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 static inline struct blob_attr *
  43 ubus_msghdr_data(struct ubus_msghdr *hdr)
  44 {
  45         struct ubus_msghdr_buf *hdrbuf = container_of(hdr, typeof(*hdrbuf), hdr);
  46         return hdrbuf->data;
  47 }
  48
  49 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  50                                       struct ubus_object_data *obj,
  51                                       void *priv);
  52 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  53                               struct ubus_request_data *req,
  54                               const char *method, struct blob_attr *msg);
  55 typedef void (*ubus_state_handler_t)(struct ubus_context *ctx, struct ubus_object *obj);
  56 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  57                                       struct ubus_subscriber *obj, uint32_t id);
  58 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  59                                      const char *type, struct blob_attr *msg);
  60 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  61                                     int type, struct blob_attr *msg);
  62 typedef void (*ubus_fd_handler_t)(struct ubus_request *req, int fd);
  63 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  64 typedef void (*ubus_notify_complete_handler_t)(struct ubus_notify_request *req,
  65                                                int idx, int ret);
  66 typedef void (*ubus_connect_handler_t)(struct ubus_context *ctx);
  67
  68 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  69         {                                               \
  70                 .name = _name,                          \
  71                 .id = 0,                                \
  72                 .n_methods = ARRAY_SIZE(_methods),      \
  73                 .methods = _methods                     \
  74         }
  75
  76 #define __UBUS_METHOD_NOARG(_name, _handler)            \
  77         .name = _name,                                  \
  78         .handler = _handler
  79
  80 #define __UBUS_METHOD(_name, _handler, _policy)         \
  81         __UBUS_METHOD_NOARG(_name, _handler),           \
  82         .policy = _policy,                              \
  83         .n_policy = ARRAY_SIZE(_policy)
  84
  85 #define UBUS_METHOD(_name, _handler, _policy)           \
  86         { __UBUS_METHOD(_name, _handler, _policy) }
  87
  88 #define UBUS_METHOD_MASK(_name, _handler, _policy, _mask) \
  89         {                                               \
  90                 __UBUS_METHOD(_name, _handler, _policy),\
  91                 .mask = _mask                           \
  92         }
  93
  94 #define UBUS_METHOD_NOARG(_name, _handler)              \
  95         { __UBUS_METHOD_NOARG(_name, _handler) }
  96
  97 struct ubus_method {
  98         const char *name;
  99         ubus_handler_t handler;
 100
 101         unsigned long mask;
 102         const struct blobmsg_policy *policy;
 103         int n_policy;
 104 };
 105
 106 struct ubus_object_type {
 107         const char *name;
 108         uint32_t id;
 109
 110         const struct ubus_method *methods;
 111         int n_methods;
 112 };
 113
 114 struct ubus_object {
 115         struct avl_node avl;
 116
 117         const char *name;
 118         uint32_t id;
 119
 120         const char *path;
 121         struct ubus_object_type *type;
 122
 123         ubus_state_handler_t subscribe_cb;
 124         bool has_subscribers;
 125
 126         const struct ubus_method *methods;
 127         int n_methods;
 128 };
 129
 130 struct ubus_subscriber {
 131         struct ubus_object obj;
 132
 133         ubus_handler_t cb;
 134         ubus_remove_handler_t remove_cb;
 135 };
 136
 137 struct ubus_event_handler {
 138         struct ubus_object obj;
 139
 140         ubus_event_handler_t cb;
 141 };
 142
 143 struct ubus_context {
 144         struct list_head requests;
 145         struct avl_tree objects;
 146         struct list_head pending;
 147
 148         struct uloop_fd sock;
 149         struct uloop_timeout pending_timer;
 150
 151         uint32_t local_id;
 152         uint16_t request_seq;
 153         int stack_depth;
 154
 155         void (*connection_lost)(struct ubus_context *ctx);
 156
 157         struct ubus_msghdr_buf msgbuf;
 158 };
 159
 160 struct ubus_object_data {
 161         uint32_t id;
 162         uint32_t type_id;
 163         const char *path;
 164         struct blob_attr *signature;
 165 };
 166
 167 struct ubus_request_data {
 168         uint32_t object;
 169         uint32_t peer;
 170         uint16_t seq;
 171
 172         /* internal use */
 173         bool deferred;
 174         int fd;
 175 };
 176
 177 struct ubus_request {
 178         struct list_head list;
 179
 180         struct list_head pending;
 181         int status_code;
 182         bool status_msg;
 183         bool blocked;
 184         bool cancelled;
 185         bool notify;
 186
 187         uint32_t peer;
 188         uint16_t seq;
 189
 190         ubus_data_handler_t raw_data_cb;
