From 4225e45a33855710437aaf154cb7b16eed0feac4 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Thu, 5 Sep 2024 23:35:01 -0700
Subject: [PATCH 01/11] reduce memory footprint for icmp ping handler

---
 Package.swift                                 |  4 +--
 Sources/LCLPing/ICMP/ICMPHandler.swift        | 31 +++++++++----------
 .../HTTPTracingHandlerTests.swift             |  1 +
 3 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/Package.swift b/Package.swift
index 4608db7..1a26e82 100644
--- a/Package.swift
+++ b/Package.swift
@@ -16,10 +16,10 @@ let package = Package(
     ],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
-        .package(url: "https://github.com/apple/swift-nio.git", from: "2.62.0"),
+        .package(url: "https://github.com/apple/swift-nio.git", from: "2.72.0"),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.5.3"),
         .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.25.0"),
-        .package(url: "https://github.com/apple/swift-collections.git", from: "1.0.4")
+        .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.1")
     ],
     targets: [
         // Targets are the basic building blocks of a package. A target can define a module or a test suite.
diff --git a/Sources/LCLPing/ICMP/ICMPHandler.swift b/Sources/LCLPing/ICMP/ICMPHandler.swift
index 9dc329c..6e9060b 100644
--- a/Sources/LCLPing/ICMP/ICMPHandler.swift
+++ b/Sources/LCLPing/ICMP/ICMPHandler.swift
@@ -12,6 +12,7 @@
 
 import Foundation
 import NIOCore
+import Collections
 
 extension ICMPPingClient {
 
@@ -139,11 +140,11 @@ final class ICMPHandler: PingHandler {
     // sequence number to ICMP request
     private var seqToRequest: [Int: ICMPPingClient.ICMPHeader]
 
-    // sequence number to an optional ICMP response
-    private var seqToResponse: [Int: ICMPPingClient.ICMPHeader?]
+    // a bit set that contains the response sequence number seen so far
+    private var seen: BitSet
 
-    // a set that contains the response sequence number received by the handler
-    private var responseSeqNumSet: Set<Int>
+    // a bit set that contains the response sequence number received by the handler
+    private var hasResponses: BitSet
 
     // a list of `PingResponse`
     private var result: [PingResponse]
@@ -154,10 +155,10 @@ final class ICMPHandler: PingHandler {
     init(totalCount: Int, promise: EventLoopPromise<[PingResponse]>) {
         self.totalCount = totalCount
         self.seqToRequest = [:]
-        self.seqToResponse = [:]
-        self.responseSeqNumSet = Set()
         self.result = []
         self.icmpPingPromise = promise
+        self.seen = BitSet(reservingCapacity: self.totalCount)
+        self.hasResponses = BitSet(reservingCapacity: self.totalCount)
     }
 
     func handleRead(response: ICMPPingClient.ICMPHeader) {
@@ -176,17 +177,16 @@ final class ICMPHandler: PingHandler {
             return
         }
 
-        if self.responseSeqNumSet.contains(sequenceNum) {
-            let pingResponse: PingResponse = self.seqToResponse[sequenceNum] ==
-                                                nil ? .timeout(sequenceNum) : .duplicated(sequenceNum)
-            logger.debug("[\(#fileID)][\(#line)][\(#function)]:: response for #\(sequenceNum) is \(self.seqToResponse[sequenceNum] == nil ? "timeout" : "duplicate")")
+        if self.seen.contains(sequenceNum) {
+            let pingResponse: PingResponse = self.hasResponses.contains(sequenceNum) ? .duplicated(sequenceNum) : .timeout(sequenceNum)
+            logger.debug("[\(#fileID)][\(#line)][\(#function)]:: response for #\(sequenceNum) is \(self.hasResponses.contains(sequenceNum) ? "timeout" : "duplicate")")
             result.append(pingResponse)
             shouldCloseHandler()
             return
         }
 
-        self.seqToResponse[sequenceNum] = response
-        self.responseSeqNumSet.insert(sequenceNum)
+        self.hasResponses.insert(sequenceNum)
+        self.seen.insert(sequenceNum)
 
         switch (type, code) {
         case (ICMPPingClient.ICMPType.echoReply.rawValue, 0):
@@ -334,9 +334,9 @@ final class ICMPHandler: PingHandler {
     }
 
     func handleTimeout(sequenceNumber: Int) {
-        if !self.responseSeqNumSet.contains(sequenceNumber) {
+        if !self.seen.contains(sequenceNumber) {
             logger.debug("[\(#fileID)][\(#line)][\(#function)]: #\(sequenceNumber) timed out")
-            self.responseSeqNumSet.insert(sequenceNumber)
+            self.seen.insert(sequenceNumber)
             self.result.append(.timeout(sequenceNumber))
             shouldCloseHandler()
         }
@@ -353,12 +353,11 @@ final class ICMPHandler: PingHandler {
 
     func reset() {
         self.seqToRequest.removeAll()
-        self.seqToResponse.removeAll()
         self.result.removeAll()
     }
 
     func shouldCloseHandler(shouldForceClose: Bool = false) {
-        if self.responseSeqNumSet.count == self.totalCount || shouldForceClose {
+        if self.seen.count == self.totalCount || shouldForceClose {
             logger.debug("[\(#fileID)][\(#line)][\(#function)]: should close icmp handler")
             self.icmpPingPromise.succeed(self.result)
         }
diff --git a/Tests/HTTPChannelTests/HTTPTracingHandlerTests.swift b/Tests/HTTPChannelTests/HTTPTracingHandlerTests.swift
index 3abd50f..b58c0b2 100644
--- a/Tests/HTTPChannelTests/HTTPTracingHandlerTests.swift
+++ b/Tests/HTTPChannelTests/HTTPTracingHandlerTests.swift
@@ -68,6 +68,7 @@ final class HTTPTracingHandlerTests: XCTestCase {
             XCTAssertEqual(request.method, HTTPMethod.GET)
             XCTAssertEqual(request.uri, config.url.uri)
             XCTAssertEqual(request.headers, config.httpHeaders)
+            promise.succeed(.ok(2, 0, 0))
         default:
             XCTFail("Should receive a head and end. But received head = \(String(describing: head)), end = \(String(describing: end))")
         }

