6d3a4f1db8
When preparing a tutorial for netxlite, I figured it is easier to tell people "hey, this is the package you should use for all low-level networking stuff" rather than introducing people to a set of packages working together where some piece of functionality is here and some other piece is there. Part of https://github.com/ooni/probe/issues/1591
57 lines
1.4 KiB
Go
57 lines
1.4 KiB
Go
package errorsx
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import (
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"context"
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"github.com/ooni/probe-cli/v3/internal/netxlite"
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)
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// Resolver is a DNS resolver. The *net.Resolver used by Go implements
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// this interface, but other implementations are possible.
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type Resolver interface {
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// LookupHost resolves a hostname to a list of IP addresses.
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LookupHost(ctx context.Context, hostname string) (addrs []string, err error)
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}
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// ErrorWrapperResolver is a Resolver that knows about wrapping errors.
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type ErrorWrapperResolver struct {
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Resolver
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}
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var _ Resolver = &ErrorWrapperResolver{}
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// LookupHost implements Resolver.LookupHost
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func (r *ErrorWrapperResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
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addrs, err := r.Resolver.LookupHost(ctx, hostname)
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err = SafeErrWrapperBuilder{
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Classifier: netxlite.ClassifyResolverError,
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Error: err,
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Operation: netxlite.ResolveOperation,
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}.MaybeBuild()
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return addrs, err
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}
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type resolverNetworker interface {
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Network() string
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}
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// Network implements Resolver.Network.
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func (r *ErrorWrapperResolver) Network() string {
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if rn, ok := r.Resolver.(resolverNetworker); ok {
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return rn.Network()
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}
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return "errorWrapper"
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}
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type resolverAddresser interface {
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Address() string
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}
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// Address implements Resolver.Address.
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func (r *ErrorWrapperResolver) Address() string {
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if ra, ok := r.Resolver.(resolverAddresser); ok {
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return ra.Address()
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}
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return ""
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}
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