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         int stack_depth;
 159
 160         void (*connection_lost)(struct ubus_context *ctx);
 161         void (*monitor_cb)(struct ubus_context *ctx, uint32_t seq, struct blob_attr *data);
 162
 163         struct ubus_msghdr_buf msgbuf;
 164         uint32_t msgbuf_data_len;
 165         int msgbuf_reduction_counter;
 166 };
 167
 168 struct ubus_object_data {
 169         uint32_t id;
 170         uint32_t type_id;
 171         const char *path;
 172         struct blob_attr *signature;
 173 };
 174
 175 struct ubus_acl_key {
 176         const char *user;
 177         const char *group;
 178         const char *object;
 179 };
 180
 181 struct ubus_request_data {
 182         uint32_t object;
 183         uint32_t peer;
 184         uint16_t seq;
 185
 186         struct ubus_acl_key acl;
 187
 188         /* internal use */
 189         bool deferred;
 190         int fd;
 191         int req_fd; /* fd received from the initial request */
 192 };
 193
 194 struct ubus_request {
 195         struct list_head list;
 196
 197         struct list_head pending;
 198         int status_code;
 199         bool status_msg;
 200         bool blocked;
 201         bool cancelled;
 202         bool notify;
 203
 204         uint32_t peer;
 205         uint16_t seq;
 206
 207         ubus_data_handler_t raw_data_cb;
 208         ubus_data_handler_t data_cb;
 209         ubus_fd_handler_t fd_cb;
 210         ubus_complete_handler_t complete_cb;
 211
 212         int fd;
 213
 214         struct ubus_context *ctx;
 215         void *priv;
 216 };
 217
 218 struct ubus_notify_request {
 219         struct ubus_request req;
 220
 221         ubus_notify_complete_handler_t status_cb;
 222         ubus_notify_complete_handler_t complete_cb;
 223
 224         uint32_t pending;
 225         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 226 };
 227
 228 struct ubus_auto_conn {
 229         struct ubus_context ctx;
 230         struct uloop_timeout timer;
 231         const char *path;
 232         ubus_connect_handler_t cb;
 233 };
 234
 235 struct ubus_context *ubus_connect(const char *path);
 236 int ubus_connect_ctx(struct ubus_context *ctx, const char *path);
 237 void ubus_auto_connect(struct ubus_auto_conn *conn);
 238 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 239
 240 /* call this only for struct ubus_context pointers returned by ubus_connect() */
 241 void ubus_free(struct ubus_context *ctx);
 242
 243 /* call this only for struct ubus_context pointers initialised by ubus_connect_ctx() */
 244 void ubus_shutdown(struct ubus_context *ctx);
 245
 246 static inline void ubus_auto_shutdown(struct ubus_auto_conn *conn)
 247 {
 248         uloop_timeout_cancel(&conn->timer);
 249         ubus_shutdown(&conn->ctx);
 250 }
 251
 252 const char *ubus_strerror(int error);
 253
 254 static inline void ubus_add_uloop(struct ubus_context *ctx)
 255 {
 256         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 257 }
 258
 259 /* call this for read events on ctx->sock.fd when not using uloop */
 260 static inline void ubus_handle_event(struct ubus_context *ctx)
 261 {
 262         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 263 }
 264
 265 /* ----------- raw request handling ----------- */
 266
 267 /* wait for a request to complete and return its status */
 268 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 269                           int timeout);
 270
 271 /* complete a request asynchronously */
 272 void ubus_complete_request_async(struct ubus_context *ctx,
 273                                  struct ubus_request *req);
 274
 275 /* abort an asynchronous request */
 276 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 277
 278 /* ----------- objects ----------- */
 279
 280 int ubus_lookup(struct ubus_context *ctx, const char *path,
 281                 ubus_lookup_handler_t cb, void *priv);
 282
 283 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 284
 285 /* make an object visible to remote connections */
 286 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 287
 288 /* remove the object from the ubus connection */
 289 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 290
 291 /* add a subscriber notifications from another object */
 292 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 293
