libubus.h

   1 /*
   2  * Copyright (C) 2011-2014 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 struct ubus_msghdr_buf {
  38         struct ubus_msghdr hdr;
  39         struct blob_attr *data;
  40 };
  41
  42 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  43                                       struct ubus_object_data *obj,
  44                                       void *priv);
  45 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  46                               struct ubus_request_data *req,
  47                               const char *method, struct blob_attr *msg);
  48 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  49 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  50                                       struct ubus_subscriber *obj, uint32_t id);
  51 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  52                                      const char *type, struct blob_attr *msg);
  53 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  54                                     int type, struct blob_attr *msg);
  55 typedef void (*ubus_fd_handler_t)(struct ubus_request *req, int fd);
  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_NOARG(_name, _handler)            \
  70         .name = _name,                                  \
  71         .handler = _handler
  72
  73 #define __UBUS_METHOD(_name, _handler, _policy)         \
  74         __UBUS_METHOD_NOARG(_name, _handler),           \
  75         .policy = _policy,                              \
  76         .n_policy = ARRAY_SIZE(_policy)
  77
  78 #define UBUS_METHOD(_name, _handler, _policy)           \
  79         { __UBUS_METHOD(_name, _handler, _policy) }
  80
  81 #define UBUS_METHOD_MASK(_name, _handler, _policy, _mask) \
  82         {                                               \
  83                 __UBUS_METHOD(_name, _handler, _policy),\
  84                 .mask = _mask                           \
  85         }
  86
  87 #define UBUS_METHOD_NOARG(_name, _handler)              \
  88         { __UBUS_METHOD_NOARG(_name, _handler) }
  89
  90 struct ubus_method {
  91         const char *name;
  92         ubus_handler_t handler;
  93
  94         unsigned long mask;
  95         const struct blobmsg_policy *policy;
  96         int n_policy;
  97 };
  98
  99 struct ubus_object_type {
 100         const char *name;
 101         uint32_t id;
 102
 103         const struct ubus_method *methods;
 104         int n_methods;
 105 };
 106
 107 struct ubus_object {
 108         struct avl_node avl;
 109
 110         const char *name;
 111         uint32_t id;
 112
 113         const char *path;
 114         struct ubus_object_type *type;
 115
 116         ubus_state_handler_t subscribe_cb;
 117         bool has_subscribers;
 118
 119         const struct ubus_method *methods;
 120         int n_methods;
 121 };
 122
 123 struct ubus_subscriber {
 124         struct ubus_object obj;
 125
 126         ubus_handler_t cb;
 127         ubus_remove_handler_t remove_cb;
 128 };
 129
 130 struct ubus_event_handler {
 131         struct ubus_object obj;
 132
 133         ubus_event_handler_t cb;
 134 };
 135
 136 struct ubus_context {
 137         struct list_head requests;
 138         struct avl_tree objects;
 139         struct list_head pending;
 140
 141         struct uloop_fd sock;
 142         struct uloop_timeout pending_timer;
 143
 144         uint32_t local_id;
 145         uint16_t request_seq;
 146         int stack_depth;
 147
 148         void (*connection_lost)(struct ubus_context *ctx);
 149
 150         struct ubus_msghdr_buf msgbuf;
 151         uint32_t msgbuf_data_len;
 152         int msgbuf_reduction_counter;
 153 };
 154
 155 struct ubus_object_data {
 156         uint32_t id;
 157         uint32_t type_id;
 158         const char *path;
 159         struct blob_attr *signature;
 160 };
 161
 162 struct ubus_request_data {
 163         uint32_t object;
 164         uint32_t peer;
 165         uint16_t seq;
 166
 167         /* internal use */
 168         bool deferred;
 169         int fd;
 170 };
 171
 172 struct ubus_request {
 173         struct list_head list;
 174
 175         struct list_head pending;
 176         int status_code;
 177         bool status_msg;
 178         bool blocked;
 179         bool cancelled;
 180         bool notify;
 181
 182         uint32_t peer;
 183         uint16_t seq;
 184
 185         ubus_data_handler_t raw_data_cb;
 186         ubus_data_handler_t data_cb;
 187         ubus_fd_handler_t fd_cb;
 188         ubus_complete_handler_t complete_cb;
 189
 190         struct ubus_context *ctx;
 191         void *priv;
 192 };
 193
 194 struct ubus_notify_request {
 195         struct ubus_request req;
 196
 197         ubus_notify_complete_handler_t status_cb;
 198         ubus_notify_complete_handler_t complete_cb;
 199
 200         uint32_t pending;
