Create afb-stub-ws by spliting afb-api-ws

The file afb-stub-ws only carries the protocol
of the internal remote calling conventions.

It as the following benefits:
 - it easies transition to symetric connection (not planned)
 - it allows to have server stub on client socket and
   conversely, client stub on server socket (planned for
   debugging).

Change-Id: I57dc8e78d7bd63427421a180abcb844f8313d37b
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

4 files changed, 1259 insertions, 1184 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3b1f1455..fe497fc9 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -77,8 +77,9 @@ ADD_LIBRARY(afb-lib STATIC
 	afb-msg-json.c
 	afb-perm.c
 	afb-session.c
-	afb-svc.c
+	afb-stub-ws.c
 	afb-subcall.c
+	afb-svc.c
 	afb-websock.c
 	afb-ws-client.c
 	afb-ws-json1.c
diff --git a/src/afb-api-ws.c b/src/afb-api-ws.c
index ba9a18a9..dba8d05b 100644
--- a/src/afb-api-ws.c
+++ b/src/afb-api-ws.c
@@ -29,206 +29,25 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
-#include <pthread.h>
 
-#include <json-c/json.h>
 #include <systemd/sd-event.h>
-
-#include <afb/afb-req-itf.h>
-
-#include "afb-common.h"
-
-#include "afb-session.h"
-#include "afb-cred.h"
-#include "afb-ws.h"
-#include "afb-msg-json.h"
 #include "afb-api.h"
 #include "afb-apiset.h"
-#include "afb-api-so.h"
-#include "afb-context.h"
-#include "afb-evt.h"
-#include "afb-xreq.h"
+#include "afb-common.h"
+#include "afb-stub-ws.h"
 #include "verbose.h"
 #include "sd-fds.h"
 
-struct api_ws_memo;
-struct api_ws_event;
-struct api_ws_client;
-
-#define CHAR_FOR_CALL             'C'
-#define CHAR_FOR_ANSWER_SUCCESS   'T'
-#define CHAR_FOR_ANSWER_FAIL      'F'
-#define CHAR_FOR_EVT_BROADCAST    '*'
-#define CHAR_FOR_EVT_ADD          '+'
-#define CHAR_FOR_EVT_DEL          '-'
-#define CHAR_FOR_EVT_PUSH         '!'
-#define CHAR_FOR_EVT_SUBSCRIBE    'S'
-#define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
-#define CHAR_FOR_SUBCALL_CALL     'B'
-#define CHAR_FOR_SUBCALL_REPLY    'R'
-
-/*
- */
 struct api_ws
 {
 	char *path;		/* path of the object for the API */
 	char *api;		/* api name of the interface */
 	int fd;			/* file descriptor */
-	pthread_mutex_t mutex;	/**< resource control */
-	union {
-		struct {
-			struct afb_ws *ws;
-			struct api_ws_event *events;
-			struct api_ws_memo *memos;
-		} client;
-		struct {
-			sd_event_source *listensrc; /**< systemd source for server socket */
-			struct afb_apiset *apiset;
-		} server;
-	};
-};
-
-#define RETOK   1
-#define RETERR  2
-#define RETRAW  3
-
-/******************* common usefull tools **********************************/
-
-/**
- * translate a pointer to some integer
- * @param ptr the pointer to translate
- * @return an integer
- */
-static inline uint32_t ptr2id(void *ptr)
-{
-	return (uint32_t)(((intptr_t)ptr) >> 6);
-}
-
-/******************* websocket interface for client part **********************************/
-
-static void api_ws_client_on_binary(void *closure, char *data, size_t size);
-
-static const struct afb_ws_itf api_ws_client_ws_itf =
-{
-	.on_close = NULL,
-	.on_text = NULL,
-	.on_binary = api_ws_client_on_binary,
-	.on_error = NULL,
-	.on_hangup = NULL
-};
-
-/******************* event structures for server part **********************************/
-
-static void api_ws_server_event_add(void *closure, const char *event, int eventid);
-static void api_ws_server_event_remove(void *closure, const char *event, int eventid);
-static void api_ws_server_event_push(void *closure, const char *event, int eventid, struct json_object *object);
-static void api_ws_server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object);
-
-/* the interface for events pushing */
-static const struct afb_evt_itf api_ws_server_evt_itf = {
-	.broadcast = api_ws_server_event_broadcast,
-	.push = api_ws_server_event_push,
-	.add = api_ws_server_event_add,
-	.remove = api_ws_server_event_remove
-};
-
-/******************* handling subcalls *****************************/
-
-/**
- * Structure on server side for recording pending
- * subcalls.
- */
-struct api_ws_subcall
-{
-	struct api_ws_subcall *next;	/**< next subcall for the client */
-	uint32_t subcallid;		/**< the subcallid */
-	void (*callback)(void*, int, struct json_object*); /**< callback on completion */
-	void *closure;			/**< closure of the callback */
-};
-
-/**
- * Structure for sending back replies on client side
- */
-struct api_ws_reply
-{
-	struct api_ws *apiws;	/**< api descriptor */
-	uint32_t subcallid;	/**< subcallid for the reply */
-};
-
-/******************* client description part for server *****************************/
-
-struct api_ws_client
-{
-	/* the server ws-api */
-	const char *api;
-
-	/* count of references */
-	int refcount;
-
-	/* file descriptor */
-	int fd;
-
-	/* resource control */
-	pthread_mutex_t mutex;
-
-	/* listener for events */
-	struct afb_evt_listener *listener;
-
-	/* websocket */
-	struct afb_ws *ws;
-
-	/* credentials */
-	struct afb_cred *cred;
-
-	/* pending subcalls */
-	struct api_ws_subcall *subcalls;
-
-	/* apiset */
+	sd_event_source *listensrc; /**< systemd source for server socket */
 	struct afb_apiset *apiset;
 };
 
-/******************* websocket interface for client part **********************************/
-
-static void api_ws_server_on_binary(void *closure, char *data, size_t size);
-static void api_ws_server_on_hangup(void *closure);
-
-static const struct afb_ws_itf api_ws_server_ws_itf =
-{
-	.on_close = NULL,
-	.on_text = NULL,
-	.on_binary = api_ws_server_on_binary,
-	.on_error = NULL,
-	.on_hangup = api_ws_server_on_hangup
-};
-
-/******************* ws request part for server *****************/
-
-/*
- * structure for a ws request
- */
-struct api_ws_server_req {
-	struct afb_xreq xreq;		/* the xreq */
-	struct api_ws_client *client;	/* the client of the request */
-	uint32_t msgid;			/* the incoming request msgid */
-};
-
-static void api_ws_server_req_success_cb(struct afb_xreq *xreq, struct json_object *obj, const char *info);
-static void api_ws_server_req_fail_cb(struct afb_xreq *xreq, const char *status, const char *info);
-static void api_ws_server_req_destroy_cb(struct afb_xreq *xreq);
-static int api_ws_server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event event);
-static int api_ws_server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event event);
-static void api_ws_server_req_subcall_cb(struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure);
-
-const struct afb_xreq_query_itf afb_api_ws_xreq_itf = {
-	.success = api_ws_server_req_success_cb,
-	.fail = api_ws_server_req_fail_cb,
-	.unref = api_ws_server_req_destroy_cb,
-	.subcall = api_ws_server_req_subcall_cb,
-	.subscribe = api_ws_server_req_subscribe_cb,
-	.unsubscribe = api_ws_server_req_unsubscribe_cb
-};
-
-/******************* common part **********************************/
+/******************************************************************************/
 
 /*
  * create a structure api_ws not connected to the 'path'.
@@ -258,7 +77,6 @@ static struct api_ws *api_ws_make(const char *path)
 		errno = EINVAL;
 		goto error2;
 	}
-	pthread_mutex_init(&api->mutex, NULL);
 
 	api->fd = -1;
 	return api;
@@ -384,1053 +202,108 @@ static int api_ws_socket(const char *path, int server)
 	return fd;
 }
 
