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Message-Id: <20180319033622.16693-18-dsahern@gmail.com>
Date: Sun, 18 Mar 2018 20:36:18 -0700
From: David Ahern <dsahern@...il.com>
To: netdev@...r.kernel.org
Cc: davem@...emloft.net, idosch@...sch.org, roopa@...ulusnetworks.com,
eric.dumazet@...il.com, weiwan@...gle.com, kafai@...com,
yoshfuji@...ux-ipv6.org, David Ahern <dsahern@...il.com>
Subject: [PATCH RFC v2 net-next 17/21] net/ipv6: Cleanup exception and cache route handling
IPv6 FIB will only contain FIB entries with exception routes added to
the FIB entry. Once this transformation is complete, FIB lookups will
return a fib6_info with the lookup functions still returning a dst
based rt6_info. The current code uses rt6_info for both paths and
overloads the rt6_info variable usually called 'rt'.
This patch introduces a new 'f6i' variable name for the result of the FIB
lookup and keeps 'rt' as the dst based return variable. 'f6i' becomes a
fib6_info in a later patch which is why it is introduced as f6i now;
avoids the additional churn in the later patch.
In addition, remove RTF_CACHE and dst checks from fib6 add and delete
since they can not happen now and will never happen after the data
type flip.
Signed-off-by: David Ahern <dsahern@...il.com>
---
include/net/ip6_route.h | 1 -
net/ipv6/ip6_fib.c | 16 +-----
net/ipv6/route.c | 137 ++++++++++++++++++++++++++----------------------
3 files changed, 75 insertions(+), 79 deletions(-)
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 76d2c31e18b7..d722fa843f31 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -106,7 +106,6 @@ int ip6_ins_rt(struct net *net, struct rt6_info *rt);
int ip6_del_rt(struct net *net, struct rt6_info *rt);
void rt6_flush_exceptions(struct rt6_info *rt);
-int rt6_remove_exception_rt(struct rt6_info *rt);
void rt6_age_exceptions(struct rt6_info *rt, struct fib6_gc_args *gc_args,
unsigned long now);
diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c
index 90df1589a6c2..e27a01aa64f4 100644
--- a/net/ipv6/ip6_fib.c
+++ b/net/ipv6/ip6_fib.c
@@ -1065,7 +1065,7 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct rt6_info *rt,
static void fib6_start_gc(struct net *net, struct rt6_info *rt)
{
if (!timer_pending(&net->ipv6.ip6_fib_timer) &&
- (rt->rt6i_flags & (RTF_EXPIRES | RTF_CACHE)))
+ (rt->rt6i_flags & RTF_EXPIRES))
mod_timer(&net->ipv6.ip6_fib_timer,
jiffies + net->ipv6.sysctl.ip6_rt_gc_interval);
}
@@ -1116,8 +1116,6 @@ int fib6_add(struct fib6_node *root, struct rt6_info *rt,
if (WARN_ON_ONCE(!atomic_read(&rt->dst.__refcnt)))
return -EINVAL;
- if (WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE))
- return -EINVAL;
if (info->nlh) {
if (!(info->nlh->nlmsg_flags & NLM_F_CREATE))
@@ -1641,8 +1639,6 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
RT6_TRACE("fib6_del_route\n");
- WARN_ON_ONCE(rt->rt6i_flags & RTF_CACHE);
-
/* Unlink it */
*rtp = rt->rt6_next;
rt->rt6i_node = NULL;
@@ -1711,21 +1707,11 @@ int fib6_del(struct rt6_info *rt, struct nl_info *info)
struct rt6_info __rcu **rtp;
struct rt6_info __rcu **rtp_next;
-#if RT6_DEBUG >= 2
- if (rt->dst.obsolete > 0) {
- WARN_ON(fn);
- return -ENOENT;
- }
-#endif
if (!fn || rt == net->ipv6.fib6_null_entry)
return -ENOENT;
WARN_ON(!(fn->fn_flags & RTN_RTINFO));
- /* remove cached dst from exception table */
- if (rt->rt6i_flags & RTF_CACHE)
- return rt6_remove_exception_rt(rt);
-
/*
* Walk the leaf entries looking for ourself
*/
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index d14dbf5ff1db..8eda7d09729b 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1013,8 +1013,8 @@ static void rt6_set_from(struct rt6_info *rt, struct rt6_info *from)
BUG_ON(from->from);
rt->rt6i_flags &= ~RTF_EXPIRES;
- dst_hold(&from->dst);
- rt->from = from;
+ if (dst_hold_safe(&from->dst))
+ rt->from = from;
dst_init_metrics(&rt->dst, from->fib6_metrics->metrics, true);
if (from->fib6_metrics != &dst_default_metrics) {
rt->dst._metrics |= DST_METRICS_REFCOUNTED;
