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1 | /**/ |
2 | |
3 | #ifndef ADNS_H_INCLUDED |
4 | #define ADNS_H_INCLUDED |
5 | |
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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; |
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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 */ |
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16 | adns_if_noautosys= 0x0008, /* do not do full flow-of-control whenever we can */ |
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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) */ |
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22 | adns_f_anyquote= 0x0004, |
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23 | } adns_queryflags; |
24 | |
25 | typedef enum { |
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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 |
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45 | } adns_rrtype; |
46 | |
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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 | |
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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 |
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76 | * used. |
77 | */ |
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78 | |
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79 | typedef struct { |
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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; |
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97 | } adns_answer; |
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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; |
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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; |
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117 | * If malloc failure occurs during internal allocation or processing |
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118 | * ands_check and _wait set *answer to 0. |
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119 | */ |
120 | |
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121 | int adns_init(adns_state *newstate_r, adns_initflags flags); |
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122 | |
123 | int adns_synchronous(adns_state ads, |
124 | const char *owner, |
125 | adns_rrtype type, |
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126 | adns_queryflags flags, |
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127 | adns_answer *answer); |
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128 | /* Will not return EINTR. */ |
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129 | |
130 | /* NB: if you set adns_if_noautosys then _submit and _check do not |
131 | * make any system calls; you must use adns_callback (possibly after |
132 | * adns_interest) to actually get things to happen. |
133 | */ |
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134 | |
135 | int adns_submit(adns_state ads, |
136 | const char *owner, |
137 | adns_rrtype type, |
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138 | adns_queryflags flags, |
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139 | void *context, |
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140 | adns_query *query_r); |
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141 | |
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142 | int adns_check(adns_state ads, |
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143 | adns_query *query_io, |
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144 | adns_answer *answer, |
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145 | void *context_r); |
146 | |
147 | int adns_wait(adns_state ads, |
148 | adns_query *query_io, |
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149 | adns_answer *answer, |
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150 | void *context_r); |
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151 | /* Might return EINTR - if so, try again */ |
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152 | |
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153 | void adns_cancel(adns_state ads, adns_query query); |
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154 | |
155 | int adns_finish(adns_state); |
156 | |
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157 | int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds, |
158 | const fd_set *exceptfds); |
159 | /* Gives adns flow-of-control for a bit. This will never block. |
160 | * If maxfd == -1 then adns will check (make nonblocking system calls on) |
161 | * all of its own filedescriptors; otherwise it will only use those |
162 | * < maxfd and specified in the fd_set's, as if select had returned them. |
163 | * Other fd's may be in the fd_sets, and will be ignored. |
164 | * _callback returns how many adns fd's were in the various sets, so |
165 | * you can tell if your select handling code has missed something and is going awol. |
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166 | */ |
167 | |
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168 | void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io, |
169 | fd_set *writefds_io, fd_set *exceptfds_io, |
170 | struct timeval **tv_mod, struct timeval *tv_buf); |
171 | /* Find out file descriptors adns is interested in, and when it |
172 | * would like the opportunity to time something out. If you do not plan to |
173 | * block then tv_mod may be 0. Otherwise, tv_mod may point to 0 meaning |
174 | * you have no timeout of your own, in which case tv_buf must be non-null and |
175 | * _interest may fill it in and set *tv_mod=tv_buf. |
176 | * readfds, writefds, exceptfds and maxfd may not be 0. |
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177 | */ |
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178 | |
179 | /* Example expected/legal calling sequences: |
180 | * adns_init |
181 | * adns_submit 1 |
182 | * adns_submit 2 |
183 | * adns_submit 3 |
184 | * adns_wait 1 |
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185 | * adns_check 3 -> EWOULDBLOCK |
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186 | * adns_wait 2 |
187 | * adns_wait 3 |
188 | * .... |
189 | * adns_finish |
190 | * |
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191 | * adns_init _noautosys |
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192 | * loop { |
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193 | * adns_interest |
194 | * select |
195 | * adns_callback |
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196 | * ... |
197 | * adns_submit / adns_check |
198 | * ... |
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199 | * } |
200 | */ |
201 | |
202 | #endif |