xref: /freebsd/contrib/tcpdump/print-ldp.c (revision ccfd87fe2ac0e2e6aeb1911a7d7cce6712a8564f)
1 /*
2  * Redistribution and use in source and binary forms, with or without
3  * modification, are permitted provided that: (1) source code
4  * distributions retain the above copyright notice and this paragraph
5  * in its entirety, and (2) distributions including binary code include
6  * the above copyright notice and this paragraph in its entirety in
7  * the documentation or other materials provided with the distribution.
8  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND
9  * WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT
10  * LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
11  * FOR A PARTICULAR PURPOSE.
12  *
13  * Original code by Hannes Gredler (hannes@gredler.at)
14  *  and Steinar Haug (sthaug@nethelp.no)
15  */
16 
17 /* \summary: Label Distribution Protocol (LDP) printer */
18 
19 #ifdef HAVE_CONFIG_H
20 #include <config.h>
21 #endif
22 
23 #include "netdissect-stdinc.h"
24 
25 #include "netdissect.h"
26 #include "extract.h"
27 #include "addrtoname.h"
28 
29 #include "l2vpn.h"
30 #include "af.h"
31 
32 
33 /*
34  * ldp common header
35  *
36  *  0                   1                   2                   3
37  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
38  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
39  * |  Version                      |         PDU Length            |
40  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
41  * |                         LDP Identifier                        |
42  * +                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
43  * |                               |
44  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
45  *
46  */
47 
48 struct ldp_common_header {
49     nd_uint16_t version;
50     nd_uint16_t pdu_length;
51     nd_ipv4     lsr_id;
52     nd_uint16_t label_space;
53 };
54 
55 #define LDP_VERSION 1
56 
57 /*
58  * ldp message header
59  *
60  *  0                   1                   2                   3
61  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
62  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
63  * |U|   Message Type              |      Message Length           |
64  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
65  * |                     Message ID                                |
66  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
67  * |                                                               |
68  * +                                                               +
69  * |                     Mandatory Parameters                      |
70  * +                                                               +
71  * |                                                               |
72  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
73  * |                                                               |
74  * +                                                               +
75  * |                     Optional Parameters                       |
76  * +                                                               +
