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, _tags)     \
  70         .name = _name,                                  \
  71         .handler = _handler,                            \
  72         .tags = _tags
  73
  74 #define __UBUS_METHOD(_name, _handler, _policy, _tags)  \
  75         __UBUS_METHOD_NOARG(_name, _handler, _tags),    \
  76         .policy = _policy,                              \
  77         .n_policy = ARRAY_SIZE(_policy)
  78
  79 #define UBUS_METHOD(_name, _handler, _policy)           \
  80         { __UBUS_METHOD(_name, _handler, _policy, 0) }
  81
  82 #define UBUS_METHOD_TAG(_name, _handler, _policy, _tags)\
  83         { __UBUS_METHOD(_name, _handler, _policy, _tags) }
  84
  85 #define UBUS_METHOD_MASK(_name, _handler, _policy, _mask) \
  86         {                                               \
  87                 __UBUS_METHOD(_name, _handler, _policy, 0),\
  88                 .mask = _mask                           \
  89         }
  90
  91 #define UBUS_METHOD_NOARG(_name, _handler)              \
  92         { __UBUS_METHOD_NOARG(_name, _handler, 0) }
  93
  94 #define UBUS_METHOD_TAG_NOARG(_name, _handler, _tags)   \
  95         { __UBUS_METHOD_NOARG(_name, _handler, _tags) }
  96
  97 #define UBUS_TAG_STATUS         BIT(0)
  98 #define UBUS_TAG_ADMIN          BIT(1)
  99 #define UBUS_TAG_PRIVATE        BIT(2)
 100
 101 struct ubus_method {
 102         const char *name;
 103         ubus_handler_t handler;
 104
 105         unsigned long mask;
 106         unsigned long tags;
 107         const struct blobmsg_policy *policy;
 108         int n_policy;
 109 };
 110
 111 struct ubus_object_type {
 112         const char *name;
 113         uint32_t id;
 114
 115         const struct ubus_method *methods;
 116         int n_methods;
 117 };
 118
 119 struct ubus_object {
 120         struct avl_node avl;
 121
 122         const char *name;
 123         uint32_t id;
 124
 125         const char *path;
 126         struct ubus_object_type *type;
 127
 128         ubus_state_handler_t subscribe_cb;
 129         bool has_subscribers;
 130
 131         const struct ubus_method *methods;
 132         int n_methods;
 133 };
 134
 135 struct ubus_subscriber {
 136         struct ubus_object obj;
 137
 138         ubus_handler_t cb;
 139         ubus_remove_handler_t remove_cb;
 140 };
 141
 142 struct ubus_event_handler {
 143         struct ubus_object obj;
 144
 145         ubus_event_handler_t cb;
 146 };
 147
 148 struct ubus_context {
 149         struct list_head requests;
 150         struct avl_tree objects;
 151         struct list_head pending;
 152
 153         struct uloop_fd sock;
 154         struct uloop_timeout pending_timer;
 155
 156         uint32_t local_id;
 157         uint16_t request_seq;
 158         bool cancel_poll;
 159         int stack_depth;
 160
 161         void (*connection_lost)(struct ubus_context *ctx);
 162         void (*monitor_cb)(struct ubus_context *ctx, uint32_t seq, struct blob_attr *data);
 163
 164         struct ubus_msghdr_buf msgbuf;
 165         uint32_t msgbuf_data_len;
 166         int msgbuf_reduction_counter;
 167 };
 168
 169 struct ubus_object_data {
 170         uint32_t id;
 171         uint32_t type_id;
 172         const char *path;
 173         struct blob_attr *signature;
 174 };
 175
 176 struct ubus_acl_key {
 177         const char *user;
 178         const char *group;
 179         const char *object;
 180 };
 181
 182 struct ubus_request_data {
 183         uint32_t object;
 184         uint32_t peer;
 185         uint16_t seq;
 186
 187         struct ubus_acl_key acl;
 188
 189         /* internal use */
 190         bool deferred;
 191         int fd;
 192         int req_fd; /* fd received from the initial request */
 193 };
 194
 195 struct ubus_request {
 196         struct list_head list;
 197
 198         struct list_head pending;
 199         int status_code;
 200         bool status_msg;
 201         bool blocked;
 202         bool cancelled;
 203         bool notify;
 204
 205         uint32_t peer;
 206         uint16_t seq;
 207
 208         ubus_data_handler_t raw_data_cb;
 209         ubus_data_handler_t data_cb;
 210         ubus_fd_handler_t fd_cb;
 211         ubus_complete_handler_t complete_cb;
 212
 213         int fd;
 214
 215         struct ubus_context *ctx;
 216         void *priv;
 217 };
 218
 219 struct ubus_notify_request {
 220         struct ubus_request req;
 221
 222         ubus_notify_complete_handler_t status_cb;
 223         ubus_notify_complete_handler_t complete_cb;
 224
 225         uint32_t pending;
 226         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 227 };
 228
 229 struct ubus_auto_conn {
 230         struct ubus_context ctx;
 231         struct uloop_timeout timer;
 232         const char *path;
 233         ubus_connect_handler_t cb;
 234 };
 235
 236 struct ubus_context *ubus_connect(const char *path);
 237 int ubus_connect_ctx(struct ubus_context *ctx, const char *path);
 238 void ubus_auto_connect(struct ubus_auto_conn *conn);
 239 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 240
 241 /* call this only for struct ubus_context pointers returned by ubus_connect() */
 242 void ubus_free(struct ubus_context *ctx);
 243
 244 /* call this only for struct ubus_context pointers initialised by ubus_connect_ctx() */
 245 void ubus_shutdown(struct ubus_context *ctx);
 246
 247 static inline void ubus_auto_shutdown(struct ubus_auto_conn *conn)
 248 {
 249         uloop_timeout_cancel(&conn->timer);
 250         ubus_shutdown(&conn->ctx);
 251 }
 252
 253 const char *ubus_strerror(int error);
 254
 255 static inline void ubus_add_uloop(struct ubus_context *ctx)
