src/net/udp/syslog.c

   1 /*
   2  * Copyright (C) 2011 Michael Brown <mbrown@fensystems.co.uk>.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * License, or any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  17  * 02110-1301, USA.
  18  *
  19  * You can also choose to distribute this program under the terms of
  20  * the Unmodified Binary Distribution Licence (as given in the file
  21  * COPYING.UBDL), provided that you have satisfied its requirements.
  22  */
  23
  24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
  25
  26 /** @file
  27  *
  28  * Syslog protocol
  29  *
  30  */
  31
  32 #include <stdint.h>
  33 #include <stdlib.h>
  34 #include <ctype.h>
  35 #include <byteswap.h>
  36 #include <ipxe/xfer.h>
  37 #include <ipxe/open.h>
  38 #include <ipxe/tcpip.h>
  39 #include <ipxe/dhcp.h>
  40 #include <ipxe/dhcpv6.h>
  41 #include <ipxe/settings.h>
  42 #include <ipxe/console.h>
  43 #include <ipxe/lineconsole.h>
  44 #include <ipxe/syslog.h>
  45 #include <config/console.h>
  46
  47 /* Set default console usage if applicable */
  48 #if ! ( defined ( CONSOLE_SYSLOG ) && CONSOLE_EXPLICIT ( CONSOLE_SYSLOG ) )
  49 #undef CONSOLE_SYSLOG
  50 #define CONSOLE_SYSLOG ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
  51 #endif
  52
  53 /** The syslog server */
  54 static union {
  55         struct sockaddr sa;
  56         struct sockaddr_tcpip st;
  57         struct sockaddr_in sin;
  58         struct sockaddr_in6 sin6;
  59 } logserver = {
  60         .st = {
  61                 .st_port = htons ( SYSLOG_PORT ),
  62         },
  63 };
  64
  65 /** Syslog UDP interface operations */
  66 static struct interface_operation syslogger_operations[] = {};
  67
  68 /** Syslog UDP interface descriptor */
  69 static struct interface_descriptor syslogger_desc =
  70         INTF_DESC_PURE ( syslogger_operations );
  71
  72 /** The syslog UDP interface */
  73 static struct interface syslogger = INTF_INIT ( syslogger_desc );
  74
  75 /******************************************************************************
  76  *
  77  * Console driver
  78  *
  79  ******************************************************************************
  80  */
  81
  82 /** Host name (for log messages) */
  83 static char *syslog_hostname;
  84
  85 /** Domain name (for log messages) */
  86 static char *syslog_domain;
  87
  88 /**
  89  * Transmit formatted syslog message
  90  *
  91  * @v xfer              Data transfer interface
  92  * @v severity          Severity
  93  * @v message           Message
  94  * @v terminator        Message terminator
  95  * @ret rc              Return status code
  96  */
  97 int syslog_send ( struct interface *xfer, unsigned int severity,
  98                   const char *message, const char *terminator ) {
  99         const char *hostname = ( syslog_hostname ? syslog_hostname : "" );
 100         const char *domain = ( ( hostname[0] && syslog_domain ) ?
 101                                syslog_domain : "" );
 102
 103         return xfer_printf ( xfer, "<%d>%s%s%s%sipxe: %s%s",
 104                              SYSLOG_PRIORITY ( SYSLOG_DEFAULT_FACILITY,
 105                                                severity ), hostname,
 106                              ( domain[0] ? "." : "" ), domain,
 107                              ( hostname[0] ? " " : "" ), message, terminator );
 108 }
 109
 110 /******************************************************************************
 111  *
 112  * Console driver
 113  *
 114  ******************************************************************************
 115  */
 116
 117 /** Syslog line buffer */
 118 static char syslog_buffer[SYSLOG_BUFSIZE];
 119
 120 /** Syslog severity */
 121 static unsigned int syslog_severity = SYSLOG_DEFAULT_SEVERITY;
 122
 123 /**
 124  * Handle ANSI set syslog priority (private sequence)
 125  *
 126  * @v ctx               ANSI escape sequence context
 127  * @v count             Parameter count
 128  * @v params            List of graphic rendition aspects
 129  */
 130 static void syslog_handle_priority ( struct ansiesc_context *ctx __unused,
 131                                      unsigned int count __unused,
 132                                      int params[] ) {
 133         if ( params[0] >= 0 ) {
 134                 syslog_severity = params[0];
 135         } else {
 136                 syslog_severity = SYSLOG_DEFAULT_SEVERITY;
 137         }
 138 }
 139
 140 /** Syslog ANSI escape sequence handlers */
 141 static struct ansiesc_handler syslog_handlers[] = {
 142         { ANSIESC_LOG_PRIORITY, syslog_handle_priority },
 143         { 0, NULL }
 144 };
 145
 146 /** Syslog line console */
 147 static struct line_console syslog_line = {
 148         .buffer = syslog_buffer,
 149         .len = sizeof ( syslog_buffer ),
 150         .ctx = {
 151                 .handlers = syslog_handlers,
 152         },
 153 };
 154
 155 /** Syslog recursion marker */
 156 static int syslog_entered;
 157
 158 /**
 159  * Print a character to syslog console
 160  *
