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