1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
|
// Copyright (C) 2013 Internet Systems Consortium, Inc. ("ISC")
//
// Permission to use, copy, modify, and/or distribute this software for any
// purpose with or without fee is hereby granted, provided that the above
// copyright notice and this permission notice appear in all copies.
//
// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
// PERFORMANCE OF THIS SOFTWARE.
#ifndef DHCP_CONFIG_PARSER_H
#define DHCP_CONFIG_PARSER_H
#include <exceptions/exceptions.h>
#include <cc/data.h>
#include <stdint.h>
#include <string>
#include <map>
namespace isc {
namespace dhcp {
/// An exception that is thrown if an error occurs while configuring
/// DHCP server.
class DhcpConfigError : public isc::Exception {
public:
/// @brief constructor
///
/// @param file name of the file, where exception occurred
/// @param line line of the file, where exception occurred
/// @param what text description of the issue that caused exception
DhcpConfigError(const char* file, size_t line, const char* what)
: isc::Exception(file, line, what) {}
};
/// @brief Forward declaration to DhcpConfigParser class.
///
/// It is only needed here to define types that are
/// based on this class before the class definition.
class DhcpConfigParser;
/// @brief a pointer to configuration parser
typedef boost::shared_ptr<DhcpConfigParser> ParserPtr;
/// @brief Collection of parsers.
///
/// This container is used to store pointer to parsers for a given scope.
typedef std::vector<ParserPtr> ParserCollection;
/// @brief Combination of parameter name and configuration contents
typedef std::pair<std::string, isc::data::ConstElementPtr> ConfigPair;
/// @brief Base abstract class for all DHCP parsers
///
/// Each instance of a class derived from this class parses one specific config
/// element. Sometimes elements are simple (e.g. a string) and sometimes quite
/// complex (e.g. a subnet). In such case, it is likely that a parser will
/// spawn child parsers to parse child elements in the configuration.
class DhcpConfigParser {
///
/// @name Constructors and Destructor
///
/// Note: The copy constructor and the assignment operator are
/// intentionally defined as private to make it explicit that this is a
/// pure base class.
//@{
private:
// Private constructor and assignment operator assures that nobody
// will be able to copy or assign a parser. There are no defined
// bodies for them.
DhcpConfigParser(const DhcpConfigParser& source);
DhcpConfigParser& operator=(const DhcpConfigParser& source);
protected:
/// @brief The default constructor.
///
/// This is intentionally defined as @c protected as this base class should
/// never be instantiated (except as part of a derived class).
DhcpConfigParser() {}
public:
/// The destructor.
virtual ~DhcpConfigParser() {}
//@}
/// @brief Prepare configuration value.
///
/// This method parses the "value part" of the configuration identifier
/// that corresponds to this derived class and prepares a new value to
/// apply to the server.
///
/// This method must validate the given value both in terms of syntax
/// and semantics of the configuration, so that the server will be
/// validly configured at the time of @c commit(). Note: the given
/// configuration value is normally syntactically validated, but the
/// @c build() implementation must also expect invalid input. If it
/// detects an error it may throw an exception of a derived class
/// of @c isc::Exception.
///
/// Preparing a configuration value will often require resource
/// allocation. If it fails, it may throw a corresponding standard
/// exception.
///
/// This method is not expected to be called more than once in the
/// life of the object. Although multiple calls are not prohibited
/// by the interface, the behavior is undefined.
///
/// @param config_value The configuration value for the identifier
/// corresponding to the derived class.
virtual void build(isc::data::ConstElementPtr config_value) = 0;
/// @brief Apply the prepared configuration value to the server.
///
/// This method is expected to be exception free, and, as a consequence,
/// it should normally not involve resource allocation.
/// Typically it would simply perform exception free assignment or swap
/// operation on the value prepared in @c build().
/// In some cases, however, it may be very difficult to meet this
/// condition in a realistic way, while the failure case should really
/// be very rare. In such a case it may throw, and, if the parser is
/// called via @c configureDhcp4Server(), the caller will convert the
/// exception as a fatal error.
///
/// This method is expected to be called after @c build(), and only once.
/// The result is undefined otherwise.
virtual void commit() = 0;
};
}; // end of isc::dhcp namespace
}; // end of isc namespace
#endif // DHCP_CONFIG_PARSER_H
|