From 46bf972af7ea9c5d7668720b79d59044da68da6f Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Thu, 26 Sep 2024 23:40:34 -0700
Subject: [PATCH 02/11] allow icmp to bind to a specific interface

---
 Sources/LCLPing/ICMP/ICMPPingClient.swift   | 92 +++++++++++++++++----
 Sources/LCLPing/Models/Errors+LCLPing.swift |  6 ++
 2 files changed, 84 insertions(+), 14 deletions(-)

diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index 7295843..f66e25c 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -78,23 +78,31 @@ public final class ICMPPingClient: Pingable {
                             }
                         }
                     }
-
-                    for cnt in 0..<self.configuration.count {
+                    
+                    let sendPromise = channel.eventLoop.makePromise(of: Void.self)
+                    sendPromise.futureResult.cascadeFailure(to: self.promise)
+                    
+                    func send(_ cnt: Int) {
+                        if cnt == self.configuration.count {
+                            sendPromise.succeed()
+                            return
+                        }
+                        let el = self.eventLoopGroup.next()
+                        let p = el.makePromise(of: Void.self)
                         logger.debug("Scheduled #\(cnt) request")
                         channel.eventLoop.scheduleTask(in: cnt * self.configuration.interval) {
-                            channel.write(
-                                ICMPPingClient.Request(
-                                    sequenceNum: UInt16(cnt),
-                                    identifier: self.identifier
-                                ),
-                                promise: nil
-                            )
-                        }
+                            channel.writeAndFlush(ICMPPingClient.Request(sequenceNum: UInt16(cnt), identifier: self.identifier), promise: p)
+                        }.futureResult.hop(to: el).cascadeFailure(to: sendPromise)
+                        
+                        p.futureResult.cascadeFailure(to: sendPromise)
+                        send(cnt + 1)
                     }
-
-                    return self.promise.futureResult.flatMap { pingResponse in
+                    
+                    send(0)
+                    
+                    return sendPromise.futureResult.and(self.promise.futureResult).flatMap { (_, pingResponse) in
                         let summary = pingResponse.summarize(host: self.configuration.resolvedAddress)
-                        self.stateLock.withLockVoid {
+                        self.stateLock.withLock {
                             self.state = .finished
                         }
                         return channel.eventLoop.makeSucceededFuture(summary)
@@ -166,6 +174,31 @@ public final class ICMPPingClient: Pingable {
                     }
                     return channel.eventLoop.makeFailedFuture(error)
                 }
+                
+                if let device = self.configuration.device {
+                    switch device.address {
+                    case .v4:
+                        #if canImport(Darwin)
+                        return channel.setOption(.ipOption(.ip_bound_if), value: CInt(device.interfaceIndex))
+                        #elseif canImport(Glibc)
+                        return channel.setOption(.ipOption(.so_bindtodevice), value: CInt(device.interfaceIndex))
+                        #endif
+                    case .v6:
+                        #if canImport(Darwin)
+                        return channel.setOption(.ipv6Option(.ip_bound_if), value: CInt(device.interfaceIndex))
+                        #elseif canImport(Glibc)
+                        return channel.setOption(.ipv6Option(.so_bindtodevice), value: CInt(device.interfaceIndex))
+                        #endif
+                    case .unixDomainSocket:
+                        self.stateLock.withLock {
+                            self.state = .error
+                        }
+                        return channel.eventLoop.makeFailedFuture(PingError.icmpUnixDomainSocketForMulticast)
+                    default:
+                        ()
+                    }
+                }
+                
                 return channel.eventLoop.makeSucceededVoidFuture()
             }
     }
@@ -202,13 +235,18 @@ extension ICMPPingClient {
         /// Time, in second, to wait for a reply for each packet sent. Default is 1s.
         public var timeout: TimeAmount
 
+        /// The resolved socket address
         public let resolvedAddress: SocketAddress
+        
+        /// The multicast outgoing device associated with the given interface name
+        public var device: NIONetworkDevice?
 
         public init(endpoint: EndpointTarget,
                     count: Int = 10,
                     interval: TimeAmount = .seconds(1),
                     timeToLive: UInt8 = 64,
-                    timeout: TimeAmount = .seconds(1)
+                    timeout: TimeAmount = .seconds(1),
+                    outgoingIntefaceName: String? = nil
         ) throws {
             self.endpoint = endpoint
             self.count = count
@@ -221,6 +259,18 @@ extension ICMPPingClient {
             case .ipv6(let addr, let port):
                 self.resolvedAddress = try SocketAddress.makeAddressResolvingHost(addr, port: port ?? 0)
             }
+
+            for device in try System.enumerateDevices() {
+                if device.name == outgoingIntefaceName, let address = device.address {
+                    switch (address.protocol, self.endpoint) {
+                    case (.inet, .ipv4), (.inet6, .ipv6):
+                        logger.info("device selcted is \(device)")
+                        self.device = device
+                    default:
+                        continue
+                    }
+                }
+            }
         }
     }
 
