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Diffstat (limited to 'adns-0.6/src/adns.h')
| -rw-r--r-- | adns-0.6/src/adns.h | 818 |
1 files changed, 0 insertions, 818 deletions
diff --git a/adns-0.6/src/adns.h b/adns-0.6/src/adns.h deleted file mode 100644 index 588acba..0000000 --- a/adns-0.6/src/adns.h +++ /dev/null @@ -1,818 +0,0 @@ -/* - * adns.h - * - adns user-visible API (single-threaded, without any locking) - */ -/* - * - * This file is - * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> - * - * It is part of adns, which is - * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> - * Copyright (C) 1999 Tony Finch <dot@dotat.at> - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2, or (at your option) - * any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * - * For the benefit of certain LGPL'd `omnibus' software which provides - * a uniform interface to various things including adns, I make the - * following additional licence. I do this because the GPL would - * otherwise force either the omnibus software to be GPL'd or for the - * adns-using part to be distributed separately. - * - * So, you may also redistribute and/or modify adns.h (but only the - * public header file adns.h and not any other part of adns) under the - * terms of the GNU Library General Public License as published by the - * Free Software Foundation; either version 2 of the License, or (at - * your option) any later version. - * - * Note that adns itself is GPL'd. Authors of adns-using applications - * with GPL-incompatible licences, and people who distribute adns with - * applications where the whole distribution is not GPL'd, are still - * likely to be in violation of the GPL. Anyone who wants to do this - * should contact Ian Jackson. Please note that to avoid encouraging - * people to infringe the GPL as it applies the body of adns, I think - * that if you take advantage of the special exception to redistribute - * just adns.h under the LGPL, you should retain this paragraph in its - * place in the appropriate copyright statements. - * - * - * You should have received a copy of the GNU General Public License, - * or the GNU Library General Public License, as appropriate, along - * with this program; if not, write to the Free Software Foundation, - * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * - * $Id: adns.h,v 1.1.1.1 2000-02-16 17:32:46 sdyoung Exp $ - */ - -#ifndef ADNS_H_INCLUDED -#define ADNS_H_INCLUDED -#ifdef __cplusplus -extern "C" { /* I really dislike this - iwj. */ -#endif - -#include <stdio.h> - -#include <sys/socket.h> -#include <netinet/in.h> -#include <sys/types.h> -#include <sys/time.h> -#include <unistd.h> - -/* All struct in_addr anywhere in adns are in NETWORK byte order. */ - -typedef struct adns__state *adns_state; -typedef struct adns__query *adns_query; - -typedef enum { - adns_if_noenv= 0x0001, /* do not look at environment */ - adns_if_noerrprint= 0x0002, /* never print output to stderr (_debug overrides) */ - adns_if_noserverwarn= 0x0004, /* do not warn to stderr about duff nameservers etc */ - adns_if_debug= 0x0008, /* enable all output to stderr plus debug msgs */ - adns_if_logpid= 0x0080, /* include pid in diagnostic output */ - adns_if_noautosys= 0x0010, /* do not make syscalls at every opportunity */ - adns_if_eintr= 0x0020, /* allow _wait and _synchronous to return EINTR */ - adns_if_nosigpipe= 0x0040, /* applic has SIGPIPE set to SIG_IGN, do not protect */ - adns_if_checkc_entex= 0x0100, /* do consistency checks on entry/exit to adns funcs */ - adns_if_checkc_freq= 0x0300 /* do consistency checks very frequently (slow!) */ -} adns_initflags; - -typedef enum { - adns_qf_search= 0x00000001, /* use the searchlist */ - adns_qf_usevc= 0x00000002, /* use a virtual circuit (TCP connection) */ - adns_qf_owner= 0x00000004, /* fill in the owner field in the answer */ - adns_qf_quoteok_query= 0x00000010, /* allow quote-requiring chars in query domain */ - adns_qf_quoteok_cname= 0x00000000, /* allow ... in CNAME we go via - now default */ - adns_qf_quoteok_anshost= 0x00000040, /* allow ... in things supposed to be hostnames */ - adns_qf_quotefail_cname= 0x00000080, /* refuse if quote-req chars in CNAME we go via */ - adns_qf_cname_loose= 0x00000100, /* allow refs to CNAMEs - without, get _s_cname */ - adns_qf_cname_forbid= 0x00000200, /* don't follow CNAMEs, instead give _s_cname */ - adns__qf_internalmask= 0x0ff00000 -} adns_queryflags; - -typedef enum { - adns__rrt_typemask= 0x0ffff, - adns__qtf_deref= 0x10000, /* dereference domains and perhaps produce extra data */ - adns__qtf_mail822= 0x20000, /* make mailboxes be in RFC822 rcpt field format */ - - adns_r_none= 0, - - adns_r_a= 1, - - adns_r_ns_raw= 2, - adns_r_ns= adns_r_ns_raw|adns__qtf_deref, - - adns_r_cname= 5, - - adns_r_soa_raw= 6, - adns_r_soa= adns_r_soa_raw|adns__qtf_mail822, - - adns_r_ptr_raw= 12, - adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, - - adns_r_hinfo= 13, - - adns_r_mx_raw= 15, - adns_r_mx= adns_r_mx_raw|adns__qtf_deref, - - adns_r_txt= 16, - - adns_r_rp_raw= 17, - adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, - - adns_r_addr= adns_r_a|adns__qtf_deref - -} adns_rrtype; - -/* - * In queries without qf_quoteok_*, all domains must have standard - * legal syntax, or you get adns_s_querydomainvalid (if the query - * domain contains bad characters) or adns_s_answerdomaininvalid (if - * the answer contains bad characters). - * - * In queries _with_ qf_quoteok_*, domains in the query or response - * may contain any characters, quoted according to RFC1035 5.1. On - * input to adns, the char* is a pointer to the interior of a " - * delimited string, except that " may appear in it, and on output, - * the char* is a pointer to a string which would be legal either - * inside or outside " delimiters, and any characters not usually - * legal in domain names will be quoted as \X (if the character is - * 33-126 except \ and ") or \DDD. - * - * If the query goes via a CNAME then the canonical name (ie, the - * thing that the CNAME record refers to) is usually allowed to - * contain any characters, which will be quoted as above. With - * adns_qf_quotefail_cname you get adns_s_answerdomaininvalid when - * this happens. (This is a change from version 0.4 and earlier, in - * which failing the query was the default, and you had to say - * adns_qf_quoteok_cname to avoid this; that flag is now deprecated.) - * - * In version 0.4 and earlier, asking for _raw records containing - * mailboxes without specifying _qf_quoteok_anshost was silly. This - * is no longer the case. In this version only parts of responses - * that are actually supposed to be hostnames will be refused by - * default if quote-requiring characters are found. - */ - -/* - * If you ask for an RR which contains domains which are actually - * encoded mailboxes, and don't ask for the _raw version, then adns - * returns the mailbox formatted suitably for an RFC822 recipient - * header field. The particular format used is that if the mailbox - * requires quoting according to the rules in RFC822 then the - * local-part is quoted in double quotes, which end at the next - * unescaped double quote. (\ is the escape char, and is doubled, and - * is used to escape only \ and ".) Otherwise the local-part is - * presented as-is. In any case this is followed by an @ and the - * domain. The domain will not contain any characters not legal in - * hostnames. adns will protect the application from local parts - * containing control characters - these appear to be legal according - * to RFC822 but are clearly a bad idea. - * - * If you ask for the domain with _raw then _no_ checking is done - * (even on the host part, regardless of adns_qf_quoteok_anshost), and - * you just get the domain name in master file format. - * - * If no mailbox is supplied the returned string will be `.' in either - * caswe. - */ - -typedef enum { - adns_s_ok, - - /* locally induced errors */ - adns_s_nomemory, - adns_s_unknownrrtype, - adns_s_systemfail, - - adns_s_max_localfail= 29, - - /* remotely induced errors, detected locally */ - adns_s_timeout, - adns_s_allservfail, - adns_s_norecurse, - adns_s_invalidresponse, - adns_s_unknownformat, - - adns_s_max_remotefail= 59, - - /* remotely induced errors, reported by remote server to us */ - adns_s_rcodeservfail, - adns_s_rcodeformaterror, - adns_s_rcodenotimplemented, - adns_s_rcoderefused, - adns_s_rcodeunknown, - - adns_s_max_tempfail= 99, - - /* remote configuration errors */ - adns_s_inconsistent, /* PTR gives domain whose A does not exist and match */ - adns_s_prohibitedcname, /* CNAME found where eg A expected (not if _qf_loosecname) */ - adns_s_answerdomaininvalid, - adns_s_answerdomaintoolong, - adns_s_invaliddata, - - adns_s_max_misconfig= 199, - - /* permanent problems with the query */ - adns_s_querydomainwrong, - adns_s_querydomaininvalid, - adns_s_querydomaintoolong, - - adns_s_max_misquery= 