X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=adns.git;a=blobdiff_plain;f=src%2Fadns.h;h=e248c10e9bf1a58bfe96b300bf80830cc0bc55c9;hp=bd6b536fad18dc3aadd9579d9f5aff82cae1c982;hb=58a876e5ac9539ff14acb7dc3ea3633f5bdb41d8;hpb=30d78b941d65919bc802d70bb264a86b705f6e20 diff --git a/src/adns.h b/src/adns.h index bd6b536..e248c10 100644 --- a/src/adns.h +++ b/src/adns.h @@ -1,19 +1,20 @@ /* * adns.h - * - adns user-visible API (single-threaded, without any locking) + * - adns user-visible API */ /* * * This file is - * Copyright (C) 1997-2000 Ian Jackson + * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson * * It is part of adns, which is - * Copyright (C) 1997-2000 Ian Jackson - * Copyright (C) 1999-2000 Tony Finch - * + * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson + * Copyright (C) 1999-2000,2003,2006 Tony Finch + * Copyright (C) 1991 Massachusetts Institute of Technology + * * 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) + * the Free Software Foundation; either version 3, or (at your option) * any later version. * * This program is distributed in the hope that it will be useful, @@ -47,8 +48,7 @@ * * 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. + * with this program; if not, write to the Free Software Foundation. * * * $Id$ @@ -58,23 +58,45 @@ #define ADNS_H_INCLUDED #include +#include #include #include #include #include #include +#include #ifdef __cplusplus extern "C" { /* I really dislike this - iwj. */ #endif +/* Whether to support address families other than IPv4 in responses which use + * the `adns_rr_addr' structure. This is a source-compatibility issue: old + * clients may not expect to find address families other than AF_INET in + * their query results. There's a separate binary compatibility issue to do + * with the size of the `adns_rr_addr' structure, but we'll assume you can + * cope with that because you have this header file. Define + * `ADNS_FEATURE_IPV4ONLY' if you only want to see AF_INET addresses by + * default, or `ADNS_FEATURE_MANYAF' to allow multiple address families; the + * default is currently to stick with AF_INET only, but this is likely to + * change in a later release of ADNS. Note that any adns_qf_want_... flags + * in your query are observed: this setting affects only the default address + * families. + */ +#if !defined(ADNS_FEATURE_IPV4ONLY) && !defined(ADNS_FEATURE_MANYAF) +# define ADNS_FEATURE_IPV4ONLY +#elif defined(ADNS_FEATURE_IPV4ONLY) && defined(ADNS_FEATURE_MANYAF) +# error "Feature flags ADNS_FEATURE_IPV4ONLY and ..._MANYAF are incompatible" +#endif + /* 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 { +typedef enum { /* In general, or together the desired flags: */ + adns_if_none= 0x0000,/* no flags. nicer than 0 for some compilers */ 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 */ @@ -84,10 +106,22 @@ typedef enum { 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_if_checkc_freq= 0x0300,/* consistency checks very frequently (slow!) */ + + adns_if_permit_ipv4= 0x0400,/* allow _addr queries to return IPv4 addresses */ + adns_if_permit_ipv6= 0x0800,/* allow _addr queries to return IPv6 addresses */ + adns_if_afmask= 0x0c00, + /* These are policy flags, and overridden by the adns_af:... option in + * resolv.conf. If the adns_qf_want_... query flags are incompatible with + * these settings (in the sense that no address families are permitted at + * all) then the query flags take precedence; otherwise only records which + * satisfy all of the stated requirements are allowed. + */ + adns__if_sizeforce= 0x7fff, } adns_initflags; -typedef enum { +typedef enum { /* In general, or together the desired flags: */ + adns_qf_none= 0x00000000,/* no flags */ 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 */ @@ -97,14 +131,58 @@ typedef enum { 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_qf_want_ipv4= 0x00000400,/* try to return IPv4 addresses */ + adns_qf_want_ipv6= 0x00000800,/* try to return IPv6 addresses */ + adns_qf_want_allaf= 0x00000c00,/* all the above flag bits */ + /* Without any of the _qf_want_... flags, _qtf_deref queries try to return + * all address families permitted by _if_permit_... (as overridden by the + * `adns_af:...' configuration option). Set flags to restrict the + * returned address families to the ones selected. + */ + adns_qf_ipv6_mapv4= 0x00001000,/* ... return IPv4 addresses as v6-mapped */ + + adns_qf_addrlit_scope_forbid=0x00002000,/* forbid % in IPv6 literals */ + adns_qf_addrlit_scope_numeric=0x00004000,/* % may only be numeric */ + adns_qf_addrlit_ipv4_quadonly=0x00008000,/* reject non-dotted-quad ipv4 */ + + adns__qf_internalmask= 0x0ff00000, + adns__qf_sizeforce= 0x7fffffff } adns_queryflags; typedef enum { - 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_rrt_typemask= 0x0ffff, + adns_rrt_reprmask= 0xffffff, + adns__qtf_deref_bit=0x10000,/* internal version of ..._deref below */ + adns__qtf_mail822= 0x20000,/* return mailboxes in RFC822 rcpt field fmt */ + + adns__qtf_bigaddr=0x1000000,/* use the new larger sockaddr union */ + adns__qtf_manyaf= 0x2000000,/* permitted to return multiple address families */ + + adns__qtf_deref= adns__qtf_deref_bit|adns__qtf_bigaddr +#ifdef ADNS_FEATURE_MANYAF + |adns__qtf_manyaf +#endif + ,/* dereference domains; perhaps get extra data */ + + adns_r_unknown= 0x40000, + /* To use this, ask for records of type |adns_r_unknown. + * adns will not process the RDATA - you'll get adns_rr_byteblocks, + * where the int is the length and the unsigned char* points to the + * data. String representation of the RR data (by adns_rrinfo) is as in + * RFC3597. adns_rr_info will not return the type name in *rrtname_r + * (due to memory management problems); *fmtname_r will be set to + * "unknown". + * + * Do not specify adns_r_unknown along with a known RR type which + * requires domain name uncompression (see RFC3597 s4); domain names + * will not be uncompressed and the resulting data would be useless. + * Asking for meta-RR types via adns_r_unknown will not work properly + * either and may make adns complain about server misbehaviour, so don't + * do that. + * + * Don't forget adns_qf_quoteok if that's what you want. */ + adns_r_none= 0, adns_r_a= 1, @@ -117,7 +195,7 @@ typedef enum { 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_raw= 12, /* do not mind PTR with wrong or missing addr */ adns_r_ptr= adns_r_ptr_raw|adns__qtf_deref, adns_r_hinfo= 13, @@ -129,8 +207,18 @@ typedef enum { adns_r_rp_raw= 17, adns_r_rp= adns_r_rp_raw|adns__qtf_mail822, + + adns_r_aaaa= 28, + + /* For SRV records, query domain without _qf_quoteok_query must look + * as expected from SRV RFC with hostname-like Name. _With_ + * _quoteok_query, any query domain is allowed. */ + adns_r_srv_raw= 33, + adns_r_srv= adns_r_srv_raw|adns__qtf_deref, - adns_r_addr= adns_r_a|adns__qtf_deref + adns_r_addr= adns_r_a|adns__qtf_deref, + + adns__rrt_sizeforce= 0x7fffffff, } adns_rrtype; @@ -231,8 +319,8 @@ typedef enum { 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_inconsistent, /* PTR gives domain whose addr is missing or mismatch */ + adns_s_prohibitedcname, /* CNAME, but eg A expected (not if _qf_cname_loose) */ adns_s_answerdomaininvalid, adns_s_answerdomaintoolong, adns_s_invaliddata, @@ -254,14 +342,29 @@ typedef enum { } adns_status; +typedef union { + struct sockaddr sa; + struct sockaddr_in inet; +} adns_sockaddr_v4only; + +typedef union { + struct sockaddr sa; + struct sockaddr_in inet; + struct sockaddr_in6 inet6; +} adns_sockaddr; + typedef struct { int len; - union { - struct sockaddr sa; - struct sockaddr_in inet; - } addr; + adns_sockaddr addr; } adns_rr_addr; +typedef struct { + /* the old v4-only structure; handy if you have complicated binary + * compatibility problems. */ + int len; + adns_sockaddr_v4only addr; +} adns_rr_addr_v4only; + typedef struct { char *host; adns_status astatus; @@ -298,6 +401,21 @@ typedef struct { unsigned long serial, refresh, retry, expire, minimum; } adns_rr_soa; +typedef struct { + int priority, weight, port; + char *host; +} adns_rr_srvraw; + +typedef struct { + int priority, weight, port; + adns_rr_hostaddr ha; +} adns_rr_srvha; + +typedef struct { + int len; + unsigned char *data; +} adns_rr_byteblock; + typedef struct { adns_status status; char *cname; /* always NULL if query was for CNAME records */ @@ -312,12 +430,16 @@ typedef struct { adns_rr_intstr *(*manyistr); /* txt (list strs ends with i=-1, str=0)*/ adns_rr_addr *addr; /* addr */ struct in_addr *inaddr; /* a */ + struct in6_addr *in6addr; /* aaaa */ 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 */ + adns_rr_srvraw *srvraw; /* srv_raw */ + adns_rr_srvha *srvha;/* srv */ + adns_rr_byteblock *byteblock; /* ...