socat/CHANGES

new features:
	new address option "escape" allows to break a socat instance even when
	raw terminal mode prevents ^C etc.

corrections:
	some raw IP and UNIX datagram modes failed on BSD systems

	when UDP-LISTEN continued to listen after packet dropped by, e.g.,
	range option, the old listen socket would not be closed but a new one
	created. open sockets could accumulate.

	there was a bug in ip*-recv with bind option: it did not bind, and
	with the first received packet an error occurred:
	socket_init(): unknown address family 0

	RECVFROM addresses with FORK option hung after processing the first
	packet.

	corrected a few mistakes that caused compiler warnings on 64bit hosts

	EXEC and SYSTEM with stderr injected socat messages into the data
	stream. test: EXECSTDERRLOG

	when the EXEC address got a string with consecutive spaces it created
	additional empty arguments (thanks to Olivier Hervieu for reporting
	this bug)

	in ignoreeof polling mode socat also blocked data transfer in the other
	direction during the 1s wait intervalls (thanks to Jorgen Cederlof for
	reporting this bug)

	corrected alphabetical order of options (proxy-auth)

	some minor corrections

	improved test.sh script: more stable timing, corrections for BSD

	replaced the select() calls by poll() to cleanly fix the problems with
	many file descriptors already open

porting:
	socat should now build under MacOS X 10.4 (thanks to Camillo Lugaresi for
	providing the patch)

further changes:
	filan -s prefixes output with FD number if more than one FD

	Makefile now supports datarootdir (thanks to Camillo Lugaresi for
	providing the patch)

####################### V 1.6.0.1:

new features:
	new make target "gitclean"

	docu source doc/socat.yo released

corrections:
	exec:...,pty did not kill child process under some circumstances; fixed
	by correcting typo in xio-progcall.c (thanks to Ralph Forsythe for
	reporting this problem) 

	service name resolution failed due to byte order mistake
	(thanks to James Sainsbury for reporting this problem)

	socat would hang when invoked with many file descriptors already opened
	fix: replaced FOPEN_MAX with FD_SETSIZE
	thanks to Daniel Lucq for reporting this problem.

	fixed bugs where sub processes would become zombies because the master
	process did not catch SIGCHLD. this affected addresses UDP-LISTEN,
	UDP-CONNECT, TCP-CONNECT, OPENSSL, PROXY, UNIX-CONNECT, UNIX-CLIENT,
	ABSTRACT-CONNECT, ABSTRACT-CLIENT, SOCKSA, SOCKS4A
	(thanks to Fernanda G Weiden for reporting this problem)

	fixed a bug where sub processes would become zombies because the master
	process caught SIGCHLD but did not wait(). this affected addresses
	UDP-RECVFROM, IP-RECVFROM, UNIX-RECVFROM, ABSTRACT-RECVFROM
	(thanks to Evan Borgstrom for reporting this problem)

	corrected option handling with STDIO; usecase: cool-write

	configure --disable-pty  also disabled option waitlock

	fixed small bugs on systems with struct ip_mreq without struct ip_mreqn
	(thanks to Roland Illig for sending a patch)

	corrected name of option intervall to interval (old form still valid
	for us German speaking guys)

	corrected some print statements and variable names

	make uninstall  did not uninstall procan

	fixed lots of weaknesses in test.sh

	corrected some bugs and typos in doc/socat.yo, EXAMPLES, C comments

further changes:
	procan -c prints C defines important for socat

	added test OPENSSLEOF for OpenSSL half close

####################### V 1.6.0.0:

new features:
	new addresses IP-DATAGRAM and UDP-DATAGRAM allow versatile broadcast
	and multicast modes 

	new option ip-add-membership for control of multicast group membership

	new address TUN for generation of Linux TUN/TAP pseudo network
	interfaces (suggested by Mat Caughron); associated options tun-device,
	tun-name, tun-type; iff-up, iff-promisc, iff-noarp, iff-no-pi etc.

	new addresses ABSTRACT-CONNECT, ABSTRACT-LISTEN, ABSTRACT-SENDTO,
	ABSTRACT-RECV, and ABSTRACT-RECVFROM for abstract UNIX domain addresses
	on Linux (requested by Zeeshan Ali); option unix-tightsocklen controls
	socklen parameter on system calls.