77  * |                                                               |
78  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
79  */
80 
81 struct ldp_msg_header {
82     nd_uint16_t type;
83     nd_uint16_t length;
84     nd_uint32_t id;
85 };
86 
87 #define	LDP_MASK_MSG_TYPE(x)  ((x)&0x7fff)
88 #define	LDP_MASK_U_BIT(x)     ((x)&0x8000)
89 
90 #define	LDP_MSG_NOTIF                0x0001
91 #define	LDP_MSG_HELLO                0x0100
92 #define	LDP_MSG_INIT                 0x0200
93 #define	LDP_MSG_KEEPALIVE            0x0201
94 #define	LDP_MSG_ADDRESS              0x0300
95 #define	LDP_MSG_ADDRESS_WITHDRAW     0x0301
96 #define	LDP_MSG_LABEL_MAPPING        0x0400
97 #define	LDP_MSG_LABEL_REQUEST        0x0401
98 #define	LDP_MSG_LABEL_WITHDRAW       0x0402
99 #define	LDP_MSG_LABEL_RELEASE        0x0403
100 #define	LDP_MSG_LABEL_ABORT_REQUEST  0x0404
101 
102 #define	LDP_VENDOR_PRIVATE_MIN       0x3e00
103 #define	LDP_VENDOR_PRIVATE_MAX       0x3eff
104 #define	LDP_EXPERIMENTAL_MIN         0x3f00
105 #define	LDP_EXPERIMENTAL_MAX         0x3fff
106 
107 static const struct tok ldp_msg_values[] = {
108     { LDP_MSG_NOTIF,	             "Notification" },
109     { LDP_MSG_HELLO,	             "Hello" },
110     { LDP_MSG_INIT,	             "Initialization" },
111     { LDP_MSG_KEEPALIVE,             "Keepalive" },
112     { LDP_MSG_ADDRESS,	             "Address" },
113     { LDP_MSG_ADDRESS_WITHDRAW,	     "Address Withdraw" },
114     { LDP_MSG_LABEL_MAPPING,	     "Label Mapping" },
115     { LDP_MSG_LABEL_REQUEST,	     "Label Request" },
116     { LDP_MSG_LABEL_WITHDRAW,	     "Label Withdraw" },
117     { LDP_MSG_LABEL_RELEASE,	     "Label Release" },
118     { LDP_MSG_LABEL_ABORT_REQUEST,   "Label Abort Request" },
119     { 0, NULL}
120 };
121 
122 #define	LDP_MASK_TLV_TYPE(x)  ((x)&0x3fff)
123 #define	LDP_MASK_F_BIT(x) ((x)&0x4000)
124 
125 #define	LDP_TLV_FEC                  0x0100
126 #define	LDP_TLV_ADDRESS_LIST         0x0101
127 #define LDP_TLV_ADDRESS_LIST_AFNUM_LEN 2
128 #define	LDP_TLV_HOP_COUNT            0x0103
129 #define	LDP_TLV_PATH_VECTOR          0x0104
130 #define	LDP_TLV_GENERIC_LABEL        0x0200
131 #define	LDP_TLV_ATM_LABEL            0x0201
132 #define	LDP_TLV_FR_LABEL             0x0202
133 #define	LDP_TLV_STATUS               0x0300
134 #define	LDP_TLV_EXTD_STATUS          0x0301
135 #define	LDP_TLV_RETURNED_PDU         0x0302
136 #define	LDP_TLV_RETURNED_MSG         0x0303
137 #define	LDP_TLV_COMMON_HELLO         0x0400
138 #define	LDP_TLV_IPV4_TRANSPORT_ADDR  0x0401
139 #define	LDP_TLV_CONFIG_SEQ_NUMBER    0x0402
140 #define	LDP_TLV_IPV6_TRANSPORT_ADDR  0x0403
141 #define	LDP_TLV_COMMON_SESSION       0x0500
142 #define	LDP_TLV_ATM_SESSION_PARM     0x0501
143 #define	LDP_TLV_FR_SESSION_PARM      0x0502
144 #define LDP_TLV_FT_SESSION	     0x0503
145 #define	LDP_TLV_LABEL_REQUEST_MSG_ID 0x0600
146 #define LDP_TLV_MTU                  0x0601 /* rfc 3988 */
147 
148 static const struct tok ldp_tlv_values[] = {
149     { LDP_TLV_FEC,	             "FEC" },
150     { LDP_TLV_ADDRESS_LIST,          "Address List" },
151     { LDP_TLV_HOP_COUNT,             "Hop Count" },
