mdw@git.distorted.org.uk Git - adns/blob - src/adns.h

   1 /**/
   2
   3 #ifndef ADNS_H_INCLUDED
   4 #define ADNS_H_INCLUDED
   5
   6 #include <sys/socket.h>
   7 #include <netinet/in.h>
   8
   9 typedef struct adns__state *adns_state;
  10 typedef struct adns__query *adns_query;
  11
  12 typedef enum {
  13   adns_if_noenv=        0x0001, /* do not look at environment */
  14   adns_if_noerrprint=   0x0002, /* never print output to stderr (_debug overrides) */
  15   adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */
  16   adns_if_debug=        0x0008, /* enable all output to stderr plus debug msgs */
  17   adns_if_noautosys=    0x0010, /* do not make syscalls at every opportunity */
  18 } adns_initflags;
  19
  20 typedef enum {
  21   adns_qf_search=     0x0001, /* use the searchlist */
  22   adns_qf_usevc=      0x0002, /* use a virtual circuit (TCP connection) */
  23   adns_qf_anyquote=   0x0004,
  24   adns_qf_loosecname= 0x0008, /* allow refs to CNAMEs - without, get _s_cname */
  25   adns_qf_nocname=    0x0010, /* don't follow CNAMEs, instead give _s_cname */
  26 } adns_queryflags;
  27
  28 typedef enum {
  29   adns__rrt_typemask=  0x0ffff,
  30   adns__qtf_deref=     0x10000, /* dereference domains and perhaps produce extra data */
  31   adns__qtf_mail822=   0x20000, /* make mailboxes be in RFC822 rcpt field format */
  32   adns__qtf_masterfmt= 0x80000, /* convert RRs to master file format, return as str */
  33
  34   adns_r_none=               0,
  35
  36   adns_r_a=                  1,
  37   adns_r_a_mf=                  adns_r_a|adns__qtf_mf,
  38
  39   adns_r_ns_raw=             2,
  40   adns_r_ns=                    adns_r_ns_raw|adns__qtf_deref,
  41   adns_r_ns_mf=                 adns_r_ns_raw|adns__qtf_mf,
  42
  43   adns_r_cname=              5,
  44   adns_r_cname_mf=              adns_r_cname|adns__qtf_mf,
  45
  46   adns_r_soa_raw=            6,
  47   adns_r_soa=                   adns_r_soa_raw|adns__qtf_mail822,
  48   adns_r_soa_mf=                adns_r_soa_raw|adns__qtf_mf,
  49
  50   adns_r_null=              10,
  51   adns_r_null_mf=               adns_r_null|adns__qtf_mf,
  52
  53   adns_r_ptr_raw=           12,
  54   adns_r_ptr=                   adns_r_ptr_raw|adns__qtf_deref,
  55   adns_r_ptr_mf=                adns_r_ptr_raw|adns__qtf_mf,
  56
  57   adns_r_hinfo=             13,
  58   adns_r_hinfo_mf=              adns_r_hinfo|adns__qtf_mf,
  59
  60   adns_r_mx_raw=            15,
  61   adns_r_mx=                    adns_r_mx_raw|adns__qtf_deref,
  62   adns_r_mx_mf=                 adns_r_mx_raw|adns__qtf_mf,
  63
  64   adns_r_txt=               16,
  65   adns_r_txt_mf=                adns_r_txt|adns__qtf_mf,
  66
  67   adns_r_rp_raw=            17,
  68   adns_r_rp=                    adns_r_rp_raw|adns__qtf_mail822
  69   adns_r_rp_mf=                 adns_r_rp_raw|adns__qtf_mf,
  70
  71 } adns_rrtype;
  72
  73 /* In queries without qtf_anyquote, all domains must have standard
  74  * legal syntax.  In queries _with_ qtf_anyquote, domains in the query
  75  * or response may contain any characters, quoted according to
  76  * RFC1035 5.1.  On input to adns, the char* is a pointer to the
  77  * interior of a " delimited string, except that " may appear in it,
  78  * and on output, the char* is a pointer to a string which would be
  79  * legal either inside or outside " delimiters, and any characters
  80  * not usually legal in domain names will be quoted as \X
  81  * (if the character is 33-126 except \ and ") or \DDD.
  82  *
  83  * _qtf_anyquote is ignored for _mf queries.
  84  *
  85  * Do not ask for _raw records containing mailboxes without
  86  * specifying _qf_anyquote.
