drivers/net/netconsole.c

   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);