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authorStephen Morris <stephen@isc.org>2014-07-30 18:15:45 +0200
committerStephen Morris <stephen@isc.org>2014-07-30 18:15:45 +0200
commit1c76dae79952d245d83a3536f7fb2cb3550c2476 (patch)
treefbdcee4dee2689d0e75b22a6d6f3901b53188a8a /src/bin/perfdhcp/pkt_transform.cc
parent[master] Merge branch 'trac3459' (diff)
downloadkea-1c76dae79952d245d83a3536f7fb2cb3550c2476.tar.xz
kea-1c76dae79952d245d83a3536f7fb2cb3550c2476.zip
[3481] Move perfdhcp source to src/bin/perfdhcp
Also modifiy Makefiles to install perfdhcp into sbin.
Diffstat (limited to 'src/bin/perfdhcp/pkt_transform.cc')
-rw-r--r--src/bin/perfdhcp/pkt_transform.cc226
1 files changed, 226 insertions, 0 deletions
diff --git a/src/bin/perfdhcp/pkt_transform.cc b/src/bin/perfdhcp/pkt_transform.cc
new file mode 100644
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+++ b/src/bin/perfdhcp/pkt_transform.cc
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+// Copyright (C) 2012-2014 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 <iostream>
+
+#include <exceptions/exceptions.h>
+#include <dhcp/option.h>
+#include <dhcp/libdhcp++.h>
+#include <dhcp/dhcp6.h>
+
+#include "pkt_transform.h"
+#include "localized_option.h"
+
+using namespace std;
+using namespace isc;
+using namespace dhcp;
+
+namespace isc {
+namespace perfdhcp {
+
+bool
+PktTransform::pack(const Option::Universe universe,
+ const OptionBuffer& in_buffer,
+ const OptionCollection& options,
+ const size_t transid_offset,
+ const uint32_t transid,
+ util::OutputBuffer& out_buffer) {
+
+ // Always override the packet if function is called.
+ out_buffer.clear();
+ // Write whole buffer to output buffer.
+ out_buffer.writeData(&in_buffer[0], in_buffer.size());
+
+ uint8_t transid_len = (universe == Option::V6) ? 3 : 4;
+
+ if ((transid_offset + transid_len >= in_buffer.size()) ||
+ (transid_offset == 0)) {
+ cout << "Failed to build packet: provided transaction id offset: "
+ << transid_offset << " is out of bounds (expected 1.."
+ << in_buffer.size()-1 << ")." << endl;
+ return (false);
+ }
+
+ try {
+ size_t offset_ptr = transid_offset;
+ if (universe == Option::V4) {
+ out_buffer.writeUint8At(transid >> 24 & 0xFF, offset_ptr++);
+ }
+ out_buffer.writeUint8At(transid >> 16 & 0xFF, offset_ptr++);
+ out_buffer.writeUint8At(transid >> 8 & 0xFF, offset_ptr++);
+ out_buffer.writeUint8At(transid & 0xFF, offset_ptr++);
+
+ // We already have packet template stored in output buffer
+ // but still some options have to be updated if client
+ // specified them along with their offsets in the buffer.
+ PktTransform::packOptions(in_buffer, options, out_buffer);
+ } catch (const isc::BadValue& e) {
+ cout << "Building packet failed: " << e.what() << endl;
+ return (false);
+ }
+ return (true);
+}
+
+bool
+PktTransform::unpack(const Option::Universe universe,
+ const OptionBuffer& in_buffer,
+ const OptionCollection& options,
+ const size_t transid_offset,
+ uint32_t& transid) {
+
+ uint8_t transid_len = (universe == Option::V6) ? 3 : 4;
+
+ // Validate transaction id offset.
+ if ((transid_offset + transid_len + 1 > in_buffer.size()) ||
+ (transid_offset == 0)) {
+ cout << "Failed to parse packet: provided transaction id offset: "
+ << transid_offset << " is out of bounds (expected 1.."
+ << in_buffer.size()-1 << ")." << endl;
+ return (false);
+ }
+
+ // Read transaction id from the buffer.
+ // For DHCPv6 we transaction id is 3 bytes long so the high byte
+ // of transid will be zero.
+ OptionBufferConstIter it = in_buffer.begin() + transid_offset;
+ transid = 0;
+ for (int i = 0; i < transid_len; ++i, ++it) {
+ // Read next byte and shift it left to its position in
+ // transid (shift by the number of bytes read so far.
