#! /usr/bin/env bash
#
# Copyright (c) 2013, 2015 Nicira, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

set -e

sim_builddir='@abs_builddir@'; export sim_builddir
sim_srcdir='@abs_top_srcdir@'; export sim_srcdir
interactive=false
scripts=

for option; do
    case $option in
        -h|--help)
            cat <<EOF
$0, for starting sandboxed dummy Open vSwitch environments
usage: $0 [OPTION...] [SCRIPT...]

Options:
  -i, --interactive    Prompt for interactive input (default if no SCRIPTs)
  -h, --help           Print this usage message.
EOF
            exit 0
            ;;

        -i|--i*)
            interactive=:
            ;;

        -*)
            echo "unrecognized option $option (use --help for help)" >&2
            exit 1
            ;;
        *)
	    case $option in
		/*) ;;
		*) option=`pwd`/$option ;;
	    esac
            scripts="$scripts $option"
            ;;
    esac
    shift
done

if test -z "$scripts"; then
    interactive=:
fi

# Check that we've got proper builddir and srcdir.
if test ! -e "$sim_builddir"/vswitchd/ovs-vswitchd; then
    echo "$sim_builddir/vswitchd/ovs-vswitchd does not exist (need to run \"make\"?)" >&2
    exit 1
fi
if test ! -e "$sim_srcdir"/WHY-OVS.md; then
    echo "$sim_srcdir/WHY-OVS.md does not exist" >&2
    exit 1
fi

# Put built tools early in $PATH.
PATH=$sim_builddir/ovsdb:$sim_builddir/vswitchd:$sim_builddir/utilities:$PATH
PATH=$sim_builddir/ovn/controller:$sim_builddir/ovn/northd:$sim_builddir/ovn/utilities:$PATH
export PATH

rm -rf sandbox
mkdir sandbox
cd sandbox
sim_base=`pwd`; export sim_base

trap_signals() {
    for signal in 0 1 2 3 13 14 15; do
	trap "
	    set +e
	    cd '$sim_base' && (kill \`cat */*.pid\`) >/dev/null 2>&1
	    trap - $signal
	    kill -$signal $$" $signal
    done
}
export -f trap_signals
trap_signals

sim_setvars() {
    sandbox=$1
    OVS_RUNDIR=$sim_base/$1; export OVS_RUNDIR
    OVS_LOGDIR=$sim_base/$1; export OVS_LOGDIR
    OVS_DBDIR=$sim_base/$1; export OVS_DBDIR
    OVS_SYSCONFDIR=$sim_base/$1; export OVS_SYSCONFDIR
    PS1="|$1: $sim_PS1"
}
export -f sim_setvars

as() {
    case $# in
	0)
            echo >&2 "$FUNCNAME: missing arguments (use --help for help)"
            return 1
	    ;;
	1) 
	    if test "$1" != --help; then
		sim_setvars $1
	    else
		cat <<EOF
$FUNCNAME: set the default sandbox for Open vSwitch commands
usage: $FUNCNAME SANDBOX [COMMAND ARG...]
where SANDBOX is the name of the desired sandbox.

With COMMAND arguments, this command sets the default target for that
single command, which it runs directly.  Otherwise, it sets the default
target for all following commands.
EOF
	    fi
	    ;;
	*)
	    (sim_setvars $1; shift; $@)
	    ;;
    esac
}
export -f as

sim_add() {
    if test "$1" == --help; then
        cat <<EOF
$FUNCNAME: create a new sandboxed Open vSwitch instance
usage: $FUNCNAME SANDBOX

where SANDBOX is the name of the new sandbox, which will be created in
a directory named $sim_base/SANDBOX.
Afterward, use "as SANDBOX" to execute OVS commands in the sandbox's
context.
EOF
	return 0
    fi
    if test $# != 1; then
        echo >&2 "$FUNCNAME: missing argument (use --help for help)"
        return 1
    fi

    set X $1; shift
    if test $# != 1; then
        echo >&2 "$FUNCNAME: sandbox name must be a single word"
        return 1
    fi

    if test -e "$sim_base/$1"; then
	echo >&2 "$1 already exists"
	return 1
    fi

    # Create sandbox.
    mkdir "$sim_base"/$1 || return 1

    daemon_opts="--detach --no-chdir --pidfile -vconsole:off --log-file"

    # Create database and start ovsdb-server.
    touch $sim_base/$1/.conf.db.~lock~
    as $1 ovsdb-tool create $sim_base/$1/conf.db "$sim_srcdir/vswitchd/vswitch.ovsschema"
    as $1 ovsdb-server $daemon_opts --remote=punix:"$sim_base"/$1/db.sock

    # Initialize database.
    as $1 ovs-vsctl --no-wait -- init

    # Start ovs-vswitchd.
    as $1 ovs-vswitchd $daemon_opts --enable-dummy=system -vvconn -vnetdev_dummy
}
export -f sim_add

net_add() {
    if test "$1" == --help; then
        cat <<EOF
$FUNCNAME: create a new interconnection network
usage: $FUNCNAME NETWORK

where NETWORK is the name of the new network.  Interconnection networks
are used with net_attach and ovn_attach.
EOF
	return 0
    fi
    if test $# != 1; then
        echo >&2 "$FUNCNAME: missing argument (use --help for help)"
        return 1
    fi

    as main ovs-vsctl add-br "$1"
}
export -f net_add

net_attach() {
    if test "$1" == --help; then
        cat <<EOF
$FUNCNAME: attach the default sandbox to an interconnection network
usage: $FUNCNAME NETWORK BRIDGE

