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1 
2 /* Copyright 1998, 2009 by the Massachusetts Institute of Technology.
3  * Copyright (C) 2007-2011 by Daniel Stenberg
4  *
5  * Permission to use, copy, modify, and distribute this
6  * software and its documentation for any purpose and without
7  * fee is hereby granted, provided that the above copyright
8  * notice appear in all copies and that both that copyright
9  * notice and this permission notice appear in supporting
10  * documentation, and that the name of M.I.T. not be used in
11  * advertising or publicity pertaining to distribution of the
12  * software without specific, written prior permission.
13  * M.I.T. makes no representations about the suitability of
14  * this software for any purpose.  It is provided "as is"
15  * without express or implied warranty.
16  */
17 
18 #ifndef ARES__H
19 #define ARES__H
20 
21 #include "ares_version.h"  /* c-ares version defines   */
22 #include "ares_build.h"    /* c-ares build definitions */
23 #include "ares_rules.h"    /* c-ares rules enforcement */
24 
25 /*
26  * Define WIN32 when build target is Win32 API
27  */
28 
29 #if (defined(_WIN32) || defined(__WIN32__)) && \
30    !defined(WIN32) && !defined(__SYMBIAN32__)
31 #  define WIN32
32 #endif
33 
34 #include <sys/types.h>
35 
36 /* HP-UX systems version 9, 10 and 11 lack sys/select.h and so does oldish
37    libc5-based Linux systems. Only include it on system that are known to
38    require it! */
39 #if defined(_AIX) || defined(__NOVELL_LIBC__) || defined(__NetBSD__) || \
40     defined(__minix) || defined(__SYMBIAN32__) || defined(__INTEGRITY) || \
41     defined(__ANDROID__)
42 #include <sys/select.h>
43 #endif
44 #if (defined(NETWARE) && !defined(__NOVELL_LIBC__))
45 #include <sys/bsdskt.h>
46 #endif
47 
48 #if defined(WATT32)
49 #  include <netinet/in.h>
50 #  include <sys/socket.h>
51 #  include <tcp.h>
52 #elif defined(_WIN32_WCE)
53 #  ifndef WIN32_LEAN_AND_MEAN
54 #    define WIN32_LEAN_AND_MEAN
55 #  endif
56 #  include <windows.h>
57 #  include <winsock.h>
58 #elif defined(WIN32)
59 #  ifndef WIN32_LEAN_AND_MEAN
60 #    define WIN32_LEAN_AND_MEAN
61 #  endif
62 #  include <windows.h>
63 #  include <winsock2.h>
64 #  include <ws2tcpip.h>
65 #else
66 #  include <sys/socket.h>
67 #  include <netinet/in.h>
68 #endif
69 
70 #ifdef  __cplusplus
71 extern "C" {
72 #endif
73 
74 /*
75 ** c-ares external API function linkage decorations.
76 */
77 
78 #if !defined(CARES_STATICLIB) && \
79    (defined(WIN32) || defined(_WIN32) || defined(__SYMBIAN32__))
80    /* __declspec function decoration for Win32 and Symbian DLL's */
81 #  if defined(CARES_BUILDING_LIBRARY)
82 #    define CARES_EXTERN  __declspec(dllexport)
83 #  else
84 #    define CARES_EXTERN  __declspec(dllimport)
85 #  endif
86 #else
87    /* visibility function decoration for other cases */
88 #  if !defined(CARES_SYMBOL_HIDING) || \
89      defined(WIN32) || defined(_WIN32) || defined(__SYMBIAN32__)
90 #    define CARES_EXTERN
91 #  else
92 #    define CARES_EXTERN CARES_SYMBOL_SCOPE_EXTERN
93 #  endif
94 #endif
95 
96 
97 #define ARES_SUCCESS            0
98 
99 /* Server error codes (ARES_ENODATA indicates no relevant answer) */
100 #define ARES_ENODATA            1
101 #define ARES_EFORMERR           2
102 #define ARES_ESERVFAIL          3
103 #define ARES_ENOTFOUND          4
104 #define ARES_ENOTIMP            5
105 #define ARES_EREFUSED           6
106 
107 /* Locally generated error codes */
108 #define ARES_EBADQUERY          7
109 #define ARES_EBADNAME           8
110 #define ARES_EBADFAMILY         9
111 #define ARES_EBADRESP           10
112 #define ARES_ECONNREFUSED       11
113 #define ARES_ETIMEOUT           12
114 #define ARES_EOF                13
115 #define ARES_EFILE              14
116 #define ARES_ENOMEM             15
117 #define ARES_EDESTRUCTION       16
118 #define ARES_EBADSTR            17
119 
120 /* ares_getnameinfo error codes */
121 #define ARES_EBADFLAGS          18
122 
