Kuniyuki Iwashima
2023-Jul-12 15:44 UTC
[Bridge] [PATCH v2 net] bridge: Add extack warning when enabling STP in netns.
When we create an L2 loop on a bridge in netns, we will see packets storm
even if STP is enabled.
# unshare -n
# ip link add br0 type bridge
# ip link add veth0 type veth peer name veth1
# ip link set veth0 master br0 up
# ip link set veth1 master br0 up
# ip link set br0 type bridge stp_state 1
# ip link set br0 up
# sleep 30
# ip -s link show br0
2: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state
UP mode DEFAULT group default qlen 1000
link/ether b6:61:98:1c:1c:b5 brd ff:ff:ff:ff:ff:ff
RX: bytes packets errors dropped missed mcast
956553768 12861249 0 0 0 12861249 <-. Keep
TX: bytes packets errors dropped carrier collsns | increasing
1027834 11951 0 0 0 0 <-' rapidly
This is because llc_rcv() drops all packets in non-root netns and BPDU
is dropped.
Let's add extack warning when enabling STP in netns.
# unshare -n
# ip link add br0 type bridge
# ip link set br0 type bridge stp_state 1
Warning: bridge: STP does not work in non-root netns.
Note this commit will be reverted later when we namespacify the whole LLC
infra.
Fixes: e730c15519d0 ("[NET]: Make packet reception network namespace
safe")
Suggested-by: Harry Coin <hcoin at quietfountain.com>
Link: https://lore.kernel.org/netdev/0f531295-e289-022d-5add-5ceffa0df9bc at
quietfountain.com/
Suggested-by: Ido Schimmel <idosch at idosch.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu at amazon.com>
---
v2:
- Just add extack instead of returning error (Ido Schimmel)
v1: https://lore.kernel.org/netdev/20230711235415.92166-1-kuniyu at amazon.com/
---
net/bridge/br_stp_if.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 75204d36d7f9..b65962682771 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -201,6 +201,9 @@ int br_stp_set_enabled(struct net_bridge *br, unsigned long
val,
{
ASSERT_RTNL();
+ if (!net_eq(dev_net(br->dev), &init_net))
+ NL_SET_ERR_MSG_MOD(extack, "STP does not work in non-root netns");
+
if (br_mrp_enabled(br)) {
NL_SET_ERR_MSG_MOD(extack,
"STP can't be enabled if MRP is already enabled");
--
2.30.2
Nikolay Aleksandrov
2023-Jul-12 15:46 UTC
[Bridge] [PATCH v2 net] bridge: Add extack warning when enabling STP in netns.
On 12/07/2023 18:44, Kuniyuki Iwashima wrote:> When we create an L2 loop on a bridge in netns, we will see packets storm > even if STP is enabled. > > # unshare -n > # ip link add br0 type bridge > # ip link add veth0 type veth peer name veth1 > # ip link set veth0 master br0 up > # ip link set veth1 master br0 up > # ip link set br0 type bridge stp_state 1 > # ip link set br0 up > # sleep 30 > # ip -s link show br0 > 2: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 > link/ether b6:61:98:1c:1c:b5 brd ff:ff:ff:ff:ff:ff > RX: bytes packets errors dropped missed mcast > 956553768 12861249 0 0 0 12861249 <-. Keep > TX: bytes packets errors dropped carrier collsns | increasing > 1027834 11951 0 0 0 0 <-' rapidly > > This is because llc_rcv() drops all packets in non-root netns and BPDU > is dropped. > > Let's add extack warning when enabling STP in netns. > > # unshare -n > # ip link add br0 type bridge > # ip link set br0 type bridge stp_state 1 > Warning: bridge: STP does not work in non-root netns. > > Note this commit will be reverted later when we namespacify the whole LLC > infra. > > Fixes: e730c15519d0 ("[NET]: Make packet reception network namespace safe") > Suggested-by: Harry Coin <hcoin at quietfountain.com> > Link: https://lore.kernel.org/netdev/0f531295-e289-022d-5add-5ceffa0df9bc at quietfountain.com/ > Suggested-by: Ido Schimmel <idosch at idosch.org> > Signed-off-by: Kuniyuki Iwashima <kuniyu at amazon.com> > --- > v2: > - Just add extack instead of returning error (Ido Schimmel) > > v1: https://lore.kernel.org/netdev/20230711235415.92166-1-kuniyu at amazon.com/ > --- > net/bridge/br_stp_if.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c > index 75204d36d7f9..b65962682771 100644 > --- a/net/bridge/br_stp_if.c > +++ b/net/bridge/br_stp_if.c > @@ -201,6 +201,9 @@ int br_stp_set_enabled(struct net_bridge *br, unsigned long val, > { > ASSERT_RTNL(); > > + if (!net_eq(dev_net(br->dev), &init_net)) > + NL_SET_ERR_MSG_MOD(extack, "STP does not work in non-root netns"); > + > if (br_mrp_enabled(br)) { > NL_SET_ERR_MSG_MOD(extack, > "STP can't be enabled if MRP is already enabled");Thanks, Acked-by: Nikolay Aleksandrov <razor at blackwall.org>
Ido Schimmel
2023-Jul-12 16:14 UTC
[Bridge] [PATCH v2 net] bridge: Add extack warning when enabling STP in netns.