-/******************* serialisation part **********************************/
-
-struct readbuf
-{
-	char *head, *end;
-};
-
-#define WRITEBUF_COUNT_MAX  32
-struct writebuf
-{
-	struct iovec iovec[WRITEBUF_COUNT_MAX];
-	uint32_t uints[WRITEBUF_COUNT_MAX];
-	int count;
-};
-
-static char *api_ws_read_get(struct readbuf *rb, uint32_t length)
-{
-	char *before = rb->head;
-	char *after = before + length;
-	if (after > rb->end)
-		return 0;
-	rb->head = after;
-	return before;
-}
-
-static int api_ws_read_char(struct readbuf *rb, char *value)
-{
-	if (rb->head >= rb->end)
-		return 0;
-	*value = *rb->head++;
-	return 1;
-}
-
-static int api_ws_read_uint32(struct readbuf *rb, uint32_t *value)
-{
-	char *after = rb->head + sizeof *value;
-	if (after > rb->end)
-		return 0;
-	memcpy(value, rb->head, sizeof *value);
-	rb->head = after;
-	*value = le32toh(*value);
-	return 1;
-}
-
-static int api_ws_read_string(struct readbuf *rb, const char **value, size_t *length)
-{
-	uint32_t len;
-	if (!api_ws_read_uint32(rb, &len) || !len)
-		return 0;
-	if (length)
-		*length = (size_t)(len - 1);
-	return (*value = api_ws_read_get(rb, len)) != NULL &&  rb->head[-1] == 0;
-}
-
-static int api_ws_read_object(struct readbuf *rb, struct json_object **object)
-{
-	const char *string;
-	struct json_object *o;
-	int rc = api_ws_read_string(rb, &string, NULL);
-	if (rc) {
-		o = json_tokener_parse(string);
-		if (o == NULL && strcmp(string, "null"))
-			o = json_object_new_string(string);
-		*object = o;
-	}
-	return rc;
-}
-
-static int api_ws_write_put(struct writebuf *wb, const void *value, size_t length)
-{
-	int i = wb->count;
-	if (i == WRITEBUF_COUNT_MAX)
-		return 0;
-	wb->iovec[i].iov_base = (void*)value;
-	wb->iovec[i].iov_len = length;
-	wb->count = i + 1;
-	return 1;
-}
-
-static int api_ws_write_char(struct writebuf *wb, char value)
-{
-	int i = wb->count;
-	if (i == WRITEBUF_COUNT_MAX)
-		return 0;
-	*(char*)&wb->uints[i] = value;
-	wb->iovec[i].iov_base = &wb->uints[i];
-	wb->iovec[i].iov_len = 1;
-	wb->count = i + 1;
-	return 1;
-}
-
-static int api_ws_write_uint32(struct writebuf *wb, uint32_t value)
-{
-	int i = wb->count;
-	if (i == WRITEBUF_COUNT_MAX)
-		return 0;
-	wb->uints[i] = htole32(value);
-	wb->iovec[i].iov_base = &wb->uints[i];
-	wb->iovec[i].iov_len = sizeof wb->uints[i];
-	wb->count = i + 1;
-	return 1;
-}
-
-static int api_ws_write_string_length(struct writebuf *wb, const char *value, size_t length)
-{
-	uint32_t len = (uint32_t)++length;
-	return (size_t)len == length && len && api_ws_write_uint32(wb, len) && api_ws_write_put(wb, value, length);
-}
-
-static int api_ws_write_string(struct writebuf *wb, const char *value)
-{
-	return api_ws_write_string_length(wb, value, strlen(value));
-}
-
-static int api_ws_write_object(struct writebuf *wb, struct json_object *object)
-{
-	const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
-	return string != NULL && api_ws_write_string(wb, string);
-}
-
-/******************* client part **********************************/
-
-/*
- * structure for recording query data
- */
-struct api_ws_memo {
-	struct api_ws_memo *next;	/* the next memo */
-	struct api_ws *api;		/* the ws api */
-	struct afb_xreq *xreq;		/* the request handle */
-	uint32_t msgid;			/* the message identifier */
-};
-
-struct api_ws_event
-{
-	struct api_ws_event *next;
-	struct afb_event event;
-	int eventid;
-	int refcount;
-};
-
-/* search a memorized request */
-static struct api_ws_memo *api_ws_client_memo_search(struct api_ws *api, uint32_t msgid)
-{
-	struct api_ws_memo *memo;
-
-	memo = api->client.memos;
-	while (memo != NULL && memo->msgid != msgid)
-		memo = memo->next;
-
-	return memo;
-}
-
-/* search the event */
-static struct api_ws_event *api_ws_client_event_search(struct api_ws *api, uint32_t eventid, const char *name)
-{
-	struct api_ws_event *ev;
-
-	ev = api->client.events;
-	while (ev != NULL && (ev->eventid != eventid || 0 != strcmp(afb_evt_event_name(ev->event), name)))
-		ev = ev->next;
-
-	return ev;
-}
-
-
-/* allocates and init the memorizing data */
-static struct api_ws_memo *api_ws_client_memo_make(struct api_ws *api, struct afb_xreq *xreq)
-{
-	struct api_ws_memo *memo;
-
-	memo = malloc(sizeof *memo);
-	if (memo != NULL) {
-		afb_xreq_addref(xreq);
-		memo->xreq = xreq;
-		memo->msgid = ptr2id(memo);
-		while(api_ws_client_memo_search(api, memo->msgid) != NULL)
-			memo->msgid++;
-		memo->api = api;
-		memo->next = api->client.memos;
-		api->client.memos = memo;
-	}
-	return memo;
-}
-
-/* free and release the memorizing data */
-static void api_ws_client_memo_destroy(struct api_ws_memo *memo)
-{
-	struct api_ws_memo **prv;
-
-	prv = &memo->api->client.memos;
-	while (*prv != NULL) {
-		if (*prv == memo) {
-			*prv = memo->next;
-			break;
-		}
-		prv = &(*prv)->next;
-	}
-
-	afb_xreq_unref(memo->xreq);
-	free(memo);
-}
-
-/* get event data from the message */
-static int api_ws_client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
-{
-	return api_ws_read_uint32(rb, eventid) && api_ws_read_string(rb, name, NULL);
-}
-
-/* get event from the message */
-static int api_ws_client_msg_event_get(struct api_ws *api, struct readbuf *rb, struct api_ws_event **ev)
-{
-	const char *name;
-	uint32_t eventid;
-
-	/* get event data from the message */
-	if (!api_ws_client_msg_event_read(rb, &eventid, &name)) {
-		ERROR("Invalid message");
-		return 0;
-	}
-
-	/* check conflicts */
-	*ev = api_ws_client_event_search(api, eventid, name);
-	if (*ev == NULL) {
-		ERROR("event %s not found", name);
-		return 0;
-	}
-
-	return 1;
-}
-
-/* get event from the message */
-static int api_ws_client_msg_memo_get(struct api_ws *api, struct readbuf *rb, struct api_ws_memo **memo)
-{
-	uint32_t msgid;
-
-	/* get event data from the message */
-	if (!api_ws_read_uint32(rb, &msgid)) {
-		ERROR("Invalid message");
-		return 0;
-	}
-
-	/* get the memo */
-	*memo = api_ws_client_memo_search(api, msgid);
-	if (*memo == NULL) {
-		ERROR("message not found");
-		return 0;
-	}
-
-	return 1;
-}
-
-/* read a subscrition message */
-static int api_ws_client_msg_subscription_get(struct api_ws *api, struct readbuf *rb, struct api_ws_memo **memo, struct api_ws_event **ev)
-{
-	return api_ws_client_msg_memo_get(api, rb, memo) && api_ws_client_msg_event_get(api, rb, ev);
-}
-
-/* adds an event */
-static void api_ws_client_event_create(struct api_ws *api, struct readbuf *rb)
-{
-	size_t offset;
-	const char *name;
-	uint32_t eventid;
-	struct api_ws_event *ev;
-
-	/* get event data from the message */
-	offset = api_ws_client_msg_event_read(rb, &eventid, &name);
-	if (offset == 0) {
-		ERROR("Invalid message");
-		return;
-	}
-
-	/* check conflicts */
-	ev = api_ws_client_event_search(api, eventid, name);
-	if (ev != NULL) {
-		ev->refcount++;
-		return;
-	}
-
-	/* no conflict, try to add it */
-	ev = malloc(sizeof *ev);
-	if (ev != NULL) {
-		ev->event = afb_evt_create_event(name);
-		if (ev->event.closure == NULL)
-			free(ev);
-		else {
-			ev->refcount = 1;
-			ev->eventid = eventid;
-			ev->next = api->client.events;
-			api->client.events = ev;
-			return;
-		}
-	}
-	ERROR("can't create event %s, out of memory", name);
-}
-
-/* removes an event */
-static void api_ws_client_event_drop(struct api_ws *api, struct readbuf *rb)
-{
-	struct api_ws_event *ev, **prv;
-
-	/* retrieves the event */
-	if (!api_ws_client_msg_event_get(api, rb, &ev))
-		return;
-
-	/* decrease the reference count */
-	if (--ev->refcount)
-		return;
-
-	/* unlinks the event */
-	prv = &api->client.events;
-	while (*prv != ev)
-		prv = &(*prv)->next;
-	*prv = ev->next;
-
-	/* destroys the event */
-	afb_event_drop(ev->event);
-	free(ev);
-}
-
-/* subscribes an event */
-static void api_ws_client_event_subscribe(struct api_ws *api, struct readbuf *rb)
-{
-	struct api_ws_event *ev;
-	struct api_ws_memo *memo;
-
-	if (api_ws_client_msg_subscription_get(api, rb, &memo, &ev)) {
-		/* subscribe the request from the event */
-		if (afb_xreq_subscribe(memo->xreq, ev->event) < 0)
-			ERROR("can't subscribe: %m");
-	}
-}
-
-/* unsubscribes an event */
-static void api_ws_client_event_unsubscribe(struct api_ws *api, struct readbuf *rb)
-{
-	struct api_ws_event *ev;
-	struct api_ws_memo *memo;
-
-	if (api_ws_client_msg_subscription_get(api, rb, &memo, &ev)) {
-		/* unsubscribe the request from the event */
-		if (afb_xreq_unsubscribe(memo->xreq, ev->event) < 0)
-			ERROR("can't unsubscribe: %m");
-	}
-}
-
-/* receives broadcasted events */
-static void api_ws_client_event_broadcast(struct api_ws *api, struct readbuf *rb)
-{
-	struct json_object *object;
-	const char *event;
-
-	if (api_ws_read_string(rb, &event, NULL) && api_ws_read_object(rb, &object))
-		afb_evt_broadcast(event, object);
-	else
-		ERROR("unreadable broadcasted event");
-}
-
-/* pushs an event */
-static void api_ws_client_event_push(struct api_ws *api, struct readbuf *rb)
-{
-	struct api_ws_event *ev;
-	struct json_object *object;
-
-	if (api_ws_client_msg_event_get(api, rb, &ev) && api_ws_read_object(rb, &object))
-		afb_event_push(ev->event, object);
-	else
-		ERROR("unreadable push event");
-}
-
-static void api_ws_client_reply_success(struct api_ws *api, struct readbuf *rb)
-{
-	struct api_ws_memo *memo;
-	struct json_object *object;
-	const char *info;
-	uint32_t flags;
-
-	/* retrieve the message data */
-	if (!api_ws_client_msg_memo_get(api, rb, &memo))
-		return;
-
-	if (api_ws_read_uint32(rb, &flags)
-	 && api_ws_read_string(rb, &info, NULL)
-	 && api_ws_read_object(rb, &object)) {
-		memo->xreq->context.flags = (unsigned)flags;
-		afb_xreq_success(memo->xreq, object, *info ? info : NULL);
-	} else {
-		/* failing to have the answer */
-		afb_xreq_fail(memo->xreq, "error", "ws error");
-	}
-	api_ws_client_memo_destroy(memo);
-}
-
-static void api_ws_client_reply_fail(struct api_ws *api, struct readbuf *rb)
-{
-	struct api_ws_memo *memo;
-	const char *info, *status;
-	uint32_t flags;
-
-	/* retrieve the message data */
-	if (!api_ws_client_msg_memo_get(api, rb, &memo))
-		return;
-
-	if (api_ws_read_uint32(rb, &flags)
-	 && api_ws_read_string(rb, &status, NULL)
-	 && api_ws_read_string(rb, &info, NULL)) {
-		memo->xreq->context.flags = (unsigned)flags;
-		afb_xreq_fail(memo->xreq, status, *info ? info : NULL);
-	} else {
-		/* failing to have the answer */
-		afb_xreq_fail(memo->xreq, "error", "ws error");
-	}
-	api_ws_client_memo_destroy(memo);
-}
-
-/* send a subcall reply */
-static void api_ws_client_send_subcall_reply(struct api_ws_reply *reply, int iserror, json_object *object)
-{
-	int rc;
-	struct writebuf wb = { .count = 0 };
-	char ie = (char)!!iserror;
-
-	if (!api_ws_write_char(&wb, CHAR_FOR_SUBCALL_REPLY)
-	 || !api_ws_write_uint32(&wb, reply->subcallid)
-	 || !api_ws_write_char(&wb, ie)
-	 || !api_ws_write_object(&wb, object)) {
-		/* write error ? */
-		return;
-	}
-
-	rc = afb_ws_binary_v(reply->apiws->client.ws, wb.iovec, wb.count);
-	if (rc >= 0)
-		return;
-	ERROR("error while sending subcall reply");
-}
-
-/* callback for subcall reply */
-static void api_ws_client_subcall_reply_cb(void *closure, int iserror, json_object *object)
-{
-	api_ws_client_send_subcall_reply(closure, iserror, object);
-	free(closure);
-}
-
-/* received a subcall request */
-static void api_ws_client_subcall(struct api_ws *apiws, struct readbuf *rb)
-{
-	struct api_ws_reply *reply;
-	struct api_ws_memo *memo;
-	const char *api, *verb;
-	uint32_t subcallid;
-	struct json_object *object;
-
-	reply = malloc(sizeof *reply);
-	if (!reply)
-		return;
-
-	/* retrieve the message data */
-	if (!api_ws_client_msg_memo_get(apiws, rb, &memo))
-		return;
-
-	if (api_ws_read_uint32(rb, &subcallid)
-	 && api_ws_read_string(rb, &api, NULL)
-	 && api_ws_read_string(rb, &verb, NULL)
-	 && api_ws_read_object(rb, &object)) {
-		reply->apiws = apiws;
-		reply->subcallid = subcallid;
-		afb_xreq_subcall(memo->xreq, api, verb, object, api_ws_client_subcall_reply_cb, reply);
-	}
-}
-
-/* callback when receiving binary data */
-static void api_ws_client_on_binary(void *closure, char *data, size_t size)
-{
-	if (size > 0) {
-		struct api_ws *apiws = closure;
-		struct readbuf rb = { .head = data, .end = data + size };
-
-		pthread_mutex_lock(&apiws->mutex);
-		switch (*rb.head++) {
-		case CHAR_FOR_ANSWER_SUCCESS: /* success */
-			api_ws_client_reply_success(apiws, &rb);
-			break;
-		case CHAR_FOR_ANSWER_FAIL: /* fail */
-			api_ws_client_reply_fail(apiws, &rb);
-			break;
-		case CHAR_FOR_EVT_BROADCAST: /* broadcast */
-			api_ws_client_event_broadcast(apiws, &rb);
-			break;
-		case CHAR_FOR_EVT_ADD: /* creates the event */
-			api_ws_client_event_create(apiws, &rb);
-			break;
-		case CHAR_FOR_EVT_DEL: /* drops the event */
-			api_ws_client_event_drop(apiws, &rb);
-			break;
-		case CHAR_FOR_EVT_PUSH: /* pushs the event */
-			api_ws_client_event_push(apiws, &rb);
-			break;
-		case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
-			api_ws_client_event_subscribe(apiws, &rb);
-			break;
-		case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
-			api_ws_client_event_unsubscribe(apiws, &rb);
-			break;
-		case CHAR_FOR_SUBCALL_CALL: /* subcall */
-			api_ws_client_subcall(apiws, &rb);
-			break;
-		default: /* unexpected message */
-			/* TODO: close the connection */
-			break;
-		}
-		pthread_mutex_unlock(&apiws->mutex);
-	}
-	free(data);
-}
-
-/* on call, propagate it to the ws service */
-static void api_ws_client_call_cb(void * closure, struct afb_xreq *xreq)
-{
-	int rc;
-	struct api_ws_memo *memo;
-	struct writebuf wb = { .count = 0 };
-	const char *raw;
-	size_t szraw;
-	struct api_ws *apiws = closure;
-
-	pthread_mutex_lock(&apiws->mutex);
-
-	/* create the recording data */
-	memo = api_ws_client_memo_make(apiws, xreq);
-	if (memo == NULL) {
-		afb_xreq_fail_f(xreq, "error", "out of memory");
-		goto end;
-	}
-
-	/* creates the call message */
-	raw = afb_xreq_raw(xreq, &szraw);
-	if (raw == NULL)
-		goto internal_error;
-	if (!api_ws_write_char(&wb, CHAR_FOR_CALL)
-	 || !api_ws_write_uint32(&wb, memo->msgid)
-	 || !api_ws_write_uint32(&wb, (uint32_t)xreq->context.flags)
-	 || !api_ws_write_string(&wb, xreq->verb)
-	 || !api_ws_write_string(&wb, afb_session_uuid(xreq->context.session))
-	 || !api_ws_write_string_length(&wb, raw, szraw))
-		goto overflow;
-
-	/* send */
-	rc = afb_ws_binary_v(apiws->client.ws, wb.iovec, wb.count);
-	if (rc >= 0)
-		goto end;
+/**********************************************************************************/
 
