1 /*
2 * Decode and print Zephyr packets.
3 *
4 * https://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-ctype.h"
36
37 #include "netdissect.h"
38 #include "extract.h"
39
40 struct z_packet {
41 const char *version;
42 int numfields;
43 int kind;
44 const char *uid;
45 int port;
46 int auth;
47 int authlen;
48 const char *authdata;
49 const char *class;
50 const char *inst;
51 const char *opcode;
52 const char *sender;
53 const char *recipient;
54 const char *format;
55 int cksum;
56 int multi;
57 const char *multi_uid;
58 /* Other fields follow here.. */
59 };
60
61 enum z_packet_type {
62 Z_PACKET_UNSAFE = 0,
63 Z_PACKET_UNACKED,
64 Z_PACKET_ACKED,
65 Z_PACKET_HMACK,
66 Z_PACKET_HMCTL,
67 Z_PACKET_SERVACK,
68 Z_PACKET_SERVNAK,
69 Z_PACKET_CLIENTACK,
70 Z_PACKET_STAT
71 };
72
73 static const struct tok z_types[] = {
74 { Z_PACKET_UNSAFE, "unsafe" },
75 { Z_PACKET_UNACKED, "unacked" },
76 { Z_PACKET_ACKED, "acked" },
77 { Z_PACKET_HMACK, "hm-ack" },
78 { Z_PACKET_HMCTL, "hm-ctl" },
79 { Z_PACKET_SERVACK, "serv-ack" },
80 { Z_PACKET_SERVNAK, "serv-nak" },
81 { Z_PACKET_CLIENTACK, "client-ack" },
82 { Z_PACKET_STAT, "stat" },
83 { 0, NULL }
84 };
85
86 static char z_buf[256];
87
88 static const char *
parse_field(netdissect_options * ndo,const char ** pptr,int * len)89 parse_field(netdissect_options *ndo, const char **pptr, int *len)
90 {
91 const char *s;
92
93 /* Start of string */
94 s = *pptr;
95 /* Scan for the NUL terminator */
96 for (;;) {
97 if (*len == 0) {
98 /* Ran out of packet data without finding it */
99 return NULL;
100 }
101 if (GET_U_1(*pptr) == '\0') {
102 /* Found it */
103 break;
104 }
105 /* Keep scanning */
106 (*pptr)++;
107 (*len)--;
108 }
109 /* Skip the NUL terminator */
110 (*pptr)++;
111 (*len)--;
112 return s;
113 }
114
115 static const char *
z_triple(const char * class,const char * inst,const char * recipient)116 z_triple(const char *class, const char *inst, const char *recipient)
117 {
118 if (!*recipient)
119 recipient = "*";
120 snprintf(z_buf, sizeof(z_buf), "<%s,%s,%s>", class, inst, recipient);
121 z_buf[sizeof(z_buf)-1] = '\0';
122 return z_buf;
123 }
124
125 static const char *
str_to_lower(const char * string)126 str_to_lower(const char *string)
127 {
128 char *zb_string;
129
130 strncpy(z_buf, string, sizeof(z_buf));
131 z_buf[sizeof(z_buf)-1] = '\0';
132
133 zb_string = z_buf;
134 while (*zb_string) {
135 *zb_string = ND_ASCII_TOLOWER(*zb_string);
136 zb_string++;
137 }
138
139 return z_buf;
140 }
141
142 void
zephyr_print(netdissect_options * ndo,const u_char * cp,u_int length)143 zephyr_print(netdissect_options *ndo, const u_char *cp, u_int length)
144 {
145 struct z_packet z = {
146 NULL, /* version */
147 0, /* numfields */
148 0, /* kind */
149 NULL, /* uid */
150 0, /* port */
151 0, /* auth */
152 0, /* authlen */
153 NULL, /* authdata */
154 NULL, /* class */
155 NULL, /* inst */
156 NULL, /* opcode */
157 NULL, /* sender */
158 NULL, /* recipient */
159 NULL, /* format */
160 0, /* cksum */
161 0, /* multi */
162 NULL /* multi_uid */
163 };
164 const char *parse = (const char *) cp;
165 int parselen = length;
166 const char *s;
167 int lose = 0;
168
169 ndo->ndo_protocol = "zephyr";
170 /* squelch compiler warnings */
171
172 #define PARSE_STRING \
173 s = parse_field(ndo, &parse, &parselen); \
174 if (!s) lose = 1;
175
176 #define PARSE_FIELD_INT(field) \
177 PARSE_STRING \
178 if (!lose) field = strtol(s, 0, 16);
179
180 #define PARSE_FIELD_STR(field) \
181 PARSE_STRING \
182 if (!lose) field = s;
183
184 PARSE_FIELD_STR(z.version);
185 if (lose)
186 goto invalid;
187
188 if (strncmp(z.version, "ZEPH", 4))
189 return;
190
191 PARSE_FIELD_INT(z.numfields);
192 PARSE_FIELD_INT(z.kind);
193 PARSE_FIELD_STR(z.uid);
194 PARSE_FIELD_INT(z.port);
195 PARSE_FIELD_INT(z.auth);
196 PARSE_FIELD_INT(z.authlen);
