linux/net/bridge
Vincent Bernat 00ba4cb36d bridge: also trigger RTM_NEWLINK when interface is released from bridge
Currently, when an interface is released from a bridge via
ioctl(), we get a RTM_DELLINK event through netlink:

Deleted 2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 master bridge0 state UNKNOWN
    link/ether 6e:23:c2:54:3a:b3

Userspace has to interpret that as a removal from the bridge, not as a
complete removal of the interface. When an bridged interface is
completely removed, we get two events:

Deleted 2: dummy0: <BROADCAST,NOARP> mtu 1500 master bridge0 state DOWN
    link/ether 6e:23:c2:54:3a:b3
Deleted 2: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN group default
    link/ether 6e:23:c2:54:3a:b3 brd ff:ff:ff:ff:ff:ff

In constrast, when an interface is released from a bond, we get a
RTM_NEWLINK with only the new characteristics (no master):

3: dummy1: <BROADCAST,NOARP,SLAVE,UP,LOWER_UP> mtu 1500 qdisc noqueue master bond0 state UNKNOWN group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
3: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
3: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff
3: dummy1: <BROADCAST,NOARP> mtu 1500 qdisc noqueue state DOWN group default
    link/ether ca:c8:7b:66:f8:25 brd ff:ff:ff:ff:ff:ff
4: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether ae:dc:7a:8c:9a:3c brd ff:ff:ff:ff:ff:ff

Userland may be confused by the fact we say a link is deleted while
its characteristics are only modified. A first solution would have
been to turn the RTM_DELLINK event in del_nbp() into a RTM_NEWLINK
event. However, maybe some piece of userland is relying on this
RTM_DELLINK to detect when a bridged interface is released. Instead,
we also emit a RTM_NEWLINK event once the interface is
released (without master info).

Deleted 2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 master bridge0 state UNKNOWN
    link/ether 8a:bb:e7:94:b1:f8
2: dummy0: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default
    link/ether 8a:bb:e7:94:b1:f8 brd ff:ff:ff:ff:ff:ff

This is done only when using ioctl(). When using Netlink, such an
event is already automatically emitted in do_setlink().

Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-09-20 14:07:40 -07:00
..
netfilter net: Remove CONFIG_NETFILTER_DEBUG and _ASSERT() macros. 2017-09-04 13:25:20 +02:00
br_device.c bridge: switchdev: Use an helper to clear forward mark 2017-09-05 11:51:47 -07:00
br_fdb.c bridge: add tracepoint in br_fdb_update 2017-08-31 11:42:41 -07:00
br_forward.c bridge: add per-port broadcast flood flag 2017-04-27 16:34:29 -04:00
br_if.c bridge: Export VLAN filtering state 2017-05-26 15:18:44 -04:00
br_input.c net: bridge: fix dest lookup when vlan proto doesn't match 2017-07-14 08:19:23 -07:00
br_ioctl.c bridge: also trigger RTM_NEWLINK when interface is released from bridge 2017-09-20 14:07:40 -07:00
br_mdb.c rtnetlink: make rtnl_register accept a flags parameter 2017-08-09 16:57:38 -07:00
br_multicast.c bridge: Export multicast enabled state 2017-05-26 15:18:44 -04:00
br_netfilter_hooks.c netfilter: convert hook list to an array 2017-08-28 17:44:00 +02:00
br_netfilter_ipv6.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
br_netlink_tunnel.c netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
br_netlink.c net: add netlink_ext_ack argument to rtnl_link_ops.slave_changelink 2017-06-26 23:13:22 -04:00
br_nf_core.c net: Remove protocol from struct dst_ops 2015-03-09 16:06:10 -04:00
br_private_stp.h net: bridge: add helper to set topology change 2016-12-10 21:27:23 -05:00
br_private_tunnel.h bridge: vlan dst_metadata hooks in ingress and egress paths 2017-02-03 15:21:22 -05:00
br_private.h bridge: switchdev: Use an helper to clear forward mark 2017-09-05 11:51:47 -07:00
br_stp_bpdu.c net: introduce __skb_put_[zero, data, u8] 2017-06-20 13:30:14 -04:00
br_stp_if.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-06-06 22:20:08 -04:00
br_stp_timer.c bridge: start hello_timer when enabling KERNEL_STP in br_stp_start 2017-05-21 13:33:28 -04:00
br_stp.c bridge: move to workqueue gc 2017-02-06 22:53:13 -05:00
br_switchdev.c bridge: check for null fdb->dst before notifying switchdev drivers 2017-08-28 16:14:00 -07:00
br_sysfs_br.c net: bridge: constify attribute_group structures. 2017-06-29 15:48:52 -04:00
br_sysfs_if.c bridge: add per-port broadcast flood flag 2017-04-27 16:34:29 -04:00
br_vlan_tunnel.c bridge: vlan_tunnel: explicitly reset metadata attrs to NULL on failure 2017-02-17 13:33:41 -05:00
br_vlan.c net, bridge: convert net_bridge_vlan.refcnt from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
br.c net: bridge: Receive notification about successful FDB offload 2017-06-08 14:16:25 -04:00
Kconfig bridge: Add vlan filtering infrastructure 2013-02-13 19:41:46 -05:00
Makefile bridge: per vlan dst_metadata netlink support 2017-02-03 15:21:22 -05:00