selftests: forwarding: Add ethtool_lib.sh

Functions:
1. speeds_arr_get
	The function returns an array of speed values from
        /usr/include/linux/ethtool.h The array looks as follows:
	[10baseT/Half] = 0,
	[10baseT/Full] = 1,
	...

2. ethtool_set:
	params: cmd
	The function runs ethtool by cmd (ethtool -s cmd) and checks if
	there was an error in configuration

3. dev_speeds_get:
	params: dev, with_mode (0 or 1), adver (0 or 1)
	return value: Array of supported/Advertised link modes
	with/without mode

	* Example 1:
	speeds_get swp1 0 0
	return: 1000 10000 40000
	* Example 2:
	speeds_get swp1 1 1
	return: 1000baseKX/Full 10000baseKR/Full 40000baseCR4/Full

4. common_speeds_get:
	params: dev1, dev2, with_mode (0 or 1), adver (0 or 1)
	return value: Array of common speeds of dev1 and dev2

	* Example:
	common_speeds_get swp1 swp2 0 0
	return: 1000 10000
	Assuming that swp1 supports 1000 10000 40000 and swp2 supports
	1000 10000
Signed-off-by: Amit Cohen <amitc@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

tools/testing/selftests/net/forwarding/ethtool_lib.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+speeds_arr_get()
+{
+	cmd='/ETHTOOL_LINK_MODE_[^[:space:]]*_BIT[[:space:]]+=[[:space:]]+/ \
+		{sub(/,$/, "") \
+		sub(/ETHTOOL_LINK_MODE_/,"") \
+		sub(/_BIT/,"") \
+		sub(/_Full/,"/Full") \
+		sub(/_Half/,"/Half");\
+		print "["$1"]="$3}'
+
+	awk "${cmd}" /usr/include/linux/ethtool.h
+}
+
+ethtool_set()
+{
+	local cmd="$@"
+	local out=$(ethtool -s $cmd 2>&1 | wc -l)
+
+	check_err $out "error in configuration. $cmd"
+}
+
+dev_speeds_get()
+{
+	local dev=$1; shift
+	local with_mode=$1; shift
+	local adver=$1; shift
+	local speeds_str
+
+	if (($adver)); then
+		mode="Advertised link modes"
+	else
+		mode="Supported link modes"
+	fi
+
+	speeds_str=$(ethtool "$dev" | \
+		# Snip everything before the link modes section.
+		sed -n '/'"$mode"':/,$p' | \
+		# Quit processing the rest at the start of the next section.
+		# When checking, skip the header of this section (hence the 2,).
+		sed -n '2,${/^[\t][^ \t]/q};p' | \
+		# Drop the section header of the current section.
+		cut -d':' -f2)
+
+	local -a speeds_arr=($speeds_str)
+	if [[ $with_mode -eq 0 ]]; then
+		for ((i=0; i<${#speeds_arr[@]}; i++)); do
+			speeds_arr[$i]=${speeds_arr[$i]%base*}
+		done
+	fi
+	echo ${speeds_arr[@]}
+}
+
+common_speeds_get()
+{
+	dev1=$1; shift
+	dev2=$1; shift
+	with_mode=$1; shift
+	adver=$1; shift
+
+	local -a dev1_speeds=($(dev_speeds_get $dev1 $with_mode $adver))
+	local -a dev2_speeds=($(dev_speeds_get $dev2 $with_mode $adver))
+
+	comm -12 \
+		<(printf '%s\n' "${dev1_speeds[@]}" | sort -u) \
+		<(printf '%s\n' "${dev2_speeds[@]}" | sort -u)
+}