@@ -230,3 +280,17 @@ extension ICMPPingClient {
         case ipv6(String, Int?)
     }
 }
+
+extension NIOBSDSocket.Option {
+    #if canImport(Darwin)
+    public static let ip_bound_if: NIOBSDSocket.Option = Self(rawValue: IP_BOUND_IF)
+    #elseif canImport(Glibc)
+    public static let so_bindtodevice = Self(rawValue: SO_BINDTODEVICE)
+    #endif
+}
+
+extension ChannelOption where Self == ChannelOptions.Types.SocketOption {
+    public static func ipv6Option(_ name: NIOBSDSocket.Option) -> Self {
+        .init(level: .ipv6, name: name)
+    }
+}
diff --git a/Sources/LCLPing/Models/Errors+LCLPing.swift b/Sources/LCLPing/Models/Errors+LCLPing.swift
index 0ba0545..2370018 100644
--- a/Sources/LCLPing/Models/Errors+LCLPing.swift
+++ b/Sources/LCLPing/Models/Errors+LCLPing.swift
@@ -52,6 +52,8 @@ public enum PingError: Error {
     case icmpPointerIndicatesError
     case icmpMissingARequiredOption
     case icmpBadLength
+    case icmpDestinationNotMulticast
+    case icmpUnixDomainSocketForMulticast
 
     case httpMissingHost
     case httpMissingSchema
@@ -165,6 +167,10 @@ extension PingError: CustomStringConvertible {
             return "Missing HTTP response."
         case .httpInvalidURLSessionTask(let id):
             return "URLSession Task \(id) is invalid."
+        case .icmpDestinationNotMulticast:
+            return "Destination address is not a multicast address."
+        case .icmpUnixDomainSocketForMulticast:
+            return "Cannot bind a unix domain soket as a multicast socket."
         }
     }
 

From 07366b27bf3d286a54578b4907cc5fba24d28210 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Thu, 26 Sep 2024 23:55:51 -0700
Subject: [PATCH 03/11] fix type for linux platform

---
 Sources/LCLPing/ICMP/ICMPPingClient.swift | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index f66e25c..2538219 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -181,13 +181,13 @@ public final class ICMPPingClient: Pingable {
                         #if canImport(Darwin)
                         return channel.setOption(.ipOption(.ip_bound_if), value: CInt(device.interfaceIndex))
                         #elseif canImport(Glibc)
-                        return channel.setOption(.ipOption(.so_bindtodevice), value: CInt(device.interfaceIndex))
+                        return channel.setOption(.ipOption(.so_bindtodevice), value: device.interfaceIndex)
                         #endif
                     case .v6:
                         #if canImport(Darwin)
                         return channel.setOption(.ipv6Option(.ip_bound_if), value: CInt(device.interfaceIndex))
                         #elseif canImport(Glibc)
-                        return channel.setOption(.ipv6Option(.so_bindtodevice), value: CInt(device.interfaceIndex))
+                        return channel.setOption(.ipv6Option(.so_bindtodevice), value: device.interfaceIndex)
                         #endif
                     case .unixDomainSocket:
                         self.stateLock.withLock {

From 6db84a424c81d4c3ef3c412755c1ed3c689d6131 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Thu, 26 Sep 2024 23:56:30 -0700
Subject: [PATCH 04/11] bump swiftnio version

---
 Package.swift | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Package.swift b/Package.swift
index 1a26e82..71b6c30 100644
--- a/Package.swift
+++ b/Package.swift
@@ -16,7 +16,7 @@ let package = Package(
     ],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
-        .package(url: "https://github.com/apple/swift-nio.git", from: "2.72.0"),
+        .package(url: "https://github.com/apple/swift-nio.git", from: "2.73.0"),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.5.3"),
         .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.25.0"),
         .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.1")

From d2a7b7f8fc0201d921317d96777d6b1730ff4395 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Sun, 29 Sep 2024 22:02:59 -0700
Subject: [PATCH 05/11] allow http ping to bind to the device

---
 Sources/LCLPing/HTTP/HTTPPingClient.swift     | 26 ++++++++++++++++---
 Sources/LCLPing/HTTP/NIOHTTPClient.swift      | 24 +++++++++++++++++
 Sources/LCLPing/ICMP/ICMPPingClient.swift     | 18 ++-----------
 Sources/LCLPing/Models/Errors+LCLPing.swift   |  9 ++++---
 .../Utilities/LCLPing+ChannelOption.swift     | 20 ++++++++++++++
 .../Utilities/LCLPing+SocketOption.swift      | 22 ++++++++++++++++
 6 files changed, 96 insertions(+), 23 deletions(-)
 create mode 100644 Sources/LCLPing/Utilities/LCLPing+ChannelOption.swift
 create mode 100644 Sources/LCLPing/Utilities/LCLPing+SocketOption.swift

diff --git a/Sources/LCLPing/HTTP/HTTPPingClient.swift b/Sources/LCLPing/HTTP/HTTPPingClient.swift
index a01d7a4..b71981f 100644
--- a/Sources/LCLPing/HTTP/HTTPPingClient.swift
+++ b/Sources/LCLPing/HTTP/HTTPPingClient.swift
@@ -178,6 +178,9 @@ extension HTTPPingClient {
 
         /// The DNS-resolved address according to the URL endpoint
         public let resolvedAddress: SocketAddress
+        
+        /// The outgoing device associated with the given interface name
+        public var device: NIONetworkDevice?
 
