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
37struct 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
58enum 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
70static 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
83static char z_buf[256];
84
85static const char *
86parse_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
117static const char *
118z_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
127static const char *
128str_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
144void
145zephyr_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
333trunc:
334    ND_PRINT((ndo, " [|zephyr] (%d)", length));
335    return;
336}
337