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diff --git a/src/lib/dns/name.cc b/src/lib/dns/name.cc
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+// Copyright (C) 2009-2019 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 <cctype>
+#include <iterator>
+#include <functional>
+#include <vector>
+#include <iostream>
+#include <algorithm>
+
+#include <exceptions/isc_assert.h>
+#include <util/buffer.h>
+#include <dns/exceptions.h>
+#include <dns/name.h>
+#include <dns/name_internal.h>
+#include <dns/messagerenderer.h>
+#include <dns/labelsequence.h>
+
+using namespace std;
+using namespace isc::util;
+using isc::dns::NameComparisonResult;
+using namespace isc::dns::name::internal;
+
+namespace isc {
+namespace dns {
+
+namespace {
+///
+/// These are shortcut arrays for efficient character conversion.
+/// digitvalue converts a digit character to the corresponding integer.
+/// maptolower convert uppercase alphabets to their lowercase counterparts.
+/// We once used a helper non-local static object to avoid hardcoding the
+/// array members, but we then realized it's susceptible to static
+/// initialization order fiasco: Since these constants are used in a Name
+/// constructor, a non-local static Name object defined in another translation
+/// unit than this file may not be initialized correctly.
+/// There are several ways to address this issue, but in this specific case
+/// we chose the naive but simple hardcoding approach.
+///
+/// These definitions are derived from BIND 9's libdns module.
+/// Note: we could use the standard tolower() function instead of the
+/// maptolower array, but a benchmark indicated that the private array could
+/// improve the performance of message rendering (which internally uses the
+/// array heavily) about 27%. Since we want to achieve very good performance
+/// for message rendering in some cases, we'll keep using it.
+const signed char digitvalue[256] = {
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 16
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 32
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 48
+ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -1, -1, -1, -1, -1, // 64
+ -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 80
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 96
+ -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 112
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 128
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, // 256
+};
+}
+
+namespace name {
+namespace internal {
+const uint8_t maptolower[] = {
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+ 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+ 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+ 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+ 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+ 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+ 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+ 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+ 0x40, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, // ..., 'A' - 'G'
+ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, // 'H' - 'O'
+ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, // 'P' - 'W'
+ 0x78, 0x79, 0x7a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f, // 'X' - 'Z', ...
+ 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+ 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
+ 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
+ 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+ 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+ 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+ 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+ 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+ 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+ 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+ 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
+ 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
+ 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+ 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
+ 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+ 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
+ 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
+ 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+ 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+ 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
+};
+} // end of internal
+} // end of name
+
+namespace {
+///
+/// Textual name parser states.
+///
+typedef enum {
+ ft_init = 0, // begin of the name
+ ft_start, // begin of a label
+ ft_ordinary, // parsing an ordinary label
+ ft_initialescape, // just found '\'
+ ft_escape, // begin of handling a '\'-escaped sequence
+ ft_escdecimal // parsing a '\DDD' octet.
+} ft_state;
+
+// The parser of name from a string. It is a template, because
+// some parameters are used with two different types, while others
+// are private type aliases.
+template<class Iterator, class Offsets, class Data>
+void
+stringParse(Iterator s, Iterator send, bool downcase, Offsets& offsets,
+ Data& ndata)
+{
+ const Iterator orig_s(s);
+ //
+ // Initialize things to make the compiler happy; they're not required.
+ //
+ unsigned int digits = 0;
+ unsigned int value = 0;
+ unsigned int count = 0;
+
+ //
+ // Set up the state machine.
+ //
+ bool done = false;
+ bool is_root = false;
+ const bool empty = s == send;
+ ft_state state = ft_init;
+
+ // Prepare the output buffers.
+ offsets.reserve(Name::MAX_LABELS);
+ offsets.push_back(0);
+ ndata.reserve(Name::MAX_WIRE);
+
+ // should we refactor this code using, e.g, the state pattern? Probably
+ // not at this point, as this is based on proved code (derived from BIND9)
+ // and it's less likely that we'll have more variations in the domain name
+ // syntax. If this ever happens next time, we should consider refactor
+ // the code, rather than adding more states and cases below.
+ while (ndata.size() < Name::MAX_WIRE && s != send && !done) {
+ unsigned char c = *s++;
+
+ switch (state) {
+ case ft_init:
+ //
+ // Is this the root name?
