unbound.h revision 249141
1219888Sed/* 2257547Sray * unbound.h - unbound validating resolver public API 3219888Sed * 4219888Sed * Copyright (c) 2007, NLnet Labs. All rights reserved. 5219888Sed * 6219888Sed * This software is open source. 7219888Sed * 8257547Sray * Redistribution and use in source and binary forms, with or without 9257547Sray * modification, are permitted provided that the following conditions 10257547Sray * are met: 11219888Sed * 12219888Sed * Redistributions of source code must retain the above copyright notice, 13219888Sed * this list of conditions and the following disclaimer. 14219888Sed * 15219888Sed * Redistributions in binary form must reproduce the above copyright notice, 16219888Sed * this list of conditions and the following disclaimer in the documentation 17219888Sed * and/or other materials provided with the distribution. 18219888Sed * 19219888Sed * Neither the name of the NLNET LABS nor the names of its contributors may 20219888Sed * be used to endorse or promote products derived from this software without 21219888Sed * specific prior written permission. 22219888Sed * 23219888Sed * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 24219888Sed * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25219888Sed * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26219888Sed * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE 27219888Sed * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 28219888Sed * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29219888Sed * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30219888Sed * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31219888Sed * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32219888Sed * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33219888Sed * POSSIBILITY OF SUCH DAMAGE. 34219888Sed */ 35219888Sed 36219888Sed/** 37219888Sed * \file 38219888Sed * 39219888Sed * This file contains functions to resolve DNS queries and 40219888Sed * validate the answers. Synchonously and asynchronously. 41219888Sed * 42219888Sed * Several ways to use this interface from an application wishing 43263817Sray * to perform (validated) DNS lookups. 44219888Sed * 45219888Sed * All start with 46257974Sray * ctx = ub_ctx_create(); 47219888Sed * err = ub_ctx_add_ta(ctx, "..."); 48256145Sray * err = ub_ctx_add_ta(ctx, "..."); 49219888Sed * ... some lookups 50257966Sray * ... call ub_ctx_delete(ctx); when you want to stop. 51263817Sray * 52257966Sray * Application not threaded. Blocking. 53263817Sray * int err = ub_resolve(ctx, "www.example.com", ... 54263817Sray * if(err) fprintf(stderr, "lookup error: %s\n", ub_strerror(err)); 55263817Sray * ... use the answer 56263817Sray * 57263817Sray * Application not threaded. Non-blocking ('asynchronous'). 58257966Sray * err = ub_resolve_async(ctx, "www.example.com", ... my_callback); 59257966Sray * ... application resumes processing ... 60257966Sray * ... and when either ub_poll(ctx) is true 61257966Sray * ... or when the file descriptor ub_fd(ctx) is readable, 62219888Sed * ... or whenever, the app calls ... 63257966Sray * ub_process(ctx); 64257966Sray * ... if no result is ready, the app resumes processing above, 65257966Sray * ... or process() calls my_callback() with results. 66258165Sray * 67258165Sray * ... if the application has nothing more to do, wait for answer 68258165Sray * ub_wait(ctx); 69258165Sray * 70219888Sed * Application threaded. Blocking. 71219888Sed * Blocking, same as above. The current thread does the work. 72257966Sray * Multiple threads can use the *same context*, each does work and uses 73257966Sray * shared cache data from the context. 74257966Sray * 75257966Sray * Application threaded. Non-blocking ('asynchronous'). 76257966Sray * ... setup threaded-asynchronous config option 77257966Sray * err = ub_ctx_async(ctx, 1); 78257966Sray * ... same as async for non-threaded 79257966Sray * ... the callbacks are called in the thread that calls process(ctx) 80256145Sray * 81256145Sray * If no threading is compiled in, the above async example uses fork(2) to 82256145Sray * create a process to perform the work. The forked process exits when the 83256145Sray * calling process exits, or ctx_delete() is called. 84256145Sray * Otherwise, for asynchronous with threading, a worker thread is created. 