On Wed, Jul 12, 2023 at 08:44:49AM -0700, Kuniyuki Iwashima wrote:> When we create an L2 loop on a bridge in netns, we will see packets storm > even if STP is enabled. > > # unshare -n > # ip link add br0 type bridge > # ip link add veth0 type veth peer name veth1 > # ip link set veth0 master br0 up > # ip link set veth1 master br0 up > # ip link set br0 type bridge stp_state 1 > # ip link set br0 up > # sleep 30 > # ip -s link show br0 > 2: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 > link/ether b6:61:98:1c:1c:b5 brd ff:ff:ff:ff:ff:ff > RX: bytes packets errors dropped missed mcast > 956553768 12861249 0 0 0 12861249 <-. Keep > TX: bytes packets errors dropped carrier collsns | increasing > 1027834 11951 0 0 0 0 <-' rapidly > > This is because llc_rcv() drops all packets in non-root netns and BPDU > is dropped. > > Let's add extack warning when enabling STP in netns. > > # unshare -n > # ip link add br0 type bridge > # ip link set br0 type bridge stp_state 1 > Warning: bridge: STP does not work in non-root netns. > > Note this commit will be reverted later when we namespacify the whole LLC > infra. > > Fixes: e730c15519d0 ("[NET]: Make packet reception network namespace safe") > Suggested-by: Harry Coin <hcoin at quietfountain.com> > Link: https://lore.kernel.org/netdev/0f531295-e289-022d-5add-5ceffa0df9bc at quietfountain.com/ > Suggested-by: Ido Schimmel <idosch at idosch.org> > Signed-off-by: Kuniyuki Iwashima <kuniyu at amazon.com>Reviewed-by: Ido Schimmel <idosch at nvidia.com>
patchwork-bot+netdevbpf at kernel.org
2023-Jul-14 07:40 UTC
[Bridge] [PATCH v2 net] bridge: Add extack warning when enabling STP in netns.
Hello: This patch was applied to netdev/net.git (main) by David S. Miller <davem at davemloft.net>: On Wed, 12 Jul 2023 08:44:49 -0700 you wrote:> When we create an L2 loop on a bridge in netns, we will see packets storm > even if STP is enabled. > > # unshare -n > # ip link add br0 type bridge > # ip link add veth0 type veth peer name veth1 > # ip link set veth0 master br0 up > # ip link set veth1 master br0 up > # ip link set br0 type bridge stp_state 1 > # ip link set br0 up > # sleep 30 > # ip -s link show br0 > 2: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP mode DEFAULT group default qlen 1000 > link/ether b6:61:98:1c:1c:b5 brd ff:ff:ff:ff:ff:ff > RX: bytes packets errors dropped missed mcast > 956553768 12861249 0 0 0 12861249 <-. Keep > TX: bytes packets errors dropped carrier collsns | increasing > 1027834 11951 0 0 0 0 <-' rapidly > > [...]Here is the summary with links: - [v2,net] bridge: Add extack warning when enabling STP in netns. https://git.kernel.org/netdev/net/c/56a16035bb6e You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html