Kea  2.1.6-git
pkt.cc
Go to the documentation of this file.
1 // Copyright (C) 2014-2022 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 #include <config.h>
8 #include <utility>
9 #include <dhcp/pkt.h>
10 #include <dhcp/iface_mgr.h>
11 #include <dhcp/hwaddr.h>
12 #include <vector>
13 
14 namespace isc {
15 namespace dhcp {
16 
17 Pkt::Pkt(uint32_t transid, const isc::asiolink::IOAddress& local_addr,
18  const isc::asiolink::IOAddress& remote_addr, uint16_t local_port,
19  uint16_t remote_port)
20  : transid_(transid), iface_(""), ifindex_(-1), local_addr_(local_addr),
21  remote_addr_(remote_addr), local_port_(local_port),
22  remote_port_(remote_port), buffer_out_(0), copy_retrieved_options_(false) {
23 }
24 
25 Pkt::Pkt(const uint8_t* buf, uint32_t len, const isc::asiolink::IOAddress& local_addr,
26  const isc::asiolink::IOAddress& remote_addr, uint16_t local_port,
27  uint16_t remote_port)
28  : transid_(0), iface_(""), ifindex_(-1), local_addr_(local_addr),
29  remote_addr_(remote_addr), local_port_(local_port),
30  remote_port_(remote_port), buffer_out_(0), copy_retrieved_options_(false) {
31  if (len != 0) {
32  if (buf == NULL) {
33  isc_throw(InvalidParameter, "data buffer passed to Pkt is NULL");
34  }
35  data_.resize(len);
36  memcpy(&data_[0], buf, len);
37  }
38 }
39 
40 void
42  options_.insert(std::pair<int, OptionPtr>(opt->getType(), opt));
43 }
44 
46 Pkt::getNonCopiedOption(const uint16_t type) const {
47  const auto& x = options_.find(type);
48  if (x != options_.end()) {
49  return (x->second);
50  }
51  return (OptionPtr());
52 }
53 
55 Pkt::getOption(const uint16_t type) {
56  const auto& x = options_.find(type);
57  if (x != options_.end()) {
59  OptionPtr option_copy = x->second->clone();
60  x->second = option_copy;
61  }
62  return (x->second);
63  }
64  return (OptionPtr()); // NULL
65 }
66 
67 bool
68 Pkt::delOption(uint16_t type) {
69  const auto& x = options_.find(type);
70  if (x != options_.end()) {
71  options_.erase(x);
72  return (true); // delete successful
73  } else {
74  return (false); // can't find option to be deleted
75  }
76 }
77 
78 bool
79 Pkt::inClass(const std::string& client_class) {
80  return (classes_.contains(client_class));
81 }
82 
83 void
84 Pkt::addClass(const std::string& client_class, bool required) {
85  // Always have ALL first.
86  if (classes_.empty()) {
87  classes_.insert("ALL");
88  }
89  ClientClasses& classes = !required ? classes_ : required_classes_;
90  if (!classes.contains(client_class)) {
91  classes.insert(client_class);
92  }
93 }
94 
95 void
97  timestamp_ = boost::posix_time::microsec_clock::universal_time();
98 }
99 
100 void Pkt::repack() {
101  if (!data_.empty()) {
102  buffer_out_.writeData(&data_[0], data_.size());
103  }
104 }
105 
106 void
107 Pkt::setRemoteHWAddr(const uint8_t htype, const uint8_t hlen,
108  const std::vector<uint8_t>& hw_addr) {
109  setHWAddrMember(htype, hlen, hw_addr, remote_hwaddr_);
110 }
111 
112 void
114  if (!hw_addr) {
115  isc_throw(BadValue, "Setting remote HW address to NULL is"
116  << " forbidden.");
117  }
118  remote_hwaddr_ = hw_addr;
119 }
120 
121 void
122 Pkt::setHWAddrMember(const uint8_t htype, const uint8_t,
123  const std::vector<uint8_t>& hw_addr,
124  HWAddrPtr& storage) {
125  storage.reset(new HWAddr(hw_addr, htype));
126 }
127 
128 HWAddrPtr
129 Pkt::getMAC(uint32_t hw_addr_src) {
130  HWAddrPtr mac;
131 
133 
134  // Method 1: from raw sockets.