         /// Initialize a HTTP Ping Client `Configuration`.
         ///
@@ -190,6 +193,7 @@ extension HTTPPingClient {
         ///     - useServerTimimg: Indicate whether the HTTP Ping Client should take `ServerTiming` attribute
         /// from the reponse header.
         ///     - useURLSession: Indicate whether the HTTP Ping Client should use native URLSession implementation.
+        ///     - outgoingInterfaceName: the interface name for which the outbound data will be sent to.
         ///
         ///     - Throws:
         ///         - httpMissingHost: if URL does not include any host information.
@@ -201,7 +205,8 @@ extension HTTPPingClient {
                     connectionTimeout: TimeAmount = .seconds(5),
                     headers: [String: String] = Configuration.defaultHeaders,
                     useServerTiming: Bool = false,
-                    useURLSession: Bool = false) throws {
+                    useURLSession: Bool = false,
+                    outgoingInterfaceName: String? = nil) throws {
             self.url = url
             self.count = count
             self.readTimeout = readTimeout
@@ -244,6 +249,17 @@ extension HTTPPingClient {
             // NOTE: URLSession is not fully supported in swift-corelibs-foundation
             self.useURLSession = false
             #endif
+            
+            for device in try System.enumerateDevices() {
+                if device.name == outgoingInterfaceName, let address = device.address {
+                    switch (address.protocol, self.resolvedAddress.protocol) {
+                    case (.inet, .inet), (.inet6, .inet6):
+                        self.device = device
+                    default:
+                        continue
+                    }
+                }
+            }
         }
 
         /// Initialize a HTTP Ping Client `Configuration`.
@@ -257,6 +273,7 @@ extension HTTPPingClient {
         ///     - useServerTimimg: Indicate whether the HTTP Ping Client should take `ServerTiming` attribute
         /// from the reponse header.
         ///     - useURLSession: Indicate whether the HTTP Ping Client should use native URLSession implementation.
+        ///     - outgoingInterfaceName: the interface name for which the outbound data will be sent to
         ///
         ///     - Throws:
         ///         - httpMissingHost: if URL does not include any host information.
@@ -268,7 +285,8 @@ extension HTTPPingClient {
                     connectionTimeout: TimeAmount = .seconds(5),
                     headers: [String: String] = Configuration.defaultHeaders,
                     useServerTiming: Bool = false,
-                    useURLSession: Bool = false) throws {
+                    useURLSession: Bool = false,
+                    outgoingIntefaceName: String? = nil) throws {
             guard let urlObj = URL(string: url) else {
                 throw PingError.invalidURL(url)
             }
@@ -279,8 +297,8 @@ extension HTTPPingClient {
                           connectionTimeout: connectionTimeout,
                           headers: headers,
                           useServerTiming: useServerTiming,
-                          useURLSession: useURLSession
-                        )
+                          useURLSession: useURLSession,
+                          outgoingInterfaceName: outgoingIntefaceName)
         }
 
         /// Initialize a HTTP Ping Client `Configuration`.
diff --git a/Sources/LCLPing/HTTP/NIOHTTPClient.swift b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
index 054d236..1f25629 100644
--- a/Sources/LCLPing/HTTP/NIOHTTPClient.swift
+++ b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
@@ -198,6 +198,30 @@ final class NIOHTTPClient: Pingable {
                 } catch {
                     return channel.eventLoop.makeFailedFuture(error)
                 }
+                
+                if let device = self.configuration.device {
+                    switch device.address {
+                    case .v4:
+                        #if canImport(Darwin)
+                        return channel.setOption(.ipOption(.ip_bound_if), value: CInt(device.interfaceIndex))
+                        #elseif canImport(Glibc)
+                        return channel.setOption(.ipOption(.so_bindtodevice), value: device.interfaceIndex)
+                        #endif
+                    case .v6:
+                        #if canImport(Darwin)
+                        return channel.setOption(.ipv6Option(.ip_bound_if), value: CInt(device.interfaceIndex))
+                        #elseif canImport(Glibc)
+                        return channel.setOption(.ipv6Option(.so_bindtodevice), value: device.interfaceIndex)
+                        #endif
+                    case .unixDomainSocket:
+                        self.stateLock.withLock {
+                            self.state = .error
+                        }
+                        return channel.eventLoop.makeFailedFuture(PingError.httpBindToUnixDomainSocket)
+                    default:
+                        ()
+                    }
+                }
 
                 return channel.eventLoop.makeSucceededVoidFuture()
             }
diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index 2538219..79b1db4 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -193,7 +193,7 @@ public final class ICMPPingClient: Pingable {
                         self.stateLock.withLock {
                             self.state = .error
                         }
-                        return channel.eventLoop.makeFailedFuture(PingError.icmpUnixDomainSocketForMulticast)
+                        return channel.eventLoop.makeFailedFuture(PingError.icmpBindToUnixDomainSocket)
                     default:
                         ()
                     }
@@ -238,7 +238,7 @@ extension ICMPPingClient {
         /// The resolved socket address
         public let resolvedAddress: SocketAddress
         
-        /// The multicast outgoing device associated with the given interface name
+        /// The outgoing device associated with the given interface name
         public var device: NIONetworkDevice?
 
