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      1 /*
      2  * unbound.h - unbound validating resolver public API
      3  *
      4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
      5  *
      6  * This software is open source.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  *
     12  * Redistributions of source code must retain the above copyright notice,
     13  * this list of conditions and the following disclaimer.
     14  *
     15  * Redistributions in binary form must reproduce the above copyright notice,
     16  * this list of conditions and the following disclaimer in the documentation
     17  * and/or other materials provided with the distribution.
     18  *
     19  * Neither the name of the NLNET LABS nor the names of its contributors may
     20  * be used to endorse or promote products derived from this software without
     21  * specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
     29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
     31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
     32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     34  */
     35 
     36 /**
     37  * \file
     38  *
     39  * This file contains functions to resolve DNS queries and
     40  * validate the answers. Synchronously and asynchronously.
     41  *
     42  * Several ways to use this interface from an application wishing
     43  * to perform (validated) DNS lookups.
     44  *
     45  * All start with
     46  *	ctx = ub_ctx_create();
     47  *	err = ub_ctx_add_ta(ctx, "...");
     48  *	err = ub_ctx_add_ta(ctx, "...");
     49  *	... some lookups
     50  *	... call ub_ctx_delete(ctx); when you want to stop.
     51  *
     52  * Application not threaded. Blocking.
     53  *	int err = ub_resolve(ctx, "www.example.com", ...
     54  *	if(err) fprintf(stderr, "lookup error: %s\n", ub_strerror(err));
     55  *	... use the answer
     56  *
     57  * Application not threaded. Non-blocking ('asynchronous').
     58  *      err = ub_resolve_async(ctx, "www.example.com", ... my_callback);
     59  *	... application resumes processing ...
     60  *	... and when either ub_poll(ctx) is true
     61  *	... or when the file descriptor ub_fd(ctx) is readable,
     62  *	... or whenever, the app calls ...
     63  *	ub_process(ctx);
     64  *	... if no result is ready, the app resumes processing above,
     65  *	... or process() calls my_callback() with results.
     66  *
     67  *      ... if the application has nothing more to do, wait for answer
     68  *      ub_wait(ctx);
     69  *
     70  * Application threaded. Blocking.
     71  *	Blocking, same as above. The current thread does the work.
     72  *	Multiple threads can use the *same context*, each does work and uses
     73  *	shared cache data from the context.
     74  *
     75  * Application threaded. Non-blocking ('asynchronous').
     76  *	... setup threaded-asynchronous config option
     77  *	err = ub_ctx_async(ctx, 1);
     78  *	... same as async for non-threaded
     79  *	... the callbacks are called in the thread that calls process(ctx)
     80  *
     81  * Openssl needs to have locking in place, and the application must set
     82  * it up, because a mere library cannot do this, use the calls
     83  * CRYPTO_set_id_callback and CRYPTO_set_locking_callback.
     84  *
     85  * If no threading is compiled in, the above async example uses fork(2) to
     86  * create a process to perform the work. The forked process exits when the
     87  * calling process exits, or ctx_delete() is called.
     88  * Otherwise, for asynchronous with threading, a worker thread is created.
     89  *
     90  * The blocking calls use shared ctx-cache when threaded. Thus
     91  * ub_resolve() and ub_resolve_async() && ub_wait() are
     92  * not the same. The first makes the current thread do the work, setting
     93  * up buffers, etc, to perform the work (but using shared cache data).
     94  * The second calls another worker thread (or process) to perform the work.
     95  * And no buffers need to be set up, but a context-switch happens.
     96  */
     97 #ifndef UB_UNBOUND_H
     98 #define UB_UNBOUND_H
     99 
    100 #ifdef __cplusplus
    101 extern "C" {
    102 #endif
    103 
    104 /** the version of this header file */
    105 #define UNBOUND_VERSION_MAJOR 1
    106 #define UNBOUND_VERSION_MINOR 9
    107 #define UNBOUND_VERSION_MICRO 1
    108 
    109 /**
    110  * The validation context is created to hold the resolver status,
    111  * validation keys and a small cache (containing messages, rrsets,
    112  * roundtrip times, trusted keys, lameness information).
    113  *
    114  * Its contents are internally defined.
    115  */
    116 struct ub_ctx;
    117 
    118 /**
    119  * The validation and resolution results.
    120  * Allocated by the resolver, and need to be freed by the application
    121  * with ub_resolve_free().
    122  */
    123 struct ub_result {
    124 	/** The original question, name text string. */
    125 	char* qname;
    126 	/** the type asked for */
    127 	int qtype;
    128 	/** the class asked for */
    129 	int qclass;
    130 
    131 	/**
    132 	 * a list of network order DNS rdata items, terminated with a
    133 	 * NULL pointer, so that data[0] is the first result entry,
    134 	 * data[1] the second, and the last entry is NULL.
