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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360 | // Copyright (C) 2014-2024 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
#ifndef CFG_SUBNETS4_H
#define CFG_SUBNETS4_H
#include <asiolink/io_address.h>
#include <cc/cfg_to_element.h>
#include <dhcp/pkt4.h>
#include <dhcpsrv/cfg_shared_networks.h>
#include <dhcpsrv/subnet.h>
#include <dhcpsrv/subnet_id.h>
#include <dhcpsrv/subnet_selector.h>
#include <boost/shared_ptr.hpp><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
#include <string><--- Include file: not found. Please note: Cppcheck does not need standard library headers to get proper results.
namespace isc {
namespace dhcp {
/// @brief Holds subnets configured for the DHCPv4 server.
///
/// This class holds a collection of subnets configured for the DHCPv4 server.
/// It allows for retrieving a subnet for the particular client using various
/// parameters extracted from the DHCPv4 message. These parameters must be
/// assigned to the appropriate members of the @c CfgSubnets4::Selector
/// structure.
///
/// See @c CfgSubnets4::selectSubnet documentation for more details on how the
/// subnet is selected for the client.
class CfgSubnets4 : public isc::data::CfgToElement {
public:
/// @brief Adds new subnet to the configuration.
///
/// @param subnet Pointer to the subnet being added.
///
/// @throw isc::DuplicateSubnetID If the subnet id for the new subnet
/// duplicates id of an existing subnet.
void add(const Subnet4Ptr& subnet);
/// @brief Replaces subnet in the configuration.
///
/// This method replaces a subnet by another subnet with the same ID.
/// The prefix should be the same too.
///
/// @param subnet Pointer to the subnet being updated.
/// @throw BadValue if the subnet to update does not exit.
/// @return Pointer to the replaced subnet or NULL if it failed.
Subnet4Ptr replace(const Subnet4Ptr& subnet);
/// @brief Removes subnet from the configuration.
///
/// @param subnet Pointer to the subnet to be removed.
///
/// @throw isc::BadValue if such subnet doesn't exist.
void del(const ConstSubnet4Ptr& subnet);
/// @brief Removes subnet from the configuration.
///
/// @param subnet_id Identifier of the subnet to be removed.
///
/// @throw isc::BadValue if such subnet doesn't exist.
void del(const SubnetID& subnet_id);
/// @brief Merges specified subnet configuration into this configuration.
///
/// This method merges subnets from the @c other configuration into this
/// configuration. The general rule is that existing subnets are replaced
/// by the subnets from @c other. If there is no corresponding subnet in
/// this configuration the subnet from @c other configuration is inserted.
///
/// The complexity of the merge process stems from the associations between
/// the subnets and shared networks. It is assumed that subnets in @c other
/// are the authority on their shared network assignments. It is also
/// assumed that @ networks is the list of shared networks that should be
/// used in making assignments. The general concept is that the overarching
/// merge process will first merge shared networks and then pass that list
/// of networks into this method. Subnets from @c other are then merged
/// into this configuration as follows:
///
/// For each subnet in @c other:
///
/// - If a subnet of the same ID already exists in this configuration:
/// -# If it belongs to a shared network, remove it from that network
/// -# Remove the subnet from this configuration and discard it
///
/// - Create the subnet's option instance, as well as any options
/// that belong to any of the subnet's pools.
/// - Add the subnet from @c other to this configuration.
/// - If that subnet is associated to shared network, find that network
/// in @ networks and add that subnet to it.
///
/// @warning The merge operation affects the @c other configuration.
/// Therefore, the caller must not rely on the data held in the @c other
/// object after the call to @c merge. Also, the data held in @c other must
/// not be modified after the call to @c merge because it may affect the
/// merged configuration.
///
/// @param cfg_def set of user-defined option definitions to use
/// when creating option instances.
/// @param networks collection of shared networks that to which assignments
/// should be added. In other words, the list of shared networks that belong
/// to the same SrvConfig instance we are merging into.
/// @param other the subnet configuration to be merged into this
/// configuration.
void merge(CfgOptionDefPtr cfg_def, CfgSharedNetworks4Ptr networks,
CfgSubnets4& other);
/// @brief Returns pointer to the collection of all IPv4 subnets.
///
/// This is used in a hook (subnet4_select), where the hook is able
/// to choose a different subnet. Server code has to offer a list
/// of possible choices (i.e. all subnets).
///
/// @return A pointer to const Subnet4 collection
const Subnet4Collection* getAll() const {
return (&subnets_);
}
/// @brief Returns const pointer to a subnet identified by the specified
/// subnet identifier.