123 /* ares_getaddrinfo error codes */
124 #define ARES_ENONAME            19
125 #define ARES_EBADHINTS          20
126 
127 /* Uninitialized library error code */
128 #define ARES_ENOTINITIALIZED    21          /* introduced in 1.7.0 */
129 
130 /* ares_library_init error codes */
131 #define ARES_ELOADIPHLPAPI           22     /* introduced in 1.7.0 */
132 #define ARES_EADDRGETNETWORKPARAMS   23     /* introduced in 1.7.0 */
133 
134 /* More error codes */
135 #define ARES_ECANCELLED         24          /* introduced in 1.7.0 */
136 
137 /* Flag values */
138 #define ARES_FLAG_USEVC         (1 << 0)
139 #define ARES_FLAG_PRIMARY       (1 << 1)
140 #define ARES_FLAG_IGNTC         (1 << 2)
141 #define ARES_FLAG_NORECURSE     (1 << 3)
142 #define ARES_FLAG_STAYOPEN      (1 << 4)
143 #define ARES_FLAG_NOSEARCH      (1 << 5)
144 #define ARES_FLAG_NOALIASES     (1 << 6)
145 #define ARES_FLAG_NOCHECKRESP   (1 << 7)
146 
147 /* Option mask values */
148 #define ARES_OPT_FLAGS          (1 << 0)
149 #define ARES_OPT_TIMEOUT        (1 << 1)
150 #define ARES_OPT_TRIES          (1 << 2)
151 #define ARES_OPT_NDOTS          (1 << 3)
152 #define ARES_OPT_UDP_PORT       (1 << 4)
153 #define ARES_OPT_TCP_PORT       (1 << 5)
154 #define ARES_OPT_SERVERS        (1 << 6)
155 #define ARES_OPT_DOMAINS        (1 << 7)
156 #define ARES_OPT_LOOKUPS        (1 << 8)
157 #define ARES_OPT_SOCK_STATE_CB  (1 << 9)
158 #define ARES_OPT_SORTLIST       (1 << 10)
159 #define ARES_OPT_SOCK_SNDBUF    (1 << 11)
160 #define ARES_OPT_SOCK_RCVBUF    (1 << 12)
161 #define ARES_OPT_TIMEOUTMS      (1 << 13)
162 #define ARES_OPT_ROTATE         (1 << 14)
163 
164 /* Nameinfo flag values */
165 #define ARES_NI_NOFQDN                  (1 << 0)
166 #define ARES_NI_NUMERICHOST             (1 << 1)
167 #define ARES_NI_NAMEREQD                (1 << 2)
168 #define ARES_NI_NUMERICSERV             (1 << 3)
169 #define ARES_NI_DGRAM                   (1 << 4)
170 #define ARES_NI_TCP                     0
171 #define ARES_NI_UDP                     ARES_NI_DGRAM
172 #define ARES_NI_SCTP                    (1 << 5)
173 #define ARES_NI_DCCP                    (1 << 6)
174 #define ARES_NI_NUMERICSCOPE            (1 << 7)
175 #define ARES_NI_LOOKUPHOST              (1 << 8)
176 #define ARES_NI_LOOKUPSERVICE           (1 << 9)
177 /* Reserved for future use */
178 #define ARES_NI_IDN                     (1 << 10)
179 #define ARES_NI_IDN_ALLOW_UNASSIGNED    (1 << 11)
180 #define ARES_NI_IDN_USE_STD3_ASCII_RULES (1 << 12)
181 
182 /* Addrinfo flag values */
183 #define ARES_AI_CANONNAME               (1 << 0)
184 #define ARES_AI_NUMERICHOST             (1 << 1)
185 #define ARES_AI_PASSIVE                 (1 << 2)
186 #define ARES_AI_NUMERICSERV             (1 << 3)
187 #define ARES_AI_V4MAPPED                (1 << 4)
188 #define ARES_AI_ALL                     (1 << 5)
189 #define ARES_AI_ADDRCONFIG              (1 << 6)
190 /* Reserved for future use */
191 #define ARES_AI_IDN                     (1 << 10)
192 #define ARES_AI_IDN_ALLOW_UNASSIGNED    (1 << 11)
193 #define ARES_AI_IDN_USE_STD3_ASCII_RULES (1 << 12)
194 #define ARES_AI_CANONIDN                (1 << 13)
195 
196 #define ARES_AI_MASK (ARES_AI_CANONNAME|ARES_AI_NUMERICHOST|ARES_AI_PASSIVE| \
197                       ARES_AI_NUMERICSERV|ARES_AI_V4MAPPED|ARES_AI_ALL| \
198                       ARES_AI_ADDRCONFIG)
199 #define ARES_GETSOCK_MAXNUM 16 /* ares_getsock() can return info about this
200                                   many sockets */
201 #define ARES_GETSOCK_READABLE(bits,num) (bits & (1<< (num)))
202 #define ARES_GETSOCK_WRITABLE(bits,num) (bits & (1 << ((num) + \
203                                          ARES_GETSOCK_MAXNUM)))
204 
205 /* c-ares library initialization flag values */
206 #define ARES_LIB_INIT_NONE   (0)
207 #define ARES_LIB_INIT_WIN32  (1 << 0)
208 #define ARES_LIB_INIT_ALL    (ARES_LIB_INIT_WIN32)
209 
210 
211 /*
212  * Typedef our socket type
213  */
214 
215 #ifndef ares_socket_typedef
216 #ifdef WIN32
217 typedef SOCKET ares_socket_t;