    135 	 * If there was no data, data[0] is NULL.
    136 	 */
    137 	char** data;
    138 
    139 	/** the length in bytes of the data items, len[i] for data[i] */
    140 	int* len;
    141 
    142 	/**
    143 	 * canonical name for the result (the final cname).
    144 	 * zero terminated string.
    145 	 * May be NULL if no canonical name exists.
    146 	 */
    147 	char* canonname;
    148 
    149 	/**
    150 	 * DNS RCODE for the result. May contain additional error code if
    151 	 * there was no data due to an error. 0 (NOERROR) if okay.
    152 	 */
    153 	int rcode;
    154 
    155 	/**
    156 	 * The DNS answer packet. Network formatted. Can contain DNSSEC types.
    157 	 */
    158 	void* answer_packet;
    159 	/** length of the answer packet in octets. */
    160 	int answer_len;
    161 
    162 	/**
    163 	 * If there is any data, this is true.
    164 	 * If false, there was no data (nxdomain may be true, rcode can be set).
    165 	 */
    166 	int havedata;
    167 
    168 	/**
    169 	 * If there was no data, and the domain did not exist, this is true.
    170 	 * If it is false, and there was no data, then the domain name
    171 	 * is purported to exist, but the requested data type is not available.
    172 	 */
    173 	int nxdomain;
    174 
    175 	/**
    176 	 * True, if the result is validated securely.
    177 	 * False, if validation failed or domain queried has no security info.
    178 	 *
    179 	 * It is possible to get a result with no data (havedata is false),
    180 	 * and secure is true. This means that the non-existence of the data
    181 	 * was cryptographically proven (with signatures).
    182 	 */
    183 	int secure;
    184 
    185 	/**
    186 	 * If the result was not secure (secure==0), and this result is due
    187 	 * to a security failure, bogus is true.
    188 	 * This means the data has been actively tampered with, signatures
    189 	 * failed, expected signatures were not present, timestamps on
    190 	 * signatures were out of date and so on.
    191 	 *
    192 	 * If !secure and !bogus, this can happen if the data is not secure
    193 	 * because security is disabled for that domain name.
    194 	 * This means the data is from a domain where data is not signed.
    195 	 */
    196 	int bogus;
    197 
    198 	/**
    199 	 * If the result is bogus this contains a string (zero terminated)
    200 	 * that describes the failure.  There may be other errors as well
    201 	 * as the one described, the description may not be perfectly accurate.
    202 	 * Is NULL if the result is not bogus.
    203 	 */
    204 	char* why_bogus;
    205 
    206 	/**
    207 	 * If the query or one of its subqueries was ratelimited.  Useful if
    208 	 * ratelimiting is enabled and answer to the client is SERVFAIL as a
    209 	 * result.
    210 	 */
    211 	int was_ratelimited;
    212 
    213 	/**
    214 	 * TTL for the result, in seconds.  If the security is bogus, then
    215 	 * you also cannot trust this value.
    216 	 */
    217 	int ttl;
    218 };
    219 
    220 /**
    221  * Callback for results of async queries.
    222  * The readable function definition looks like:
    223  * void my_callback(void* my_arg, int err, struct ub_result* result);
    224  * It is called with
    225  *	void* my_arg: your pointer to a (struct of) data of your choice,
    226  *		or NULL.
    227  *	int err: if 0 all is OK, otherwise an error occurred and no results
    228  *	     are forthcoming.
    229  *	struct result: pointer to more detailed result structure.
    230  *		This structure is allocated on the heap and needs to be
    231  *		freed with ub_resolve_free(result);
    232  */
    233 typedef void (*ub_callback_type)(void*, int, struct ub_result*);
    234 
    235 /**
    236  * The error constants
    237  */
    238 enum ub_ctx_err {
    239 	/** no error */
    240 	UB_NOERROR = 0,
    241 	/** socket operation. Set to -1, so that if an error from _fd() is
    242 	 * passed (-1) it gives a socket error. */
    243 	UB_SOCKET = -1,
    244 	/** alloc failure */
    245 	UB_NOMEM = -2,
    246 	/** syntax error */
    247 	UB_SYNTAX = -3,
    248 	/** DNS service failed */
    249 	UB_SERVFAIL = -4,
    250 	/** fork() failed */
    251 	UB_FORKFAIL = -5,
    252 	/** cfg change after finalize() */
    253 	UB_AFTERFINAL = -6,
    254 	/** initialization failed (bad settings) */
    255 	UB_INITFAIL = -7,
    256 	/** error in pipe communication with async bg worker */
    257 	UB_PIPE = -8,
    258 	/** error reading from file (resolv.conf) */
    259 	UB_READFILE = -9,
    260 	/** error async_id does not exist or result already been delivered */
    261 	UB_NOID = -10
    262 };
    263 
    264 /**
    265  * Create a resolving and validation context.
