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