xref: /linux/drivers/net/netconsole.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 	.drop = netpoll_queue,
64 };
65 static int configured = 0;
66 
67 #define MAX_PRINT_CHUNK 1000
68 
69 static void write_msg(struct console *con, const char *msg, unsigned int len)
70 {
71 	int frag, left;
72 	unsigned long flags;
73 
74 	if (!np.dev)
75 		return;
76 
77 	local_irq_save(flags);
78 
79 	for(left = len; left; ) {
80 		frag = min(left, MAX_PRINT_CHUNK);
81 		netpoll_send_udp(&np, msg, frag);
82 		msg += frag;
83 		left -= frag;
84 	}
85 
86 	local_irq_restore(flags);
87 }
88 
89 static struct console netconsole = {
90 	.name = "netcon",
91 	.flags = CON_ENABLED | CON_PRINTBUFFER,
92 	.write = write_msg
93 };
94 
95 static int option_setup(char *opt)
96 {
97 	configured = !netpoll_parse_options(&np, opt);
98 	return 1;
99 }
100 
101 __setup("netconsole=", option_setup);
102 
103 static int init_netconsole(void)
104 {
105 	if(strlen(config))
106 		option_setup(config);
107 
108 	if(!configured) {
109 		printk("netconsole: not configured, aborting\n");
110 		return 0;
111 	}
112 
113 	if(netpoll_setup(&np))
114 		return -EINVAL;
115 
116 	register_console(&netconsole);
117 	printk(KERN_INFO "netconsole: network logging started\n");
118 	return 0;
119 }
120 
121 static void cleanup_netconsole(void)
122 {
123 	unregister_console(&netconsole);
124 	netpoll_cleanup(&np);
125 }
126 
127 module_init(init_netconsole);
128 module_exit(cleanup_netconsole);
129