197 PARSE_FIELD_STR(z.authdata);
198 PARSE_FIELD_STR(z.class);
199 PARSE_FIELD_STR(z.inst);
200 PARSE_FIELD_STR(z.opcode);
201 PARSE_FIELD_STR(z.sender);
202 PARSE_FIELD_STR(z.recipient);
203 PARSE_FIELD_STR(z.format);
204 PARSE_FIELD_INT(z.cksum);
205 PARSE_FIELD_INT(z.multi);
206 PARSE_FIELD_STR(z.multi_uid);
207
208 if (lose)
209 goto invalid;
210
211 ND_PRINT(" zephyr");
212 if (strncmp(z.version+4, "0.2", 3)) {
213 ND_PRINT(" v%s", z.version+4);
214 return;
215 }
216
217 ND_PRINT(" %s", tok2str(z_types, "type %d", z.kind));
218 if (z.kind == Z_PACKET_SERVACK) {
219 /* Initialization to silence warnings */
220 const char *ackdata = NULL;
221 PARSE_FIELD_STR(ackdata);
222 if (!lose && strcmp(ackdata, "SENT"))
223 ND_PRINT("/%s", str_to_lower(ackdata));
224 }
225 if (*z.sender) ND_PRINT(" %s", z.sender);
226
227 if (!strcmp(z.class, "USER_LOCATE")) {
228 if (!strcmp(z.opcode, "USER_HIDE"))
229 ND_PRINT(" hide");
230 else if (!strcmp(z.opcode, "USER_UNHIDE"))
231 ND_PRINT(" unhide");
232 else
233 ND_PRINT(" locate %s", z.inst);
234 return;
235 }
236
237 if (!strcmp(z.class, "ZEPHYR_ADMIN")) {
238 ND_PRINT(" zephyr-admin %s", str_to_lower(z.opcode));
239 return;
240 }
241
242 if (!strcmp(z.class, "ZEPHYR_CTL")) {
243 if (!strcmp(z.inst, "CLIENT")) {
244 if (!strcmp(z.opcode, "SUBSCRIBE") ||
245 !strcmp(z.opcode, "SUBSCRIBE_NODEFS") ||
246 !strcmp(z.opcode, "UNSUBSCRIBE")) {
247
248 ND_PRINT(" %ssub%s", strcmp(z.opcode, "SUBSCRIBE") ? "un" : "",
249 strcmp(z.opcode, "SUBSCRIBE_NODEFS") ? "" :
250 "-nodefs");
251 if (z.kind != Z_PACKET_SERVACK) {
252 /* Initialization to silence warnings */
253 const char *c = NULL, *i = NULL, *r = NULL;
254 PARSE_FIELD_STR(c);
255 PARSE_FIELD_STR(i);
256 PARSE_FIELD_STR(r);
257 if (!lose) ND_PRINT(" %s", z_triple(c, i, r));
258 }
259 return;
260 }
261
262 if (!strcmp(z.opcode, "GIMME")) {
263 ND_PRINT(" ret");
264 return;
265 }
266
267 if (!strcmp(z.opcode, "GIMMEDEFS")) {
268 ND_PRINT(" gimme-defs");
269 return;
270 }
271
272 if (!strcmp(z.opcode, "CLEARSUB")) {
273 ND_PRINT(" clear-subs");
274 return;
275 }
276
277 ND_PRINT(" %s", str_to_lower(z.opcode));
278 return;
279 }
280
281 if (!strcmp(z.inst, "HM")) {
282 ND_PRINT(" %s", str_to_lower(z.opcode));
283 return;
284 }
285
286 if (!strcmp(z.inst, "REALM")) {
287 if (!strcmp(z.opcode, "ADD_SUBSCRIBE"))
288 ND_PRINT(" realm add-subs");
289 if (!strcmp(z.opcode, "REQ_SUBSCRIBE"))
290 ND_PRINT(" realm req-subs");
291 if (!strcmp(z.opcode, "RLM_SUBSCRIBE"))
292 ND_PRINT(" realm rlm-sub");
293 if (!strcmp(z.opcode, "RLM_UNSUBSCRIBE"))
294 ND_PRINT(" realm rlm-unsub");
295 return;
296 }
297 }
298
299 if (!strcmp(z.class, "HM_CTL")) {
300 ND_PRINT(" hm_ctl %s", str_to_lower(z.inst));
301 ND_PRINT(" %s", str_to_lower(z.opcode));
302 return;
303 }
304
305 if (!strcmp(z.class, "HM_STAT")) {
306 if (!strcmp(z.inst, "HMST_CLIENT") && !strcmp(z.opcode, "GIMMESTATS")) {
307 ND_PRINT(" get-client-stats");
308 return;
309 }
310 }
311
312 if (!strcmp(z.class, "WG_CTL")) {
313 ND_PRINT(" wg_ctl %s", str_to_lower(z.inst));
314 ND_PRINT(" %s", str_to_lower(z.opcode));
315 return;
316 }
317
318 if (!strcmp(z.class, "LOGIN")) {
319 if (!strcmp(z.opcode, "USER_FLUSH")) {
320 ND_PRINT(" flush_locs");
321 return;
322 }
323
324 if (!strcmp(z.opcode, "NONE") ||
325 !strcmp(z.opcode, "OPSTAFF") ||
326 !strcmp(z.opcode, "REALM-VISIBLE") ||
327 !strcmp(z.opcode, "REALM-ANNOUNCED") ||
328 !strcmp(z.opcode, "NET-VISIBLE") ||
329 !strcmp(z.opcode, "NET-ANNOUNCED")) {
330 ND_PRINT(" set-exposure %s", str_to_lower(z.opcode));
331 return;
332 }
333 }
334
335 if (!*z.recipient)
336 z.recipient = "*";
337
338 ND_PRINT(" to %s", z_triple(z.class, z.inst, z.recipient));
339 if (*z.opcode)
340 ND_PRINT(" op %s", z.opcode);
341 return;
342
343 invalid:
344 nd_print_invalid(ndo);
345 }
346