net/ipv4/fib_notifier.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <linux/rtnetlink.h>
   3 #include <linux/notifier.h>
   4 #include <linux/socket.h>
   5 #include <linux/kernel.h>
   6 #include <linux/export.h>
   7 #include <net/net_namespace.h>
   8 #include <net/fib_notifier.h>
   9 #include <net/netns/ipv4.h>
  10 #include <net/ip_fib.h>
  11
  12 int call_fib4_notifier(struct notifier_block *nb,
  13                        enum fib_event_type event_type,
  14                        struct fib_notifier_info *info)
  15 {
  16         info->family = AF_INET;
  17         return call_fib_notifier(nb, event_type, info);
  18 }
  19
  20 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
  21                         struct fib_notifier_info *info)
  22 {
  23         ASSERT_RTNL();
  24
  25         info->family = AF_INET;
  26         net->ipv4.fib_seq++;
  27         return call_fib_notifiers(net, event_type, info);
  28 }
  29
  30 static unsigned int fib4_seq_read(struct net *net)
  31 {
  32         ASSERT_RTNL();
  33
  34         return net->ipv4.fib_seq + fib4_rules_seq_read(net);
  35 }
  36
  37 static int fib4_dump(struct net *net, struct notifier_block *nb,
  38                      struct netlink_ext_ack *extack)
  39 {
  40         int err;
  41
  42         err = fib4_rules_dump(net, nb, extack);
  43         if (err)
  44                 return err;
  45
  46         return fib_notify(net, nb, extack);
  47 }
  48
  49 static const struct fib_notifier_ops fib4_notifier_ops_template = {
  50         .family         = AF_INET,
  51         .fib_seq_read   = fib4_seq_read,
  52         .fib_dump       = fib4_dump,
  53         .owner          = THIS_MODULE,
  54 };
  55
  56 int __net_init fib4_notifier_init(struct net *net)
  57 {
  58         struct fib_notifier_ops *ops;
  59
  60         net->ipv4.fib_seq = 0;
  61
  62         ops = fib_notifier_ops_register(&fib4_notifier_ops_template, net);
  63         if (IS_ERR(ops))
  64                 return PTR_ERR(ops);
  65         net->ipv4.notifier_ops = ops;
  66
  67         return 0;
  68 }
  69
  70 void __net_exit fib4_notifier_exit(struct net *net)
  71 {
  72         fib_notifier_ops_unregister(net->ipv4.notifier_ops);
  73 }