299, - - /* permanent errors */ - adns_s_nxdomain, - adns_s_nodata, - - adns_s_max_permfail= 499 - -} adns_status; - -typedef struct { - int len; - union { - struct sockaddr sa; - struct sockaddr_in inet; - } addr; -} adns_rr_addr; - -typedef struct { - char *host; - adns_status astatus; - int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */ - adns_rr_addr *addrs; -} adns_rr_hostaddr; - -typedef struct { - char *(array[2]); -} adns_rr_strpair; - -typedef struct { - int i; - adns_rr_hostaddr ha; -} adns_rr_inthostaddr; - -typedef struct { - /* Used both for mx_raw, in which case i is the preference and str the domain, - * and for txt, in which case each entry has i for the `text' length, - * and str for the data (which will have had an extra nul appended - * so that if it was plain text it is now a null-terminated string). - */ - int i; - char *str; -} adns_rr_intstr; - -typedef struct { - adns_rr_intstr array[2]; -} adns_rr_intstrpair; - -typedef struct { - char *mname, *rname; - unsigned long serial, refresh, retry, expire, minimum; -} adns_rr_soa; - -typedef struct { - adns_status status; - char *cname; /* always NULL if query was for CNAME records */ - char *owner; /* only set if requested in query flags */ - adns_rrtype type; /* guaranteed to be same as in query */ - time_t expires; /* expiry time, defined only if _s_ok, nxdomain or nodata. NOT TTL! */ - int nrrs, rrsz; /* nrrs is 0 if an error occurs */ - union { - void *untyped; - unsigned char *bytes; - char *(*str); /* ns_raw, cname, ptr, ptr_raw */ - adns_rr_intstr *(*manyistr); /* txt (list of strings ends with i=-1, str=0) */ - adns_rr_addr *addr; /* addr */ - struct in_addr *inaddr; /* a */ - adns_rr_hostaddr *hostaddr; /* ns */ - adns_rr_intstrpair *intstrpair; /* hinfo */ - adns_rr_strpair *strpair; /* rp, rp_raw */ - adns_rr_inthostaddr *inthostaddr; /* mx */ - adns_rr_intstr *intstr; /* mx_raw */ - adns_rr_soa *soa; /* soa, soa_raw */ - } rrs; -} adns_answer; - -/* Memory management: - * adns_state and adns_query are actually pointers to malloc'd state; - * On submission questions are copied, including the owner domain; - * Answers are malloc'd as a single piece of memory; pointers in the - * answer struct point into further memory in the answer. - * query_io: - * Must always be non-null pointer; - * If *query_io is 0 to start with then any query may be returned; - * If *query_io is !0 adns_query then only that query may be returned. - * If the call is successful, *query_io, *answer_r, and *context_r - * will all be set. - * Errors: - * Return values are 0 or an errno value. - * - * For _init, _init_strcfg, _submit and _synchronous, system errors - * (eg, failure to create sockets, malloc failure, etc.) return errno - * values. - * - * For _wait and _check failures are reported in the answer - * structure, and only 0, ESRCH or (for _check) EAGAIN is - * returned: if no (appropriate) requests are done adns_check returns - * EAGAIN; if no (appropriate) requests are outstanding both - * adns_query and adns_wait return ESRCH. - * - * Additionally, _wait can return EINTR if you set adns_if_eintr. - * - * All other errors (nameserver failure, timed out connections, &c) - * are returned in the status field of the answer. After a - * successful _wait or _check, if status is nonzero then nrrs will be - * 0, otherwise it will be >0. type will always be the type - * requested. - */ - -int adns_init(adns_state *newstate_r, adns_initflags flags, - FILE *diagfile /*0=>stderr*/); - -int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, - FILE *diagfile /*0=>discard*/, const char *configtext); - -/* Configuration: - * adns_init reads /etc/resolv.conf, which is expected to be (broadly - * speaking) in the format expected by libresolv, and then - * /etc/resolv-adns.conf if it exists. adns_init_strcfg is instead - * passed a string which is interpreted as if it were the contents of - * resolv.conf or resolv-adns.conf. In general, configuration which - * is set later overrides any that is set earlier. - * - * Standard directives understood in resolv[-adns].conf: - * - * nameserver <address> - * Must be followed by the IP address of a nameserver. Several - * nameservers may be specified, and they will be tried in the order - * found. There is a compiled in limit, currently 5, on the number - * of nameservers. (libresolv supports only 3 nameservers.) - * - * search <domain> ... - * Specifies the search list for queries which specify - * adns_qf_search. This is a list of domains to append to the query - * domain. The query domain will be tried as-is either before all - * of these or after them, depending on the ndots option setting - * (see below). - * - * domain <domain> - * This is present only for backward compatibility with obsolete - * versions of libresolv. It should not be used, and is interpreted - * by adns as if it were `search' - note that this is subtly - * different to libresolv's interpretation of this directive. - * - * sortlist <addr>/<mask> ... - * Should be followed by a sequence of IP-address and netmask pairs, - * separated by spaces. They may be specified as - * eg. 172.30.206.0/24 or 172.30.206.0/255.255.255.0. Currently up - * to 15 pairs may be specified (but note that libresolv only - * supports up to 10). - * - * options - * Should followed by one or more options, separated by spaces. - * Each option consists of an option name, followed by optionally - * a colon and a value. Options are listed below. - * - * Non-standard directives understood in resolv[-adns].conf: - * - * clearnameservers - * Clears the list of nameservers, so that further nameserver lines - * start again from the beginning. - * - * include <filename> - * The specified file will be read. - * - * Additionally, adns will ignore lines in resolv[-adns].conf which - * start with a #. - * - * Standard options understood: - * - * debug - * Enables debugging output from the resolver, which will be written - * to stderr. - * - * ndots:<count> - * Affects whether queries with adns_qf_search will be tried first - * without adding domains from the searchlist, or whether the bare - * query domain will be tried last. Queries which contain at least - * <count> dots will be tried bare first. The default is 1. - * - * Non-standard options understood: - * - * adns_checkc:none - * adns_checkc:entex - * adns_checkc:freq - * Changes the consistency checking frequency; this overrides the - * setting of adns_if_check_entex, adns_if_check_freq, or neither, - * in the flags passed to adns_init. - * - * There are a number of environment variables which can modify the - * behaviour of adns. They take effect only if adns_init is used, and - * the caller of adns_init can disable them using adns_if_noenv. In - * each case there is both a FOO and an ADNS_FOO; the latter is - * interpreted later so that it can override the former. Unless - * otherwise stated, environment variables are interpreted after - * resolv[-adns].conf are read, in the order they are listed here. - * - * RES_CONF, ADNS_RES_CONF - * A filename, whose contets are in the format of resolv.conf. - * - * RES_CONF_TEXT, ADNS_RES_CONF_TEXT - * A string in the format of resolv.conf. - * - * RES_OPTIONS, ADNS_RES_OPTIONS - * These are parsed as if they appeared in the `options' line of a - * resolv.conf. In addition to being parsed at this point in the - * sequence, they are also parsed at the very beginning before - * resolv.conf or any other environment variables are read, so that - * any debug option can affect the processing of the configuration. - * - * LOCALDOMAIN, ADNS_LOCALDOMAIN - * These are interpreted as if their contents appeared in a `search' - * line in resolv.conf. - */ - -int adns_synchronous(adns_state ads, - const char *owner, - adns_rrtype type, - adns_queryflags flags, - adns_answer **answer_r); - -/* NB: if you set adns_if_noautosys then _submit and _check do not - * make any system calls; you must use some of the asynch-io event - * processing functions to actually get things to happen. - */ - -int adns_submit(adns_state ads, - const char *owner, - adns_rrtype type, - adns_queryflags flags, - void *context, - adns_query *query_r); - -/* The owner should be quoted in master file format. */ - -int adns_check(adns_state ads, - adns_query *query_io, - adns_answer **answer_r, - void **context_r); - -int adns_wait(adns_state ads, - adns_query *query_io, - adns_answer **answer_r, - void **context_r); - -/* same as adns_wait but uses poll(2) internally */ -int adns_wait_poll(adns_state ads, - adns_query *query_io, - adns_answer **answer_r, - void **context_r); - -void adns_cancel(adns_query query); - -/* The adns_query you get back from _submit is valid (ie, can be - * legitimately passed into adns functions) until it is returned by - * adns_check or adns_wait, or passed to adns_cancel. After that it - * must not be used. You can rely on it not being reused until the - * first adns_submit or _transact call using the same adns_state after - * it became invalid, so you may compare it for equality with other - * query handles until you next call _query or _transact. - * - * _submit and _synchronous return ENOSYS if they don't understand the - * query type. - */ - -int adns_submit_reverse(adns_state ads, - const struct sockaddr *addr, - adns_rrtype type, - adns_queryflags flags, - void *context, - adns_query *query_r); -/* type must be _r_ptr or _r_ptr_raw. _qf_search is ignored. - * addr->sa_family must be AF_INET or you get ENOSYS. - */ - -void adns_finish(adns_state ads); -/* You may call this even if you have queries outstanding; - * they will be cancelled. - */ - - -void adns_forallqueries_begin(adns_state ads); -adns_query adns_forallqueries_next(adns_state ads, void **context_r); -/* Iterator functions, which you can use to loop over the outstanding - * (submitted but not yet successfuly checked/waited) queries. - * - * You can only have one iteration going at once. You may call _begin - * at any time; after that, an iteration will be in progress. You may - * only call _next when an iteration is in progress - anything else - * may coredump. The iteration remains in progress until _next - * returns 0, indicating that all the queries have been walked over, - * or ANY other adns function is called with the same adns_state (or a - * query in the same adns_state). There is no need to explicitly - * finish an iteration. - * - * context_r may be 0. *context_r may not be set when _next returns 0. - */ - -void adns_checkconsistency(adns_state ads, adns_query qu); -/* Checks the consistency of adns's internal data structures. - * If any error is found, the program will abort(). - * You may pass 0 for qu; if you pass non-null then additional checks - * are done to make sure that qu is a valid query. - */ - -/* - * Example expected/legal calling sequence for submit/check/wait: - * adns_init - * adns_submit 1 - * adns_submit 2 - * adns_submit 3 - * adns_wait 1 - * adns_check 3 -> EAGAIN - * adns_wait 2 - * adns_wait 3 - * .... - * adns_finish - */ - -/* - * Entrypoints for generic asynch io: - * (these entrypoints are not very useful except in combination with * - * some of the other I/O model calls which can tell you which fds to - * be interested in): - * - * Note that any adns call may cause adns to open and close fds, so - * you must call beforeselect or beforepoll again just before - * blocking, or you may not have an up-to-date list of it's fds. - */ - -int adns_processany(adns_state ads); -/* Gives adns flow-of-control for a bit. This will never block, and - * can be used with any threading/asynch-io model. If some error - * occurred which might cause an event loop to spin then the errno - * value is returned. - */ - -int adns_processreadable(adns_state ads, int fd, const struct timeval *now); -int adns_processwriteable(adns_state ads, int fd, const struct timeval *now); -int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); -/* Gives adns flow-of-control so that it can process incoming data - * from, or send outgoing data via, fd. Very like _processany. If it - * returns zero then fd will no longer be readable or writeable - * (unless of course more data has arrived since). adns will _only_ - * use that fd and only in the manner specified, regardless of whether - * adns_if_noautosys was specified. - * - * adns_processexceptional should be called when select(2) reports an - * exceptional condition, or poll(2) reports POLLPRI. - * - * It is fine to call _processreabable or _processwriteable when the - * fd is not ready, or with an fd that doesn't belong to adns; it will - * then just return 0. - * - * If some error occurred which might prevent an event loop to spin - * then the errno value is returned. - */ - -void adns_processtimeouts(adns_state ads, const struct timeval *now); -/* Gives adns flow-of-control so that it can process any timeouts - * which might have happened. Very like _processreadable/writeable. - * - * now may be 0; if it isn't, *now must be the current time, recently - * obtained from gettimeofday. - */ - -void adns_firsttimeout(adns_state ads, - struct timeval **tv_mod, struct timeval *tv_buf, - struct timeval now); -/* Asks adns when it would first like the opportunity to time - * something out. now must be the current time, from gettimeofday. - * - * If tv_mod points to 0 then tv_buf must be non-null, and - * _firsttimeout will fill in *tv_buf with the time until