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