summaryrefslogtreecommitdiffstats
path: root/libnetutil/IPv4Header.h
blob: 55410002940540303ecffa3cbe4315e848c28f5f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
/***************************************************************************
 * IPv4Header.h -- The IPv4Header Class represents an IPv4 datagram. It    *
 * contains methods to set any header field. In general, these methods do  *
 * error checkings and byte order conversion.                              *
 *                                                                         *
 ***********************IMPORTANT NMAP LICENSE TERMS************************
 *
 * The Nmap Security Scanner is (C) 1996-2023 Nmap Software LLC ("The Nmap
 * Project"). Nmap is also a registered trademark of the Nmap Project.
 *
 * This program is distributed under the terms of the Nmap Public Source
 * License (NPSL). The exact license text applying to a particular Nmap
 * release or source code control revision is contained in the LICENSE
 * file distributed with that version of Nmap or source code control
 * revision. More Nmap copyright/legal information is available from
 * https://nmap.org/book/man-legal.html, and further information on the
 * NPSL license itself can be found at https://nmap.org/npsl/ . This
 * header summarizes some key points from the Nmap license, but is no
 * substitute for the actual license text.
 *
 * Nmap is generally free for end users to download and use themselves,
 * including commercial use. It is available from https://nmap.org.
 *
 * The Nmap license generally prohibits companies from using and
 * redistributing Nmap in commercial products, but we sell a special Nmap
 * OEM Edition with a more permissive license and special features for
 * this purpose. See https://nmap.org/oem/
 *
 * If you have received a written Nmap license agreement or contract
 * stating terms other than these (such as an Nmap OEM license), you may
 * choose to use and redistribute Nmap under those terms instead.
 *
 * The official Nmap Windows builds include the Npcap software
 * (https://npcap.com) for packet capture and transmission. It is under
 * separate license terms which forbid redistribution without special
 * permission. So the official Nmap Windows builds may not be redistributed
 * without special permission (such as an Nmap OEM license).
 *
 * Source is provided to this software because we believe users have a
 * right to know exactly what a program is going to do before they run it.
 * This also allows you to audit the software for security holes.
 *
 * Source code also allows you to port Nmap to new platforms, fix bugs, and add
 * new features. You are highly encouraged to submit your changes as a Github PR
 * or by email to the dev@nmap.org mailing list for possible incorporation into
 * the main distribution. Unless you specify otherwise, it is understood that
 * you are offering us very broad rights to use your submissions as described in
 * the Nmap Public Source License Contributor Agreement. This is important
 * because we fund the project by selling licenses with various terms, and also
 * because the inability to relicense code has caused devastating problems for
 * other Free Software projects (such as KDE and NASM).
 *
 * The free version of Nmap is distributed in the hope that it will be
 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Warranties,
 * indemnification and commercial support are all available through the
 * Npcap OEM program--see https://nmap.org/oem/
 *
 ***************************************************************************/
/* This code was originally part of the Nping tool.                        */

#ifndef IPV4HEADER_H
#define IPV4HEADER_H 1

#include "NetworkLayerElement.h"

#define IP_RF 0x8000               /* Reserved fragment flag         */
#define IP_DF 0x4000               /* Don't fragment flag            */
#define IP_MF 0x2000               /* More fragments flag            */
#define IP_OFFMASK 0x1fff          /* Mask for fragmenting bits      */
#define IP_HEADER_LEN 20           /* Length of the standard header  */
#define MAX_IP_OPTIONS_LEN 40      /* Max Length for IP Options      */

/* Default header values */
#define IPv4_DEFAULT_TOS      0
#define IPv4_DEFAULT_ID       0
#define IPv4_DEFAULT_TTL      64
#define IPv4_DEFAULT_PROTO    6 /* TCP */

class IPv4Header : public NetworkLayerElement {

    private:
        /*
         0                   1                   2                   3
         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |Version|  IHL  |Type of Service|          Total Length         |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |         Identification        |Flags|      Fragment Offset    |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |  Time to Live |    Protocol   |         Header Checksum       |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                       Source Address                          |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                    Destination Address                        |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        |                    Options                    |    Padding    |
        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
        */
        struct nping_ipv4_hdr {
        #if WORDS_BIGENDIAN
            u8 ip_v:4;                     /* Version                        */
            u8 ip_hl:4;                    /* Header length                  */
        #else
            u8 ip_hl:4;                    /* Header length                  */
            u8 ip_v:4;                     /* Version                        */
        #endif
            u8 ip_tos;                     /* Type of service                */
            u16 ip_len;                    /* Total length                   */
            u16 ip_id;                     /* Identification                 */
            u16 ip_off;                    /* Fragment offset field          */
            u8 ip_ttl;                     /* Time to live                   */
            u8 ip_p;                       /* Protocol                       */
            u16 ip_sum;                    /* Checksum                       */
            struct in_addr ip_src;         /* Source IP address              */
            struct in_addr ip_dst;         /* Destination IP address         */
            u8 options[MAX_IP_OPTIONS_LEN];  /* IP Options                   */
        }__attribute__((__packed__));

        typedef struct nping_ipv4_hdr nping_ipv4_hdr_t;

        nping_ipv4_hdr_t h;

        int ipoptlen; /**< Length of IP options */

    public:

        /* Misc */
        IPv4Header();
        ~IPv4Header();
        void reset();
        u8 *getBufferPointer();
        int storeRecvData(const u8 *buf, size_t len);
        int protocol_id() const;
        int validate();
        int print(FILE *output, int detail) const;

        /* IP version */
        int setVersion();
        u8 getVersion() const;

        /* Header Length */
        int setHeaderLength();
        int setHeaderLength(u8 l);
        u8 getHeaderLength() const;

        /* Type of Service */
        int setTOS(u8 v);
        u8 getTOS() const;

        /* Total length of the datagram */
        int setTotalLength();
        int setTotalLength(u16 l);
        u16 getTotalLength() const;

        /* Identification value */
        int setIdentification();
        int setIdentification(u16 i);
        u16 getIdentification() const;

        /* Fragment Offset */
        int setFragOffset();
        int setFragOffset(u16 f);
        u16 getFragOffset() const;

        /* Flags */
        int setRF();
        int unsetRF();
        bool getRF() const;
        int setDF();
        int unsetDF();
        bool getDF() const;
        int setMF();
        int unsetMF();
        bool getMF() const;

        /* Time to live */
        int setTTL();
        int setTTL(u8 t);
        u8 getTTL() const;

        /* Next protocol */
        int setNextProto(u8 p);
        int setNextProto(const char *p);
        u8 getNextProto() const;
        int setNextHeader(u8 val);
        u8 getNextHeader() const;

        /* Checksum */
        int setSum();
        int setSum(u16 s);
        int setSumRandom();
        u16 getSum() const;

        /* Destination IP */
        int setDestinationAddress(u32 d);
        int setDestinationAddress(struct in_addr d);
        const u8 *getDestinationAddress() const;
        struct in_addr getDestinationAddress(struct in_addr *result) const;


        /* Source IP */
        int setSourceAddress(u32 d);
        int setSourceAddress(struct in_addr d);
        const u8 *getSourceAddress() const;
        struct in_addr getSourceAddress(struct in_addr *result) const;

        u16 getAddressLength() const;

        /* IP Options */
        int setOpts(const char *txt);
        int setOpts(u8 *opts_buff,  u32 opts_len);
        const u8 *getOpts() const;
        const u8 *getOpts(int *len) const;
        int printOptions() const;
        const char *getOptionsString() const;

}; /* End of class IPv4Header */

#endif