kernel/linux.git/include/linux/netdevice.h, branch v5.0.15

failover: allow name change on IFF_UP slave interfaces

2019-04-27T07:37:26+00:00

[ Upstream commit 8065a779f17e94536a1c4dcee4f9d88011672f97 ] When a netdev appears through hot plug then gets enslaved by a failover master that is already up and running, the slave will be opened right away after getting enslaved. Today there's a race that userspace (udev) may fail to rename the slave if the kernel (net_failover) opens the slave earlier than when the userspace rename happens. Unlike bond or team, the primary slave of failover can't be renamed by userspace ahead of time, since the kernel initiated auto-enslavement is unable to, or rather, is never meant to be synchronized with the rename request from userspace. As the failover slave interfaces are not designed to be operated directly by userspace apps: IP configuration, filter rules with regard to network traffic passing and etc., should all be done on master interface. In general, userspace apps only care about the name of master interface, while slave names are less important as long as admin users can see reliable names that may carry other information describing the netdev. For e.g., they can infer that "ens3nsby" is a standby slave of "ens3", while for a name like "eth0" they can't tell which master it belongs to. Historically the name of IFF_UP interface can't be changed because there might be admin script or management software that is already relying on such behavior and assumes that the slave name can't be changed once UP. But failover is special: with the in-kernel auto-enslavement mechanism, the userspace expectation for device enumeration and bring-up order is already broken. Previously initramfs and various userspace config tools were modified to bypass failover slaves because of auto-enslavement and duplicate MAC address. Similarly, in case that users care about seeing reliable slave name, the new type of failover slaves needs to be taken care of specifically in userspace anyway. It's less risky to lift up the rename restriction on failover slave which is already UP. Although it's possible this change may potentially break userspace component (most likely configuration scripts or management software) that assumes slave name can't be changed while UP, it's relatively a limited and controllable set among all userspace components, which can be fixed specifically to listen for the rename events on failover slaves. Userspace component interacting with slaves is expected to be changed to operate on failover master interface instead, as the failover slave is dynamic in nature which may come and go at any point. The goal is to make the role of failover slaves less relevant, and userspace components should only deal with failover master in the long run. Fixes: 30c8bd5aa8b2 ("net: Introduce generic failover module") Signed-off-by: Si-Wei Liu Reviewed-by: Liran Alon Acked-by: Sridhar Samudrala Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: dev: Use unsigned integer as an argument to left-shift

2019-02-27T17:34:39+00:00

1 << 31 is Undefined Behaviour according to the C standard. Use U type modifier to avoid theoretical overflow. Signed-off-by: Andy Shevchenko Signed-off-by: David S. Miller

ipvlan, l3mdev: fix broken l3s mode wrt local routes

2019-01-31T06:13:34+00:00

While implementing ipvlan l3 and l3s mode for kubernetes CNI plugin, I ran into the issue that while l3 mode is working fine, l3s mode does not have any connectivity to kube-apiserver and hence all pods end up in Error state as well. The ipvlan master device sits on top of a bond device and hostns traffic to kube-apiserver (also running in hostns) is DNATed from 10.152.183.1:443 to 139.178.29.207:37573 where the latter is the address of the bond0. While in l3 mode, a curl to https://10.152.183.1:443 or to https://139.178.29.207:37573 works fine from hostns, neither of them do in case of l3s. In the latter only a curl to https://127.0.0.1:37573 appeared to work where for local addresses of bond0 I saw kernel suddenly starting to emit ARP requests to query HW address of bond0 which remained unanswered and neighbor entries in INCOMPLETE state. These ARP requests only happen while in l3s. Debugging this further, I found the issue is that l3s mode is piggy- backing on l3 master device, and in this case local routes are using l3mdev_master_dev_rcu(dev) instead of net->loopback_dev as per commit f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant") and 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be a loopback"). I found that reverting them back into using the net->loopback_dev fixed ipvlan l3s connectivity and got everything working for the CNI. Now judging from 4fbae7d83c98 ("ipvlan: Introduce l3s mode") and the l3mdev paper in [0] the only sole reason why ipvlan l3s is relying on l3 master device is to get the l3mdev_ip_rcv() receive hook for setting the dst entry of the input route without adding its own ipvlan specific hacks into the receive path, however, any l3 domain semantics beyond just that are breaking l3s operation. Note that ipvlan also has the ability to dynamically switch its internal operation from l3 to l3s for all ports via ipvlan_set_port_mode() at runtime. In any case, l3 vs l3s soley distinguishes itself by 'de-confusing' netfilter through switching skb->dev to ipvlan slave device late in NF_INET_LOCAL_IN before handing the skb to L4. Minimal fix taken here is to add a IFF_L3MDEV_RX_HANDLER flag which, if set from ipvlan setup, gets us only the wanted l3mdev_l3_rcv() hook without any additional l3mdev semantics on top. This should also have minimal impact since dev->priv_flags is already hot in cache. With this set, l3s mode is working fine and I also get things like masquerading pod traffic on the ipvlan master properly working. [0] https://netdevconf.org/1.2/papers/ahern-what-is-l3mdev-paper.pdf Fixes: f5a0aab84b74 ("net: ipv4: dst for local input routes should use l3mdev if relevant") Fixes: 5f02ce24c269 ("net: l3mdev: Allow the l3mdev to be a loopback") Fixes: 4fbae7d83c98 ("ipvlan: Introduce l3s mode") Signed-off-by: Daniel Borkmann Cc: Mahesh Bandewar Cc: David Ahern Cc: Florian Westphal Cc: Martynas Pumputis Acked-by: David Ahern Signed-off-by: David S. Miller

