| 1 | /* |
| 2 | * Copyright (C)1998 Ian Jackson. |
| 3 | * This version provided for review and comment only. |
| 4 | * |
| 5 | * $Id: adns.h,v 1.38 1998/12/05 18:51:37 ian Exp $ |
| 6 | */ |
| 7 | /* |
| 8 | * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson |
| 9 | * |
| 10 | * This program is free software; you can redistribute it and/or modify |
| 11 | * it under the terms of the GNU General Public License as published by |
| 12 | * the Free Software Foundation; either version 2, or (at your option) |
| 13 | * any later version. |
| 14 | * |
| 15 | * This program is distributed in the hope that it will be useful, |
| 16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 18 | * GNU General Public License for more details. |
| 19 | * |
| 20 | * You should have received a copy of the GNU General Public License |
| 21 | * along with this program; if not, write to the Free Software Foundation, |
| 22 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 23 | */ |
| 24 | |
| 25 | #ifndef ADNS_H_INCLUDED |
| 26 | #define ADNS_H_INCLUDED |
| 27 | |
| 28 | #include <stdio.h> |
| 29 | |
| 30 | #include <sys/socket.h> |
| 31 | #include <netinet/in.h> |
| 32 | |
| 33 | /* All struct in_addr anywhere in adns are in NETWORK byte order. */ |
| 34 | |
| 35 | typedef struct adns__state *adns_state; |
| 36 | typedef struct adns__query *adns_query; |
| 37 | |
| 38 | typedef enum { |
| 39 | adns_if_noenv= 0x0001, /* do not look at environment */ |
| 40 | adns_if_noerrprint= 0x0002, /* never print output to stderr (_debug overrides) */ |
| 41 | adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */ |
| 42 | adns_if_debug= 0x0008, /* enable all output to stderr plus debug msgs */ |
| 43 | adns_if_noautosys= 0x0010, /* do not make syscalls at every opportunity */ |
| 44 | adns_if_eintr= 0x0020, /* allow _wait and _synchronous to return EINTR */ |
| 45 | } adns_initflags; |
| 46 | |
| 47 | typedef enum { |
| 48 | adns_qf_search= 0x000001, /* use the searchlist */ |
| 49 | adns_qf_usevc= 0x000002, /* use a virtual circuit (TCP connection) */ |
| 50 | adns_qf_quoteok_query= 0x000010, /* allow quote-requiring chars in query domain */ |
| 51 | adns_qf_quoteok_cname= 0x000020, /* allow ... in CNAME we go via */ |
| 52 | adns_qf_quoteok_anshost= 0x000040, /* allow ... in answers expected to be hostnames */ |
| 53 | adns_qf_cname_loose= 0x000100, /* allow refs to CNAMEs - without, get _s_cname */ |
| 54 | adns_qf_cname_forbid= 0x000200, /* don't follow CNAMEs, instead give _s_cname */ |
| 55 | adns__qf_internalmask= 0x0ff000 |
| 56 | } adns_queryflags; |
| 57 | |
| 58 | typedef enum { |
| 59 | adns__rrt_typemask= 0x0ffff, |
| 60 | adns__qtf_deref= 0x10000, /* dereference domains and perhaps produce extra data */ |
| 61 | adns__qtf_mail822= 0x20000, /* make mailboxes be in RFC822 rcpt field format */ |
| 62 | |
| 63 | adns_r_none= 0, |
| 64 | |
| 65 | adns_r_a= 1, |
| 66 | |
| 67 | adns_r_ns_raw= 2, |
| 68 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, |
| 69 | |
| 70 | adns_r_cname= 5, |
| 71 | |
| 72 | adns_r_soa_raw= 6, |
| 73 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, |
| 74 | |
| 75 | adns_r_ptr_raw= 12, |
| 76 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
| 77 | |
| 78 | adns_r_hinfo= 13, |
| 79 | |
| 80 | adns_r_mx_raw= 15, |
| 81 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, |
| 82 | |
| 83 | adns_r_txt= 16, |
| 84 | |
| 85 | adns_r_rp_raw= 17, |
| 86 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, |
| 87 | |
| 88 | adns_r_addr= adns_r_a|adns__qtf_deref |