Adds a port to BRIDGE within the default sandbox that connects BRIDGE
to the interconnection network NETWORK.  (Use "as" to set the default
sandbox.)
EOF
	return 0
    fi
    if test $# != 2; then
        echo >&2 "$FUNCNAME: wrong number of arguments (use --help for help)"
        return 1
    fi
    if test $sandbox = main; then
	echo >&2 "$FUNCNAME: can only attach interconnection networks to sandboxes other than main"
	return 1
    fi

    local net=$1 bridge=$2

    port=${sandbox}_$bridge
    as main ovs-vsctl \
	-- add-port $net "$port" \
	-- set Interface "$port" options:pstream="punix:$sim_base/main/$port.sock" options:rxq_pcap="$sim_base/main/$port-rx.pcap" options:tx_pcap="$sim_base/main/$port-tx.pcap" options:header=extended

    ovs-vsctl \
	-- set Interface $bridge options:tx_pcap="$sim_base/$sandbox/$bridge-tx.pcap" options:rxq_pcap="$sim_base/$sandbox/$bridge-rx.pcap" \
	-- add-port $bridge ${bridge}_$net \
	-- set Interface ${bridge}_$net options:stream="unix:$sim_base/main/$port.sock" options:rxq_pcap="$sim_base/$sandbox/${bridge}_$net-rx.pcap" options:tx_pcap="$sim_base/$sandbox/${bridge}_$net-tx.pcap" options:header=extended
}
export -f net_attach

ovn_start() {
    if test "$1" == --help; then
        cat <<EOF
$FUNCNAME: start OVN central databases and daemons
usage: $FUNCNAME

This creates and initializes the central OVN databases (northbound and
southbound), starts their ovsdb-server daemons, and starts the ovn-northd
daemon.
EOF
	return 0
    fi
    if test $# != 0; then
        echo >&2 "$FUNCNAME: no arguments accepted (use --help for help)"
        return 1
    fi

    if test -d ovn-sb || test -d ovn-nb; then
	echo >&2 "OVN already started"
	exit 1
    fi

    daemon_opts="--detach --no-chdir --pidfile -vconsole:off --log-file"
    for db in ovn-sb ovn-nb; do
	mkdir "$sim_base"/$db
	touch "$sim_base"/$db/.$db.db.~lock~
	as $db ovsdb-tool create "$sim_base"/$db/$db.db "$sim_srcdir"/ovn/$db.ovsschema
	as $db ovsdb-server $daemon_opts --remote=punix:"$sim_base"/$db/$db.sock "$sim_base"/$db/$db.db
    done

    OVN_NB_DB=unix:$sim_base/ovn-nb/ovn-nb.sock; export OVN_NB_DB
    OVN_SB_DB=unix:$sim_base/ovn-sb/ovn-sb.sock; export OVN_SB_DB

    mkdir "$sim_base"/northd
    as northd ovn-northd $daemon_opts \
	       --ovnnb-db="$OVN_NB_DB" \
	       --ovnsb-db="$OVN_SB_DB"
}
export -f ovn_start

ovn_attach() {
    if test "$1" == --help; then
        cat <<EOF
$FUNCNAME: attach default sandbox to an interconnection network for OVN
usage: $FUNCNAME NETWORK BRIDGE IP [MASKLEN]

This starts by doing everything that net_attach does.  Then it configures the
specified IP and MASKLEN (e.g. 192.168.0.1 and 24) on BRIDGE and starts
and configures ovn-controller.

MASKLEN defaults to 24 if it is not specified.
EOF
	return 0
    fi
    if test $# != 3 && test $# != 4; then
        echo >&2 "$FUNCNAME: wrong number of arguments (use --help for help)"
        return 1
    fi

    local net=$1 bridge=$2 ip=$3 masklen=${4-24}
    net_attach $net $bridge || return $?

    ovs-appctl netdev-dummy/ip4addr $bridge $ip/$masklen >/dev/null
    ovs-appctl ovs/route/add $ip/$masklen $bridge > /dev/null
    ovs-vsctl \
	-- set Open_vSwitch . external-ids:system-id=$sandbox \
        -- set Open_vSwitch . external-ids:ovn-remote=unix:$sim_base/ovn-sb/ovn-sb.sock \
	-- set Open_vSwitch . external-ids:ovn-encap-type=geneve \
	-- set Open_vSwitch . external-ids:ovn-encap-ip=$ip\
	-- add-br br-int \
	-- set bridge br-int fail-mode=secure other-config:disable-in-band=true
    ovn-controller --detach --no-chdir --pidfile -vconsole:off --log-file
}
export -f ovn_attach

# Easy access to OVS manpages.
mkdir $sim_base/man
mandir=`cd $sim_base/man && pwd`
(cd "$sim_builddir" && ${MAKE-make} install-man mandir=$mandir >/dev/null)
MANPATH=$mandir:; export MANPATH

export scripts
export interactive
rc='
    if [ -f /etc/bashrc ]; then
	. /etc/bashrc
    fi
    if [ -f ~/.bashrc ]; then
	. ~/.bashrc
    fi

    trap_signals
    sim_PS1=$PS1
    sim_add main
    as main

    for script in $scripts; do
        . $script || exit $?
    done

    $interactive || exit 0

    cat <<EOF
 ______________________________________________________________________
|
| You are running in a nested shell environment meant for Open vSwitch
| and OVN testing in simulation.   The OVS manpages are available via
| "man".  Please see ovs-sim(1) for more information.
|
| Exit the shell to kill the running daemons and leave the simulation
| environment.
EOF
'

status=0; bash --rcfile <(echo "$rc") || status=$?

if $interactive; then
    cat <<EOF
|______________________________________________________________________

EOF
fi

exit $status