websocket transparancy for C/S bindings

Change-Id: Ia78621ca4d3298fd45f3486ee64c3785c8ab6d8d
Signed-off-by: José Bollo <jose.bollo@iot.bzh>

4 files changed, 1352 insertions, 0 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index af4f10c1..b16c3121 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -32,6 +32,7 @@ INCLUDE_DIRECTORIES(
 ADD_LIBRARY(afb-lib STATIC
 	afb-api-dbus.c
 	afb-api-so.c
+	afb-api-ws.c
 	afb-apis.c
 	afb-common.c
 	afb-context.c
diff --git a/src/afb-api-ws.c b/src/afb-api-ws.c
new file mode 100644
index 00000000..663170ee
--- /dev/null
+++ b/src/afb-api-ws.c
@@ -0,0 +1,1302 @@
+/*
+ * Copyright (C) 2015, 2016 "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 <json-c/json.h>
+#include <systemd/sd-event.h>
+
+#include <afb/afb-req-itf.h>
+
+#include "afb-common.h"
+
+#include "session.h"
+#include "afb-ws.h"
+#include "afb-msg-json.h"
+#include "afb-apis.h"
+#include "afb-api-so.h"
+#include "afb-context.h"
+#include "afb-evt.h"
+#include "afb-subcall.h"
+#include "verbose.h"
+
+struct api_ws_memo;
+struct api_ws_event;
+struct api_ws_client;
+
+
+
+/*
+ */
+struct api_ws
+{
+	char *path;		/* path of the object for the API */
+	char *api;		/* api name of the interface */
+	int fd;			/* file descriptor */
+	union {
+		struct {
+			uint32_t id;
+			struct afb_ws *ws;
+			struct api_ws_event *events;
+			struct api_ws_memo *memos;
+		} client;
+		struct {
+			sd_event_source *listensrc;
+			struct afb_evt_listener *listener; /* listener for broadcasted events */
+		} server;
+	};
+};
+
+#define RETOK   1
+#define RETERR  2
+#define RETRAW  3
+
+/******************* 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
+};
+
+/******************* client description part for server *****************************/
+
+struct api_ws_client
+{
+	/* the server ws-api */
+	const char *api;
+
+	/* count of references */
+	int refcount;
+
+	/* listener for events */
+	struct afb_evt_listener *listener;
+
+	/* file descriptor */
+	int fd;
+
+	/* websocket */
+	struct afb_ws *ws;
+};
+
+/******************* 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_context context;	/* the context, should be THE FIRST */
+	struct api_ws_client *client;	/* the client of the request */
+	char *rcvdata;			/* the received data to free */
+	struct json_object *json;	/* the readen request as object */
+	const char *request;		/* the readen request as string */
+	size_t lenreq;			/* the length of the request */
+	int refcount;			/* reference count of the request */
+	uint32_t msgid;			/* the incoming request msgid */
+};
+
+static struct json_object *api_ws_server_req_json(struct api_ws_server_req *wreq);
+static struct afb_arg api_ws_server_req_get(struct api_ws_server_req *wreq, const char *name);
+static void api_ws_server_req_success(struct api_ws_server_req *wreq, struct json_object *obj, const char *info);
+static void api_ws_server_req_fail(struct api_ws_server_req *wreq, const char *status, const char *info);
+static const char *api_ws_server_req_raw(struct api_ws_server_req *wreq, size_t *size);
+static void api_ws_server_req_send(struct api_ws_server_req *wreq, const char *buffer, size_t size);
+static void api_ws_server_req_addref(struct api_ws_server_req *wreq);
+static void api_ws_server_req_unref(struct api_ws_server_req *wreq);
+static int api_ws_server_req_subscribe(struct api_ws_server_req *wreq, struct afb_event event);
+static int api_ws_server_req_unsubscribe(struct api_ws_server_req *wreq, struct afb_event event);
+static void api_ws_server_req_subcall(struct api_ws_server_req *wreq, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *closure);
+
+const struct afb_req_itf afb_api_ws_req_itf = {
+	.json = (void*)api_ws_server_req_json,
+	.get = (void*)api_ws_server_req_get,
+	.success = (void*)api_ws_server_req_success,
+	.fail = (void*)api_ws_server_req_fail,
+	.raw = (void*)api_ws_server_req_raw,
+	.send = (void*)api_ws_server_req_send,
+	.context_get = (void*)afb_context_get,
+	.context_set = (void*)afb_context_set,
+	.addref = (void*)api_ws_server_req_addref,
+	.unref = (void*)api_ws_server_req_unref,
+	.session_close = (void*)afb_context_close,
+	.session_set_LOA = (void*)afb_context_change_loa,
+	.subscribe = (void*)api_ws_server_req_subscribe,
+	.unsubscribe = (void*)api_ws_server_req_unsubscribe,
+	.subcall = (void*)api_ws_server_req_subcall
+};
+
+/******************* common part **********************************/
+
+/*
+ * create a structure api_ws not connected to the 'path'.
