1 /*
2 * Decode and print Zephyr packets.
3 *
4 * http://web.mit.edu/zephyr/doc/protocol
5 *
6 * Copyright (c) 2001 Nickolai Zeldovich <kolya@MIT.EDU>
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that: (1) source code
11 * distributions retain the above copyright notice and this paragraph
12 * in its entirety, and (2) distributions including binary code include
13 * the above copyright notice and this paragraph in its entirety in
14 * the documentation or other materials provided with the distribution.
15 * The name of the author(s) may not be used to endorse or promote
16 * products derived from this software without specific prior written
17 * permission. THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY
18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE.
21 */
22
23 /* \summary: Zephyr printer */
24
25 #ifdef HAVE_CONFIG_H
26 #include "config.h"
27 #endif
28
29 #include <netdissect-stdinc.h>
30
31 #include <stdio.h>
32 #include <string.h>
33 #include <stdlib.h>
34
35 #include "netdissect.h"
36
37 struct z_packet {
38 const char *version;
39 int numfields;
40 int kind;
41 const char *uid;
42 int port;
43 int auth;
44 int authlen;
45 const char *authdata;
46 const char *class;
47 const char *inst;
48 const char *opcode;
49 const char *sender;
50 const char *recipient;
51 const char *format;
52 int cksum;
53 int multi;
54 const char *multi_uid;
55 /* Other fields follow here.. */
56 };
57
58 enum z_packet_type {
59 Z_PACKET_UNSAFE = 0,
60 Z_PACKET_UNACKED,
61 Z_PACKET_ACKED,
62 Z_PACKET_HMACK,
63 Z_PACKET_HMCTL,
64 Z_PACKET_SERVACK,
65 Z_PACKET_SERVNAK,
66 Z_PACKET_CLIENTACK,
67 Z_PACKET_STAT
68 };
69
70 static const struct tok z_types[] = {
71 { Z_PACKET_UNSAFE, "unsafe" },
72 { Z_PACKET_UNACKED, "unacked" },
73 { Z_PACKET_ACKED, "acked" },
74 { Z_PACKET_HMACK, "hm-ack" },
75 { Z_PACKET_HMCTL, "hm-ctl" },
76 { Z_PACKET_SERVACK, "serv-ack" },
77 { Z_PACKET_SERVNAK, "serv-nak" },
78 { Z_PACKET_CLIENTACK, "client-ack" },
79 { Z_PACKET_STAT, "stat" },
80 { 0, NULL }
81 };
82
83 static char z_buf[256];
84
85 static const char *
parse_field(netdissect_options * ndo,const char ** pptr,int * len,int * truncated)86 parse_field(netdissect_options *ndo, const char **pptr, int *len, int *truncated)
87 {
88 const char *s;
89
90 /* Start of string */
91 s = *pptr;
92 /* Scan for the NUL terminator */
93 for (;;) {
94 if (*len == 0) {
95 /* Ran out of packet data without finding it */
96 return NULL;
97 }
98 if (!ND_TTEST(**pptr)) {
99 /* Ran out of captured data without finding it */
100 *truncated = 1;
101 return NULL;
102 }
103 if (**pptr == '\0') {
104 /* Found it */
105 break;
106 }
107 /* Keep scanning */
108 (*pptr)++;
109 (*len)--;
110 }
111 /* Skip the NUL terminator */
112 (*pptr)++;
113 (*len)--;
114 return s;
115 }
116
117 static const char *
