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