+ */
+static struct api_ws *api_ws_make(const char *path)
+{
+	struct api_ws *api;
+	size_t length;
+
+	/* allocates the structure */
+	length = strlen(path);
+	api = calloc(1, sizeof *api + 1 + length);
+	if (api == NULL) {
+		errno = ENOMEM;
+		goto error;
+	}
+
+	/* path is copied after the struct */
+	api->path = (void*)(api+1);
+	memcpy(api->path, path, length + 1);
+
+	/* api name is at the end of the path */
+	api->api = strrchr(api->path, '/');
+	if (api->api == NULL || !afb_apis_is_valid_api_name(++api->api)) {
+		errno = EINVAL;
+		goto error2;
+	}
+
+	api->fd = -1;
+	return api;
+
+error2:
+	free(api);
+error:
+	return NULL;
+}
+
+static int api_ws_socket_unix(const char *path, int server)
+{
+	int fd, rc;
+	struct sockaddr_un addr;
+	size_t length;
+
+	length = strlen(path);
+	if (length >= 108) {
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+
+	if (server)
+		unlink(path);
+
+	fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd < 0)
+		return fd;
+
+	memset(&addr, 0, sizeof addr);
+	addr.sun_family = AF_UNIX;
+	strcpy(addr.sun_path, path);
+	if (server) {
+		rc = bind(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
+	} else {
+		rc = connect(fd, (struct sockaddr *) &addr, (socklen_t)(sizeof addr));
+	}
+	if (rc < 0) {
+		close(fd);
+		return rc;
+	}
+	return fd;
+}
+
+static int api_ws_socket_inet(const char *path, int server)
+{
+	int rc, fd;
+	const char *service, *host, *api;
+	struct addrinfo hint, *rai, *iai;
+
+	/* scan the uri */
+	api = strrchr(path, '/');
+	service = strrchr(path, ':');
+	if (api == NULL || service == NULL || api < service) {
+		errno = EINVAL;
+		return -1;
+	}
+	host = strndupa(path, service++ - path);
+	service = strndupa(service, api - service);
+
+	/* get addr */
+	memset(&hint, 0, sizeof hint);
+	hint.ai_family = AF_INET;
+	hint.ai_socktype = SOCK_STREAM;
+	rc = getaddrinfo(host, service, &hint, &rai);
+	if (rc != 0) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	/* get the socket */
+	iai = rai;
+	while (iai != NULL) {
+		fd = socket(iai->ai_family, iai->ai_socktype, iai->ai_protocol);
+		if (fd >= 0) {
+			if (server) {
+				rc = bind(fd, iai->ai_addr, iai->ai_addrlen);
+			} else {
+				rc = connect(fd, iai->ai_addr, iai->ai_addrlen);
+			}
+			if (rc == 0) {
+				freeaddrinfo(rai);
+				return fd;
+			}
+			close(fd);
+		}
+		iai = iai->ai_next;
+	}
+	freeaddrinfo(rai);
+	return -1;
+	
+}
+
+static int api_ws_socket(const char *path, int server)
+{
+	int fd, rc;
+
+	/* check for unix socket */
+	if (0 == strncmp(path, "unix:", 5))
+		fd = api_ws_socket_unix(path + 5, server);
+	else
+		fd = api_ws_socket_inet(path, server);
+
+	if (fd >= 0) {
+		fcntl(fd, F_SETFD, FD_CLOEXEC);
+		fcntl(fd, F_SETFL, O_NONBLOCK);
+		if (server) {
+			rc = 1;
+			setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &rc, sizeof rc);
+			rc = listen(fd, 5);
+		}
+	}
+	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_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)
+{
+	size_t length;
+	const char *string;
+	return api_ws_read_string(rb, &string, &length) && ((*object = json_tokener_parse(string)) != NULL) == (strcmp(string, "null") != 0);
+}
+
+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_nz(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) && api_ws_write_char(wb, '\0');
+}
+
+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_req req;		/* the request handle */
+	struct afb_context *context;	/* the context of the query */
+	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_req req, struct afb_context *context)
+{
+	struct api_ws_memo *memo;
+
+	memo = malloc(sizeof *memo);
+	if (memo != NULL) {
+		afb_req_addref(req);
+		memo->req = req;
+		memo->context = context;
