Jailed process listening to broadcast address of host system - possible?

Matthias Petermann matthias at d2ux.org
Tue Mar 5 17:48:01 UTC 2013


Hello,

is there any way to listen to a networks broadcast adress from within a Jail?

Given ist the following setup:

  * The host (IP 192.168.2.127)
  * The jail (same IP as host, 192.168.2.127)

When I do:

  $ nc -l 192.168.2.255 9999

I got the following results:

     root at host # nc -l 192.168.2.255 9999
     <Listening for connections, ok>

     root at jail # nc -l 192.168.2.255 9999
     nc: Can't assign requested address

The latter is the problem. I already sat security.jail.allow_raw_sockets=1
and now not sure if I am trying to do something which is not allowed  
by design?

Thanks in advance,
Matthias



# Additional Information:

## ifconfig (host):

root at host # ifconfig -a
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
         ether 08:00:27:b3:64:f2
         inet 192.168.2.127 netmask 0xffffff00 broadcast 192.168.2.255
         nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
         media: Ethernet autoselect (1000baseT <full-duplex>)
         status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
         options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
         inet6 ::1 prefixlen 128
         inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
         inet 127.0.0.1 netmask 0xff000000
         inet 10.0.0.1 netmask 0xffffffff
         inet 10.0.0.2 netmask 0xffffffff
         inet 10.0.0.3 netmask 0xffffffff
         inet 10.0.0.4 netmask 0xffffffff
         inet 10.0.0.5 netmask 0xffffffff
         nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
pflog0: flags=141<UP,RUNNING,PROMISC> metric 0 mtu 33152
         nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>

## ifconfig (jail):

root at jail # ifconfig -a
em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
         options=9b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM>
         ether 08:00:27:b3:64:f2
         inet 192.168.2.127 netmask 0xffffff00 broadcast 192.168.2.255
         media: Ethernet autoselect (1000baseT <full-duplex>)
         status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
         options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
pflog0: flags=141<UP,RUNNING,PROMISC> metric 0 mtu 33152






-- 
Matthias Petermann <matthias at d2ux.org>



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