libubus.h

   1 /*
   2  * Copyright (C) 2011-2012 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 #define UBUS_MAX_NOTIFY_PEERS   16
  26
  27 struct ubus_context;
  28 struct ubus_msg_src;
  29 struct ubus_object;
  30 struct ubus_request;
  31 struct ubus_request_data;
  32 struct ubus_object_data;
  33 struct ubus_event_handler;
  34 struct ubus_subscriber;
  35 struct ubus_notify_request;
  36
  37 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  38                                       struct ubus_object_data *obj,
  39                                       void *priv);
  40 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  41                               struct ubus_request_data *req,
  42                               const char *method, struct blob_attr *msg);
  43 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  44 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  45                                       struct ubus_subscriber *obj, uint32_t id);
  46 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  47                                      const char *type, struct blob_attr *msg);
  48 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  49                                     int type, struct blob_attr *msg);
  50 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  51 typedef void (*ubus_notify_complete_handler_t)(struct ubus_notify_request *req,
  52                                                int idx, int ret);
  53
  54 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  55         {                                               \
  56                 .name = _name,                          \
  57                 .id = 0,                                \
  58                 .n_methods = ARRAY_SIZE(_methods),      \
  59                 .methods = _methods                     \
  60         }
  61
  62 #define UBUS_METHOD(_name, _handler, _policy)           \
  63         {                                               \
  64                 .name = _name,                          \
  65                 .handler = _handler,                    \
  66                 .policy = _policy,                      \
  67                 .n_policy = ARRAY_SIZE(_policy)         \
  68         }
  69
  70 struct ubus_method {
  71         const char *name;
  72         ubus_handler_t handler;
  73
  74         const struct blobmsg_policy *policy;
  75         int n_policy;
  76 };
  77
  78 struct ubus_object_type {
  79         const char *name;
  80         uint32_t id;
  81
  82         const struct ubus_method *methods;
  83         int n_methods;
  84 };
  85
  86 struct ubus_object {
  87         struct avl_node avl;
  88
  89         const char *name;
  90         uint32_t id;
  91
  92         const char *path;
  93         struct ubus_object_type *type;
  94
  95         ubus_state_handler_t subscribe_cb;
  96         bool has_subscribers;
  97
  98         const struct ubus_method *methods;
  99         int n_methods;
 100 };
 101
 102 struct ubus_subscriber {
 103         struct ubus_object obj;
 104
 105         ubus_handler_t cb;
 106         ubus_remove_handler_t remove_cb;
 107 };
 108
 109 struct ubus_event_handler {
 110         struct ubus_object obj;
 111
 112         ubus_event_handler_t cb;
 113 };
 114
 115 struct ubus_context {
 116         struct list_head requests;
 117         struct avl_tree objects;
 118         struct list_head pending;
 119
 120         struct uloop_fd sock;
 121
 122         uint32_t local_id;
 123         uint16_t request_seq;
 124         int stack_depth;
 125
 126         void (*connection_lost)(struct ubus_context *ctx);
 127
 128         struct {
 129                 struct ubus_msghdr hdr;
 130                 char data[UBUS_MAX_MSGLEN];
 131         } msgbuf;
 132 };
 133
 134 struct ubus_object_data {
 135         uint32_t id;
 136         uint32_t type_id;
 137         const char *path;
 138         struct blob_attr *signature;
 139 };
 140
 141 struct ubus_request_data {
 142         uint32_t object;
 143         uint32_t peer;
 144         uint16_t seq;
 145         bool deferred;
 146 };
 147
 148 struct ubus_request {
 149         struct list_head list;
 150
 151         struct list_head pending;
 152         int status_code;
 153         bool status_msg;
 154         bool blocked;
 155         bool cancelled;
 156         bool notify;
 157
 158         uint32_t peer;
 159         uint16_t seq;
 160
 161         ubus_data_handler_t raw_data_cb;
 162         ubus_data_handler_t data_cb;
 163         ubus_complete_handler_t complete_cb;
 164
 165         struct ubus_context *ctx;
 166         void *priv;
 167 };
 168
 169 struct ubus_notify_request {
 170         struct ubus_request req;
 171
 172         ubus_notify_complete_handler_t status_cb;
 173         ubus_notify_complete_handler_t complete_cb;
 174
 175         uint32_t pending;
 176         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 177 };
 178
 179 struct ubus_context *ubus_connect(const char *path);
 180 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 181 void ubus_free(struct ubus_context *ctx);
 182
 183 const char *ubus_strerror(int error);
 184
 185 static inline void ubus_add_uloop(struct ubus_context *ctx)
 186 {
 187         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 188 }
 189
 190 /* call this for read events on ctx->sock.fd when not using uloop */
 191 static inline void ubus_handle_event(struct ubus_context *ctx)
 192 {
 193         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 194 }
 195
 196 /* ----------- raw request handling ----------- */
 197
 198 /* wait for a request to complete and return its status */
 199 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 200                           int timeout);
 201
 202 /* complete a request asynchronously */
 203 void ubus_complete_request_async(struct ubus_context *ctx,
 204                                  struct ubus_request *req);
 205
 206 /* abort an asynchronous request */
 207 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 208
 209 /* ----------- objects ----------- */
 210
 211 int ubus_lookup(struct ubus_context *ctx, const char *path,
 212                 ubus_lookup_handler_t cb, void *priv);
 213
 214 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 215
 216 /* make an object visible to remote connections */
 217 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 218
 219 /* remove the object from the ubus connection */
 220 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 221
 222 /* add a subscriber notifications from another object */
 223 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 224 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 225 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 226
 227 /* ----------- rpc ----------- */
 228
 229 /* invoke a method on a specific object */
 230 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 231                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 232                 int timeout);
 233
 234 /* asynchronous version of ubus_invoke() */
 235 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 236                       struct blob_attr *msg, struct ubus_request *req);
 237
 238 /* send a reply to an incoming object method call */
 239 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 240                     struct blob_attr *msg);
 241
 242 static inline void ubus_defer_request(struct ubus_context *ctx,
 243                                       struct ubus_request_data *req,
 244                                       struct ubus_request_data *new_req)
 245 {
 246     memcpy(new_req, req, sizeof(*req));
 247     req->deferred = true;
 248 }
 249
 250 void ubus_complete_deferred_request(struct ubus_context *ctx,
 251                                     struct ubus_request_data *req, int ret);
 252
 253 /*
 254  * send a notification to all subscribers of an object
 255  * if timeout < 0, no reply is expected from subscribers
 256  */
 257 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 258                 const char *type, struct blob_attr *msg, int timeout);
 259
 260 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 261                       const char *type, struct blob_attr *msg,
 262                       struct ubus_notify_request *req);
 263
 264
 265 /* ----------- events ----------- */
 266
 267 int ubus_send_event(struct ubus_context *ctx, const char *id,
 268                     struct blob_attr *data);
 269
 270 int ubus_register_event_handler(struct ubus_context *ctx,
 271                                 struct ubus_event_handler *ev,
 272                                 const char *pattern);
 273
 274 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 275                                                 struct ubus_event_handler *ev)
 276 {
 277     return ubus_remove_object(ctx, &ev->obj);
 278 }
 279
 280 #endif