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 #include <asm/unaligned.h>
  49
  50 #include "netdump.h"
  51
  52 MODULE_AUTHOR("Maintainer: Matt Mackall <mpm@selenic.com>");
  53 MODULE_DESCRIPTION("Console driver for network interfaces");
  54 MODULE_LICENSE("GPL");
  55
  56 static char config[256];
  57 module_param_string(netconsole, config, 256, 0);
  58 MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
  59
  60 static struct netpoll np = {
  61         .name = "netconsole",
  62         .dev_name = "eth0",
  63         .local_port = 6665,
  64         .remote_port = 514,
  65         .remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
  66 };
  67 static int configured = 0;
  68
  69 static char netlog_config[256];
  70 module_param_string(netlog, netlog_config, 256, 0);
  71 MODULE_PARM_DESC(netlog, " netlog=[src-port]@[src-ip]/[dev],[tgt-port]@<tgt-ip>/[tgt-macaddr]\n");
  72 static struct netpoll netlog_np = {
  73         .name = "netlog",
  74         .dev_name = "eth0",
  75         .local_port = 6664,
  76         .remote_port = 6666,
  77         .remote_mac = {0xff, 0xff, 0xff, 0xff, 0xff, 0xff},
  78 };
  79 static int netlog_configured = 0;
  80
  81 #define MAX_PRINT_CHUNK 1000
  82 #define SYSLOG_HEADER_LEN 4
  83
  84 static int syslog_chars = SYSLOG_HEADER_LEN;
  85 static unsigned char syslog_line [MAX_PRINT_CHUNK + 10] = {
  86         '<',
  87         '5',
  88         '>',
  89         ' ',
  90         [4 ... MAX_PRINT_CHUNK+5] = '\0',
  91 };
  92 static unsigned char netlog_line[MAX_PRINT_CHUNK + HEADER_LEN];
  93 static unsigned int log_offset;
  94
  95 /*
  96  * We feed kernel messages char by char, and send the UDP packet
  97  * one linefeed. We buffer all characters received.
  98  */
  99 static inline void feed_syslog_char(const unsigned char c)
 100 {
 101         if (syslog_chars == MAX_PRINT_CHUNK)
 102                 syslog_chars--;
 103         syslog_line[syslog_chars] = c;
 104         syslog_chars++;
 105         if (c == '\n') {
 106                 netpoll_send_udp(&np, syslog_line, syslog_chars);
 107                 syslog_chars = SYSLOG_HEADER_LEN;
 108         }
 109 }
 110
 111 static void write_msg(struct console *con, const char *msg, unsigned int len)
 112 {
 113         int left, i;
 114         unsigned long flags;
 115         reply_t reply;
 116         char *netlog_buf = &netlog_line[HEADER_LEN];
 117
 118         if (!np.dev && !netlog_np.dev)
 119                 return;
 120
 121         if (unlikely(netdump_mode))
 122                 return;
 123
 124         local_irq_save(flags);
 125
 126         if (np.dev)
 127                 for (i = 0; i < len; i++)
 128                         feed_syslog_char(msg[i]);
 129
 130         if (netlog_np.dev) {
 131                 left = len;
 132                 while (left) {
 133                         if (left > MAX_PRINT_CHUNK)
 134                                 len = MAX_PRINT_CHUNK;
 135                         else
 136                                 len = left;
 137                         netlog_line[0] = NETDUMP_VERSION;
 138
 139                         reply.nr = 0;
 140                         reply.code = REPLY_LOG;
 141                         reply.info = log_offset;
 142
 143                         put_unaligned(htonl(reply.nr),
 144                                       (u32 *)(netlog_line + 1));
 145                         put_unaligned(htonl(reply.code),
 146                                       (u32 *)(netlog_line + 5));
 147                         put_unaligned(htonl(reply.info),
 148                                       (u32 *)(netlog_line + 9));
 149
 150                         log_offset += len;
 151                         memcpy(netlog_buf, msg, len);
 152
 153                         netpoll_send_udp(&netlog_np,
 154                                          netlog_line, len + HEADER_LEN);
 155                         msg += len;
 156                         left -= len;
 157                 }
 158         }
 159
 160         local_irq_restore(flags);
 161 }
 162
 163 static struct console netconsole = {
 164         .flags = CON_ENABLED | CON_PRINTBUFFER,
 165         .write = write_msg
 166 };
 167
 168 static int option_setup(char *opt)
 169 {
 170         configured = !netpoll_parse_options(&np, opt);
 171         return 0;
 172 }
 173
 174 __setup("netconsole=", option_setup);
 175
 176 static int netlog_option_setup(char *opt)
 177 {
 178         netlog_configured = !netpoll_parse_options(&netlog_np, opt);
 179         return 0;
 180 }
 181
 182 __setup("netlog=", netlog_option_setup);
 183
 184 static int init_netconsole(void)
 185 {
 186         if(strlen(config))
 187                 option_setup(config);
 188
 189         if (strlen(netlog_config))
 190                 netlog_option_setup(netlog_config);
 191
 192         if (configured && netpoll_setup(&np))
 193                 printk("netconsole: failed to configure syslog service\n");
 194
 195         if (netlog_configured && netpoll_setup(&netlog_np))
 196                 printk("netconsole: failed to configured netlog service.\n");
 197
 198         if (!configured && !netlog_configured)
 199                 return -EINVAL;
 200
 201         register_console(&netconsole);
 202         printk(KERN_INFO "netconsole: network logging started\n");
 203         return 0;
 204 }
 205
 206 static void cleanup_netconsole(void)
 207 {
 208         unregister_console(&netconsole);
 209
 210         if (configured)
 211                 netpoll_cleanup(&np);
 212
 213         if (netlog_configured)
 214                 netpoll_cleanup(&netlog_np);
 215 }
 216
 217 module_init(init_netconsole);
 218 module_exit(cleanup_netconsole);