net 04/05: fib_rules: allow to delete local rule

Patrick McHardy
2009-11-30T17:55:29Z

commit ca1ba96aaa05cc0a2a7f172990e7787354c8b7b9
Author: Patrick McHardy <kaber@trash.net>
Date: Mon Nov 30 16:05:51 2009 +0100

net: fib_rules: allow to delete local rule

Allow to delete the local rule and recreate it with a lower priority. This
can be used to force packets with a local destination out on the wire instead
of routing them to loopback. Additionally this patch allows to recreate rules
with a priority of 0.

Combined with the previous patch to allow oif classification, a socket can
be bound to the desired interface and packets routed to the wire like this:

# move local rule to lower priority
ip rule add pref 1000 lookup local
ip rule del pref 0

# route packets of sockets bound to eth0 to the wire independant
# of the destination address
ip rule add pref 100 oif eth0 lookup 100
ip route add default dev eth0 lookup 100

Signed-off-by: Patrick McHardy <kaber@trash.net>

diff --git a/net/core/fib_rules.c b/net/core/fib_rules.c
index d1a70ad..ef0e7d9 100644
--- a/net/core/fib_rules.c
+++ b/net/core/fib_rules.c
@@ -287,7 +287,7 @@ static int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg)
rule->flags = frh->flags;
rule->table = frh_get_table(frh, tb);

- if (!rule->pref && ops->default_pref)
+ if (!tb[FRA_PRIORITY] && ops->default_pref)
rule->pref = ops->default_pref(ops);

err = -EINVAL;
diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c
index 835262c..1239ed2 100644
--- a/net/ipv4/fib_rules.c
+++ b/net/ipv4/fib_rules.c
@@ -284,7 +284,7 @@ static int fib_default_rules_init(struct fib_rules_ops *ops)
{
int err;

- err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, FIB_RULE_PERMANENT);
+ err = fib_default_rule_add(ops, 0, RT_TABLE_LOCAL, 0);
if (err < 0)
return err;
err = fib_default_rule_add(ops, 0x7FFE, RT_TABLE_MAIN, 0);
diff --git a/net/ipv6/fib6_rules.c b/net/ipv6/fib6_rules.c
index 00a7a5e..3b38f49 100644
--- a/net/ipv6/fib6_rules.c
+++ b/net/ipv6/fib6_rules.c
@@ -276,7 +276,7 @@ static int fib6_rules_net_init(struct net *net)
INIT_LIST_HEAD(&net->ipv6.fib6_rules_ops->rules_list);

err = fib_default_rule_add(net->ipv6.fib6_rules_ops, 0,
- RT6_TABLE_LOCAL, FIB_RULE_PERMANENT);
+ RT6_TABLE_LOCAL, 0);
if (err)
goto out_fib6_rules_ops;