152     { LDP_TLV_PATH_VECTOR,           "Path Vector" },
153     { LDP_TLV_GENERIC_LABEL,         "Generic Label" },
154     { LDP_TLV_ATM_LABEL,             "ATM Label" },
155     { LDP_TLV_FR_LABEL,              "Frame-Relay Label" },
156     { LDP_TLV_STATUS,                "Status" },
157     { LDP_TLV_EXTD_STATUS,           "Extended Status" },
158     { LDP_TLV_RETURNED_PDU,          "Returned PDU" },
159     { LDP_TLV_RETURNED_MSG,          "Returned Message" },
160     { LDP_TLV_COMMON_HELLO,          "Common Hello Parameters" },
161     { LDP_TLV_IPV4_TRANSPORT_ADDR,   "IPv4 Transport Address" },
162     { LDP_TLV_CONFIG_SEQ_NUMBER,     "Configuration Sequence Number" },
163     { LDP_TLV_IPV6_TRANSPORT_ADDR,   "IPv6 Transport Address" },
164     { LDP_TLV_COMMON_SESSION,        "Common Session Parameters" },
165     { LDP_TLV_ATM_SESSION_PARM,      "ATM Session Parameters" },
166     { LDP_TLV_FR_SESSION_PARM,       "Frame-Relay Session Parameters" },
167     { LDP_TLV_FT_SESSION,            "Fault-Tolerant Session Parameters" },
168     { LDP_TLV_LABEL_REQUEST_MSG_ID,  "Label Request Message ID" },
169     { LDP_TLV_MTU,                   "MTU" },
170     { 0, NULL}
171 };
172 
173 #define LDP_FEC_WILDCARD	0x01
174 #define LDP_FEC_PREFIX		0x02
175 #define LDP_FEC_HOSTADDRESS	0x03
176 /* From RFC 4906; should probably be updated to RFC 4447 (e.g., VC -> PW) */
177 #define LDP_FEC_MARTINI_VC	0x80
178 
179 static const struct tok ldp_fec_values[] = {
180     { LDP_FEC_WILDCARD,		"Wildcard" },
181     { LDP_FEC_PREFIX,		"Prefix" },
182     { LDP_FEC_HOSTADDRESS,	"Host address" },
183     { LDP_FEC_MARTINI_VC,	"Martini VC" },
184     { 0, NULL}
185 };
186 
187 #define LDP_FEC_MARTINI_IFPARM_MTU  0x01
188 #define LDP_FEC_MARTINI_IFPARM_DESC 0x03
189 #define LDP_FEC_MARTINI_IFPARM_VCCV 0x0c
190 
191 static const struct tok ldp_fec_martini_ifparm_values[] = {
192     { LDP_FEC_MARTINI_IFPARM_MTU, "MTU" },
193     { LDP_FEC_MARTINI_IFPARM_DESC, "Description" },
194     { LDP_FEC_MARTINI_IFPARM_VCCV, "VCCV" },
195     { 0, NULL}
196 };
197 
198 /* draft-ietf-pwe3-vccv-04.txt */
199 static const struct tok ldp_fec_martini_ifparm_vccv_cc_values[] = {
200     { 0x01, "PWE3 control word" },
201     { 0x02, "MPLS Router Alert Label" },
202     { 0x04, "MPLS inner label TTL = 1" },
203     { 0, NULL}
204 };
205 
206 /* draft-ietf-pwe3-vccv-04.txt */
207 static const struct tok ldp_fec_martini_ifparm_vccv_cv_values[] = {
208     { 0x01, "ICMP Ping" },
209     { 0x02, "LSP Ping" },
210     { 0x04, "BFD" },
211     { 0, NULL}
212 };
213 
214 static u_int ldp_pdu_print(netdissect_options *, const u_char *);
215 
216 /*
217  * ldp tlv header
218  *
219  *  0                   1                   2                   3
220  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
221  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
222  * |U|F|        Type               |            Length             |
223  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
224  * |                                                               |
225  * |                             Value                             |
