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ipv4: Maintain redirect and PMTU info in struct rtable again.
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Maintaining this in the inetpeer entries was not the right way to do
this at all.

Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller committed Jul 11, 2012
1 parent 87a5069 commit 5943634
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Showing 5 changed files with 41 additions and 154 deletions.
4 changes: 0 additions & 4 deletions include/net/inetpeer.h
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Original file line number Diff line number Diff line change
Expand Up @@ -36,10 +36,6 @@ struct inet_peer {
u32 metrics[RTAX_MAX];
u32 rate_tokens; /* rate limiting for ICMP */
unsigned long rate_last;
unsigned long pmtu_expires;
u32 pmtu_orig;
u32 pmtu_learned;
struct inetpeer_addr_base redirect_learned;
union {
struct list_head gc_list;
struct rcu_head gc_rcu;
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2 changes: 1 addition & 1 deletion include/net/route.h
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Original file line number Diff line number Diff line change
Expand Up @@ -65,7 +65,7 @@ struct rtable {
__be32 rt_gateway;

/* Miscellaneous cached information */
u32 rt_peer_genid;
u32 rt_pmtu;
unsigned long _peer; /* long-living peer info */
struct fib_info *fi; /* for client ref to shared metrics */
};
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3 changes: 0 additions & 3 deletions net/ipv4/inetpeer.c
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Original file line number Diff line number Diff line change
Expand Up @@ -511,9 +511,6 @@ struct inet_peer *inet_getpeer(struct inet_peer_base *base,
p->metrics[RTAX_LOCK-1] = INETPEER_METRICS_NEW;
p->rate_tokens = 0;
p->rate_last = 0;
p->pmtu_expires = 0;
p->pmtu_orig = 0;
memset(&p->redirect_learned, 0, sizeof(p->redirect_learned));
INIT_LIST_HEAD(&p->gc_list);

/* Link the node. */
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185 changes: 39 additions & 146 deletions net/ipv4/route.c
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Original file line number Diff line number Diff line change
Expand Up @@ -669,7 +669,7 @@ static inline int rt_fast_clean(struct rtable *rth)
static inline int rt_valuable(struct rtable *rth)
{
return (rth->rt_flags & (RTCF_REDIRECTED | RTCF_NOTIFY)) ||
(rt_has_peer(rth) && rt_peer_ptr(rth)->pmtu_expires);
rth->dst.expires;
}

static int rt_may_expire(struct rtable *rth, unsigned long tmo1, unsigned long tmo2)
Expand Down Expand Up @@ -1242,13 +1242,6 @@ static struct rtable *rt_intern_hash(unsigned int hash, struct rtable *rt,
return rt;
}

static atomic_t __rt_peer_genid = ATOMIC_INIT(0);

static u32 rt_peer_genid(void)
{
return atomic_read(&__rt_peer_genid);
}

void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
{
struct inet_peer_base *base;
Expand All @@ -1262,8 +1255,6 @@ void rt_bind_peer(struct rtable *rt, __be32 daddr, int create)
if (peer) {
if (!rt_set_peer(rt, peer))
inet_putpeer(peer);
else
rt->rt_peer_genid = rt_peer_genid();
}
}

Expand Down Expand Up @@ -1323,30 +1314,6 @@ static void rt_del(unsigned int hash, struct rtable *rt)
spin_unlock_bh(rt_hash_lock_addr(hash));
}

static void check_peer_redir(struct dst_entry *dst, struct inet_peer *peer)
{
struct rtable *rt = (struct rtable *) dst;
__be32 orig_gw = rt->rt_gateway;
struct neighbour *n;

dst_confirm(&rt->dst);

rt->rt_gateway = peer->redirect_learned.a4;

n = ipv4_neigh_lookup(&rt->dst, NULL, &rt->rt_gateway);
if (!n) {
rt->rt_gateway = orig_gw;
return;
}
if (!(n->nud_state & NUD_VALID)) {
neigh_event_send(n, NULL);
} else {
rt->rt_flags |= RTCF_REDIRECTED;
call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
}
neigh_release(n);
}

