src/core/settings.c

   1 /*
   2  * Copyright (C) 2006 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., 675 Mass Ave, Cambridge, MA 02139, USA.
  17  */
  18
  19 #include <stdint.h>
  20 #include <stdlib.h>
  21 #include <stdio.h>
  22 #include <string.h>
  23 #include <strings.h>
  24 #include <byteswap.h>
  25 #include <errno.h>
  26 #include <assert.h>
  27 #include <gpxe/in.h>
  28 #include <gpxe/settings.h>
  29
  30 /** @file
  31  *
  32  * Configuration settings
  33  *
  34  */
  35
  36 /** Registered configuration setting types */
  37 static struct config_setting_type config_setting_types[0]
  38         __table_start ( struct config_setting_type, config_setting_types );
  39 static struct config_setting_type config_setting_types_end[0]
  40         __table_end ( struct config_setting_type, config_setting_types );
  41
  42 /** Registered configuration settings */
  43 static struct config_setting config_settings[0]
  44         __table_start ( struct config_setting, config_settings );
  45 static struct config_setting config_settings_end[0]
  46         __table_end ( struct config_setting, config_settings );
  47
  48 /**
  49  * Find configuration setting type
  50  *
  51  * @v name              Name
  52  * @ret type            Configuration setting type, or NULL
  53  */
  54 static struct config_setting_type *
  55 find_config_setting_type ( const char *name ) {
  56         struct config_setting_type *type;
  57
  58         for ( type = config_setting_types ; type < config_setting_types_end ;
  59               type++ ) {
  60                 if ( strcasecmp ( name, type->name ) == 0 )
  61                         return type;
  62         }
  63         return NULL;
  64 }
  65
  66 /**
  67  * Find configuration setting
  68  *
  69  * @v name              Name
  70  * @ret setting         Configuration setting, or NULL
  71  */
  72 static struct config_setting * find_config_setting ( const char *name ) {
  73         struct config_setting *setting;
  74
  75         for ( setting = config_settings ; setting < config_settings_end ;
  76               setting++ ) {
  77                 if ( strcasecmp ( name, setting->name ) == 0 )
  78                         return setting;
  79         }
  80         return NULL;
  81 }
  82
  83 /**
  84  * Find or build configuration setting
  85  *
  86  * @v name              Name
  87  * @v tmp_setting       Temporary buffer for constructing a setting
  88  * @ret setting         Configuration setting, or NULL
  89  *
  90  * Find setting if it exists.  If it doesn't exist, but the name is of
  91  * the form "<num>.<type>" (e.g. "12.string"), then construct a
  92  * setting for that tag and data type, and return it.  The constructed
  93  * setting will be placed in the temporary buffer.
  94  */
  95 static struct config_setting *
  96 find_or_build_config_setting ( const char *name,
  97                                struct config_setting *tmp_setting ) {
  98         struct config_setting *setting;
  99         char *separator;
 100
 101         /* Look in the list of registered settings first */
 102         setting = find_config_setting ( name );
 103         if ( setting )
 104                 return setting;
 105
 106         /* If name is of the form "<num>.<type>", try to construct a setting */
 107         setting = tmp_setting;
 108         memset ( setting, 0, sizeof ( *setting ) );
 109         setting->name = name;
 110         setting->tag = strtoul ( name, &separator, 10 );
 111         if ( *separator != '.' )
 112                 return NULL;
 113         setting->type = find_config_setting_type ( separator + 1 );
 114         if ( ! setting->type )
 115                 return NULL;
 116         return setting;
 117 }
 118
 119 /**
 120  * Show value of named setting
 121  *
 122  * @v context           Configuration context
 123  * @v name              Configuration setting name
 124  * @v buf               Buffer to contain value
 125  * @v len               Length of buffer
 126  * @ret rc              Return status code
 127  */
 128 int show_named_setting ( struct config_context *context, const char *name,
 129                          char *buf, size_t len ) {
 130         struct config_setting *setting;
 131         struct config_setting tmp_setting;
 132
 133         setting = find_or_build_config_setting ( name, &tmp_setting );
 134         if ( ! setting )
 135                 return -ENOENT;
 136         return show_setting ( context, setting, buf, len );
 137 }
 138
 139 /**
 140  * Set value of named setting
 141  *
 142  * @v context           Configuration context
 143  * @v name              Configuration setting name
 144  * @v value             Setting value (as a string)
 145  * @ret rc              Return status code
 146  */
