*/
/*
*
- * This file is
- * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson
- *
- * It is part of adns, which is
- * Copyright (C) 1997-2000,2003,2006,2014 Ian Jackson
+ * 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
*
* or the GNU Library General Public License, as appropriate, along
* with this program; if not, write to the Free Software Foundation.
*
- *
- * $Id$
*/
#ifndef ADNS_H_INCLUDED
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_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_want_ipv4= 0x00000400,/* try to return IPv4 addresses */
* 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*/);
* 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
* 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.
+ * The only flags supported are adns_qf_addrlit_...
*
* Error return values are:
*
*
* 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:
*
* 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).
*
/* 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. (You are also guaranteed
+ * that the return value will not be NULL for values in the
+ * adns_status enum, *except* for adns_s_max_XXXX.)
*/
#ifdef __cplusplus
~ianmdlvl / adns.git / blobdiff