         public init(endpoint: EndpointTarget,
@@ -280,17 +280,3 @@ extension ICMPPingClient {
         case ipv6(String, Int?)
     }
 }
-
-extension NIOBSDSocket.Option {
-    #if canImport(Darwin)
-    public static let ip_bound_if: NIOBSDSocket.Option = Self(rawValue: IP_BOUND_IF)
-    #elseif canImport(Glibc)
-    public static let so_bindtodevice = Self(rawValue: SO_BINDTODEVICE)
-    #endif
-}
-
-extension ChannelOption where Self == ChannelOptions.Types.SocketOption {
-    public static func ipv6Option(_ name: NIOBSDSocket.Option) -> Self {
-        .init(level: .ipv6, name: name)
-    }
-}
diff --git a/Sources/LCLPing/Models/Errors+LCLPing.swift b/Sources/LCLPing/Models/Errors+LCLPing.swift
index 2370018..e33924d 100644
--- a/Sources/LCLPing/Models/Errors+LCLPing.swift
+++ b/Sources/LCLPing/Models/Errors+LCLPing.swift
@@ -53,7 +53,7 @@ public enum PingError: Error {
     case icmpMissingARequiredOption
     case icmpBadLength
     case icmpDestinationNotMulticast
-    case icmpUnixDomainSocketForMulticast
+    case icmpBindToUnixDomainSocket
 
     case httpMissingHost
     case httpMissingSchema
@@ -61,6 +61,7 @@ public enum PingError: Error {
     case httpInvalidHandlerState
     case httpMissingResponse
     case httpInvalidURLSessionTask(Int)
+    case httpBindToUnixDomainSocket
 
     case invalidHexFormat
 
@@ -169,8 +170,10 @@ extension PingError: CustomStringConvertible {
             return "URLSession Task \(id) is invalid."
         case .icmpDestinationNotMulticast:
             return "Destination address is not a multicast address."
-        case .icmpUnixDomainSocketForMulticast:
-            return "Cannot bind a unix domain soket as a multicast socket."
+        case .icmpBindToUnixDomainSocket:
+            return "Cannot bind to a unix domain socket device."
+        case .httpBindToUnixDomainSocket:
+            return "Cannot bind to a unix domain socket device."
         }
     }
 
diff --git a/Sources/LCLPing/Utilities/LCLPing+ChannelOption.swift b/Sources/LCLPing/Utilities/LCLPing+ChannelOption.swift
new file mode 100644
index 0000000..fd65e42
--- /dev/null
+++ b/Sources/LCLPing/Utilities/LCLPing+ChannelOption.swift
@@ -0,0 +1,20 @@
+//
+// This source file is part of the LCL open source project
+//
+// Copyright (c) 2021-2024 Local Connectivity Lab and the project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE for license information
+// See CONTRIBUTORS for the list of project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+import NIOCore
+
+extension ChannelOption where Self == ChannelOptions.Types.SocketOption {
+    public static func ipv6Option(_ name: NIOBSDSocket.Option) -> Self {
+        .init(level: .ipv6, name: name)
+    }
+}
diff --git a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
new file mode 100644
index 0000000..0b47ef9
--- /dev/null
+++ b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
@@ -0,0 +1,22 @@
+//
+// This source file is part of the LCL open source project
+//
+// Copyright (c) 2021-2024 Local Connectivity Lab and the project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE for license information
+// See CONTRIBUTORS for the list of project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+import Foundation
+import NIOCore
+
+extension NIOBSDSocket.Option {
+    #if canImport(Darwin)
+    public static let ip_bound_if: NIOBSDSocket.Option = Self(rawValue: IP_BOUND_IF)
+    #elseif canImport(Glibc)
+    public static let so_bindtodevice = Self(rawValue: SO_BINDTODEVICE)
+    #endif
+}

From 10d3417babfebd1d9d3e3f13915cb6045558b809 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Mon, 30 Sep 2024 00:37:06 -0700
Subject: [PATCH 06/11] add ipv6_bound_if option and fix comments

---
 Sources/LCLPing/HTTP/HTTPPingClient.swift       |  3 +++
 Sources/LCLPing/HTTP/NIOHTTPClient.swift        | 16 ++++++----------
 Sources/LCLPing/ICMP/ICMPPingClient.swift       | 17 ++++++++---------
 .../Utilities/LCLPing+SocketOption.swift        |  1 +
 4 files changed, 18 insertions(+), 19 deletions(-)

diff --git a/Sources/LCLPing/HTTP/HTTPPingClient.swift b/Sources/LCLPing/HTTP/HTTPPingClient.swift
index b71981f..409da9e 100644
--- a/Sources/LCLPing/HTTP/HTTPPingClient.swift
+++ b/Sources/LCLPing/HTTP/HTTPPingClient.swift
@@ -259,6 +259,9 @@ extension HTTPPingClient {
                         continue
                     }
                 }
+                if self.device != nil {
+                    break
+                }
             }
         }
 
diff --git a/Sources/LCLPing/HTTP/NIOHTTPClient.swift b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
index 1f25629..f350ba8 100644
--- a/Sources/LCLPing/HTTP/NIOHTTPClient.swift
+++ b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
@@ -200,27 +200,23 @@ final class NIOHTTPClient: Pingable {
                 }
                 
