On 5/31/23 20:11, Guillaume Nault wrote:
On Wed, May 24, 2023 at 02:17:09PM +0200, Mirsad Todorovac wrote:
Hi,
Hi Mirsad,
The very recent 6.4-rc3 kernel build with AlmaLinux 8.7 on LENOVO 10TX000VCR
desktop box fails one test:
[root@host net]# ./fcnal-test.sh
[...]
TEST: ping out, vrf device+address bind - ns-B loopback IPv6 [ OK ]
TEST: ping out, vrf device+address bind - ns-B IPv6 LLA [FAIL]
TEST: ping in - ns-A IPv6 [ OK ]
[...]
Tests passed: 887
Tests failed: 1
[root@host net]#
This test also fails on -net. The problem is specific to ping sockets
(same test passes with raw sockets). I believe this test has always
failed since fcnal-test.sh started using net.ipv4.ping_group_range
(commit e71b7f1f44d3 ("selftests: add ping test with ping_group_range
tuned")).
The executed command is:
ip netns exec ns-A ip vrf exec red /usr/bin/ping6 -c1 -w1 -I 2001:db8:3::1 fe80::a846:b5ff:fe4c:da4e%eth1
So ping6 is executed inside VRF 'red' and sets .sin6_scope_id to 'eth1'
(which is a slave device of VRF 'red'). Therefore, we have
sk->sk_bound_dev_if == 'red' and .sin6_scope_id == 'eth1'. This fails
because ping_v6_sendmsg() expects them to be equal:
static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
{
...
if (__ipv6_addr_needs_scope_id(ipv6_addr_type(daddr)))
oif = u->sin6_scope_id;
...
if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
(addr_type & IPV6_ADDR_MAPPED) ||
(oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if)) <-- oif='eth1', but ->sk_bound_dev_if='red'
return -EINVAL;
...
}
I believe this condition should be relaxed to allow the case where
->sk_bound_dev_if is oif's master device (and maybe there are other
VRF cases to also consider).
I've tried something like this, but something makes the kernel stuck
here:
TEST: ping out, blocked by route - ns-B loopback IPv6 [ OK ]
TEST: ping out, device bind, blocked by route - ns-B loopback IPv6 [ OK ]
TEST: ping in, blocked by route - ns-A loopback IPv6 [ OK ]
TEST: ping out, unreachable route - ns-B loopback IPv6 [ OK ]
TEST: ping out, device bind, unreachable route - ns-B loopback IPv6 [ OK ]
#################################################################
With VRF
[hanged process and kernel won't shutdown]
The code is:
---
net/ipv6/ping.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/net/ipv6/ping.c b/net/ipv6/ping.c
index c4835dbdfcff..81293e902293 100644
--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -73,6 +73,9 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
struct rt6_info *rt;
struct pingfakehdr pfh;
struct ipcm6_cookie ipc6;
+ struct net *net = sock_net(sk);
+ struct net_device *dev = NULL;
+ struct net_device *mdev = NULL;
err = ping_common_sendmsg(AF_INET6, msg, len, &user_icmph,
sizeof(user_icmph));
@@ -111,10 +114,17 @@ static int ping_v6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
else if (!oif)
oif = np->ucast_oif;
+ if (oif) {
+ dev = dev_get_by_index(net, oif);
+ mdev = netdev_master_upper_dev_get(dev);
+ }
+
addr_type = ipv6_addr_type(daddr);
if ((__ipv6_addr_needs_scope_id(addr_type) && !oif) ||
(addr_type & IPV6_ADDR_MAPPED) ||
- (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if))
+ (oif && sk->sk_bound_dev_if && oif != sk->sk_bound_dev_if &&
+ !(mdev && sk->sk_bound_dev_if &&
+ mdev != dev_get_by_index(net, sk->sk_bound_dev_if))))
return -EINVAL;
ipcm6_init_sk(&ipc6, np);
I am obviously doing something very stupid.
Regards,
Mirsad
