netconsole: Enable compile time configuration

Enable netconsole features to be set at compilation time. Create two
Kconfig options that allow users to set extended logs and release
prepending features at compilation time.

Right now, the user needs to pass command line parameters to netconsole,
such as "+"/"r" to enable extended logs and version prepending features.

With these two options, the user could set the default values for the
features at compile time, and don't need to pass it in the command line
to get them enabled, simplifying the command line.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230811093158.1678322-3-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/Kconfig

@@ -332,6 +332,28 @@ config NETCONSOLE_DYNAMIC
 	  at runtime through a userspace interface exported using configfs.
 	  See <file:Documentation/networking/netconsole.rst> for details.
 
+config NETCONSOLE_EXTENDED_LOG
+	bool "Set kernel extended message by default"
+	depends on NETCONSOLE
+	default n
+	help
+	  Set extended log support for netconsole message. If this option is
+	  set, log messages are transmitted with extended metadata header in a
+	  format similar to /dev/kmsg.  See
+	  <file:Documentation/networking/netconsole.rst> for details.
+
+config NETCONSOLE_PREPEND_RELEASE
+	bool "Prepend kernel release version in the message by default"
+	depends on NETCONSOLE_EXTENDED_LOG
+	default n
+	help
+	  Set kernel release to be prepended to each netconsole message by
+	  default. If this option is set, the kernel release is prepended into
+	  the first field of every netconsole message, so, the netconsole
+	  server/peer can easily identify what kernel release is logging each
+	  message.  See <file:Documentation/networking/netconsole.rst> for
+	  details.
+
 config NETPOLL
 	def_bool NETCONSOLE
 

drivers/net/netconsole.c

@@ -178,6 +178,11 @@ static struct netconsole_target *alloc_and_init(void)
 	if (!nt)
 		return nt;
 
+	if (IS_ENABLED(CONFIG_NETCONSOLE_EXTENDED_LOG))
+		nt->extended = true;
+	if (IS_ENABLED(CONFIG_NETCONSOLE_PREPEND_RELEASE))
+		nt->release = true;
+
 	nt->np.name = "netconsole";
 	strscpy(nt->np.dev_name, "eth0", IFNAMSIZ);
 	nt->np.local_port = 6665;