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 #ifdef __cplusplus
  18 extern "C" {
  19 #endif
  20
  21 #include <libubox/avl.h>
  22 #include <libubox/list.h>
  23 #include <libubox/blobmsg.h>
  24 #include <libubox/uloop.h>
  25 #include <stdint.h>
  26 #include "ubusmsg.h"
  27 #include "ubus_common.h"
  28
  29 #define UBUS_MAX_NOTIFY_PEERS   16
  30
  31 struct ubus_context;
  32 struct ubus_msg_src;
  33 struct ubus_object;
  34 struct ubus_request;
  35 struct ubus_request_data;
  36 struct ubus_object_data;
  37 struct ubus_event_handler;
  38 struct ubus_subscriber;
  39 struct ubus_notify_request;
  40
  41 struct ubus_msghdr_buf {
  42         struct ubus_msghdr hdr;
  43         struct blob_attr *data;
  44 };
  45
  46 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  47                                       struct ubus_object_data *obj,
  48                                       void *priv);
  49 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  50                               struct ubus_request_data *req,
  51                               const char *method, struct blob_attr *msg);
  52 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  53 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  54                                       struct ubus_subscriber *obj, uint32_t id);
  55 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  56                                      const char *type, struct blob_attr *msg);
  57 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  58                                     int type, struct blob_attr *msg);
  59 typedef void (*ubus_fd_handler_t)(struct ubus_request *req, int fd);
  60 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  61 typedef void (*ubus_notify_complete_handler_t)(struct ubus_notify_request *req,
  62                                                int idx, int ret);
  63 typedef void (*ubus_notify_data_handler_t)(struct ubus_notify_request *req,
  64                                            int type, struct blob_attr *msg);
  65 typedef void (*ubus_connect_handler_t)(struct ubus_context *ctx);
  66 typedef bool (*ubus_new_object_handler_t)(struct ubus_context *ctx, struct ubus_subscriber *sub, const char *path);
  67
  68 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  69         {                                               \
  70                 .name = _name,                          \
  71                 .id = 0,                                \
  72                 .n_methods = ARRAY_SIZE(_methods),      \
  73                 .methods = _methods                     \
  74         }
  75
  76 #define __UBUS_METHOD_NOARG(_name, _handler, _tags)     \
  77         .name = _name,                                  \
  78         .handler = _handler,                            \
  79         .tags = _tags
  80
  81 #define __UBUS_METHOD(_name, _handler, _policy, _tags)  \
  82         __UBUS_METHOD_NOARG(_name, _handler, _tags),    \
  83         .policy = _policy,                              \
  84         .n_policy = ARRAY_SIZE(_policy)
  85
  86 #define UBUS_METHOD(_name, _handler, _policy)           \
  87         { __UBUS_METHOD(_name, _handler, _policy, 0) }
  88
  89 #define UBUS_METHOD_TAG(_name, _handler, _policy, _tags)\
  90         { __UBUS_METHOD(_name, _handler, _policy, _tags) }
  91
  92 #define UBUS_METHOD_MASK(_name, _handler, _policy, _mask) \
  93         {                                               \
  94                 __UBUS_METHOD(_name, _handler, _policy, 0),\
  95                 .mask = _mask                           \
  96         }
  97
  98 #define UBUS_METHOD_NOARG(_name, _handler)              \
  99         { __UBUS_METHOD_NOARG(_name, _handler, 0) }
 100
 101 #define UBUS_METHOD_TAG_NOARG(_name, _handler, _tags)   \
 102         { __UBUS_METHOD_NOARG(_name, _handler, _tags) }
 103
 104 #define UBUS_TAG_STATUS         BIT(0)
 105 #define UBUS_TAG_ADMIN          BIT(1)
 106 #define UBUS_TAG_PRIVATE        BIT(2)
 107
 108 struct ubus_method {
 109         const char *name;
 110         ubus_handler_t handler;
 111
 112         unsigned long mask;
 113         unsigned long tags;
 114         const struct blobmsg_policy *policy;
 115         int n_policy;
 116 };
 117
 118 struct ubus_object_type {
 119         const char *name;
 120         uint32_t id;
 121
 122         const struct ubus_method *methods;
 123         int n_methods;
 124 };
 125
 126 struct ubus_object {
 127         struct avl_node avl;
 128
 129         const char *name;
 130         uint32_t id;
 131
 132         const char *path;
 133         struct ubus_object_type *type;
 134
 135         ubus_state_handler_t subscribe_cb;
 136         bool has_subscribers;
 137
 138         const struct ubus_method *methods;
