From 8792771cdcd673f1b612cd6befc7b7e41598036f Mon Sep 17 00:00:00 2001
From: Neel Chauhan <neel@neelc.org>
Date: Mon, 14 Oct 2024 13:38:20 -0400
Subject: [PATCH] broker and proxy must not reject client offers with no ICE
 candidates

Fixes #40371. Partially reverts !141.
---
 broker/http.go                  |  7 -------
 broker/snowflake-broker_test.go | 16 ----------------
 client/lib/webrtc.go            |  5 -----
 proxy/lib/snowflake.go          |  7 -------
 4 files changed, 35 deletions(-)

diff --git a/broker/http.go b/broker/http.go
index d3e43c1..b6f449d 100644
--- a/broker/http.go
+++ b/broker/http.go
@@ -139,13 +139,6 @@ func clientOffers(i *IPC, w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	err = validateSDP(body)
-	if err != nil {
-		log.Println("Error client SDP: ", err.Error())
-		w.WriteHeader(http.StatusBadRequest)
-		return
-	}
-
 	// Handle the legacy version
 	//
 	// We support two client message formats. The legacy format is for backwards
diff --git a/broker/snowflake-broker_test.go b/broker/snowflake-broker_test.go
index 8e9f4a0..f8a45b9 100644
--- a/broker/snowflake-broker_test.go
+++ b/broker/snowflake-broker_test.go
@@ -137,14 +137,6 @@ func TestBroker(t *testing.T) {
 			r, err := http.NewRequest("POST", "snowflake.broker/client", data)
 			So(err, ShouldBeNil)
 
-			Convey("with HTTP Bad Request when client offer contains invalid SDP", func() {
-				data, err = createClientOffer("fake", NATUnknown, "")
-				invalidRequest, err := http.NewRequest("POST", "snowflake.broker/client", data)
-				So(err, ShouldBeNil)
-				clientOffers(i, w, invalidRequest)
-				So(w.Code, ShouldEqual, http.StatusBadRequest)
-			})
-
 			Convey("with error when no snowflakes are available.", func() {
 				clientOffers(i, w, r)
 				So(w.Code, ShouldEqual, http.StatusOK)
@@ -246,14 +238,6 @@ client-sqs-ips
 			So(err, ShouldBeNil)
 			r.Header.Set("Snowflake-NAT-TYPE", "restricted")
 
-			Convey("with HTTP Bad Request when client offer contains invalid SDP", func() {
-				invalidOffer := bytes.NewReader([]byte("{test}"))
-				invalidRequest, err := http.NewRequest("POST", "snowflake.broker/client", invalidOffer)
-				So(err, ShouldBeNil)
-				clientOffers(i, w, invalidRequest)
-				So(w.Code, ShouldEqual, http.StatusBadRequest)
-			})
-
 			Convey("with 503 when no snowflakes are available.", func() {
 				clientOffers(i, w, r)
 				So(w.Code, ShouldEqual, http.StatusServiceUnavailable)
diff --git a/client/lib/webrtc.go b/client/lib/webrtc.go
index 8ccc3d0..39cd6f1 100644
--- a/client/lib/webrtc.go
+++ b/client/lib/webrtc.go
@@ -4,11 +4,9 @@ import (
 	"crypto/rand"
 	"encoding/hex"
 	"errors"
-	"fmt"
 	"io"
 	"log"
 	"net/url"
-	"strings"
 	"sync"
 	"time"
 
@@ -301,9 +299,6 @@ func (c *WebRTCPeer) preparePeerConnection(config *webrtc.Configuration) error {
 
 	<-done // Wait for ICE candidate gathering to complete.
 
-	if !strings.Contains(c.pc.LocalDescription().SDP, "\na=candidate:") {
-		return fmt.Errorf("SDP offer contains no candidate")
-	}
 	return nil
 }
 
diff --git a/proxy/lib/snowflake.go b/proxy/lib/snowflake.go
index 34bda5a..7897200 100644
--- a/proxy/lib/snowflake.go
+++ b/proxy/lib/snowflake.go
@@ -545,9 +545,6 @@ func (sf *SnowflakeProxy) makePeerConnectionFromOffer(
 			" before the client times out")
 	}
 
-	if !strings.Contains(pc.LocalDescription().SDP, "\na=candidate:") {
-		return nil, fmt.Errorf("SDP answer contains no candidate")
-	}
 	log.Printf("Answer: \n\t%s", strings.ReplaceAll(pc.LocalDescription().SDP, "\n", "\n\t"))
 
 	return pc, nil
@@ -608,10 +605,6 @@ func (sf *SnowflakeProxy) makeNewPeerConnection(
 	// Wait for ICE candidate gathering to complete
 	<-done
 
-	if !strings.Contains(pc.LocalDescription().SDP, "\na=candidate:") {
-		return nil, fmt.Errorf("Probetest SDP offer contains no candidate")
-	}
-
 	return pc, nil
 }