+ //
+ if (c == '.') {
+ if (s != send) {
+ isc_throw(EmptyLabel,
+ "non terminating empty label in " <<
+ string(orig_s, send));
+ }
+ is_root = true;
+ } else if (c == '@' && s == send) {
+ // handle a single '@' as the root name.
+ is_root = true;
+ }
+
+ if (is_root) {
+ ndata.push_back(0);
+ done = true;
+ break;
+ }
+
+ // FALLTHROUGH
+ case ft_start:
+ ndata.push_back(0); // placeholder for the label length field
+ count = 0;
+ if (c == '\\') {
+ state = ft_initialescape;
+ break;
+ }
+ state = ft_ordinary;
+ isc_throw_assert(ndata.size() < Name::MAX_WIRE);
+ // FALLTHROUGH
+ case ft_ordinary:
+ if (c == '.') {
+ if (count == 0) {
+ isc_throw(EmptyLabel,
+ "duplicate period in " << string(orig_s, send));
+ }
+ ndata.at(offsets.back()) = count;
+ offsets.push_back(ndata.size());
+ if (s == send) {
+ ndata.push_back(0);
+ done = true;
+ }
+ state = ft_start;
+ } else if (c == '\\') {
+ state = ft_escape;
+ } else {
+ if (++count > Name::MAX_LABELLEN) {
+ isc_throw(TooLongLabel,
+ "label is too long in " << string(orig_s, send));
+ }
+ ndata.push_back(downcase ? maptolower[c] : c);
+ }
+ break;
+ case ft_initialescape:
+ if (c == '[') {
+ // This looks like a bitstring label, which was deprecated.
+ // Intentionally drop it.
+ isc_throw(BadLabelType,
+ "invalid label type in " << string(orig_s, send));
+ }
+ // FALLTHROUGH
+ case ft_escape:
+ if (!isdigit(c & 0xff)) {
+ if (++count > Name::MAX_LABELLEN) {
+ isc_throw(TooLongLabel,
+ "label is too long in " << string(orig_s, send));
+ }
+ ndata.push_back(downcase ? maptolower[c] : c);
+ state = ft_ordinary;
+ break;
+ }
+ digits = 0;
+ value = 0;
+ state = ft_escdecimal;
+ // FALLTHROUGH
+ case ft_escdecimal:
+ if (!isdigit(c & 0xff)) {
+ isc_throw(BadEscape,
+ "mixture of escaped digit and non-digit in "
+ << string(orig_s, send));
+ }
+ value *= 10;
+ value += digitvalue[c];
+ digits++;
+ if (digits == 3) {
+ if (value > 255) {
+ isc_throw(BadEscape,
+ "escaped decimal is too large in "
+ << string(orig_s, send));
+ }
+ if (++count > Name::MAX_LABELLEN) {
+ isc_throw(TooLongLabel,
+ "label is too long in " << string(orig_s, send));
+ }
+ ndata.push_back(downcase ? maptolower[value] : value);
+ state = ft_ordinary;
+ }
+ break;
+ default:
+ // impossible case
+ isc_throw_assert(false);
+ }
+ }
+
+ if (!done) { // no trailing '.' was found.
+ if (ndata.size() == Name::MAX_WIRE) {
+ isc_throw(TooLongName,
+ "name is too long for termination in " <<
+ string(orig_s, send));
+ }
+ isc_throw_assert(s == send);
+ if (state != ft_ordinary) {
+ isc_throw(IncompleteName,
+ "incomplete textual name in " <<
+ (empty ? "<empty>" : string(orig_s, send)));
+ }
+ if (state == ft_ordinary) {
+ isc_throw_assert(count != 0);
+ ndata.at(offsets.back()) = count;
+
+ offsets.push_back(ndata.size());
+ // add a trailing \0
+ ndata.push_back('\0');
+ }
+ }
+}
+
+}
+
+Name::Name(const std::string &namestring, bool downcase) {
+ // Prepare inputs for the parser
+ const std::string::const_iterator s = namestring.begin();
+ const std::string::const_iterator send = namestring.end();
+
+ // Prepare outputs
+ NameOffsets offsets;
+ NameString ndata;
+
+ // To the parsing
+ stringParse(s, send, downcase, offsets, ndata);
+
+ // And get the output
+ labelcount_ = offsets.size();
+ isc_throw_assert(labelcount_ > 0 && labelcount_ <= Name::MAX_LABELS);
+ ndata_.assign(ndata.data(), ndata.size());
+ length_ = ndata_.size();
+ offsets_.assign(offsets.begin(), offsets.end());
+}
+
+Name::Name(const char* namedata, size_t data_len, const Name* origin,
+ bool downcase)
+{
+ // Check validity of data
+ if (namedata == NULL || data_len == 0) {
+ isc_throw(isc::InvalidParameter,
+ "No data provided to Name constructor");
+ }
+ // If the last character is not a dot, it is a relative to origin.