218 #define ARES_SOCKET_BAD INVALID_SOCKET
219 #else
220 typedef int ares_socket_t;
221 #define ARES_SOCKET_BAD -1
222 #endif
223 #define ares_socket_typedef
224 #endif /* ares_socket_typedef */
225 
226 typedef void (*ares_sock_state_cb)(void *data,
227                                    ares_socket_t socket_fd,
228                                    int readable,
229                                    int writable);
230 
231 struct apattern;
232 
233 /* NOTE about the ares_options struct to users and developers.
234 
235    This struct will remain looking like this. It will not be extended nor
236    shrunk in future releases, but all new options will be set by ares_set_*()
237    options instead of with the ares_init_options() function.
238 
239    Eventually (in a galaxy far far away), all options will be settable by
240    ares_set_*() options and the ares_init_options() function will become
241    deprecated.
242 
243    When new options are added to c-ares, they are not added to this
244    struct. And they are not "saved" with the ares_save_options() function but
245    instead we encourage the use of the ares_dup() function. Needless to say,
246    if you add config options to c-ares you need to make sure ares_dup()
247    duplicates this new option.
248 
249  */
250 struct ares_options {
251   int flags;
252   int timeout; /* in seconds or milliseconds, depending on options */
253   int tries;
254   int ndots;
255   unsigned short udp_port;
256   unsigned short tcp_port;
257   int socket_send_buffer_size;
258   int socket_receive_buffer_size;
259   struct in_addr *servers;
260   int nservers;
261   char **domains;
262   int ndomains;
263   char *lookups;
264   ares_sock_state_cb sock_state_cb;
265   void *sock_state_cb_data;
266   struct apattern *sortlist;
267   int nsort;
268 };
269 
270 struct hostent;
271 struct timeval;
272 struct sockaddr;
273 struct ares_channeldata;
274 
275 typedef struct ares_channeldata *ares_channel;
276 
277 typedef void (*ares_callback)(void *arg,
278                               int status,
279                               int timeouts,
280                               unsigned char *abuf,
281                               int alen);
282 
283 typedef void (*ares_host_callback)(void *arg,
284                                    int status,
285                                    int timeouts,
286                                    struct hostent *hostent);
287 
288 typedef void (*ares_nameinfo_callback)(void *arg,
289                                        int status,
290                                        int timeouts,
291                                        char *node,
292                                        char *service);
293 
294 typedef int  (*ares_sock_create_callback)(ares_socket_t socket_fd,
295                                           int type,
296                                           void *data);
297 
298 CARES_EXTERN int ares_library_init(int flags);
299 
300 CARES_EXTERN void ares_library_cleanup(void);
301 
302 CARES_EXTERN const char *ares_version(int *version);
303 
304 CARES_EXTERN int ares_init(ares_channel *channelptr);
305 
306 CARES_EXTERN int ares_init_options(ares_channel *channelptr,
307                                    struct ares_options *options,
308                                    int optmask);
309 
310 CARES_EXTERN int ares_save_options(ares_channel channel,
311                                    struct ares_options *options,
312                                    int *optmask);
313 
314 CARES_EXTERN void ares_destroy_options(struct ares_options *options);
315 
316 CARES_EXTERN int ares_dup(ares_channel *dest,
317                           ares_channel src);
318 
319 CARES_EXTERN void ares_destroy(ares_channel channel);
320 
321 CARES_EXTERN void ares_cancel(ares_channel channel);
322 
323 /* These next 3 configure local binding for the out-going socket
324  * connection.  Use these to specify source IP and/or network device
325  * on multi-homed systems.
