xref: /freebsd/share/examples/jails/jib (revision 517ca8c0f1a5c595f587943fa8abac34d7f4e22c)
1#!/bin/sh
2#-
3# Copyright (c) 2016 Devin Teske
4# All rights reserved.
5#
6# Redistribution and use in source and binary forms, with or without
7# modification, are permitted provided that the following conditions
8# are met:
9# 1. Redistributions of source code must retain the above copyright
10#    notice, this list of conditions and the following disclaimer.
11# 2. Redistributions in binary form must reproduce the above copyright
12#    notice, this list of conditions and the following disclaimer in the
13#    documentation and/or other materials provided with the distribution.
14#
15# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25# SUCH DAMAGE.
26#
27# $FreeBSD$
28#
29############################################################ IDENT(1)
30#
31# $Title: if_bridge(4) management script for vnet jails $
32#
33############################################################ INFORMATION
34#
35# Use this tool with jail.conf(5) (or rc.conf(5) ``legacy'' configuration) to
36# manage `vnet' interfaces for jails. Designed to automate the creation of vnet
37# interface(s) during jail `prestart' and destroy said interface(s) during jail
38# `poststop'.
39#
40# In jail.conf(5) format:
41#
42# ### BEGIN EXCERPT ###
43#
44# xxx {
45# 	host.hostname = "xxx.yyy";
46# 	path = "/vm/xxx";
47#
48# 	#
49# 	# NB: Below 2-lines required
50# 	# NB: The number of eNb_xxx interfaces should match the number of
51# 	#     arguments given to `jib addm xxx' in exec.prestart value.
52# 	#
53# 	vnet;
54# 	vnet.interface = "e0b_xxx e1b_xxx ...";
55#
56# 	exec.clean;
57# 	exec.system_user = "root";
58# 	exec.jail_user = "root";
59#
60# 	#
61# 	# NB: Below 2-lines required
62# 	# NB: The number of arguments after `jib addm xxx' should match
63# 	#     the number of eNb_xxx arguments in vnet.interface value.
64# 	#
65# 	exec.prestart += "jib addm xxx em0 em1 ...";
66# 	exec.poststop += "jib destroy xxx";
67#
68# 	# Standard recipe
69# 	exec.start += "/bin/sh /etc/rc";
70# 	exec.stop = "/bin/sh /etc/rc.shutdown";
71# 	exec.consolelog = "/var/log/jail_xxx_console.log";
72# 	mount.devfs;
73#
74# 	# Optional (default off)
75# 	#allow.mount;
76# 	#allow.set_hostname = 1;
77# 	#allow.sysvipc = 1;
78# 	#devfs_ruleset = "11"; # rule to unhide bpf for DHCP
79# }
80#
81# ### END EXCERPT ###
82#
83# In rc.conf(5) ``legacy'' format (used when /etc/jail.conf does not exist):
84#
85# ### BEGIN EXCERPT ###
86#
87# jail_enable="YES"
88# jail_list="xxx"
89#
90# #
91# # Global presets for all jails
92# #
93# jail_devfs_enable="YES"	# mount devfs
94#
95# #
96# # Global options (default off)
97# #
98# #jail_mount_enable="YES"		# mount /etc/fstab.{name}
99# #jail_set_hostname_allow="YES"	# Allow hostname to change
100# #jail_sysvipc_allow="YES"		# Allow SysV Interprocess Comm.
101#
102# # xxx
103# jail_xxx_hostname="xxx.shxd.cx"		# hostname
104# jail_xxx_rootdir="/vm/xxx"			# root directory
105# jail_xxx_vnet_interfaces="e0b_xxx e1bxxx ..."	# vnet interface(s)
106# jail_xxx_exec_prestart0="jib addm xxx em0 em1 ..."	# bridge interface(s)
107# jail_xxx_exec_poststop0="jib destroy xxx"	# destroy interface(s)
108# #jail_xxx_mount_enable="YES"			# mount /etc/fstab.xxx
109# #jail_xxx_devfs_ruleset="11"			# rule to unhide bpf for DHCP
110#
111# ### END EXCERPT ###
112#
113# Note that the legacy rc.conf(5) format is converted to
114# /var/run/jail.{name}.conf by /etc/rc.d/jail if jail.conf(5) is missing.
115#
116# ASIDE: dhclient(8) inside a vnet jail...
117#
118# To allow dhclient(8) to work inside a vnet jail, make sure the following
119# appears in /etc/devfs.rules (which should be created if it doesn't exist):
120#
121# 	[devfsrules_jail=11]
122# 	add include $devfsrules_hide_all
123# 	add include $devfsrules_unhide_basic
124# 	add include $devfsrules_unhide_login
125# 	add path 'bpf*' unhide
126#
127# And set ether devfs.ruleset="11" (jail.conf(5)) or
128# jail_{name}_devfs_ruleset="11" (rc.conf(5)).
