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-rw-r--r--net/ipv4/route.c209
1 files changed, 89 insertions, 120 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 163086b2f058..8842ecb9be48 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -117,8 +117,6 @@
#define RT_GC_TIMEOUT (300*HZ)
-static int ip_rt_min_delay = 2 * HZ;
-static int ip_rt_max_delay = 10 * HZ;
static int ip_rt_max_size;
static int ip_rt_gc_timeout = RT_GC_TIMEOUT;
static int ip_rt_gc_interval = 60 * HZ;
@@ -133,12 +131,9 @@ static int ip_rt_mtu_expires = 10 * 60 * HZ;
static int ip_rt_min_pmtu = 512 + 20 + 20;
static int ip_rt_min_advmss = 256;
static int ip_rt_secret_interval = 10 * 60 * HZ;
-static int ip_rt_flush_expected;
-static unsigned long rt_deadline;
#define RTprint(a...) printk(KERN_DEBUG a)
-static struct timer_list rt_flush_timer;
static void rt_worker_func(struct work_struct *work);
static DECLARE_DELAYED_WORK(expires_work, rt_worker_func);
static struct timer_list rt_secret_timer;
@@ -260,19 +255,16 @@ static inline void rt_hash_lock_init(void)
static struct rt_hash_bucket *rt_hash_table;
static unsigned rt_hash_mask;
static unsigned int rt_hash_log;
-static unsigned int rt_hash_rnd;
+static atomic_t rt_genid;
static DEFINE_PER_CPU(struct rt_cache_stat, rt_cache_stat);
#define RT_CACHE_STAT_INC(field) \
(__raw_get_cpu_var(rt_cache_stat).field++)
-static int rt_intern_hash(unsigned hash, struct rtable *rth,
- struct rtable **res);
-
static unsigned int rt_hash_code(u32 daddr, u32 saddr)
{
- return (jhash_2words(daddr, saddr, rt_hash_rnd)
- & rt_hash_mask);
+ return jhash_2words(daddr, saddr, atomic_read(&rt_genid))
+ & rt_hash_mask;
}
#define rt_hash(daddr, saddr, idx) \
@@ -282,27 +274,28 @@ static unsigned int rt_hash_code(u32 daddr, u32 saddr)
#ifdef CONFIG_PROC_FS
struct rt_cache_iter_state {
int bucket;
+ int genid;
};
-static struct rtable *rt_cache_get_first(struct seq_file *seq)
+static struct rtable *rt_cache_get_first(struct rt_cache_iter_state *st)
{
struct rtable *r = NULL;
- struct rt_cache_iter_state *st = seq->private;
for (st->bucket = rt_hash_mask; st->bucket >= 0; --st->bucket) {
rcu_read_lock_bh();
- r = rt_hash_table[st->bucket].chain;
- if (r)
- break;
+ r = rcu_dereference(rt_hash_table[st->bucket].chain);
+ while (r) {
+ if (r->rt_genid == st->genid)
+ return r;
+ r = rcu_dereference(r->u.dst.rt_next);
+ }
rcu_read_unlock_bh();
}
- return rcu_dereference(r);
+ return r;
}
-static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
+static struct rtable *rt_cache_get_next(struct rt_cache_iter_state *st, struct rtable *r)
{
- struct rt_cache_iter_state *st = seq->private;
-
r = r->u.dst.rt_next;
while (!r) {
rcu_read_unlock_bh();
@@ -314,29 +307,38 @@ static struct rtable *rt_cache_get_next(struct seq_file *seq, struct rtable *r)
return rcu_dereference(r);
}
-static struct rtable *rt_cache_get_idx(struct seq_file *seq, loff_t pos)
+static struct rtable *rt_cache_get_idx(struct rt_cache_iter_state *st, loff_t pos)
{
- struct rtable *r = rt_cache_get_first(seq);
+ struct rtable *r = rt_cache_get_first(st);
if (r)
- while (pos && (r = rt_cache_get_next(seq, r)))
+ while (pos && (r = rt_cache_get_next(st, r))) {
+ if (r->rt_genid != st->genid)
+ continue;
--pos;
+ }
return pos ? NULL : r;
}
static void *rt_cache_seq_start(struct seq_file *seq, loff_t *pos)
{
- return *pos ? rt_cache_get_idx(seq, *pos - 1) : SEQ_START_TOKEN;
+ struct rt_cache_iter_state *st = seq->private;
+
+ if (*pos)
+ return rt_cache_get_idx(st, *pos - 1);
+ st->genid = atomic_read(&rt_genid);
+ return SEQ_START_TOKEN;
}
static void *rt_cache_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
- struct rtable *r = NULL;
+ struct rtable *r;
+ struct rt_cache_iter_state *st = seq->private;
if (v == SEQ_START_TOKEN)
- r = rt_cache_get_first(seq);
+ r = rt_cache_get_first(st);
else
- r = rt_cache_get_next(seq, v);
+ r = rt_cache_get_next(st, v);
++*pos;
return r;
}
@@ -709,6 +711,11 @@ static void rt_check_expire(void)
continue;
spin_lock_bh(rt_hash_lock_addr(i));
while ((rth = *rthp) != NULL) {
+ if (rth->rt_genid != atomic_read(&rt_genid)) {
+ *rthp = rth->u.dst.rt_next;
+ rt_free(rth);
+ continue;
+ }
if (rth->u.dst.expires) {
/* Entry is expired even if it is in use */
if (time_before_eq(jiffies, rth->u.dst.expires)) {
@@ -733,83 +740,45 @@ static void rt_check_expire(void)
/*
* rt_worker_func() is run in process context.
