linux-stable/tools
Rocco Yue 49b99da2c9 ipv6: add IFLA_INET6_RA_MTU to expose mtu value
The kernel provides a "/proc/sys/net/ipv6/conf/<iface>/mtu"
file, which can temporarily record the mtu value of the last
received RA message when the RA mtu value is lower than the
interface mtu, but this proc has following limitations:

(1) when the interface mtu (/sys/class/net/<iface>/mtu) is
updeated, mtu6 (/proc/sys/net/ipv6/conf/<iface>/mtu) will
be updated to the value of interface mtu;
(2) mtu6 (/proc/sys/net/ipv6/conf/<iface>/mtu) only affect
ipv6 connection, and not affect ipv4.

Therefore, when the mtu option is carried in the RA message,
there will be a problem that the user sometimes cannot obtain
RA mtu value correctly by reading mtu6.

After this patch set, if a RA message carries the mtu option,
you can send a netlink msg which nlmsg_type is RTM_GETLINK,
and then by parsing the attribute of IFLA_INET6_RA_MTU to
get the mtu value carried in the RA message received on the
inet6 device. In addition, you can also get a link notification
when ra_mtu is updated so it doesn't have to poll.

In this way, if the MTU values that the device receives from
the network in the PCO IPv4 and the RA IPv6 procedures are
different, the user can obtain the correct ipv6 ra_mtu value
and compare the value of ra_mtu and ipv4 mtu, then the device
can use the lower MTU value for both IPv4 and IPv6.

Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210827150412.9267-1-rocco.yue@mediatek.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-27 17:29:18 -07:00
..
accounting
arch tools headers UAPI: Sync files changed by the memfd_secret new syscall 2021-07-14 10:05:35 -03:00
bootconfig bootconfig: Share the checksum function with tools 2021-06-10 13:41:26 -04:00
bpf Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next 2021-07-31 11:23:26 -07:00
build tools build: Fix quiet cmd indentation 2021-05-17 12:10:03 +09:00
cgroup tools/cgroup/slabinfo.py: updated to work on current kernel 2021-04-23 14:42:40 -07:00
debugging tools: Fix "the the" in a message in kernel-chktaint 2021-06-13 17:01:17 -06:00
edid
firewire
firmware
gpio
hv
iio
include ipv6: add IFLA_INET6_RA_MTU to expose mtu value 2021-08-27 17:29:18 -07:00
io_uring tools/io_uring/io_uring-cp: sync with liburing example 2021-08-13 08:58:11 -06:00
kvm/kvm_stat tools/kvm_stat: Fix documentation typo 2021-05-07 06:06:22 -04:00
laptop
leds
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-13 06:41:22 -07:00
memory-model tools/memory-model: Fix smp_mb__after_spinlock() spelling 2021-05-10 16:27:20 -07:00
objtool A single ELF format fix for a section flags mismatch bug that breaks 2021-06-28 11:35:55 -07:00
pci
pcmcia
perf Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2021-08-05 15:08:47 -07:00
power tools/power/x86/intel-speed-select: v1.10 release 2021-06-18 15:29:32 +02:00
rcu tools/rcu: Add drgn script to dump number of RCU callbacks 2021-05-10 15:39:19 -07:00
scripts tools build: Fix quiet cmd indentation 2021-05-17 12:10:03 +09:00
spi spi: tools: make a symbolic link to the header file spi.h 2021-04-22 16:30:39 +01:00
testing selftests/net: allow GRO coalesce test on veth 2021-08-26 12:03:49 +01:00
thermal/tmon tools: do not include scripts/Kbuild.include 2021-04-25 05:26:13 +09:00
time
tracing
usb treewide: remove editor modelines and cruft 2021-05-07 00:26:34 -07:00
virtio tools/virtio: fix build 2021-08-11 06:44:24 -04:00
vm tools/vm/page_owner_sort.c: check malloc() return 2021-06-29 10:53:47 -07:00
wmi
Makefile