261 lines
8.5 KiB
C++
261 lines
8.5 KiB
C++
/*
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* Copyright (c) 2017, Matias Fontanini
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are
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* met:
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*
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* * Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* * Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following disclaimer
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* in the documentation and/or other materials provided with the
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* distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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*/
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#include <cstring>
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#include <tins/endianness.h>
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#include <tins/dhcp.h>
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#include <tins/exceptions.h>
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#include <tins/memory_helpers.h>
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using std::string;
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using std::vector;
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using std::runtime_error;
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using Tins::Memory::InputMemoryStream;
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using Tins::Memory::OutputMemoryStream;
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namespace Tins {
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PDU::metadata DHCP::extract_metadata(const uint8_t* /*buffer*/, uint32_t total_sz) {
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if (TINS_UNLIKELY(total_sz < sizeof(bootp_header))) {
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throw malformed_packet();
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}
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return metadata(total_sz, pdu_flag, PDU::UNKNOWN);
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}
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// Magic cookie: uint32_t.
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DHCP::DHCP()
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: size_(sizeof(uint32_t)) {
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opcode(BOOTREQUEST);
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htype(1); // ethernet
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hlen(6); // MAC address length
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}
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DHCP::DHCP(const uint8_t* buffer, uint32_t total_sz)
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: BootP(buffer, total_sz, 0), size_(sizeof(uint32_t)) {
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InputMemoryStream stream(buffer, total_sz);
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stream.skip(BootP::header_size() - vend().size());
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const uint32_t magic_number = stream.read<uint32_t>();
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if (magic_number != Endian::host_to_be<uint32_t>(0x63825363)) {
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throw malformed_packet();
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}
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// While there's data left
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while (stream) {
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OptionTypes option_type;
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uint8_t option_length = 0;
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option_type = (OptionTypes)stream.read<uint8_t>();
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// We should only read the length if it's not END nor PAD
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if (option_type != END && option_type != PAD) {
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option_length = stream.read<uint8_t>();
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}
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// Make sure we can read the payload size
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if (!stream.can_read(option_length)) {
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throw malformed_packet();
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}
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add_option(option(option_type, option_length, stream.pointer()));
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stream.skip(option_length);
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}
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}
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void DHCP::add_option(const option& opt) {
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internal_add_option(opt);
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options_.push_back(opt);
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}
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void DHCP::internal_add_option(const option& opt) {
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size_ += static_cast<uint32_t>(opt.data_size() + (sizeof(uint8_t) << 1));
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}
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bool DHCP::remove_option(OptionTypes type) {
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options_type::iterator iter = search_option_iterator(type);
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if (iter == options_.end()) {
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return false;
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}
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size_ -= static_cast<uint32_t>(iter->data_size() + (sizeof(uint8_t) << 1));
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options_.erase(iter);
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return true;
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}
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const DHCP::option* DHCP::search_option(OptionTypes opt) const {
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// Search for the iterator. If we found something, return it, otherwise return nullptr.
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options_type::const_iterator iter = search_option_iterator(opt);
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return (iter != options_.end()) ? &*iter : 0;
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}
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DHCP::options_type::const_iterator DHCP::search_option_iterator(OptionTypes opt) const {
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return Internals::find_option_const<option>(options_, opt);
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}
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DHCP::options_type::iterator DHCP::search_option_iterator(OptionTypes opt) {
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return Internals::find_option<option>(options_, opt);
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}
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void DHCP::type(Flags type) {
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uint8_t int_type = type;
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add_option(option(DHCP_MESSAGE_TYPE, sizeof(uint8_t), &int_type));
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}
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void DHCP::end() {
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add_option(option(END));
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}
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uint8_t DHCP::type() const {
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return search_and_convert<uint8_t>(DHCP_MESSAGE_TYPE);
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}
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void DHCP::server_identifier(ipaddress_type ip) {
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uint32_t ip_int = ip;
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add_option(option(DHCP_SERVER_IDENTIFIER, sizeof(uint32_t), (const uint8_t*)&ip_int));
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}
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DHCP::ipaddress_type DHCP::server_identifier() const {
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return search_and_convert<ipaddress_type>(DHCP_SERVER_IDENTIFIER);
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}
