ubusd_obj.c

   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 #include "ubusd.h"
  15 #include "ubusd_obj.h"
  16
  17 struct avl_tree obj_types;
  18 struct avl_tree objects;
  19 struct avl_tree path;
  20
  21 static void ubus_unref_object_type(struct ubus_object_type *type)
  22 {
  23         struct ubus_method *m;
  24
  25         if (--type->refcount > 0)
  26                 return;
  27
  28         while (!list_empty(&type->methods)) {
  29                 m = list_first_entry(&type->methods, struct ubus_method, list);
  30                 list_del(&m->list);
  31                 free(m);
  32         }
  33
  34         ubus_free_id(&obj_types, &type->id);
  35         free(type);
  36 }
  37
  38 static bool ubus_create_obj_method(struct ubus_object_type *type, struct blob_attr *attr)
  39 {
  40         struct ubus_method *m;
  41         int bloblen = blob_raw_len(attr);
  42
  43         m = calloc(1, sizeof(*m) + bloblen);
  44         if (!m)
  45                 return false;
  46
  47         list_add_tail(&m->list, &type->methods);
  48         memcpy(m->data, attr, bloblen);
  49         m->name = blobmsg_name(m->data);
  50
  51         return true;
  52 }
  53
  54 static struct ubus_object_type *ubus_create_obj_type(struct blob_attr *sig)
  55 {
  56         struct ubus_object_type *type;
  57         struct blob_attr *pos;
  58         int rem;
  59
  60         type = calloc(1, sizeof(*type));
  61         if (!type)
  62                 return NULL;
  63
  64         type->refcount = 1;
  65
  66         if (!ubus_alloc_id(&obj_types, &type->id, 0))
  67                 goto error_free;
  68
  69         INIT_LIST_HEAD(&type->methods);
  70
  71         blob_for_each_attr(pos, sig, rem) {
  72                 if (!blobmsg_check_attr(pos, true))
  73                         goto error_unref;
  74
  75                 if (!ubus_create_obj_method(type, pos))
  76                         goto error_unref;
  77         }
  78
  79         return type;
  80
  81 error_unref:
  82         ubus_unref_object_type(type);
  83         return NULL;
  84
  85 error_free:
  86         free(type);
  87         return NULL;
  88 }
  89
  90 static struct ubus_object_type *ubus_get_obj_type(uint32_t obj_id)
  91 {
  92         struct ubus_object_type *type;
  93         struct ubus_id *id;
  94
  95         id = ubus_find_id(&obj_types, obj_id);
  96         if (!id)
  97                 return NULL;
  98
  99         type = container_of(id, struct ubus_object_type, id);
 100         type->refcount++;
 101         return type;
 102 }
 103
 104 struct ubus_object *ubusd_create_object_internal(struct ubus_object_type *type, uint32_t id)
 105 {
 106         struct ubus_object *obj;
 107
 108         obj = calloc(1, sizeof(*obj));
 109         if (!obj)
 110                 return NULL;
 111
 112         if (!ubus_alloc_id(&objects, &obj->id, id))
 113                 goto error_free;
 114
 115         obj->type = type;
 116         INIT_LIST_HEAD(&obj->list);
 117         INIT_LIST_HEAD(&obj->events);
 118         INIT_LIST_HEAD(&obj->subscribers);
 119         INIT_LIST_HEAD(&obj->target_list);
 120         if (type)
 121                 type->refcount++;
 122
 123         return obj;
 124
 125 error_free:
 126         free(obj);
 127         return NULL;
 128 }
 129
 130 struct ubus_object *ubusd_create_object(struct ubus_client *cl, struct blob_attr **attr)
 131 {
 132         struct ubus_object *obj;
 133         struct ubus_object_type *type = NULL;
 134
 135         if (attr[UBUS_ATTR_OBJTYPE])
 136                 type = ubus_get_obj_type(blob_get_u32(attr[UBUS_ATTR_OBJTYPE]));
 137         else if (attr[UBUS_ATTR_SIGNATURE])
 138                 type = ubus_create_obj_type(attr[UBUS_ATTR_SIGNATURE]);
 139
 140         obj = ubusd_create_object_internal(type, 0);
 141         if (type)
 142                 ubus_unref_object_type(type);
 143
 144         if (!obj)
 145                 return NULL;
 146
 147         if (attr[UBUS_ATTR_OBJPATH]) {
 148                 obj->path.key = strdup(blob_data(attr[UBUS_ATTR_OBJPATH]));
 149                 if (!obj->path.key)
 150                         goto free;
 151
 152                 if (avl_insert(&path, &obj->path) != 0) {
 153                         free((void *) obj->path.key);
 154                         obj->path.key = NULL;
 155                         goto free;
 156                 }
 157                 ubusd_send_obj_event(obj, true);
 158         }
 159
 160         obj->client = cl;
 161         list_add(&obj->list, &cl->objects);
 162
 163         return obj;
 164
 165 free:
 166         ubusd_free_object(obj);
 167         return NULL;
 168 }
 169
 170 void ubus_subscribe(struct ubus_object *obj, struct ubus_object *target)
 171 {
 172         struct ubus_subscription *s;
 173         bool first = list_empty(&target->subscribers);
 174
 175         s = calloc(1, sizeof(*s));
 176         if (!s)
 177                 return;
 178
 179         s->subscriber = obj;
 180         s->target = target;
 181         list_add(&s->list, &target->subscribers);
 182         list_add(&s->target_list, &obj->target_list);
 183
 184         if (first)
 185                 ubus_notify_subscription(target);
 186 }
 187
 188 void ubus_unsubscribe(struct ubus_subscription *s)
 189 {
 190         struct ubus_object *obj = s->target;
 191
 192         list_del(&s->list);
 193         list_del(&s->target_list);
 194         free(s);
 195
 196         if (list_empty(&obj->subscribers))
 197                 ubus_notify_subscription(obj);
 198 }
 199
 200 void ubusd_free_object(struct ubus_object *obj)
 201 {
 202         struct ubus_subscription *s, *tmp;
 203
 204         list_for_each_entry_safe(s, tmp, &obj->target_list, target_list) {
 205                 ubus_unsubscribe(s);
 206         }
 207         list_for_each_entry_safe(s, tmp, &obj->subscribers, list) {
 208                 ubus_notify_unsubscribe(s);
 209         }
 210
 211         ubusd_event_cleanup_object(obj);
 212         if (obj->path.key) {
 213                 ubusd_send_obj_event(obj, false);
 214                 avl_delete(&path, &obj->path);
 215                 free((void *) obj->path.key);
 216         }
 217         if (!list_empty(&obj->list))
 218                 list_del(&obj->list);
 219         ubus_free_id(&objects, &obj->id);
 220         if (obj->type)
 221                 ubus_unref_object_type(obj->type);
 222         free(obj);
 223 }
 224
 225 static void __constructor ubusd_obj_init(void)
 226 {
 227         ubus_init_id_tree(&objects);
 228         ubus_init_id_tree(&obj_types);
 229         ubus_init_string_tree(&path, false);
 230         ubusd_event_init();
 231 }