@@ -1098,42 +1098,36 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
const struct sk_buff *skb,
int flags)
{
- struct rt6_info *rt, *rt_cache;
+ struct rt6_info *f6i;
struct fib6_node *fn;
+ struct rt6_info *rt;
rcu_read_lock();
fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
- rt = rcu_dereference(fn->leaf);
- if (!rt) {
- rt = net->ipv6.fib6_null_entry;
+ f6i = rcu_dereference(fn->leaf);
+ if (!f6i) {
+ f6i = net->ipv6.fib6_null_entry;
} else {
- rt = rt6_device_match(net, rt, &fl6->saddr,
+ f6i = rt6_device_match(net, f6i, &fl6->saddr,
fl6->flowi6_oif, flags);
- if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
- rt = rt6_multipath_select(net, rt, fl6, fl6->flowi6_oif,
- skb, flags);
+ if (f6i->rt6i_nsiblings && fl6->flowi6_oif == 0)
+ f6i = rt6_multipath_select(net, f6i, fl6,
+ fl6->flowi6_oif, skb, flags);
}
- if (rt == net->ipv6.fib6_null_entry) {
+ if (f6i == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto restart;
}
+
/* Search through exception table */
- rt_cache = rt6_find_cached_rt(rt, &fl6->daddr, &fl6->saddr);
- if (rt_cache) {
- rt = rt_cache;
+ rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
+ if (rt) {
if (ip6_hold_safe(net, &rt, true))
dst_use_noref(&rt->dst, jiffies);
- } else if (dst_hold_safe(&rt->dst)) {
- struct rt6_info *nrt;
-
- nrt = ip6_create_rt_rcu(rt);
- dst_release(&rt->dst);
- rt = nrt;
} else {
- rt = net->ipv6.ip6_null_entry;
- dst_hold(&rt->dst);
+ rt = ip6_create_rt_rcu(f6i);
}
rcu_read_unlock();
@@ -1216,9 +1210,6 @@ static struct rt6_info *ip6_rt_cache_alloc(struct rt6_info *ort,
* Clone the route.
*/
- if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
- ort = ort->from;
-
rcu_read_lock();
dev = ip6_rt_get_dev_rcu(ort);
rt = __ip6_dst_alloc(dev_net(dev), dev, 0);
@@ -1444,11 +1435,6 @@ static int rt6_insert_exception(struct rt6_info *nrt,
struct rt6_exception *rt6_ex;
int err = 0;
- /* ort can't be a cache or pcpu route */
- if (ort->rt6i_flags & (RTF_CACHE | RTF_PCPU))
- ort = ort->from;
- WARN_ON_ONCE(ort->rt6i_flags & (RTF_CACHE | RTF_PCPU));
-
spin_lock_bh(&rt6_exception_lock);
if (ort->exception_bucket_flushed) {
@@ -1587,7 +1573,7 @@ static struct rt6_info *rt6_find_cached_rt(struct rt6_info *rt,
}
/* Remove the passed in cached rt from the hash table that contains it */
-int rt6_remove_exception_rt(struct rt6_info *rt)
+static int rt6_remove_exception_rt(struct rt6_info *rt)
{
struct rt6_exception_bucket *bucket;
struct rt6_info *from = rt->from;
@@ -1828,7 +1814,8 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
const struct sk_buff *skb, int flags)
{
struct fib6_node *fn, *saved_fn;
- struct rt6_info *rt, *rt_cache;
+ struct rt6_info *f6i;
+ struct rt6_info *rt;
int strict = 0;
strict |= flags & RT6_LOOKUP_F_IFACE;
@@ -1845,10 +1832,10 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
oif = 0;
redo_rt6_select:
- rt = rt6_select(net, fn, oif, strict);
- if (rt->rt6i_nsiblings)
- rt = rt6_multipath_select(net, rt, fl6, oif, skb, strict);
- if (rt == net->ipv6.fib6_null_entry) {
+ f6i = rt6_select(net, fn, oif, strict);
+ if (f6i->rt6i_nsiblings)
+ f6i = rt6_multipath_select(net, f6i, fl6, oif, skb, strict);
+ if (f6i == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto redo_rt6_select;
@@ -1860,18 +1847,17 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
}
}
- /*Search through exception table */
- rt_cache = rt6_find_cached_rt(rt, &fl6->daddr, &fl6->saddr);
- if (rt_cache)
- rt = rt_cache;
-
- if (rt == net->ipv6.fib6_null_entry) {
+ if (f6i == net->ipv6.fib6_null_entry) {
rt = net->ipv6.ip6_null_entry;
rcu_read_unlock();
dst_hold(&rt->dst);
trace_fib6_table_lookup(net, rt, table, fl6);
return rt;
- } else if (rt->rt6i_flags & RTF_CACHE) {
+ }
+
+ /*Search through exception table */
+ rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
+ if (rt) {
if (ip6_hold_safe(net, &rt, true))
dst_use_noref(&rt->dst, jiffies);
@@ -1879,7 +1865,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
trace_fib6_table_lookup(net, rt, table, fl6);
