1 /* osi-utils.c
2 * Routines for ISO/OSI network and transport protocol packet disassembly
3 * Main entrance point and common functions
4 *
5 * Laurent Deniel <laurent.deniel@free.fr>
6 * Ralf Schneider <Ralf.Schneider@t-online.de>
7 *
8 * Wireshark - Network traffic analyzer
9 * By Gerald Combs <gerald@wireshark.org>
10 * Copyright 1998 Gerald Combs
11 *
12 * SPDX-License-Identifier: GPL-2.0-or-later
13 */
14
15 #include "config.h"
16
17 #include <stdio.h>
18 #include <string.h>
19 #include <glib.h>
20
21 #include "tvbuff.h"
22 #include "osi-utils.h"
23 #include "address.h"
24 #include "address_types.h"
25
26 static void print_nsap_net_buf( const guint8 *, int, gchar *, int);
27 static void print_area_buf ( const guint8 *, int, gchar *, int);
28 static void print_address_prefix_buf ( const guint8 *, int, gchar *, int);
29
30 /*
31 * XXX - shouldn't there be a centralized routine for dissecting NSAPs?
32 * See also "dissect_atm_nsap()" in epan/dissectors/packet-arp.c and
33 * "dissect_nsap()" in epan/dissectors/packet-isup.c.
34 */
35 gchar *
print_nsap_net(wmem_allocator_t * scope,tvbuff_t * tvb,const gint offset,int length)36 print_nsap_net( wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, int length )
37 {
38 gchar *cur;
39
40 cur = (gchar *)wmem_alloc(scope, MAX_NSAP_LEN * 3 + 50);
41 print_nsap_net_buf( tvb_get_ptr(tvb, offset, length), length, cur, MAX_NSAP_LEN * 3 + 50);
42 return( cur );
43 }
44
45 static void
print_nsap_net_buf(const guint8 * ad,int length,gchar * buf,int buf_len)46 print_nsap_net_buf( const guint8 *ad, int length, gchar *buf, int buf_len)
47 {
48 gchar *cur;
49
50 /* to do : NSAP / NET decoding */
51
52 if ( (length <= 0 ) || ( length > MAX_NSAP_LEN ) ) {
53 (void) g_strlcpy(buf, "<Invalid length of NSAP>", buf_len);
54 return;
55 }
56 cur = buf;
57 if ( ( length == RFC1237_NSAP_LEN ) || ( length == RFC1237_NSAP_LEN + 1 ) ) {
58 print_area_buf(ad, RFC1237_FULLAREA_LEN, cur, buf_len);
59 cur += strlen( cur );
60 print_system_id_buf( ad + RFC1237_FULLAREA_LEN, RFC1237_SYSTEMID_LEN, cur, (int) (buf_len-(cur-buf)));
61 cur += strlen( cur );
62 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "[%02x]",
63 ad[ RFC1237_FULLAREA_LEN + RFC1237_SYSTEMID_LEN ] );
64 if ( length == RFC1237_NSAP_LEN + 1 ) {
65 g_snprintf(cur, (int) (buf_len-(cur-buf)), "-%02x", ad[ length -1 ] );
66 }
67 }
68 else { /* probably format as standard */
69 /* XXX - this is an NSAP, not an area address/address prefix */
70 print_area_buf( ad, length, buf, buf_len);
71 }
72 } /* print_nsap */
73
74 gchar *
print_system_id(wmem_allocator_t * scope,const guint8 * ad,int length)75 print_system_id(wmem_allocator_t* scope, const guint8 *ad, int length )
76 {
77 gchar *cur;
78
79 cur = (gchar *)wmem_alloc(scope, MAX_SYSTEMID_LEN * 3 + 5);
80 print_system_id_buf(ad, length, cur, MAX_SYSTEMID_LEN * 3 + 5);
81 return( cur );
82 }
83
84 gchar *
tvb_print_system_id(wmem_allocator_t * scope,tvbuff_t * tvb,const gint offset,int length)85 tvb_print_system_id( wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, int length )
86 {
87 return( print_system_id(scope, tvb_get_ptr(tvb, offset, length), length) );
88 }
89
90 void
print_system_id_buf(const guint8 * ad,int length,gchar * buf,int buf_len)91 print_system_id_buf( const guint8 *ad, int length, gchar *buf, int buf_len)
92 {
93 gchar *cur;
94 int tmp;
95
96 if ( ( length <= 0 ) || ( length > MAX_SYSTEMID_LEN ) ) {
97 (void) g_strlcpy(buf, "<Invalid length of SYSTEM ID>", buf_len);
98 return;
