Commit f613b6e2 authored by Ido Schimmel's avatar Ido Schimmel Committed by David S. Miller
Browse files

ipv4: Handle route deletion notification 



When a route is deleted we potentially need to promote the next route in
the FIB alias list (e.g., with an higher metric). In case we find such a
route, a replace notification is emitted. Otherwise, a delete
notification for the deleted route.

v2:
* Convert to use fib_find_alias() instead of fib_find_first_alias()

Signed-off-by: default avatarIdo Schimmel <idosch@mellanox.com>
Reviewed-by: default avatarDavid Ahern <dsahern@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent a8674f75

net/ipv4/fib_trie.c

+31 −0
Original line number Diff line number Diff line
@@ -1570,6 +1570,36 @@ static void fib_remove_alias(struct trie *t, struct key_vector *tp, 
	node_pull_suffix(tp, fa->fa_slen);

}



static void fib_notify_alias_delete(struct net *net, u32 key,

				    struct hlist_head *fah,

				    struct fib_alias *fa_to_delete,

				    struct netlink_ext_ack *extack)

{

	struct fib_alias *fa_next, *fa_to_notify;

	u32 tb_id = fa_to_delete->tb_id;

	u8 slen = fa_to_delete->fa_slen;

	enum fib_event_type fib_event;



	/* Do not notify if we do not care about the route. */

	if (fib_find_alias(fah, slen, 0, 0, tb_id, true) != fa_to_delete)

		return;



	/* Determine if the route should be replaced by the next route in the

	 * list.

	 */

	fa_next = hlist_entry_safe(fa_to_delete->fa_list.next,

				   struct fib_alias, fa_list);

	if (fa_next && fa_next->fa_slen == slen && fa_next->tb_id == tb_id) {

		fib_event = FIB_EVENT_ENTRY_REPLACE_TMP;

		fa_to_notify = fa_next;

	} else {

		fib_event = FIB_EVENT_ENTRY_DEL_TMP;

		fa_to_notify = fa_to_delete;

	}

	call_fib_entry_notifiers(net, fib_event, key, KEYLENGTH - slen,

				 fa_to_notify, extack);

}



/* Caller must hold RTNL. */

int fib_table_delete(struct net *net, struct fib_table *tb,

		     struct fib_config *cfg, struct netlink_ext_ack *extack)
@@ -1623,6 +1653,7 @@ int fib_table_delete(struct net *net, struct fib_table *tb, 
	if (!fa_to_delete)

		return -ESRCH;



	fib_notify_alias_delete(net, key, &l->leaf, fa_to_delete, extack);

	call_fib_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, key, plen,

				 fa_to_delete, extack);

	rtmsg_fib(RTM_DELROUTE, htonl(key), fa_to_delete, plen, tb->tb_id,

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