return rt;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
- !(rt->rt6i_flags & RTF_GATEWAY))) {
+ !(f6i->rt6i_flags & RTF_GATEWAY))) {
/* Create a RTF_CACHE clone which will not be
* owned by the fib6 tree. It is for the special case where
* the daddr in the skb during the neighbor look-up is different
@@ -1888,16 +1874,16 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
struct rt6_info *uncached_rt;
- if (ip6_hold_safe(net, &rt, true)) {
- dst_use_noref(&rt->dst, jiffies);
+ if (ip6_hold_safe(net, &f6i, true)) {
+ dst_use_noref(&f6i->dst, jiffies);
} else {
rcu_read_unlock();
- uncached_rt = rt;
+ uncached_rt = f6i;
goto uncached_rt_out;
}
rcu_read_unlock();
- uncached_rt = ip6_rt_cache_alloc(rt, &fl6->daddr, NULL);
+ uncached_rt = ip6_rt_cache_alloc(f6i, &fl6->daddr, NULL);
dst_release(&rt->dst);
if (uncached_rt) {
@@ -1920,18 +1906,18 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
struct rt6_info *pcpu_rt;
- dst_use_noref(&rt->dst, jiffies);
+ dst_use_noref(&f6i->dst, jiffies);
local_bh_disable();
- pcpu_rt = rt6_get_pcpu_route(rt);
+ pcpu_rt = rt6_get_pcpu_route(f6i);
if (!pcpu_rt) {
/* atomic_inc_not_zero() is needed when using rcu */
- if (atomic_inc_not_zero(&rt->rt6i_ref)) {
+ if (atomic_inc_not_zero(&f6i->rt6i_ref)) {
/* No dst_hold() on rt is needed because grabbing
* rt->rt6i_ref makes sure rt can't be released.
*/
- pcpu_rt = rt6_make_pcpu_route(net, rt);
- rt6_release(rt);
+ pcpu_rt = rt6_make_pcpu_route(net, f6i);
+ rt6_release(f6i);
} else {
/* rt is already removed from tree */
pcpu_rt = net->ipv6.ip6_null_entry;
@@ -2376,7 +2362,8 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
int flags)
{
struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
- struct rt6_info *rt, *rt_cache;
+ struct rt6_info *ret = NULL, *rt_cache;
+ struct rt6_info *rt;
struct fib6_node *fn;
/* Get the "current" route for this destination and
@@ -2415,7 +2402,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
if (rt_cache &&
ipv6_addr_equal(&rdfl->gateway,
&rt_cache->rt6i_gateway)) {
- rt = rt_cache;
+ ret = rt_cache;
break;
}
continue;
@@ -2426,7 +2413,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
if (!rt)
rt = net->ipv6.fib6_null_entry;
else if (rt->rt6i_flags & RTF_REJECT) {
- rt = net->ipv6.ip6_null_entry;
+ ret = net->ipv6.ip6_null_entry;
goto out;
}
@@ -2437,12 +2424,15 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
}
out:
- ip6_hold_safe(net, &rt, true);
+ if (ret)
+ dst_hold(&ret->dst);
+ else
+ ret = ip6_create_rt_rcu(rt);
rcu_read_unlock();
- trace_fib6_table_lookup(net, rt, table, fl6);
- return rt;
+ trace_fib6_table_lookup(net, ret, table, fl6);
+ return ret;
};
static struct dst_entry *ip6_route_redirect(struct net *net,
@@ -3133,6 +3123,22 @@ static int __ip6_del_rt_siblings(struct rt6_info *rt, struct fib6_config *cfg)
return err;
}
+static int ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
+{
+ int rc = -ESRCH;
+
+ if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
+ goto out;
+
+ if (cfg->fc_flags & RTF_GATEWAY &&
+ !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
+ goto out;
+ if (dst_hold_safe(&rt->dst))
+ rc = rt6_remove_exception_rt(rt);
+out:
+ return rc;
+}
+
static int ip6_route_del(struct fib6_config *cfg,
struct netlink_ext_ack *extack)
{
@@ -3157,11 +3163,16 @@ static int ip6_route_del(struct fib6_config *cfg,
if (fn) {
for_each_fib6_node_rt_rcu(fn) {
if (cfg->fc_flags & RTF_CACHE) {
+ int rc;
+
rt_cache = rt6_find_cached_rt(rt, &cfg->fc_dst,
&cfg->fc_src);
- if (!rt_cache)
- continue;
- rt = rt_cache;
+ if (rt_cache) {
+ rc = ip6_del_cached_rt(rt_cache, cfg);
+ if (rc != -ESRCH)
+ return rc;
+ }
+ continue;
}
if (cfg->fc_ifindex &&
(!rt->fib6_nh.nh_dev ||
@@ -3278,7 +3289,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
NEIGH_UPDATE_F_ISROUTER)),
NDISC_REDIRECT, &ndopts);
- nrt = ip6_rt_cache_alloc(rt, &msg->dest, NULL);
+ nrt = ip6_rt_cache_alloc(rt->from, &msg->dest, NULL);
if (!nrt)
goto out;
--
2.11.0
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