[3807] Improved log messages for the DHCPv6 server.

Also added a few minor corrections to the DHCPv4 server and implemented
new Option6StatusCode.

src/lib/dhcp/option6_status_code.cc

@@ -0,0 +1,144 @@
+// Copyright (C) 2015 Internet Systems Consortium, Inc. ("ISC")
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+// OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+#include <config.h>
+
+#include <dhcp/dhcp6.h>
+#include <dhcp/option6_status_code.h>
+#include <util/io_utilities.h>
+#include <iterator>
+#include <sstream>
+
+using namespace isc;
+using namespace isc::dhcp;
+
+namespace {
+
+/// @brief Minimum length of the option (when status message is empty).
+const size_t OPTION6_STATUS_CODE_MIN_LEN = sizeof(uint16_t);
+
+}; // end of anonymous namespace
+
+namespace isc {
+namespace dhcp {
+
+Option6StatusCode::Option6StatusCode(const uint16_t status_code,
+                                     const std::string& status_message)
+    : Option(Option::V6, D6O_STATUS_CODE),
+      status_code_(status_code), status_message_(status_message) {
+}
+
+Option6StatusCode::Option6StatusCode(OptionBufferConstIter begin,
+                                     OptionBufferConstIter end)
+    : Option(Option::V6, D6O_STATUS_CODE),
+      status_code_(STATUS_Success), status_message_() {
+
+    // Parse data 
+    unpack(begin, end);
+}
+
+void
+Option6StatusCode::pack(isc::util::OutputBuffer& buf) {
+    // Pack option header.
+    packHeader(buf);
+    // Write numeric status code.
+    buf.writeUint16(getStatusCode());
+    // If there is any status message, write it.
+    if (!status_message_.empty()) {
+        buf.writeData(&status_message_[0], status_message_.size());
+    }
+
+    // Status code has no options, so leave here.
+}
+
+void
+Option6StatusCode::unpack(OptionBufferConstIter begin, OptionBufferConstIter end) {
+    // Make sure that the option is not truncated.
+    if (std::distance(begin, end) < OPTION6_STATUS_CODE_MIN_LEN) {
+        isc_throw(OutOfRange, "Status Code option ("
+                  << D6O_STATUS_CODE << ") truncated");
+    }
+
+    status_code_ = util::readUint16(&(*begin), std::distance(begin, end));
+    begin += sizeof(uint16_t);
+
+    status_message_.assign(begin, end);
+}
+
+uint16_t
+Option6StatusCode::len() {
+    return (getHeaderLen() + sizeof(uint16_t) + status_message_.size());
+}
+
+std::string
+Option6StatusCode::toText(int indent) {
+    std::ostringstream output;
+    output << headerToText(indent) << ": "
+        << getStatusCodeName() << "(" << getStatusCode() << ") "
+        << dataToText();
+
+    return (output.str());
+}
+
+std::string
+Option6StatusCode::dataToText() const {
+    std::ostringstream output;
+    // Add status code name and numeric status code.
+    output << getStatusCodeName() << "(" << getStatusCode() << ") ";
+
+    // Include status message in quotes if status code is
+    // non-empty.
+    if (!status_message_.empty()) {
+        output << "\"" << status_message_ << "\"";
+
+    } else {
+        output << "(no status message)";
+    }
+
+    return (output.str());
+}
+
+std::string
+Option6StatusCode::getStatusCodeName() const {
+    switch (getStatusCode()) {
+    case STATUS_Success:
+        return ("Success");
+    case STATUS_UnspecFail:
+        return ("UnspecFail");
+    case STATUS_NoAddrsAvail:
+        return ("NoAddrsAvail");
+    case STATUS_NoBinding:
+        return ("NoBinding");
+    case STATUS_NotOnLink:
+        return ("NotOnLink");
+    case STATUS_UseMulticast:
+        return ("UseMulticast");
+    case STATUS_NoPrefixAvail:
+        return ("NoPrefixAvail");
+    case STATUS_UnknownQueryType:
+        return ("UnknownQueryType");
+    case STATUS_MalformedQuery:
+        return ("MalformedQuery");
+    case STATUS_NotConfigured:
+        return ("NotConfigured");
+    case STATUS_NotAllowed:
+        return ("NotAllowed");
+    default:
+        ;
+    }
+    return ("(unknown status code)");
+}
+
+} // end of namespace isc::dhcp
+} // end of namespace isc