X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Fadns.h;h=f262d478ce38898a978d5089c519dff818d4f2e8;hp=21bc52495d73960ac913dc01551657715215e25d;hb=c227e3bcc4a3d9e4a076e19976f8b2bb153143e7;hpb=02b47faadfe03c3b302dadb78422e14648f07b50 diff --git a/src/adns.h b/src/adns.h index 21bc524..f262d47 100644 --- a/src/adns.h +++ b/src/adns.h @@ -3,7 +3,13 @@ * - adns user-visible API (single-threaded, without any locking) */ /* - * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson + * + * This file is + * Copyright (C) 1997-2000 Ian Jackson + * + * It is part of adns, which is + * Copyright (C) 1997-2000 Ian Jackson + * Copyright (C) 1999-2000 Tony Finch * * 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 @@ -14,24 +20,55 @@ * 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 + * 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. * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software Foundation, + * 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 to the body of adns, Ian + * thinks 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. * + * * $Id$ */ #ifndef ADNS_H_INCLUDED #define ADNS_H_INCLUDED -#ifdef __cplusplus -extern "C" { /* I really dislike this - iwj. */ -#endif #include +#include +#include #include #include +#include +#include + +#ifdef __cplusplus +extern "C" { /* I really dislike this - iwj. */ +#endif /* All struct in_addr anywhere in adns are in NETWORK byte order. */ @@ -39,123 +76,183 @@ 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_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_noenv= 0x0001,/* do not look at environment */ + adns_if_noerrprint= 0x0002,/* never print to stderr (_debug overrides) */ + adns_if_noserverwarn=0x0004,/* do not warn to stderr about duff servers 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 ignored, do not protect */ + adns_if_checkc_entex=0x0100,/* consistency checks on entry/exit to adns fns */ + adns_if_checkc_freq= 0x0300 /* consistency checks very frequently (slow!) */ } adns_initflags; typedef enum { - adns_qf_search= 0x000001, /* use the searchlist */ - adns_qf_usevc= 0x000002, /* use a virtual circuit (TCP connection) */ - adns_qf_owner= 0x000004, /* fill in the owner field in the answer */ - adns_qf_quoteok_query= 0x000010, /* allow quote-requiring chars in query domain */ - adns_qf_quoteok_cname= 0x000020, /* allow ... in CNAME we go via */ - adns_qf_quoteok_anshost= 0x000040, /* allow ... in answers expected to be hostnames */ - adns_qf_cname_loose= 0x000100, /* allow refs to CNAMEs - without, get _s_cname */ - adns_qf_cname_forbid= 0x000200, /* don't follow CNAMEs, instead give _s_cname */ - adns__qf_internalmask= 0x0ff000 + adns_qf_search= 0x00000001,/* use the searchlist */ + adns_qf_usevc= 0x00000002,/* use a virtual circuit (TCP conn) */ + adns_qf_owner= 0x00000004,/* fill in the owner field in the answer */ + adns_qf_quoteok_query= 0x00000010,/* allow special chars in query domain */ + adns_qf_quoteok_cname= 0x00000000,/* ... in CNAME we go via (now default) */ + adns_qf_quoteok_anshost=0x00000040,/* ... in things supposedly 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__rrt_typemask=0x0ffff, + adns__qtf_deref= 0x10000, /* dereference domains; perhaps get extra data */ + adns__qtf_mail822= 0x20000, /* return mailboxes in RFC822 rcpt field fmt */ + + 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, /* do not mind PTR with wrong or missing A */ + 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. 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. - * - * Do not ask for _raw records containing mailboxes without - * specifying _qf_anyquote. +/* + * 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 unquoted. On + * output, the char* is a pointer to a string which would be legal + * either inside or outside " delimiters; any character which isn't + * legal in a hostname (ie alphanumeric or hyphen) or one of _ / + + * (the three other punctuation characters commonly abused in domain + * names) will be quoted, as \X if it is a printing ASCII character or + * \DDD otherwise. + * + * 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 "). If the local-part is legal + * without quoting according to RFC822, it is presented as-is. In any + * case the local-part is followed by an @ and the domain. The domain + * will not contain any characters not legal in hostnames. + * + * Unquoted local-parts may contain any printing 7-bit ASCII + * except the punctuation characters ( ) < > @ , ; : \ " [ ] + * I.e. they may contain alphanumerics, and the following + * punctuation characters: ! # % ^ & * - _ = + { } . + * + * adns will reject local parts containing control characters (byte + * values 0-31, 127-159, and 255) - these appear to be legal according + * to RFC822 (at least 0-127) but are clearly a bad idea. RFC1035 + * syntax does not make any distinction between a single RFC822 + * quoted-string containing full stops, and a series of quoted-strings + * separated by full stops; adns will return anything that isn't all + * valid atoms as a single quoted-string. RFC822 does not allow + * high-bit-set characters at all, but adns does allow them in + * local-parts, treating them as needing quoting. + * + * 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 + * case. */ 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_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, but 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 { @@ -183,10 +280,11 @@ typedef struct { } 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). + /* 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; @@ -204,23 +302,23 @@ typedef struct { typedef