-	afb_xreq_fail(xreq, "error", "websocket sending error");
-	goto clean_memo;
-
-internal_error:
-	afb_xreq_fail(xreq, "error", "internal: raw is NULL!");
-	goto clean_memo;
-
-overflow:
-	afb_xreq_fail(xreq, "error", "overflow: size doesn't match 32 bits!");
-
-clean_memo:
-	api_ws_client_memo_destroy(memo);
-end:
-	pthread_mutex_unlock(&apiws->mutex);
-}
-
-/*  */
-static void api_ws_client_disconnect(struct api_ws *api)
-{
-	if (api->fd >= 0) {
-		afb_ws_destroy(api->client.ws);
-		api->client.ws = NULL;
-		close(api->fd);
-		api->fd = -1;
-	}
-}
-
-/*  */
-static int api_ws_client_connect(struct api_ws *api)
-{
-	struct afb_ws *ws;
-	int fd;
-
-	fd = api_ws_socket(api->path, 0);
-	if (fd >= 0) {
-		ws = afb_ws_create(afb_common_get_event_loop(), fd, &api_ws_client_ws_itf, api);
-		if (ws != NULL) {
-			api->client.ws = ws;
-			api->fd = fd;
-			return 0;
-		}
-		close(fd);
-	}
-	return -1;
-}
-
-static struct afb_api_itf ws_api_itf = {
-	.call = api_ws_client_call_cb
-};
-
-/* adds a afb-ws-service client api */
 int afb_api_ws_add_client(const char *path, struct afb_apiset *apiset)
 {
-	int rc;
-	struct api_ws *api;
-	struct afb_api afb_api;
+	struct api_ws *apiws;
+	struct afb_stub_ws *stubws;
 
 	/* create the ws client api */
-	api = api_ws_make(path);
-	if (api == NULL)
+	apiws = api_ws_make(path);
+	if (apiws == NULL)
 		goto error;
 
 	/* connect to the service */
-	rc = api_ws_client_connect(api);
-	if (rc < 0) {
-		ERROR("can't connect to ws service %s", api->path);
+	apiws->fd = api_ws_socket(apiws->path, 0);
+	if (apiws->fd < 0) {
+		ERROR("can't connect to ws service %s", apiws->path);
 		goto error2;
 	}
 
-	/* record it as an API */
-	afb_api.closure = api;
-	afb_api.itf = &ws_api_itf;
-	if (afb_apiset_add(apiset, api->api, afb_api) < 0)
+	stubws = afb_stub_ws_create_client(apiws->fd, apiws->api, apiset);
+	if (!stubws) {
+		ERROR("can't setup client ws service to %s", apiws->path);
 		goto error3;
-
+	}
+	free(apiws);
 	return 0;
 
 error3:
-	api_ws_client_disconnect(api);
+	close(apiws->fd);
 error2:
-	free(api);
+	free(apiws);
 error:
 	return -1;
 }
 
-/******************* client description part for server *****************************/
-
-static void api_ws_server_client_unref(struct api_ws_client *client)
-{
-	struct api_ws_subcall *sc, *nsc;
-
-	if (!__atomic_sub_fetch(&client->refcount, 1, __ATOMIC_RELAXED)) {
-		afb_evt_listener_unref(client->listener);
-		afb_ws_destroy(client->ws);
-		nsc = client->subcalls;
-		while (nsc) {
-			sc= nsc;
-			nsc = sc->next;
-			sc->callback(sc->closure, 1, NULL);
-			free(sc);
-		}
-		afb_cred_unref(client->cred);
-		afb_apiset_unref(client->apiset);
-		free(client);
-	}
-}
-
-static void api_ws_server_client_addref(struct api_ws_client *client)
-{
-	__atomic_add_fetch(&client->refcount, 1, __ATOMIC_RELAXED);
-}
-
-/* on call, propagate it to the ws service */
-static void api_ws_server_on_call(struct api_ws_client *client, struct readbuf *rb)
-{
-	struct api_ws_server_req *wreq;
-	char *cverb;
-	const char *uuid, *verb;
-	uint32_t flags, msgid;
-	size_t lenverb;
-	struct json_object *object;
-
-	api_ws_server_client_addref(client);
-
-	/* reads the call message data */
-	if (!api_ws_read_uint32(rb, &msgid)
-	 || !api_ws_read_uint32(rb, &flags)
-	 || !api_ws_read_string(rb, &verb, &lenverb)
-	 || !api_ws_read_string(rb, &uuid, NULL)
-	 || !api_ws_read_object(rb, &object))
-		goto overflow;
-
-	/* create the request */
-	wreq = malloc(++lenverb + sizeof *wreq);
-	if (wreq == NULL)
-		goto out_of_memory;
-
-	afb_xreq_init(&wreq->xreq, &afb_api_ws_xreq_itf);
-	wreq->client = client;
-	wreq->msgid = msgid;
-	cverb = (char*)&wreq[1];
-	memcpy(cverb, verb, lenverb);
-
-	/* init the context */
-	if (afb_context_connect(&wreq->xreq.context, uuid, NULL) < 0)
-		goto unconnected;
-	wreq->xreq.context.flags = flags;
-
-	/* makes the call */
-	wreq->xreq.cred = afb_cred_addref(client->cred);
-	wreq->xreq.api = client->api;
-	wreq->xreq.verb = cverb;
-	wreq->xreq.json = object;
-	afb_xreq_process(&wreq->xreq, client->apiset);
-	return;
-
-unconnected:
-	free(wreq);
-out_of_memory:
-	json_object_put(object);
-overflow:
-	api_ws_server_client_unref(client);
-}
-
-/* on subcall reply */
-static void api_ws_server_on_subcall_reply(struct api_ws_client *client, struct readbuf *rb)
-{
-	char iserror;
-	uint32_t subcallid;
-	struct json_object *object;
-	struct api_ws_subcall *sc, **psc;
-
-	/* reads the call message data */
-	if (!api_ws_read_uint32(rb, &subcallid)
-	 || !api_ws_read_char(rb, &iserror)
-	 || !api_ws_read_object(rb, &object)) {
-		/* TODO bad protocol */
-		return;
-	}
-
-	/* search the subcall and unlink it */
-	pthread_mutex_lock(&client->mutex);
-	psc = &client->subcalls;
-	while ((sc = *psc) && sc->subcallid != subcallid)
-		psc = &sc->next;
-	if (!sc) {
-		pthread_mutex_unlock(&client->mutex);
-		/* TODO subcall not found */
-	} else {
-		*psc = sc->next;
-		pthread_mutex_unlock(&client->mutex);
-		sc->callback(sc->closure, (int)iserror, object);
-		free(sc);
-	}
-	json_object_put(object);
-}
-
-/* callback when receiving binary data */
-static void api_ws_server_on_binary(void *closure, char *data, size_t size)
-{
-	if (size > 0) {
-		struct readbuf rb = { .head = data, .end = data + size };
-		switch (*rb.head++) {
-		case CHAR_FOR_CALL:
-			api_ws_server_on_call(closure, &rb);
-			break;
-		case CHAR_FOR_SUBCALL_REPLY:
-			api_ws_server_on_subcall_reply(closure, &rb);
-			break;
-		default: /* unexpected message */
-			/* TODO: close the connection */
-			break;
-		}
-	}
-	free(data);
-}
-
-/* callback when receiving a hangup */
-static void api_ws_server_on_hangup(void *closure)
+static int api_ws_server_accept_client(struct api_ws *apiws, int fd)
 {
-	struct api_ws_client *client = closure;
-
-	/* close the socket */
-	if (client->fd >= 0) {
-		close(client->fd);
-		client->fd = -1;
-	}
-
-	/* release the client */
-	api_ws_server_client_unref(client);
+	return -!afb_stub_ws_create_server(fd, apiws->api, apiws->apiset);
 }
 