85256145Sray * 86256145Sray * The blocking calls use shared ctx-cache when threaded. Thus 87256145Sray * ub_resolve() and ub_resolve_async() && ub_wait() are 88256145Sray * not the same. The first makes the current thread do the work, setting 89256145Sray * up buffers, etc, to perform the work (but using shared cache data). 90219888Sed * The second calls another worker thread (or process) to perform the work. 91219888Sed * And no buffers need to be set up, but a context-switch happens. 92219888Sed */ 93257815Sray#ifndef _UB_UNBOUND_H 94257815Sray#define _UB_UNBOUND_H 95219888Sed 96219888Sed#ifdef __cplusplus 97219888Sedextern "C" { 98219888Sed#endif 99219888Sed 100219888Sed/** 101219888Sed * The validation context is created to hold the resolver status, 102219888Sed * validation keys and a small cache (containing messages, rrsets, 103219888Sed * roundtrip times, trusted keys, lameness information). 104219888Sed * 105219888Sed * Its contents are internally defined. 106219888Sed */ 107219888Sedstruct ub_ctx; 108219888Sed 109219888Sed/** 110219888Sed * The validation and resolution results. 111219888Sed * Allocated by the resolver, and need to be freed by the application 112219888Sed * with ub_resolve_free(). 113219888Sed */ 114219888Sedstruct ub_result { 115257815Sray /** The original question, name text string. */ 116258090Sray char* qname; 117219888Sed /** the type asked for */ 118219888Sed int qtype; 119257974Sray /** the class asked for */ 120257974Sray int qclass; 121257974Sray 122257974Sray /** 123257974Sray * a list of network order DNS rdata items, terminated with a 124257974Sray * NULL pointer, so that data[0] is the first result entry, 125219888Sed * data[1] the second, and the last entry is NULL. 126219888Sed * If there was no data, data[0] is NULL. 127219888Sed */ 128219888Sed char** data; 129219888Sed 130219888Sed /** the length in bytes of the data items, len[i] for data[i] */ 131219888Sed int* len; 132219888Sed 133219888Sed /** 134219888Sed * canonical name for the result (the final cname). 135219888Sed * zero terminated string. 136256145Sray * May be NULL if no canonical name exists. 137257974Sray */ 138263817Sray char* canonname; 139219888Sed 140258165Sray /** 141219888Sed * DNS RCODE for the result. May contain additional error code if 142219888Sed * there was no data due to an error. 0 (NOERROR) if okay. 143219888Sed */ 144219888Sed int rcode; 145219888Sed 146219888Sed /** 147219888Sed * The DNS answer packet. Network formatted. Can contain DNSSEC types. 148219888Sed */ 149219888Sed void* answer_packet; 150219888Sed /** length of the answer packet in octets. */ 151219888Sed int answer_len; 152219888Sed 153219888Sed /** 154219888Sed * If there is any data, this is true. 155219888Sed * If false, there was no data (nxdomain may be true, rcode can be set). 156219888Sed */ 157219888Sed int havedata; 158219888Sed 159219888Sed /** 160219888Sed * If there was no data, and the domain did not exist, this is true. 161219888Sed * If it is false, and there was no data, then the domain name 162256145Sray * is purported to exist, but the requested data type is not available. 163219888Sed */ 164219888Sed int nxdomain; 165219888Sed 166256145Sray /** 167256145Sray * True, if the result is validated securely. 168256964Sray * False, if validation failed or domain queried has no security info. 169256145Sray * 170257723Sray * It is possible to get a result with no data (havedata is false), 171256145Sray * and secure is true. This means that the non-existance of the data 172256145Sray * was cryptographically proven (with signatures). 173219888Sed */ 174257972Sray int secure; 175257972Sray 176258130Sray /** 177219888Sed * If the result was not secure (secure==0), and this result is due 178219888Sed * to a security failure, bogus is true. 179219888Sed * This means the data has been actively tampered with, signatures 180256145Sray * failed, expected signatures were not present, timestamps on 181219888Sed * signatures were out of date and so on. 182219888Sed * 183219888Sed * If !secure and !bogus, this can happen if the data is not secure 184256145Sray * because security is disabled for that domain name. 185219888Sed * This means the data is from a domain where data is not signed. 