netxlite: do not call netgo the CGO_ENABLED=0 resolver (#766)

In https://github.com/ooni/probe/issues/2029#issuecomment-1140805266, we
explained why calling it "netgo" would be incorrect.

In other words, we can get the platform's `getaddrinfo` as long as
we're not cross compiling. We do cross compile `ooniprobe`, actually
it's not even possible to cross compile it.

For increased accuracy, we should stop cross compiling `miniooni`
as well, so it would also directly use `getaddrinfo`.

This diff fixes at the same time ooni/probe-cli and ooni/spec
and we'll open two pull requests in parallel.
This commit is contained in:
Simone Basso 2022-05-30 10:06:53 +02:00 committed by GitHub
parent f3912188e1
commit 595d0744db
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2 changed files with 14 additions and 6 deletions

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@ -201,10 +201,11 @@ type SimpleResolver interface {
// Network returns the resolver type. It should be one of:
//
// - netgo: means we're using golang's "netgo" UDP resolver, which
// reads /etc/resolv.conf and only works on Unix systems;
// - go: means we're using whatever resolver the Go stdlib uses
// depending on the current build configuration;
//
// - system: means we're calling getaddrinfo;
// - system: means we've been compiled with `CGO_ENABLED=1`
// so we can bypass the go resolver and call getaddrinfo directly;
//
// - udp: is a custom DNS-over-UDP resolver;
//
@ -215,6 +216,10 @@ type SimpleResolver interface {
// - doh: is a custom DNS-over-HTTPS resolver;
//
// - doh3: is a custom DNS-over-HTTP3 resolver.
//
// See https://github.com/ooni/probe/issues/2029#issuecomment-1140805266
// for an explanation of why it would not be proper to call "netgo" the
// resolver we get by default from the standard library.
Network() string
}

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@ -11,10 +11,13 @@ import (
// been used to implement the getaddrinfo resolver.
//
// This is the CGO_ENABLED=0 implementation of this function, which
// always returns the string "netgo", because in this scenario we
// are actually using the netgo implementation of net.Resolver.
// always returns the string "go", because in this scenario we are actually
// using whatever resolver is used under the hood by the stdlib.
//
// See https://github.com/ooni/probe/issues/2029#issuecomment-1140805266
// for an explanation of why calling this resolver "netgo" is wrong.
func getaddrinfoResolverNetwork() string {
return "netgo"
return "go"
}
// getaddrinfoLookupANY attempts to perform an ANY lookup using getaddrinfo.