Details explaining how to use qjail to build a
NON-VIMAGE jail system.
This howto will strive to explain how the qjail utility is used in a real world
application Utilizing a documentation approach that fills in the blanks of how
all the separate network functions fit together.
Please keep in mind that all this is fictitious, completely fake. For the
purpose of this discussion, this host is typical of a home user or a Small
Business. There is an officially registered domain name that points to the
hosts IP address assigned by the ISP. The user has purchased a Home Class type
of Internet service which gets assigned a Dynamic IP address. A business may
purchase Business Class type of Internet service which gets assigned a static
IP address. In both cases the host jails get configured the same way. All this
is predicated on the jail being configured correctly first. This can be tested
by logging into the running jail from the host console using this qjail
command qjail console jail-name
then issuing whois 188.8.131.52
command, you will receive a reply if jail is configured correctly.
There is a big difference between the two in how they get configured on the host
system and the yearly fee the ISP charges.
Static IP addresses are only assigned by the ISP for Business Class Internet
service. The IP addresses assigned are public routable and permanent. The ISP
does not provide any auto configuration services for Static IP address. The
host configuration files have to be manually configured. The ISP will convey
the following information;
The one or more assigned static IP addresses. These will need ifconfig
statements added to the hosts /etc/rc.conf file to enable their usage. The
fully qualified domain names of the ISP's two DNS servers plus their IP
addresses. This info is used to populate the hosts /etc/resolv.conf file.
Dynamic IP addresses are only assigned by the ISP for Home Class Internet
service. A single assigned IP address is public routable. The ISP provides
auto configuration services through DHCP. Dynamic means the ISP can change the
assigned IP address on you while in use or change the DSN IP addresses and
their domain names or reconfigure their network on the fly to use a different
block of network IP address. The /etc/rc.conf
statement will automatically handle this
change on the fly transparently. This class of service is far cheaper than
Business Class. Don't be fooled by who uses Home Class internet service. Many
small to medium sized businesses have this type of service.
While were talking about IP addresses, per RFC 1918, there are groups of IP
address ranges reserved for private networks that will never be connected to
the public internet. These are intended for Local Area Networks. They are not
routable on the public Internet without first being NATed.
10.0.0.0 - 10.255.255.255
172.16.0.0 - 172.31.255.255
192.168.0.0 - 192.168.255.255
Domain names have to be registered in the country where they are located and a
yearly fee is charged. The domain name is linked to your IP address and this
information is distributed to public Internet DNS servers so users on the
internet can put your fully qualified domain name in the URL field of their
web browser and find it's way to the IP address of your host.
If you used a dynamic IP address to link to your domain name then when the
dynamic IP address changes the linked domain name no longer points to your
host and all Internet traffic stops. Now there are solutions to address this
problem. Some domain name registers, and companies that host domain names,
offer services where a program is run on the host that watches for dynamic IP
changes and then updates the linked IP address of the domain name with the new
dynamic IP address when a change occurs. Using this technique will keep your
domain name pointing at your host.
The users domain name register hosts the domain name and points it to your hosts
ip address. The ISP assigned one dynamic IP address to the host. The host is
running RELEASE 11.0 and its already connected to the public internet and
working correctly. All firewall rules are keep state and only inbound ports
53, 67, 22 are allowed in and only outbound ports 43, 53, 3690 are allowed
out. All other inbound/outbound ports are blocked by default. Issuing whois
command from the hosts console should work as the test to verify
the host is functional. It's assumed that all host commands are issued from
the host's local console keyboard.
The host only has 2 services running on it, SSH and IPFILTER firewall. The
firewall allows remote public Internet access to SSH. SSH login authentication
method is not important here as what ever method you want to use can be setup.
The Host has two jails one for apache web server and the other one with ssh
1. NON-VIMAGE jails which we are talking about here do not have their
own firewalls. All jail traffic passes through the hosts firewall.
Security of what you want allowed in/out of the jail is controlled by
the hosts firewall based on the port numbers being used.
2. For jails to receive unsolicited inbound public access, each jail
needs a unique port number assigned to each separate jail for each
service you are going to run in that jail.
3. A firewall keep state rule to allow that unique port number in has to
be added to your hosts firewall rule set.
4. A NAT forward rule forwarding that unique port number to the IP
address assigned to the jail is required to be added to the hosts
firewall rule set. Different firewalls code this in different ways.
Read your firewall manual for details.
5. You can NOT run the same service on the host and in a jail or in
other jails without using a unique inbound port number to forward the
selected traffic to the desired jail.
