feat: sctp connection using usrsctp

examples/ping.nim

@@ -0,0 +1,21 @@
+import chronos, stew/byteutils
+import ../webrtc/udp_transport
+import ../webrtc/stun/stun_transport
+import ../webrtc/dtls/dtls_transport
+import ../webrtc/sctp/[sctp_transport, sctp_connection]
+
+proc main() {.async.} =
+  let laddr = initTAddress("127.0.0.1:4244")
+  let udp = UdpTransport.new(laddr)
+  let stun = Stun.new(udp)
+  let dtls = Dtls.new(stun)
+  let sctp = Sctp.new(dtls)
+
+  let conn = await sctp.connect(initTAddress("127.0.0.1:4242"), sctpPort = 13)
+  while true:
+    await conn.write("ping".toBytes)
+    let msg = await conn.read()
+    echo "Received: ", string.fromBytes(msg.data)
+    await sleepAsync(1.seconds)
+
+waitFor(main())

examples/pong.nim

@@ -0,0 +1,27 @@
+import chronos, stew/byteutils
+import ../webrtc/udp_transport
+import ../webrtc/stun/stun_transport
+import ../webrtc/dtls/dtls_transport
+import ../webrtc/sctp/[sctp_transport, sctp_connection]
+
+proc sendPong(conn: SctpConn) {.async.} =
+  var i = 0
+  while true:
+    let msg = await conn.read()
+    echo "Received: ", string.fromBytes(msg.data)
+    await conn.write(("pong " & $i).toBytes)
+    i.inc()
+
+proc main() {.async.} =
+  let laddr = initTAddress("127.0.0.1:4242")
+  let udp = UdpTransport.new(laddr)
+  let stun = Stun.new(udp)
+  let dtls = Dtls.new(stun)
+  let sctp = Sctp.new(dtls)
+
+  sctp.listen(13)
+  while true:
+    let conn = await sctp.accept()
+    asyncSpawn conn.sendPong()
+
+waitFor(main())