z_triple(const char * class,const char * inst,const char * recipient)118 z_triple(const char *class, const char *inst, const char *recipient)
119 {
120 if (!*recipient)
121 recipient = "*";
122 snprintf(z_buf, sizeof(z_buf), "<%s,%s,%s>", class, inst, recipient);
123 z_buf[sizeof(z_buf)-1] = '\0';
124 return z_buf;
125 }
126
127 static const char *
str_to_lower(const char * string)128 str_to_lower(const char *string)
129 {
130 char *zb_string;
131
132 strncpy(z_buf, string, sizeof(z_buf));
133 z_buf[sizeof(z_buf)-1] = '\0';
134
135 zb_string = z_buf;
136 while (*zb_string) {
137 *zb_string = tolower((unsigned char)(*zb_string));
138 zb_string++;
139 }
140
141 return z_buf;
142 }
143
144 void
zephyr_print(netdissect_options * ndo,const u_char * cp,int length)145 zephyr_print(netdissect_options *ndo, const u_char *cp, int length)
146 {
147 struct z_packet z;
148 const char *parse = (const char *) cp;
149 int parselen = length;
150 const char *s;
151 int lose = 0;
152 int truncated = 0;
153
154 /* squelch compiler warnings */
155
156 z.kind = 0;
157 z.class = 0;
158 z.inst = 0;
159 z.opcode = 0;
160 z.sender = 0;
161 z.recipient = 0;
162
163 #define PARSE_STRING \
164 s = parse_field(ndo, &parse, &parselen, &truncated); \
165 if (truncated) goto trunc; \
166 if (!s) lose = 1;
167
168 #define PARSE_FIELD_INT(field) \
169 PARSE_STRING \
170 if (!lose) field = strtol(s, 0, 16);
171
172 #define PARSE_FIELD_STR(field) \
173 PARSE_STRING \
174 if (!lose) field = s;
175
176 PARSE_FIELD_STR(z.version);
177 if (lose) return;
178 if (strncmp(z.version, "ZEPH", 4))
179 return;
180
181 PARSE_FIELD_INT(z.numfields);
182 PARSE_FIELD_INT(z.kind);
183 PARSE_FIELD_STR(z.uid);
184 PARSE_FIELD_INT(z.port);
185 PARSE_FIELD_INT(z.auth);
186 PARSE_FIELD_INT(z.authlen);
187 PARSE_FIELD_STR(z.authdata);
188 PARSE_FIELD_STR(z.class);
189 PARSE_FIELD_STR(z.inst);
190 PARSE_FIELD_STR(z.opcode);
191 PARSE_FIELD_STR(z.sender);
192 PARSE_FIELD_STR(z.recipient);
193 PARSE_FIELD_STR(z.format);
194 PARSE_FIELD_INT(z.cksum);
195 PARSE_FIELD_INT(z.multi);
196 PARSE_FIELD_STR(z.multi_uid);
197
198 if (lose)
199 goto trunc;
200
201 ND_PRINT((ndo, " zephyr"));
202 if (strncmp(z.version+4, "0.2", 3)) {
203 ND_PRINT((ndo, " v%s", z.version+4));
204 return;
205 }
206
207 ND_PRINT((ndo, " %s", tok2str(z_types, "type %d", z.kind)));
208 if (z.kind == Z_PACKET_SERVACK) {
209 /* Initialization to silence warnings */
210 const char *ackdata = NULL;
211 PARSE_FIELD_STR(ackdata);
212 if (!lose && strcmp(ackdata, "SENT"))
213 ND_PRINT((ndo, "/%s", str_to_lower(ackdata)));
214 }
215 if (*z.sender) ND_PRINT((ndo, " %s", z.sender));
216
217 if (!strcmp(z.class, "USER_LOCATE")) {
218 if (!strcmp(z.opcode, "USER_HIDE"))
219 ND_PRINT((ndo, " hide"));
220 else if (!strcmp(z.opcode, "USER_UNHIDE"))
221 ND_PRINT((ndo, " unhide"));
222 else
223 ND_PRINT((ndo, " locate %s", z.inst));
224 return;
225 }
226
227 if (!strcmp(z.class, "ZEPHYR_ADMIN")) {
