#!/bin/bash

_XTRACE_OVS_DPDK_CTL=$(set +o | grep xtrace)
if [[ "${OVS_DPDK_CTL_DEBUG}" == "True" ]]; then
    set -o xtrace
fi

FULL_PATH=$(realpath "${BASH_SOURCE[0]}")
CONFIG_FILE=${CONFIG_FILE:-"/etc/default/ovs-dpdk.conf"}
SERVICE_FILE="/etc/systemd/system/ovs-dpdkctl.service"

function get_value {
    crudini --get $CONFIG_FILE $@
}

function set_value {
    crudini --set $CONFIG_FILE $1 $2 "$3"
}

function del_value {
    crudini --del $CONFIG_FILE $@
}

function is_set {
    output=$(crudini --get $CONFIG_FILE $* &> /dev/null ) && [ -n "$(crudini --get $CONFIG_FILE $*)" ]; echo $?
}

function show_config {
    cat $CONFIG_FILE
}

function get_config {
    echo $CONFIG_FILE
}

function del_config {
    rm -f $CONFIG_FILE
}

function generate_pciwhitelist {
    local _Whitelist=''
    for nic in $(list_dpdk_nics); do
        address="$(get_value $nic address)"
        if [ "$_Whitelist" == '' ]; then
            _Whitelist="-w $address"
        else
            _Whitelist="$_Whitelist -w $address"
        fi
    done
    echo $_Whitelist
}

function gen_port_mappings {
    OVS_BRIDGE_MAPPINGS=$(get_value ovs bridge_mappings)
    OVS_BRIDGES=${OVS_BRIDGE_MAPPINGS//,/ }
    OVS_DPDK_PORT_MAPPINGS=""
    ARRAY=( $OVS_BRIDGES )
    for net in "${ARRAY[@]}"; do
        bridge="${net##*:}"
        nic=${bridge/br-/}
        if [[ -z "$OVS_DPDK_PORT_MAPPINGS" ]]; then
            OVS_DPDK_PORT_MAPPINGS="$nic:$bridge"
        else
            OVS_DPDK_PORT_MAPPINGS="$OVS_DPDK_PORT_MAPPINGS,$nic:$bridge"
        fi
    done
    echo "$OVS_DPDK_PORT_MAPPINGS"
}

function gen_config {
    del_config
    touch $CONFIG_FILE
    set_value ovs bridge_mappings ${bridge_mappings:-""}
    set_value ovs port_mappings ${port_mappings:-$(gen_port_mappings)}
    set_value ovs cidr_mappings ${cidr_mappings:-""}
    set_value ovs ovs_coremask ${ovs_coremask:-"0x1"}
    set_value ovs pmd_coremask ${pmd_coremask:-"0x2"}
    set_value ovs ovs_mem_channels ${ovs_mem_channels:-4}
    set_value ovs ovs_socket_mem ${ovs_socket_mem:-"512"}
    set_value ovs dpdk_interface_driver ${dpdk_interface_driver:-"uio_pci_generic"}
    set_value ovs hugepage_mountpoint ${hugepage_mountpoint:-"/dev/hugepages"}

    ls -al /sys/class/net/* | awk '$0 ~ /pci/ {n=split($NF,a,"/"); print "\n[" a[n] "]\naddress = " a[n-2]  "\ndriver ="}' >> $CONFIG_FILE

    for nic in $(get_value | grep -v ovs); do
        set_value $nic driver $(get_driver_by_address $(get_value $nic address))
    done
    for nic in $(list_dpdk_nics); do
        set_value $nic driver ${dpdk_interface_driver:-"uio_pci_generic"}
    done
    set_value ovs pci_whitelist "'${pci_whitelist:-$(generate_pciwhitelist)}'"

}

function bind_nic {
    echo $1 > /sys/bus/pci/drivers/$2/bind
    echo $2 > /sys/bus/pci/devices/$1/driver_override
}

function unbind_nic {
    echo $1 > /sys/bus/pci/drivers/$2/unbind
    echo > /sys/bus/pci/devices/$1/driver_override

}

function list_dpdk_nics {
    for nic in $(crudini --get $CONFIG_FILE ovs port_mappings | cut -d : -f 1); do
        echo $nic;
    done
}

function bind_nics {
    for nic in $(list_dpdk_nics); do
        device_address="$(get_value $nic address)"
        current_driver="$(get_driver_by_address $device_address)"
        target_driver="$(get_value $nic driver)"
        if [ "$current_driver" != "$target_driver" ]; then
            set_value $nic old_driver $current_driver
            unbind_nic $device_address $current_driver
            bind_nic $device_address $target_driver
        fi
    done
}

function unbind_nics {
    for nic in $(list_dpdk_nics); do
        if [ "$(is_set $nic old_driver)" == 0 ]; then
            device_address="$(get_value $nic address)"
            current_driver="$(get_driver_by_address $device_address)"
            target_driver="$(get_value $nic old_driver)"
            if [ "$current_driver" != "$target_driver" ]; then
                unbind_nic $device_address $current_driver
                bind_nic $device_address $target_driver
                del_value $nic old_driver
            fi
        fi
    done
}


