feat(nameresolving): Add {.async: (raises).} annotations (#1214)

Modernize `nameresolving` modules to track `{.async: (raises).}`.

---------

Co-authored-by: kaiserd <1684595+kaiserd@users.noreply.github.com>
Co-authored-by: richΛrd <info@richardramos.me>

libp2p/nameresolving/dnsresolver.nim

@@ -1,5 +1,5 @@
 # Nim-LibP2P
-# Copyright (c) 2023 Status Research & Development GmbH
+# Copyright (c) 2023-2024 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -10,7 +10,7 @@
 {.push raises: [].}
 
 import
-  std/[streams, strutils, sets, sequtils],
+  std/[streams, sets, sequtils],
   chronos,
   chronicles,
   stew/byteutils,
@@ -39,24 +39,32 @@ proc questionToBuf(address: string, kind: QKind): seq[byte] =
 
     var buf = newSeq[byte](dataLen)
     discard requestStream.readData(addr buf[0], dataLen)
-    return buf
+    buf
-  except CatchableError as exc:
+  except IOError as exc:
     info "Failed to created DNS buffer", description = exc.msg
-    return newSeq[byte](0)
+    newSeq[byte](0)
+  except OSError as exc:
+    info "Failed to created DNS buffer", description = exc.msg
+    newSeq[byte](0)
+  except ValueError as exc:
+    info "Failed to created DNS buffer", description = exc.msg
+    newSeq[byte](0)
 
 proc getDnsResponse(
     dnsServer: TransportAddress, address: string, kind: QKind
-): Future[Response] {.async.} =
+): Future[Response] {.
+    async: (raises: [CancelledError, IOError, OSError, TransportError, ValueError])
+.} =
   var sendBuf = questionToBuf(address, kind)
 
   if sendBuf.len == 0:
     raise newException(ValueError, "Incorrect DNS query")
 
-  let receivedDataFuture = newFuture[void]()
+  let receivedDataFuture = Future[void].Raising([CancelledError]).init()
 
   proc datagramDataReceived(
       transp: DatagramTransport, raddr: TransportAddress
-  ): Future[void] {.async, closure.} =
+  ): Future[void] {.async: (raises: []), closure.} =
     receivedDataFuture.complete()
 
   let sock =
@@ -68,27 +76,41 @@ proc getDnsResponse(
   try:
     await sock.sendTo(dnsServer, addr sendBuf[0], sendBuf.len)
 
-    await receivedDataFuture or sleepAsync(5.seconds) #unix default
+    try:
-
+      await receivedDataFuture.wait(5.seconds) #unix default
-    if not receivedDataFuture.finished:
+    except AsyncTimeoutError:
       raise newException(IOError, "DNS server timeout")
 
     let rawResponse = sock.getMessage()
-    # parseResponse can has a raises: [Exception, ..] because of
+    try:
-    # https://github.com/nim-lang/Nim/commit/035134de429b5d99c5607c5fae912762bebb6008
-    # it can't actually raise though
-    return exceptionToAssert:
       parseResponse(string.fromBytes(rawResponse))
+    except IOError as exc:
+      raise exc
+    except OSError as exc:
+      raise exc
+    except ValueError as exc:
+      raise exc
+    except Exception as exc:
+      # Nim 1.6: parseResponse can has a raises: [Exception, ..] because of
+      # https://github.com/nim-lang/Nim/commit/035134de429b5d99c5607c5fae912762bebb6008
+      # it can't actually raise though
+      raiseAssert exc.msg
   finally:
     await sock.closeWait()
 
 method resolveIp*(
     self: DnsResolver, address: string, port: Port, domain: Domain = Domain.AF_UNSPEC
-): Future[seq[TransportAddress]] {.async.} =
+): Future[seq[TransportAddress]] {.
+    async: (raises: [CancelledError, TransportAddressError])
+.} =
   trace "Resolving IP using DNS", address, servers = self.nameServers.mapIt($it), domain
   for _ in 0 ..< self.nameServers.len:
     let server = self.nameServers[0]
-    var responseFutures: seq[Future[Response]]
+    var responseFutures: seq[
+      Future[Response].Raising(
+        [CancelledError, IOError, OSError, TransportError, ValueError]
+      )
+    ]
     if domain == Domain.AF_INET or domain == Domain.AF_UNSPEC:
       responseFutures.add(getDnsResponse(server, address, A))
 
