Adding upstream version 2.2.0.upstream/2.2.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 737 insertions, 0 deletions

diff --git a/src/lib/dhcp/option_custom.cc b/src/lib/dhcp/option_custom.cc
new file mode 100644
index 0000000..301e883
--- /dev/null
+++ b/src/lib/dhcp/option_custom.cc
@@ -0,0 +1,737 @@
+// Copyright (C) 2012-2022 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/.
+
+#include <config.h>
+#include <dhcp/libdhcp++.h>
+#include <dhcp/option_data_types.h>
+#include <dhcp/option_custom.h>
+#include <exceptions/isc_assert.h>
+#include <util/encode/hex.h>
+
+using namespace isc::asiolink;
+
+namespace isc {
+namespace dhcp {
+
+OptionCustom::OptionCustom(const OptionDefinition& def,
+                           Universe u)
+    : Option(u, def.getCode(), OptionBuffer()),
+      definition_(def) {
+    setEncapsulatedSpace(def.getEncapsulatedSpace());
+    createBuffers();
+}
+
+OptionCustom::OptionCustom(const OptionDefinition& def,
+                           Universe u,
+                           const OptionBuffer& data)
+    : Option(u, def.getCode(), data.begin(), data.end()),
+      definition_(def) {
+    setEncapsulatedSpace(def.getEncapsulatedSpace());
+    createBuffers(getData());
+}
+
+OptionCustom::OptionCustom(const OptionDefinition& def,
+                           Universe u,
+                           OptionBufferConstIter first,
+                           OptionBufferConstIter last)
+    : Option(u, def.getCode(), first, last),
+      definition_(def) {
+    setEncapsulatedSpace(def.getEncapsulatedSpace());
+    createBuffers(getData());
+}
+
+OptionPtr
+OptionCustom::clone() const {
+    return (cloneInternal<OptionCustom>());
+}
+
+void
+OptionCustom::addArrayDataField(const IOAddress& address) {
+    checkArrayType();
+
+    if ((address.isV4() && definition_.getType() != OPT_IPV4_ADDRESS_TYPE) ||
+        (address.isV6() && definition_.getType() != OPT_IPV6_ADDRESS_TYPE)) {
+        isc_throw(BadDataTypeCast, "invalid address specified "
+                  << address << ". Expected a valid IPv"
+                  << (definition_.getType() == OPT_IPV4_ADDRESS_TYPE ?
+                      "4" : "6") << " address.");
+    }
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writeAddress(address, buf);
+    buffers_.push_back(buf);
+}
+
+void
+OptionCustom::addArrayDataField(const std::string& value) {
+    checkArrayType();
+
+    OpaqueDataTuple::LengthFieldType lft = getUniverse() == Option::V4 ?
+        OpaqueDataTuple::LENGTH_1_BYTE : OpaqueDataTuple::LENGTH_2_BYTES;
+    OptionBuffer buf;
+    OptionDataTypeUtil::writeTuple(value, lft, buf);
+    buffers_.push_back(buf);
+}
+
+void
+OptionCustom::addArrayDataField(const OpaqueDataTuple& value) {
+    checkArrayType();
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writeTuple(value, buf);
+    buffers_.push_back(buf);
+}
+
+void
+OptionCustom::addArrayDataField(const bool value) {
+    checkArrayType();
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writeBool(value, buf);
+    buffers_.push_back(buf);
+}
+
+void
+OptionCustom::addArrayDataField(const PrefixLen& prefix_len,
+                                const asiolink::IOAddress& prefix) {
+    checkArrayType();
+
+    if (definition_.getType() != OPT_IPV6_PREFIX_TYPE) {
+        isc_throw(BadDataTypeCast, "IPv6 prefix can be specified only for"
+                  " an option comprising an array of IPv6 prefix values");
+    }
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writePrefix(prefix_len, prefix, buf);
+    buffers_.push_back(buf);
+}
+
+void
+OptionCustom::addArrayDataField(const PSIDLen& psid_len, const PSID& psid) {
+    checkArrayType();
+
+    if (definition_.getType() != OPT_PSID_TYPE) {
+        isc_throw(BadDataTypeCast, "PSID value can be specified onlu for"
+                  " an option comprising an array of PSID length / value"
+                  " tuples");
+    }
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writePsid(psid_len, psid, buf);
+    buffers_.push_back(buf);
+}
+
+void
+OptionCustom::checkIndex(const uint32_t index) const {
+    if (index >= buffers_.size()) {
+        isc_throw(isc::OutOfRange, "specified data field index " << index
+                  << " is out of range.");
+    }
+}
+
+void
+OptionCustom::createBuffer(OptionBuffer& buffer,
+                           const OptionDataType data_type) const {
+    // For data types that have a fixed size we can use the
+    // utility function to get the buffer's size.
