3 #ifndef ADNS_H_INCLUDED
4 #define ADNS_H_INCLUDED
6 #include <sys/socket.h>
7 #include <netinet/in.h>
9 typedef struct adns__state *adns_state;
10 typedef struct adns__query *adns_query;
13 adns_if_noenv= 0x0001, /* do not look at environment */
14 adns_if_noerrprint= 0x0002, /* never print output to stderr */
15 adns_if_debug= 0x0004, /* print debugging output to stderr */
16 adns_if_noautosys= 0x0008, /* do not do full flow-of-control whenever we can */
20 adns_f_search= 0x0001, /* use the searchlist */
21 adns_f_usevc= 0x0002, /* use a virtual circuit (TCP connection) */
22 adns_f_anyquote= 0x0004,
26 adns__rrt_typemask= 0x0ffff,
27 adns__qtf_deref= 0x10000, /* dereference domains and produce extra data */
28 adns__qtf_mailconv= 0x20000, /* put @ between first and second labels */
32 adns_r_ns= adns_r_ns_raw|adns__qtf_deref,
35 adns_r_soa= adns_r_soa_raw|adns__qtf_mailconv,
38 adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref,
41 adns_r_mx= adns_r_mx_raw|adns__qtf_deref,
44 adns_r_rp= adns_r_rp_raw|adns__qtf_mailconv
47 /* In queries without qtf_anyquote, all domains must have standard
48 * legal syntax. In queries _with_ qtf_anyquote, domains in the query
49 * or response may contain any characters, quoted according to
50 * RFC1035 5.1. On input to adns, the char* is a pointer to the
51 * interior of a " delimited string, except that " may appear in it,
52 * and on output, the char* is a pointer to a string which would be
53 * legal either inside or outside " delimiters, and any characters
54 * not usually legal in domain names will be quoted as \X
55 * (if the character is 33-126 except \ and ") or \DDD.
57 * Do not ask for records containing mailboxes without
58 * specifying qtf_mailconv or qtf_anyquote.
68 adns_s_max_tempfail= 99,
74 /* In dereferenced answers, multiple addresses show up as multiple
75 * answers with all the dm pointers being the same. If no
76 * address is available (permanent failure) then INADDR_NONE is
82 char *cname; /* always NULL if query was for CNAME records */
86 struct in_addr inaddr[1]; /* a */
87 char (*str)[1]; /* ns_raw, cname, ptr, ptr_raw, txt */
88 struct { char *dm; struct in_addr addr; } dmaddr; /* ns */
89 struct { char *a, *b; } strpair[1]; /* hinfo, rp, rp_raw */
90 struct { int pref; char *dm; struct in_addr addr; } intdmaddr[1]; /* mx */
91 struct { int pref; char *str; } intstr[1]; /* mx_raw */
94 unsigned long serial, refresh, retry, expire, minimum;
95 } soa[1]; /* soa, soa_raw */
100 /* Memory management:
101 * adns_state and adns_query are actually pointers to malloc'd state;
102 * On submission questions are copied, including the owner domain;
103 * Answers are malloc'd as a single piece of memory.
105 * Must always be non-null pointer;
106 * If *query_io is 0 to start with then any query may be returned;
107 * If *query_io is !0 adns_query then only that query may be returned.
109 * Return values are 0 or an errno value;
110 * Seriously fatal system errors (eg, failure to create sockets,
111 * malloc failure, etc.) return errno values;
112 * Other errors (nameserver failure, timed out connections, &c)
113 * are returned in the status field of the answer. If status is
114 * nonzero then nrrs will be 0, otherwise it will be >0.
115 * type will always be the type requested;
116 * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
117 * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
118 * If malloc failure occurs during internal allocation or processing
119 * ands_check and _wait set *answer to 0.
122 int adns_init(adns_state *newstate_r, adns_initflags flags);
124 int adns_synchronous(adns_state ads,
127 adns_queryflags flags,
128 adns_answer *answer);
129 /* Will not return EINTR. */
131 /* NB: if you set adns_if_noautosys then _submit and _check do not
132 * make any system calls; you must use adns_callback (possibly after
133 * adns_interest) to actually get things to happen.
136 int adns_submit(adns_state ads,
139 adns_queryflags flags,
141 adns_query *query_r);
143 int adns_check(adns_state ads,
144 adns_query *query_io,
148 int adns_wait(adns_state ads,
149 adns_query *query_io,
152 /* Might return EINTR - if so, try again */
154 void adns_cancel(adns_state ads, adns_query query);
156 int adns_finish(adns_state);
158 int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
159 const fd_set *exceptfds);
160 /* Gives adns flow-of-control for a bit. This will never block.
161 * If maxfd == -1 then adns will check (make nonblocking system calls on)
162 * all of its own filedescriptors; otherwise it will only use those
163 * < maxfd and specified in the fd_set's, as if select had returned them.
164 * Other fd's may be in the fd_sets, and will be ignored.
165 * _callback returns how many adns fd's were in the various sets, so
166 * you can tell if your select handling code has missed something and is going awol.
169 void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
170 fd_set *writefds_io, fd_set *exceptfds_io,
171 struct timeval **tv_mod, struct timeval *tv_buf);
172 /* Find out file descriptors adns is interested in, and when it
173 * would like the opportunity to time something out. If you do not plan to
174 * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
175 * you have no timeout of your own, in which case tv_buf must be non-null and
176 * _interest may fill it in and set *tv_mod=tv_buf.
177 * readfds, writefds, exceptfds and maxfd may not be 0.
180 /* Example expected/legal calling sequences:
186 * adns_check 3 -> EWOULDBLOCK
192 * adns_init _noautosys
198 * adns_submit / adns_check