external/ibm-public/postfix/dist/src/dns/dns.h

   1 /*      $NetBSD$        */
   2
   3 #ifndef _DNS_H_INCLUDED_
   4 #define _DNS_H_INCLUDED_
   5
   6 /*++
   7 /* NAME
   8 /*      dns 3h
   9 /* SUMMARY
  10 /*      domain name service lookup
  11 /* SYNOPSIS
  12 /*      #include <dns.h>
  13 /* DESCRIPTION
  14 /* .nf
  15
  16  /*
  17   * System library.
  18   */
  19 #include <netinet/in.h>
  20 #include <arpa/nameser.h>
  21 #ifdef RESOLVE_H_NEEDS_STDIO_H
  22 #include <stdio.h>
  23 #endif
  24 #ifdef RESOLVE_H_NEEDS_NAMESER8_COMPAT_H
  25 #include <nameser8_compat.h>
  26 #endif
  27 #include <resolv.h>
  28
  29  /*
  30   * Name server compatibility. These undocumented macros appear in the file
  31   * <arpa/nameser.h>, but since they are undocumented we should not count on
  32   * their presence, and so they are included here just in case.
  33   */
  34 #ifndef GETSHORT
  35
  36 #define GETSHORT(s, cp) { \
  37         unsigned char *t_cp = (u_char *)(cp); \
  38         (s) = ((unsigned)t_cp[0] << 8) \
  39             | ((unsigned)t_cp[1]) \
  40             ; \
  41         (cp) += 2; \
  42 }
  43
  44 #define GETLONG(l, cp) { \
  45         unsigned char *t_cp = (u_char *)(cp); \
  46         (l) = ((unsigned)t_cp[0] << 24) \
  47             | ((unsigned)t_cp[1] << 16) \
  48             | ((unsigned)t_cp[2] << 8) \
  49             | ((unsigned)t_cp[3]) \
  50             ; \
  51         (cp) += 4; \
  52 }
  53
  54 #endif
  55
  56  /*
  57   * SunOS 4 needs this.
  58   */
  59 #ifndef T_TXT
  60 #define T_TXT   16
  61 #endif
  62
  63  /*
  64   * Utility library.
  65   */
  66 #include <vstring.h>
  67 #include <sock_addr.h>
  68 #include <myaddrinfo.h>
  69
  70  /*
  71   * Structure for fixed resource record data.
  72   */
  73 typedef struct DNS_FIXED {
  74     unsigned short type;                /* T_A, T_CNAME, etc. */
  75     unsigned short class;               /* C_IN, etc. */
  76     unsigned int ttl;                   /* always */
  77     unsigned length;                    /* record length */
  78 } DNS_FIXED;
  79
  80  /*
  81   * Structure of a DNS resource record after expansion. The components are
  82   * named after the things one can expect to find in a DNS resource record.
  83   */
  84 typedef struct DNS_RR {
  85     char   *qname;                      /* query name, mystrdup()ed */
  86     char   *rname;                      /* reply name, mystrdup()ed */
  87     unsigned short type;                /* T_A, T_CNAME, etc. */
  88     unsigned short class;               /* C_IN, etc. */
  89     unsigned int ttl;                   /* always */
  90     unsigned short pref;                /* T_MX only */
  91     struct DNS_RR *next;                /* linkage */
  92     size_t  data_len;                   /* actual data size */
  93     char    data[1];                    /* actually a bunch of data */
  94 } DNS_RR;
  95
  96  /*
  97   * dns_strerror.c
  98   */
  99 extern const char *dns_strerror(unsigned);
 100
 101  /*
 102   * dns_strtype.c
 103   */
 104 extern const char *dns_strtype(unsigned);
 105 extern unsigned dns_type(const char *);
 106
 107  /*
 108   * dns_rr.c
 109   */
 110 extern DNS_RR *dns_rr_create(const char *, const char *,