+ // It is safe to check now, we know there's at least one character.
+ const bool absolute = (namedata[data_len - 1] == '.');
+ // If we are not absolute, we need the origin to complete the name.
+ if (!absolute && origin == NULL) {
+ isc_throw(MissingNameOrigin,
+ "No origin available and name is relative");
+ }
+ // Prepare inputs for the parser
+ const char* end = namedata + data_len;
+
+ // Prepare outputs
+ NameOffsets offsets;
+ NameString ndata;
+
+ // Do the actual parsing
+ stringParse(namedata, end, downcase, offsets, ndata);
+
+ // Get the output
+ labelcount_ = offsets.size();
+ isc_throw_assert(labelcount_ > 0 && labelcount_ <= Name::MAX_LABELS);
+ ndata_.assign(ndata.data(), ndata.size());
+ length_ = ndata_.size();
+ offsets_.assign(offsets.begin(), offsets.end());
+
+ if (!absolute) {
+ // Now, extend the data with the ones from origin. But eat the
+ // last label (the empty one).
+
+ // Drop the last character of the data (the \0) and append a copy of
+ // the origin's data
+ ndata_.erase(ndata_.end() - 1);
+ ndata_.append(origin->ndata_);
+
+ // Do a similar thing with offsets. However, we need to move them
+ // so they point after the prefix we parsed before.
+ size_t offset = offsets_.back();
+ offsets_.pop_back();
+ size_t offset_count = offsets_.size();
+ offsets_.insert(offsets_.end(), origin->offsets_.begin(),
+ origin->offsets_.end());
+ for (NameOffsets::iterator it(offsets_.begin() + offset_count);
+ it != offsets_.end(); ++it) {
+ *it += offset;
+ }
+
+ // Adjust sizes.
+ length_ = ndata_.size();
+ labelcount_ = offsets_.size();
+
+ // And check the sizes are OK.
+ if (labelcount_ > Name::MAX_LABELS || length_ > Name::MAX_WIRE) {
+ isc_throw(TooLongName, "Combined name is too long");
+ }
+ }
+}
+
+namespace {
+///
+/// Wire-format name parser states.
+///
+typedef enum {
+ fw_start = 0, // beginning of a label
+ fw_ordinary, // inside an ordinary (non compressed) label
+ fw_newcurrent // beginning of a compression pointer
+} fw_state;
+}
+
+Name::Name(InputBuffer& buffer, bool downcase) {
+ NameOffsets offsets;
+ offsets.reserve(Name::MAX_LABELS);
+
+ /*
+ * Initialize things to make the compiler happy; they're not required.
+ */
+ unsigned int n = 0;
+
+ //
+ // Set up.
+ //
+ bool done = false;
+ unsigned int nused = 0;
+ bool seen_pointer = false;
+ fw_state state = fw_start;
+
+ unsigned int cused = 0; // Bytes of compressed name data used
+ unsigned int current = buffer.getPosition();
+ unsigned int pos_begin = current;
+ unsigned int biggest_pointer = current;
+
+ // Make the compiler happy; this is not required.
+ // XXX: bad style in that we initialize it with a dummy value and define
+ // it far from where it's used. But alternatives seemed even worse.
+ unsigned int new_current = 0;
+
+ //
+ // Note: The following code is not optimized for speed, but
+ // rather for correctness. Speed will be addressed in the future.
+ //
+ while (current < buffer.getLength() && !done) {
+ unsigned int c = buffer.readUint8();
+ current++;
+ if (!seen_pointer) {
+ cused++;
+ }
+
+ switch (state) {
+ case fw_start:
+ if (c <= MAX_LABELLEN) {
+ offsets.push_back(nused);
+ if (nused + c + 1 > Name::MAX_WIRE) {
+ isc_throw(DNSMessageFORMERR, "wire name is too long: "
+ << nused + c + 1 << " bytes");
+ }
+ nused += c + 1;
+ ndata_.push_back(c);
+ if (c == 0) {
+ done = true;
+ }
+ n = c;
+ state = fw_ordinary;
+ } else if ((c & COMPRESS_POINTER_MARK8) == COMPRESS_POINTER_MARK8) {
+ //
+ // Ordinary 14-bit pointer.