186219888Sed */ 187256145Sray int bogus; 188219888Sed 189219888Sed /** 190258090Sray * If the result is bogus this contains a string (zero terminated) 191219888Sed * that describes the failure. There may be other errors as well 192256145Sray * as the one described, the description may not be perfectly accurate. 193263817Sray * Is NULL if the result is not bogus. 194263817Sray */ 195263817Sray char* why_bogus; 196263817Sray 197258090Sray /** 198258090Sray * TTL for the result, in seconds. If the security is bogus, then 199258090Sray * you also cannot trust this value. 200263817Sray */ 201256145Sray int ttl; 202258090Sray}; 203257973Sray 204257973Sray/** 205257973Sray * Callback for results of async queries. 206257973Sray * The readable function definition looks like: 207257973Sray * void my_callback(void* my_arg, int err, struct ub_result* result); 208258130Sray * It is called with 209257973Sray * void* my_arg: your pointer to a (struct of) data of your choice, 210258090Sray * or NULL. 211258090Sray * int err: if 0 all is OK, otherwise an error occured and no results 212256145Sray * are forthcoming. 213256145Sray * struct result: pointer to more detailed result structure. 214256145Sray * This structure is allocated on the heap and needs to be 215256145Sray * freed with ub_resolve_free(result); 216256145Sray */ 217256145Sraytypedef void (*ub_callback_t)(void*, int, struct ub_result*); 218256145Sray 219219888Sed/** 220256145Sray * Create a resolving and validation context. 221219888Sed * The information from /etc/resolv.conf and /etc/hosts is not utilised by 222257975Sray * default. Use ub_ctx_resolvconf and ub_ctx_hosts to read them. 223219888Sed * @return a new context. default initialisation. 224219888Sed * returns NULL on error. 225219888Sed */ 226219888Sedstruct ub_ctx* ub_ctx_create(void); 227256145Sray 228219888Sed/** 229219888Sed * Destroy a validation context and free all its resources. 230219888Sed * Outstanding async queries are killed and callbacks are not called for them. 231219888Sed * @param ctx: context to delete. 232256145Sray */ 233256145Srayvoid ub_ctx_delete(struct ub_ctx* ctx); 234256145Sray 235219888Sed/** 236219888Sed * Set an option for the context. 237219888Sed * @param ctx: context. 238219888Sed * @param opt: option name from the unbound.conf config file format. 239219888Sed * (not all settings applicable). The name includes the trailing ':' 240219888Sed * for example ub_ctx_set_option(ctx, "logfile:", "mylog.txt"); 241219888Sed * This is a power-users interface that lets you specify all sorts 242219888Sed * of options. 243219888Sed * For some specific options, such as adding trust anchors, special 244219888Sed * routines exist. 245219888Sed * @param val: value of the option. 246219888Sed * @return: 0 if OK, else error. 247257076Sray */ 248219888Sedint ub_ctx_set_option(struct ub_ctx* ctx, char* opt, char* val); 249263817Sray 250219888Sed/** 251219888Sed * Get an option from the context. 252219888Sed * @param ctx: context. 253219888Sed * @param opt: option name from the unbound.conf config file format. 254256145Sray * (not all settings applicable). The name excludes the trailing ':' 255258327Sray * for example ub_ctx_get_option(ctx, "logfile", &result); 256256145Sray * This is a power-users interface that lets you specify all sorts 257256145Sray * of options. 258256145Sray * @param str: the string is malloced and returned here. NULL on error. 259256145Sray * The caller must free() the string. In cases with multiple 260256145Sray * entries (auto-trust-anchor-file), a newline delimited list is 261256145Sray * returned in the string. 262256145Sray * @return 0 if OK else an error code (malloc failure, syntax error). 263219888Sed */ 264219888Sedint ub_ctx_get_option(struct ub_ctx* ctx, char* opt, char** str); 265256145Sray 266256145Sray/** 267256145Sray * setup configuration for the given context. 268256145Sray * @param ctx: context. 269256145Sray * @param fname: unbound config file (not all settings applicable). 270256145Sray * This is a power-users interface that lets you specify all sorts 271219888Sed * of options. 272219888Sed * For some specific options, such as adding trust anchors, special 273219888Sed * routines exist. 274256527Sray * @return: 0 if OK, else error. 