we should query getaddrinfo more precisely

[weissi]

Expected behavior

When asking getaddrinfo about an IP address, we should not get two results that contain the same IP address.

Actual behavior

we do get two, example here:

(lldb) p info.pointee
(addrinfo) $R13 = {
  ai_flags = 0
  ai_family = 2
  ai_socktype = 2
  ai_protocol = 17
  ai_addrlen = 16
  ai_canonname = nil
  ai_addr = 0x0000000104904ab0
  ai_next = 0x0000000104904f60
}
(lldb) p info.pointee.ai_next.pointee
(addrinfo) $R14 = {
  ai_flags = 0
  ai_family = 2
  ai_socktype = 1
  ai_protocol = 6
  ai_addrlen = 16
  ai_canonname = nil
  ai_addr = 0x0000000104904f90
  ai_next = nil
}

whereby ai_protocol = 17 is IPPROTO_UDP and ai_protocol = 6 is IPPROTO_TCP. But since we know which one we want we should query correctly.

Steps to reproduce

• connect to say 127.0.0.1
• set a break point at the last line of private func parseResults(_ info: UnsafeMutablePointer<addrinfo>, host: String)

If possible, minimal yet complete reproducer code (or URL to code)

bootstrap.connect(host: "127.0.0.1", port: 1234)

SwiftNIO version/commit hash

1.2.0

Swift & OS version (output of swift --version && uname -a)

$ uname -a 
Darwin jwmbp.local 17.5.0 Darwin Kernel Version 17.5.0: Mon Jan 22 18:03:58 PST 2018; root:xnu-4570.50.252~1/DEVELOPMENT_X86_64 x86_64
$ swift --version
Apple Swift version 4.0.3 (swiftlang-900.0.71 clang-900.0.38)
Target: x86_64-apple-macosx10.9

[normanmaurer]

Should be fixed by https://github.com/apple/swift-nio/pull/221