1 // Copyright (C) 2014-2021 Internet Systems Consortium, Inc. ("ISC")
2 //
3 // This Source Code Form is subject to the terms of the Mozilla Public
4 // License, v. 2.0. If a copy of the MPL was not distributed with this
5 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
6 
7 #ifndef SUBNET_ID_H
8 #define SUBNET_ID_H
9 
10 #include <exceptions/exceptions.h>
11 #include <stdint.h>
12 #include <typeinfo>
13 #include <limits>
14 
15 namespace isc {
16 namespace dhcp {
17 
18 /// @brief Defines unique IPv4 or IPv6 subnet identifier.
19 ///
20 /// Each subnet for which the DHCP service has been configured is identified
21 /// by the unique value called subnet id. Right now it is represented as
22 /// a simple unsigned integer. In the future it may be extended to more complex
23 /// type.
24 typedef uint32_t SubnetID;
25 
26 /// @brief Special value is used for storing/recognizing global host reservations.
27 static const SubnetID SUBNET_ID_GLOBAL = 0;
28 /// @brief The largest valid value for auto-generated subnet IDs.
29 static const SubnetID SUBNET_ID_MAX = std::numeric_limits<uint32_t>::max()-1;
30 /// @brief Special value used to signify that a SubnetID is "not set"
31 static const SubnetID SUBNET_ID_UNUSED = std::numeric_limits<uint32_t>::max();
32 
33 /// @brief Exception thrown upon attempt to add subnet with an ID that belongs
34 /// to the subnet that already exists.
35 class DuplicateSubnetID : public Exception {
36 public:
DuplicateSubnetID(const char * file,size_t line,const char * what)37     DuplicateSubnetID(const char* file, size_t line, const char* what) :
38         isc::Exception(file, line, what) { };
39 };
40 
41 }
42 }
43 
44 #endif // SUBNET_ID_H
45