| 1 | /* |
| 2 | * Copyright (C)1998 Ian Jackson. |
| 3 | * This version provided for review and comment only. |
| 4 | * |
| 5 | * $Id$ |
| 6 | */ |
| 7 | |
| 8 | #ifndef ADNS_H_INCLUDED |
| 9 | #define ADNS_H_INCLUDED |
| 10 | |
| 11 | #include <stdio.h> |
| 12 | |
| 13 | #include <sys/socket.h> |
| 14 | #include <netinet/in.h> |
| 15 | |
| 16 | typedef struct adns__state *adns_state; |
| 17 | typedef struct adns__query *adns_query; |
| 18 | |
| 19 | typedef enum { |
| 20 | adns_if_noenv= 0x0001, /* do not look at environment */ |
| 21 | adns_if_noerrprint= 0x0002, /* never print output to stderr (_debug overrides) */ |
| 22 | adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */ |
| 23 | adns_if_debug= 0x0008, /* enable all output to stderr plus debug msgs */ |
| 24 | adns_if_noautosys= 0x0010, /* do not make syscalls at every opportunity */ |
| 25 | } adns_initflags; |
| 26 | |
| 27 | typedef enum { |
| 28 | adns_qf_search= 0x0001, /* use the searchlist */ |
| 29 | adns_qf_usevc= 0x0002, /* use a virtual circuit (TCP connection) */ |
| 30 | adns_qf_anyquote= 0x0004, |
| 31 | adns_qf_loosecname= 0x0008, /* allow refs to CNAMEs - without, get _s_cname */ |
| 32 | adns_qf_nocname= 0x0010, /* don't follow CNAMEs, instead give _s_cname */ |
| 33 | } adns_queryflags; |
| 34 | |
| 35 | typedef enum { |
| 36 | adns__rrt_typemask= 0x0ffff, |
| 37 | adns__qtf_deref= 0x10000, /* dereference domains and perhaps produce extra data */ |
| 38 | adns__qtf_mail822= 0x20000, /* make mailboxes be in RFC822 rcpt field format */ |
| 39 | adns__qtf_masterfmt= 0x80000, /* convert RRs to master file format, return as str */ |
| 40 | |
| 41 | adns_r_none= 0, |
| 42 | |
| 43 | adns_r_a= 1, |
| 44 | adns_r_a_mf= adns_r_a|adns__qtf_masterfmt, |
| 45 | |
| 46 | adns_r_ns_raw= 2, |
| 47 | adns_r_ns= adns_r_ns_raw|adns__qtf_deref, |
| 48 | adns_r_ns_mf= adns_r_ns_raw|adns__qtf_masterfmt, |
| 49 | |
| 50 | adns_r_cname= 5, |
| 51 | adns_r_cname_mf= adns_r_cname|adns__qtf_masterfmt, |
| 52 | |
| 53 | adns_r_soa_raw= 6, |
| 54 | adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, |
| 55 | adns_r_soa_mf= adns_r_soa_raw|adns__qtf_masterfmt, |
| 56 | |
| 57 | adns_r_null= 10, |
| 58 | adns_r_null_mf= adns_r_null|adns__qtf_masterfmt, |
| 59 | |
| 60 | adns_r_ptr_raw= 12, |
| 61 | adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, |
| 62 | adns_r_ptr_mf= adns_r_ptr_raw|adns__qtf_masterfmt, |
| 63 | |
| 64 | adns_r_hinfo= 13, |
| 65 | adns_r_hinfo_mf= adns_r_hinfo|adns__qtf_masterfmt, |
| 66 | |
| 67 | adns_r_mx_raw= 15, |
| 68 | adns_r_mx= adns_r_mx_raw|adns__qtf_deref, |
| 69 | adns_r_mx_mf= adns_r_mx_raw|adns__qtf_masterfmt, |
| 70 | |
| 71 | adns_r_txt= 16, |
| 72 | adns_r_txt_mf= adns_r_txt|adns__qtf_masterfmt, |
| 73 | |
| 74 | adns_r_rp_raw= 17, |
| 75 | adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, |
| 76 | adns_r_rp_mf= adns_r_rp_raw|adns__qtf_masterfmt |
| 77 | |
| 78 | } adns_rrtype; |
| 79 | |
| 80 | /* In queries without qtf_anyquote, all domains must have standard |
| 81 | * legal syntax. In queries _with_ qtf_anyquote, domains in the query |
| 82 | * or response may contain any characters, quoted according to |
| 83 | * RFC1035 5.1. On input to adns, the char* is a pointer to the |
| 84 | * interior of a " delimited string, except that " may appear in it, |
| 85 | * and on output, the char* is a pointer to a string which would be |
| 86 | * legal either inside or outside " delimiters, and any characters |
