Some more fiddlings.
[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 (_debug overrides) */
15 adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */
16 adns_if_debug= 0x0008, /* enable all output to stderr plus debug msgs*/
17 adns_if_noautosys= 0x0010, /* do not make syscalls at every opportunity */
18 } adns_initflags;
19
20 typedef enum {
21 adns_f_search= 0x0001, /* use the searchlist */
22 adns_f_usevc= 0x0002, /* use a virtual circuit (TCP connection) */
23 adns_f_anyquote= 0x0004,
24 } adns_queryflags;
25
26 typedef enum {
27 adns__rrt_typemask= 0x0ffff,
28 adns__qtf_deref= 0x10000, /* dereference domains and produce extra data */
29 adns__qtf_mailconv= 0x20000, /* put @ between first and second labels */
30 adns_r_none= 0,
31 adns_r_a= 1,
32 adns_r_ns_raw= 2,
33 adns_r_ns= adns_r_ns_raw|adns__qtf_deref,
34 adns_r_cname= 5,
35 adns_r_soa_raw= 6,
36 adns_r_soa= adns_r_soa_raw|adns__qtf_mailconv,
37 adns_r_null= 10,
38 adns_r_ptr_raw= 12,
39 adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref,
40 adns_r_hinfo= 13,
41 adns_r_mx_raw= 15,
42 adns_r_mx= adns_r_mx_raw|adns__qtf_deref,
43 adns_r_txt= 16,
44 adns_r_rp_raw= 17,
45 adns_r_rp= adns_r_rp_raw|adns__qtf_mailconv
46 } adns_rrtype;
47
48 /* In queries without qtf_anyquote, all domains must have standard
49 * legal syntax. In queries _with_ qtf_anyquote, domains in the query
50 * or response may contain any characters, quoted according to
51 * RFC1035 5.1. On input to adns, the char* is a pointer to the
52 * interior of a " delimited string, except that " may appear in it,
53 * and on output, the char* is a pointer to a string which would be
54 * legal either inside or outside " delimiters, and any characters
55 * not usually legal in domain names will be quoted as \X
56 * (if the character is 33-126 except \ and ") or \DDD.
57 *
58 * Do not ask for records containing mailboxes without
59 * specifying qtf_mailconv or qtf_anyquote.
60 */
61
62 typedef enum {
63 adns_s_ok,
64 adns_s_timeout,
65 adns_s_unknownqtype,
66 adns_s_nolocalmem,
67 adns_s_connlost,
68 adns_s_max_tempfail= 99,
69 adns_s_inconsistent, /* PTR gives domain whose A does not match */
70 adns_s_badcname, /* CNAME found where actual record expected */
71 adns_s_max_misconfig= 199;
72 adns_s_nxdomain,
73 adns_s_norecord,
74 adns_s_invaliddomain
75 } adns_status;
76
77 typedef struct {
78 char *dm;
79 adns_status astatus;
80 int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */
81 struct in_addr *addrs;
82 } adns_dmaddr;
83
84 typedef struct {
85 adns_status status;
86 char *cname; /* always NULL if query was for CNAME records */
87 adns_rrtype type;
88 int nrrs;
89 union {
90 struct in_addr inaddr[1]; /* a */
91 char (*str)[1]; /* ns_raw, cname, ptr, ptr_raw, txt */
92 adns_dmaddr dmaddr[1]; /* ns */
93 struct { char *a, *b; } strpair[1]; /* hinfo, rp, rp_raw */
94 struct { int pref; adns_dmaddrs dmaddr; } intdmaddr[1]; /* mx */
95 struct { int pref; char *str; } intstr[1]; /* mx_raw */
96 struct {
97 char *ns0, *rp;
98 unsigned long serial, refresh, retry, expire, minimum;
99 } soa[1]; /* soa, soa_raw */
100 /* NULL is empty */
101 } rrs;
102 } adns_answer;
103
104 /* Memory management:
105 * adns_state and adns_query are actually pointers to malloc'd state;
106 * On submission questions are copied, including the owner domain;
107 * Answers are malloc'd as a single piece of memory.
108 * query_io:
109 * Must always be non-null pointer;
110 * If *query_io is 0 to start with then any query may be returned;
111 * If *query_io is !0 adns_query then only that query may be returned.
112 * Errors:
113 * Return values are 0 or an errno value;
114 * Seriously fatal system errors (eg, failure to create sockets,
115 * malloc failure, etc.) return errno values;
116 * Other errors (nameserver failure, timed out connections, &c)
117 * are returned in the status field of the answer. If status is
118 * nonzero then nrrs will be 0, otherwise it will be >0.
119 * type will always be the type requested;
120 * If no (appropriate) requests are done adns_check returns EWOULDBLOCK;
121 * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH;
122 * If malloc failure occurs during internal allocation or processing
123 * ands_check and _wait set *answer to 0.
124 */
125
126 int adns_init(adns_state *newstate_r, adns_initflags flags, FILE *diagfile/*0=>stderr*/);
127
128 int adns_synchronous(adns_state ads,
129 const char *owner,
130 adns_rrtype type,
131 adns_queryflags flags,
132 adns_answer **answer_r);
133 /* Will not return EINTR. */
134
135 /* NB: if you set adns_if_noautosys then _submit and _check do not
136 * make any system calls; you must use adns_callback (possibly after
137 * adns_interest) to actually get things to happen.
138 */
139
140 int adns_submit(adns_state ads,
141 const char *owner,
142 adns_rrtype type,
143 adns_queryflags flags,
144 void *context,
145 adns_query *query_r);
146
147 int adns_check(adns_state ads,
148 adns_query *query_io,
149 adns_answer **answer_r,
150 void **context_r);
151
152 int adns_wait(adns_state ads,
153 adns_query *query_io,
154 adns_answer **answer_r,
155 void **context_r);
156 /* Might return EINTR - if so, try again */
157
158 void adns_cancel(adns_state ads, adns_query query);
159
160 int adns_finish(adns_state);
161
162 int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds,
163 const fd_set *exceptfds);
164 /* Gives adns flow-of-control for a bit. This will never block.
165 * If maxfd == -1 then adns will check (make nonblocking system calls on)
166 * all of its own filedescriptors; otherwise it will only use those
167 * < maxfd and specified in the fd_set's, as if select had returned them.
168 * Other fd's may be in the fd_sets, and will be ignored.
169 * _callback returns how many adns fd's were in the various sets, so
170 * you can tell if your select handling code has missed something and is going awol.
171 */
172
173 void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io,
174 fd_set *writefds_io, fd_set *exceptfds_io,
175 struct timeval **tv_mod, struct timeval *tv_buf);
176 /* Find out file descriptors adns is interested in, and when it
177 * would like the opportunity to time something out. If you do not plan to
178 * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning
179 * you have no timeout of your own, in which case tv_buf must be non-null and
180 * _interest may fill it in and set *tv_mod=tv_buf.
181 * readfds, writefds, exceptfds and maxfd may not be 0.
182 */
183
184 /* Example expected/legal calling sequences:
185 * adns_init
186 * adns_submit 1
187 * adns_submit 2
188 * adns_submit 3
189 * adns_wait 1
190 * adns_check 3 -> EWOULDBLOCK
191 * adns_wait 2
192 * adns_wait 3
193 * ....
194 * adns_finish
195 *
196 * adns_init _noautosys
197 * loop {
198 * adns_interest
199 * select
200 * adns_callback
201 * ...
202 * adns_submit / adns_check
203 * ...
204 * }
205 */
206
207 #endif