| 89 | |
| 90 | } adns_rrtype; |
| 91 | |
| 92 | /* In queries without qtf_anyquote, all domains must have standard |
| 93 | * legal syntax. In queries _with_ qtf_anyquote, domains in the query |
| 94 | * or response may contain any characters, quoted according to |
| 95 | * RFC1035 5.1. On input to adns, the char* is a pointer to the |
| 96 | * interior of a " delimited string, except that " may appear in it, |
| 97 | * and on output, the char* is a pointer to a string which would be |
| 98 | * legal either inside or outside " delimiters, and any characters |
| 99 | * not usually legal in domain names will be quoted as \X |
| 100 | * (if the character is 33-126 except \ and ") or \DDD. |
| 101 | * |
| 102 | * Do not ask for _raw records containing mailboxes without |
| 103 | * specifying _qf_anyquote. |
| 104 | */ |
| 105 | |
| 106 | typedef enum { |
| 107 | adns_s_ok, |
| 108 | |
| 109 | /* locally induced errors */ |
| 110 | adns_s_nomemory, |
| 111 | adns_s_unknownrrtype, |
| 112 | |
| 113 | /* remotely induced errors, detected locally */ |
| 114 | adns_s_timeout, |
| 115 | adns_s_allservfail, |
| 116 | adns_s_norecurse, |
| 117 | adns_s_invalidresponse, |
| 118 | adns_s_unknownformat, |
| 119 | |
| 120 | /* remotely induced errors, reported by remote server to us */ |
| 121 | adns_s_rcodeservfail, |
| 122 | adns_s_rcodeformaterror, |
| 123 | adns_s_rcodenotimplemented, |
| 124 | adns_s_rcoderefused, |
| 125 | adns_s_rcodeunknown, |
| 126 | |
| 127 | adns_s_max_tempfail= 99, |
| 128 | |
| 129 | /* remote configuration errors */ |
| 130 | adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ |
| 131 | adns_s_prohibitedcname, /* CNAME found where eg A expected (not if _qf_loosecname) */ |
| 132 | adns_s_answerdomaininvalid, |
| 133 | adns_s_answerdomaintoolong, |
| 134 | adns_s_invaliddata, |
| 135 | |
| 136 | adns_s_max_misconfig= 199, |
| 137 | |
| 138 | /* permanent problems with the query */ |
| 139 | adns_s_querydomainwrong, |
| 140 | adns_s_querydomaininvalid, |
| 141 | adns_s_querydomaintoolong, |
| 142 | |
| 143 | adns_s_max_misquery= 299, |
| 144 | |
| 145 | /* permanent errors */ |
| 146 | adns_s_nxdomain, |
| 147 | adns_s_nodata, |
| 148 | |
| 149 | } adns_status; |
| 150 | |
| 151 | typedef struct { |
| 152 | int len; |
| 153 | union { |
| 154 | struct sockaddr sa; |
| 155 | struct sockaddr_in inet; |
| 156 | } addr; |
| 157 | } adns_rr_addr; |
| 158 | |
| 159 | typedef struct { |
| 160 | char *host; |
| 161 | adns_status astatus; |
| 162 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ |
| 163 | adns_rr_addr *addrs; |
| 164 | } adns_rr_hostaddr; |
| 165 | |
| 166 | typedef struct { |
| 167 | char *(array[2]); |
| 168 | } adns_rr_strpair; |
| 169 | |
| 170 | typedef struct { |
| 171 | int i; |
| 172 | adns_rr_hostaddr ha; |
| 173 | } adns_rr_inthostaddr; |
| 174 | |
| 175 | typedef struct { |
| 176 | /* Used both for mx_raw, in which case i is the preference and str the domain, |
| 177 | * and for txt, in which case each entry has i for the `text' length, |
| 178 | * and str for the data (which will have had an extra nul appended |
| 179 | * so that if it was plain text it is now a null-terminated string). |
| 180 | */ |
| 181 | int i; |
| 182 | char *str; |
| 183 | } adns_rr_intstr; |
| 184 | |
| 185 | typedef struct { |
| 186 | adns_rr_intstr array[2]; |
| 187 | } adns_rr_intstrpair; |
| 188 | |
| 189 | typedef struct { |
| 190 | char *mname, *rname; |
| 191 | unsigned long serial, refresh, retry, expire, minimum; |
| 192 | } adns_rr_soa; |
