ubusd_monitor.c

   1 /*
   2  * Copyright (C) 2015 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
  16 static struct ubus_object *monitor_obj;
  17 static LIST_HEAD(monitors);
  18
  19 struct ubus_monitor {
  20         struct list_head list;
  21         struct ubus_client *cl;
  22         uint32_t seq;
  23 };
  24
  25 static void
  26 ubusd_monitor_free(struct ubus_monitor *m)
  27 {
  28         list_del(&m->list);
  29         free(m);
  30 }
  31
  32 static bool
  33 ubusd_monitor_connect(struct ubus_client *cl, struct ubus_msg_buf *ub)
  34 {
  35         struct ubus_monitor *m;
  36
  37         ubusd_monitor_disconnect(cl);
  38
  39         m = calloc(1, sizeof(*m));
  40         if (!m)
  41                 return false;
  42
  43         m->cl = cl;
  44         list_add_tail(&m->list, &monitors);
  45
  46         return true;
  47 }
  48
  49 static struct ubus_monitor*
  50 ubusd_monitor_find(struct ubus_client *cl)
  51 {
  52         struct ubus_monitor *m, *tmp;
  53
  54         list_for_each_entry_safe(m, tmp, &monitors, list) {
  55                 if (m->cl != cl)
  56                         continue;
  57
  58                 return m;
  59         }
  60
  61         return NULL;
  62 }
  63
  64 void
  65 ubusd_monitor_disconnect(struct ubus_client *cl)
  66 {
  67         struct ubus_monitor *m;
  68
  69         m = ubusd_monitor_find(cl);
  70         if (!m)
  71                 return;
  72
  73         ubusd_monitor_free(m);
  74 }
  75
  76 void
  77 ubusd_monitor_message(struct ubus_client *cl, struct ubus_msg_buf *ub, bool send)
  78 {
  79         static struct blob_buf mb;
  80         struct ubus_monitor *m;
  81
  82         if (list_empty(&monitors))
  83                 return;
  84
  85         blob_buf_init(&mb, 0);
  86         blob_put_int32(&mb, UBUS_MONITOR_CLIENT, cl->id.id);
  87         blob_put_int32(&mb, UBUS_MONITOR_PEER, ub->hdr.peer);
  88         blob_put_int32(&mb, UBUS_MONITOR_SEQ, ub->hdr.seq);
  89         blob_put_int32(&mb, UBUS_MONITOR_TYPE, ub->hdr.type);
  90         blob_put_int8(&mb, UBUS_MONITOR_SEND, send);
  91         blob_put(&mb, UBUS_MONITOR_DATA, blob_data(ub->data), blob_len(ub->data));
  92
  93         ub = ubus_msg_new(mb.head, blob_raw_len(mb.head), true);
  94         ub->hdr.type = UBUS_MSG_MONITOR;
  95
  96         list_for_each_entry(m, &monitors, list) {
  97                 ub->hdr.seq = ++m->seq;
  98                 ubus_msg_send(m->cl, ub);
  99         }
 100
 101         ubus_msg_free(ub);
 102 }
 103
 104 static int
 105 ubusd_monitor_recv(struct ubus_client *cl, struct ubus_msg_buf *ub,
 106                    const char *method, struct blob_attr *msg)
 107 {
 108         /* Only root is allowed for now */
 109         if (cl->uid != 0 || cl->gid != 0)
 110                 return UBUS_STATUS_PERMISSION_DENIED;
 111
 112         if (!strcmp(method, "add")) {
 113                 if (!ubusd_monitor_connect(cl, ub))
 114                         return UBUS_STATUS_UNKNOWN_ERROR;
 115
 116                 return UBUS_STATUS_OK;
 117         }
 118
 119         if (!strcmp(method, "remove")) {
 120                 ubusd_monitor_disconnect(cl);
 121                 return UBUS_STATUS_OK;
 122         }
 123
 124         return UBUS_STATUS_METHOD_NOT_FOUND;
 125 }
 126
 127 void
 128 ubusd_monitor_init(void)
 129 {
 130         monitor_obj = ubusd_create_object_internal(NULL, UBUS_SYSTEM_OBJECT_MONITOR);
 131         if (monitor_obj != NULL)
 132                 monitor_obj->recv_msg = ubusd_monitor_recv;
 133 }