@@ -103,23 +125,32 @@ method resolveIp*(
     var
       resolvedAddresses: OrderedSet[string]
       resolveFailed = false
+    template handleFail(e): untyped =
+      info "Failed to query DNS", address, error = e.msg
+      resolveFailed = true
+      break
+
     for fut in responseFutures:
       try:
         let resp = await fut
         for answer in resp.answers:
-          # toString can has a raises: [Exception, ..] because of
+          resolvedAddresses.incl(answer.toString())
-          # https://github.com/nim-lang/Nim/commit/035134de429b5d99c5607c5fae912762bebb6008
-          # it can't actually raise though
-          resolvedAddresses.incl(exceptionToAssert(answer.toString()))
       except CancelledError as e:
         raise e
       except ValueError as e:
         info "Invalid DNS query", address, error = e.msg
         return @[]
-      except CatchableError as e:
+      except IOError as e:
-        info "Failed to query DNS", address, error = e.msg
+        handleFail(e)
-        resolveFailed = true
+      except OSError as e:
-        break
+        handleFail(e)
+      except TransportError as e:
+        handleFail(e)
+      except Exception as e:
+        # Nim 1.6: answer.toString can has a raises: [Exception, ..] because of
+        # https://github.com/nim-lang/Nim/commit/035134de429b5d99c5607c5fae912762bebb6008
+        # it can't actually raise though
+        raiseAssert e.msg
 
     if resolveFailed:
       self.nameServers.add(self.nameServers[0])
@@ -132,27 +163,39 @@ method resolveIp*(
   debug "Failed to resolve address, returning empty set"
   return @[]
 
-method resolveTxt*(self: DnsResolver, address: string): Future[seq[string]] {.async.} =
+method resolveTxt*(
+    self: DnsResolver, address: string
+): Future[seq[string]] {.async: (raises: [CancelledError]).} =
   trace "Resolving TXT using DNS", address, servers = self.nameServers.mapIt($it)
   for _ in 0 ..< self.nameServers.len:
     let server = self.nameServers[0]
-    try:
+    template handleFail(e): untyped =
-      # toString can has a raises: [Exception, ..] because of
-      # https://github.com/nim-lang/Nim/commit/035134de429b5d99c5607c5fae912762bebb6008
-      # it can't actually raise though
-      let response = await getDnsResponse(server, address, TXT)
-      return exceptionToAssert:
-        trace "Got TXT response",
-          server = $server, answer = response.answers.mapIt(it.toString())
-        response.answers.mapIt(it.toString())
-    except CancelledError as e:
-      raise e
-    except CatchableError as e:
       info "Failed to query DNS", address, error = e.msg
       self.nameServers.add(self.nameServers[0])
       self.nameServers.delete(0)
       continue
 
+    try:
+      let response = await getDnsResponse(server, address, TXT)
+      trace "Got TXT response",
+        server = $server, answer = response.answers.mapIt(it.toString())
+      return response.answers.mapIt(it.toString())
+    except CancelledError as e:
+      raise e
+    except IOError as e:
+      handleFail(e)
+    except OSError as e:
+      handleFail(e)
+    except TransportError as e:
+      handleFail(e)
+    except ValueError as e:
+      handleFail(e)
+    except Exception as e:
+      # Nim 1.6: toString can has a raises: [Exception, ..] because of
+      # https://github.com/nim-lang/Nim/commit/035134de429b5d99c5607c5fae912762bebb6008
+      # it can't actually raise though
+      raiseAssert e.msg
+
   debug "Failed to resolve TXT, returning empty set"
   return @[]
 

libp2p/nameresolving/mockresolver.nim

@@ -1,5 +1,5 @@
 # Nim-LibP2P
-# Copyright (c) 2023 Status Research & Development GmbH
+# Copyright (c) 2023-2024 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -25,17 +25,25 @@ type MockResolver* = ref object of NameResolver
 