275219888Sed */ 276219888Sedint ub_ctx_config(struct ub_ctx* ctx, char* fname); 277219888Sed 278219888Sed/** 279219888Sed * Set machine to forward DNS queries to, the caching resolver to use. 280256145Sray * IP4 or IP6 address. Forwards all DNS requests to that machine, which 281219888Sed * is expected to run a recursive resolver. If the proxy is not 282256527Sray * DNSSEC-capable, validation may fail. Can be called several times, in 283257988Sray * that case the addresses are used as backup servers. 284257988Sray * 285264113Sray * To read the list of nameservers from /etc/resolv.conf (from DHCP or so), 286264113Sray * use the call ub_ctx_resolvconf. 287264113Sray * 288219888Sed * @param ctx: context. 289219888Sed * At this time it is only possible to set configuration before the 290263817Sray * first resolve is done. 291263817Sray * @param addr: address, IP4 or IP6 in string format. 292263817Sray * If the addr is NULL, forwarding is disabled. 293263817Sray * @return 0 if OK, else error. 294263817Sray */ 295263817Srayint ub_ctx_set_fwd(struct ub_ctx* ctx, char* addr); 296219888Sed 297219888Sed/** 298219888Sed * Read list of nameservers to use from the filename given. 299256145Sray * Usually "/etc/resolv.conf". Uses those nameservers as caching proxies. 300219888Sed * If they do not support DNSSEC, validation may fail. 301219888Sed * 302256145Sray * Only nameservers are picked up, the searchdomain, ndots and other 303256527Sray * settings from resolv.conf(5) are ignored. 304264113Sray * 305263817Sray * @param ctx: context. 306263817Sray * At this time it is only possible to set configuration before the 307219888Sed * first resolve is done. 308263817Sray * @param fname: file name string. If NULL "/etc/resolv.conf" is used. 309263817Sray * @return 0 if OK, else error. 310263817Sray */ 311263817Srayint ub_ctx_resolvconf(struct ub_ctx* ctx, char* fname); 312263817Sray 313263817Sray/** 314219888Sed * Read list of hosts from the filename given. 315256145Sray * Usually "/etc/hosts". 316256145Sray * These addresses are not flagged as DNSSEC secure when queried for. 317256145Sray * 318256145Sray * @param ctx: context. 319256145Sray * At this time it is only possible to set configuration before the 320256145Sray * first resolve is done. 321256145Sray * @param fname: file name string. If NULL "/etc/hosts" is used. 322256902Sray * @return 0 if OK, else error. 323256902Sray */ 324256902Srayint ub_ctx_hosts(struct ub_ctx* ctx, char* fname); 325219888Sed 326219888Sed/** 327219888Sed * Add a trust anchor to the given context. 328219888Sed * The trust anchor is a string, on one line, that holds a valid DNSKEY or 329219888Sed * DS RR. 330219888Sed * @param ctx: context. 331219888Sed * At this time it is only possible to add trusted keys before the 332219888Sed * first resolve is done. 333219888Sed * @param ta: string, with zone-format RR on one line. 334219888Sed * [domainname] [TTL optional] [type] [class optional] [rdata contents] 335219888Sed * @return 0 if OK, else error. 336219888Sed */ 337219888Sedint ub_ctx_add_ta(struct ub_ctx* ctx, char* ta); 338219888Sed 339257724Sray/** 340257724Sray * Add trust anchors to the given context. 341257724Sray * Pass name of a file with DS and DNSKEY records (like from dig or drill). 342257724Sray * @param ctx: context. 343257724Sray * At this time it is only possible to add trusted keys before the 344257724Sray * first resolve is done. 345257724Sray * @param fname: filename of file with keyfile with trust anchors. 346219888Sed * @return 0 if OK, else error. 347219888Sed */ 348219888Sedint ub_ctx_add_ta_file(struct ub_ctx* ctx, char* fname); 349219888Sed 350219888Sed/** 351219888Sed * Add trust anchors to the given context. 352219888Sed * Pass the name of a bind-style config file with trusted-keys{}. 353219888Sed * @param ctx: context. 354219888Sed * At this time it is only possible to add trusted keys before the 355258090Sray * first resolve is done. 356258165Sray * @param fname: filename of file with bind-style config entries with trust 357219888Sed * anchors. 358256145Sray * @return 0 if OK, else error. 359256145Sray */ 360256145Srayint ub_ctx_trustedkeys(struct ub_ctx* ctx, char* fname); 361256145Sray 362219888Sed/** 363219888Sed * Set debug output (and error output) to the specified stream. 