function get_address_by_name {
    ls -al /sys/class/net/$1 | awk '$0 ~ /pci/ {n=split($NF,a,"/"); print a[n-2] }'
}

function get_driver_by_address {
    ls /sys/bus/pci/devices/$1/driver -al | awk '{n=split($NF,a,"/"); print a[n]}'
}

function get_port_bridge {
    for pair in $(get_value ovs port port_mappings); do
        nic=`echo $pair | cut -f 1 -d ":"`
        if [[ "$nic" == "$1" ]]; then
            bridge=`echo $pair | cut -f 2 -d ":"`
            echo $bridge
            return 0
        fi
    done
    return 1
}

function init_ovs_db {
    ovs-vsctl init
    ovs-vsctl --no-wait set Open_vSwitch . other_config:pmd-cpu-mask="$(get_value ovs pmd_coremask)" \
    other_config:dpdk-init=True other_config:dpdk-lcore-mask="$(get_value ovs ovs_coremask)" \
    other_config:dpdk-mem-channels="$(get_value ovs ovs_mem_channels)" \
    other_config:dpdk-socket-mem="$(get_value ovs ovs_socket_mem)" \
    other_config:dpdk-hugepage-dir="$(get_value ovs hugepage_mountpoint)"  \
    other_config:dpdk-extra=" --proc-type primary $(get_value ovs pci_whitelist) "
}

function init_ovs_bridges {
    raw_bridge_mappings=$(get_value ovs bridge_mappings)
    bridge_mappings=( ${raw_bridge_mappings//,/ } )
    for pair in "${bridge_mappings[@]}"; do
        bridge=`echo $pair | cut -f 2 -d ":"`
        sudo ovs-vsctl --no-wait -- --may-exist add-br $bridge -- set Bridge $bridge datapath_type=netdev
    done
}

function init_ovs_interfaces {
    local pci_port_pairs ==''
    for nic in $(list_dpdk_nics); do
        address="$(get_value $nic address)"
        if [ "$pci_port_pairs" == '' ]; then
            pci_port_pairs ="$address,$nic"
        else
            pci_port_pairs="$pci_port_pairs $address,$nic"
        fi
    done
    pci_port_pairs="$(echo $pci_port_pairs | sort)"
    dpdk_port_number=0
    for pair in  $pci_port_pairs; do
        addr="$(echo $pair | cut -f 1 -d ",")"
        nic="$(echo $pair | cut -f 2 -d ",")"
        bridge="$(get_port_bridge $nic)"
        # ovs 2.6 and older requires dpdkX names, ovs 2.7+ requires dpdk-devargs instead.
        ovs-vsctl --no-wait --may-exist add-port $bridge "dpdk${dpdk_port_number}" \
        -- set Interface  "dpdk${dpdk_port_number}" type=dpdk ||  \
        ovs-vsctl --no-wait --may-exist add-port $bridge $nic \
        -- set Interface  $nic type=dpdk options:dpdk-devargs=$addr

        dpdk_port_number=$((dpdk_port_number+1))
    done

}

function init {
    init_ovs_db
    init_ovs_bridges
    init_ovs_interfaces
}

function install_service {
    cat << EOF | tee "$SERVICE_FILE"

[Unit]
Description=configuration service for ovs-dpdk nics.
Before=network-pre.target
After=syslog.target

[Service]
# Uncomment to enable debug logging.
# Environment=OVS_DPDK_CTL_DEBUG=True
Environment=CONFIG_FILE=$CONFIG_FILE
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/ovs-dpdkctl bind_nics
ExecStop=/bin/ovs-dpdkctl unbind_nics

[Install]
WantedBy=multi-user.target

EOF
    systemctl daemon-reload
    systemctl enable ovs-dpdkctl
}

function uninstall_service {
    systemctl disable ovs-dpdkctl
    rm -f "$SERVICE_FILE"
    systemctl daemon-reload
}

function install {
    if [ ! -e "$SERVICE_FILE" ]; then
        install_service
    fi
    if [ ! -e /bin/ovs-dpdkctl ]; then
        cp "$FULL_PATH" /bin/ovs-dpdkctl
        chmod +x /bin/ovs-dpdkctl
    fi
    if [ ! -e "$CONFIG_FILE" ]; then
        gen_config
    fi
    systemctl start ovs-dpdkctl
}

function uninstall {
    systemctl stop ovs-dpdkctl
    if [ -e "$SERVICE_FILE" ]; then
        uninstall_service
    fi
    if [ -e /bin/ovs-dpdkctl ]; then
        rm -f /bin/ovs-dpdkctl
    fi
    if [ -e "$CONFIG_FILE" ]; then
        rm -f "$CONFIG_FILE"
    fi
}


function useage {
    cat << "EOF"
ovs-dpdkctl.sh: A tool to configure ovs with dpdk.

