[openwrt/openwrt] kernel: netconsole: add network console logging support

[LEDE Commits]

chunkeey pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/488b25f5ac5028923f67e3beade92dab0c2591f1

commit 488b25f5ac5028923f67e3beade92dab0c2591f1
Author: Catalin Toda <catalinii at yahoo.com>
AuthorDate: Fri Jul 15 10:18:23 2022 -0700

    kernel: netconsole: add network console logging support
    
    Accessing the console on many devices is difficult.
    netconsole eases debugging on devices that crash
    after the network is up.
    
    Reference to the netconsole documentation in upstream Linux:
    <https://www.kernel.org/doc/html/latest/networking/netconsole.html>
    |
    |netconsole=[+][src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
    |
    | where
    |  +            if present, enable extended console support
    |  src-port     source for UDP packets (defaults to 6665)
    |  src-ip       source IP to use (interface address)
    |  dev          network interface (eth0)
    |  tgt-port     port for logging agent (6666)
    |  tgt-ip       IP address for logging agent
    |  tgt-macaddr  ethernet MAC address for logging agent (broadcast)
    
    OpenWrt specific notes:
    
    OpenWrt's device userspace scripts are attaching the network
    interface (i.e. eth0) to a (virtual) bridge (br-lan) device.
    This will cause netconsole to report:
    |network logging stopped on interface eth0 as it is joining a master device
    (and unfortunately the traffic/logs to stop at this point)
    
    As a workaround, the netconsole module can be manually loaded
    again after the bridge has been setup with:
    
     insmod netconsole netconsole=@/br-lan, at 192.168.1.x/MA:C...
    
    One way of catching errors before the handoff, try to
    append the /etc/modules.conf file with the following extra line:
     options netconsole netconsole=@/eth0, at 192.168.1.x/MA:C...
    
    and install the kmod-netconsole (=y) into the base image.
    
    Signed-off-by: Catalin Toda <catalinii at yahoo.com>
    (Added commit message from PR, added links to documentation)
    Signed-off-by: Christian Lamparter <chunkeey at gmail.com>
---
 package/kernel/linux/modules/netsupport.mk | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/package/kernel/linux/modules/netsupport.mk b/package/kernel/linux/modules/netsupport.mk
index 6fb3b57e12..af720128eb 100644
--- a/package/kernel/linux/modules/netsupport.mk
+++ b/package/kernel/linux/modules/netsupport.mk
@@ -1346,3 +1346,19 @@ define KernelPackage/wireguard/description
 endef
 
 $(eval $(call KernelPackage,wireguard))
+
+
+define KernelPackage/netconsole
+  SUBMENU:=$(NETWORK_SUPPORT_MENU)
+  TITLE:=Network console logging support
+  KCONFIG:=CONFIG_NETCONSOLE \
+	  CONFIG_NETCONSOLE_DYNAMIC=n
+  FILES:=$(LINUX_DIR)/drivers/net/netconsole.ko
+  AUTOLOAD:=$(call AutoProbe,netconsole)
+endef
+
+define KernelPackage/netconsole/description
+  Network console logging support.
+endef
+
+$(eval $(call KernelPackage,netconsole))