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
|
#ifndef INCLUDED_IPSTRUCTS_
#define INCLUDED_IPSTRUCTS_
#include <arpa/inet.h>
// struct ifaddrs {
// struct ifaddrs *ifa_next; /* Next item in list */
// char *ifa_name; /* Name of interface */
// unsigned int ifa_flags; /* Flags from SIOCGIFFLAGS */
// struct sockaddr *ifa_addr; /* Address of interface */
// struct sockaddr *ifa_netmask; /* Netmask of interface */
// union {
// struct sockaddr *ifu_broadaddr;
// /* Broadcast address of interface */
// struct sockaddr *ifu_dstaddr;
// /* Point-to-point destination address */
// };
// #define ifa_broadaddr ifa_ifu.ifu_broadaddr
// #define ifa_dstaddr ifa_ifu.ifu_dstaddr
// void *ifa_data; /* Address-specific data */
// };
//
// struct sockaddr {
// unsigned short sa_family; // address family, AF_xxx
// char sa_data[14]; // 14 bytes of protocol address
// };
//
//
// // IPv4 AF_INET sockets:
//
// struct sockaddr_in {
// short sin_family; // e.g. AF_INET, AF_INET6
// unsigned short sin_port; // e.g. htons(3490)
// struct in_addr sin_addr; // see struct in_addr, below
// char sin_zero[8]; // zero this if you want to
// };
//
// typedef uint32_t in_addr_t;
//
// struct in_addr {
// uint32_t s_addr; // load with inet_aton()
// };
struct IP_Types
{
enum Protocol // update record/protocolstr.cc when modified
{
ICMP = 1,
TCP = 6,
UDP = 17
};
enum TCP_Flags
{
FIN = 0x01,
SYN = 0x02,
RST = 0x04,
PUSH = 0x08,
ACK = 0x10,
URG = 0x20,
ECE = 0x40,
CWR = 0x80,
TCP_Flags_MASK = (CWR << 1) - 1
};
enum class IP_Fragment
{
RESERVED = 0x8000,
DONT_FRAGMENT = 0x4000,
MORE_FRAGMENTS = 0x2000,
MASK = 0x1fff
};
struct Ethernet_Header // http://en.wikipedia.org/wiki/EtherType
{
u_char destMac[6]; // Destination host MAC address
u_char srcMac[6]; // Source host MAC address
u_short ether_type; // IP? ARP? RARP? etc
};
struct IP_Header
{
u_char hdrLength:4, // in 4-byte words
version:4;
u_char tos; // type of service
u_short length; // total length
u_short identification;
u_short fragmentOffset;
u_char timeToLive;
u_char protocol;
u_short checkSum;
struct in_addr sourceAddr;
struct in_addr destAddr;
};
struct TCP_Header
{
u_short sourcePort;
u_short destPort;
uint32_t sequenceNr;
uint32_t ackNumber;
u_char dataOffset; // data offset,
// (((th)->th_offx2 & 0xf0) >> 4)
u_char flags;
u_short window;
u_short checkSum;
u_short urgentPtr;
};
struct UDP_Header // udp header length: 8 bytes
{
u_short sourcePort;
u_short destPort;
u_short length;
u_short checkSum;
};
struct ICMP_Header
{
u_char type;
u_char code;
u_short chksum;
u_short ident;
u_short seqnum;
}; // icmp header length: 8 bytes
enum Offsets // offsets to the various headers
{ // the Ethernet header starts at `d_packet'
ETHER_OFFSET = 0,
IP_OFFSET = ETHER_OFFSET + sizeof(Ethernet_Header),
TCP_OFFSET = IP_OFFSET + sizeof(IP_Header),
UDP_OFFSET = TCP_OFFSET,
ICMP_OFFSET = TCP_OFFSET,
};
enum SizeofTCPheader
{
SIZEOF_ETHERNET_HEADER = IP_OFFSET,
};
template <typename Type>
static Type const &get(u_char const *packet);
};
//static
template <>
inline IP_Types::IP_Header const &IP_Types::get(u_char const *packet)
{
return *reinterpret_cast<IP_Header const *>(packet + IP_OFFSET);
}
//static
template <>
inline IP_Types::TCP_Header const &IP_Types::get(u_char const *packet)
{
return *reinterpret_cast<TCP_Header const *>(packet + TCP_OFFSET);
}
//static
template <>
inline IP_Types::UDP_Header const &IP_Types::get(u_char const *packet)
{
return *reinterpret_cast<UDP_Header const *>(packet + UDP_OFFSET);
}
//static
template <>
inline IP_Types::ICMP_Header const &IP_Types::get(u_char const *packet)
{
return *reinterpret_cast<ICMP_Header const *>(packet + ICMP_OFFSET);
}
#endif
|
