[LEDE-DEV] [PATCH] Allow sending a fd in a ubus_request
John Crispin
john at phrozen.org
Thu Dec 8 04:56:21 PST 2016
On 08/12/2016 13:47, amine.ahd wrote:
> In the current implementation, a fd can be sent in the reply to an existing request which can be inefficient in certain cases.
> Example: when you want to create a pipe between two process with the help of a 3rd process acting as a manager: you need 3 pipe with the current implementation and only one pipe with this patch.
>
explain how you achieve this
> Basically the patch adds two new functions (ubus_invoke_fd and ubus_invoke_async_fd) that are very similar to the original functions (open to any other alternatives here) and a new msg type (UBUS_MSG_INVOKE_FD) to copy the received fd to req_fd when processing the invocation.
missing SoB here
> ---
> libubus-internal.h | 4 +++-
> libubus-obj.c | 19 ++++++++++++++-----
> libubus-req.c | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
> libubus.c | 3 ++-
> libubus.h | 9 +++++++++
> ubusd.c | 1 -
> ubusd_proto.c | 13 +++++++++++--
> ubusmsg.h | 2 ++
> 8 files changed, 90 insertions(+), 10 deletions(-)
>
> diff --git a/libubus-internal.h b/libubus-internal.h
> index f62edc3..9513fb7 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_fd(struct ubus_context *ctx, struct ubus_request *req,
> + struct blob_attr *msg, int cmd, uint32_t peer, int fd);
> +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..94af630 100644
> --- a/libubus-obj.c
> +++ b/libubus-obj.c
> @@ -44,11 +44,13 @@ ubus_process_notify(struct ubus_context *ctx, struct ubus_msghdr *hdr,
> }
> 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;
> @@ -94,11 +96,13 @@ found:
> 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 **);
> + void (*cb_fd)(struct ubus_context *, struct ubus_msghdr *,
> + struct ubus_object *, struct blob_attr **, int fd);
> struct ubus_msghdr *hdr = &buf->hdr;
> struct blob_attr **attrbuf;
> struct ubus_object *obj;
> @@ -114,7 +118,9 @@ void __hidden ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_
>
> switch (hdr->type) {
> case UBUS_MSG_INVOKE:
> - cb = ubus_process_invoke;
> + case UBUS_MSG_INVOKE_FD:
> + cb_fd = ubus_process_invoke;
> + cb = NULL;
> break;
> case UBUS_MSG_UNSUBSCRIBE:
> cb = ubus_process_unsubscribe;
> @@ -131,7 +137,10 @@ void __hidden ubus_process_obj_msg(struct ubus_context *ctx, struct ubus_msghdr_
> buf->data = NULL;
> }
>
> - cb(ctx, hdr, obj, attrbuf);
> + if (hdr->type == UBUS_MSG_INVOKE || hdr->type == UBUS_MSG_INVOKE_FD)
> + cb_fd(ctx, hdr, obj, attrbuf, fd);
> + else
> + cb(ctx, hdr, obj, attrbuf);
>
> if (prev_data) {
> if (buf->data)
> diff --git a/libubus-req.c b/libubus-req.c
> index 416adab..9913f1e 100644
> --- a/libubus-req.c
> +++ b/libubus-req.c
> @@ -62,9 +62,27 @@ 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);
> }
>
> +int __hidden ubus_start_request_fd(struct ubus_context *ctx, struct ubus_request *req,
> + struct blob_attr *msg, int cmd, uint32_t peer, int fd)
> +{
> + memset(req, 0, sizeof(*req));
> +
> + if (msg && blob_pad_len(msg) > UBUS_MAX_MSGLEN)
> + return -1;
> +
> + INIT_LIST_HEAD(&req->list);
> + INIT_LIST_HEAD(&req->pending);
