/README (1d1d3e899fc8ab15171086de21f9636b2141f8a9) (5008 bytes) (mode 100644) (type blob)

Name:		force_bind

Author:		Catalin(ux) M. BOIE - catab at embedromix dot ro

Start date:	2010-10-26

Description:	Force binding on a specific IP and/or port.
		Plus forcing setsockopt calls on the socket.
		Works with both IPv4 and IPv6.
		It is useful if you have a binary application without sources
		and without the possibility to configure address or port to
		bind to.

License:	GPLv3

How it works:	force_bind is a shared object that is loaded with LD_PRELOAD and hooks 'bind' function.
		Forcing an IP/port to bind to is done with environments variables.

Examples:
		0. Output debug stuff in a log file (for debugging):
		export FORCE_NET_VERBOSE=999
		export FORCE_NET_LOG="xxx.log"
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		1. Force bind to 127.0.0.1, port 33, verbose operations:
		export FORCE_NET_VERBOSE=1
		export FORCE_BIND_ADDRESS_V4=127.0.0.1
		export FORCE_BIND_PORT_V4=33
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		2. Force binding to 127.0.0.2, port unchanged
		export FORCE_BIND_ADDRESS_V4=127.0.0.2
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		3. Force binding to ::1 (IPv6), port unchanged
		export FORCE_BIND_ADDRESS_V6=::1
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		4. Changing TOS on all sockets to 30
		export FORCE_NET_TOS=30
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		5. Force Keep alive to 60 seconds:
		export FORCE_NET_KA=60
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		6. Force MSS to 1400
		export FORCE_NET_MSS=1400
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		7. Force bandwidth to 1000 bytes/s for _all_ connections, cumulated
		export FORCE_NET_BW=1000
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		8. Force bandwidth to 20000 bytes/s per socket
		export FORCE_NET_BW_PER_SOCKET=20000
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		scp root@machine1:/image.iso .

		9. Force REUSEADDR
		export FORCE_NET_REUSEADDR=1
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		10. Force NODELAY
		export FORCE_NET_NODELAY=1
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		11. Force client connections (for example 'telnet', 'ssh',
		'firefox') to connect from a specified address, not the auto
		selected one:
		export FORCE_NET_VERBOSE=1
		export FORCE_BIND_ADDRESS_V4=127.0.0.2
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		12. Set a FLOWINFO (flow label + class) for a client connection:
		export FORCE_NET_VERBOSE=1
		export FORCE_NET_FLOWINFO=0x7812345 # class 0x78, label 0x12345
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here
		A tcpdump of a connection will look like:
		00:00:00:00:00:00 > 00:00:00:00:00:00, ethertype IPv6 (0x86dd),
		length 94: (class 0x78, flowlabel 0x12345, hlim 64, next-header TCP (6) payload length: 40)
		::1.56981 > ::1.krb524: Flags [S], cksum 0x0030 (incorrect -> 0x91cf),
		seq 1154252590, win 32752, options [mss 16376,sackOK,TS val 28395104 ecr 0,nop,wscale 4], length 0

		13. Force FWMARK on a connection (only root can do it):
		export FORCE_NET_VERBOSE=1
		export FORCE_NET_FWMARK=0x1234
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		14: Force priority (between 0 and 6 for non-root users). You can
		use 'tc' command from iproute to set-up 'prio' qdisc and to
		assign prio to queues:
		# 0. setup
		export FORCE_NET_VERBOSE=1
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		# 1. Make sure you have a 'prio' qdisc attached to eth0, for example:
		tc qdisc add dev eth0 root handle 1: prio
		# 2. Assign applications to classed (bands):
		export FORCE_NET_PRIO=6 # interactive, band 0
		your_voip_program_here
		export FORCE_NET_PRIO=0 # best effort, band 1
		your_mail_program_here
		export FORCE_NET_PRIO=2 # bulk, band 2
		your_remote_backup_program_here
		# 3. Run tc statistics so you can see the classification:
		tc -s class show dev eth0

		15: Deny binding to any IPv4 sockets. The bind syscall
		will return -1 and errno will be set to EACCES.
		export FORCE_NET_VERBOSE=1
		export FORCE_BIND_ADDRESS_V4=deny
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		16: Silent fake binding to any IPv6 sockets. The bind will
		return success, but will never accept any connection.
		export FORCE_NET_VERBOSE=1
		export FORCE_BIND_ADDRESS_V6=fake
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here

		17. Forcing a return code for the connect() call
		export FORCE_NET_V4_CONN_ERROR=refused
		export FORCE_NET_V6_CONN_ERROR=refused
		export LD_PRELOAD=${LD_PRELOAD}:/usr/lib/force_bind.so
		your_program_here
		# Supported errors: refused, unreach

