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#include <sys/cdefs.h>
24#ifndef lint
25__RCSID("$NetBSD: print-zephyr.c,v 1.9 2023/08/17 20:19:40 christos Exp $");
26#endif
27
28/* \summary: Zephyr printer */
29
30#ifdef HAVE_CONFIG_H
31#include <config.h>
32#endif
33
34#include "netdissect-stdinc.h"
35
36#include <stdio.h>
37#include <string.h>
38#include <stdlib.h>
39
40#include "netdissect-ctype.h"
41
42#include "netdissect.h"
43#include "extract.h"
44
45struct z_packet {
46    const char *version;
47    int numfields;
48    int kind;
49    const char *uid;
50    int port;
51    int auth;
52    int authlen;
53    const char *authdata;
54    const char *class;
55    const char *inst;
56    const char *opcode;
57    const char *sender;
58    const char *recipient;
59    const char *format;
60    int cksum;
61    int multi;
62    const char *multi_uid;
63    /* Other fields follow here.. */
64};
65
66enum z_packet_type {
67    Z_PACKET_UNSAFE = 0,
68    Z_PACKET_UNACKED,
69    Z_PACKET_ACKED,
70    Z_PACKET_HMACK,
71    Z_PACKET_HMCTL,
72    Z_PACKET_SERVACK,
73    Z_PACKET_SERVNAK,
74    Z_PACKET_CLIENTACK,
75    Z_PACKET_STAT
76};
77
78static const struct tok z_types[] = {
79    { Z_PACKET_UNSAFE,		"unsafe" },
80    { Z_PACKET_UNACKED,		"unacked" },
81    { Z_PACKET_ACKED,		"acked" },
82    { Z_PACKET_HMACK,		"hm-ack" },
83    { Z_PACKET_HMCTL,		"hm-ctl" },
84    { Z_PACKET_SERVACK,		"serv-ack" },
85    { Z_PACKET_SERVNAK,		"serv-nak" },
86    { Z_PACKET_CLIENTACK,	"client-ack" },
87    { Z_PACKET_STAT,		"stat" },
88    { 0,			NULL }
89};
90
91static char z_buf[256];
92
93static const char *
94parse_field(netdissect_options *ndo, const char **pptr, int *len)
95{
96    const char *s;
97
98    /* Start of string */
99    s = *pptr;
100    /* Scan for the NUL terminator */
101    for (;;) {
102	if (*len == 0) {
103	    /* Ran out of packet data without finding it */
104	    return NULL;
105	}
106	if (GET_U_1(*pptr) == '\0') {
107	    /* Found it */
108	    break;
109	}
110	/* Keep scanning */
111	(*pptr)++;
112	(*len)--;
113    }
114    /* Skip the NUL terminator */
115    (*pptr)++;
116    (*len)--;
117    return s;
118}
119
120static const char *
121z_triple(const char *class, const char *inst, const char *recipient)
122{
123    if (!*recipient)
124	recipient = "*";
125    snprintf(z_buf, sizeof(z_buf), "<%s,%s,%s>", class, inst, recipient);
126    z_buf[sizeof(z_buf)-1] = '\0';
127    return z_buf;
128}
129
130static const char *
131str_to_lower(const char *string)
132{
133    char *zb_string;
134
135    strncpy(z_buf, string, sizeof(z_buf));
136    z_buf[sizeof(z_buf)-1] = '\0';
137
138    zb_string = z_buf;
139    while (*zb_string) {
140	*zb_string = ND_ASCII_TOLOWER(*zb_string);
141	zb_string++;
142    }
143
144    return z_buf;
145}
146
