#!/bin/bash
#
#    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.

# Defaults
# --------

# Set variables for building OVS from source
OVS_REPO=${OVS_REPO:-https://github.com/openvswitch/ovs.git}
OVS_REPO_NAME=$(basename ${OVS_REPO} | cut -f1 -d'.')
OVS_REPO_NAME=${OVS_REPO_NAME:-ovs}
OVS_BRANCH=${OVS_BRANCH:-0047ca3a0290f1ef954f2c76b31477cf4b9755f5}

# Functions

# load_module() - Load module using modprobe module given by argument and dies
#                 on failure
#               - fatal argument is optional and says whether function should
#                 exit if module can't be loaded
function load_module {
    local module=$1
    local fatal=$2

    if [ "$(trueorfalse True fatal)" == "True" ]; then
        sudo modprobe $module || (dmesg && die $LINENO "FAILED TO LOAD $module")
    else
        sudo modprobe $module || (echo "FAILED TO LOAD $module" && dmesg)
    fi
}

# prepare_for_compilation() - Fetch ovs git repository and install packages needed for
#                             compilation.
function prepare_for_ovs_compilation {
    local build_modules=${1:-False}
    OVS_DIR=$DEST/$OVS_REPO_NAME

    if [ ! -d $OVS_DIR ] ; then
        # We can't use git_clone here because we want to ignore ERROR_ON_CLONE
        git_timed clone $OVS_REPO $OVS_DIR
        cd $OVS_DIR
        git checkout $OVS_BRANCH
    else
        # Even though the directory already exists, call git_clone to update it
        # if needed based on the RECLONE option
        git_clone $OVS_REPO $OVS_DIR $OVS_BRANCH
        cd $OVS_DIR
    fi

    # TODO: Can you create package list files like you can inside devstack?
    install_package autoconf automake libtool gcc patch make

    # If build_modules is False, we don't need to install the kernel-*
    # packages. Just return.
    if [[ "$build_modules" == "False" ]]; then
        return
    fi

    KERNEL_VERSION=`uname -r`
    if is_fedora ; then
        # is_fedora covers Fedora, RHEL, CentOS, etc...
        if [[ "$os_VENDOR" == "Fedora" ]]; then
            install_package elfutils-libelf-devel
            KERNEL_VERSION=`echo $KERNEL_VERSION | cut --delimiter='-' --field 1`
        elif [[ ${KERNEL_VERSION:0:2} != "3." ]]; then
            # dash is illegal character in rpm version so replace
            # them with underscore like it is done in the kernel
            # https://github.com/torvalds/linux/blob/master/scripts/package/mkspec#L25
            # but only for latest series of the kernel, not 3.x

            KERNEL_VERSION=`echo $KERNEL_VERSION | tr - _`
        fi

        echo NOTE: if kernel-devel-$KERNEL_VERSION or kernel-headers-$KERNEL_VERSION installation
        echo failed, please, provide a repository with the package, or yum update / reboot
        echo your machine to get the latest kernel.

        install_package kernel-devel-$KERNEL_VERSION
        install_package kernel-headers-$KERNEL_VERSION

    elif is_ubuntu ; then
        install_package linux-headers-$KERNEL_VERSION
    fi
}

# load_ovs_kernel_modules() - load openvswitch kernel module
function load_ovs_kernel_modules {
    load_module openvswitch
    load_module vport-geneve False
    dmesg | tail
}

# reload_ovs_kernel_modules() - reload openvswitch kernel module
function reload_ovs_kernel_modules {
    set +e
    ovs_system=$(sudo ovs-dpctl dump-dps | grep ovs-system)
    if [ -n "$ovs_system" ]; then
        sudo ovs-dpctl del-dp ovs-system
    fi
    set -e
    sudo modprobe -r vport_geneve
    sudo modprobe -r openvswitch
    load_ovs_kernel_modules
}

# compile_ovs() - Compile OVS from source and load needed modules.
#                 Accepts two parameters:
#                   - first one is False by default and means that modules are not built and installed.
#                   - second optional parameter defines prefix for ovs compilation
#                   - third optional parameter defines localstatedir for ovs single machine runtime
#                 Env variables OVS_REPO_NAME, OVS_REPO and OVS_BRANCH must be set
function compile_ovs {
    local _pwd=$PWD
    local build_modules=${1:-False}
    local prefix=$2
    local localstatedir=$3

    if [ -n "$prefix" ]; then
        prefix="--prefix=$prefix"
    fi

    if [ -n "$localstatedir" ]; then
        localstatedir="--localstatedir=$localstatedir"
    fi

    prepare_for_ovs_compilation $build_modules

    KERNEL_VERSION=$(uname -r)
    major_version=$(echo "${KERNEL_VERSION}" | cut -d '.' -f1)
    patch_level=$(echo "${KERNEL_VERSION}" | cut -d '.' -f2)
    if [ "${major_version}" -gt 5 ] || [ "${major_version}" == 5 ] && [ "${patch_level}" -gt 5 ]; then
        echo "NOTE: KERNEL VERSION is ${KERNEL_VERSION} and OVS doesn't support compiling "
        echo "Kernel module for version higher than 5.5. Skipping module compilation..."
        build_modules="False"
    fi

    if [ ! -f configure ] ; then
        ./boot.sh
    fi
    if [ ! -f config.status ] || [ configure -nt config.status ] ; then
        if [[ "$build_modules" == "True" ]]; then
            ./configure $prefix $localstatedir --with-linux=/lib/modules/$(uname -r)/build
        else
            ./configure $prefix $localstatedir
        fi
    fi
    make -j$(($(nproc) + 1))
    sudo make install
    if [[ "$build_modules" == "True" ]]; then
        sudo make INSTALL_MOD_DIR=kernel/net/openvswitch modules_install
        reload_ovs_kernel_modules
    else
        load_ovs_kernel_modules
    fi

    cd $_pwd
}

# action_service - call an action over openvswitch service
#                  Accepts one parameter that can be either
#                  'start', 'restart' and 'stop'.
function action_openvswitch {
    local action=$1

    if is_ubuntu; then
        ${action}_service openvswitch-switch
    elif is_fedora; then
        ${action}_service openvswitch
    elif is_suse; then
        if [[ $DISTRO == "sle12" ]] && [[ $os_RELEASE -lt 12.2 ]]; then
            ${action}_service openvswitch-switch
        else
            ${action}_service openvswitch
        fi
    fi
}

# start_new_ovs() - removes old ovs database, creates a new one and starts ovs
function start_new_ovs {
    sudo rm -f /etc/openvswitch/conf.db /etc/openvswitch/.conf.db~lock~
    sudo /usr/share/openvswitch/scripts/ovs-ctl start
}

# stop_new_ovs() - stops ovs
function stop_new_ovs {
    local ovs_ctl='/usr/share/openvswitch/scripts/ovs-ctl'

    if [ -x $ovs_ctl ] ; then
        sudo $ovs_ctl stop
    fi
}

# remove_ovs_packages() - removes old ovs packages from the system
function remove_ovs_packages {
    for package in openvswitch openvswitch-switch openvswitch-common; do
        if is_package_installed $package; then
            uninstall_package $package
        fi
    done
}


# load_conntrack_gre_module() - loads nf_conntrack_proto_gre kernel module
function load_conntrack_gre_module {
    sudo modprobe nf_conntrack_proto_gre
}