135  if (hw_addr_src & HWAddr::HWADDR_SOURCE_RAW) {
136  mac = getRemoteHWAddr();
137  if (mac) {
138  mac->source_ = HWAddr::HWADDR_SOURCE_RAW;
139  return (mac);
140  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_RAW) {
141  // If we're interested only in RAW sockets as source of that info,
142  // there's no point in trying other options.
143  return (HWAddrPtr());
144  }
145  }
146 
147  // Method 2: From client link-layer address option inserted by a relay
149  mac = getMACFromIPv6RelayOpt();
150  if (mac) {
151  return (mac);
152  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION) {
153  // If we're interested only in RFC6939 link layer address as source
154  // of that info, there's no point in trying other options.
155  return (HWAddrPtr());
156  }
157  }
158 
159  // Method 3: Extracted from DUID-LLT or DUID-LL
160  if(hw_addr_src & HWAddr::HWADDR_SOURCE_DUID) {
161  mac = getMACFromDUID();
162  if (mac) {
163  return (mac);
164  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_DUID) {
165  // If the only source allowed is DUID then we can skip the other
166  // methods.
167  return (HWAddrPtr());
168  }
169  }
170 
171  // Method 4: Extracted from source IPv6 link-local address
172  if (hw_addr_src & HWAddr::HWADDR_SOURCE_IPV6_LINK_LOCAL) {
174  if (mac) {
175  return (mac);
176  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_IPV6_LINK_LOCAL) {
177  // If we're interested only in link-local addr as source of that
178  // info, there's no point in trying other options.
179  return (HWAddrPtr());
180  }
181  }
182 
183  // Method 5: From remote-id option inserted by a relay
184  if(hw_addr_src & HWAddr::HWADDR_SOURCE_REMOTE_ID) {
186  if (mac) {
187  return (mac);
188  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_REMOTE_ID) {
189  // If the only source allowed is remote-id option then we can skip
190  // the other methods.
191  return (HWAddrPtr());
192  }
193  }
194 
195  // Method 6: From subscriber-id option inserted by a relay
196 
197  // Method 7: From docsis options
198  if (hw_addr_src & HWAddr::HWADDR_SOURCE_DOCSIS_CMTS) {
199  mac = getMACFromDocsisCMTS();
200  if (mac) {
201  return (mac);
202  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_DOCSIS_CMTS) {
203  // If we're interested only in CMTS options as a source of that
204  // info, there's no point in trying other options.
205  return (HWAddrPtr());
206  }
207  }
208 
209  // Method 8: From docsis options
210  if (hw_addr_src & HWAddr::HWADDR_SOURCE_DOCSIS_MODEM) {
211  mac = getMACFromDocsisModem();
212  if (mac) {
213  return (mac);
214  } else if (hw_addr_src == HWAddr::HWADDR_SOURCE_DOCSIS_MODEM) {
215  // If we're interested only in CMTS options as a source of that
216  // info, there's no point in trying other options.
217  return (HWAddrPtr());
218  }
219  }
220 
221  // Ok, none of the methods were suitable. Return NULL.
222  return (HWAddrPtr());
223 }
224 
225 HWAddrPtr
227  HWAddrPtr mac;
228 
229  if (addr.isV6LinkLocal()) {
230  std::vector<uint8_t> bin = addr.toBytes();
231 
232  // Double check that it's of appropriate size
233  if ((bin.size() == isc::asiolink::V6ADDRESS_LEN) &&
234  // Check that it's link-local (starts with fe80).
235  (bin[0] == 0xfe) && (bin[1] == 0x80) &&
236  // Check that u bit is set and g is clear.