| 87 | * not usually legal in domain names will be quoted as \X |
| 88 | * (if the character is 33-126 except \ and ") or \DDD. |
| 89 | * |
| 90 | * _qtf_anyquote is ignored for _mf queries. |
| 91 | * |
| 92 | * Do not ask for _raw records containing mailboxes without |
| 93 | * specifying _qf_anyquote. |
| 94 | */ |
| 95 | |
| 96 | typedef enum { |
| 97 | adns_s_ok, |
| 98 | adns_s_timeout, |
| 99 | adns_s_nolocalmem, |
| 100 | adns_s_allservfail, |
| 101 | adns_s_servfail, |
| 102 | adns_s_notimplemented, |
| 103 | adns_s_refused, |
| 104 | adns_s_reasonunknown, |
| 105 | adns_s_norecurse, |
| 106 | adns_s_serverfaulty, |
| 107 | adns_s_unknownreply, |
| 108 | adns_s_max_tempfail= 99, |
| 109 | adns_s_inconsistent, /* PTR gives domain whose A does not match */ |
| 110 | adns_s_cname, /* CNAME found where data eg A expected (not if _qf_loosecname) */ |
| 111 | /* fixme: implement _s_cname */ |
| 112 | adns_s_max_remotemisconfig= 199, |
| 113 | adns_s_nxdomain, |
| 114 | adns_s_nodata, |
| 115 | adns_s_invaliddomain, |
| 116 | adns_s_domaintoolong, |
| 117 | } adns_status; |
| 118 | |
| 119 | typedef struct { |
| 120 | char *dm; |
| 121 | adns_status astatus; |
| 122 | int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ |
| 123 | struct in_addr *addrs; |
| 124 | } adns_rr_dmaddr; |
| 125 | |
| 126 | typedef struct { |
| 127 | char *a, *b; |
| 128 | } adns_rr_strpair; |
| 129 | |
| 130 | typedef struct { |
| 131 | int i; |
| 132 | adns_rr_dmaddr dmaddr; |
| 133 | } adns_rr_intdmaddr; |
| 134 | |
| 135 | typedef struct { |
| 136 | int i; |
| 137 | char *str; |
| 138 | } adns_rr_intstr; |
| 139 | |
| 140 | typedef struct { |
| 141 | char *ns0, *rp; |
| 142 | unsigned long serial, refresh, retry, expire, minimum; |
| 143 | } adns_rr_soa; |
| 144 | |
| 145 | typedef struct { |
| 146 | adns_status status; |
| 147 | char *cname; /* always NULL if query was for CNAME records */ |
| 148 | adns_rrtype type; |
| 149 | int nrrs; |
| 150 | union { |
| 151 | char *(*str); /* ns_raw, cname, ptr, ptr_raw, txt, <any>_mf */ |
| 152 | struct in_addr *inaddr; /* a */ |
| 153 | adns_rr_dmaddr *dmaddr; /* ns */ |
| 154 | adns_rr_strpair *strpair; /* hinfo, rp, rp_raw */ |
| 155 | adns_rr_intdmaddr *intdmaddr; /* mx */ |
| 156 | adns_rr_intstr *intstr; /* mx_raw */ |
| 157 | adns_rr_soa *soa; /* soa, soa_raw */ |
| 158 | /* NULL is empty */ |
| 159 | } rrs; |
| 160 | } adns_answer; |
| 161 | |
| 162 | /* Memory management: |
| 163 | * adns_state and adns_query are actually pointers to malloc'd state; |
| 164 | * On submission questions are copied, including the owner domain; |
| 165 | * Answers are malloc'd as a single piece of memory; pointers in the |
| 166 | * answer struct point into further memory in the answer. |
| 167 | * query_io: |
| 168 | * Must always be non-null pointer; |
| 169 | * If *query_io is 0 to start with then any query may be returned; |
| 170 | * If *query_io is !0 adns_query then only that query may be returned. |
| 171 | * If the call is successful, *query_io, *answer_r, and *context_r |
| 172 | * will all be set. |
| 173 | * Errors: |
| 174 | * Return values are 0 or an errno value; |
| 175 | * Seriously fatal system errors (eg, failure to create sockets, |
| 176 | * malloc failure, etc.) return errno values; |
| 177 | * Other errors (nameserver failure, timed out connections, &c) |
| 178 | * are returned in the status field of the answer. If status is |
| 179 | * nonzero then nrrs will be 0, otherwise it will be >0. |