/* called in rcu_read_lock() section */
void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
__be32 saddr, struct net_device *dev)
Expand All @@ -1355,7 +1322,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
struct in_device *in_dev = __in_dev_get_rcu(dev);
__be32 skeys[2] = { saddr, 0 };
int ikeys[2] = { dev->ifindex, 0 };
struct inet_peer *peer;
struct net *net;

if (!in_dev)
Expand Down Expand Up @@ -1388,6 +1354,8 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
rthp = &rt_hash_table[hash].chain;

while ((rt = rcu_dereference(*rthp)) != NULL) {
struct neighbour *n;

rthp = &rt->dst.rt_next;

if (rt->rt_key_dst != daddr ||
Expand All @@ -1401,13 +1369,16 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
rt->rt_gateway != old_gw)
continue;

peer = rt_get_peer_create(rt, rt->rt_dst);
if (peer) {
if (peer->redirect_learned.a4 != new_gw) {
peer->redirect_learned.a4 = new_gw;
atomic_inc(&__rt_peer_genid);
n = ipv4_neigh_lookup(&rt->dst, NULL, &new_gw);
if (n) {
if (!(n->nud_state & NUD_VALID)) {
neigh_event_send(n, NULL);
} else {
rt->rt_gateway = new_gw;
rt->rt_flags |= RTCF_REDIRECTED;
call_netevent_notifiers(NETEVENT_NEIGH_UPDATE, n);
}
check_peer_redir(&rt->dst, peer);
neigh_release(n);
}
}
}
Expand All @@ -1425,23 +1396,6 @@ void ip_rt_redirect(__be32 old_gw, __be32 daddr, __be32 new_gw,
;
}

static bool peer_pmtu_expired(struct inet_peer *peer)
{
unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);

return orig &&
time_after_eq(jiffies, orig) &&
cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
}

static bool peer_pmtu_cleaned(struct inet_peer *peer)
{
unsigned long orig = ACCESS_ONCE(peer->pmtu_expires);

return orig &&
cmpxchg(&peer->pmtu_expires, orig, 0) == orig;
}

static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
{
struct rtable *rt = (struct rtable *)dst;
Expand All @@ -1451,16 +1405,13 @@ static struct dst_entry *ipv4_negative_advice(struct dst_entry *dst)
if (dst->obsolete > 0) {
ip_rt_put(rt);
ret = NULL;
} else if (rt->rt_flags & RTCF_REDIRECTED) {
} else if ((rt->rt_flags & RTCF_REDIRECTED) ||
rt->dst.expires) {
unsigned int hash = rt_hash(rt->rt_key_dst, rt->rt_key_src,
rt->rt_oif,
rt_genid(dev_net(dst->dev)));
rt_del(hash, rt);
ret = NULL;
} else if (rt_has_peer(rt)) {
struct inet_peer *peer = rt_peer_ptr(rt);
if (peer_pmtu_expired(peer))
dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
}
}
return ret;
Expand Down Expand Up @@ -1604,50 +1555,17 @@ out: kfree_skb(skb);
return 0;
}

static void check_peer_pmtu(struct dst_entry *dst, struct inet_peer *peer)
{
unsigned long expires = ACCESS_ONCE(peer->pmtu_expires);

if (!expires)
return;
if (time_before(jiffies, expires)) {
u32 orig_dst_mtu = dst_mtu(dst);
if (peer->pmtu_learned < orig_dst_mtu) {
if (!peer->pmtu_orig)
peer->pmtu_orig = dst_metric_raw(dst, RTAX_MTU);
dst_metric_set(dst, RTAX_MTU, peer->pmtu_learned);
}
} else if (cmpxchg(&peer->pmtu_expires, expires, 0) == expires)
dst_metric_set(dst, RTAX_MTU, peer->pmtu_orig);
}

static void ip_rt_update_pmtu(struct dst_entry *dst, u32 mtu)
{
struct rtable *rt = (struct rtable *) dst;
struct inet_peer *peer;

