X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Fadns.h;h=400ba9f466b68a26bc303475be1c1d738cf6392d;hp=61b3fc8138d3c33fa2bc096420d3896c811d8a4d;hb=a1d593db283023f2f7763df26389eb6a54b82d7f;hpb=a17d3a1d960ca40434205a80aa106ca4c7224ec9 diff --git a/src/adns.h b/src/adns.h index 61b3fc8..400ba9f 100644 --- a/src/adns.h +++ b/src/adns.h @@ -1,89 +1,232 @@ -/**/ +/* + * adns.h + * - adns user-visible API (single-threaded, without any locking) + */ +/* + * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson + * + * 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. + * + * You should have received a copy of the GNU General Public License + * 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 -typedef struct adns__state adns_state; -typedef struct adns__query adns_query; +#include + +#include +#include + +/* 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 */ - adns_if_debug= 0x0004, /* print debugging output to stderr */ + 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_initflags; typedef enum { - adns_f_search= 0x0001, /* use the searchlist */ - adns_f_usevc= 0x0002, /* use a virtual circuit (TCP connection) */ + 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_queryflags; typedef enum { - adns_rrttype_mask= 0x0fff, - adns_qtf_deref= 0x1000, - adns_qtf_mailconv= 0x2000, - 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_mailconv, - adns_r_null= 10, - adns_r_ptr_raw= 12, - adns_r_ptr= adns_r_ptr_raw|adns_rf_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_mailconv + 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 qtf_quoteok_*, all domains must have standard + * legal syntax. In queries _with_ qtf_anyquote, 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. + */ + typedef enum { adns_s_ok, - adns_s_notresponding, - adns_s_serverfailure, - adns_s_unknownqtype, - adns_s_remoteerror, + + /* locally induced errors */ + adns_s_nomemory, + adns_s_unknownrrtype, + + /* remotely induced errors, detected locally */ + adns_s_timeout, + adns_s_allservfail, + adns_s_norecurse, + adns_s_invalidresponse, + adns_s_unknownformat, + + /* 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_norecord, - adns_s_invaliddomain + adns_s_nodata, + } adns_status; -/* In dereferenced answers, multiple addresses show up as multiple - * answers with all the dm pointers being the same. If no - * address is available (permanent failure) then INADDR_NONE is - * used. */ +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; -struct adns_answer { +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 */ - adns_rrtype type; - int nrrs; + 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; union { - struct in_addr inaddr[1]; /* a */ - char (*str)[1]; /* ns_raw, cname, ptr, ptr_raw, txt */ - struct { char *dm; struct in_addr addr; } dmaddr; /* ns */ - struct { char *a, *b; } strpair[1]; /* hinfo, rp, rp_raw */ - struct { int pref; char *dm; struct in_addr addr; } intdmaddr[1]; /* mx */ - struct { int pref; char *str; } intstr[1]; /* mx_raw */ - struct { - char *ns0, *rp; - unsigned long serial, refresh, retry, expire, minimum; - } soa[1]; /* soa, soa_raw */ - /* NULL is empty */ + 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. + * 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; * Seriously fatal system errors (eg, failure to create sockets, @@ -92,47 +235,74 @@ struct adns_answer { * are returned in the status field of the answer. If status is * nonzero then nrrs will be 0, otherwise it will be >0. * type will always be the type requested; - * If no (appropriate) requests are done adns_query returns EWOULDBLOCK; - * If no requests are outstanding adns_query and adns_wait return ESRCH; - * If malloc failure occurs during internal allocation or processing - * ands_query, _wait and _answer set *answer to 0. + * If no (appropriate) requests are done adns_check returns EWOULDBLOCK; + * If no (appropriate) requests are outstanding adns_query and adns_wait return ESRCH; */ -int adns_init(adns_state *newstate_r); +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); int adns_synchronous(adns_state ads, const char *owner, adns_rrtype type, - int flags, - struct adns_answer *answer); + 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 adns_callback (possibly after + * adns_interest) to actually get things to happen. + */ int adns_submit(adns_state ads, const char *owner, adns_rrtype type, - int flags, + adns_queryflags flags, void *context, - const struct adns_query *query_r); + adns_query *query_r); -int adns_query(adns_state ads, +int adns_check(adns_state ads, adns_query *query_io, - struct adns_answer *answer, - void *context_r); + adns_answer **answer_r, + void **context_r); int adns_wait(adns_state ads, adns_query *query_io, - struct adns_answer *answer, - void *context_r); + adns_answer **answer_r, + void **context_r); -int adns_cancel(adns_state ads, adns_query query); +void adns_cancel(adns_query query); -int adns_finish(adns_state); +void adns_finish(adns_state); +/* You may call this even if you have queries outstanding; + * they will be cancelled. + */ -void adns_event(adns_state, fd_set *readfds_mod, - fd_set *writefds_mod, fd_set *exceptfds_mod, - int *maxfd_mod, struct timeval *tv_mod); -/* You may call this with *_mod=0 to have a simple callback, - or with *fds_mod=*maxfd_mod=0 but tv_mod!=0 if you are - not going to sleep, or with all !=0 if you are going to sleep. */ +int adns_callback(adns_state, int maxfd, const fd_set *readfds, const fd_set *writefds, + const fd_set *exceptfds); +/* Gives adns flow-of-control for a bit. This will never block. + * If maxfd == -1 then adns will check (make nonblocking system calls on) + * all of its own filedescriptors; otherwise it will only use those + * < maxfd and specified in the fd_set's, as if select had returned them. + * Other fd's may be in the fd_sets, and will be ignored. + * _callback returns how many adns fd's were in the various sets, so + * you can tell if your select handling code has missed something and is going awol. + * + * May also return -1 if a critical syscall failed, setting errno. + */ + +void adns_interest(adns_state, int *maxfd_io, fd_set *readfds_io, + fd_set *writefds_io, fd_set *exceptfds_io, + struct timeval **tv_mod, struct timeval *tv_buf); +/* 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 may point to 0 meaning + * you have no timeout of your own, in which case tv_buf must be non-null and + * _interest may fill it in and set *tv_mod=tv_buf. + * readfds, writefds, exceptfds and maxfd may not be 0. + */ /* Example expected/legal calling sequences: * adns_init @@ -140,21 +310,51 @@ void adns_event(adns_state, fd_set *readfds_mod, * adns_submit 2 * adns_submit 3 * adns_wait 1 - * adns_query 3 -> EWOULDBLOCK + * adns_check 3 -> EWOULDBLOCK * adns_wait 2 * adns_wait 3 * .... * adns_finish * - * adns_init - * adns_submit ... + * adns_init _noautosys * loop { - * adns_query * adns_interest * select * adns_callback - * other things + * ... + * adns_submit / adns_check + * ... * } */ +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. + * + * 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. + */ + +const char *adns_strerror(adns_status st); + #endif