+    size_t data_size = OptionDataTypeUtil::getDataTypeLen(data_type);
+
+    // For variable data sizes the utility function returns zero.
+    // It is ok for string values because the default string
+    // is 'empty'. However for FQDN the empty value is not valid
+    // so we initialize it to '.'. For prefix there is a prefix
+    // length fixed field.
+    if (data_size == 0) {
+        if (data_type == OPT_FQDN_TYPE) {
+            OptionDataTypeUtil::writeFqdn(".", buffer);
+
+        } else if (data_type == OPT_IPV6_PREFIX_TYPE) {
+            OptionDataTypeUtil::writePrefix(PrefixLen(0),
+                                            IOAddress::IPV6_ZERO_ADDRESS(),
+                                            buffer);
+        }
+    } else {
+        // At this point we can resize the buffer. Note that
+        // for string values we are setting the empty buffer
+        // here.
+        buffer.resize(data_size);
+    }
+}
+
+void
+OptionCustom::createBuffers() {
+    definition_.validate();
+
+    std::vector<OptionBuffer> buffers;
+
+    OptionDataType data_type = definition_.getType();
+    // This function is called when an empty data buffer has been
+    // passed to the constructor. In such cases values for particular
+    // data fields will be set using modifier functions but for now
+    // we need to initialize a set of buffers that are specified
+    // for an option by its definition. Since there is no data yet,
+    // we are going to fill these buffers with default values.
+    if (data_type == OPT_RECORD_TYPE) {
+        // For record types we need to iterate over all data fields
+        // specified in option definition and create corresponding
+        // buffers for each of them.
+        const OptionDefinition::RecordFieldsCollection fields =
+            definition_.getRecordFields();
+
+        for (OptionDefinition::RecordFieldsConstIter field = fields.begin();
+             field != fields.end(); ++field) {
+            OptionBuffer buf;
+            createBuffer(buf, *field);
+            // We have the buffer with default value prepared so we
+            // add it to the set of buffers.
+            buffers.push_back(buf);
+        }
+    } else if (!definition_.getArrayType() &&
+               data_type != OPT_EMPTY_TYPE) {
+        // For either 'empty' options we don't have to create any buffers
+        // for obvious reason. For arrays we also don't create any buffers
+        // yet because the set of fields that belong to the array is open
+        // ended so we can't allocate required buffers until we know how
+        // many of them are needed.
+        // For non-arrays we have a single value being held by the option
+        // so we have to allocate exactly one buffer.
+        OptionBuffer buf;
+        createBuffer(buf, data_type);
+        // Add a buffer that we have created and leave.
+        buffers.push_back(buf);
+    }
+    // The 'swap' is used here because we want to make sure that we
+    // don't touch buffers_ until we successfully allocate all
+    // buffers to be stored there.
+    std::swap(buffers, buffers_);
+}
+
+size_t
+OptionCustom::bufferLength(const OptionDataType data_type, bool in_array,
+                           OptionBuffer::const_iterator begin,
+                           OptionBuffer::const_iterator end) const {
+    // For fixed-size data type such as boolean, integer, even
+    // IP address we can use the utility function to get the required
+    // buffer size.