 191         ubus_data_handler_t data_cb;
 192         ubus_fd_handler_t fd_cb;
 193         ubus_complete_handler_t complete_cb;
 194
 195         struct ubus_context *ctx;
 196         void *priv;
 197 };
 198
 199 struct ubus_notify_request {
 200         struct ubus_request req;
 201
 202         ubus_notify_complete_handler_t status_cb;
 203         ubus_notify_complete_handler_t complete_cb;
 204
 205         uint32_t pending;
 206         uint32_t id[UBUS_MAX_NOTIFY_PEERS + 1];
 207 };
 208
 209 struct ubus_auto_conn {
 210         struct ubus_context ctx;
 211         struct uloop_timeout timer;
 212         const char *path;
 213         ubus_connect_handler_t cb;
 214 };
 215
 216 struct ubus_context *ubus_connect(const char *path);
 217 void ubus_auto_connect(struct ubus_auto_conn *conn);
 218 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 219 void ubus_free(struct ubus_context *ctx);
 220
 221 const char *ubus_strerror(int error);
 222
 223 static inline void ubus_add_uloop(struct ubus_context *ctx)
 224 {
 225         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 226 }
 227
 228 /* call this for read events on ctx->sock.fd when not using uloop */
 229 static inline void ubus_handle_event(struct ubus_context *ctx)
 230 {
 231         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 232 }
 233
 234 /* ----------- raw request handling ----------- */
 235
 236 /* wait for a request to complete and return its status */
 237 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 238                           int timeout);
 239
 240 /* complete a request asynchronously */
 241 void ubus_complete_request_async(struct ubus_context *ctx,
 242                                  struct ubus_request *req);
 243
 244 /* abort an asynchronous request */
 245 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 246
 247 /* ----------- objects ----------- */
 248
 249 int ubus_lookup(struct ubus_context *ctx, const char *path,
 250                 ubus_lookup_handler_t cb, void *priv);
 251
 252 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 253
 254 /* make an object visible to remote connections */
 255 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 256
 257 /* remove the object from the ubus connection */
 258 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 259
 260 /* add a subscriber notifications from another object */
 261 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 262
 263 static inline int
 264 ubus_unregister_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj)
 265 {
 266         return ubus_remove_object(ctx, &obj->obj);
 267 }
 268
 269 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 270 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 271
 272 /* ----------- rpc ----------- */
 273
 274 /* invoke a method on a specific object */
 275 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 276                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 277                 int timeout);
 278
 279 /* asynchronous version of ubus_invoke() */
 280 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 281                       struct blob_attr *msg, struct ubus_request *req);
 282
 283 /* send a reply to an incoming object method call */
 284 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 285                     struct blob_attr *msg);
 286
 287 static inline void ubus_defer_request(struct ubus_context *ctx,
 288                                       struct ubus_request_data *req,
 289                                       struct ubus_request_data *new_req)
 290 {
 291     memcpy(new_req, req, sizeof(*req));
 292     req->deferred = true;
 293 }
 294
 295 static inline void ubus_request_set_fd(struct ubus_context *ctx,
 296                                        struct ubus_request_data *req, int fd)
 297 {
 298     req->fd = fd;
 299 }
 300
 301 void ubus_complete_deferred_request(struct ubus_context *ctx,
 302                                     struct ubus_request_data *req, int ret);
 303
 304 /*
 305  * send a notification to all subscribers of an object
 306  * if timeout < 0, no reply is expected from subscribers
 307  */
 308 int ubus_notify(struct ubus_context *ctx, struct ubus_object *obj,
 309                 const char *type, struct blob_attr *msg, int timeout);
 310
 311 int ubus_notify_async(struct ubus_context *ctx, struct ubus_object *obj,
 312                       const char *type, struct blob_attr *msg,
 313                       struct ubus_notify_request *req);
 314
 315
 316 /* ----------- events ----------- */
 317
 318 int ubus_send_event(struct ubus_context *ctx, const char *id,
 319                     struct blob_attr *data);
 320
 321 int ubus_register_event_handler(struct ubus_context *ctx,
 322                                 struct ubus_event_handler *ev,
 323                                 const char *pattern);
 324
 325 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 326                                                 struct ubus_event_handler *ev)
 327 {
 328     return ubus_remove_object(ctx, &ev->obj);
 329 }
 330
 331 #endif