226  * ~                                                               ~
227  * |                                                               |
228  * |                               +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
229  * |                               |
230  * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
231  */
232 
233 #define TLV_TCHECK(minlen) \
234     if (tlv_tlen < minlen) { \
235         ND_PRINT(" [tlv length %u < %u]", tlv_tlen, minlen); \
236         nd_print_invalid(ndo); \
237         goto invalid; \
238     }
239 
240 static u_int
241 ldp_tlv_print(netdissect_options *ndo,
242               const u_char *tptr,
243               u_int msg_tlen)
244 {
245     struct ldp_tlv_header {
246         nd_uint16_t type;
247         nd_uint16_t length;
248     };
249 
250     const struct ldp_tlv_header *ldp_tlv_header;
251     u_short tlv_type,tlv_len,tlv_tlen,af,ft_flags;
252     u_char fec_type;
253     u_int ui,vc_info_len, vc_info_tlv_type, vc_info_tlv_len,idx;
254     char buf[100];
255     int i;
256 
257     ldp_tlv_header = (const struct ldp_tlv_header *)tptr;
258     ND_TCHECK_SIZE(ldp_tlv_header);
259     tlv_len=GET_BE_U_2(ldp_tlv_header->length);
260     if (tlv_len + 4U > msg_tlen) {
261         ND_PRINT("\n\t\t TLV contents go past end of message");
262         return 0;
263     }
264     tlv_tlen=tlv_len;
265     tlv_type=LDP_MASK_TLV_TYPE(GET_BE_U_2(ldp_tlv_header->type));
266 
267     /* FIXME vendor private / experimental check */
268     ND_PRINT("\n\t    %s TLV (0x%04x), length: %u, Flags: [%s and %s forward if unknown]",
269            tok2str(ldp_tlv_values,
270                    "Unknown",
271                    tlv_type),
272            tlv_type,
273            tlv_len,
274            LDP_MASK_U_BIT(GET_BE_U_2(ldp_tlv_header->type)) ? "continue processing" : "ignore",
275            LDP_MASK_F_BIT(GET_BE_U_2(ldp_tlv_header->type)) ? "do" : "don't");
276 
277     tptr+=sizeof(struct ldp_tlv_header);
278 
279     switch(tlv_type) {
280 
281     case LDP_TLV_COMMON_HELLO:
282         TLV_TCHECK(4);
283         ND_PRINT("\n\t      Hold Time: %us, Flags: [%s Hello%s]",
284                GET_BE_U_2(tptr),
285                (GET_BE_U_2(tptr + 2)&0x8000) ? "Targeted" : "Link",
286                (GET_BE_U_2(tptr + 2)&0x4000) ? ", Request for targeted Hellos" : "");
287         break;
288 
289     case LDP_TLV_IPV4_TRANSPORT_ADDR:
290         TLV_TCHECK(4);
291         ND_PRINT("\n\t      IPv4 Transport Address: %s", GET_IPADDR_STRING(tptr));
292         break;
293     case LDP_TLV_IPV6_TRANSPORT_ADDR:
294         TLV_TCHECK(16);
295         ND_PRINT("\n\t      IPv6 Transport Address: %s", GET_IP6ADDR_STRING(tptr));
296         break;
297     case LDP_TLV_CONFIG_SEQ_NUMBER:
298         TLV_TCHECK(4);
299         ND_PRINT("\n\t      Sequence Number: %u", GET_BE_U_4(tptr));
300         break;
301 
302     case LDP_TLV_ADDRESS_LIST:
303         TLV_TCHECK(LDP_TLV_ADDRESS_LIST_AFNUM_LEN);
304 	af = GET_BE_U_2(tptr);
305 	tptr+=LDP_TLV_ADDRESS_LIST_AFNUM_LEN;
306         tlv_tlen -= LDP_TLV_ADDRESS_LIST_AFNUM_LEN;
307 	ND_PRINT("\n\t      Address Family: %s, addresses",