- * If a whole flush was scheduled, it is done.
- * Else, we call rt_check_expire() to scan part of the hash table
+ * we call rt_check_expire() to scan part of the hash table
*/
static void rt_worker_func(struct work_struct *work)
{
- if (ip_rt_flush_expected) {
- ip_rt_flush_expected = 0;
- rt_do_flush(1);
- } else
- rt_check_expire();
+ rt_check_expire();
schedule_delayed_work(&expires_work, ip_rt_gc_interval);
}
-/* This can run from both BH and non-BH contexts, the latter
- * in the case of a forced flush event.
+/*
+ * Pertubation of rt_genid by a small quantity [1..256]
+ * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
+ * many times (2^24) without giving recent rt_genid.
+ * Jenkins hash is strong enough that litle changes of rt_genid are OK.
*/
-static void rt_run_flush(unsigned long process_context)
+static void rt_cache_invalidate(void)
{
- rt_deadline = 0;
-
- get_random_bytes(&rt_hash_rnd, 4);
+ unsigned char shuffle;
- rt_do_flush(process_context);
+ get_random_bytes(&shuffle, sizeof(shuffle));
+ atomic_add(shuffle + 1U, &rt_genid);
}
-static DEFINE_SPINLOCK(rt_flush_lock);
-
+/*
+ * delay < 0 : invalidate cache (fast : entries will be deleted later)
+ * delay >= 0 : invalidate & flush cache (can be long)
+ */
void rt_cache_flush(int delay)
{
- unsigned long now = jiffies;
- int user_mode = !in_softirq();
-
- if (delay < 0)
- delay = ip_rt_min_delay;
-
- spin_lock_bh(&rt_flush_lock);
-
- if (del_timer(&rt_flush_timer) && delay > 0 && rt_deadline) {
- long tmo = (long)(rt_deadline - now);
-
- /* If flush timer is already running
- and flush request is not immediate (delay > 0):
-
- if deadline is not achieved, prolongate timer to "delay",
- otherwise fire it at deadline time.