-static void api_ws_server_accept(struct api_ws *api)
+static void api_ws_server_accept(struct api_ws *apiws)
 {
-	struct api_ws_client *client;
+	int rc, fd;
 	struct sockaddr addr;
 	socklen_t lenaddr;
 
-	client = calloc(1, sizeof *client);
-	if (client != NULL) {
-		client->listener = afb_evt_listener_create(&api_ws_server_evt_itf, client);
-		if (client->listener != NULL) {
-			lenaddr = (socklen_t)sizeof addr;
-			client->fd = accept(api->fd, &addr, &lenaddr);
-			if (client->fd >= 0) {
-				client->cred = afb_cred_create_for_socket(client->fd);
-				fcntl(client->fd, F_SETFD, FD_CLOEXEC);
-				fcntl(client->fd, F_SETFL, O_NONBLOCK);
-				client->ws = afb_ws_create(afb_common_get_event_loop(), client->fd, &api_ws_server_ws_itf, client);
-				if (client->ws != NULL) {
-					client->api = api->api;
-					client->apiset = afb_apiset_addref(api->server.apiset);
-					client->refcount = 1;
-					client->subcalls = NULL;
-					return;
-				}
-				afb_cred_unref(client->cred);
-				close(client->fd);
-			}
-			afb_evt_listener_unref(client->listener);
-		}
-		free(client);
-	}
-}
-
-/******************* server part: manage events **********************************/
-
-static void api_ws_server_event_send(struct api_ws_client *client, char order, const char *event, int eventid, const char *data)
-{
-	int rc;
-	struct writebuf wb = { .count = 0 };
-
-	if (api_ws_write_char(&wb, order)
-	 && api_ws_write_uint32(&wb, eventid)
-	 && api_ws_write_string(&wb, event)
-	 && (data == NULL || api_ws_write_string(&wb, data))) {
-		rc = afb_ws_binary_v(client->ws, wb.iovec, wb.count);
-		if (rc >= 0)
-			return;
-	}
-	ERROR("error while sending %c for event %s", order, event);
-}
-
-static void api_ws_server_event_add(void *closure, const char *event, int eventid)
-{
-	api_ws_server_event_send(closure, CHAR_FOR_EVT_ADD, event, eventid, NULL);
-}
-
-static void api_ws_server_event_remove(void *closure, const char *event, int eventid)
-{
-	api_ws_server_event_send(closure, CHAR_FOR_EVT_DEL, event, eventid, NULL);
-}
-
-static void api_ws_server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
-{
-	const char *data = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
-	api_ws_server_event_send(closure, CHAR_FOR_EVT_PUSH, event, eventid, data ? : "null");
-	json_object_put(object);
-}
-
-static void api_ws_server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
-{
-	int rc;
-	struct api_ws_client *client = closure;
-
-	struct writebuf wb = { .count = 0 };
-
-	if (api_ws_write_char(&wb, CHAR_FOR_EVT_BROADCAST) && api_ws_write_string(&wb, event) && api_ws_write_object(&wb, object)) {
-		rc = afb_ws_binary_v(client->ws, wb.iovec, wb.count);
-		if (rc < 0)
-			ERROR("error while broadcasting event %s", event);
-	} else
-		ERROR("error while broadcasting event %s", event);
-	json_object_put(object);
-}
-
-/******************* ws request part for server *****************/
-
-/* decrement the reference count of the request and free/release it on falling to null */
-static void api_ws_server_req_destroy_cb(struct afb_xreq *xreq)
-{
-	struct api_ws_server_req *wreq = CONTAINER_OF_XREQ(struct api_ws_server_req, xreq);
-
-	afb_context_disconnect(&wreq->xreq.context);
-	afb_cred_unref(wreq->xreq.cred);
-	json_object_put(wreq->xreq.json);
-	api_ws_server_client_unref(wreq->client);
-	free(wreq);
-}
-
-static void api_ws_server_req_success_cb(struct afb_xreq *xreq, struct json_object *obj, const char *info)
-{
-	int rc;
-	struct writebuf wb = { .count = 0 };
-	struct api_ws_server_req *wreq = CONTAINER_OF_XREQ(struct api_ws_server_req, xreq);
-
-	if (api_ws_write_char(&wb, CHAR_FOR_ANSWER_SUCCESS)
-	 && api_ws_write_uint32(&wb, wreq->msgid)
-	 && api_ws_write_uint32(&wb, (uint32_t)wreq->xreq.context.flags)
-	 && api_ws_write_string(&wb, info ? : "")
-	 && api_ws_write_object(&wb, obj)) {
-		rc = afb_ws_binary_v(wreq->client->ws, wb.iovec, wb.count);
-		if (rc >= 0)
-			goto success;
-	}
-	ERROR("error while sending success");
-success:
-	json_object_put(obj);
-}
-
-static void api_ws_server_req_fail_cb(struct afb_xreq *xreq, const char *status, const char *info)
-{
-	int rc;
-	struct writebuf wb = { .count = 0 };
-	struct api_ws_server_req *wreq = CONTAINER_OF_XREQ(struct api_ws_server_req, xreq);
-
-	if (api_ws_write_char(&wb, CHAR_FOR_ANSWER_FAIL)
-	 && api_ws_write_uint32(&wb, wreq->msgid)
-	 && api_ws_write_uint32(&wb, (uint32_t)wreq->xreq.context.flags)
-	 && api_ws_write_string(&wb, status)
-	 && api_ws_write_string(&wb, info ? : "")) {
-		rc = afb_ws_binary_v(wreq->client->ws, wb.iovec, wb.count);
+	lenaddr = (socklen_t)sizeof addr;
+	fd = accept(apiws->fd, &addr, &lenaddr);
+	if (fd >= 0) {
+		rc = api_ws_server_accept_client(apiws, fd);
 		if (rc >= 0)
 			return;
+		close(fd);
 	}
-	ERROR("error while sending fail");
-}
-
-static void api_ws_server_req_subcall_cb(struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
-{
-	int rc;
-	struct writebuf wb = { .count = 0 };
-	struct api_ws_subcall *sc, *osc;
-	struct api_ws_server_req *wreq = CONTAINER_OF_XREQ(struct api_ws_server_req, xreq);
-	struct api_ws_client *client = wreq->client;
-
-	sc = malloc(sizeof *sc);
-	if (!sc) {
-
-	} else {
-		sc->callback = callback;
-		sc->closure = cb_closure;
-
-		pthread_mutex_unlock(&client->mutex);
-		sc->subcallid = ptr2id(sc);
-		do {
-			sc->subcallid++;
-			osc = client->subcalls;
-			while(osc && osc->subcallid != sc->subcallid)
-				osc = osc->next;
-		} while (osc);
-		sc->next = client->subcalls;
-		client->subcalls = sc;
-		pthread_mutex_unlock(&client->mutex);
-
-		if (api_ws_write_char(&wb, CHAR_FOR_SUBCALL_CALL)
-		 && api_ws_write_uint32(&wb, wreq->msgid)
-		 && api_ws_write_uint32(&wb, sc->subcallid)
-		 && api_ws_write_string(&wb, api)
-		 && api_ws_write_string(&wb, verb)
-		 && api_ws_write_object(&wb, args)) {
-			rc = afb_ws_binary_v(wreq->client->ws, wb.iovec, wb.count);
-			if (rc >= 0)
-				return;
-		}
-		ERROR("error while sending fail");
-	}
-}
-
-static int api_ws_server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event event)
-{
-	int rc, rc2;
-	struct writebuf wb = { .count = 0 };
-	struct api_ws_server_req *wreq = CONTAINER_OF_XREQ(struct api_ws_server_req, xreq);
-
-	rc = afb_evt_add_watch(wreq->client->listener, event);
-	if (rc < 0)
-		return rc;
-
-	if (api_ws_write_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
-	 && api_ws_write_uint32(&wb, wreq->msgid)
-	 && api_ws_write_uint32(&wb, (uint32_t)afb_evt_event_id(event))
-	 && api_ws_write_string(&wb, afb_evt_event_name(event))) {
-		rc2 = afb_ws_binary_v(wreq->client->ws, wb.iovec, wb.count);
-		if (rc2 >= 0)
-			goto success;
-	}
-	ERROR("error while subscribing event");
-success:
-	return rc;
-}
-
-static int api_ws_server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event event)
-{
-	int rc, rc2;
-	struct writebuf wb = { .count = 0 };
-	struct api_ws_server_req *wreq = CONTAINER_OF_XREQ(struct api_ws_server_req, xreq);
-
-	if (api_ws_write_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
-	 && api_ws_write_uint32(&wb, wreq->msgid)
-	 && api_ws_write_uint32(&wb, (uint32_t)afb_evt_event_id(event))
-	 && api_ws_write_string(&wb, afb_evt_event_name(event))) {
-		rc2 = afb_ws_binary_v(wreq->client->ws, wb.iovec, wb.count);
-		if (rc2 >= 0)
-			goto success;
-	}
-	ERROR("error while subscribing event");
-success:
-	rc = afb_evt_remove_watch(wreq->client->listener, event);
-	return rc;
 }
 
