libubus.h

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/*
 * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */
 
#ifndef __LIBUBUS_H
#define __LIBUBUS_H
 
#ifdef __cplusplus
extern "C" {
#endif
 
#include <libubox/avl.h>
#include <libubox/list.h>
#include <libubox/blobmsg.h>
#include <libubox/uloop.h>
#include <stdint.h>
#include "ubusmsg.h"
#include "ubus_common.h"
 
#define UBUS_MAX_NOTIFY_PEERS   16
 
struct ubus_context;
struct ubus_msg_src;
struct ubus_object;
struct ubus_request;
struct ubus_request_data;
struct ubus_object_data;
struct ubus_event_handler;
struct ubus_subscriber;
struct ubus_notify_request;
 
struct ubus_msghdr_buf {
        struct ubus_msghdr hdr;
        struct blob_attr *data;
};
 
typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
                                      struct ubus_object_data *obj,
                                      void *priv);
typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
                              struct ubus_request_data *req,
                              const char *method, struct blob_attr *msg);
typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
                                      struct ubus_subscriber *obj, uint32_t id);
typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
                                     const char *type, struct blob_attr *msg);
typedef void (*ubus_data_handler_t)(struct ubus_request *req,
                                    int type, struct blob_attr *msg);
typedef void (*ubus_fd_handler_t)(struct ubus_request *req, int fd);
typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
typedef void (*ubus_notify_complete_handler_t)(struct ubus_notify_request *req,
                                               int idx, int ret);
typedef void (*ubus_notify_data_handler_t)(struct ubus_notify_request *req,
                                           int type, struct blob_attr *msg);
typedef void (*ubus_connect_handler_t)(struct ubus_context *ctx);
typedef bool (*ubus_new_object_handler_t)(struct ubus_context *ctx, struct ubus_subscriber *sub, const char *path);
 
#define UBUS_OBJECT_TYPE(_name, _methods)               \
        {                                               \
                .name = _name,                          \
                .id = 0,                                \
                .n_methods = ARRAY_SIZE(_methods),      \
                .methods = _methods                     \
        }
 
#define __UBUS_METHOD_NOARG(_name, _handler, _tags)     \
        .name = _name,                                  \
        .handler = _handler,                            \
        .tags = _tags
 
#define __UBUS_METHOD(_name, _handler, _policy, _tags)  \
        __UBUS_METHOD_NOARG(_name, _handler, _tags),    \
        .policy = _policy,                              \
        .n_policy = ARRAY_SIZE(_policy)
 
#define UBUS_METHOD(_name, _handler, _policy)           \
        { __UBUS_METHOD(_name, _handler, _policy, 0) }
 
#define UBUS_METHOD_TAG(_name, _handler, _policy, _tags)\
        { __UBUS_METHOD(_name, _handler, _policy, _tags) }
 
#define UBUS_METHOD_MASK(_name, _handler, _policy, _mask) \
        {                                               \
                __UBUS_METHOD(_name, _handler, _policy, 0),\
                .mask = _mask                           \
        }
 
#define UBUS_METHOD_NOARG(_name, _handler)              \
        { __UBUS_METHOD_NOARG(_name, _handler, 0) }
 
#define UBUS_METHOD_TAG_NOARG(_name, _handler, _tags)   \
        { __UBUS_METHOD_NOARG(_name, _handler, _tags) }
 
#define UBUS_TAG_STATUS         BIT(0)
#define UBUS_TAG_ADMIN          BIT(1)
#define UBUS_TAG_PRIVATE        BIT(2)
 
struct ubus_method {
        const char *name;
        ubus_handler_t handler;
 
        unsigned long mask;
        unsigned long tags;
        const struct blobmsg_policy *policy;
        int n_policy;
};
 
struct ubus_object_type {
        const char *name;
        uint32_t id;
 
        const struct ubus_method *methods;
        int n_methods;
};
 
struct ubus_object {
        struct avl_node avl;
 
        const char *name;
        uint32_t id;
 
        const char *path;
        struct ubus_object_type *type;
 
        ubus_state_handler_t subscribe_cb;
        bool has_subscribers;
 
        const struct ubus_method *methods;
        int n_methods;
};
 
struct ubus_subscriber {
        struct list_head list;
        struct ubus_object obj;
 
        ubus_handler_t cb;
        ubus_remove_handler_t remove_cb;
        ubus_new_object_handler_t new_obj_cb;
};
 
struct ubus_event_handler {
        struct ubus_object obj;
 
        ubus_event_handler_t cb;
};
 
struct ubus_context {
        struct list_head requests;
        struct avl_tree objects;
        struct list_head pending;
 
        struct uloop_fd sock;
        struct uloop_timeout pending_timer;
 
        uint32_t local_id;
        uint16_t request_seq;
        bool cancel_poll;
        int stack_depth;
 
        void (*connection_lost)(struct ubus_context *ctx);
        void (*monitor_cb)(struct ubus_context *ctx, uint32_t seq, struct blob_attr *data);
 
        struct ubus_msghdr_buf msgbuf;
        uint32_t msgbuf_data_len;
        int msgbuf_reduction_counter;
 
        struct list_head auto_subscribers;
        struct ubus_event_handler auto_subscribe_event_handler;
};
 
struct ubus_object_data {
        uint32_t id;
        uint32_t type_id;
        const char *path;
        struct blob_attr *signature;
};
 
struct ubus_acl_key {
        const char *user;
        const char *group;
        const char *object;
};
 
struct ubus_request_data {
        uint32_t object;
        uint32_t peer;
        uint16_t seq;
 
        struct ubus_acl_key acl;
 