+    size_t data_size = OptionDataTypeUtil::getDataTypeLen(data_type);
+
+    // For variable size types (e.g. string) the function above will
+    // return 0 so we need to do a runtime check of the length.
+    if (data_size == 0) {
+        // FQDN is a special data type as it stores variable length data
+        // but the data length is encoded in the buffer. The easiest way
+        // to obtain the length of the data is to read the FQDN. The
+        // utility function will return the size of the buffer on success.
+        if (data_type == OPT_FQDN_TYPE) {
+            std::string fqdn =
+                OptionDataTypeUtil::readFqdn(OptionBuffer(begin, end));
+            // The size of the buffer holding an FQDN is always
+            // 1 byte larger than the size of the string
+            // representation of this FQDN.
+            data_size = fqdn.size() + 1;
+        } else if (!definition_.getArrayType() &&
+                   ((data_type == OPT_BINARY_TYPE) ||
+                    (data_type == OPT_STRING_TYPE))) {
+            // In other case we are dealing with string or binary value
+            // which size can't be determined. Thus we consume the
+            // remaining part of the buffer for it. Note that variable
+            // size data can be laid at the end of the option only and
+            // that the validate() function in OptionDefinition object
+            // should have checked wheter it is a case for this option.
+            data_size = std::distance(begin, end);
+        } else if (data_type == OPT_IPV6_PREFIX_TYPE) {
+            // The size of the IPV6 prefix type is determined as
+            // one byte (which is the size of the prefix in bits)
+            // followed by the prefix bits (right-padded with
+            // zeros to the nearest octet boundary)
+            if ((begin == end) && !in_array)
+                return 0;
+            PrefixTuple prefix =
+                OptionDataTypeUtil::readPrefix(OptionBuffer(begin, end));
+            // Data size comprises 1 byte holding a prefix length and the
+            // prefix length (in bytes) rounded to the nearest byte boundary.
+            data_size = sizeof(uint8_t) + (prefix.first.asUint8() + 7) / 8;
+        } else if (data_type == OPT_TUPLE_TYPE) {
+            OpaqueDataTuple::LengthFieldType lft =
+                getUniverse() == Option::V4 ?
+                OpaqueDataTuple::LENGTH_1_BYTE :
+                OpaqueDataTuple::LENGTH_2_BYTES;
+            std::string value =
+                OptionDataTypeUtil::readTuple(OptionBuffer(begin, end), lft);
+            data_size = value.size();
+            // The size of the buffer holding a tuple is always
+            // 1 or 2 byte larger than the size of the string
+            data_size += getUniverse() == Option::V4 ? 1 : 2;
+        } else {
+            // If we reached the end of buffer we assume that this option is
+            // truncated because there is no remaining data to initialize
+            // an option field.
+            isc_throw(OutOfRange, "option buffer truncated");
+        }
+    }
+
+    return data_size;
+}
+
+void
+OptionCustom::createBuffers(const OptionBuffer& data_buf) {
+    // Check that the option definition is correct as we are going
+    // to use it to split the data_ buffer into set of sub buffers.
+    definition_.validate();
+
+    std::vector<OptionBuffer> buffers;
+    OptionBuffer::const_iterator data = data_buf.begin();
+
+    OptionDataType data_type = definition_.getType();
+    if (data_type == OPT_RECORD_TYPE) {
+        // An option comprises a record of data fields. We need to
+        // get types of these data fields to allocate enough space
+        // for each buffer.
+        const OptionDefinition::RecordFieldsCollection& fields =
+            definition_.getRecordFields();
+
+        // Go over all data fields within a record.
+        for (OptionDefinition::RecordFieldsConstIter field = fields.begin();
+             field != fields.end(); ++field) {
+            size_t data_size = bufferLength(*field, false,
+                                            data, data_buf.end());
+
+            // Our data field requires that there is a certain chunk of
+            // data left in the buffer. If not, option is truncated.