308                tok2str(af_values, "Unknown (%u)", af));
309         switch (af) {
310         case AFNUM_INET:
311 	    while(tlv_tlen >= sizeof(nd_ipv4)) {
312 		ND_PRINT(" %s", GET_IPADDR_STRING(tptr));
313 		tlv_tlen-=sizeof(nd_ipv4);
314 		tptr+=sizeof(nd_ipv4);
315 	    }
316             break;
317         case AFNUM_INET6:
318 	    while(tlv_tlen >= sizeof(nd_ipv6)) {
319 		ND_PRINT(" %s", GET_IP6ADDR_STRING(tptr));
320 		tlv_tlen-=sizeof(nd_ipv6);
321 		tptr+=sizeof(nd_ipv6);
322 	    }
323             break;
324         default:
325             /* unknown AF */
326             break;
327         }
328 	break;
329 
330     case LDP_TLV_COMMON_SESSION:
331 	TLV_TCHECK(8);
332 	ND_PRINT("\n\t      Version: %u, Keepalive: %us, Flags: [Downstream %s, Loop Detection %s]",
333 	       GET_BE_U_2(tptr), GET_BE_U_2(tptr + 2),
334 	       (GET_BE_U_2(tptr + 6)&0x8000) ? "On Demand" : "Unsolicited",
335 	       (GET_BE_U_2(tptr + 6)&0x4000) ? "Enabled" : "Disabled"
336 	       );
337 	break;
338 
339     case LDP_TLV_FEC:
340         TLV_TCHECK(1);
341         fec_type = GET_U_1(tptr);
342 	ND_PRINT("\n\t      %s FEC (0x%02x)",
343 	       tok2str(ldp_fec_values, "Unknown", fec_type),
344 	       fec_type);
345 
346 	tptr+=1;
347 	tlv_tlen-=1;
348 	switch(fec_type) {
349 
350 	case LDP_FEC_WILDCARD:
351 	    break;
352 	case LDP_FEC_PREFIX:
353 	    TLV_TCHECK(2);
354 	    af = GET_BE_U_2(tptr);
355 	    tptr+=2;
356 	    tlv_tlen-=2;
357 	    if (af == AFNUM_INET) {
358 		i=decode_prefix4(ndo, tptr, tlv_tlen, buf, sizeof(buf));
359 		if (i == -2)
360 		    goto trunc;
361 		if (i == -3)
362 		    ND_PRINT(": IPv4 prefix (goes past end of TLV)");
363 		else if (i == -1)
364 		    ND_PRINT(": IPv4 prefix (invalid length)");
365 		else
366 		    ND_PRINT(": IPv4 prefix %s", buf);
367 	    }
368 	    else if (af == AFNUM_INET6) {
369 		i=decode_prefix6(ndo, tptr, tlv_tlen, buf, sizeof(buf));
370 		if (i == -2)
371 		    goto trunc;
372 		if (i == -3)
373 		    ND_PRINT(": IPv4 prefix (goes past end of TLV)");
374 		else if (i == -1)
375 		    ND_PRINT(": IPv6 prefix (invalid length)");
376 		else
377 		    ND_PRINT(": IPv6 prefix %s", buf);
378 	    }
379 	    else
380 		ND_PRINT(": Address family %u prefix", af);
381 	    break;
382 	case LDP_FEC_HOSTADDRESS:
383 	    break;
384 	case LDP_FEC_MARTINI_VC:
385             /*
386              * We assume the type was supposed to be one of the MPLS
387              * Pseudowire Types.
388              */
389             TLV_TCHECK(7);
390             vc_info_len = GET_U_1(tptr + 2);
391 
392             /*
393 	     * According to RFC 4908, the VC info Length field can be zero,
394 	     * in which case not only are there no interface parameters,
395 	     * there's no VC ID.
396 	     */
397             if (vc_info_len == 0) {
398                 ND_PRINT(": %s, %scontrol word, group-ID %u, VC-info-length: %u",
399                        tok2str(mpls_pw_types_values, "Unknown", GET_BE_U_2(tptr)&0x7fff),
400                        GET_BE_U_2(tptr)&0x8000 ? "" : "no ",
401                        GET_BE_U_4(tptr + 3),
402                        vc_info_len);
403                 break;