 147 int set_named_setting ( struct config_context *context, const char *name,
 148                         const char *value ) {
 149         struct config_setting *setting;
 150         struct config_setting tmp_setting;
 151
 152         setting = find_or_build_config_setting ( name, &tmp_setting );
 153         if ( ! setting )
 154                 return -ENOENT;
 155         return setting->type->set ( context, setting, value );
 156 }
 157
 158 /**
 159  * Set value of setting
 160  *
 161  * @v context           Configuration context
 162  * @v setting           Configuration setting
 163  * @v value             Setting value (as a string), or NULL
 164  * @ret rc              Return status code
 165  */
 166 int set_setting ( struct config_context *context,
 167                   struct config_setting *setting,
 168                   const char *value ) {
 169         if ( ( ! value ) || ( ! *value ) ) {
 170                 /* Save putting deletion logic in each individual handler */
 171                 return clear_setting ( context, setting );
 172         }
 173         return setting->type->set ( context, setting, value );
 174 }
 175
 176 /**
 177  * Show value of string setting
 178  *
 179  * @v context           Configuration context
 180  * @v setting           Configuration setting
 181  * @v buf               Buffer to contain value
 182  * @v len               Length of buffer
 183  * @ret rc              Return status code
 184  */
 185 static int show_string ( struct config_context *context,
 186                          struct config_setting *setting,
 187                          char *buf, size_t len ) {
 188         struct dhcp_option *option;
 189
 190         option = find_dhcp_option ( context->options, setting->tag );
 191         if ( ! option )
 192                 return -ENODATA;
 193         dhcp_snprintf ( buf, len, option );
 194         return 0;
 195 }
 196
 197 /**
 198  * Set value of string setting
 199  *
 200  * @v context           Configuration context
 201  * @v setting           Configuration setting
 202  * @v value             Setting value (as a string)
 203  * @ret rc              Return status code
 204  */
 205 static int set_string ( struct config_context *context,
 206                         struct config_setting *setting,
 207                         const char *value ) {
 208         struct dhcp_option *option;
 209
 210         option = set_dhcp_option ( context->options, setting->tag,
 211                                    value, strlen ( value ) );
 212         if ( ! option )
 213                 return -ENOSPC;
 214         return 0;
 215 }
 216
 217 /** A string configuration setting */
 218 struct config_setting_type config_setting_type_string __config_setting_type = {
 219         .name = "string",
 220         .description = "Text string",
 221         .show = show_string,
 222         .set = set_string,
 223 };
 224
 225 /**
 226  * Show value of IPv4 setting
 227  *
 228  * @v context           Configuration context
 229  * @v setting           Configuration setting
 230  * @v buf               Buffer to contain value
 231  * @v len               Length of buffer
 232  * @ret rc              Return status code
 233  */
 234 static int show_ipv4 ( struct config_context *context,
 235                        struct config_setting *setting,
 236                        char *buf, size_t len ) {
 237         struct dhcp_option *option;
 238         struct in_addr ipv4;
 239
 240         option = find_dhcp_option ( context->options, setting->tag );
 241         if ( ! option )
 242                 return -ENODATA;
 243         dhcp_ipv4_option ( option, &ipv4 );
 244         snprintf ( buf, len, inet_ntoa ( ipv4 ) );
 245         return 0;
 246 }
 247
 248 /**
 249  * Set value of IPV4 setting
 250  *
 251  * @v context           Configuration context
 252  * @v setting           Configuration setting
 253  * @v value             Setting value (as a string)
 254  * @ret rc              Return status code
 255  */
 256 static int set_ipv4 ( struct config_context *context,
 257                       struct config_setting *setting,
 258                       const char *value ) {
 259         struct dhcp_option *option;
 260         struct in_addr ipv4;
 261
 262         if ( inet_aton ( value, &ipv4 ) == 0 )
 263                 return -EINVAL;
 264         option = set_dhcp_option ( context->options, setting->tag,
 265                                    &ipv4, sizeof ( ipv4 ) );
 266         if ( ! option )
 267                 return -ENOSPC;
 268         return 0;
 269 }
 270
 271 /** An IPv4 configuration setting */
 272 struct config_setting_type config_setting_type_ipv4 __config_setting_type = {
 273         .name = "ipv4",
 274         .description = "IPv4 address",
