#!/bin/bash
# SPDX-License-Identifier: BSD-3-Clause
#
# fetch_from_guest.sh - copy a file out of a running Open-IOV guest.
#
# The guest agent is used to start a netcat transfer from the guest to the
# host (QEMU user networking: the host is 10.0.2.2), which is much faster and
# more robust than pushing tens of megabytes through the agent in base64
# chunks.
#
# Usage: scripts/fetch_from_guest.sh <guest-path> [guest-bind-ip]
#        e.g. scripts/fetch_from_guest.sh \
#               /usr/lib/x86_64-linux-gnu/libcuda.so.570.144
set -e

HERE="$(cd "$(dirname "$0")" && pwd)"
RUN="$(cd "$HERE/.." && pwd)/run"
VMEXEC="$HERE/../../../scripts/vgpu_vm.py"
PORT="${PORT:-47311}"

GUEST_PATH="${1:?usage: $0 <guest-path> [guest-bind-ip]}"
HOST_IP="${2:-10.0.2.2}"
OUT="$RUN/$(basename "$GUEST_PATH")"

mkdir -p "$RUN"

# Guest-side md5 for verification
GUEST_MD5=$("$VMEXEC" exec "md5sum '$GUEST_PATH'" 2>/dev/null | awk '{print $1}')
[ -n "$GUEST_MD5" ] || { echo "cannot stat $GUEST_PATH in guest"; exit 1; }

echo "[*] guest md5: $GUEST_MD5"
echo "[*] listening on :$PORT -> $OUT"
rm -f "$OUT"

nc -l "$PORT" > "$OUT" &
NCPID=$!
sleep 1

"$VMEXEC" exec "setsid sh -c 'nc $HOST_IP $PORT < $GUEST_PATH' >/dev/null 2>&1 &" >/dev/null 2>&1 || true

# Wait for the transfer to settle (size stable for two checks)
prev=0
for _ in $(seq 1 60); do
    sleep 2
    cur=$(stat -c%s "$OUT" 2>/dev/null || echo 0)
    [ "$cur" -gt 0 ] && [ "$cur" = "$prev" ] && break
    prev=$cur
done
wait $NCPID 2>/dev/null || true

HOST_MD5=$(md5sum "$OUT" | awk '{print $1}')
echo "[*] host  md5: $HOST_MD5"
if [ "$GUEST_MD5" != "$HOST_MD5" ]; then
    echo "[FAIL] md5 mismatch"
    exit 1
fi
echo "[ok] $OUT ($(stat -c%s "$OUT") bytes)"