364219888Sed * Pass NULL to disable. Default is stderr. 365219888Sed * @param ctx: context. 366219888Sed * @param out: FILE* out file stream to log to. 367256145Sray * Type void* to avoid stdio dependency of this header file. 368256145Sray * @return 0 if OK, else error. 369256145Sray */ 370256145Srayint ub_ctx_debugout(struct ub_ctx* ctx, void* out); 371219888Sed 372257972Sray/** 373257972Sray * Set debug verbosity for the context 374257972Sray * Output is directed to stderr. 375257972Sray * @param ctx: context. 376257972Sray * @param d: debug level, 0 is off, 1 is very minimal, 2 is detailed, 377257972Sray * and 3 is lots. 378257972Sray * @return 0 if OK, else error. 379257972Sray */ 380256145Srayint ub_ctx_debuglevel(struct ub_ctx* ctx, int d); 381219888Sed 382219888Sed/** 383219888Sed * Set a context behaviour for asynchronous action. 384219888Sed * @param ctx: context. 385219888Sed * @param dothread: if true, enables threading and a call to resolve_async() 386219888Sed * creates a thread to handle work in the background. 387219888Sed * If false, a process is forked to handle work in the background. 388219888Sed * Changes to this setting after async() calls have been made have 389219888Sed * no effect (delete and re-create the context to change). 390219888Sed * @return 0 if OK, else error. 391219888Sed */ 392219888Sedint ub_ctx_async(struct ub_ctx* ctx, int dothread); 393219888Sed 394219888Sed/** 395219888Sed * Poll a context to see if it has any new results 396219888Sed * Do not poll in a loop, instead extract the fd below to poll for readiness, 397219888Sed * and then check, or wait using the wait routine. 398219888Sed * @param ctx: context. 399219888Sed * @return: 0 if nothing to read, or nonzero if a result is available. 400219888Sed * If nonzero, call ctx_process() to do callbacks. 401219888Sed */ 402219888Sedint ub_poll(struct ub_ctx* ctx); 403219888Sed 404219888Sed/** 405219888Sed * Wait for a context to finish with results. Calls ub_process() after 406219888Sed * the wait for you. After the wait, there are no more outstanding 407219888Sed * asynchronous queries. 408219888Sed * @param ctx: context. 409219888Sed * @return: 0 if OK, else error. 410219888Sed */ 411263817Srayint ub_wait(struct ub_ctx* ctx); 412219888Sed 413263817Sray/** 414263817Sray * Get file descriptor. Wait for it to become readable, at this point 415219888Sed * answers are returned from the asynchronous validating resolver. 416219888Sed * Then call the ub_process to continue processing. 417219888Sed * This routine works immediately after context creation, the fd 418263817Sray * does not change. 419257967Sray * @param ctx: context. 420257967Sray * @return: -1 on error, or file descriptor to use select(2) with. 421257967Sray */ 422257967Srayint ub_fd(struct ub_ctx* ctx); 423257967Sray 424257967Sray/** 425263817Sray * Call this routine to continue processing results from the validating 426257967Sray * resolver (when the fd becomes readable). 427219888Sed * Will perform necessary callbacks. 428219888Sed * @param ctx: context 429219888Sed * @return: 0 if OK, else error. 430219888Sed */ 431219888Sedint ub_process(struct ub_ctx* ctx); 432219888Sed 433219888Sed/** 434263817Sray * Perform resolution and validation of the target name. 435263817Sray * @param ctx: context. 436258327Sray * The context is finalized, and can no longer accept config changes. 437263817Sray * @param name: domain name in text format (a zero terminated text string). 438258327Sray * @param rrtype: type of RR in host order, 1 is A (address). 439258327Sray * @param rrclass: class of RR in host order, 1 is IN (for internet). 440219888Sed * @param result: the result data is returned in a newly allocated result 441219888Sed * structure. May be NULL on return, return value is set to an error 442258327Sray * in that case (out of memory). 443 * @return 0 if OK, else error. 444 */ 445int ub_resolve(struct ub_ctx* ctx, char* name, int rrtype, 446 int rrclass, struct ub_result** result); 447 448/** 449 * Perform resolution and validation of the target name. 450 * Asynchronous, after a while, the callback will be called with your 451 * data and the result. 452 * @param ctx: context. 