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 static inline struct blob_attr *
  38 ubus_msghdr_data(struct ubus_msghdr *hdr)
  39 {
  40         return (struct blob_attr *) (hdr + 1);
  41 }
  42
  43 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  44                                       struct ubus_object_data *obj,
  45                                       void *priv);
  46 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  47                               struct ubus_request_data *req,
  48                               const char *method, struct blob_attr *msg);
  49 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  50 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  51                                       struct ubus_subscriber *obj, uint32_t id);
  52 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  53                                      const char *type, struct blob_attr *msg);
  54 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  55                                     int type, struct blob_attr *msg);
  56 typedef void (*ubus_fd_handler_t)(struct ubus_request *req, int fd);
  57 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  58 typedef void (*ubus_notify_complete_handler_t)(struct ubus_notify_request *req,
  59                                                int idx, int ret);
  60 typedef void (*ubus_connect_handler_t)(struct ubus_context *ctx);
  61
  62 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  63         {                                               \
  64                 .name = _name,                          \
  65                 .id = 0,                                \
  66                 .n_methods = ARRAY_SIZE(_methods),      \
  67                 .methods = _methods                     \
  68         }
  69
  70 #define __UBUS_METHOD_NOARG(_name, _handler)            \
  71         .name = _name,                                  \
  72         .handler = _handler
  73
  74 #define __UBUS_METHOD(_name, _handler, _policy)         \
  75         __UBUS_METHOD_NOARG(_name, _handler),           \
  76         .policy = _policy,                              \
  77         .n_policy = ARRAY_SIZE(_policy)
  78
  79 #define UBUS_METHOD(_name, _handler, _policy)           \
  80         { __UBUS_METHOD(_name, _handler, _policy) }
  81
  82 #define UBUS_METHOD_MASK(_name, _handler, _policy, _mask) \
  83         {                                               \
  84                 __UBUS_METHOD(_name, _handler, _policy),\
  85                 .mask = _mask                           \
  86         }
  87
  88 #define UBUS_METHOD_NOARG(_name, _handler)              \
  89         { __UBUS_METHOD_NOARG(_name, _handler) }
  90
  91 struct ubus_method {
  92         const char *name;
  93         ubus_handler_t handler;
  94
  95         unsigned long mask;
  96         const struct blobmsg_policy *policy;
  97         int n_policy;
  98 };
  99
 100 struct ubus_object_type {
 101         const char *name;
 102         uint32_t id;
 103
 104         const struct ubus_method *methods;
 105         int n_methods;
 106 };
 107
 108 struct ubus_object {
 109         struct avl_node avl;
 110
 111         const char *name;
 112         uint32_t id;
 113
 114         const char *path;
 115         struct ubus_object_type *type;
 116
 117         ubus_state_handler_t subscribe_cb;
 118         bool has_subscribers;
 119
 120         const struct ubus_method *methods;
 121         int n_methods;
 122 };
 123
 124 struct ubus_subscriber {
 125         struct ubus_object obj;
 126
 127         ubus_handler_t cb;
 128         ubus_remove_handler_t remove_cb;
 129 };
 130
 131 struct ubus_event_handler {
 132         struct ubus_object obj;
 133
 134         ubus_event_handler_t cb;
 135 };
 136
 137 struct ubus_context {
 138         struct list_head requests;
 139         struct avl_tree objects;
 140         struct list_head pending;
 141
 142         struct uloop_fd sock;
 143         struct uloop_timeout pending_timer;
 144
 145         uint32_t local_id;
 146         uint16_t request_seq;
 147         int stack_depth;
 148
 149         void (*connection_lost)(struct ubus_context *ctx);
 150
 151         struct {
 152                 struct ubus_msghdr hdr;
 153                 char data[UBUS_MAX_MSGLEN];
 154         } msgbuf;
 155 };
 156
 157 struct ubus_object_data {
 158         uint32_t id;
 159         uint32_t type_id;
 160         const char *path;
 161         struct blob_attr *signature;
 162 };
 163
 164 struct ubus_request_data {
 165         uint32_t object;
 166         uint32_t peer;
 167         uint16_t seq;
 168
 169         /* internal use */
 170         bool deferred;
 171         int fd;
 172 };
 173
 174 struct ubus_request {
 175         struct list_head list;
 176
 177         struct list_head pending;
 178         int status_code;
 179         bool status_msg;
 180         bool blocked;
 181         bool cancelled;
 182         bool notify;
 183
 184         uint32_t peer;
 185         uint16_t seq;
 186
 187         ubus_data_handler_t raw_data_cb;
