xref: /freebsd/contrib/tcpdump/print-zep.c (revision aa1a8ff2d6dbc51ef058f46f3db5a8bb77967145)
1 /*
2  * Copyright (c) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that: (1) source code distributions
7  * retain the above copyright notice and this paragraph in its entirety, (2)
8  * distributions including binary code include the above copyright notice and
9  * this paragraph in its entirety in the documentation or other materials
10  * provided with the distribution, and (3) all advertising materials mentioning
11  * features or use of this software display the following acknowledgement:
12  * ``This product includes software developed by the University of California,
13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
14  * the University nor the names of its contributors may be used to endorse
15  * or promote products derived from this software without specific prior
16  * written permission.
17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
20  */
21 
22 /* \summary: ZigBee Encapsulation Protocol (ZEP) printer */
23 
24 #ifdef HAVE_CONFIG_H
25 #include <config.h>
26 #endif
27 
28 #include "netdissect-stdinc.h"
29 
30 #define ND_LONGJMP_FROM_TCHECK
31 #include "netdissect.h"
32 
33 #include "extract.h"
34 
35 /* From wireshark packet-zep.c:
36  *
37  ***********************************************************************
38  *
39  * ZEP Packets must be received in the following format:
40  *
41  * |UDP Header|  ZEP Header |IEEE 802.15.4 Packet|
42  * | 8 bytes  | 16/32 bytes |    <= 127 bytes    |
43  *
44  ***********************************************************************
45  *
46  * ZEP v1 Header will have the following format:
47  * |Preamble|Version|Channel ID|Device ID|CRC/LQI Mode|LQI Val|Reserved|Length|
48  * |2 bytes |1 byte |  1 byte  | 2 bytes |   1 byte   |1 byte |7 bytes |1 byte|
49  *
50  * ZEP v2 Header will have the following format (if type=1/Data):
51  * |Prmbl|Ver  |Type |ChnlID|DevID|C/L Mode|LQI|NTP TS|Seq#|Res |Len|
52  * | 2   | 1   | 1   | 1    | 2   | 1      | 1 | 8    | 4  | 10 | 1 |
53  *
54  * ZEP v2 Header will have the following format (if type=2/Ack):
55  * |Preamble|Version| Type |Sequence#|
56  * |2 bytes |1 byte |1 byte| 4 bytes |
57  *------------------------------------------------------------
58  */
59 
60 #define     JAN_1970        2208988800U
61 
62 /* Print timestamp */
63 static void zep_print_ts(netdissect_options *ndo, const u_char *p)
64 {
65 	int32_t i;
66 	uint32_t uf;
67 	uint32_t f;
68 	float ff;
69 
70 	i = GET_BE_U_4(p);
71 	uf = GET_BE_U_4(p + 4);
72 	ff = (float) uf;
73 	if (ff < 0.0)           /* some compilers are buggy */
74 		ff += FMAXINT;
75 	ff = (float) (ff / FMAXINT); /* shift radix point by 32 bits */
76 	f = (uint32_t) (ff * 1000000000.0);  /* treat fraction as parts per
77 						billion */
78 	ND_PRINT("%u.%09d", i, f);
79 
80 	/*
81 	 * print the time in human-readable format.
82 	 */
83 	if (i) {
84 		time_t seconds = i - JAN_1970;
85 		char time_buf[128];
86 
87 		ND_PRINT(" (%s)",
88 		    nd_format_time(time_buf, sizeof (time_buf), "%Y/%m/%d %H:%M:%S",
89 		      localtime(&seconds)));
90 	}
91 }
92 
93 /*
94  * Main function to print packets.
95  */
96 
97 void
98 zep_print(netdissect_options *ndo,
99 	  const u_char *bp, u_int len)
100 {
101 	uint8_t version, inner_len;
102 	uint32_t seq_no;
103 
104 	ndo->ndo_protocol = "zep";
105 
106 	nd_print_protocol_caps(ndo);
107 
108 	/* Preamble Code (must be "EX") */
109 	if (GET_U_1(bp) != 'E' || GET_U_1(bp + 1) != 'X') {
110 		ND_PRINT(" [Preamble Code: ");
111 		fn_print_char(ndo, GET_U_1(bp));
112 		fn_print_char(ndo, GET_U_1(bp + 1));
113 		ND_PRINT("]");
114 		nd_print_invalid(ndo);
115 		return;
116 	}
117 
118 	version = GET_U_1(bp + 2);
119 	ND_PRINT("v%u ", version);
120 
121 	if (version == 1) {
122 		/* ZEP v1 packet. */
123 		ND_LCHECK_U(len, 16);
124 		ND_PRINT("Channel ID %u, Device ID 0x%04x, ",
125 			 GET_U_1(bp + 3), GET_BE_U_2(bp + 4));
126 		if (GET_U_1(bp + 6))
127 			ND_PRINT("CRC, ");
128 		else
129 			ND_PRINT("LQI %u, ", GET_U_1(bp + 7));
130 		inner_len = GET_U_1(bp + 15);
131 		ND_PRINT("inner len = %u", inner_len);
132 
133 		bp += 16;
134 		len -= 16;
135 	} else {
136 		/* ZEP v2 packet. */
137 		if (GET_U_1(bp + 3) == 2) {
138 			/* ZEP v2 ack. */
139 			ND_LCHECK_U(len, 8);
140 			seq_no = GET_BE_U_4(bp + 4);
141 			ND_PRINT("ACK, seq# = %u", seq_no);
142 			inner_len = 0;
143 			bp += 8;
144 			len -= 8;
145 		} else {
146 			/* ZEP v2 data, or some other. */
147 			ND_LCHECK_U(len, 32);
148 			ND_PRINT("Type %u, Channel ID %u, Device ID 0x%04x, ",
149 				 GET_U_1(bp + 3), GET_U_1(bp + 4),
150 				 GET_BE_U_2(bp + 5));
151 			if (GET_U_1(bp + 7))
152 				ND_PRINT("CRC, ");
153 			else
154 				ND_PRINT("LQI %u, ", GET_U_1(bp + 8));
155 
156 			zep_print_ts(ndo, bp + 9);
157 			seq_no = GET_BE_U_4(bp + 17);
158 			inner_len = GET_U_1(bp + 31);
159 			ND_PRINT(", seq# = %u, inner len = %u",
160 				 seq_no, inner_len);
161 			bp += 32;
162 			len -= 32;
163 		}
164 	}
165 
166 	if (inner_len != 0) {
167 		/* Call 802.15.4 dissector. */
168 		ND_PRINT("\n\t");
169 		if (ieee802_15_4_print(ndo, bp, inner_len)) {
170 			ND_TCHECK_LEN(bp, len);
171 			bp += len;
172 			len = 0;
173 		}
174 	}
175 
176 	if (!ndo->ndo_suppress_default_print)
177 		ND_DEFAULTPRINT(bp, len);
178 	return;
179 invalid:
180 	nd_print_invalid(ndo);
181 }
182