#! /bin/sh
#
# SPDX-License-Identifier: AGPL-3.0-or-later
#
# PASST - Plug A Simple Socket Transport
#  for qemu/UNIX domain socket mode
#
# PASTA - Pack A Subtle Tap Abstraction
#  for network namespace/tap device mode
#
# test/lib/context - Run commands in different contexts (host, guest, namespace etc.)
#
# Copyright Red Hat
# Author: David Gibson <david@gibson.dropbear.id.au>

# context_setup_common() - Create outline of a new context
# $1:	Context name
context_setup_common() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	echo -n "${__name}$ " > "${__prefix}.log"
}

# context_setup_host() - Create a new context for running commands on the host
# $1:	Context name
context_setup_host() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	context_setup_common "${__name}"
	echo sh -c > "${__prefix}.enter"
}

# context_setup_nsenter() - Create a new context for running commands in a namespace
# $1:	Context name
# $2:	Namespace PID
context_setup_nsenter() {
	__name="$1"
	shift
	__prefix="${LOGDIR}/context_${__name}"
	context_setup_common "${__name}"
	echo "nsenter $@ sh -c" > "${__prefix}.enter"
}

# context_setup_guest() - Create a new context for running commands in a guest
# $1:        Context name
# $2:        CID to use for vsock
context_setup_guest() {
	__name="$1"
	__cid="$2"
	__prefix="${LOGDIR}/context_${__name}"
	context_setup_common "${__name}"

	cat > "${__prefix}.ssh" <<EOF
Host ${__name}
	User root
	UserKnownHostsFile ${__prefix}.hosts
	StrictHostKeyChecking no
	IdentityFile ${BASEPATH}/guest-key
	IdentityAgent none
	ProxyCommand socat - VSOCK-CONNECT:${__cid}:22
EOF
	echo "ssh -F ${__prefix}.ssh ${__name}" > "${__prefix}.enter"

	# Wait for the guest to be booted and accepting connections
	while ! ssh -F "${__prefix}.ssh" "${__name}" :; do
		sleep 0.1
	done
}

# context_teardown() - Remove a context (leave log files intact)
# $1:	Context name
context_teardown() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	rm -f "${__prefix}.enter" "${__prefix}.ssh" "${__prefix}.hosts"
}

# context_exists() - Test if a context currently exists
# $1:	Context name
context_exists() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	[ -f "${__prefix}.enter" ]
}

# context_run() - Run a shell command in a context, and wait for it to finish
# $1:	Context name
# $*:	Command to start
context_run() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	__enter="$(cat "${__prefix}.enter")"
	shift
	echo "$*" >> "${__prefix}.log"
	mkfifo "${__prefix}.stdout" "${__prefix}.stderr"
	tee -a "${__prefix}.log" < "${__prefix}.stdout" &
	tee -a "${__prefix}.log" < "${__prefix}.stderr" >&2 &
	${__enter} "$*" >> "${__prefix}.stdout" 2>> "${__prefix}.stderr"
	rc=$?
	rm "${__prefix}.stdout" "${__prefix}.stderr"
	[ ${DEBUG} -eq 1 ] && echo "[Exit code: $rc]" >> "${__prefix}.log"
	echo -n "${__name}$ " >> "${__prefix}.log"
	return $rc
}

# context_run_bg() - Start a shell command in a context
# $1:	Context name
# $*:	Command to start
context_run_bg() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	context_run "$@" &
	echo $! > "${__prefix}.pid"
}

# context_wait() - Wait for background command in a context to complete
# $1:	Context name
# Returns the status of the completed command
context_wait() {
	__name="$1"
	__prefix="${LOGDIR}/context_${__name}"
	__pid=$(cat "${__prefix}.pid")
	rm "${__prefix}.pid"
	wait ${__pid}
}