service/watch.c

   1 /*
   2  * Copyright (C) 2013 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2013 John Crispin <blogic@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU Lesser General Public License version 2.1
   7  * as published by the Free Software Foundation
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  */
  14
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17
  18 #include <libubox/blobmsg_json.h>
  19
  20 #include "../procd.h"
  21
  22 struct watch_object {
  23         struct list_head list;
  24
  25         void *id;
  26         char *name;
  27 };
  28
  29 static struct ubus_event_handler watch_event;
  30 static struct ubus_subscriber watch_subscribe;
  31 static LIST_HEAD(watch_objects);
  32
  33 static void watch_subscribe_cb(struct ubus_context *ctx, struct ubus_event_handler *ev,
  34                 const char *type, struct blob_attr *msg)
  35 {
  36         static const struct blobmsg_policy policy = {
  37                 "path", BLOBMSG_TYPE_STRING
  38         };
  39         struct watch_object *o;
  40         struct blob_attr *attr;
  41         const char *path;
  42
  43         DEBUG(3, "ubus event %s\n", type);
  44         if (strcmp(type, "ubus.object.add") != 0)
  45                 return;
  46
  47         blobmsg_parse(&policy, 1, &attr, blob_data(msg), blob_len(msg));
  48         if (!attr)
  49                 return;
  50
  51         path = blobmsg_data(attr);
  52         DEBUG(3, "ubus path %s\n", path);
  53
  54         list_for_each_entry(o, &watch_objects, list) {
  55                 unsigned int id;
  56
  57                 if (strcmp(o->name, path))
  58                         continue;
  59                 if (ubus_lookup_id(ctx, path, &id))
  60                         continue;
  61                 if (!ubus_subscribe(ctx, &watch_subscribe, id))
  62                         return;
  63                 ERROR("failed to subscribe %d\n", id);
  64         }
  65 }
  66
  67 void
  68 watch_add(const char *_name, void *id)
  69 {
  70         int len = strlen(_name);
  71         char *name;
  72         struct watch_object *o = calloc_a(sizeof(*o), &name, len + 1);
  73
  74         o->name = name;
  75         strcpy(name, _name);
  76         o->id = id;
  77         list_add(&o->list, &watch_objects);
  78 }
  79
  80 void
  81 watch_del(void *id)
  82 {
  83         struct watch_object *t, *n;
  84
  85         list_for_each_entry_safe(t, n, &watch_objects, list) {
  86                 if (t->id != id)
  87                         continue;
  88                 list_del(&t->list);
  89                 free(t);
  90         }
  91 }
  92
  93 static int
  94 watch_notify_cb(struct ubus_context *ctx, struct ubus_object *obj,
  95                 struct ubus_request_data *req, const char *method,
  96                 struct blob_attr *msg)
  97 {
  98         if (debug >= 3) {
  99                 char *str;
 100
 101                 str = blobmsg_format_json(msg, true);
 102                 DEBUG(3, "Received ubus notify '%s': %s\n", method, str);
 103                 free(str);
 104         }
 105
 106         trigger_event(method, msg);
 107         return 0;
 108 }
 109
 110 void
 111 watch_ubus(struct ubus_context *ctx)
 112 {
 113         watch_event.cb = watch_subscribe_cb;
 114         watch_subscribe.cb = watch_notify_cb;
 115         if (ubus_register_subscriber(ctx, &watch_subscribe))
 116                 ERROR("failed to register ubus subscriber\n");
 117         if (ubus_register_event_handler(ctx, &watch_event, "ubus.object.add"))
 118                 ERROR("failed to add ubus event handler\n");
 119 }