1 files changed, 145 insertions, 0 deletions
diff --git a/src/lib/dhcp/option6_dnr.cc b/src/lib/dhcp/option6_dnr.cc
new file mode 100644
index 0000000..3d7bb0f
--- /dev/null
+++ b/src/lib/dhcp/option6_dnr.cc
@@ -0,0 +1,145 @@
+// Copyright (C) 2023 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/option6_dnr.h>
+
+using namespace isc::asiolink;
+
+namespace isc {
+namespace dhcp {
+
+Option6Dnr::Option6Dnr(OptionBufferConstIter begin, OptionBufferConstIter end)
+    : Option(V6, D6O_V6_DNR), DnrInstance(V6) {
+    unpack(begin, end);
+}
+
+OptionPtr
+Option6Dnr::clone() const {
+    return (cloneInternal<Option6Dnr>());
+}
+
+void
+Option6Dnr::pack(util::OutputBuffer& buf, bool check) const {
+    packHeader(buf, check);
+
+    buf.writeUint16(service_priority_);
+    buf.writeUint16(adn_length_);
+    packAdn(buf);
+    if (adn_only_mode_) {
+        return;
+    }
+
+    buf.writeUint16(addr_length_);
+    packAddresses(buf);
+    packSvcParams(buf);
+}
+
+void
+Option6Dnr::packAddresses(util::OutputBuffer& buf) const {
+    for (const auto& address : ip_addresses_) {
+        if (!address.isV6()) {
+            isc_throw(isc::BadValue, getLogPrefix()
+                                         << address.toText() << " is not an IPv6 address");
+        }
+
+        buf.writeData(&address.toBytes()[0], V6ADDRESS_LEN);
+    }
+}
+
+void
+Option6Dnr::unpack(OptionBufferConstIter begin, OptionBufferConstIter end) {
+    if (std::distance(begin, end) < getMinimalLength()) {
+        isc_throw(OutOfRange, getLogPrefix()
+                                  << "data truncated to size " << std::distance(begin, end));
+    }
+
+    setData(begin, end);
+
+    // First two octets of Option data is Service Priority - this is mandatory field.
+    unpackServicePriority(begin);
+
+    // Next come two octets of ADN Length plus the ADN data itself (variable length).
+    // This is Opaque Data Tuple so let's use this class to retrieve the ADN data.
+    unpackAdn(begin, end);
+
+    if (begin == end) {
+        // ADN only mode, other fields are not included.
+        return;
+    }
+
+    adn_only_mode_ = false;
+
+    unpackAddresses(begin, end);
+
+    // SvcParams (variable length) field is last.
+    unpackSvcParams(begin, end);
+}
+
+std::string
+Option6Dnr::toText(int indent) const {
+    std::ostringstream stream;
+    std::string in(indent, ' ');  // base indentation
+    stream << in << "type=" << type_ << "(V6_DNR), "
+           << "len=" << (len() - getHeaderLen()) << ", " << getDnrInstanceAsText();
+    return (stream.str());
+}
+
+uint16_t
+Option6Dnr::len() const {
+    return (OPTION6_HDR_LEN + dnrInstanceLen());
+}
+
+void
+Option6Dnr::unpackAddresses(OptionBufferConstIter& begin, OptionBufferConstIter end) {
+    if (std::distance(begin, end) < getAddrLengthSize()) {
+        isc_throw(OutOfRange, getLogPrefix() << "after"
+                                                " ADN field, there should be at least "
+                                                "2 bytes long Addr Length field");
+    }
+
+    // Next come two octets of Addr Length.
+    addr_length_ = isc::util::readUint16(&(*begin), getAddrLengthSize());
+    begin += getAddrLengthSize();
+    // It MUST be a multiple of 16.
+    if ((addr_length_ % V6ADDRESS_LEN) != 0) {
+        isc_throw(OutOfRange, getLogPrefix()
+                                  << "Addr Len=" << addr_length_ << " is not divisible by 16");
+    }
+
+    // As per draft-ietf-add-dnr 3.1.8:
+    // If additional data is supplied (i.e. not ADN only mode),
+    // the option includes at least one valid IP address.
+    if (addr_length_ == 0) {
+        isc_throw(OutOfRange, getLogPrefix()
+                                  << "Addr Len=" << addr_length_
+                                  << " but it must contain at least one valid IP address");
+    }
+
+    // Check if IPv6 Address(es) field is not truncated.
+    if (std::distance(begin, end) < addr_length_) {
+        isc_throw(OutOfRange, getLogPrefix() << "Addr Len=" << addr_length_
+                                             << " but IPv6 address(es) are truncated to len="
+                                             << std::distance(begin, end));
+    }
+
+    // Let's unpack the ipv6-address(es).
+    auto addr_end = begin + addr_length_;
+    while (begin != addr_end) {
+        try {
+            ip_addresses_.push_back(IOAddress::fromBytes(AF_INET6, &(*begin)));
+        } catch (const Exception& ex) {
+            isc_throw(BadValue, getLogPrefix() << "failed to parse IPv6 address"
+                                               << " - " << ex.what());
+        }
+
+        begin += V6ADDRESS_LEN;
+    }
+}
+
+}  // namespace dhcp
+}  // namespace isc