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 #define UBUS_METHOD_NOARG(_name, _handler)              \
  71         {                                               \
  72                 .name = _name,                          \
  73                 .handler = _handler,                    \
  74         }
  75
  76 struct ubus_method {
  77         const char *name;
  78         ubus_handler_t handler;
  79
  80         const struct blobmsg_policy *policy;
  81         int n_policy;
  82 };
  83
  84 struct ubus_object_type {
  85         const char *name;
  86         uint32_t id;
  87
  88         const struct ubus_method *methods;
  89         int n_methods;
  90 };
  91
  92 struct ubus_object {
  93         struct avl_node avl;
  94
  95         const char *name;
  96         uint32_t id;
  97
  98         const char *path;
  99         struct ubus_object_type *type;
 100
 101         ubus_state_handler_t subscribe_cb;
 102         bool has_subscribers;
 103
 104         const struct ubus_method *methods;
 105         int n_methods;
 106 };
 107
 108 struct ubus_subscriber {
 109         struct ubus_object obj;
 110
 111         ubus_handler_t cb;
 112         ubus_remove_handler_t remove_cb;
 113 };
 114
 115 struct ubus_event_handler {
 116         struct ubus_object obj;
 117
 118         ubus_event_handler_t cb;
 119 };
 120
 121 struct ubus_context {
 122         struct list_head requests;
 123         struct avl_tree objects;
 124         struct list_head pending;
 125
 126         struct uloop_fd sock;
 127
 128         uint32_t local_id;
 129         uint16_t request_seq;
 130         int stack_depth;
 131
 132         void (*connection_lost)(struct ubus_context *ctx);
 133
 134         struct {
 135                 struct ubus_msghdr hdr;
 136                 char data[UBUS_MAX_MSGLEN];
 137         } msgbuf;
 138 };
 139
 140 struct ubus_object_data {
 141         uint32_t id;
 142         uint32_t type_id;
 143         const char *path;
 144         struct blob_attr *signature;
 145 };
 146
 147 struct ubus_request_data {
 148         uint32_t object;
 149         uint32_t peer;
 150         uint16_t seq;
 151         bool deferred;
 152 };
 153
 154 struct ubus_request {
 155         struct list_head list;
 156
 157         struct list_head pending;
 158         int status_code;
 159         bool status_msg;
 160         bool blocked;
 161         bool cancelled;
 162         bool notify;
 163
 164         uint32_t peer;
 165         uint16_t seq;
 166
 167         ubus_data_handler_t raw_data_cb;
 168         ubus_data_handler_t data_cb;
 169         ubus_complete_handler_t complete_cb;
 170
 171         struct ubus_context *ctx;
 172         void *priv;
 173 };
 174
 175 struct ubus_notify_request {
 176         struct ubus_request req;
 177
 178         ubus_notify_complete_handler_t status_cb;
 179         ubus_notify_complete_handler_t complete_cb;
 180
 181         uint32_t pending;
 182         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 183 };
 184
 185 struct ubus_context *ubus_connect(const char *path);
 186 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 187 void ubus_free(struct ubus_context *ctx);
 188
 189 const char *ubus_strerror(int error);
 190
 191 static inline void ubus_add_uloop(struct ubus_context *ctx)
 192 {
 193         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 194 }
 195
 196 /* call this for read events on ctx->sock.fd when not using uloop */
 197 static inline void ubus_handle_event(struct ubus_context *ctx)
 198 {
 199         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 200 }
 201
 202 /* ----------- raw request handling ----------- */
 203
 204 /* wait for a request to complete and return its status */
 205 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 206                           int timeout);
 207
 208 /* complete a request asynchronously */
 209 void ubus_complete_request_async(struct ubus_context *ctx,
 210                                  struct ubus_request *req);
 211
 212 /* abort an asynchronous request */
 213 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 214
 215 /* ----------- objects ----------- */
 216
 217 int ubus_lookup(struct ubus_context *ctx, const char *path,
 218                 ubus_lookup_handler_t cb, void *priv);
 219
 220 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 221
 222 /* make an object visible to remote connections */
 223 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 224
 225 /* remove the object from the ubus connection */
 226 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 227
 228 /* add a subscriber notifications from another object */
 229 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 230
 231 static inline int
 232 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 233 {
 234         return ubus_remove_object(ctx, &obj->obj);
 235 }
 236
 237 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 238 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 239
 240 /* ----------- rpc ----------- */
 241
 242 /* invoke a method on a specific object */
 243 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 244                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 245                 int timeout);
 246
 247 /* asynchronous version of ubus_invoke() */
 248 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 249                       struct blob_attr *msg, struct ubus_request *req);
 250
 251 /* send a reply to an incoming object method call */
 252 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 253                     struct blob_attr *msg);
 254
 255 static inline void ubus_defer_request(struct ubus_context *ctx,
 256                                       struct ubus_request_data *req,
 257                                       struct ubus_request_data *new_req)
 258 {
 259     memcpy(new_req, req, sizeof(*req));
 260     req->deferred = true;
 261 }
 262
 263 void ubus_complete_deferred_request(struct ubus_context *ctx,
 264                                     struct ubus_request_data *req, int ret);
 265
 266 /*
 267  * send a notification to all subscribers of an object
 268  * if timeout < 0, no reply is expected from subscribers
 269  */
 270 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 271                 const char *type, struct blob_attr *msg, int timeout);
 272
 273 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 274                       const char *type, struct blob_attr *msg,
 275                       struct ubus_notify_request *req);
 276
 277
 278 /* ----------- events ----------- */
 279
 280 int ubus_send_event(struct ubus_context *ctx, const char *id,
 281                     struct blob_attr *data);
 282
 283 int ubus_register_event_handler(struct ubus_context *ctx,
 284                                 struct ubus_event_handler *ev,
 285                                 const char *pattern);
 286
 287 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 288                                                 struct ubus_event_handler *ev)
 289 {
 290     return ubus_remove_object(ctx, &ev->obj);
 291 }
 292
 293 #endif