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authorMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-02-18 10:12:12 -0500
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2019-02-18 10:12:12 -0500
commit5f09bc8cc4010a3ea17c5881a62fc45192ebe7b0 (patch)
treec8e30ba4eaf357699ef97a786bf56661f4591be8 /Documentation/networking/operstates.txt
parent6fd369dd1cb65a032f1ab9227033ecb7b759656d (diff)
parenta3b22b9f11d9fbc48b0291ea92259a5a810e9438 (diff)
Merge tag 'v5.0-rc7' into patchwork
Linux 5.0-rc7 * tag 'v5.0-rc7': (1667 commits) Linux 5.0-rc7 Input: elan_i2c - add ACPI ID for touchpad in Lenovo V330-15ISK Input: st-keyscan - fix potential zalloc NULL dereference Input: apanel - switch to using brightness_set_blocking() powerpc/64s: Fix possible corruption on big endian due to pgd/pud_present() efi/arm: Revert "Defer persistent reservations until after paging_init()" arm64, mm, efi: Account for GICv3 LPI tables in static memblock reserve table sunrpc: fix 4 more call sites that were using stack memory with a scatterlist include/linux/module.h: copy __init/__exit attrs to init/cleanup_module Compiler Attributes: add support for __copy (gcc >= 9) lib/crc32.c: mark crc32_le_base/__crc32c_le_base aliases as __pure auxdisplay: ht16k33: fix potential user-after-free on module unload x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls i2c: bcm2835: Clear current buffer pointers and counts after a transfer i2c: cadence: Fix the hold bit setting drm: Use array_size() when creating lease dm thin: fix bug where bio that overwrites thin block ignores FUA Revert "exec: load_script: don't blindly truncate shebang string" Revert "gfs2: read journal in large chunks to locate the head" net: ethernet: freescale: set FEC ethtool regs version ... Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
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