    266  * The information from /etc/resolv.conf and /etc/hosts is not utilised by
    267  * default. Use ub_ctx_resolvconf and ub_ctx_hosts to read them.
    268  * @return a new context. default initialisation.
    269  * 	returns NULL on error.
    270  */
    271 struct ub_ctx* ub_ctx_create(void);
    272 
    273 /**
    274  * Destroy a validation context and free all its resources.
    275  * Outstanding async queries are killed and callbacks are not called for them.
    276  * @param ctx: context to delete.
    277  */
    278 void ub_ctx_delete(struct ub_ctx* ctx);
    279 
    280 /**
    281  * Set an option for the context.
    282  * @param ctx: context.
    283  * @param opt: option name from the unbound.conf config file format.
    284  *	(not all settings applicable). The name includes the trailing ':'
    285  *	for example ub_ctx_set_option(ctx, "logfile:", "mylog.txt");
    286  * 	This is a power-users interface that lets you specify all sorts
    287  * 	of options.
    288  * 	For some specific options, such as adding trust anchors, special
    289  * 	routines exist.
    290  * @param val: value of the option.
    291  * @return: 0 if OK, else error.
    292  */
    293 int ub_ctx_set_option(struct ub_ctx* ctx, const char* opt, const char* val);
    294 
    295 /**
    296  * Get an option from the context.
    297  * @param ctx: context.
    298  * @param opt: option name from the unbound.conf config file format.
    299  *	(not all settings applicable). The name excludes the trailing ':'
    300  *	for example ub_ctx_get_option(ctx, "logfile", &result);
    301  * 	This is a power-users interface that lets you specify all sorts
    302  * 	of options.
    303  * @param str: the string is malloced and returned here. NULL on error.
    304  * 	The caller must free() the string.  In cases with multiple
    305  * 	entries (auto-trust-anchor-file), a newline delimited list is
    306  * 	returned in the string.
    307  * @return 0 if OK else an error code (malloc failure, syntax error).
    308  */
    309 int ub_ctx_get_option(struct ub_ctx* ctx, const char* opt, char** str);
    310 
    311 /**
    312  * setup configuration for the given context.
    313  * @param ctx: context.
    314  * @param fname: unbound config file (not all settings applicable).
    315  * 	This is a power-users interface that lets you specify all sorts
    316  * 	of options.
    317  * 	For some specific options, such as adding trust anchors, special
    318  * 	routines exist.
    319  * @return: 0 if OK, else error.
    320  */
    321 int ub_ctx_config(struct ub_ctx* ctx, const char* fname);
    322 
    323 /**
    324  * Set machine to forward DNS queries to, the caching resolver to use.
    325  * IP4 or IP6 address. Forwards all DNS requests to that machine, which
    326  * is expected to run a recursive resolver. If the proxy is not
    327  * DNSSEC-capable, validation may fail. Can be called several times, in
    328  * that case the addresses are used as backup servers.
    329  *
    330  * To read the list of nameservers from /etc/resolv.conf (from DHCP or so),
    331  * use the call ub_ctx_resolvconf.
    332  *
    333  * @param ctx: context.
    334  *	At this time it is only possible to set configuration before the
    335  *	first resolve is done.
    336  * @param addr: address, IP4 or IP6 in string format.
    337  * 	If the addr is NULL, forwarding is disabled.
    338  * @return 0 if OK, else error.
    339  */
    340 int ub_ctx_set_fwd(struct ub_ctx* ctx, const char* addr);
    341 
    342 /**
    343  * Use DNS over TLS to send queries to machines set with ub_ctx_set_fwd().
    344  *
    345  * @param ctx: context.
    346  *	At this time it is only possible to set configuration before the
    347  *	first resolve is done.
    348  * @param tls: enable or disable DNS over TLS
    349  * @return 0 if OK, else error.
    350  */
    351 int ub_ctx_set_tls(struct ub_ctx* ctx, int tls);
    352 
    353 /**
    354  * Add a stub zone, with given address to send to.  This is for custom
    355  * root hints or pointing to a local authoritative dns server.
    356  * For dns resolvers and the 'DHCP DNS' ip address, use ub_ctx_set_fwd.
    357  * This is similar to a stub-zone entry in unbound.conf.