        /* internal use */
        bool deferred;
        int fd;
        int req_fd; /* fd received from the initial request */
};
 
struct ubus_request {
        struct list_head list;
 
        struct list_head pending;
        int status_code;
        bool status_msg;
        bool blocked;
        bool cancelled;
        bool notify;
 
        uint32_t peer;
        uint16_t seq;
 
        ubus_data_handler_t raw_data_cb;
        ubus_data_handler_t data_cb;
        ubus_fd_handler_t fd_cb;
        ubus_complete_handler_t complete_cb;
 
        int fd;
 
        struct ubus_context *ctx;
        void *priv;
};
 
struct ubus_notify_request {
        struct ubus_request req;
 
        ubus_notify_complete_handler_t status_cb;
        ubus_notify_complete_handler_t complete_cb;
        ubus_notify_data_handler_t data_cb;
 
        uint32_t pending;
        uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
};
 
struct ubus_auto_conn {
        struct ubus_context ctx;
        struct uloop_timeout timer;
        const char *path;
        ubus_connect_handler_t cb;
};
 
struct ubus_context *ubus_connect(const char *path);
int ubus_connect_ctx(struct ubus_context *ctx, const char *path);
void ubus_auto_connect(struct ubus_auto_conn *conn);
int ubus_reconnect(struct ubus_context *ctx, const char *path);
 
/* call this only for struct ubus_context pointers returned by ubus_connect() */
void ubus_free(struct ubus_context *ctx);
 
/* call this only for struct ubus_context pointers initialised by ubus_connect_ctx() */
void ubus_shutdown(struct ubus_context *ctx);
 
static inline void ubus_auto_shutdown(struct ubus_auto_conn *conn)
{
        uloop_timeout_cancel(&conn->timer);
        ubus_shutdown(&conn->ctx);
}
 
const char *ubus_strerror(int error);
 
static inline void ubus_add_uloop(struct ubus_context *ctx)
{
        uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
}
 
/* call this for read events on ctx->sock.fd when not using uloop */
static inline void ubus_handle_event(struct ubus_context *ctx)
{
        ctx->sock.cb(&ctx->sock, ULOOP_READ);
}
 
/* ----------- raw request handling ----------- */
 
/* wait for a request to complete and return its status */
int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
                          int timeout);
 
/* complete a request asynchronously */
void ubus_complete_request_async(struct ubus_context *ctx,
                                 struct ubus_request *req);
 
/* abort an asynchronous request */
void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 
/* ----------- objects ----------- */
 
int ubus_lookup(struct ubus_context *ctx, const char *path,
                ubus_lookup_handler_t cb, void *priv);
 
int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 
/* make an object visible to remote connections */
int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 
/* remove the object from the ubus connection */
int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 
/* add a subscriber notifications from another object */
int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 
static inline int
ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
{
        if (!list_empty(&obj->list))
                list_del_init(&obj->list);
        return ubus_remove_object(ctx, &obj->obj);
}
 
int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 
int __ubus_monitor(struct ubus_context *ctx, const char *type);
 
static inline int ubus_monitor_start(struct ubus_context *ctx)
{
        return __ubus_monitor(ctx, "add");
}
 
static inline int ubus_monitor_stop(struct ubus_context *ctx)
{
        return __ubus_monitor(ctx, "remove");
}
 
 
/* ----------- acl ----------- */
 
struct acl_object {
        struct ubus_acl_key key;
        struct avl_node avl;
        struct blob_attr *acl;
};
 
extern struct avl_tree acl_objects;
int ubus_register_acl(struct ubus_context *ctx);
 
#define acl_for_each(o, m) \
        if ((m)->object && (m)->user && (m)->group) \
                avl_for_element_range(avl_find_ge_element(&acl_objects, m, o, avl), avl_find_le_element(&acl_objects, m, o, avl), o, avl)
 
/* ----------- rpc ----------- */
 
/* invoke a method on a specific object */
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);
static inline 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)
{
        return ubus_invoke_fd(ctx, obj, method, msg, cb, priv, timeout, -1);
}
 
/* 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);
static inline int
ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
                  struct blob_attr *msg, struct ubus_request *req)
{
        return ubus_invoke_async_fd(ctx, obj, method, msg, req, -1);
}
 
/* 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);
 
static inline void ubus_defer_request(struct ubus_context *ctx,
                                      struct ubus_request_data *req,
                                      struct ubus_request_data *new_req)
{
    (void) ctx;
    memcpy(new_req, req, sizeof(*req));
    req->deferred = true;
}
 
static inline void ubus_request_set_fd(struct ubus_context *ctx,
                                       struct ubus_request_data *req, int fd)
{
    (void) 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);
 
/*
 * send a notification to all subscribers of an object
 * if timeout < 0, no reply is expected from subscribers
 */
int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
                const char *type, struct blob_attr *msg, int timeout);
 
int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
                      const char *type, struct blob_attr *msg,
                      struct ubus_notify_request *req);
 
 
/* ----------- events ----------- */
 
int ubus_send_event(struct ubus_context *ctx, const char *id,
                    struct blob_attr *data);
 
int ubus_register_event_handler(struct ubus_context *ctx,
                                struct ubus_event_handler *ev,
                                const char *pattern);
 
static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
                                                struct ubus_event_handler *ev)
{
    return ubus_remove_object(ctx, &ev->obj);
}
 
#ifdef __cplusplus
}
#endif
 
#endif