ipv6: fib: Dump tables during registration to FIB chain
Dump all the FIB tables in each net namespace upon registration to the
FIB notification chain so that the callee will have a complete view of
the tables.
The integrity of the dump is ensured by a per-table sequence counter
that is incremented (under write lock) whenever a route is added or
deleted from the table.
All the sequence counters are read (under each table's read lock) and
summed, prior and after the dump. In case the counters differ, then the
dump is either restarted or the registration fails.
While it's possible for a table to be modified after its counter has
been read, this isn't really a problem. In case it happened before it
was read the second time, then the comparison at the end will fail. If
it happened afterwards, then we're guaranteed to be notified about the
change, as the notification block is registered prior to the second
read.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index dbe5537..0b30521 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -235,6 +235,7 @@ struct fib6_table {
struct fib6_node tb6_root;
struct inet_peer_base tb6_peers;
unsigned int flags;
+ unsigned int fib_seq;
#define RT6_TABLE_HAS_DFLT_ROUTER BIT(0)
};
@@ -308,6 +309,9 @@ int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
int __net_init fib6_notifier_init(struct net *net);
void __net_exit fib6_notifier_exit(struct net *net);
+unsigned int fib6_tables_seq_read(struct net *net);
+int fib6_tables_dump(struct net *net, struct notifier_block *nb);
+
#ifdef CONFIG_IPV6_MULTIPLE_TABLES
int fib6_rules_init(void);
void fib6_rules_cleanup(void);