@@ -125,7 +125,7 @@ public final class Pinger: PingerProtocol {
125125 }
126126
127127 let sequenceNumber = nextSequenceNumber ( )
128- let packetData = Self . createICMPPacket (
128+ let packetData = ICMP . createICMPPacket (
129129 identifier: identifier,
130130 sequenceNumber: sequenceNumber
131131 )
@@ -177,7 +177,13 @@ public final class Pinger: PingerProtocol {
177177 do {
178178 guard bytesRead > 0 else { throw Error . receivePacket ( errno) }
179179
180- let icmpHeader = try parseICMPResponse ( buffer: & readBuffer, length: bytesRead)
180+ let icmpHeader = try ICMP . parseICMPResponse ( buffer: & readBuffer, length: bytesRead)
181+ guard icmpHeader. identifier == identifier else {
182+ throw Error . clientIdentifierMismatch
183+ }
184+ guard icmpHeader. type == ICMP_ECHOREPLY else {
185+ throw Error . invalidICMPType ( icmpHeader. type)
186+ }
181187 guard let sender = Self . makeIPAddress ( from: address) else { throw Error . parseIPAddress }
182188
183189 replyQueue. async {
@@ -192,65 +198,6 @@ public final class Pinger: PingerProtocol {
192198 }
193199 }
194200
195- private func parseICMPResponse( buffer: inout [ UInt8 ] , length: Int ) throws -> ICMPHeader {
196- try . withUnsafeMutableBytes { bufferPointer in
197- // Check IP packet size.
198- guard length >= MemoryLayout< IPv4Header> . size else {
199- throw Error . malformedResponse ( . ipv4PacketTooSmall)
200- }
201-
202- // Verify IPv4 header.
203- let ipv4Header = bufferPointer. load ( as: IPv4Header . self)
204- let payloadLength = length - ipv4Header. headerLength
205-
206- guard payloadLength >= MemoryLayout< ICMPHeader> . size else {
207- throw Error . malformedResponse ( . icmpHeaderTooSmall)
208- }
209-
210- guard ipv4Header. isIPv4Version else {
211- throw Error . malformedResponse ( . invalidIPVersion)
212- }
213-
214- // Parse ICMP header.
215- let icmpHeaderPointer = bufferPointer. baseAddress!
216- . advanced ( by: ipv4Header. headerLength)
217- . assumingMemoryBound ( to: ICMPHeader . self)
218-
219- // Check if ICMP response identifier matches the one from sender.
220- guard icmpHeaderPointer. pointee. identifier. bigEndian == identifier else {
221- throw Error . clientIdentifierMismatch
222- }
223-
224- // Verify ICMP type.
225- guard icmpHeaderPointer. pointee. type == ICMP_ECHOREPLY else {
226- throw Error . malformedResponse ( . invalidEchoReplyType)
227- }
228-
229- // Copy server checksum.
230- let serverChecksum = icmpHeaderPointer. pointee. checksum. bigEndian
231-
232- // Reset checksum field before calculating checksum.
233- icmpHeaderPointer. pointee. checksum = 0
234-
235- // Verify ICMP checksum.
236- let payloadPointer = UnsafeRawBufferPointer (
237- start: icmpHeaderPointer,
238- count: payloadLength
239- )
240- let clientChecksum = in_chksum ( payloadPointer)
241- if clientChecksum != serverChecksum {
242- throw Error . malformedResponse ( . checksumMismatch( clientChecksum, serverChecksum) )
243- }
244-
245- // Ensure endianness before returning ICMP packet to delegate.
246- var icmpHeader = icmpHeaderPointer. pointee
247- icmpHeader. identifier = icmpHeader. identifier. bigEndian
248- icmpHeader. sequenceNumber = icmpHeader. sequenceNumber. bigEndian
249- icmpHeader. checksum = serverChecksum
250- return icmpHeader
251- }
252- }
253-
254201 private func bindSocket( _ socket: CFSocket , to interfaceName: String ) throws {
255202 var index = if_nametoindex ( interfaceName)
256203 guard index > 0 else {
@@ -270,19 +217,6 @@ public final class Pinger: PingerProtocol {
270217 }
271218 }
272219
273- private class func createICMPPacket( identifier: UInt16 , sequenceNumber: UInt16 ) -> Data {
274- var header = ICMPHeader (
275- type: UInt8 ( ICMP_ECHO) ,
276- code: 0 ,
277- checksum: 0 ,
278- identifier: identifier. bigEndian,
279- sequenceNumber: sequenceNumber. bigEndian
280- )
281- header. checksum = withUnsafeBytes ( of: & header) { in_chksum ( $0) . bigEndian }
282-
283- return withUnsafeBytes ( of: & header) { Data ( $0) }
284- }
285-
286220 private class func makeIPAddress( from sa: sockaddr ) -> IPAddress ? {
287221 if sa. sa_family == AF_INET {
288222 return withUnsafeBytes ( of: sa) { buffer -> IPAddress ? in
@@ -337,12 +271,12 @@ extension Pinger {
337271 /// Failure to receive packet. Contains the `errno`.
338272 case receivePacket( Int32 )
339273
274+ /// Unexpected ICMP reply type
275+ case invalidICMPType( UInt8 )
276+
340277 /// Response identifier does not match the sender identifier.
341278 case clientIdentifierMismatch
342279
343- /// Malformed response.
344- case malformedResponse( MalformedResponseReason )
345-
346280 /// Failure to parse IP address.
347281 case parseIPAddress
348282
@@ -362,51 +296,13 @@ extension Pinger {
362296 return " Failure to send packet (errno: \( code) ). "
363297 case let . receivePacket( code) :
364298 return " Failure to receive packet (errno: \( code) ). "
299+ case let . invalidICMPType( type) :
300+ return " Unexpected ICMP reply type: \( type) "
365301 case . clientIdentifierMismatch:
366302 return " Response identifier does not match the sender identifier. "
367- case let . malformedResponse( reason) :
368- return " Malformed response: \( reason) . "
369303 case . parseIPAddress:
370304 return " Failed to parse IP address. "
371305 }
372306 }
373307 }
374-
375- public enum MalformedResponseReason {
376- case ipv4PacketTooSmall
377- case icmpHeaderTooSmall
378- case invalidIPVersion
379- case invalidEchoReplyType
380- case checksumMismatch( UInt16 , UInt16 )
381- }
382- }
383-
384- private func in_chksum( _ data: some Sequence < UInt8 > ) -> UInt16 {
385- var iterator = data. makeIterator ( )
386- var words = [ UInt16] ( )
387-
388- while let byte = iterator. next ( ) {
389- let nextByte = iterator. next ( ) ?? 0
390- let word = UInt16 ( byte) << 8 | UInt16 ( nextByte)
391-
392- words. append ( word)
393- }
394-
395- let sum = words. reduce ( 0 , &+ )
396-
397- return ~ sum
398- }
399-
400- private extension IPv4Header {
401- /// Returns IPv4 header length.
402- var headerLength : Int {
403- Int ( versionAndHeaderLength & 0x0F ) * MemoryLayout< UInt32> . size
404- }
405-
406- /// Returns `true` if version header indicates IPv4.
407- var isIPv4Version : Bool {
408- ( versionAndHeaderLength & 0xF0 ) == 0x40
409- }
410-
411- // swiftlint:disable:next file_length
412308}
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