-/******************* server part **********************************/
-
-static int api_ws_server_connect(struct api_ws *api);
+static int api_ws_server_connect(struct api_ws *apiws);
 
 static int api_ws_server_listen_callback(sd_event_source *src, int fd, uint32_t revents, void *closure)
 {
+	struct api_ws *apiws = closure;
+
 	if ((revents & EPOLLIN) != 0)
-		api_ws_server_accept(closure);
+		api_ws_server_accept(apiws);
 	if ((revents & EPOLLHUP) != 0)
-		api_ws_server_connect(closure);
+		api_ws_server_connect(apiws);
 	return 0;
 }
 
-static void api_ws_server_disconnect(struct api_ws *api)
+static void api_ws_server_disconnect(struct api_ws *apiws)
 {
-	if (api->server.listensrc != NULL) {
-		sd_event_source_unref(api->server.listensrc);
-		api->server.listensrc = NULL;
+	if (apiws->listensrc != NULL) {
+		sd_event_source_unref(apiws->listensrc);
+		apiws->listensrc = NULL;
 	}
-	if (api->fd >= 0) {
-		close(api->fd);
-		api->fd = -1;
+	if (apiws->fd >= 0) {
+		close(apiws->fd);
+		apiws->fd = -1;
 	}
 }
 
-static int api_ws_server_connect(struct api_ws *api)
+static int api_ws_server_connect(struct api_ws *apiws)
 {
 	int rc;
 
 	/* ensure disconnected */
-	api_ws_server_disconnect(api);
+	api_ws_server_disconnect(apiws);
 
 	/* request the service object name */
-	api->fd = api_ws_socket(api->path, 1);
-	if (api->fd < 0)
-		ERROR("can't create socket %s", api->path);
+	apiws->fd = api_ws_socket(apiws->path, 1);
+	if (apiws->fd < 0)
+		ERROR("can't create socket %s", apiws->path);
 	else {
 		/* listen for service */
-		rc = sd_event_add_io(afb_common_get_event_loop(), &api->server.listensrc, api->fd, EPOLLIN, api_ws_server_listen_callback, api);
+		rc = sd_event_add_io(afb_common_get_event_loop(),
+				&apiws->listensrc, apiws->fd, EPOLLIN,
+				api_ws_server_listen_callback, apiws);
 		if (rc >= 0)
 			return 0;
-		close(api->fd);
+		close(apiws->fd);
 		errno = -rc;
-		ERROR("can't add ws object %s", api->path);
+		ERROR("can't add ws object %s", apiws->path);
 	}
 	return -1;
 }
@@ -1439,23 +312,23 @@ static int api_ws_server_connect(struct api_ws *api)
 int afb_api_ws_add_server(const char *path, struct afb_apiset *apiset)
 {
 	int rc;
-	struct api_ws *api;
+	struct api_ws *apiws;
 
 	/* creates the ws api object */
-	api = api_ws_make(path);
-	if (api == NULL)
+	apiws = api_ws_make(path);
+	if (apiws == NULL)
 		goto error;
 
 	/* connect for serving */
-	rc = api_ws_server_connect(api);
+	rc = api_ws_server_connect(apiws);
 	if (rc < 0)
 		goto error2;
 
-	api->server.apiset = afb_apiset_addref(apiset);
+	apiws->apiset = afb_apiset_addref(apiset);
 	return 0;
 