6. Your domain name hoster plays a big part here. They have online
administrator functions where you can configure all port 80 traffic to
be forwarded to what ever port number you have used to point to the
desired jail. You can do this same thing for what ever other standard
port numbers you want forwarded to a jails unique port numbers. This
is how you drive different public domain name traffic to a single host
with jails serving services for just that domain name.
Step 1. Enter pkg install qjail
to Install the qjail software.
Step 2. Enter qjail install
to install the qjail environment.
Step 3. Enter qjail create -4 10.10.0.1 -c ssh
To create a
directory tree type jail with ssh enabled.
Step 4. Enter qjail create -4 10.10.0.2 www
To create a
directory tree type jail.
Step 5. Enter qjail start ssh
Start this jail.
Step 6. Enter qjail restart ssh
to stop and start the jail so
SSH will start running in the jail.
Step 7. Enter qjail start www
Start this jail.
Step 8. Enter qjail console www
Auto login to this jails console.
Enter pkg install apache24
Install web server software.
Enter echo "apache24_enable="YES"" >>
to leave jail console.
Step 9. Enter qjail restart www
to stop and start the jail so
apache web server will start running.
For the purpose of this discussion the host system is using the ipfilter
firewall which is based on a IPF rules file and IPF NAT rules file. The actual
IPF rules will be shown to illustrate their syntax.
To drive public traffic to a jail and have that same service run on the host
means the same default port numbers can not be used in both the host and the
jails. So port numbers 22 & 80 are used for the host. To target traffic to
a jail we must assign the jails unique port numbers, 6122 for the ssh jail and
6180 for the www jail. These unique port numbers are arbitrarily chosen. You
can chose whatever number fits your fancy.
These 2 unique port numbers must be allowed to pass through the IPF firewall. To
do so add these 2 rules to the IPF rule set.
# Allow in www function for apache in qjail jail www pass in quick rl0 tcp
from any to any port = 6188 flags S keep state
# Allow in ssh function in qjail jail ssh pass in quick rl0 tcp from any to
any port = 6122 flags S keep state
In the NAT rules file is where the real action takes place. First of all, the
MAP command must cover the compete range of IP addresses you plan to use on
the host system for assignment to jails or LAN machines. In this case that's
map rl0 10.0.0.0/8 -> 0/32
# for normal lan + all jails
Now we have to code forward commands to point the inbound port numbers 6122
& 6188 to the jails IP addresses like this.
# Forward inbound unique port to jail ssh rdr rl0 0.0.0.0/0 port 6122 ->
10.10.0.1 port 22 tcp
# Forward inbound unique port to jail www rdr rl0 0.0.0.0/0 port 6188 ->
10.10.0.2 port 80 tcp
Load the NAT file to the system.
#This command loads the ipnat rules ipnat -FC -f /etc/ipnat.rules
#This command will resync ipnat with current host ip address ipf -y
Now we have to return to the IPF rules file and add rules to allow traffic
outputted by the NAT forward rules to pass through the firewall by adding
these two rules.
pass in quick rl0 tcp from any to 10.10.0.1 port = 22 flags S keep state
pass in quick rl0 tcp from any to 10.10.0.2 port = 80 flags S keep
Load the IPF rules file. ipf -FS -Fa -f /etc/ipf.rules
From any device with a browser, as long as its IP address is not associated with
the hosts IP address. Enter this URL format hosts_domain_name:8010/ or
hosts_ip_address:8010/ Your browser will get this message It worked
meaning you now have remote access to your www apache web server.
From any device with a ssh client, as long as its IP address is not associated
with the hosts IP address. Use "hosts_domain_name" and port 8010 for
ssh login or "hosts_ip_address" and port 8010. Use login name of
"ssh" and first time password of ssh. You will be prompted to change
the password. You now have remote SSH access to your ssh jail.
sockstat -j jid
jib=jail running number sockstat -4
the in use host ip address and port number
being listened on. sockstat -4 | grep 10.10.0.1
display only info for
that ip number ipnat -lhd
display nat info with count of times rule was
hit ipfstat -hni
list inbound firewall rules with hit count. Note: Any
rule that is allowing in a unique port number that gets
forwarded does not show a hit count. Look for the rule that
allows in the jails ip address port number for the count.
You can add the tcpdump function to a jail be changing the devfs_ruleset number
in the jails jail.conf definition from 4 to 50. There is a customized ruleset
number 50 that adds the "bfp" device that tcpdump requires to work.
The first time you use the "qjail config -b 50" command it will be
From inside running jail issue tcpdump -v ip host jail-ip-address
tcpdump -v tcp port 6122
qjail(8), qjail-intro(8), qjail-vnet-howto(8), qjail-ipv6-testing