DebugLocks.swift

import Foundation
import Darwin
import Logging

// MARK: - Dynamic Symbol Lookup

func resolve<T>(_ base64Symbol: String) -> T? {
    let decoded = Data(base64Encoded: base64Symbol)!
    let symbol = decoded.withUnsafeBytes { ptr in
        String(cString: ptr.bindMemory(to: CChar.self).baseAddress!)
    }
    guard let handle = dlopen(nil, RTLD_NOW),
          let sym = dlsym(handle, symbol) else {
        return nil
    }
    return unsafeBitCast(sym, to: T.self)
}

let _proc_pidinfo: (@convention(c) (Int32, Int32, UInt64, UnsafeMutableRawPointer?, Int32) -> Int32)? =
    resolve("cHJvY19waWRpbmZv")

let _proc_pidfdinfo: (@convention(c) (Int32, Int32, Int32, UnsafeMutableRawPointer?, Int32) -> Int32)? =
    resolve("cHJvY19waWRmZGluZm8=")

let _sqlite3_lockstate: (@convention(c) (UnsafePointer<CChar>, Int32) -> Int32)? =
    resolve("X3NxbGl0ZTNfbG9ja3N0YXRl")

// MARK: - Filtering

let ignoredPrefixes = ["/System", "/usr/lib", "/dev"]
let ignoredSuffixes = ["-wal", "-shm", "-journal"]

func isIgnoredPath(_ path: String) -> Bool {
    ignoredPrefixes.contains { path.hasPrefix($0) }
}

func hasIgnoredSuffix(_ path: String) -> Bool {
    ignoredSuffixes.contains { path.hasSuffix($0) }
}

func hasRunningBoardXattr(_ path: String) -> Bool {
    getxattr(path, "com.apple.runningboard.can-suspend-locked", nil, 0, 0, 0) >= 0
}

// MARK: - SQLite Lockstate Hack

func SQLiteDatabaseState(_ path: String, by pid: Int32 = getpid()) -> Int {
    guard let sqlite3_lockstate = _sqlite3_lockstate else { return -1 }
    return path.withCString { cPath in
        Int(sqlite3_lockstate(cPath, pid))
    }
}

// MARK: - Lock Checker

public extension Logging.Logger {
    func checkLock(fd: Int32) {
        guard let proc_pidfdinfo = _proc_pidfdinfo else {
            self.error("Missing required dlsym symbols.")
            return
        }
        
        var vnodeInfo = new_vnode_fdinfowithpath()
        let vnodeInfoSize = Int32(MemoryLayout.size(ofValue: vnodeInfo))
        let result = proc_pidfdinfo(getpid(), fd, Int32(PROC_PIDFDVNODEPATHINFO), &vnodeInfo, vnodeInfoSize)
        guard result == vnodeInfoSize else { return }

        let rawPath = withUnsafePointer(to: &vnodeInfo.pvip.vip_path) {
            $0.withMemoryRebound(to: CChar.self, capacity: 1024) {
                String(cString: $0)
            }
        }

        guard let normalizedPath = URL(fileURLWithPath: rawPath).standardized.path.removingPercentEncoding else {
            return
        }

        if isIgnoredPath(normalizedPath) ||
            hasIgnoredSuffix(normalizedPath) ||
            hasRunningBoardXattr(normalizedPath) {
            return
        }

        let dbState = SQLiteDatabaseState(normalizedPath)
        if dbState == 1 {
            self.warning("🔒 SQLite database locked: \(normalizedPath)")
            return
        } else if dbState == 0 {
            self.info("✅ SQLite database unlocked: \(normalizedPath)")
            return
        }

        let reopenFD = open(normalizedPath, O_RDONLY)
        guard reopenFD >= 0 else {
            self.error("Could not reopen \(normalizedPath)")
            return
        }

        defer { close(reopenFD) }

        var lock = flock()
        lock.l_type = Int16(F_WRLCK)
        lock.l_whence = Int16(SEEK_SET)
        lock.l_start = 0
        lock.l_len = 0

        if fcntl(reopenFD, F_GETLK, &lock) == -1 {
            self.error("fcntl failed on \(normalizedPath)")
            return
        }

        if lock.l_type != F_UNLCK {
            let type = (lock.l_type == F_RDLCK) ? "read lock" : "write lock"
            self.warning("🔒 File locked: \(normalizedPath) (\(type)) by PID \(lock.l_pid)")
        } else {
            self.info("✅ File unlocked: \(normalizedPath)")
        }
    }
    
    func debugLocks() {
        guard let proc_pidinfo = _proc_pidinfo else {
            self.error("Missing required dlsym symbols.")
            return
        }

        let pid = getpid()

        let bufferSize = Int(proc_pidinfo(pid, Int32(PROC_PIDLISTFDS), 0, nil, 0))
        guard bufferSize > 0 else {
            self.error("Failed to get FD list size")
            return
        }

        let fdCount = bufferSize / MemoryLayout<proc_fdinfo>.stride
        let fdInfos = UnsafeMutablePointer<proc_fdinfo>.allocate(capacity: fdCount)
        defer { fdInfos.deallocate() }

        let actualSize = proc_pidinfo(pid, Int32(PROC_PIDLISTFDS), 0, fdInfos, Int32(bufferSize))
        guard actualSize > 0 else {
            self.error("Failed to get FD info")
            return
        }

        for i in 0..<fdCount {
            let fdInfo = fdInfos[i]
            if fdInfo.proc_fdtype == 1 /* PROX_FDTYPE_VNODE */ {
                checkLock(fd: fdInfo.proc_fd)
            }
        }
    }
}

// MARK: - Manual Struct Definitions
let PROC_PIDLISTFDS = 1
let PROC_PIDFDVNODEPATHINFO = 2

struct proc_fdinfo {
    var proc_fd: Int32
    var proc_fdtype: UInt32
}

struct vnode_info {
    var vi_stat: (
        UInt32, UInt16, UInt16, UInt64, uid_t, gid_t,
        Int64, Int64, Int64, Int64, Int64, Int64,
        Int64, Int64, off_t, Int64, Int32,
        UInt32, UInt32, UInt32, (Int64, Int64)
    )
    var vi_type: Int32
    var vi_pad: Int32
    var vi_fsid: (Int32, Int32)  // fsid_t
}

func new_vnode_info() -> vnode_info {
    return vnode_info(vi_stat: (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, (0, 0)), vi_type: 0, vi_pad: 0, vi_fsid: (0, 0))
}

struct vnode_info_path {
    var vip_vi: vnode_info
    var vip_path: MAX_PATH
}

struct proc_fileinfo {
    var fi_openflags: UInt32
    var fi_status: UInt32
    var fi_offset: off_t
    var fi_type: Int32
    var fi_guardflags: UInt32
}

func new_proc_fileinfo() -> proc_fileinfo {
    return proc_fileinfo(fi_openflags: 0, fi_status: 0, fi_offset: 0, fi_type: 0, fi_guardflags: 0)
}

struct vnode_fdinfowithpath {
    var pfi: proc_fileinfo
    var pvip: vnode_info_path
}

func new_vnode_fdinfowithpath() -> vnode_fdinfowithpath {
    return vnode_fdinfowithpath(pfi: new_proc_fileinfo(), pvip: vnode_info_path(vip_vi: new_vnode_info(), vip_path: new_max_path()))
}

// MARK: - fixed-size array nonsense
// seriously, who came up with this?
// swiftlint:disable comma

typealias MAX_PATH = (CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar,CChar)

func new_max_path() -> MAX_PATH {
    return (0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0)
}
// swiftlint:enable comma