> + req->ctx = ctx;
> + req->peer = peer;
> + req->seq = ++ctx->request_seq;
> +
> + return ubus_send_msg(ctx, req->seq, msg, cmd, peer, fd);
> +}
> +
> void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req)
> {
> if (list_empty(&req->list))
> @@ -224,6 +242,21 @@ 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));
> +
> + if (ubus_start_request_fd(ctx, req, b.head, UBUS_MSG_INVOKE_FD, obj, fd) < 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 +273,22 @@ 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..d9602e7 100644
> --- a/libubus.c
> +++ b/libubus.c
> @@ -96,6 +96,7 @@ ubus_process_msg(struct ubus_context *ctx, struct ubus_msghdr_buf *buf, int fd)
> break;
>
> case UBUS_MSG_INVOKE:
> + case UBUS_MSG_INVOKE_FD:
> case UBUS_MSG_UNSUBSCRIBE:
> case UBUS_MSG_NOTIFY:
> if (ctx->stack_depth) {
> @@ -103,7 +104,7 @@ 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..0a05416 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 {
> @@ -336,6 +337,14 @@ 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);
> diff --git a/ubusd.c b/ubusd.c
> index 7279a70..cf38c31 100644
> --- a/ubusd.c
> +++ b/ubusd.c
> @@ -345,7 +345,6 @@ static bool get_next_connection(int fd)
> uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
> else
> close(client_fd);
> -
> return true;
> }
>
> diff --git a/ubusd_proto.c b/ubusd_proto.c
> index b591384..596a981 100644
> --- a/ubusd_proto.c
> +++ b/ubusd_proto.c
> @@ -80,11 +80,16 @@ 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_FD */
> + int fd = ub->fd;
> ub = ubus_reply_from_blob(ub, true);
> if (!ub)
> return;
>
> ub->hdr.type = type;
> + if(type == UBUS_MSG_INVOKE_FD)
> + ub->fd = fd;
> +
> ubus_msg_send(cl, ub, true);
> }
>
> @@ -239,7 +244,10 @@ ubusd_forward_invoke(struct ubus_client *cl, struct ubus_object *obj,
> if (data)
> blob_put(&b, UBUS_ATTR_DATA, blob_data(data), blob_len(data));
>
> - ubus_proto_send_msg_from_blob(obj->client, ub, UBUS_MSG_INVOKE);
> + if (ub->hdr.type == UBUS_MSG_INVOKE_FD)
> + ubus_proto_send_msg_from_blob(obj->client, ub, UBUS_MSG_INVOKE_FD);
> + else
> + ubus_proto_send_msg_from_blob(obj->client, ub, UBUS_MSG_INVOKE);
> }
>
> static int ubusd_handle_invoke(struct ubus_client *cl, struct ubus_msg_buf *ub, struct blob_attr **attr)
> @@ -428,6 +436,7 @@ static const ubus_cmd_cb handlers[__UBUS_MSG_LAST] = {
> [UBUS_MSG_REMOVE_OBJECT] = ubusd_handle_remove_object,
> [UBUS_MSG_LOOKUP] = ubusd_handle_lookup,
> [UBUS_MSG_INVOKE] = ubusd_handle_invoke,
> + [UBUS_MSG_INVOKE_FD] = ubusd_handle_invoke,
> [UBUS_MSG_STATUS] = ubusd_handle_response,
> [UBUS_MSG_DATA] = ubusd_handle_response,
> [UBUS_MSG_SUBSCRIBE] = ubusd_handle_add_watch,
> @@ -446,7 +455,7 @@ 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_FD)
> ubus_msg_close_fd(ub);
>
> if (cb)
> diff --git a/ubusmsg.h b/ubusmsg.h
> index 398b126..aa3955c 100644
> --- a/ubusmsg.h
> +++ b/ubusmsg.h
> @@ -51,6 +51,8 @@ enum ubus_msg_type {
>
> /* invoke a method on a single object */
> UBUS_MSG_INVOKE,
> + /* invoke a method and send a fd along */
> + UBUS_MSG_INVOKE_FD,
>
> UBUS_MSG_ADD_OBJECT,
> UBUS_MSG_REMOVE_OBJECT,
>
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