 error2:
-	free(api);
+	free(apiws);
 error:
 	return -1;
 }
diff --git a/src/afb-stub-ws.c b/src/afb-stub-ws.c
new file mode 100644
index 00000000..042ed252
--- /dev/null
+++ b/src/afb-stub-ws.c
@@ -0,0 +1,1170 @@
+/*
+ * Copyright (C) 2015, 2016, 2017 "IoT.bzh"
+ * Author José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define _GNU_SOURCE
+
+#define NO_PLUGIN_VERBOSE_MACRO
+
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <endian.h>
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <pthread.h>
+
+#include <json-c/json.h>
+#include <systemd/sd-event.h>
+
+#include <afb/afb-req-itf.h>
+
+#include "afb-common.h"
+
+#include "afb-session.h"
+#include "afb-cred.h"
+#include "afb-ws.h"
+#include "afb-msg-json.h"
+#include "afb-api.h"
+#include "afb-apiset.h"
+#include "afb-stub-ws.h"
+#include "afb-context.h"
+#include "afb-evt.h"
+#include "afb-xreq.h"
+#include "verbose.h"
+
+struct client_call;
+struct client_event;
+struct afb_stub_ws;
+
+/************** constants for protocol definition *************************/
+
+#define CHAR_FOR_CALL             'C'
+#define CHAR_FOR_ANSWER_SUCCESS   'T'
+#define CHAR_FOR_ANSWER_FAIL      'F'
+#define CHAR_FOR_EVT_BROADCAST    '*'
+#define CHAR_FOR_EVT_ADD          '+'
+#define CHAR_FOR_EVT_DEL          '-'
+#define CHAR_FOR_EVT_PUSH         '!'
+#define CHAR_FOR_EVT_SUBSCRIBE    'S'
+#define CHAR_FOR_EVT_UNSUBSCRIBE  'U'
+#define CHAR_FOR_SUBCALL_CALL     'B'
+#define CHAR_FOR_SUBCALL_REPLY    'R'
+
+/******************* handling subcalls *****************************/
+
+/**
+ * Structure on server side for recording pending
+ * subcalls.
+ */
+struct server_subcall
+{
+	struct server_subcall *next;	/**< next subcall for the client */
+	uint32_t subcallid;		/**< the subcallid */
+	void (*callback)(void*, int, struct json_object*); /**< callback on completion */
+	void *closure;			/**< closure of the callback */
+};
+
+/**
+ * Structure for sending back replies on client side
+ */
+struct client_subcall
+{
+	struct afb_stub_ws *stubws;	/**< stub descriptor */
+	uint32_t subcallid;		/**< subcallid for the reply */
+};
+
+/*
+ * structure for recording calls on client side
+ */
+struct client_call {
+	struct client_call *next;	/* the next call */
+	struct afb_stub_ws *stubws;	/* the stub_ws */
+	struct afb_xreq *xreq;		/* the request handle */
+	uint32_t msgid;			/* the message identifier */
+};
+
+/*
+ * structure for a ws request
+ */
+struct server_req {
+	struct afb_xreq xreq;		/* the xreq */
+	struct afb_stub_ws *stubws;	/* the client of the request */
+	uint32_t msgid;			/* the incoming request msgid */
+};
+
+/*
+ * structure for recording events on client side
+ */
+struct client_event
+{
+	struct client_event *next;
+	struct afb_event event;
+	int eventid;
+	int refcount;
+};
+
+/******************* client description part for server *****************************/
+
+struct afb_stub_ws
+{
+	/* count of references */
+	int refcount;
+
+	/* file descriptor */
+	int fd;
+
+	/* resource control */
+	pthread_mutex_t mutex;
+
+	/* websocket */
+	struct afb_ws *ws;
+
+	/* listener for events (server side) */
+	struct afb_evt_listener *listener;
+
+	/* event replica (client side) */
+	struct client_event *events;
+
+	/* emitted calls (client side) */
+	struct client_call *calls;
+
+	/* credentials (server side) */
+	struct afb_cred *cred;
+
+	/* pending subcalls (server side) */
+	struct server_subcall *subcalls;
+
+	/* apiset */
+	struct afb_apiset *apiset;
+
+	/* the api name */
+	char apiname[1];
+};
+
+/******************* common useful tools **********************************/
+
+/**
+ * translate a pointer to some integer
+ * @param ptr the pointer to translate
+ * @return an integer
+ */
+static inline uint32_t ptr2id(void *ptr)
+{
+	return (uint32_t)(((intptr_t)ptr) >> 6);
+}
+
+/******************* serialisation part **********************************/
+
+struct readbuf
+{
+	char *head, *end;
+};
+
+#define WRITEBUF_COUNT_MAX  32
+struct writebuf
+{
+	struct iovec iovec[WRITEBUF_COUNT_MAX];
+	uint32_t uints[WRITEBUF_COUNT_MAX];
+	int count;
+};
+
+static char *readbuf_get(struct readbuf *rb, uint32_t length)
+{
+	char *before = rb->head;
+	char *after = before + length;
+	if (after > rb->end)
+		return 0;
+	rb->head = after;
+	return before;
+}
+
+static int readbuf_char(struct readbuf *rb, char *value)
+{
+	if (rb->head >= rb->end)
+		return 0;
+	*value = *rb->head++;
+	return 1;
+}
+
+static int readbuf_uint32(struct readbuf *rb, uint32_t *value)
+{
+	char *after = rb->head + sizeof *value;
+	if (after > rb->end)
+		return 0;
+	memcpy(value, rb->head, sizeof *value);
+	rb->head = after;
+	*value = le32toh(*value);
+	return 1;
+}
+
+static int readbuf_string(struct readbuf *rb, const char **value, size_t *length)
+{
+	uint32_t len;
+	if (!readbuf_uint32(rb, &len) || !len)
+		return 0;
+	if (length)
+		*length = (size_t)(len - 1);
+	return (*value = readbuf_get(rb, len)) != NULL &&  rb->head[-1] == 0;
+}
+
+static int readbuf_object(struct readbuf *rb, struct json_object **object)
+{
+	const char *string;
+	struct json_object *o;
+	int rc = readbuf_string(rb, &string, NULL);
+	if (rc) {
+		o = json_tokener_parse(string);
+		if (o == NULL && strcmp(string, "null"))
+			o = json_object_new_string(string);
+		*object = o;
+	}
+	return rc;
+}
+
+static int writebuf_put(struct writebuf *wb, const void *value, size_t length)
+{
+	int i = wb->count;
+	if (i == WRITEBUF_COUNT_MAX)
+		return 0;
+	wb->iovec[i].iov_base = (void*)value;
+	wb->iovec[i].iov_len = length;
+	wb->count = i + 1;
+	return 1;
+}
+
+static int writebuf_char(struct writebuf *wb, char value)
+{
+	int i = wb->count;
+	if (i == WRITEBUF_COUNT_MAX)
+		return 0;
+	*(char*)&wb->uints[i] = value;
+	wb->iovec[i].iov_base = &wb->uints[i];
+	wb->iovec[i].iov_len = 1;
+	wb->count = i + 1;
+	return 1;
+}
+
+static int writebuf_uint32(struct writebuf *wb, uint32_t value)
+{
+	int i = wb->count;
+	if (i == WRITEBUF_COUNT_MAX)
+		return 0;
+	wb->uints[i] = htole32(value);
+	wb->iovec[i].iov_base = &wb->uints[i];
+	wb->iovec[i].iov_len = sizeof wb->uints[i];
+	wb->count = i + 1;
+	return 1;
+}
+
+static int writebuf_string_length(struct writebuf *wb, const char *value, size_t length)
+{
+	uint32_t len = (uint32_t)++length;
+	return (size_t)len == length && len && writebuf_uint32(wb, len) && writebuf_put(wb, value, length);
+}
+
+static int writebuf_string(struct writebuf *wb, const char *value)
+{
+	return writebuf_string_length(wb, value, strlen(value));
+}
+
+static int writebuf_object(struct writebuf *wb, struct json_object *object)
+{
+	const char *string = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
+	return string != NULL && writebuf_string(wb, string);
+}
+
+/******************* ws request part for server *****************/
+
+/* decrement the reference count of the request and free/release it on falling to null */
+static void server_req_destroy_cb(struct afb_xreq *xreq)
+{
+	struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
+
+	afb_context_disconnect(&wreq->xreq.context);
+	afb_cred_unref(wreq->xreq.cred);
+	json_object_put(wreq->xreq.json);
+	afb_stub_ws_unref(wreq->stubws);
+	free(wreq);
+}
+
+static void server_req_success_cb(struct afb_xreq *xreq, struct json_object *obj, const char *info)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+	struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
+
+	if (writebuf_char(&wb, CHAR_FOR_ANSWER_SUCCESS)
+	 && writebuf_uint32(&wb, wreq->msgid)
+	 && writebuf_uint32(&wb, (uint32_t)wreq->xreq.context.flags)
+	 && writebuf_string(&wb, info ? : "")
+	 && writebuf_object(&wb, obj)) {
+		rc = afb_ws_binary_v(wreq->stubws->ws, wb.iovec, wb.count);
+		if (rc >= 0)
+			goto success;
+	}
+	ERROR("error while sending success");
+success:
+	json_object_put(obj);
+}
+
+static void server_req_fail_cb(struct afb_xreq *xreq, const char *status, const char *info)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+	struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
+
+	if (writebuf_char(&wb, CHAR_FOR_ANSWER_FAIL)
+	 && writebuf_uint32(&wb, wreq->msgid)
+	 && writebuf_uint32(&wb, (uint32_t)wreq->xreq.context.flags)
+	 && writebuf_string(&wb, status)
+	 && writebuf_string(&wb, info ? : "")) {
+		rc = afb_ws_binary_v(wreq->stubws->ws, wb.iovec, wb.count);
+		if (rc >= 0)
+			return;
+	}
+	ERROR("error while sending fail");
+}
+
+static void server_req_subcall_cb(struct afb_xreq *xreq, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *cb_closure)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+	struct server_subcall *sc, *osc;
+	struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
+	struct afb_stub_ws *stubws = wreq->stubws;
+
+	sc = malloc(sizeof *sc);
+	if (!sc) {
+
+	} else {
+		sc->callback = callback;
+		sc->closure = cb_closure;
+
+		pthread_mutex_unlock(&stubws->mutex);
+		sc->subcallid = ptr2id(sc);
+		do {
+			sc->subcallid++;
+			osc = stubws->subcalls;
+			while(osc && osc->subcallid != sc->subcallid)
+				osc = osc->next;
+		} while (osc);
+		sc->next = stubws->subcalls;
+		stubws->subcalls = sc;
+		pthread_mutex_unlock(&stubws->mutex);
+
+		if (writebuf_char(&wb, CHAR_FOR_SUBCALL_CALL)
+		 && writebuf_uint32(&wb, wreq->msgid)
+		 && writebuf_uint32(&wb, sc->subcallid)
+		 && writebuf_string(&wb, api)
+		 && writebuf_string(&wb, verb)
+		 && writebuf_object(&wb, args)) {
+			rc = afb_ws_binary_v(wreq->stubws->ws, wb.iovec, wb.count);
+			if (rc >= 0)
+				return;
+		}
+		ERROR("error while sending fail");
+	}
+}
+
+static int server_req_subscribe_cb(struct afb_xreq *xreq, struct afb_event event)
+{
+	int rc, rc2;
+	struct writebuf wb = { .count = 0 };
+	struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
+
+	rc = afb_evt_add_watch(wreq->stubws->listener, event);
+	if (rc < 0)
+		return rc;
+
+	if (writebuf_char(&wb, CHAR_FOR_EVT_SUBSCRIBE)
+	 && writebuf_uint32(&wb, wreq->msgid)
+	 && writebuf_uint32(&wb, (uint32_t)afb_evt_event_id(event))
+	 && writebuf_string(&wb, afb_evt_event_name(event))) {
+		rc2 = afb_ws_binary_v(wreq->stubws->ws, wb.iovec, wb.count);
+		if (rc2 >= 0)
+			goto success;
+	}
+	ERROR("error while subscribing event");
+success:
+	return rc;
+}
+
+static int server_req_unsubscribe_cb(struct afb_xreq *xreq, struct afb_event event)
+{
+	int rc, rc2;
+	struct writebuf wb = { .count = 0 };
