netdev - [PATCH net-next 14/14] mlxsw: spectrum_router: Allow programming link-local prefix routes

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: <20200525230556.1455927-15-idosch@idosch.org>
Date:   Tue, 26 May 2020 02:05:56 +0300
From:   Ido Schimmel <idosch@...sch.org>
To:     netdev@...r.kernel.org
Cc:     davem@...emloft.net, kuba@...nel.org, jiri@...lanox.com,
        mlxsw@...lanox.com, Ido Schimmel <idosch@...lanox.com>
Subject: [PATCH net-next 14/14] mlxsw: spectrum_router: Allow programming link-local prefix routes

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

The device has a trap for IPv6 packets that need be routed and have a
unicast link-local destination IP (i.e., fe80::/10). This allows mlxsw
to ignore link-local routes, as the packets will be trapped to the CPU
in any case.

However, since link-local routes are not programmed, it is possible for
routed packets to hit the default route which might also be programmed
to trap packets. This means that packets with a link-local destination
IP might be trapped for the wrong reason.

To overcome this, allow programming link-local prefix routes (usually
one fe80::/64 per-table), so that the packets will be forwarded until
reaching the link-local trap.

Signed-off-by: Ido Schimmel <idosch@...lanox.com>
Reviewed-by: Jiri Pirko <jiri@...lanox.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index 71aee4914619..c939b3596566 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -5003,9 +5003,11 @@ static bool mlxsw_sp_fib6_rt_should_ignore(const struct fib6_info *rt)
 {
 	/* Packets with link-local destination IP arriving to the router
 	 * are trapped to the CPU, so no need to program specific routes
-	 * for them.
+	 * for them. Only allow prefix routes (usually one fe80::/64) so
+	 * that packets are trapped for the right reason.
 	 */
-	if (ipv6_addr_type(&rt->fib6_dst.addr) & IPV6_ADDR_LINKLOCAL)
+	if ((ipv6_addr_type(&rt->fib6_dst.addr) & IPV6_ADDR_LINKLOCAL) &&
+	    (rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)))
 		return true;
 
 	/* Multicast routes aren't supported, so ignore them. Neighbour
-- 
2.26.2