 139         int n_methods;
 140 };
 141
 142 struct ubus_subscriber {
 143         struct list_head list;
 144         struct ubus_object obj;
 145
 146         ubus_handler_t cb;
 147         ubus_remove_handler_t remove_cb;
 148         ubus_new_object_handler_t new_obj_cb;
 149 };
 150
 151 struct ubus_event_handler {
 152         struct ubus_object obj;
 153
 154         ubus_event_handler_t cb;
 155 };
 156
 157 struct ubus_context {
 158         struct list_head requests;
 159         struct avl_tree objects;
 160         struct list_head pending;
 161
 162         struct uloop_fd sock;
 163         struct uloop_timeout pending_timer;
 164
 165         uint32_t local_id;
 166         uint16_t request_seq;
 167         bool cancel_poll;
 168         int stack_depth;
 169
 170         void (*connection_lost)(struct ubus_context *ctx);
 171         void (*monitor_cb)(struct ubus_context *ctx, uint32_t seq, struct blob_attr *data);
 172
 173         struct ubus_msghdr_buf msgbuf;
 174         uint32_t msgbuf_data_len;
 175         int msgbuf_reduction_counter;
 176
 177         struct list_head auto_subscribers;
 178         struct ubus_event_handler auto_subscribe_event_handler;
 179 };
 180
 181 struct ubus_object_data {
 182         uint32_t id;
 183         uint32_t type_id;
 184         const char *path;
 185         struct blob_attr *signature;
 186 };
 187
 188 struct ubus_acl_key {
 189         const char *user;
 190         const char *group;
 191         const char *object;
 192 };
 193
 194 struct ubus_request_data {
 195         uint32_t object;
 196         uint32_t peer;
 197         uint16_t seq;
 198
 199         struct ubus_acl_key acl;
 200
 201         /* internal use */
 202         bool deferred;
 203         int fd;
 204         int req_fd; /* fd received from the initial request */
 205 };
 206
 207 struct ubus_request {
 208         struct list_head list;
 209
 210         struct list_head pending;
 211         int status_code;
 212         bool status_msg;
 213         bool blocked;
 214         bool cancelled;
 215         bool notify;
 216
 217         uint32_t peer;
 218         uint16_t seq;
 219
 220         ubus_data_handler_t raw_data_cb;
 221         ubus_data_handler_t data_cb;
 222         ubus_fd_handler_t fd_cb;
 223         ubus_complete_handler_t complete_cb;
 224
 225         int fd;
 226
 227         struct ubus_context *ctx;
 228         void *priv;
 229 };
 230
 231 struct ubus_notify_request {
 232         struct ubus_request req;
 233
 234         ubus_notify_complete_handler_t status_cb;
 235         ubus_notify_complete_handler_t complete_cb;
 236         ubus_notify_data_handler_t data_cb;
 237
 238         uint32_t pending;
 239         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 240 };
 241
 242 struct ubus_auto_conn {
 243         struct ubus_context ctx;
 244         struct uloop_timeout timer;
 245         const char *path;
 246         ubus_connect_handler_t cb;
 247 };
 248
 249 struct ubus_context *ubus_connect(const char *path);
 250 int ubus_connect_ctx(struct ubus_context *ctx, const char *path);
 251 void ubus_auto_connect(struct ubus_auto_conn *conn);
 252 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 253
 254 /* call this only for struct ubus_context pointers returned by ubus_connect() */
 255 void ubus_free(struct ubus_context *ctx);
 256
 257 /* call this only for struct ubus_context pointers initialised by ubus_connect_ctx() */
 258 void ubus_shutdown(struct ubus_context *ctx);
 259
 260 static inline void ubus_auto_shutdown(struct ubus_auto_conn *conn)
 261 {
 262         uloop_timeout_cancel(&conn->timer);
 263         ubus_shutdown(&conn->ctx);
 264 }
 265
 266 const char *ubus_strerror(int error);
 267
 268 static inline void ubus_add_uloop(struct ubus_context *ctx)
 269 {
 270         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 271 }
 272
 273 /* call this for read events on ctx->sock.fd when not using uloop */
 274 static inline void ubus_handle_event(struct ubus_context *ctx)
 275 {
 276         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 277 }
 278
 279 /* ----------- raw request handling ----------- */
 280
 281 /* wait for a request to complete and return its status */
 282 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 283                           int timeout);
 284
 285 /* complete a request asynchronously */
 286 void ubus_complete_request_async(struct ubus_context *ctx,
 287                                  struct ubus_request *req);
 288
 289 /* abort an asynchronous request */
 290 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 291
 292 /* ----------- objects ----------- */
 293
 294 int ubus_lookup(struct ubus_context *ctx, const char *path,
 295                 ubus_lookup_handler_t cb, void *priv);
 296