+		do { memo->msgid = ++api->client.id; } while(api_ws_client_memo_search(api, memo->msgid) != NULL);
+		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_req_unref(memo->req);
+	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_event **ev, struct api_ws_memo **memo)
+{
+	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, &ev, &memo)) {
+		/* subscribe the request from the event */
+		if (afb_req_subscribe(memo->req, 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, &ev, &memo)) {
+		/* unsubscribe the request from the event */
+		if (afb_req_unsubscribe(memo->req, 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->context->flags = (unsigned)flags;
+		afb_req_success(memo->req, object, *info ? info : NULL);
+	} else {
+		/* failing to have the answer */
+		afb_req_fail(memo->req, "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->context->flags = (unsigned)flags;
+		afb_req_fail(memo->req, status, *info ? info : NULL);
+	} else {
+		/* failing to have the answer */
+		afb_req_fail(memo->req, "error", "ws error");
+	}
+	api_ws_client_memo_destroy(memo);
+}
+
+static void api_ws_client_reply_send(struct api_ws *api, struct readbuf *rb)
+{
+	struct api_ws_memo *memo;
+	const char *data;
+	size_t length;
+	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, &data, &length)) {
+		memo->context->flags = (unsigned)flags;
+		afb_req_send(memo->req, data, length);
+	} else {
+		/* failing to have the answer */
+		afb_req_fail(memo->req, "error", "ws error");
+	}
+	api_ws_client_memo_destroy(memo);
+}
+
+/* callback when receiving binary data */
+static void api_ws_client_on_binary(void *closure, char *data, size_t size)
+{
+	if (size > 0) {
+		struct readbuf rb = { .head = data, .end = data + size };
+		switch (*rb.head++) {
+		case 'T': /* success */
+			api_ws_client_reply_success(closure, &rb);
+			break;
+		case 'F': /* fail */
+			api_ws_client_reply_fail(closure, &rb);
+			break;
+		case 'X': /* send */
+			api_ws_client_reply_send(closure, &rb);
+			break;
+		case '*': /* broadcast */
+			api_ws_client_event_broadcast(closure, &rb);
+			break;
+		case '+': /* creates the event */
+			api_ws_client_event_create(closure, &rb);
+			break;
+		case '-': /* drops the event */
+			api_ws_client_event_drop(closure, &rb);
+			break;
+		case '!': /* pushs the event */
+			api_ws_client_event_push(closure, &rb);
+			break;
+		case 'S': /* subscribe event for a request */
+			api_ws_client_event_subscribe(closure, &rb);
+			break;
+		case 'U': /* unsubscribe event for a request */
+			api_ws_client_event_unsubscribe(closure, &rb);
+			break;
+		default: /* unexpected message */
+			break;
+		}
+	}
+}
+
+/* on call, propagate it to the ws service */
+static void api_ws_client_call(struct api_ws *api, struct afb_req req, struct afb_context *context, const char *verb, size_t lenverb)
+{
+	int rc;
+	struct api_ws_memo *memo;
+	struct writebuf wb = { .count = 0 };
+	const char *raw;
+	size_t szraw;
+
+	/* create the recording data */
+	memo = api_ws_client_memo_make(api, req, context);
+	if (memo == NULL) {
+		afb_req_fail(req, "error", "out of memory");
+		return;
+	}
+
+	/* creates the call message */
+	raw = afb_req_raw(req, &szraw);
+	if (raw == NULL)
+		goto internal_error;
+	if (!api_ws_write_uint32(&wb, memo->msgid)
+	 || !api_ws_write_uint32(&wb, (uint32_t)context->flags)
+	 || !api_ws_write_string_nz(&wb, verb, lenverb)
+	 || !api_ws_write_string(&wb, ctxClientGetUuid(context->session))
+	 || !api_ws_write_string_length(&wb, raw, szraw))
+		goto overflow;
+
+	/* send */
+	rc = afb_ws_binary_v(api->client.ws, wb.iovec, wb.count);
+	if (rc < 0)
+		goto ws_send_error;
+	return;
+
+ws_send_error:
+	afb_req_fail(req, "error", "websocket sending error");
