libubus.h

   1 /*
   2  * Copyright (C) 2011 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 struct ubus_context;
  26 struct ubus_msg_src;
  27 struct ubus_object;
  28 struct ubus_request;
  29 struct ubus_request_data;
  30 struct ubus_object_data;
  31 struct ubus_event_handler;
  32 struct ubus_subscriber;
  33
  34 typedef void (*ubus_lookup_handler_t)(struct ubus_context *ctx,
  35                                       struct ubus_object_data *obj,
  36                                       void *priv);
  37 typedef int (*ubus_handler_t)(struct ubus_context *ctx, struct ubus_object *obj,
  38                               struct ubus_request_data *req,
  39                               const char *method, struct blob_attr *msg);
  40 typedef void (*ubus_remove_handler_t)(struct ubus_context *ctx,
  41                                       struct ubus_subscriber *obj, uint32_t id);
  42 typedef void (*ubus_event_handler_t)(struct ubus_context *ctx, struct ubus_event_handler *ev,
  43                                      const char *type, struct blob_attr *msg);
  44 typedef void (*ubus_data_handler_t)(struct ubus_request *req,
  45                                     int type, struct blob_attr *msg);
  46 typedef void (*ubus_complete_handler_t)(struct ubus_request *req, int ret);
  47
  48 #define UBUS_OBJECT_TYPE(_name, _methods)               \
  49         {                                               \
  50                 .name = _name,                          \
  51                 .id = 0,                                \
  52                 .n_methods = ARRAY_SIZE(_methods),      \
  53                 .methods = _methods                     \
  54         }
  55
  56 #define UBUS_METHOD(_name, _handler, _policy)           \
  57         {                                               \
  58                 .name = _name,                          \
  59                 .handler = _handler,                    \
  60                 .policy = _policy,                      \
  61                 .n_policy = ARRAY_SIZE(_policy)         \
  62         }
  63
  64 struct ubus_method {
  65         const char *name;
  66         ubus_handler_t handler;
  67
  68         const struct blobmsg_policy *policy;
  69         int n_policy;
  70 };
  71
  72 struct ubus_object_type {
  73         const char *name;
  74         uint32_t id;
  75
  76         const struct ubus_method *methods;
  77         int n_methods;
  78 };
  79
  80 struct ubus_object {
  81         struct avl_node avl;
  82
  83         const char *name;
  84         uint32_t id;
  85
  86         const char *path;
  87         struct ubus_object_type *type;
  88
  89         const struct ubus_method *methods;
  90         int n_methods;
  91 };
  92
  93 struct ubus_subscriber {
  94         struct ubus_object obj;
  95
  96         ubus_handler_t cb;
  97         ubus_remove_handler_t remove_cb;
  98 };
  99
 100 struct ubus_event_handler {
 101         struct ubus_object obj;
 102
 103         ubus_event_handler_t cb;
 104 };
 105
 106 struct ubus_context {
 107         struct list_head requests;
 108         struct avl_tree objects;
 109         struct list_head pending;
 110
 111         struct uloop_fd sock;
 112
 113         uint32_t local_id;
 114         uint32_t request_seq;
 115         int stack_depth;
 116
 117         void (*connection_lost)(struct ubus_context *ctx);
 118
 119         struct {
 120                 struct ubus_msghdr hdr;
 121                 char data[UBUS_MAX_MSGLEN];
 122         } msgbuf;
 123 };
 124
 125 struct ubus_object_data {
 126         uint32_t id;
 127         uint32_t type_id;
 128         const char *path;
 129         struct blob_attr *signature;
 130 };
 131
 132 struct ubus_request_data {
 133         uint32_t object;
 134         uint32_t peer;
 135         uint32_t seq;
 136         bool deferred;
 137 };
 138
 139 struct ubus_request {
 140         struct list_head list;
 141
 142         struct list_head pending;
 143         bool status_msg;
 144         int status_code;
 145         bool blocked;
