Add Registrar permission to attaching chains

context.go

@@ -43,6 +43,13 @@ func (a Actor) Empty() bool {
 	return a.ChainID == "" && a.App == "" && len(a.Address) == 0
 }
 
+// WithChain creates a copy of the actor with a different chainID
+func (a Actor) WithChain(chainID string) (b Actor) {
+	b = a
+	b.ChainID = chainID
+	return
+}
+
 // Context is an interface, so we can implement "secure" variants that
 // rely on private fields to control the actions
 type Context interface {

modules/ibc/handler.go

@@ -1,6 +1,9 @@
 package ibc
 
 import (
+	"github.com/tendermint/go-wire/data"
+	"github.com/tendermint/tmlibs/log"
+
 	"github.com/tendermint/basecoin"
 	"github.com/tendermint/basecoin/errors"
 	"github.com/tendermint/basecoin/stack"
@@ -10,6 +13,9 @@ import (
 const (
 	// NameIBC is the name of this module
 	NameIBC = "ibc"
+	// OptionRegistrar is the option name to set the actor
+	// to handle ibc chain registration
+	OptionRegistrar = "registrar"
 )
 
 var (
@@ -23,29 +29,44 @@ func AllowIBC(app string) basecoin.Actor {
 }
 
 // Handler allows us to update the chain state or create a packet
-//
-// TODO: require auth for registration, the authorized actor (or role)
-// should be defined in the handler, and set via SetOption
 type Handler struct {
-	// TODO: add option to set who can permit registration and store it
-	basecoin.NopOption
+	Registrar basecoin.Actor
 }
 
-var _ basecoin.Handler = Handler{}
+var _ basecoin.Handler = &Handler{}
 
-// NewHandler makes a role handler to create roles
-func NewHandler() Handler {
-	return Handler{}
+// NewHandler makes a Handler that allows all chains to connect via IBC.
+// Set a Registrar via SetOption to restrict it.
+func NewHandler() *Handler {
+	return new(Handler)
 }
 
 // Name - return name space
-func (Handler) Name() string {
+func (*Handler) Name() string {
 	return NameIBC
 }
 
+// SetOption - sets the registrar for IBC
+func (h *Handler) SetOption(l log.Logger, store state.KVStore, module, key, value string) (log string, err error) {
+	if module != NameIBC {
+		return "", errors.ErrUnknownModule(module)
+	}
+	if key == OptionRegistrar {
+		var act basecoin.Actor
+		err = data.FromJSON([]byte(value), &act)
+		if err != nil {
+			return "", err
+		}
+		h.Registrar = act
+		// TODO: save/load from disk!
+		return "Success", nil
+	}
+	return "", errors.ErrUnknownKey(key)
+}
+
 // CheckTx verifies the packet is formated correctly, and has the proper sequence
 // for a registered chain
-func (h Handler) CheckTx(ctx basecoin.Context, store state.KVStore, tx basecoin.Tx) (res basecoin.Result, err error) {
+func (h *Handler) CheckTx(ctx basecoin.Context, store state.KVStore, tx basecoin.Tx) (res basecoin.Result, err error) {
 	err = tx.ValidateBasic()
 	if err != nil {
 		return res, err
@@ -64,7 +85,7 @@ func (h Handler) CheckTx(ctx basecoin.Context, store state.KVStore, tx basecoin.
 
