Convertion procs for (IpAddress, Port) <-> (SockAddr, Socklen)

lib/pure/net.nim

@@ -414,6 +414,39 @@ proc isIpAddress*(address_str: string): bool {.tags: [].} =
     return false
   return true
 
+proc toSockAddr*(address: IpAddress, port: Port, sa: var SockAddr, sl: var Socklen) =
+  ## Converts `IpAddress` and `Port` to `SockAddr` and `Socklen`
+  let port = htons(uint16(port))
+  case address.family
+  of IpAddressFamily.IPv4:
+    sl = sizeof(Sockaddr_in).Socklen
+    let s = cast[ptr Sockaddr_in](addr sa)
+    s.sin_family = type(s.sin_family)(AF_INET)
+    s.sin_port = port
+    copyMem(addr s.sin_addr, unsafeAddr address.address_v4[0], sizeof(s.sin_addr))
+  of IpAddressFamily.IPv6:
+    sl = sizeof(Sockaddr_in6).Socklen
+    let s = cast[ptr Sockaddr_in6](addr sa)
+    s.sin6_family = type(s.sin6_family)(AF_INET6)
+    s.sin6_port = port
+    copyMem(addr s.sin6_addr, unsafeAddr address.address_v6[0], sizeof(s.sin6_addr))
+
+proc fromSockAddr*(sa: SockAddr, sl: Socklen, address: var IpAddress, port: var Port) =
+  ## Converts `SockAddr` and `Socklen` to `IpAddress` and `Port`. Raises
+  ## `ObjectConversionError` in case of invalid `sa` and `sl` arguments.
+  if sa.sa_family.int == AF_INET.int and sl == sizeof(Sockaddr_in).Socklen:
+    address = IpAddress(family: IpAddressFamily.IPv4)
+    let s = cast[ptr Sockaddr_in](unsafeAddr sa)
+    copyMem(addr address.address_v4, addr s.sin_addr, sizeof(address.address_v4))
+    port = ntohs(s.sin_port).Port
+  elif sa.sa_family.int == AF_INET6.int and sl == sizeof(Sockaddr_in6).Socklen:
+    address = IpAddress(family: IpAddressFamily.IPv6)
+    let s = cast[ptr Sockaddr_in6](unsafeAddr sa)
+    copyMem(addr address.address_v6, addr s.sin6_addr, sizeof(address.address_v6))
+    port = ntohs(s.sin6_port).Port
+  else:
+    raise newException(ObjectConversionError, "Unexpected SockAddr/Socklen")
+
 when defineSsl:
   CRYPTO_malloc_init()
   doAssert SslLibraryInit() == 1