|unknown */ } rrs; } adns_answer; @@ -337,7 +459,8 @@ typedef struct { * * For _init, _init_strcfg, _submit and _synchronous, system errors * (eg, failure to create sockets, malloc failure, etc.) return errno - * values. + * values. EINVAL from _init et al means the configuration file + * is erroneous and cannot be parsed. * * For _wait and _check failures are reported in the answer * structure, and only 0, ESRCH or (for _check) EAGAIN is @@ -354,12 +477,37 @@ typedef struct { * requested. */ +/* Threads: + * adns does not use any static modifiable state, so it + * is safe to call adns_init several times and then use the + * resulting adns_states concurrently. + * However, it is NOT safe to make simultaneous calls into + * adns using the same adns_state; a single adns_state must be used + * only by one thread at a time. You can solve this problem by + * having one adns_state per thread, or if that isn't feasible, you + * could maintain a pool of adns_states. Unfortunately neither of + * these approaches has optimal performance. + */ + 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); +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 @@ -433,6 +581,15 @@ int adns_init_strcfg(adns_state *newstate_r, adns_initflags flags, * 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. + * + * adns_af:{ipv4,ipv6},... adns_af:any + * Determines which address families ADNS looks up (either as an + * adns_r_addr query, or when dereferencing an answer yielding hostnames + * (e.g., adns_r_mx). The argument is a comma-separated list: only the + * address families listed will be looked up. The default is `any'. + * Lookups occur (logically) concurrently; use the `sortlist' directive to + * control the relative order of addresses in answers. This option + * overrides the corresponding init flags (covered by adns_if_afmask). * * There are a number of environment variables which can modify the * behaviour of adns. They take effect only if adns_init is used, and @@ -538,6 +695,60 @@ void adns_finish(adns_state ads); * they will be cancelled. */ +#define ADNS_ADDR2TEXT_BUFLEN \ + (INET6_ADDRSTRLEN + 1/*%*/ \ + + ((IF_NAMESIZE-1) > 9 ? (IF_NAMESIZE-1) : 9/*uint32*/) \ + + 1/* nul; included in IF_NAMESIZE */) + +int adns_text2addr(const char *text, uint16_t port, adns_queryflags flags, + struct sockaddr *sa_r, + socklen_t *salen_io /* updated iff OK or ENOSPC */); +int adns_addr2text(const struct sockaddr *sa, adns_queryflags flags, + char *buffer, int *buflen_io /* updated ONLY on ENOSPC */, + int *port_r /* may be 0 */); + /* + * port is always in host byte order and is simply copied to and + * from the appropriate sockaddr field (byteswapped as necessary). + * + * The only flags supported are adns_qf_addrlit_...; others are + * ignored. + * + * Error return values are: + * + * ENOSPC Output buffer is too small. Can only happen if + * *buflen_io < ADNS_ADDR2TEXT_BUFLEN or + * *salen_io < sizeof(adns_sockaddr). On return, + * *buflen_io or *salen_io has been updated by adns. + * + * EINVAL text has invalid syntax. + * + * text represents an address family not supported by + * this version of adns. + * + * Scoped address supplied (text contained "%" or + * sin6_scope_id nonzero) but caller specified + * adns_qf_addrlit_scope_forbid. + * + * Scope name (rather than number) supplied in text but + * caller specified adns_qf_addrlit_scope_numeric. + * + * EAFNOSUPPORT sa->sa_family is not supported (addr2text only). + * + * Only if neither adns_qf_addrlit_scope_forbid nor + * adns_qf_addrlit_scope_numeric are set: + * + * ENOSYS Scope name supplied in text but IPv6 address part of + * sockaddr is not a link local address. + * + * ENXIO Scope name supplied in text but if_nametoindex + * said it wasn't a valid local interface name. + * + * EIO Scoped address supplied but if_nametoindex failed + * in an unexpected way; adns has printed a message to + * stderr. + * + * any other if_nametoindex failed in a more-or-less expected way. + */ void adns_forallqueries_begin(adns_state ads); adns_query adns_forallqueries_next(adns_state ads, void **context_r); @@ -672,10 +883,10 @@ 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, and it will set the timeout to zero if a query - * finishes in _beforeselect. + * 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, @@ -758,7 +969,7 @@ int adns_beforepoll(adns_state ads, struct pollfd *fds, * In any case this call won't block. */ -#define ADNS_POLLFDS_RECOMMENDED 2 +#define ADNS_POLLFDS_RECOMMENDED 3 /* 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