Allow sending a fd along a ubus_request

Signed-off-by: amine.ahd <amine.ahd@gmail.com>

6 files changed, 91 insertions, 14 deletions

diff --git a/libubus-internal.h b/libubus-internal.h
index f62edc3..c4067d3 100644
--- a/libubus-internal.h
+++ b/libubus-internal.h
@@ -24,7 +24,9 @@ int ubus_send_msg(struct ubus_context *ctx, uint32_t seq,
 void ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd);
 int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 				struct blob_attr *msg, int cmd, uint32_t peer);
-void ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf);
+int __hidden __ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
+				struct blob_attr *msg, int cmd, uint32_t peer);
+void ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd);
 void ubus_process_req_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd);
 void __hidden ubus_poll_data(struct ubus_context *ctx, int timeout);
 
diff --git a/libubus-obj.c b/libubus-obj.c
index 990d04b..a9972c5 100644
--- a/libubus-obj.c
+++ b/libubus-obj.c
@@ -11,12 +11,13 @@
  * GNU General Public License for more details.
  */
 
+#include <unistd.h>
 #include "libubus.h"
 #include "libubus-internal.h"
 
 static void
 ubus_process_unsubscribe(struct ubus_context *ctx, struct ubus_msghdr *hdr,
-			 struct ubus_object *obj, struct blob_attr **attrbuf)
+			 struct ubus_object *obj, struct blob_attr **attrbuf, int fd)
 {
 	struct ubus_subscriber *s;
 
@@ -29,11 +30,13 @@ ubus_process_unsubscribe(struct ubus_context *ctx, struct ubus_msghdr *hdr,
 	s = container_of(obj, struct ubus_subscriber, obj);
 	if (s->remove_cb)
 		s->remove_cb(ctx, s, blob_get_u32(attrbuf[UBUS_ATTR_TARGET]));
+
+	close(fd);
 }
 
 static void
 ubus_process_notify(struct ubus_context *ctx, struct ubus_msghdr *hdr,
-		    struct ubus_object *obj, struct blob_attr **attrbuf)
+		    struct ubus_object *obj, struct blob_attr **attrbuf, int fd)
 {
 	if (!obj || !attrbuf[UBUS_ATTR_ACTIVE])
 		return;
@@ -41,14 +44,18 @@ ubus_process_notify(struct ubus_context *ctx, struct ubus_msghdr *hdr,
 	obj->has_subscribers = blob_get_u8(attrbuf[UBUS_ATTR_ACTIVE]);
 	if (obj->subscribe_cb)
 		obj->subscribe_cb(ctx, obj);
+
+	close(fd);
 }
 static void
 ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr,
-		    struct ubus_object *obj, struct blob_attr **attrbuf)
+		    struct ubus_object *obj, struct blob_attr **attrbuf, int fd)
 {
 	struct ubus_request_data req = {
 		.fd = -1,
+		.req_fd = fd,
 	};
+
 	int method;
 	int ret;
 	bool no_reply = false;
@@ -65,7 +72,7 @@ ubus_process_invoke(struct ubus_context *ctx, struct ubus_msghdr *hdr,
 
 	if (attrbuf[UBUS_ATTR_NO_REPLY])
 		no_reply = blob_get_int8(attrbuf[UBUS_ATTR_NO_REPLY]);
-
+		
 	req.peer = hdr->peer;
 	req.seq = hdr->seq;
 	req.object = obj->id;
@@ -88,6 +95,7 @@ found:
 	ret = obj->methods[method].handler(ctx, obj, &req,
 					   blob_data(attrbuf[UBUS_ATTR_METHOD]),
 					   attrbuf[UBUS_ATTR_DATA]);
+	close(req.req_fd);
 	if (req.deferred || no_reply)
 		return;
 
@@ -95,16 +103,16 @@ send:
 	ubus_complete_deferred_request(ctx, &req, ret);
 }
 
-void __hidden ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf)
+
+void __hidden ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 {
 	void (*cb)(struct ubus_context *, struct ubus_msghdr *,
-		   struct ubus_object *, struct blob_attr **);
+		   struct ubus_object *, struct blob_attr **, int fd);
 	struct ubus_msghdr *hdr = &buf->hdr;
 	struct blob_attr **attrbuf;
 	struct ubus_object *obj;
 	uint32_t objid;
 	void *prev_data = NULL;
-
 	attrbuf = ubus_parse_msg(buf->data);
 	if (!attrbuf[UBUS_ATTR_OBJID])
 		return;
@@ -131,7 +139,7 @@ void __hidden ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_
 		buf->data = NULL;
 	}
 
-	cb(ctx, hdr, obj, attrbuf);
+	cb(ctx, hdr, obj, attrbuf, fd);
 
 	if (prev_data) {
 		if (buf->data)
diff --git a/libubus-req.c b/libubus-req.c
index 416adab..5180a6f 100644
--- a/libubus-req.c
+++ b/libubus-req.c
@@ -49,10 +49,9 @@ static void __ubus_process_req_data(struct ubus_request *req)
 	}
 }
 