129#
130# NB: While this tool can't create every type of desirable topology, it should
131# handle most setups, minus some which considered exotic or purpose-built.
132#
133############################################################ GLOBALS
134
135pgm="${0##*/}" # Program basename
136
137#
138# Global exit status
139#
140SUCCESS=0
141FAILURE=1
142
143############################################################ FUNCTIONS
144
145usage()
146{
147	local action usage descr
148	exec >&2
149	echo "Usage: $pgm action [arguments]"
150	echo "Actions:"
151	for action in \
152		addm		\
153		show		\
154		show1		\
155		destroy		\
156	; do
157		eval usage=\"\$jib_${action}_usage\"
158		[ "$usage" ] || continue
159		eval descr=\"\$jib_${action}_descr\"
160		printf "\t%s\n\t\t%s\n" "$usage" "$descr"
161	done
162	exit $FAILURE
163}
164
165action_usage()
166{
167	local usage action="$1"
168	eval usage=\"\$jib_${action}_usage\"
169	echo "Usage: $pgm $usage" >&2
170	exit $FAILURE
171}
172
173mustberoot_to_continue()
174{
175	if [ "$( id -u )" -ne 0 ]; then
176		echo "Must run as root!" >&2
177		exit $FAILURE
178	fi
179}
180
181jib_addm_usage="addm [-b BRIDGE_NAME] NAME interface0 [interface1 ...]"
182jib_addm_descr="Creates e0b_NAME [e1b_NAME ...]"
183jib_addm()
184{
185	local OPTIND=1 OPTARG flag bridge=bridge
186	while getopts b: flag; do
187		case "$flag" in
188		b) bridge="${OPTARG:-bridge}" ;;
189		*) action_usage addm # NOTREACHED
190		esac
191	done
192	shift $(( $OPTIND - 1 ))
193
194	local name="$1"
195	[ "${name:-x}" = "${name#*[!0-9a-zA-Z_]}" -a $# -gt 1 ] ||
196		action_usage addm # NOTREACHED
197	shift 1 # name
198
199	mustberoot_to_continue
200
201	local iface iface_devid eiface_devid_a eiface_devid_b
202	local new num quad i=0
203	for iface in $*; do
204
205		# 1. Make sure the interface doesn't exist already
206		ifconfig "e${i}a_$name" > /dev/null 2>&1 && continue
207
208		# 2. Bring the interface up
209		ifconfig $iface up || return
210
211		# 3. Make sure the interface has been bridged
212		if ! ifconfig "$iface$bridge" > /dev/null 2>&1; then
213			new=$( ifconfig bridge create ) || return
214			ifconfig $new addm $iface || return
215			ifconfig $new name "$iface$bridge" || return
216		fi
217
218		# 4. Create a new interface to the bridge
219		new=$( ifconfig epair create ) || return
220		ifconfig "$iface$bridge" addm $new || return
221
222		# 5. Rename the new interface
223		ifconfig $new name "e${i}a_$name" || return
224		ifconfig ${new%a}b name "e${i}b_$name" || return
225
226		#
227		# 6. Set the MAC address of the new interface using a sensible
228		# algorithm to prevent conflicts on the network.
229		#
230		# The formula I'm using is ``NP:SS:SS:II:II:II'' where:
231		# + N denotes 4 bits used as a counter to support branching
232		#   each parent interface up to 15 times under the same jail
233		#   name (see S below).
234		# + P denotes the special nibble whose value, if one of
235		#   2, 6, A, or E (but usually 2) denotes a privately
236		#   administered MAC address (while remaining routable).
237		# + S denotes 16 bits, the sum(1) value of the jail name.
238		# + I denotes bits that are inherited from parent interface.
239		#
240		# The S bits are a CRC-16 checksum of NAME, allowing the jail
241		# to change the epair(4) generation order without affecting the
242		# MAC address. Meanwhile, if...
243		#   + the jail NAME changes (e.g., it was duplicated and given
244		#     a new name with no other changes)
245		#   + the underlying network interface changes
246		#   + the jail is moved to another host
247		# the MAC address will be recalculated to a new, similarly
248		# unique value preventing conflict.
