From f613b6e2ffe13e9acba0d330a058b87aa0e19a2a Mon Sep 17 00:00:00 2001 From: Ido Schimmel Date: Sat, 14 Dec 2019 17:53:11 +0200 Subject: 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: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller --- net/ipv4/fib_trie.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index f56945d00d7a..012aca433a91 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -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, -- cgit v1.2.3