 method resolveIp*(
     self: MockResolver, address: string, port: Port, domain: Domain = Domain.AF_UNSPEC
-): Future[seq[TransportAddress]] {.async.} =
+): Future[seq[TransportAddress]] {.
+    async: (raises: [CancelledError, TransportAddressError])
+.} =
+  var res: seq[TransportAddress]
+
   if domain == Domain.AF_INET or domain == Domain.AF_UNSPEC:
     for resp in self.ipResponses.getOrDefault((address, false)):
-      result.add(initTAddress(resp, port))
+      res.add(initTAddress(resp, port))
 
   if domain == Domain.AF_INET6 or domain == Domain.AF_UNSPEC:
     for resp in self.ipResponses.getOrDefault((address, true)):
-      result.add(initTAddress(resp, port))
+      res.add(initTAddress(resp, port))
 
-method resolveTxt*(self: MockResolver, address: string): Future[seq[string]] {.async.} =
+  res
-  return self.txtResponses.getOrDefault(address)
+
+method resolveTxt*(
+    self: MockResolver, address: string
+): Future[seq[string]] {.async: (raises: [CancelledError]).} =
+  self.txtResponses.getOrDefault(address)
 
 proc new*(T: typedesc[MockResolver]): T =
   T()

libp2p/nameresolving/nameresolver.nim

@@ -1,5 +1,5 @@
 # Nim-LibP2P
-# Copyright (c) 2023 Status Research & Development GmbH
+# Copyright (c) 2023-2024 Status Research & Development GmbH
 # Licensed under either of
 #  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
 #  * MIT license ([LICENSE-MIT](LICENSE-MIT))
@@ -9,7 +9,7 @@
 
 {.push raises: [].}
 
-import std/[sugar, sets, sequtils, strutils]
+import std/[sets, sequtils, strutils]
 import chronos, chronicles, stew/endians2
 import ".."/[multiaddress, multicodec]
 
@@ -20,19 +20,17 @@ type NameResolver* = ref object of RootObj
 
 method resolveTxt*(
     self: NameResolver, address: string
-): Future[seq[string]] {.async, base.} =
+): Future[seq[string]] {.async: (raises: [CancelledError]), base.} =
   ## Get TXT record
-  ##
+  raiseAssert "Not implemented!"
-
-  doAssert(false, "Not implemented!")
 
 method resolveIp*(
     self: NameResolver, address: string, port: Port, domain: Domain = Domain.AF_UNSPEC
-): Future[seq[TransportAddress]] {.async, base.} =
+): Future[seq[TransportAddress]] {.
+    async: (raises: [CancelledError, TransportAddressError]), base
+.} =
   ## Resolve the specified address
-  ##
+  raiseAssert "Not implemented!"
-
-  doAssert(false, "Not implemented!")
 
 proc getHostname*(ma: MultiAddress): string =
   let
@@ -46,30 +44,40 @@ proc getHostname*(ma: MultiAddress): string =
 
 proc resolveOneAddress(
     self: NameResolver, ma: MultiAddress, domain: Domain = Domain.AF_UNSPEC, prefix = ""
-): Future[seq[MultiAddress]] {.async.} =
+): Future[seq[MultiAddress]] {.
-  #Resolve a single address
+    async: (raises: [CancelledError, MaError, TransportAddressError])
+.} =
+  # Resolve a single address
+  let portPart = ma[1].valueOr:
+    raise maErr error
   var pbuf: array[2, byte]
-
+  let plen = portPart.protoArgument(pbuf).valueOr:
-  var dnsval = getHostname(ma)
+    raise maErr error
-
+  if plen == 0:
-  if ma[1].tryGet().protoArgument(pbuf).tryGet() == 0:
+    raise maErr "Incorrect port number"
-    raise newException(MaError, "Incorrect port number")
   let
     port = Port(fromBytesBE(uint16, pbuf))
+    dnsval = getHostname(ma)
     resolvedAddresses = await self.resolveIp(prefix & dnsval, port, domain)
 