404             }
405 
406             /* Make sure we have the VC ID as well */
407             TLV_TCHECK(11);
408 	    ND_PRINT(": %s, %scontrol word, group-ID %u, VC-ID %u, VC-info-length: %u",
409 		   tok2str(mpls_pw_types_values, "Unknown", GET_BE_U_2(tptr)&0x7fff),
410 		   GET_BE_U_2(tptr)&0x8000 ? "" : "no ",
411 		   GET_BE_U_4(tptr + 3),
412 		   GET_BE_U_4(tptr + 7),
413 		   vc_info_len);
414             if (vc_info_len < 4) {
415                 /* minimum 4, for the VC ID */
416                 ND_PRINT(" (invalid, < 4");
417                 return(tlv_len+4); /* Type & Length fields not included */
418 	    }
419             vc_info_len -= 4; /* subtract out the VC ID, giving the length of the interface parameters */
420 
421             /* Skip past the fixed information and the VC ID */
422             tptr+=11;
423             tlv_tlen-=11;
424             TLV_TCHECK(vc_info_len);
425 
426             while (vc_info_len > 2) {
427                 vc_info_tlv_type = GET_U_1(tptr);
428                 vc_info_tlv_len = GET_U_1(tptr + 1);
429                 if (vc_info_tlv_len < 2)
430                     break;
431                 if (vc_info_len < vc_info_tlv_len)
432                     break;
433 
434                 ND_PRINT("\n\t\tInterface Parameter: %s (0x%02x), len %u",
435                        tok2str(ldp_fec_martini_ifparm_values,"Unknown",vc_info_tlv_type),
436                        vc_info_tlv_type,
437                        vc_info_tlv_len);
438 
439                 switch(vc_info_tlv_type) {
440                 case LDP_FEC_MARTINI_IFPARM_MTU:
441                     ND_PRINT(": %u", GET_BE_U_2(tptr + 2));
442                     break;
443 
444                 case LDP_FEC_MARTINI_IFPARM_DESC:
445                     ND_PRINT(": ");
446                     for (idx = 2; idx < vc_info_tlv_len; idx++)
447                         fn_print_char(ndo, GET_U_1(tptr + idx));
448                     break;
449 
450                 case LDP_FEC_MARTINI_IFPARM_VCCV:
451                     ND_PRINT("\n\t\t  Control Channels (0x%02x) = [%s]",
452                            GET_U_1((tptr + 2)),
453                            bittok2str(ldp_fec_martini_ifparm_vccv_cc_values, "none", GET_U_1((tptr + 2))));
454                     ND_PRINT("\n\t\t  CV Types (0x%02x) = [%s]",
455                            GET_U_1((tptr + 3)),
456                            bittok2str(ldp_fec_martini_ifparm_vccv_cv_values, "none", GET_U_1((tptr + 3))));
457                     break;
458 
459                 default:
460                     print_unknown_data(ndo, tptr+2, "\n\t\t  ", vc_info_tlv_len-2);
461                     break;
462                 }
463 
464                 vc_info_len -= vc_info_tlv_len;
465                 tptr += vc_info_tlv_len;
466             }
467 	    break;
468 	}
469 
470 	break;
471 
472     case LDP_TLV_GENERIC_LABEL:
473 	TLV_TCHECK(4);
474 	ND_PRINT("\n\t      Label: %u", GET_BE_U_4(tptr) & 0xfffff);
475 	break;
476 
477     case LDP_TLV_STATUS:
478 	TLV_TCHECK(8);
479 	ui = GET_BE_U_4(tptr);
480 	tptr+=4;
481 	ND_PRINT("\n\t      Status: 0x%02x, Flags: [%s and %s forward]",
