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Serenity Operating System
1/*
2 * Copyright (c) 2020, The SerenityOS developers.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * 1. Redistributions of source code must retain the above copyright notice, this
9 * list of conditions and the following disclaimer.
10 *
11 * 2. Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
22 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
23 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#include "DHCPv4.h"
28
29//#define DHCPV4_DEBUG
30
31ParsedDHCPv4Options DHCPv4Packet::parse_options() const
32{
33 ParsedDHCPv4Options options;
34 for (size_t index = 4; index < DHCPV4_OPTION_FIELD_MAX_LENGTH; ++index) {
35 auto opt_name = *(const DHCPOption*)&m_options[index];
36 switch (opt_name) {
37 case DHCPOption::Pad:
38 continue;
39 case DHCPOption::End:
40 goto escape;
41 default:
42 ++index;
43 auto length = m_options[index];
44 if ((size_t)length > DHCPV4_OPTION_FIELD_MAX_LENGTH - index) {
45 dbg() << "Bogus option length " << length << " assuming forgotten END";
46 break;
47 }
48#ifdef DHCPV4_DEBUG
49 dbg() << "DHCP Option " << (u8)opt_name << " with length " << length;
50#endif
51 ++index;
52 options.options.set(opt_name, { length, &m_options[index] });
53 index += length - 1;
54 break;
55 }
56 }
57escape:;
58 return options;
59}