Various frameworks; ready for meat.
[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__rrttype_mask= 0x0fff,
27 adns__qtf_deref= 0x1000, /* dereference domains and produce extra data */
28 adns__qtf_mailconv= 0x2000, /* 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_max_tempfail= 99,
68 adns_s_nxdomain,
69 adns_s_norecord,
70 adns_s_invaliddomain
71 } adns_status;
72
73 /* In dereferenced answers, multiple addresses show up as multiple
74 * answers with all the dm pointers being the same. If no
75 * address is available (permanent failure) then INADDR_NONE is
76 * used.
77 */
78
79 typedef struct {
80 adns_status status;
81 char *cname; /* always NULL if query was for CNAME records */
82 adns_rrtype type;
83 int nrrs;
84 union {
85 struct in_addr inaddr[1]; /* a */
86 char (*str)[1]; /* ns_raw, cname, ptr, ptr_raw, txt */
87 struct { char *dm; struct in_addr addr; } dmaddr; /* ns */
88 struct { char *a, *b; } strpair[1]; /* hinfo, rp, rp_raw */
89 struct { int pref; char *dm; struct in_addr addr; } intdmaddr[1]; /* mx */
90 struct { int pref; char *str; } intstr[1]; /* mx_raw */
91 struct {
92 char *ns0, *rp;
93 unsigned long serial, refresh, retry, expire, minimum;
94 } soa[1]; /* soa, soa_raw */
95 /* NULL is empty */
96 } rrs;
97 } adns_answer;
98
99 /* Memory management:
100 * adns_state and adns_query are actually pointers to malloc'd state;
101 * On submission questions are copied, including the owner domain;
102 * Answers are malloc'd as a single piece of memory.
103 * query_io:
104 * Must always be non-null pointer;
105 * If *query_io is 0 to start with then any query may be returned;
106 * If *query_io is !0 adns_query then only that query may be returned.
107 * Errors:
108 * Return values are 0 or an errno value;
109 * Seriously fatal system errors (eg, failure to create sockets,
110 * malloc failure, etc.) return errno values;
111 * Other errors (nameserver failure, timed out connections, &c)
112 * are returned in the status field of the answer. If status is
113 * nonzero then nrrs will be 0, otherwise it will be >0.
114 * type will always be the type requested;
115 * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
116 * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
117 * If malloc failure occurs during internal allocation or processing
118 * ands_check and _wait set *answer to 0.
119 */
120
121 int adns_init(adns_state *newstate_r, adns_initflags flags);
122
123 int adns_synchronous(adns_state ads,
124 const char *owner,
125 adns_rrtype type,
126 int flags,
127 adns_answer *answer);
128
129 /* NB: if you set adns_if_noautosys then _submit and _check do not
130 * make any system calls; you must use adns_callback (possibly after
131 * adns_interest) to actually get things to happen.
132 */
133
134 int adns_submit(adns_state ads,
135 const char *owner,
136 adns_rrtype type,
137 int flags,
138 void *context,
139 adns_query *query_r);
140
141 int adns_check(adns_state ads,
142 adns_query *query_io,
143 adns_answer *answer,
144 void *context_r);
145
146 int adns_wait(adns_state ads,
147 adns_query *query_io,
148 adns_answer *answer,
149 void *context_r);
150
151 void adns_cancel(adns_state ads, adns_query query);
152
153 int adns_finish(adns_state);
154
155 int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
156 const fd_set *exceptfds);
157 /* Gives adns flow-of-control for a bit. This will never block.
158 * If maxfd == -1 then adns will check (make nonblocking system calls on)
159 * all of its own filedescriptors; otherwise it will only use those
160 * < maxfd and specified in the fd_set's, as if select had returned them.
161 * Other fd's may be in the fd_sets, and will be ignored.
162 * _callback returns how many adns fd's were in the various sets, so
163 * you can tell if your select handling code has missed something and is going awol.
164 */
165
166 void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
167 fd_set *writefds_io, fd_set *exceptfds_io,
168 struct timeval **tv_mod, struct timeval *tv_buf);
169 /* Find out file descriptors adns is interested in, and when it
170 * would like the opportunity to time something out. If you do not plan to
171 * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
172 * you have no timeout of your own, in which case tv_buf must be non-null and
173 * _interest may fill it in and set *tv_mod=tv_buf.
174 * readfds, writefds, exceptfds and maxfd may not be 0.
175 */
176
177 /* Example expected/legal calling sequences:
178 * adns_init
179 * adns_submit 1
180 * adns_submit 2
181 * adns_submit 3
182 * adns_wait 1
183 * adns_check 3 -> EWOULDBLOCK
184 * adns_wait 2
185 * adns_wait 3
186 * ....
187 * adns_finish
188 *
189 * adns_init _noautosys
190 * loop {
191 * adns_interest
192 * select
193 * adns_callback
194 * ...
195 * adns_submit / adns_check
196 * ...
197 * }
198 */
199
200 #endif