 275         .show = show_ipv4,
 276         .set = set_ipv4,
 277 };
 278
 279 /**
 280  * Show value of integer setting
 281  *
 282  * @v context           Configuration context
 283  * @v setting           Configuration setting
 284  * @v buf               Buffer to contain value
 285  * @v len               Length of buffer
 286  * @ret rc              Return status code
 287  */
 288 static int show_int ( struct config_context *context,
 289                       struct config_setting *setting,
 290                       char *buf, size_t len ) {
 291         struct dhcp_option *option;
 292         long num;
 293
 294         option = find_dhcp_option ( context->options, setting->tag );
 295         if ( ! option )
 296                 return -ENODATA;
 297         num = dhcp_num_option ( option );
 298         snprintf ( buf, len, "%ld", num );
 299         return 0;
 300 }
 301
 302 /**
 303  * Set value of integer setting
 304  *
 305  * @v context           Configuration context
 306  * @v setting           Configuration setting
 307  * @v value             Setting value (as a string)
 308  * @v size              Size of integer (in bytes)
 309  * @ret rc              Return status code
 310  */
 311 static int set_int ( struct config_context *context,
 312                      struct config_setting *setting,
 313                      const char *value, unsigned int size ) {
 314         struct dhcp_option *option;
 315         union {
 316                 uint32_t num;
 317                 uint8_t bytes[4];
 318         } u;
 319         char *endp;
 320
 321         /* Parse number */
 322         if ( ! *value )
 323                 return -EINVAL;
 324         u.num = htonl ( strtoul ( value, &endp, 0 ) );
 325         if ( *endp )
 326                 return -EINVAL;
 327
 328         /* Set option */
 329         option = set_dhcp_option ( context->options, setting->tag,
 330                                    &u.bytes[ sizeof ( u ) - size ], size );
 331         if ( ! option )
 332                 return -ENOSPC;
 333         return 0;
 334 }
 335
 336 /**
 337  * Set value of 8-bit integer setting
 338  *
 339  * @v context           Configuration context
 340  * @v setting           Configuration setting
 341  * @v value             Setting value (as a string)
 342  * @v size              Size of integer (in bytes)
 343  * @ret rc              Return status code
 344  */
 345 static int set_int8 ( struct config_context *context,
 346                            struct config_setting *setting,
 347                            const char *value ) {
 348         return set_int ( context, setting, value, 1 );
 349 }
 350
 351 /** An 8-bit integer configuration setting */
 352 struct config_setting_type config_setting_type_int8 __config_setting_type = {
 353         .name = "int8",
 354         .description = "8-bit integer",
 355         .show = show_int,
 356         .set = set_int8,
 357 };
 358
 359 /** Some basic setting definitions */
 360 struct config_setting basic_config_settings[] __config_setting = {
 361         {
 362                 .name = "ip",
 363                 .description = "IP address of this machine (e.g. 192.168.0.1)",
 364                 .tag = DHCP_EB_YIADDR,
 365                 .type = &config_setting_type_ipv4,
 366         },
 367         {
 368                 .name = "hostname",
 369                 .description = "Host name of this machine",
 370                 .tag = DHCP_HOST_NAME,
 371                 .type = &config_setting_type_string,
 372         },
 373         {
 374                 .name = "username",
 375                 .description = "User name for authentication to servers",
 376                 .tag = DHCP_EB_USERNAME,
 377                 .type = &config_setting_type_string,
 378         },
 379         {
 380                 .name = "password",
 381                 .description = "Password for authentication to servers",
 382                 .tag = DHCP_EB_PASSWORD,
 383                 .type = &config_setting_type_string,
 384         },
 385         {
 386                 .name = "root-path",
 387                 .description = "NFS/iSCSI root path",
 388                 .tag = DHCP_ROOT_PATH,
 389                 .type = &config_setting_type_string,
 390         },
 391         {
 392                 .name = "priority",
 393                 .description = "Priority of these options",
 394                 .tag = DHCP_EB_PRIORITY,
 395                 .type = &config_setting_type_int8,
 396         },
 397         {
 398                 .name = "initiator-iqn",
 399                 .description = "iSCSI qualified name of this machine",
 400                 .tag = DHCP_ISCSI_INITIATOR_IQN,
 401                 .type = &config_setting_type_string,
 402         }
 403 };