dns_util.h

   1 /*
   2  * Copyright (c) 2003-2006 Apple Computer, 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 __DNS_UTIL_H__
  25 #define __DNS_UTIL_H__
  26
  27 #include <sys/cdefs.h>
  28 #include <sys/types.h>
  29 #include <sys/socket.h>
  30 #include <sys/time.h>
  31 #include <netinet/in.h>
  32 #include <arpa/inet.h>
  33 #include <dns.h>
  34
  35 /*
  36  * Status returned in a dns_reply_t
  37  */
  38 #define DNS_STATUS_OK                                   0
  39 #define DNS_STATUS_BAD_HANDLE                   1
  40 #define DNS_STATUS_MALFORMED_QUERY              2
  41 #define DNS_STATUS_TIMEOUT                              3
  42 #define DNS_STATUS_SEND_FAILED                  4
  43 #define DNS_STATUS_RECEIVE_FAILED               5
  44 #define DNS_STATUS_CONNECTION_FAILED    6
  45 #define DNS_STATUS_WRONG_SERVER                 7
  46 #define DNS_STATUS_WRONG_XID                    8
  47 #define DNS_STATUS_WRONG_QUESTION               9
  48
  49 /*
  50  * dns_print_reply mask
  51  */
  52 #define DNS_PRINT_XID        0x0001
  53 #define DNS_PRINT_QR         0x0002
  54 #define DNS_PRINT_OPCODE     0x0004
  55 #define DNS_PRINT_AA         0x0008
  56 #define DNS_PRINT_TC         0x0010
  57 #define DNS_PRINT_RD         0x0020
  58 #define DNS_PRINT_RA         0x0040
  59 #define DNS_PRINT_PR         0x0080
  60 #define DNS_PRINT_RCODE      0x0100
  61 #define DNS_PRINT_QUESTION   0x0200
  62 #define DNS_PRINT_ANSWER     0x0400
  63 #define DNS_PRINT_AUTHORITY  0x0800
  64 #define DNS_PRINT_ADDITIONAL 0x1000
  65 #define DNS_PRINT_SERVER     0x2000
  66
  67 /*
  68  * DNS query / reply header
  69  */
  70 typedef struct {
  71         uint16_t xid;
  72         uint16_t flags;
  73         uint16_t qdcount;
  74         uint16_t ancount;
  75         uint16_t nscount;
  76         uint16_t arcount;
  77 } dns_header_t;
  78
  79 /*
  80  * DNS query
  81  */
  82 typedef struct
  83 {
  84         char *name;
  85         uint16_t dnstype;
  86         uint16_t dnsclass;
  87 } dns_question_t;
  88
  89 /*
  90  * Resource Record types
  91  * dns_parse_packet() creates resourse records of these types.
  92  */
  93 typedef struct
  94 {
  95         uint16_t length;
  96         char *data;
  97 } dns_raw_resource_record_t;
  98
  99 typedef struct
 100 {
 101         struct in_addr addr;
 102 } dns_address_record_t;
 103
 104 typedef struct
 105 {
 106         struct in6_addr addr;
 107 } dns_in6_address_record_t;
 108
 109 typedef struct
 110 {
 111         char *name;
 112 } dns_domain_name_record_t;
 113
 114 typedef struct
 115 {
 116         char *mname;
 117         char *rname;
 118         uint32_t serial;
 119         uint32_t refresh;
 120         uint32_t retry;
 121         uint32_t expire;
 122         uint32_t minimum;
 123 } dns_SOA_record_t;
 124
 125 typedef struct
 126 {
 127         char *cpu;
 128         char *os;
 129 } dns_HINFO_record_t;
 130
 131 typedef struct
 132 {
 133         char *rmailbx;
 134         char *emailbx;
 135 } dns_MINFO_record_t;
 136
 137 typedef struct
 138 {
 139         uint16_t preference;
 140         char *name;
 141 } dns_MX_record_t;
 142
 143 typedef struct
 144 {
 145         uint32_t string_count;
 146         char **strings;
 147 } dns_TXT_record_t;
 148
 149 typedef struct
 150 {
 151         struct in_addr addr;
 152         uint8_t protocol;
 153         uint32_t maplength;
 154         uint8_t *map;
 155 } dns_WKS_record_t;
 156
 157 typedef struct
 158 {
 159         char *mailbox;
 160         char *txtdname;
 161 } dns_RP_record_t;
 162
 163 typedef struct
 164 {
 165         uint32_t subtype;
 166         char *hostname;
 167 } dns_AFSDB_record_t;
 168
 169 typedef struct
 170 {
 171         char *psdn_address;
 172 } dns_X25_record_t;
 173
 174 typedef struct
 175 {
 176         char *isdn_address;
 177         char *subaddress;
 178 } dns_ISDN_record_t;
 179
 180 typedef struct
 181 {
 182         uint16_t preference;
 183         char * intermediate;
 184 } dns_RT_record_t;
 185
 186 typedef struct
 187 {
 188         uint8_t version;
 189         uint8_t size;
 190         uint8_t horizontal_precision;
 191         uint8_t vertical_precision;
 192         uint32_t latitude;
 193         uint32_t longitude;
 194         uint32_t altitude;
 195 } dns_LOC_record_t;
 196
 197 typedef struct
 198 {
 199         uint16_t priority;
 200         uint16_t weight;
 201         uint16_t port;
 202         char *target;
 203 } dns_SRV_record_t;
 204
 205 /*
 206  * DNS Resource Record
 207  *
 208  * Data contained in unsupported or obsolete Resource Record types
 209  * may be accessed via DNSNULL as a dns_raw_resource_record_t.