+ transid += *it << (transid_len - i - 1) * 8;
+ }
+
+ try {
+ PktTransform::unpackOptions(in_buffer, options);
+ } catch (const isc::BadValue& e) {
+ cout << "Packet parsing failed: " << e.what() << endl;
+ return (false);
+ }
+
+ return (true);
+}
+
+void
+PktTransform::packOptions(const OptionBuffer& in_buffer,
+ const OptionCollection& options,
+ util::OutputBuffer& out_buffer) {
+ try {
+ // If there are any options on the list, we will use provided
+ // options offsets to override them in the output buffer
+ // with new contents.
+ for (OptionCollection::const_iterator it = options.begin();
+ it != options.end(); ++it) {
+ // Get options with their position (offset).
+ boost::shared_ptr<LocalizedOption> option =
+ boost::dynamic_pointer_cast<LocalizedOption>(it->second);
+ if (option == NULL) {
+ isc_throw(isc::BadValue, "option is null");
+ }
+ uint32_t offset = option->getOffset();
+ if ((offset == 0) ||
+ (offset + option->len() > in_buffer.size())) {
+ isc_throw(isc::BadValue,
+ "option offset for option: " << option->getType()
+ << " is out of bounds (expected 1.."
+ << in_buffer.size() - option->len() << ")");
+ }
+
+ // Create temporary buffer to store option contents.
+ util::OutputBuffer buf(option->len());
+ // Pack option contents into temporary buffer.
+ option->pack(buf);
+ // OutputBuffer class has nice functions that write
+ // data at the specified position so we can use it to
+ // inject contents of temporary buffer to output buffer.
+ const uint8_t *buf_data =
+ static_cast<const uint8_t*>(buf.getData());
+ for (int i = 0; i < buf.getLength(); ++i) {
+ out_buffer.writeUint8At(buf_data[i], offset + i);
+ }
+ }
+ }
+ catch (const Exception&) {
+ isc_throw(isc::BadValue, "failed to pack options into buffer.");
+ }
+}
+
+void
+PktTransform::unpackOptions(const OptionBuffer& in_buffer,
+ const OptionCollection& options) {
+ for (OptionCollection::const_iterator it = options.begin();
+ it != options.end(); ++it) {
+
+ boost::shared_ptr<LocalizedOption> option =
+ boost::dynamic_pointer_cast<LocalizedOption>(it->second);
+ if (option == NULL) {
+ isc_throw(isc::BadValue, "option is null");
+ }
+ size_t opt_pos = option->getOffset();
+ if (opt_pos == 0) {
+ isc_throw(isc::BadValue, "failed to unpack packet from raw buffer "
+ "(Option position not specified)");
+ } else if (opt_pos + option->getHeaderLen() > in_buffer.size()) {
+ isc_throw(isc::BadValue,
+ "failed to unpack options from from raw buffer "
+ "(Option position out of bounds)");
+ }
+
+ size_t offset = opt_pos;
+ size_t offset_step = 1;
+ uint16_t opt_type = 0;
+ if (option->getUniverse() == Option::V6) {
+ offset_step = 2;
+ // For DHCPv6 option type is in first two octets.
+ opt_type = in_buffer[offset] * 256 + in_buffer[offset + 1];
+ } else {
+ // For DHCPv4 option type is in first octet.
+ opt_type = in_buffer[offset];
+ }
+ // Check if we got expected option type.
+ if (opt_type != option->getType()) {
+ isc_throw(isc::BadValue,
+ "failed to unpack option from raw buffer "
+ "(option type mismatch)");
+ }
+
+ // Get option length which is supposed to be after option type.
+ offset += offset_step;
+ const uint16_t opt_len =
+ (option->getUniverse() == Option::V6) ?
+ in_buffer[offset] * 256 + in_buffer[offset + 1] :
+ in_buffer[offset];
+
+ // Check if packet is not truncated.
+ if (offset + option->getHeaderLen() + opt_len > in_buffer.size()) {
+ isc_throw(isc::BadValue,
+ "failed to unpack option from raw buffer "
+ "(option truncated)");
+ }
+
+ // Seek to actual option data and replace it.
+ offset += offset_step;
+ option->setData(in_buffer.begin() + offset,
+ in_buffer.begin() + offset + opt_len);
+ }
+}
+
+void
+PktTransform::writeAt(dhcp::OptionBuffer& in_buffer, size_t dest_pos,
+ dhcp::OptionBuffer::iterator first,
+ dhcp::OptionBuffer::iterator last) {
+ memcpy(&in_buffer[dest_pos], &(*first), std::distance(first, last));
+}
+
+} // namespace perfdhcp
+} // namespace isc