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 static inline struct blob_attr *
  38 ubus_msghdr_data(struct ubus_msghdr *hdr)
  39 {
  40         return (struct blob_attr *) (hdr + 1);
  41 }
  42
  43 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  44                                       struct ubus_object_data *obj,
  45                                       void *priv);
  46 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  47                               struct ubus_request_data *req,
  48                               const char *method, struct blob_attr *msg);
  49 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  50 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  51                                       struct ubus_subscriber *obj, uint32_t id);
  52 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  53                                      const char *type, struct blob_attr *msg);
  54 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  55                                     int type, struct blob_attr *msg);
  56 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  57 typedef void (*ubus_notify_complete_handler_t)(struct ubus_notify_request *req,
  58                                                int idx, int ret);
  59 typedef void (*ubus_connect_handler_t)(struct ubus_context *ctx);
  60
  61 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  62         {                                               \
  63                 .name = _name,                          \
  64                 .id = 0,                                \
  65                 .n_methods = ARRAY_SIZE(_methods),      \
  66                 .methods = _methods                     \
  67         }
  68
  69 #define UBUS_METHOD(_name, _handler, _policy)           \
  70         {                                               \
  71                 .name = _name,                          \
  72                 .handler = _handler,                    \
  73                 .policy = _policy,                      \
  74                 .n_policy = ARRAY_SIZE(_policy)         \
  75         }
  76
  77 #define UBUS_METHOD_NOARG(_name, _handler)              \
  78         {                                               \
  79                 .name = _name,                          \
  80                 .handler = _handler,                    \
  81         }
  82
  83 struct ubus_method {
  84         const char *name;
  85         ubus_handler_t handler;
  86
  87         const struct blobmsg_policy *policy;
  88         int n_policy;
  89 };
  90
  91 struct ubus_object_type {
  92         const char *name;
  93         uint32_t id;
  94
  95         const struct ubus_method *methods;
  96         int n_methods;
  97 };
  98
  99 struct ubus_object {
 100         struct avl_node avl;
 101
 102         const char *name;
 103         uint32_t id;
 104
 105         const char *path;
 106         struct ubus_object_type *type;
 107
 108         ubus_state_handler_t subscribe_cb;
 109         bool has_subscribers;
 110
 111         const struct ubus_method *methods;
 112         int n_methods;
 113 };
 114
 115 struct ubus_subscriber {
 116         struct ubus_object obj;
 117
 118         ubus_handler_t cb;
 119         ubus_remove_handler_t remove_cb;
 120 };
 121
 122 struct ubus_event_handler {
 123         struct ubus_object obj;
 124
 125         ubus_event_handler_t cb;
 126 };
 127
 128 struct ubus_context {
 129         struct list_head requests;
 130         struct avl_tree objects;
 131         struct list_head pending;
 132
 133         struct uloop_fd sock;
 134
 135         uint32_t local_id;
 136         uint16_t request_seq;
 137         int stack_depth;
 138
 139         void (*connection_lost)(struct ubus_context *ctx);
 140
 141         struct {
 142                 struct ubus_msghdr hdr;
 143                 char data[UBUS_MAX_MSGLEN];
 144         } msgbuf;
 145 };
 146
 147 struct ubus_object_data {
 148         uint32_t id;
 149         uint32_t type_id;
 150         const char *path;
 151         struct blob_attr *signature;
 152 };
 153
 154 struct ubus_request_data {
 155         uint32_t object;
 156         uint32_t peer;
 157         uint16_t seq;
 158         bool deferred;
 159 };
 160
 161 struct ubus_request {
 162         struct list_head list;
 163
 164         struct list_head pending;
 165         int status_code;
 166         bool status_msg;
 167         bool blocked;
 168         bool cancelled;
 169         bool notify;
 170
 171         uint32_t peer;
 172         uint16_t seq;
 173
 174         ubus_data_handler_t raw_data_cb;
 175         ubus_data_handler_t data_cb;
 176         ubus_complete_handler_t complete_cb;
 177
 178         struct ubus_context *ctx;
 179         void *priv;
 180 };
 181
 182 struct ubus_notify_request {
 183         struct ubus_request req;
 184
 185         ubus_notify_complete_handler_t status_cb;
 186         ubus_notify_complete_handler_t complete_cb;
 187
 188         uint32_t pending;
 189         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 190 };
 191
 192 struct ubus_auto_conn {
 193         struct ubus_context ctx;
 194         struct uloop_timeout timer;
 195         const char *path;
 196         ubus_connect_handler_t cb;
 197 };
 198
 199 struct ubus_context *ubus_connect(const char *path);
 200 void ubus_auto_connect(struct ubus_auto_conn *conn);
 201 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 202 void ubus_free(struct ubus_context *ctx);
 203
 204 const char *ubus_strerror(int error);
 205
 206 static inline void ubus_add_uloop(struct ubus_context *ctx)
 207 {
 208         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 209 }
 210
 211 /* call this for read events on ctx->sock.fd when not using uloop */
 212 static inline void ubus_handle_event(struct ubus_context *ctx)
 213 {
 214         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 215 }
 216
 217 /* ----------- raw request handling ----------- */
 218
 219 /* wait for a request to complete and return its status */
 220 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 221                           int timeout);
 222
 223 /* complete a request asynchronously */
 224 void ubus_complete_request_async(struct ubus_context *ctx,
 225                                  struct ubus_request *req);
 226
 227 /* abort an asynchronous request */
 228 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 229
 230 /* ----------- objects ----------- */
 231
 232 int ubus_lookup(struct ubus_context *ctx, const char *path,
 233                 ubus_lookup_handler_t cb, void *priv);
 234
 235 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 236
 237 /* make an object visible to remote connections */
 238 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 239
 240 /* remove the object from the ubus connection */
 241 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 242
 243 /* add a subscriber notifications from another object */
 244 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 245
 246 static inline int
 247 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 248 {
 249         return ubus_remove_object(ctx, &obj->obj);
 250 }
 251
 252 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 253 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 254
 255 /* ----------- rpc ----------- */
 256
 257 /* invoke a method on a specific object */
 258 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 259                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 260                 int timeout);
 261
 262 /* asynchronous version of ubus_invoke() */
 263 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 264                       struct blob_attr *msg, struct ubus_request *req);
 265
 266 /* send a reply to an incoming object method call */
 267 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 268                     struct blob_attr *msg);
 269
 270 static inline void ubus_defer_request(struct ubus_context *ctx,
 271                                       struct ubus_request_data *req,
 272                                       struct ubus_request_data *new_req)
 273 {
 274     memcpy(new_req, req, sizeof(*req));
 275     req->deferred = true;
 276 }
 277
 278 void ubus_complete_deferred_request(struct ubus_context *ctx,
 279                                     struct ubus_request_data *req, int ret);
 280
 281 /*
 282  * send a notification to all subscribers of an object
 283  * if timeout < 0, no reply is expected from subscribers
 284  */
 285 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 286                 const char *type, struct blob_attr *msg, int timeout);
 287
 288 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 289                       const char *type, struct blob_attr *msg,
 290                       struct ubus_notify_request *req);
 291
 292
 293 /* ----------- events ----------- */
 294
 295 int ubus_send_event(struct ubus_context *ctx, const char *id,
 296                     struct blob_attr *data);
 297
 298 int ubus_register_event_handler(struct ubus_context *ctx,
 299                                 struct ubus_event_handler *ev,
 300                                 const char *pattern);
 301
 302 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 303                                                 struct ubus_event_handler *ev)
 304 {
 305     return ubus_remove_object(ctx, &ev->obj);
 306 }
 307
 308 #endif