 161  * @v character         Character to be printed
 162  */
 163 static void syslog_putchar ( int character ) {
 164         int rc;
 165
 166         /* Ignore if we are already mid-logging */
 167         if ( syslog_entered )
 168                 return;
 169
 170         /* Fill line buffer */
 171         if ( line_putchar ( &syslog_line, character ) == 0 )
 172                 return;
 173
 174         /* Guard against re-entry */
 175         syslog_entered = 1;
 176
 177         /* Send log message */
 178         if ( ( rc = syslog_send ( &syslogger, syslog_severity,
 179                                   syslog_buffer, "" ) ) != 0 ) {
 180                 DBG ( "SYSLOG could not send log message: %s\n",
 181                       strerror ( rc ) );
 182         }
 183
 184         /* Clear re-entry flag */
 185         syslog_entered = 0;
 186 }
 187
 188 /** Syslog console driver */
 189 struct console_driver syslog_console __console_driver = {
 190         .putchar = syslog_putchar,
 191         .disabled = CONSOLE_DISABLED,
 192         .usage = CONSOLE_SYSLOG,
 193 };
 194
 195 /******************************************************************************
 196  *
 197  * Settings
 198  *
 199  ******************************************************************************
 200  */
 201
 202 /** IPv4 syslog server setting */
 203 const struct setting syslog_setting __setting ( SETTING_MISC, syslog ) = {
 204         .name = "syslog",
 205         .description = "Syslog server",
 206         .tag = DHCP_LOG_SERVERS,
 207         .type = &setting_type_ipv4,
 208 };
 209
 210 /** IPv6 syslog server setting */
 211 const struct setting syslog6_setting __setting ( SETTING_MISC, syslog6 ) = {
 212         .name = "syslog6",
 213         .description = "Syslog server",
 214         .tag = DHCPV6_LOG_SERVERS,
 215         .type = &setting_type_ipv6,
 216         .scope = &dhcpv6_scope,
 217 };
 218
 219 /**
 220  * Strip invalid characters from host/domain name
 221  *
 222  * @v name              Name to strip
 223  */
 224 static void syslog_fix_name ( char *name ) {
 225         char *fixed = name;
 226         int c;
 227
 228         /* Do nothing if name does not exist */
 229         if ( ! name )
 230                 return;
 231
 232         /* Strip any non-printable or whitespace characters from the name */
 233         do {
 234                 c = *(name++);
 235                 *fixed = c;
 236                 if ( isprint ( c ) && ! isspace ( c ) )
 237                         fixed++;
 238         } while ( c );
 239 }
 240
 241 /**
 242  * Apply syslog settings
 243  *
 244  * @ret rc              Return status code
 245  */
 246 static int apply_syslog_settings ( void ) {
 247         struct sockaddr old_logserver;
 248         int rc;
 249
 250         /* Fetch hostname and domain name */
 251         free ( syslog_hostname );
 252         fetch_string_setting_copy ( NULL, &hostname_setting, &syslog_hostname );
 253         syslog_fix_name ( syslog_hostname );
 254         free ( syslog_domain );
 255         fetch_string_setting_copy ( NULL, &domain_setting, &syslog_domain );
 256         syslog_fix_name ( syslog_domain );
 257
 258         /* Fetch log server */
 259         syslog_console.disabled = CONSOLE_DISABLED;
 260         memcpy ( &old_logserver, &logserver, sizeof ( old_logserver ) );
 261         logserver.sa.sa_family = 0;
 262         if ( fetch_ipv6_setting ( NULL, &syslog6_setting,
 263                                   &logserver.sin6.sin6_addr ) >= 0 ) {
 264                 logserver.sin6.sin6_family = AF_INET6;
 265         } else if ( fetch_ipv4_setting ( NULL, &syslog_setting,
 266                                          &logserver.sin.sin_addr ) >= 0 ) {
 267                 logserver.sin.sin_family = AF_INET;
 268         }
 269         if ( logserver.sa.sa_family ) {
 270                 syslog_console.disabled = 0;
 271                 DBG ( "SYSLOG using log server %s\n",
 272                       sock_ntoa ( &logserver.sa ) );
 273         }
 274
 275         /* Do nothing unless log server has changed */
 276         if ( memcmp ( &logserver, &old_logserver, sizeof ( logserver ) ) == 0 )
 277                 return 0;
 278
 279         /* Reset syslog connection */
 280         intf_restart ( &syslogger, 0 );
 281
 282         /* Do nothing unless we have a log server */
 283         if ( syslog_console.disabled ) {
 284                 DBG ( "SYSLOG has no log server\n" );
 285                 return 0;
 286         }
 287
 288         /* Connect to log server */
 289         if ( ( rc = xfer_open_socket ( &syslogger, SOCK_DGRAM,
 290                                        &logserver.sa, NULL ) ) != 0 ) {
 291                 DBG ( "SYSLOG cannot connect to log server: %s\n",
 292                       strerror ( rc ) );
 293                 return rc;
 294         }
 295
 296         return 0;
 297 }
 298
 299 /** Syslog settings applicator */
 300 struct settings_applicator syslog_applicator __settings_applicator = {
 301         .apply = apply_syslog_settings,
 302 };