ooni-probe-cli/internal/netxlite/getaddrinfo_otherwise.go

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//go:build !cgo
package netxlite
import (
"context"
"net"
)
getaddrinfo: fix CGO_ENABLED=0 and record resolver type (#765) After https://github.com/ooni/probe-cli/pull/764, the build for CGO_ENABLED=0 has been broken for miniooni: https://github.com/ooni/probe-cli/runs/6636995859?check_suite_focus=true Likewise, it's not possible to run tests with CGO_ENABLED=0. To make tests work with `CGO_ENABLED=0`, I needed to sacrifice some unit tests run for the CGO case. It is not fully clear to me what was happening here, but basically `getaddrinfo_cgo_test.go` was compiled with CGO being disabled, even though the ``//go:build cgo` flag was specified. Additionally, @hellais previously raised a valid point in the review of https://github.com/ooni/probe-cli/pull/698: > Another issue we should consider is that, if I understand how > this works correctly, depending on whether or not we have built > with CGO_ENABLED=0 on or not, we are going to be measuring > things in a different way (using our cgo inspired getaddrinfo > implementation or using netgo). This might present issues when > analyzing or interpreting the data. > > Do we perhaps want to add some field to the output data format that > gives us an indication of which DNS resolution code was used to > generate the the metric? This comment is relevant to the current commit because https://github.com/ooni/probe-cli/pull/698 is the previous iteration of https://github.com/ooni/probe-cli/pull/764. So, while fixing the build and test issues, let us also distinguish between the CGO_ENABLED=1 and CGO_ENABLED=0 cases. Before this commit, OONI used "system" to indicate the case where we were using net.DefaultResolver. This behavior dates back to the Measurement Kit days. While it is true that ooni/probe-engine and ooni/probe-cli could have been using netgo in the past when we said "system" as the resolver, it also seems reasonable to continue to use "system" top indicate getaddrinfo. So, the choice here is basically to use "netgo" from now on to indicate the cases in which we were built with CGO_ENABLED=0. This change will need to be documented into ooni/spec along with the introduction of the `android_dns_cache_no_data` error. ## Checklist - [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md) - [x] reference issue for this pull request: https://github.com/ooni/probe/issues/2029 - [x] if you changed anything related how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request: https://github.com/ooni/spec/pull/242
2022-05-30 07:34:25 +02:00
// getaddrinfoResolverNetwork returns the "network" that is actually
// been used to implement the getaddrinfo resolver.
//
// This is the CGO_ENABLED=0 implementation of this function, which
// always returns the string [StdlibResolverGolangNetResolver], 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" was wrong.
//
// See https://github.com/ooni/spec/pull/257 for additional documentation
// regarding using "golang_net_resolver" instead of "go".
getaddrinfo: fix CGO_ENABLED=0 and record resolver type (#765) After https://github.com/ooni/probe-cli/pull/764, the build for CGO_ENABLED=0 has been broken for miniooni: https://github.com/ooni/probe-cli/runs/6636995859?check_suite_focus=true Likewise, it's not possible to run tests with CGO_ENABLED=0. To make tests work with `CGO_ENABLED=0`, I needed to sacrifice some unit tests run for the CGO case. It is not fully clear to me what was happening here, but basically `getaddrinfo_cgo_test.go` was compiled with CGO being disabled, even though the ``//go:build cgo` flag was specified. Additionally, @hellais previously raised a valid point in the review of https://github.com/ooni/probe-cli/pull/698: > Another issue we should consider is that, if I understand how > this works correctly, depending on whether or not we have built > with CGO_ENABLED=0 on or not, we are going to be measuring > things in a different way (using our cgo inspired getaddrinfo > implementation or using netgo). This might present issues when > analyzing or interpreting the data. > > Do we perhaps want to add some field to the output data format that > gives us an indication of which DNS resolution code was used to > generate the the metric? This comment is relevant to the current commit because https://github.com/ooni/probe-cli/pull/698 is the previous iteration of https://github.com/ooni/probe-cli/pull/764. So, while fixing the build and test issues, let us also distinguish between the CGO_ENABLED=1 and CGO_ENABLED=0 cases. Before this commit, OONI used "system" to indicate the case where we were using net.DefaultResolver. This behavior dates back to the Measurement Kit days. While it is true that ooni/probe-engine and ooni/probe-cli could have been using netgo in the past when we said "system" as the resolver, it also seems reasonable to continue to use "system" top indicate getaddrinfo. So, the choice here is basically to use "netgo" from now on to indicate the cases in which we were built with CGO_ENABLED=0. This change will need to be documented into ooni/spec along with the introduction of the `android_dns_cache_no_data` error. ## Checklist - [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md) - [x] reference issue for this pull request: https://github.com/ooni/probe/issues/2029 - [x] if you changed anything related how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request: https://github.com/ooni/spec/pull/242
2022-05-30 07:34:25 +02:00
func getaddrinfoResolverNetwork() string {
return StdlibResolverGolangNetResolver
getaddrinfo: fix CGO_ENABLED=0 and record resolver type (#765) After https://github.com/ooni/probe-cli/pull/764, the build for CGO_ENABLED=0 has been broken for miniooni: https://github.com/ooni/probe-cli/runs/6636995859?check_suite_focus=true Likewise, it's not possible to run tests with CGO_ENABLED=0. To make tests work with `CGO_ENABLED=0`, I needed to sacrifice some unit tests run for the CGO case. It is not fully clear to me what was happening here, but basically `getaddrinfo_cgo_test.go` was compiled with CGO being disabled, even though the ``//go:build cgo` flag was specified. Additionally, @hellais previously raised a valid point in the review of https://github.com/ooni/probe-cli/pull/698: > Another issue we should consider is that, if I understand how > this works correctly, depending on whether or not we have built > with CGO_ENABLED=0 on or not, we are going to be measuring > things in a different way (using our cgo inspired getaddrinfo > implementation or using netgo). This might present issues when > analyzing or interpreting the data. > > Do we perhaps want to add some field to the output data format that > gives us an indication of which DNS resolution code was used to > generate the the metric? This comment is relevant to the current commit because https://github.com/ooni/probe-cli/pull/698 is the previous iteration of https://github.com/ooni/probe-cli/pull/764. So, while fixing the build and test issues, let us also distinguish between the CGO_ENABLED=1 and CGO_ENABLED=0 cases. Before this commit, OONI used "system" to indicate the case where we were using net.DefaultResolver. This behavior dates back to the Measurement Kit days. While it is true that ooni/probe-engine and ooni/probe-cli could have been using netgo in the past when we said "system" as the resolver, it also seems reasonable to continue to use "system" top indicate getaddrinfo. So, the choice here is basically to use "netgo" from now on to indicate the cases in which we were built with CGO_ENABLED=0. This change will need to be documented into ooni/spec along with the introduction of the `android_dns_cache_no_data` error. ## Checklist - [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md) - [x] reference issue for this pull request: https://github.com/ooni/probe/issues/2029 - [x] if you changed anything related how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request: https://github.com/ooni/spec/pull/242
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}
// getaddrinfoLookupANY attempts to perform an ANY lookup using getaddrinfo.
//
// This is the CGO_ENABLED=0 implementation of this function.
//
// Arguments:
//
// - ctx is the context for deadline/timeout/cancellation
//
// - domain is the domain to lookup
//
// This function returns the list of looked up addresses, an always-empty
// CNAME, and the error that occurred. On error, the list of addresses is empty.
func getaddrinfoLookupANY(ctx context.Context, domain string) ([]string, string, error) {
getaddrinfo: fix CGO_ENABLED=0 and record resolver type (#765) After https://github.com/ooni/probe-cli/pull/764, the build for CGO_ENABLED=0 has been broken for miniooni: https://github.com/ooni/probe-cli/runs/6636995859?check_suite_focus=true Likewise, it's not possible to run tests with CGO_ENABLED=0. To make tests work with `CGO_ENABLED=0`, I needed to sacrifice some unit tests run for the CGO case. It is not fully clear to me what was happening here, but basically `getaddrinfo_cgo_test.go` was compiled with CGO being disabled, even though the ``//go:build cgo` flag was specified. Additionally, @hellais previously raised a valid point in the review of https://github.com/ooni/probe-cli/pull/698: > Another issue we should consider is that, if I understand how > this works correctly, depending on whether or not we have built > with CGO_ENABLED=0 on or not, we are going to be measuring > things in a different way (using our cgo inspired getaddrinfo > implementation or using netgo). This might present issues when > analyzing or interpreting the data. > > Do we perhaps want to add some field to the output data format that > gives us an indication of which DNS resolution code was used to > generate the the metric? This comment is relevant to the current commit because https://github.com/ooni/probe-cli/pull/698 is the previous iteration of https://github.com/ooni/probe-cli/pull/764. So, while fixing the build and test issues, let us also distinguish between the CGO_ENABLED=1 and CGO_ENABLED=0 cases. Before this commit, OONI used "system" to indicate the case where we were using net.DefaultResolver. This behavior dates back to the Measurement Kit days. While it is true that ooni/probe-engine and ooni/probe-cli could have been using netgo in the past when we said "system" as the resolver, it also seems reasonable to continue to use "system" top indicate getaddrinfo. So, the choice here is basically to use "netgo" from now on to indicate the cases in which we were built with CGO_ENABLED=0. This change will need to be documented into ooni/spec along with the introduction of the `android_dns_cache_no_data` error. ## Checklist - [x] I have read the [contribution guidelines](https://github.com/ooni/probe-cli/blob/master/CONTRIBUTING.md) - [x] reference issue for this pull request: https://github.com/ooni/probe/issues/2029 - [x] if you changed anything related how experiments work and you need to reflect these changes in the ooni/spec repository, please link to the related ooni/spec pull request: https://github.com/ooni/spec/pull/242
2022-05-30 07:34:25 +02:00
al, err := net.DefaultResolver.LookupHost(ctx, domain)
return al, "", err
}