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
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
|
--
-- pcap.lua: libpcap file format
--
-- Copyright (c) 2017, Přemysl Janouch <p.janouch@gmail.com>
--
-- 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 THE AUTHOR DISCLAIMS ALL WARRANTIES
-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR 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.
--
local detect = function (c)
local magic = c:u32 ()
return magic == 0xa1b2c3d4 or magic == 0xd4c3b2a1
end
local detect_ng = function (c)
local magic = c (9):u32 ()
return c:u32 () == 0x0a0d0d0a
and (magic == 0x1a2b3c4d or magic == 0x4d3c2b1a)
end
-- Specified in http://www.tcpdump.org/linktypes.html
local link_types = {
[0] = "NULL",
[1] = "ETHERNET",
[3] = "AX25",
[6] = "IEEE802_5",
[7] = "ARCNET_BSD",
[8] = "SLIP",
[9] = "PPP",
[10] = "FDDI",
[50] = "PPP_HDLC",
[51] = "PPP_ETHER",
[100] = "ATM_RFC1483",
[101] = "RAW",
[104] = "C_HDLC",
[105] = "IEEE802_11",
[107] = "FRELAY",
[108] = "LOOP",
[113] = "LINUX_SLL",
[114] = "LTALK",
[117] = "PFLOG",
[119] = "IEEE802_11_PRISM",
[122] = "IP_OVER_FC",
[123] = "SUNATM",
[127] = "IEEE802_11_RADIOTAP",
[129] = "ARCNET_LINUX",
[138] = "APPLE_IP_OVER_IEEE1394",
[139] = "MTP2_WITH_PHDR",
[140] = "MTP2",
[141] = "MTP3",
[142] = "SCCP",
[143] = "DOCSIS",
[144] = "LINUX_IRDA",
[147] = "USER0",
[148] = "USER1",
[149] = "USER2",
[150] = "USER3",
[151] = "USER4",
[152] = "USER5",
[153] = "USER6",
[154] = "USER7",
[155] = "USER8",
[156] = "USER9",
[157] = "USER10",
[158] = "USER11",
[159] = "USER12",
[160] = "USER13",
[161] = "USER14",
[162] = "USER15",
[163] = "IEEE802_11_AVS",
[165] = "BACNET_MS_TP",
[166] = "PPP_PPPD",
[169] = "GPRS_LLC",
[170] = "GPF_T",
[171] = "GPF_F",
[177] = "LINUX_LAPD",
[187] = "BLUETOOTH_HCI_H4",
[189] = "USB_LINUX",
[192] = "PPI",
[195] = "IEEE802_15_4",
[196] = "SITA",
[197] = "ERF",
[201] = "BLUETOOTH_HCI_H4_WITH_PHDR",
[202] = "AX25_KISS",
[203] = "LAPD",
[204] = "PPP_WITH_DIR",
[205] = "C_HDLC_WITH_DIR",
[206] = "FRELAY_WITH_DIR",
[209] = "IPMB_LINUX",
[215] = "IEEE802_15_4_NONASK_PHY",
[220] = "USB_LINUX_MMAPPED",
[224] = "FC_2",
[225] = "FC_2_WITH_FRAME_DELIMS",
[226] = "IPNET",
[227] = "CAN_SOCKETCAN",
[228] = "IPV4",
[229] = "IPV6",
[230] = "IEEE802_15_4_NOFCS",
[231] = "DBUS",
[235] = "DVB_CI",
[236] = "MUX27010",
[237] = "STANAG_5066_D_PDU",
[239] = "NFLOG",
[240] = "NETANALYZER",
[241] = "NETANALYZER_TRANSPARENT",
[242] = "IPOIB",
[243] = "MPEG_2_TS",
[244] = "NG40",
[245] = "NFC_LLCP",
[247] = "INFINIBAND",
[248] = "SCTP",
[249] = "USBPCAP",
[250] = "RTAC_SERIAL",
[251] = "BLUETOOTH_LE_LL",
[253] = "NETLINK",
[254] = "BLUETOOTH_LINUX_MONITOR",
[255] = "BLUETOOTH_BREDR_BB",
[256] = "BLUETOOTH_LE_LL_WITH_PHDR",
[257] = "PROFIBUS_DL",
[258] = "PKTAP",
[259] = "EPON",
[260] = "IPMI_HPM_2",
[261] = "ZWAVE_R1_R2",
[262] = "ZWAVE_R3",
[263] = "WATTSTOPPER_DLM",
[264] = "ISO_14443",
[265] = "RDS",
[266] = "USB_DARWIN"
}
-- As described by https://wiki.wireshark.org/Development/LibpcapFileFormat
local decode = function (c)