+            if (std::distance(data, data_buf.end()) < data_size) {
+                isc_throw(OutOfRange, "option buffer truncated");
+            }
+
+            // Store the created buffer.
+            buffers.push_back(OptionBuffer(data, data + data_size));
+            // Proceed to the next data field.
+            data += data_size;
+        }
+
+        // Get extra buffers when the last field is an array.
+        if (definition_.getArrayType()) {
+            while (data != data_buf.end()) {
+                // Code copied from the standard array case
+                size_t data_size = bufferLength(fields.back(), true,
+                                                data, data_buf.end());
+                isc_throw_assert(data_size > 0);
+                if (std::distance(data, data_buf.end()) < data_size) {
+                    break;
+                }
+                buffers.push_back(OptionBuffer(data, data + data_size));
+                data += data_size;
+            }
+        }
+
+        // Unpack suboptions if any.
+        else if (data != data_buf.end() && !getEncapsulatedSpace().empty()) {
+            unpackOptions(OptionBuffer(data, data_buf.end()));
+        }
+
+    } else if (data_type != OPT_EMPTY_TYPE) {
+        // If data_type value is other than OPT_RECORD_TYPE, our option is
+        // empty (have no data at all) or it comprises one or more
+        // data fields of the same type. The type of those fields
+        // is held in the data_type variable so let's use it to determine
+        // a size of buffers.
+        size_t data_size = OptionDataTypeUtil::getDataTypeLen(data_type);
+        // The check below will fail if the input buffer is too short
+        // for the data size being held by this option.
+        // Note that data_size returned by getDataTypeLen may be zero
+        // if variable length data is being held by the option but
+        // this will not cause this check to throw exception.
+        if (std::distance(data, data_buf.end()) < data_size) {
+            isc_throw(OutOfRange, "option buffer truncated");
+        }
+        // For an array of values we are taking different path because
+        // we have to handle multiple buffers.
+        if (definition_.getArrayType()) {
+            while (data != data_buf.end()) {
+                data_size = bufferLength(data_type, true, data, data_buf.end());
+                // We don't perform other checks for data types that can't be
+                // used together with array indicator such as strings, empty field
+                // etc. This is because OptionDefinition::validate function should
+                // have checked this already. Thus data_size must be greater than
+                // zero.
+                isc_throw_assert(data_size > 0);
+                // Get chunks of data and store as a collection of buffers.
+                // Truncate any remaining part which length is not divisible by
+                // data_size. Note that it is ok to truncate the data if and only
+                // if the data buffer is long enough to keep at least one value.
+                // This has been checked above already.
+                if (std::distance(data, data_buf.end()) < data_size) {
+                    break;
+                }
+                buffers.push_back(OptionBuffer(data, data + data_size));
+                data += data_size;
+            }
+        } else {
+            // For non-arrays the data_size can be zero because
+            // getDataTypeLen returns zero for variable size data types
+            // such as strings. Simply take whole buffer.
+            data_size = bufferLength(data_type, false, data, data_buf.end());
+            if ((data_size > 0) && (std::distance(data, data_buf.end()) >= data_size)) {
+                buffers.push_back(OptionBuffer(data, data + data_size));
+                data += data_size;
+            } else {
+                isc_throw(OutOfRange, "option buffer truncated");
+            }
+
+            // Unpack suboptions if any.
+            if (data != data_buf.end() && !getEncapsulatedSpace().empty()) {
+                unpackOptions(OptionBuffer(data, data_buf.end()));
+            }
+        }
+    } else {
+        // Unpack suboptions if any.
+        if (data != data_buf.end() && !getEncapsulatedSpace().empty()) {
+            unpackOptions(OptionBuffer(data, data_buf.end()));
+        }
+    }
+    // If everything went ok we can replace old buffer set with new ones.