	option end-close for control of connection closing allows FD sharing
	by sub processes

	range option supports form address:mask with IPv4

	changed behaviour of SSL-LISTEN to require and verify client
	certificate per default

	options f-setlkw-rd, f-setlkw-wr, f-setlk-rd, f-setlk-wr allow finer
	grained locking on regular files

	uninstall target in Makefile (lack reported by Zeeshan Ali)

corrections:
	fixed bug where only first tcpwrap option was applied; fixed bug where
	tcpwrap IPv6 check always failed (thanks to Rudolf Cejka for reporting
	and fixing this bug) 

	filan (and socat -D) could hang when a socket was involved

	corrected PTYs on HP-UX (and maybe others) using STREAMS (inspired by
	Roberto Mackun)

	correct bind with udp6-listen (thanks to Jan Horak for reporting this
	bug)

	corrected filan.c peekbuff[0] which did not compile with Sun Studio Pro
	(thanks to Leo Zhadanovsky for reporting this problem)

	corrected problem with read data buffered in OpenSSL layer (thanks to
	Jon Nelson for reporting this bug)

	corrected problem with option readbytes when input stream stayed idle
	after so many bytes

	fixed a bug where a datagram receiver with option fork could fork two
	sub processes per packet

further changes:
	moved documentation to new doc/ subdir

	new documents (kind of mini tutorials) are provided in doc/

####################### V 1.5.0.0:

new features:
	new datagram modes for udp, rawip, unix domain sockets

	socat option -T specifies inactivity timeout

	rewrote lexical analysis to allow nested socat calls

	addresses tcp, udp, tcp-l, udp-l, and rawip now support IPv4 and IPv6

	socat options -4, -6 and environment variables SOCAT_DEFAULT_LISTEN_IP,
	SOCAT_PREFERRED_RESOLVE_IP for control of protocol selection

	addresses ssl, ssl-l, socks, proxy now support IPv4 and IPv6

	option protocol-family (pf), esp. for openssl-listen

	range option supports IPv6 - syntax: range=[::1/128]

	option ipv6-v6only (ipv6only)

	new tcp-wrappers options allow-table, deny-table, tcpwrap-etc

	FIPS version of OpenSSL can be integrated - initial patch provided by
	David Acker. See README.FIPS

	support for resolver options res-debug, aaonly, usevc, primary, igntc,
	recurse, defnames, stayopen, dnsrch

	options for file attributes on advanced filesystems (ext2, ext3,
	reiser): secrm, unrm, compr, ext2-sync, immutable, ext2-append, nodump,
	ext2-noatime, journal-data etc.

	option cool-write controls severeness of write failure (EPIPE,
	ECONNRESET)

	option o-noatime

	socat option -lh for hostname in log output

	traffic dumping provides packet headers

	configure.in became part of distribution

	socats unpack directory now has full version, e.g. socat-1.5.0.0/

	corrected docu of option verify

corrections:
	fixed tcpwrappers integration - initial fix provided by Rudolf Cejka

	exec with pipes,stderr produced error

	setuid-early was ignored with many address types

	some minor corrections

####################### V 1.4.3.1:

corrections:
	PROBLEM: UNIX socket listen accepted only one (or a few) connections.
	FIX: do not remove listening UNIX socket in child process

	PROBLEM: SIGSEGV when TCP part of SSL connect failed
	FIX: check ssl pointer before calling SSL_shutdown

	In debug mode, show connect client port even when connect fails

####################### V 1.4.3.0:

new features:
	socat options -L, -W for application level locking

	options "lockfile", "waitlock" for address level locking
	(Stefan Luethje)

	option "readbytes" limits read length (Adam Osuchowski)

	option "retry" for unix-connect, unix-listen, tcp6-listen (Dale Dude)

	pty symlink, unix listen socket, and named pipe are per default removed
	after use; option unlink-close overrides this new behaviour and also
	controls removal of other socat generated files (Stefan Luethje)

corrections:
	option "retry" did not work with tcp-listen

	EPIPE condition could result in a 100% CPU loop

further changes:
	support systems without SHUT_RD etc.
	handle more size_t types
	try to find makedepend options with gcc 3 (richard/OpenMacNews)

####################### V 1.4.2.0:

new features:
	option "connect-timeout" limits wait time for connect operations
	(requested by Giulio Orsero)

	option "dhparam" for explicit Diffie-Hellman parameter file

corrections:
	support for OpenSSL DSA certificates (Miika Komu)

	create install directories before copying files (Miika Komu)

	when exiting on signal, return status 128+signum instead of 1

	on EPIPE and ECONNRESET, only issue a warning (Santiago Garcia
	Mantinan)

	-lu could cause a core dump on long messages

further changes:
	modifications to simplify using socats features in applications

####################### V 1.4.1.0:

new features:
	option "wait-slave" blocks open of pty master side until a client
	connects, "pty-intervall" controls polling

	option -h as synonym to -? for help (contributed by Christian
	Lademann)

	filan prints formatted time stamps and rdev (disable with -r)

	redirect filan's output, so stdout is not affected (contributed by
	Luigi Iotti) 

	filan option -L to follow symbolic links

	filan shows termios control characters

corrections:
	proxy address no longer performs unsolicited retries

	filan -f no longer needs read permission to analyze a file (but still
	needs access permission to directory, of course)

porting:
	Option dsusp
	FreeBSD options noopt, nopush, md5sig
	OpenBSD options sack-disable, signature-enable
	HP-UX, Solaris options abort-threshold, conn-abort-threshold
	HP-UX options b900, b3600, b7200
	Tru64/OSF1 options keepinit, paws, sackena, tsoptena

further corrections:
	address pty now uses ptmx as default if openpty is also available

####################### V 1.4.0.3:

corrections:
	fix to a syslog() based format string vulnerability that can lead to
	remote code execution. See advisory socat-adv-1.txt

####################### V 1.4.0.2:

corrections:
	exec'd write-only addresses get a chance to flush before being killed

	error handler: print notice on error-exit

	filan printed wrong file type information

####################### V 1.4.0.1:

corrections:
	socks4a constructed invalid header. Problem found, reported, and fixed
	by Thomas Themel, by Peter Palfrader, and by rik

	with nofork, don't forget to apply some process related options
	(chroot, setsid, setpgid, ...)

####################### V 1.4.0.0:

new features:
	simple openssl server (ssl-l), experimental openssl trust

	new options "cafile", "capath", "key", "cert", "egd", and "pseudo" for
	openssl

	new options "retry", "forever", and "intervall"

	option "fork" for address TCP improves `gender changer<65>

	options "sigint", "sigquit", and "sighup" control passing of signals to
	sub process (thanks to David Shea who contributed to this issue)

	readline takes respect to the prompt issued by the peer address

	options "prompt" and "noprompt" allow to override readline's new
	default behaviour

	readline supports invisible password with option "noecho"

	socat option -lp allows to set hostname in log output

	socat option -lu turns on microsecond resolution in log output


corrections:
	before reading available data, check if writing on other channel is
	possible

	tcp6, udp6: support hostname specification (not only IP address), and
	map IP4 names to IP6 addresses

	openssl client checks server certificate per default

	support unidirectional communication with exec/system subprocess

	try to restore original terminal settings when terminating

	test.sh uses tmp dir /tmp/$USER/$$ instead of /tmp/$$ 

	socks4 failed on platforms where long does not have 32 bits
	(thanks to Peter Palfrader and Thomas Seyrat)

	hstrerror substitute wrote wrong messages (HP-UX, Solaris)

	proxy error message was truncated when answer contained multiple spaces


porting:
	compiles with AIX xlc, HP-UX cc, Tru64 cc (but might not link)

####################### V 1.3.2.2:

corrections:
	PROXY CONNECT failed when the status reply from the proxy server
	contained more than one consecutive spaces. Problem reported by
	Alexandre Bezroutchko

	do not SIGSEGV when proxy address fails to resolve server name

	udp-listen failed on systems where AF_INET != SOCK_DGRAM (e.g. SunOS).
	Problem reported by Christoph Schittel

	test.sh only tests available features

	added missing IP and TCP options in filan analyzer

	do not apply stdio address options to both directions when in 
	unidirectional mode

	on systems lacking /dev/*random and egd, provide (weak) entropy from
	libc random()


porting:
	changes for HP-UX (VREPRINT, h_NETDB_INTERNAL)

	compiles on True64, FreeBSD (again), NetBSD, OpenBSD

	support for  long long  as  st_ino type (Cygwin 1.5)

	compile on systems where pty can not be featured

####################### V 1.3.2.1:

corrections:
	"final" solution for the ENOCHLD problem

	corrected "make strip"

	default gcc debug/opt is "-O" again

	check for /proc at runtime, even if configure found it

	src.rpm accidently supported SuSE instead of RedHat

####################### V 1.3.2.0:

new features:
	option "nofork" connects an exec'd script or program directly
	to the file descriptors of the other address, circumventing the socat
	transfer engine

	support for files >2GB, using ftruncate64(), lseek64(), stat64()

	filan has new "simple" output style (filan -s)


porting:
	options "binary" and "text" for controlling line termination on Cygwin
	file system access (hint from Yang Wu-Zhou)

	fix by Yang Wu-Zhou for the Cygwin "No Children" problem

	improved support for OSR: _SVID3; no IS_SOCK, no F_GETOWN (thanks to
	John DuBois)

	minor corrections to avoid warnings with gcc 3


further corrections and minor improvements:
	configure script is generated with autoconf 2.57 (no longer 2.52)

	configure passes CFLAGS to Makefile

	option -??? for complete list of address options and their short forms

	program name in syslog messages is derived from argv[0]

	SIGHUP now prints notice instead of error

	EIO during read of pty now gives Notice instead of Error, and
	triggers EOF

	use of hstrerror() for printing resolver error messages

	setgrent() got required endgrent()

####################### V 1.3.1.0:

new features:
	integration of Wietse Venema's tcpwrapper library (libwrap)

	with "proxy" address, option "resolve" controls if hostname or IP
	address is sent in request

	option "lowport" establishes limited authorization for TCP and UDP
	connections 

	improvement of .spec file for RPM creation (thanks to Gerd v. Egidy)
	An accompanying change in the numbering scheme results in an 
	incompatibility with earlier socat RPMs!


solved problems and bugs:
	PROBLEM: socat daemon terminated when the address of a connecting
	client did not match range option value instead of continue listening
	SOLVED: in this case, print warning instead of error to keep daemon
	active 

	PROBLEM: tcp-listen with fork sometimes left excessive number of zombie
	processes
	SOLVED: dont assume that each exiting child process generates SIGCHLD

	when converting CRNL to CR, socat converted to NL


further corrections:
	configure script now disables features that depend on missing files
	making it more robust in "unsupported" environments

	server.pem permissions corrected to 600

	"make install" now does not strip; use "make strip; make install"
	if you like strip (suggested by Peter Bray)

####################### V 1.3.0.1:

solved problems and bugs:
	PROBLEM: OPENSSL did not apply tcp, ip, and socket options
	SOLVED: OPENSSL now correctly handles the options list

	PROBLEM: CRNL to NL and CRNL to CR conversions failed when CRNL crossed
	block boundary
	SOLVED: these conversions now simply strip all CR's or NL's from input
	stream 


porting:
	SunOS ptys now work on x86, too (thanks to Peter Bray)

	configure looks for freeware libs in /pkgs/lib/ (thanks to Peter Bray)


further corrections:
	added WITH_PROXY value to -V output

	added compile dependencies of WITH_PTY and WITH_PROXY

	-?? did not print option group of proxy options

	corrected syntax for bind option in docu

	corrected an issue with stdio in unidirectional mode

	options socksport and proxyport support service names

	ftp.sh script supports proxy address

	man page no longer installed with execute permissions (thanks to Peter
        Bray) 

	fixed a malloc call bug that could cause SIGSEGV or false "out of
	memory" errors on EXEC and SYSTEM, depending on program name length and
	libc.

####################### V 1.3.0.0:

new features:
	proxy connect with optional proxy authentication

	combined hex and text dump mode, credits to Gregory Margo

	address pty applies options user, group, and perm to device


solved problems and bugs:
	PROBLEM: option reuseport was not applied (BSD, AIX)
	SOLVED:	option reuseport now in phase PASTSOCKET instead of PREBIND,
		credits to Jean-Baptiste Marchand

	PROBLEM: ignoreeof with stdio was ignored
	SOLVED: ignoreeof now works correctly with address stdio

	PROBLEM: ftp.sh did not use user supplied password
	SOLVED: ftp.sh now correctly passes password from command line