228 ND_PRINT((ndo, " zephyr-admin %s", str_to_lower(z.opcode)));
229 return;
230 }
231
232 if (!strcmp(z.class, "ZEPHYR_CTL")) {
233 if (!strcmp(z.inst, "CLIENT")) {
234 if (!strcmp(z.opcode, "SUBSCRIBE") ||
235 !strcmp(z.opcode, "SUBSCRIBE_NODEFS") ||
236 !strcmp(z.opcode, "UNSUBSCRIBE")) {
237
238 ND_PRINT((ndo, " %ssub%s", strcmp(z.opcode, "SUBSCRIBE") ? "un" : "",
239 strcmp(z.opcode, "SUBSCRIBE_NODEFS") ? "" :
240 "-nodefs"));
241 if (z.kind != Z_PACKET_SERVACK) {
242 /* Initialization to silence warnings */
243 const char *c = NULL, *i = NULL, *r = NULL;
244 PARSE_FIELD_STR(c);
245 PARSE_FIELD_STR(i);
246 PARSE_FIELD_STR(r);
247 if (!lose) ND_PRINT((ndo, " %s", z_triple(c, i, r)));
248 }
249 return;
250 }
251
252 if (!strcmp(z.opcode, "GIMME")) {
253 ND_PRINT((ndo, " ret"));
254 return;
255 }
256
257 if (!strcmp(z.opcode, "GIMMEDEFS")) {
258 ND_PRINT((ndo, " gimme-defs"));
259 return;
260 }
261
262 if (!strcmp(z.opcode, "CLEARSUB")) {
263 ND_PRINT((ndo, " clear-subs"));
264 return;
265 }
266
267 ND_PRINT((ndo, " %s", str_to_lower(z.opcode)));
268 return;
269 }
270
271 if (!strcmp(z.inst, "HM")) {
272 ND_PRINT((ndo, " %s", str_to_lower(z.opcode)));
273 return;
274 }
275
276 if (!strcmp(z.inst, "REALM")) {
277 if (!strcmp(z.opcode, "ADD_SUBSCRIBE"))
278 ND_PRINT((ndo, " realm add-subs"));
279 if (!strcmp(z.opcode, "REQ_SUBSCRIBE"))
280 ND_PRINT((ndo, " realm req-subs"));
281 if (!strcmp(z.opcode, "RLM_SUBSCRIBE"))
282 ND_PRINT((ndo, " realm rlm-sub"));
283 if (!strcmp(z.opcode, "RLM_UNSUBSCRIBE"))
284 ND_PRINT((ndo, " realm rlm-unsub"));
285 return;
286 }
287 }
288
289 if (!strcmp(z.class, "HM_CTL")) {
290 ND_PRINT((ndo, " hm_ctl %s", str_to_lower(z.inst)));
291 ND_PRINT((ndo, " %s", str_to_lower(z.opcode)));
292 return;
293 }
294
295 if (!strcmp(z.class, "HM_STAT")) {
296 if (!strcmp(z.inst, "HMST_CLIENT") && !strcmp(z.opcode, "GIMMESTATS")) {
297 ND_PRINT((ndo, " get-client-stats"));
298 return;
299 }
300 }
301
302 if (!strcmp(z.class, "WG_CTL")) {
303 ND_PRINT((ndo, " wg_ctl %s", str_to_lower(z.inst)));
304 ND_PRINT((ndo, " %s", str_to_lower(z.opcode)));
305 return;
306 }
307
308 if (!strcmp(z.class, "LOGIN")) {
309 if (!strcmp(z.opcode, "USER_FLUSH")) {
310 ND_PRINT((ndo, " flush_locs"));
311 return;
312 }
313
314 if (!strcmp(z.opcode, "NONE") ||
315 !strcmp(z.opcode, "OPSTAFF") ||
316 !strcmp(z.opcode, "REALM-VISIBLE") ||
317 !strcmp(z.opcode, "REALM-ANNOUNCED") ||
318 !strcmp(z.opcode, "NET-VISIBLE") ||
319 !strcmp(z.opcode, "NET-ANNOUNCED")) {
320 ND_PRINT((ndo, " set-exposure %s", str_to_lower(z.opcode)));
321 return;
322 }
323 }
324
325 if (!*z.recipient)
326 z.recipient = "*";
327
328 ND_PRINT((ndo, " to %s", z_triple(z.class, z.inst, z.recipient)));
329 if (*z.opcode)
330 ND_PRINT((ndo, " op %s", z.opcode));
331 return;
332
333 trunc:
334 ND_PRINT((ndo, " [|zephyr] (%d)", length));
335 return;
336 }
337