+ //
+ new_current = c & ~COMPRESS_POINTER_MARK8;
+ n = 1;
+ state = fw_newcurrent;
+ } else {
+ // this case includes local compression pointer, which hasn't
+ // been standardized.
+ isc_throw(DNSMessageFORMERR, "unknown label character: " << c);
+ }
+ break;
+ case fw_ordinary:
+ if (downcase) {
+ c = maptolower[c];
+ }
+ ndata_.push_back(c);
+ if (--n == 0) {
+ state = fw_start;
+ }
+ break;
+ case fw_newcurrent:
+ new_current *= 256;
+ new_current += c;
+ if (--n != 0) {
+ break;
+ }
+ if (new_current >= biggest_pointer) {
+ isc_throw(DNSMessageFORMERR,
+ "bad compression pointer (out of range): " <<
+ new_current);
+ }
+ biggest_pointer = new_current;
+ current = new_current;
+ buffer.setPosition(current);
+ seen_pointer = true;
+ state = fw_start;
+ break;
+ default:
+ isc_throw_assert(false);
+ }
+ }
+
+ if (!done) {
+ isc_throw(DNSMessageFORMERR, "incomplete wire-format name");
+ }
+
+ labelcount_ = offsets.size();
+ length_ = nused;
+ offsets_.assign(offsets.begin(), offsets.end());
+ buffer.setPosition(pos_begin + cused);
+}
+
+void
+Name::toWire(OutputBuffer& buffer) const {
+ buffer.writeData(ndata_.data(), ndata_.size());
+}
+
+void
+Name::toWire(AbstractMessageRenderer& renderer) const {
+ renderer.writeName(*this);
+}
+
+std::string
+Name::toText(bool omit_final_dot) const {
+ LabelSequence ls(*this);
+ return (ls.toText(omit_final_dot));
+}
+
+std::string
+Name::toRawText(bool omit_final_dot) const {
+ LabelSequence ls(*this);
+ return (ls.toRawText(omit_final_dot));
+}
+
+NameComparisonResult
+Name::compare(const Name& other) const {
+ const LabelSequence ls1(*this);
+ const LabelSequence ls2(other);
+ return (ls1.compare(ls2));
+}
+
+bool
+Name::equals(const Name& other) const {
+ if (length_ != other.length_ || labelcount_ != other.labelcount_) {
+ return (false);
+ }
+
+ for (unsigned int l = labelcount_, pos = 0; l > 0; --l) {
+ uint8_t count = ndata_[pos];
+ if (count != other.ndata_[pos]) {
+ return (false);
+ }
+ ++pos;
+
+ while (count-- > 0) {
+ uint8_t label1 = ndata_[pos];
+ uint8_t label2 = other.ndata_[pos];
+
+ if (maptolower[label1] != maptolower[label2]) {
+ return (false);
+ }
+ ++pos;
+ }
+ }
+
+ return (true);
+}
+
+bool
+Name::leq(const Name& other) const {
+ return (compare(other).getOrder() <= 0);
+}
+
+bool
+Name::geq(const Name& other) const {
+ return (compare(other).getOrder() >= 0);
+}
+
+bool
+Name::lthan(const Name& other) const {
+ return (compare(other).getOrder() < 0);
+}
+
+bool
+Name::gthan(const Name& other) const {
+ return (compare(other).getOrder() > 0);
+}
+
+bool
+Name::isWildcard() const {
+ return (length_ >= 2 && ndata_[0] == 1 && ndata_[1] == '*');
+}
+
+Name
+Name::concatenate(const Name& suffix) const {
+ isc_throw_assert(length_ > 0 && suffix.length_ > 0);
+ isc_throw_assert(labelcount_ > 0 && suffix.labelcount_ > 0);
+
+ unsigned int length = length_ + suffix.length_ - 1;
+ if (length > Name::MAX_WIRE) {
+ isc_throw(TooLongName, "names are too long to concatenate");
+ }
+
+ Name retname;
+ retname.ndata_.reserve(length);
+ retname.ndata_.assign(ndata_, 0, length_ - 1);
+ retname.ndata_.insert(retname.ndata_.end(),
+ suffix.ndata_.begin(), suffix.ndata_.end());
+ isc_throw_assert(retname.ndata_.size() == length);
+ retname.length_ = length;
+
+ //
+ // Setup the offsets vector. Copy the offsets of this (prefix) name,
+ // excluding that for the trailing dot, and append the offsets of the
+ // suffix name with the additional offset of the length of the prefix.
