libubus.h

   1 /*
   2  * Copyright (C) 2011-2012 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_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
  60 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  61         {                                               \
  62                 .name = _name,                          \
  63                 .id = 0,                                \
  64                 .n_methods = ARRAY_SIZE(_methods),      \
  65                 .methods = _methods                     \
  66         }
  67
  68 #define UBUS_METHOD(_name, _handler, _policy)           \
  69         {                                               \
  70                 .name = _name,                          \
  71                 .handler = _handler,                    \
  72                 .policy = _policy,                      \
  73                 .n_policy = ARRAY_SIZE(_policy)         \
  74         }
  75
  76 #define UBUS_METHOD_NOARG(_name, _handler)              \
  77         {                                               \
  78                 .name = _name,                          \
  79                 .handler = _handler,                    \
  80         }
  81
  82 struct ubus_method {
  83         const char *name;
  84         ubus_handler_t handler;
  85
  86         const struct blobmsg_policy *policy;
  87         int n_policy;
  88 };
  89
  90 struct ubus_object_type {
  91         const char *name;
  92         uint32_t id;
  93
  94         const struct ubus_method *methods;
  95         int n_methods;
  96 };
  97
  98 struct ubus_object {
  99         struct avl_node avl;
 100
 101         const char *name;
 102         uint32_t id;
 103
 104         const char *path;
 105         struct ubus_object_type *type;
 106
 107         ubus_state_handler_t subscribe_cb;
 108         bool has_subscribers;
 109
 110         const struct ubus_method *methods;
 111         int n_methods;
 112 };
 113
 114 struct ubus_subscriber {
 115         struct ubus_object obj;
 116
 117         ubus_handler_t cb;
 118         ubus_remove_handler_t remove_cb;
 119 };
 120
 121 struct ubus_event_handler {
 122         struct ubus_object obj;
 123
 124         ubus_event_handler_t cb;
 125 };
 126
 127 struct ubus_context {
 128         struct list_head requests;
 129         struct avl_tree objects;
 130         struct list_head pending;
 131
 132         struct uloop_fd sock;
 133
 134         uint32_t local_id;
 135         uint16_t request_seq;
 136         int stack_depth;
 137
 138         void (*connection_lost)(struct ubus_context *ctx);
 139
 140         struct {
 141                 struct ubus_msghdr hdr;
 142                 char data[UBUS_MAX_MSGLEN];
 143         } msgbuf;
 144 };
 145
 146 struct ubus_object_data {
 147         uint32_t id;
 148         uint32_t type_id;
 149         const char *path;
 150         struct blob_attr *signature;
 151 };
 152
 153 struct ubus_request_data {
 154         uint32_t object;
 155         uint32_t peer;
 156         uint16_t seq;
 157         bool deferred;
 158 };
 159
 160 struct ubus_request {
 161         struct list_head list;
 162
 163         struct list_head pending;
 164         int status_code;
 165         bool status_msg;
 166         bool blocked;
 167         bool cancelled;
 168         bool notify;
 169
 170         uint32_t peer;
 171         uint16_t seq;
 172
 173         ubus_data_handler_t raw_data_cb;
 174         ubus_data_handler_t data_cb;
 175         ubus_complete_handler_t complete_cb;
 176
 177         struct ubus_context *ctx;
 178         void *priv;
 179 };
 180
 181 struct ubus_notify_request {
 182         struct ubus_request req;
 183
 184         ubus_notify_complete_handler_t status_cb;
 185         ubus_notify_complete_handler_t complete_cb;
 186
 187         uint32_t pending;
 188         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 189 };
 190
 191 struct ubus_context *ubus_connect(const char *path);
 192 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 193 void ubus_free(struct ubus_context *ctx);
 194
 195 const char *ubus_strerror(int error);
 196
 197 static inline void ubus_add_uloop(struct ubus_context *ctx)
 198 {
 199         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 200 }
 201
 202 /* call this for read events on ctx->sock.fd when not using uloop */
 203 static inline void ubus_handle_event(struct ubus_context *ctx)
 204 {
 205         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 206 }
 207
 208 /* ----------- raw request handling ----------- */
 209
 210 /* wait for a request to complete and return its status */
 211 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 212                           int timeout);
 213
 214 /* complete a request asynchronously */
 215 void ubus_complete_request_async(struct ubus_context *ctx,
 216                                  struct ubus_request *req);
 217
 218 /* abort an asynchronous request */
 219 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 220
 221 /* ----------- objects ----------- */
 222
 223 int ubus_lookup(struct ubus_context *ctx, const char *path,
 224                 ubus_lookup_handler_t cb, void *priv);
 225
 226 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 227
 228 /* make an object visible to remote connections */
 229 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 230
 231 /* remove the object from the ubus connection */
 232 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 233
 234 /* add a subscriber notifications from another object */
 235 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 236
 237 static inline int
 238 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 239 {
 240         return ubus_remove_object(ctx, &obj->obj);
 241 }
 242
 243 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 244 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 245
 246 /* ----------- rpc ----------- */
 247
 248 /* invoke a method on a specific object */
 249 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 250                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 251                 int timeout);
 252
 253 /* asynchronous version of ubus_invoke() */
 254 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 255                       struct blob_attr *msg, struct ubus_request *req);
 256
 257 /* send a reply to an incoming object method call */
 258 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 259                     struct blob_attr *msg);
 260
 261 static inline void ubus_defer_request(struct ubus_context *ctx,
 262                                       struct ubus_request_data *req,
 263                                       struct ubus_request_data *new_req)
 264 {
 265     memcpy(new_req, req, sizeof(*req));
 266     req->deferred = true;
 267 }
 268
 269 void ubus_complete_deferred_request(struct ubus_context *ctx,
 270                                     struct ubus_request_data *req, int ret);
 271
 272 /*
 273  * send a notification to all subscribers of an object
 274  * if timeout < 0, no reply is expected from subscribers
 275  */
 276 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 277                 const char *type, struct blob_attr *msg, int timeout);
 278
 279 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 280                       const char *type, struct blob_attr *msg,
 281                       struct ubus_notify_request *req);
 282
 283
 284 /* ----------- events ----------- */
 285
 286 int ubus_send_event(struct ubus_context *ctx, const char *id,
 287                     struct blob_attr *data);
 288
 289 int ubus_register_event_handler(struct ubus_context *ctx,
 290                                 struct ubus_event_handler *ev,
 291                                 const char *pattern);
 292
 293 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 294                                                 struct ubus_event_handler *ev)
 295 {
 296     return ubus_remove_object(ctx, &ev->obj);
 297 }
 298
 299 #endif