237  // See Section 2.5.1 of RFC2373 for details.
238  ((bin[8] & 3) == 2) &&
239  // And that the IID is of EUI-64 type.
240  (bin[11] == 0xff) && (bin[12] == 0xfe)) {
241 
242  // Remove 8 most significant bytes
243  bin.erase(bin.begin(), bin.begin() + 8);
244 
245  // Ok, we're down to EUI-64 only now: XX:XX:XX:ff:fe:XX:XX:XX
246  bin.erase(bin.begin() + 3, bin.begin() + 5);
247 
248  // MAC-48 to EUI-64 involves inverting u bit (see explanation
249  // in Section 2.5.1 of RFC2373). We need to revert that.
250  bin[0] = bin[0] ^ 2;
251 
252  // Let's get the interface this packet was received on.
253  // We need it to get hardware type
255  uint16_t hwtype = 0; // not specified
256  if (iface) {
257  hwtype = iface->getHWType();
258  }
259 
260  mac.reset(new HWAddr(bin, hwtype));
262  }
263  }
264 
265  return (mac);
266 }
267 
268 } // end of namespace isc::dhcp
269 } // end of namespace isc
virtual HWAddrPtr getMACFromRemoteIdRelayOption()=0
Attempts to obtain MAC address from remote-id relay option.
IfacePtr getIface(int ifindex)
Returns interface specified interface index.
Definition: iface_mgr.cc:894
isc::asiolink::IOAddress local_addr_
Local IP (v4 or v6) address.
Definition: pkt.h:742
HWAddrPtr getMACFromIPv6(const isc::asiolink::IOAddress &addr)
Attempts to convert IPv6 address into MAC.
Definition: pkt.cc:226
int64_t ifindex_
Interface index.
Definition: pkt.h:736
OptionBuffer data_
Unparsed data (in received packets).
Definition: pkt.h:312
Pkt(uint32_t transid, const isc::asiolink::IOAddress &local_addr, const isc::asiolink::IOAddress &remote_addr, uint16_t local_port, uint16_t remote_port)
Constructor.
Definition: pkt.cc:17
std::string iface_
Name of the network interface the packet was received/to be sent over.
Definition: pkt.h:729
bool inClass(const isc::dhcp::ClientClass &client_class)
Checks whether a client belongs to a given class.
Definition: pkt.cc:79
static const uint32_t HWADDR_SOURCE_DOCSIS_MODEM
A cable modem (acting as DHCP client) that supports DOCSIS standard can insert DOCSIS options that co...
Definition: hwaddr.h:79
A generic exception that is thrown if a parameter given to a method or function is considered invalid...
boost::shared_ptr< HWAddr > HWAddrPtr
Shared pointer to a hardware address structure.
Definition: hwaddr.h:154
bool contains(const ClientClass &x) const
returns if class x belongs to the defined classes
Definition: classify.cc:43
virtual size_t len()=0
Returns packet size in binary format.
uint32_t transid_
Transaction-id (32 bits for v4, 24 bits for v6)
Definition: pkt.h:726
boost::shared_ptr< Iface > IfacePtr
Type definition for the pointer to an Iface object.
Definition: iface_mgr.h:463
boost::shared_ptr< Option > OptionPtr
Definition: option.h:36
virtual HWAddrPtr getMACFromDocsisModem()=0
Attempts to extract MAC/Hardware address from DOCSIS options inserted by the modem itself...
virtual void addOption(const OptionPtr &opt)
Adds an option to this packet.
Definition: pkt.cc:41
static const uint32_t HWADDR_SOURCE_REMOTE_ID
A relay can insert remote-id.
Definition: hwaddr.h:63
static const uint32_t HWADDR_SOURCE_CLIENT_ADDR_RELAY_OPTION
Get it from RFC6939 option.
Definition: hwaddr.h:59
void writeData(const void *data, size_t len)
Copy an arbitrary length of data into the buffer.
