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