- */
-
- if (user_mode && tmo < ip_rt_max_delay-ip_rt_min_delay)
- tmo = 0;
-
- if (delay > tmo)
- delay = tmo;
- }
-
- if (delay <= 0) {
- spin_unlock_bh(&rt_flush_lock);
- rt_run_flush(user_mode);
- return;
- }
-
- if (rt_deadline == 0)
- rt_deadline = now + ip_rt_max_delay;
-
- mod_timer(&rt_flush_timer, now+delay);
- spin_unlock_bh(&rt_flush_lock);
+ rt_cache_invalidate();
+ if (delay >= 0)
+ rt_do_flush(!in_softirq());
}
/*
- * We change rt_hash_rnd and ask next rt_worker_func() invocation
- * to perform a flush in process context
+ * We change rt_genid and let gc do the cleanup
*/
static void rt_secret_rebuild(unsigned long dummy)
{
- get_random_bytes(&rt_hash_rnd, 4);
- ip_rt_flush_expected = 1;
- cancel_delayed_work(&expires_work);
- schedule_delayed_work(&expires_work, HZ/10);
+ rt_cache_invalidate();
mod_timer(&rt_secret_timer, jiffies + ip_rt_secret_interval);
}
@@ -886,7 +855,8 @@ static int rt_garbage_collect(struct dst_ops *ops)
rthp = &rt_hash_table[k].chain;
spin_lock_bh(rt_hash_lock_addr(k));
while ((rth = *rthp) != NULL) {
- if (!rt_may_expire(rth, tmo, expire)) {
+ if (rth->rt_genid == atomic_read(&rt_genid) &&
+ !rt_may_expire(rth, tmo, expire)) {
tmo >>= 1;
rthp = &rth->u.dst.rt_next;
continue;
@@ -967,6 +937,11 @@ restart:
spin_lock_bh(rt_hash_lock_addr(hash));
while ((rth = *rthp) != NULL) {
+ if (rth->rt_genid != atomic_read(&rt_genid)) {
+ *rthp = rth->u.dst.rt_next;
+ rt_free(rth);
+ continue;
+ }
if (compare_keys(&rth->fl, &rt->fl) && compare_netns(rth, rt)) {
/* Put it first */
*rthp = rth->u.dst.rt_next;
@@ -1132,17 +1107,19 @@ void __ip_select_ident(struct iphdr *iph, struct dst_entry *dst, int more)
static void rt_del(unsigned hash, struct rtable *rt)
{
- struct rtable **rthp;
+ struct rtable **rthp, *aux;
+ rthp = &rt_hash_table[hash].chain;
spin_lock_bh(rt_hash_lock_addr(hash));
ip_rt_put(rt);
- for (rthp = &rt_hash_table[hash].chain; *rthp;
- rthp = &(*rthp)->u.dst.rt_next)
- if (*rthp == rt) {
- *rthp = rt->u.dst.rt_next;
- rt_free(rt);
- break;
+ while ((aux = *rthp) != NULL) {
+ if (aux == rt || (aux->rt_genid != atomic_read(&rt_genid))) {
+ *rthp = aux->u.dst.rt_next;
+ rt_free(aux);
+ continue;
}
+ rthp = &aux->u.dst.rt_next;
+ }
spin_unlock_bh(rt_hash_lock_addr(hash));
}
@@ -1187,7 +1164,8 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
if (rth->fl.fl4_dst != daddr ||
rth->fl.fl4_src != skeys[i] ||
rth->fl.oif != ikeys[k] ||
- rth->fl.iif != 0) {
+ rth->fl.iif != 0 ||
+ rth->rt_genid != atomic_read(&rt_genid)) {
rthp = &rth->u.dst.rt_next;
continue;
}
@@ -1225,7 +1203,7 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
rt->u.dst.neighbour = NULL;
rt->u.dst.hh = NULL;
rt->u.dst.xfrm = NULL;
-
+ rt->rt_genid = atomic_read(&rt_genid);
rt->rt_flags |= RTCF_REDIRECTED;
/* Gateway is different ... */
@@ -1446,7 +1424,8 @@ unsigned short ip_rt_frag_needed(struct net *net, struct iphdr *iph,
rth->rt_src == iph->saddr &&
rth->fl.iif == 0 &&
!(dst_metric_locked(&rth->u.dst, RTAX_MTU)) &&
- rth->u.dst.dev->nd_net == net) {
+ rth->u.dst.dev->nd_net == net &&
+ rth->rt_genid == atomic_read(&rt_genid)) {
unsigned short mtu = new_mtu;
if (new_mtu < 68 || new_mtu >= old_mtu) {
@@ -1681,8 +1660,9 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
rth->fl.oif = 0;
rth->rt_gateway = daddr;
rth->rt_spec_dst= spec_dst;
- rth->rt_type = RTN_MULTICAST;
+ rth->rt_genid = atomic_read(&rt_genid);
