selftest/ns/start_in_ns.sh

   1 #!/bin/sh
   2 #
   3 # Starts samba in a separate namespace. This gets passed the interface/IP
   4 # to use, as well as the Samba command to run. The whole script gets run
   5 # (via unshare) in a separate namespace.
   6
   7 # the first 3 args are our interface-name, parent-PID, and a exports file
   8 # containing environment variables ($SERVER, $SERVER_IP, etc)
   9 interface=$1
  10 exports_file=$2
  11 parent_pid=$3
  12
  13 # we write the testenv environment variables to file, which makes it easier
  14 # to work out the $SERVER, $SERVER_IP, etc
  15 . $exports_file
  16
  17 # The namespaces we use are anonymous, which means other processes would need
  18 # to use our PID to access the new namespace
  19 echo "-------------------------------------------------------------"
  20 echo "Created namespace for $NETBIOSNAME ($ENVNAME) PID $$"
  21
  22 # generate a helper script if the developer wants to talk to this namespace
  23 # in another shell
  24 mk_nsenter_script="$(dirname $0)/mk_nsenter.sh"
  25 helper_script=$($mk_nsenter_script $$ $exports_file)
  26
  27 echo "To communicate with this testenv, use: $helper_script"
  28 echo "-------------------------------------------------------------"
  29
  30 # the rest of the args are the samba command to run
  31 shift 3
  32 SAMBA_CMD=$@
  33
  34 # make sure namespace loopback is up (it's needed for ping, etc)
  35 ip link set dev lo up
  36
  37 # Create the interfaces needed for communication between namespaces.
  38 # We use a veth pair, which acts as a tunnel between the namespaces.
  39 # One end of the veth link is added to a common bridge in the top-level (i.e.
  40 # selftest) namespace, and the other end is added to the testenv's namespace.
  41 # This means each testenv DC is in its own namespace, but they can talk to
  42 # each other via the common bridge interface.
  43 # The new veth interfaces are named "vethX" and "vethX-br", where
  44 # X = the testenv IP (i.e. Samba::get_interface()). E.g. ad_dc = veth30,
  45 # and veth30-br.
  46 # The "vethX" interface will live in the new testenv's namespace.
  47 # The "vethX-br" end is added to the bridge in the main selftest namespace.
  48 ip link add dev $interface-br type veth peer name $interface
  49
  50 # move the bridge end of the link back into the parent namespace.
  51 ip link set $interface-br netns $parent_pid
  52
  53 # configure our IP address and bring the interface up
  54 ip addr add $SERVER_IP/24 dev $interface
  55 # Note that samba can't bind to the IPv6 address while DAD is in progress,
  56 # so we use 'nodad' when configuring the address
  57 ip addr add $SERVER_IPV6/112 dev $interface nodad
  58 ip link set dev $interface up
  59
  60 # start samba
  61 $SAMBA_CMD