+	struct server_req *wreq = CONTAINER_OF_XREQ(struct server_req, xreq);
+
+	if (writebuf_char(&wb, CHAR_FOR_EVT_UNSUBSCRIBE)
+	 && writebuf_uint32(&wb, wreq->msgid)
+	 && writebuf_uint32(&wb, (uint32_t)afb_evt_event_id(event))
+	 && writebuf_string(&wb, afb_evt_event_name(event))) {
+		rc2 = afb_ws_binary_v(wreq->stubws->ws, wb.iovec, wb.count);
+		if (rc2 >= 0)
+			goto success;
+	}
+	ERROR("error while subscribing event");
+success:
+	rc = afb_evt_remove_watch(wreq->stubws->listener, event);
+	return rc;
+}
+
+static const struct afb_xreq_query_itf server_req_xreq_itf = {
+	.success = server_req_success_cb,
+	.fail = server_req_fail_cb,
+	.unref = server_req_destroy_cb,
+	.subcall = server_req_subcall_cb,
+	.subscribe = server_req_subscribe_cb,
+	.unsubscribe = server_req_unsubscribe_cb
+};
+
+/******************* client part **********************************/
+
+/* search a memorized call */
+static struct client_call *client_call_search(struct afb_stub_ws *stubws, uint32_t msgid)
+{
+	struct client_call *call;
+
+	call = stubws->calls;
+	while (call != NULL && call->msgid != msgid)
+		call = call->next;
+
+	return call;
+}
+
+/* search the event */
+static struct client_event *client_event_search(struct afb_stub_ws *stubws, uint32_t eventid, const char *name)
+{
+	struct client_event *ev;
+
+	ev = stubws->events;
+	while (ev != NULL && (ev->eventid != eventid || 0 != strcmp(afb_evt_event_name(ev->event), name)))
+		ev = ev->next;
+
+	return ev;
+}
+
+
+/* allocates and init the memorizing call */
+static struct client_call *client_call_make(struct afb_stub_ws *stubws, struct afb_xreq *xreq)
+{
+	struct client_call *call;
+
+	call = malloc(sizeof *call);
+	if (call != NULL) {
+		afb_xreq_addref(xreq);
+		call->xreq = xreq;
+		call->msgid = ptr2id(call);
+		while(client_call_search(stubws, call->msgid) != NULL)
+			call->msgid++;
+		call->stubws = stubws;
+		call->next = stubws->calls;
+		stubws->calls = call;
+	}
+	return call;
+}
+
+/* free and release the memorizing call */
+static void client_call_destroy(struct client_call *call)
+{
+	struct client_call **prv;
+
+	prv = &call->stubws->calls;
+	while (*prv != NULL) {
+		if (*prv == call) {
+			*prv = call->next;
+			break;
+		}
+		prv = &(*prv)->next;
+	}
+
+	afb_xreq_unref(call->xreq);
+	free(call);
+}
+
+/* get event data from the message */
+static int client_msg_event_read(struct readbuf *rb, uint32_t *eventid, const char **name)
+{
+	return readbuf_uint32(rb, eventid) && readbuf_string(rb, name, NULL);
+}
+
+/* get event from the message */
+static int client_msg_event_get(struct afb_stub_ws *stubws, struct readbuf *rb, struct client_event **ev)
+{
+	const char *name;
+	uint32_t eventid;
+
+	/* get event data from the message */
+	if (!client_msg_event_read(rb, &eventid, &name)) {
+		ERROR("Invalid message");
+		return 0;
+	}
+
+	/* check conflicts */
+	*ev = client_event_search(stubws, eventid, name);
+	if (*ev == NULL) {
+		ERROR("event %s not found", name);
+		return 0;
+	}
+
+	return 1;
+}
+
+/* get event from the message */
+static int client_msg_call_get(struct afb_stub_ws *stubws, struct readbuf *rb, struct client_call **call)
+{
+	uint32_t msgid;
+
+	/* get event data from the message */
+	if (!readbuf_uint32(rb, &msgid)) {
+		ERROR("Invalid message");
+		return 0;
+	}
+
+	/* get the call */
+	*call = client_call_search(stubws, msgid);
+	if (*call == NULL) {
+		ERROR("message not found");
+		return 0;
+	}
+
+	return 1;
+}
+
+/* read a subscrition message */
+static int client_msg_subscription_get(struct afb_stub_ws *stubws, struct readbuf *rb, struct client_call **call, struct client_event **ev)
+{
+	return client_msg_call_get(stubws, rb, call) && client_msg_event_get(stubws, rb, ev);
+}
+
+/* adds an event */
+static void client_event_create(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	size_t offset;
+	const char *name;
+	uint32_t eventid;
+	struct client_event *ev;
+
+	/* get event data from the message */
+	offset = client_msg_event_read(rb, &eventid, &name);
+	if (offset == 0) {
+		ERROR("Invalid message");
+		return;
+	}
+
+	/* check conflicts */
+	ev = client_event_search(stubws, eventid, name);
+	if (ev != NULL) {
+		ev->refcount++;
+		return;
+	}
+
+	/* no conflict, try to add it */
+	ev = malloc(sizeof *ev);
+	if (ev != NULL) {
+		ev->event = afb_evt_create_event(name);
+		if (ev->event.closure == NULL)
+			free(ev);
+		else {
+			ev->refcount = 1;
+			ev->eventid = eventid;
+			ev->next = stubws->events;
+			stubws->events = ev;
+			return;
+		}
+	}
+	ERROR("can't create event %s, out of memory", name);
+}
+
+/* removes an event */
+static void client_event_drop(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_event *ev, **prv;
+
+	/* retrieves the event */
+	if (!client_msg_event_get(stubws, rb, &ev))
+		return;
+
+	/* decrease the reference count */
+	if (--ev->refcount)
+		return;
+
+	/* unlinks the event */
+	prv = &stubws->events;
+	while (*prv != ev)
+		prv = &(*prv)->next;
+	*prv = ev->next;
+
+	/* destroys the event */
+	afb_event_drop(ev->event);
+	free(ev);
+}
+
+/* subscribes an event */
+static void client_event_subscribe(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_event *ev;
+	struct client_call *call;
+
+	if (client_msg_subscription_get(stubws, rb, &call, &ev)) {
+		/* subscribe the request from the event */
+		if (afb_xreq_subscribe(call->xreq, ev->event) < 0)
+			ERROR("can't subscribe: %m");
+	}
+}
+
+/* unsubscribes an event */
+static void client_event_unsubscribe(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_event *ev;
+	struct client_call *call;
+
+	if (client_msg_subscription_get(stubws, rb, &call, &ev)) {
+		/* unsubscribe the request from the event */
+		if (afb_xreq_unsubscribe(call->xreq, ev->event) < 0)
+			ERROR("can't unsubscribe: %m");
+	}
+}
+
+/* receives broadcasted events */
+static void client_event_broadcast(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct json_object *object;
+	const char *event;
+
+	if (readbuf_string(rb, &event, NULL) && readbuf_object(rb, &object))
+		afb_evt_broadcast(event, object);
+	else
+		ERROR("unreadable broadcasted event");
+}
+
+/* pushs an event */
+static void client_event_push(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_event *ev;
+	struct json_object *object;
+
+	if (client_msg_event_get(stubws, rb, &ev) && readbuf_object(rb, &object))
+		afb_event_push(ev->event, object);
+	else
+		ERROR("unreadable push event");
+}
+
+static void client_reply_success(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_call *call;
+	struct json_object *object;
+	const char *info;
+	uint32_t flags;
+
+	/* retrieve the message data */
+	if (!client_msg_call_get(stubws, rb, &call))
+		return;
+
+	if (readbuf_uint32(rb, &flags)
+	 && readbuf_string(rb, &info, NULL)
+	 && readbuf_object(rb, &object)) {
+		call->xreq->context.flags = (unsigned)flags;
+		afb_xreq_success(call->xreq, object, *info ? info : NULL);
+	} else {
+		/* failing to have the answer */
+		afb_xreq_fail(call->xreq, "error", "ws error");
+	}
+	client_call_destroy(call);
+}
+
+static void client_reply_fail(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_call *call;
+	const char *info, *status;
+	uint32_t flags;
+
+	/* retrieve the message data */
+	if (!client_msg_call_get(stubws, rb, &call))
+		return;
+
+	if (readbuf_uint32(rb, &flags)
+	 && readbuf_string(rb, &status, NULL)
+	 && readbuf_string(rb, &info, NULL)) {
+		call->xreq->context.flags = (unsigned)flags;
+		afb_xreq_fail(call->xreq, status, *info ? info : NULL);
+	} else {
+		/* failing to have the answer */
+		afb_xreq_fail(call->xreq, "error", "ws error");
+	}
+	client_call_destroy(call);
+}
+
+/* send a subcall reply */
+static void client_send_subcall_reply(struct client_subcall *subcall, int iserror, json_object *object)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+	char ie = (char)!!iserror;
+
+	if (!writebuf_char(&wb, CHAR_FOR_SUBCALL_REPLY)
+	 || !writebuf_uint32(&wb, subcall->subcallid)
+	 || !writebuf_char(&wb, ie)
+	 || !writebuf_object(&wb, object)) {
+		/* write error ? */
+		return;
+	}
+
+	rc = afb_ws_binary_v(subcall->stubws->ws, wb.iovec, wb.count);
+	if (rc >= 0)
+		return;
+	ERROR("error while sending subcall reply");
+}
+
+/* callback for subcall reply */
+static void client_subcall_reply_cb(void *closure, int iserror, json_object *object)
+{
+	client_send_subcall_reply(closure, iserror, object);
+	free(closure);
+}
+
+/* received a subcall request */
+static void client_subcall(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct client_subcall *subcall;
+	struct client_call *call;
+	const char *api, *verb;
+	uint32_t subcallid;
+	struct json_object *object;
+
+	subcall = malloc(sizeof *subcall);
+	if (!subcall)
+		return;
+
+	/* retrieve the message data */
+	if (!client_msg_call_get(stubws, rb, &call))
+		return;
+
+	if (readbuf_uint32(rb, &subcallid)
+	 && readbuf_string(rb, &api, NULL)
+	 && readbuf_string(rb, &verb, NULL)
+	 && readbuf_object(rb, &object)) {
+		subcall->stubws = stubws;
+		subcall->subcallid = subcallid;
+		afb_xreq_subcall(call->xreq, api, verb, object, client_subcall_reply_cb, subcall);
+	}
+}
+
+/* callback when receiving binary data */
+static void client_on_binary(void *closure, char *data, size_t size)
+{
+	if (size > 0) {
+		struct afb_stub_ws *stubws = closure;
+		struct readbuf rb = { .head = data, .end = data + size };
+
+		pthread_mutex_lock(&stubws->mutex);
+		switch (*rb.head++) {
+		case CHAR_FOR_ANSWER_SUCCESS: /* success */
+			client_reply_success(stubws, &rb);
+			break;
+		case CHAR_FOR_ANSWER_FAIL: /* fail */
+			client_reply_fail(stubws, &rb);
+			break;
+		case CHAR_FOR_EVT_BROADCAST: /* broadcast */
+			client_event_broadcast(stubws, &rb);
+			break;
+		case CHAR_FOR_EVT_ADD: /* creates the event */
+			client_event_create(stubws, &rb);
+			break;
+		case CHAR_FOR_EVT_DEL: /* drops the event */
+			client_event_drop(stubws, &rb);
+			break;
+		case CHAR_FOR_EVT_PUSH: /* pushs the event */
+			client_event_push(stubws, &rb);
+			break;
+		case CHAR_FOR_EVT_SUBSCRIBE: /* subscribe event for a request */
+			client_event_subscribe(stubws, &rb);
+			break;
+		case CHAR_FOR_EVT_UNSUBSCRIBE: /* unsubscribe event for a request */
+			client_event_unsubscribe(stubws, &rb);
+			break;