rth->rt_flags = RTCF_MULTICAST;
+ rth->rt_type = RTN_MULTICAST;
if (our) {
rth->u.dst.input= ip_local_deliver;
rth->rt_flags |= RTCF_LOCAL;
@@ -1821,6 +1801,7 @@ static inline int __mkroute_input(struct sk_buff *skb,
rth->u.dst.input = ip_forward;
rth->u.dst.output = ip_output;
+ rth->rt_genid = atomic_read(&rt_genid);
rt_set_nexthop(rth, res, itag);
@@ -1981,6 +1962,7 @@ local_input:
goto e_nobufs;
rth->u.dst.output= ip_rt_bug;
+ rth->rt_genid = atomic_read(&rt_genid);
atomic_set(&rth->u.dst.__refcnt, 1);
rth->u.dst.flags= DST_HOST;
@@ -2072,7 +2054,8 @@ int ip_route_input(struct sk_buff *skb, __be32 daddr, __be32 saddr,
rth->fl.oif == 0 &&
rth->fl.mark == skb->mark &&
rth->fl.fl4_tos == tos &&
- rth->u.dst.dev->nd_net == net) {
+ rth->u.dst.dev->nd_net == net &&
+ rth->rt_genid == atomic_read(&rt_genid)) {
dst_use(&rth->u.dst, jiffies);
RT_CACHE_STAT_INC(in_hit);
rcu_read_unlock();
@@ -2200,6 +2183,7 @@ static inline int __mkroute_output(struct rtable **result,
rth->rt_spec_dst= fl->fl4_src;
rth->u.dst.output=ip_output;
+ rth->rt_genid = atomic_read(&rt_genid);
RT_CACHE_STAT_INC(out_slow_tot);
@@ -2472,7 +2456,8 @@ int __ip_route_output_key(struct net *net, struct rtable **rp,
rth->fl.mark == flp->mark &&
!((rth->fl.fl4_tos ^ flp->fl4_tos) &
(IPTOS_RT_MASK | RTO_ONLINK)) &&
- rth->u.dst.dev->nd_net == net) {
+ rth->u.dst.dev->nd_net == net &&
+ rth->rt_genid == atomic_read(&rt_genid)) {
dst_use(&rth->u.dst, jiffies);
RT_CACHE_STAT_INC(out_hit);
rcu_read_unlock_bh();
@@ -2527,6 +2512,7 @@ static int ipv4_dst_blackhole(struct rtable **rp, struct flowi *flp, struct sock
rt->idev = ort->idev;
if (rt->idev)
in_dev_hold(rt->idev);
+ rt->rt_genid = atomic_read(&rt_genid);
rt->rt_flags = ort->rt_flags;
rt->rt_type = ort->rt_type;
rt->rt_dst = ort->rt_dst;
@@ -2781,6 +2767,8 @@ int ip_rt_dump(struct sk_buff *skb, struct netlink_callback *cb)
rt = rcu_dereference(rt->u.dst.rt_next), idx++) {
if (idx < s_idx)
continue;
+ if (rt->rt_genid != atomic_read(&rt_genid))
+ continue;
skb->dst = dst_clone(&rt->u.dst);
if (rt_fill_info(skb, NETLINK_CB(cb->skb).pid,
cb->nlh->nlmsg_seq, RTM_NEWROUTE,
@@ -2850,24 +2838,6 @@ ctl_table ipv4_route_table[] = {
.strategy = &ipv4_sysctl_rtcache_flush_strategy,
},
{
- .ctl_name = NET_IPV4_ROUTE_MIN_DELAY,
- .procname = "min_delay",
- .data = &ip_rt_min_delay,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec_jiffies,
- .strategy = &sysctl_jiffies,
- },
- {
- .ctl_name = NET_IPV4_ROUTE_MAX_DELAY,
- .procname = "max_delay",
- .data = &ip_rt_max_delay,
- .maxlen = sizeof(int),
- .mode = 0644,
- .proc_handler = &proc_dointvec_jiffies,
- .strategy = &sysctl_jiffies,
- },
- {
.ctl_name = NET_IPV4_ROUTE_GC_THRESH,
.procname = "gc_thresh",
.data = &ipv4_dst_ops.gc_thresh,
@@ -3025,8 +2995,8 @@ int __init ip_rt_init(void)
{
int rc = 0;
- rt_hash_rnd = (int) ((num_physpages ^ (num_physpages>>8)) ^
- (jiffies ^ (jiffies >> 7)));
+ atomic_set(&rt_genid, (int) ((num_physpages ^ (num_physpages>>8)) ^
+ (jiffies ^ (jiffies >> 7))));
#ifdef CONFIG_NET_CLS_ROUTE
ip_rt_acct = __alloc_percpu(256 * sizeof(struct ip_rt_acct));
@@ -3059,7 +3029,6 @@ int __init ip_rt_init(void)
devinet_init();
ip_fib_init();
- setup_timer(&rt_flush_timer, rt_run_flush, 0);
setup_timer(&rt_secret_timer, rt_secret_rebuild, 0);
/* All the timers, started at system startup tend
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 19:06:30 +0000