the first - * timeout, and make *tv_mod point to tv_buf. If adns doesn't have - * anything that might need timing out it will leave *tv_mod as 0. - * - * If *tv_mod is not 0 then tv_buf is not used. adns will update - * *tv_mod if it has any earlier timeout, and leave it alone if it - * doesn't. - * - * This call will not actually do any I/O, or change the fds that adns - * is using. It always succeeds and never blocks. - */ - -void adns_globalsystemfailure(adns_state ads); -/* If serious problem(s) happen which globally affect your ability to - * interact properly with adns, or adns's ability to function - * properly, you or adns can call this function. - * - * All currently outstanding queries will be made to fail with - * adns_s_systemfail, and adns will close any stream sockets it has - * open. - * - * This is used by adns, for example, if gettimeofday() fails. - * Without this the program's event loop might start to spin ! - * - * This call will never block. - */ - -/* - * Entrypoints for select-loop based asynch io: - */ - -void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, - fd_set *writefds, fd_set *exceptfds, - struct timeval **tv_mod, struct timeval *tv_buf, - const struct timeval *now); -/* Find out file descriptors adns is interested in, and when it would - * like the opportunity to time something out. If you do not plan to - * block then tv_mod may be 0. Otherwise, tv_mod and tv_buf are as - * for adns_firsttimeout. readfds, writefds, exceptfds and maxfd_io may - * not be 0. - * - * If *now is not 0 then this will never actually do any I/O, or - * change the fds that adns is using or the timeouts it wants. In any - * case it won't block. - */ - -void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, - const fd_set *writefds, const fd_set *exceptfds, - const struct timeval *now); -/* Gives adns flow-of-control for a bit; intended for use after - * select. This is just a fancy way of calling adns_processreadable/ - * writeable/timeouts as appropriate, as if select had returned the - * data being passed. Always succeeds. - */ - -/* - * Example calling sequence: - * - * adns_init _noautosys - * loop { - * adns_beforeselect - * select - * adns_afterselect - * ... - * adns_submit / adns_check - * ... - * } - */ - -/* - * Entrypoints for poll-loop based asynch io: - */ - -struct pollfd; -/* In case your system doesn't have it or you forgot to include - * <sys/poll.h>, to stop the following declarations from causing - * problems. If your system doesn't have poll then the following - * entrypoints will not be defined in libadns. Sorry ! - */ - -int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeout_io, - const struct timeval *now); -/* Finds out which fd's adns is interested in, and when it would like - * to be able to time things out. This is in a form suitable for use - * with poll(2). - * - * On entry, usually fds should point to at least *nfds_io structs. - * adns will fill up to that many structs will information for poll, - * and record in *nfds_io how many structs it filled. If it wants to - * listen for more structs then *nfds_io will be set to the number - * required and _beforepoll will return ERANGE. - * - * You may call _beforepoll with fds==0 and *nfds_io 0, in which case - * adns will fill in the number of fds that it might be interested in - * in *nfds_io, and always return either 0 (if it is not interested in - * any fds) or ERANGE (if it is). - * - * NOTE that (unless now is 0) adns may acquire additional fds - * from one call to the next, so you must put adns_beforepoll in a - * loop, rather than assuming that the second call (with the buffer - * size requested by the first) will not return ERANGE. - * - * adns only ever sets POLLIN, POLLOUT and POLLPRI in its pollfd - * structs, and only ever looks at those bits. POLLPRI is required to - * detect TCP Urgent Data (which should not be used by a DNS server) - * so that adns can know that the TCP stream is now useless. - * - * In any case, *timeout_io should be a timeout value as for poll(2), - * which adns will modify downwards as required. If the caller does - * not plan to block then *timeout_io should be 0 on entry, or - * alternatively, timeout_io may be 0. (Alternatively, the caller may - * use _beforeselect with timeout_io==0 to find out about file - * descriptors, and use _firsttimeout is used to find out when adns - * might want to time something out.) - * - * adns_beforepoll will return 0 on success, and