147#define ZEPHYR_PRINT(str1,str2) \
148{ ND_PRINT("%s", (str1)); fn_print_str(ndo, (const u_char *)(str2)); }
149
150void
151zephyr_print(netdissect_options *ndo, const u_char *cp, u_int length)
152{
153    struct z_packet z = {
154	NULL,	/* version */
155	0,	/* numfields */
156	0,	/* kind */
157	NULL,	/* uid */
158	0,	/* port */
159	0,	/* auth */
160	0,	/* authlen */
161	NULL,	/* authdata */
162	NULL,	/* class */
163	NULL,	/* inst */
164	NULL,	/* opcode */
165	NULL,	/* sender */
166	NULL,	/* recipient */
167	NULL,	/* format */
168	0,	/* cksum */
169	0,	/* multi */
170	NULL	/* multi_uid */
171    };
172    const char *parse = (const char *) cp;
173    int parselen = length;
174    const char *s;
175    int lose = 0;
176
177    ndo->ndo_protocol = "zephyr";
178    /* squelch compiler warnings */
179
180#define PARSE_STRING						\
181	s = parse_field(ndo, &parse, &parselen);	\
182	if (!s) lose = 1;
183
184#define PARSE_FIELD_INT(field)			\
185	PARSE_STRING				\
186	if (!lose) field = strtol(s, 0, 16);
187
188#define PARSE_FIELD_STR(field)			\
189	PARSE_STRING				\
190	if (!lose) field = s;
191
192    PARSE_FIELD_STR(z.version);
193    if (lose)
194	goto invalid;
195
196    if (strncmp(z.version, "ZEPH", 4))
197	return;
198
199    PARSE_FIELD_INT(z.numfields);
200    PARSE_FIELD_INT(z.kind);
201    PARSE_FIELD_STR(z.uid);
202    PARSE_FIELD_INT(z.port);
203    PARSE_FIELD_INT(z.auth);
204    PARSE_FIELD_INT(z.authlen);
205    PARSE_FIELD_STR(z.authdata);
206    PARSE_FIELD_STR(z.class);
207    PARSE_FIELD_STR(z.inst);
208    PARSE_FIELD_STR(z.opcode);
209    PARSE_FIELD_STR(z.sender);
210    PARSE_FIELD_STR(z.recipient);
211    PARSE_FIELD_STR(z.format);
212    PARSE_FIELD_INT(z.cksum);
213    PARSE_FIELD_INT(z.multi);
214    PARSE_FIELD_STR(z.multi_uid);
215
216    if (lose)
217	goto invalid;
218
219    ND_PRINT(" zephyr");
220    if (strncmp(z.version+4, "0.2", 3)) {
221	ZEPHYR_PRINT(" v", z.version+4)
222	return;
223    }
224
225    ND_PRINT(" %s", tok2str(z_types, "type %d", z.kind));
226    if (z.kind == Z_PACKET_SERVACK) {
227	/* Initialization to silence warnings */
228	const char *ackdata = NULL;
229	PARSE_FIELD_STR(ackdata);
230	if (!lose && strcmp(ackdata, "SENT"))
231	    ZEPHYR_PRINT("/", str_to_lower(ackdata))
232    }
233    if (*z.sender) ZEPHYR_PRINT(" ", z.sender);
234
235    if (!strcmp(z.class, "USER_LOCATE")) {
236	if (!strcmp(z.opcode, "USER_HIDE"))
237	    ND_PRINT(" hide");
238	else if (!strcmp(z.opcode, "USER_UNHIDE"))
239	    ND_PRINT(" unhide");
240	else
241	    ZEPHYR_PRINT(" locate ", z.inst);
242	return;
243    }
244
245    if (!strcmp(z.class, "ZEPHYR_ADMIN")) {
246	ZEPHYR_PRINT(" zephyr-admin ", str_to_lower(z.opcode));
247	return;
248    }
249
250    if (!strcmp(z.class, "ZEPHYR_CTL")) {
251	if (!strcmp(z.inst, "CLIENT")) {