-  return collect(newSeqOfCap(4)):
+  resolvedAddresses.mapIt:
-    for address in resolvedAddresses:
+    let address = MultiAddress.init(it).valueOr:
-      var createdAddress = MultiAddress.init(address).tryGet()[0].tryGet()
+      raise maErr error
-      for part in ma:
+    var createdAddress = address[0].valueOr:
-        if DNS.match(part.tryGet()):
+      raise maErr error
-          continue
+    for part in ma:
-        createdAddress &= part.tryGet()
+      let part = part.valueOr:
-      createdAddress
+        raise maErr error
+      if DNS.match(part):
+        continue
+      createdAddress &= part
+    createdAddress
 
 proc resolveDnsAddr*(
     self: NameResolver, ma: MultiAddress, depth: int = 0
-): Future[seq[MultiAddress]] {.async.} =
+): Future[seq[MultiAddress]] {.
+    async: (raises: [CancelledError, MaError, TransportAddressError])
+.} =
   if not DNSADDR.matchPartial(ma):
     return @[ma]
 
@@ -78,54 +86,67 @@ proc resolveDnsAddr*(
     info "Stopping DNSADDR recursion, probably malicious", ma
     return @[]
 
-  var dnsval = getHostname(ma)
+  let
-
+    dnsval = getHostname(ma)
-  let txt = await self.resolveTxt("_dnsaddr." & dnsval)
+    txt = await self.resolveTxt("_dnsaddr." & dnsval)
 
   trace "txt entries", txt
 
-  var result: seq[MultiAddress]
+  const codec = multiCodec("p2p")
+  let maCodec = block:
+    let hasCodec = ma.contains(codec).valueOr:
+      raise maErr error
+    if hasCodec:
+      ma[codec]
+    else:
+      (static(default(MaResult[MultiAddress])))
+
+  var res: seq[MultiAddress]
   for entry in txt:
     if not entry.startsWith("dnsaddr="):
       continue
-    let entryValue = MultiAddress.init(entry[8 ..^ 1]).tryGet()
+    let
-
+      entryValue = MultiAddress.init(entry[8 ..^ 1]).valueOr:
-    if entryValue.contains(multiCodec("p2p")).tryGet() and
+        raise maErr error
-        ma.contains(multiCodec("p2p")).tryGet():
+      entryHasCodec = entryValue.contains(multiCodec("p2p")).valueOr:
-      if entryValue[multiCodec("p2p")] != ma[multiCodec("p2p")]:
+        raise maErr error
-        continue
+    if entryHasCodec and maCodec.isOk and entryValue[codec] != maCodec:
+      continue
 
     let resolved = await self.resolveDnsAddr(entryValue, depth + 1)
     for r in resolved:
-      result.add(r)
+      res.add(r)
 
-  if result.len == 0:
+  if res.len == 0:
     debug "Failed to resolve a DNSADDR", ma
-    return @[]
+  res
-  return result
 
 proc resolveMAddress*(
     self: NameResolver, address: MultiAddress
-): Future[seq[MultiAddress]] {.async.} =
+): Future[seq[MultiAddress]] {.
+    async: (raises: [CancelledError, MaError, TransportAddressError])
+.} =
   var res = initOrderedSet[MultiAddress]()
-
   if not DNS.matchPartial(address):
     res.incl(address)
   else:
-    let code = address[0].tryGet().protoCode().tryGet()
+    let
-    let seq =
+      firstPart = address[0].valueOr:
-      case code
+        raise maErr error
-      of multiCodec("dns"):
+      code = firstPart.protoCode().valueOr:
-        await self.resolveOneAddress(address)
+        raise maErr error
-      of multiCodec("dns4"):
+      ads =
-        await self.resolveOneAddress(address, Domain.AF_INET)
+        case code
-      of multiCodec("dns6"):
+        of multiCodec("dns"):
-        await self.resolveOneAddress(address, Domain.AF_INET6)
+          await self.resolveOneAddress(address)
-      of multiCodec("dnsaddr"):
+        of multiCodec("dns4"):
-        await self.resolveDnsAddr(address)
+          await self.resolveOneAddress(address, Domain.AF_INET)
-      else:
+        of multiCodec("dns6"):
-        assert false
+          await self.resolveOneAddress(address, Domain.AF_INET6)
-        @[address]
+        of multiCodec("dnsaddr"):
-    for ad in seq:
+          await self.resolveDnsAddr(address)
+        else:
+          raise maErr("Unsupported codec " & $code)
+    for ad in ads:
       res.incl(ad)
-  return res.toSeq
+  res.toSeq