will not fail for any - * reason other than the fds buffer being too small (ERANGE). - * - * This call will never actually do any I/O. If you supply the - * current time it will not change the fds that adns is using or the - * timeouts it wants. - * - * In any case this call won't block. - */ - -#define ADNS_POLLFDS_RECOMMENDED 2 -/* If you allocate an fds buf with at least RECOMMENDED entries then - * you are unlikely to need to enlarge it. You are recommended to do - * so if it's convenient. However, you must be prepared for adns to - * require more space than this. - */ - -void adns_afterpoll(adns_state ads, const struct pollfd *fds, int nfds, - const struct timeval *now); -/* Gives adns flow-of-control for a bit; intended for use after - * poll(2). fds and nfds should be the results from poll(). pollfd - * structs mentioning fds not belonging to adns will be ignored. - */ - - -adns_status adns_rr_info(adns_rrtype type, - const char **rrtname_r, const char **fmtname_r, - int *len_r, - const void *datap, char **data_r); -/* - * Get information about a query type, or convert reply data to a - * textual form. type must be specified, and the official name of the - * corresponding RR type will be returned in *rrtname_r, and - * information about the processing style in *fmtname_r. The length - * of the table entry in an answer for that type will be returned in - * in *len_r. Any or all of rrtname_r, fmtname_r and len_r may be 0. - * If fmtname_r is non-null then *fmtname_r may be null on return, - * indicating that no special processing is involved. - * - * data_r be must be non-null iff datap is. In this case *data_r will - * be set to point to a string pointing to a representation of the RR - * data in master file format. (The owner name, timeout, class and - * type will not be present - only the data part of the RR.) The - * memory will have been obtained from malloc() and must be freed by - * the caller. - * - * Usually this routine will succeed. Possible errors include: - * adns_s_nomemory - * adns_s_rrtypeunknown - * adns_s_invaliddata (*datap contained garbage) - * If an error occurs then no memory has been allocated, - * and *rrtname_r, *fmtname_r, *len_r and *data_r are undefined. - * - * There are some adns-invented data formats which are not official - * master file formats. These include: - * - * Mailboxes if __qtf_mail822: these are just included as-is. - * - * Addresses (adns_rr_addr): these may be of pretty much any type. - * The representation is in two parts: first, a word for the address - * family (ie, in AF_XXX, the XXX), and then one or more items for the - * address itself, depending on the format. For an IPv4 address the - * syntax is INET followed by the dotted quad (from inet_ntoa). - * Currently only IPv4 is supported. - * - * Text strings (as in adns_rr_txt) appear inside double quotes, and - * use \" and \\ to represent " and \, and \xHH to represent - * characters not in the range 32-126. - * - * Hostname with addresses (adns_rr_hostaddr): this consists of the - * hostname, as usual, followed by the adns_status value, as an - * abbreviation, and then a descriptive string (encoded as if it were - * a piece of text), for the address lookup, followed by zero or more - * addresses enclosed in ( and ). If the result was a permanent - * failure, then a single ? appears instead of the ( ). If the - * result was a temporary failure then an empty pair of parentheses - * appears (which a space in between). For example, one of the NS - * records for greenend.org.uk comes out like - * ns.chiark.greenend.org.uk ok "OK" ( INET 195.224.76.132 ) - * an MX referring to a nonexistent host might come out like: - * 50 sun2.nsfnet-relay.ac.uk nxdomain "No such domain" ( ) - * and if nameserver information is not available you might get: - * dns2.spong.dyn.ml.org timeout "DNS query timed out" ? - */ - -const char *adns_strerror(adns_status st); -const char *adns_errabbrev(adns_status st); -const char *adns_errtypeabbrev(adns_status st); -/* Like strerror but for adns_status values. adns_errabbrev returns - * the abbreviation of the error - eg, for adns_s_timeout it returns - * "timeout". adns_errtypeabbrev returns the abbreviation of the - * error class: ie, for values up to adns_s_max_XXX it will return the - * string XXX. You MUST NOT call these functions with status values - * not returned by the same adns library. - */ - -#ifdef __cplusplus -} /* end of extern "C" */ -#endif -#endif |