    358  *
    359  * @param ctx: context.
    360  *	It is only possible to set configuration before the
    361  *	first resolve is done.
    362  * @param zone: name of the zone, string.
    363  * @param addr: address, IP4 or IP6 in string format.
    364  * 	The addr is added to the list of stub-addresses if the entry exists.
    365  * 	If the addr is NULL the stub entry is removed.
    366  * @param isprime: set to true to set stub-prime to yes for the stub.
    367  * 	For local authoritative servers, people usually set it to false,
    368  * 	For root hints it should be set to true.
    369  * @return 0 if OK, else error.
    370  */
    371 int ub_ctx_set_stub(struct ub_ctx* ctx, const char* zone, const char* addr,
    372 	int isprime);
    373 
    374 /**
    375  * Read list of nameservers to use from the filename given.
    376  * Usually "/etc/resolv.conf". Uses those nameservers as caching proxies.
    377  * If they do not support DNSSEC, validation may fail.
    378  *
    379  * Only nameservers are picked up, the searchdomain, ndots and other
    380  * settings from resolv.conf(5) are ignored.
    381  *
    382  * @param ctx: context.
    383  *	At this time it is only possible to set configuration before the
    384  *	first resolve is done.
    385  * @param fname: file name string. If NULL "/etc/resolv.conf" is used.
    386  * @return 0 if OK, else error.
    387  */
    388 int ub_ctx_resolvconf(struct ub_ctx* ctx, const char* fname);
    389 
    390 /**
    391  * Read list of hosts from the filename given.
    392  * Usually "/etc/hosts".
    393  * These addresses are not flagged as DNSSEC secure when queried for.
    394  *
    395  * @param ctx: context.
    396  *	At this time it is only possible to set configuration before the
    397  *	first resolve is done.
    398  * @param fname: file name string. If NULL "/etc/hosts" is used.
    399  * @return 0 if OK, else error.
    400  */
    401 int ub_ctx_hosts(struct ub_ctx* ctx, const char* fname);
    402 
    403 /**
    404  * Add a trust anchor to the given context.
    405  * The trust anchor is a string, on one line, that holds a valid DNSKEY or
    406  * DS RR.
    407  * @param ctx: context.
    408  *	At this time it is only possible to add trusted keys before the
    409  *	first resolve is done.
    410  * @param ta: string, with zone-format RR on one line.
    411  * 	[domainname] [TTL optional] [type] [class optional] [rdata contents]
    412  * @return 0 if OK, else error.
    413  */
    414 int ub_ctx_add_ta(struct ub_ctx* ctx, const char* ta);
    415 
    416 /**
    417  * Add trust anchors to the given context.
    418  * Pass name of a file with DS and DNSKEY records (like from dig or drill).
    419  * @param ctx: context.
    420  *	At this time it is only possible to add trusted keys before the
    421  *	first resolve is done.
    422  * @param fname: filename of file with keyfile with trust anchors.
    423  * @return 0 if OK, else error.
    424  */
    425 int ub_ctx_add_ta_file(struct ub_ctx* ctx, const char* fname);
    426 
    427 /**
    428  * Add trust anchor to the given context that is tracked with RFC5011
    429  * automated trust anchor maintenance.  The file is written to when the
    430  * trust anchor is changed.
    431  * Pass the name of a file that was output from eg. unbound-anchor,
    432  * or you can start it by providing a trusted DNSKEY or DS record on one
    433  * line in the file.
    434  * @param ctx: context.
    435  *	At this time it is only possible to add trusted keys before the
    436  *	first resolve is done.
    437  * @param fname: filename of file with trust anchor.
    438  * @return 0 if OK, else error.
    439  */
    440 int ub_ctx_add_ta_autr(struct ub_ctx* ctx, const char* fname);
    441 
    442 /**
    443  * Add trust anchors to the given context.
    444  * Pass the name of a bind-style config file with trusted-keys{}.
    445  * @param ctx: context.
    446  *	At this time it is only possible to add trusted keys before the
    447  *	first resolve is done.
    448  * @param fname: filename of file with bind-style config entries with trust
    449  * 	anchors.
    450  * @return 0 if OK, else error.
    451  */
    452 int ub_ctx_trustedkeys(struct ub_ctx* ctx, const char* fname);
    453 
    454 /**
    455  * Set debug output (and error output) to the specified stream.
    456  * Pass NULL to disable. Default is stderr.
    457  * @param ctx: context.
    458  * @param out: FILE* out file stream to log to.
    459  * 	Type void* to avoid stdio dependency of this header file.
    460  * @return 0 if OK, else error.