482 	       ui&0x3fffffff,
483 	       ui&0x80000000 ? "Fatal error" : "Advisory Notification",
484 	       ui&0x40000000 ? "do" : "don't");
485 	ui = GET_BE_U_4(tptr);
486 	tptr+=4;
487 	if (ui)
488 	    ND_PRINT(", causing Message ID: 0x%08x", ui);
489 	break;
490 
491     case LDP_TLV_FT_SESSION:
492 	TLV_TCHECK(12);
493 	ft_flags = GET_BE_U_2(tptr);
494 	ND_PRINT("\n\t      Flags: [%sReconnect, %sSave State, %sAll-Label Protection, %s Checkpoint, %sRe-Learn State]",
495 	       ft_flags&0x8000 ? "" : "No ",
496 	       ft_flags&0x8 ? "" : "Don't ",
497 	       ft_flags&0x4 ? "" : "No ",
498 	       ft_flags&0x2 ? "Sequence Numbered Label" : "All Labels",
499 	       ft_flags&0x1 ? "" : "Don't ");
500 	/* 16 bits (FT Flags) + 16 bits (Reserved) */
501 	tptr+=4;
502 	ui = GET_BE_U_4(tptr);
503 	if (ui)
504 	    ND_PRINT(", Reconnect Timeout: %ums", ui);
505 	tptr+=4;
506 	ui = GET_BE_U_4(tptr);
507 	if (ui)
508 	    ND_PRINT(", Recovery Time: %ums", ui);
509 	break;
510 
511     case LDP_TLV_MTU:
512 	TLV_TCHECK(2);
513 	ND_PRINT("\n\t      MTU: %u", GET_BE_U_2(tptr));
514 	break;
515 
516 
517     /*
518      *  FIXME those are the defined TLVs that lack a decoder
519      *  you are welcome to contribute code ;-)
520      */
521 
522     case LDP_TLV_HOP_COUNT:
523     case LDP_TLV_PATH_VECTOR:
524     case LDP_TLV_ATM_LABEL:
525     case LDP_TLV_FR_LABEL:
526     case LDP_TLV_EXTD_STATUS:
527     case LDP_TLV_RETURNED_PDU:
528     case LDP_TLV_RETURNED_MSG:
529     case LDP_TLV_ATM_SESSION_PARM:
530     case LDP_TLV_FR_SESSION_PARM:
531     case LDP_TLV_LABEL_REQUEST_MSG_ID:
532 
533     default:
534         if (ndo->ndo_vflag <= 1)
535             print_unknown_data(ndo, tptr, "\n\t      ", tlv_tlen);
536         break;
537     }
538     return(tlv_len+4); /* Type & Length fields not included */
539 
540 trunc:
541     nd_trunc_longjmp(ndo);
542 
543 invalid:
544     return(tlv_len+4); /* Type & Length fields not included */
545 }
546 
547 void
548 ldp_print(netdissect_options *ndo,
549           const u_char *pptr, u_int len)
550 {
551     u_int processed;
552 
553     ndo->ndo_protocol = "ldp";
554     while (len > (sizeof(struct ldp_common_header) + sizeof(struct ldp_msg_header))) {
555         processed = ldp_pdu_print(ndo, pptr);
556         if (processed == 0)
557             return;
558         if (len < processed) {
559             ND_PRINT(" [remaining length %u < %u]", len, processed);
560             nd_print_invalid(ndo);
561             break;
562         }
563         len -= processed;
564         pptr += processed;
565     }
566 }
567 
568 static u_int
569 ldp_pdu_print(netdissect_options *ndo,
570               const u_char *pptr)
571 {
572     const struct ldp_common_header *ldp_com_header;
573     const struct ldp_msg_header *ldp_msg_header;
574     const u_char *tptr,*msg_tptr;
575     u_short tlen;
576     u_short pdu_len,msg_len,msg_type;
577     u_int msg_tlen;
578     int hexdump,processed;
579 
580     ldp_com_header = (const struct ldp_common_header *)pptr;
581     ND_TCHECK_SIZE(ldp_com_header);
582 
583     /*
584      * Sanity checking of the header.