+	goto clean_memo;
+
+internal_error:
+	afb_req_fail(req, "error", "internal: raw is NULL!");
+	goto clean_memo;
+
+overflow:
+	afb_req_fail(req, "error", "overflow: size doesn't match 32 bits!");
+
+clean_memo:
+	api_ws_client_memo_destroy(memo);
+}
+
+static int api_ws_service_start(struct api_ws *api, int share_session, int onneed)
+{
+	/* not an error when onneed */
+	if (onneed != 0)
+		return 0;
+
+	/* already started: it is an error */
+	ERROR("The WS binding %s is not a startable service", api->path);
+	return -1;
+}
+
+/*  */
+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;
+}
+
+/* adds a afb-ws-service client api */
+int afb_api_ws_add_client(const char *path)
+{
+	int rc;
+	struct api_ws *api;
+	struct afb_api afb_api;
+
+	/* create the ws client api */
+	api = api_ws_make(path);
+	if (api == 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);
+		goto error2;
+	}
+
+	/* record it as an API */
+	afb_api.closure = api;
+	afb_api.call = (void*)api_ws_client_call;
+	afb_api.service_start = (void*)api_ws_service_start;
+	if (afb_apis_add(api->api, afb_api) < 0)
+		goto error3;
+
+	return 0;
+
+error3:
+	api_ws_client_disconnect(api);
+error2:
+	free(api);
+error:
+	return -1;
+}
+
+/******************* client description part for server *****************************/
+
+static void api_ws_server_client_unref(struct api_ws_client *client)
+{
+	if (!--client->refcount) {
+		afb_evt_listener_unref(client->listener);
+		afb_ws_destroy(client->ws);
+		free(client);
+	}
+}
+
+/* on call, propagate it to the ws service */
+static void api_ws_server_called(struct api_ws_client *client, struct readbuf *rb, char *data, size_t size)
+{
+	struct api_ws_server_req *wreq;
+	struct afb_req areq;
+	const char *uuid, *verb;
+	uint32_t flags;
+
+	client->refcount++;
+
+	/* create the request */
+	wreq = calloc(1 , sizeof *wreq);
+	if (wreq == NULL)
+		goto out_of_memory;
+
+	wreq->client = client;
+	wreq->rcvdata = data;
+	wreq->refcount = 1;
+
+	/* reads the call message data */
+	if (!api_ws_read_uint32(rb, &wreq->msgid)
+	 || !api_ws_read_uint32(rb, &flags)
+	 || !api_ws_read_string(rb, &verb, NULL)
+	 || !api_ws_read_string(rb, &uuid, NULL)
+	 || !api_ws_read_string(rb, &wreq->request, &wreq->lenreq))
+		goto overflow;
+
+	/* init the context */
+	if (afb_context_connect(&wreq->context, uuid, NULL) < 0)
+		goto out_of_memory;
+	wreq->context.flags = flags;
+
+	/* makes the call */
+	areq.itf = &afb_api_ws_req_itf;
+	areq.closure = wreq;
+	afb_apis_call_(areq, &wreq->context, client->api, verb);
+	api_ws_server_req_unref(wreq);
+	return;
+
+out_of_memory:
+overflow:
+	free(wreq);
+	free(data);
+	api_ws_server_client_unref(client);
+}
+
+/* callback when receiving binary data */
+static void api_ws_server_on_binary(void *closure, char *data, size_t size)
+{
+	struct readbuf rb = { .head = data, .end = data + size };
+	api_ws_server_called(closure, &rb, data, size);
+}
+
+/* callback when receiving a hangup */
+static void api_ws_server_on_hangup(void *closure)
+{
+	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);
+}
+
+static void api_ws_server_accept(struct api_ws *api)
+{
+	struct api_ws_client *client;
+	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->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->refcount = 1;
+					return;
+				}
+				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, '+', event, eventid, NULL);
+}
+
+static void api_ws_server_event_remove(void *closure, const char *event, int eventid)
+{
+	api_ws_server_event_send(closure, '-', 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, '!', 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, '*') && 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 *****************/
