dnsinfo/dnsinfo_private.h

   1 /*
   2  * Copyright (c) 2004-2006, 2008, 2009 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24 #ifndef __DNSINFO_PRIVATE_H__
  25 #define __DNSINFO_PRIVATE_H__
  26
  27
  28 #include <Availability.h>
  29 #include <sys/cdefs.h>
  30 #include <stdint.h>
  31 #include <sys/types.h>
  32 #include <sys/socket.h>
  33 #include <netinet/in.h>
  34 #include <mach/mach.h>
  35
  36 #include "dnsinfo.h"
  37
  38 /*
  39  * What's all of this stuff about???
  40  *
  41  * In order to minimize the amount of data conversions associated with
  42  * storing, retrieving, and accessing the systems DNS configuration I
  43  * have opted to create a memory image filled with the actual data
  44  * types / structures that would be used by those applications which
  45  * make use of these APIS.  The implication here is that we use
  46  * sockaddr's for addresses, char *'s for strings, etc.
  47  *
  48  * To achieve this goal the APIs which are used to store and access the
  49  * configuration data build and use a single buffer of the relevant
  50  * bits.  When multiple instances of a given type / structure are needed
  51  * we maintain a count, the actual data, and when the configuration has
  52  * been unpacked, arrays of pointers to the data.
  53  *
  54  * In memory, the data looks as follows:
  55  *
  56  * +-------------------------------------------------------------------+
  57  * | struct _dns_config_buf_t                                          |
  58  * +-+-------------+---------------------------------------------------+
  59  * | | config      | struct dns_config_t                               |
  60  * | |             +-+--------------+----------------------------------+
  61  * | |             | | n_resolver   | int32_t                          | <- # of name resolvers
  62  * | |             | +--------------+----------------------------------+
  63  * | |             | | resolver     | dns_resolver_t **                | <- not used during creation, filled
  64  * | |             | |              |                                  |    in with pointer to a list of
  65  * | |             | |              |                                  |    resolver configurations which be
  66  * | |             | |              |                                  |    established in the "padding"
  67  * | |             | +--------------+----------------------------------+
  68  * | |             | | ...          | ...                              |
  69  * | +-------------+-+--------------+----------------------------------+
  70  * | | n_attribute | uint32_t                                          | <- how many bytes of "attribute"
  71  * | |             |                                                   |    data is associated with the
  72  * | |             |                                                   |    configuration
  73  * |-+-------------+---------------------------------------------------+
  74  * | | n_padding   | uint32_t                                          | <- how many additional bytes
  75  * | |             |                                                   |    for arrays (of pointers), ...
  76  * +-+-------------+---------------------------------------------------+
  77  * | struct dns_attribute_t                                            |
  78  * |-+-------------+---------------------------------------------------+
  79  * | | type        | uint32_t                                          | <- type of attribute (e.g. CONFIG_ATTRIBUTE_RESOLVER)
  80  * | +-------------+---------------------------------------------------+
  81  * | | length      | uint32_t                                          | <- length of the attribute
  82  * | +-------------+---------------------------------------------------+
  83  * | | attribute   | struct _dns_resolver_buf_t                        | <- the attribute data (resolver configuration #1)
  84  * | |             +-+-------------+-----------------------------------+
  85  * | |             | | resolver    | struct dns_resolver_t             |
  86  * | |             | |             +--------------+--------------------+
  87  * | |             | |             | domain       | char *             | <- not used during creation,
  88  * | |             | |             |              |                    |    filled in with pointer to
  89  * | |             | |             |              |                    |    domain name in the "padding"
  90  * | |             | |             +--------------+--------------------+
  91  * | |             | |             | n_nameserver | int32_t            | <- # of name server addresses
  92  * | |             | |             +--------------+--------------------+
  93  * | |             | |             | nameserver   | struct sockaddr ** | <- not used during creation,
  94  * | |             | |             |              |                    |    filled in with pointer to
  95  * | |             | |             |              |                    |    a list of addresses which
  96  * | |             | |             |              |                    |    will be established in the
  97  * | |             | |             |              |                    |    "padding"