+    std::swap(buffers_, buffers);
+}
+
+std::string
+OptionCustom::dataFieldToText(const OptionDataType data_type,
+                              const uint32_t index) const {
+    std::ostringstream text;
+
+    // Get the value of the data field.
+    switch (data_type) {
+    case OPT_BINARY_TYPE:
+        text << util::encode::encodeHex(readBinary(index));
+        break;
+    case OPT_BOOLEAN_TYPE:
+        text << (readBoolean(index) ? "true" : "false");
+        break;
+    case OPT_INT8_TYPE:
+        text << static_cast<int>(readInteger<int8_t>(index));
+        break;
+    case OPT_INT16_TYPE:
+        text << readInteger<int16_t>(index);
+        break;
+    case OPT_INT32_TYPE:
+        text << readInteger<int32_t>(index);
+        break;
+    case OPT_UINT8_TYPE:
+        text << static_cast<unsigned>(readInteger<uint8_t>(index));
+        break;
+    case OPT_UINT16_TYPE:
+        text << readInteger<uint16_t>(index);
+        break;
+    case OPT_UINT32_TYPE:
+        text << readInteger<uint32_t>(index);
+        break;
+    case OPT_IPV4_ADDRESS_TYPE:
+    case OPT_IPV6_ADDRESS_TYPE:
+        text << readAddress(index);
+        break;
+    case OPT_FQDN_TYPE:
+        text << "\"" << readFqdn(index) << "\"";
+        break;
+    case OPT_TUPLE_TYPE:
+        text << "\"" << readTuple(index) << "\"";
+        break;
+    case OPT_STRING_TYPE:
+        text << "\"" << readString(index) << "\"";
+        break;
+    case OPT_PSID_TYPE:
+    {
+        PSIDTuple t = readPsid(index);
+        text << "len=" << t.first.asUnsigned() << ",psid=" << t.second.asUint16();
+    }
+    default:
+        ;
+    }
+
+    // Append data field type in brackets.
+    text << " (" << OptionDataTypeUtil::getDataTypeName(data_type) << ")";
+
+    return (text.str());
+}
+
+void
+OptionCustom::pack(isc::util::OutputBuffer& buf, bool check) const {
+
+    // Pack DHCP header (V4 or V6).
+    packHeader(buf, check);
+
+    // Write data from buffers.
+    for (std::vector<OptionBuffer>::const_iterator it = buffers_.begin();
+         it != buffers_.end(); ++it) {
+        // In theory the createBuffers function should have taken
+        // care that there are no empty buffers added to the
+        // collection but it is almost always good to make sure.
+        if (!it->empty()) {
+            buf.writeData(&(*it)[0], it->size());
+        }
+    }
+
+    // Write suboptions.
+    packOptions(buf, check);
+}
+
+
+IOAddress
+OptionCustom::readAddress(const uint32_t index) const {
+    checkIndex(index);
+
+    // The address being read can be either IPv4 or IPv6. The decision
+    // is made based on the buffer length. If it holds 4 bytes it is IPv4
+    // address, if it holds 16 bytes it is IPv6.
+    if (buffers_[index].size() == asiolink::V4ADDRESS_LEN) {
+        return (OptionDataTypeUtil::readAddress(buffers_[index], AF_INET));
+    } else if (buffers_[index].size() == asiolink::V6ADDRESS_LEN) {
+        return (OptionDataTypeUtil::readAddress(buffers_[index], AF_INET6));
+    } else {
+        isc_throw(BadDataTypeCast, "unable to read data from the buffer as"
+                  << " IP address. Invalid buffer length "
+                  << buffers_[index].size() << ".");
+    }
+}
+
+void
+OptionCustom::writeAddress(const IOAddress& address,
+                           const uint32_t index) {
+    checkIndex(index);
+
+    if ((address.isV4() && buffers_[index].size() != V4ADDRESS_LEN) ||
+        (address.isV6() && buffers_[index].size() != V6ADDRESS_LEN)) {
+        isc_throw(BadDataTypeCast, "invalid address specified "
+                  << address << ". Expected a valid IPv"
+                  << (buffers_[index].size() == V4ADDRESS_LEN ? "4" : "6")
+                  << " address.");
+    }
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writeAddress(address, buf);
+    std::swap(buf, buffers_[index]);
+}
+
+const OptionBuffer&
+OptionCustom::readBinary(const uint32_t index) const {
+    checkIndex(index);
+    return (buffers_[index]);
+}
+
+void
+OptionCustom::writeBinary(const OptionBuffer& buf,
+                          const uint32_t index) {
+    checkIndex(index);
+    buffers_[index] = buf;
+}
+
+std::string
+OptionCustom::readTuple(const uint32_t index) const {
+    checkIndex(index);
+    OpaqueDataTuple::LengthFieldType lft = getUniverse() == Option::V4 ?
