jiffies(table, oldval, oldlenp, newval, newlen);
+
+ rt_secret_reschedule(old);
+
+ return ret;
+}
+
+static ctl_table ipv4_route_table[] = {
{
.ctl_name = NET_IPV4_ROUTE_GC_THRESH,
.procname = "gc_thresh",
.data = &ip_rt_secret_interval,
.maxlen = sizeof(int),
.mode = 0644,
- .proc_handler = &proc_dointvec_jiffies,
- .strategy = &sysctl_jiffies,
+ .proc_handler = &ipv4_sysctl_rt_secret_interval,
+ .strategy = &ipv4_sysctl_rt_secret_interval_strategy,
},
{ .ctl_name = 0 }
};
-static __net_initdata struct ctl_path ipv4_route_path[] = {
+static struct ctl_table empty[1];
+
+static struct ctl_table ipv4_skeleton[] =
+{
+ { .procname = "route", .ctl_name = NET_IPV4_ROUTE,
+ .mode = 0555, .child = ipv4_route_table},
+ { .procname = "neigh", .ctl_name = NET_IPV4_NEIGH,
+ .mode = 0555, .child = empty},
+ { }
+};
+
+static __net_initdata struct ctl_path ipv4_path[] = {
{ .procname = "net", .ctl_name = CTL_NET, },
{ .procname = "ipv4", .ctl_name = NET_IPV4, },
- { .procname = "route", .ctl_name = NET_IPV4_ROUTE, },
{ },
};
-
static struct ctl_table ipv4_route_flush_table[] = {
{
.ctl_name = NET_IPV4_ROUTE_FLUSH,
{ .ctl_name = 0 },
};
+static __net_initdata struct ctl_path ipv4_route_path[] = {
+ { .procname = "net", .ctl_name = CTL_NET, },
+ { .procname = "ipv4", .ctl_name = NET_IPV4, },
+ { .procname = "route", .ctl_name = NET_IPV4_ROUTE, },
+ { },
+};
+
static __net_init int sysctl_route_net_init(struct net *net)
{
struct ctl_table *tbl;
net->ipv4.rt_secret_timer.data = (unsigned long)net;
init_timer_deferrable(&net->ipv4.rt_secret_timer);
- net->ipv4.rt_secret_timer.expires =
- jiffies + net_random() % ip_rt_secret_interval +
- ip_rt_secret_interval;
- add_timer(&net->ipv4.rt_secret_timer);
+ if (ip_rt_secret_interval) {
+ net->ipv4.rt_secret_timer.expires =
+ jiffies + net_random() % ip_rt_secret_interval +
+ ip_rt_secret_interval;
+ add_timer(&net->ipv4.rt_secret_timer);
+ }
return 0;
}
return rc;
}
+#ifdef CONFIG_SYSCTL
+/*
+ * We really need to sanitize the damn ipv4 init order, then all
+ * this nonsense will go away.
+ */
+void __init ip_static_sysctl_init(void)
+{
+ register_sysctl_paths(ipv4_path, ipv4_skeleton);
+}
+#endif
+
EXPORT_SYMBOL(__ip_select_ident);
EXPORT_SYMBOL(ip_route_input);
EXPORT_SYMBOL(ip_route_output_key);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff