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rofl0r cc7bc891ff allocator_thread: fix segfault with weechat 2.0
it was reported that weechat 2.0 on ubuntu 16.04 LTS x86_64 segfaulted like this:

4 0x00007f6bf0e7e0c0 in __stack_chk_fail () at stack_chk_fail.c:28
5 0x00007f6bf2536bce in at_get_ip_for_host (host=0x339c4d0 "abcdefghijklmnop.onion", len=22) at src/allocator_thread.c:290
 readbuf = {octet = "irc.", as_int = 778269289} msg = {msgtype = ATM_GETNAME, datalen = 13}

what happened was that weechat forked, thus got its own private copy of the VM
and thus a private copy of the mutex which should prevent parallel use of
at_get_ip_for_host() & friends. therefore the following race was possible:
- process A writes a message of type ATM_GETIP into the server pipe
- process B writes a message of type ATM_GETNAME into the server pipe
- process A write transaction is finished, and goes into receive mode
- server thread reads process B's message and responds with a ATM_GETNAME msg
- process A reads the response which was intended for process B into the 4 byte
  ip address buffer, but ATM_GETNAME are much larger than ATM_GETIP responses,
  resulting in stack corruption.

to prevent this issue, the storage of the mutex must reside in shared memory,
which we achieve via mmap. alternatively, shm_open() or sysvipc shm stuff could
be used. the former requires the mmap call to happen before the fork, the latter
not, however the shm would require a named object in /dev/shm (which requires
generating a unique name per proxychains instance, and subsequent cleanup).
so in the end, the mmap is easier to deal with, and we can be reasonably
certain that our constructor is being run before the hooked application forks.
2017-12-19 00:29:23 +00:00
src allocator_thread: fix segfault with weechat 2.0 2017-12-19 00:29:23 +00:00
tests test_getnameinfo: improve, check ipv6 2015-12-06 13:01:07 +00:00
tools use musl's install.sh rather than doing workarounds for BSD install 2014-07-22 14:32:27 +02:00
.gitignore update .gitignore 2014-07-22 14:34:13 +02:00
AUTHORS update AUTHORS 2014-01-22 22:33:09 +01:00
COPYING fix FSF address in COPYING to mute opensuse build service complaints 2014-09-13 23:33:26 +02:00
Makefile Revert "Makefile: suppress pedantic warnings in user CFLAGS" 2016-12-24 12:49:14 +00:00
README release 4.12 2016-12-24 13:14:08 +00:00
TODO updated TODO 2012-01-26 13:25:48 +01:00
VERSION release 4.12 2016-12-24 13:14:08 +00:00
configure configure: use quotes for echo calls 2016-12-24 12:48:41 +00:00

README

ProxyChains-NG ver 4.12 README
=============================

  ProxyChains is a UNIX program, that hooks network-related libc functions
  in DYNAMICALLY LINKED programs via a preloaded DLL (dlsym(), LD_PRELOAD)
  and redirects the connections through SOCKS4a/5 or HTTP proxies.
  It supports TCP only (no UDP/ICMP etc).

  The way it works is basically a HACK; so it is possible that it doesn't
  work with your program, especially when it's a script, or starts
  numerous processes like background daemons or uses dlopen() to load
  "modules" (bug in glibc dynlinker).
  It should work with simple compiled (C/C++) dynamically linked programs
  though.

  If your program doesn't work with proxychains, consider using an
  iptables based solution instead; this is much more robust.

  Supported Platforms: Linux, BSD, Mac.


*********** ATTENTION ***********

  this program can be used to circumvent censorship.
  doing so can be VERY DANGEROUS in certain countries.

  ALWAYS MAKE SURE THAT PROXYCHAINS WORKS AS EXPECTED
  BEFORE USING IT FOR ANYTHING SERIOUS.

  this involves both the program and the proxy that you're going to
  use.

  for example, you can connect to some "what is my ip" service
  like ifconfig.me to make sure that it's not using your real ip.

  ONLY USE PROXYCHAINS IF YOU KNOW WHAT YOU'RE DOING.

  THE AUTHORS AND MAINTAINERS OF PROXYCHAINS DO NOT TAKE ANY
  RESPONSIBILITY FOR ANY ABUSE OR MISUSE OF THIS SOFTWARE AND
  THE RESULTING CONSEQUENCES.

*** Installation ***

  # needs a working C compiler, preferably gcc
  ./configure --prefix=/usr --sysconfdir=/etc
  make
  [optional] sudo make install
  [optional] sudo make install-config (installs proxychains.conf)

  if you dont install, you can use proxychains from the build directory
  like this: ./proxychains4 -f src/proxychains.conf telnet google.com 80

Changelog:
----------
Version 4.12
- fix several build issues
  - for MAC
  - with -pie
  - with custom CC
- compatibility fix for some GUI apps (8870140)
- compatibility fix for some HTTP proxies (cf9a16d)
- fix several warnings for cleaner build on debian
- fix random_chain on OSX (0f6b226)

Version 4.11
- preliminary IPv6 support
- fixed bug in hostsreader
- preliminary support for usage on OpenBSD (caveat emptor)

Version 4.10
- fix regression in linking order with custom LDFLAGS
- fix segfault in DNS mapping code in programs with > ~400 different lookups

