/*
* adns.h
- * - adns user-visible API (single-threaded, without any locking)
+ * - adns user-visible API
*/
/*
*
* This file is
- * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
+ * Copyright (C) 1997-2000,2003,2006 Ian Jackson
*
* It is part of adns, which is
- * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
- * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
- *
+ * Copyright (C) 1997-2000,2003,2006 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)
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
*
- * $Id: adns.h,v 1.86 2005/04/05 20:34:38 ian Exp $
+ * $Id: adns.h,v 1.96 2006/08/09 11:16:59 ian Exp $
*/
#ifndef ADNS_H_INCLUDED
#define ADNS_H_INCLUDED
#include <stdio.h>
+#include <stdarg.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/time.h>
#include <unistd.h>
+#include <net/if.h>
#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, 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.
+ */
+#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 */
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_af_v4only= 0x0400,/* only return IPv4 addresses, given the choice */
+ adns_if_af_v6only= 0x0800,/* only return IPv6 addresses, ... */
+ adns_if_afmask= adns_if_af_v4only|adns_if_af_v6only
+ /* Only set one of these. They are policy flags, and overridden by the
+ * adns_af:... options in resolv.conf. If the adns_qf_ipv... 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_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 */
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_ipv4_only= 0x00000400,/* only ever return IPv4 addresses */
+ adns_qf_ipv6_only= 0x00000800,/* ... and don't bother looking for IPv4 */
+ adns_qf_ipv6_ok= 0x00000c00,/* returning IPv6 addresses is acceptable */
+ adns_qf_domapv4= 0x00001000,/* ... any IPv4 addresses should be v6-mapped */
+ adns_qf_ipv6_mapv4= adns_qf_ipv6_ok|adns_qf_domapv4,
+ adns__qf_afmask= 0x00001c00,/* all the above flag bits */
adns__qf_internalmask= 0x0ff00000
} 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_r_unknown= 0x40000,
+ /* To use this, ask for records of type <rr-type-code>|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__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_none= 0,
adns_r_a= 1,
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_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;
+ char adns__padding[240]; /* Good idea? I'm inclined to think not. */
+} adns_sockaddr;
+
typedef struct {
int len;
- union {
- struct sockaddr sa;
- struct sockaddr_in inet;
- } addr;
+ adns_sockaddr addr;
} adns_rr_addr;
typedef struct {
+ int len;
+ adns_sockaddr_v4only addr;
+} adns_rr_addr_v4only;
+
+typedef struct {
char *host;
adns_status astatus;
int naddrs; /* temp fail => -1, perm fail => 0, s_ok => >0 */
} 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 */
char *owner; /* only set if req'd in query flags; maybe 0 on error anyway */
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;
*
* 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
* 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
* 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:v4only
+ * adns_af:v6only
+ * adns_af:any
+ * Controls whether ADNS looks for IPv4 (A records) and IPv6 (AAAA
+ * records) addresses when it's trying to build a socket address.
+ * The default is `any' which means to allow both. The `sortlist'
+ * directive can be used to control the relative preference of IPv4
+ * and IPv6 addresses if both are returned for the same query.
+ * These override 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
* 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 *addr, uint16_t port, struct sockaddr *sa,
+ socklen_t *salen /* set if OK or ENOSPC; otherwise undef */);
+int adns_addr2text(const struct sockaddr *sa,
+ char *addr_buffer, int *addr_buflen /* set iff ENOSPC */,
+ int *port_r /* may be 0 */);
+ /* Error return values are:
+ * EAFNOSUPPORT addr2text only
+ * EINVAL text2addr only: addr has invalid syntax
+ * ENOSPC only if *buflen < _BUFLEN or *salen < sizeof(adns_sockaddr)
+ * Extra errors are possible from text2addr if addr specifies a scope
+ * name suffix (ie, it has a "%") and the scope suffix is not numeric:
+ * ENOSYS address is not link local
+ * ENXIO if_nametoindex said it wasn't a valid name
+ * EIO if_nametoindex went crazy (adns prints a message to stderr)
+ * Extra errors are possible from text2addr and addr2text with scopes:
+ * any other if_nametoindex failed
+ * port is always in host byte order and is simply copied to and
+ * from the appropriate sockaddr field (byteswapped as necessary).
+ */
void adns_forallqueries_begin(adns_state ads);
adns_query adns_forallqueries_next(adns_state ads, void **context_r);
* 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,
* 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