 297 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 298
 299 /* make an object visible to remote connections */
 300 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 301
 302 /* remove the object from the ubus connection */
 303 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 304
 305 /* add a subscriber notifications from another object */
 306 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 307
 308 static inline int
 309 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 310 {
 311         if (!list_empty(&obj->list))
 312                 list_del_init(&obj->list);
 313         return ubus_remove_object(ctx, &obj->obj);
 314 }
 315
 316 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 317 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 318
 319 int __ubus_monitor(struct ubus_context *ctx, const char *type);
 320
 321 static inline int ubus_monitor_start(struct ubus_context *ctx)
 322 {
 323         return __ubus_monitor(ctx, "add");
 324 }
 325
 326 static inline int ubus_monitor_stop(struct ubus_context *ctx)
 327 {
 328         return __ubus_monitor(ctx, "remove");
 329 }
 330
 331
 332 /* ----------- acl ----------- */
 333
 334 struct acl_object {
 335         struct ubus_acl_key key;
 336         struct avl_node avl;
 337         struct blob_attr *acl;
 338 };
 339
 340 extern struct avl_tree acl_objects;
 341 int ubus_register_acl(struct ubus_context *ctx);
 342
 343 #define acl_for_each(o, m) \
 344         if ((m)->object && (m)->user && (m)->group) \
 345                 avl_for_element_range(avl_find_ge_element(&acl_objects, m, o, avl), avl_find_le_element(&acl_objects, m, o, avl), o, avl)
 346
 347 /* ----------- rpc ----------- */
 348
 349 /* invoke a method on a specific object */
 350 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 351                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 352                 int timeout, int fd);
 353 static inline int
 354 ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 355             struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 356             int timeout)
 357 {
 358         return ubus_invoke_fd(ctx, obj, method, msg, cb, priv, timeout, -1);
 359 }
 360
 361 /* asynchronous version of ubus_invoke() */
 362 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 363                       struct blob_attr *msg, struct ubus_request *req, int fd);
 364 static inline int
 365 ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 366                   struct blob_attr *msg, struct ubus_request *req)
 367 {
 368         return ubus_invoke_async_fd(ctx, obj, method, msg, req, -1);
 369 }
 370
 371 /* send a reply to an incoming object method call */
 372 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 373                     struct blob_attr *msg);
 374
 375 static inline void ubus_defer_request(struct ubus_context *ctx,
 376                                       struct ubus_request_data *req,
 377                                       struct ubus_request_data *new_req)
 378 {
 379     (void) ctx;
 380     memcpy(new_req, req, sizeof(*req));
 381     req->deferred = true;
 382 }
 383
 384 static inline void ubus_request_set_fd(struct ubus_context *ctx,
 385                                        struct ubus_request_data *req, int fd)
 386 {
 387     (void) ctx;
 388     req->fd = fd;
 389 }
 390
 391 static inline int ubus_request_get_caller_fd(struct ubus_request_data *req)
 392 {
 393     int fd = req->req_fd;
 394     req->req_fd = -1;
 395
 396     return fd;
 397 }
 398
 399 void ubus_complete_deferred_request(struct ubus_context *ctx,
 400                                     struct ubus_request_data *req, int ret);
 401
 402 /*
 403  * send a notification to all subscribers of an object
 404  * if timeout < 0, no reply is expected from subscribers
 405  */
 406 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 407                 const char *type, struct blob_attr *msg, int timeout);
 408
 409 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 410                       const char *type, struct blob_attr *msg,
 411                       struct ubus_notify_request *req);
 412
 413
 414 /* ----------- events ----------- */
 415
 416 int ubus_send_event(struct ubus_context *ctx, const char *id,
 417                     struct blob_attr *data);
 418
 419 int ubus_register_event_handler(struct ubus_context *ctx,
 420                                 struct ubus_event_handler *ev,
 421                                 const char *pattern);
 422
 423 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 424                                                 struct ubus_event_handler *ev)
 425 {
 426     return ubus_remove_object(ctx, &ev->obj);
 427 }
 428
 429 #ifdef __cplusplus
 430 }
 431 #endif
 432
 433 #endif