    461  */
    462 int ub_ctx_debugout(struct ub_ctx* ctx, void* out);
    463 
    464 /**
    465  * Set debug verbosity for the context
    466  * Output is directed to stderr.
    467  * @param ctx: context.
    468  * @param d: debug level, 0 is off, 1 is very minimal, 2 is detailed,
    469  *	and 3 is lots.
    470  * @return 0 if OK, else error.
    471  */
    472 int ub_ctx_debuglevel(struct ub_ctx* ctx, int d);
    473 
    474 /**
    475  * Set a context behaviour for asynchronous action.
    476  * @param ctx: context.
    477  * @param dothread: if true, enables threading and a call to resolve_async()
    478  *	creates a thread to handle work in the background.
    479  *	If false, a process is forked to handle work in the background.
    480  *	Changes to this setting after async() calls have been made have
    481  *	no effect (delete and re-create the context to change).
    482  * @return 0 if OK, else error.
    483  */
    484 int ub_ctx_async(struct ub_ctx* ctx, int dothread);
    485 
    486 /**
    487  * Poll a context to see if it has any new results
    488  * Do not poll in a loop, instead extract the fd below to poll for readiness,
    489  * and then check, or wait using the wait routine.
    490  * @param ctx: context.
    491  * @return: 0 if nothing to read, or nonzero if a result is available.
    492  * 	If nonzero, call ctx_process() to do callbacks.
    493  */
    494 int ub_poll(struct ub_ctx* ctx);
    495 
    496 /**
    497  * Wait for a context to finish with results. Calls ub_process() after
    498  * the wait for you. After the wait, there are no more outstanding
    499  * asynchronous queries.
    500  * @param ctx: context.
    501  * @return: 0 if OK, else error.
    502  */
    503 int ub_wait(struct ub_ctx* ctx);
    504 
    505 /**
    506  * Get file descriptor. Wait for it to become readable, at this point
    507  * answers are returned from the asynchronous validating resolver.
    508  * Then call the ub_process to continue processing.
    509  * This routine works immediately after context creation, the fd
    510  * does not change.
    511  * @param ctx: context.
    512  * @return: -1 on error, or file descriptor to use select(2) with.
    513  */
    514 int ub_fd(struct ub_ctx* ctx);
    515 
    516 /**
    517  * Call this routine to continue processing results from the validating
    518  * resolver (when the fd becomes readable).
    519  * Will perform necessary callbacks.
    520  * @param ctx: context
    521  * @return: 0 if OK, else error.
    522  */
    523 int ub_process(struct ub_ctx* ctx);
    524 
    525 /**
    526  * Perform resolution and validation of the target name.
    527  * @param ctx: context.
    528  *	The context is finalized, and can no longer accept config changes.
    529  * @param name: domain name in text format (a zero terminated text string).
    530  * @param rrtype: type of RR in host order, 1 is A (address).
    531  * @param rrclass: class of RR in host order, 1 is IN (for internet).
    532  * @param result: the result data is returned in a newly allocated result
    533  * 	structure. May be NULL on return, return value is set to an error
    534  * 	in that case (out of memory).
    535  * @return 0 if OK, else error.
    536  */
    537 int ub_resolve(struct ub_ctx* ctx, const char* name, int rrtype,
    538 	int rrclass, struct ub_result** result);
    539 
    540 /**
    541  * Perform resolution and validation of the target name.
    542  * Asynchronous, after a while, the callback will be called with your
    543  * data and the result.
    544  * @param ctx: context.
    545  *	If no thread or process has been created yet to perform the
    546  *	work in the background, it is created now.
    547  *	The context is finalized, and can no longer accept config changes.
    548  * @param name: domain name in text format (a string).
    549  * @param rrtype: type of RR in host order, 1 is A.
    550  * @param rrclass: class of RR in host order, 1 is IN (for internet).
    551  * @param mydata: this data is your own data (you can pass NULL),
    552  * 	and is passed on to the callback function.
    553  * @param callback: this is called on completion of the resolution.
    554  * 	It is called as:
    555  * 	void callback(void* mydata, int err, struct ub_result* result)
    556  * 	with mydata: the same as passed here, you may pass NULL,
    557  * 	with err: is 0 when a result has been found.
    558  * 	with result: a newly allocated result structure.
    559  *		The result may be NULL, in that case err is set.
    560  *
    561  * 	If an error happens during processing, your callback will be called
    562  * 	with error set to a nonzero value (and result==NULL).
    563  * @param async_id: if you pass a non-NULL value, an identifier number is
    564  *	returned for the query as it is in progress. It can be used to
    565  *	cancel the query.
    566  * @return 0 if OK, else error.
