genetlink: make genl_info->nlhdr const

struct netlink_callback has a const nlh pointer, make the
pointer in struct genl_info const as well, to make copying
between the two easier.

Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230814214723.2924989-3-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/ncsi: Fix netlink registration

If a user unbinds and re-binds a NC-SI aware driver the kernel will
attempt to register the netlink interface at runtime. The structure is
marked __ro_after_init so registration fails spectacularly at this point.

# echo 1e660000.ethernet > /sys/bus/platform/drivers/ftgmac100/unbind
# echo 1e660000.ethernet > /sys/bus/platform/drivers/ftgmac100/bind
ftgmac100 1e660000.ethernet: Read MAC address 52:54:00:12:34:56 from chip
ftgmac100 1e660000.ethernet: Using NCSI interface
8<--- cut here ---
Unable to handle kernel paging request at virtual address 80a8f858
pgd = 8c768dd6
[80a8f858] *pgd=80a0841e(bad)
Internal error: Oops: 80d [#1] SMP ARM
CPU: 0 PID: 116 Comm: sh Not tainted 5.10.0-rc3-next-20201111-00003-gdd25b227ec1e #51
Hardware name: Generic DT based system
PC is at genl_register_family+0x1f8/0x6d4
LR is at 0xff26ffff
pc : [<8073f930>] lr : [<ff26ffff>] psr: 20000153
sp : 8553bc80 ip : 81406244 fp : 8553bd04
r10: 8085d12c r9 : 80a8f73c r8 : 85739000
r7 : 00000017 r6 : 80a8f860 r5 : 80c8ab98 r4 : 80a8f858
r3 : 00000000 r2 : 00000000 r1 : 81406130 r0 : 00000017
Flags: nzCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment none
Control: 00c5387d Table: 85524008 DAC: 00000051
Process sh (pid: 116, stack limit = 0x1f1988d6)
...
Backtrace:
[<8073f738>] (genl_register_family) from [<80860ac0>] (ncsi_init_netlink+0x20/0x48)
r10:8085d12c r9:80c8fb0c r8:85739000 r7:00000000 r6:81218000 r5:85739000
r4:8121c000
[<80860aa0>] (ncsi_init_netlink) from [<8085d740>] (ncsi_register_dev+0x1b0/0x210)
r5:8121c400 r4:8121c000
[<8085d590>] (ncsi_register_dev) from [<805a8060>] (ftgmac100_probe+0x6e0/0x778)
r10:00000004 r9:80950228 r8:8115bc10 r7:8115ab00 r6:9eae2c24 r5:813b6f88
r4:85739000
[<805a7980>] (ftgmac100_probe) from [<805355ec>] (platform_drv_probe+0x58/0xa8)
r9:80c76bb0 r8:00000000 r7:80cd4974 r6:80c76bb0 r5:8115bc10 r4:00000000
[<80535594>] (platform_drv_probe) from [<80532d58>] (really_probe+0x204/0x514)
r7:80cd4974 r6:00000000 r5:80cd4868 r4:8115bc10

Jakub pointed out that ncsi_register_dev is obviously broken, because
there is only one family so it would never work if there was more than
one ncsi netdev.

Fix the crash by registering the netlink family once on boot, and drop
the code to unregister it.

Fixes: 955dc68cb9b2 ("net/ncsi: Add generic netlink family")
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Link: https://lore.kernel.org/r/20201112061210.914621-1-joel@jms.id.au
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/ncsi: Extend NC-SI Netlink interface to allow user space to send NC-SI command

The new command (NCSI_CMD_SEND_CMD) is added to allow user space application
to send NC-SI command to the network card.
Also, add a new attribute (NCSI_ATTR_DATA) for transferring request and response.

The work flow is as below.

Request:
User space application
-> Netlink interface (msg)
-> new Netlink handler - ncsi_send_cmd_nl()
-> ncsi_xmit_cmd()

Response:
Response received - ncsi_rcv_rsp()
-> internal response handler - ncsi_rsp_handler_xxx()
-> ncsi_rsp_handler_netlink()
-> ncsi_send_netlink_rsp ()
-> Netlink interface (msg)
-> user space application

Command timeout - ncsi_request_timeout()
-> ncsi_send_netlink_timeout ()
-> Netlink interface (msg with zero data length)
-> user space application

Error:
Error detected
-> ncsi_send_netlink_err ()
-> Netlink interface (err msg)
-> user space application

Signed-off-by: Justin Lee <justin.lee1@dell.com>
Reviewed-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ncsi: Add generic netlink family

Add a generic netlink family for NCSI. This supports three commands;
NCSI_CMD_PKG_INFO which returns information on packages and their
associated channels, NCSI_CMD_SET_INTERFACE which allows a specific
package or package/channel combination to be set as the preferred
choice, and NCSI_CMD_CLEAR_INTERFACE which clears any preferred setting.

Signed-off-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>