99 }
100
101 cur = buf;
102 if ( ( 6 == length ) || /* System-ID */
103 ( 7 == length ) || /* LAN-ID */
104 ( 8 == length )) { /* LSP-ID */
105 cur += g_snprintf(cur, buf_len, "%02x%02x.%02x%02x.%02x%02x", ad[0], ad[1],
106 ad[2], ad[3], ad[4], ad[5] );
107 if ( ( 7 == length ) ||
108 ( 8 == length )) {
109 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), ".%02x", ad[6] );
110 }
111 if ( 8 == length ) {
112 g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "-%02x", ad[7] );
113 }
114 }
115 else {
116 tmp = 0;
117 while ( tmp < length / 4 ) { /* 16 / 4 == 4 > four Octets left to print */
118 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
119 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
120 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
121 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x.", ad[tmp++] );
122 }
123 if ( 1 == tmp ) { /* Special case for Designated IS */
124 cur--;
125 g_snprintf(cur, (gulong) (buf_len-(cur-buf)), ".%02x", ad[tmp] );
126 }
127 else {
128 for ( ; tmp < length; ) { /* print the rest without dot */
129 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
130 }
131 }
132 }
133 }
134
135 gchar *
print_area(wmem_allocator_t * scope,tvbuff_t * tvb,const gint offset,int length)136 print_area(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, int length)
137 {
138 gchar *cur;
139
140 cur = (gchar *)wmem_alloc(scope, MAX_AREA_LEN * 3 + 20);
141 print_area_buf(tvb_get_ptr(tvb, offset, length), length, cur, MAX_AREA_LEN * 3 + 20);
142 return cur;
143 }
144
145 /*
146 * Note: length is in units of half-octets.
147 */
148 gchar *
print_address_prefix(wmem_allocator_t * scope,tvbuff_t * tvb,const gint offset,int length)149 print_address_prefix(wmem_allocator_t *scope, tvbuff_t *tvb, const gint offset, int length)
150 {
151 gchar *cur;
152
153 cur = (gchar *)wmem_alloc(scope, MAX_AREA_LEN * 3 + 20);
154 print_address_prefix_buf(tvb_get_ptr(tvb, offset, (length+1)/2), length, cur, MAX_AREA_LEN * 3 + 20);
155 return cur;
156 }
157
158 /*
159 * Note: length is in units of octets.
160 */
161 static void
print_area_buf(const guint8 * ad,int length,gchar * buf,int buf_len)162 print_area_buf(const guint8 *ad, int length, gchar *buf, int buf_len)
163 {
164 print_address_prefix_buf(ad, length*2, buf, buf_len);
165 }
166
167 /*
168 * Note: length is in units of half-octets.
169 */
170 static void
print_address_prefix_buf(const guint8 * ad,int length,gchar * buf,int buf_len)171 print_address_prefix_buf(const guint8 *ad, int length, gchar *buf, int buf_len)
172 {
173 gchar *cur;
174 int tmp = 0;
175
176 /* to do : all real area decoding now: NET is assumed if id len is 1 more byte
177 */
178 if (length <= 0 || length > MAX_AREA_LEN*2) {
179 (void) g_strlcpy(buf, "<Invalid length of AREA>", buf_len);
180 return;
181 }
182
183 cur = buf;
184 /* Check the AFI and length. */
185 if ( ( ( NSAP_IDI_ISO_DCC_BIN == *ad )
186 || ( NSAP_IDI_ISO_6523_ICD_BIN == *ad )
187 )
188 &&
189 ( ( RFC1237_FULLAREA_LEN*2 == length )
190 || ( (RFC1237_FULLAREA_LEN + 1)*2 == length )
191 )
192 ) { /* AFI is good and length is long enough */
193
194 /* The AFI is either ISO DCC, binary or ISO 6523-ICD, binary,
195 * and the area length corresponds either to the area length
196 * for RFC 1237 (GOSIP) addresses or that length + 1.
197 *
198 * XXX - RFC 1237 doesn't mention ISO DCC, binary, as a valid
199 * AFI; is that from GOSIP Version 1? If it's ISO DCC, binary,
200 * the IDI is 3 digits, i.e. 1 1/2 octets.