  87  */
  88
  89 typedef enum {
  90   adns_s_ok,
  91   adns_s_timeout,
  92   adns_s_unknownqtype,
  93   adns_s_nolocalmem,
  94   adns_s_allservfail,
  95   adns_s_max_tempfail= 99,
  96   adns_s_inconsistent, /* PTR gives domain whose A does not match */
  97   adns_s_cname, /* CNAME found where data eg A expected (not if _qf_loosecname) */
  98   adns_s_max_misconfig= 199;
  99   adns_s_nxdomain,
 100   adns_s_norecord,
 101   adns_s_invaliddomain
 102 } adns_status;
 103
 104 typedef struct {
 105   char *dm;
 106   adns_status astatus;
 107   int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */
 108   struct in_addr *addrs;
 109 } adns_dmaddr;
 110
 111 typedef struct {
 112   adns_status status;
 113   char *cname; /* always NULL if query was for CNAME records */
 114   adns_rrtype type;
 115   int nrrs;
 116   union {
 117     struct in_addr inaddr[1];                                                    /* a */
 118     char (*str)[1];                     /* ns_raw, cname, ptr, ptr_raw, txt, <any>_mf */
 119     adns_dmaddr dmaddr[1];                                                      /* ns */
 120     struct { char *a, *b; } strpair[1];                          /* hinfo, rp, rp_raw */
 121     struct { int pref; adns_dmaddrs dmaddr; } intdmaddr[1];                     /* mx */
 122     struct { int pref; char *str; } intstr[1];                              /* mx_raw */
 123     struct {
 124       char *ns0, *rp;
 125       unsigned long serial, refresh, retry, expire, minimum;
 126     } soa[1];                                                         /* soa, soa_raw */
 127     /* NULL is empty */
 128   } rrs;
 129 } adns_answer;
 130
 131 /* Memory management:
 132  *  adns_state and adns_query are actually pointers to malloc'd state;
 133  *  On submission questions are copied, including the owner domain;
 134  *  Answers are malloc'd as a single piece of memory.
 135  * query_io:
 136  *  Must always be non-null pointer;
 137  *  If *query_io is 0 to start with then any query may be returned;
 138  *  If *query_io is !0 adns_query then only that query may be returned.
 139  * Errors:
 140  *  Return values are 0 or an errno value;
 141  *  Seriously fatal system errors (eg, failure to create sockets,
 142  *  malloc failure, etc.) return errno values;
 143  *  Other errors (nameserver failure, timed out connections, &c)
 144  *  are returned in the status field of the answer.  If status is
 145  *  nonzero then nrrs will be 0, otherwise it will be >0.
 146  *  type will always be the type requested;
 147  *  If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
 148  *  If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
 149  *  If malloc failure occurs during internal allocation or processing
 150  *  ands_check and _wait set *answer to 0.
 151  */
 152
 153 int adns_init(adns_state *newstate_r, adns_initflags flags, FILE *diagfile/*0=>stderr*/);
 154
 155 int adns_synchronous(adns_state ads,
 156                      const char *owner,
 157                      adns_rrtype type,
 158                      adns_queryflags flags,
 159                      adns_answer **answer_r);
 160 /* Will not return EINTR. */
 161
 162 /* NB: if you set adns_if_noautosys then _submit and _check do not
 163  * make any system calls; you must use adns_callback (possibly after
 164  * adns_interest) to actually get things to happen.
 165  */
 166
 167 int adns_submit(adns_state ads,
 168                 const char *owner,
 169                 adns_rrtype type,
 170                 adns_queryflags flags,
 171                 void *context,
 172                 adns_query *query_r);
 173
 174 int adns_check(adns_state ads,
 175                adns_query *query_io,
 176                adns_answer **answer_r,
 177                void **context_r);
 178
 179 int adns_wait(adns_state ads,
 180               adns_query *query_io,
 181               adns_answer **answer_r,
 182               void **context_r);
 183 /* Might return EINTR - if so, try again */
 184
 185 void adns_cancel(adns_state ads, adns_query query);
 186
 187 int adns_finish(adns_state);
 188
 189 int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
 190                   const fd_set *exceptfds);
 191 /* Gives adns flow-of-control for a bit.  This will never block.
 192  * If maxfd == -1 then adns will check (make nonblocking system calls on)
 193  * all of its own filedescriptors; otherwise it will only use those
 194  * < maxfd and specified in the fd_set's, as if select had returned them.
 195  * Other fd's may be in the fd_sets, and will be ignored.
 196  * _callback returns how many adns fd's were in the various sets, so
 197  * you can tell if your select handling code has missed something and is going awol.
 198  */
 199
 200 void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
 201                    fd_set *writefds_io, fd_set *exceptfds_io,
 202                    struct timeval **tv_mod, struct timeval *tv_buf);
 203 /* Find out file descriptors adns is interested in, and when it
 204  * would like the opportunity to time something out.  If you do not plan to
 205  * block then tv_mod may be 0.  Otherwise, tv_mod may point to 0 meaning
 206  * you have no timeout of your own, in which case tv_buf must be non-null and
 207  * _interest may fill it in and set *tv_mod=tv_buf.
 208  * readfds, writefds, exceptfds and maxfd may not be 0.
 209  */
 210
 211 /* Example expected/legal calling sequences:
 212  *  adns_init
 213  *  adns_submit 1
 214  *  adns_submit 2
 215  *  adns_submit 3
 216  *  adns_wait 1
 217  *  adns_check 3 -> EWOULDBLOCK
 218  *  adns_wait 2
 219  *  adns_wait 3
 220  *  ....
 221  *  adns_finish
 222  *
 223  *  adns_init _noautosys
 224  *  loop {
 225  *   adns_interest
 226  *   select
 227  *   adns_callback
 228  *   ...
 229  *   adns_submit / adns_check
 230  *   ...
 231  *  }
 232  */
 233
 234 #endif