326  */
327 CARES_EXTERN void ares_set_local_ip4(ares_channel channel, unsigned int local_ip);
328 
329 /* local_ip6 should be 16 bytes in length */
330 CARES_EXTERN void ares_set_local_ip6(ares_channel channel,
331                                      const unsigned char* local_ip6);
332 
333 /* local_dev_name should be null terminated. */
334 CARES_EXTERN void ares_set_local_dev(ares_channel channel,
335                                      const char* local_dev_name);
336 
337 CARES_EXTERN void ares_set_socket_callback(ares_channel channel,
338                                            ares_sock_create_callback callback,
339                                            void *user_data);
340 
341 CARES_EXTERN void ares_send(ares_channel channel,
342                             const unsigned char *qbuf,
343                             int qlen,
344                             ares_callback callback,
345                             void *arg);
346 
347 CARES_EXTERN void ares_query(ares_channel channel,
348                              const char *name,
349                              int dnsclass,
350                              int type,
351                              ares_callback callback,
352                              void *arg);
353 
354 CARES_EXTERN void ares_search(ares_channel channel,
355                               const char *name,
356                               int dnsclass,
357                               int type,
358                               ares_callback callback,
359                               void *arg);
360 
361 CARES_EXTERN void ares_gethostbyname(ares_channel channel,
362                                      const char *name,
363                                      int family,
364                                      ares_host_callback callback,
365                                      void *arg);
366 
367 CARES_EXTERN int ares_gethostbyname_file(ares_channel channel,
368                                          const char *name,
369                                          int family,
370                                          struct hostent **host);
371 
372 CARES_EXTERN void ares_gethostbyaddr(ares_channel channel,
373                                      const void *addr,
374                                      int addrlen,
375                                      int family,
376                                      ares_host_callback callback,
377                                      void *arg);
378 
379 CARES_EXTERN void ares_getnameinfo(ares_channel channel,
380                                    const struct sockaddr *sa,
381                                    ares_socklen_t salen,
382                                    int flags,
383                                    ares_nameinfo_callback callback,
384                                    void *arg);
385 
386 CARES_EXTERN int ares_fds(ares_channel channel,
387                           fd_set *read_fds,
388                           fd_set *write_fds);
389 
390 CARES_EXTERN int ares_getsock(ares_channel channel,
391                               ares_socket_t *socks,
392                               int numsocks);
393 
394 CARES_EXTERN struct timeval *ares_timeout(ares_channel channel,
395                                           struct timeval *maxtv,
396                                           struct timeval *tv);
397 
398 CARES_EXTERN void ares_process(ares_channel channel,
399                                fd_set *read_fds,
400                                fd_set *write_fds);
401 
402 CARES_EXTERN void ares_process_fd(ares_channel channel,
403                                   ares_socket_t read_fd,
404                                   ares_socket_t write_fd);
405 
406 CARES_EXTERN int ares_mkquery(const char *name,
407                               int dnsclass,
408                               int type,
409                               unsigned short id,
410                               int rd,
411                               unsigned char **buf,
412                               int *buflen);
413 
414 CARES_EXTERN int ares_expand_name(const unsigned char *encoded,
415                                   const unsigned char *abuf,
416                                   int alen,
417                                   char **s,
418                                   long *enclen);
419 
420 CARES_EXTERN int ares_expand_string(const unsigned char *encoded,
421                                     const unsigned char *abuf,
422                                     int alen,
423                                     unsigned char **s,
424                                     long *enclen);
425 
426 /*
427  * NOTE: before c-ares 1.7.0 we would most often use the system in6_addr
428  * struct below when ares itself was built, but many apps would use this
429  * private version since the header checked a HAVE_* define for it. Starting
430  * with 1.7.0 we always declare and use our own to stop relying on the
431  * system's one.
