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-rw-r--r--src/lib/dns/char_string.cc264
1 files changed, 264 insertions, 0 deletions
diff --git a/src/lib/dns/char_string.cc b/src/lib/dns/char_string.cc
new file mode 100644
index 0000000..25cb1f1
--- /dev/null
+++ b/src/lib/dns/char_string.cc
@@ -0,0 +1,264 @@
+// Copyright (C) 2012-2024 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/.
+
+#include <config.h>
+
+#include <exceptions/exceptions.h>
+
+#include <dns/exceptions.h>
+#include <dns/rdata.h>
+#include <dns/master_lexer.h>
+#include <dns/char_string.h>
+#include <util/buffer.h>
+
+#include <boost/lexical_cast.hpp>
+
+#include <cctype>
+#include <cstring>
+#include <vector>
+
+#include <stdint.h>
+
+namespace isc {
+namespace dns {
+namespace rdata {
+namespace generic {
+namespace detail {
+
+namespace {
+// Convert a DDD form to the corresponding integer
+int
+decimalToNumber(const char* s, const char* s_end) {
+ if (s_end - s < 3) {
+ isc_throw(InvalidRdataText, "Escaped digits too short");
+ }
+
+ const std::string num_str(s, s + 3);
+ try {
+ const int i = boost::lexical_cast<int>(num_str);
+ if (i > 255) {
+ isc_throw(InvalidRdataText, "Escaped digits too large: "
+ << num_str);
+ }
+ return (i);
+ } catch (const boost::bad_lexical_cast&) {
+ isc_throw(InvalidRdataText,
+ "Invalid form for escaped digits: " << num_str);
+ }
+}
+}
+
+void
+stringToCharString(const MasterToken::StringRegion& str_region,
+ CharString& result) {
+ // make a space for the 1-byte length field; filled in at the end
+ result.push_back(0);
+
+ bool escape = false;
+ const char* s = str_region.beg;
+ const char* const s_end = str_region.beg + str_region.len;
+
+ for (size_t n = str_region.len; n != 0; --n, ++s) {
+ int c = (*s & 0xff);
+ if (escape && std::isdigit(c) != 0) {
+ c = decimalToNumber(s, s_end);
+ // decimalToNumber() already throws if (s_end - s) is less
+ // than 3. 'n' is an unsigned type (size_t) and can underflow.
+ // 'n' and 's' are also updated by 1 in the for statement's
+ // expression, so we update them by 2 instead of 3 here.
+ n -= 2;
+ s += 2;
+ } else if (!escape && c == '\\') {
+ escape = true;
+ continue;
+ }
+ escape = false;
+ result.push_back(c);
+ }
+ if (escape) { // terminated by non-escaped '\'
+ isc_throw(InvalidRdataText, "character-string ends with '\\'");
+ }
+ if (result.size() > MAX_CHARSTRING_LEN + 1) { // '+ 1' due to the len field
+ isc_throw(CharStringTooLong, "character-string is too long: " <<
+ (result.size() - 1) << "(+1) characters");
+ }
+ result[0] = result.size() - 1;
+}
+
+void
+stringToCharStringData(const MasterToken::StringRegion& str_region,
+ CharStringData& result) {
+ bool escape = false;
+ const char* s = str_region.beg;
+ const char* const s_end = str_region.beg + str_region.len;
+
+ for (size_t n = str_region.len; n != 0; --n, ++s) {
+ int c = (*s & 0xff);
+ if (escape && std::isdigit(c) != 0) {
+ c = decimalToNumber(s, s_end);
+ // decimalToNumber() already throws if (s_end - s) is less
+ // than 3. 'n' is an unsigned type (size_t) and can underflow.
+ // 'n' and 's' are also updated by 1 in the for statement's
+ // expression, so we update them by 2 instead of 3 here.
