[PATCH 3/3] netconsole using netpoll api
From: Matt Mackall
Date: Mon Sep 22 2003 - 13:51:44 EST
This patch uses the netpoll API to transmit kernel printks over UDP
l-mpm/Documentation/networking/netconsole.txt | 57 +++++++++++
l-mpm/drivers/net/Kconfig | 7 +
l-mpm/drivers/net/Makefile | 1
l-mpm/drivers/net/netconsole.c | 129 ++++++++++++++++++++++++++
l-mpm/net/Kconfig | 2
5 files changed, 195 insertions(+), 1 deletion(-)
diff -puN -L net/core/netconsole.c /dev/null /dev/null
diff -puN net/core/Makefile~netconsole net/core/Makefile
diff -puN net/Kconfig~netconsole net/Kconfig
--- l/net/Kconfig~netconsole 2003-09-22 13:16:50.000000000 -0500
+++ l-mpm/net/Kconfig 2003-09-22 13:16:50.000000000 -0500
@@ -690,6 +690,6 @@ endmenu
source "drivers/net/Kconfig"
config NETPOLL
- def_bool KGDB
+ def_bool KGDB || NETCONSOLE
endmenu
diff -puN /dev/null Documentation/networking/netconsole.txt
--- /dev/null 2003-09-12 12:14:37.000000000 -0500
+++ l-mpm/Documentation/networking/netconsole.txt 2003-09-22 13:16:50.000000000 -0500
@@ -0,0 +1,57 @@
+
+started by Ingo Molnar <mingo@xxxxxxxxxx>, 2001.09.17
+2.6 port and netpoll api by Matt Mackall <mpm@xxxxxxxxxxx>, Sep 9 2003
+
+Please send bug reports to Matt Mackall <mpm@xxxxxxxxxxx>
+
+This module logs kernel printk messages over UDP allowing debugging of
+problem where disk logging fails and serial consoles are impractical.
+
+It can be used either built-in or as a module. As a built-in,
+netconsole initializes immediately after NIC cards and will bring up
+the specified interface as soon as possible. While this doesn't allow
+capture of early kernel panics, it does capture most of the boot
+process.
+
+It takes a string configuration parameter "netconsole" in the
+following format:
+
+ netconsole=[src-port]@[src-ip]/[<dev>],[tgt-port]@<tgt-ip>/[tgt-macaddr]
+
+ where
+ src-port source for UDP packets (defaults to 6666)
+ src-ip source IP to use (interface address)
+ dev network interface (eth0)
+ tgt-port port for logging agent (514)
+ tgt-ip IP address for logging agent
+ tgt-macaddr ethernet MAC address for logging agent (broadcast)
+
+Examples:
+
+ linux netconsole=4444@xxxxxxxx/eth1,9353@xxxxxxxx/12:34:56:78:9a:bc
+
+ or
+
+ insmod netconsole netconsole=@/,@10.0.0.2/
+
+Built-in netconsole starts immediately after the TCP stack is
+initialized and attempts to bring up the supplied dev at the supplied
+address.
+
+The remote host can run either 'netcat -u -l -p <port>' or syslogd.
+
+WARNING: the default target ethernet setting uses the broadcast
+ethernet address to send packets, which can cause increased load on
+other systems on the same ethernet segment.
+
+NOTE: the network device (eth1 in the above case) can run any kind
+of other network traffic, netconsole is not intrusive. Netconsole
+might cause slight delays in other traffic if the volume of kernel
+messages is high, but should have no other impact.
+
+Netconsole was designed to be as instantaneous as possible, to
+enable the logging of even the most critical kernel bugs. It works
+from IRQ contexts as well, and does not enable interrupts while
+sending packets. Due to these unique needs, configuration can not
+be more automatic, and some fundamental limitations will remain:
+only IP networks, UDP packets and ethernet devices are supported.
