xref: /openbmc/linux/drivers/net/netconsole.c (revision 64c70b1c)
1 /*
2  *  linux/drivers/net/netconsole.c
3  *
4  *  Copyright (C) 2001  Ingo Molnar <mingo@redhat.com>
5  *
6  *  This file contains the implementation of an IRQ-safe, crash-safe
7  *  kernel console implementation that outputs kernel messages to the
8  *  network.
9  *
10  * Modification history:
11  *
12  * 2001-09-17    started by Ingo Molnar.
13  * 2003-08-11    2.6 port by Matt Mackall
14  *               simplified options
15  *               generic card hooks
16  *               works non-modular
17  * 2003-09-07    rewritten with netpoll api
18  */
19 
20 /****************************************************************
21  *      This program is free software; you can redistribute it and/or modify
22  *      it under the terms of the GNU General Public License as published by
23  *      the Free Software Foundation; either version 2, or (at your option)
24  *      any later version.
25  *
26  *      This program is distributed in the hope that it will be useful,
27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
29  *      GNU General Public License for more details.
30  *
31  *      You should have received a copy of the GNU General Public License
32  *      along with this program; if not, write to the Free Software
33  *      Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
34  *
35  ****************************************************************/
36 
37 #include <linux/mm.h>
38 #include <linux/tty.h>
39 #include <linux/init.h>
40 #include <linux/module.h>
41 #include <linux/console.h>
42 #include <linux/tty_driver.h>
43 #include <linux/moduleparam.h>
44 #include <linux/string.h>
45 #include <linux/sysrq.h>
46 #include <linux/smp.h>
47 #include <linux/netpoll.h>
48 
49 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
50 MODULE_DESCRIPTION("Console driver for network interfaces");
51 MODULE_LICENSE("GPL");
52 
53 static char config[256];
54 module_param_string(netconsole, config, 256, 0);
55 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
56 
57 static struct netpoll np = {
58 	.name = "netconsole",
59 	.dev_name = "eth0",
60 	.local_port = 6665,
61 	.remote_port = 6666,
62 	.remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
63 };
64 static int configured = 0;
65 
66 #define MAX_PRINT_CHUNK 1000
67 
68 static void write_msg(struct console *con, const char *msg, unsigned int len)
69 {
70 	int frag, left;
71 	unsigned long flags;
72 
73 	if (!np.dev)
74 		return;
75 
76 	local_irq_save(flags);
77 
78 	for(left = len; left; ) {
79 		frag = min(left, MAX_PRINT_CHUNK);
80 		netpoll_send_udp(&np, msg, frag);
81 		msg += frag;
82 		left -= frag;
83 	}
84 
85 	local_irq_restore(flags);
86 }
87 
88 static struct console netconsole = {
89 	.name = "netcon",
90 	.flags = CON_ENABLED | CON_PRINTBUFFER,
91 	.write = write_msg
92 };
93 
94 static int option_setup(char *opt)
95 {
96 	configured = !netpoll_parse_options(&np, opt);
97 	return 1;
98 }
99 
100 __setup("netconsole=", option_setup);
101 
102 static int init_netconsole(void)
103 {
104 	int err;
105 
106 	if(strlen(config))
107 		option_setup(config);
108 
109 	if(!configured) {
110 		printk("netconsole: not configured, aborting\n");
111 		return 0;
112 	}
113 
114 	err = netpoll_setup(&np);
115 	if (err)
116 		return err;
117 
118 	register_console(&netconsole);
119 	printk(KERN_INFO "netconsole: network logging started\n");
120 	return 0;
121 }
122 
123 static void cleanup_netconsole(void)
124 {
125 	unregister_console(&netconsole);
126 	netpoll_cleanup(&np);
127 }
128 
129 module_init(init_netconsole);
130 module_exit(cleanup_netconsole);
131