                 if let device = self.configuration.device {
+                    #if canImport(Darwin)
                     switch device.address {
                     case .v4:
-                        #if canImport(Darwin)
                         return channel.setOption(.ipOption(.ip_bound_if), value: CInt(device.interfaceIndex))
-                        #elseif canImport(Glibc)
-                        return channel.setOption(.ipOption(.so_bindtodevice), value: device.interfaceIndex)
-                        #endif
                     case .v6:
-                        #if canImport(Darwin)
-                        return channel.setOption(.ipv6Option(.ip_bound_if), value: CInt(device.interfaceIndex))
-                        #elseif canImport(Glibc)
-                        return channel.setOption(.ipv6Option(.so_bindtodevice), value: device.interfaceIndex)
-                        #endif
+                        return channel.setOption(.ipv6Option(.ipv6_bound_if), value: CInt(device.interfaceIndex))
                     case .unixDomainSocket:
                         self.stateLock.withLock {
                             self.state = .error
                         }
-                        return channel.eventLoop.makeFailedFuture(PingError.httpBindToUnixDomainSocket)
+                        return channel.eventLoop.makeFailedFuture(PingError.icmpBindToUnixDomainSocket)
                     default:
                         ()
                     }
+                    #elseif canImport(Glibc)
+                    return channel.setOption(.socketOption(.so_bindtodevice), value: device.interfaceIndex)
+                    #endif
                 }
 
                 return channel.eventLoop.makeSucceededVoidFuture()
diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index 79b1db4..0cdef56 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -176,19 +176,12 @@ public final class ICMPPingClient: Pingable {
                 }
                 
                 if let device = self.configuration.device {
+                    #if canImport(Darwin)
                     switch device.address {
                     case .v4:
-                        #if canImport(Darwin)
                         return channel.setOption(.ipOption(.ip_bound_if), value: CInt(device.interfaceIndex))
-                        #elseif canImport(Glibc)
-                        return channel.setOption(.ipOption(.so_bindtodevice), value: device.interfaceIndex)
-                        #endif
                     case .v6:
-                        #if canImport(Darwin)
-                        return channel.setOption(.ipv6Option(.ip_bound_if), value: CInt(device.interfaceIndex))
-                        #elseif canImport(Glibc)
-                        return channel.setOption(.ipv6Option(.so_bindtodevice), value: device.interfaceIndex)
-                        #endif
+                        return channel.setOption(.ipv6Option(.ipv6_bound_if), value: CInt(device.interfaceIndex))
                     case .unixDomainSocket:
                         self.stateLock.withLock {
                             self.state = .error
@@ -197,6 +190,9 @@ public final class ICMPPingClient: Pingable {
                     default:
                         ()
                     }
+                    #elseif canImport(Glibc)
+                    return channel.setOption(.socketOption(.so_bindtodevice), value: device.interfaceIndex)
+                    #endif
                 }
                 
                 return channel.eventLoop.makeSucceededVoidFuture()
@@ -270,6 +266,9 @@ extension ICMPPingClient {
                         continue
                     }
                 }
+                if self.device != nil {
+                    break
+                }
             }
         }
     }
diff --git a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
index 0b47ef9..17d2083 100644
--- a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
+++ b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
@@ -16,6 +16,7 @@ import NIOCore
 extension NIOBSDSocket.Option {
     #if canImport(Darwin)
     public static let ip_bound_if: NIOBSDSocket.Option = Self(rawValue: IP_BOUND_IF)
+    public static let ipv6_bound_if: NIOBSDSocket.Option = Self(rawValue: IPV6_BOUND_IF)
     #elseif canImport(Glibc)
     public static let so_bindtodevice = Self(rawValue: SO_BINDTODEVICE)
     #endif

From a1f798105ebe79d3b0dac3ff75a90a0576d84d76 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Mon, 30 Sep 2024 10:58:01 -0700
Subject: [PATCH 07/11] fix comment

---
 Sources/LCLPing/HTTP/HTTPPingClient.swift | 12 ++++++------
 Sources/LCLPing/ICMP/ICMPPingClient.swift |  4 ++--
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/Sources/LCLPing/HTTP/HTTPPingClient.swift b/Sources/LCLPing/HTTP/HTTPPingClient.swift
index 409da9e..86bdd47 100644
--- a/Sources/LCLPing/HTTP/HTTPPingClient.swift
+++ b/Sources/LCLPing/HTTP/HTTPPingClient.swift
@@ -193,7 +193,7 @@ extension HTTPPingClient {
         ///     - useServerTimimg: Indicate whether the HTTP Ping Client should take `ServerTiming` attribute
         /// from the reponse header.
         ///     - useURLSession: Indicate whether the HTTP Ping Client should use native URLSession implementation.
-        ///     - outgoingInterfaceName: the interface name for which the outbound data will be sent to.
+        ///     - deviceName: the interface name for which the outbound data will be sent to.
         ///
         ///     - Throws:
         ///         - httpMissingHost: if URL does not include any host information.
@@ -206,7 +206,7 @@ extension HTTPPingClient {
                     headers: [String: String] = Configuration.defaultHeaders,
                     useServerTiming: Bool = false,
                     useURLSession: Bool = false,
-                    outgoingInterfaceName: String? = nil) throws {
+                    deviceName: String? = nil) throws {
             self.url = url
             self.count = count
             self.readTimeout = readTimeout
@@ -251,7 +251,7 @@ extension HTTPPingClient {
             #endif
             
