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