net: rtnetlink: support for fdb get

2018-12-16T22:42:34+00:00

This patch adds support for fdb get similar to route get. arguments can be any of the following (similar to fdb add/del/dump): [bridge, mac, vlan] or [bridge_port, mac, vlan, flags=[NTF_MASTER]] or [dev, mac, [vni|vlan], flags=[NTF_SELF]] Signed-off-by: Roopa Prabhu Reviewed-by: David Ahern Signed-off-by: David S. Miller

net: dev: Issue NETDEV_PRE_CHANGEADDR

2018-12-14T02:41:38+00:00

When a device address is about to be changed, or an address added to the list of device HW addresses, it is necessary to ensure that all interested parties can support the address. Therefore, send the NETDEV_PRE_CHANGEADDR notification, and if anyone bails on it, do not change the address. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller

net: dev: Add NETDEV_PRE_CHANGEADDR

2018-12-14T02:41:38+00:00

The NETDEV_CHANGEADDR notification is emitted after a device address changes. Extending this message to allow vetoing is certainly possible, but several other notification types have instead adopted a simple two-stage approach: first a "pre" notification is sent to make sure all interested parties are OK with a change that's about to be done. Then the change is done, and afterwards a "post" notification is sent. This dual approach is easier to use: when the change is vetoed, nothing has changed yet, and it's therefore unnecessary to roll anything back. Therefore adopt it for NETDEV_CHANGEADDR as well. To that end, add NETDEV_PRE_CHANGEADDR and an info structure to go along with it. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller

net: dev: Add extack argument to dev_set_mac_address()

2018-12-14T02:41:38+00:00

A follow-up patch will add a notifier type NETDEV_PRE_CHANGEADDR, which allows vetoing of MAC address changes. One prominent path to that notification is through dev_set_mac_address(). Therefore give this function an extack argument, so that it can be packed together with the notification. Thus a textual reason for rejection (or a warning) can be communicated back to the user. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller

net: ndo_bridge_setlink: Add extack

2018-12-13T00:34:21+00:00

Drivers may not be able to implement a VLAN addition or reconfiguration. In those cases it's desirable to explain to the user that it was rejected (and why). To that end, add extack argument to ndo_bridge_setlink. Adapt all users to that change. Following patches will use the new argument in the bridge driver. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Signed-off-by: David S. Miller

net: core: dev: Add extack argument to __dev_change_flags()

2018-12-06T21:26:07+00:00

In order to pass extack together with NETDEV_PRE_UP notifications, it's necessary to route the extack to __dev_open() from diverse (possibly indirect) callers. The last missing API is __dev_change_flags(). Therefore extend __dev_change_flags() with and extra extack argument and update the two existing users. Since the function declaration line is changed anyway, name the struct net_device argument to placate checkpatch. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

net: core: dev: Add extack argument to dev_change_flags()

2018-12-06T21:26:07+00:00

In order to pass extack together with NETDEV_PRE_UP notifications, it's necessary to route the extack to __dev_open() from diverse (possibly indirect) callers. One prominent API through which the notification is invoked is dev_change_flags(). Therefore extend dev_change_flags() with and extra extack argument and update all users. Most of the calls end up just encoding NULL, but several sites (VLAN, ipvlan, VRF, rtnetlink) do have extack available. Since the function declaration line is changed anyway, name the other function arguments to placate checkpatch. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller