More details of the yamux implementation

identify/identify.c

@@ -40,7 +40,7 @@ int libp2p_identify_send_protocol(struct IdentifyContext *context) {
 	struct StreamMessage msg;
 	msg.data = (uint8_t*) protocol;
 	msg.data_size = strlen(protocol);
-	if (!context->parent_stream->write(context, &msg)) {
+	if (!context->parent_stream->write(context->parent_stream->stream_context, &msg)) {
 		libp2p_logger_error("identify", "send_protocol: Unable to send identify protocol header.\n");
 		return 0;
 	}
@@ -56,21 +56,34 @@ int libp2p_identify_send_protocol(struct IdentifyContext *context) {
 int libp2p_identify_receive_protocol(struct IdentifyContext* context) {
 	const char *protocol = "/ipfs/id/1.0.0\n";
 	struct StreamMessage* results = NULL;
-	if (!context->parent_stream->read(context, &results, 30)) {
+	if (!context->parent_stream->read(context->parent_stream->stream_context, &results, 30)) {
 		libp2p_logger_error("identify", "receive_protocol: Unable to read results.\n");
 		return 0;
 	}
-	// the first byte is the size, so skip it
+	// the first byte may be the size, so skip it
-	char* ptr = strstr((char*)&results[1], protocol);
+	int start = 0;
+	if (results->data[0] != '/')
+		start = 1;
+	char* ptr = strstr((char*)&results->data[start], protocol);
 	if (ptr == NULL || ptr - (char*)results > 1) {
 		return 0;
 	}
 	return 1;
 }
 
+/**
+ * A remote node is attempting to send us an Identify message
+ * @param msg the message sent
+ * @param context the SessionContext
+ * @param protocol_context the identify protocol context
+ * @returns <0 on error, 0 if loop should not continue, >0 on success
+ */
 int libp2p_identify_handle_message(const struct StreamMessage* msg, struct SessionContext* context, void* protocol_context) {
-	//TODO: Implement
+	if (protocol_context == NULL)
-	return 0;
+		return -1;
+	//struct IdentifyContext* ctx = (struct IdentifyContext*) protocol_context;
+	// TODO: Do something with the incoming msg
+	return 1;
 }
 
 /**
@@ -108,6 +121,7 @@ struct Stream* libp2p_identify_stream_new(struct Stream* parent_stream) {
 		return NULL;
 	struct Stream* out = libp2p_stream_new();
 	if (out != NULL) {
+		out->parent_stream = parent_stream;
 		struct IdentifyContext* ctx = (struct IdentifyContext*) malloc(sizeof(struct IdentifyContext));
 		if (ctx == NULL) {
 			libp2p_stream_free(out);

include/libp2p/identify/identify.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include "libp2p/utils/vector.h"
+
 typedef struct {
         // publicKey is this node's public key (which also gives its node.ID)
         // - may not need to be sent, as secure channel implies it has been sent.

include/libp2p/net/stream.h

@@ -46,7 +46,6 @@ struct Stream {
 	struct MultiAddress* address; // helps identify who is on the other end
 	pthread_mutex_t* socket_mutex; // only 1 transmission at a time
 	struct Stream* parent_stream; // what stream wraps this stream
-	int channel; // the channel this stream uses, for multiplexing protocols such as yamux
 	/**
 	 * A generic place to store implementation-specific context items
 	 */

include/libp2p/yamux/session.h

@@ -3,11 +3,12 @@
 #include <stddef.h>
 #include <stdint.h>
 #include <time.h>
+#include <sys/types.h>
 
 #include "config.h"
 #include "frame.h"
 #include "stream.h"
-#include "libp2p/conn/session.h"
+#include "libp2p/net/stream.h"
 
 enum yamux_session_type
 {
@@ -57,7 +58,7 @@ struct yamux_session
 
     enum yamux_session_type type;
 
-    struct SessionContext* session_context;
+    struct Stream* parent_stream;
 
     yamux_streamid nextid;
 
@@ -72,13 +73,14 @@ struct yamux_session
  * @param userdata user data
  * @returns the yamux_session struct
  */
-struct yamux_session* yamux_session_new(struct yamux_config* config, struct SessionContext* session_context, enum yamux_session_type type, void* userdata);
+struct yamux_session* yamux_session_new(struct yamux_config* config, struct Stream* parent_stream, enum yamux_session_type type, void* userdata);
 
 // does not close the socket, but does close the session
-void                  yamux_session_free(struct yamux_session* session);
+void yamux_session_free(struct yamux_session* session);
 
 // does not free used memory
 ssize_t yamux_session_close(struct yamux_session* session, enum yamux_error err);
+
 inline ssize_t yamux_session_go_away(struct yamux_session* session, enum yamux_error err)
 {
     return yamux_session_close(session, err);
@@ -96,5 +98,3 @@ ssize_t yamux_session_read(struct yamux_session* session);
  * @returns true(1) on success, false(0) otherwise
  */
 int yamux_decode(struct yamux_session* session, const uint8_t* incoming, size_t incoming_size);
-
-

include/libp2p/yamux/yamux.h

@@ -2,6 +2,7 @@
 
 #include "libp2p/net/protocol.h"
 #include "libp2p/net/stream.h"
+#include "libp2p/yamux/stream.h"
 
 /***
  * Declarations for the Yamux protocol
@@ -9,15 +10,25 @@
 
 static const int yamux_default_timeout = 10;
 
+static const char YAMUX_CONTEXT = 'Y';
+static const char YAMUX_CHANNEL_CONTEXT = 'C';
+
 /***
  * Context struct for Yamux
  */
 struct YamuxContext {
+	char type;
 	struct Stream* stream;
 	struct yamux_session* session;
 	struct Libp2pVector* channels;
 };
 
+struct YamuxChannelContext {
+	char type;
+	struct YamuxContext* yamux_context;
+	struct yamux_stream* channel;
+};
+
 /**
  * Build a handler that can handle the yamux protocol
  */
@@ -40,6 +51,8 @@ int yamux_receive_protocol(struct SessionContext* context);
 
 struct Stream* libp2p_yamux_stream_new(struct Stream* parent_stream);
 
+void libp2p_yamux_stream_free(struct Stream* stream);
+
 /****
  * Add a stream "channel" to the yamux handler
  * @param ctx the context
@@ -47,3 +60,10 @@ struct Stream* libp2p_yamux_stream_new(struct Stream* parent_stream);
  * @returns true(1) on success, false(0) otherwise
  */
 int libp2p_yamux_stream_add(struct YamuxContext* ctx, struct Stream* stream);
+
+/**
+ * Create a stream that has a "YamuxChannelContext" related to this yamux protocol
+ * @param parent_stream the parent yamux stream
+ * @returns a new Stream that is a YamuxChannelContext
+ */
+struct Stream* libp2p_yamux_channel_new(struct Stream* parent_stream);

net/stream.c

@@ -15,7 +15,6 @@ struct Stream* libp2p_stream_new() {
 		stream->socket_mutex = NULL;
 		stream->stream_context = NULL;
 		stream->write = NULL;
-		stream->channel = 0;
 	}
 	return stream;
 }

peer/Makefile

@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS = -O0 -I../include -I../../c-protobuf -I../../c-multihash/include -I../../c-multiaddr/include -g3 -std=c99
+CFLAGS = -O0 -I../include -I../../c-protobuf -I../../c-multihash/include -I../../c-multiaddr/include -g3 -std=c11
 LFLAGS =
 DEPS = 
 OBJS = peer.o peerstore.o providerstore.o

test/Makefile

@@ -1,5 +1,5 @@
 CC = gcc
-CFLAGS = -O0 -I../include -I. -I../../c-multihash/include -I../../c-multiaddr/include -std=c99
+CFLAGS = -O0 -I../include -I. -I../../c-multihash/include -I../../c-multiaddr/include -std=c11
 
 ifdef DEBUG
 CFLAGS += -g3

test/mock_stream.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include <unistd.h>
+#include "libp2p/net/stream.h"
+
+struct MockContext {
+	struct Stream* stream;
+};
+
+void mock_stream_free(struct Stream* stream);
+
+int mock_stream_close(void* context) {
+	if (context == NULL)
+		return 1;
+	struct MockContext* ctx = (struct MockContext*)context;
+	mock_stream_free(ctx->stream);
+	return 1;
+}
+
+int mock_stream_peek(void* context) {
+	return 1;
+}
+
+int mock_stream_read(void* context, struct StreamMessage** msg, int timeout_secs) {
+	return 1;
+}
+
+int mock_stream_read_raw(void* context, uint8_t* buffer, int buffer_size, int timeout_secs) {
+	return 1;
+}
+
+int mock_stream_write(void* context, struct StreamMessage* msg) {
+	return 1;
+}
+
+struct Stream* mock_stream_new() {
+	struct Stream* out = libp2p_stream_new();
+	if (out != NULL) {
+		out->close = mock_stream_close;
+		out->peek = mock_stream_peek;
+		out->read = mock_stream_read;
+		out->read_raw = mock_stream_read_raw;
+		out->write = mock_stream_write;
+		struct MockContext* ctx = malloc(sizeof(struct MockContext));
+		ctx->stream = out;
+		out->stream_context = ctx;
+	}
+	return out;
+}
+
+void mock_stream_free(struct Stream* stream) {
+	if (stream == NULL)
+		return;
+	if (stream->stream_context != NULL)
+		free(stream->stream_context);
+	free(stream);
+}

test/test_yamux.h

@@ -0,0 +1,79 @@
+#pragma once
+#include "libp2p/yamux/yamux.h"
+#include "libp2p/identify/identify.h"
+#include "mock_stream.h"
+
+/***
+ * Helpers
+ */
+
+/***
+ * Sends back the yamux protocol to fake negotiation
+ */
+int mock_yamux_read_protocol(void* context, struct StreamMessage** msg, int network_timeout) {
+	*msg = libp2p_stream_message_new();
+	struct StreamMessage* message = *msg;
+	message->data = "/yamux/1.0.0\n";
+	message->data_size = strlen(message->data);
+	return 1;
+}
+
+/***
+ * Sends back the yamux protocol to fake negotiation
+ */
+int mock_identify_read_protocol(void* context, struct StreamMessage** msg, int network_timeout) {
+	*msg = libp2p_stream_message_new();
+	struct StreamMessage* message = *msg;
+	message->data = "/ipfs/id/1.0.0\n";
+	message->data_size = strlen(message->data);
+	return 1;
+}
+
+/***
+ * Tests
+ */
+
+/***
+ * Verify that we can initiate a yamux session
+ */
+int test_yamux_stream_new() {
+	int retVal = 0;
+	// setup
+	struct Stream* mock_stream = mock_stream_new();
+	mock_stream->read = mock_yamux_read_protocol;
+	struct Stream* yamux_stream = libp2p_yamux_stream_new(mock_stream);
+	if (yamux_stream == NULL)
+		goto exit;
+	// tear down
+	retVal = 1;
+	exit:
+	if (yamux_stream != NULL)
+		yamux_stream->close(yamux_stream->stream_context);
+	mock_stream->close(mock_stream->stream_context);
+	return retVal;
+}
+
+/***
+ * Attempt to add a protocol to the Yamux protocol
+ */
+int test_yamux_identify() {
+	int retVal = 0;
+	// setup
+	struct Stream* mock_stream = mock_stream_new();
+	mock_stream->read = mock_yamux_read_protocol;
+	struct Stream* yamux_stream = libp2p_yamux_stream_new(mock_stream);
+	if (yamux_stream == NULL)
+		goto exit;
+	// TODO: Now add in another protocol
+	mock_stream->read = mock_identify_read_protocol;
+	if (!libp2p_yamux_stream_add(yamux_stream->stream_context, libp2p_identify_stream_new(libp2p_yamux_channel_new(yamux_stream)))) {
+		goto exit;
+	}
+	// tear down
+	retVal = 1;
+	exit:
+	if (yamux_stream != NULL)
+		yamux_stream->close(yamux_stream->stream_context);
+	mock_stream->close(mock_stream->stream_context);
+	return retVal;
+}

test/testit.c

@@ -13,6 +13,7 @@
 #include "test_conn.h"
 #include "test_record.h"
 #include "test_peer.h"
+#include "test_yamux.h"
 #include "libp2p/utils/logger.h"
 
 struct test {
@@ -113,6 +114,8 @@ int build_test_collection() {
 	add_test("test_peer_protobuf", test_peer_protobuf,1);
 	add_test("test_peerstore", test_peerstore,1);
 	add_test("test_aes", test_aes, 1);
+	add_test("test_yamux_stream_new", test_yamux_stream_new, 1);
+	add_test("test_yamux_identify", test_yamux_identify, 1);
 	return 1;
 };
 

yamux/session.c

@@ -22,9 +22,9 @@ static struct yamux_config dcfg = YAMUX_DEFAULT_CONFIG;
  * @param userdata user data
  * @returns the yamux_session struct
  */
-struct yamux_session* yamux_session_new(struct yamux_config* config, struct SessionContext* session_context, enum yamux_session_type type, void* userdata)
+struct yamux_session* yamux_session_new(struct yamux_config* config, struct Stream* parent_stream, enum yamux_session_type type, void* userdata)
 {
-    if (!session_context)
+    if (!parent_stream)
         return NULL;
 
     if (!config)
@@ -42,7 +42,7 @@ struct yamux_session* yamux_session_new(struct yamux_config* config, struct Sess
     if (sess != NULL) {
         sess->config = config;
         sess->type   = type;
-        sess->session_context = session_context;
+        sess->parent_stream = parent_stream;
         sess->closed = 0;
         sess->nextid = 1 + (type == yamux_session_server);
         sess->num_streams = 0;
@@ -108,7 +108,7 @@ ssize_t yamux_session_close(struct yamux_session* session, enum yamux_error err)
     outgoing.data = (uint8_t*)&f;
     outgoing.data_size = sizeof(struct yamux_frame);
 
-    if (!session->session_context->default_stream->write(session->session_context, &outgoing))
+    if (!session->parent_stream->write(session->parent_stream->stream_context, &outgoing))
     		return 0;
     return outgoing.data_size;
 }
@@ -139,13 +139,14 @@ ssize_t yamux_session_ping(struct yamux_session* session, uint32_t value, int po
     struct StreamMessage outgoing;
     outgoing.data = (uint8_t*)&f;
     outgoing.data_size = sizeof(struct yamux_frame);
-    if (!session->session_context->default_stream->write(session->session_context, &outgoing))
+    if (!session->parent_stream->write(session->parent_stream->stream_context, &outgoing))
     		return 0;
     return outgoing.data_size;
 }
 
 /**
  * Decode an incoming message
+ * @param session the session
  * @param incoming the incoming bytes
  * @param incoming_size the size of the incoming bytes
  * @returns true(1) on success, false(0) otherwise
@@ -157,13 +158,15 @@ int yamux_decode(struct yamux_session* session, const uint8_t* incoming, size_t
 	if (incoming_size < sizeof(struct yamux_frame)) {
 		return 0;
 	}
+	memcpy(f, incoming, sizeof(struct yamux_frame));
+
     decode_frame(&f);
 
     // check yamux version
     if (f.version != YAMUX_VERSION)
         return 0;
 
-    if (!f.streamid) // we're not dealing with a stream
+    if (!f.streamid) // we're not dealing with a stream, we're dealing with something at the yamux protocol level
         switch (f.type)
         {
             case yamux_frame_ping: // ping
@@ -202,7 +205,7 @@ int yamux_decode(struct yamux_session* session, const uint8_t* incoming, size_t
             default:
                 return -EPROTO;
         }
-    else { // we're handling a stream
+    else { // we're handling a stream, not something at the yamux protocol level
         for (size_t i = 0; i < session->cap_streams; ++i)
         {
             struct yamux_session_stream* ss = &session->streams[i];
@@ -242,15 +245,16 @@ int yamux_decode(struct yamux_session* session, const uint8_t* incoming, size_t
                     return -EPROTO;
 
                 int sz = sizeof(struct yamux_frame);
-                ssize_t re = yamux_stream_process(s, &f, &incoming[sz], incoming_size - sz, session->session_context);
+                ssize_t re = yamux_stream_process(s, &f, &incoming[sz], incoming_size - sz, session->parent_stream->stream_context);
                 return (re < 0) ? re : (re + incoming_size);
             }
         }
 
-        // stream doesn't exist yet
+        // This stream is not in my list of streams.
+        // It must not exist yet, so let's try to make it
         if (f.flags & yamux_frame_syn)
         {
-            void* ud = NULL;
+            void* ud = NULL; // user data
 
             if (session->get_str_ud_fn)
                 ud = session->get_str_ud_fn(session, f.streamid);

yamux/stream.c

@@ -13,6 +13,14 @@
 #define MIN(x,y) (y^((x^y)&-(x<y)))
 #define MAX(x,y) (x^((x^y)&-(x<y)))
 
+
+/***
+ * Create a new stream
+ * @param session the session
+ * @param id the id (0 to set it to the next id)
+ * @Param userdata the user data
+ * @returns a new yamux_stream struct
+ */
 struct yamux_stream* yamux_stream_new(struct yamux_session* session, yamux_streamid id, void* userdata)
 {
     if (!session)
@@ -82,7 +90,7 @@ int yamux_write_frame(struct yamux_stream* yamux_stream, struct yamux_frame* f)
 	struct StreamMessage outgoing;
 	outgoing.data = (uint8_t*)f;
 	outgoing.data_size = sizeof(struct yamux_frame);
-	if (!yamux_stream->session->session_context->default_stream->write(yamux_stream->session->session_context, &outgoing))
+	if (!yamux_stream->session->parent_stream->write(yamux_stream->session->parent_stream->stream_context, &outgoing))
 		return 0;
 	return outgoing.data_size;
 }
@@ -196,32 +204,31 @@ ssize_t yamux_stream_window_update(struct yamux_stream* stream, int32_t delta)
 }
 
 /***
- * Write data to the stream
+ * Write data to the stream.
- * @param stream the stream
+ * @param stream the stream (includes the "channel")
  * @param data_length the length of the data to be sent
  * @param data_ the data to be sent
  * @return the number of bytes sent
  */
 ssize_t yamux_stream_write(struct yamux_stream* stream, uint32_t data_length, void* data_)
 {
+	// validate parameters
     if (!((size_t)stream | (size_t)data_) || stream->state == yamux_stream_closed
             || stream->state == yamux_stream_closing || stream->session->closed)
         return -EINVAL;
 
+    // gather details
     char* data = (char*)data_;
-
     struct yamux_session* s = stream->session;
-
     char* data_end = data + data_length;
-
     uint32_t ws = stream->window_size;
     yamux_streamid id = stream->id;
     char sendd[ws + sizeof(struct yamux_frame)];
 
+    // Send the data, breaking it up into pieces if it is too large
     while (data < data_end) {
-        uint32_t
+        uint32_t dr  = (uint32_t)(data_end - data); // length of the data for this round
-            dr  = (uint32_t)(data_end - data),
+        uint32_t adv = MIN(dr, ws); // the size of the data we will send this round
-            adv = MIN(dr, ws);
 
         struct yamux_frame f = (struct yamux_frame){
             .version  = YAMUX_VERSION   ,
@@ -232,15 +239,19 @@ ssize_t yamux_stream_write(struct yamux_stream* stream, uint32_t data_length, vo
         };
 
         encode_frame(&f);
+        // put the frame into the buffer
         memcpy(sendd, &f, sizeof(struct yamux_frame));
+        // put the data into the buffer
         memcpy(sendd + sizeof(struct yamux_frame), data, (size_t)adv);
 
+        // send the buffer through the network
         struct StreamMessage outgoing;
         outgoing.data = (uint8_t*)sendd;
         outgoing.data_size = adv + sizeof(struct yamux_frame);
-        if (!s->session_context->default_stream->write(s->session_context, &outgoing))
+        if (!s->parent_stream->write(s->parent_stream->stream_context, &outgoing))
         		return adv;
 
+        // prepare to loop again
         data += adv;
     }
 

yamux/yamux.c

@@ -35,6 +35,7 @@ int yamux_can_handle(const struct StreamMessage* msg) {
  * @param msg the message
  * @param incoming the stream buffer
  */
+/*
 void yamux_read_stream(struct yamux_stream* stream, struct StreamMessage* msg) {
 	struct Libp2pVector* handlers = stream->userdata;
 	int retVal = libp2p_protocol_marshal(msg, stream->session->session_context, handlers);
@@ -50,6 +51,7 @@ void yamux_read_stream(struct yamux_stream* stream, struct StreamMessage* msg) {
 	}
 	return;
 }
+*/
 
 /***
  * Send the yamux protocol out the default stream
@@ -94,7 +96,7 @@ int yamux_receive_protocol(struct SessionContext* context) {
 }
 
 /***
- * Handles the message
+ * The remote is attempting to negotiate yamux
  * @param msg the incoming message
  * @param incoming_size the size of the incoming data buffer
  * @param session_context the information about the incoming connection
@@ -102,8 +104,7 @@ int yamux_receive_protocol(struct SessionContext* context) {
  * @returns 0 if the caller should not continue looping, <0 on error, >0 on success
  */
 int yamux_handle_message(const struct StreamMessage* msg, struct SessionContext* session_context, void* protocol_context) {
-	// they've asked to swicth to yamux. Do the switch and return 0 so that nothing else listens on this stream
+	struct yamux_session* yamux = yamux_session_new(NULL, session_context->default_stream, yamux_session_server, protocol_context);
-	struct yamux_session* yamux = yamux_session_new(NULL, session_context, yamux_session_server, protocol_context);
 	uint8_t* buf = (uint8_t*) malloc(msg->data_size);
 	if (buf == NULL)
 		return -1;
@@ -119,37 +120,7 @@ int yamux_handle_message(const struct StreamMessage* msg, struct SessionContext*
 		}
 	}
 
-	/*
+	return 1;
-	struct Libp2pVector* handlers = (struct Libp2pVector*)protocol_context;
-	uint8_t* results = NULL;
-	size_t bytes_read = 0;
-	int numRetries = 0;
-	int retVal = 0;
-	int max_retries = 100; // try for 5 minutes
-	for(;;) {
-   		// try to read for 5 seconds
-   	    if (session_context->default_stream->read(session_context, &results, &bytes_read, 5)) {
-   	    	// we read something from the network. Process it.
-   	    	// NOTE: If it is a multistream protocol that we are receiving, ignore it.
-   	    	if (yamux_can_handle(results, bytes_read))
-   	    		continue;
-   	    	numRetries = 0;
-   	   	retVal = libp2p_protocol_marshal(results, bytes_read, session_context, handlers);
-   	   	if (results != NULL)
-   	   		free(results);
-   	   	// exit the loop on error (or if they ask us to no longer loop by returning 0)
-   	   	if (retVal <= 0)
-   	   		break;
-   	    } else {
-   	    		// we were unable to read from the network.
-   	   	    // if it timed out, we should try again (if we're not out of retries)
-   	    		if (numRetries >= max_retries)
-   	    			break;
-   	    		numRetries++;
-   	    }
-	}
-	*/
-	return 0;
 }
 
 /**
@@ -173,7 +144,10 @@ struct Libp2pProtocolHandler* yamux_build_protocol_handler(struct Libp2pVector*
 }
 
 int libp2p_yamux_close(void* stream_context) {
-	//TODO: Implement
+	if (stream_context == NULL)
+		return 0;
+	struct YamuxContext* ctx = (struct YamuxContext*)stream_context;
+	libp2p_yamux_stream_free(ctx->stream);
 	return 0;
 }
 
@@ -186,19 +160,62 @@ int libp2p_yamux_close(void* stream_context) {
  * @returns true(1) on success, false(0) on failure
  */
 int libp2p_yamux_read(void* stream_context, struct StreamMessage** message, int timeout_secs) {
-	struct YamuxContext* ctx = (struct YamuxContext*)stream_context;
+	if (stream_context == NULL)
-	struct Stream* parent_stream = ctx->stream->parent_stream;
-
-	struct StreamMessage* incoming;
-	if (!parent_stream->read(parent_stream->stream_context, &incoming, timeout_secs))
 		return 0;
+	// look at the first byte of the context to determine if this is a YamuxContext (we're negotiating)
+	// or a YamuxChannelContext (we're talking to an established channel)
+	struct YamuxContext* ctx = NULL;
+	struct YamuxChannelContext* channel = NULL;
+	char proto = ((uint8_t*)stream_context)[0];
+	if (proto == YAMUX_CHANNEL_CONTEXT) {
+		channel = (struct YamuxChannelContext*)stream_context;
+		ctx = channel->yamux_context;
+	} else if (proto == YAMUX_CONTEXT) {
+		ctx = (struct YamuxContext*)stream_context;
+	}
 
-	// we've got bytes from the network. process them as a yamux frame
+	if (channel != NULL && channel->channel != NULL) {
-	return yamux_decode(ctx->session, incoming->data, incoming->data_size);
+		// we have an established channel. Use it.
+		if (!channel->yamux_context->stream->parent_stream->read(channel->yamux_context->stream->parent_stream->stream_context, message, yamux_default_timeout))
+			return 0;
+		// TODO: This is not right. It must be sorted out.
+		struct StreamMessage* msg = *message;
+		return yamux_decode(channel->channel->session, msg->data, msg->data_size);
+	} else if (ctx != NULL) {
+		// We are still negotiating...
+		return ctx->stream->parent_stream->read(ctx->stream->parent_stream->stream_context, message, yamux_default_timeout);
+	}
+	return 0;
 }
 
+/***
+ * Write to the remote
+ * @param stream_context the context. Could be a YamuxContext or YamuxChannelContext
+ * @param message the message to write
+ * @returns the number of bytes written
+ */
 int libp2p_yamux_write(void* stream_context, struct StreamMessage* message) {
-	//TODO: Implement
+	if (stream_context == NULL)
+		return 0;
+	// look at the first byte of the context to determine if this is a YamuxContext (we're negotiating)
+	// or a YamuxChannelContext (we're talking to an established channel)
+	struct YamuxContext* ctx = NULL;
+	struct YamuxChannelContext* channel = NULL;
+	char proto = ((uint8_t*)stream_context)[0];
+	if (proto == YAMUX_CHANNEL_CONTEXT) {
+		channel = (struct YamuxChannelContext*)stream_context;
+		ctx = channel->yamux_context;
+	} else if (proto == YAMUX_CONTEXT) {
+		ctx = (struct YamuxContext*)stream_context;
+	}
+
+	if (channel != NULL && channel->channel != NULL) {
+		// we have an established channel. Use it.
+		return yamux_stream_write(channel->channel, message->data_size, message->data);
+	} else if (ctx != NULL) {
+		// We are still negotiating...
+		return ctx->stream->parent_stream->write(ctx->stream->parent_stream->stream_context, message);
+	}
 	return 0;
 }
 
@@ -227,14 +244,19 @@ int libp2p_yamux_read_raw(void* stream_context, uint8_t* buffer, int buffer_size
 struct YamuxContext* libp2p_yamux_context_new() {
 	struct YamuxContext* ctx = (struct YamuxContext*) malloc(sizeof(struct YamuxContext));
 	if (ctx != NULL) {
+		ctx->type = YAMUX_CONTEXT;
 		ctx->stream = NULL;
 		ctx->channels = libp2p_utils_vector_new(1);
 	}
 	return ctx;
 }
 
-void libp2p_yamux_stream_free(struct Stream* yamux_stream) {
+void libp2p_yamux_context_free(struct YamuxContext* ctx) {
-	//TODO: Implement
+	if (ctx == NULL)
+		return;
+	libp2p_utils_vector_free(ctx->channels);
+	free(ctx);
+	return;
 }
 
 int libp2p_yamux_negotiate(struct YamuxContext* ctx) {
@@ -302,7 +324,7 @@ int libp2p_yamux_negotiate(struct YamuxContext* ctx) {
  * @returns a Stream initialized and ready for yamux
  */
 struct Stream* libp2p_yamux_stream_new(struct Stream* parent_stream) {
-	struct Stream* out = (struct Stream*)malloc(sizeof(struct Stream));
+	struct Stream* out = libp2p_stream_new();
 	if (out != NULL) {
 		out->parent_stream = parent_stream;
 		out->close = libp2p_yamux_close;
@@ -328,6 +350,18 @@ struct Stream* libp2p_yamux_stream_new(struct Stream* parent_stream) {
 	return out;
 }
 
+/**
+ * Frees resources held by the stream
+ * @param yamux_stream the stream
+ */
+void libp2p_yamux_stream_free(struct Stream* yamux_stream) {
+	if (yamux_stream == NULL)
+		return;
+	struct YamuxContext* ctx = (struct YamuxContext*)yamux_stream->stream_context;
+	libp2p_yamux_context_free(ctx);
+	libp2p_stream_free(yamux_stream);
+}
+
 /****
  * Add a stream "channel" to the yamux handler
  * @param ctx the context
@@ -335,8 +369,46 @@ struct Stream* libp2p_yamux_stream_new(struct Stream* parent_stream) {
  * @returns true(1) on success, false(0) otherwise
  */
 int libp2p_yamux_stream_add(struct YamuxContext* ctx, struct Stream* stream) {
-	int itemNo = libp2p_utils_vector_add(ctx->channels, stream);
+	if (stream == NULL)
-	stream->channel = itemNo;
+		return 0;
-	return 1;
+	// the stream's parent should have a YamuxChannelContext
+	char proto = ((uint8_t*)stream->parent_stream->stream_context)[0];
+	if (proto == YAMUX_CHANNEL_CONTEXT) {
+		// the negotiation was successful. Add it to the list of channels that we have
+		int itemNo = libp2p_utils_vector_add(ctx->channels, stream);
+		struct YamuxChannelContext* incoming = (struct YamuxChannelContext*)stream->parent_stream->stream_context;
+		if (incoming->channel == NULL) {
+			// this is wrong. There should have been a yamux_stream there
+			return 0;
+		}
+		incoming->channel->id = itemNo;
+		return 1;
+	}
+	return 0;
 }
 
+/**
+ * Create a stream that has a "YamuxChannelContext" related to this yamux protocol
+ * @param parent_stream the parent yamux stream
+ * @returns a new Stream that is a YamuxChannelContext
+ */
+struct Stream* libp2p_yamux_channel_new(struct Stream* parent_stream) {
+	struct Stream* out = libp2p_stream_new();
+	if (out != NULL) {
+		out->address = parent_stream->address;
+		out->close = parent_stream->close;
+		out->parent_stream = parent_stream;
+		out->peek = parent_stream->peek;
+		out->read = parent_stream->read;
+		out->read_raw = parent_stream->read_raw;
+		out->socket_mutex = parent_stream->socket_mutex;
+		struct YamuxChannelContext* ctx = (struct YamuxChannelContext*)malloc(sizeof(struct YamuxChannelContext));
+		ctx->type = YAMUX_CHANNEL_CONTEXT;
+		ctx->yamux_context = parent_stream->stream_context;
+		out->stream_context = ctx;
+		out->write = parent_stream->write;
+	}
+	return out;
+}
+
+