Version 4.9
- fix a security issue CVE-2015-3887
- add sendto hook to handle MSG_FASTOPEN flag
- replace problematic hostentdb with hostsreader
- fix compilation on OpenBSD (although doesn't work there)

Version 4.8.1:
- fix regression in 4.8 install-config Makefile target

Version 4.8:
- fix for odd cornercase where getaddrinfo was used with AI_NUMERICHOST
  to test for a numeric ip instead of resolving it (fixes nmap).
- allow usage with programs that rely on LD_PRELOAD themselves
- reject wrong entries in config file
- print version number on startup

Version 4.7:
- new round_robin chaintype by crass.
- fix bug with lazy allocation when GCC constructor was not used.
- new configure flag --fat-binary to create a "fat" binary/library on OS X
- return EBADF rather than EINTR in close hook.
  it's legal for a program to retry close() calls when they receive
  EINTR, which could cause an infinite loop, as seen in chromium.

Version 4.6:
- some cosmetic fixes to Makefile, fix a bug when non-numeric ip was
  used as proxy server address.

Version 4.5:
- hook close() to prevent OpenSSH from messing with internal infrastructure.
  this caused ssh client to segfault when proxified.

Version 4.4:
- FreeBSD port
- fixes some installation issues on Debian and Mac.

Version 4.3:
- fixes programs that do dns-lookups in child processes (fork()ed),
  like irssi. to achieve this, support for compilation without pthreads
  was sacrified.
- fixes thread safety for gethostent() calls.
- improved DNS handling speed, since hostent db is cached.

Version 4.2:
- fixes compilation issues with ubuntu 12.04 toolchain
- fixes segfault in rare codepath

Version 4.1
- support for mac os x (all archs)
- all internal functions are threadsafe when compiled with -DTHREAD_SAFE
  (default).

Version 4.0
- replaced dnsresolver script (which required a dynamically linked "dig"
  binary to be present) with remote DNS lookup.
  this speeds up any operation involving DNS, as the old script had to use TCP.
  additionally it allows to use .onion urls when used with TOR.
- removed broken autoconf build system with a simple Makefile.
  there's a ./configure script though for convenience.
  it also adds support for a config file passed via command line switches/
  environment variables.

Version 3.0
- support for DNS resolving through proxy
  supports SOCKS4, SOCKS5 and HTTP CONNECT proxy servers.
  Auth-types: socks - "user/pass" , http - "basic".

When to use it ?
1) When the only way to get "outside" from your LAN is through proxy server.
2) To get out from behind restrictive firewall which filters outgoing ports.
3) To use two (or more) proxies in chain:
	like: your_host <--> proxy1 <--> proxy2 <--> target_host
4) To "proxify" some program with no proxy support built-in (like telnet)
5) Access intranet from outside via proxy.
6) To use DNS behind proxy.
7) To access hidden tor onion services.

Some cool features:

* This program can mix different proxy types in the same chain
	like: your_host <-->socks5 <--> http <--> socks4 <--> target_host
* Different chaining options supported
	random order from the list ( user defined length of chain ).
	exact order  (as they appear in the list )
	dynamic order (smart exclude dead proxies from chain)
* You can use it with most TCP client applications, possibly even network
	scanners, as long as they use standard libc functionality.
	pcap based scanning does not work.
* You can use it with servers, like squid, sendmail, or whatever.
* DNS resolving through proxy.


Configuration:
--------------

proxychains looks for config file in following order:
1)	file listed in environment variable PROXYCHAINS_CONF_FILE or
	provided as a -f argument to proxychains script or binary.
2)	./proxychains.conf
3)	$(HOME)/.proxychains/proxychains.conf
4)	$(sysconfdir)/proxychains.conf  **

** usually /etc/proxychains.conf

Usage Example:

	$ proxychains telnet targethost.com

in this example it will run telnet through proxy(or chained proxies)
specified by proxychains.conf

Usage Example:

	$ proxychains -f /etc/proxychains-other.conf telnet targethost2.com

in this example it will use different configuration file then proxychains.conf
to connect to targethost2.com host.

Usage Example:

	$ proxyresolv targethost.com

in this example it will resolve targethost.com through proxy(or chained proxies)
specified by proxychains.conf

Known Problems:
---------------
- newer versions of nmap try to determine the network interface to use
  even if it's not needed (like when doing simple syn scans which use the
  standard POSIX socket API. this results in errors when proxychains hands
  out an ip address to a reserved address space.
  possible workarounds: disable proxy_dns, use a numeric ip, or use nmap's
  native support for SOCKS proxies.

- Mac OS X 10.11 (El Capitan) ships with a new security feature called SIP
  that prevents hooking of system apps.
  workarounds are to partially disable SIP by issuing
  csrutil enable --without debug in recovery mode,
  or to copy the system binary into the home directory and run it from there.
  see github issue #78 for details.

- the glibc dynlinker has a bug or security feature that inhibits dlopen()ed
  modules from being subject to the same dlsym hooks as installed for the main
  program. this mainly affects scripting languages such as perl or python
  that heavily rely on dlopen() for modules written in C to work.
  there are unconfirmed reports that it works as root though.
  musl libc is unaffected from the bug.


Community:
----------
#proxychains on irc.freenode.net

Donations:
----------
bitcoins donations are welcome - please send to this address:
1C9LBpuy56veBqw5N33sZMoZW8mwCw3tPh