tests/runalltests.nim

@@ -9,5 +9,8 @@
 
 {.used.}
 
+{.passc: "-DSCTP_DEBUG".}
+
 import teststun
 import testdtls
+import testsctp

tests/testsctp.nim

@@ -0,0 +1,102 @@
+# Nim-WebRTC
+# Copyright (c) 2024 Status Research & Development GmbH
+# Licensed under either of
+#  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+#  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+# at your option.
+# This file may not be copied, modified, or distributed except according to
+# those terms.
+
+{.used.}
+
+import chronos
+import ../webrtc/udp_transport
+import ../webrtc/stun/stun_transport
+import ../webrtc/dtls/dtls_transport
+import ../webrtc/sctp/sctp_transport
+import ../webrtc/sctp/sctp_connection
+import ./asyncunit
+
+suite "SCTP":
+  teardown:
+    checkLeaks()
+
+  type
+    SctpStackForTest = object
+      localAddress: TransportAddress
+      udp: UdpTransport
+      stun: Stun
+      dtls: Dtls
+      sctp: Sctp
+
+  proc initSctpStack(localAddress: TransportAddress): SctpStackForTest =
+    result.localAddress = localAddress
+    result.udp = UdpTransport.new(result.localAddress)
+    result.stun = Stun.new(result.udp)
+    result.dtls = Dtls.new(result.stun)
+    result.sctp = Sctp.new(result.dtls)
+    result.sctp.listen()
+
+  proc closeSctpStack(self: SctpStackForTest) {.async: (raises: [CancelledError]).} =
+    await self.sctp.stop()
+    await self.dtls.stop()
+    await self.stun.stop()
+    await self.udp.close()
+
+  asyncTest "Two SCTP nodes connecting to each other, then sending/receiving data":
+    var
+      sctpServer = initSctpStack(initTAddress("127.0.0.1:4444"))
+      sctpClient = initSctpStack(initTAddress("127.0.0.1:5555"))
+    let
+      serverConnFut = sctpServer.sctp.accept()
+      clientConn = await sctpClient.sctp.connect(sctpServer.localAddress)
+      serverConn = await serverConnFut
+
+    await clientConn.write(@[1'u8, 2, 3, 4])
+    check (await serverConn.read()).data == @[1'u8, 2, 3, 4]
+
+    await serverConn.write(@[5'u8, 6, 7, 8])
+    check (await clientConn.read()).data == @[5'u8, 6, 7, 8]
+
+    await clientConn.write(@[10'u8, 11, 12, 13])
+    await serverConn.write(@[14'u8, 15, 16, 17])
+    check (await clientConn.read()).data == @[14'u8, 15, 16, 17]
+    check (await serverConn.read()).data == @[10'u8, 11, 12, 13]
+
+    await allFutures(clientConn.close(), serverConn.close())
+    await allFutures(sctpClient.closeSctpStack(), sctpServer.closeSctpStack())
+
+  asyncTest "Two DTLS nodes connecting to the same DTLS server, sending/receiving data":
+    var
+      sctpServer = initSctpStack(initTAddress("127.0.0.1:4444"))
+      sctpClient1 = initSctpStack(initTAddress("127.0.0.1:5555"))
+      sctpClient2 = initSctpStack(initTAddress("127.0.0.1:6666"))
+    let
+      serverConn1Fut = sctpServer.sctp.accept()
+      serverConn2Fut = sctpServer.sctp.accept()
+      clientConn1 = await sctpClient1.sctp.connect(sctpServer.localAddress)
+      clientConn2 = await sctpClient2.sctp.connect(sctpServer.localAddress)
+      serverConn1 = await serverConn1Fut
+      serverConn2 = await serverConn2Fut
+
+    await serverConn1.write(@[1'u8, 2, 3, 4])
+    await serverConn2.write(@[5'u8, 6, 7, 8])
+    await clientConn1.write(@[9'u8, 10, 11, 12])
+    await clientConn2.write(@[13'u8, 14, 15, 16])
+    check:
+      (await clientConn1.read()).data == @[1'u8, 2, 3, 4]
+      (await clientConn2.read()).data == @[5'u8, 6, 7, 8]
+      (await serverConn1.read()).data == @[9'u8, 10, 11, 12]
+      (await serverConn2.read()).data == @[13'u8, 14, 15, 16]
+    await allFutures(clientConn1.close(), serverConn1.close())
+
+    await serverConn2.write(@[5'u8, 6, 7, 8])
+    await clientConn2.write(@[13'u8, 14, 15, 16])
+    check:
+      (await clientConn2.read()).data == @[5'u8, 6, 7, 8]
+      (await serverConn2.read()).data == @[13'u8, 14, 15, 16]
+    await allFutures(clientConn2.close(), serverConn2.close())
+
+    await allFutures(sctpClient1.closeSctpStack(),
+                     sctpClient2.closeSctpStack(),
+                     sctpServer.closeSctpStack())

webrtc.nimble

@@ -24,10 +24,18 @@ var cfg =
   " --threads:on --opt:speed"
 
 when defined(windows):
-  cfg = cfg & " --clib:ws2_32"
+  cfg = cfg & " --clib:ws2_32 --clib:iphlpapi"
 
 import hashes
 
+proc buildExample(filename: string, run = false, extraFlags = "") =
+  var excstr = nimc & " " & lang & " " & flags & " -p:. " & extraFlags
+  excstr.add(" examples/" & filename)
+  exec excstr
+  if run:
+    exec "./examples/" & filename.toExe
+  rmFile "examples/" & filename.toExe
+
 proc runTest(filename: string) =
   var excstr = nimc & " " & lang & " -d:debug " & cfg & " " & flags
   excstr.add(" -d:nimOldCaseObjects") # TODO: fix this in binary-serialization
@@ -36,5 +44,10 @@ proc runTest(filename: string) =
   exec excstr & " -r " & " tests/" & filename
   rmFile "tests/" & filename.toExe
 
-task test, "Run test":
+task test, "Run the test suite":
   runTest("runalltests")
+  exec "nimble build_example"
+
+task build_example, "Build the examples":
+  buildExample("ping")
+  buildExample("pong")