+
+/* increment the reference count of the request */
+static void api_ws_server_req_addref(struct api_ws_server_req *wreq)
+{
+	wreq->refcount++;
+}
+
+/* decrement the reference count of the request and free/release it on falling to null */
+static void api_ws_server_req_unref(struct api_ws_server_req *wreq)
+{
+	if (wreq == NULL || --wreq->refcount)
+		return;
+
+	afb_context_disconnect(&wreq->context);
+	json_object_put(wreq->json);
+	free(wreq->rcvdata);
+	api_ws_server_client_unref(wreq->client);
+	free(wreq);
+}
+
+/* get the object of the request */
+static struct json_object *api_ws_server_req_json(struct api_ws_server_req *wreq)
+{
+	if (wreq->json == NULL) {
+		wreq->json = json_tokener_parse(wreq->request);
+		if (wreq->json == NULL && strcmp(wreq->request, "null")) {
+			/* lazy error detection of json request. Is it to improve? */
+			wreq->json = json_object_new_string(wreq->request);
+		}
+	}
+	return wreq->json;
+}
+
+/* get the argument of the request of 'name' */
+static struct afb_arg api_ws_server_req_get(struct api_ws_server_req *wreq, const char *name)
+{
+	return afb_msg_json_get_arg(api_ws_server_req_json(wreq), name);
+}
+
+static void api_ws_server_req_success(struct api_ws_server_req *wreq, struct json_object *obj, const char *info)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+
+	if (api_ws_write_char(&wb, 'T')
+	 && api_ws_write_uint32(&wb, wreq->msgid)
+	 && api_ws_write_uint32(&wb, (uint32_t)wreq->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(struct api_ws_server_req *wreq, const char *status, const char *info)
+{
+	int rc;
+	struct writebuf wb = { .count = 0 };
+
+	if (api_ws_write_char(&wb, 'F')
+	 && api_ws_write_uint32(&wb, wreq->msgid)
+	 && api_ws_write_uint32(&wb, (uint32_t)wreq->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);
+		if (rc >= 0)
+			return;
+	}
+	ERROR("error while sending fail");
+}
+
+static const char *api_ws_server_req_raw(struct api_ws_server_req *wreq, size_t *size)
+{
+	if (size != NULL)
+		*size = wreq->lenreq;
+	return wreq->request;
+}
+
+static void api_ws_server_req_send(struct api_ws_server_req *wreq, const char *buffer, size_t size)
+{
+	/* TODO: how to put sized buffer as strings? things aren't clear here!!! */
+	int rc;
+	struct writebuf wb = { .count = 0 };
+
+	if (api_ws_write_char(&wb, 'X')
+	 && api_ws_write_uint32(&wb, wreq->msgid)
+	 && api_ws_write_uint32(&wb, (uint32_t)wreq->context.flags)
+	 && api_ws_write_string_length(&wb, buffer, size)) {
+		rc = afb_ws_binary_v(wreq->client->ws, wb.iovec, wb.count);
+		if (rc >= 0)
+			return;
+	}
+	ERROR("error while sending raw");
+}
+
+static int api_ws_server_req_subscribe(struct api_ws_server_req *wreq, struct afb_event event)
+{
+	int rc, rc2;
+	struct writebuf wb = { .count = 0 };
+
+	rc = afb_evt_add_watch(wreq->client->listener, event);
+	if (rc < 0)
+		return rc;
+
+	if (api_ws_write_char(&wb, 'S')
+	 && 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(struct api_ws_server_req *wreq, struct afb_event event)
+{
+	int rc, rc2;
+	struct writebuf wb = { .count = 0 };
+
+	if (api_ws_write_char(&wb, 'U')
+	 && 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;
+}
+
+static void api_ws_server_req_subcall(struct api_ws_server_req *wreq, const char *api, const char *verb, struct json_object *args, void (*callback)(void*, int, struct json_object*), void *closure)
+{
+	afb_subcall(&wreq->context, api, verb, args, callback, closure, (struct afb_req){ .itf = &afb_api_ws_req_itf, .closure = wreq });
+}
+
+/******************* server part **********************************/
+
+static int api_ws_server_connect(struct api_ws *api);
+
