linux/net/ipv4/fib_notifier.c
Ido Schimmel 864150dfa3 net: Add module reference to FIB notifiers
When a listener registers to the FIB notification chain it receives a
dump of the FIB entries and rules from existing address families by
invoking their dump operations.

While we call into these modules we need to make sure they aren't
removed. Do that by increasing their reference count before invoking
their dump operations and decrease it afterwards.

Fixes: 04b1d4e50e ("net: core: Make the FIB notification chain generic")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-01 20:33:42 -07:00

74 lines
1.5 KiB
C

#include <linux/rtnetlink.h>
#include <linux/notifier.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/fib_notifier.h>
#include <net/netns/ipv4.h>
#include <net/ip_fib.h>
int call_fib4_notifier(struct notifier_block *nb, struct net *net,
enum fib_event_type event_type,
struct fib_notifier_info *info)
{
info->family = AF_INET;
return call_fib_notifier(nb, net, event_type, info);
}
int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
struct fib_notifier_info *info)
{
ASSERT_RTNL();
info->family = AF_INET;
net->ipv4.fib_seq++;
return call_fib_notifiers(net, event_type, info);
}
static unsigned int fib4_seq_read(struct net *net)
{
ASSERT_RTNL();
return net->ipv4.fib_seq + fib4_rules_seq_read(net);
}
static int fib4_dump(struct net *net, struct notifier_block *nb)
{
int err;
err = fib4_rules_dump(net, nb);
if (err)
return err;
fib_notify(net, nb);
return 0;
}
static const struct fib_notifier_ops fib4_notifier_ops_template = {
.family = AF_INET,
.fib_seq_read = fib4_seq_read,
.fib_dump = fib4_dump,
.owner = THIS_MODULE,
};
int __net_init fib4_notifier_init(struct net *net)
{
struct fib_notifier_ops *ops;
net->ipv4.fib_seq = 0;
ops = fib_notifier_ops_register(&fib4_notifier_ops_template, net);
if (IS_ERR(ops))
return PTR_ERR(ops);
net->ipv4.notifier_ops = ops;
return 0;
}
void __net_exit fib4_notifier_exit(struct net *net)
{
fib_notifier_ops_unregister(net->ipv4.notifier_ops);
}