/*
* 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>
+ * This file is part of adns, which is
+ * Copyright (C) 1997-2000,2003,2006,2014-2016 Ian Jackson
+ * Copyright (C) 1999-2000,2003,2006 Tony Finch
+ * Copyright (C) 1991 Massachusetts Institute of Technology
*
- * 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>
- *
* 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,
*
* 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.
*
- * $Id$
*/
#ifndef ADNS_H_INCLUDED
#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 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;
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_monotonic= 0x0080,/* enable if you can; see adns_processtimeouts */
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 { /* In general, or together the desired flags: */
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_strict= 0x00010000,/* forbid CNAME refs (default, currently) */
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 %<scope> in IPv6 literals */
+ adns_qf_addrlit_scope_numeric=0x00004000,/* %<scope> 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_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 <rr-type-code>|adns_r_unknown.
* adns will not process the RDATA - you'll get adns_rr_byteblocks,
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,
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;
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,
} 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;
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 */
* 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.
+ */
+
+/*
+ * Use of time:
+ *
+ * adns needs to manipulate timeouts. For API compatibility reasons
+ * (adns predates clock_gettime) the default is to use wall clock time
+ * from gettimeofday. This will malfunction if the system clock is
+ * not suitably stable. To avoid this, you should set
+ * adns_if_monotonic
+ *
+ * If you specify adns_if_monotonic then all `now' values passed to
+ * adns must be from clock_gettime(CLOCK_MONOTONIC). clock_gettime
+ * returns a struct timespec; you must convert it to a struct timeval
+ * by dividing the nsec by 1000 to make usec, rounding down.
+ */
+
int adns_init(adns_state *newstate_r, adns_initflags flags,
FILE *diagfile /*0=>stderr*/);
* 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).
+ *
+ * adns_ignoreunkcfg
+ * Ignore unknown options and configuration directives, rather than
+ * logging them. To be effective, appear in the configuration
+ * before the unknown options. ADNS_RES_OPTIONS is generally early
+ * enough.
*
* 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 *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_...
+ *
+ * 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).
+ *
+ * ENOSYS Unsupported flags set.
+ *
+ * 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);
* use that fd and only in the manner specified, regardless of whether
* adns_if_noautosys was specified.
*
+ * now is as for adns_processtimeouts.
+ *
* adns_processexceptional should be called when select(2) reports an
* exceptional condition, or poll(2) reports POLLPRI.
*
/* 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.
+ * now may be 0; if it isn't, *now must be the current time from
+ * gettimeofday, or iff adns_if_monotonic it must be converted
+ * from the results of clock_gettime(CLOCK_MONOTONIC) (with the
+ * timespec.tv_nsec rounded down to make timeval.tv_usec).
*/
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.
+ * something out.
+ *
+ * now must be the current time, as for adns_processtimeouts.
*
* 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
* 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 is used by adns, for example, if gettimeofday() or
+ * clock_gettime fails. Without this the program's event loop might
+ * start to spin !
*
* This call will never block.
*/
/* 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
+ * for adns_processtimeouts. readfds, writefds, exceptfds and maxfd_io may
* not be 0.
*
+ * now is as for adns_processtimeouts.
+ *
* 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
* 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.
+ *
+ * now is as for adns_processtimeouts.
*/
/*
* descriptors, and use _firsttimeout is used to find out when adns
* might want to time something out.)
*
+ * now is as for adns_processtimeouts.
+ *
* adns_beforepoll will return 0 on success, and will not fail for any
* reason other than the fds buffer being too small (ERANGE).
*
* 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
/* 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.
+ *
+ * now is as for adns_processtimeouts.
*/
* 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.
+ * string XXX.
+ *
+ * If you call these functions with status values not actually
+ * returned from other functions in the same adns library, the
+ * returned information may be NULL.
*/
#ifdef __cplusplus
~ianmdlvl / adns.git / blobdiff