	PROBLEM: server.pem had expired
	SOLVED: new server.pem valid for ten years

	PROBLEM: socks notice printed wrong port on some platforms
	SOLVED: socks now uses correct byte-order for port number in notice


further corrections:
	option name o_trunc corrected to o-trunc

	combined use of -u and -U is now detected and prevented

	made message system a little more robust against format string attacks


####################### V 1.2.0.0:

new features:
	address pty for putting socat behind a new pseudo terminal that may
	fake a serial line, modem etc.

	experimental openssl integration
	(it does not provide any trust between the peers because is does not
	 check certificates!)

	options flock-ex, flock-ex-nb, flock-sh, flock-sh-nb to control all
	locking mechanism provided by flock()

	options setsid and setpgid now available with all address types

	option ctty (controlling terminal) now available for all TERMIOS
	addresses 

	option truncate (a hybrid of open(.., O_TRUNC) and ftruncate()) is
	replaced by options o-trunc and ftruncate=offset

	option sourceport now available with TCP and UDP listen addresses to
	restrict incoming client connections

	unidirectional mode right-to-left (-U)


solved problems and bugs:
	PROBLEM: addresses without required parameters but an option containing
		a '/' were incorrectly interpreted as implicit GOPEN address
	SOLVED: if an address does not have ':' separator but contains '/',
		check if the slash is before the first ',' before assuming
		implicit GOPEN.


porting:
	ptys under SunOS work now due to use of stream options


further corrections:
	with -d -d -d -d -D, don't print debug info during file analysis


####################### V 1.1.0.1:

new features:
	.spec file for RPM generation


solved problems and bugs:
	PROBLEM: GOPEN on socket did not apply option unlink-late
	SOLUTION: GOPEN for socket now applies group NAMED, phase PASTOPEN
		options 

	PROBLEM: with unidirectional mode, an unnecessary close timeout was
		applied
	SOLUTION: in unidirectional mode, terminate without wait time

	PROBLEM: using GOPEN on a unix domain socket failed for datagram
		sockets
	SOLUTION: when connect() fails with EPROTOTYPE, use a datagram socket


further corrections:

	open() flag options had names starting with "o_", now corrected to "o-"

	in docu, *-listen addresses were called *_listen

	address unix now called unix-connect because it does not handle unix
	datagram sockets

	in test.sh, apply global command line options with all tests


####################### V 1.1.0.0:

new features:
	regular man page and html doc - thanks to kromJx for prototype

	new address type "readline", utilizing GNU readline and history libs

	address option "history-file" for readline

	new option "dash" to "exec" address that allows to start login shells

	syslog facility can be set per command line option

	new address option "tcp-quickack", found in Linux 2.4

	option -g prevents option group checking

	filan and procan can print usage

	procan prints rlimit infos


solved problems and bugs:
	PROBLEM: raw IP socket SIGSEGV'ed when it had been shut down.
	SOLVED: set eof flag of channel on shutdown.

	PROBLEM: if channel 2 uses a single non-socket FD in bidirectional mode
		and has data available while channel 1 reaches EOF, the data is
		lost. 
	SOLVED: during one loop run, first handle all data transfers and
		_afterwards_ handle EOF. 

	PROBLEM: despite to option NONBLOCK, the connect() call blocked
	SOLVED: option NONBLOCK is now applied in phase FD instead of LATE

	PROBLEM: UNLINK options issued error when file did not exist,
		terminating socat
	SOLVED: failure of unlink() is only warning if errno==ENOENT

	PROBLEM: TCP6-LISTEN required numeric port specification
	SOLVED: now uses common TCP service resolver

	PROBLEM: with PIPE, wrong FDs were shown for data transfer loop
	SOLVED: retrieval of FDs now pays respect to PIPE pecularities

	PROBLEM: using address EXEC against an address with IGNOREEOF, socat
		never terminated
	SOLVED: corrected EOF handling of sigchld


porting:
	MacOS and old AIX versions now have pty

	flock() now available on Linux (configure check was wrong)

	named pipe were generated using mknod(), which requires root under BSD
	now they are generated using mkfifo


further corrections:
	lots of address options that were "forgotten" at runtime are now
	available 

	option BINDTODEVICE now also called SO-BINDTODEVICE, IF

	"make install" now installs binaries with ownership 0:0


####################### V 1.0.4.2:

solved problems and bugs:
	PROBLEM: EOF of one stream caused close of other stream, giving it no
	chance to go down regularly
	SOLVED: EOF of one stream now causes shutdown of write part of other
	stream

	PROBLEM: sending mail via socks address to qmail showed that crlf
	option does not work
	SOLVED: socks address applies PH_LATE options

	PROBLEM: in debug mode, no info about socat and platform was issued
	SOLVED: print socat version and uname output in debug mode

	PROBLEM: invoking socat with -t and no following parameters caused
	SIGSEGV
	SOLVED: -t and -b now check next argv entry

	PROBLEM: when opening of logfile (-lf) failed, no error was reported
	and no further messages were printed
	SOLVED: check result of fopen and print error message if it failed

new features:
	address type UDP-LISTEN now supports option fork: it internally applies
	socket option SO_REUSEADDR so a new UDP socket can bind to port after
	`accepting<6E> a connection (child processes might live forever though)
	(suggestion from Damjan Lango)


####################### V 1.0.4.1:

solved problems and bugs:
	PROB: assert in libc caused an endless recursion
	SOLVED: no longer catch SIGABRT

	PROB: socat printed wrong verbose prefix for "right to left" packets
	SOLVED: new parameter for xiotransfer() passes correct prefix

new features:
	in debug mode, socat prints its command line arguments
	in verbose mode, escape special characters and replace unprintables
		with '.'. Patch from Adrian Thurston.


####################### V 1.0.4.0:

solved problems and bugs:
	Debug output for lstat and fstat said "stat"

further corrections:
	FreeBSD now includes libutil.h

new features:
	option setsid with exec/pty
	option setpgid with exec/pty
	option ctty with exec/pty
	TCP V6 connect test
	gettimeofday in sycls.c (no use yet)

porting:
	before Gethostbyname, invoke inet_aton for MacOSX


####################### V 1.0.3.0:

solved problems and bugs:

	PROB: test 9 of test.sh (echo via file) failed on some platforms,
	socat exited without error message
	SOLVED: _xioopen_named_early(): preset statbuf.st_mode with 0

	PROB: test 17 hung forever
	REASON: child death before select loop did not result in EOF
	SOLVED: check of existence of children before starting select loop

	PROB: test 17 failed
	REASON: child dead triggered EOF before last data was read
	SOLVED: after child death, read last data before setting EOF

	PROB: filan showed that exec processes incorrectly had fd3 open
	REASON: inherited open fd3 from main process
	SOLVED: set CLOEXEC flag on pty fd in main process

	PROB: help printed "undef" instead of group "FORK"
	SOLVED: added "FORK" to group name array

	PROB: fatal messages did not include severity classifier
	SOLVED: added "F" to severity classifier array 

	PROB: IP6 addresses where printed incorrectly
	SOLVED: removed type casts to unsigned short *

further corrections:
	socat catches illegal -l modes
	corrected error message on setsockopt(linger)
	option tabdly is of type uint
	correction for UDP over IP6
	more cpp conditionals, esp. for IP6 situations
	better handling of group NAMED options with listening UNIX sockets
	applyopts2 now includes last given phase
	corrected option group handling for most address types
	introduce dropping of unappliable options (dropopts, dropopts2)
	gopen now accepts socket and unix-socket options
	exec and system now accept all socket and termios options
	child process for exec and system addresses with option pty
	improved descriptions and options for EXAMPLES
	printf format for file mode changed to "0%03o" with length spec.
	added va_end() in branch of msg()
	changed phase of lock options from PASTOPEN to FD
	support up to four early dying processes

structural changes:
	xiosysincludes now includes sysincludes.h for non xio files

new features:
	option umask
	CHANGES file
	TYPE_DOUBLE, u_double
	OFUNC_OFFSET
	added getsid(), setsid(), send() to sycls
	procan prints sid (session id)
	mail.sh gets -f (from) option
	new EXAMPLEs for file creation
	gatherinfo.sh now tells about failures
	test.sh can check for much more address/option combinations

porting:
	ispeed, ospeed for termios on FreeBSD
	getpgid() conditional for MacOS 10
	added ranlib in Makefile.in for MacOS 10
	disable pty option if no pty mechanism is available (MacOS 10)
	now compiles and runs on MacOS 10 (still some tests fail)
	setgroups() conditional for cygwin
	sighandler_t defined conditionally
	use gcc option -D_GNU_SOURCE