From 4c99423f4fc1f0efe6480b9c27639471283c485c Mon Sep 17 00:00:00 2001
From: Tshaka Eric Lekholoane <_@tshaka.co>
Date: Mon, 29 Aug 2022 13:47:36 +0200
Subject: [PATCH 1/3] Configure protocolVersion for Identify protocol

Allows the protocolVersion field of the Idenfity protocol to be
configured on the host. The current value is fixed for what appears to
be for backwards compatibility with IPFS which makes it difficult for
non-IPFS protocols to use the library.

References:
  - https://github.com/libp2p/go-libp2p/issues/714
  - https://github.com/libp2p/go-libp2p/pull/1137
  - https://github.com/libp2p/rust-libp2p/blob/6855ab943bd7427a2135b46ad3d08f48fbf10872/protocols/identify/src/identify.rs#L125-L127
---
 config/config.go                 |  6 ++++++
 options.go                       |  9 +++++++++
 p2p/host/basic/basic_host.go     | 16 +++++++++++++--
 p2p/protocol/identify/id.go      | 34 +++++++++++++++++---------------
 p2p/protocol/identify/id_test.go |  2 +-
 p2p/protocol/identify/opts.go    |  9 +++++++++
 6 files changed, 57 insertions(+), 19 deletions(-)

diff --git a/config/config.go b/config/config.go
index 4ccbc509f8..90fa9c16cf 100644
--- a/config/config.go
+++ b/config/config.go
@@ -64,6 +64,11 @@ type Config struct {
 	// Set it via the UserAgent option function.
 	UserAgent string
 
+	// ProtocolVersion is the protocol version that identifies the family
+	// of protocols used by the peer in the Identify protocol. It is set
+	// using the [ProtocolVersion] option.
+	ProtocolVersion string
+
 	PeerKey crypto.PrivKey
 
 	Transports         []TptC
@@ -223,6 +228,7 @@ func (cfg *Config) NewNode() (host.Host, error) {
 		NATManager:          cfg.NATManager,
 		EnablePing:          !cfg.DisablePing,
 		UserAgent:           cfg.UserAgent,
+		ProtocolVersion:     cfg.ProtocolVersion,
 		MultiaddrResolver:   cfg.MultiaddrResolver,
 		EnableHolePunching:  cfg.EnableHolePunching,
 		HolePunchingOptions: cfg.HolePunchingOptions,
diff --git a/options.go b/options.go
index 6ed6a94d35..f9225f22bb 100644
--- a/options.go
+++ b/options.go
@@ -414,6 +414,15 @@ var NoTransports = func(cfg *Config) error {
 	return nil
 }
 
+// ProtocolVersion sets the protocolVersion string required by the 
+// libp2p Identify protocol.
+func ProtocolVersion(s string) Option {
+	return func(cfg *Config) error {
+		cfg.ProtocolVersion = s
+		return nil
+	}
+}
+
 // UserAgent sets the libp2p user-agent sent along with the identify protocol
 func UserAgent(userAgent string) Option {
 	return func(cfg *Config) error {
diff --git a/p2p/host/basic/basic_host.go b/p2p/host/basic/basic_host.go
index d3642bd810..9997876395 100644
--- a/p2p/host/basic/basic_host.go
+++ b/p2p/host/basic/basic_host.go
@@ -145,6 +145,9 @@ type HostOpts struct {
 	// UserAgent sets the user-agent for the host.
 	UserAgent string
 
+	// ProtocolVersion sets the protocol version for the host.
+	ProtocolVersion string
+
 	// DisableSignedPeerRecord disables the generation of Signed Peer Records on this host.
 	DisableSignedPeerRecord bool
 
@@ -226,9 +229,18 @@ func NewHost(n network.Network, opts *HostOpts) (*BasicHost, error) {
 
 	// we can't set this as a default above because it depends on the *BasicHost.
 	if h.disableSignedPeerRecord {
-		h.ids, err = identify.NewIDService(h, identify.UserAgent(opts.UserAgent), identify.DisableSignedPeerRecord())
+		h.ids, err = identify.NewIDService(
+			h,
+			identify.UserAgent(opts.UserAgent),
+			identify.ProtocolVersion(opts.ProtocolVersion),
+			identify.DisableSignedPeerRecord(),
+		)
 	} else {
-		h.ids, err = identify.NewIDService(h, identify.UserAgent(opts.UserAgent))
+		h.ids, err = identify.NewIDService(
+			h,
+			identify.UserAgent(opts.UserAgent),
+			identify.ProtocolVersion(opts.ProtocolVersion),
+		)
 	}
 	if err != nil {
 		return nil, fmt.Errorf("failed to create Identify service: %s", err)
diff --git a/p2p/protocol/identify/id.go b/p2p/protocol/identify/id.go
index 4794619d9a..0a84431c9c 100644
--- a/p2p/protocol/identify/id.go
+++ b/p2p/protocol/identify/id.go
@@ -33,11 +33,7 @@ var log = logging.Logger("net/identify")
 // service.
 const ID = "/ipfs/id/1.0.0"
 
-// LibP2PVersion holds the current protocol version for a client running this code
-// TODO(jbenet): fix the versioning mess.
-// XXX: Don't change this till 2020. You'll break all go-ipfs versions prior to
-// 0.4.17 which asserted an exact version match.
-const LibP2PVersion = "ipfs/0.1.0"
+const DefaultProtocolVersion = "ipfs/0.1.0"
 
 const ServiceName = "libp2p.identify"
 
@@ -89,8 +85,9 @@ type IDService interface {
 //   - Our IPFS Agent Version
 //   - Our public Listen Addresses
 type idService struct {
-	Host      host.Host
-	UserAgent string
+	Host            host.Host
+	UserAgent       string
+	ProtocolVersion string
 
 	ctx       context.Context
 	ctxCancel context.CancelFunc
@@ -135,9 +132,15 @@ func NewIDService(h host.Host, opts ...Option) (*idService, error) {
 		userAgent = cfg.userAgent
 	}
 
+	protocolVersion := DefaultProtocolVersion
+	if cfg.protocolVersion != "" {
+		protocolVersion = cfg.userAgent
+	}
+
 	s := &idService{
-		Host:      h,
-		UserAgent: userAgent,
+		Host:            h,
+		UserAgent:       userAgent,
+		ProtocolVersion: protocolVersion,
 
 		conns: make(map[network.Conn]chan struct{}),
 
@@ -188,8 +191,10 @@ func (ids *idService) loop() {
 	defer ids.refCount.Done()
 
 	phs := make(map[peer.ID]*peerHandler)
-	sub, err := ids.Host.EventBus().Subscribe([]interface{}{&event.EvtLocalProtocolsUpdated{},
-		&event.EvtLocalAddressesUpdated{}}, eventbus.BufSize(256))
+	sub, err := ids.Host.EventBus().Subscribe([]interface{}{
+		&event.EvtLocalProtocolsUpdated{},
+		&event.EvtLocalAddressesUpdated{},
+	}, eventbus.BufSize(256))
 	if err != nil {
 		log.Errorf("failed to subscribe to events on the bus, err=%s", err)
 		return
@@ -489,7 +494,6 @@ func (ids *idService) writeChunkedIdentifyMsg(c network.Conn, snapshot *identify
 	m := &pb.Identify{SignedPeerRecord: sr}
 	err := writer.WriteMsg(m)
 	return err
-
 }
 
 func (ids *idService) createBaseIdentifyResponse(
@@ -541,10 +545,8 @@ func (ids *idService) createBaseIdentifyResponse(
 	}
 
 	// set protocol versions
-	pv := LibP2PVersion
-	av := ids.UserAgent
-	mes.ProtocolVersion = &pv
-	mes.AgentVersion = &av
+	mes.ProtocolVersion = &ids.ProtocolVersion
+	mes.AgentVersion = &ids.UserAgent
 
 	return mes
 }
diff --git a/p2p/protocol/identify/id_test.go b/p2p/protocol/identify/id_test.go
index d86fc915e6..ebdb634961 100644
--- a/p2p/protocol/identify/id_test.go
+++ b/p2p/protocol/identify/id_test.go
@@ -75,7 +75,7 @@ func testHasProtocolVersions(t *testing.T, h host.Host, p peer.ID) {
 		t.Error("no protocol version")
 		return
 	}
-	if v.(string) != identify.LibP2PVersion {
+	if v.(string) != identify.DefaultProtocolVersion {
 		t.Error("protocol mismatch", err)
 	}
 	v, err = h.Peerstore().Get(p, "AgentVersion")
diff --git a/p2p/protocol/identify/opts.go b/p2p/protocol/identify/opts.go
index 0eb1d96644..38f505b69b 100644
--- a/p2p/protocol/identify/opts.go
+++ b/p2p/protocol/identify/opts.go
@@ -1,6 +1,7 @@
 package identify
 
 type config struct {
+	protocolVersion         string
 	userAgent               string
 	disableSignedPeerRecord bool
 }
@@ -8,6 +9,14 @@ type config struct {
 // Option is an option function for identify.
 type Option func(*config)
 
+// ProtocolVersion sets the protocol version string that will be used to
+// identify the family of protocols used by the peer.
+func ProtocolVersion(s string) Option {
+	return func(cfg *config) {
+		cfg.protocolVersion = s
+	}
+}
+
 // UserAgent sets the user agent this node will identify itself with to peers.
 func UserAgent(ua string) Option {
 	return func(cfg *config) {

From 734986f966c847c7b5954febccab4a5c224d26b2 Mon Sep 17 00:00:00 2001
From: Tshaka Eric Lekholoane <_@tshaka.co>
Date: Tue, 30 Aug 2022 13:38:15 +0200
Subject: [PATCH 2/3] Fix protocol version assignment

Fix an issue where the protocolVersion string for the Identify protocol
was wrongly being assigned the agentVersion string.
---
 p2p/protocol/identify/id.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/p2p/protocol/identify/id.go b/p2p/protocol/identify/id.go
index 0a84431c9c..b9d95240e3 100644
--- a/p2p/protocol/identify/id.go
+++ b/p2p/protocol/identify/id.go
@@ -134,7 +134,7 @@ func NewIDService(h host.Host, opts ...Option) (*idService, error) {
 
 	protocolVersion := DefaultProtocolVersion
 	if cfg.protocolVersion != "" {
-		protocolVersion = cfg.userAgent
+		protocolVersion = cfg.protocolVersion
 	}
 
 	s := &idService{

From 4e0c2c5f062ba10dc57032a66278bc6b8ce2f8ae Mon Sep 17 00:00:00 2001
From: Tshaka Eric Lekholoane <_@tshaka.co>
Date: Wed, 31 Aug 2022 14:07:54 +0200
Subject: [PATCH 3/3] Delete trailing whitespace

---
 options.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/options.go b/options.go
index f9225f22bb..3509c61d4c 100644
--- a/options.go
+++ b/options.go
@@ -414,7 +414,7 @@ var NoTransports = func(cfg *Config) error {
 	return nil
 }
 
-// ProtocolVersion sets the protocolVersion string required by the 
+// ProtocolVersion sets the protocolVersion string required by the
 // libp2p Identify protocol.
 func ProtocolVersion(s string) Option {
 	return func(cfg *Config) error {