Re: [PATCHv3 net-next 01/14] selftests/net: add lib.sh

[Paolo Abeni <pabeni@redhat.com>]

On Sat, 2023-12-02 at 10:00 +0800, Hangbin Liu wrote:
> Add a lib.sh for net selftests. This file can be used to define commonly
> used variables and functions. Some commonly used functions can be moved
> from forwarding/lib.sh to this lib file. e.g. busywait().
> 
> Add function setup_ns() for user to create unique namespaces with given
> prefix name.
> 
> Reviewed-by: Petr Machata <petrm@nvidia.com>
> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
> ---
>  tools/testing/selftests/net/Makefile          |  2 +-
>  tools/testing/selftests/net/forwarding/lib.sh | 27 +-----
>  tools/testing/selftests/net/lib.sh            | 85 +++++++++++++++++++
>  3 files changed, 87 insertions(+), 27 deletions(-)
>  create mode 100644 tools/testing/selftests/net/lib.sh
> 
> diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile
> index 9274edfb76ff..14bd68da7466 100644
> --- a/tools/testing/selftests/net/Makefile
> +++ b/tools/testing/selftests/net/Makefile
> @@ -54,7 +54,7 @@ TEST_PROGS += ip_local_port_range.sh
>  TEST_PROGS += rps_default_mask.sh
>  TEST_PROGS += big_tcp.sh
>  TEST_PROGS_EXTENDED := in_netns.sh setup_loopback.sh setup_veth.sh
> -TEST_PROGS_EXTENDED += toeplitz_client.sh toeplitz.sh
> +TEST_PROGS_EXTENDED += toeplitz_client.sh toeplitz.sh lib.sh
>  TEST_GEN_FILES =  socket nettest
>  TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy reuseport_addr_any
>  TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd txring_overwrite
> diff --git a/tools/testing/selftests/net/forwarding/lib.sh b/tools/testing/selftests/net/forwarding/lib.sh
> index e37a15eda6c2..8f6ca458af9a 100755
> --- a/tools/testing/selftests/net/forwarding/lib.sh
> +++ b/tools/testing/selftests/net/forwarding/lib.sh
> @@ -4,9 +4,6 @@
>  ##############################################################################
>  # Defines
>  
> -# Kselftest framework requirement - SKIP code is 4.
> -ksft_skip=4
> -
>  # Can be overridden by the configuration file.
>  PING=${PING:=ping}
>  PING6=${PING6:=ping6}
> @@ -41,6 +38,7 @@ if [[ -f $relative_path/forwarding.config ]]; then
>  	source "$relative_path/forwarding.config"
>  fi
>  
> +source ../lib.sh
>  ##############################################################################
>  # Sanity checks
>  
> @@ -395,29 +393,6 @@ log_info()
>  	echo "INFO: $msg"
>  }
>  
> -busywait()
> -{
> -	local timeout=$1; shift
> -
> -	local start_time="$(date -u +%s%3N)"
> -	while true
> -	do
> -		local out
> -		out=$("$@")
> -		local ret=$?
> -		if ((!ret)); then
> -			echo -n "$out"
> -			return 0
> -		fi
> -
> -		local current_time="$(date -u +%s%3N)"
> -		if ((current_time - start_time > timeout)); then
> -			echo -n "$out"
> -			return 1
> -		fi
> -	done
> -}
> -
>  not()
>  {
>  	"$@"
> diff --git a/tools/testing/selftests/net/lib.sh b/tools/testing/selftests/net/lib.sh
> new file mode 100644
> index 000000000000..518eca57b815
> --- /dev/null
> +++ b/tools/testing/selftests/net/lib.sh
> @@ -0,0 +1,85 @@
> +#!/bin/bash
> +# SPDX-License-Identifier: GPL-2.0
> +
> +##############################################################################
> +# Defines
> +
> +# Kselftest framework requirement - SKIP code is 4.
> +ksft_skip=4
> +
> +##############################################################################
> +# Helpers
> +busywait()
> +{
> +	local timeout=$1; shift
> +
> +	local start_time="$(date -u +%s%3N)"
> +	while true
> +	do
> +		local out
> +		out=$("$@")
> +		local ret=$?
> +		if ((!ret)); then
> +			echo -n "$out"
> +			return 0
> +		fi
> +
> +		local current_time="$(date -u +%s%3N)"
> +		if ((current_time - start_time > timeout)); then
> +			echo -n "$out"
> +			return 1
> +		fi
> +	done
> +}
> +
> +cleanup_ns()
> +{
> +	local ns=""
> +	local errexit=0
> +	local ret=0
> +
> +	# disable errexit temporary
> +	if [[ $- =~ "e" ]]; then
> +		errexit=1
> +		set +e
> +	fi
> +
> +	for ns in "$@"; do
> +		ip netns delete "${ns}" &> /dev/null
> +		if ! busywait 2 ip netns list \| grep -vq "^$ns$" &> /dev/null; then
> +			echo "Warn: Failed to remove namespace $ns"
> +			ret=1
> +		fi
> +	done
> +
> +	[ $errexit -eq 1 ] && set -e
> +	return $ret
> +}
> +
> +# setup netns with given names as prefix. e.g
> +# setup_ns local remote
> +setup_ns()
> +{
> +	local ns=""
> +	local ns_name=""
> +	local ns_list=""
> +	for ns_name in "$@"; do
> +		# Some test may setup/remove same netns multi times
> +		if unset ${ns_name} 2> /dev/null; then
> +			ns="${ns_name,,}-$(mktemp -u XXXXXX)"
> +			eval readonly ${ns_name}="$ns"
> +		else
> +			eval ns='$'${ns_name}
> +			cleanup_ns "$ns"
> +
> +		fi
> +
> +		if ! ip netns add "$ns"; then
> +			echo "Failed to create namespace $ns_name"
> +			cleanup_ns "$ns_list"
> +			return $ksft_skip
> +		fi
> +		ip -n "$ns" link set lo up
> +		ns_list="$ns_list $ns"

Side note for a possible follow-up: if you maintain $ns_list as global
variable, and remove from such list the ns deleted by cleanup_ns, you
could remove the cleanup trap from the individual test with something
alike:

final_cleanup_ns()
{
	cleanup_ns $ns_list
}

trap final_cleanup_ns EXIT

No respin needed for the above, could be a follow-up if agreed upon.

Cheers,

Paolo