#! /usr/bin/env bash
#
# Copyright (c) 2013, 2015, 2016 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 "$sim_srcdir"/README.rst; then
    echo "$sim_srcdir/README.rst does not exist" >&2
    exit 1
fi

# Put built tools early in $PATH.
PATH=$sim_builddir/ovsdb:$sim_builddir/vswitchd:$sim_builddir/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

ovs-vsctl () { command ovs-vsctl -vsyslog:off "$@"; }; export -f ovs-vsctl
vtep-ctl () { command vtep-ctl -vsyslog:off "$@"; }; export -f vtep-ctl

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 -vsyslog: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 $1 ovsdb-server --remote=punix:"$sim_base"/$1/db.sock $daemon_opts

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

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

# Easy access to OVS manpages.
mkdir $sim_base/man
mandir=`cd $sim_base/man && pwd`
(cd "$sim_builddir" && ${MAKE-make} install-man install-man-rst mandir=$mandir EXTRA_RST_MANPAGES=ovs-sim.1.rst >/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
| 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
'

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

if $interactive; then
    cat <<EOF
|______________________________________________________________________

EOF
fi

exit $status