struct { adns_status status; char *cname; /* always NULL if query was for CNAME records */ - char *owner; /* only set if requested in query flags */ + char *owner; /* only set if req'd in query flags; maybe 0 on error anyway */ 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; + time_t expires;/*abs time. def 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 */ + char *(*str); /* ns_raw, cname, ptr, ptr_raw */ + adns_rr_intstr *(*manyistr); /* txt (list strs 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; @@ -243,9 +341,9 @@ typedef struct { * values. * * For _wait and _check failures are reported in the answer - * structure, and only 0, ESRCH or (for _check) EWOULDBLOCK is + * structure, and only 0, ESRCH or (for _check) EAGAIN is * returned: if no (appropriate) requests are done adns_check returns - * EWOULDBLOCK; if no (appropriate) requests are outstanding both + * 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. @@ -263,6 +361,119 @@ int adns_init(adns_state *newstate_r, adns_initflags flags, int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, FILE *diagfile /*0=>discard*/, const char *configtext); +typedef void adns_logcallbackfn(adns_state ads, void *logfndata, + const char *fmt, va_list al); + /* Will be called perhaps several times for each message; when the + * message is complete, the string implied by fmt and al will end in + * a newline. Log messages start with `adns debug:' or `adns + * warning:' or `adns:' (for errors), or `adns debug [PID]:' + * etc. if adns_if_logpid is set. */ + +int adns_init_logfn(adns_state *newstate_r, adns_initflags flags, + const char *configtext /*0=>use default config files*/, + adns_logcallbackfn *logfn /*0=>logfndata is a FILE* */, + void *logfndata /*0 with logfn==0 => discard*/); + +/* 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
+ * 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 ... + * 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 + * 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 / ... + * 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 + * 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: + * 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 + * 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, @@ -281,6 +492,8 @@ int adns_submit(adns_state ads, 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, @@ -291,6 +504,12 @@ int adns_wait(adns_state ads, 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 @@ -300,6 +519,32 @@ void adns_cancel(adns_query query); * 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. + */ + +int adns_submit_reverse_any(adns_state ads, + const struct sockaddr *addr, + const char *rzone, + adns_rrtype type, + adns_queryflags flags, + void *context, + adns_query *query_r); +/* For RBL-style reverse `zone's; look up + * . + * Any type is allowed. _qf_search is ignored. + * addr->sa_family must be AF_INET or you get ENOSYS. */ void adns_finish(adns_state ads); @@ -325,6 +570,13 @@ adns_query adns_forallqueries_next(adns_state ads, void **context_r); * 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 @@ -332,7 +584,7 @@ adns_query adns_forallqueries_next(adns_state ads, void **context_r); * adns_submit 2 * adns_submit 3 * adns_wait 1 - * adns_check 3 -> EWOULDBLOCK + * adns_check 3 -> EAGAIN * adns_wait 2 * adns_wait 3 * .... @@ -364,7 +616,7 @@ int adns_processexceptional(adns_state ads, int fd, const struct timeval *now); * 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_ - * that fd and only in the manner specified, regardless of whether + * 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 @@ -434,9 +686,10 @@ void adns_beforeselect(adns_state ads, int *maxfd, fd_set *readfds, * 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. + * If tv_mod is 0 on entry 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, and it will set the timeout to zero if a + * query finishes in _beforeselect. */ void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, @@ -473,7 +726,8 @@ struct pollfd; * entrypoints will not be defined in libadns. Sorry ! */ -int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeout_io, +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 @@ -490,7 +744,7 @@ int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeo * in *nfds_io, and always return either 0 (if it is not interested in * any fds) or ERANGE (if it is). * - * NOTE that (unless timeout_io is 0) adns may acquire additional fds + * 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. @@ -511,9 +765,11 @@ int adns_beforepoll(adns_state ads, struct pollfd *fds, int *nfds_io, int *timeo * 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, or change the fds that - * adns is using or the timeouts it wants; and in any case it won't - * block. + * 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 @@ -535,21 +791,22 @@ 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); -/* Gets information in human-readable (but non-i18n) form - * for eg debugging purposes. 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 human-readable text - * string representing the RR data. The text will have - * been obtained from malloc() and must be freed by the caller. +/* + * 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 @@ -557,13 +814,47 @@ adns_status adns_rr_info(adns_rrtype type, * 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 temporary + * failure, then a single ? appears instead of the ( ). If the + * result was a permanent 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". You MUST NOT call these functions with status values + * "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. */