| 193 | |
| 194 | typedef struct { |
| 195 | adns_status status; |
| 196 | char *cname; /* always NULL if query was for CNAME records */ |
| 197 | adns_rrtype type; /* guaranteed to be same as in query */ |
| 198 | int nrrs, rrsz; |
| 199 | union { |
| 200 | void *untyped; |
| 201 | unsigned char *bytes; |
| 202 | char *(*str); /* ns_raw, cname, ptr, ptr_raw */ |
| 203 | adns_rr_intstr *(*manyistr); /* txt (list of strings ends with i=-1, str=0) */ |
| 204 | adns_rr_addr *addr; /* addr */ |
| 205 | struct in_addr *inaddr; /* a */ |
| 206 | adns_rr_hostaddr *hostaddr; /* ns */ |
| 207 | adns_rr_intstrpair *intstrpair; /* hinfo */ |
| 208 | adns_rr_strpair *strpair; /* rp, rp_raw */ |
| 209 | adns_rr_inthostaddr *inthostaddr; /* mx */ |
| 210 | adns_rr_intstr *intstr; /* mx_raw */ |
| 211 | adns_rr_soa *soa; /* soa, soa_raw */ |
| 212 | } rrs; |
| 213 | } adns_answer; |
| 214 | |
| 215 | /* Memory management: |
| 216 | * adns_state and adns_query are actually pointers to malloc'd state; |
| 217 | * On submission questions are copied, including the owner domain; |
| 218 | * Answers are malloc'd as a single piece of memory; pointers in the |
| 219 | * answer struct point into further memory in the answer. |
| 220 | * query_io: |
| 221 | * Must always be non-null pointer; |
| 222 | * If *query_io is 0 to start with then any query may be returned; |
| 223 | * If *query_io is !0 adns_query then only that query may be returned. |
| 224 | * If the call is successful, *query_io, *answer_r, and *context_r |
| 225 | * will all be set. |
| 226 | * Errors: |
| 227 | * Return values are 0 or an errno value; |
| 228 | * Seriously fatal system errors (eg, failure to create sockets, |
| 229 | * malloc failure, etc.) return errno values; |
| 230 | * Other errors (nameserver failure, timed out connections, &c) |
| 231 | * are returned in the status field of the answer. If status is |
| 232 | * nonzero then nrrs will be 0, otherwise it will be >0. |
| 233 | * type will always be the type requested; |
| 234 | * If no (appropriate) requests are done adns_check returns EWOULDBLOCK; |
| 235 | * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH; |
| 236 | */ |
| 237 | |
| 238 | int adns_init(adns_state *newstate_r, adns_initflags flags, |
| 239 | FILE *diagfile /*0=>stderr*/); |
| 240 | |
| 241 | int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, |
| 242 | FILE *diagfile /*0=>discard*/, const char *configtext); |
| 243 | |
| 244 | int adns_synchronous(adns_state ads, |
| 245 | const char *owner, |
| 246 | adns_rrtype type, |
| 247 | adns_queryflags flags, |
| 248 | adns_answer **answer_r); |
| 249 | |
| 250 | /* NB: if you set adns_if_noautosys then _submit and _check do not |
| 251 | * make any system calls; you must use adns_callback (possibly after |
| 252 | * adns_interest) to actually get things to happen. |
| 253 | */ |
| 254 | |
| 255 | int adns_submit(adns_state ads, |
| 256 | const char *owner, |
| 257 | adns_rrtype type, |
| 258 | adns_queryflags flags, |
| 259 | void *context, |
| 260 | adns_query *query_r); |
| 261 | |
| 262 | int adns_check(adns_state ads, |
| 263 | adns_query *query_io, |
| 264 | adns_answer **answer_r, |
| 265 | void **context_r); |
| 266 | |
| 267 | int adns_wait(adns_state ads, |
| 268 | adns_query *query_io, |
| 269 | adns_answer **answer_r, |
| 270 | void **context_r); |
| 271 | |
| 272 | void adns_cancel(adns_query query); |
| 273 | |
| 274 | void adns_finish(adns_state); |
| 275 | /* You may call this even if you have queries outstanding; |