    567  */
    568 int ub_resolve_async(struct ub_ctx* ctx, const char* name, int rrtype,
    569 	int rrclass, void* mydata, ub_callback_type callback, int* async_id);
    570 
    571 /**
    572  * Cancel an async query in progress.
    573  * Its callback will not be called.
    574  *
    575  * @param ctx: context.
    576  * @param async_id: which query to cancel.
    577  * @return 0 if OK, else error.
    578  * This routine can return an error if the async_id passed does not exist
    579  * or has already been delivered. If another thread is processing results
    580  * at the same time, the result may be delivered at the same time and the
    581  * cancel fails with an error.  Also the cancel can fail due to a system
    582  * error, no memory or socket failures.
    583  */
    584 int ub_cancel(struct ub_ctx* ctx, int async_id);
    585 
    586 /**
    587  * Free storage associated with a result structure.
    588  * @param result: to free
    589  */
    590 void ub_resolve_free(struct ub_result* result);
    591 
    592 /**
    593  * Convert error value to a human readable string.
    594  * @param err: error code from one of the libunbound functions.
    595  * 	The error codes are from the type enum ub_ctx_err.
    596  * @return pointer to constant text string, zero terminated.
    597  */
    598 const char* ub_strerror(int err);
    599 
    600 /**
    601  * Debug routine.  Print the local zone information to debug output.
    602  * @param ctx: context.  Is finalized by the routine.
    603  * @return 0 if OK, else error.
    604  */
    605 int ub_ctx_print_local_zones(struct ub_ctx* ctx);
    606 
    607 /**
    608  * Add a new zone with the zonetype to the local authority info of the
    609  * library.
    610  * @param ctx: context.  Is finalized by the routine.
    611  * @param zone_name: name of the zone in text, "example.com"
    612  *	If it already exists, the type is updated.
    613  * @param zone_type: type of the zone (like for unbound.conf) in text.
    614  * @return 0 if OK, else error.
    615  */
    616 int ub_ctx_zone_add(struct ub_ctx* ctx, const char *zone_name,
    617 	const char *zone_type);
    618 
    619 /**
    620  * Remove zone from local authority info of the library.
    621  * @param ctx: context.  Is finalized by the routine.
    622  * @param zone_name: name of the zone in text, "example.com"
    623  *	If it does not exist, nothing happens.
    624  * @return 0 if OK, else error.
    625  */
    626 int ub_ctx_zone_remove(struct ub_ctx* ctx, const char *zone_name);
    627 
    628 /**
    629  * Add localdata to the library local authority info.
    630  * Similar to local-data config statement.
    631  * @param ctx: context.  Is finalized by the routine.
    632  * @param data: the resource record in text format, for example
    633  *	"www.example.com IN A 127.0.0.1"
    634  * @return 0 if OK, else error.
    635  */
    636 int ub_ctx_data_add(struct ub_ctx* ctx, const char *data);
    637 
    638 /**
    639  * Remove localdata from the library local authority info.
    640  * @param ctx: context.  Is finalized by the routine.
    641  * @param data: the name to delete all data from, like "www.example.com".
    642  * @return 0 if OK, else error.
    643  */
    644 int ub_ctx_data_remove(struct ub_ctx* ctx, const char *data);
    645 
    646 /**
    647  * Get a version string from the libunbound implementation.
    648  * @return a static constant string with the version number.
    649  */
    650 const char* ub_version(void);
    651 
    652 /**
    653  * Some global statistics that are not in struct stats_info,
    654  * this struct is shared on a shm segment (shm-key in unbound.conf)
    655  */
    656 struct ub_shm_stat_info {
    657 	int num_threads;
    658 
    659 	struct {
    660 		long long now_sec, now_usec;
    661 		long long up_sec, up_usec;
    662 		long long elapsed_sec, elapsed_usec;
    663 	} time;
    664 
    665 	struct {
    666 		long long msg;
    667 		long long rrset;
    668 		long long val;
    669 		long long iter;
    670 		long long subnet;
    671 		long long ipsecmod;
    672 		long long respip;
    673 		long long dnscrypt_shared_secret;
    674 		long long dnscrypt_nonce;
    675 		long long dynlib;
    676 	} mem;
    677 };
    678 
    679 /** number of qtype that is stored for in array */
    680 #define UB_STATS_QTYPE_NUM 256
    681 /** number of qclass that is stored for in array */
    682 #define UB_STATS_QCLASS_NUM 256
    683 /** number of rcodes in stats */
    684 #define UB_STATS_RCODE_NUM 16
    685 /** number of opcodes in stats */
    686 #define UB_STATS_OPCODE_NUM 16
    687 /** number of histogram buckets */
    688 #define UB_STATS_BUCKET_NUM 40
    689 /** number of RPZ actions */
    690 #define UB_STATS_RPZ_ACTION_NUM 10
    691 
    692 /** per worker statistics. */
    693 struct ub_server_stats {
    694 	/** number of queries from clients received. */
    695 	long long num_queries;
    696 	/** number of queries that have been dropped/ratelimited by ip. */
    697 	long long num_queries_ip_ratelimited;
    698 	/** number of queries with a valid DNS Cookie. */
    699 	long long num_queries_cookie_valid;
    700 	/** number of queries with only the client part of the DNS Cookie. */
    701 	long long num_queries_cookie_client;
    702 	/** number of queries with invalid DNS Cookie. */
    703 	long long num_queries_cookie_invalid;
    704 	/** number of queries that had a cache-miss. */
    705 	long long num_queries_missed_cache;
    706 	/** number of prefetch queries - cachehits with prefetch */
    707 	long long num_queries_prefetch;
    708 	/** number of queries which are too late to process */
    709 	long long num_queries_timed_out;
    710 	/** the longest wait time in the queue */
    711 	long long max_query_time_us;
    712 	/**
    713 	 * Sum of the querylistsize of the worker for
    714 	 * every query that missed cache. To calculate average.
