netdev - [PATCH net-next 3/9] ipv4: Notify route if replacing currently offloaded one

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20191210172402.463397-4-idosch@idosch.org>
Date:   Tue, 10 Dec 2019 19:23:56 +0200
From:   Ido Schimmel <idosch@...sch.org>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, jiri@...lanox.com, dsahern@...il.com,
        roopa@...ulusnetworks.com, mlxsw@...lanox.com,
        Ido Schimmel <idosch@...lanox.com>
Subject: [PATCH net-next 3/9] ipv4: Notify route if replacing currently offloaded one

From: Ido Schimmel <idosch@...lanox.com>

When replacing a route, its replacement should only be notified in case
the replaced route is of any interest to listeners. In other words, if
the replaced route is currently used in the data path, which means it is
the first route in the FIB alias list with the given {prefix, prefix
length, table ID}.

Signed-off-by: Ido Schimmel <idosch@...lanox.com>
---
 net/ipv4/fib_trie.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 9264d6628e9f..6822aa90657a 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -978,6 +978,27 @@ static struct key_vector *fib_find_node(struct trie *t,
 	return n;
 }
 
+/* Return the first fib alias matching prefix length and table ID. */
+static struct fib_alias *fib_find_first_alias(struct hlist_head *fah, u8 slen,
+					      u32 tb_id)
+{
+	struct fib_alias *fa;
+
+	hlist_for_each_entry(fa, fah, fa_list) {
+		if (fa->fa_slen < slen)
+			continue;
+		if (fa->fa_slen != slen)
+			break;
+		if (fa->tb_id > tb_id)
+			continue;
+		if (fa->tb_id != tb_id)
+			break;
+		return fa;
+	}
+
+	return NULL;
+}
+
 /* Return the first fib alias matching TOS with
  * priority less than or equal to PRIO.
  */
@@ -1217,6 +1238,17 @@ int fib_table_insert(struct net *net, struct fib_table *tb,
 			new_fa->tb_id = tb->tb_id;
 			new_fa->fa_default = -1;
 
+			if (fib_find_first_alias(&l->leaf, fa->fa_slen,
+						 tb->tb_id) == fa) {
+				enum fib_event_type fib_event;
+
+				fib_event = FIB_EVENT_ENTRY_REPLACE_TMP;
+				err = call_fib_entry_notifiers(net, fib_event,
+							       key, plen,
+							       new_fa, extack);
+				if (err)
+					goto out_free_new_fa;
+			}
 			err = call_fib_entry_notifiers(net,
 						       FIB_EVENT_ENTRY_REPLACE,
 						       key, plen, new_fa,
-- 
2.23.0