 111                                      ushort, ushort,
 112                                      unsigned, unsigned,
 113                                      const char *, size_t);
 114 extern void dns_rr_free(DNS_RR *);
 115 extern DNS_RR *dns_rr_copy(DNS_RR *);
 116 extern DNS_RR *dns_rr_append(DNS_RR *, DNS_RR *);
 117 extern DNS_RR *dns_rr_sort(DNS_RR *, int (*) (DNS_RR *, DNS_RR *));
 118 extern int dns_rr_compare_pref(DNS_RR *, DNS_RR *);
 119 extern DNS_RR *dns_rr_shuffle(DNS_RR *);
 120 extern DNS_RR *dns_rr_remove(DNS_RR *, DNS_RR *);
 121
 122  /*
 123   * dns_rr_to_pa.c
 124   */
 125 extern const char *dns_rr_to_pa(DNS_RR *, MAI_HOSTADDR_STR *);
 126
 127  /*
 128   * dns_sa_to_rr.c
 129   */
 130 extern DNS_RR *dns_sa_to_rr(const char *, unsigned, struct sockaddr *);
 131
 132  /*
 133   * dns_rr_to_sa.c
 134   */
 135 extern int dns_rr_to_sa(DNS_RR *, unsigned, struct sockaddr *, SOCKADDR_SIZE *);
 136
 137  /*
 138   * dns_rr_eq_sa.c
 139   */
 140 extern int dns_rr_eq_sa(DNS_RR *, struct sockaddr *);
 141
 142 #ifdef HAS_IPV6
 143 #define DNS_RR_EQ_SA(rr, sa) \
 144     ((SOCK_ADDR_IN_FAMILY(sa) == AF_INET && (rr)->type == T_A \
 145      && SOCK_ADDR_IN_ADDR(sa).s_addr == IN_ADDR((rr)->data).s_addr) \
 146     || (SOCK_ADDR_IN_FAMILY(sa) == AF_INET6 && (rr)->type == T_AAAA \
 147         && memcmp((char *) &(SOCK_ADDR_IN6_ADDR(sa)), \
 148                   (rr)->data, (rr)->data_len) == 0))
 149 #else
 150 #define DNS_RR_EQ_SA(rr, sa) \
 151     (SOCK_ADDR_IN_FAMILY(sa) == AF_INET && (rr)->type == T_A \
 152      && SOCK_ADDR_IN_ADDR(sa).s_addr == IN_ADDR((rr)->data).s_addr)
 153 #endif
 154
 155  /*
 156   * dns_lookup.c
 157   */
 158 extern int dns_lookup(const char *, unsigned, unsigned, DNS_RR **,
 159                               VSTRING *, VSTRING *);
 160 extern int dns_lookup_l(const char *, unsigned, DNS_RR **, VSTRING *,
 161                                 VSTRING *, int,...);
 162 extern int dns_lookup_v(const char *, unsigned, DNS_RR **, VSTRING *,
 163                                 VSTRING *, int, unsigned *);
 164
 165  /*
 166   * Request flags.
 167   */
 168 #define DNS_REQ_FLAG_STOP_OK    (1<<0)
 169 #define DNS_REQ_FLAG_STOP_INVAL (1<<1)
 170 #define DNS_REQ_FLAG_NONE       (0)
 171
 172  /*
 173   * Status codes. Failures must have negative codes so they will not collide
 174   * with valid counts of answer records etc.
 175   */
 176 #define DNS_INVAL       (-5)            /* query ok, malformed reply */
 177 #define DNS_FAIL        (-4)            /* query failed, don't retry */
 178 #define DNS_NOTFOUND    (-3)            /* query ok, data not found */
 179 #define DNS_RETRY       (-2)            /* query failed, try again */
 180 #define DNS_RECURSE     (-1)            /* recursion needed */
 181 #define DNS_OK          0               /* query succeeded */
 182
 183  /*
 184   * How long can a DNS name or single text value be?
 185   */
 186 #define DNS_NAME_LEN    1024
 187
 188 /* LICENSE
 189 /* .ad
 190 /* .fi
 191 /*      The Secure Mailer license must be distributed with this software.
 192 /* AUTHOR(S)
 193 /*      Wietse Venema
 194 /*      IBM T.J. Watson Research
 195 /*      P.O. Box 704
 196 /*      Yorktown Heights, NY 10598, USA
 197 /*--*/
 198
 199 #endif