+ //
+ unsigned int labels = labelcount_ + suffix.labelcount_ - 1;
+ isc_throw_assert(labels <= Name::MAX_LABELS);
+ retname.offsets_.reserve(labels);
+ retname.offsets_.assign(&offsets_[0], &offsets_[0] + labelcount_ - 1);
+ transform(suffix.offsets_.begin(), suffix.offsets_.end(),
+ back_inserter(retname.offsets_),
+ [this] (char x) { return (x + length_ - 1); });
+ isc_throw_assert(retname.offsets_.size() == labels);
+ retname.labelcount_ = labels;
+
+ return (retname);
+}
+
+Name
+Name::reverse() const {
+ Name retname;
+ //
+ // Set up offsets: The size of the string and number of labels will
+ // be the same in as in the original.
+ //
+ retname.offsets_.reserve(labelcount_);
+ retname.ndata_.reserve(length_);
+
+ // Copy the original name, label by label, from tail to head.
+ NameOffsets::const_reverse_iterator rit0 = offsets_.rbegin();
+ NameOffsets::const_reverse_iterator rit1 = rit0 + 1;
+ NameString::const_iterator n0 = ndata_.begin();
+ retname.offsets_.push_back(0);
+ while (rit1 != offsets_.rend()) {
+ retname.ndata_.append(n0 + *rit1, n0 + *rit0);
+ retname.offsets_.push_back(retname.ndata_.size());
+ ++rit0;
+ ++rit1;
+ }
+ retname.ndata_.push_back(0);
+
+ retname.labelcount_ = labelcount_;
+ retname.length_ = length_;
+
+ return (retname);
+}
+
+Name
+Name::split(const unsigned int first, const unsigned int n) const {
+ if (n == 0 || n > labelcount_ || first > labelcount_ - n) {
+ isc_throw(OutOfRange, "Name::split: invalid split range");
+ }
+
+ Name retname;
+ // If the specified range doesn't include the trailing dot, we need one
+ // more label for that.
+ unsigned int newlabels = (first + n == labelcount_) ? n : n + 1;
+
+ //
+ // Set up offsets: copy the corresponding range of the original offsets
+ // with subtracting an offset of the prefix length.
+ //
+ retname.offsets_.reserve(newlabels);
+ transform(offsets_.begin() + first, offsets_.begin() + first + newlabels,
+ back_inserter(retname.offsets_),
+ [&](char x) { return (x - offsets_[first]); });
+
+ //
+ // Set up the new name. At this point the tail of the new offsets specifies
+ // the position of the trailing dot, which should be equal to the length of
+ // the extracted portion excluding the dot. First copy that part from the
+ // original name, and append the trailing dot explicitly.
+ //
+ retname.ndata_.reserve(retname.offsets_.back() + 1);
+ retname.ndata_.assign(ndata_, offsets_[first], retname.offsets_.back());
+ retname.ndata_.push_back(0);
+
+ retname.length_ = retname.ndata_.size();
+ retname.labelcount_ = retname.offsets_.size();
+ isc_throw_assert(retname.labelcount_ == newlabels);
+
+ return (retname);
+}
+
+Name
+Name::split(const unsigned int level) const {
+ if (level >= getLabelCount()) {
+ isc_throw(OutOfRange, "invalid level for name split (" << level
+ << ") for name " << *this);
+ }
+
+ return (split(level, getLabelCount() - level));
+}
+
+Name&
+Name::downcase() {
+ unsigned int nlen = length_;
+ unsigned int labels = labelcount_;
+ unsigned int pos = 0;
+
+ while (labels > 0 && nlen > 0) {
+ --labels;
+ --nlen;
+
+ // we assume a valid name, and do abort() if the assumption fails
+ // rather than throwing an exception.
+ unsigned int count = ndata_.at(pos++);
+ isc_throw_assert(count <= MAX_LABELLEN);
+ isc_throw_assert(nlen >= count);
+
+ while (count > 0) {
+ ndata_.at(pos) =
+ maptolower[ndata_.at(pos)];
+ ++pos;
+ --nlen;
+ --count;
+ }
+ }
+
+ return (*this);
+}
+
+std::ostream&
+operator<<(std::ostream& os, const Name& name) {
+ os << name.toText();
+ return (os);
+}
+
+}
+}