- This tool automate the process of binding host insterfacesto a dpdk
  compaible driver (uio_pci_generic | vfio-pci) at boot.
- This tool automate bootstraping ovs so that it can use the
  dpdk accelerated netdev datapath.

commands:
  - install:
    - installs ovs-dpdkctl as a systemd service.
    - installs ovs-dpdkctl binary.
    - generates ovs-dpdkctl configuration file.
    - starts ovs-dpdkctl service.
  - uninstall:
    - stops ovs-dpdkctl service.
    - uninstalls ovs-dpdkctl systemd service.
    - uninstalls ovs-dpdkctl binary.
    - removes ovs-dpdkctl configuration file.
  - bind_nics:
    - iterates over all dpdk interfaces defined in ovs-dpdkctl config
      and binds the interface to the target driver specifed in the config
      if current driver does not equal target.
  - unbind_nics:
    - iterates over all dpdk interfaces defined in ovs-dpdkctl config
      and restores the interface to its original non dpdk driver.
  - init:
    - defines dpdk specific configuration paramater in the ovsdb.
    - creates bridges as spcified by ovs bridge_mappings in
      ovs-dpdkctl config.
    - creates dpdk ports as defined by ovs port_mappings in
      ovs-dpdkctl config.
  - useage:
    - prints this message

options:
  - debuging:
    - To enable debuging export OVS_DPDK_CTL_DEBUG=True
  - install:
    - The varibles discribed below can be defined to customise
      installation of ovs-dpdkctl.
      <variable>=<value> ovs-dpdkctl.sh install
    - bridge_mappings:
      - A comma seperated list of physnet to bridge mappings.
      - Example: bridge_mappings=physnet1:br-ex1,physnet2:br-ex2
      - Default: ""
    - port_mappings:
      - A comma seperated list of port to bridge mappings.
      - Example: port_mappings=eth1:br-ex1,eth2:br-ex2
      - Default: generated form bridge_mappings assuming bridge names
                 are constructed by appending br- to port name.
    - cidr_mappings:
      - A comma seperated list of bridge to cidr mappings.
      - Example: cidr_mappings=br-ex1:192.168.1.1/24,br-ex2:192.168.2.1/24
      - Default: ""
    - ovs_coremask:
      - A hex encoded string container a bitmask of what cpu core
        to pin the non dataplane treads of the ovs-vswitchd to.
      - Node that only the first core of the bit mask is currently
        used by ovs.
      - Example: ovs_coremask=0x1
      - Default: "0x1"
    - pmd_coremask:
      - A hex encoded string container a bitmask of what cpu cores
        to pin the dataplane pool mode driver treads of the ovs-vswitchd to.
      - Each bit set in the bitmask will result in the creating of a pmd.
      - For best performance it is recomended to allocate at least 1 pmd per
        numa node. On systems with HyperThreading enabled it is recomended to also
        allocate the HT sibling core in the pmd_coremask.cores allocated
        to ovs with dpdk via the pmd_coremask should be removed from the
        nova vcpu_pin_set and isolated from the kernel scheduler.
      - Note it is not recommended to isolate cores in the nova vcpu_pin_set
        unless the host will be dedicated for vms that request cpu pinning.
      - Example: pmd_coremask=0x4
      - Default: "0x4"
    - ovs_mem_channels:
      - The number of memory channels supported by the plathforms.
      - Example: ovs_mem_channels=2
      - Default: "4"
    - ovs_socket_mem:
      - A comma seperated list of hugepage memory, specifed in MBs per numa node,
        allocated to the ovs-vswitchd to use for the dpdk dataplane.
      - For best performance memory should be allocated evenly across all numa node
        that will run a pmd.
      - Example: ovs_socket_mem=512,512
      - Default: "512"
    - hugepage_mountpoint:
      - The hugepage mountpoint to use when allocating memory for dpdk.
      - Example: hugepage_mountpoint=/dev/my_custom_mountpoint
      - Default: "/dev/hugepages"
    - dpdk_interface_driver:
      - The dpdk compatible userspace driver to use when binding host interfaces.
      - Example: dpdk_interface_driver=vfio_pci
      - Default: "uio_pci_generic"
    - pci_whitelist:
      - A repeated space seperated list of pci whitelist flags
        for allowed ovs-dpdk ports.
      - The pci_whitelist allows multiple dpdk primary process to
        utilise different pci devices without resulting in a conflict
        of ownership.
      - Example: pci_whitelist="-w <pci address 1> -w <pci address 2>"
      - Default: auto generated form port_mappings.
EOF

}

if [ $# -ge  1 ]; then
    func=$1
    shift
else
    func="useage"
fi

#replace with switch later
eval "$func $@"


${_XTRACE_OVS_DPDK_CTL}