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 #include <config.h>
26
27 #include "netdissect-stdinc.h"
28
29 #include <stdio.h>
30 #include <string.h>
31 #include <stdlib.h>
32
33 #include "netdissect-ctype.h"
34
35 #include "netdissect.h"
36 #include "extract.h"
37
38 struct z_packet {
39 const char *version;
40 int numfields;
41 int kind;
42 const char *uid;
43 int port;
44 int auth;
45 int authlen;
46 const char *authdata;
47 const char *class;
48 const char *inst;
49 const char *opcode;
50 const char *sender;
51 const char *recipient;
52 const char *format;
53 int cksum;
54 int multi;
55 const char *multi_uid;
56 /* Other fields follow here.. */
57 };
58
59 enum z_packet_type {
60 Z_PACKET_UNSAFE = 0,
61 Z_PACKET_UNACKED,
62 Z_PACKET_ACKED,
63 Z_PACKET_HMACK,
64 Z_PACKET_HMCTL,
65 Z_PACKET_SERVACK,
66 Z_PACKET_SERVNAK,
67 Z_PACKET_CLIENTACK,
68 Z_PACKET_STAT
69 };
70
71 static const struct tok z_types[] = {
72 { Z_PACKET_UNSAFE, "unsafe" },
73 { Z_PACKET_UNACKED, "unacked" },
74 { Z_PACKET_ACKED, "acked" },
75 { Z_PACKET_HMACK, "hm-ack" },
76 { Z_PACKET_HMCTL, "hm-ctl" },
77 { Z_PACKET_SERVACK, "serv-ack" },
78 { Z_PACKET_SERVNAK, "serv-nak" },
79 { Z_PACKET_CLIENTACK, "client-ack" },
80 { Z_PACKET_STAT, "stat" },
81 { 0, NULL }
82 };
83
84 static char z_buf[256];
85
86 static const char *
parse_field(netdissect_options * ndo,const char ** pptr,int * len)87 parse_field(netdissect_options *ndo, const char **pptr, int *len)
88 {
89 const char *s;
90
91 /* Start of string */
92 s = *pptr;
93 /* Scan for the NUL terminator */
94 for (;;) {
95 if (*len == 0) {
96 /* Ran out of packet data without finding it */
97 return NULL;
98 }
99 if (GET_U_1(*pptr) == '\0') {
100 /* Found it */
101 break;
102 }
103 /* Keep scanning */
104 (*pptr)++;
105 (*len)--;
106 }
107 /* Skip the NUL terminator */
108 (*pptr)++;
109 (*len)--;
110 return s;
111 }
112
113 static const char *
z_triple(const char * class,const char * inst,const char * recipient)114 z_triple(const char *class, const char *inst, const char *recipient)
115 {
116 if (!*recipient)
117 recipient = "*";
118 snprintf(z_buf, sizeof(z_buf), "<%s,%s,%s>", class, inst, recipient);
119 z_buf[sizeof(z_buf)-1] = '\0';
120 return z_buf;
121 }
122
123 static const char *
str_to_lower(const char * string)124 str_to_lower(const char *string)
125 {
126 char *zb_string;
127
128 strncpy(z_buf, string, sizeof(z_buf));
129 z_buf[sizeof(z_buf)-1] = '\0';
130
131 zb_string = z_buf;
132 while (*zb_string) {
133 *zb_string = ND_ASCII_TOLOWER(*zb_string);
134 zb_string++;
135 }
136
137 return z_buf;
138 }
139
140 #define ZEPHYR_PRINT(str1,str2) \
141 { ND_PRINT("%s", (str1)); fn_print_str(ndo, (const u_char *)(str2)); }
142
143 void
zephyr_print(netdissect_options * ndo,const u_char * cp,u_int length)144 zephyr_print(netdissect_options *ndo, const u_char *cp, u_int length)
145 {
146 struct z_packet z = {
147 NULL, /* version */
148 0, /* numfields */
149 0, /* kind */
150 NULL, /* uid */
151 0, /* port */
152 0, /* auth */
153 0, /* authlen */
154 NULL, /* authdata */
155 NULL, /* class */
156 NULL, /* inst */
157 NULL, /* opcode */
158 NULL, /* sender */
159 NULL, /* recipient */
160 NULL, /* format */
161 0, /* cksum */
162 0, /* multi */
163 NULL /* multi_uid */
164 };
165 const char *parse = (const char *) cp;
166 int parselen = length;
167 const char *s;
168 int lose = 0;
169
170 ndo->ndo_protocol = "zephyr";
171 /* squelch compiler warnings */
172
173 #define PARSE_STRING \
174 s = parse_field(ndo, &parse, &parselen); \
175 if (!s) lose = 1;
176
177 #define PARSE_FIELD_INT(field) \
178 PARSE_STRING \
179 if (!lose) field = strtol(s, 0, 16);
180
181 #define PARSE_FIELD_STR(field) \
182 PARSE_STRING \
183 if (!lose) field = s;
184
185 PARSE_FIELD_STR(z.version);
186 if (lose)
187 goto invalid;
188
189 if (strncmp(z.version, "ZEPH", 4))
190 return;
191
192 PARSE_FIELD_INT(z.numfields);
193 PARSE_FIELD_INT(z.kind);
194 PARSE_FIELD_STR(z.uid);
