libubus.h

   1 /*
   2  * Copyright (C) 2011 Felix Fietkau <nbd@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU Lesser General Public License version 2.1
   6  * as published by the Free Software Foundation
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #ifndef __LIBUBUS_H
  15 #define __LIBUBUS_H
  16
  17 #include <libubox/avl.h>
  18 #include <libubox/list.h>
  19 #include <libubox/blobmsg.h>
  20 #include <libubox/uloop.h>
  21 #include <stdint.h>
  22 #include "ubusmsg.h"
  23 #include "ubus_common.h"
  24
  25 struct ubus_context;
  26 struct ubus_msg_src;
  27 struct ubus_object;
  28 struct ubus_request;
  29 struct ubus_request_data;
  30 struct ubus_object_data;
  31 struct ubus_event_handler;
  32 struct ubus_subscriber;
  33
  34 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  35                                       struct ubus_object_data *obj,
  36                                       void *priv);
  37 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  38                               struct ubus_request_data *req,
  39                               const char *method, struct blob_attr *msg);
  40 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  41 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  42                                       struct ubus_subscriber *obj, uint32_t id);
  43 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  44                                      const char *type, struct blob_attr *msg);
  45 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  46                                     int type, struct blob_attr *msg);
  47 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  48
  49 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  50         {                                               \
  51                 .name = _name,                          \
  52                 .id = 0,                                \
  53                 .n_methods = ARRAY_SIZE(_methods),      \
  54                 .methods = _methods                     \
  55         }
  56
  57 #define UBUS_METHOD(_name, _handler, _policy)           \
  58         {                                               \
  59                 .name = _name,                          \
  60                 .handler = _handler,                    \
  61                 .policy = _policy,                      \
  62                 .n_policy = ARRAY_SIZE(_policy)         \
  63         }
  64
  65 struct ubus_method {
  66         const char *name;
  67         ubus_handler_t handler;
  68
  69         const struct blobmsg_policy *policy;
  70         int n_policy;
  71 };
  72
  73 struct ubus_object_type {
  74         const char *name;
  75         uint32_t id;
  76
  77         const struct ubus_method *methods;
  78         int n_methods;
  79 };
  80
  81 struct ubus_object {
  82         struct avl_node avl;
  83
  84         const char *name;
  85         uint32_t id;
  86
  87         const char *path;
  88         struct ubus_object_type *type;
  89
  90         ubus_state_handler_t subscribe_cb;
  91         bool has_subscribers;
  92
  93         const struct ubus_method *methods;
  94         int n_methods;
  95 };
  96
  97 struct ubus_subscriber {
  98         struct ubus_object obj;
  99
 100         ubus_handler_t cb;
 101         ubus_remove_handler_t remove_cb;
 102 };
 103
 104 struct ubus_event_handler {
 105         struct ubus_object obj;
 106
 107         ubus_event_handler_t cb;
 108 };
 109
 110 struct ubus_context {
 111         struct list_head requests;
 112         struct avl_tree objects;
 113         struct list_head pending;
 114
 115         struct uloop_fd sock;
 116
 117         uint32_t local_id;
 118         uint32_t request_seq;
 119         int stack_depth;
 120
 121         void (*connection_lost)(struct ubus_context *ctx);
 122
 123         struct {
 124                 struct ubus_msghdr hdr;
 125                 char data[UBUS_MAX_MSGLEN];
 126         } msgbuf;
 127 };
 128
 129 struct ubus_object_data {
 130         uint32_t id;
 131         uint32_t type_id;
 132         const char *path;
 133         struct blob_attr *signature;
 134 };
 135
 136 struct ubus_request_data {
 137         uint32_t object;
 138         uint32_t peer;
 139         uint32_t seq;
 140         bool deferred;
 141         bool notify;
 142 };
 143
 144 struct ubus_request {
 145         struct list_head list;
 146
 147         struct list_head pending;
 148         bool status_msg;
 149         int status_code;
 150         bool blocked;
 151         bool cancelled;
 152
 153         uint32_t peer;
 154         uint32_t seq;
 155
 156         ubus_data_handler_t raw_data_cb;
 157         ubus_data_handler_t data_cb;
 158         ubus_complete_handler_t complete_cb;
 159
 160         struct ubus_context *ctx;
 161         void *priv;
 162 };
 163
 164
 165 struct ubus_context *ubus_connect(const char *path);
 166 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 167 void ubus_free(struct ubus_context *ctx);
 168
 169 const char *ubus_strerror(int error);
 170
 171 static inline void ubus_add_uloop(struct ubus_context *ctx)
 172 {
 173         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 174 }
 175
 176 /* call this for read events on ctx->sock.fd when not using uloop */
 177 static inline void ubus_handle_event(struct ubus_context *ctx)
 178 {
 179         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 180 }
 181
 182 /* ----------- raw request handling ----------- */
 183
 184 /* wait for a request to complete and return its status */
 185 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 186                           int timeout);
 187
 188 /* complete a request asynchronously */
 189 void ubus_complete_request_async(struct ubus_context *ctx,
 190                                  struct ubus_request *req);
 191
 192 /* abort an asynchronous request */
 193 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 194
 195 /* ----------- objects ----------- */
 196
 197 int ubus_lookup(struct ubus_context *ctx, const char *path,
 198                 ubus_lookup_handler_t cb, void *priv);
 199
 200 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 201
 202 /* make an object visible to remote connections */
 203 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 204
 205 /* remove the object from the ubus connection */
 206 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 207
 208 /* add a subscriber notifications from another object */
 209 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 210 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 211 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 212
 213 /* ----------- rpc ----------- */
 214
 215 /* invoke a method on a specific object */
 216 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 217                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 218                 int timeout);
 219
 220 /* asynchronous version of ubus_invoke() */
 221 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 222                       struct blob_attr *msg, struct ubus_request *req);
 223
 224 /* send a reply to an incoming object method call */
 225 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 226                     struct blob_attr *msg);
 227
 228 static inline void ubus_defer_request(struct ubus_context *ctx,
 229                                       struct ubus_request_data *req,
 230                                       struct ubus_request_data *new_req)
 231 {
 232     memcpy(new_req, req, sizeof(*req));
 233     req->deferred = true;
 234 }
 235
 236 void ubus_complete_deferred_request(struct ubus_context *ctx,
 237                                     struct ubus_request_data *req, int ret);
 238
 239 /* ----------- events ----------- */
 240
 241 int ubus_send_event(struct ubus_context *ctx, const char *id,
 242                     struct blob_attr *data);
 243
 244 int ubus_register_event_handler(struct ubus_context *ctx,
 245                                 struct ubus_event_handler *ev,
 246                                 const char *pattern);
 247
 248 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 249                                                 struct ubus_event_handler *ev)
 250 {
 251     return ubus_remove_object(ctx, &ev->obj);
 252 }
 253
 254 #endif