#!/system/bin/sh
# Runs early in boot, before apps start. Loads the kernel module and
# records load_status so the app can explain *why* the module didn't
# come up (wrong GKI variant, missing kretprobes, etc.) without having
# to guess from a missing /proc entry.

MODDIR="${0%/*}"
KO="$MODDIR/vpnhide_kmod.ko"
MODULE_PROP="$MODDIR/module.prop"
STATUS_DIR="/data/adb/vpnhide_kmod"
STATUS_FILE="$STATUS_DIR/load_status"
DMESG_FILE="$STATUS_DIR/load_dmesg"

# Already loaded on a previous trigger in this boot — nothing to do.
if grep -q vpnhide_kmod /proc/modules 2>/dev/null; then
    exit 0
fi

mkdir -p "$STATUS_DIR"

# Collapse newlines and tabs in a value so the key=value parser in the
# app stays line-based even when insmod stderr is multi-line.
sanitize() {
    printf '%s' "$1" | tr '\n\r\t' '   ' | sed 's/  */ /g'
}

BOOT_ID=$(cat /proc/sys/kernel/random/boot_id 2>/dev/null)
UNAME_R=$(uname -r 2>/dev/null)
NOW=$(date +%s 2>/dev/null)
GKI_VARIANT=$(grep '^gkiVariant=' "$MODULE_PROP" 2>/dev/null | cut -d= -f2-)
KMOD_VERSION=$(grep '^version=' "$MODULE_PROP" 2>/dev/null | cut -d= -f2-)

ROOT_MANAGER="unknown"
[ -d /data/adb/ksu ] && ROOT_MANAGER="kernelsu"
[ -d /data/adb/ap ] && ROOT_MANAGER="apatch"
[ -d /data/adb/magisk ] && ROOT_MANAGER="magisk"

KPROBES="unknown"
KRETPROBES="unknown"
if [ -r /proc/config.gz ]; then
    CFG=$(zcat /proc/config.gz 2>/dev/null || gunzip -c /proc/config.gz 2>/dev/null)
    if [ -n "$CFG" ]; then
        KPROBES=$(printf '%s\n' "$CFG" | awk -F= '/^CONFIG_KPROBES=/{print $2; exit}')
        KRETPROBES=$(printf '%s\n' "$CFG" | awk -F= '/^CONFIG_KRETPROBES=/{print $2; exit}')
        [ -z "$KPROBES" ] && KPROBES="n"
        [ -z "$KRETPROBES" ] && KRETPROBES="n"
    fi
fi

if [ ! -f "$KO" ]; then
    INSMOD_EXIT=127
    INSMOD_STDERR="vpnhide_kmod.ko not found at $KO"
else
    INSMOD_STDERR=$(insmod "$KO" 2>&1 >/dev/null)
    INSMOD_EXIT=$?
fi

if grep -q vpnhide_kmod /proc/modules 2>/dev/null; then
    LOADED=1
else
    LOADED=0
fi

# Separate file for dmesg excerpt — may span many lines.
dmesg 2>/dev/null | grep -iE 'vpnhide|kretprobe|modules.verify|version magic' | tail -n 40 > "$DMESG_FILE" 2>/dev/null
chmod 0644 "$DMESG_FILE" 2>/dev/null

{
    printf 'timestamp=%s\n' "$NOW"
    printf 'boot_id=%s\n' "$BOOT_ID"
    printf 'uname_r=%s\n' "$UNAME_R"
    printf 'gki_variant=%s\n' "$GKI_VARIANT"
    printf 'kmod_version=%s\n' "$KMOD_VERSION"
    printf 'root_manager=%s\n' "$ROOT_MANAGER"
    printf 'kprobes=%s\n' "$KPROBES"
    printf 'kretprobes=%s\n' "$KRETPROBES"
    printf 'insmod_exit=%s\n' "$INSMOD_EXIT"
    printf 'loaded=%s\n' "$LOADED"
    printf 'insmod_stderr=%s\n' "$(sanitize "$INSMOD_STDERR")"
} > "$STATUS_FILE.tmp" && mv "$STATUS_FILE.tmp" "$STATUS_FILE"
chmod 0644 "$STATUS_FILE" 2>/dev/null

if [ "$LOADED" = "1" ]; then
    log -t vpnhide "kernel module loaded (gki=$GKI_VARIANT kernel=$UNAME_R)"
    exit 0
else
    log -t vpnhide "kernel module NOT loaded (exit=$INSMOD_EXIT gki=$GKI_VARIANT kernel=$UNAME_R): $INSMOD_STDERR"
    exit 1
fi