 210  */
 211 typedef struct
 212 {
 213         char *name;
 214         uint16_t dnstype;
 215         uint16_t dnsclass;
 216         uint32_t ttl;
 217         union
 218         {
 219                 dns_address_record_t *A;
 220                 dns_domain_name_record_t *NS;
 221                 dns_domain_name_record_t *MD;           /* Obsolete */
 222                 dns_domain_name_record_t *MF;           /* Obsolete */
 223                 dns_domain_name_record_t *CNAME;
 224                 dns_SOA_record_t *SOA;
 225                 dns_domain_name_record_t *MB;
 226                 dns_domain_name_record_t *MG;
 227                 dns_domain_name_record_t *MR;
 228                 dns_raw_resource_record_t *DNSNULL;
 229                 dns_WKS_record_t *WKS;
 230                 dns_domain_name_record_t *PTR;
 231                 dns_HINFO_record_t *HINFO;
 232                 dns_MINFO_record_t *MINFO;
 233                 dns_MX_record_t *MX;
 234                 dns_TXT_record_t *TXT;
 235                 dns_RP_record_t *RP;
 236                 dns_AFSDB_record_t *AFSDB;
 237                 dns_X25_record_t *X25;
 238                 dns_ISDN_record_t *ISDN;
 239                 dns_RT_record_t *RT;
 240                 dns_in6_address_record_t *AAAA;
 241                 dns_LOC_record_t *LOC;
 242                 dns_SRV_record_t *SRV;
 243         } data;
 244 } dns_resource_record_t;
 245
 246 /*
 247  * A parsed DNS record.  Returned by dns_parse_packet() and dns_lookup().
 248  * The contents may be printed using dns_print_reply().
 249  */
 250 typedef struct
 251 {
 252         uint32_t status;
 253         struct sockaddr *server;
 254         dns_header_t *header;
 255         dns_question_t **question;
 256         dns_resource_record_t **answer;
 257         dns_resource_record_t **authority;
 258         dns_resource_record_t **additional;
 259 } dns_reply_t;
 260
 261
 262 __BEGIN_DECLS
 263
 264 /*
 265  * High-level lookup performs a search (using dns_search), parses the
 266  * reply and returns a dns_reply_t structure.
 267  *
 268  * The DNS handle contains an internal buffer used for fetching replies.
 269  * The buffer is reused for each query, and is released with the DNS client
 270  * handle when dns_free() is called.  The default buffer size is 1024 bytes.
 271  * The size may be changed with dns_set_buffer_size.
 272  *
 273  * Note that in a multithreaded application, each thread using this API must
 274  * open a separate handle.
 275  */
 276 extern dns_reply_t *dns_lookup(dns_handle_t dns, const char *name, uint32_t dnsclass, uint32_t dnstype);
 277
 278 /*
 279  * Get / Set the size of the internal receive buffer used by dns_lookup()
 280  */
 281 extern uint32_t dns_get_buffer_size(dns_handle_t d);
 282 extern void dns_set_buffer_size(dns_handle_t d, uint32_t len);
 283
 284 /*
 285  * Parse a reply packet into a reply structure.
 286  */
 287 extern dns_reply_t *dns_parse_packet(const char *buf, uint32_t len);
 288
 289 /*
 290  * Free a reply structure.
 291  */
 292 extern void dns_free_reply(dns_reply_t *r);
 293
 294 /*
 295  * Parse a query packet into a question structure.
 296  */
 297 extern dns_question_t *dns_parse_question(const char *buf, uint32_t len);
 298
 299 /*
 300  * Free a question structure.
 301  */
 302 extern void dns_free_question(dns_question_t *q);
 303
 304 /*
 305  * Parse a resource record into a structure.
 306  */
 307 extern dns_resource_record_t *dns_parse_resource_record(const char *buf, uint32_t len);
 308
 309 /*
 310  * Free a resource record structure.
 311  */
 312 extern void dns_free_resource_record(dns_resource_record_t *rr);
 313
 314 /*
 315  * String / number representation of a DNS class
 316  * dns_class_number returns 0 if the string is recognized,
 317  * non-zero if the class string is unknown.
 318  */
 319 extern const char *dns_class_string(uint16_t dnsclass);
 320 extern int32_t dns_class_number(const char *c, uint16_t *n);
 321
 322 /*
 323  * String / number representation of a DNS type
 324  * dns_type_number returns 0 if the string is recognized,
 325  * non-zero if the class string is unknown.
 326  */
 327 extern const char *dns_type_string(uint16_t dnstype);
 328 extern int32_t dns_type_number(const char *t, uint16_t *n);
 329
 330 /*
 331  * Print a dns handle.
 332  */
 333 extern void dns_print_handle(dns_handle_t d, FILE *f);
 334
 335 /*
 336  * Print the contents of a question structure.
 337  */
 338 extern void dns_print_question(const dns_question_t *q, FILE *f);
 339
 340 /*
 341  * Print the contents of a resource record structure.
 342  */
 343 extern void dns_print_resource_record(const dns_resource_record_t *r, FILE *f);
 344
 345 /*
 346  * Print the contents of a reply structure.
 347  */
 348 extern void dns_print_reply(const dns_reply_t *r, FILE *f, uint16_t mask);
 349
 350 __END_DECLS
 351
 352 #endif /* __DNS_UTIL_H__ */