///
/// The const pointer is returned by this method to prevent a caller from
/// modifying the subnet configuration. Modifications to subnet configuration
/// is dangerous and must be done carefully. The subnets' configuration is
/// held in the multi index container and any modifications to the subnet
/// id or subnet prefix must trigger re-indexing of multi index container.
/// There is no possibility to enforce this when the non-const pointer is
/// returned.
///
/// @param subnet_id Subnet identifier.
///
/// @return Pointer to the @c Subnet4 object or null pointer if such
/// subnet doesn't exist.
ConstSubnet4Ptr getBySubnetId(const SubnetID& subnet_id) const {
return (getSubnet(subnet_id));
}
/// @brief Returns const pointer to a subnet which matches the specified
/// prefix in the canonical form.
///
/// The const pointer is returned by this method to prevent a caller from
/// modifying the subnet configuration. Modifications to subnet configuration
/// is dangerous and must be done carefully. The subnets' configuration is
/// held in the multi index container and any modifications to the subnet
/// id or subnet prefix must trigger re-indexing of multi index container.
/// There is no possibility to enforce this when the non-const pointer is
/// returned.
///
/// @param subnet_prefix Subnet prefix, e.g. 10.2.3.0/24
///
/// @return Pointer to the @c Subnet4 object or null pointer if such
/// subnet doesn't exist.
ConstSubnet4Ptr getByPrefix(const std::string& subnet_prefix) const;
/// @brief Checks if specified server identifier has been specified for
/// any subnet.
///
/// @param server_id Server identifier.
///
/// @return true if there is a subnet with a specified server identifier.
bool hasSubnetWithServerId(const asiolink::IOAddress& server_id) const;
/// @brief Build selector from a client's message.
///
/// @note: code moved from server.
///
/// @param query client's message.
/// @return filled selector.
static SubnetSelector initSelector(const Pkt4Ptr& query);
/// @brief Returns a pointer to the selected subnet.
///
/// This method tries to retrieve the subnet for the client using various
/// parameters extracted from the client's message using the following
/// logic.
///
/// First when link select suboption of relay agent information option
/// or subnet select option in this order exists the address is used
///
/// If the giaddr value is set in the selector it means that the client's
/// message was relayed. The subnet configuration allows for setting the
/// relay address for each subnet to indicate that the subnet must be
/// assigned when the packet was transmitted over the particular relay.
/// This method first tries to match the giaddr with the relay addresses
/// specified for all subnets. If the relay address for the subnet is equal
/// to the address of the relay through which the message was transmitted,
/// the particular subnet is returned.
///
/// If the giaddr is not matched with any of the relay addresses in any
/// subnet or the message was not relayed, the method will need to try to
/// match one of the addresses in the client's message with the prefixes
/// of the existing subnets. Depending whether it is a relayed message,
/// message from the renewing client or a new allocation, the server will
/// pick one of the following addresses for this matching:
/// - giaddr - for relayed message
/// - ciaddr - for renewing or rebinding client
/// - source address - for the renewing client which didn't provide ciaddr
/// - address on the local server's interface if this is a new allocation
/// requested by the directly connected client
///
/// If the address matches with a subnet, the subnet is returned.
///
/// @todo This method requires performance improvement! It currently
/// iterates over all existing subnets (possibly a couple of times)
/// to find the one which fulfills the search criteria. The subnet storage
/// is implemented as a simple STL vector which precludes fast searches
/// using specific keys. Hence, full scan is required. To improve the
/// search performance a different container type is required, e.g.
/// multi-index container, or something of a similar functionality.
///
/// @param selector Const reference to the selector structure which holds
/// various information extracted from the client's packet which are used
/// to find appropriate subnet.
///
/// @return Pointer to the selected subnet or NULL if no subnet found.
/// @throw isc::BadValue if the values in the subnet selector are invalid
/// or they are insufficient to select a subnet.
Subnet4Ptr selectSubnet(const SubnetSelector& selector) const;
/// @brief Returns subnet with specified subnet-id value
///
/// Please use @ref getBySubnetId instead when possible.
///
/// @return Subnet (or null)
Subnet4Ptr getSubnet(const SubnetID id) const;
/// @brief Returns a pointer to a subnet if provided address is in its range.
///
/// This method returns a pointer to the subnet if the address passed in
/// parameter is in range with this subnet. This is mainly used for unit
/// testing. This method is also called by the
/// @c selectSubnet(SubnetSelector).
