Documentation: bring operstate documentation up-to-date

Netlink has moved from bitmasks to group numbers long ago.

Signed-off-by: Jouke Witteveen <j.witteveen@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jouke Witteveen 2019-02-07 17:14:32 +01:00 committed by David S. Miller
parent 4d73eaee24
commit 989723b00b
2 changed files with 9 additions and 7 deletions

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@ -22,8 +22,9 @@ and changeable from userspace under certain rules.
2. Querying from userspace
Both admin and operational state can be queried via the netlink
operation RTM_GETLINK. It is also possible to subscribe to RTMGRP_LINK
to be notified of updates. This is important for setting from userspace.
operation RTM_GETLINK. It is also possible to subscribe to RTNLGRP_LINK
to be notified of updates while the interface is admin up. This is
important for setting from userspace.
These values contain interface state:
@ -101,8 +102,9 @@ because some driver controlled protocol establishment has to
complete. Corresponding functions are netif_dormant_on() to set the
flag, netif_dormant_off() to clear it and netif_dormant() to query.
On device allocation, networking core sets the flags equivalent to
netif_carrier_ok() and !netif_dormant().
On device allocation, both flags __LINK_STATE_NOCARRIER and
__LINK_STATE_DORMANT are cleared, so the effective state is equivalent
to netif_carrier_ok() and !netif_dormant().
Whenever the driver CHANGES one of these flags, a workqueue event is
@ -133,11 +135,11 @@ netif_carrier_ok() && !netif_dormant() is set by the
driver. Afterwards, the userspace application can set IFLA_OPERSTATE
to IF_OPER_DORMANT or IF_OPER_UP as long as the driver does not set
netif_carrier_off() or netif_dormant_on(). Changes made by userspace
are multicasted on the netlink group RTMGRP_LINK.
are multicasted on the netlink group RTNLGRP_LINK.
So basically a 802.1X supplicant interacts with the kernel like this:
-subscribe to RTMGRP_LINK
-subscribe to RTNLGRP_LINK
-set IFLA_LINKMODE to 1 via RTM_SETLINK
-query RTM_GETLINK once to get initial state
-if initial flags are not (IFF_LOWER_UP && !IFF_DORMANT), wait until

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@ -500,7 +500,7 @@ static void dev_watchdog_down(struct net_device *dev)
* netif_carrier_on - set carrier
* @dev: network device
*
* Device has detected that carrier.
* Device has detected acquisition of carrier.
*/
void netif_carrier_on(struct net_device *dev)
{