 188         ubus_data_handler_t data_cb;
 189         ubus_fd_handler_t fd_cb;
 190         ubus_complete_handler_t complete_cb;
 191
 192         struct ubus_context *ctx;
 193         void *priv;
 194 };
 195
 196 struct ubus_notify_request {
 197         struct ubus_request req;
 198
 199         ubus_notify_complete_handler_t status_cb;
 200         ubus_notify_complete_handler_t complete_cb;
 201
 202         uint32_t pending;
 203         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 204 };
 205
 206 struct ubus_auto_conn {
 207         struct ubus_context ctx;
 208         struct uloop_timeout timer;
 209         const char *path;
 210         ubus_connect_handler_t cb;
 211 };
 212
 213 struct ubus_context *ubus_connect(const char *path);
 214 void ubus_auto_connect(struct ubus_auto_conn *conn);
 215 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 216 void ubus_free(struct ubus_context *ctx);
 217
 218 const char *ubus_strerror(int error);
 219
 220 static inline void ubus_add_uloop(struct ubus_context *ctx)
 221 {
 222         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 223 }
 224
 225 /* call this for read events on ctx->sock.fd when not using uloop */
 226 static inline void ubus_handle_event(struct ubus_context *ctx)
 227 {
 228         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 229 }
 230
 231 /* ----------- raw request handling ----------- */
 232
 233 /* wait for a request to complete and return its status */
 234 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 235                           int timeout);
 236
 237 /* complete a request asynchronously */
 238 void ubus_complete_request_async(struct ubus_context *ctx,
 239                                  struct ubus_request *req);
 240
 241 /* abort an asynchronous request */
 242 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 243
 244 /* ----------- objects ----------- */
 245
 246 int ubus_lookup(struct ubus_context *ctx, const char *path,
 247                 ubus_lookup_handler_t cb, void *priv);
 248
 249 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 250
 251 /* make an object visible to remote connections */
 252 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 253
 254 /* remove the object from the ubus connection */
 255 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 256
 257 /* add a subscriber notifications from another object */
 258 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 259
 260 static inline int
 261 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 262 {
 263         return ubus_remove_object(ctx, &obj->obj);
 264 }
 265
 266 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 267 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 268
 269 /* ----------- rpc ----------- */
 270
 271 /* invoke a method on a specific object */
 272 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 273                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 274                 int timeout);
 275
 276 /* asynchronous version of ubus_invoke() */
 277 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 278                       struct blob_attr *msg, struct ubus_request *req);
 279
 280 /* send a reply to an incoming object method call */
 281 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 282                     struct blob_attr *msg);
 283
 284 static inline void ubus_defer_request(struct ubus_context *ctx,
 285                                       struct ubus_request_data *req,
 286                                       struct ubus_request_data *new_req)
 287 {
 288     memcpy(new_req, req, sizeof(*req));
 289     req->deferred = true;
 290 }
 291
 292 static inline void ubus_request_set_fd(struct ubus_context *ctx,
 293                                        struct ubus_request_data *req, int fd)
 294 {
 295     req->fd = fd;
 296 }
 297
 298 void ubus_complete_deferred_request(struct ubus_context *ctx,
 299                                     struct ubus_request_data *req, int ret);
 300
 301 /*
 302  * send a notification to all subscribers of an object
 303  * if timeout < 0, no reply is expected from subscribers
 304  */
 305 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 306                 const char *type, struct blob_attr *msg, int timeout);
 307
 308 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 309                       const char *type, struct blob_attr *msg,
 310                       struct ubus_notify_request *req);
 311
 312
 313 /* ----------- events ----------- */
 314
 315 int ubus_send_event(struct ubus_context *ctx, const char *id,
 316                     struct blob_attr *data);
 317
 318 int ubus_register_event_handler(struct ubus_context *ctx,
 319                                 struct ubus_event_handler *ev,
 320                                 const char *pattern);
 321
 322 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 323                                                 struct ubus_event_handler *ev)
 324 {
 325     return ubus_remove_object(ctx, &ev->obj);
 326 }
 327
 328 #endif