| 180 | * type will always be the type requested; |
| 181 | * If no (appropriate) requests are done adns_check returns EWOULDBLOCK; |
| 182 | * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH; |
| 183 | */ |
| 184 | |
| 185 | int adns_init(adns_state *newstate_r, adns_initflags flags, FILE *diagfile/*0=>stderr*/); |
| 186 | |
| 187 | int adns_synchronous(adns_state ads, |
| 188 | const char *owner, |
| 189 | adns_rrtype type, |
| 190 | adns_queryflags flags, |
| 191 | adns_answer **answer_r); |
| 192 | /* Will not return EINTR. */ |
| 193 | |
| 194 | /* NB: if you set adns_if_noautosys then _submit and _check do not |
| 195 | * make any system calls; you must use adns_callback (possibly after |
| 196 | * adns_interest) to actually get things to happen. |
| 197 | */ |
| 198 | |
| 199 | int adns_submit(adns_state ads, |
| 200 | const char *owner, |
| 201 | adns_rrtype type, |
| 202 | adns_queryflags flags, |
| 203 | void *context, |
| 204 | adns_query *query_r); |
| 205 | |
| 206 | int adns_check(adns_state ads, |
| 207 | adns_query *query_io, |
| 208 | adns_answer **answer_r, |
| 209 | void **context_r); |
| 210 | |
| 211 | int adns_wait(adns_state ads, |
| 212 | adns_query *query_io, |
| 213 | adns_answer **answer_r, |
| 214 | void **context_r); |
| 215 | /* Might return EINTR - if so, try again */ |
| 216 | |
| 217 | void adns_cancel(adns_state ads, adns_query query); |
| 218 | |
| 219 | int adns_finish(adns_state); |
| 220 | |
| 221 | int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds, |
| 222 | const fd_set *exceptfds); |
| 223 | /* Gives adns flow-of-control for a bit. This will never block. |
| 224 | * If maxfd == -1 then adns will check (make nonblocking system calls on) |
| 225 | * all of its own filedescriptors; otherwise it will only use those |
| 226 | * < maxfd and specified in the fd_set's, as if select had returned them. |
| 227 | * Other fd's may be in the fd_sets, and will be ignored. |
| 228 | * _callback returns how many adns fd's were in the various sets, so |
| 229 | * you can tell if your select handling code has missed something and is going awol. |
| 230 | * |
| 231 | * May also return -1 if a critical syscall failed, setting errno. |
| 232 | */ |
| 233 | |
| 234 | void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io, |
| 235 | fd_set *writefds_io, fd_set *exceptfds_io, |
| 236 | struct timeval **tv_mod, struct timeval *tv_buf); |
| 237 | /* Find out file descriptors adns is interested in, and when it |
| 238 | * would like the opportunity to time something out. If you do not plan to |
| 239 | * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning |
| 240 | * you have no timeout of your own, in which case tv_buf must be non-null and |
| 241 | * _interest may fill it in and set *tv_mod=tv_buf. |
| 242 | * readfds, writefds, exceptfds and maxfd may not be 0. |
| 243 | */ |
| 244 | |
| 245 | /* Example expected/legal calling sequences: |
| 246 | * adns_init |
| 247 | * adns_submit 1 |
| 248 | * adns_submit 2 |
| 249 | * adns_submit 3 |
| 250 | * adns_wait 1 |
| 251 | * adns_check 3 -> EWOULDBLOCK |
| 252 | * adns_wait 2 |
| 253 | * adns_wait 3 |
| 254 | * .... |
| 255 | * adns_finish |
| 256 | * |
| 257 | * adns_init _noautosys |
| 258 | * loop { |
| 259 | * adns_interest |
| 260 | * select |
| 261 | * adns_callback |
| 262 | * ... |
| 263 | * adns_submit / adns_check |
| 264 | * ... |
| 265 | * } |
| 266 | */ |
| 267 | |
| 268 | const char *adns_strerror(adns_status st); |
| 269 | |
| 270 | #endif |