+        OpaqueDataTuple::LENGTH_1_BYTE : OpaqueDataTuple::LENGTH_2_BYTES;
+    return (OptionDataTypeUtil::readTuple(buffers_[index], lft));
+}
+
+void
+OptionCustom::readTuple(OpaqueDataTuple& tuple,
+                        const uint32_t index) const {
+    checkIndex(index);
+    OptionDataTypeUtil::readTuple(buffers_[index], tuple);
+}
+
+void
+OptionCustom::writeTuple(const std::string& value, const uint32_t index) {
+    checkIndex(index);
+
+    buffers_[index].clear();
+    OpaqueDataTuple::LengthFieldType lft = getUniverse() == Option::V4 ?
+        OpaqueDataTuple::LENGTH_1_BYTE : OpaqueDataTuple::LENGTH_2_BYTES;
+    OptionDataTypeUtil::writeTuple(value, lft, buffers_[index]);
+}
+
+void
+OptionCustom::writeTuple(const OpaqueDataTuple& value, const uint32_t index) {
+    checkIndex(index);
+
+    buffers_[index].clear();
+    OptionDataTypeUtil::writeTuple(value, buffers_[index]);
+}
+
+bool
+OptionCustom::readBoolean(const uint32_t index) const {
+    checkIndex(index);
+    return (OptionDataTypeUtil::readBool(buffers_[index]));
+}
+
+void
+OptionCustom::writeBoolean(const bool value, const uint32_t index) {
+    checkIndex(index);
+
+    buffers_[index].clear();
+    OptionDataTypeUtil::writeBool(value, buffers_[index]);
+}
+
+std::string
+OptionCustom::readFqdn(const uint32_t index) const {
+    checkIndex(index);
+    return (OptionDataTypeUtil::readFqdn(buffers_[index]));
+}
+
+void
+OptionCustom::writeFqdn(const std::string& fqdn, const uint32_t index) {
+    checkIndex(index);
+
+    // Create a temporary buffer where the FQDN will be written.
+    OptionBuffer buf;
+    // Try to write to the temporary buffer rather than to the
+    // buffers_ member directly guarantees that we don't modify
+    // (clear) buffers_ until we are sure that the provided FQDN
+    // is valid.
+    OptionDataTypeUtil::writeFqdn(fqdn, buf);
+    // If we got to this point it means that the FQDN is valid.
+    // We can move the contents of the temporary buffer to the
+    // target buffer.
+    std::swap(buffers_[index], buf);
+}
+
+PrefixTuple
+OptionCustom::readPrefix(const uint32_t index) const {
+    checkIndex(index);
+    return (OptionDataTypeUtil::readPrefix(buffers_[index]));
+}
+
+void
+OptionCustom::writePrefix(const PrefixLen& prefix_len,
+                          const IOAddress& prefix,
+                          const uint32_t index) {
+    checkIndex(index);
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writePrefix(prefix_len, prefix, buf);
+    // If there are no errors while writing PSID to a buffer, we can
+    // replace the current buffer with a new buffer.