diff -puN drivers/net/Makefile~netconsole drivers/net/Makefile
--- l/drivers/net/Makefile~netconsole 2003-09-22 13:16:50.000000000 -0500
+++ l-mpm/drivers/net/Makefile 2003-09-22 13:16:50.000000000 -0500
@@ -197,3 +197,4 @@ include $(TOPDIR)/drivers/usb/net/Makefi
# Must come after all NICs it might use
obj-$(CONFIG_KGDB) += kgdb_eth.o
+obj-$(CONFIG_NETCONSOLE) += netconsole.o
diff -puN drivers/net/Kconfig~netconsole drivers/net/Kconfig
--- l/drivers/net/Kconfig~netconsole 2003-09-22 13:16:50.000000000 -0500
+++ l-mpm/drivers/net/Kconfig 2003-09-22 13:16:50.000000000 -0500
@@ -2718,6 +2718,13 @@ config SHAPER
config NET_POLL_CONTROLLER
def_bool KGDB
+config NETCONSOLE
+ tristate "Network console logging support"
+ depends on NETDEVICES
+ ---help---
+ If you want to log kernel messages over the network, enable this.
+ See Documentation/networking/netconsole.txt for details.
+
source "drivers/net/wan/Kconfig"
source "drivers/net/pcmcia/Kconfig"
diff -puN /dev/null drivers/net/netconsole.c
--- /dev/null 2003-09-12 12:14:37.000000000 -0500
+++ l-mpm/drivers/net/netconsole.c 2003-09-22 13:16:50.000000000 -0500
@@ -0,0 +1,129 @@
+/*
+ * linux/drivers/net/netconsole.c
+ *
+ * Copyright (C) 2001 Ingo Molnar <mingo@xxxxxxxxxx>
+ *
+ * This file contains the implementation of an IRQ-safe, crash-safe
+ * kernel console implementation that outputs kernel messages to the
+ * network.
+ *
+ * Modification history:
+ *
+ * 2001-09-17 started by Ingo Molnar.
+ * 2003-08-11 2.6 port by Matt Mackall
+ * simplified options
+ * generic card hooks
+ * works non-modular
+ * 2003-09-07 rewritten with netpoll api
+ */
+
+/****************************************************************
+ * 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, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ ****************************************************************/
+
+#include <linux/mm.h>
+#include <linux/tty.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/tty_driver.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/string.h>
+#include <linux/sysrq.h>
+#include <linux/smp.h>
+#include <linux/netpoll.h>
+
+MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@xxxxxxxxxxx>");
+MODULE_DESCRIPTION("Console driver for network interfaces");
+MODULE_LICENSE("GPL");
+
+static char config[256];
+module_param_string(netconsole, config, 256, 0);
+MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
+
+static void rx_hook(struct netpoll *np, int port, char *msg, int len);
+
+static struct netpoll np = {
+ .name = "netconsole",
+ .dev_name = "eth0",
+ .rx_hook = rx_hook,
+ .local_port = 6666,
+ .remote_port = 6666,
+ .remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
+};
+
+#define MAX_PRINT_CHUNK 1000
+
+static void write_msg(struct console *con, const char *msg, unsigned int len)
+{
+ int frag, left;
+ unsigned long flags;
+
+ if (!np.dev)
+ return;
+
+ local_irq_save(flags);
+
+ for(left = len; left; ) {
+ frag = min(left, MAX_PRINT_CHUNK);
+ netpoll_send_udp(&np, msg, frag);
+ msg += frag;
+ left -= frag;
+ }
+
+ local_irq_restore(flags);
+}
+
+static void rx_hook(struct netpoll *np, int port, char *msg, int len)
+{
+ /* add sysrq support */
+ printk("netconsole: no sysrq yet\n");
+}
+
+static struct console netconsole = {
+ .flags = CON_ENABLED | CON_PRINTBUFFER,
+ .write = write_msg
+};
+
+static int option_setup(char *opt)
+{
+ return netpoll_parse_options(&np, opt);
+}
+
+__setup("netconsole=", option_setup);
+
+static int init_netconsole(void)
+{
+ if(strlen(config) && option_setup(config))
+ return 1;
+
+ if(!np.remote_ip || netpoll_setup(&np))
+ return 1;
+
+ register_console(&netconsole);
+ printk(KERN_INFO "netconsole: network logging started\n");
+ return 0;
+}
+
+static void cleanup_netconsole(void)
+{
+ unregister_console(&netconsole);
+ netpoll_cleanup(&np);
+}
+
+module_init(init_netconsole);
+module_exit(cleanup_netconsole);
_
--
Matt Mackall : http://www.selenic.com : of or relating to the moon
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/