dst_confirm(dst);

peer = rt_get_peer_create(rt, rt->rt_dst);
if (peer) {
unsigned long pmtu_expires = ACCESS_ONCE(peer->pmtu_expires);

if (mtu < ip_rt_min_pmtu)
mtu = ip_rt_min_pmtu;
if (!pmtu_expires || mtu < peer->pmtu_learned) {

pmtu_expires = jiffies + ip_rt_mtu_expires;
if (!pmtu_expires)
pmtu_expires = 1UL;

peer->pmtu_learned = mtu;
peer->pmtu_expires = pmtu_expires;
if (mtu < ip_rt_min_pmtu)
mtu = ip_rt_min_pmtu;

atomic_inc(&__rt_peer_genid);
rt->rt_peer_genid = rt_peer_genid();
}
check_peer_pmtu(dst, peer);
}
rt->rt_pmtu = mtu;
dst_set_expires(&rt->dst, ip_rt_mtu_expires);
}

void ipv4_update_pmtu(struct sk_buff *skb, struct net *net, u32 mtu,
Expand Down Expand Up @@ -1679,30 +1597,12 @@ void ipv4_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, u32 mtu)
}
EXPORT_SYMBOL_GPL(ipv4_sk_update_pmtu);

static void ipv4_validate_peer(struct rtable *rt)
{
if (rt->rt_peer_genid != rt_peer_genid()) {
struct inet_peer *peer = rt_get_peer(rt, rt->rt_dst);

if (peer) {
check_peer_pmtu(&rt->dst, peer);

if (peer->redirect_learned.a4 &&
peer->redirect_learned.a4 != rt->rt_gateway)
check_peer_redir(&rt->dst, peer);
}

rt->rt_peer_genid = rt_peer_genid();
}
}

static struct dst_entry *ipv4_dst_check(struct dst_entry *dst, u32 cookie)
{
struct rtable *rt = (struct rtable *) dst;

if (rt_is_expired(rt))
return NULL;
ipv4_validate_peer(rt);
return dst;
}

Expand All @@ -1728,11 +1628,8 @@ static void ipv4_link_failure(struct sk_buff *skb)
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_HOST_UNREACH, 0);

rt = skb_rtable(skb);
if (rt && rt_has_peer(rt)) {
struct inet_peer *peer = rt_peer_ptr(rt);
if (peer_pmtu_cleaned(peer))
dst_metric_set(&rt->dst, RTAX_MTU, peer->pmtu_orig);
}
if (rt)
dst_set_expires(&rt->dst, 0);
}

static int ip_rt_bug(struct sk_buff *skb)
Expand Down Expand Up @@ -1812,7 +1709,13 @@ static unsigned int ipv4_default_advmss(const struct dst_entry *dst)
static unsigned int ipv4_mtu(const struct dst_entry *dst)
{
const struct rtable *rt = (const struct rtable *) dst;
unsigned int mtu = dst_metric_raw(dst, RTAX_MTU);
unsigned int mtu = rt->rt_pmtu;

if (mtu && time_after_eq(jiffies, rt->dst.expires))
mtu = 0;

if (!mtu)
mtu = dst_metric_raw(dst, RTAX_MTU);

if (mtu && rt_is_output_route(rt))
return mtu;
Expand Down Expand Up @@ -1843,19 +1746,10 @@ static void rt_init_metrics(struct rtable *rt, const struct flowi4 *fl4,
peer = inet_getpeer_v4(base, rt->rt_dst, 0);
if (peer) {
__rt_set_peer(rt, peer);
rt->rt_peer_genid = rt_peer_genid();
if (inet_metrics_new(peer))
memcpy(peer->metrics, fi->fib_metrics,
sizeof(u32) * RTAX_MAX);
dst_init_metrics(&rt->dst, peer->metrics, false);

check_peer_pmtu(&rt->dst, peer);

