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