  98  * | |             | |             +--------------+--------------------+
  99  * | |             | |             | ...                               |
 100  * | |             +-+-------------+--------------+--------------------+
 101  * | |             | | n_attribute | uint32_t                          |
 102  * | |             +-+-------------+-----------------------------------+
 103  * | |             | | attribute   | struct dns_attribute_t            |
 104  * | |             | |             +-+-----------+---------------------+
 105  * | |             | |             | | type      | uint32_t            | <- type of attribute (e.g. RESOLVER_ATTRIBUTE_DOMAIN)
 106  * | |             | |             | +-----------+---------------------+
 107  * | |             | |             | | length    | uint32_t            | <- length of the attribute
 108  * | |             | |             | +-----------+---------------------+
 109  * | |             | |             | | attribute |                     | <- the attribute data ("apple.com")
 110  * | |             +-+-------------+-------------+---------------------+
 111  * | |             | | attribute   | struct dns_attribute_t            |
 112  * | |             | |             +-+-----------+---------------------+
 113  * | |             | |             | | type      | uint32_t            | <- type of attribute (e.g. RESOLVER_ATTRIBUTE_ADDRESS)
 114  * | |             | |             | +-----------+---------------------+
 115  * | |             | |             | | length    | uint32_t            | <- length of the attribute
 116  * | |             | |             | +-----------+---------------------+
 117  * | |             | |             | | attribute |                     | <- the attribute data ("struct sockaddr_in" #1)
 118  * | |             +---------------+-----------------------------------+
 119  * | |             | | attribute   | struct dns_attribute_t            |
 120  * | |             | |             +-+-----------+---------------------+
 121  * | |             | |             | | type      | uint32_t            | <- type of attribute (e.g. RESOLVER_ATTRIBUTE_ADDRESS)
 122  * | |             | |             | +-----------+---------------------+
 123  * | |             | |             | | length    | uint32_t            | <- length of the attribute
 124  * | |             | |             | +-----------+---------------------+
 125  * | |             | |             | | attribute |                     | <- the attribute data ("struct sockaddr_in" #2)
 126  * | |             +---------------+-----------------------------------+
 127  * | |             | ...                                               |
 128  * +-+-------------+---------------------------------------------------+
 129  * | | attribute   | struct _dns_resolver_buf_t                        | <- the attribute data (resolver configuration #2)
 130  * | |             +---------------+-----------------------------------+
 131  * | |             | ...                                               |
 132  * +---------------+---------------------------------------------------+
 133  * | | ...                                                             |
 134  * +---------------+---------------------------------------------------+
 135  *
 136  * When the data is unpacked the "n_padding" additional bytes
 137  * specified in configuration buffer will be allocated at the
 138  * end of this buffer. Arrays of pointers will be allocated
 139  * within the extra space array element (an "attribute") is
 140  * encountered the pointer reference will be filled in.
 141  */
 142
 143
 144 // configuration buffer attributes
 145 enum {
 146         CONFIG_ATTRIBUTE_RESOLVER       = 1
 147 };
 148
 149
 150 // resolver buffer attributes
 151 enum {
 152         RESOLVER_ATTRIBUTE_DOMAIN       = 10,
 153         RESOLVER_ATTRIBUTE_ADDRESS,
 154         RESOLVER_ATTRIBUTE_SEARCH,
 155         RESOLVER_ATTRIBUTE_SORTADDR,
 156         RESOLVER_ATTRIBUTE_OPTIONS
 157 };
 158
 159
 160 #pragma pack(4)
 161 typedef struct {
 162         uint32_t        type;
 163         uint32_t        length;
 164         uint8_t         attribute[0];
 165 } dns_attribute_t;
 166 #pragma pack()
 167
 168
 169 #pragma pack(4)
 170 typedef struct {
 171         dns_config_t    config;
 172         uint32_t        n_attribute;
 173         uint32_t        n_padding;
 174         uint8_t         attribute[0];
 175 } _dns_config_buf_t;
 176 #pragma pack()
 177
 178
 179 #pragma pack(4)
 180 typedef struct {
 181         dns_resolver_t  resolver;
 182         uint32_t        n_attribute;
 183         uint8_t         attribute[0];
 184 } _dns_resolver_buf_t;
 185 #pragma pack()
 186
 187
 188 __BEGIN_DECLS
 189
 190 /*
 191  * NOTE: __private_extern__ and __OSX_AVAILABLE_STARTING() cannot be mixed
 192  *       due to a "visibility" conflict
 193  */
 194
 195 __private_extern__
 196 const char *
 197 _dns_configuration_notify_key   ()      /*__OSX_AVAILABLE_STARTING(__MAC_10_4,__IPHONE_2_0)*/;
 198
 199 __private_extern__
 200 mach_port_t
 201 _dns_configuration_server_port  ()      /*__OSX_AVAILABLE_STARTING(__MAC_10_4,__IPHONE_2_0)*/;
 202
 203 __END_DECLS
 204
 205 #endif  /* __DNSINFO_PRIVATE_H__ */