if not detect (c ()) then error ("not a PCAP file") end
c.endianity = "le"
c:u32 ("PCAP magic: %s", function (u32)
if u32 == 0xa1b2c3d4 then return "little-endian" end
c.endianity = "be"
return "big-endian"
end)
local p, vmajor, vminor = c.position, c:u16 (), c:u16 ()
c (p, c.position - 1):mark ("PCAP version: %d.%d", vmajor, vminor)
local zone = c:i32 ("UTC to local TZ correction: %d seconds")
local sigfigs = c:u32 ("timestamp accuracy")
local snaplen = c:u32 ("max. length of captured packets")
local network = c:u32 ("data link type: %s", function (u32)
name = link_types[u32]
if name then return name end
return "unknown: %d", u32
end)
local i = 0
while not c.eof do
c (c.position, c.position + 23):mark ("PCAP record %d header", i)
i = i + 1
local p, ts_sec, ts_usec = p, c:u32 (), c:u32 ()
c (p, c.position - 1):mark ("timestamp: %s.%06d",
os.date ("!%F %T", ts_sec + zonen), ts_usec)
local incl_len = c:u32 ("included record length")
local orig_len = c:u32 ("original record length")
local p = c.position
c.position = c.position + incl_len
-- TODO: also decode record contents as per the huge table
c (p, c.position - 1):mark ("PCAP record %d data", i)
end
end
hex.register { type="pcap", detect=detect, decode=decode }
local block_types = {
[0x0a0d0d0a] = "Section Header Block",
[0x00000001] = "Interface Description Block",
[0x00000003] = "Simple Packet Block",
[0x00000004] = "Name Resolution Block",
[0x00000005] = "Interface Statistics Block",
[0x00000006] = "Enhanced Packet Block",
[0x00000BAD] = "Custom Block",
[0x40000BAD] = "Custom Block"
}
local decode_shb = function (c)
local magic = c:u32 ()
local p, vmajor, vminor = c.position, c:u16 (), c:u16 ()
c (p, c.position - 1):mark ("PCAPNG version: %d.%d", vmajor, vminor)
-- XXX: what exactly does section_len mean?
local section_len = c:u64 ("section length: %d")
while not c.eof do
-- TODO: decode the meaning of options as well
local type = c:u16 ("option type: %d")
local length = c:u16 ("option length: %d")
local p = c.position
c.position = c.position + length + (-length & 3)
c (p, c.position - 1):mark ("option value")
end
end
local block_decoders = {
-- TODO: also decode other types of blocks
[0x0a0d0d0a] = decode_shb
}
-- As described by https://github.com/pcapng/pcapng
local decode_ng = function (c)
assert (c.position == 1)
if not detect_ng (c ()) then error ("not a PCAPNG file") end
c.endianity = "le"
c (9):u32 ("byte-order magic: %s", function (u32)
if u32 == 0x1a2b3c4d then return "little-endian" end
c.endianity = "be"
return "big-endian"
end)
while not c.eof do
local block_start = c.position
local block_type = c:u32 ("PCAPNG block type: %s", function (u32)
local name = block_types[u32]
if name then return name end
return "unknown: %d", u32
end)
local block_len = c:u32 ("PCAPNG block length: %d")
local data_start = c.position
c.position = block_start + block_len - 4
local decoder = block_decoders[block_type]
if decoder then decoder (c (data_start, c.position - 1)) end
c:u32 ("PCAPNG trailing block length: %d")
end
end
hex.register { type="pcapng", detect=detect_ng, decode=decode_ng }
|