 294 static inline int
 295 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 296 {
 297         return ubus_remove_object(ctx, &obj->obj);
 298 }
 299
 300 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 301 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 302
 303 int __ubus_monitor(struct ubus_context *ctx, const char *type);
 304
 305 static inline int ubus_monitor_start(struct ubus_context *ctx)
 306 {
 307         return __ubus_monitor(ctx, "add");
 308 }
 309
 310 static inline int ubus_monitor_stop(struct ubus_context *ctx)
 311 {
 312         return __ubus_monitor(ctx, "remove");
 313 }
 314
 315
 316 /* ----------- acl ----------- */
 317
 318 struct acl_object {
 319         struct ubus_acl_key key;
 320         struct avl_node avl;
 321         struct blob_attr *acl;
 322 };
 323
 324 extern struct avl_tree acl_objects;
 325 int ubus_register_acl(struct ubus_context *ctx);
 326
 327 #define acl_for_each(o, m) \
 328         if ((m)->object && (m)->user && (m)->group) \
 329                 avl_for_element_range(avl_find_ge_element(&acl_objects, m, o, avl), avl_find_le_element(&acl_objects, m, o, avl), o, avl)
 330
 331 /* ----------- rpc ----------- */
 332
 333 /* invoke a method on a specific object */
 334 int ubus_invoke_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 335                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 336                 int timeout, int fd);
 337 static inline int
 338 ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 339             struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 340             int timeout)
 341 {
 342         return ubus_invoke_fd(ctx, obj, method, msg, cb, priv, timeout, -1);
 343 }
 344
 345 /* asynchronous version of ubus_invoke() */
 346 int ubus_invoke_async_fd(struct ubus_context *ctx, uint32_t obj, const char *method,
 347                       struct blob_attr *msg, struct ubus_request *req, int fd);
 348 static inline int
 349 ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 350                   struct blob_attr *msg, struct ubus_request *req)
 351 {
 352         return ubus_invoke_async_fd(ctx, obj, method, msg, req, -1);
 353 }
 354
 355 /* send a reply to an incoming object method call */
 356 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 357                     struct blob_attr *msg);
 358
 359 static inline void ubus_defer_request(struct ubus_context *ctx,
 360                                       struct ubus_request_data *req,
 361                                       struct ubus_request_data *new_req)
 362 {
 363     (void) ctx;
 364     memcpy(new_req, req, sizeof(*req));
 365     req->deferred = true;
 366 }
 367
 368 static inline void ubus_request_set_fd(struct ubus_context *ctx,
 369                                        struct ubus_request_data *req, int fd)
 370 {
 371     (void) ctx;
 372     req->fd = fd;
 373 }
 374
 375 static inline int ubus_request_get_caller_fd(struct ubus_request_data *req)
 376 {
 377     int fd = req->req_fd;
 378     req->req_fd = -1;
 379
 380     return fd;
 381 }
 382
 383 void ubus_complete_deferred_request(struct ubus_context *ctx,
 384                                     struct ubus_request_data *req, int ret);
 385
 386 /*
 387  * send a notification to all subscribers of an object
 388  * if timeout < 0, no reply is expected from subscribers
 389  */
 390 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 391                 const char *type, struct blob_attr *msg, int timeout);
 392
 393 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 394                       const char *type, struct blob_attr *msg,
 395                       struct ubus_notify_request *req);
 396
 397
 398 /* ----------- events ----------- */
 399
 400 int ubus_send_event(struct ubus_context *ctx, const char *id,
 401                     struct blob_attr *data);
 402
 403 int ubus_register_event_handler(struct ubus_context *ctx,
 404                                 struct ubus_event_handler *ev,
 405                                 const char *pattern);
 406
 407 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 408                                                 struct ubus_event_handler *ev)
 409 {
 410     return ubus_remove_object(ctx, &ev->obj);
 411 }
 412
 413 #endif