From f7fd29b2461d80d34ace5d6224436b75e40975be Mon Sep 17 00:00:00 2001
From: Srijan Srivastava <79690889+SrijanSriv@users.noreply.github.com>
Date: Wed, 9 Feb 2022 16:24:19 +0530
Subject: [PATCH] geolocate: add cloudflare-based IP lookup (#676)

Cloudflare hosted services provide a certain service of `/cdn-cgi/trace` with their base url (for example, `www.cloudflare.com` or `www.nginx.com`), which can be used to obtain `ip` in the probe's `geolocate` feature.

The same feature was added in this pr, hence, increasing the number of `baseURL`s in `geolocate`.

Co-authored-by: Simone Basso <bassosimone@gmail.com>
---
 internal/engine/geolocate/cloudflare.go      | 33 ++++++++++++++++++++
 internal/engine/geolocate/cloudflare_test.go | 26 +++++++++++++++
 internal/engine/geolocate/iplookup.go        |  4 +++
 3 files changed, 63 insertions(+)
 create mode 100644 internal/engine/geolocate/cloudflare.go
 create mode 100644 internal/engine/geolocate/cloudflare_test.go

diff --git a/internal/engine/geolocate/cloudflare.go b/internal/engine/geolocate/cloudflare.go
new file mode 100644
index 0000000..61664e9
--- /dev/null
+++ b/internal/engine/geolocate/cloudflare.go
@@ -0,0 +1,33 @@
+package geolocate
+
+import (
+	"context"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"github.com/ooni/probe-cli/v3/internal/engine/httpheader"
+	"github.com/ooni/probe-cli/v3/internal/httpx"
+	"github.com/ooni/probe-cli/v3/internal/model"
+)
+
+func cloudflareIPLookup(
+	ctx context.Context,
+	httpClient *http.Client,
+	logger model.Logger,
+	userAgent string,
+) (string, error) {
+	data, err := (&httpx.APIClientTemplate{
+		BaseURL:    "https://www.cloudflare.com",
+		HTTPClient: httpClient,
+		Logger:     logger,
+		UserAgent:  httpheader.CLIUserAgent(),
+	}).WithBodyLogging().Build().FetchResource(ctx, "/cdn-cgi/trace")
+	if err != nil {
+		return DefaultProbeIP, err
+	}
+	r := regexp.MustCompile("(?:ip)=(.*)")
+	ip := strings.Trim(string(r.Find(data)), "ip=")
+	logger.Debugf("cloudflare: body: %s", ip)
+	return ip, nil
+}
diff --git a/internal/engine/geolocate/cloudflare_test.go b/internal/engine/geolocate/cloudflare_test.go
new file mode 100644
index 0000000..a3a9ef3
--- /dev/null
+++ b/internal/engine/geolocate/cloudflare_test.go
@@ -0,0 +1,26 @@
+package geolocate
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"testing"
+
+	"github.com/apex/log"
+	"github.com/ooni/probe-cli/v3/internal/engine/httpheader"
+)
+
+func TestIPLookupWorksUsingcloudlflare(t *testing.T) {
+	ip, err := cloudflareIPLookup(
+		context.Background(),
+		http.DefaultClient,
+		log.Log,
+		httpheader.UserAgent(),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if net.ParseIP(ip) == nil {
+		t.Fatalf("not an IP address: '%s'", ip)
+	}
+}
diff --git a/internal/engine/geolocate/iplookup.go b/internal/engine/geolocate/iplookup.go
index 4cb46f0..52438a0 100644
--- a/internal/engine/geolocate/iplookup.go
+++ b/internal/engine/geolocate/iplookup.go
@@ -40,6 +40,10 @@ var (
 			name: "avast",
 			fn:   avastIPLookup,
 		},
+		{
+			name: "cloudflare",
+			fn:   cloudflareIPLookup,
+		},
 		{
 			name: "ipconfig",
 			fn:   ipConfigIPLookup,