 201         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 202 };
 203
 204 struct ubus_auto_conn {
 205         struct ubus_context ctx;
 206         struct uloop_timeout timer;
 207         const char *path;
 208         ubus_connect_handler_t cb;
 209 };
 210
 211 struct ubus_context *ubus_connect(const char *path);
 212 int ubus_connect_ctx(struct ubus_context *ctx, const char *path);
 213 void ubus_auto_connect(struct ubus_auto_conn *conn);
 214 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 215
 216 /* call this only for struct ubus_context pointers returned by ubus_connect() */
 217 void ubus_free(struct ubus_context *ctx);
 218
 219 /* call this only for struct ubus_context pointers initialised by ubus_connect_ctx() */
 220 void ubus_shutdown(struct ubus_context *ctx);
 221
 222 const char *ubus_strerror(int error);
 223
 224 static inline void ubus_add_uloop(struct ubus_context *ctx)
 225 {
 226         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 227 }
 228
 229 /* call this for read events on ctx->sock.fd when not using uloop */
 230 static inline void ubus_handle_event(struct ubus_context *ctx)
 231 {
 232         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 233 }
 234
 235 /* ----------- raw request handling ----------- */
 236
 237 /* wait for a request to complete and return its status */
 238 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 239                           int timeout);
 240
 241 /* complete a request asynchronously */
 242 void ubus_complete_request_async(struct ubus_context *ctx,
 243                                  struct ubus_request *req);
 244
 245 /* abort an asynchronous request */
 246 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 247
 248 /* ----------- objects ----------- */
 249
 250 int ubus_lookup(struct ubus_context *ctx, const char *path,
 251                 ubus_lookup_handler_t cb, void *priv);
 252
 253 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 254
 255 /* make an object visible to remote connections */
 256 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 257
 258 /* remove the object from the ubus connection */
 259 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 260
 261 /* add a subscriber notifications from another object */
 262 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 263
 264 static inline int
 265 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 266 {
 267         return ubus_remove_object(ctx, &obj->obj);
 268 }
 269
 270 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 271 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 272
 273 /* ----------- rpc ----------- */
 274
 275 /* invoke a method on a specific object */
 276 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 277                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 278                 int timeout);
 279
 280 /* asynchronous version of ubus_invoke() */
 281 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 282                       struct blob_attr *msg, struct ubus_request *req);
 283
 284 /* send a reply to an incoming object method call */
 285 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 286                     struct blob_attr *msg);
 287
 288 static inline void ubus_defer_request(struct ubus_context *ctx,
 289                                       struct ubus_request_data *req,
 290                                       struct ubus_request_data *new_req)
 291 {
 292     memcpy(new_req, req, sizeof(*req));
 293     req->deferred = true;
 294 }
 295
 296 static inline void ubus_request_set_fd(struct ubus_context *ctx,
 297                                        struct ubus_request_data *req, int fd)
 298 {
 299     req->fd = fd;
 300 }
 301
 302 void ubus_complete_deferred_request(struct ubus_context *ctx,
 303                                     struct ubus_request_data *req, int ret);
 304
 305 /*
 306  * send a notification to all subscribers of an object
 307  * if timeout < 0, no reply is expected from subscribers
 308  */
 309 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 310                 const char *type, struct blob_attr *msg, int timeout);
 311
 312 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 313                       const char *type, struct blob_attr *msg,
 314                       struct ubus_notify_request *req);
 315
 316
 317 /* ----------- events ----------- */
 318
 319 int ubus_send_event(struct ubus_context *ctx, const char *id,
 320                     struct blob_attr *data);
 321
 322 int ubus_register_event_handler(struct ubus_context *ctx,
 323                                 struct ubus_event_handler *ev,
 324                                 const char *pattern);
 325
 326 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 327                                                 struct ubus_event_handler *ev)
 328 {
 329     return ubus_remove_object(ctx, &ev->obj);
 330 }
 331
 332 #endif