-int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
+int __hidden __ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
 				struct blob_attr *msg, int cmd, uint32_t peer)
 {
-	memset(req, 0, sizeof(*req));
 
 	if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
 		return -1;
@@ -62,9 +61,21 @@ int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *r
 	req->ctx = ctx;
 	req->peer = peer;
 	req->seq = ++ctx->request_seq;
-	return ubus_send_msg(ctx, req->seq, msg, cmd, peer, -1);
+
+	return ubus_send_msg(ctx, req->seq, msg, cmd, peer, req->fd);
 }
 
+int __hidden ubus_start_request(struct ubus_context *ctx, struct ubus_request *req,
+				struct blob_attr *msg, int cmd, uint32_t peer)
+{
+	memset(req, 0, sizeof(*req));
+
+	req->fd = -1;
+
+	return __ubus_start_request(ctx, req, msg, cmd, peer);
+}
+
+
 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
 {
 	if (list_empty(&req->list))
@@ -224,6 +235,23 @@ int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method
 	return 0;
 }
 
+
+int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
+                       struct blob_attr *msg, struct ubus_request *req, int fd)
+{
+	blob_buf_init(&b, 0);
+	blob_put_int32(&b, UBUS_ATTR_OBJID, obj);
+	blob_put_string(&b, UBUS_ATTR_METHOD, method);
+	if (msg)
+		blob_put(&b, UBUS_ATTR_DATA, blob_data(msg), blob_len(msg));
+
+	memset(req, 0, sizeof(*req));
+	req->fd = fd;
+	if (__ubus_start_request(ctx, req, b.head, UBUS_MSG_INVOKE, obj) < 0)
+		return UBUS_STATUS_INVALID_ARGUMENT;
+	return 0;
+}
+
 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 		int timeout)
@@ -240,6 +268,22 @@ int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 	return ubus_complete_request(ctx, &req, timeout);
 }
 
+int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
+                struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
+		int timeout, int fd)
+{
+	struct ubus_request req;
+	int rc;
+
+	rc = ubus_invoke_async_fd(ctx, obj, method, msg, &req, fd);
+	if (rc)
+		return rc;
+
+	req.data_cb = cb;
+	req.priv = priv;
+	return ubus_complete_request(ctx, &req, timeout);
+}
+
 static void
 ubus_notify_complete_cb(struct ubus_request *req, int ret)
 {
diff --git a/libubus.c b/libubus.c
index 8163ff7..b25d8b0 100644
--- a/libubus.c
+++ b/libubus.c
@@ -103,7 +103,7 @@ ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
 			break;
 		}
 
-		ubus_process_obj_msg(ctx, buf);
+		ubus_process_obj_msg(ctx, buf, fd);
 		break;
 	case UBUS_MSG_MONITOR:
 		if (ctx->monitor_cb)
diff --git a/libubus.h b/libubus.h
index 07239d6..350e694 100644
--- a/libubus.h
+++ b/libubus.h
@@ -188,6 +188,7 @@ struct ubus_request_data {
 	/* internal use */
 	bool deferred;
 	int fd;
+	int req_fd; /* fd received from the initial request */
 };
 
 struct ubus_request {
@@ -208,6 +209,8 @@ struct ubus_request {
 	ubus_fd_handler_t fd_cb;
 	ubus_complete_handler_t complete_cb;
 
+	int fd;
+
 	struct ubus_context *ctx;
 	void *priv;
 };
@@ -336,6 +339,14 @@ int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 		      struct blob_attr *msg, struct ubus_request *req);
 
+int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
+		struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
+		int timeout, int fd);
+
+/* asynchronous version of ubus_invoke() */
+int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
+		      struct blob_attr *msg, struct ubus_request *req, int fd);
+
 /* send a reply to an incoming object method call */
 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 		    struct blob_attr *msg);
@@ -356,6 +367,14 @@ static inline void ubus_request_set_fd(struct ubus_context *ctx,
     req->fd = fd;
 }
 
+static inline int ubus_request_get_caller_fd(struct ubus_request_data *req)
+{
+    int fd = req->req_fd;
+    req->req_fd = -1;
+    
+    return fd;
+}
+
 void ubus_complete_deferred_request(struct ubus_context *ctx,
 				    struct ubus_request_data *req, int ret);
 
diff --git a/ubusd_proto.c b/ubusd_proto.c
index d2feed9..72da7a7 100644
--- a/ubusd_proto.c
+++ b/ubusd_proto.c
@@ -80,11 +80,15 @@ void
 ubus_proto_send_msg_from_blob(struct ubus_client *cl, struct ubus_msg_buf *ub,
 			uint8_t type)
 {
+	/* keep the fd to be passed if it is UBUS_MSG_INVOKE */
+	int fd = ub->fd;
 	ub = ubus_reply_from_blob(ub, true);
 	if (!ub)
 		return;
 
 	ub->hdr.type = type;
+	ub->fd = fd;
+
 	ubus_msg_send(cl, ub, true);
 }
 
@@ -447,7 +451,7 @@ void ubusd_proto_receive_message(struct ubus_client *cl, struct ubus_msg_buf *ub
 	if (ub->hdr.type < __UBUS_MSG_LAST)
 		cb = handlers[ub->hdr.type];
 
-	if (ub->hdr.type != UBUS_MSG_STATUS)
+	if (ub->hdr.type != UBUS_MSG_STATUS && ub->hdr.type != UBUS_MSG_INVOKE)
 		ubus_msg_close_fd(ub);
 
 	if (cb)