if (peer->redirect_learned.a4 &&
peer->redirect_learned.a4 != rt->rt_gateway) {
rt->rt_gateway = peer->redirect_learned.a4;
rt->rt_flags |= RTCF_REDIRECTED;
}
} else {
if (fi->fib_metrics != (u32 *) dst_default_metrics) {
rt->fi = fi;
Expand Down Expand Up @@ -1955,8 +1849,8 @@ static int ip_route_input_mc(struct sk_buff *skb, __be32 daddr, __be32 saddr,
rth->rt_iif = dev->ifindex;
rth->rt_oif = 0;
rth->rt_mark = skb->mark;
rth->rt_pmtu = 0;
rth->rt_gateway = daddr;
rth->rt_peer_genid = 0;
rt_init_peer(rth, dev_net(dev)->ipv4.peers);
rth->fi = NULL;
if (our) {
Expand Down Expand Up @@ -2081,8 +1975,8 @@ static int __mkroute_input(struct sk_buff *skb,
rth->rt_iif = in_dev->dev->ifindex;
rth->rt_oif = 0;
rth->rt_mark = skb->mark;
rth->rt_pmtu = 0;
rth->rt_gateway = daddr;
rth->rt_peer_genid = 0;
rt_init_peer(rth, &res->table->tb_peers);
rth->fi = NULL;

Expand Down Expand Up @@ -2260,8 +2154,8 @@ out: return err;
rth->rt_iif = dev->ifindex;
rth->rt_oif = 0;
rth->rt_mark = skb->mark;
rth->rt_pmtu = 0;
rth->rt_gateway = daddr;
rth->rt_peer_genid = 0;
rt_init_peer(rth, net->ipv4.peers);
rth->fi = NULL;
if (res.type == RTN_UNREACHABLE) {
Expand Down Expand Up @@ -2337,7 +2231,6 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
rth->rt_mark == skb->mark &&
net_eq(dev_net(rth->dst.dev), net) &&
!rt_is_expired(rth)) {
ipv4_validate_peer(rth);
if (noref) {
dst_use_noref(&rth->dst, jiffies);
skb_dst_set_noref(skb, &rth->dst);
Expand Down Expand Up @@ -2459,8 +2352,8 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
rth->rt_iif = orig_oif ? : dev_out->ifindex;
rth->rt_oif = orig_oif;
rth->rt_mark = fl4->flowi4_mark;
rth->rt_pmtu = 0;
rth->rt_gateway = fl4->daddr;
rth->rt_peer_genid = 0;
rt_init_peer(rth, (res->table ?
&res->table->tb_peers :
dev_net(dev_out)->ipv4.peers));
Expand Down Expand Up @@ -2717,7 +2610,6 @@ struct rtable *__ip_route_output_key(struct net *net, struct flowi4 *flp4)
(IPTOS_RT_MASK | RTO_ONLINK)) &&
net_eq(dev_net(rth->dst.dev), net) &&
!rt_is_expired(rth)) {
ipv4_validate_peer(rth);
dst_use(&rth->dst, jiffies);
RT_CACHE_STAT_INC(out_hit);
rcu_read_unlock_bh();
Expand Down Expand Up @@ -2794,6 +2686,7 @@ struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_or
rt->rt_iif = ort->rt_iif;
rt->rt_oif = ort->rt_oif;
rt->rt_mark = ort->rt_mark;
rt->rt_pmtu = ort->rt_pmtu;

rt->rt_genid = rt_genid(net);
rt->rt_flags = ort->rt_flags;
Expand Down Expand Up @@ -2896,13 +2789,13 @@ static int rt_fill_info(struct net *net,
const struct inet_peer *peer = rt_peer_ptr(rt);
inet_peer_refcheck(peer);
id = atomic_read(&peer->ip_id_count) & 0xffff;
expires = ACCESS_ONCE(peer->pmtu_expires);
if (expires) {
if (time_before(jiffies, expires))
expires -= jiffies;
else
expires = 0;
}
}
expires = rt->dst.expires;
if (expires) {
if (time_before(jiffies, expires))
expires -= jiffies;
else
expires = 0;
}

if (rt_is_input_route(rt)) {
Expand Down
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