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authorJouke Witteveen <j.witteveen@gmail.com>2019-02-07 17:14:32 +0100
committerDavid S. Miller <davem@davemloft.net>2019-02-11 12:38:51 -0800
commit989723b00b7fecad9acad55b151c73ccf2eac3ca (patch)
treefe1b23bc927071424cbd6ff3a31efd692bee57f2 /Documentation/networking/operstates.txt
parent4d73eaee24ff0cc2736c304927c1425d2541d6ab (diff)
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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>
Diffstat (limited to 'Documentation/networking/operstates.txt')
-rw-r--r--Documentation/networking/operstates.txt14
1 files changed, 8 insertions, 6 deletions
diff --git a/Documentation/networking/operstates.txt b/Documentation/networking/operstates.txt
index 355c6d8ef8ad..b203d1334822 100644
--- a/Documentation/networking/operstates.txt
+++ b/Documentation/networking/operstates.txt
@@ -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