 256 {
 257         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 258 }
 259
 260 /* call this for read events on ctx->sock.fd when not using uloop */
 261 static inline void ubus_handle_event(struct ubus_context *ctx)
 262 {
 263         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 264 }
 265
 266 /* ----------- raw request handling ----------- */
 267
 268 /* wait for a request to complete and return its status */
 269 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 270                           int timeout);
 271
 272 /* complete a request asynchronously */
 273 void ubus_complete_request_async(struct ubus_context *ctx,
 274                                  struct ubus_request *req);
 275
 276 /* abort an asynchronous request */
 277 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 278
 279 /* ----------- objects ----------- */
 280
 281 int ubus_lookup(struct ubus_context *ctx, const char *path,
 282                 ubus_lookup_handler_t cb, void *priv);
 283
 284 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 285
 286 /* make an object visible to remote connections */
 287 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 288
 289 /* remove the object from the ubus connection */
 290 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 291
 292 /* add a subscriber notifications from another object */
 293 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 294
 295 static inline int
 296 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 297 {
 298         return ubus_remove_object(ctx, &obj->obj);
 299 }
 300
 301 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 302 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 303
 304 int __ubus_monitor(struct ubus_context *ctx, const char *type);
 305
 306 static inline int ubus_monitor_start(struct ubus_context *ctx)
 307 {
 308         return __ubus_monitor(ctx, "add");
 309 }
 310
 311 static inline int ubus_monitor_stop(struct ubus_context *ctx)
 312 {
 313         return __ubus_monitor(ctx, "remove");
 314 }
 315
 316
 317 /* ----------- acl ----------- */
 318
 319 struct acl_object {
 320         struct ubus_acl_key key;
 321         struct avl_node avl;
 322         struct blob_attr *acl;
 323 };
 324
 325 extern struct avl_tree acl_objects;
 326 int ubus_register_acl(struct ubus_context *ctx);
 327
 328 #define acl_for_each(o, m) \
 329         if ((m)->object && (m)->user && (m)->group) \
 330                 avl_for_element_range(avl_find_ge_element(&acl_objects, m, o, avl), avl_find_le_element(&acl_objects, m, o, avl), o, avl)
 331
 332 /* ----------- rpc ----------- */
 333
 334 /* invoke a method on a specific object */
 335 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 336                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 337                 int timeout, int fd);
 338 static inline int
 339 ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 340             struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 341             int timeout)
 342 {
 343         return ubus_invoke_fd(ctx, obj, method, msg, cb, priv, timeout, -1);
 344 }
 345
 346 /* asynchronous version of ubus_invoke() */
 347 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 348                       struct blob_attr *msg, struct ubus_request *req, int fd);
 349 static inline int
 350 ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 351                   struct blob_attr *msg, struct ubus_request *req)
 352 {
 353         return ubus_invoke_async_fd(ctx, obj, method, msg, req, -1);
 354 }
 355
 356 /* send a reply to an incoming object method call */
 357 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 358                     struct blob_attr *msg);
 359
 360 static inline void ubus_defer_request(struct ubus_context *ctx,
 361                                       struct ubus_request_data *req,
 362                                       struct ubus_request_data *new_req)
 363 {
 364     (void) ctx;
 365     memcpy(new_req, req, sizeof(*req));
 366     req->deferred = true;
 367 }
 368
 369 static inline void ubus_request_set_fd(struct ubus_context *ctx,
 370                                        struct ubus_request_data *req, int fd)
 371 {
 372     (void) ctx;
 373     req->fd = fd;
 374 }
 375
 376 static inline int ubus_request_get_caller_fd(struct ubus_request_data *req)
 377 {
 378     int fd = req->req_fd;
 379     req->req_fd = -1;
 380
 381     return fd;
 382 }
 383
 384 void ubus_complete_deferred_request(struct ubus_context *ctx,
 385                                     struct ubus_request_data *req, int ret);
 386
 387 /*
 388  * send a notification to all subscribers of an object
 389  * if timeout < 0, no reply is expected from subscribers
 390  */
 391 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 392                 const char *type, struct blob_attr *msg, int timeout);
 393
 394 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 395                       const char *type, struct blob_attr *msg,
 396                       struct ubus_notify_request *req);
 397
 398
 399 /* ----------- events ----------- */
 400
 401 int ubus_send_event(struct ubus_context *ctx, const char *id,
 402                     struct blob_attr *data);
 403
 404 int ubus_register_event_handler(struct ubus_context *ctx,
 405                                 struct ubus_event_handler *ev,
 406                                 const char *pattern);
 407
 408 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 409                                                 struct ubus_event_handler *ev)
 410 {
 411     return ubus_remove_object(ctx, &ev->obj);
 412 }
 413
 414 #endif