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void DHCP::lease_time(uint32_t time) {
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time = Endian::host_to_be(time);
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add_option(option(DHCP_LEASE_TIME, sizeof(uint32_t), (const uint8_t*)&time));
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}
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uint32_t DHCP::lease_time() const {
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return search_and_convert<uint32_t>(DHCP_LEASE_TIME);
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}
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void DHCP::renewal_time(uint32_t time) {
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time = Endian::host_to_be(time);
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add_option(option(DHCP_RENEWAL_TIME, sizeof(uint32_t), (const uint8_t*)&time));
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}
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uint32_t DHCP::renewal_time() const {
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return search_and_convert<uint32_t>(DHCP_RENEWAL_TIME);
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}
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void DHCP::subnet_mask(ipaddress_type mask) {
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uint32_t mask_int = mask;
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add_option(option(SUBNET_MASK, sizeof(uint32_t), (const uint8_t*)&mask_int));
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}
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DHCP::ipaddress_type DHCP::subnet_mask() const {
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return search_and_convert<ipaddress_type>(SUBNET_MASK);
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}
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void DHCP::routers(const vector<ipaddress_type>& routers) {
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serialization_type buffer = serialize_list(routers);
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add_option(option(ROUTERS, buffer.begin(), buffer.end()));
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}
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vector<DHCP::ipaddress_type> DHCP::routers() const {
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return search_and_convert<vector<DHCP::ipaddress_type> >(ROUTERS);
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}
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void DHCP::domain_name_servers(const vector<ipaddress_type>& dns) {
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serialization_type buffer = serialize_list(dns);
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add_option(option(DOMAIN_NAME_SERVERS, buffer.begin(), buffer.end()));
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}
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vector<DHCP::ipaddress_type> DHCP::domain_name_servers() const {
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return search_and_convert<vector<DHCP::ipaddress_type> >(DOMAIN_NAME_SERVERS);
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}
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void DHCP::broadcast(ipaddress_type addr) {
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uint32_t int_addr = addr;
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add_option(option(BROADCAST_ADDRESS, sizeof(uint32_t), (uint8_t*)&int_addr));
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}
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DHCP::ipaddress_type DHCP::broadcast() const {
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return search_and_convert<ipaddress_type>(BROADCAST_ADDRESS);
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}
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void DHCP::requested_ip(ipaddress_type addr) {
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uint32_t int_addr = addr;
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add_option(option(DHCP_REQUESTED_ADDRESS, sizeof(uint32_t), (uint8_t*)&int_addr));
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}
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DHCP::ipaddress_type DHCP::requested_ip() const {
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return search_and_convert<ipaddress_type>(DHCP_REQUESTED_ADDRESS);
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}
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void DHCP::domain_name(const string& name) {
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add_option(option(DOMAIN_NAME, name.size(), (const uint8_t*)name.c_str()));
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}
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string DHCP::domain_name() const {
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return search_and_convert<string>(DOMAIN_NAME);
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}
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void DHCP::hostname(const string& name) {
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add_option(option(HOST_NAME, name.size(), (const uint8_t*)name.c_str()));
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}
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string DHCP::hostname() const {
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return search_and_convert<string>(HOST_NAME);
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}
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void DHCP::rebind_time(uint32_t time) {
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time = Endian::host_to_be(time);
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add_option(option(DHCP_REBINDING_TIME, sizeof(uint32_t), (uint8_t*)&time));
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}
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uint32_t DHCP::rebind_time() const {
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return search_and_convert<uint32_t>(DHCP_REBINDING_TIME);
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}
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PDU::serialization_type DHCP::serialize_list(const vector<ipaddress_type>& ip_list) {
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serialization_type buffer(ip_list.size() * sizeof(uint32_t));
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uint32_t* ptr = (uint32_t*)&buffer[0];
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typedef vector<ipaddress_type>::const_iterator iterator;
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for (iterator it = ip_list.begin(); it != ip_list.end(); ++it) {
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*(ptr++) = *it;
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}
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return buffer;
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}
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uint32_t DHCP::header_size() const {
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return static_cast<uint32_t>(BootP::header_size() - vend().size() + size_);
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}
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void DHCP::write_serialization(uint8_t* buffer, uint32_t total_sz) {
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if (size_) {
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vend_type& result = BootP::vend();
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result.resize(size_);
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// Build a stream over the vend vector
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OutputMemoryStream stream(&result[0], result.size());
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// Magic cookie
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stream.write(Endian::host_to_be<uint32_t>(0x63825363));
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for (options_type::const_iterator it = options_.begin(); it != options_.end(); ++it) {
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stream.write(it->option());
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stream.write<uint8_t>(it->length_field());
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stream.write(it->data_ptr(), it->data_size());
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}
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}
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BootP::write_serialization(buffer, total_sz);
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}
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} // Tins
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