#!/usr/bin/bash
# Copyright 2015 Mellanox Technologies, Ltd
#
# 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.

# Constants
readonly SCOPE=`basename $0`
readonly UDEV_FILE='/etc/udev/rules.d/70-persistent-net.rules'

# Variables
STORAGE_PORT='<%=@storage_parent%>'
ISER_NAME='<%=@iser_interface_name%>'
PARENT_FIRST_VF="/sys/class/net/$STORAGE_PORT/device/virtfn0"

# This functions print logs to /var/log/messages
function logger_print () {
   priority=$1
   msg=$2
   logger -t $SCOPE "$priority: $msg"
}

DEVICES='/sys/class/net/*/device'
if [ -e $PARENT_FIRST_VF ];then
  CHILD_BUS=`basename $(readlink /sys/class/net/$STORAGE_PORT/device/virtfn0)`
  logger_print info "Found first probed port of ${STORAGE_PORT} with bus ID: ${CHILD_BUS}."
else
  PARENT_BUS=`cat /sys/class/net/$STORAGE_PORT/device/uevent | grep -i pci_slot | cut -d = -f 2`
  CHILD_BUS=`echo $PARENT_BUS | sed -e s/0$/1/g`
  PROBED_PORT_NAME="eth_iser_guess"
  logger_print info "Did not find probed ports of ${STORAGE_PORT}, guessing its bus is: ${CHILD_BUS}."
fi
STORAGE_PORT_NUMBER=`cat /sys/class/net/$STORAGE_PORT/dev_id`

# Find the probe VF port that fits the storage ports number and BUS
for dev in $DEVICES; do
  # Check for correct bus
  CANDIDATE_BUS=`readlink -nq $dev`;
  if [[  $CANDIDATE_BUS != *$CHILD_BUS* ]]; then
    continue;
  fi

  # Check for correct dev_id
  CANDIDATE_DIRNAME=`dirname $dev`
  PORT_NUMBER=`cat $CANDIDATE_DIRNAME/dev_id`
  if [ $PORT_NUMBER = $STORAGE_PORT_NUMBER ]; then
      PROBED_DIRNAME=`dirname $dev`
      PROBED_PORT_NAME=`basename $PROBED_DIRNAME`
  fi
done

# Verify that we find the appropriate virtual port
if [ -z "$PROBED_PORT_NAME" ]; then
    logger_print error "Did not find $STORAGE_PORT_NUMBER probed ports of $STORAGE_PORT, exiting."
    exit 1
fi

# Verify that udev file exists
if [ ! -r "$UDEV_FILE" ]; then
    logger_print error "Did not find $UDEV_FILE to rename iser port."
    exit 1
fi

# Persistantly rename the matched probed port
if [ $PROBED_PORT_NAME != $ISER_NAME ]; then
  # Prepare line for udev
  UDEV_LINE="SUBSYSTEM==\"net\", ACTION==\"add\", "
  UDEV_LINE+="ATTR{dev_id}==\"$STORAGE_PORT_NUMBER\", KERNELS==\"$CHILD_BUS\", "
  UDEV_LINE+="ATTR{type}==\"1\", KERNEL==\"eth*\", NAME=\"$ISER_NAME\""

  # Change/add line in udev file
  grep $PROBED_PORT_NAME $UDEV_FILE > /dev/null 2>&1
  if [ $? -eq 0  ]; then
    OLD_LINE_NUMBER=`grep -n $PROBED_PORT_NAME $UDEV_FILE | cut -d : -f 1`
    eval "sed '"$OLD_LINE_NUMBER"d' -i $UDEV_FILE"
  fi

  # Insert new name config if not exists
  grep $ISER_NAME $UDEV_FILE > /dev/null 2>&1
  if [ $? -ne 0  ]; then
    echo >> $UDEV_FILE
    echo $UDEV_LINE >> $UDEV_FILE
  fi

  # restart OFED modules for udev changes to take effect
  modprobe -r mlx4_en
  modprobe -r mlx5_ib && modprobe -r mlx5_core
  udevadm control --reload-rules
  udevadm trigger
  modprobe mlx4_en
  modprobe mlx5_ib && modprobe mlx5_core

  if [ $? -ne 0 ]; then
    logger_print error "Mellanox drivers restart failed."
    exit 1
  fi
  logger_print info "Changed probed port name from $PROBED_PORT_NAME to $ISER_NAME."
else
  logger_print info "Probed port name is configured properly to $ISER_NAME."
fi

exit 0