             for device in try System.enumerateDevices() {
-                if device.name == outgoingInterfaceName, let address = device.address {
+                if device.name == deviceName, let address = device.address {
                     switch (address.protocol, self.resolvedAddress.protocol) {
                     case (.inet, .inet), (.inet6, .inet6):
                         self.device = device
@@ -276,7 +276,7 @@ extension HTTPPingClient {
         ///     - useServerTimimg: Indicate whether the HTTP Ping Client should take `ServerTiming` attribute
         /// from the reponse header.
         ///     - useURLSession: Indicate whether the HTTP Ping Client should use native URLSession implementation.
-        ///     - outgoingInterfaceName: the interface name for which the outbound data will be sent to
+        ///     - deviceName: the interface name for which the outbound data will be sent to
         ///
         ///     - Throws:
         ///         - httpMissingHost: if URL does not include any host information.
@@ -289,7 +289,7 @@ extension HTTPPingClient {
                     headers: [String: String] = Configuration.defaultHeaders,
                     useServerTiming: Bool = false,
                     useURLSession: Bool = false,
-                    outgoingIntefaceName: String? = nil) throws {
+                    deviceName: String? = nil) throws {
             guard let urlObj = URL(string: url) else {
                 throw PingError.invalidURL(url)
             }
@@ -301,7 +301,7 @@ extension HTTPPingClient {
                           headers: headers,
                           useServerTiming: useServerTiming,
                           useURLSession: useURLSession,
-                          outgoingInterfaceName: outgoingIntefaceName)
+                          deviceName: deviceName)
         }
 
         /// Initialize a HTTP Ping Client `Configuration`.
diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index 0cdef56..5163bd7 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -242,7 +242,7 @@ extension ICMPPingClient {
                     interval: TimeAmount = .seconds(1),
                     timeToLive: UInt8 = 64,
                     timeout: TimeAmount = .seconds(1),
-                    outgoingIntefaceName: String? = nil
+                    deviceName: String? = nil
         ) throws {
             self.endpoint = endpoint
             self.count = count
@@ -257,7 +257,7 @@ extension ICMPPingClient {
             }
 
             for device in try System.enumerateDevices() {
-                if device.name == outgoingIntefaceName, let address = device.address {
+                if device.name == deviceName, let address = device.address {
                     switch (address.protocol, self.endpoint) {
                     case (.inet, .ipv4), (.inet6, .ipv6):
                         logger.info("device selcted is \(device)")

From 74e4a795e35645caca517a128d230776ec09268f Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Tue, 1 Oct 2024 00:55:32 -0700
Subject: [PATCH 08/11] fix bind to device on linux

---
 Sources/LCLPing/HTTP/NIOHTTPClient.swift           |  2 +-
 Sources/LCLPing/ICMP/ICMPPingClient.swift          |  2 +-
 .../LCLPing/Utilities/LCLPing+SocketOption.swift   | 14 ++++++++++++++
 3 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/Sources/LCLPing/HTTP/NIOHTTPClient.swift b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
index f350ba8..c6fa3eb 100644
--- a/Sources/LCLPing/HTTP/NIOHTTPClient.swift
+++ b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
@@ -215,7 +215,7 @@ final class NIOHTTPClient: Pingable {
                         ()
                     }
                     #elseif canImport(Glibc)
-                    return channel.setOption(.socketOption(.so_bindtodevice), value: device.interfaceIndex)
+                    return (channel as! SocketOptionProvider).setBindToDevice(device.name)
                     #endif
                 }
 
diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index 5163bd7..7898297 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -191,7 +191,7 @@ public final class ICMPPingClient: Pingable {
                         ()
                     }
                     #elseif canImport(Glibc)
-                    return channel.setOption(.socketOption(.so_bindtodevice), value: device.interfaceIndex)
+                    return (channel as! SocketOptionProvider).setBindToDevice(device.name)
                     #endif
                 }
                 
diff --git a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
index 17d2083..2e654be 100644
--- a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
+++ b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
@@ -21,3 +21,17 @@ extension NIOBSDSocket.Option {
     public static let so_bindtodevice = Self(rawValue: SO_BINDTODEVICE)
     #endif
 }
+
+extension SocketOptionProvider {
+    #if canImport(Glibc)
+    /// Sets the socket option SO_BINDTODEVICE to `value`.
+    ///
+    /// - parameters:
+    ///     - value: The value to set SO_BINDTODEVICE to.
+    /// - returns: An `EventLoopFuture` that fires when the option has been set,
+    ///     or if an error has occurred.
+    public func setBindToDevice(_ value: String) -> EventLoopFuture<Void> {
+        self.unsafeSetSocketOption(level: .socket, name: .so_bindtodevice, value: value)
+    }
+    #endif
+}

From ac64fa4f8b0b85b8b854b1c7dad4be6b8409f520 Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Tue, 1 Oct 2024 23:43:31 -0700
Subject: [PATCH 09/11] make device object immutable; support musl platform

---
 Sources/LCLPing/HTTP/HTTPPingClient.swift            |  2 +-
 Sources/LCLPing/HTTP/NIOHTTPClient.swift             |  2 +-
 Sources/LCLPing/ICMP/ICMPPingClient.swift            |  4 ++--
 Sources/LCLPing/Utilities/LCLPing+SocketOption.swift | 12 ++++++++++--
 4 files changed, 14 insertions(+), 6 deletions(-)

diff --git a/Sources/LCLPing/HTTP/HTTPPingClient.swift b/Sources/LCLPing/HTTP/HTTPPingClient.swift
index 86bdd47..57f4a44 100644
--- a/Sources/LCLPing/HTTP/HTTPPingClient.swift
+++ b/Sources/LCLPing/HTTP/HTTPPingClient.swift
@@ -180,7 +180,7 @@ extension HTTPPingClient {
         public let resolvedAddress: SocketAddress
         
         /// The outgoing device associated with the given interface name
-        public var device: NIONetworkDevice?
+        public private(set) var device: NIONetworkDevice?
 