585      */
586     if (GET_BE_U_2(ldp_com_header->version) != LDP_VERSION) {
587 	ND_PRINT("%sLDP version %u packet not supported",
588                (ndo->ndo_vflag < 1) ? "" : "\n\t",
589                GET_BE_U_2(ldp_com_header->version));
590 	return 0;
591     }
592 
593     pdu_len = GET_BE_U_2(ldp_com_header->pdu_length);
594     if (pdu_len < sizeof(struct ldp_common_header)-4) {
595         /* length too short */
596         ND_PRINT("%sLDP, pdu-length: %u (too short, < %zu)",
597                  (ndo->ndo_vflag < 1) ? "" : "\n\t",
598                  pdu_len,
599                  sizeof(struct ldp_common_header)-4);
600         return 0;
601     }
602 
603     /* print the LSR-ID, label-space & length */
604     ND_PRINT("%sLDP, Label-Space-ID: %s:%u, pdu-length: %u",
605            (ndo->ndo_vflag < 1) ? "" : "\n\t",
606            GET_IPADDR_STRING(ldp_com_header->lsr_id),
607            GET_BE_U_2(ldp_com_header->label_space),
608            pdu_len);
609 
610     /* bail out if non-verbose */
611     if (ndo->ndo_vflag < 1)
612         return 0;
613 
614     /* ok they seem to want to know everything - lets fully decode it */
615     tptr = pptr + sizeof(struct ldp_common_header);
616     tlen = pdu_len - (sizeof(struct ldp_common_header)-4);	/* Type & Length fields not included */
617 
618     while(tlen>0) {
619         /* did we capture enough for fully decoding the msg header ? */
620         ND_TCHECK_LEN(tptr, sizeof(struct ldp_msg_header));
621 
622         ldp_msg_header = (const struct ldp_msg_header *)tptr;
623         msg_len=GET_BE_U_2(ldp_msg_header->length);
624         msg_type=LDP_MASK_MSG_TYPE(GET_BE_U_2(ldp_msg_header->type));
625 
626         if (msg_len < sizeof(struct ldp_msg_header)-4) {
627             /* length too short */
628             /* FIXME vendor private / experimental check */
629             ND_PRINT("\n\t  %s Message (0x%04x), length: %u (too short, < %zu)",
630                      tok2str(ldp_msg_values,
631                              "Unknown",
632                              msg_type),
633                      msg_type,
634                      msg_len,
635                      sizeof(struct ldp_msg_header)-4);
636             return 0;
637         }
638 
639         /* FIXME vendor private / experimental check */
640         ND_PRINT("\n\t  %s Message (0x%04x), length: %u, Message ID: 0x%08x, Flags: [%s if unknown]",
641                tok2str(ldp_msg_values,
642                        "Unknown",
643                        msg_type),
644                msg_type,
645                msg_len,
646                GET_BE_U_4(ldp_msg_header->id),
647                LDP_MASK_U_BIT(GET_BE_U_2(ldp_msg_header->type)) ? "continue processing" : "ignore");
648 
649         msg_tptr=tptr+sizeof(struct ldp_msg_header);
650         msg_tlen=msg_len-(sizeof(struct ldp_msg_header)-4); /* Type & Length fields not included */
651 
652         /* did we capture enough for fully decoding the message ? */
653         ND_TCHECK_LEN(tptr, msg_len);
654         hexdump=FALSE;
655 
656         switch(msg_type) {
657 
658         case LDP_MSG_NOTIF:
659         case LDP_MSG_HELLO:
660         case LDP_MSG_INIT:
661         case LDP_MSG_KEEPALIVE:
662         case LDP_MSG_ADDRESS:
663         case LDP_MSG_LABEL_MAPPING:
664         case LDP_MSG_ADDRESS_WITHDRAW:
665         case LDP_MSG_LABEL_WITHDRAW:
666             while(msg_tlen >= 4) {
667                 processed = ldp_tlv_print(ndo, msg_tptr, msg_tlen);
668                 if (processed == 0)
669                     break;
670                 msg_tlen-=processed;
671                 msg_tptr+=processed;
672             }
673             break;
674 
675         /*
676          *  FIXME those are the defined messages that lack a decoder
677          *  you are welcome to contribute code ;-)
678          */
679 
680         case LDP_MSG_LABEL_REQUEST:
681         case LDP_MSG_LABEL_RELEASE:
682         case LDP_MSG_LABEL_ABORT_REQUEST:
683 
684         default:
685             if (ndo->ndo_vflag <= 1)
686                 print_unknown_data(ndo, msg_tptr, "\n\t  ", msg_tlen);
687             break;
688         }
689         /* do we want to see an additionally hexdump ? */
690         if (ndo->ndo_vflag > 1 || hexdump==TRUE)
691             print_unknown_data(ndo, tptr+sizeof(struct ldp_msg_header), "\n\t  ",
692                                msg_len);
693 
694         tptr += msg_len+4;
695         tlen -= msg_len+4;
696     }
697     return pdu_len+4;
698 trunc:
699     nd_trunc_longjmp(ndo);
700 }
701