Installation:
		- ./configure
		- make
		- make install


Mode Type Size Ref File
100644 blob 140 35830e127b44696a7248171faab4378de2a69c7e .gitignore
100644 blob 30 d987fa5df957830331139935d517009e2911b0cf INSTALL
100644 blob 35147 94a9ed024d3859793618152ea559a168bbcbb5e2 LICENSE
100644 blob 1281 649b1ec7f7cabbd7023afd475d81d79f93889f6d Makefile.in
100644 blob 5008 1d1d3e899fc8ab15171086de21f9636b2141f8a9 README
100644 blob 1690 c1e2ed80cb60389cac0201fdbde5c42deaa028b6 TODO
100755 blob 30 92c4bc48245c00408cd7e1fd89bc1a03058f4ce4 configure
100755 blob 16967 e058c68e85b03661803926184406b16fe0b0e089 duilder
100644 blob 292 c20881a3719cdaba1a9ca8a049ee04445a81d0f6 duilder.conf
100644 blob 29878 fd1b612d553844c6aa7ac0835efe61820f40ef8c force_bind.c
100644 blob 1190 9ff243feb33534f55026c5e8ad26d57df2659059 force_bind.spec.in
100644 blob 35 6fa1dc02f112e09cbe388b61590c412dd1aae134 force_bind_config.h.in
100644 blob 1656 39482737be7bbbf3357a3750e79fec34dd323541 send_udp.c
100755 blob 198 69df55fb33fd2f66c8563d40f8e94c4a050d71f0 test1.sh
100755 blob 178 2d9a688355eeb88be7ab177ba95952a155c9e217 test2.sh
100755 blob 350 711d78469121dce161d13d338b0d281e0e646ef6 test_all.sh
100644 blob 1138 504ddf640ca53898c0d147b17cc70860c0290e61 test_bind.c
100644 blob 1382 f874e2199e08c65be67223c47373071d0e483e72 test_bind6.c
100755 blob 305 7f1903c485612a1bd82535e406afb842a9e60755 test_bind6.sh
100755 blob 193 964f25f5ab76011470436d4fb8894b975e0a1cba test_bw1.sh
100755 blob 236 484f1016e84d41ad4d393b5f6f23e5cfa9071f08 test_bw2.sh
100755 blob 286 805a280956a5a00dd52f54a8803efc6776739314 test_bw3.sh
100755 blob 448 088e71224a13f412fec15399f7bd1c0701160119 test_bw4.sh
100644 blob 1497 13d4c8bfde7655151199dc0d4ba9f5acea6512e0 test_client.c
100755 blob 179 39bb823c1a0f4c32c35141422abc61a19084f384 test_client1.sh
100755 blob 171 f988d1903cd9c89720fd6ea12b487a9e8189ef5d test_client2.sh
100755 blob 164 32459ed2d2194fa83f99ec724bf195c86dab8716 test_client3.sh
100755 blob 253 eeea81bc7eb348714945b7a5794a21f9dd813275 test_client6-1.sh
100755 blob 308 2bd1070ea27b4e6f80d6500d2d0005c2b7aaa4ec test_client6-2.sh
100644 blob 1735 7e679738e033c2425677cdfeed543cb4d32ddd11 test_client6.c
100755 blob 292 a225478d8f6b8df5cbfa115192b839bbae0276cf test_deny.sh
100755 blob 285 acf74df00776908d43b38b910140074668e9fc66 test_fake.sh
100755 blob 138 15e7a1b1bf39128dc737ba3df39498ad91e56044 test_ka1.sh
100755 blob 136 2f0bf21c57db70f4a61e1b4337f41a3c548d099b test_mss1.sh
100644 blob 488 0e31b618fc9df7f831e9396a8614a40e791d689d test_poll.c
100755 blob 292 c76f4237565a9b4012eb1129cb0ac4bc9e608829 test_poll.sh
100755 blob 144 e9620dd6d54a12e3582d38ca4fb74861fa540b88 test_tos1.sh
100755 blob 246 cdeba6d1ee85f938c06e548e3f70d07d2c6db9ff test_udp_local_bind.sh
Hints:
Before first commit, do not forget to setup your git environment:
git config --global user.name "your_name_here"
git config --global user.email "your@email_here"

Clone this repository using HTTP(S):
git clone https://rocketgit.com/user/catalinux/force_bind

Clone this repository using ssh (do not forget to upload a key first):
git clone ssh://rocketgit@ssh.rocketgit.com/user/catalinux/force_bind

Clone this repository using git:
git clone git://git.rocketgit.com/user/catalinux/force_bind

You are allowed to anonymously push to this repository.
This means that your pushed commits will automatically be transformed into a merge request:
... clone the repository ...
... make some changes and some commits ...
git push origin main