 // DeliverTx verifies all signatures on the tx and updated the chain state
 // apropriately
-func (h Handler) DeliverTx(ctx basecoin.Context, store state.KVStore, tx basecoin.Tx) (res basecoin.Result, err error) {
+func (h *Handler) DeliverTx(ctx basecoin.Context, store state.KVStore, tx basecoin.Tx) (res basecoin.Result, err error) {
 	err = tx.ValidateBasic()
 	if err != nil {
 		return res, err
@@ -72,7 +93,6 @@ func (h Handler) DeliverTx(ctx basecoin.Context, store state.KVStore, tx basecoi
 
 	switch t := tx.Unwrap().(type) {
 	case RegisterChainTx:
-		// TODO: do we want some permissioning for this???
 		return h.initSeed(ctx, store, t)
 	case UpdateChainTx:
 		return h.updateSeed(ctx, store, t)
@@ -82,10 +102,19 @@ func (h Handler) DeliverTx(ctx basecoin.Context, store state.KVStore, tx basecoi
 	return res, errors.ErrUnknownTxType(tx.Unwrap())
 }
 
-// initSeed imports the first seed for this chain and accepts it as the root of trust
-func (h Handler) initSeed(ctx basecoin.Context, store state.KVStore,
+// initSeed imports the first seed for this chain and
+// accepts it as the root of trust.
+//
+// only the registrar, if set, is allowed to do this
+func (h *Handler) initSeed(ctx basecoin.Context, store state.KVStore,
 	t RegisterChainTx) (res basecoin.Result, err error) {
 
+	// check permission to attach
+	// nothing set, means anyone can connect
+	if !h.Registrar.Empty() && !ctx.HasPermission(h.Registrar) {
+		return res, errors.ErrUnauthorized()
+	}
+
 	chainID := t.ChainID()
 	s := NewChainSet(store)
 	err = s.Register(chainID, ctx.BlockHeight(), t.Seed.Height())
@@ -101,7 +130,7 @@ func (h Handler) initSeed(ctx basecoin.Context, store state.KVStore,
 
 // updateSeed checks the seed against the existing chain data and rejects it if it
 // doesn't fit (or no chain data)
-func (h Handler) updateSeed(ctx basecoin.Context, store state.KVStore,
+func (h *Handler) updateSeed(ctx basecoin.Context, store state.KVStore,
 	t UpdateChainTx) (res basecoin.Result, err error) {
 
 	chainID := t.ChainID()
@@ -124,7 +153,7 @@ func (h Handler) updateSeed(ctx basecoin.Context, store state.KVStore,
 
 // createPacket makes sure all permissions are good and the destination
 // chain is registed.  If so, it appends it to the outgoing queue
-func (h Handler) createPacket(ctx basecoin.Context, store state.KVStore,
+func (h *Handler) createPacket(ctx basecoin.Context, store state.KVStore,
 	t CreatePacketTx) (res basecoin.Result, err error) {
 
 	// make sure the chain is registed
@@ -134,7 +163,7 @@ func (h Handler) createPacket(ctx basecoin.Context, store state.KVStore,
 	}
 
 	// make sure we have the special IBC permission
-	mod, err := t.Tx.GetKind()
+	mod, err := t.Tx.GetMod()
 	if err != nil {
 		return res, err
 	}
@@ -155,8 +184,7 @@ func (h Handler) createPacket(ctx basecoin.Context, store state.KVStore,
 			return res, ErrCannotSetPermission()
 		}
 		// add the permission with the current ChainID
-		packet.Permissions[i] = p
-		packet.Permissions[i].ChainID = ctx.ChainID()
+		packet.Permissions[i] = p.WithChain(ctx.ChainID())
 	}
 
 	// now add it to the output queue....

tx.go

@@ -1,6 +1,8 @@
 package basecoin
 
 import (
+	"strings"
+
 	"github.com/tendermint/go-wire/data"
 
 	"github.com/tendermint/basecoin/errors"
@@ -75,3 +77,16 @@ func (t Tx) GetKind() (string, error) {
 	// grab the type we used in json
 	return text.Kind, nil
 }
+
+func (t Tx) GetMod() (string, error) {
+	kind, err := t.GetKind()
+	if err != nil {
+		return "", err
+	}
+	parts := strings.SplitN(kind, "/", 2)
+	if len(parts) != 2 {
+		// TODO: return "base"?
+		return "", errors.ErrUnknownTxType(t)
+	}
+	return parts[0], nil
+}