195 PARSE_FIELD_INT(z.port);
196 PARSE_FIELD_INT(z.auth);
197 PARSE_FIELD_INT(z.authlen);
198 PARSE_FIELD_STR(z.authdata);
199 PARSE_FIELD_STR(z.class);
200 PARSE_FIELD_STR(z.inst);
201 PARSE_FIELD_STR(z.opcode);
202 PARSE_FIELD_STR(z.sender);
203 PARSE_FIELD_STR(z.recipient);
204 PARSE_FIELD_STR(z.format);
205 PARSE_FIELD_INT(z.cksum);
206 PARSE_FIELD_INT(z.multi);
207 PARSE_FIELD_STR(z.multi_uid);
208
209 if (lose)
210 goto invalid;
211
212 ND_PRINT(" zephyr");
213 if (strncmp(z.version+4, "0.2", 3)) {
214 ZEPHYR_PRINT(" v", z.version+4)
215 return;
216 }
217
218 ND_PRINT(" %s", tok2str(z_types, "type %d", z.kind));
219 if (z.kind == Z_PACKET_SERVACK) {
220 /* Initialization to silence warnings */
221 const char *ackdata = NULL;
222 PARSE_FIELD_STR(ackdata);
223 if (!lose && strcmp(ackdata, "SENT"))
224 ZEPHYR_PRINT("/", str_to_lower(ackdata))
225 }
226 if (*z.sender) ZEPHYR_PRINT(" ", z.sender);
227
228 if (!strcmp(z.class, "USER_LOCATE")) {
229 if (!strcmp(z.opcode, "USER_HIDE"))
230 ND_PRINT(" hide");
231 else if (!strcmp(z.opcode, "USER_UNHIDE"))
232 ND_PRINT(" unhide");
233 else
234 ZEPHYR_PRINT(" locate ", z.inst);
235 return;
236 }
237
238 if (!strcmp(z.class, "ZEPHYR_ADMIN")) {
239 ZEPHYR_PRINT(" zephyr-admin ", str_to_lower(z.opcode));
240 return;
241 }
242
243 if (!strcmp(z.class, "ZEPHYR_CTL")) {
244 if (!strcmp(z.inst, "CLIENT")) {
245 if (!strcmp(z.opcode, "SUBSCRIBE") ||
246 !strcmp(z.opcode, "SUBSCRIBE_NODEFS") ||
247 !strcmp(z.opcode, "UNSUBSCRIBE")) {
248
249 ND_PRINT(" %ssub%s", strcmp(z.opcode, "SUBSCRIBE") ? "un" : "",
250 strcmp(z.opcode, "SUBSCRIBE_NODEFS") ? "" :
251 "-nodefs");
252 if (z.kind != Z_PACKET_SERVACK) {
253 /* Initialization to silence warnings */
254 const char *c = NULL, *i = NULL, *r = NULL;
255 PARSE_FIELD_STR(c);
256 PARSE_FIELD_STR(i);
257 PARSE_FIELD_STR(r);
258 if (!lose) ZEPHYR_PRINT(" ", z_triple(c, i, r));
259 }
260 return;
261 }
262
263 if (!strcmp(z.opcode, "GIMME")) {
264 ND_PRINT(" ret");
265 return;
266 }
267
268 if (!strcmp(z.opcode, "GIMMEDEFS")) {
269 ND_PRINT(" gimme-defs");
270 return;
271 }
272
273 if (!strcmp(z.opcode, "CLEARSUB")) {
274 ND_PRINT(" clear-subs");
275 return;
276 }
277
278 ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
279 return;
280 }
281
282 if (!strcmp(z.inst, "HM")) {
283 ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
284 return;
285 }
286
287 if (!strcmp(z.inst, "REALM")) {
288 if (!strcmp(z.opcode, "ADD_SUBSCRIBE"))
289 ND_PRINT(" realm add-subs");
290 if (!strcmp(z.opcode, "REQ_SUBSCRIBE"))
291 ND_PRINT(" realm req-subs");
292 if (!strcmp(z.opcode, "RLM_SUBSCRIBE"))
293 ND_PRINT(" realm rlm-sub");
294 if (!strcmp(z.opcode, "RLM_UNSUBSCRIBE"))
295 ND_PRINT(" realm rlm-unsub");
296 return;
297 }
298 }
299
300 if (!strcmp(z.class, "HM_CTL")) {
301 ZEPHYR_PRINT(" hm_ctl ", str_to_lower(z.inst));
302 ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
303 return;
304 }
305
306 if (!strcmp(z.class, "HM_STAT")) {
307 if (!strcmp(z.inst, "HMST_CLIENT") && !strcmp(z.opcode, "GIMMESTATS")) {
308 ND_PRINT(" get-client-stats");
309 return;
310 }
311 }
312
313 if (!strcmp(z.class, "WG_CTL")) {
314 ZEPHYR_PRINT(" wg_ctl ", str_to_lower(z.inst));
315 ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
316 return;
317 }
318
319 if (!strcmp(z.class, "LOGIN")) {
320 if (!strcmp(z.opcode, "USER_FLUSH")) {
321 ND_PRINT(" flush_locs");
322 return;
323 }
324
325 if (!strcmp(z.opcode, "NONE") ||
326 !strcmp(z.opcode, "OPSTAFF") ||
327 !strcmp(z.opcode, "REALM-VISIBLE") ||
328 !strcmp(z.opcode, "REALM-ANNOUNCED") ||
329 !strcmp(z.opcode, "NET-VISIBLE") ||
330 !strcmp(z.opcode, "NET-ANNOUNCED")) {
331 ZEPHYR_PRINT(" set-exposure ", str_to_lower(z.opcode));
332 return;
333 }
334 }
335
336 if (!*z.recipient)
337 z.recipient = "*";
338
339 ZEPHYR_PRINT(" to ", z_triple(z.class, z.inst, z.recipient));
340 if (*z.opcode)
341 ZEPHYR_PRINT(" op ", z.opcode);
342 return;
343
344 invalid:
345 nd_print_invalid(ndo);
346 }
347