249		#
250		iface_devid=$( ifconfig $iface ether | awk '/ether/,$0=$2' )
251		eiface_devid_a=${iface_devid#??:??:??}
252		eiface_devid_b=${iface_devid#??:??:??}
253		num=$( set -- `echo -n $name | sum` && echo $1 )
254		quad=$(( $num & 15 ))
255		case "$quad" in
256		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
257		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
258		esac
259		eiface_devid_a=$quad$eiface_devid_a
260		eiface_devid_b=$quad$eiface_devid_b
261		num=$(( $num >> 4 ))
262		quad=$(( $num & 15 ))
263		case "$quad" in
264		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
265		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
266		esac
267		eiface_devid_a=$quad$eiface_devid_a
268		eiface_devid_b=$quad$eiface_devid_b
269		num=$(( $num >> 4 ))
270		quad=$(( $num & 15 ))
271		case "$quad" in
272		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
273		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
274		esac
275		eiface_devid_a=$quad:$eiface_devid_a
276		eiface_devid_b=$quad:$eiface_devid_b
277		num=$(( $num >> 4 ))
278		quad=$(( $num & 15 ))
279		case "$quad" in
280		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
281		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
282		esac
283		case "$iface_devid" in
284		?2:*|?6:*)
285			eiface_devid_a=a:$quad$eiface_devid_a
286			eiface_devid_b=e:$quad$eiface_devid_b
287			;;
288		*)
289			eiface_devid_a=2:$quad$eiface_devid_a
290			eiface_devid_b=6:$quad$eiface_devid_b
291		esac
292		eval num=\$_${iface}_num
293		if [ "$num" ]; then
294			num=$(( $num + 1 ))
295			eval _${iface}_num=$num
296		else
297			num=0
298			local _${iface}_num=$num
299		fi
300		quad=$(( $num & 15 ))
301		case "$quad" in
302		10) quad=a ;; 11) quad=b ;; 12) quad=c ;;
303		13) quad=d ;; 14) quad=e ;; 15) quad=f ;;
304		esac
305		eiface_devid_a=$quad$eiface_devid_a
306		eiface_devid_b=$quad$eiface_devid_b
307		ifconfig "e${i}a_$name" ether $eiface_devid_a > /dev/null 2>&1
308		ifconfig "e${i}b_$name" ether $eiface_devid_b > /dev/null 2>&1
309
310		i=$(( $i + 1 )) # on to next e{i}b_name
311	done # for iface
312}
313
314jib_show_usage="show"
315jib_show_descr="List possible NAME values for \`show NAME'"
316jib_show1_usage="show NAME"
317jib_show1_descr="Lists e0b_NAME [e1b_NAME ...]"
318jib_show2_usage="show [NAME]"
319jib_show()
320{
321	local OPTIND=1 OPTARG flag
322	while getopts "" flag; do
323		case "$flag" in
324		*) action_usage show2 # NOTREACHED
325		esac
326	done
327	shift $(( $OPTIND - 1 ))
328	if [ $# -eq 0 ]; then
329		ifconfig | awk '
330			/^[^:[:space:]]+:/ {
331				iface = $1
332				sub(/:.*/, "", iface)
333				next
334			}
335			$1 == "groups:" {
336				for (n = split($0, group); n > 1; n--) {
337					if (group[n] != "bridge") continue
338					print iface
339					next
340				}
341			}' |
342			xargs -rn1 ifconfig |
343			awk '$1 == "member:" &&
344				sub(/^e[[:digit:]]+a_/, "", $2), $0 = $2' |
345			sort -u
346		return
347	fi
348	ifconfig | awk -v name="$1" '
349		match($0, /^e[[:digit:]]+a_/) && sub(/:.*/, "") &&
350			substr($1, RSTART + RLENGTH) == name
351	' | sort
352}
353
354jib_destroy_usage="destroy NAME"
355jib_destroy_descr="Destroy e0b_NAME [e1b_NAME ...]"
356jib_destroy()
357{
358	local OPTIND=1 OPTARG flag
359	while getopts "" flag; do
360		case "$flag" in
361		*) action_usage destroy # NOTREACHED
362		esac
363	done
364	shift $(( $OPTIND -1 ))
365	local name="$1"
366	[ "${name:-x}" = "${name#*[!0-9a-zA-Z_]}" -a $# -eq 1 ] ||
367		action_usage destroy # NOTREACHED
368	mustberoot_to_continue
369	jib_show "$name" | xargs -rn1 -I eiface ifconfig eiface destroy
370}
371
372############################################################ MAIN
373
374#
375# Command-line arguments
376#
377action="$1"
378[ "$action" ] || usage # NOTREACHED
379
380#
381# Validate action argument
382#
383if [ "$BASH_VERSION" ]; then
384	type="$( type -t "jib_$action" )" || usage # NOTREACHED
385else
386	type="$( type "jib_$action" 2> /dev/null )" || usage # NOTREACHED
387fi
388case "$type" in
389*function)
390	shift 1 # action
391	eval "jib_$action" \"\$@\"
392	;;
393*) usage # NOTREACHED
394esac
395
396################################################################################
397# END
398################################################################################
399