+ n -= 2;
+ s += 2;
+ } else if (!escape && c == '\\') {
+ escape = true;
+ continue;
+ }
+ escape = false;
+ result.push_back(c);
+ }
+ if (escape) { // terminated by non-escaped '\'
+ isc_throw(InvalidRdataText, "character-string ends with '\\'");
+ }
+}
+
+std::string
+charStringToString(const CharString& char_string) {
+ std::string s;
+ bool first = true;
+ for (auto const& it : char_string) {
+ if (first) {
+ first = false;
+ continue;
+ }
+ const uint8_t ch = it;
+ if ((ch < 0x20) || (ch >= 0x7f)) {
+ // convert to escaped \xxx (decimal) format
+ s.push_back('\\');
+ s.push_back('0' + ((ch / 100) % 10));
+ s.push_back('0' + ((ch / 10) % 10));
+ s.push_back('0' + (ch % 10));
+ continue;
+ }
+ if ((ch == '"') || (ch == ';') || (ch == '\\')) {
+ s.push_back('\\');
+ }
+ s.push_back(ch);
+ }
+
+ return (s);
+}
+
+std::string
+charStringDataToString(const CharStringData& char_string) {
+ std::string s;
+ for (auto const& it : char_string) {
+ const uint8_t ch = it;
+ if ((ch < 0x20) || (ch >= 0x7f)) {
+ // convert to escaped \xxx (decimal) format
+ s.push_back('\\');
+ s.push_back('0' + ((ch / 100) % 10));
+ s.push_back('0' + ((ch / 10) % 10));
+ s.push_back('0' + (ch % 10));
+ continue;
+ }
+ if ((ch == '"') || (ch == ';') || (ch == '\\')) {
+ s.push_back('\\');
+ }
+ s.push_back(ch);
+ }
+
+ return (s);
+}
+
+int compareCharStrings(const detail::CharString& self,
+ const detail::CharString& other) {
+ if (self.size() == 0 && other.size() == 0) {
+ return (0);
+ }
+ if (self.size() == 0) {
+ return (-1);
+ }
+ if (other.size() == 0) {
+ return (1);
+ }
+ const size_t self_len = self[0];
+ const size_t other_len = other[0];
+ const size_t cmp_len = std::min(self_len, other_len);
+ if (cmp_len == 0) {
+ if (self_len < other_len) {
+ return (-1);
+ } else if (self_len > other_len) {
+ return (1);
+ } else {
+ return (0);
+ }
+ }
+ const int cmp = std::memcmp(&self[1], &other[1], cmp_len);
+ if (cmp < 0) {
+ return (-1);
+ } else if (cmp > 0) {
+ return (1);
+ } else if (self_len < other_len) {
+ return (-1);
+ } else if (self_len > other_len) {
+ return (1);
+ } else {
+ return (0);
+ }
+}
+
+int compareCharStringDatas(const detail::CharStringData& self,
+ const detail::CharStringData& other) {
+ if (self.size() == 0 && other.size() == 0) {
+ return (0);
+ }
+ if (self.size() == 0) {
+ return (-1);
+ }
+ if (other.size() == 0) {
+ return (1);
+ }
+ const size_t self_len = self.size();
+ const size_t other_len = other.size();
+ const size_t cmp_len = std::min(self_len, other_len);
+ const int cmp = std::memcmp(&self[0], &other[0], cmp_len);
+ if (cmp < 0) {
+ return (-1);
+ } else if (cmp > 0) {
+ return (1);
+ } else if (self_len < other_len) {
+ return (-1);
+ } else if (self_len > other_len) {
+ return (1);
+ } else {
+ return (0);
+ }
+}
+
+size_t
+bufferToCharString(isc::util::InputBuffer& buffer, size_t rdata_len,
+ CharString& target) {
+ if (rdata_len < 1 || buffer.getLength() - buffer.getPosition() < 1) {
+ isc_throw(isc::dns::DNSMessageFORMERR,
+ "insufficient data to read character-string length");
+ }
+ const uint8_t len = buffer.readUint8();
+ if (rdata_len < len + 1) {
+ isc_throw(isc::dns::DNSMessageFORMERR,
+ "character string length is too large: " <<
+ static_cast<int>(len));
+ }
+ if (buffer.getLength() - buffer.getPosition() < len) {
+ isc_throw(isc::dns::DNSMessageFORMERR,
+ "not enough data in buffer to read character-string of len"
+ << static_cast<int>(len));
+ }
+
+ target.resize(len + 1);
+ target[0] = len;
+ buffer.readData(&target[0] + 1, len);
+
+ return (len + 1);
+}
+
+} // end of detail
+} // end of generic
+} // end of rdata
+} // end of dns
+} // end of isc
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