201 */
202 /* there used to be a check for (length > RFC1237_FULLAREA_LEN + 1) here,
203 * in order to report an invalied length of AREA for DCC / ISO 6523 AFI,
204 * but that can *never* be the case because the if() test above explicitly
205 * tests for (length == RFC1237_FULLAREA_LEN) or (length == RFC1237_FULLAREA_LEN + 1)
206 */
207
208 /* Show the one-octet AFI, the two-octet IDI, the one-octet DFI, the
209 * 3-octet AA, and the 2 reserved octets.
210 */
211 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "[%02x|%02x:%02x][%02x|%02x:%02x:%02x|%02x:%02x]",
212 ad[0], ad[1], ad[2], ad[3], ad[4],
213 ad[5], ad[6], ad[7], ad[8] );
214 /* Show the 2-octet RD and the 2-octet Area. */
215 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "[%02x:%02x|%02x:%02x]",
216 ad[9], ad[10], ad[11], ad[12] );
217 /* Show whatever the heck this is; it's not specified by RFC 1237,
218 * but we also handle 14-octet areas. Is it the "Designated IS"
219 * stuff mentioned below? (I didn't find anything in the IS-IS
220 * spec about that.)
221 */
222 if ( (RFC1237_FULLAREA_LEN + 1)*2 == length )
223 g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "-[%02x]", ad[13] );
224 }
225 else {
226 /* This doesn't look like a full RFC 1237 IS-IS area, so all we know
227 * is that the first octet is an AFI. Print it separately from all
228 * the other octets.
229 */
230 if ( length == RFC1237_AREA_LEN*2 ) {
231 /* XXX - RFC1237_AREA_LEN, which is 3 octets, doesn't seem to
232 * correspond to anything in RFC 1237. Where did it come from?
233 */
234 g_snprintf(buf, buf_len, "%02x.%02x%02x", ad[0], ad[1], ad[2] );
235 return;
236 }
237 if ( length == 4*2 ) {
238 g_snprintf(buf, buf_len, "%02x%02x%02x%02x", ad[0], ad[1], ad[2], ad[3] );
239 return;
240 }
241 while ( tmp < length / 8 ) { /* 32/8==4 > four Octets left to print */
242 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
243 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
244 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
245 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x.", ad[tmp++] );
246 }
247 if ( 2 == tmp ) { /* Special case for Designated IS */
248 cur--;
249 g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "-%02x", ad[tmp] );
250 }
251 else {
252 for ( ; tmp < length / 2; ) { /* print the rest without dot or dash */
253 cur += g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%02x", ad[tmp++] );
254 }
255 /* Odd half-octet? */
256 if (length & 1) {
257 /* Yes - print it (it's the upper half-octet) */
258 g_snprintf(cur, (gulong) (buf_len-(cur-buf)), "%x", (ad[tmp] & 0xF0)>>4 );
259 }
260 }
261 }
262 } /* print_address_prefix_buf */
263
264 /******************************************************************************
265 * OSI Address Type
266 ******************************************************************************/
267 static int osi_address_type = -1;
268
osi_address_to_str(const address * addr,gchar * buf,int buf_len)269 static int osi_address_to_str(const address* addr, gchar *buf, int buf_len)
270 {
271 print_nsap_net_buf((const guint8 *)addr->data, addr->len, buf, buf_len);
272 return (int)strlen(buf)+1;
273 }
274
osi_address_str_len(const address * addr _U_)275 static int osi_address_str_len(const address* addr _U_)
276 {
277 return MAX_NSAP_LEN * 3 + 50;
278 }
279
get_osi_address_type(void)280 int get_osi_address_type(void)
281 {
282 return osi_address_type;
283 }
284
register_osi_address_type(void)285 void register_osi_address_type(void)
286 {
287 if (osi_address_type != -1)
288 return;
289
290 osi_address_type = address_type_dissector_register("AT_OSI", "OSI Address", osi_address_to_str, osi_address_str_len, NULL, NULL, NULL, NULL, NULL);
291 }
292
293
294 /*
295 * Editor modelines
296 *
297 * Local Variables:
298 * c-basic-offset: 2
299 * tab-width: 8
300 * indent-tabs-mode: nil
301 * End:
302 *
303 * ex: set shiftwidth=2 tabstop=8 expandtab:
304 * :indentSize=2:tabSize=8:noTabs=true:
305 */
306