///
/// @todo This method requires performance improvement! It currently
/// iterates over all existing subnets to find the one which fulfills
/// the search criteria. The subnet storage is implemented as a simple
/// STL vector which precludes fast searches using specific keys.
/// Hence, full scan is required. To improve the search performance a
/// different container type is required, e.g. multi-index container,
/// or something of a similar functionality.
///
/// @param address Address for which the subnet is searched.
/// @param client_classes Optional parameter specifying the classes that
/// the client belongs to.
///
/// @return Pointer to the selected subnet or NULL if no subnet found.
Subnet4Ptr selectSubnet(const asiolink::IOAddress& address,
const ClientClasses& client_classes
= ClientClasses()) const;
/// @brief Returns a pointer to a subnet if provided interface name matches.
///
/// This method returns a pointer to the subnet if the interface name passed
/// in parameter iface matches that of a subnet. This is mainly used for matching
/// local incoming traffic, even when the addresses on local interfaces do
/// not match a subnet definition. This method is also called by the
/// @c selectSubnet(SubnetSelector).
///
/// @todo This method requires performance improvement! It currently
/// iterates over all existing subnets to find the one which fulfills
/// the search criteria. The subnet storage is implemented as a simple
/// STL vector which precludes fast searches using specific keys.
/// Hence, full scan is required. To improve the search performance a
/// different container type is required, e.g. multi-index container,
/// or something of a similar functionality.
///
/// @param iface name of the interface to be matched.
/// @param client_classes Optional parameter specifying the classes that
/// the client belongs to.
///
/// @return Pointer to the selected subnet or NULL if no subnet found.
Subnet4Ptr selectSubnet(const std::string& iface,
const ClientClasses& client_classes) const;
/// @brief Attempts to do subnet selection based on DHCP4o6 information
///
/// The algorithm implemented is as follows:
///
/// - First: try to match IPv6 subnet (4o6-subnet parameter) with the
/// remote IPv6 address of the incoming packet
/// - Second: try to match interface-id (4o6-interface-id parameter)
/// with the interface-id option in the incoming 4o6 packet
/// - Third: try to match interface-name (4o6-interface parameter)
/// with the name of the interface the incoming 4o6 packet was
/// received over.
///
/// @todo: Add additional selection criteria. See
/// https://gitlab.isc.org/isc-projects/kea/wikis/designs/dhcpv4o6-design for details.
///
/// @param selector Const reference to the selector structure which holds
/// various information extracted from the client's packet which are used
/// to find appropriate subnet.
/// @return Pointer to the selected subnet or NULL if no subnet found.
Subnet4Ptr
selectSubnet4o6(const SubnetSelector& selector) const;
/// @brief Convert a link address into a link set.
///
/// Given a link address this returns the ordered list aka set of id
/// of subnets the address belongs to.
///
/// @todo: extend to consider whether a shared network is a link.
///
/// @param link_addr The link address.
/// @return The set of subnet ids the link address belongs to.
SubnetIDSet getLinks(const asiolink::IOAddress& link_addr) const;
/// @brief Updates statistics.
///
/// This method updates statistics that are affected by the newly committed
/// configuration. In particular, it updates the number of available addresses
/// in each subnet. Other statistics may be added in the future. In general,
/// these are statistics that are dependent only on configuration, so they are
/// not expected to change until the next reconfiguration event.
void updateStatistics();
/// @brief Removes statistics.
///
/// During commitment of a new configuration, we need to get rid of the old
/// statistics for the old configuration. In particular, we need to remove
/// anything related to subnets, as there may be fewer subnets in the new
/// configuration and also subnet-ids may change.
void removeStatistics();
/// @brief Calls @c initAllocatorsAfterConfigure for each subnet.
void initAllocatorsAfterConfigure();
/// @brief Clears all subnets from the configuration.
void clear();
/// @brief Unparse a configuration object
///
/// @return a pointer to unparsed configuration
virtual isc::data::ElementPtr toElement() const;<--- Function in derived class
private:
/// @brief A container for IPv4 subnets.
Subnet4Collection subnets_;
};
/// @name Pointer to the @c CfgSubnets4 objects.
//@{
/// @brief Non-const pointer.
typedef boost::shared_ptr<CfgSubnets4> CfgSubnets4Ptr;
/// @brief Const pointer.
typedef boost::shared_ptr<const CfgSubnets4> ConstCfgSubnets4Ptr;
//@}
}
}
#endif // CFG_SUBNETS4_H
|