252	    if (!strcmp(z.opcode, "SUBSCRIBE") ||
253		!strcmp(z.opcode, "SUBSCRIBE_NODEFS") ||
254		!strcmp(z.opcode, "UNSUBSCRIBE")) {
255
256		ND_PRINT(" %ssub%s", strcmp(z.opcode, "SUBSCRIBE") ? "un" : "",
257				   strcmp(z.opcode, "SUBSCRIBE_NODEFS") ? "" :
258								   "-nodefs");
259		if (z.kind != Z_PACKET_SERVACK) {
260		    /* Initialization to silence warnings */
261		    const char *c = NULL, *i = NULL, *r = NULL;
262		    PARSE_FIELD_STR(c);
263		    PARSE_FIELD_STR(i);
264		    PARSE_FIELD_STR(r);
265		    if (!lose) ZEPHYR_PRINT(" ", z_triple(c, i, r));
266		}
267		return;
268	    }
269
270	    if (!strcmp(z.opcode, "GIMME")) {
271		ND_PRINT(" ret");
272		return;
273	    }
274
275	    if (!strcmp(z.opcode, "GIMMEDEFS")) {
276		ND_PRINT(" gimme-defs");
277		return;
278	    }
279
280	    if (!strcmp(z.opcode, "CLEARSUB")) {
281		ND_PRINT(" clear-subs");
282		return;
283	    }
284
285	    ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
286	    return;
287	}
288
289	if (!strcmp(z.inst, "HM")) {
290	    ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
291	    return;
292	}
293
294	if (!strcmp(z.inst, "REALM")) {
295	    if (!strcmp(z.opcode, "ADD_SUBSCRIBE"))
296		ND_PRINT(" realm add-subs");
297	    if (!strcmp(z.opcode, "REQ_SUBSCRIBE"))
298		ND_PRINT(" realm req-subs");
299	    if (!strcmp(z.opcode, "RLM_SUBSCRIBE"))
300		ND_PRINT(" realm rlm-sub");
301	    if (!strcmp(z.opcode, "RLM_UNSUBSCRIBE"))
302		ND_PRINT(" realm rlm-unsub");
303	    return;
304	}
305    }
306
307    if (!strcmp(z.class, "HM_CTL")) {
308	ZEPHYR_PRINT(" hm_ctl ", str_to_lower(z.inst));
309	ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
310	return;
311    }
312
313    if (!strcmp(z.class, "HM_STAT")) {
314	if (!strcmp(z.inst, "HMST_CLIENT") && !strcmp(z.opcode, "GIMMESTATS")) {
315	    ND_PRINT(" get-client-stats");
316	    return;
317	}
318    }
319
320    if (!strcmp(z.class, "WG_CTL")) {
321	ZEPHYR_PRINT(" wg_ctl ", str_to_lower(z.inst));
322	ZEPHYR_PRINT(" ", str_to_lower(z.opcode));
323	return;
324    }
325
326    if (!strcmp(z.class, "LOGIN")) {
327	if (!strcmp(z.opcode, "USER_FLUSH")) {
328	    ND_PRINT(" flush_locs");
329	    return;
330	}
331
332	if (!strcmp(z.opcode, "NONE") ||
333	    !strcmp(z.opcode, "OPSTAFF") ||
334	    !strcmp(z.opcode, "REALM-VISIBLE") ||
335	    !strcmp(z.opcode, "REALM-ANNOUNCED") ||
336	    !strcmp(z.opcode, "NET-VISIBLE") ||
337	    !strcmp(z.opcode, "NET-ANNOUNCED")) {
338	    ZEPHYR_PRINT(" set-exposure ", str_to_lower(z.opcode));
339	    return;
340	}
341    }
342
343    if (!*z.recipient)
344	z.recipient = "*";
345
346    ZEPHYR_PRINT(" to ", z_triple(z.class, z.inst, z.recipient));
347    if (*z.opcode)
348	ZEPHYR_PRINT(" op ", z.opcode);
349    return;
350
351invalid:
352    nd_print_invalid(ndo);
353}
354