+		case CHAR_FOR_SUBCALL_CALL: /* subcall */
+			client_subcall(stubws, &rb);
+			break;
+		default: /* unexpected message */
+			/* TODO: close the connection */
+			break;
+		}
+		pthread_mutex_unlock(&stubws->mutex);
+	}
+	free(data);
+}
+
+/* on call, propagate it to the ws service */
+static void client_call_cb(void * closure, struct afb_xreq *xreq)
+{
+	int rc;
+	struct client_call *call;
+	struct writebuf wb = { .count = 0 };
+	const char *raw;
+	size_t szraw;
+	struct afb_stub_ws *stubws = closure;
+
+	pthread_mutex_lock(&stubws->mutex);
+
+	/* create the recording data */
+	call = client_call_make(stubws, xreq);
+	if (call == NULL) {
+		afb_xreq_fail_f(xreq, "error", "out of memory");
+		goto end;
+	}
+
+	/* creates the call message */
+	raw = afb_xreq_raw(xreq, &szraw);
+	if (raw == NULL)
+		goto internal_error;
+	if (!writebuf_char(&wb, CHAR_FOR_CALL)
+	 || !writebuf_uint32(&wb, call->msgid)
+	 || !writebuf_uint32(&wb, (uint32_t)xreq->context.flags)
+	 || !writebuf_string(&wb, xreq->verb)
+	 || !writebuf_string(&wb, afb_session_uuid(xreq->context.session))
+	 || !writebuf_string_length(&wb, raw, szraw))
+		goto overflow;
+
+	/* send */
+	rc = afb_ws_binary_v(stubws->ws, wb.iovec, wb.count);
+	if (rc >= 0)
+		goto end;
+
+	afb_xreq_fail(xreq, "error", "websocket sending error");
+	goto clean_call;
+
+internal_error:
+	afb_xreq_fail(xreq, "error", "internal: raw is NULL!");
+	goto clean_call;
+
+overflow:
+	afb_xreq_fail(xreq, "error", "overflow: size doesn't match 32 bits!");
+
+clean_call:
+	client_call_destroy(call);
+end:
+	pthread_mutex_unlock(&stubws->mutex);
+}
+
+/******************* client description part for server *****************************/
+
+/* on call, propagate it to the ws service */
+static void server_on_call(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	struct server_req *wreq;
+	char *cverb;
+	const char *uuid, *verb;
+	uint32_t flags, msgid;
+	size_t lenverb;
+	struct json_object *object;
+
+	afb_stub_ws_addref(stubws);
+
+	/* reads the call message data */
+	if (!readbuf_uint32(rb, &msgid)
+	 || !readbuf_uint32(rb, &flags)
+	 || !readbuf_string(rb, &verb, &lenverb)
+	 || !readbuf_string(rb, &uuid, NULL)
+	 || !readbuf_object(rb, &object))
+		goto overflow;
+
+	/* create the request */
+	wreq = malloc(++lenverb + sizeof *wreq);
+	if (wreq == NULL)
+		goto out_of_memory;
+
+	afb_xreq_init(&wreq->xreq, &server_req_xreq_itf);
+	wreq->stubws = stubws;
+	wreq->msgid = msgid;
+	cverb = (char*)&wreq[1];
+	memcpy(cverb, verb, lenverb);
+
+	/* init the context */
+	if (afb_context_connect(&wreq->xreq.context, uuid, NULL) < 0)
+		goto unconnected;
+	wreq->xreq.context.flags = flags;
+
+	/* makes the call */
+	wreq->xreq.cred = afb_cred_addref(stubws->cred);
+	wreq->xreq.api = stubws->apiname;
+	wreq->xreq.verb = cverb;
+	wreq->xreq.json = object;
+	afb_xreq_process(&wreq->xreq, stubws->apiset);
+	return;
+
+unconnected:
+	free(wreq);
+out_of_memory:
+	json_object_put(object);
+overflow:
+	afb_stub_ws_unref(stubws);
+}
+
+/* on subcall reply */
+static void server_on_subcall_reply(struct afb_stub_ws *stubws, struct readbuf *rb)
+{
+	char iserror;
+	uint32_t subcallid;
+	struct json_object *object;
+	struct server_subcall *sc, **psc;
+
+	/* reads the call message data */
+	if (!readbuf_uint32(rb, &subcallid)
+	 || !readbuf_char(rb, &iserror)
+	 || !readbuf_object(rb, &object)) {
+		/* TODO bad protocol */
+		return;
+	}
+
+	/* search the subcall and unlink it */
+	pthread_mutex_lock(&stubws->mutex);
+	psc = &stubws->subcalls;
+	while ((sc = *psc) && sc->subcallid != subcallid)
+		psc = &sc->next;
+	if (!sc) {
+		pthread_mutex_unlock(&stubws->mutex);
+		/* TODO subcall not found */
+	} else {
+		*psc = sc->next;
+		pthread_mutex_unlock(&stubws->mutex);
+		sc->callback(sc->closure, (int)iserror, object);
+		free(sc);
+	}
+	json_object_put(object);
+}
+
+/* callback when receiving binary data */
+static void server_on_binary(void *closure, char *data, size_t size)
+{
+	if (size > 0) {
+		struct readbuf rb = { .head = data, .end = data + size };
+		switch (*rb.head++) {
+		case CHAR_FOR_CALL:
+			server_on_call(closure, &rb);
+			break;
+		case CHAR_FOR_SUBCALL_REPLY:
+			server_on_subcall_reply(closure, &rb);
+			break;
+		default: /* unexpected message */
+			/* TODO: close the connection */
+			break;
+		}
+	}
+	free(data);
+}
+
+/******************* server part: manage events **********************************/
+
+static void server_event_send(struct afb_stub_ws *stubws, char order, const char *event, int eventid, const char *data)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+
+	if (writebuf_char(&wb, order)
+	 && writebuf_uint32(&wb, eventid)
+	 && writebuf_string(&wb, event)
+	 && (data == NULL || writebuf_string(&wb, data))) {
+		rc = afb_ws_binary_v(stubws->ws, wb.iovec, wb.count);
+		if (rc >= 0)
+			return;
+	}
+	ERROR("error while sending %c for event %s", order, event);
+}
+
+static void server_event_add(void *closure, const char *event, int eventid)
+{
+	server_event_send(closure, CHAR_FOR_EVT_ADD, event, eventid, NULL);
+}
+
+static void server_event_remove(void *closure, const char *event, int eventid)
+{
+	server_event_send(closure, CHAR_FOR_EVT_DEL, event, eventid, NULL);
+}
+
+static void server_event_push(void *closure, const char *event, int eventid, struct json_object *object)
+{
+	const char *data = json_object_to_json_string_ext(object, JSON_C_TO_STRING_PLAIN);
+	server_event_send(closure, CHAR_FOR_EVT_PUSH, event, eventid, data ? : "null");
+	json_object_put(object);
+}
+
+static void server_event_broadcast(void *closure, const char *event, int eventid, struct json_object *object)
+{
+	int rc;
+	struct afb_stub_ws *stubws = closure;
+
+	struct writebuf wb = { .count = 0 };
+
+	if (writebuf_char(&wb, CHAR_FOR_EVT_BROADCAST) && writebuf_string(&wb, event) && writebuf_object(&wb, object)) {
+		rc = afb_ws_binary_v(stubws->ws, wb.iovec, wb.count);
+		if (rc < 0)
+			ERROR("error while broadcasting event %s", event);
+	} else
+		ERROR("error while broadcasting event %s", event);
+	json_object_put(object);
+}
+
+/*****************************************************/
+
+/* callback when receiving a hangup */
+static void server_on_hangup(void *closure)
+{
+	struct afb_stub_ws *stubws = closure;
+
+	/* close the socket */
+	if (stubws->fd >= 0) {
+		close(stubws->fd);
+		stubws->fd = -1;
+	}
+
+	/* release the client */
+	afb_stub_ws_unref(stubws);
+}
+
+/*****************************************************/
+
+/* the interface for events pushing */
+static const struct afb_evt_itf server_evt_itf = {
+	.broadcast = server_event_broadcast,
+	.push = server_event_push,
+	.add = server_event_add,
+	.remove = server_event_remove
+};
+
+static const struct afb_ws_itf stub_ws_client_ws_itf =
+{
+	.on_close = NULL,
+	.on_text = NULL,
+	.on_binary = client_on_binary,
+	.on_error = NULL,
+	.on_hangup = NULL
+};
+
+static const struct afb_ws_itf server_ws_itf =
+{
+	.on_close = NULL,
+	.on_text = NULL,
+	.on_binary = server_on_binary,
+	.on_error = NULL,
+	.on_hangup = server_on_hangup
+};
+
+static struct afb_api_itf ws_api_itf = {
+	.call = client_call_cb
+};
+
+/*****************************************************/
+
+static struct afb_stub_ws *afb_stub_ws_create(int fd, const char *apiname, struct afb_apiset *apiset, const struct afb_ws_itf *itf)
+{
+	struct afb_stub_ws *stubws;
+
+	stubws = calloc(1, sizeof *stubws + strlen(apiname));
+	if (stubws == NULL)
+		errno = ENOMEM;
+	else {
+		fcntl(fd, F_SETFD, FD_CLOEXEC);
+		fcntl(fd, F_SETFL, O_NONBLOCK);
+		stubws->ws = afb_ws_create(afb_common_get_event_loop(), fd, itf, stubws);
+		if (stubws->ws != NULL) {
+			stubws->fd = fd;
+			strcpy(stubws->apiname, apiname);
+			stubws->apiset = afb_apiset_addref(apiset);
+			stubws->refcount = 1;
+			stubws->subcalls = NULL;
+			return stubws;
+		}
+		free(stubws);
+	}
+	return NULL;
+}
+
+struct afb_stub_ws *afb_stub_ws_create_client(int fd, const char *apiname, struct afb_apiset *apiset)
+{
+	struct afb_api afb_api;
+	struct afb_stub_ws *stubws;
+
+	stubws = afb_stub_ws_create(fd, apiname, apiset, &stub_ws_client_ws_itf);
+	if (stubws) {
+		afb_api.closure = stubws;
+		afb_api.itf = &ws_api_itf;
+		if (afb_apiset_add(apiset, stubws->apiname, afb_api) >= 0)
+			return stubws;
+		afb_stub_ws_unref(stubws);
+	}
+	return NULL;
+
+}
+
+struct afb_stub_ws *afb_stub_ws_create_server(int fd, const char *apiname, struct afb_apiset *apiset)
+{
+	struct afb_stub_ws *stubws;
+
+	stubws = afb_stub_ws_create(fd, apiname, apiset, &server_ws_itf);
+	if (stubws) {
+		stubws->cred = afb_cred_create_for_socket(fd);
+		stubws->listener = afb_evt_listener_create(&server_evt_itf, stubws);
+		if (stubws->listener != NULL)
+			return stubws;
+		afb_stub_ws_unref(stubws);
+	}
+	return NULL;
+}
+
+void afb_stub_ws_unref(struct afb_stub_ws *stubws)
+{
+	struct server_subcall *sc, *nsc;
+
+	if (!__atomic_sub_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED)) {
+		afb_evt_listener_unref(stubws->listener);
+		afb_ws_destroy(stubws->ws);
+		nsc = stubws->subcalls;
+		while (nsc) {
+			sc= nsc;
+			nsc = sc->next;
+			sc->callback(sc->closure, 1, NULL);
+			free(sc);
+		}
+		afb_cred_unref(stubws->cred);
+		afb_apiset_unref(stubws->apiset);
+		free(stubws);
+	}
+}
+
+void afb_stub_ws_addref(struct afb_stub_ws *stubws)
+{
+	__atomic_add_fetch(&stubws->refcount, 1, __ATOMIC_RELAXED);
+}
+
+/*
+static void client_disconnect(struct afb_stub_ws *stubws)
+{
+	if (stubws->fd >= 0) {
+		afb_ws_destroy(stubws->ws);
+		stubws->ws = NULL;
+		close(stubws->fd);
+		stubws->fd = -1;
+	}
+}
+*/
+
diff --git a/src/afb-stub-ws.h b/src/afb-stub-ws.h
new file mode 100644
index 00000000..33ab5b2f
--- /dev/null
+++ b/src/afb-stub-ws.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2016, 2017 "IoT.bzh"
+ * Author: José Bollo <jose.bollo@iot.bzh>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+#pragma once
+
+struct afb_stub_ws;
+struct afb_apiset;
+
+extern struct afb_stub_ws *afb_stub_ws_create_client(int fd, const char *apiname, struct afb_apiset *apiset);
+
+extern struct afb_stub_ws *afb_stub_ws_create_server(int fd, const char *apiname, struct afb_apiset *apiset);
+
+extern void afb_stub_ws_unref(struct afb_stub_ws *stubws);
+
+extern void afb_stub_ws_addref(struct afb_stub_ws *stubws);
+