diff options
| -rw-r--r-- | ios/PacketTunnel/Pinger.swift | 30 |
1 files changed, 10 insertions, 20 deletions
diff --git a/ios/PacketTunnel/Pinger.swift b/ios/PacketTunnel/Pinger.swift index ea143d0ca6..fd76fdc5ec 100644 --- a/ios/PacketTunnel/Pinger.swift +++ b/ios/PacketTunnel/Pinger.swift @@ -231,27 +231,17 @@ extension Pinger { } private func in_chksum(_ data: Data) -> UInt16 { - return data.withUnsafeBytes { buffer in - let length = buffer.count - - var sum: Int32 = 0 - - let isOdd = length % 2 != 0 - let strideTo = isOdd ? length - 1 : length - - for offset in stride(from: 0, to: strideTo, by: 2) { - let word = buffer.load(fromByteOffset: offset, as: UInt16.self) - sum += Int32(word) - } - - if isOdd { - let byte = buffer.load(fromByteOffset: length - 1, as: UInt8.self) - sum += Int32(byte) + let words = sequence(state: data.makeIterator()) { iterator in + return iterator.next().map { byte in + return iterator.next().map { nextByte in + return [byte, nextByte].withUnsafeBytes { buffer in + return buffer.load(as: UInt16.self) + } + } ?? UInt16(byte) } + } - sum = (sum >> 16) + (sum & 0xffff) - sum += (sum >> 16) + let sum = words.reduce(0, &+) - return UInt16(truncatingIfNeeded: ~sum) - } + return ~sum } |