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