    715 	 */
    716 	long long sum_query_list_size;
    717 	/** max value of query list size reached. */
    718 	long long max_query_list_size;
    719 
    720 	/** Extended stats below (bool) */
    721 	int extended;
    722 
    723 	/** qtype stats */
    724 	long long qtype[UB_STATS_QTYPE_NUM];
    725 	/** bigger qtype values not in array */
    726 	long long qtype_big;
    727 	/** qclass stats */
    728 	long long qclass[UB_STATS_QCLASS_NUM];
    729 	/** bigger qclass values not in array */
    730 	long long qclass_big;
    731 	/** query opcodes */
    732 	long long qopcode[UB_STATS_OPCODE_NUM];
    733 	/** number of queries over TCP */
    734 	long long qtcp;
    735 	/** number of outgoing queries over TCP */
    736 	long long qtcp_outgoing;
    737 	/** number of outgoing queries over UDP */
    738 	long long qudp_outgoing;
    739 	/** number of queries over (DNS over) TLS */
    740 	long long qtls;
    741 	/** number of queries over (DNS over) HTTPS */
    742 	long long qhttps;
    743 	/** number of queries over IPv6 */
    744 	long long qipv6;
    745 	/** number of queries with QR bit */
    746 	long long qbit_QR;
    747 	/** number of queries with AA bit */
    748 	long long qbit_AA;
    749 	/** number of queries with TC bit */
    750 	long long qbit_TC;
    751 	/** number of queries with RD bit */
    752 	long long qbit_RD;
    753 	/** number of queries with RA bit */
    754 	long long qbit_RA;
    755 	/** number of queries with Z bit */
    756 	long long qbit_Z;
    757 	/** number of queries with AD bit */
    758 	long long qbit_AD;
    759 	/** number of queries with CD bit */
    760 	long long qbit_CD;
    761 	/** number of queries with EDNS OPT record */
    762 	long long qEDNS;
    763 	/** number of queries with EDNS with DO flag */
    764 	long long qEDNS_DO;
    765 	/** answer rcodes */
    766 	long long ans_rcode[UB_STATS_RCODE_NUM];
    767 	/** answers with pseudo rcode 'nodata' */
    768 	long long ans_rcode_nodata;
    769 	/** answers that were secure (AD) */
    770 	long long ans_secure;
    771 	/** answers that were bogus (withheld as SERVFAIL) */
    772 	long long ans_bogus;
    773 	/** rrsets marked bogus by validator */
    774 	long long rrset_bogus;
    775 	/** number of signature validation operations performed by validator */
    776 	long long val_ops;
    777 	/** number of queries that have been ratelimited by domain recursion. */
    778 	long long queries_ratelimited;
    779 	/** unwanted traffic received on server-facing ports */
    780 	long long unwanted_replies;
    781 	/** unwanted traffic received on client-facing ports */
    782 	long long unwanted_queries;
    783 	/** usage of tcp accept list */
    784 	long long tcp_accept_usage;
    785 	/** expired answers served from cache */
    786 	long long ans_expired;
    787 	/** histogram data exported to array
    788 	 * if the array is the same size, no data is lost, and
    789 	 * if all histograms are same size (is so by default) then
    790 	 * adding up works well. */
    791 	long long hist[UB_STATS_BUCKET_NUM];
    792 
    793 	/** number of message cache entries */
    794 	long long msg_cache_count;
    795 	/** number of rrset cache entries */
    796 	long long rrset_cache_count;
    797 	/** number of infra cache entries */
    798 	long long infra_cache_count;
    799 	/** number of key cache entries */
    800 	long long key_cache_count;
    801 
    802 	/** maximum number of collisions in the msg cache */
    803 	long long msg_cache_max_collisions;
    804 	/** maximum number of collisions in the rrset cache */
    805 	long long rrset_cache_max_collisions;
    806 
    807 	/** number of queries that used dnscrypt */
    808 	long long num_query_dnscrypt_crypted;
    809 	/** number of queries that queried dnscrypt certificates */
    810 	long long num_query_dnscrypt_cert;