+static int api_ws_server_listen_callback(sd_event_source *src, int fd, uint32_t revents, void *closure)
+{
+	if ((revents & EPOLLIN) != 0)
+		api_ws_server_accept(closure);
+	if ((revents & EPOLLHUP) != 0)
+		api_ws_server_connect(closure);
+	return 0;
+}
+
+static void api_ws_server_disconnect(struct api_ws *api)
+{
+	if (api->server.listensrc != NULL) {
+		sd_event_source_unref(api->server.listensrc);
+		api->server.listensrc = NULL;
+	}
+	if (api->fd >= 0) {
+		close(api->fd);
+		api->fd = -1;
+	}
+}
+
+static int api_ws_server_connect(struct api_ws *api)
+{
+	int rc;
+
+	/* ensure disconnected */
+	api_ws_server_disconnect(api);
+
+	/* 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);
+	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);
+		if (rc >= 0)
+			return 0;
+		close(api->fd);
+		errno = -rc;
+		ERROR("can't add ws object %s", api->path);
+	}
+	return -1;
+}
+
+/* create the service */
+int afb_api_ws_add_server(const char *path)
+{
+	int rc;
+	struct api_ws *api;
+
+	/* creates the ws api object */
+	api = api_ws_make(path);
+	if (api == NULL)
+		goto error;
+
+	/* connect for serving */
+	rc = api_ws_server_connect(api);
+	if (rc < 0)
+		goto error2;
+
+	return 0;
+
+error2:
+	free(api);
+error:
+	return -1;
+}
+
+
diff --git a/src/afb-api-ws.h b/src/afb-api-ws.h
new file mode 100644
index 00000000..aef02d5b
--- /dev/null
+++ b/src/afb-api-ws.h
@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2016 "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_req_itf;
+
+extern const struct afb_req_itf afb_api_ws_req_itf;
+
+extern int afb_api_ws_add_client(const char *path);
+
+extern int afb_api_ws_add_server(const char *path);
+
+
diff --git a/src/main.c b/src/main.c
index c474fafa..cb44bdfa 100644
--- a/src/main.c
+++ b/src/main.c
@@ -34,6 +34,7 @@
 #include "afb-apis.h"
 #include "afb-api-so.h"
 #include "afb-api-dbus.h"
+#include "afb-api-ws.h"
 #include "afb-hsrv.h"
 #include "afb-context.h"
 #include "afb-hreq.h"
@@ -81,6 +82,9 @@
 
 #define SET_SESSIONMAX     23
 
+#define WS_CLIENT          24
+#define WS_SERVICE         25
+
 // Command line structure hold cli --command + help text
 typedef struct {
   int  val;        // command number within application
@@ -120,6 +124,8 @@ static  AFB_options cliOptions [] = {
 
   {DBUS_CLIENT      ,1,"dbus-client"     , "bind to an afb service through dbus"},
   {DBUS_SERVICE     ,1,"dbus-server"     , "provides an afb service through dbus"},
+  {WS_CLIENT        ,1,"ws-client"       , "bind to an afb service through websocket"},
+  {WS_SERVICE       ,1,"ws-server"       , "provides an afb service through websockets"},
   {SO_BINDING       ,1,"binding"         , "load the binding of path"},
 
   {SET_SESSIONMAX   ,1,"session-max"     , "max count of session simultaneously [default 10]"},
@@ -384,6 +390,8 @@ static void parse_arguments(int argc, char *argv[], struct afb_config *config)
 
     case DBUS_CLIENT:
     case DBUS_SERVICE:
+    case WS_CLIENT:
+    case WS_SERVICE:
     case SO_BINDING:
        if (optarg == 0) goto needValueForOption;
        add_item(config, optc, optarg);
@@ -559,6 +567,18 @@ static void start_items(struct afb_config_item *item)
 	exit(1);
       }
       break;
+    case WS_CLIENT:
+      if (afb_api_ws_add_client(item->value) < 0) {
+        ERROR("can't start the afb-websocket client of path %s",item->value);
+	exit(1);
+      }
+      break;
+    case WS_SERVICE:
+      if (afb_api_ws_add_server(item->value) < 0) {
+        ERROR("can't start the afb-websocket service of path %s",item->value);
+	exit(1);
+      }
+      break;
     case SO_BINDING:
       if (afb_api_so_add_binding(item->value) < 0) {
         ERROR("can't start the binding of path %s",item->value);