453 * If no thread or process has been created yet to perform the 454 * work in the background, it is created now. 455 * The context is finalized, and can no longer accept config changes. 456 * @param name: domain name in text format (a string). 457 * @param rrtype: type of RR in host order, 1 is A. 458 * @param rrclass: class of RR in host order, 1 is IN (for internet). 459 * @param mydata: this data is your own data (you can pass NULL), 460 * and is passed on to the callback function. 461 * @param callback: this is called on completion of the resolution. 462 * It is called as: 463 * void callback(void* mydata, int err, struct ub_result* result) 464 * with mydata: the same as passed here, you may pass NULL, 465 * with err: is 0 when a result has been found. 466 * with result: a newly allocated result structure. 467 * The result may be NULL, in that case err is set. 468 * 469 * If an error happens during processing, your callback will be called 470 * with error set to a nonzero value (and result==NULL). 471 * @param async_id: if you pass a non-NULL value, an identifier number is 472 * returned for the query as it is in progress. It can be used to 473 * cancel the query. 474 * @return 0 if OK, else error. 475 */ 476int ub_resolve_async(struct ub_ctx* ctx, char* name, int rrtype, 477 int rrclass, void* mydata, ub_callback_t callback, int* async_id); 478 479/** 480 * Cancel an async query in progress. 481 * Its callback will not be called. 482 * 483 * @param ctx: context. 484 * @param async_id: which query to cancel. 485 * @return 0 if OK, else error. 486 * This routine can return an error if the async_id passed does not exist 487 * or has already been delivered. If another thread is processing results 488 * at the same time, the result may be delivered at the same time and the 489 * cancel fails with an error. Also the cancel can fail due to a system 490 * error, no memory or socket failures. 491 */ 492int ub_cancel(struct ub_ctx* ctx, int async_id); 493 494/** 495 * Free storage associated with a result structure. 496 * @param result: to free 497 */ 498void ub_resolve_free(struct ub_result* result); 499 500/** 501 * Convert error value to a human readable string. 502 * @param err: error code from one of the ub_val* functions. 503 * @return pointer to constant text string, zero terminated. 504 */ 505const char* ub_strerror(int err); 506 507/** 508 * Debug routine. Print the local zone information to debug output. 509 * @param ctx: context. Is finalized by the routine. 510 * @return 0 if OK, else error. 511 */ 512int ub_ctx_print_local_zones(struct ub_ctx* ctx); 513 514/** 515 * Add a new zone with the zonetype to the local authority info of the 516 * library. 517 * @param ctx: context. Is finalized by the routine. 518 * @param zone_name: name of the zone in text, "example.com" 519 * If it already exists, the type is updated. 520 * @param zone_type: type of the zone (like for unbound.conf) in text. 521 * @return 0 if OK, else error. 522 */ 523int ub_ctx_zone_add(struct ub_ctx* ctx, char *zone_name, char *zone_type); 524 525/** 526 * Remove zone from local authority info of the library. 527 * @param ctx: context. Is finalized by the routine. 528 * @param zone_name: name of the zone in text, "example.com" 529 * If it does not exist, nothing happens. 530 * @return 0 if OK, else error. 531 */ 532int ub_ctx_zone_remove(struct ub_ctx* ctx, char *zone_name); 533 534/** 535 * Add localdata to the library local authority info. 536 * Similar to local-data config statement. 537 * @param ctx: context. Is finalized by the routine. 538 * @param data: the resource record in text format, for example 539 * "www.example.com IN A 127.0.0.1" 540 * @return 0 if OK, else error. 541 */ 542int ub_ctx_data_add(struct ub_ctx* ctx, char *data); 543 544/** 545 * Remove localdata from the library local authority info. 546 * @param ctx: context. Is finalized by the routine. 547 * @param data: the name to delete all data from, like "www.example.com". 548 * @return 0 if OK, else error. 549 */ 550int ub_ctx_data_remove(struct ub_ctx* ctx, char *data); 551 552/** 553 * Get a version string from the libunbound implementation. 554 * @return a static constant string with the version number. 555 */ 556const char* ub_version(void); 557 558#ifdef __cplusplus 559} 560#endif 561 562#endif /* _UB_UNBOUND_H */ 563