         /// Initialize a HTTP Ping Client `Configuration`.
         ///
diff --git a/Sources/LCLPing/HTTP/NIOHTTPClient.swift b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
index c6fa3eb..f30fc58 100644
--- a/Sources/LCLPing/HTTP/NIOHTTPClient.swift
+++ b/Sources/LCLPing/HTTP/NIOHTTPClient.swift
@@ -214,7 +214,7 @@ final class NIOHTTPClient: Pingable {
                     default:
                         ()
                     }
-                    #elseif canImport(Glibc)
+                    #elseif canImport(Glibc) || canImport(Musl)
                     return (channel as! SocketOptionProvider).setBindToDevice(device.name)
                     #endif
                 }
diff --git a/Sources/LCLPing/ICMP/ICMPPingClient.swift b/Sources/LCLPing/ICMP/ICMPPingClient.swift
index 7898297..513475d 100644
--- a/Sources/LCLPing/ICMP/ICMPPingClient.swift
+++ b/Sources/LCLPing/ICMP/ICMPPingClient.swift
@@ -190,7 +190,7 @@ public final class ICMPPingClient: Pingable {
                     default:
                         ()
                     }
-                    #elseif canImport(Glibc)
+                    #elseif canImport(Glibc) || canImport(Musl)
                     return (channel as! SocketOptionProvider).setBindToDevice(device.name)
                     #endif
                 }
@@ -235,7 +235,7 @@ extension ICMPPingClient {
         public let resolvedAddress: SocketAddress
         
         /// The outgoing device associated with the given interface name
-        public var device: NIONetworkDevice?
+        public private(set) var device: NIONetworkDevice?
 
         public init(endpoint: EndpointTarget,
                     count: Int = 10,
diff --git a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
index 2e654be..158948a 100644
--- a/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
+++ b/Sources/LCLPing/Utilities/LCLPing+SocketOption.swift
@@ -12,18 +12,26 @@
 
 import Foundation
 import NIOCore
+#if canImport(Darwin)
+import Darwin
+#elseif canImport(Glibc)
+import Glibc
+#elseif canImport(Musl)
+import Musl
+#endif
 
 extension NIOBSDSocket.Option {
     #if canImport(Darwin)
     public static let ip_bound_if: NIOBSDSocket.Option = Self(rawValue: IP_BOUND_IF)
     public static let ipv6_bound_if: NIOBSDSocket.Option = Self(rawValue: IPV6_BOUND_IF)
-    #elseif canImport(Glibc)
+    #elseif canImport(Glibc) || canImport(Musl)
     public static let so_bindtodevice = Self(rawValue: SO_BINDTODEVICE)
     #endif
 }
 
 extension SocketOptionProvider {
-    #if canImport(Glibc)
+    #if canImport(Glibc) || canImport(Musl)
+    
     /// Sets the socket option SO_BINDTODEVICE to `value`.
     ///
     /// - parameters:

From db042d097d7cffb97d8ac91854f0d21385a6319b Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Wed, 9 Apr 2025 23:15:30 -0700
Subject: [PATCH 10/11] bump swiftnio to 2.81.0

---
 Package.swift                       | 2 +-
 Sources/LCLPing/Configuration.swift | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Package.swift b/Package.swift
index 71b6c30..2055e39 100644
--- a/Package.swift
+++ b/Package.swift
@@ -16,7 +16,7 @@ let package = Package(
     ],
     dependencies: [
         // Dependencies declare other packages that this package depends on.
-        .package(url: "https://github.com/apple/swift-nio.git", from: "2.73.0"),
+        .package(url: "https://github.com/apple/swift-nio.git", from: "2.81.0"),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.5.3"),
         .package(url: "https://github.com/apple/swift-nio-ssl.git", from: "2.25.0"),
         .package(url: "https://github.com/apple/swift-collections.git", from: "1.1.1")
diff --git a/Sources/LCLPing/Configuration.swift b/Sources/LCLPing/Configuration.swift
index 46d031a..1175244 100644
--- a/Sources/LCLPing/Configuration.swift
+++ b/Sources/LCLPing/Configuration.swift
@@ -13,7 +13,7 @@
 import Foundation
 
 /// Type of reachability test that `LCLPing` supports
-public enum PingType {
+public enum PingType: String, CaseIterable {
     /// Perform reachability ping test through the ICMP protocol.
     case icmp
 

From f4f3068da5d04431de52a667bab0c2ee493fe3dc Mon Sep 17 00:00:00 2001
From: Zhennan Zhou <zhouz46@uw.edu>
Date: Wed, 9 Apr 2025 23:38:44 -0700
Subject: [PATCH 11/11] add caseIterable and identifiable to PingType

---
 Sources/LCLPing/Configuration.swift | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Sources/LCLPing/Configuration.swift b/Sources/LCLPing/Configuration.swift
index 1175244..5246e92 100644
--- a/Sources/LCLPing/Configuration.swift
+++ b/Sources/LCLPing/Configuration.swift
@@ -13,7 +13,8 @@
 import Foundation
 
 /// Type of reachability test that `LCLPing` supports
-public enum PingType: String, CaseIterable {
+public enum PingType: String, CaseIterable, Identifiable {
+    public var id: Self { self }
     /// Perform reachability ping test through the ICMP protocol.
     case icmp