    811 	/** number of queries in clear text and not asking for the certificates */
    812 	long long num_query_dnscrypt_cleartext;
    813 	/** number of malformed encrypted queries */
    814 	long long num_query_dnscrypt_crypted_malformed;
    815 	/** number of queries which did not have a shared secret in cache */
    816 	long long num_query_dnscrypt_secret_missed_cache;
    817 	/** number of dnscrypt shared secret cache entries */
    818 	long long shared_secret_cache_count;
    819 	/** number of queries which are replays */
    820 	long long num_query_dnscrypt_replay;
    821 	/** number of dnscrypt nonces cache entries */
    822 	long long nonce_cache_count;
    823 	/** number of queries for unbound's auth_zones, upstream query */
    824 	long long num_query_authzone_up;
    825 	/** number of queries for unbound's auth_zones, downstream answers */
    826 	long long num_query_authzone_down;
    827 	/** number of times neg cache records were used to generate NOERROR
    828 	 * responses. */
    829 	long long num_neg_cache_noerror;
    830 	/** number of times neg cache records were used to generate NXDOMAIN
    831 	 * responses. */
    832 	long long num_neg_cache_nxdomain;
    833 	/** number of queries answered from edns-subnet specific data */
    834 	long long num_query_subnet;
    835 	/** number of queries answered from edns-subnet specific data, and
    836 	 * the answer was from the edns-subnet cache. */
    837 	long long num_query_subnet_cache;
    838 	/** number of queries served from cachedb */
    839 	long long num_query_cachedb;
    840 	/** number of bytes in the stream wait buffers */
    841 	long long mem_stream_wait;
    842 	/** number of bytes in the HTTP2 query buffers */
    843 	long long mem_http2_query_buffer;
    844 	/** number of bytes in the HTTP2 response buffers */
    845 	long long mem_http2_response_buffer;
    846 	/** number of TLS connection resume */
    847 	long long qtls_resume;
    848 	/** RPZ action stats */
    849 	long long rpz_action[UB_STATS_RPZ_ACTION_NUM];
    850 	/** number of bytes in QUIC buffers */
    851 	long long mem_quic;
    852 	/** number of queries over (DNS over) QUIC */
    853 	long long qquic;
    854 	/** number of queries removed due to discard-timeout */
    855 	long long num_queries_discard_timeout;
    856 	/** number of queries removed due to replyaddr limit */
    857 	long long num_queries_replyaddr_limit;
    858 	/** number of queries removed due to wait-limit */
    859 	long long num_queries_wait_limit;
    860 	/** number of dns error reports generated */
    861 	long long num_dns_error_reports;
    862 };
    863 
    864 /**
    865  * Statistics to send over the control pipe when asked
    866  * This struct is made to be memcopied, sent in binary.
    867  * shm mapped with (number+1) at num_threads+1, with first as total
    868  */
    869 struct ub_stats_info {
    870 	/** the thread stats */
    871 	struct ub_server_stats svr;
    872 
    873 	/** mesh stats: current number of states */
    874 	long long mesh_num_states;
    875 	/** mesh stats: current number of reply (user) states */
    876 	long long mesh_num_reply_states;
    877 	/** mesh stats: current number of reply entries */
    878 	long long mesh_num_reply_addrs;
    879 	/** mesh stats: number of reply states overwritten with a new one */
    880 	long long mesh_jostled;
    881 	/** mesh stats: number of incoming queries dropped */
    882 	long long mesh_dropped;
    883 	/** mesh stats: replies sent */
    884 	long long mesh_replies_sent;
    885 	/** mesh stats: sum of waiting times for the replies */
    886 	long long mesh_replies_sum_wait_sec, mesh_replies_sum_wait_usec;
    887 	/** mesh stats: median of waiting times for replies (in sec) */
    888 	double mesh_time_median;
    889 };
    890 
    891 #ifdef __cplusplus
    892 }
    893 #endif
    894 
    895 #endif /* UB_UNBOUND_H */
    896