Definition: buffer.h:550
#define isc_throw(type, stream)
A shortcut macro to insert known values into exception arguments.
A generic exception that is thrown if a parameter given to a method is considered invalid in that con...
ClientClasses classes_
Classes this packet belongs to.
Definition: pkt.h:596
virtual HWAddrPtr getMACFromDocsisCMTS()=0
Attempts to extract MAC/Hardware address from DOCSIS options inserted by the CMTS (the relay agent) ...
bool delOption(uint16_t type)
Attempts to delete first suboption of requested type.
Definition: pkt.cc:68
bool empty() const
Check if classes is empty.
Definition: classify.h:95
bool copy_retrieved_options_
Indicates if a copy of the retrieved option should be returned when Pkt::getOption is called...
Definition: pkt.h:770
uint16_t remote_port_
remote TCP or UDP port
Definition: pkt.h:754
static const uint32_t HWADDR_SOURCE_IPV6_LINK_LOCAL
Extracted from IPv6 link-local address.
Definition: hwaddr.h:53
static const uint32_t HWADDR_SOURCE_DOCSIS_CMTS
A CMTS (acting as DHCP relay agent) that supports DOCSIS standard can insert DOCSIS options that cont...
Definition: hwaddr.h:73
void setRemoteHWAddr(const HWAddrPtr &hw_addr)
Sets remote hardware address.
Definition: pkt.cc:113
Defines the logger used by the top-level component of kea-lfc.
void updateTimestamp()
Update packet timestamp.
Definition: pkt.cc:96
HWAddrPtr remote_hwaddr_
Definition: pkt.h:776
uint16_t local_port_
local TDP or UDP port
Definition: pkt.h:751
virtual HWAddrPtr getMACFromIPv6RelayOpt()=0
Attempts to obtain MAC address from relay option client-linklayer-addr.
void addClass(const isc::dhcp::ClientClass &client_class, bool required=false)
Adds packet to a specified class.
Definition: pkt.cc:84
virtual HWAddrPtr getMACFromDUID()=0
Attempts to obtain MAC address from DUID-LL or DUID-LLT.
static const uint32_t HWADDR_SOURCE_RAW
Obtained first hand from raw socket (100% reliable).
Definition: hwaddr.h:44
isc::asiolink::IOAddress remote_addr_
Remote IP address.
Definition: pkt.h:748
OptionPtr getNonCopiedOption(const uint16_t type) const
Returns the first option of specified type without copying.
Definition: pkt.cc:46
OptionPtr getOption(const uint16_t type)
Returns the first option of specified type.
Definition: pkt.cc:55
void repack()
Copies content of input buffer to output buffer.
Definition: pkt.cc:100
static IfaceMgr & instance()
IfaceMgr is a singleton class.
Definition: iface_mgr.cc:53
Hardware type that represents information from DHCPv4 packet.
Definition: hwaddr.h:20
void insert(const ClientClass &class_name)
Insert an element.
Definition: classify.h:85
isc::util::OutputBuffer buffer_out_
Output buffer (used during message transmission)
Definition: pkt.h:764
virtual HWAddrPtr getMACFromSrcLinkLocalAddr()=0
Attempts to obtain MAC address from source link-local IPv6 address.
HWAddrPtr getRemoteHWAddr() const
Returns the remote HW address obtained from raw sockets.
Definition: pkt.h:559
ClientClasses required_classes_
Classes which are required to be evaluated.
Definition: pkt.h:604
isc::dhcp::OptionCollection options_
Collection of options present in this message.
Definition: pkt.h:614
Container for storing client class names.
Definition: classify.h:66
static const uint32_t HWADDR_SOURCE_DUID
Extracted from DUID-LL or DUID-LLT (not 100% reliable as the client can send fake DUID)...
Definition: hwaddr.h:48
boost::posix_time::ptime timestamp_
packet timestamp
Definition: pkt.h:773
HWAddrPtr getMAC(uint32_t hw_addr_src)
Returns MAC address.
Definition: pkt.cc:129