432  */
433 struct ares_in6_addr {
434   union {
435     unsigned char _S6_u8[16];
436   } _S6_un;
437 };
438 
439 struct ares_addrttl {
440   struct in_addr ipaddr;
441   int            ttl;
442 };
443 
444 struct ares_addr6ttl {
445   struct ares_in6_addr ip6addr;
446   int             ttl;
447 };
448 
449 struct ares_srv_reply {
450   struct ares_srv_reply  *next;
451   char                   *host;
452   unsigned short          priority;
453   unsigned short          weight;
454   unsigned short          port;
455 };
456 
457 struct ares_mx_reply {
458   struct ares_mx_reply   *next;
459   char                   *host;
460   unsigned short          priority;
461 };
462 
463 struct ares_txt_reply {
464   struct ares_txt_reply  *next;
465   unsigned char          *txt;
466   size_t                  length;  /* length excludes null termination */
467 };
468 
469 /*
470 ** Parse the buffer, starting at *abuf and of length alen bytes, previously
471 ** obtained from an ares_search call.  Put the results in *host, if nonnull.
472 ** Also, if addrttls is nonnull, put up to *naddrttls IPv4 addresses along with
473 ** their TTLs in that array, and set *naddrttls to the number of addresses
474 ** so written.
475 */
476 
477 CARES_EXTERN int ares_parse_a_reply(const unsigned char *abuf,
478                                     int alen,
479                                     struct hostent **host,
480                                     struct ares_addrttl *addrttls,
481                                     int *naddrttls);
482 
483 CARES_EXTERN int ares_parse_aaaa_reply(const unsigned char *abuf,
484                                        int alen,
485                                        struct hostent **host,
486                                        struct ares_addr6ttl *addrttls,
487                                        int *naddrttls);
488 
489 CARES_EXTERN int ares_parse_ptr_reply(const unsigned char *abuf,
490                                       int alen,
491                                       const void *addr,
492                                       int addrlen,
493                                       int family,
494                                       struct hostent **host);
495 
496 CARES_EXTERN int ares_parse_ns_reply(const unsigned char *abuf,
497                                      int alen,
498                                      struct hostent **host);
499 
500 CARES_EXTERN int ares_parse_srv_reply(const unsigned char* abuf,
501                                       int alen,
502                                       struct ares_srv_reply** srv_out);
503 
504 CARES_EXTERN int ares_parse_mx_reply(const unsigned char* abuf,
505                                       int alen,
506                                       struct ares_mx_reply** mx_out);
507 
508 CARES_EXTERN int ares_parse_txt_reply(const unsigned char* abuf,
509                                       int alen,
510                                       struct ares_txt_reply** txt_out);
511 
512 CARES_EXTERN void ares_free_string(void *str);
513 
514 CARES_EXTERN void ares_free_hostent(struct hostent *host);
515 
516 CARES_EXTERN void ares_free_data(void *dataptr);
517 
518 CARES_EXTERN const char *ares_strerror(int code);
519 
520 /* TODO:  Hold port here as well. */
521 struct ares_addr_node {
522   struct ares_addr_node *next;
523   int family;
524   union {
525     struct in_addr       addr4;
526     struct ares_in6_addr addr6;
527   } addr;
528 };
529 
530 CARES_EXTERN int ares_set_servers(ares_channel channel,
531                                   struct ares_addr_node *servers);
532 
533 /* Incomming string format: host[:port][,host[:port]]... */
534 CARES_EXTERN int ares_set_servers_csv(ares_channel channel,
535                                       const char* servers);
536 
537 CARES_EXTERN int ares_get_servers(ares_channel channel,
538                                   struct ares_addr_node **servers);
539 
540 #ifdef  __cplusplus
541 }
542 #endif
543 
544 #endif /* ARES__H */
545