+    std::swap(buffers_[index], buf);
+}
+
+
+PSIDTuple
+OptionCustom::readPsid(const uint32_t index) const {
+    checkIndex(index);
+    return (OptionDataTypeUtil::readPsid(buffers_[index]));
+}
+
+void
+OptionCustom::writePsid(const PSIDLen& psid_len, const PSID& psid,
+                        const uint32_t index) {
+    checkIndex(index);
+
+    OptionBuffer buf;
+    OptionDataTypeUtil::writePsid(psid_len, psid, buf);
+    // If there are no errors while writing PSID to a buffer, we can
+    // replace the current buffer with a new buffer.
+    std::swap(buffers_[index], buf);
+}
+
+
+std::string
+OptionCustom::readString(const uint32_t index) const {
+    checkIndex(index);
+    return (OptionDataTypeUtil::readString(buffers_[index]));
+}
+
+void
+OptionCustom::writeString(const std::string& text, const uint32_t index) {
+    checkIndex(index);
+
+    // Let's clear a buffer as we want to replace the value of the
+    // whole buffer. If we fail to clear the buffer the data will
+    // be appended.
+    buffers_[index].clear();
+    // If the text value is empty we can leave because the buffer
+    // is already empty.
+    if (!text.empty()) {
+        OptionDataTypeUtil::writeString(text, buffers_[index]);
+    }
+}
+
+void
+OptionCustom::unpack(OptionBufferConstIter begin,
+                     OptionBufferConstIter end) {
+    initialize(begin, end);
+}
+
+uint16_t
+OptionCustom::len() const {
+    // The length of the option is a sum of option header ...
+    size_t length = getHeaderLen();
+
+    // ... lengths of all buffers that hold option data ...
+    for (std::vector<OptionBuffer>::const_iterator buf = buffers_.begin();
+         buf != buffers_.end(); ++buf) {
+        length += buf->size();
+    }
+
+    // ... and lengths of all suboptions
+    for (OptionCollection::const_iterator it = options_.begin();
+         it != options_.end();
+         ++it) {
+        length += (*it).second->len();
+    }
+
+    return (static_cast<uint16_t>(length));
+}
+
+void OptionCustom::initialize(const OptionBufferConstIter first,
+                              const OptionBufferConstIter last) {
+    setData(first, last);
+
+    // Chop the data_ buffer into set of buffers that represent
+    // option fields data.
+    createBuffers(getData());
+}
+
+std::string OptionCustom::toText(int indent) const {
+    std::stringstream output;
+
+    output << headerToText(indent) << ":";
+
+    OptionDataType data_type = definition_.getType();
+    if (data_type == OPT_RECORD_TYPE) {
+        const OptionDefinition::RecordFieldsCollection& fields =
+            definition_.getRecordFields();
+
+        // For record types we iterate over fields defined in
+        // option definition and match the appropriate buffer
+        // with them.
+        for (OptionDefinition::RecordFieldsConstIter field = fields.begin();
+             field != fields.end(); ++field) {
+            output << " " << dataFieldToText(*field, std::distance(fields.begin(),
+                                                                   field));
+        }
+
+        // If the last record field is an array iterate on extra buffers
+        if (definition_.getArrayType()) {
+            for (unsigned int i = fields.size(); i < getDataFieldsNum(); ++i) {
+                output << " " << dataFieldToText(fields.back(), i);
+            }
+        }
+    } else {
+        // For non-record types we iterate over all buffers
+        // and print the data type set globally for an option
+        // definition. We take the same code path for arrays
+        // and non-arrays as they only differ in such a way that
+        // non-arrays have just single data field.
+        for (unsigned int i = 0; i < getDataFieldsNum(); ++i) {
+            output << " " << dataFieldToText(definition_.getType(), i);
+        }
+    }
+
+    // Append suboptions.
+    output << suboptionsToText(indent + 2);
+
+    return (output.str());
+}
+
+} // end of isc::dhcp namespace
+} // end of isc namespace