Cleanups, development.
[adns] / 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 */
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 */
17 } adns_initflags;
18
19 typedef enum {
20 adns_f_search= 0x0001, /* use the searchlist */
21 adns_f_usevc= 0x0002, /* use a virtual circuit (TCP connection) */
22 adns_f_anyquote= 0x0004,
23 } adns_queryflags;
24
25 typedef enum {
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 */
29 adns_r_none= 0,
30 adns_r_a= 1,
31 adns_r_ns_raw= 2,
32 adns_r_ns= adns_r_ns_raw|adns__qtf_deref,
33 adns_r_cname= 5,
34 adns_r_soa_raw= 6,
35 adns_r_soa= adns_r_soa_raw|adns__qtf_mailconv,
36 adns_r_null= 10,
37 adns_r_ptr_raw= 12,
38 adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref,
39 adns_r_hinfo= 13,
40 adns_r_mx_raw= 15,
41 adns_r_mx= adns_r_mx_raw|adns__qtf_deref,
42 adns_r_txt= 16,
43 adns_r_rp_raw= 17,
44 adns_r_rp= adns_r_rp_raw|adns__qtf_mailconv
45 } adns_rrtype;
46
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.
56 *
57 * Do not ask for records containing mailboxes without
58 * specifying qtf_mailconv or qtf_anyquote.
59 */
60
61 typedef enum {
62 adns_s_ok,
63 adns_s_notresponding,
64 adns_s_serverfailure,
65 adns_s_unknownqtype,
66 adns_s_remoteerror,
67 adns_s_nolocalmem,
68 adns_s_max_tempfail= 99,
69 adns_s_nxdomain,
70 adns_s_norecord,
71 adns_s_inconsistent, /* for bad PTR */
72 adns_s_invaliddomain
73 } adns_status;
74
75 /* In dereferenced answers, multiple addresses show up as multiple
76 * answers with all the dm pointers being the same, with ref= adns_s_ok.
77 * If no address is available then INADDR_NONE is used, and ref indicates
78 * the error.
79 */
80
81 typedef struct {
82 char *dm;
83 adns_status astatus;
84 int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */
85 struct in_addr *addrs;
86 } adns_dmaddr;
87
88 typedef struct {
89 adns_status status;
90 char *cname; /* always NULL if query was for CNAME records */
91 adns_rrtype type;
92 int nrrs;
93 union {
94 struct in_addr inaddr[1]; /* a */
95 char (*str)[1]; /* ns_raw, cname, ptr, ptr_raw, txt */
96 adns_dmaddr dmaddr[1]; /* ns */
97 struct { char *a, *b; } strpair[1]; /* hinfo, rp, rp_raw */
98 struct { int pref; adns_dmaddrs dmaddr; } intdmaddr[1]; /* mx */
99 struct { int pref; char *str; } intstr[1]; /* mx_raw */
100 struct {
101 char *ns0, *rp;
102 unsigned long serial, refresh, retry, expire, minimum;
103 } soa[1]; /* soa, soa_raw */
104 /* NULL is empty */
105 } rrs;
106 } adns_answer;
107
108 /* Memory management:
109 * adns_state and adns_query are actually pointers to malloc'd state;
110 * On submission questions are copied, including the owner domain;
111 * Answers are malloc'd as a single piece of memory.
112 * query_io:
113 * Must always be non-null pointer;
114 * If *query_io is 0 to start with then any query may be returned;
115 * If *query_io is !0 adns_query then only that query may be returned.
116 * Errors:
117 * Return values are 0 or an errno value;
118 * Seriously fatal system errors (eg, failure to create sockets,
119 * malloc failure, etc.) return errno values;
120 * Other errors (nameserver failure, timed out connections, &c)
121 * are returned in the status field of the answer. If status is
122 * nonzero then nrrs will be 0, otherwise it will be >0.
123 * type will always be the type requested;
124 * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
125 * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
126 * If malloc failure occurs during internal allocation or processing
127 * ands_check and _wait set *answer to 0.
128 */
129
130 int adns_init(adns_state *newstate_r, adns_initflags flags);
131
132 int adns_synchronous(adns_state ads,
133 const char *owner,
134 adns_rrtype type,
135 adns_queryflags flags,
136 adns_answer **answer_r);
137 /* Will not return EINTR. */
138
139 /* NB: if you set adns_if_noautosys then _submit and _check do not
140 * make any system calls; you must use adns_callback (possibly after
141 * adns_interest) to actually get things to happen.
142 */
143
144 int adns_submit(adns_state ads,
145 const char *owner,
146 adns_rrtype type,
147 adns_queryflags flags,
148 void *context,
149 adns_query *query_r);
150
151 int adns_check(adns_state ads,
152 adns_query *query_io,
153 adns_answer **answer_r,
154 void **context_r);
155
156 int adns_wait(adns_state ads,
157 adns_query *query_io,
158 adns_answer **answer_r,
159 void **context_r);
160 /* Might return EINTR - if so, try again */
161
162 void adns_cancel(adns_state ads, adns_query query);
163
164 int adns_finish(adns_state);
165
166 int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
167 const fd_set *exceptfds);
168 /* Gives adns flow-of-control for a bit. This will never block.
169 * If maxfd == -1 then adns will check (make nonblocking system calls on)
170 * all of its own filedescriptors; otherwise it will only use those
171 * < maxfd and specified in the fd_set's, as if select had returned them.
172 * Other fd's may be in the fd_sets, and will be ignored.
173 * _callback returns how many adns fd's were in the various sets, so
174 * you can tell if your select handling code has missed something and is going awol.
175 */
176
177 void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
178 fd_set *writefds_io, fd_set *exceptfds_io,
179 struct timeval **tv_mod, struct timeval *tv_buf);
180 /* Find out file descriptors adns is interested in, and when it
181 * would like the opportunity to time something out. If you do not plan to
182 * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
183 * you have no timeout of your own, in which case tv_buf must be non-null and
184 * _interest may fill it in and set *tv_mod=tv_buf.
185 * readfds, writefds, exceptfds and maxfd may not be 0.
186 */
187
188 /* Example expected/legal calling sequences:
189 * adns_init
190 * adns_submit 1
191 * adns_submit 2
192 * adns_submit 3
193 * adns_wait 1
194 * adns_check 3 -> EWOULDBLOCK
195 * adns_wait 2
196 * adns_wait 3
197 * ....
198 * adns_finish
199 *
200 * adns_init _noautosys
201 * loop {
202 * adns_interest
203 * select
204 * adns_callback
205 * ...
206 * adns_submit / adns_check
207 * ...
208 * }
209 */
210
211 #endif