| 276 | * they will be cancelled. |
| 277 | */ |
| 278 | |
| 279 | int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds, |
| 280 | const fd_set *exceptfds); |
| 281 | /* Gives adns flow-of-control for a bit. This will never block. |
| 282 | * If maxfd == -1 then adns will check (make nonblocking system calls on) |
| 283 | * all of its own filedescriptors; otherwise it will only use those |
| 284 | * < maxfd and specified in the fd_set's, as if select had returned them. |
| 285 | * Other fd's may be in the fd_sets, and will be ignored. |
| 286 | * _callback returns how many adns fd's were in the various sets, so |
| 287 | * you can tell if your select handling code has missed something and is going awol. |
| 288 | * |
| 289 | * May also return -1 if a critical syscall failed, setting errno. |
| 290 | */ |
| 291 | |
| 292 | void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io, |
| 293 | fd_set *writefds_io, fd_set *exceptfds_io, |
| 294 | struct timeval **tv_mod, struct timeval *tv_buf); |
| 295 | /* Find out file descriptors adns is interested in, and when it |
| 296 | * would like the opportunity to time something out. If you do not plan to |
| 297 | * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning |
| 298 | * you have no timeout of your own, in which case tv_buf must be non-null and |
| 299 | * _interest may fill it in and set *tv_mod=tv_buf. |
| 300 | * readfds, writefds, exceptfds and maxfd may not be 0. |
| 301 | */ |
| 302 | |
| 303 | /* Example expected/legal calling sequences: |
| 304 | * adns_init |
| 305 | * adns_submit 1 |
| 306 | * adns_submit 2 |
| 307 | * adns_submit 3 |
| 308 | * adns_wait 1 |
| 309 | * adns_check 3 -> EWOULDBLOCK |
| 310 | * adns_wait 2 |
| 311 | * adns_wait 3 |
| 312 | * .... |
| 313 | * adns_finish |
| 314 | * |
| 315 | * adns_init _noautosys |
| 316 | * loop { |
| 317 | * adns_interest |
| 318 | * select |
| 319 | * adns_callback |
| 320 | * ... |
| 321 | * adns_submit / adns_check |
| 322 | * ... |
| 323 | * } |
| 324 | */ |
| 325 | |
| 326 | adns_status adns_rr_info(adns_rrtype type, |
| 327 | const char **rrtname_r, const char **fmtname_r, |
| 328 | int *len_r, |
| 329 | const void *datap, char **data_r); |
| 330 | /* Gets information in human-readable (but non-i18n) form |
| 331 | * for eg debugging purposes. type must be specified, |
| 332 | * and the official name of the corresponding RR type will |
| 333 | * be returned in *rrtname_r, and information about the processing |
| 334 | * style in *fmtname_r. The length of the table entry in an answer |
| 335 | * for that type will be returned in in *len_r. |
| 336 | * Any or all of rrtname_r, fmtname_r and len_r may be 0. |
| 337 | * If fmtname_r is non-null then *fmtname_r may be |
| 338 | * null on return, indicating that no special processing is |
| 339 | * involved. |
| 340 | * |
| 341 | * data_r be must be non-null iff datap is. In this case |
| 342 | * *data_r will be set to point to a human-readable text |
| 343 | * string representing the RR data. The text will have |
| 344 | * been obtained from malloc() and must be freed by the caller. |
| 345 | * |
| 346 | * Usually this routine will succeed. Possible errors include: |
| 347 | * adns_s_nomemory |
| 348 | * adns_s_rrtypeunknown |
| 349 | * adns_s_invaliddata (*datap contained garbage) |
| 350 | * If an error occurs then no memory has been allocated, |
| 351 | * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. |
| 352 | */ |
| 353 | |
| 354 | const char *adns_strerror(adns_status st); |
| 355 | |
| 356 | #endif |