ooni-probe-cli/internal/engine/geolocate/iplookup.go
Simone Basso fbee736e90
fix(geolocate): no proxy when discovering our IP address (#251)
* fix(geolocate): no proxy when discovering our IP address

The use case of --proxy is that you cannot contact the OONI
backend otherwise. It is wrong, though, using the proxy when
discovering our IP address. The measurement won't use the
proxy anyway. Therefore, we need to use the IP address that
is performing the measurement. Not the one of the proxy.

What's more, stun is not using a proxy. Therefore, it does
not make much sense that http IP resolvers use a proxy. This
leads to inconsistencies. So, here's anothe reason why this
patch is a good thing (TM).

Finally, because knowing the IP address enables us to sanitize
the data, it's important we discover the correct IP.

Now, up until this point, the `--proxy` option has mostly
been a developers toy. But, users have asked us to have the
possibility of configuring a proxy.

This explains why I have been looking into making `--proxy`
right for a couple of hours now.

See https://github.com/ooni/probe/issues/1382

* fix(session): properly configure the IP lookupper
2021-03-10 12:01:08 +01:00

123 lines
2.6 KiB
Go

package geolocate
import (
"context"
"errors"
"fmt"
"math/rand"
"net"
"net/http"
"sync"
"time"
"github.com/ooni/probe-cli/v3/internal/engine/internal/multierror"
"github.com/ooni/probe-cli/v3/internal/engine/netx"
)
var (
// ErrAllIPLookuppersFailed indicates that we failed with looking
// up the probe IP for with all the lookuppers that we tried.
ErrAllIPLookuppersFailed = errors.New("all IP lookuppers failed")
// ErrInvalidIPAddress indicates that the code returned to us a
// string that actually isn't a valid IP address.
ErrInvalidIPAddress = errors.New("lookupper did not return a valid IP")
)
type lookupFunc func(
ctx context.Context, client *http.Client,
logger Logger, userAgent string,
) (string, error)
type method struct {
name string
fn lookupFunc
}
var (
methods = []method{
{
name: "avast",
fn: avastIPLookup,
},
{
name: "ipconfig",
fn: ipConfigIPLookup,
},
{
name: "ipinfo",
fn: ipInfoIPLookup,
},
{
name: "stun_ekiga",
fn: stunEkigaIPLookup,
},
{
name: "stun_google",
fn: stunGoogleIPLookup,
},
{
name: "ubuntu",
fn: ubuntuIPLookup,
},
}
once sync.Once
)
type ipLookupClient struct {
// Resolver is the resolver to use for HTTP.
Resolver Resolver
// Logger is the logger to use
Logger Logger
// UserAgent is the user agent to use
UserAgent string
}
func makeSlice() []method {
r := rand.New(rand.NewSource(time.Now().UnixNano()))
ret := make([]method, len(methods))
perm := r.Perm(len(methods))
for idx, randIdx := range perm {
ret[idx] = methods[randIdx]
}
return ret
}
func (c ipLookupClient) doWithCustomFunc(
ctx context.Context, fn lookupFunc,
) (string, error) {
// Implementation note: we MUST use an HTTP client that we're
// sure IS NOT using any proxy. To this end, we construct a
// client ourself that we know is not proxied.
clnt := &http.Client{Transport: netx.NewHTTPTransport(netx.Config{
Logger: c.Logger,
FullResolver: c.Resolver,
})}
defer clnt.CloseIdleConnections()
ip, err := fn(ctx, clnt, c.Logger, c.UserAgent)
if err != nil {
return DefaultProbeIP, err
}
if net.ParseIP(ip) == nil {
return DefaultProbeIP, fmt.Errorf("%w: %s", ErrInvalidIPAddress, ip)
}
c.Logger.Debugf("iplookup: IP: %s", ip)
return ip, nil
}
func (c ipLookupClient) LookupProbeIP(ctx context.Context) (string, error) {
union := multierror.New(ErrAllIPLookuppersFailed)
for _, method := range makeSlice() {
c.Logger.Infof("iplookup: using %s", method.name)
ip, err := c.doWithCustomFunc(ctx, method.fn)
if err == nil {
return ip, nil
}
union.Add(err)
}
return DefaultProbeIP, union
}