 146         bool cancelled;
 147
 148         uint32_t peer;
 149         uint32_t seq;
 150
 151         ubus_data_handler_t raw_data_cb;
 152         ubus_data_handler_t data_cb;
 153         ubus_complete_handler_t complete_cb;
 154
 155         struct ubus_context *ctx;
 156         void *priv;
 157 };
 158
 159
 160 struct ubus_context *ubus_connect(const char *path);
 161 int ubus_reconnect(struct ubus_context *ctx, const char *path);
 162 void ubus_free(struct ubus_context *ctx);
 163
 164 const char *ubus_strerror(int error);
 165
 166 static inline void ubus_add_uloop(struct ubus_context *ctx)
 167 {
 168         uloop_fd_add(&ctx->sock, ULOOP_BLOCKING | ULOOP_READ);
 169 }
 170
 171 /* call this for read events on ctx->sock.fd when not using uloop */
 172 static inline void ubus_handle_event(struct ubus_context *ctx)
 173 {
 174         ctx->sock.cb(&ctx->sock, ULOOP_READ);
 175 }
 176
 177 /* ----------- raw request handling ----------- */
 178
 179 /* wait for a request to complete and return its status */
 180 int ubus_complete_request(struct ubus_context *ctx, struct ubus_request *req,
 181                           int timeout);
 182
 183 /* complete a request asynchronously */
 184 void ubus_complete_request_async(struct ubus_context *ctx,
 185                                  struct ubus_request *req);
 186
 187 /* abort an asynchronous request */
 188 void ubus_abort_request(struct ubus_context *ctx, struct ubus_request *req);
 189
 190 /* ----------- objects ----------- */
 191
 192 int ubus_lookup(struct ubus_context *ctx, const char *path,
 193                 ubus_lookup_handler_t cb, void *priv);
 194
 195 int ubus_lookup_id(struct ubus_context *ctx, const char *path, uint32_t *id);
 196
 197 /* make an object visible to remote connections */
 198 int ubus_add_object(struct ubus_context *ctx, struct ubus_object *obj);
 199
 200 /* remove the object from the ubus connection */
 201 int ubus_remove_object(struct ubus_context *ctx, struct ubus_object *obj);
 202
 203 /* add a subscriber notifications from another object */
 204 int ubus_register_subscriber(struct ubus_context *ctx, struct ubus_subscriber *obj);
 205 int ubus_subscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 206 int ubus_unsubscribe(struct ubus_context *ctx, struct ubus_subscriber *obj, uint32_t id);
 207
 208 /* ----------- rpc ----------- */
 209
 210 /* invoke a method on a specific object */
 211 int ubus_invoke(struct ubus_context *ctx, uint32_t obj, const char *method,
 212                 struct blob_attr *msg, ubus_data_handler_t cb, void *priv,
 213                 int timeout);
 214
 215 /* asynchronous version of ubus_invoke() */
 216 int ubus_invoke_async(struct ubus_context *ctx, uint32_t obj, const char *method,
 217                       struct blob_attr *msg, struct ubus_request *req);
 218
 219 /* send a reply to an incoming object method call */
 220 int ubus_send_reply(struct ubus_context *ctx, struct ubus_request_data *req,
 221                     struct blob_attr *msg);
 222
 223 static inline void ubus_defer_request(struct ubus_context *ctx,
 224                                       struct ubus_request_data *req,
 225                                       struct ubus_request_data *new_req)
 226 {
 227     memcpy(new_req, req, sizeof(*req));
 228     req->deferred = true;
 229 }
 230
 231 void ubus_complete_deferred_request(struct ubus_context *ctx,
 232                                     struct ubus_request_data *req, int ret);
 233
 234 /* ----------- events ----------- */
 235
 236 int ubus_send_event(struct ubus_context *ctx, const char *id,
 237                     struct blob_attr *data);
 238
 239 int ubus_register_event_handler(struct ubus_context *ctx,
 240                                 struct ubus_event_handler *ev,
 241                                 const char *pattern);
 242
 243 static inline int ubus_unregister_event_handler(struct ubus_context *ctx,
 244                                                 struct ubus_event_handler *ev)
 245 {
 246     return ubus_remove_object(ctx, &ev->obj);
 247 }
 248
 249 #endif